JPH04150678A - Image pickup device - Google Patents

Abstract

PURPOSE:To prevent futile driving current from flowing when detaching a lens unit by stopping a driving means changing the image forming state of the light receiving surface of an imaging device when the lens unit is detached. CONSTITUTION:A main body unit CU of a camera and a lens unit LU are connected mechanically attachable and detachable by a mount part MT where a mutual solderless terminal is arranged. Here, the attaching and detaching state of the lens unit LU to the main body unit CU of the camera is discriminated, 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 detached, this driving means is stopped. Thus, it is possible to prevent the futile driving current from flowing when detaching the lens unit LU, to reduce power consumption, and to prolong the photopraphing time.

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 VTRs with an integrated camera generally do not have interchangeable lenses, and unlike still cameras that use silver halide film, they are not capable of large telephoto shooting or wide-angle shooting. It is not easy and the shooting range is narrow. 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 is fully functional.

Therefore, the inventors of the present application developed a video camera with interchangeable lenses, in which a lens unit containing a photographic lens and an aperture is detachably and replaceably attached to a camera body unit containing an image sensor. We are currently developing a video camera of this type. In this video camera, the camera body unit and the lens unit are each equipped with a control device consisting of a microcomputer, etc., and when the two units are combined, the control devices in both units are connected via a data transmission line (communication line). are now connected to each other. Then, in the camera body unit, the field sound intensity is detected from the output of the image sensor, and the control device in the camera expansion unit performs exposure calculation based on the field brightness, and the σ exposure calculation result is calculated. The control device in the lens unit determines the aperture opening amount based on the exposure six calculation result, and drives the aperture driving means in accordance with the determined opening amount. J Unafutaru. In addition, the field brightness signal in the camera body unit is band-limited by passing it through a plurality of band-pass filters, and based on the band-limited signal, the control device in the camera body unit is subjected to a point calculation. The calculation result is transmitted to the lens unit-〇 control device, and the control device in the lens unit determines the direction and speed of the focus motor C based on the focus calculation result, and performs focus drive according to the determined direction and υ speed. It is designed to drive the means.

[C] Invention or problem to be solved] By the way, in an image pickup device having an exposure control system and a focusing system 1a system with interchangeable lenses as described above, for example, if a photographer leaves the lens unit removed and does not turn off the power for a long time, If left unused, there are problems in that a wasteful drive current flows, high power consumption, and short photographing time.

The present invention was made with attention to these problems, and it prevents unnecessary drive current from flowing when the lens unit is removed, reduces power consumption, and allows for interchangeable lenses that prolongs shooting time. The purpose is to provide an imaging device.

[Means to solve the problem]

The naked image 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 attachment/detachment determination means for determining whether the lens unit is attached or detached. and a driving means for changing the imaging state of the light-receiving surface of the image sensor, and a control means for controlling the driving means, and is configured to stop the driving means when the lens unit is removed.

[Effect]

In the imaging device of the present invention, the attachment/detachment determination means determines whether the lens unit is attached to or detached from the camera body unit, and the control means controls the drive means for changing the imaging state of the light receiving surface of the image pickup element, and the lens unit When it comes off, the drive means is stopped.

(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 CU and LU are
is a known mount part MT in which mutual pressure contact terminals are arranged.
The microcomputer (hereinafter referred to as the lens microcomputer) 14, which is the control device in the lens unit LU, and the microcomputer (hereinafter referred to as the camera), which is the control device in the camera body unit CU, are mechanically and detachably connected via mutual pressure contact terminals. A data transmission path 39 for serial data transmission is formed between the microcomputer and the microcomputer 34.

In addition to the lens microcomputer 14 described above, the lens unit LU includes a photographic lens 1. g Comparison of light adjustment 2. Aperture encoder that detects the aperture opening amount (comparison value)3. Focus center (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 7 that drives the aperture 2
．． A D/A converter 8.9 that converts a digital signal to an analog signal and an A/A converter that converts an analog signal to a digital signal.
A D conversion 1110 is provided, and the lens microcomputer 14 includes a drive data circuit 11 which outputs drive data for the lens 1 and the lens 2, and a data transmission/reception 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 such as a CCD, into which the luminous flux of the photographing light that has passed through the lens 1 and the diaphragm 2 enters! 6. A piezoelectric element 15 that vibrates this image sensor 16. A sample hold (S/H) holds 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 17 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 drive circuit (driving means) 21, which is a modulation means for periodically changing the imaging state of the light-receiving surface of the piezoelectric element 15, and the sample hold circuit 1.
An exposure circuit 24 for obtaining proper exposure from the output of the sample hold circuit 17 and a focus detection circuit 27 for obtaining the optimum focus from the output of the sample hold circuit 17 are provided. The focus detection circuit 27 includes a plurality of BPs that limit the signal band.
F (band pass filter)25. It consists of a peak detection circuit 26 that samples and holds the output signal of the BPF 25 to detect peaks, and a gate circuit 42 interposed therebetween. Furthermore, this camera body unit CU
A/D converters 30, 31 . Determine whether the lens unit LLJ is attached to or detached from the camera body unit CU (
Here, an attachment/detachment switch (determination means for determining whether or not the camera is properly attached) 35, a microcomputer (hereinafter referred to as system microcomputer) 36 which controls the entire camera system, and 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 (ENC) circuit 40 that outputs a decoded video signal and 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 generation circuit 41 that generates a focus frame signal for a specific area are provided.
is the data transmitting/receiving circuit 32. It is composed of a control calculation circuit 33 and the like.

The camera microcomputer 34 of the camera body unit CU constitutes a control means that controls the voltage element drive circuit 2 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. stops the piezoelectric element drive circuit 21. Further, power is supplied from the battery 37 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 imaging light that enters the image sensor 16 via the photographic lens 1 and the aperture 2 is photoelectrically converted and becomes an image signal. Output. This image signal is inputted to a camera signal processing circuit 18 through a sample hold circuit 17, and after being subjected to gamma conversion and the like in the circuit 18, it is separated into one color image signal C and a luminance signal Yγ, and then extracted. These color signal C and luminance signal Yγ are
The encoder circuit 40 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 supplied to the lens microcomputer 14 of the lens unit LU via the data transmission lines 3 and 9. 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 L
If a certain amount of time has passed since U 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 camera body unit CU. In this case, the lens microcomputer 14 calculates the aperture drive amount based on the aperture control signal sent from the camera microcomputer 34, and outputs the 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, thereby driving the aperture 22. The amount of movement of the aperture 2 is detected by an encoder 3, and the detection signal is converted into a digital signal by an A/D converter 10 and input to a lens microcomputer 14. The encoder conversion circuit 13 in the lens microcomputer 14 generates a signal representing the state of the aperture, and this signal is transmitted to the camera microcomputer 34 via the data transmission line 39.

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. A proper focal voltage signal is output from the peak detection circuit 26, converted into a digital signal by the A/D converter 31, and then 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 manually 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, the signal is input to a D/A converter 9, where it is converted into an analog signal, and then supplied to a motor drive circuit 6, which drives a focus motor 4 to control focus. This focus state is detected by the focus encoder 5, and the 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-mentioned operation is performed when the lens unit LU is normally attached to the camera body unit CU, but when the lens unit LU is detached, normal camera operation is not performed. Therefore, lens unit L
When U is disconnected, it is effective to prevent the various parts of the camera body unit Cυ from operating unnecessarily, in order to reduce dissipated power. Therefore, in this embodiment, when the attachment/detachment switch 35 detects that the lens unit LU has come off, the information is transmitted to the camera microcomputer 34. At this time, the camera microcomputer 34
1 to stop driving the piezoelectric element drive circuit 21 and the piezoelectric element 15. As a result, piezoelectric element 1
5, unnecessary drive current (oscillation current) is prevented from flowing, power consumption is reduced, and photographing time is lengthened.

Further, in the above embodiment, the camera microcomputer 34 immediately causes the piezoelectric element drive circuit 2 to
! Rather than stopping the drive of the camera microcomputer 34,
An internal timer function may be used to stop the piezoelectric element drive circuit 21 after a predetermined period of time has elapsed since the determination signal was input. As a result, even if the photographer leaves the lens unit LLI removed for some reason, the piezoelectric element drive circuit 21 is stopped after a predetermined period of time has elapsed, so that a selfless current will not flow.

Note that the circuit shown in Figure 1 is equipped with a Bushiray generation circuit 19, so when the lens unit LU is removed, a blue image is displayed on the viewfinder and the image is taken during shooting 1.
You can also notify the person.

Of course, instead of this blue image, it is also possible to project images of other colors or multicolored images and sounds.

Also, since it is equipped with a character generator, a circuit 29, and a focus frame generation circuit 41, the Shins unit L
When the υ is not properly attached, the focus frame can be removed from the viewfinder and arbitrary galactor information can be displayed.

(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 image formation state of the light receiving surface of the image sensor, and to Since the drive means is stopped when the lens unit is removed, unnecessary drive current is prevented from flowing when the lens unit is removed, reducing power consumption.
This has the effect of lengthening the shooting time.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention. CU　---・Camera body unit L　U　----Lens unit MT--Mount part 1------・Photography lens 2-=- comparison 15---Piezoelectric element 16------Image sensor 18--Camera signal processing circuit 20-All switching circuit 22---Exposed circuit 27・-Single focus detection circuit 28--- 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 unit for the image pickup element. An imaging device comprising: a drive means for changing the imaging state of a surface; and a control means for controlling the drive means, the drive means being stopped when a lens unit is removed.