JPH04150675A - Image pickup device - Google Patents

Abstract

PURPOSE:To eliminate the futile consumption of electric power by controlling a changeover means for applying a driving power from the main power source of a main body unit of a camera to each part according to the discriminated result of the attaching and detaching state of a lens unit to the main body unit of the camera. 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, a changeover means 38 for applying the driving power from a main power source 37 of the main body unit CU of the camera to each part is controlled. Thus, it is possible to reduce the futile power consumption when detaching the lens unit LU, and to prevent the main body unit CU of the camera from being damaged even if the electric connection point of a mount part MT is shorted by mistake.

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. .

[Conventional technology]

Traditionally, video cameras configured as camera-integrated VTRs generally do not have interchangeable lenses, and unlike still cameras that use silver halide film, it is not easy to take large telephoto or wide-angle shots. The scope is narrow. However, recently, integrated VTRs with interchangeable lenses have been proposed, but they also have autofocus functions and auto iris (automatic exposure) functions.
It has not yet reached the point where it is fully functional.

Therefore, the inventors of the present application have proposed 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. We are proceeding with the development of In this video camera, a control device such as a microcomputer is installed in each of the camera body unit and lens unit, and when the two units are combined, the control device in both units is connected via a data transmission path (communication line). They 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 sent to the lens unit. The control device in the lens unit determines the aperture opening amount based on the exposure calculation result, and drives the aperture driving means in accordance with the determined aperture amount. .

Furthermore, 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 operates the focus drive means according to the determined direction and speed. It is designed to be driven.

[Invention or Problem to be Solved] However, in an image pickup device having an exposure control system and a focus control system as described above with interchangeable lenses, for example, if the photographer leaves the lens unit removed and turns off the power for a long time, If you leave it unattended, it will waste power, shorten your shooting time, and the electrical contacts on the mount are exposed, so if you accidentally short out the camera, the camera unit will be damaged. be.

The present invention was developed with a focus on these problems, and it reduces wasted power consumption when the lens unit is removed, and also prevents damage to the camera body unit even if the electrical contacts on the mount are accidentally shorted. The purpose of the present invention is to provide an imaging device with interchangeable lenses that does not need to be replaced.

(Means for Solving the Problems) An imaging device of the present invention includes a camera body unit and a lens unit that is detachably attached to the camera body unit, and includes attachment/detachment determination means for determining whether the lens unit is attached or detached, and the camera The apparatus includes a switching means for supplying driving power to each part from the main power supply of the main unit, and a control means for controlling the switching means according to the determination result of the attachment/detachment determining means.

(Function) In the imaging device of the present invention, the attachment/detachment determination means determines whether the lens unit is attached or detached from the camera body unit, and the control means supplies drive power to each part from the main power source of the camera body unit according to the determination result. control the switching means for

〔Example〕

FIG. 1 is a block diagram showing the circuit configuration of an imaging device according to a first embodiment of the present invention, and shows the main parts of a hiteo camera with interchangeable lenses.

In the figure, CU is a camera body unit, LLI is a lens unit that can be attached to and detached from this camera body unit CU, and both units CU and LU are mechanically attachable and detachable using a known mount part MT in which 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 camera microcomputer) 34, which is a control device in the camera body unit CU, are coupled together via mutual pressure contact terminals. A data transmission path 39 is formed for serial data transmission.

Inside the lens unit U, in addition to the above-mentioned lens microcomputer 14, there is a photographic lens l, an aperture 2 for adjusting exposure. Aperture encoder that detects the aperture opening amount (aperture 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 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 converter 10 is provided, and a lens microcomputer 1
4 is a tribe take circuit 11 which outputs the tribe take of the lens 1 and the aperture 2; and a data transmitting/receiving circuit 12 which transmits and receives the tribe take. It is composed of an encoder conversion circuit 13 and the like.

On the other hand, in addition to the above-mentioned camera microcomputer 34, the camera body unit CU includes an image sensor 16, such as a CCD, into which the 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. Sample hold (S/) that samples and holds the output signal of the image sensor 16
l) 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. A piezoelectric element drive circuit 21 for driving the piezoelectric element 15. An exposure circuit 24 for obtaining proper exposure from the output of the sample and hold circuit 17 and a focus detection circuit 27 for obtaining optimum focus from the output of the sample and hold circuit 17 are provided. and a photometry circuit 23, and the focus detection circuit 27 includes a plurality of B
PF (band pass filter)25. A peak detection circuit 26 that samples and holds the output signal of this BPF 25 and performs peak detection, and a gate circuit 42 interposed therebetween.
It consists of Furthermore, this camera body unit C
U includes A/D converters 30, 31 . Attachment/disassembly switch (attachment/disassembly determination means) 35. Determines whether the lens unit LU is attached or detached from the camera body unit CLI (here, it is determined whether or not it is normally attached). A microcomputer that controls the entire camera system (hereinafter referred to as F system microcomputer) 36. Battery 37, which is the main power source. A switching circuit (switching means) 38 for supplying driving power from the battery 37 to each part of the camera; a signal switching circuit 30 controlled by the system microcomputer 36; An encoder (ENC) circuit 40 for outputting a decoded video signal and an EVF circuit 28 for monitoring the video on a viewfinder are provided, and the camera microcomputer 34 is provided with a data transmitting/receiving circuit 32 . It is composed of a control calculation circuit 33 and the like.

In addition, the system microcomputer 36 of the camera body unit CU
constitutes a control means that controls the switching circuit 38 according to the on/off signal that is the determination result of the attachment/detachment switch 35, and also controls the regulator (REG) of the lens unit LLI from the note 1/note 37. Power is supplied to the power supply 43, and from there power is supplied to each power supply.

Next, the operation will be explained.

When the lens unit LU is normally attached to the camera body unit CU, the luminous flux of the imaging light that enters the image sensor 16 through the photographic lens 1 and the aperture 2 is photoelectrically converted and output as an image signal. Ru. This image signal is passed through the sample hold circuit 17 to the camera signal processing circuit 1.
After being subjected to gamma conversion and the like in the circuit 18, the signal is separated into a color signal C and a luminance signal Yγ and taken out. The color signal C and luminance signal Yγ are converted into decoded video signals by the encoder circuit 40 and output to the outside, and are also monitored by the EVF circuit 28 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 transmitting/receiving circuit 32 of the camera microcomputer 34, and this signal is supplied to the lens microcomputer 14 of the lens unit LU via the data transmission path 39. 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 the LI and camera body unit CU have been connected for a certain period of time after being attached to each other, or if there is no abnormality or malfunction in the data transmission line 39, or if there is a problem with the power supply inside the camera body unit CU. ), 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 tribe 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 this aperture 2 is
The encoder 3 detects the signal, and the detection signal is converted into a digital signal by the A/D converter 10 and sent to the lens microcomputer 14.
is input. 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 a plurality of BPFs 25 here, the luminance signal Y is outputted 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 this signal is 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 control calculation circuit 33 performs a predetermined calculation, and focal voltage data obtained as a result of the calculation is input from the data transmission/reception circuit 32 to the lens microcomputer 14 via a data transmission path 39. Ru. 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, it is possible to perform appropriate aperture control and focus control in a video camera with interchangeable lenses.

Here, the above-mentioned operation is performed when the lens unit LU or the camera body unit CU is normally attached, but when the lens unit is detached, normal camera operation is not performed. However, if the lens unit LU is removed, remove the camera body unit C.
This is also effective in preventing unnecessary operation of each part of U and in reducing power consumption. Therefore, in this embodiment, the current is always available for supply from the battery 37 to each part of the camera body unit CU, but when the attachment/detachment switch 35 detects that the lens unit LLI is detached, the system microcomputer The information is transmitted to 36. At this time, the system microcomputer 36
A control signal is sent to each part of the camera to stop power supply from the battery 37 to each part of the camera, thereby preventing drive current from flowing to each part of the camera. This reduces unnecessary power consumption, and prevents current from flowing even if the exposed electrical contacts on the mount MT are accidentally short-circuited.
is protected without being damaged.

In the above embodiment, instead of immediately stopping the power supply to each part of the camera through the system microcomputer 36 or the switching circuit 38 in response to the determination signal that the lens unit LU is detached from the attachment/detachment switch 35, the system microcomputer 36 An internal timer function may be used to stop the power supply to each part of the camera after a predetermined period of time has elapsed since the determination signal was input.

As a result, even if the lens unit LU is left unattended due to the photographer or some other reason, the power supply to each part of the camera will be stopped after a predetermined period of time, preventing damage to the camera body unit. I'll come.

FIG. 2 is a block diagram showing a second embodiment of the present invention,
The same reference numerals as in FIG. 1 indicate the same components. In the figure, reference numeral 19 denotes a blue generation circuit that outputs a blue color signal regardless of the output signal of the camera signal processing circuit 18.

If the lens unit LU is disconnected from the camera body unit CU, or if some abnormality occurs in the data transmission line 39, for example, a contact failure may occur on the mutual connection terminal of the lens unit LU and camera body unit CU. In the embodiment shown in FIG. 2, this information is immediately communicated to the photographer.

That is, when the lens unit LU is removed due to the photographer's intention, or when an abnormality occurs in the data transmission line 39, the lens unit LtJ is correctly attached to the camera body unit CU from the attachment/detachment switch 35 or the camera microcomputer 34. An information signal indicating that the system is not running is input to the system microcomputer 36. The system microcomputer 6 outputs a control signal to the switching circuit 38 according to the information signal to stop the power supply to each part of the camera, and at the same time outputs a control signal to the image signal switching circuit 20 to output the control signal to the encoder circuit 40.
Switch the signal to At this time, if the lens unit LU is normally attached, the switching circuit 20 selects the output of the camera signal processing circuit 18 and transmits it to the encoder circuit 40, but if the above control signal is input, The blue signal output from the blue generation circuit 19 is selected and transmitted to the encoder circuit 40. As a result, a blue video signal is output from the output terminal, and a blue video is displayed on the viewfinder monitor by the EVF circuit 28. By visually checking this, the photographer can confirm that the lens unit LU is correctly attached. You can know that it is not.

In this way, since it is possible to visually determine whether the lens unit Lυ is properly attached, the photographer does not have to worry about using unnecessary nerves and does not feel anxious.

In the above embodiment, a blue image is displayed by the blue generation circuit 19, but it is of course possible to construct an image of any color or a multicolor image.

FIG. 3 is a block diagram showing a third embodiment of the present invention.

In the figure, 29 is a character generator circuit that generates arbitrary character information, and 41 is a focus frame generation circuit that generates a focus frame (frame) signal for a specific area.

In this embodiment, as in the second embodiment described above, when the lens unit LU is detached from the camera body unit CU,
Alternatively, if any abnormality occurs in the data transmission path 39 due to poor contact of a connecting terminal, etc., the configuration is such that the information can be immediately transmitted to the photographer.

That is, the camera microcomputer 34 normally outputs a gate pulse to the gate circuit 42 in order to obtain the above-mentioned focal voltage signal within an arbitrary square area on the screen of the viewfinder, and the gate circuit 42 uses the pulse signal to output a gate pulse. multiple BPs
The signal band-limited by F25 is gated.

The focus frame generation circuit 41 outputs the above-mentioned focus frame signal in order to cause the EVF circuit 28 to display the gated area on the viewfinder. However, if the lens unit LU is not properly attached, the information is input to the system microcomputer 36 by the attachment/detachment switch 25 and the camera microcomputer 34, and the output of the focus frame generation circuit 41 is stopped. At the same time, the character information that the lens unit LLJ is not attached properly is sent from the character generator circuit 29 to the EVF.
The information is output to the circuit 28 and can be conveyed to the photographer at a glance through the viewfinder.

In this way, when the lens unit Lυ is not installed properly, the focus frame disappears from the viewfinder and character information is displayed, which more clearly conveys the situation that the lens unit LU is not installed properly. be able to. At that time, blue generation circuit 1
By 9th grade.

Desired display is possible.

Next, a fourth embodiment of the present invention will be described.

The configuration of this embodiment is the same as that shown in FIG. 1, so the explanation will be omitted.
In this embodiment, the method for driving the piezoelectric element 15 required for focus control is designed to reduce power consumption so as not to waste power when the lens unit LU is out of position.

As mentioned above, in order to obtain proper focus, the aperture encoder 3 (see Figure 1) detects the aperture opening amount (aperture value), and the detection signal is digitized by the A/D converter 10 and sent to the lens. After inputting into the microcomputer 14 and converting the signal by the encoder conversion circuit 13 in the lens microcomputer 14, the data is transmitted from the data transmitting/receiving circuit 12 to the data transmission line 3.
9 is input to the camera microcomputer 34. Then, the camera microcomputer 34 outputs a control signal for changing the amplitude of the piezoelectric element 15 according to the aperture value data to the piezoelectric element drive circuit 21, thereby driving the piezoelectric element 15. At this time, when a determination signal indicating that the lens unit LU is detached from the attachment/detachment switch 35 is inputted to the camera microcomputer 34, the camera microcomputer 34 detects the piezoelectric element drive circuit 21.
Then, a control signal for stopping the drive of the piezoelectric element 15 is sent out regardless of the aperture value data, or a control signal for arbitrary small drive is sent out, which is the same as in manual focusing. This makes it possible to reduce wasteful power consumption. At this time, as in the first embodiment, the camera microcomputer 34 does not immediately output a control signal to stop or drive the piezoelectric element 15 in response to a signal from the detachable switch 35; A timer function may be used to output a control signal to the piezoelectric element 15 after a certain period of time has elapsed since the signal from the attachment/detachment switch 35 was input, thereby improving usability.

Even with such a configuration, wasteful power consumption can be reduced as in each of the above-described embodiments, and the camera body unit CU can be protected, making it possible to extend the photographing time for a longer period of time.

〔Effect of the invention〕

As described above, according to the present invention, the attachment/detachment state of the lens unit to the camera body unit is determined, and according to the determination result, the switching means for supplying drive power to each part from the main power source of the camera body unit is controlled. This has the effect of reducing wasted power consumption when the lens unit is removed, and also prevents damage to the camera body unit even if the electrical contacts on the mount are accidentally shorted. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of the invention, FIG. 2 is a block diagram showing a second embodiment of the invention, and FIG. 3 is a block diagram showing a third embodiment of the invention. CU--Camera body unit L U--Lens unit MT--Mount section 1.--Photographing lens 2--Comparison 5--Piezoelectric element 6--Imaging element 8- ---Camera signal processing circuit 9--Blue generation circuit 0.--All switching circuit 2.---Exposure circuit? --- Single focus detection circuit 8 --- EVF circuit 29 --- Character generator 35 ---
- Attachment/detachment switch (attachment/detachment control means) 36...Microcomputer (control means) 37...Battery (main power supply) 3B -------Switching circuit (switching means) 41-- −
--- Focus frame generation circuit 42 --- Gate circuit

Claims (1)

[Claims] It has a camera body unit and a lens unit that can be attached or detached from the camera body unit, and includes attachment/detachment determination means for determining whether the lens unit is attached or detached, and switching for supplying drive power to each part from the main power source of the camera body unit. and a control means for controlling the switching means according to the determination result of the attachment/detachment determination means.