JPH0654253A - Camera - Google Patents

Abstract

PURPOSE:To provide a compact and inexpensive lens barrel of an image pickup optical system by using a physical property element to adjust the quantity of light made incident on an image pickup surface. CONSTITUTION:A camera is provided with a camera control circuit 100, a recording part 101 which is electrically connected to the circuit 100, and a power supply 102. At the same time, the camera is electrically connected to a zooming motor 8 which drives a cam barrel 4, focusing motor 7 which drives a holding mirror barrel 2, a physical property element 9, an image pickup element 10, an electronic viewfinder 12, a power switch 14, and a zoom operating part 15 respectively. The exposure value is controlled so that quantity of light made incident on the element 10 is constant when the quantity of the transmitted light of the element 9 is controlled by an exposure value control circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera for photographing a still image and a moving image having a photoelectric conversion means on the image pickup surface of a photographing optical system or a surface optically equivalent to the image pickup surface.

[0002]

2. Description of the Related Art In recent years, video cameras have become widespread in which an object image formed by a photographing optical system by a photoelectric conversion element such as a CCD is converted into an electric signal and recorded on a recording medium such as a magnetic tape.

Further, a part of the luminous flux in the photographing optical system is extracted, and the extracted luminous flux is guided onto a photoelectric conversion element, and A
Cameras that perform E or autofocus have become widespread. In such a camera, there is a demand for miniaturization of the camera from the viewpoint of ease of use, etc., and high density mounting of electric circuits and C
A compact video camera is currently being developed by reducing the size of a CD and the size of a photographing optical system. A camera has been proposed in which the amount of light incident on the imaging surface is adjusted by a physical property element in order to reduce the size of the photographic optical system.

[0004]

However, at the present time,
The amount of light incident on the image pickup unit of the video camera is adjusted by mounting a diaphragm whose mechanical opening can be adjusted in the photographing optical system and adjusting the aperture diameter of this diaphragm. However, since the mechanical aperture unit has a large motor section, the photoelectric conversion element such as CCD is now downsized, and it is larger than the taking optical system lens barrel. This is a major issue in reducing the size of the lens barrel. Further, it has been proposed to use a physical property element such as a liquid crystal element or an EC element instead of the mechanical diaphragm unit as a diaphragm or a variable ND filter of a photographing optical system. However, the above-mentioned physical property element has some problems in the wavelength dependence of the transmittance (spectral transmittance).

By the way, when the amount of light incident on a photoelectric conversion element such as a CCD is adjusted by a physical property element such as an EC (electrochromic) element or a liquid crystal element, the power of the camera is turned off when the light transmittance of the physical property element is high. If the control of the physical property element is stopped by putting the camera in the playback mode, the light with high intensity such as sunlight may enter the photoelectric conversion element and damage the photoelectric conversion element. There is.

Further, since the photoelectric conversion element has high sensitivity to near-infrared light other than visible light, the photoelectric conversion element such as CCD is formed on the image forming surface of the photographing optical system or a surface optically equivalent thereto. The camera having the above has a near infrared light cut filter in the photographing optical system. Improving the assemblability of this near-infrared light cut filter is an issue for downsizing and cost reduction of the camera.

An object of the present invention is to solve the above problems, and in a camera having a photoelectric conversion element on the image pickup surface of an image pickup optical system or a surface optically equivalent to the image pickup surface, adjustment of the amount of light incident on the image pickup surface is performed by a physical property element. When the image pickup device is not driven, light with high light intensity is less likely to be incident and damage the image pickup device. Furthermore, the incorporation property of the near infrared light cut filter is improved, An object of the present invention is to provide a compact and low-priced camera by reducing the size and cost of a photographing optical system lens barrel.

[0008]

In order to achieve each of the above objects, the camera of the present invention is characterized in that, in Claim 1, a physical property element capable of controlling a light transmittance or a light transmission amount is used as a photographing optical system. In the camera having a photoelectric conversion means on an image pickup surface of this photographing optical system or a surface optically equivalent to this image pickup surface, the physical property element has a filter function for removing near infrared light, According to a second aspect of the present invention, the physical property element and a filter for removing near-infrared light are integrally configured, and in the third aspect, a means for correcting the light transmittance wavelength dependent characteristic of the physical property element is provided. Claim 4
In claim 5, the optical device further comprises a storage unit for storing the light transmittance wavelength-dependent characteristic of the physical device when the physical device is in a certain state, and the storage unit according to claim 5 further comprises: A storage means for storing a plurality of wavelength dependence characteristics of the light transmittance of the physical property element when a certain constant value is given. Further, in claim 6, temperature detection means is provided, and the storage means is provided at a certain constant temperature. The storage means stores a plurality of wavelength dependence characteristics of the light transmittance of the physical property element under the conditions. When the photoelectric conversion means is not performing a photoelectric conversion operation as claimed in claim 7 or 10, the physical property element is set in a light non-transmissive state, a substantially minimum light transmittance state, or a substantially minimum light transmission amount state, or When the conversion means is not performing a photoelectric conversion operation, the voltage is not applied to the physical property element, and at that time, when the voltage application is stopped, the physical property element has its light transmittance or light The transmission amount is maintained in the state when the voltage application to the physical property element is stopped, and when the photoelectric conversion means stops the photoelectric conversion operation, the physical property element is in a light non-transmissive state or a substantially minimum light transmittance state. Alternatively, the voltage application to the physical property element is stopped after the substantially minimum light transmission amount state,
Further, in claim 8, when the power switch of the video camera is turned off, the physical property element is brought into a non-light-transmitting state, a substantially minimum light transmittance state, or a substantially minimum light transmission amount state, and in the ninth aspect. When the video camera is in the recorded image reproduction state or the recorded image reproduction mode, the physical property element is set in a light non-transmissive state or a substantially minimum light transmittance state or a substantially minimum light transmission amount. In the twelfth aspect, the physical property element is in a light non-transmissive state, a minimum light transmittance state, or a minimum light transmission amount state.

[0009]

With the structure of the present invention, the taking optical system lens barrel can be miniaturized and the price can be reduced, whereby a compact and low-priced camera can be provided.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing an outline of a camera which is an embodiment of the present invention. FIG. 2 is a block diagram showing the circuit configuration of the first embodiment. FIG. 3 is a flow chart for controlling the operation of the camera of the first embodiment.

In FIG. 1, reference numeral 1 is a photographing optical system, and
a is a focusing lens, 1b and 1c are zoom lenses, and 1d is a fixed lens. Reference numeral 2 denotes a holding barrel for holding the focusing lens 1a, which has a gear portion 2a.
Reference numeral 3 denotes a fixed portion, which is screwed with the holding barrel 2. Reference numeral 4 denotes a cam barrel which has a cam groove for determining the positions of the zoom lenses 1b and 1c and is rotatably held by the fixed portion 3.
Reference numerals 6 and 6 are lens frames for holding the zoom lenses 1b and 1c. Reference numeral 7 is a focusing motor for rotating the holding barrel 2, 7a is a gear of a motor output shaft that engages with the gear portion 2a of the holding barrel 2, and 8 is for rotating the cam barrel 4. It is a zoom motor. 8a is a cam barrel 4
The gear of the motor output shaft that engages with the gear portion 4a of
Is a physical property element for adjusting the light quantity, and 10 is a CCD
11 is an optical axis of the photographing optical system.
Reference numeral 12 is an electronic viewfinder, 13 is a lens of the electronic viewfinder 12, 14 is a power switch of the camera, and 15 is a zoom operation unit of the camera. Further, the camera includes a camera control circuit 100 and the camera control circuit 1
00 and a power supply 102. Further, the focus motor 7, the zoom motor 8, the physical property element 9, the image sensor 10, the electronic viewfinder 12, the power switch 14, and the zoom operation unit 15 are electrically connected.

Next, the operation of FIG. 1 will be described with reference to FIGS. 2 and 3.

When the power switch 14 of the camera is operated and the power supply 102 is turned on (S1), the image pickup device 1
The focusing lens 1a is moved in the optical axis direction by the focus control circuit 107 so that the high frequency component of the 0 video signal becomes the highest (S2). Focus lens 1
To move a, the focusing motor 7 is rotated. Then, since the gear 7a of the motor output shaft is engaged with the gear portion 2a of the holding barrel 2 and the holding barrel 2 is screwed with the fixing portion 3, the focusing lens 1a moves in the optical axis direction. Moving. As a result, the focusing operation is performed (S3). To control the exposure amount, the light transmission amount of the physical property element 9 is controlled by the exposure amount control circuit 105 so that the amount of light incident on the image sensor 10 is constant. The image from the image pickup device 10 is displayed on the electronic viewfinder 12 by the electronic viewfinder control circuit 106 so that the photographer can observe it (this state is set to the standby state (S4)). When the zoom operation unit 15 is operated, the zoom control circuit 108 rotates the zoom motor 8. Since the gear 8a and the gear portion 4a of the cam barrel 4 are engaged with each other, the cam barrel 4 rotates, which causes the zoom lenses 1b and 1c to move in the optical axis direction by the cam of the cam barrel 4 to perform zoom operation. Done. The zoom operation unit 15 is provided with a zoom switch 1 and a zoom switch 2, and when the zoom switch 1 is turned on (S11), the zoom motor 8 rotates forward (S13),
The zoom lenses 1b and 1c move to the wide-angle side, and when the zoom switch 2 is turned on (S12), the zoom motor 8 reverses (S14) and the zoom lenses 1b and 1c move to the telephoto side. Further, the zoom switch 1 and the zoom switch 2 cannot be turned on at the same time.

When the photographer presses a photographing button (not shown) (S
5), the shooting switch is turned on, and the camera control circuit 10
When 0 confirms that the photographing switch is turned on, photographing is started (S6), the video signal from the image sensor 10 is transferred to the recording unit by the camera control circuit 100, and recorded on the recording medium by the recording unit control circuit 103. . At this time, the focusing operation and the exposure amount adjustment described above are performed (S7, S
8, S15, S17, S16), the image is displayed on the electronic viewfinder 12 by the electronic viewfinder control circuit 106.
Is displayed in. When the photographer releases a photographing button (not shown), the photographing switch is turned off, and the camera control circuit 10
When 0 confirms that the shooting switch is turned off (S
9) The shooting operation is stopped and the camera returns to the standby state (S18).

Here, the physical property element 9 having a near infrared light cut filter function will be described.

FIG. 4 shows an example of spectral transmission characteristics of the near infrared light cut filter. Usually, an image pickup device such as a CCD has a relatively high sensitivity to near infrared light. Therefore, a camera having such an image sensor has a near infrared light cut filter having a spectral transmittance characteristic as shown in FIG. 4 on the light receiving side of the image sensor. Therefore, the spectral transmission characteristics as shown in FIG. 5 (the solid line in FIG. 5 shows the characteristics of the maximum transmission state of the physical property element, the characteristics when the light transmittance is lowered are the broken lines,
If a physical property element having a one-dot chain line and a two-dot chain line) is used as a light amount adjusting means of the photographing optical system, this physical property element has a function of a near-infrared light cut filter. It is not necessary to separately provide a near infrared light cut filter. Further, the spectral transmission characteristics as shown in FIG. 6 (the solid line in FIG. 6 shows the characteristics in the maximum transmission state of the physical property element, and the characteristics when the light transmittance is lowered are shown in the order of the broken line, the one-dot chain line, and the two-dot chain line. And a near-infrared light cut filter having the characteristics shown in FIG. 4 are integrally configured to form a light adjusting unit having the spectral transmission characteristics shown in FIG. You can also An example of this light amount adjustment unit will be described with reference to FIGS. 7 to 1
Reference numerals are the same in 1; 16 is a near infrared light cut filter; 17 is a physical element; 18 is a film made of a transition metal oxide or the like (for example, IrO _x , Ta ₂ O ₅ , WO ₃ etc.) E
It is a C (electrochromic) element, and the light transmission amount of the film can be controlled by applying a voltage to this film. 19 is a liquid crystal, 20 is a polarizing plate (or a glass plate),
Reference numeral 21 is an electric signal line, and 22 is a glass plate. As shown in FIG. 7, the above-mentioned light quantity adjusting unit is one in which the physical property element 17 and the near infrared light cut filter 16 are integrally configured. Here, when the physical property element 17 is an EC element, the EC element 18 may be formed on the surface of the near infrared light cut filter 16 by vapor deposition or the like as shown in FIG. 8, and as shown in FIG. The glass plate 22 on which the EC element 18 is deposited may be attached to the near infrared light cut filter 16. Further, one of the polarizing plate (or glass plate) 20 enclosing the liquid crystal in the physical property element 17 may be the near infrared light cut filter 16, or the liquid crystal element and the near infrared light cut filter 16 as shown in FIG. It may be pasted together. 7 to 11
The electric signal line 21 shown in FIG.
And the physical property element 17 is connected to the exposure amount control circuit 10
Controlled by 5.

FIG. 12 is a sectional view showing a schematic structure of a camera which is a second embodiment of the present invention, FIG. 13 is a block diagram showing a circuit structure of the second embodiment, and FIG. 14 is this embodiment. 3 is a flowchart for controlling the operation of the camera of FIG.

Reference numeral A is a lens unit, and B is a camera body unit. Reference numeral 31 is a photographing optical system, and
Reference numeral a is a focusing lens, 31b and 31c are zoom lenses, and 31d is a fixed lens. Reference numeral 32 denotes a holding barrel that holds the focusing lens 31a, and the gear portion 32a
Have. A fixed portion 33 is screwed with the holding barrel 32. Reference numeral 34 is a focusing motor for rotating the holding barrel 32. A gear 34a of the motor output shaft is engaged with the gear 32a of the holding barrel 32. Reference numeral 35 is a physical property element, 36 is a lens contact point, 37 is a lens mount, 38 is an optical axis of a photographing optical system, 39 is a quick return mirror, and has a half mirror portion. 40 is a sub mirror attached to the quick return mirror, 41
Is a shutter unit, 42 is a pentaprism, 43 is a finder lens, 44 is an image pickup surface, 45 is a camera contact point, 46 is a camera mount that can be combined with the lens mount 37, 47 is an AF sensor unit, and a photoelectric conversion element such as a CCD 47a. Reference numeral 48 is an AE sensor unit having a photoelectric conversion element, and 49 is a motor for driving the quick return mirror 40. Also, the lens unit A
Has a lens control circuit 111 electrically connected to the focusing motor 34, the physical property element 35, and the lens contact 36. The camera unit B has a camera control circuit 110 and a power supply 112 that electrically connects the camera control circuit 110, and the camera control circuit includes a shutter unit 41,
It is electrically connected to the camera contact 45, the AF sensor unit 47, the AE sensor unit 48, and the motor 49. The lens control circuit and the camera control circuit are electrically connected via the lens contact 36 and the camera contact 45.

Next, the operation of FIG. 12 will be described with reference to FIGS.
4 will be described.

When the power switch of the camera (not shown) is operated and the power supply 112 is turned on (S20), the physical property element 3
The light transmittance of 5 is maximized (S21). Then, when the photographer decides on the composition and the release button (not shown) is pressed for half the stroke, the switch 1 in FIG. 13 is turned on (S22), which means that the camera control circuit 11
When detected by 0, the AE sensor unit 48 having a photoelectric conversion element measures the subject brightness through the photometric circuit 112, and the light reflected by the sub mirror 40 after passing through the half mirror portion of the quick return mirror 39 causes photoelectric conversion. AF sensor unit 47 having conversion element
The amount of movement of the focusing lens 31a for focusing is detected at, and the power supply voltage is checked (S2).
3). Then, the shutter speed, the light transmittance of the physical property element 35, and the movement amount of the focusing lens 1a are determined (S24). Here, the holding barrel 32 and the fixing portion 33 are screwed together, and the rotation of the focusing motor 34 is transmitted to the holding barrel 32 via the gear 34a and the gear 32a, so that the focusing motor control circuit is provided. When the focusing motor 34 is rotated by 117, the focusing lens 3
1a moves in the optical axis direction while rotating. Then, according to the determined movement amount of the focusing lens 31a, the focusing motor 34 is rotated, and the focusing lens 31a is moved to the in-focus position to perform autofocusing (S25). When the release button is further pressed from this state, the switch 2 in FIG. 13 is turned on (S
26), when this is detected by the camera control circuit 110, the light transmittance of the physical property element 35 is changed to the determined value (S28), and the quick return mirror control circuit 11
The quick return mirror 39 is retracted to the outside of the light flux by 6 (-S29 shown by the broken line in FIG. 12). And
According to the determined value of the shutter speed, the shutter unit is opened and closed through the shutter control circuit 114 to expose the image pickup surface (film surface) 44 (S30). And
Return the quick return mirror 39 to its original position (S3
1) The light transmittance of the physical property element 35 is maximized (original state) (S32), the film is fed by one frame, and the photographing operation is completed.

Here, the image pickup device such as CCD used in the AF sensor unit or the like has a relatively high sensitivity to near infrared light. Therefore, a near infrared light cut filter having a spectral transmittance characteristic as shown in FIG. 4 is provided on the light receiving portion side of such an image sensor. Therefore, the first aspect of the present invention
If the physical property element of the embodiment of the present invention is used as a physical property element that is the light amount adjusting means of the photographing optical system of the present embodiment, since this physical property element has a near infrared light cut filter function, another near infrared light cut filter is used. There is no need to provide it. Further, as in the first embodiment of the present invention, the physical property element of this embodiment is configured integrally with a physical property element and a near-infrared light cut filter. The same effect can be obtained by using the characteristic light quantity adjusting unit. However, in this embodiment, the electric signal line 21 in FIGS. 7 to 11 is connected to the lens control circuit, and the physical property element 35 is It is controlled by the physical property element control circuit 118.

In addition to the above, the first embodiment of the present invention is a video camera integrated with a photographing optical system, and the second embodiment of the present invention is an interchangeable lens type camera. It may be a system-integrated type camera or an interchangeable lens type camera.

A third embodiment of the present invention will be described with reference to the drawings.

The schematic block diagram of the video camera of the third embodiment of the present invention and the flow chart for controlling the operation of the camera of this embodiment are the same as those of FIGS. 1 and 3. Figure 15
Is a block diagram showing the circuit configuration of this embodiment, FIG. 16 is a graph showing the light transmittance wavelength dependence characteristics of the physical property element,
FIG. 17 is a graph showing the light transmittance wavelength dependence characteristic of the physical property element due to temperature change.

In FIG. 15, description of the same circuit configuration as that of the first embodiment shown in FIG. 2 is omitted.

Referring to FIG. 15, the physical property element 9 and the spectral transmittance characteristic storage circuit of the physical property element 9 will be described.

The physical property element 9 is a known liquid crystal element or electrochromic element, and the amount of light transmission can be electrically controlled. Ideally, the physical property element 9 has a constant light transmittance irrespective of the light wavelength. However, in general, even if the light transmittance of the physical property element is the highest, as shown in FIG. The light transmittance changes. Also, depending on the physical property element,
Depending on the light transmittance, the spectral transmittance changes, for example, as shown by the broken line in FIG. Also, depending on the temperature conditions,
As shown in 7, the spectral transmittance may change.
Therefore, in order to prevent the color balance of the camera from being deviated by using this physical property element, the physical property element spectral transmittance characteristic storage circuit 122 that stores the spectral transmittance characteristic of the physical property element under each condition is provided. The camera control circuit and the temperature detection circuit 12 determine the light transmission state and temperature conditions of the physical property element.
The white balance is corrected by the camera control circuit 100 based on the information of the spectral transmittance characteristic of the physical element 9 stored in the physical element spectral transmittance characteristic storage circuit 122.

The operation of the third embodiment is the same as that shown in the flow chart of FIG. 3, except that the light transmission amount of the physical property element is adjusted so that the light amount incident on the image pickup device 10 becomes constant. Is controlled by the exposure amount control circuit 105, the white balance correction for preventing the color balance shift due to the physical property element 9 is simultaneously performed.

In addition, when the spectral transmittance characteristic of the physical property element does not largely change due to the temperature change, the temperature detection circuit 121 of the present embodiment may be omitted and the white balance correction due to the temperature change may not be performed.

In the present embodiment, the physical property element spectral transmittance characteristic storage circuit 122 is controlled by the camera control circuit 100. However, in the case of an interchangeable lens type camera, the physical property element spectral transmittance characteristic storage circuit 122 is replaced. It may be provided on the lens side.

When the color balance does not change significantly due to the transmittance of the physical property element, the representative characteristic of the spectral transmittance characteristic of the physical property element may be stored.

Further, the color balance may be corrected by any method such as changing the transmittance of the color filter of the image pickup device regardless of the white balance.

FIG. 18 is a block diagram showing the outline of a video camera which is the fourth embodiment of the present invention, FIG. 19 is a block diagram showing the circuit structure of this embodiment, and FIG. 20 is this embodiment. 3 is a flowchart for controlling the operation of the video camera which is

In FIG. 18, those having the same or the same functions as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

Reference numeral 16 denotes a mode change switch of the camera, which can switch between a recording mode and a reproduction mode. The camera also includes a camera control circuit 100, a recording unit 101 electrically connecting the camera control circuit 100, and a power supply 10.
Have two. Further, the focus motor 7, the zoom motor 8, the physical property element 9, the image pickup element 10, the electronic viewfinder 12, the power switch 14, the zoom operation unit 15, and the mode changeover switch 16 are electrically connected.

Next, the operation of FIG. 18 will be described with reference to FIGS.
However, the same points as those in the first embodiment of FIG. 1 will be omitted, and only different points will be described.

When the power switch 14 of the camera is operated and the power is turned on (S1), the mode change switch 16 determines whether or not the camera is in the recording mode (S41). The focusing lens 1a is moved in the optical axis direction so that the high frequency component of the image signal of the image sensor 10 becomes the highest.

When the photographer operates a photographing button (not shown), the photographing switch is turned off. When the camera control circuit 100 confirms that the photographing switch is turned off, the photographing operation is stopped and the camera returns to the standby state. In this state, when the power switch 14 is turned off (S4
2) The camera control circuit 100 confirms that the power switch 14 has been turned off, and the display of an image by the electronic viewfinder, the driving of the image sensor 10, the zoom operation, the focusing operation, and the exposure amount control operation are stopped. (S5
5, 56, 57), the physical quantity element 9 is brought to the minimum light transmittance state by the exposure amount control circuit 105 (S5).
8) This state is maintained. In this way, the power of the camera is turned off (S59, 60).

When the camera is switched to the reproduction mode by the mode changeover switch 16 from the standby state (S43), this is confirmed by the camera control circuit 100, and the driving of the image pickup device 10, the zooming operation, the focusing operation,
When the exposure amount control operation is stopped (S51, 5
2, 53), at the same time, the physical quantity element 9 is brought to the lowest light transmittance state by the exposure amount control circuit 105 (S54), and this state is maintained. In this way, the standby state of the recording mode is switched to the reproduction mode.

When the power switch 14 of the camera is operated and the power is turned on and the camera is in the reproduction mode by the mode changeover switch 16 (S41), the exposure amount control circuit 105 causes the physical property element 9 to have the minimum light transmission. It is kept as a rate. At this time, when a play button (not shown) is pressed (S45), the image of the recording medium inserted in the camera is displayed on the electronic viewfinder 12 (S46). Then, if a stop button (not shown) is pressed (S47), the reproduction of the image is stopped (S48). In this state, when the power switch 14 is turned off, the power switch 14 is turned off.
The FF is confirmed by the camera control circuit 100, and the display of the image by the electronic viewfinder is stopped, and at the same time, the physical property element 9 is kept in the minimum light transmittance state. In this way, the power of the camera is turned off.

When the camera reproduction mode is switched from the camera reproduction mode to the recording mode by the mode selector switch 16 and this is confirmed by the camera control circuit 100 (S49),
The driving of the image sensor 10, the focusing operation, the zoom operation, the exposure amount control operation, and the like as described above are started, and the camera enters the recording mode standby state (S50).

Next, in this embodiment, an example of a method for keeping the light transmittance or the light transmission amount of the physical property element to the minimum state and holding the state will be described.

In the case where the physical property element of the present embodiment has the lowest light transmittance or light transmission amount when no voltage is applied (for example, a negative type liquid crystal element), the light transmittance or light transmission amount of the physical property element is the lowest. In order to enter the state and maintain the state, the power supply to the physical property element may be turned off.

In the case where the physical property element of this embodiment retains the light transmittance or the amount of light transmission when no voltage is applied to the physical property element (for example, an EC element) when the power is cut off to the physical property element.
In order to keep the light transmittance or the amount of light transmission of the physical property element to the minimum state and to keep the state, it is sufficient to energize until the light transmittance or the amount of light transmission of the physical property element becomes the minimum state, and then turn off the power. (For example, a constant voltage is applied for a fixed time.) Here, when the image pickup device 10 is not driven (when the camera power is off, in the camera reproduction mode, etc.), the physical property element 9 has the lowest light transmission state. Although it is supposed to be held as it is, it may be in the vicinity of the lowest light transmission state. Further, the light may not be completely transmitted.

[0046]

As described above, according to the present invention, the photographing optical system has a physical element capable of controlling the light transmittance or the light transmission amount, and the photographing surface of the photographing optical system or an optical equivalent thereof. In a camera having a photoelectric conversion means on its surface, the physical property element has a near-infrared light cut filter function, or since the physical property element and the near-infrared light cut filter are integrally configured, the near-infrared light cut filter is incorporated. Is improved,
There is an effect that the photographing optical system lens barrel can be miniaturized and reduced in price, and a compact and low-priced camera can be provided.

Further, since the storage circuit for the light transmittance wavelength dependence characteristic of the physical property element of the present invention and the color balance correction means are provided, the physical property element can be used instead of the conventional diaphragm for mechanically adjusting the opening. Therefore, it is possible to provide a small photographing optical system lens barrel, that is, a small video camera by eliminating the diaphragm driving unit for mechanically adjusting the opening.

Also in the interchangeable lens type video camera, there is an effect that a physical property element can be used instead of the conventional diaphragm.

Further, in the present invention, in a video camera having a physical property element capable of controlling the light transmittance or the amount of light transmission in a photographing optical system, when the photographing element is not driven or the power of the camera is turned off, Since the physical element is set to the light non-transmissive state, the lowest light transmittance state, or the vicinity thereof, or the lowest light transmission amount state or the vicinity thereof, a small video that does not damage the image sensor even when light with high light intensity is incident. There is an effect that a camera can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic configuration of a camera that is a first embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of a first exemplary embodiment of the present invention.

FIG. 3 is a flowchart for controlling the operation of the camera of the first embodiment of the present invention.

FIG. 4 is a diagram showing an example of a spectral transmission characteristic of a near infrared light cut filter.

FIG. 5 is a diagram showing a spectral transmission characteristic of the physical property element according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a spectral transmission characteristic of the physical property element according to the first embodiment of the present invention.

FIG. 7 is a diagram showing a configuration of a physical property element integrated with a near infrared light cut filter according to an example of the present invention.

FIG. 8 is a diagram showing a configuration of a physical property element integrated with a near infrared light cut filter according to an example of the present invention.

FIG. 9 is a diagram showing a configuration of a physical property element integrated with a near-infrared light cut filter according to an example of the present invention.

FIG. 10 is a diagram showing a configuration of a physical property element integrated with a near infrared light cut filter according to an example of the present invention.

FIG. 11 is a diagram showing a configuration of a physical property element integrated with a near infrared light cut filter according to an example of the present invention.

FIG. 12 is a sectional view showing a schematic configuration of a camera that is a second embodiment of the present invention.

FIG. 13 is a block diagram showing a circuit configuration of a second embodiment of the present invention.

FIG. 14 is a flow chart for controlling the operation of the camera of the second embodiment of the present invention.

FIG. 15 is a block diagram showing a circuit configuration of a third exemplary embodiment of the present invention.

FIG. 16 is a graph showing a light transmittance wavelength dependence characteristic of a physical property element.

FIG. 17 is a graph showing light transmittance wavelength dependence characteristics of a physical property element due to temperature change.

FIG. 18 is a configuration diagram showing an outline of a video camera which is a fourth embodiment of the present invention.

FIG. 19 is a block diagram showing a circuit configuration of a fourth example of the present invention.

FIG. 20 is a flow chart for controlling the operation of the video camera of the fourth embodiment of the present invention.

[Explanation of symbols]

 A lens unit B body unit 1 photographing optical system 1a focusing lens 1b, 1c zoom lens 1d fixed lens 2 holding lens barrel 2a gear part 3 fixing part 4 cam barrel 4a gear part 5 lens frame 6 lens frame 7 focusing motor 7a Gear 8 Zoom motor 8a Gear 9 Physical element 10 Image sensor 11 Optical axis 12 Electronic viewfinder 13 Lens 14 Power switch 15 Zoom operation part 16 Near infrared light cut filter 17 Physical element 18 EC element 19 Liquid crystal 20 Polarizing plate or glass plate 21 Electric Signal Line 22 Glass Plate 31 Photographing Optical System 31a Focusing Lens 31b, 31c Zoom Lens 31d Fixed Lens 32 Holding Lens Barrel 32a Gear Part 33 Fixing Part 34 Focusing Motor 34a Gear 35 Physical Property Element 36 Lens Contact 37 Lens Mount 38 Optical axis 39 Quick return mirror 40 Sub mirror 41 Shutter unit 42 Penta prism 43 Lens 44 Imaging surface (film surface) 45 Camera contact 46 Camera mount 47 AF sensor unit 47a Photoelectric conversion element 48 AE sensor unit 49 Motor

Claims (13)

[Claims] 1. A photographic optical system having a physical element capable of controlling a light transmittance or a light transmission amount, and photoelectric conversion is performed on an image pickup surface of this photographic optical system or a surface optically equivalent to this image pickup surface. A camera having means, wherein the physical property element has a filter function for removing near infrared light. 2. A physical property element capable of controlling a light transmittance or a light transmission amount is provided in a photographing optical system, and photoelectric conversion is performed on an image pickup surface of the image pickup optical system or a surface optically equivalent to this image pickup surface. A camera having means, wherein the physical property element and a filter for removing near infrared light are integrally configured. 3. A video camera having a physical property element capable of controlling light transmittance in a photographing optical system, and having a photoelectric conversion means on an image pickup surface of the photographing optical system. A video camera having means for correcting dependency characteristics. 4. The video camera according to claim 3,
A video camera, comprising: a storage unit for storing the light transmittance wavelength dependent characteristic of the physical property element when the physical property element is in a certain state. 5. The video camera according to claim 4,
The video camera, wherein the storage means is a storage means that stores a plurality of wavelength dependency characteristics of the light transmittance of the physical element when the light transmittance of the physical element has a constant value. 6. The video camera according to claim 4,
A video camera, wherein a temperature detecting means is provided, and the storing means is a storing means for storing a plurality of wavelength dependence characteristics of the light transmittance of the physical property element under a certain constant temperature condition. 7. A video camera having a physical element capable of controlling a light transmittance or a light transmission amount in a photographing optical system, and having a photoelectric conversion means on an image pickup surface of the photographing optical system, wherein the photoelectric conversion means is used. Is not performing a photoelectric conversion operation, the physical property element is set in a light non-transmissive state, a substantially minimum light transmittance state, or a substantially minimum light transmission amount state. 8. The video camera according to claim 7,
A camera, characterized in that, when the power switch of the video camera is turned off, the physical property element is brought into a non-light-transmitting state, a substantially minimum light transmittance state or a substantially minimum light transmission amount state. 9. The video camera according to claim 7, wherein
When the video camera is provided with a recording image reproducing means and the video camera is in the recording image reproducing state or the recording image reproducing mode,
A video camera, characterized in that the physical property element is in a light non-transmissive state, a substantially minimum light transmittance state, or a substantially minimum light transmission amount state. 10. The video camera according to claim 7, wherein a voltage is not applied to the physical property element when the photoelectric conversion means is not performing a photoelectric conversion operation. 11. The video camera according to claim 7, wherein when the photoelectric conversion means stops the photoelectric conversion operation, the physical property element is in a light non-transmissive state, a substantially minimum light transmittance state, or a minimum light transmission amount state. The video camera, characterized in that the voltage application to the physical property element is stopped after the above-mentioned setting. 12. The video camera according to claim 10, wherein the physical property element is in a light non-transmissive state, a substantially minimum light transmittance state, or a minimum light transmission amount state when a voltage is not applied. And a video camera. 13. The video camera according to claim 11, wherein when the voltage application to the physical property element is stopped, the light transmittance or the light transmission amount of the physical property element is in a state when the voltage application to the physical property element is stopped. A video camera characterized by being retained.