JPS62168122A - Light measurement mode changeable camera - Google Patents

Abstract

PURPOSE:To perform exposure control based upon a light measured value in each light measurement mode by converting light measured values corresponding to respective light measurement modes from analog to digital at the 1st period and storing then, and read and operation them at the 2nd period shorter than the 1st period. CONSTITUTION:A photographic 19 and an electronic flash device 20 are mounted on a camera body detachably. A light measurement part 13 is equipped with a photodetecting element 16 for averaged light measurement and a photodetecting element 17 for spot light measurement and its light measured value is outputted to a microcomputer 11. The microcomputer 11 converts the outputs of the elements 16 and 17 from analog to digital at the 1st period and stores respective A/D conversion data individually and repeatedly. The switching of specified light measurement sensitivity distributions is specified by the attachment and detachment of the flash device 20 and the microcomputer 11 repeats the operation in which each stored A/D conversion data is read and specific exposure arithmetic is performed on the basis of A/D conversion data corresponding to the specific light measurement sensitivity distribution at the 2nd period shorter than the 1st period. Thus, an exposure control part 14 performs the exposure control in light measurement mode in response to the switching of the light measurement mode.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a photometric operation based on a plurality of photometric sensitivity distributions (hereinafter referred to as
The present invention relates to a variable metering mode camera in which a photometric mode (referred to as a photometric mode) can be freely selected, and particularly to a variable metering mode camera in which photometric values are A/D converted at a predetermined cycle and exposure calculations are performed based on the A/D converted data.

4 Atsushi In this type of variable metering mode camera, only the metering value corresponding to the selected metering mode is A/D converted, and this A/D conversion is performed.
An exposure control device that performs exposure calculations based on /D conversion data has been proposed, for example, in Japanese Patent Laid-Open No. 59-123824. Generally, when converting photometric values from A/D,
For example, the A/D
The conversion cycle is determined. That is, at least the above A/D conversion period is required after the photometry mode is switched until the exposure control value is calculated based on the photometry value in that photometry mode.

However, the cycle of the A/D conversion described above is relatively long, and when continuous photographing is performed using a motor drive, for example, the following problems occur. In other words, if the A/D conversion cycle is long, if the shooting mode is switched during continuous shooting, the exposure calculation value based on the photometry value in that metering mode will be obtained at the time when the next shirt release is to be performed. There may be cases where this is not done. Therefore, in this case, photography cannot be performed in that photography mode.

SUMMARY OF THE INVENTION The present invention aims to solve the above-mentioned problems and provide a variable metering mode camera that can quickly respond to switching of metering modes even if the A/D conversion cycle is long, and can perform exposure control based on the metering value in that metering mode. It is something to do.

. The present invention provides a variable metering mode camera including a storage means for A/D converting and repeatedly storing each photometric value corresponding to each photometry mode in a first cycle, and A/D conversion of these stored A/D conversions. It is characterized by comprising a reading/calculating means that repeats an operation of reading A/D conversion data of a specified photometry mode among the data and performing exposure calculation based on the data in a second period shorter than the first period. shall be.

According to the above configuration, each photometry value corresponding to each photometry mode is stored in a batch with A/D conversion, and when switching of the photometry mode is specified, the corresponding data is read and exposure calculation is performed. .

Figure 1 is a top plan view of a single-lens reflex camera body equipped with a focal plane shutter to which the present invention is applied, and Figure 2 is a block diagram showing the circuit configuration of the camera body of Figure 1. It is. In Figure 1, the camera body (1
) are the main switch (2) and release button (3).
), up key (4).

A down key (5), an AE lock switch (6), a liquid crystal display (7) and an accessory shoe (8) are provided. Here, a symbol X indicating the flash synchronization limit speed (for example, 1/250 seconds) is printed near the up key (4), and a symbol B indicating bulb exposure is printed near the down key (5). There is. Also.

The AE lock switch (6) performs exposure control based on the photometric value when operated prior to the shirt release operation (so-called AE lock photography), and locks the AE lock from the non-AE lock position where AE lock is not possible. The AE lock position is switched to a possible AE lock position, but in addition to the characters "AEL" indicating AE lock is possible, the characters "5POT" indicating partial photometry are displayed in the AE lock position, and the characters "5POT" indicating AE lock is not available in the non-AE lock position. In addition to “OFF”, the characters “AV” indicating average photometry are displayed.
E” is printed on each.

In FIG. 2, the camera body (1) mainly includes a microcomputer (11), a film information reading section (12)
, a photometry section (13), an FI output control section (14), and a display control section (15). Here, the film information reading section (12) reads film information formed in the form of an electrical code signal (hereinafter referred to as DX code) on the outer peripheral side of the film cartridge, and reads the film information formed on the outer circumferential side of the film cartridge.
This is a circuit unit that outputs data to a microcomputer (hereinafter referred to as a microcomputer). The photometry section (13) includes a light-receiving element (16) for average photometry and a light-receiving element (17) for spot photometry.
ii 1,000≠-The photometric output of the light receiving element is output to the microcomputer (11). In addition, these light receiving elements (
16) and (17) are arranged, for example, at positions outside the photographing optical path where they can receive light from the subject that has passed through the semi-transparent part of the photographic lens and reflective mirror and been reflected on the shutter curtain surface or film surface. There is. The exposure control section (14) is controlled by a microcomputer (1
A zero display control section (15) that controls the shutter speed and aperture according to the output of 1) drives the viewfinder internal display section (18) and the external display section (7) according to the output of the microcomputer (11). Control. In addition, the main switch (2)
When it is in the "LOCK" position, as shown in FIG. 12, which will be described later, the control is performed so that all the display elements of the two display sections are turned off.

Further, a photographic lens (19) and an electronic flash device (20) are removably attached to the camera body (1).

Here, the photographing lens (19) stores lens-specific data regarding its optical and mechanical characteristics, aperture value, etc. on the camera body (19).
1) is output to the microcomputer (11), and the microcomputer (11) receives this lens information and the film information.

Exposure control information is calculated based on photometric information and the like.

Similarly, the electronic flash device (20) outputs flash information such as a mounting signal and a charging completion signal to the microcomputer (11). The microcomputer (11) has input terminals (IPo) to (IPs
), output end (OP, ), interrupt end (INT>, clear end (
CLR), and a signal falling to the interrupt end (INT) starts an interrupt operation, which will be described later, and a signal rising to the clear end (CLR) starts a reset operation, which will be described later. Switch (S
o), (Su), (Sd), and (Sa) are switches operated by the aforementioned main switch (2), up key (4), down key (5), and AE lock switch (6), respectively. In addition, when the main switch (2) is in the "ON" position, the switch (So) is closed, and when the up key (4) and down key (5) are pressed, the switches (Su) and (Sd) are closed, and the AE lock switch (6) is closed. The switch (Sa) closes at the “AEL” position of the switch (S).
+) and (Ss) are linked to the press operation of the release button (3) mentioned above, the photometering switch (S,) is closed at the beginning of the press operation, and the photometry switch (S,) is closed at the final stage when the release is released. Switch (S2) is engaged.

The switch (So) is connected to the input terminal (IP) of the microcomputer (11).
o) and one-shot circuit (2
1), AND gate (A N + ), OR gate (
It is connected to the interrupt terminal (INT) via OR+).

In addition, a switch (
S+), (Sa) and the OR gate (OR2) described below
The output of the microcomputer (11) is connected to the other input terminal of the OR gate (OR+).
11) input terminal (IF5), (IP,).

(I Ps) and (I Pg), and the switch (S2) is connected to the microcontroller (1) via the OR gate (OR2).
1) is connected to the input terminal (IF3). Further, the outputs of the switches (S+), (Sa) and the OR gate (OR2) are input to an AND gate (AN2), and the output thereof is connected to the input terminal (IF5) of the microcomputer (11).

This input terminal (ip,) is connected to switches (S +), (S 2), (
Sa) is provided to maintain the photometry state for a predetermined period after closing (hereinafter referred to as photometry hold).

The camera of this embodiment has a program mode in which the combination of shutter speed and aperture is uniquely determined based on a predetermined program diagram.

There are two types of program modes: a program mode for natural light photography (hereinafter referred to as P mode) and a program mode for flash photography (hereinafter referred to as FP mode). In addition, in each mode, the combination according to the predetermined program diagram can be manually shifted while maintaining the appropriate exposure (hereinafter referred to as P shift or FP shift). In addition to control, it also has a manual mode that allows you to manually set the shutter speed and aperture.

The switch (S,) is a switch that opens when the exposure control operation of the exposure control section (14) is completed and closes when the film winding operation is completed. This switch (S3) is directly connected to the input terminal (IF7>) of the microcomputer (11), and is also connected to the other input terminal of the OR gate (ORi). (3)
Even if the release switch (S2) is pressed and the release switch (S2) is pressed, the output of the OR gate (OR,) remains 'High', so the microcomputer (11) does not shift to exposure control operation.
Further, when the microcomputer (11) determines from the input terminal (IPt) that the switch (S, ) is open, it stops the exposure control operation.

The switch (Sx) is a so-called )It is connected to the.

While this switch (Sx) is connected to contact (a), the integral operation of integrating the light reflected from the film surface in the photometering section (13) is prohibited, and when it is switched to contact (b), the integral operation is prohibited. At the same time, the electronic flash device (20) starts emitting light.

The photometry section (13) immediately and selectively inputs the photometry circuits provided for each of the average photometry photoreceptor (16) and the partial photometry photoreceptor (17), and the outputs of these two photometry circuits; The A/D converter performs A/D conversion, and the A/D converted data is used. Based on this output data, the microcomputer (11) performs exposure calculations. The photometering section (13) further includes the microcomputer (11), which performs exposure calculations. 1
1) A part that reads the film sensitivity data sent from 1), a D/A converter that converts the film sensitivity data into an analog signal, and a film sensitivity signal from the D/A converter that is output from the photometry circuit for average photometry. a circuit that integrates the output of the adder circuit when the switch (Sx) is connected to the contact (b), and a circuit that integrates the output of the adder circuit when the switch (Sx) is connected to the contact (b); ) is provided with a light emission amount control section consisting of a circuit that outputs a signal for stopping light emission.

In addition, this light emission amount control section controls F 1ll- in FP mode.
When the I n area is determined (described later) and when P shift is performed in FP mode, the film sensitivity data is converted to, for example, IEv.
The amount of flash light is increased by IEv and sent to the photometry circuit to reduce the amount of flash light from the appropriate exposure level by IEv. During flash photography other than the above, the film sensitivity data is output as is to set the amount of flash light at an appropriate exposure level.

The electronic flash (2o) is connected to the microcomputer (1) from the output end (g).
A charging completion signal indicating completion/incomplete of charging is output to the input terminal (IP@) of 1), and an electronic signal is output from the output terminal (f) to the input terminal (IP, ) of the microcomputer (11). Flash device (20
) outputs a mounting signal indicating that the power switch is closed.

FIG. 3 is a flowchart showing the operation of the microcomputer (11) shown in FIG. 2, and the operation of the entire camera will be explained based on this flow.

First, when the power supply (22) is loaded into the camera body, the clear terminal (CLR) is activated by the power-up clear circuit (23).
) momentarily goes to LOW level. As a result, the microcomputer (11) starts the RESET routine and initializes the turnout boat and RAM (#1) f&
Then proceed to the 5TOP routine.

This routine also jumps to the end of the photometry bold described later. First, stop the photometry operation (#2), and set the output port (OPo) to "High" to set the interrupt. Allow (#3 >, and
Reset the AE lock flag AP and set the mounting flag NF (#4>, where flag AF is AE
Set when locked, flag NF is electronic flash (20
) is set when not installed. By this step #4, even if the AE lock switch (6) is set to the "AEL" position, the photometry section (13) always performs the photometry operation for the first time.

Next, the manual flag MF is determined (#5).
Here, the flag MF is set when either the switch (Su) or (Sd) is closed when the main switch (So) is closed. By this setting, the exposure control of the camera is subsequently switched from program mode to manual mode. Here, if the flag MP is reset, the display units (7) and (15) display the standby display shown in FIG. 13 (#6), and if the flag MP is set, the
Only the shutter speed is displayed as shown in the figure or Fig. 15.The specific display form will be described later, but by changing the display form according to the state of the flag MF, auto is enabled even when not in the photometry mode. I know it's a manual.

After these displays, the microcomputer stops operating (#8>
.

Next, when the main switch (S,) of the camera is closed, the interrupt terminal (INT) of the microcomputer (11) becomes - instantaneous "LOW" by the one-shot circuit (21) shown in Fig. 2, and the interrupt It takes. As a result, the microcomputer (11)
Start running the NT routine.

In the INT routine, the next interrupt is disabled by setting the output terminal (oPo) to "LOW"(#9), and this I
0 to prevent other interrupts from occurring during the execution of the NT routine Next, the input terminal (IPI) switches (St), (
Sa), C5a) are all open (#10). Here, the switch (St>) is determined.

If (Sa) and (Sa) are all open, proceed to step #11, reset flag MF, and switch (S
u), (Sd) are closed or not (#
12. #13) If the switch (Su) is closed, set the shutter speed to 1/250 seconds (#14) and then set the flag MP. #16) If the switch (Sd) is closed, set the shutter speed to 1/250 seconds. As a valve (#15)
Set the flag MF from (#16). Once the flag MF is set, the shutter speed will be fixed at the set value (1/250 seconds or bulb) and the aperture will be set using the up key (4) and down key. The manual mode is set according to the operation in (5). On the other hand, the switch (S
u).

(Sd) are both open, proceed to step #17 with flag MP remaining reset, step #17
Now, clear registers PR and FR and reset flag FF. Register PR here.

The FR stores the program shift amounts in the natural light photography program mode and the flash photography program mode, that is, the P shift amount and FP shift amount, and the flag FF allows you to set the aperture manually by removing auto during flash photography. mode (hereinafter referred to as FL manual mode)
It is set when That is, the main switch (S,
), P shift, FP shift, and FL manual will all be canceled. And the aforementioned 5TO
The program advances to the P routine and the microcomputer stops.

When either the switch (Sl) path S*> or (St> is closed while the microcomputer is running the 5TOP routine or is stopped, an interrupt is generated to the microcomputer and the microcomputer starts running the INT routine. ), (St
) and (Sa) are collectively referred to as starting switches.

When executing the INT routine using any of these startup switches, the input terminal (IPI) is “LOW” (
#10) Proceeding to the 17) Te, S, and LoOP routines, first, it is determined by the input terminal (IPe) whether the main switch (So) is closed or not (#18).

Here, if the main switch (So) is open, the process proceeds to step #17 described above, cancels the P shift, FP shift, and FL manual, executes the 5TOP routine, and then stops. On the other hand, read the film information from the DX code on the main switch cartridge, and if there is no DX code, the IS
Set the O value to 100 (#20), read the attached and fully charged flash information from the electronic flash (20) (#21>, and read the open aperture value (#21) from the photographic lens (19).
AVo), minimum aperture value Avmax, etc. are read (#22), key switches (Su) and (Sa) are determined (823), exposure calculation is performed based on the above information, and shooting is performed. Find the shutter speed and aperture value (#24) and display them (#25>).

Next, use the input terminal (IP, ) to determine whether the start switch is closed or not (#26), and if any of the start switches is closed, reset the timer and restart the timing operation (#27). Proceeds to step #28, and if all are open, immediately proceeds to step #28. This timer is a timer for photometry hold determination, and when 10 seconds have elapsed since all the start switches were opened, the photometry section (13
) and the microcomputer is configured to stop. If the release switch ($2) is idle, exposure control is performed using the shutter speed and aperture value determined in step #24. (The time counting state of the timer is determined from #29>#30), and if the switch (S2) is open, the process immediately jumps to step #30.

Here, if 10 seconds have not elapsed, the above S and L
If the OOP routine is repeated and 10 seconds have elapsed (
That is, when the photometry hold ends), the process proceeds to the 5TOP routine and stops. Note that at the end of this photometry hold, unlike when the main switch (SO) is opened, step #1 is completed.
7 is not executed, P shift, FP shift, and PL manual are not canceled.

The above is the general operation of this embodiment. The detailed operation of this embodiment will be described below.

FIG. 4 shows in detail step #22 of lens information reading and step #23 of KEY determination in the flow of FIG. 3. First, open the aperture value A from the lens.
The lens information of vo and the minimum aperture value Avllax is read (#31), and then the presence or absence of lens information is determined (#32). If the lens information is not read, such as when the lens information is attached to the camera, proceed to step #33 and read A Vo , A
Both vmax are set to 0", registers PR and FR are cleared, and the actual aperture calculation described later is performed. In addition, P shift,
FP shift is canceled when the lens is removed from the camera body (when the lens information is lost).

On the other hand, if there is lens information, the process proceeds to the KEY determination routine and first determines the flag MP (#34). If the flag MF has been reset, then the input terminal (rp
s) to determine whether the electronic flash device (20) is attached (#3
5) Here, if the electronic flash device (20) is not attached, determine whether the up key (4) or the down key (5) has been pressed #36. #38), and by adding or subtracting 1 to the register PR each time these keys are pressed (#37, #39), the P shift amount in the P mode is set. If the secondary flasher (20) is attached, proceed to step #40 and connect the input terminal (IPs
) to determine the charging completion state. If charging is not completed, immediately proceed to step #24 in Figure 3 and KE
If you do not make a Y judgment, that is, if charging is not completed even if the electronic flash device (20) is attached, press the up key (4).
), the down key (5) does not function. On the other hand, if charging is complete, check whether the AE lock is set using the flag AF ($41), and if the AE lock is activated, the up key (5) does not function. , the down key is determined (#42, #44), and the FP shift amount in the FP mode is set by adding or subtracting 1 to the register PR each time these keys are pressed (#43, #45).

If the AE lock is not locked, step #
Proceed to #46, move the shooting aperture value to the setting register Avs, and judge the up key and down key #47
．． #49), each time these keys are pressed, register Ay
Add or subtract 0.5EV to s #48. #50
), set the flag FF (#51), where the aperture can only be changed within the range of Av6 to Avmax,
When Av6 or less or Avmax or more, Av
The contents of s are fixed to AVo or Avmax, respectively. In addition, if there is no lens information, the contents of Avs will automatically become O, and by processing 0 or more, FL manual mode,
The aperture value in manual mode and without lens information is determined.

The calculation routine of step #24 in FIG. 3 will be explained in detail based on FIG. First, the input terminal (IPs) determines whether the electronic flash device (20) is installed (#53>, and if the electronic flash device (20) is not installed, the register FR
Clear, reset flag FF, FP shift, F
To cancel the L manual (#56), set the flag NF to remember that the electronic flash (20) is not installed (#57).On the other hand, if the electronic flash (20) is installed, , clear the register PR and reset the P shift amount in P mode (#54), and check the flag NF (#55), if it is not a new installation, check whether the AE lock is done by the flag AF or not. (#59). If the AE lock is not activated, the photometry unit (13) selects AVE.

Read the 5POT re-measured value, input the AVE value to the R1 register, and input the 5POT value to the R2 register (#60).
If the AE is locked, do not input the photometric value; be sure to re-measure the photometric value AVE.

Compared to the photometry cycle, reading 5POT is S, LOOP.
This is because the routine cycle (that is, the cycle in which the microcomputer reads information from the photometry section) is short.

For example, when the switch (S a) is closed and the spot photometry value 5POT must be locked, by constantly inputting the side photometry value in this way, you can immediately check the photometry value without waiting until the next photometry cycle. You can select and lock the value and perform calculations, display, and exposure control based on that value.

On the other hand, if the flag NF is set in step #55, that is, if the electronic flash device (20) has just been installed, the flag NF is reset and the electronic flash device (20)
Remember that the flash unit is attached (#58), and immediately proceed to step #60 to enter the photometric value without determining the flag AP.This is because the electronic flash unit (2
0), the shooting conditions will completely change from before, so the purpose is to re-measure the light so as not to carry the light metering values from P mode into FP mode.

Next, if the AE lock switch (S a) is closed, set the flag AF (#62); if it is open, clear the register FR and reset the flag AF (#63);
Furthermore, the photometric value AVE is determined depending on whether or not an electronic flash device is attached and whether or not an AE lock is installed.

Selectively adopt any of the 5POTs (#64 to #6
7), that is, when an electronic flash is attached, the average photometric value AVE is taken regardless of whether or not AE lock is installed, when the electronic flash is not installed, the spot photometric value is 5POT with AE lock, and the average photometric value AVE is obtained without AE lock. Adopt. After that, the metered manual register for displaying the sign or negative of the difference between the set exposure value and the appropriate exposure value in manual mode is cleared, and the Fill In flash flag FI in FP mode is reset (#68 ).

Next, the exposure values F and v are calculated by adding the photometric value information By obtained in step #66 or #67 described above to the film sensitivity information Sv obtained in step #20 of FIG. 3 (#69
), and the calculation mode is determined depending on the manual flag MF and whether charging of the electronic flash device (20) is completed (#70, #71).

That is, when the flag MF is set, it becomes a manual mode with a constant Tv value and AV setting value regardless of whether charging is completed or not.
When the flag MF is reset, the mode becomes P mode when charging is not completed, and the mode becomes FP mode when charging is completed.

In the case of P mode, in FIG. 6A, the presence or absence of lens information is first determined (#72). If there is no lens information, the actual aperture AE calculation is performed to determine the shutter speed based on the actual aperture of the lens. (#73). In this case, the aperture value will be displayed as "-1". On the other hand, if there is lens information, program AE calculation in P mode is performed to calculate the shutter speed and aperture value based on a predetermined program diagram (#74). Note that the contents of register PR are
If the value is not 0', a program shift operation is performed to shift the shutter speed and aperture value from the calculated values according to the value (#76).

In the case of FP mode, in FIG. 6B, first, the presence or absence of lens information, the presence or absence of AE lock, and the FL manual flag F are
The calculation mode is determined depending on the state of F. In other words, if lens information is available and AE lock is set, perform FP mode program AE calculation (details will be described later) that is compatible with AE lock to calculate the shutter speed and aperture value #7
9) If the contents of the register PR are not "0", shift the shutter speed and aperture value from the above calculated values according to that value (#81), and there is lens information, so the flag FF is reset instead of AE lock. If the flag FF is set, the program AE calculation for FP mode is performed (#83>.If the flag FF is set, the mode becomes manual mode as in the case where there is no lens information, and the shutter speed is set to L.
/250 seconds (#84), and the aperture value is the value set by the up key (4) or down key (5) (#85), and the difference between the exposure value for this combination and the appropriate exposure value is Calculated as a metered manual value (#8
7).

FIG. 7A shows in detail the FP mode program AE calculation in step #83 of FIG. This FP calculation sets the shutter speed to 1/1 of the flash sync speed limit.
The aperture value is fixed at 250 seconds (Tv=8) and the aperture value is IEv under from the appropriate exposure value determined only by natural light.

First, the shutter speed is set to 1/250 seconds (#88), and the 0th order is fixed, and the BV obtained in step #69 in Figure 5 is
Add IEv to the value to obtain Ev', and at the same time set the fill-in flush flag FI. This is to adjust the light emission control of the electronic flash device to remove it from the appropriate level. Next, subtract Sv from Ev (#90). If BV is 8 or more in APEX value, it is the value obtained by adding 1 to Sv. If Bv is less than 8, the value obtained by subtracting Tv from Ev' is set as Ay (#92). Furthermore, Ay is determined from the larger Av value of Awe and F2.8. Up to Avmax (
For example, it is determined within the range of F2.8 to F22). Then, if (Tv+Av) becomes larger than Ev' (that is, IEv or more below the appropriate exposure value Ev), the shutter speed and aperture value in the FP mode are determined by a process of 0 or more that resets the flag FI. Figure 9 shows this FP
A program diagram for the mode is shown. In FIG. 9, the horizontal axis shows the Bv value, and the vertical axis shows the Av value and
It shows the Tv value and ΔEv value (deviation amount from the appropriate exposure level).

FIG. 7B shows the program AE calculation for the FP mode adapted to the AE lock in step #79 of FIG.
In this AE lock FP mode, the shutter speed changes depending on the subject brightness, and so-called slow synchronization at a speed lower than 1/250 second is also possible. For this reason, exposure to natural light can be maintained from appropriate to IEv under or higher even at low luminance, resulting in Fill I n at all luminances. Also, the upper limit of the aperture value set by ISO is removed. This A
In the FP calculation for E-lock, the flag FI is first set, and the value obtained by adding 1 to Ev obtained in step #69 of FIG. 5 is set as Ev'(#97). Next, the shutter speed is set to 1.
/250 seconds #98), subtract Tv from Ev',
A value limited within the range of Av to Avmax is defined as Av (#99). At this time, if Av is limited by AVO, the limited Av is subtracted from Ev' to obtain Tv. 1st
The solid line in Figure 0 shows the program diagram in this AE lock FP mode. Furthermore, as in Fig. 9, the horizontal axis is B.
The vertical axes are the Av value, Tv value, and ΔE, respectively.
Indicates v value.

FIG. 7C shows details of the FP shift calculation in step #81 of FIG. Here, FP shift means T v calculated by the above AE lock FP calculation,
This means changing the combination based on the set shift amount while keeping the A v value (Tv + Av) constant.
The diagram shows how the program diagram changes with FP shift using broken lines other than solid lines, dashed lines, etc. First, register R3 that counts the number of shift stages is set to 0 (#103). Next, register R3 and FR are set to 0. #104), it is determined whether the shift amount has been analyzed according to the set shift stage number according to the contents of the register FR. Here, if R3 and FR match, the process proceeds to step #120 and the FP shift ends.

On the other hand, if the shift amount has not been analyzed by the set shift stage number, it is determined whether the register FR is positive or negative (#105), and if it is positive, the process proceeds to the overshift routine, and if it is negative, the process proceeds to the undershift routine.

The overshift routine is a routine that shifts Tv in the up direction and Ay in the down direction. First, if the shutter speed is higher than 1/250 seconds, shifting to a higher speed will cause the electronic flash to emit synchronized light. Since this is not possible, the process proceeds to step #12o and the shift ends. on the other hand,
If the shutter speed is low, 1/250 seconds or less, add 1 to shift register R3 (#107) and add 0.5 to Tv (#108), at this time the shutter speed is 1/250 seconds. If the speed is higher, reduce the shutter speed by 1/2.
Fix it to 50 seconds #110), calculate Av by subtracting Tv from Ev #111), set Av to Avo~A vma
The shift is limited within the range of x and the process proceeds to step #12o to end the shift. Also, the shifted shutter speed is 1/250
If the speed is slower than a second, then it is determined whether the aperture value is Av- (i.e., the open aperture value) (#113), and if it is wide open, 1 is subtracted from R3 (#114); Since Av is already open due to overshifting and cannot be shifted further to the open side, the shift counter is decremented by 1. Then subtract 0.5Ev from Av#
115), if the shifted Av is greater than or equal to Av0, the process returns to step #104 and the shifting is continued again. On the other hand, if the shifted Av is less than Avo, AV is changed to A
Fix v o #117), subtract Av from Ev to calculate Tv $118), TV for 30 seconds to 1/250
The shift is limited within seconds and the process proceeds to step #120, where the shift ends. Incidentally, the broken line in FIG. 10 indicates a state in which overshift has been performed twice.

The undershift routine is a routine that shifts Tv in the down direction and Ay in the up direction. First, if Tv is lower than 30 seconds, it is impossible to shift to a lower speed than this, so the process proceeds to step #120. Shift ends. On the other hand, if Tv is higher than 30 seconds, subtract 1 to R3, $122>, and subtract 0.5Ev from Tv (#12
3) At this time, if Tv becomes slower than 30 seconds (#1
24), fix Tv to 30 seconds #125), calculate Av by subtracting Tv from Ev #111>, set Ay to A
Step #1 by limiting within the range of vo to A vmax
Proceed to 20, and the shift ends. On the other hand, if Tv is faster than 30 seconds, then it is determined whether Av is Avmax (i.e., the minimum aperture value) (#126), and if it is the minimum aperture, 1 is added to R3 ( #127), this is because Av is already at the minimum aperture due to undershift and cannot be narrowed down any further, so the shift counter is incremented by 1. After that, add 0.5EV to Av #128)
, if the shifted Av is less than Avmax, the process returns to step #104 and the shifting is continued again. On the other hand, if the shifted Av is greater than or equal to Avwnx, fix Av to Av, +max #130), calculate Tv by subtracting Av from Ev #118), and set Tv to 30 seconds to 1
/250 seconds, the process proceeds to step #120, and the shift ends. Incidentally, in FIG. 10, the dashed line indicates a state undershifted twice.

In step #120, the contents of R3 are stored in FR, but the reason why this is done is to avoid replacing FR with the limited shift amount when the subject brightness changes during shift and the shift amount is limited. As a result, when shifting in the opposite direction, T v and A v change immediately, improving responsiveness when operating the up key or down key.

Fig. 11 shows the external display section (7) and viewfinder display section (15) of this embodiment in a fully lit state, and Fig. 12 shows the state in which all lights are turned off when the main switch (S o) is opened. It is a figure showing a state. 13 to 15 both show the display in the standby state (when the main switch is closed and there is no photometry mode). Figure 14 shows the up switch (Su
), if you close the main switch (S, ),
FIG. 15 shows the case where the main switch (So) is closed while pressing the down switch (Sd), and Tv is displayed even in the standby state, indicating that it is the manual mode.

FIG. 16 shows the display in each mode during photometry,
Furthermore, even if the AE lock switch (Sa) is closed, the average photometric value AVE displayed by the 5POT display when an electronic flash device is attached.
1/250 seconds is set when the electronic flash is fully charged and the up switch or down switch is pressed (in other words, when the PL is in manual mode) or in manual mode. At this time, the metered manual display is indicated by the symbol e. In the display of these data in Fig. 16, the calculated data is sent to the display control unit (15) in time series, and T v , A v and metered/manual symbols are displayed, and photometry, calculation, and metered manual symbols are displayed. The exposure control mode and charging completion signal are sent to the display control section (15) to display the mode and charging completion. This operation is performed in step #25 in FIG. 3, but the specific flow will be omitted since it can be easily deduced by those skilled in the art.

In this embodiment, when the electronic flash device is fully charged and the AE lock switch is open, when the up switch or down switch is pressed, Tv is fixed at 1/250 seconds,
FL manual mode is used as the setting value for Av, but as another example, Tv is fixed at 1/250 seconds and Av is set to 1/250 seconds.
v can also be a value shifted by a shift amount determined by an up switch or a down switch from a value obtained by FP calculation from By and Sv. The program diagram for this FL manual shift is shown in FIG. 17. At this time, A
v changes depending on the brightness, and has a difference corresponding to the set number of shift stages with respect to Av found by FP calculation at all brightnesses.

In addition, when the aperture value reaches the limit when switching from the Fill In area to the normal area, the shutter speed is changed from 1/250 seconds to the low speed side according to the brightness, and
/60 seconds when the brightness is lower than F2.8 and 1
Fix it at 760 seconds and fill in
The area may be expanded.

In addition, in the above-mentioned embodiment, there were two types of photometry mode to be switched and selected: average photometry and spot photometry, but there is also a multi-point photometry mode in which the shooting screen is divided into many areas and the subject brightness is measured for each area. A split metering mode may be used, and the metering mode may be switched uniquely depending on manual operation, or depending on the brightness distribution of the subject measured by the metering means, the condition of the photographic lens, or the camera. This may be done automatically depending on the exposure control mode, focus adjustment mode, etc.

肱--1 As described above, according to the present invention, each photometry value corresponding to each photometry mode is A/D converted and stored separately in the first cycle, and specified in a shorter cycle. Metering mode A
/D conversion data is read and exposure calculations are performed, so even if the A/D conversion cycle of the photometry value is long, it can immediately respond to switching the photometry mode, and exposure control based on the photometry value in that photometry mode can be performed quickly. I can do it.

[Brief explanation of drawings]

Fig. 1 is a plan view showing the external appearance of a camera to which the present invention is applied, Fig. 2 is a block diagram showing the circuit configuration of the camera shown in Fig. 1, and Figs. 3 to 7 are operations of the microcomputer shown in Fig. 2. 8 to 10 are program diagrams showing exposure control data in each flash photography mode, and FIGS. 11 to 16 are explanatory diagrams showing display states of the display unit in each operating state of the camera. FIG. 17 is a block diagram showing exposure control data in another flash photography mode. 13.16,17: Photometric means, 13. #60: Data storage means, #64. #65: Specifying means, S, LOOP: Reading/calculating means, 14, #29: n output control means. Applicant: Minolta Camera Co., Ltd. Fig. 1 #-23 Fig. 5 Fig. 7 (sword (b) I25 #25 No. 1/ Fig. external display section (7) Viewfinder inner layer 7r, Iku (7, 5)
) Zene, Fumiko A Kashiichi 1

Claims (1)

[Claims] (1) A photometric means that can select photometric operations based on a plurality of different photometric sensitivity distributions and outputs a plurality of photometric values corresponding to each photometric sensitivity distribution, and an A/D converter that outputs a plurality of photometric values in a first cycle.
data storage means for repeating the operation of converting and storing each A/D converted data separately; a specifying means for specifying switching of the photometric sensitivity distribution of the photometry means; and each A/D conversion stored in the storage means. a reading/calculating means that repeats an operation of reading the data and performing a predetermined exposure calculation based on the A/D conversion data corresponding to the specified photometric sensitivity distribution in a second cycle shorter than the first cycle; A variable metering mode camera comprising an exposure control means for controlling exposure based on calculation results.