JP2764414B2 - Camera device and interchangeable lens - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interchangeable lens camera apparatus and an interchangeable lens thereof.

[Conventional technology]

This type of camera device, in which the lens portion and the camera body portion are detachable and allows a plurality of interchangeable lenses to be used, is well known in the field of video cameras in addition to single-lens reflex cameras of silver halide film. is there. In this type of lens exchange system, the interchangeable lens includes a photographing lens, a zoom drive unit, an aperture, an aperture drive mechanism, a mount unit, and the like, and this mount unit is mechanically coupled to a similar mount unit of the camera body. Thereby, the interchangeable lens is mounted on the mount portion of the camera body.

Further, a system for exchanging signals such as aperture information and control information for automatic focusing between the interchangeable lens and the camera body is known. In such a system,
The electrical connection of the signal lines is realized by the connection of the electrical contacts of the two mount portions, and by an external cable or connector.

As interchangeable lenses, for example, a plurality of types of lenses having different focal lengths, zoom ratios, F values, and the like are prepared.

[Problems to be solved by the invention]

However, in the above-described conventional example, there is no problem regarding the mechanical, electrical, and optical coupling itself between the lens and the camera body, but the following problems regarding the aperture and its driving mechanism. was there. That is, various drive methods (for example, a servo motor method, a pulse motor method, an IG meter method, etc.) are used for the aperture drive mechanism according to a lens method, an F value, a zoom ratio, an image size, and the like. Furthermore, even in the same method, the number of diaphragm blades, the mass thereof, the torque of the motor, the rotation speed, and the like vary. Therefore, the control characteristics are greatly different from each other.

DC operating characteristics can be shared, but it is extremely difficult to share the parts with different dynamic characteristics, and the cost is greatly increased. It may not be possible to take advantage of the features.

Therefore, in the field of video cameras, when the lens is replaced, the control characteristics of the aperture, especially the dynamic characteristics, are manually adjusted on the camera body side each time the lens is replaced. Outside of homes, changing lenses was virtually impossible.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the conventional example, and has as its object to provide a camera device and an interchangeable lens that allow easy lens exchange.

[Means for Solving the Problems] For this reason, the above-mentioned object is achieved by configuring such a camera and an interchangeable lens according to the present invention as shown in the following items (1) and (2), respectively. Is what you do.

(1) A camera device with interchangeable lenses, in a camera body, an imaging unit that photoelectrically converts an optical image formed by the lens to output an imaging signal, and the imaging unit that is output from the imaging unit. Control means for calculating a predetermined aperture control signal for opening / closing the aperture and transmitting the signal to the lens side so that the imaging signal level becomes equal to a predetermined reference level; Aperture, a memory for storing identification data relating to dynamic characteristics of the aperture, and for the predetermined aperture control signal transmitted from the camera side, using the identification data read from the memory, A camera device comprising: aperture control means for correcting dynamic characteristics of the aperture; and aperture drive means for driving the aperture based on an output of the aperture control means.

(2) An imaging unit for photoelectrically converting the optical image formed by the lens to output an imaging signal, and opening and closing the aperture so that the imaging signal level output from the imaging unit is equal to a predetermined reference level. An interchangeable lens that is detachable from a camera body and includes control means for calculating an aperture control signal for controlling the aperture, the aperture controlling an incident light amount, a memory storing identification data relating to dynamic characteristics of the aperture, and Aperture control means for correcting the dynamic characteristic of the aperture using the identification data read from the memory for the predetermined aperture control signal transmitted from the camera side;
An interchangeable lens, comprising: aperture drive means for driving the aperture based on an output of the aperture control means.

[Action]

On the camera body side of the present invention having the above configuration, by referring to the memory in the interchangeable lens, the aperture characteristics of the individual interchangeable lenses are known, and the aperture control of the interchangeable lens is changed according to the aperture characteristics. 1 to adjust
Interchangeable lenses having various characteristics can be easily exchanged and used for one camera body, and no manual adjustment is required for the exchange.

〔Example〕

 Hereinafter, the present invention will be described based on examples.

(Configuration) FIG. 1 is a block diagram showing the configuration of an embodiment of an interchangeable lens camera according to the present invention. Reference numeral 10 denotes a lens unit, and reference numeral 30 denotes a camera body. In the lens unit 10, 12 is a photographing optical system, 14
Is aperture, 16 is lens mount, 18 is lens mount 16
, An aperture drive mechanism 20, and a memory 22 in which data for identifying the types of the aperture 14 and the aperture drive mechanism 20 are written.

Next, in the camera body 30, reference numeral 32 denotes a mount that is detachably mountable to the mount 16 of the lens unit 10, and reference numeral 34 denotes an electric contact 18 of the lens unit 10, and the lens unit 10 is attached to the camera body.
An electrical contact for electrically connecting to the electrical contact 18 in a state of being mounted on the device 30, a solid-state imaging device 36 such as a CCD, and a sample-hold (S) for sample-holding the output of the imaging device 36 / H) circuit, 40 is a signal processing circuit for processing the output of the S / H circuit 38 and outputting a video signal,
42 is a video output terminal, 44 is a variable gain amplifier, 46 is a variable time constant circuit, and 48 is a microcomputer.

(Operation) In a state where the mount 16 of the lens 10 is mechanically coupled to the mount 32 of the camera body 30, the electric contact 18 is electrically connected to the electric contact 34. At the time of this electrical connection, the microcomputer 48 reads data stored in the memory 22 and
The gain of the amplifier 44 and the time constant of the variable time constant circuit 46 are controlled.

The subject image passes through the photographing optical system 12, and the amount of light is limited by the aperture 14, and then enters the image sensor 36 through the openings of both mounts 16 and 32. The imaging element 36 outputs a photoelectric conversion signal, and the S / H circuit 38 extracts a signal component and applies it to the signal processing circuit 40. The signal processing circuit 40 outputs the video signal to an output terminal 42.
To supply. On the other hand, the output of the S / H circuit 38 is first amplified by the amplifier 44 with a predetermined gain, and is applied to the aperture driving mechanism 20 via the variable time constant circuit 46 and the electric contacts 34 and 18. The aperture drive mechanism 20 controls the aperture of the aperture 14 according to this signal. As described above, the gain of the amplifier 44 and the time constant of the variable time constant circuit 46 are adjusted by the microcomputer 48 to values according to the characteristics of the lens unit 10.

FIG. 2 shows a flowchart of the operation sequence of the microcomputer 48. After starting in step S1, it is checked in step S2 whether the power is on. If the power is off, the process waits until the power is turned on. If the power is on, the data stored in the memory 22 of the lens unit 10 is read in step S3, and it is checked in step S4 whether the data is appropriate. If it is proper (Y), in step S5, data suitable for the attached lens is selected from the data previously written in the memory of the microcomputer 48, and in step S6, the gain and the gain of the amplifier 44 are selected according to the selected data. The time constant of the variable time constant circuit 46 is adjusted. Thereafter, the process proceeds to another routine in step S7. If the read data is not proper in step S4 (N), it is determined in step S8 that the lens unit 10 is not connected or the connection is poor.
A warning of a lens abnormality is displayed, and the process returns to step S3.

Even in the other routine, if the removal and / or attachment of the lens unit 10 is detected in step S9, the process proceeds to step S3, and the memory 22 of the lens unit 10 is read out preferentially.

FIG. 3 is a block diagram showing a configuration example of a portion of the amplifier 44 and the variable time constant circuit 46 in FIG. 50 and 52 are operational amplifiers, 54 and 56 are reference voltages (power supplies), 58 and 60 are switch circuits, 62, 64, 66, 68, 70 and 71 are resistors, 72, 74 and 76.
Is each capacitor. Each of the switch circuits 58 and 60 is switched and controlled by the microcomputer 48, and the switch circuit 58
By selecting one or more of the resistors 64, 66, 68, the gain of the amplifier 44 changes, and the switching circuit 60
Selects one or more of the capacitors 72, 74, and 76, so that the time constant of the time constant circuit 46 changes.

In the configuration of FIG. 3, the gain and the time constant are discretely changed by selecting each of the three elements. However, the number of elements may be other than three.
In addition, it goes without saying that the gain and / or the time constant may be continuously changed.

(Other Embodiment) FIG. 4 is a block diagram showing a configuration of another embodiment according to the present invention, and the same or corresponding components as those in FIG. 1 are denoted by the same reference numerals.

101 is a microcomputer on the camera body side, 102
Is an A / D converter, 103 is a microcomputer on the lens side, 104 is a D / A converter, 105 is an encoder that is mechanically coupled to the aperture 14 and reads each aperture, 10
6 is an A / D converter.

A video signal generated by the image sensor 36 as shown in FIG. 1 is converted into a digital signal by an A / D converter 102 via a sample-and-hold circuit 38, and is input to a microcomputer 101. Microcomputer 1
Reference numeral 01 has a serial communication line, and exchanges signals with the microcomputer 103 on the lens side. And A / D
Based on the output of the converter 102 and the signal obtained from the microcomputer 103, control data of the aperture is generated and sent to the microcomputer 103. The microcomputer 103 generates aperture driving data based on the aperture control data obtained from the serial communication line and the output of the A / D converter 106, outputs the data to the D / A converter 104, and outputs the data to the D / A converter 104.
The aperture 14 is driven by the output of. The encoder 105 converts the aperture angle of the aperture 14 into an electric signal, and the A / D converter
At 106, the signal is converted into a digital signal and input to the microcomputer 103 as described above.

5 to 7 are operation sequence flowcharts of the microcomputer 101 on the camera body side and the microcomputer 103 on the lens side in FIG. 4, respectively. Arrows connecting the mutual charts indicate communication by the serial signal lines described above.

FIG. 5 is a flowchart showing an operation sequence when the power is turned on. Microcomputer 101 on camera side
In step S11, when power is turned on, an initial data request is sent out in step S12, an aperture operation time constant is received in step S13, and an aperture operation time constant is used in step S14, using a predetermined lookup table. , Integration constant
Set K _1, at step S15, to allow interruption by the vertical synchronizing signal V _D, ends in step S16.

On the other hand, the lens side microcomputer 13
When the power is turned on in S17, an initial data request is received from the microcomputer 101 on the camera main body side in step S18, and in step S19, the lens has or has been written in the memory of the microcomputer in advance. The data of the squeezing time constant unique to each type is sent out, and the process ends in step S20.

Figure 6 shows an operation sequence flow chart of when an interrupt by the vertical synchronizing signal V _D to the camera body microphone computer 101 occurs. Microcomputer 101
In step S21, the vertical synchronizing signal V _D interrupt is generated, at step S22, reads the signal level S ₁ than A / D converter 102, at step S23, reads from the memory the predetermined reference level S _2, step in S24, the S ₃ = S ₁ -S _2, the calculated error S _3, communicating step S25, as _{I = I + S 3 × K} 1, obtains the integrated value I, in step S26, the microcomputer 103 of the lens side A start code is transmitted, and the above-described integrated value I is transmitted in step S27, and the process ends in step S28.

In the lens microcomputer 103, step 29
Then, upon receiving the above-described communication start code, a communication interrupt is generated. In step S30, the integral value I is received, and the process ends in step S31.

FIG. 7 shows a sequence flowchart of the aperture driving operation of the lens microcomputer 103. That is, starting at step S32, at step S33, the aforementioned A / D
Reads the throttle position P _I is the output of the converter 106, the position error EP determined as EP = P _I -I in step S34, in step S35, the sign of the position error EP, branched, EP ≧ 0 if (Y ), At step 36, the output voltage V is changed to V = −V ₀ −EP ×
And K _2.

Here, V ₀ is a voltage corresponding to a loss due to friction of the throttle, and K ₂ is a constant determined by an operation constant of the throttle. Also, EP <
If 0 (N), the output voltage V is set to V = V _{0 in} step S37.
And -EP × K _2.

(Still Another Embodiment) In the embodiment shown in FIG. 1, the microcomputer 48 of the camera body reads out the data stored in the memory 22 of the lens unit 10. A circuit element for reading data and transmitting the data to the camera body 30, for example, a memory control circuit or a microcomputer may be provided, and necessary data may be transmitted to the camera body in response to a command from the camera body 30. .

In transmitting the signal for controlling the aperture from the camera body 30 to the lens unit 10, the gain and the time constant are adjusted in the embodiment of FIG. 1, but other control values, for example, error detection One or more of the gain, the phase shift characteristic, the delay time, the maximum control width, the dead band width, and the like may be adjusted.

Instead of the aperture control or the method illustrated in FIG. 1, partial photometry and peak detection may be used. The data stored in the memory 22 may be a code for identifying an aperture control method, an absolute value or a relative value of a control constant of an aperture control loop, or both, or a plurality of control constants may be stored. .

In the other embodiment shown in FIG. 4, the aperture angle of the aperture is read by the encoder. However, the present invention is not limited to this. May be used. Furthermore,
Although the A / D converter 102 performs A / D conversion of the image signal as it is, it may perform A / D conversion on a value obtained by smoothing, integrating, sampling and holding, or peak detection in advance. In addition, the fifth to seventh
The respective operations of the camera body microcomputer 101 and the lens microcomputer 103 have been described with reference to the flowcharts in the figure. However, the sharing between the two is not a fixed one in the example of the figure, but is in one of the flowcharts. Of course, the processing may be performed on the other side.

(Effects) As can be easily understood from the above description, according to the present embodiment, the camera body can know the aperture characteristics of the individual interchangeable lenses and change the aperture control of the interchangeable lenses according to the aperture characteristics. With this configuration, the interchangeable lens 10 having various characteristics can be used for one camera body 30 and can be quickly replaced.

The control of the aperture 14 is controlled by the microcomputer on the lens side.
Since the aperture angle is determined in accordance with the input signal to the lens 103, the camera body 30 does not need to read the output of the encoder 105 of the lens aperture 14 from the data currently transmitted to the lens. Because you can know the opening angle of
Using this, the current aperture angle can be displayed in an EVF (electronic viewfinder) or the like.

Further, when performing aperture control manually, it is possible to simply send a value corresponding to a voltage generated by a variable resistor or the like to the lens microcomputer 103. Further, as described above, since the output value of the camera-side microcomputer 101 corresponds to the aperture angle of the aperture 14, the control characteristics of the aperture 14 can be appropriately varied according to the aperture angle of the aperture. Furthermore, since the setting of the control coefficient of the aperture 14 is performed by software, there is no deviation in the adjustment values such as the time constant and the gain due to the impedance of the switch circuit, and accurate control can be performed.

〔The invention's effect〕

As described above, according to the present invention, in the interchangeable lens camera, the camera body is configured to know the aperture characteristics of the individual interchangeable lenses and to change the aperture control of the interchangeable lenses accordingly. Interchangeable lenses having various characteristics can be easily used for one camera body, and manual adjustment for each exchange can be eliminated.

Also, according to the present invention, as the aperture characteristics of individual interchangeable lenses, in particular, dynamic characteristics such as the type of an actuator for driving the aperture, its time constant, and the response due to a delay due to friction are targeted. As described above, in a video camera that constantly performs aperture control by a feedback group to maintain a constant brightness while constantly opening and closing the aperture on the lens side so that the imaging signal level on the camera side is constant. Control without oscillation, delay, unstable brightness change, and the like becomes possible, which is extremely advantageous in stabilizing aperture control.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a flowchart showing the operation sequence of the microcomputer shown in FIG. 1, and FIG. 3 is the configuration of the amplifier and the variable time constant circuit shown in FIG. FIG. 4 is a block diagram of another embodiment of the present invention, and FIGS. 5 to 7 show examples of operation sequence charts of the microcomputers 101/103 of FIG. 4 respectively. . 10 Lens unit 14 Aperture 20 Aperture drive mechanism 22 Memory 30 Camera body 36 Image sensor 101/103 Camera / lens microcomputer

Claims (2)

(57) [Claims] 1. A camera device having interchangeable lenses, comprising: an imaging unit for photoelectrically converting an optical image formed by the lens and outputting an imaging signal in a camera body; Control means for calculating a predetermined aperture control signal for controlling the opening and closing of the aperture and transmitting the signal to the lens side such that the imaging signal level becomes equal to a predetermined reference level; An aperture for controlling the amount of incident light, a memory for storing identification data relating to dynamic characteristics of the aperture, and the identification data read from the memory for the predetermined aperture control signal transmitted from the camera side. Aperture control means for performing correction on the dynamic characteristics of the aperture,
A camera device, comprising: aperture drive means for driving the aperture based on an output of the aperture control means. 2. An imaging means for photoelectrically converting an optical image formed by a lens to output an imaging signal, and a diaphragm so that the imaging signal level output from the imaging means is equal to a predetermined reference level. An interchangeable lens that is detachable from a camera body and includes control means for calculating an aperture control signal for controlling the opening and closing of the aperture; an aperture for controlling the amount of incident light; and a memory for storing identification data relating to dynamic characteristics of the aperture. An aperture control unit for correcting the dynamic characteristic of the aperture using the identification data read from the memory for the predetermined aperture control signal transmitted from the camera, and an output of the aperture control unit And an aperture driving means for driving the aperture based on the above.