JPH0462364B2 - - Google Patents

Description

[Detailed description of the invention]

Technical Field The present invention detects, on the camera body side, the amount of deviation of the imaging position of the object to be focused from the expected focal position upon receiving light from the object to be focused that has passed through a photographic lens, and adjusts the focus based on this amount of deviation. The present invention relates to an interchangeable lens for automatic focusing that calculates a driving amount relative to the moving amount of an automatic focusing lens, and adjusts the focus by moving the focusing lens by an amount corresponding to the driving amount. Prior Art In automatic focus adjustment as described above, the drive amount of the drive means is calculated from the detected shift amount (in other words, shift amount data is converted to drive amount data).
In this case, since the amount of deviation and the amount of drive are in a substantially proportional relationship, the amount of drive data can be obtained by multiplying the amount of deviation data by an appropriate conversion coefficient. The value of this conversion coefficient changes depending on optical conditions such as the focal length and lens configuration of the interchangeable lens, and mechanical conditions such as the configuration of the focus adjustment mechanism within the interchangeable lens. That is, the value of the conversion coefficient differs for each interchangeable lens. Therefore, the data of this conversion coefficient is provided in the interchangeable lens, the data of this conversion coefficient is taken in from the interchangeable lens by the camera body, and the data of the driving amount is obtained from this data and the data of the amount of deviation obtained by the camera body. It is conceivable to calculate it. However, since the value of this conversion coefficient changes for each interchangeable lens, if the data of this conversion coefficient were to be made compatible with various interchangeable lenses, the number of bits would increase. When transferring such conversion coefficient data in parallel, the number of terminals for transmitting and receiving signals between the camera body and the interchangeable lens increases, and problems such as dust adhesion to these terminals and poor contact between the terminals may occur. There may be disadvantages in that the reliability of the data decreases or the transfer time takes a long time when serially transferred. Purpose The present invention provides, when calculating the drive amount data of a driving means on the camera body side based on the shift amount data calculated on the camera body side and the conversion coefficient data from the interchangeable lens, the conversion coefficient can be calculated without causing the above-mentioned inconvenience. The purpose of the present invention is to provide an automatic focus adjustment method that allows data to be transferred to the camera body, and an interchangeable lens for the same. Summary The present invention utilizes the fact that even if the data of the conversion coefficient changes significantly, a predetermined number of significant digits is sufficient for calculating the drive amount, and the data of the conversion coefficient is changed. is (m+n) bit data separated into an exponent part of the upper m bits and a significant part of the lower n bits. Embodiment An outline of a camera system for automatic focus adjustment according to the present invention will be explained based on FIG. In Figure 1, the left side of the dashed-dotted line is the zoom lens LZ,
On the right side is the camera body BD, and both are mechanically connected via clutches 106 and 107 and electrically connected via connection terminals JL1 to JL5 and JB1 to JB5, respectively. In this camera system, the focus lens FL of the zoom lens LZ, the zoom lens
The subject light that has passed through ZL and master lens ML is
The light passes through the central semi-transparent part of the reflection mirror 108 of the camera body BD, is reflected by the sub-mirror 109, and is received by the focus detection light receiving part FLM.
The optical system is configured. The signal processing circuit 112 is a light receiving unit FLM for focus detection.
Based on the signal from the in-focus position, the differential focus amount |ΔL| indicating the amount of deviation from the in-focus position and the differential focus direction (front focus, rear focus) signals are calculated. The motor MO is driven based on these signals, and its rotation is transmitted through the slip mechanism SLP, drive mechanism LDR, and camera body side clutch 107 to the zoom lens LZ.
transmitted to. Note that the slip mechanism SLP prevents the motor MO from being subjected to any torque when a torque exceeding a predetermined value is applied to the driven portion of the zoom lens LZ. In the zoom lens LZ, a female helicoid screw is formed on the inner periphery of the focus adjusting member 102 for driving the focus lens FL, and a fixing member integrated with the lens mount 121 is screwed into the female helicoid screw. A male helicoid thread is formed on the outer periphery of the portion 101. A large gear 103 is provided on the outer periphery of the focusing member 102, and this large gear 103 is connected to a lens side clutch 107 via a small gear 104 and a transmission mechanism 105.
As a result, the rotation of the motor MO is caused by the slip mechanism SLP on the camera body, the clutch 107 on the camera body side,
It is transmitted to the focus adjustment member 102 via the clutch 106 on the lens side, the transmission mechanism 105 in the lens, the small gear 104, and the large gear 103, and the focus lens FL is moved back and forth in the optical axis direction by the helicoid screw. Focus adjustment is performed using Also,
An encoder for monitoring the amount of drive of the lens FL is connected to the drive mechanism LDR of the camera body BD, and this encoder ENC outputs a number of pulses corresponding to the amount of drive of the lens FL. Here, the rotation speed of the motor MO is NM (rot),
The number of pulses from the encoder ENC is N, the resolution of the encoder is ρ (1/rot), the reduction ratio of the mechanical transmission system from the rotation axis of the motor MO to the mounting axis of the encoder ENC is μP, and the reduction ratio from the rotation axis of the motor MO to the camera body The reduction ratio of the mechanical transmission system up to the side clutch 107 is μB, and the large gear 1 from the lens side clutch 106 is
The reduction ratio of the mechanical transmission system up to 03 is μL, the helicoid lead of the focusing member 102 is LH (mm/rot),
If the movement amount of the focus lens FL is Δd (mm), then N=ρ・μP・NM Δd=NM・μB・μL・LH In other words, Δd=μB・N・μL・LH/(ρ・μp)... The relational expression (1) is obtained. In addition, when the ratio of the movement amount ΔL (mm) of the imaging plane when the lens is moved by Δd (mm) and the above Δd is expressed as K op = Δd/ΔL... (2), the formula (1) , (2), we can obtain the relational expression N=(ρ・μP/μB)・Kop・ΔL/(μL・LH)...(3). Here, if KL=Kop/(μL・LH)...(4) KB=ρ・μP/μB...(5), the relational expression N=KB・KL・ΔL...(6) is obtained. . In addition, in equation (6), ΔL is the signal processing circuit 112
is obtained as a defocus amount |ΔL| and a signal in the defocus direction. Further, KL in equation (4) is output from the lens circuit LEC in accordance with the focal length set by the rotational operation of the zoom ring ZR for zooming operation of the zoom lens LZ. In other words, the data corresponding to the rotational position of the zoom ring ZR is sent to the code plate FCD.
is output, this data is sent to the lens circuit LEC, and the KL data stored at the address corresponding to the data from the code board FCD is read in series by the reading circuit LDC in the camera body. The code plate FCD has a predetermined code pattern so as to output data corresponding to the rotation setting position of the zoom ring ZR. Also, the lens circuit
A fixed storage means such as a ROM built into the LEC stores KL data corresponding to the focal length set by the zoom ring ZR on each code board.
It is fixedly stored in advance at an address corresponding to the data from the FCD. Furthermore, KB in equation (5) is data that is fixedly determined according to the reduction ratio μB in the camera body,
This data KB is output from the fixed data output circuit 110. Here, terminals JB1 and JL1 are connected from the reading circuit LDC on the camera body side to the lens circuit LEC on the lens side.
A power supply is sent through the terminals JB2 and JL2, a synchronizing clock pulse is sent through the terminals JB2 and JL2, and a read start signal is sent through the terminals JB3 and JL2, respectively. Also, terminals JL4 and JB are connected from the lens circuit LEC to the reading circuit LDC.
Data KL is output in series via 4. still,
Terminals JB5 and JL5 are common ground terminals. When the reading start signal is input through terminals JB3 and JL3, the lens circuit LEC reads KL data corresponding to the focal length determined by the rotation setting of the zoom ring.
The reading circuit is connected in series in synchronization with the clock pulse input from the camera body via terminals JB2 and JL2.
Output to LDC. And the reading circuit LDC is terminal
Based on the same clock pulse as the clock pulse output to JB2, serial data from the terminal is read and converted to parallel data. The multiplication circuit 111 receives data KL from the reading circuit LDC and data from the fixed data output circuit 110.
Based on KB, the calculation KL·KB=K is performed.
The multiplication circuit 113 calculates the differential focus amount data |ΔL| from the signal processing circuit 112 and the multiplication circuit 111.
The calculation of K·|ΔL|=N is performed based on the data K from , and the number of pulses to be detected by the encoder ENC is calculated. The motor control circuit 114 is
The motor MO is rotated clockwise or counterclockwise according to the signal in the defocus direction from the signal processing circuit 112, and when a number of pulses equal to the value N calculated in the multiplication circuit 113 is input from the encoder ENC, the focus It is determined that the lens FL has moved by the amount of movement Δd to the in-focus position, and the rotation of the motor MO is stopped. In the above explanation, data is stored on the BD side of the camera body.
By fixedly storing KB and multiplying this data KB by the data KL from the lens, K=KL・KB
However, the calculation of the K value is not limited to the above method. For example, if a zoom lens can be attached to any of multiple types of camera bodies with different KB values, K1 = KL・KB1 corresponding to the camera body with a specific KB value from the lens circuit LEC of the zoom lens LZ. output data according to the set focal length. On the other hand, in the camera body of this specific model, the fixed data output circuit 110 and the multiplication circuit 111 are unnecessary, and the data K1 from the reading circuit LDC is directly sent to the multiplication circuit 113.
When the above lens is attached to another camera body having a value KB2 (KB1) different from the above specific KB value, the data of KB2/KB1 is output from the fixed data output circuit 110. The multiplication circuit 111 calculates K2=K1・KB2/KB1=KL・
The value of KL·KB2 may be obtained by calculating KB2. In addition, all KB value data of multiple types of camera bodies with different KB values K1 = KL・KB1, K2 =
Even if you store all KL・KB2,..., Kn=KL・KBn in the lens, send all these data to the camera body, and have the camera body select the data according to its own KB value. good.
Alternatively, data indicating the type of camera may be sent from the camera body to the lens, and data corresponding to the type of camera may be sent from the lens side to the camera. In this way, the fixed data output circuit 110 and the multiplication circuit 111 on the camera side become unnecessary. In particular, in the case of a front group extension type zoom lens in which the focus lens FL is placed in front of the zoom lens ZL as described later, the value of Kop is Kop=f1 ² /F ² ...(7 ) f1: This is the focal length of the focus lens, and the KL value or K value for one zoom lens changes over a very wide range. in this case,
Divide the data KL or K stored in the lens into exponent data and significant figure data (for example, if it is 8-bit data, the upper 4 bits are the exponent part and the lower 4 bits are the significant figure number), If the data of the lower 4 bits of the data read by the reading circuit LDC of the camera body is shifted by the data of the exponent part and input to the multiplication circuit 111 or 113, even if the value of KL or K changes significantly. I can deal with it fully. In the explanation of FIG. 1 above, in order to make it easier to understand the overall function and operation of the present invention, the device of the present invention was shown to be constructed by a combination of circuit blocks. Most of the functions of these circuit blocks are accomplished by a microcomputer (hereinafter referred to as microcomputer), as described below. FIG. 2 is a block diagram mainly showing the configuration of the circuit section on the camera body BD side of the configuration shown in FIG. 1. In the figure, a converter CV is inserted between the camera body BD and the lens LE to extend the focal length of the lens LE by, for example, 1.4 times or 2 times. The camera body BD and converter CV are connected through connection terminal groups CN1 and CN2, respectively.
The converter CV and lens LE are connected through respective connection terminal groups CN3 and CN4, so that various information from the converter CV and lens LE is given to the camera body BD side. When the power switch MAS is closed, the power only reset circuit POR1, microcomputer MC1,
Power is started to be supplied to MC2, display control circuit DSC, oscillation circuit OSC, inverters IN1 to IN8, and AND circuit AN1 via power supply line +E. With this start of power supply, a reset signal PO1 is output from the power-on reset circuit POR1, and the microcomputer MC
1. MC2 and display control circuit DSC are reset. The microcomputer MC2 is a microcomputer that sequentially performs the overall operation of this camera system, and the microcomputer MC1 is a microcomputer that sequentially performs focus adjustment operations in response to control signals from the microcomputer MC2. The operation of microcomputer MC2 is shown in the flowchart in Figure 3, and the operation of microcomputer MC1 is shown in figure 8.
This is shown in the flowcharts in Figures 1 to 10. The photometry switch MES is a release button (not shown)
When this switch MES is closed, a "High" level signal is applied to the input terminal i0 of the microcomputer MC2 via the inverter IN1. In response to this, the microcontroller
The terminal O0 of MC2 becomes “High” and the inverter
Transistor BT1 becomes conductive via IN2. Due to the conduction of this transistor BT1, the power-on reset circuit POR3, the photometry circuit LMC, and the decoder
DEC1, light emitting diode driving transistor BT
3. Film sensitivity setting device SSE, aperture value setting device
ASE, exposure time setting device TSE, exposure control mode setting device MSE, exposure control device EXC, latch circuit
Power begins to be supplied to LA via power line VB.
By starting this power supply, the power-on reset circuit
A reset signal PO3 is output from POR3 and the exposure control device EXC is reset. In addition, the "High" level signal from the output terminal O0 of the microcomputer MC2 is used as the power supply voltage VL of the converter CV and lens LE by the buffer BF, and is applied to the connection terminal group CN1,
Converter CV via CN2, CN3, CN4
is applied to the circuit CVC within the lens and the circuit LEC within the lens LE. In addition to this power supply terminal, the connection terminal group includes a signal transmission terminal that is output from the output terminal O6 of the microcomputer MC2 and releases the converter circuit CVC and lens circuit LEC from the reset state.
Input data from the converter CV and lens LE to the clock pulse transmission terminal for transmitting synchronization clock pulses from the clock output terminal SCO of the microcomputer MC2 to the converter circuit CVC and lens circuit LEC, and to the serial data input terminal SDI of the microcomputer MC2. It has a signal input terminal and a ground terminal. The circuit configuration of the serial data input section of the microcomputer MC2 is shown in Figure 4, and the converter CV
The circuit configurations of the circuit CVC of the lens LE and the circuit LEC of the lens LE are shown in FIG. The photometric circuit LMC provides an analog value photometric signal to the analog input terminal ANI of the microcomputer MC2, and provides a reference voltage signal for DA conversion to the reference voltage input terminal VR. Microcontroller MC2 is a photometric circuit
Based on the reference voltage signal from LMC, terminal ANI
Converts the analog photometry signal input to the digital signal into a digital signal. Display control circuit DSC is data bus DB
In response to various data inputted through the LCD, the liquid crystal display DSP displays exposure control values, and the light emitting diodes LD10 to LD1n display warnings and the like. The output terminal O8 of the microcomputer MC2 is "High" from the time when the photometry switch MES is closed until the exposure control operation of the camera starts, and the output terminal O8 of the microcomputer MC2 is set to "High" from the time when the photometry switch MES is closed until the exposure control operation of the camera starts.
allows the light emitting diodes LD10 to LD1n to emit light only during this period. The decoder DEC1 outputs a signal to the device according to the signal given from the output port OP1 of the microcomputer MC2.
Output terminals a0 to an+1 output a signal indicating whether data is to be exchanged via data bus DB between any device or circuit among MSE, TSE, ASE, SSE, circuit DSC, and LA and microcomputer MC2.
give to For example, when the microcomputer MC2 reads exposure control mode data, the output port OP
Output terminal a0 is “High” with specific data from 1
As a result, data indicating the set exposure control mode is output from the exposure control mode setting device MSE to the data bus DB, and this data is sent to the microcontroller MC.
It is read from the input/output port I/O of No.2. Similarly, when reading the set aperture value, the terminal a2 becomes "High". When sending display data to the display control circuit DSC, terminal A4 is connected depending on the data to be sent.
One of ~an becomes “High”. In addition, when sending lens conversion coefficient data KD, which will be described later, after outputting this conversion coefficient data from the input/output port I/O to the data bus DB, output specific data to the output port OP1 for a certain period of time, and then output it from the terminal an+1. The pulse causes the latch circuit LA to latch the conversion coefficient data. The exposure control device EXC starts the following exposure control operations when a "High" interrupt signal is applied to the interrupt signal input terminal IT of the microcomputer MC2, and the exposure control device EXC starts the following exposure control operations. Equipped with a control circuit and an exposure time control circuit. When a pulse is output from the output terminal O4 of the microcomputer MC2, this device EXC connects to the data bus DB.
Import the number of refinement stages data output to
Activate the release circuit to start exposure control operation. When a certain period of time has elapsed from the start of the exposure control operation, the microcomputer MC2 outputs exposure time data to the data bus DB and pulses to the terminal O5.
As a result, the exposure control device EXC takes in the exposure time data, activates the mirror drive circuit to start raising the reflecting mirror, and activates the aperture control circuit to narrow down the aperture by the number of aperture steps. When the reflection mirror has finished rising, the shutter front curtain starts running. At the same time, the count switch COS is closed, so that the exposure time control circuit is activated and starts counting the time corresponding to the exposure time data. When the count is completed, the rear shutter curtain starts running, the aperture opens, and the mirror moves down, completing the exposure control operation. The release switch RLS is closed in the second step of pressing down the release button, and this switch
When RLS is closed, the output of inverter IN3, that is, one input terminal of AND circuit AN1 becomes “High”
become. The switch EES is closed when the exposure control operation is completed, and opened when the exposure control mechanism (not shown) is charged to an operable state. A signal indicating the open/closed state of this switch is applied to the input terminal i2 of the microcomputer MC2 and the other input terminal of the AND circuit AN1 via the inverter IN4. still,
The output terminal of the AND circuit AN1 is connected to the interrupt signal input terminal it of the microcomputer MC2. Therefore, if the exposure control mechanism is not fully charged,
The gate of the AND circuit AN1 is closed, and even if the release switch RLS is closed, the gate of the AND circuit AN1 is closed.
The output of AN1 remains “Low”. That is, no interrupt signal is input to the microcomputer MC2, and no exposure control operation is started. On the other hand, when the exposure control mechanism is fully charged, the AND circuit AN
Gate 1 is open and the release switch is
When RLS is closed, the output of the AND circuit AN1 becomes "High" and an interrupt signal is input to the interrupt terminal it of the microcomputer MC2, and the microcomputer MC2 immediately shifts to exposure control operation. Output terminals O1, O2, O3 of microcomputer MC2 are input terminals i11, i1 of microcomputer MC1, respectively.
2, connected to i13. Here, the output terminal O1 becomes "High" when the microcomputer MC1 performs the focus detection operation, and becomes "Low" when the focus detection operation is not performed. Output terminal O2 is the motor MO
When rotated clockwise, the focus lens
“High” if an interchangeable lens configured to extend the FL is installed, and the motor MO
For interchangeable lenses that are extended by rotating counterclockwise, the setting is "Low." The output terminal O3 is
An exchange in which focus adjustment is performed only in accordance with a method (hereinafter referred to as the predictor method) in which the focus lens is driven toward the in-focus position based on the amount of deviation of the imaging position from the in-focus position and the defocus direction. In the case of a lens, there is a method in which the lens is driven by a signal in the direction of deviation from the in-focus position (front focus, rear focus, focus) (hereinafter referred to as the three-point indication method) and this predictor method. In the case of an interchangeable lens that can be used in combination to adjust the focus, it will be "High". The switch FAS is opened and closed by a manual switching member (not shown), and the focus lens is driven to the in-focus position according to the detection result of the in-focus state, and the focus is automatically adjusted (hereinafter referred to as AF mode).
mode), the camera is closed, only the focus state is displayed according to the detection result of the focus state, and focus adjustment is performed manually (hereinafter referred to as "mode").
(referred to as FA mode). The open/close signal of the switch FAS is applied to the input terminal i1 of the microcomputer MC2 and the input terminal i14 of the microcomputer MC1 via the inverter IN6. The output terminal O16 of the microcomputer MC1 is connected to the base of the transistor BT2 via an inverter IN5. Therefore, terminal O16 is “High”
, the transistor BT2 becomes conductive and the power-on reset circuit PO2 and the focus detection light receiving section are activated.
FLM, light receiving section control circuit COT, motor drive circuit
Power is started to be supplied to the MDR, encoder ENC, and light emitting diode drive circuit FAD via the power supply line VF. With this start of power supply, a reset signal PO2 is output from the power-on reset circuit POR2. The light emitting diode drive circuit FAD is, for example, the sixth
The circuit configuration is as shown in the figure, and the microcomputer
Output port OP0 of MC1, that is, output terminal O17,
Light emitting diodes LD0, LD1, and LD2 are driven according to data output from O18 and O19.
With this circuit configuration, when any one of the output terminals O17, O18, and O19 of the microcomputer MC1 becomes "High", the light emitting diode for displaying the previous pin
Any one of LD0, focus display light emitting diode LD1, and back focus display light emitting diode LD2 lights up to indicate front focus, focus, or back focus. Furthermore, when the two output terminals O17 and O19 become "High", the light emitting diodes LD0 and LD are activated based on the clock pulse CP from the oscillation circuit OSC.
2 blinks at the same time to indicate that focus cannot be detected. Table 1 shows its operating status.

【table】

[Table] Light receiving section for focus detection FLM is a CCD (Charge Coupled Device) with multiple light receiving sections for focus detection.
It is formed of. The control circuit COT is a microcomputer
It has functions of driving the CCD (FLM) based on signals from MC1, A-D conversion of CCD output, and transmission of A-D conversion output to microcomputer MC1. Note that a pulse signal from the microcomputer MC1 to the control circuit COT for starting the integration operation of the CCD (FLM) is sent from the output terminal O10 to the control circuit COT.
From 1 onwards, a pulse signal for forcibly stopping this integration operation is outputted. Also, from the control circuit COT to the microcomputer MC1, the CCD
A signal indicating that the integration operation in the CCD (FLM) has been completed is sent to the interrupt terminal it, and a signal indicating that the A-D conversion operation of the accumulated charge has been completed for each light receiving element of the CCD (FLM) is sent to the input terminal. At i10, the above A-D converted data is input to the input port IP0. Furthermore, the control circuit for CCD (FLM)
From COT, the reset signal is sent to the terminal φR, the transfer command signal is sent to the terminal φT, and the transfer clock is sent to the terminal φ1,
A reference potential is input to the terminal ANB at φ2 and φ3, and a potential corresponding to the amount of light received by the monitoring light receiving section is sent from the CCD (FLM) to the control circuit COT from the terminal AOT to each light receiving section from the terminal AOT. The accumulated charges of are output respectively. This control circuit
The specific circuit configuration of the COT will be explained in detail in FIG. 14, which will be described later. Here, to briefly explain the operations of the CCD (FLM), control circuit COT, and microcomputer MC1, the control circuit COT is
In response to the integration start signal from the output terminal O10 of the microcomputer MC1, a reset signal is sent to the CCD (FLM) to reset the CCD (FLM), and a reference potential signal is given to the CCD (FLM). CCD
In each light receiving section within the FLM, the accumulated charge increases according to the amount of light received, and as a result, the potential output from the terminal ANB decreases. control circuit
When the level of terminal ANB reaches a predetermined value, COT outputs a transfer command signal to CCD (FLM).
Accumulated charge in each light receiving part of CCD (FLM)
(FLM) and transfer it to the transfer gate in
Give the integration completion signal to the interrupt terminal it of the microcomputer MC1. And the control circuit COT is CCD (FLM)
The accumulated charge transferred to the transfer gate of φ1, φ
2. Receive A based on the transfer clock of φ3
-D conversion and A- of the accumulated charge by one light receiving part
Every time the D conversion is completed, an A-D conversion completion signal is given to the input terminal i10 of the microcomputer MC1. Microcomputer
In response to this signal, MC1 takes in the A-D converted data from input port IP0. and,
After the microcomputer MC1 has taken in the same number of A-D converted data as the number of light receiving elements of the CCD (FLM), it finishes taking in the CCD output. Note that if the microcomputer MC1 does not receive an interrupt signal even after a certain period of time has passed since the start of integration,
A pulse for forcibly stopping the integration operation of the CCD is output from the terminal O11 of the microcomputer MC1. In response to this pulse, the control circuit COT gives a transfer command signal to the CCD from the terminal φT, and
Output an interrupt signal to microcontroller MC1 and perform the above
Performs A-D changes of CCD output and data transfer operations. The motor drive circuit MDR drives the motor MO based on signals given from output terminals O12, O13, and O14 of the microcomputer MC1. When the output terminal O12 of the microcomputer MC1 is "High", the motor MO is driven clockwise, and when the output terminal O13 is "High", the motor MO is driven counterclockwise, and both output terminals O12 and O13 are "Low".
When , motor MO stops driving. Furthermore, the output terminal O14 of the microcomputer MC1 is “High”
When , the motor MO is driven at high speed, and when it is “Low”, it is driven at low speed. This motor control circuit
A specific example of MDR has already been filed by the applicant in the patent application filed in 1982.
Although it was proposed in No. 136772, the explanation is omitted because it is unrelated to the gist of the present invention. The encoder ENC is a transmission mechanism on the camera body side that transmits the rotational torque of the motor MO to the lens.
The amount of drive of the LMD is monitored by, for example, a photocoupler, and a number of pulses proportional to the amount of drive is output. This pulse is input to the clock input terminal DCL of microcomputer MC1 and is automatically counted, and the count value ECD is
Used for counter interrupt in MC1 flow.
Furthermore, this pulse is sent to the motor drive circuit MDR, and the rotational speed of the motor MO is controlled according to the number of pulses. FIG. 3 is a flowchart showing the operation of the microcomputer MC2 shown in FIG. The operation of the microcomputer MC2 can be roughly divided into the following three flows.
The flow starting from step #1 is the main flow that starts when the power switch MAS is closed, and the photometry switch MES is closed (#2).
As a result, the power supply to circuits other than the focus adjustment circuit starts (#4), the exposure control information set on the camera body BD starts (#5), and the lens
Reading data from LE, converter CV (#6
~ #12), reading photometric values (#13, 14), automatic setting of AF mode and FA mode (#16 ~ #27), calculation of exposure control values (#28) and display (#31, #32) Repeat these actions. The flow starting from step #45 is based on a timer signal that is periodically output from the timer built into the microcomputer MC2 for a predetermined period of time (for example, 15
(seconds) is a timer interrupt flow for performing the operation of the above main flow. Also, the flow starting from step #59 is the release switch
This is a flowchart of a release interrupt for starting the exposure control operation of the camera by closing the RLS.
The following is a microcontroller based on Figures 3 to 6.
The operation of the camera system shown in FIG. 2 related to MC2 will be described in detail. First, when the power switch MAS is closed, a reset signal is output from the power-on reset circuit POR1.
PO1 is output. In response to this reset signal PO1, the microcomputer MC2 performs a reset operation in the main flow at step #1. When it is determined that the input terminal i0 has become "High" in step #2 by closing the photometry switch MES, the timer interrupt is disabled (#3) and the terminal O0 is set to "High". ”(#4). As a result, the transistor BT1 becomes conductive and power supply from the power supply line VB is started. At the same time, converter CV from power line VL through buffer BF
Then, power supply to the interchangeable lens LE is started.
In step #5, the exposure control mode setting device
MSE, exposure time setting device TSE, aperture value setting device
Data from the ASE and the film sensitivity setting device SSE are sequentially taken in to the input/output port I/O via the data bus DB. In steps #6 to #12, data "O" is first set in register A (#6), and terminal O6 is set.
is set to “High”, the reset state of the converter circuit CVC and lens circuit LEC is released, and (#7
-1), a data serial input command is output (#7-2). Converter circuit CVC, lens circuit
When the input of one piece of data from the LEC is completed (#8), the fetched data is set in register M(A) corresponding to the contents of register A (#9). Next, "1" is added to the contents of register A (#10), and it is determined whether the contents have become Ac (a constant value). Here, if A≠Ac, the process returns to step #7-2 and the next data is taken in again. When A=Ac, the lens
Since the data import from LE and converter CV has been completed, output terminal O6 is set to “Low”.
(#12) to reset the converter circuit CVC and lens circuit LEC. Here, a specific example of taking in data from the lens LE and converter CV will be explained based on FIGS. 4 and 5. For example, when inputting 8-bit serial data, the serial data input section shown in FIG. Read sequentially. In other words, the serial data input command SIIN causes the flip-flop to
FF1 is set and the reset state of the 3-bit binary counter CO1 is released. At the same time, the gate of the AND circuit AN7 is opened, and the clock pulse DP frequency-divided within the microcomputer MC2 is sent as a synchronizing clock output from the output terminal SCO to the converter CV and lens LE circuits CVC and LEC. Also, this clock pulse is
CO1 is sent to the clock input terminal of shift register SR1. The shift register SR1 sequentially takes in the data input to the input terminal SDI of the microcomputer MC2 at the falling edge of the clock pulse DP. Here, carry terminal CY of counter CO1
remains "High" during the period from when the 8th clock pulse DP is input until the next cross pulse DP is input. On the other hand, AND circuit AN5
This carry output is input to one input terminal of , and the clock pulse DP is input to the other input terminal via the inverter and IN15, so the AND circuit AN5
becomes "High" at the falling edge of the 8th clock pulse DP, resets the flip-flop FF1, and also puts the counter CO1 in the reset state. Therefore, the output of the AND circuit AN5 also becomes "Low" as the carry terminal CY of the counter CO1 becomes "Low" and prepares for the next operation. The “High” pulse from the AND circuit AN5 sets the serial input flag SIFL to determine the completion of data input, and the microcomputer MC2 inputs the shift register.
The data being output from SR1 to the internal data bus IDB is stored in predetermined registers M and A. In FIG. 5, the left side of the dashed line is the converter circuit CVC of the converter CV, and the right side is the lens circuit LEC of the lens LE. Microcomputer MC2
When the output terminal O6 of the counter becomes “High”, the counter CO
3. The reset state of CO5, CO7, and CO9 is released, and these counters are enabled to count the clock pulse DP given from the output terminal SCO of the microcomputer MC2. The 3-bit binary counters CO3 and CO7 use this clock pulse.
The rising edge of DP is counted and the carry terminal CY is set to "High" from the rising edge of the 8th clock pulse until the rising edge of the next clock pulse DP. 4-bit binary counter CO5, CO
9 counts the falling edge of this carry terminal CY, and the count values of counters CO5 and CO9 change to 1 every time the first pulse of 8 clock pulses rises.
Increase by increments. The registers of the ROM and RO1 of the converter circuit CVC are directly specified based on the count value of the counter CO3. Lens circuit LEC ROM,
The register of RO3 is designated indirectly via the decoder DE9 and the data selector DS1 based on the count value of the counter CO1. ROM, RO′1,
The lens LE and converter CV data output from RO3 are either output depending on the output of decoder DE5 or serial adder circuit AL1.
The output of the sum of the two added together or the data of all "O" is selectively output. here,
Table 2 shows the relationship between the counter CO9, decoder DE9, ROM, and RO3 in the case of a lens with a fixed focal length, and Table 3 shows the above relationship in the case of a zoom lens with a variable focal length. In addition, counter CO5, decoder DE5, ROM, RO in the converter
Table 4 shows the relationship between 1 and the output data to the camera body. Note that φ indicates that the data of each bit may be "0" or "1".

【table】

【table】

[Table] Outputs b0, b1, b2 of counters CO3 and CO7
is input to decoders DE3 and DE7, and
DE3 and DE7 output the signals shown in Table 5 according to this input data.

[Table] Therefore, each time the clock pulse rises,
The data in ROM, R3 is sent one bit at a time sequentially from the lowest bit r0 to AND circuits AN20 to AN27,
The data in ROM and RO1 are outputted via the OR circuit OR5, and at the same timing, the data in the ROM and RO1 are sequentially output one bit at a time starting from the lowest bit e0 at each rising edge of the clock pulse.
1. In the case of a zoom lens, a code plate FCD is provided in the lens circuit LEC to output 5-bit data according to the focal length set by operating the zoom ring ZR. Code plate that changes depending on the set focal length
The value of the lower 5 bits of the input terminal α2 of the data selector DS1 is uniquely determined by the output of the FCD. Therefore, the data selector DS1 is the decoder
When the output h4 of DE9 is “Low”, input terminal α
1, the data “0000 h3 h2 h1 h0” from input terminal α2, and “h2 h1
Specify the address of ROM and RO3 by outputting the data “h0 ＊＊＊＊＊” (* is code board data). If the output of counter CO9 is “0000”,
Check data indicating that the lens is attached is stored at the address “OOH” (H indicates hexadecimal) in ROM, RO3, and this data is common to all types of interchangeable lenses (e.g.
01010101). At this time, the camera body
If a converter CV is installed between the BD and the lens LE, the data “01010101” sent from the lens LE will be passed through the AND circuit AN32 and the off circuit OR3 due to “High” of the output terminal g2 of the decoder DE5. Also, the lens LE is attached to the camera body.
If it is directly attached to the BD, it will be sent directly to the camera body side and sent from the input terminal SDI to the microcomputer.
Read into MC2. If it is determined from this check data that an interchangeable lens is attached, the camera switches to open metering mode and uses the exposure control device EXC.
Aperture control is performed. On the other hand, if it is determined that no interchangeable lens is attached, the aperture metering mode is set and aperture control is not performed. When the output of counters CO5 and CO9 becomes "0001", address "01H" of lens ROM and RO3 is specified, and the open aperture value data is sent from ROM and RO3.
Avo is output. Note that in the case of a zoom lens whose effective aperture value changes depending on the set focal length, the open aperture value at the shortest focal length is output. Also,
Converter CV ROM, RO1 address “1H”
Stores constant value data β corresponding to the amount of change in the open aperture value of the lens due to the attachment of the converter CV, and the constant value data β is output from the ROM and RO1. Due to “High” of terminal g0 of decoder DE5, data from ROM, RO1, and RO3 are added by serial adder circuit AL1 (Avo+
β) is calculated, and this data is used as the AND circuit AN3
0, is output via the OR circuit OR3. When the output of counters CO5 and CO9 becomes “0010”,
ROM, RO3, and RO1 each have address “02H”
is specified. Lens ROM, minimum aperture data Avmax from RO3 and converter ROM,
Based on the data β from RO1, the data of Avmax+β is output as in the case of the open aperture value, and if the lens is not installed, the data of Avmax is output. When the outputs of the counters CO5 and CO9 become "0011", the address "03H" of the lens ROM and RO3 is designated, and the data of the open photometry error is output from the ROM and RO3. Here, if the converter is not installed, this data is read into the camera body as is. On the other hand, if the converter CV is installed, the decoder DE5
All outputs are “Low”, and the output of OR circuit OR3 is “Low” regardless of the data from the lens.
The camera body reads "0" data as an open metering error. This is because by installing the converter CV, the open aperture becomes relatively small and the open aperture metering error can be considered to be "0". When the outputs of counts CO5 and CO9 become "0100", addresses of "04H" are designated for ROM, RO1 and RO3, respectively. Lens ROM, RO3
Address “04H” contains the focus lens.
Data indicating the rotational direction of the motor MO when extending the FL, and data indicating whether this interchangeable lens is a type of lens whose exchange coefficient changes depending on the set shooting distance are stored. for example,
If the lens is of a type in which the focus lens is extended when the motor is rotated clockwise, the lowest bit is "1", and if the lens is of a type in which the focus lens is extended if the motor is rotated counterclockwise. The least significant bit is "0". In addition, for lenses whose exchange coefficient changes depending on the set shooting distance, the most significant bit is "1".
In the case of a type of lens that does not change, the most significant bit is "0". This data is sent directly to the camera body regardless of whether a converter CV is installed. When the output of the counter CO9 becomes "0101", the output of the decoder DE9 becomes "00101" for a fixed focal length lens, "1001φ" for a zoom lens, and the ROM and RO3 of the lens circuit LEC are "05H" or "05H" respectively. The address “001＊＊＊＊＊” is specified. Note that "＊＊＊＊＊" is data from the code board FCD. This address of ROM, RO3 contains the data corresponding to the base 2 logarithm value log ₂ f of the fixed focal length f of the lens for a fixed focal length lens, and the set focal length of the zoom lens for a zoom lens. Data corresponding to the logarithm value log ₂ f of f is stored, and this data is output to the camera body. Also, converter ROM,
Address “5H” is specified for RO1, and the converter CV is connected to the camera body BD at this address.
Data γ corresponding to the amount of change in the focal length that changes when the lens is attached between the lens and the interchangeable lens LE is stored. At this time, since the output terminal g0 of decoder DE5 is "High", the adder circuit
AL1 sends data obtained by adding constant value data γ to focal length data log ₂ f to the camera body. This focal length is used for determining camera shake warnings, etc. When the output of counter CO9 becomes "0110", in the case of a zoom lens, data of "1010φ" is output from decoder DE9, and after terminal h4 becomes "High", data from input terminal α2 of data selector DS1 is output. is output. As a result, the ROM and RO3 are designated with the address "010＊＊＊＊＊". In this address, data ΔAv of the amount of change in aperture value from the effective aperture value at the shortest focal length when the focal length of the zoom lens is changed from the shortest focal length is stored in accordance with the set focal length. Also, for fixed focal length lenses,
Since ΔAv=0, the address “06H” is “0”
data is stored. This data is sent directly to the camera body regardless of whether a converter CV is installed or not. This data includes the calculation (Bv − Avo − ΔAv) − Avo − ΔAv for removing the aperture component from the aperture metering data and the calculation Av − Avo for controlling the effective aperture to the set or calculated aperture aperture. -Used for ΔAv. When the output of counter CO9 becomes "0111", the output of decoder DE9 becomes "1011φ" in the case of a zoom lens, and ROM and RO3 become "011＊＊＊＊
*" address is specified. Conversion coefficient data KD corresponding to the set focal length is stored in this address. Also, in the case of a fixed focal length lens, the address "07H" is specified in ROM and RO3. specified, and this address contains fixed conversion coefficient data.
KD is remembered. If a converter with a built-in mechanical transmission mechanism that compensates for changes in the conversion coefficient is installed, this data will be transmitted directly to the body. The data KD of this conversion coefficient
is used to obtain data on the drive amount of the motor drive mechanism LMD by calculating |ΔL|×KD from the differential focus amount |ΔL| calculated by the microcomputer MC1. In addition, the data of the conversion coefficient is, for example, 8
In the case of bits, it is divided into an exponent part of the upper 4 bits and a significant figure part of the lower 4 bits, which are coded as shown in Table 6.

[Table] The conversion coefficient data KD is KD = (k3・2 ⁰ +k2・2 ^-1 +k1・2 ^-2 +k0・2 ^-3 )・2 ⁿ・2 ^m m=k4・2 ⁰ +k5・2 ¹ +k6・Calculate by calculating 2 ² + k7・2 ³ n = constant value (eg -7). Note that since k3 is the most significant bit of the significant figure part, it is always "1". Therefore, by coding in this way, even if the value of KD changes over a fairly wide range, it can be stored as data with a small number of bits that is easy to calculate within the microcomputer MC1. Figure 7 is a graph showing the relationship between conversion coefficient data output from a zoom lens and focal length, where the horizontal axis corresponds to log ₂ f and the vertical axis corresponds to the conversion coefficient KD.
corresponds to By the way, KD is a straight line A, depending on the focal length f.
Although it changes continuously as shown in B and C, in this embodiment, the value of KD is set to discrete values of K1 to K33 as shown in broken lines A', B', and C'. Here, when K1=2°, KD="01111000", when K2=2 ^-1 +2 ^-2 +2 ^-3 +2 ^-4 , KD="01101111", K3=2 ^-1 +2 ^-2 +2 ^{- 3} , KD="01101110", K4=2 ^-1 +2 ^-2 +2 ^-4 , KD="01101101", K31=2 ^-4 +2 ^-6 , KD="00101000", K32=2 ^-4 For +2 ^-7 , KD = "00111001", and for K33 = 2 ^-5 , KD = "00101000". The focal length of a zoom lens is divided into many regions corresponding to the 5-bit output of the code plate FCD. For example, a lens that changes along a straight line A is divided into 9 zones from f17 to f25. . With this configuration, in the f25 zone, the data closest to the smallest K value in that zone and with the smallest value
Data will be output as K16 for K17 and f24 zones, K15 for f23 zones, and K13 for f22 zones. The reason for determining the value of KD in this way is as follows. In other words, if KD is set to a value larger than the actual data, N=KD×|ΔL|
This is because the value of N determined by is larger, and as a result, the lens passes through the in-focus position, causing the lens to hunt before and after the in-focus position. Therefore, if KD is set to a small value, it will gradually approach the in-focus position from one direction, and since the difference with the actual KD is made as small as possible, the focus lens will be at the in-focus position. The time it takes to reach can be shortened. Note that if the KD value is always set to a small value, the difference from the actual KD value may become too large and it may take too long to reach the in-focus position. In addition, it is also possible to provide a slightly larger area than the actual value, such as zones f18 and f12 shown in B', so that it is possible to go a little too far from the in-focus position. There are also zoom lenses whose conversion coefficients change significantly depending on the shooting distance, such as the solid line C (∞) when the shooting distance is infinite, and the dashed line C (near) when the shooting distance is close. With this zoom lens, for example, the focal length is f1
When the shooting distance changes from the infinite position to the closest position in the zone, KD = k17 = 2 ^-2 to KD = K15
Changes to =2 ^-2 +2 ^-4 . In order to be compatible with such a zoom lens, in this embodiment, only the data of the conversion coefficient at the infinite position is stored in the ROM, RO3.
The focus lens is driven based only on the positive and negative signals of ΔL (i.e. in the defocus direction) until it reaches the area near the focus range (hereinafter referred to as the near focus zone). When the lens enters the in-focus zone, the lens is driven based on the value of N determined by the above-mentioned KD and |ΔL|. In addition to the code board FCD for the focal length, a code board for the set shooting distance may be provided separately, and the addresses of ROM and RO3 may be specified using these code boards to obtain accurate conversion coefficient data. but,
It is not practical because of problems such as an increase in the number of parts, an increase in the number of bits for address specification, and an increase in the capacity of ROM. Furthermore, there are zoom lenses that are configured so that macro photography can be performed by moving the zoom ring, for example, to the shortest focal length side from the position of the shortest focal length. (The mechanism of this zoom lens is not related to the gist of this application, so its explanation will be omitted.)
In this embodiment, for such a zoom lens, when switching to macro photography, data "11111" is output from the code plate FCD, and a specific address "01111111" is specified. In the case of macro photography, the position of the pupil diameter changes, the depth of focus becomes shallower, the aperture value becomes darker, etc.
Since focus adjustment in AF mode is difficult, data "φφφφ0110" is stored at that address, and k3 is "0". Microcomputer MC2 uses this data to determine that macro photography has been switched, and activates AF using switch FAS.
Even if the mode is set, the focus adjustment mode is automatically switched to FA mode, which is only for display. Furthermore, there are zoom lenses that are configured such that switching to micro photography cannot be performed unless the photographing distance is set to the closest position. In the case of such a lens, the switch MCS shown in Fig. 5 is closed when switching to macro photography, and the AND circuits AN40 to AN are connected via inverters IN17 and IN19.
All 44 outputs become “Low”. As a result, address "0110000" of ROM, RO3 is specified. The data "φφφφ0100" is stored as KD in this address, and the microcomputer MC1 determines that the switching operation to macro photography has been performed based on this data k3=k1=0, and automatically changes the shooting distance to the latest one. Rotate the motor MO so that it is in the close position and extend the focus lens. The light receiving part for focus detection is designed to look at the exit pupil where the photographing lens is located, and the position of the pupil with respect to the diameter of this pupil and the light receiving element (located at a position optically equivalent to the film surface). Whether the light-receiving element receives the light from the subject that has passed through the photographic lens is determined depending on the photographing lens. Therefore, depending on the lens, light may not enter some of the light receiving sections. With such a lens, even if focus detection is performed, it is not reliable, so it is preferable not to operate in AF mode or FA mode. Therefore, in the case of such a lens, store the data of "φφφφ0001" as KD in the ROM, RO3 address ("011＊＊＊＊＊" for a zoom lens, "00000111" for a fixed focal length lens). . Using this data, the microcomputer MC2 prevents the microcomputer MC1 from performing a focus detection operation in the AF mode or FA mode in step #16-2, which will be described later. In addition, by macro switching, AND circuit AN40 ~
When the data “00000” or “11111” is output from the AN44, the data corresponding to the focal length f during macro photography is stored in the addresses “00100000” and “00111111” of the ROM and RO3, and the data corresponding to the focal length f during macro photography is stored in the addresses “01000000” and “01011111” stores data corresponding to ΔAv during macro photography, and is output from the ROM and RO3, respectively. In addition, in the case of an interchangeable lens that does not have a mechanism to transmit the rotation of the drive shaft in the camera body to the focus adjustment member, "φφφφ0110" is stored as KD in the same way as when switching to macro photography, and FA mode only possible. Furthermore, in the case of a converter that does not have a transmission mechanism like the above-mentioned lens, when the output of the counter CO2 reaches "0111", "φφφφ0110" is output from the ROM and RO1, and the terminal g1 of the decoder DE5 is output. If only "High" is set to transmit data from ROM and RO1 to the camera body, only FA mode operation will be performed no matter what kind of interchangeable lens is attached. When a converter is inserted and connected between the camera body and an interchangeable lens, the focal length changes due to the converter, so a deceleration mechanism is installed inside the converter to reduce the amount of rotation of the drive shaft from the camera body by an amount corresponding to the increase in focal length. It is necessary to provide In other words, if the converter is equipped with only a mechanism that directly transmits the amount of rotation of the drive shaft of the camera body to the drive shaft of the focus lens, the KD of the lens will be transmitted to the camera body as is, and the amount of rotation of the camera body will be transferred by N=KD×〓ΔL〓. There is a problem in that when the drive shaft of the lens is rotated, it deviates from the in-focus position by an amount corresponding to the increase in focal length. Therefore, in this embodiment, for a converter that does not have the above-mentioned speed reduction mechanism, for example, a converter that increases the focal length by 1.4 times has a KD of 1/2,
For a 2x converter, KD will be 1/4,
From the exponent data of the upper 4 bits of KD (k7k6k5k4), 1 is subtracted for a 1.4x converter, and 2 is subtracted for a 2x converter. Returning to Figure 5, when the output of counter CO5 reaches "1000", check data "01010101" indicating that the converter CV is installed is output from the ROM and RO1 of the converter circuit CVC as shown in Table 4. Output. At this time, decoder DE
Since the terminal g1 of 5 is set to “High”, this check data is stored in the ROM of the lens circuit LEC,
AND circuit AN regardless of data from RO3
31, sent to the camera body BD via the OR circuit OR3. When the output of counter CO5 reaches "1001", the aperture value data Avl is determined based on the vignetting of light due to the luminous flux being restricted by installing this converter.
is output from ROM, RO1 and in the same way as above,
The signal is sent to the camera body via the AND circuit AN31 and the OR circuit OR3. This data Avl is compared with the open aperture value data Avo+β by the microcomputer MC2. When Avo+β<Avl, the photometric output is Bv
−Avl, so (Bv − Avl) + Avl = Bv
and refinement stage number data Av-(Avo+β) are calculated. When the data acquisition from the lens LE and converter CV is completed as described above, in the flowchart of Fig. 3, the photometry circuit LMC
A-D conversion is performed on the output of (#13), and this
-D-converted photometric output data is stored in a predetermined register (#13). In step #15, it is determined whether the release flag RLF is “1” and if this flag is “1”.
When it is "0", it goes directly to step #28, and when it is "0", it goes through steps #16 to #26 and then goes to step #28. Here, release flag
RLF is a flag that is set to "1" when the release switch RLS is closed and the interrupt operation after step #59 is performed and the exposure control value of the camera is being calculated. If it is determined in step #63 that the exposure control value has not been calculated during this interrupt operation, the above-mentioned data import operation is performed in steps #5 and thereafter.
If RLF=1 in step #15, the flow of focus detection operation in AF and FA modes in steps after #16 is skipped, exposure calculation is performed in step #28, and then step #30 is performed. Exposure control is performed in steps after #64. In step #16, it is determined whether focus detection operation in AF mode or FA mode is possible, and if possible, the process moves to step #17, and if not, it moves to step #28. . In this step, check whether the lens is attached (#16-1), whether the conditions determined by the diameter and position of the exit pupil are compatible with the light receiving section (#16-2), and whether the focus detection It is sequentially determined whether the light from the subject is incident on all the light receiving sections (#16-3) and whether the photometry switch is closed (#16-5). Here, if check data "01010101" is not input (#16-1), KD data k3~
When k0 is “0001” (#16-2), the exit pupil diameter of the lens is too small, and the open aperture value Avo, Avo+β,
Avo + ΔAv or Avl is a constant aperture value

[For example 5
(F5.6)] If larger than Avc (#16-3),
Since focus detection operation is not possible in both AF mode and FA mode, after the display control circuit DSC displays a warning that focus detection operation will not be performed in step #16-4, the process moves to step #28. do. If the photometric switch MES is open and i0 is "Low"(#16-5), the process moves to step #28 in order to operate only in the FA mode for 15 seconds. Input check data, k3~k0≠“0001”,
Avo, Avo+β, Avo+Av or Avl≦Avc,i
#17 if both “High” of 0 is determined
Move on to the next step. At step #17, output terminal O1 is “High”
Then, the microcomputer MC1 starts the focus detection operation in the AF and FA modes by setting the input terminal i11 to "High". In step #18, the microcomputer MC
The conversion coefficient data KD read into the input/output port I/O is outputted to the data bus and latched by the latch circuit LA. The data latched by this latch circuit LA is No. 93 (described later) of microcomputer MC1.
is read in steps. In step #19, based on the data read when the output of counter CO9 is "0100",
The attached lens changes the conversion coefficient according to the shooting distance.
Determine whether the lens is of a type that changes KD. Here, if the lens changes, the microcomputer
The output terminal O3 of MC2, ie, the input terminal i13 of microcomputer MC1, is set to "High", and if the lens does not change, it is set to "Low". Using this signal, the microcomputer MC1 determines whether the imaging position is within the near focus zone or whether the integration time is longer than a certain value, as will be described in detail in steps No. 192 to No. 197 below. Switch the motor MO drive in AF mode according to the In step #22, the direction of rotation of the motor MO when extending the focus lens is determined based on the data read when the counter CO9 is "0100". Here, if the direction is clockwise, the output terminal O2 of the microcomputer MC2, that is, the microcomputer MC
1 input terminal i12 is set to "High", and if it is counterclockwise, set to "Low". The microcomputer MC1 determines the rotational direction of the motor MO based on the signal to the terminal i12 and the differential focus direction signal. In step #25, 3 of the conversion coefficient data KD
By detecting whether the th bit k3 is “1” or “0”, the installed converter CV and lens
Determines whether focus adjustment operation using AF mode is possible in LE. At this time, if k3=1, AF mode is possible, so set flag MFF to "0" and #28
Move on to the next step. On the other hand, if k3=0, AF mode is not possible, so MFF is set to "1", and then switch FAS detects whether AF or FA mode is selected. here,
If the AF mode is selected and the input terminal i1 is "High", the display control circuit DSC will display a warning that the camera will automatically switch to the FA mode even if the AF mode has been set by the photographer. Then move on to step #28. If the input terminal i1 is "Low", the FA mode is originally selected, so the process moves directly to step #28. In step #28, a known exposure calculation is performed based on the set exposure control value, photometry value, and data from the lens read in steps #5 to #14, and the exposure time and aperture value data are calculated. flag
Set LMF to “1”. In step #30, it is determined whether the release flag RLF is "1" or not. If it is "1", the flow returns to the exposure control operation flow of steps after #64, and the release flag RLF is set to "0".
In this case, move to step #31. In step #31, the inverter IN8 is connected to the transistor BT3 by setting it to "High" via the output terminal O8.
is made conductive, and the light emitting diodes LD10 to LD1n display a warning and the liquid crystal display DSP displays an exposure control value. In step #33, it is determined whether the photometry switch MES is open or closed. Here, if the photometry switch MES is closed and i0 is "High", set the 15-second count data for the timer interrupt in the timer register Tc (#34) and start the timer. (#35), enable timer interrupt (#36) and return to step #2. In this case, since i0 is "High" (the photometric switch MES remains closed), the process immediately moves to step #3, disables timer interrupts, and repeats the same operation as described above. On the other hand, the photometry switch MES is open and
If 0 is “Low”, the switch FAS will
It is determined whether the AF or FA mode is selected (#37), and the mode determined in step #25 is determined based on the data from the lens (#38). Here, input terminal i1 is “Low” and FA mode is selected (#37)
or flag even if AF mode is selected.
If MFF is "1" and the lens side can only operate in FA mode, proceed to step #40. When the AF mode is selected and MFF is "0", the output terminal O1 is set to "Low"(#39) to stop the operation of the microcomputer MC1, and then the process moves to step #40. Incidentally, when the FA mode is determined in steps #37 and #38, the terminal O1 remains at "High" and the process moves to step #40, and the operation of the microcomputer MC1 continues. In step #40, the open/closed state of the switch EES is determined, and if the charging of the exposure control mechanism is not completed and i2 is "High", the process moves to step #47 to return to the initial state, which will be described later. Do this. Charge of the exposure control mechanism has been completed and i2
If is “Low”, enable timer interrupt in step #36, then return to step #2,
The photometry switch MES is closed again and the input terminal i
Wait until 0 becomes "High" or there is a timer interrupt. Now, when there is a timer interrupt, 1 is subtracted from the contents of register Tc (#45), and the contents of Tc become "0".
It is determined whether it has changed (#46). Tc≠0
In this case, the process moves to steps #5 and subsequent steps, and the aforementioned data acquisition, exposure calculation, etc. are performed. At this time, in the FA mode, since the terminal O1 is "High", the microcomputer MC1 repeats the operation for FA,
In the AF mode, the operation of the microcomputer MC1 is stopped because the terminal O1 is set to "Low" in step #39. On the other hand, when Tc=0, the output terminals O0, O1,
O8 is set to “Low”, power supply by transistor BT1 and buffer BF is stopped, microcontroller MC1 stops operating in FA mode, and transistor
Power supply by BT3 is stopped. moreover,
Blank display on LCD display DSP, flag MFF,
After resetting the LMF, return to step #2. To summarize the above operation, the photometry switch MES
While the camera is closed, data acquisition, microcomputer MC1 operation, exposure calculation, and display operations are performed repeatedly. Next, when the light metering switch MES is released, the microcontroller immediately
The operation of MC1 is stopped and data import, exposure calculation, and display operations are repeated for 15 seconds.In FA mode, data import, FA operation by microcontroller MC1, exposure calculation, and display operations are repeated for 15 seconds. . Furthermore, if the exposure control mechanism has not yet been fully charged, data acquisition, microcomputer MC1 operation, exposure calculation, and display operations are immediately stopped when the photometry switch MES is released. Note that even if a warning is displayed in steps #16-4 and #27-2, if the warning is no longer necessary in the next flow, data for canceling this warning is sent to the display control circuit DSC. Needless to say, it needs to be communicated. Next, the operation when the release switch RLS is closed with the exposure control mechanism completely charged will be described. In this case, no matter what operation the microcomputer MC2 is performing, it immediately performs the release interrupt operation from step #59. First, in consideration of the possibility that an interrupt may occur while reading data from the lens, set the terminal O6 to "Low" to reset the converter and lens circuits CVC and LEC (#59), and then set the terminal O1 to "Low". to stop the AF or FA mode operation by the microcomputer MC1 (#60). Furthermore, the output terminal O8 is set to “Low” and the warning light emitting diode LD10~
Turn off LD1n (#61), release flag
After setting RLF to "1"(#62), it is determined whether the aforementioned flag LMF is "1"(#63). Here, if the flag LMF is "1", the calculation of the exposure control value has been completed, and the process moves to step #64. On the other hand, if LMF is "0", the calculation of the exposure control value has not been completed, so the process moves to steps after #5, calculates the exposure control value, and moves to step #64. In step #64, the data Av−Avo, Av−
(Avo+ΔAv), Av−(Avo+β), Av−(Avo+
β+ΔAv) is output to the data bus DB, and a pulse for data acquisition is output from the output terminal O4 (#65). As a result, data on the number of stops is imported into the exposure control device EXC, and
A narrowing down operation of the exposure control mechanism is started, and when the aperture is narrowed down by the number of stops taken in, the narrowing down operation is completed. When a certain period of time has elapsed since the pulse output from the output terminal O4 (#66), the data Tv of the calculated exposure time is output to the data bus DB, and the data Tv is output from the output terminal O5.
Pulses for data acquisition are output from (#67, #68). The exposure control device is controlled by this pulse.
Exposure time data is loaded into EXC, and mirror up operation is started by the built-in mirror drive circuit. When the mirror up is completed, the front shutter curtain starts running and
The count switch COS closes and starts counting the time corresponding to the captured exposure time data. When the count ends, the shutter rear curtain starts running, the rear curtain travel is completed, the mirror is lowered,
When the aperture is opened, the switch EES is closed. When the microcomputer MC2 determines that this switch EES is closed and the input terminal i2 becomes "High", #69, it resets the release flag RLF and #70 indicates that the photometry switch MES is closed and the input terminal i2 becomes "High". Determine whether i0 is "High"(#71). Here, if i0 is “High”,
Return to step #2 and subsequent steps, and repeat the aforementioned data acquisition, operation of the microcomputer MC1, exposure calculation, and display operation. On the other hand, in step #71, the photometry switch MES is open and the input terminal i0 is “Low”.
If so, move on to steps after #47 and install the microcontroller.
Set MC2 to the initial state and return to step #2. Figures 8, 9, and 10 are microcomputer MC1
This is a flowchart showing the operation. Microcomputer
The operation of MC1 is roughly divided into the following three flows. The flow starting with step No. 1 is
This is the main flow started by the focusing operation command from MC2, and the CCD is controlled by the control circuit COT.
(FLM) operation start (No. 8), determination of whether the motor is rotating (No. 10 to No. 13), CCD longest integration time measurement, and operation when the longest integration time has elapsed (No. 14 to 19) ,
Detecting the end position of the focus lens and measuring the longest integration time (No. 35 to 44), stopping the motor at the end position and restarting rotation when the contrast is low (No. 43 to 44)
48, 51 to 67), Initial settings when microcomputer MC1 stops operating (No. 25 to 33), Conversion of CCD data at low brightness (No. 78 to 80), Calculation of the amount of defocus and direction of defocus (No. 48). 81 to 91), determining whether the lens can operate in AF mode (No. 92 to 96), determining contrast (No. 100), driving the motor to the focus zone in AF mode, and determining focus. (No.125～
196) (Fig. 9), Focus determination in FA mode (No.
240-261) (Fig. 10), operation at low contrast (No. 105-115, 205-214), motor drive for lenses that can switch to macro photography at the closest shooting position (No. 220) -232), etc. are performed. Steps Nos. 70 to 76 are a terminal interrupt flow in which a CCD output data reading operation is performed in response to a CCD integration completion signal sent from the control circuit COT to the terminal it. Steps Nos. 200 to 204 in FIG. 8 are a counter interrupt flow in which focus is determined by outputting a coincidence signal from the counter ECC via the encoder ENC. Note that once pin interrupts are enabled, the priority order of both interrupt operations is determined so that even if a counter interrupt signal is generated thereafter, the counter interrupt will not be executed until after the pin interrupt operation has finished. ing. The operations of the AF and FA modes in this embodiment will be explained below based on this flowchart. First, in response to the closing of the power switch MAS, a reset signal is sent from the power-on reset circuit POR1.
PO1 is output, and this reset signal causes the microcomputer to
MC1 performs a reset operation (No. 1) from a specific address. In step No. 2, it is determined whether the switch FAS is closed and the input terminal i14 is at "High" level. Here, if i14 is "High", the AF mode is selected, so set the flag MOF to "0", and if it is "Low", the FA mode is selected, so set the flag MOF to "1". Set. In step No. 5, it is determined whether the output terminal O1 of the microcomputer MC2 is "High", that is, whether the input terminal i11 is "High". Here, if the input terminal i11 is "Low", the process returns to step No. 2 and the above operation is repeated. When it is determined that i11 is "High", output terminal O16 is set "High" (No. 6), transistor BT2 is made conductive via inverter IN5, and power supply from power supply line VF is started. let next,
Set fixed data C1 corresponding to the longest integration time in the integral time measurement register ITR of the CCD (FLM) (No. 7). Next, output a “High” pulse from the output terminal O10 (No. 8) and send the CCD to the control circuit COT.
(FLM) starts the integral operation and enables interrupts (No.
9), then move on to step No. 10. In steps No. 10 to No. 13, it is sequentially determined whether or not the motor MO is rotating. In other words, whether or not the first focus detection operation has been performed is determined by the flag FPF (No. 10), and the focus lens FL
The end flag ENF determines whether the drive position has reached the nearest or infinite end position (No.
11) The focus flag IFF (No. 12) determines whether the drive position is within the focus zone or not.
Which mode is selected by FAS is sequentially determined by flag MOF (No. 13). Here, if the first focus detection operation has been performed, the lens has reached the end position, entered the focus zone, or FA mode is selected, the rotation of the motor MO will stop. Therefore, move on to step No. 14 and onwards. Also, 2
A focus detection operation has been performed since the first time, and the lens has not reached the final position or the focus zone, and
If AF mode is selected, the motor
Since MO is rotating, move on to steps after No. 35. The flag FPF is "1" during the first focus detection operation, and "0" during the second and subsequent operations, and the end flag ENF is set when the drive position of the focus lens FL is closest. When the position or the infinite position is reached and no pulse is output from the encoder ENC even if the motor MO is rotated further, it becomes "1" and the focus flag is set.
IFF becomes "1" when the lens is in the in-focus zone, and "0" when it is out of focus. In steps after No. 14, "1" is first subtracted from the contents of the integral time measurement register ITR (No.
14) Determine whether borrow BRW is issued from this register ITR (No. 15). Here, the borough
If BRW is not output, set the low brightness flag LLF to “0” (No. 18) and determine whether the “High” signal for operating the microcomputer MC1 is input from the microcomputer MC2 to the input terminal i11. (No. 19), and if i11 is "High", the process returns to step No. 14 and this operation is repeated. Also, “Low”
If so, the program moves to step No. 25 and subsequent steps to perform a return operation to the initial state, and then returns to step No. 2 and waits for the input terminal i11 to become "High" again. On the other hand, if it is determined that a borrow BRW has occurred at step No. 15, it means that the longest integration time has elapsed, and a pulse is output to the output terminal O11 (No. 16) to output the CCD (FLM). Forcibly stop the integral operation and set the low brightness flag LLF to “1”.
Wait for the interrupt signal to be output from the control circuit COT to the interrupt terminal it. In steps after No. 35, first, fixed time data C2 is set in the clock register TWR (No.
35), subtract n (for example, 3) from the contents of register ITR to determine whether a borrow BRW has appeared (No. 37). Here, borrow from register ITR
If BRW is displayed, it means that the longest integration time has elapsed as described above, so proceed to step No. 16, forcibly stop the integration operation of the CCD (FLM), and set the low brightness flag LLF. is set to "1" and waits for an interrupt signal to be input from the control circuit COT to the interrupt terminal it. If a borrow BRW is not issued, the low brightness flag LLF is set to "0", and "1" is subtracted from the register TWR to determine whether a borrow BRW is issued (No. 40). At this time, the borough BRW
If not, it is determined in step No. 41 whether the input terminal i11 has become "High". If i11 has become "High", the process returns to step No. 36, and if it has become "Low", the process moves to step No. 25. Incidentally, since C1/n>C2, a borrow occurs multiple times in the determination in step No. 40 until a borrow BRW appears in the determination in step No. 37. When a borrow BRW occurs at step No. 40, the data ECD that counts the number of pulses from the encoder ENC is set in register ECD1 (No. 42), and this setting data is compared with the contents of register ECR2 (No. .43). Note that the count data taken in previously is set in the register ECR2.
Here, if the contents of registers ECR1 and ECR2 do not match, it means that the lens has moved, so the contents of register ECR1 are changed to register ECR2.
(No.44) and return to step No.35. If the contents of registers ECR1 and ECR2 match in step No. 43, the pulse count data from the encoder ENC that was captured last time has not changed, that is, the lens has not moved and the closest position or This means that it has reached the infinity position. Therefore, in this case, interrupts are not possible (No.
45) and output a pulse to output terminal O11 (No.
46) to forcibly stop the integration operation of the CCD (FLM) and set both output terminals O12 and O13 to “Low”.
(No.47) to stop the rotation of the motor MO,
Determine whether the low contrast flag is “1” (No. 48). Note that this flag LCF becomes "1" when the subject has a low contrast and the defocus amount ΔL calculated based on the output of the CCD (FLM) is unreliable. Here, the flag LCF
When is "0", the termination flag ENF is set to "1" (No. 49) and the process moves to step No. 270 in FIG. In step No. 270, it is determined whether the input terminal i14 remains "High", and if i14 remains "High" and the AF mode remains selected, the process directly proceeds to step No. 2. On the other hand, i1
4 is “Low” and has been switched to FA mode, the flag FPF is set to “1” and the terminal O
12, O13 is set to "Low" to stop the motor MO, flags LCF, LCF1, and LCF3 are set to "0", and then the process returns to step No. 2. To summarize the above operation, in response to a focus detection command from the microcomputer MC2, the CCD starts integrating, enables interrupts, and starts counting the longest integration time. If the motor MO is not rotating at this time, wait for an interrupt signal to be input while counting the longest integration time, and if no interrupt signal is input even after the longest integration time, the CCD
Force the integration to stop and wait for an interrupt signal to be input. On the other hand, if the motor MO is rotating when the CCD starts integrating, it will wait for an interrupt signal to be input while periodically determining whether the lens has reached the end position while counting the integration time. , if the interrupt signal is not input even after the longest integration time has elapsed, and the lens has not reached the end,
Force the CCD integration to stop and wait for an interrupt signal. Also, if the lens has reached the end, interrupts are not possible and the integration is forcibly stopped, and the motor
Stop the rotation of the MO, integrate the CCD again, calculate ΔL to determine whether or not it is in focus, as described later.
Even if a "High" signal is input to the input terminal i11 of MC1, the microcomputer MC1 does not perform focus detection or focus adjustment, and when this signal becomes "Low", the photometry switch MES is closed again and the input signal is input. When the terminal i11 becomes "High", the operation starts from step No. 2. Now, at step No. 48, the flag LCF is “1”
If it is determined that
It is determined whether or not is "1" (No. 51). here,
If LCF is “0”, set LCF1 to “1” (No.52), and at step No.60, focus direction flag FDF is set.
is “1”. In addition, the flag
LCF1 is a flag used to scan the lens position where the contrast exceeds a predetermined value in order to determine whether or not the lens position is significantly deviated from the in-focus position, a so-called bokeh state.Flag FDF is
“1” when the lens is extended (front focus) when ΔL>0, and “1” when the lens is extended when ΔL<0 (rear focus)
is a flag that becomes "0". At this time, if FDF is "1", it is reset to "0", and if it is "0", it is reset to "1", and it is determined whether the input terminal i12 is "High" or not (Nos. 63 and 64). In other words, the direction of rotation of the motor for feeding out the lens is determined, and No. 63
If i12 is "High" in step No. 66, the lens must be rotated clockwise to extend it, so move to step No. 66 and connect terminal O12.
Set O13 to “High” and O13 to “Low”. If i12 is “Low”, the motor is required to extend the lens.
Since MO must be rotated counterclockwise, move to step No. 65 and set terminal O12 to "Low" and terminal O13 to "High". Also, No.64
If i12 is "High" in step No. 65, the motor MO must be rotated counterclockwise to retract the lens, so move to step No. 65. If i12 is "Low", the motor MO must be rotated clockwise to retract the lens, so move to step No. 66. Next No.67
In step No. 270, the terminal O14 is set to "High" to rotate the motor MO at high speed, and the process moves to step No. 270. If flag LCF1 is determined to be "1" in step No. 51, it means that the closest or infinite end position has been reached with low contrast, and the motor MO is stopped (No. 53 ), wait for i11 to become “Low” (No.55), and set the flag LCF,
Set LCF1 and LCF3 to “0” and return to step No.25. Now, a series of operations in the case of low contrast will be explained. First, if the contrast is low in AF mode, "101" is output to output port OP0 to display a warning (No.105), and then flag LCF is set to "1".
Determine whether it is. (No.107). Here, if the flag LCF is not "1" and the contrast has become low for the first time, then the flag
Set LCF and LCF3 to “1” (No.108, 109), and set No.
At step 110, it is determined whether it is the first operation (FPF=1). If the flag FPF is "0", the contrast was not low in the previous operation, and there is a possibility that the current measurement was incorrect, so No.
The process moves to step 280, passes through steps 270 and 271, returns to step 2, and performs the measurement again. At this time, the motor is rotating toward the previously calculated value. In addition, the termination flag ENF is “1”
If the step moves to step No. 280 after passing through step No. 110, the rotation of the motor MO has stopped, so wait for input terminal i11 to become “Low” (No. 281) and set the flag. After setting LCF and LCF3 to "0" (No. 282), initial values for stopping the operation of the microcomputer MC1 are set in steps from No. 25 onwards. Also, the flag FPF is “1” at step No. 110.
is determined to be the first action, the flag
Set FPF and LCF3 to “0” (No.111, 113), and set No.
At step 205, it is determined whether the defocus amount ΔL is positive or negative. If ΔL>0 and front pin, set flag FDF to “1”,
If ΔL<0 and the rear focus is set, set the flag FDF to "0" (No. 206, 209), and in the same way as steps No. 63 to 66 above, set the motor according to the rotational direction of the motor MO for extending the lens. Rotate MO counterclockwise or clockwise. Next, in step No. 212, it is determined whether the integral time (contents of register ITR) is shorter than a constant value C7, and if the integral time is less than a constant value (ITR≧C7), terminal O14 is set to “High”. ”
The motor MO is driven at high speed (No. 213), and when the integral time is greater than a certain value, the terminal O14 is set to "Low" and the motor MO is driven at a low speed (No. 213).
214), return to step No. 2 via step No. 270, and start measurement again. In this way, the lens is first moved in the correct direction until the measured value becomes a value that is not low contrast. When the lens reaches one end position with low contrast, flag LCF1 is set at step No.52.
is set to "1", the direction of movement is reversed, and the lens is moved while repeating the measurement. If the other end position is reached while the contrast remains low, it means that the lens has been scanned from one end to the other, so the process moves to step No. 55 and stops the operation. If it is determined during this operation that the photometric value is not low contrast, the process moves to step No. 101, and a lens control operation based on the amount of defocus described later is performed. Here, if the contrast suddenly becomes low, as mentioned above, ignore the first measurement value and perform the measurement again. At this time, too, if the contrast is low, the flag LCF3 is set to "1" (No. .112), set LCF3 to “0”
Proceed to step No. 205, determine the direction of movement of the lens based on the measured value, and search for a position where the contrast is above a certain value. If the contrast is low in FA mode (MOF=1), move from step No. 106 to step No. 115, set flag LCF to "1", flag LCF1,
Set LCF3 to "0", flag FPF to "1", termination flag ENF to "0", and output terminals O12 and O13 to "Low", move to step No. 258, perform the operations described later, and repeat. Take measurements. Microcomputer MC1 takes No. 1 from steps No. 9 to 13.
Loops of 14, 15, 18, 19 or No. 35-40, 42-44
When the CCD (FLM) integration operation is completed and a "High" pulse is input from the control circuit COT to the interrupt terminal it while executing the loop or the loop No. 36 to No. 41, the microcomputer MC1 selects No. Jump to step .70 and start interrupt operation. First, the value of counting pulses from the encoder ENC
ECD is set in register ECR3 (No.70), and CCD
The number of light receiving parts, that is, the input port of microcontroller MC1
Value C3 corresponding to the number of data input to IP0
is set in the register DNR (No. 71), and waits for a "High" pulse to be input to the input terminal i10 at step No. 72. When the A/D conversion of the CCD output is completed and the input terminal i10 becomes "High", one CCD output data CD input to the input port IP0 is set in the register M (DNR) (No.
73). Next, “1” is subtracted from the contents of register DNR (No. 74), and a borrow is generated from this register DNR.
Steps Nos. 72 to 75 are repeated until BRW is output. In this way, CCD output data CD
are sequentially set in registers M and DNR. When all CCD output data CDs have been imported,
Set a return address, perform a return operation to that address, and move on to the main flow after step No. 77. In step No. 77, it is determined whether the flag LLF is "1". Here, if LLF is “1”, the largest data among the data CDs from the CCD
MACD is searched (No.78). This data MACD
If the most significant bit of
CCD output data ALCD is doubled (No. 80), and when it is "1", doubling results in overflow data, so the process directly proceeds to step No. 81. On the other hand, if the flag LLF is "0", the process immediately moves to step No. 81. In steps No. 81 and 90, calculations are performed on the integer part and decimal part of the shift amount of the two images in a plane equivalent to the film plane, respectively. Specific examples of calculating the shift amount in these steps are proposed in, for example, U.S. Pat. Omitted. In steps Nos. 82 to 85, it is determined whether or not the motor MO is rotating, similarly to steps Nos. 10 to 13 described above. Here, if the motor MO is rotating, the count data ECD of the number of pulses from the encoder ENC is in the register ECR.
1 (No. 86), and this data is compared with the contents of the register ECR2, which was previously fetched in step No. 44. If ECR1=ECR2, the lens has reached the end, so move on to the operation from step No. 47 mentioned above, and if ECR1≠ECR2, the lens has not reached the end, so set the contents of ECR1 to ECR2. repair
Move to step No.89. On the other hand, motor MO
If it is not rotating, immediately proceed to step No. 89. In step No. 89, input terminal i11 is “High”
When it is “Low”, the focus detection operation after step No. 25 is stopped and initial settings are made, and when it is “High”, it moves to step No. 90 and the decimal part of the shift amount is performed. The defocus amount ΔL is calculated based on the shift amount calculated in steps No. 81 and No. 90 (No. 91). At step No. 92, it is determined whether the mode is AF mode or not based on the flag MOF, and if the mode is AF mode, the process moves to step No. 93, and if it is FA mode, the process moves to step No. 100. In the case of AF mode, first the microcomputer MC2
The conversion coefficient KD latched in the latch circuit LA is taken in from the input port IP1 (No.93),
It is determined whether k3 of this data is "0" and k2 is "1" (No. 94). Here, k3=0 and k2=
In case 1, as mentioned above, the interchangeable lens is AF
Since operation in mode is not possible, the mode flag
Set MOF to “1” (FA mode) and move to step No.96. On the other hand, if k3=1 or k2=0, it means that an interchangeable lens capable of AF mode is attached, and the process moves to step No. 100.
Furthermore, in step No. 96, it is determined whether k1=0 or not, and if k1=1, the process moves to step No. 100. If k1=0, as described above, this means that a lens is attached that cannot be switched to macro photography unless the lens is extended to the closest position, and a switch to macro photography is being attempted. At this time, No.
Move to step 220, set output terminal O14 to "High" and rotate motor MO at high speed.
Next, it is determined whether the input terminal i12 is "High" (No. 221). Here, if i12 is "High", the lens is extended by rotating clockwise, so the output terminal O12 is set to "High".
Also, if it is “Low”, it is fed out by rotating counterclockwise, so after setting O13 to “High”, the pulse count data from the encoder
Load ECD into register ECR2 (No.224). Next, data C8 for a certain period of time is stored in register TWR.
(No. 225), repeats the operation of subtracting "1" from the contents of this register TWR to determine whether a borrow BRW has occurred, and when a borrow BRW occurs after a certain period of time, the pulse from the encoder is Load count data ECD into register ECR1 (No. 228). Next, it is determined whether the contents of registers ECR1 and ECR2 match (No. 229), and ECR
When 1≠ECR2, set the contents of ECR1 to ECR2 (No. 230) and repeat steps No. 225 to 230.
On the other hand, when ECR1=ECR2, the lens has reached the closest position, so the output terminals O12 and O13
to “Low” to stop the motor MO (No.
231), set the flag FPF to “1” (No. 232), and set the flag FPF to “1” (No. 232).
Return to step 2. Note that from now on, the operation will be in FA mode. In step No. 100, it is determined whether the data from the CCD is low contrast. A specific example of this step will be described later with reference to FIG. Here, if the contrast is low, the process moves to the steps from No. 105 described above. On the other hand, if the contrast is not low, it is determined in step No. 101 whether the flag LCF is "1". Here, if LCF is "1", the previous measurement value is low contrast, so the flag FPF is set to "1", the flag LCF,
Set LCF1 and LCF3 to "0", move to step No. 290, and refer to the mode flag MOF.
If MOF=0, that is, AF mode, output terminal O1
2. After setting O13 to "Low" and stopping the motor MO, return to step No. 2 and perform measurement again. Also, if MOF=1, that is, FA code, No.
The program moves to step 240 and performs the FA mode operation, which will be described later. Flag LCF=1 at step No.101
If the previous measurement value is not low contrast, refer to the mode flag MOF in No. 104, and if MOF is "1", that is, FA mode, go to step No. 240.
If the MOF is "0", that is, the AF mode, the process moves to step No. 125. In steps Nos. 125 to 130, an operation is performed to determine whether or not the defocus amount ΔL is within the range of the focusing zone ZN1. First, when the lens has not reached the final position and the flag ENF is "0" (No. 125), and once it has reached the in-focus zone and the in-focus flag IFF is "1" (No. 126), The current measured value |ΔL| and ZN1 are compared at step No. 127. Here, if |ΔL| Stop. On the other hand, if |ΔL|≧ZN1, the flag FPF is set to "1", the flag IFF is set to "0", the process moves to step No. 135, and a lens control operation is performed using the defocus amount based on the current measurement value. If the end of the lens has been reached and the flag ENF is "1", in step No. 127, if |ΔL|<ZN1, in-focus display is performed (No. 128), and |ΔL|
If so, move to step No. 129 with the previous def focus direction still displayed, and do the same as above.
When i11 becomes "Low", the operation is stopped. Here, if |ΔL|≧ZN1, the previous defocus direction remains displayed and the process moves to step No. 129. However, in this case, the lens does not come into focus even at the end position, and the motor MO is controlled from now on. Since it is useless to do so, we forcibly stop the operation of the microcomputer MC1. When it is determined in steps No. 125 and 126 that the lens has not reached the final position or within the focusing zone, first, in step No. 131, it is determined whether the first pass flag FPF is "1". be done. Here, when the flag FPF is "0", the above-mentioned No. 86~
Similar to step 88, after the operation to determine whether the lens has reached the end is performed (Nos. 132 to 134),
Move to step No. 135 and FPF is “1”
In this case, proceed directly to step No. 135.
At step No. 135, the focus detection command signal from the microcomputer MC2 is determined. When the input terminal i11 is "Low", the operation returns to step No. 25 and the operation is stopped; when it is "High", the focus detection command signal from the microcomputer MC2 is determined. Move on to the next step. In step No. 136, the calculated defocus amount ΔL is multiplied by the read conversion coefficient KD.
Data N of the drive amount of the lens drive mechanism LDR is calculated, and it is again determined in step No. 137 whether the flag FPF is "1". Here, the flag FPF
If is "1", first it is determined whether N is positive or negative (No. 140), and if it is positive, the focusing direction flag FDF is set to "1".
If it is negative, it is set to "0", and then the absolute value of the drive amount N is set as Nm in the register ECR4 (No.
144), the flag FPF is set to "0" and the process moves to step No. 166. On the other hand, the flag FPF is “0” at step No. 137.
If so, first, the contents of register ECR4, which stores the data of the previous drive amount, are stored in register ECR.
5 (No. 150), and instead the pulse count data ECD from the encoder ENC at this point
is taken into register ECR4 (No. 151). That is, the ECR5 is set with the count data Tc1 at the time when the CCD integration ends, and the ECR4 is set with the count data Tc2 at this time.
Next, the amount of movement of the lens in the period required for CCD integration τ = Tc0 - Tc1 is the amount of movement of the lens in the period required to calculate N t0 = Tc
1-Tc2 is calculated. Here, assuming that N is obtained at a position in the middle of the CCD integration period, at this point the lens has moved by τ/2+t0 from the point in time when N was obtained. Also, from N′m obtained in the previous flow, the lens movement τ + t
Data N″m=N′m−τ−t0 is calculated by correcting 0. Note that this data N″m is always positive. In steps Nos. 155 to 157, it is determined whether or not the focusing direction has been reversed based on the sign of the defocus amount N and the flag FDF. First, in step No. 155,
It is determined whether the currently calculated differential focus amount N is positive, and if N is positive, it is determined whether the flag FDF=0 (No. 156). At this time FDF=0
If so, the direction has been reversed, and the process moves to step No. 158. If FDF=1, it has not been reversed, so step No.
Move to step 159. On the other hand, if N is negative, it is determined whether FDF=1 (No. 157), and FDF
If = 1, the rotation is reversed, so proceed to step No. 158; if FDF = 0, the rotation is not reversed, and proceed to step No. 159. When the direction is not reversed, that is, at step No. 159, the focus position is approached by the rotation of the motor, so assuming that the value of N is obtained in the middle of the integration period, |N|-
The movement due to the rotation of the motor is corrected by calculating τ/2-t0=N', and then it is determined whether or not N' is negative (No. 160). Here, N′<
If it is 0, it means that you have passed the in-focus position.
Set N′|=N′ and move to step No. 164, N′>
If it is 0, at step No. 161, the average of the data N″m and N′ obtained up to the previous time (N″m+N′)/2
=Na (No. 161), set this data Na as Nm (No. 162), and proceed to step No. 166. When the direction is reversed, that is, at step No. 158, τ/2 from the time when the current data was obtained.
Since it is away from the in-focus position by +t0 in the current defofocus direction, a correction calculation of |N|+τ/2+t0=N' is performed, and the process moves to step No. 164. In step No. 164, the average of N″m and N′ (N″m−N′)/2=Na is calculated, and then it is determined whether this average value Na is negative (No. 165) . Here, if Na > 0, proceed to step No. 162 described above, and if Na < 0, set terminals O12 and O13 to "Low" to stop the rotation of the motor (No.
174), conversion coefficient KD to focus zone data ZN1
Multiply by to obtain the data of the motor rotation amount in the focusing zone.
Calculate Ni (No.175). Next, it is determined whether |Na|<Ni (No.176), and |Na|<Ni.
If Ni is in the focus zone, the focus flag IFF is set to "1" and the process moves to step No. 2 via step No. 270. On the other hand, |Na|>
If it is Ni, it means that it has passed through the focus zone, so the flag FPF is set to "1", and the process similarly moves to step No. 2 via step No. 270, and repeats the measurement operation. Now, in step No. 166, data NZ indicating the near focus zone is multiplied by KD to calculate data corresponding to the amount of lens drive from the near focus zone to the in-focus position. Next, in step No. 167, the calculation Ni = ZN1 × KD is calculated from the values ZN1 and KD of the near focus zone, and the data Ni of the lens drive amount in the focus zone is calculated (No. 167 ), Nm and Nn are compared (No. 168). Here, if Nm≧Nn, that is, outside the near focus zone, move to step No. 181,
Set terminal O14 to “High” to rotate motor MO at high speed, and input Nm− to counter ECC to count down the pulses from encoder ENC.
Set Nn (No.182) and move to step No.185. On the other hand, if it is determined that Nm<Nn, that is, within the near focus zone, then in step No. 169, Nm<Nn
Determine whether or not. Here, if Nm≧Ni, even if it is within the near focus zone, it is not within the focus zone, so the output terminal O14 is set to “Low” and the rotational speed of the motor MO is set to a low speed (No.
183), set Nm to counter ECC (No. 184),
Move to step No.185. In addition, in the case of a lens whose KD changes depending on the shooting distance, if it is not in the near focusing zone, lens control is performed only by the signal in the direction of defocus, but when calculating the amount of defocus, it is necessary to start from No. 150. Since the amount of movement of the lens is corrected, Nm-Nn is set in the counter ECC in step No. 182 for this correction data. Also, if Nm<Ni, the output terminal O
12. Set O13 to "Low" to stop the motor MO (No. 171), set the focus flag IFF to "1" (No. 172), disable counter interrupt (No. 173),
Return to step No. 270 and perform the confirmation measurement again. Now, in step No. 185, it is determined whether the flag FDF is "1". Here, if FDF is “1”, it is the front pin, so “100” is sent to the output port OP0.
Outputs , lights up the light emitting diode LD0, and displays the front pin (No.186).If it is "0", it is the rear pin, so outputs "001" to the output port OP0, lights up the light emitting diode LD2, and displays the rear pin. (No.189) Next, the motor MO is rotated clockwise or counterclockwise according to the contents of this flag FDF and the rotation direction signal of the interchangeable lens to the input terminal i12 (No. 188, 191), and the process moves to step No. 192. Then, it is determined whether the input terminal i13 is "High". Here, if an interchangeable lens whose conversion coefficient changes depending on the shooting distance is attached and i13 is "High", then in step No. 193, Nm<Nn
Determine whether or not. At this time, if it is outside the near focus zone and Nm≧Nn, the directional signal is applied regardless of the calculated Nm, as shown in the above-mentioned step No. 182 immediately proceeding to step No. 185. The direction of rotation of the motor MO is determined and rotated only by this. Next, determine whether the integration time is longer than the fixed time value corresponding to C7 (No. 194), and if it is long, the lens may go too far at the in-focus position, so set terminal O14 to "Low". drive the motor MO at low speed (No. 195), disable counter interrupt (No. 196), and go through the steps of No. 270.
Return to step No.2. On the other hand, when it is determined in step No. 193 that Nm < Nn and the lens is in the near focus zone, a counter interrupt is enabled (No. 197), just like a normal interchangeable lens. ,
Return to step No.270. In addition, input terminal i13
Even if is “Low”, counter interrupt is enabled and the process returns to step No. 270. Now, while the motor MO is rotating, the encoder ENC
When the contents of the counter ECC, which counts pulses from
In 200 steps, it is determined whether Nm<Nn. Here, if Nm<Nn, it means that the motor MO was rotating in the near focus zone, that is, the focus zone has been reached, and the output terminals O12 and O13
is set to "Low" to stop the rotation of the motor MO (No. 203), the focus flag IFF is set to "1", and the process returns to step No. 270. On the other hand, if Nm≧Nn, it means that the near focus zone has been reached, and the output terminal O14
to “Low” to make the motor slow (No. 201),
After setting Nn to counter ECC (No. 202), return to the address where the interrupt occurred. Next, flag at step No. 104 or No. 290.
When it is determined that MOF is “1”, No.240
The FA mode operation is performed in the subsequent steps.
First, at step No. 240, the flag FPF is “1”
It is determined whether Here, FPF is “1”
If so, you will be operating in FA mode for the first time, and in case you switch from AF mode,
Set end flag ENF to “0” and focus flag IFF to “0”
Then, the in-focus zone data ZN2 is set in the in-focus zone discrimination register IZR. Furthermore, this data ZN
2 is a larger value than data ZN1 in AF mode. This is because in AF mode, the lens position can be adjusted with high precision by motor drive, but in FA mode, the lens position is adjusted manually, so it is very difficult to adjust the lens position as precisely as with motor drive. be. Next, in step No. 245, the first pass flag FPF is set to "0" and the process moves to step No. 246. one hand flag
If FPF is "0", the process immediately moves to step No. 246. At step No. 246, the focus flag IFF is “1”
It is determined whether Here, if the flag IFF is "1", it means that the previous calculated value is in the in-focus zone, so the average value of the previous calculated value ΔLn-1 and the current calculated value ΔL, that is, ΔLn=(ΔL+ΔLn-
1) The operation of /2 is performed (No. 247) and the register
Zw (>ZN2) as data for focusing zone in IZR
is set (No. 248), the process moves to step No. 250. This is because there are variations in the measured values each time, and once the lens enters the in-focus zone, the width of the in-focus zone increases, increasing the probability that the lens is in focus. This is to prevent the display from flickering when near the boundary. On the other hand, the focus flag IFF becomes “0” at step No. 246.
If so, let the current measured value ΔL be ΔLn (No. 249),
Move to step No.250. In step No. 250, it is determined whether |ΔLn|<(IZR), that is, whether the calculated value is within the focus zone. If it is determined that it is within the focus zone, the focus flag IFF is set to "1" (No. 251), the focus is displayed by the light emitting diode LD1 (No. 252), and the focus flag IFF is set to "1" (No. 251). Move on to the next step. On the other hand, if it is determined that it is outside the in-focus zone, it is determined whether ΔLn>0 (No.
253), if ΔLn>0, the front pin is displayed by the light emitting diode LD0, and if ΔLn<0, the rear pin is displayed by LD2. Next, the focus flag IFF is set to "0", data ZN2 is set in IZR, and the process moves to step No. 258. In step No. 258, input terminal i
14 is “High”, and if it is “High”
If the mode is switched to AF mode, set the flag FPF to "1", IFF to "0", and LCF to "0" and go to step No. 2. If it is set to "Low" and remains in FA mode, go to step No. .Return to step 2 and take the next measurement. In steps Nos. 25 to 33, focus detection operations in AF and FA modes are stopped and initial conditions are set. First, interrupts are disabled (No. 25), and a pulse is output to terminal O11 to forcibly stop the CCD integration operation (No. 26).
2. Motor MO is stopped by setting O13 to "Low" (No. 27), output port OP0 is set to "000", light emitting diodes LD0, LD1, and LD2 are turned off (No. 28), and terminal O16 is set to "Low". Power supply from power line VF is stopped (No. 32). Also, flags ENF, IFF, and LCF3 are set to “0”.
“1” is set in the FPF (Nos. 29 to 31, 33). After this initial setting is made, the process returns to step No. 2. Next, as a modification of the above-mentioned embodiment, when the subject area to be focused in the focus adjustment operation in AF mode reaches the in-focus zone, check whether other subject areas are within the depth of focus. 11, 12, and 13 show examples in which it is possible to confirm whether
This will be explained based on the diagram. Here, Figure 11 is the second
Main part circuit diagram showing only the parts different from the diagram, No. 12
This figure is a flowchart of the main part showing only the parts different from FIG. 3, and FIG. 13 is a flowchart of the main part showing only the parts different from FIGS. 8 to 10. That is, when it is determined at step No. 127 that the focus zone has been reached and the focus is displayed (No. 128), flag IFF1 is set to "1" (No. 300).
The output terminal O30 of the microcomputer MC1 in FIG. 11 is set to "High" (No. 301). This output terminal O30
is connected to the input terminal i5 of the microcomputer MC2, and the microcomputer MC2 determines that the lens has reached the in-focus position based on the "High" level of the input terminal i5. Next, the microcomputer MC1 moves to step No. 270, and if it has not switched to FA mode, returns to step No. 2 and performs measurement again. In this case, since the flag IFF is "1", the process goes through the same flow as in the case of in-focus confirmation and reaches step No. 91. A step (No. 305) is provided between the step No. 91 and the step No. 92 to determine whether the flag IFF1 is "1". If the flag IFF1 is "0", the step No. 92 is If it is “1”, move to step No. 306. Step No. 306 reads data from input port IP2. here,
As shown in Figure 12, between step #30 and step #31 in Figure 3, there is an aperture value for exposure control.
Av is output from the I/O port (#80), and this aperture value is latched in the latch circuit LA1 by a pulse from the output terminal an+2 of the decoder DEC. Therefore, data on the aperture value for exposure control is input to the input port IP2. The read data Av is converted to FNo. (No.
307), and in step No. 308, the calculation ΔD=δ×FNo. is performed. Here, δ is a value equivalent to the diameter of allowable blur, and ΔD is a value equivalent to the depth of focus.
Next, the differential focus amount |ΔL| obtained in step No. 91 in this flow and ΔD are compared in step No. 309, and after the focus status display below, No.
Move to step 270. Here, |ΔL|≦ΔD
If so, the part of the object measured at that time is within the depth of focus, and a signal of "010" is output to the output port OP5, and the light emitting diode LD4 shown in Fig. 11 is lit to display the focus. It is done.
On the other hand, if |ΔL|>ΔD, depending on whether ΔL is positive or negative, “100” is output to OP5 and light emitting diode LD3 is lit to display the previous pin, or “001” is output. Output light emitting diode
LD5 is turned on to display the rear pin. If you do something like this,
After the lens reaches the in-focus position in AF mode, check whether there is any part other than the part measured to drive the lens to the in-focus position within the depth of focus, or whether it is in front or back focus. Once you can confirm this, you will get effects that are very easy to use. Although the accurate depth of focus is calculated in step No. 308, it is difficult to accurately align the measurement position with the desired part of the subject due to camera shake, etc., and the calculated value of ΔL also varies. , as in the case of FA mode mentioned above, the width of the focus zone can be widened, once the focus zone has been reached, the width of the focus zone can be widened, and the average value of the data calculated several times can be processed. The accuracy may be increased by
For example, to increase the width of the focusing zone, ΔD=|×
It is sufficient to perform the calculation δ×FN0 (|=2 to 3). In addition, in this modification, step No. 33 and step No.
The following steps are inserted between step No. 273 and step No. 2. That is, the flag IFF1 is set to "0" (No. 320, No. 325), "000" is output to the output port OP5, and the light emitting diodes LD3, LD4, LD5 are turned off (No. 321, No. 326). Set the output terminal O30 to “Low” (No. 322, No. 327). In addition, step #81 in FIG. 12 is an input between step #38 and step #39 in order to continue the display operation of the above-mentioned modification for a certain period of time even after the photometry switch MES is released. Step #81 is inserted to determine the state of terminal i5. In other words, even if the photometry switch MES is opened and it is determined that the camera is in AF mode, the input terminal i5 remains "High" and the microcomputer MC1 performs the operation to check whether the depth of focus is within the aforementioned depth of focus. In this case, output terminal O1 is not set to “Low”,
Leave it at “High”. Figure 14 shows the control circuit of the CCD (FLM) in Figure 2.
FIG. 2 is a circuit diagram showing a specific example of COT. counter CO
24 is the clock pulse CP from counter CO22
The falling edge of pulse DP2, which is frequency-divided, is counted, and the output signals p0 to p4 of this counter CO24 are
Accordingly, the decoder DE20 outputs the output terminals T0 to T
9 outputs a “High” signal. This counter
The output of CO24, the output of decoder DE20 and flip-flops FF22, FF24, FF26,
Table 7 shows the relationship with the Q output of FF28.

[Table] As is clear from Table 7, the Q output φ1 of the flip-flop FF26 is “High” while the output of the counter CO24 is “11101” to “00101”, and the Q output φ2 of the flip-flop FF24 is “High” from “00100” to “00101”.
“High” during “10111”, flip-flop FF2
The Q output φ3 of No. 2 becomes “High” between “10110” and “11110”. This output signal φ1, φ2, φ3
is while power is being supplied from the power line VF.
The signal is applied to the CCD (FLM), and analog signals are constantly transferred within the transfer gate. Note that this operation also discharges the accumulated charges remaining in the transfer gate. The reset signal PO2 from the power-on reset circuit POR2 based on the start of power supply activates the flip-flops FF20 to FF28, FF32, the D flip-flops DF20, DF22, DF24, and the counter.
CO20, CO22, CO24 are reset.
Furthermore, flip-flop FF30 is set and the Q output becomes "High". This output signal φR makes the analog switch AS2 conductive, and the constant voltage source
The output potential of Vr1 is applied to the CCD via the signal line ANB.
(FLM), and the potential of the charge storage section of the CCD (FLM) is set to this potential. When a "High" pulse for starting an integral operation is output from the output terminal O10 of the microcomputer MC1, the flip-flop FF30 is reset via the one-shot circuit OS18, and the terminal φR becomes "Low". As a result, the CCD (FLM) starts accumulating charges according to the amount of light received by each light receiving section. Further, the analog switch AS1 is made conductive via the inverter IN50, and the monitor output of the CCD is input from the terminal ANB to the (-) terminal of the comparator AC1. The CCD monitor output from the terminal ANB decreases from the potential Vr1 in accordance with the accumulation of charge, and when it reaches the potential of the constant voltage source Vr2, the output of the comparator AC1 is inverted to "High". This detects that CCD (FLM) storage is complete. With this reversal, a “High” pulse is output from the one-shot circuit OS10, and the OR circuit OR20 outputs a “High” pulse.
Flip-flop FF20 is set via. This "High" signal of the Q output is taken into the D flip-flop DF20 at the rising edge of the terminal φ1, and the "High" of the Q output releases the reset state of the counter CO20, and the AND circuits AN60, AN64, AN66, AN68 becomes enabled. After the terminal φ1 rises to “High”, when the terminal T0 becomes “High”, the flip-flop FF2
8 is set by "High" at the terminal T0, and reset by "High" at the terminal T1. This Q output is sent to the CCD (FLM) as a "High" pulse from the terminal φT via the AND circuit AN68, and the accumulated charge is transferred to the transfer gate by this signal. Furthermore, this φT signal is sent to the interrupt terminal it of the microcomputer MC1, and the microcomputer MC1
Performs the operation to capture the output data of CCD (FLM). When this terminal φT falls to “Low”, the flip-flop FF is activated via the one-shot circuit OS16.
32 is set, and the gate of the AND circuit AN68 is closed due to the "Low" output thereof, and after that, the "High" signal from the Q output of the flip-flop FF28 is not output. Furthermore, the flip-flop FF30 is set via the one-shot circuit OS16 and the OR circuit OR32, and the terminal φR is set to "High" again. CCD (FLM) by transfer signals φ1, φ2, φ3
Accumulated charges are sequentially output from the terminal AOT, and this charge is output while φ2 is "High". Therefore, D flip-flop DF2
When the Q output of 0 becomes "High", the signal φS for sample and hold is sent from the AND circuit AN66 by the "High" of the terminal T4 during the period when φ2 is "High", and also by the "High" of the terminal T5. A signal φA for starting AD conversion is output from the AND circuit AN64. In addition, the accumulated charge signal first sent from the terminal AOT of the CCD (FLM) is used for offset adjustment, so that only the charge corresponding to leakage in the light receiving section is accumulated, and is almost equal to Vr1. It is equal to the output potential. At this time, since the output of the D flip-flop DF24 is "High", the sample and hold signal φS is passed through the AND circuit AN70 to the sample and hold circuit SH.
1, and the potential for offset adjustment is applied to the CCD.
(FLM) and is stored in the sample hold circuit SH1 via the terminal AOT. When the first sample and hold signal φS falls, the Q output of the D flip-flop DF24 becomes “High”, and the subsequent sample and hold signal φS is output to the AND circuit AN72.
is applied to the sample hold circuit SH2 via
Potentials corresponding to subsequent amounts of received light are sequentially stored in the sample and hold circuit SH2. When the Q output of the D flip-flop DF20 becomes “High”, the signal of φ3 is sent to the AND circuit AN
60 to one input terminal of the AND circuit AN62. At the first fall of this φ3, the Q output of the D flip-flop DF22 becomes “High”
Therefore, the second and subsequent pulse signals of φ3 are applied to the input terminal i10 of the microcomputer MC1 via the AND circuit AN62, and become a signal instructing the microcomputer MC1 to take in data to the input port IP0. Here, the Q output of the D flip-flop DF20 becomes "High" and the first AND circuit is activated.
AND circuit AN6 for the φ3 pulse from AN60
The reason why the data from the first CCD (FLM) is not output from the first CCD (FLM) is that the data from the first CCD (FLM) is used for offset adjustment as described above. The signal φ3 is also applied to the clock input terminal of the counter CO20, and the counter CO20 is released from the reset state by the "High" level of the Q output of the D flip-flop DF20, and counts the falling edge of the pulse from φ3. This counter CO20 is CCD
When the pulses from φ3 are counted as many as the number of light receiving parts of (FLM), the carry terminal CY is set to “High”. After the second time, the sample and hold circuit is
The output data of the CCD (FLM) is sampled and held in SH2 based on the signal φS, and the resistors R1, R2,
A subtraction circuit including an operational amplifier OA1 calculates the difference between the output of the sample and hold circuit SH1 and the output of SH2, and provides the calculated difference to the analog input terminal of the AD converter AD. The A-D converter AD starts operating with the signal φA, and converts this input data to A- based on the clock pulse DP1 from the counter CO22.
D-convert. Here, the output of constant voltage source Vr1 is set to Vr
1. If the voltage drop due to leakage is Vd, and the voltage drop due to the amount of light received is Vl, the sample hold circuit SH
1 output is Vr1-Vd, sample and hold circuit
The output of SH2 is Vr1-Vl-Vd. Therefore, the output of the subtraction circuit is a signal component of only the amount of received light, Vl. It is preferable that the A/D converter AD is of a type that performs A/D conversion at high speed, such as a successive approximation type. After the A-D conversion of all data from CCD (FLM) is completed, carry terminal CY of counter CO20 is
becomes “High”. As a result, the flip-flops FF20, FF32, and the D flip-flop are connected via the one-shot circuit OS14 and the OR circuit OR22.
DF20, DF22, DF24 are reset and D
When the Q output of the flip-flop DF20 becomes "Low", the counter CO20 goes into a reset state and returns to the state before the "High" pulse was input from the terminal O10. Also, the timer of microcomputer MC1 determines that the integration time has reached a certain value or more, and the terminal O
When a “High” pulse is input to 11,
One-shot circuit OS is activated at the falling edge of this pulse.
12. Flip-flop FF20 is set via OR circuit OR20. Therefore, from now on, the same operation as when the output of the comparator AC1 is inverted to "High" is performed, and the output data of the CCD (FLM) is A-D converted and sequentially output to the input port IP0 of the microcomputer MC1. . Figure 15 is a modified example in which a part of the circuit diagram in Figure 14 is changed.When the output data from the CCD is small, after importing the data to the microcomputer MC1,
The operation of doubling the data was performed using the software in the microcomputer MC1 (steps No. 78 to 82 in Figure 8), but now it is performed using the hardware before performing A-D conversion. It is. While the terminal φR is “High”, the potential Vr1 determined by the constant current source CIS and resistors R10 to R13 is CCD (FLM).
During the "Low" period, the monitor output of the CCD (FLM) is given to the (-) input terminals of the comparators AC10 to AC12. Then, when the integration progresses and the monitor output reaches the potential of Vr2, the output of the comparator AC12 becomes "High" and a "High" pulse is output from the one-shot circuit OS10, and this pulse passes through the OR circuit OR20 to the flip-flop FF20. is reset and thereafter performs the same operation as described above. Furthermore, this pulse is applied to the D flip-flop DF
It is applied to the clock terminals of DF32 to DF38. At this time, the output of comparator AC12 is “High”
Therefore, the Q output of the D flip-flop DF38 becomes “High”, and the analog switches AS48 and AS
38 becomes conductive. Here, the values of resistors R30 to R40 are R30=R40=R38=R48=R36/
1.5=R46/1.5=R34/2=R44/2=R
32/2.5=R42/2.5=, and due to the conduction of analog switches AS38 and AS48, R30
=R40=R38=R48, so the operational amplifier
The Vl signal is output as is from the OA10. On the other hand, when the CCD output has a low contrast and the output of the comparator AC12 is not inverted within the longest integration time, the output terminal of the microcomputer MC1
One-shot circuit OS12 is activated by the signal from 11.
A “High” pulse is output from the OR circuit OR20, and the monitor output at that time is Vr2~
Depending on whether it is between Vr3, Vr3 to Vr4, or Vr4 to Vr1, D flip-flops DF36, DF34, and DF32 are connected via exclusive OR circuits EO4 and EO2 and inverter IN52.
One of the Q outputs becomes “High”, and the analog switches AS36, AS46, and AS3 respectively
4. AS44, AS32, and AS42 are electrically connected. Therefore, the integration is forcibly stopped, and signals of 1.5Vl, 2Vl, and 2.5Vl are output from the operational amplifier OA10 in accordance with the monitor output at that time. Figure 16 shows the microcontroller shown in Figures 8 to 10.
A modified example of the operation of MC1 is shown, and the main part of the flowchart is shown when out-of-focus is continuously detected in the measurement results after in-focus is detected, and steps No. 130 and No. Flag IFF between 138 steps
2 has been inserted. In other words, if the lens focus is adjusted to the in-focus zone and the end flag ENF is "0" (No. 130), No. 351
In step , it is determined whether the flag IFF is "1". Here, if the flag IFF2 is "0", the flag IFF2 is set to "1" and the process moves to step No. 270, where measurement is performed again for confirmation. On the other hand, if flag IFF2 is “1”, the measurement result for confirmation is out of focus twice in a row (|ΔL|≧ZN1)
In this case, the flag IFF,
IFF2 is set to "0", flag FPF is set to "1", the process moves to step No. 135, and the focus adjustment operation is performed again. Note that a step (No. 34) for resetting the flag IFF2 to return to the initial state is provided between the step No. 33 and the step No. 2, and between the step No. 240 and the step No. 241. ，No.
241) is provided. FIG. 17 shows a specific flow of step No. 100 in FIG. 8, that is, the step for determining whether or not the contrast is low. First, the contents of register C are set to "0" (No. 370), and register i is set to "1" (No. 371). Next, the absolute value of the difference between the outputs ai and ai+1 of the i-th and i+1-th light receiving elements |ai−ai+1
The value obtained by adding the contents of register C to ) are compared (No. 374). Here, if i<n-1, return to step No. 372,
The absolute values of the differences are successively integrated, and when i=n-1, the process moves to step No. 375. That is, at the time of moving to step No. 375, the contents of register C are as follows.
｜a1−a2｜＋｜a2−a3｜＋｜a3−a4｜＋……＋
|an-2-an-1|+|an-1-an|, which is a value indicating the contrast of the subject, as is well known. In step No. 375, it is determined whether this value is greater than a constant value CD, and
(C)>CD has enough contrast, so No.101
If (C)≦CD, the contrast is low, so the process moves to step No. 105. Note that when the focus adjustment state is detected using two series of light receiving element outputs, it is sufficient to use only one series of outputs for contrast determination. In addition, if data that can be associated with the contrast of the subject can be found in the process of calculating the amount of defocus and the direction of defocus, this data can be stored and the contrast can be determined by determining whether it is below a certain value. The determination may be made as follows. Conversion coefficient data output from interchangeable lenses
KL is connected to the microcomputer MC1 via the microcomputer MC2.
It is read in step No. 93 and used, for example, in step No. 136 to calculate motor drive data N. This data KL is as shown in Table 6 above.
The code is divided into an exponent part and a significant figure part, and the above calculation is of course performed based on a value obtained by logarithmically expanding the value of the significant figure part according to the value of the exponent part. Incidentally, FIG. 18 shows the configuration of a reading circuit when this data conversion is performed, for example, by hardware. In the figure, the shift circuit 131 has data
For example, the effective exponent value of the lower 4 bits of KL is input. On the other hand, for example, the exponent value for the upper 4 bits is input to the shift control circuit 130, and the shift control circuit 130 shifts the data set in the shift circuit 131 according to this exponent value.
With such a configuration, the significant figure value set in the shift circuit 131 is shifted according to the exponent value,
As a result, the logarithmically expanded value is output from the shift circuit 131 as the value of the conversion coefficient. Effects As described above, the present invention calculates the drive amount data of the drive means on the camera body side based on the shift amount data calculated on the camera body side and the conversion coefficient data from the interchangeable lens, and uses this drive amount data. When automatic focus adjustment is performed by moving the focus adjustment lens of an interchangeable lens based on ) bit data, it is possible to reduce the number of bits of this conversion coefficient data to the minimum number of bits required for calculating the drive amount data, and also to shorten the transfer time.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an outline of the camera system according to the present invention, Fig. 2 is a circuit diagram showing its circuit configuration, Fig. 3 is a flowchart showing the operation of the microcomputer MC2 in Fig. 2, and Fig. 4 is a microcomputer
A circuit diagram showing the specific circuit configuration of the serial data input section SDI of MC2, Figure 5 is a circuit diagram showing the circuit configuration of the converter CV and interchangeable lens LE attached to the camera body, and Figure 6 is controlled by the microcontroller MC1. A circuit diagram showing a specific circuit configuration of the light emitting diode drive circuit FAD, and FIG. 7 shows the relationship between the focal length and the conversion coefficient of a variable magnification lens having an optical system in which the conversion coefficient changes depending on the focal length. graph,
Figures 8 to 10 are the microcontroller MC1 shown in Figure 2.
11 is a circuit diagram showing the main circuit configuration of the first modified example of the camera system shown in FIG. 2, and FIGS. 12 and 13 are microcontroller MC2 corresponding to this modified example. and
A flowchart diagram showing the main parts of the flow of MC1,
Fig. 14 is a circuit diagram showing the specific circuit configuration of the control circuit COT controlled by the microcomputer MC1, Fig. 15 is a circuit diagram showing the main circuit configuration of a modification thereof, and Fig. 16 is a flowchart of the microcomputer MC1. 17 is a flowchart specifically showing the operation of the microcomputer MC1 in step No. 100 in FIG. 8; FIG. 18 is a flowchart showing the main part of another modification; FIG. 18 is the reading circuit LDC in FIG. 1. FIG. BD...Camera body, MO...Driving means, LZ,
LE...Photographing lens, FL...Focus adjustment member, 10
1 to 106...transmission mechanism, LEC...data output means.

Claims (1)

[Claims] 1. An interchangeable lens that is replaceably attached to a camera body, comprising: an optical system that forms an image of subject light; a focusing lens that moves the imaging position of the subject light by an amount of movement; a storage means that stores conversion data for converting the desired imaging position movement amount into the driving amount; An interchangeable lens comprising: output means for outputting data to a camera body as a signal consisting of an m-bit exponent part and an n-bit significant figure part.