JPH04150676A - Image pickup device - Google Patents

Abstract

PURPOSE:To change the image forming state of the light receiving surface of an imaging device immediately by an appropriate drive when attaching a lens unit by controlling a driving means changing the image forming state of the light receiving surface of the imaging device by a same driving quantity as a manual focusing when the lens unit is disengaged. CONSTITUTION:The attaching and detaching state of a lens unit LU to a main body unit CU of a camera is discriminated. According to the discriminated result, the driving means changing the image forming state of the light receiving surface of an imaging device 16 is controlled, and when the lens unit LU is disengaged, the means is controlled by the same driving quantity as the manual focusing. Thus, it is possible to reduce futile power consumption when disengaging the lens unit LU, to prolong a photographing time, and to change the image forming state of the light receiving surface of the imaging device 16 immediately by the appropriate driving quantity when attaching the lens unit LU.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an imaging device such as a video camera, and particularly to an imaging device in which a lens unit is replaceable with respect to a camera body unit. .

(Prior Art) Conventionally, video cameras configured as camera-integrated VTRs generally do not have interchangeable lenses, and unlike still cameras that use silver halide film, are capable of large telephoto shooting or wide-angle shooting. However, although integrated VTRs with interchangeable lenses have recently been proposed, they still do not have an autofocus function or auto iris (automatic exposure).
It has not yet reached the point where it has functionality.

Therefore, the inventors of the present application have developed a video camera with interchangeable lenses, in which a lens unit with a built-in photographic lens and an aperture is detachably and replaceably attached to a camera body unit with a built-in image sensor. Development is progressing. In this video camera, a control device consisting of a microcomputer, etc. is mounted on each of the camera body unit and lens unit, and when the two units are combined, the control devices in both units are connected via a data transmission line (communication line). and are connected to each other. Then, in the camera body unit, field brightness is detected from the output of the image sensor, a control device in the camera body unit performs exposure calculation based on the field brightness, and the exposure calculation result is transmitted to the lens unit. The control device in the lens unit determines the amount of aperture opening based on the result of the exposure calculation, and drives the aperture driving means in accordance with the determined amount of aperture. Further, the field brightness signal in the camera body unit is band-limited by passing it through a plurality of band pass filters, and the focus calculation of the control device in the camera body unit is performed based on this band-limited signal, and the calculation result is is transmitted to the control device in the lens unit, and the control device in the lens unit determines the direction and speed of the focus motor based on the focus calculation result, and drives the focus drive means according to the determined direction and speed. It is designed to let you do so.

(Problem to be Solved by the Invention) By the way, in an image pickup device having an exposure control system and a focus control system as described above and having interchangeable lenses, for example, a photographer may leave the lens unit removed and do not turn off the power for a long time. If left unattended, there is a problem that power is wasted and the shooting time is shortened.

The present invention has been made with attention to these problems, and it reduces wasted power consumption when the lens unit is removed, increases the shooting time, and allows the lens unit to be immediately and properly driven to capture images when the lens unit is attached. It is an object of the present invention to provide an imaging device with interchangeable lenses that can change the imaging state of the light-receiving surface of the element.

[Means to solve the problem]

The imaging device of the present invention includes a camera body unit including an image sensor, a lens unit that is detachably attached to the camera body unit and whose focus is adjustable, and includes attachment/detachment determination means for determining whether the lens unit is attached or detached. , comprising: a drive means for changing the imaging state of the light receiving surface of the image sensor; and a control means for controlling the drive means according to the determination result of the attachment/detachment determination means, and the drive means is configured to manually control the focus when the lens unit is removed. The configuration is such that control is performed using the same drive amount as during adjustment.

(Function) In the imaging device of the present invention, the attachment/detachment determination means determines the attachment/detachment state of the lens unit to the camera body unit, and according to the determination result, the driving means for changing the imaging state of the light receiving surface of the image sensor is controlled. When the lens unit is removed, its driving means is controlled with the same amount of driving as during manual focus adjustment.

(Embodiment) FIG. 1 is a block diagram showing the circuit configuration of an imaging device according to an embodiment of the present invention, and here shows the main parts of a video camera with interchangeable lenses. In the figure, CU is a camera body unit, LU is a lens unit that can be attached to and detached from this camera body unit CU, and both units CLI and L
U is a known mount part M where mutual pressure contact terminals are arranged.
A microcomputer (hereinafter referred to as a lens microcomputer) 14, which is a control device in the lens unit LU, and a microcomputer (hereinafter referred to as a control device in the camera body unit CU) are mechanically and detachably connected by T and are connected via mutual pressure contact terminals. A data transmission line 39 for serial data transmission is formed between the camera microcomputer (referred to as a camera microcomputer) 34.

In addition to the lens microcomputer 14 described above, the lens unit LU includes a photographing lens 1. 'n Aperture for light adjustment 2.
Aperture encoder that detects the aperture opening amount (comparison value)3. Focus motor (M) for adjusting focus 4. Focus encoder for detecting focus 5. A motor drive circuit 6 for driving the focus motor 4. Aperture drive circuit that drives the aperture 2 7. D/A converter 8.9 that converts digital signals to analog signals and A that converts analog signals to digital signals
/D converter 10, and the lens microcomputer 14 includes a drive data circuit 11 which outputs drive data for the lens 1 and the aperture 2, and a data transmitting/receiving circuit 12 which transmits and receives data. Encoder conversion circuit 13
It is composed of etc.

On the other hand, the camera body unit CU includes, in addition to the above-mentioned camera microcomputer 34, an image sensor 16, such as a CCD, into which the luminous flux of photographing light that has passed through the lens 1 and the aperture 2 enters. A piezoelectric element 15 that vibrates this image sensor 16. A sample hold (S/H) sample and bold the output signal of the image sensor 16.
) Circuit 17゜Camera signal processing circuit 18 which inputs the image signal output from this sample hold circuit I7 and outputs a luminance signal and a color signal. This camera signal processing circuit 18
A blue generation circuit 19 that outputs a blue color signal regardless of the output signal of . A piezoelectric element driving circuit (FFI driving means) 21 is a modulating means for periodically changing the imaging state of the light-receiving surface of the piezoelectric element 15, and an exposure circuit 24 is for obtaining appropriate exposure from the output of the sample and hold circuit 17.
and a focus detection circuit 27 for obtaining the optimum focus from the output of the sample and hold circuit 17.
The exposure circuit 24 includes an integrating circuit 22 and a photometric circuit 23, and the focus detection circuit 27 includes a plurality of BPFs (band pass filters) 25. This BPF25
A peak detection circuit 26 that performs peak detection by sampling and holding the output signal of , and a gate circuit 4 interposed therebetween.
It is composed of two parts. Furthermore, this camera body unit CU includes A/D converters 30, 31 . An attachment/detachment switch (attachment/detachment determination means) 35 that determines whether the lens unit LU is attached or detached from the camera body unit Ct+ (in this case, determines whether or not it is attached normally), a microcomputer (hereinafter referred to as a system) that controls the entire camera system. (referred to as a microcomputer) 36, a battery 37 which is the main power source. A switching circuit 38 for supplying driving power from this battery 37 to each part of the camera. Signal switching circuit 30 controlled by system microcomputer 36. An encoder (ESC) circuit 40 that outputs a decoded video signal, an EVF circuit 28 that monitors the video on a viewfinder, a character generator circuit 29 that generates arbitrary character information, and a focus frame signal of a specific area. A focus generation circuit 41 is provided, and the camera microcomputer 34 is provided with a data transmission/reception circuit 32. Control calculation circuit 33
It is composed of etc.

The camera microcomputer 34 of the camera body unit CU constitutes a control means that controls the piezoelectric element drive circuit 21 according to the on/off signal that is the determination result of the attachment/detachment switch 35, and when the lens unit LU is detached, This piezoelectric element drive circuit 21 is controlled with the same drive amount as during manual focus adjustment. Also, battery 3
Power is supplied from 7 to a regulator (REG) power supply 43 of the lens unit LU, and from there power is supplied to each power supply.

Next, the operation will be explained.

When the lens unit LLI is normally attached to the camera body unit CU, the luminous flux of the imaging light that has passed through the photographic lens 1 and the aperture 2 and entered the image sensor 16 is photoelectrically converted and output as an image signal. Ru. This image signal is
The signal is inputted to the camera signal processing circuit 18 through the sample and hold circuit 17, and after being subjected to gamma conversion and the like in the circuit 18, it is separated into a color signal C and a luminance signal Yγ and taken out. These color signal C and luminance signal Yγ are
The encoder circuit 4o converts it into a decoded video signal and outputs it to the outside, and the EVF circuit 28 monitors it on a viewfinder.

Further, the luminance signal Y output from the sample hold circuit 17 is input to the exposure circuit 24 as described above, and is integrated there by the integration circuit 22. Then, photometry is performed by the photometry circuit 23, from which an appropriate photometry signal is output. After this signal is converted into a digital signal by the A/D converter 30, it is input to the control calculation circuit 33 of the camera microcomputer 34, where a predetermined exposure calculation is performed. Then, as a result of the calculation, an aperture control signal is output from the data transmission/reception circuit 32 of the camera microcomputer 34.
This signal is transmitted to the lens unit L via the data transmission line 39.
It is supplied to the lens microcomputer 14 of U. At this time, if the electrical connection between the lens unit LU and the camera body unit CU is stable, for example, the lens unit LU
If a certain amount of time has passed since the and camera body unit CU were attached to each other, if there is no abnormality or malfunction in the data transmission path 39, or if there is no abnormality in the power supply inside the camera body unit CU. In this case, lens microcontroller 1
4 calculates an aperture drive amount based on the aperture control signal sent from the camera microcomputer 34, and outputs an aperture drive signal obtained as a result of the calculation from the drive data circuit 11. This signal is converted into an analog signal by the D/A converter 8 and then input to the aperture drive circuit 7, which drives the aperture 22. The amount of movement of the diaphragm 2 is detected by an encoder 3, and the detection signal is converted into a digital signal by an A/D converter 10 and then manually inputted to a lens microcomputer 14. Then, the encoder conversion circuit 13 in the lens microcomputer 14 becomes a signal representing the aperture state, and this signal is sent to the camera microcomputer 3 through a data transmission line 39.
is transmitted to.

Appropriate aperture control is performed through the above operations, and similar operations are performed for focus control.

That is, the luminance signal Y output from the sample hold circuit 17 described above is also input to the focus detection circuit 27 in order to obtain the optimum focus, and after being band-limited by the plurality of BPFs 25, it is gated by the gate circuit 42. and is input to the peak detection circuit 26. Then, an appropriate focal voltage signal is output from the peak detection circuit 26, and after this signal is converted into a digital signal by the A/D converter 31, it is manually input to the camera microcomputer 34. In this camera microcomputer 34, a predetermined calculation is performed by a control calculation circuit 33, and focal voltage data obtained as a result of the calculation is inputted from the data transmission/reception circuit 32 to the lens microcomputer 14 via a data transmission path 39. . Furthermore, this data is sent to the data transmitting/receiving circuit 12 and the drive data circuit 1.
1 to the D/A converter 9, where it is converted into an analog signal and then supplied to the motor drive circuit 6, which drives the focus motor 4 and controls the focus. This focus state is detected by the focus encoder 5, and its detection signal is input to the lens microcomputer 14. After the signal is converted by the encoder conversion circuit 13, the signal is transmitted to the camera microcomputer 34 via the data transmission/reception circuit 12 and the data transmission path 39.

Through the series of closed-loop operations described above, appropriate aperture control and focus control can be performed in a video camera with interchangeable lenses.

Here, the above operation is for the case where the lens unit LU is normally attached to the camera body unit CU, or when the lens unit LLI is detached, it is normally 2.
No camera movement is performed. Therefore, when the lens unit LU is detached, it is effective to prevent the various parts of the camera body unit CU from operating unnecessarily, in order to reduce power consumption. Therefore, in this embodiment, the attachment/detachment switch 35 indicates that the lens unit LU is detached.
When detected, the information is transmitted to the camera microcomputer 34. At this time, the camera microcomputer 34 sends a control signal to the piezoelectric element drive circuit 21, and the piezoelectric element 15, which consumes a large amount of power, is driven in the same minute manner as during manual focus adjustment. This reduces unnecessary power consumption, lengthens the shooting time, and when the lens unit LU is attached, the image sensor 1 is immediately and appropriately driven.
The image formation state of the light receiving surface 6 can be changed. Moreover, this can be done by simply adding control switching to the program.

Further, in the above embodiment, the camera microcomputer 34 immediately activates the piezoelectric element drive circuit 2 in response to a signal indicating that the lens unit LU is detached from the attachment/detachment switch 35.
Rather than minutely driving the piezoelectric element 15 through 1,
A timer function within the camera microcomputer 34 may be used to minutely drive the piezoelectric element 15 after a predetermined period of time has elapsed since the above-mentioned discrimination signal was input. As a result, even if the photographer leaves the lens unit LU removed for some reason, driving of the piezoelectric element 15 is restricted after a predetermined period of time has elapsed, reducing unnecessary power consumption.

The circuit shown in FIG. 1 includes the blue generating circuit 19, so that when the lens unit LU is removed, a blue image can be displayed on the viewfinder to notify the photographer.

Of course, instead of this blue image, it is also possible to display images of other colors or images of multiple colors. Furthermore, since it is equipped with a character generator circuit 29 and a focus frame generation circuit 41, when the lens unit LU is not properly attached, the focus frame can be erased from the viewfinder and arbitrary character information can be displayed.
You can also do that.

[Effects of the Invention] As described above, according to the present invention, it is possible to determine whether the lens unit is attached to or removed from the camera body unit, and to control the driving means that changes the imaging state of the light receiving surface of the image sensor according to the determination result. However, when the lens unit is removed, it is controlled using the same amount of drive as when adjusting the focus manually.
It is possible to reduce wasted power consumption when the lens unit is removed, increasing the shooting time, and to change the image formation state of the light receiving surface of the image sensor with an appropriate amount of drive immediately when the lens unit is attached. It has the effect of being able to.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention. Cu2-Camera body unit L　U　---Lens unit MT　---Mount part 1-1・Photography lens 2.-one stop 15---One piezoelectric element 16・-1 image sensor 1s---Camera signal processing circuit 20---Switching circuit 2...--Exposed circuit 7---, focus detection circuit 8----E V F circuit

Claims (1)

[Claims] A camera body unit including an image sensor, a lens unit that is detachably attached to the camera body unit and whose focus can be adjusted, an attachment/detachment determination means for determining whether the lens unit is attached or detached, and a light-receiving surface of the image pickup element. and a control means for controlling the driving means according to the determination result of the attachment/detachment determining means, and when the lens unit is detached, the driving means is driven by the same amount as during manual focus adjustment. An imaging device characterized by controlling.