JPH1032832A - Video camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video camera having a material filter. SOLUTION: An optical path is provided with a diaphragm device 3 which adjusts an aperture area and a material filter 4 which adjusts a light transmission state, and a camera control circuit 50 controls the device 3 and the filter 4 and adjusts incident light quantity to an image pickup device 2, based on white balance setting established by a white balance changeover switch 12. Also, this camera has a color signal correction quantity storing circuit and a color signal correcting circuit and performs color correction of an image signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a video camera having an incident light amount adjusting function.

[0002]

2. Description of the Related Art Conventionally, a light amount adjusting device used for an optical system of a video camera or the like mechanically moves a plurality of diaphragm blades each having an ND filter attached to one diaphragm blade to change the diameter of the diaphragm. The light amount of the light beam incident on the imaging surface is adjusted. Alternatively, a device for directly inserting the ND filter into the optical path without attaching the ND filter to the diaphragm blade is provided separately from the diaphragm device to adjust the light amount of the light beam incident on the imaging surface. With these methods, the adjustment range of the light amount of the light beam incident on the imaging surface is widened, and the aperture diameter becomes too small to prevent the image quality from deteriorating due to the diffraction phenomenon.

However, the conventional example has the following disadvantages.

[0004] In the former conventional example, the diaphragm blade is N
Since the D filter is attached, ghost is easily generated by the ND filter, and at the same time, the captured image is deteriorated by the diffracted light generated when the distance between the ND filter and other aperture blades is reduced in the intermediate aperture area. Has the significant disadvantage of doing so.

In the latter conventional example, since it is necessary to provide an ND filter insertion device in the optical path in addition to the stop device, the entire device for adjusting the light amount of the light beam incident on the image pickup surface becomes large and complicated. When the ND filter is inserted into the optical path and when the ND filter is removed, the incident light on the imaging surface is blocked, so that there is a disadvantage that a continuous image cannot be obtained in the movie camera.

[0006]

Therefore, a physical filter such as a liquid crystal element capable of adjusting the light transmittance is conventionally provided in the optical path, the light transmittance of the physical filter is adjusted, and the light amount of the light beam incident on the imaging surface is conventionally adjusted. There have been many proposals to adjust the.

However, in the conventional transmitted light amount adjusting device for a video camera, the light amount can be adjusted in a light amount ratio (maximum transmitted light amount / minimum transmitted light amount) of about 1,000 to 4,000. Nothing can provide a large light amount ratio up to that.

[0008] Also, most existing physical property filters are:
There is a large swell in the spectral transmission characteristics. That is, there is a serious disadvantage that transmitted light is colored even when white light is incident on the physical property filter, and the above proposal has not been put to practical use yet.

According to the present invention, there is provided a physical filter capable of adjusting the light transmittance in the optical path of the optical system and a diaphragm device capable of mechanically moving the diaphragm blades to adjust the aperture diameter thereof. It is an object of the present invention to provide a video camera having a small incident light amount adjusting device that can obtain a wide light amount adjusting range, is not affected by the spectral transmission characteristics of a physical filter, and can sufficiently obtain an aperture effect. I do.

[0010]

Therefore, a video camera according to the present invention achieves the above object by the following constitution.

(1) An imaging optical system having, in the optical path, a diaphragm means for mechanically adjusting the opening area of the optical path, a physical filter for adjusting the light transmission state, and an imaging means on an imaging surface of the imaging optical system. A video camera having a white balance adjusting unit having at least a mode in which the amount of light incident on the imaging unit is adjusted by the diaphragm unit and the physical property filter and having at least a manually operable mode; and a light transmission state detecting unit of the physical property filter In, the physical property filter is used in a plurality of predetermined light transmission states, at least when the white balance adjustment means is in a manually operable mode, a predetermined color signal is obtained by the output of the light transmission state detection means,
A video camera comprising a correction unit for correcting an output signal of the imaging unit.

(2) The video camera according to (1), further comprising storage means for storing an output signal correction amount of the imaging means based on an output of the light transmission state detecting means.

(3) The video camera described in (1) or (2) above is a video camera having an interchangeable photographic optical system composed of an interchangeable lens unit and a camera body unit. The physical property filter, the light transmission state detection means, and at least when the white balance adjusting means is in a manually operable mode, the light transmission state of the physical property filter or the correction amount of the output signal of the imaging means is communicated to a camera body unit. A video camera comprising communication means.

(4) The video camera according to any one of (1) to (3), wherein:
At least when the white balance adjustment unit is in the manual operation mode, the output signal of the imaging unit is corrected so that a predetermined color signal is obtained by the output of the light transmission state detection unit and the output of the environmental temperature detection unit. A video camera, comprising: a correction unit that performs correction.

(5) The video camera according to any one of (2) to (4), further comprising storage means for storing the output signal correction amount of the image pickup means in which the output signal correction amount for each light wavelength is stored. A video camera characterized by the following.

[0016]

For this reason, according to the present invention, there is provided a photographing optical system having, in an optical path, a diaphragm means for mechanically adjusting an opening area, and a physical filter for adjusting a light transmission state, and an image pickup system for the photographing optical system. White balance adjusting means having an image pickup means on a surface thereof, adjusting the amount of light incident on the image pickup means by the stop means and the physical property filter, and having at least a manually operable mode; and a light transmission state detecting means of the physical property filter Wherein the physical property filter is used in a plurality of predetermined light transmission states, and when at least the white balance adjusting means is in a manually operable mode, a predetermined color signal is output by the light transmission state detection means. This is an embodiment in which the above-mentioned object is achieved by providing a correction means for correcting the output signal of the imaging means so as to obtain the following.

The above embodiment will be described in detail with reference to examples.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A plurality of embodiments of a video camera according to the present invention will be described below with reference to the drawings.

(First Embodiment) A first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a schematic block diagram of a main part of a video camera according to a first embodiment of the present invention, FIG. 2 is a block diagram of a main part showing a circuit configuration of the video camera shown in FIG. 1, and FIG. FIG. 4 is a flowchart for controlling the operation of the physical filter, FIG. 5 is an explanatory diagram of the spectral transmission characteristics of the physical filter, and FIG. 6 is a flowchart for controlling the correction operation of the output image.

In FIG. 1, reference numeral 1 denotes a photographing optical system, and reference numeral 2 denotes an image sensor, which comprises, for example, a CCD. Reference numeral 3 denotes a diaphragm device for mechanically adjusting the aperture diameter.

Reference numeral 4 denotes a physical filter, which is a liquid crystal element or an electrochromic (EC) element (for example, a thin film of a transition metal oxide (IrOx, Ta ₂ O ₅ , W
O _3, etc.) as was formed) is made from such. By applying a voltage as is known,
It has the function of controlling the light transmittance of the filter. A sensor 5 detects the light transmittance of the physical property filter 4.

Reference numeral 6 denotes an electronic viewfinder, and reference numeral 7 denotes an eyepiece for enlarging and observing an image displayed on the electronic viewfinder 6. Reference numeral 8 denotes a switch for switching the light transmittance of the physical property filter 4. In this embodiment, four switches are provided. 9 is a power switch of the video camera, 10 is the optical axis of the photographing optical system 1, 11 is the maximum effective light flux of the photographing optical system 1, 12 is a white balance switch for auto white balance and manual white balance, and 13 is a manual white balance switch. Adjustment knob.

The video camera shown in FIG. 1 has a recording unit 51 and a power supply 52 which are electrically connected to the camera control circuit 50.

The image sensor 2, aperture device 3, physical filter 4, sensor 5, electronic viewfinder 6, switch 8, power switch 9, white balance switch 12, and adjustment knob 13 are electrically connected to the camera control circuit 50, respectively. Connected. Next, the operation of the video camera according to the present embodiment will be described.

First, when the power switch 9 of the video camera is operated and the power is turned on, the aperture diameter of the aperture device 3 is adjusted so that the amount of light incident on the image sensor 2 becomes appropriate.
Further, the position of the switch 8 is detected, and the light transmittance of the physical property filter 4 is adjusted so that the light transmittance becomes a state corresponding to the position.

Here, in the video camera according to the present embodiment, the light transmittance of the physical property filter 4 can be selected from the four by the switch 8. FIG. 5 shows the spectral characteristics of each light transmittance (state I to state IV) of the physical property filter 4.

State I shown in FIG. 5 is a state where the light transmittance of the physical property filter 4 is maximum. State II is in the visible light region (wavelength 4
(100-700 nm) in which the average light transmittance is 状態 of the average light transmittance in state I. State III has an average light transmittance of state I
1/4 of the state. In state IV, the average light transmittance is 1 /
8. In this embodiment, the light transmittance of the physical property filter 4 is detected by the sensor 5 including a photo interrupter or the like, and the physical filter 4 is controlled to have a predetermined light transmittance.

Further, as shown in FIG. 5, the spectral transmission characteristic of the physical property filter 4 is not flat in the visible light region,
Each state of the light transmittance of the physical property filter 4 (states I to IV)
, R region (wavelength 600-700 nm), G region (wavelength 500-600 nm), B region (wavelength 400-5)
(00 nm) (light balance).

However, when the white balance of the camera is in the auto mode, the white balance of the video signal is automatically obtained, so that even if the light transmission state of the physical filter 4 changes, the output video is hardly affected. However,
When the white balance is in the manual mode, the color balance changes when the light transmittance of the physical property filter 4 changes, so that the color (color balance) of the output image changes.

Therefore, in the present embodiment, when the white balance is in the manual mode, the current physical property filter 4
The light transmission state (states I to IV) is detected by the switch 8 or the sensor 5 and color correction (color balance correction) of the video signal is performed according to the state. This color correction amount is stored in the color signal correction amount storage circuit for each state (I to IV), and the color correction of the video signal is performed by the color signal correction circuit. This control flow is shown in the flowchart of FIG.

The image which has been color-balanced by the above method is displayed on the electronic viewfinder 6 via the camera control circuit and is observed by the photographer through the eyepiece 7. This state is called a standby state.

When the photographer presses a photographing button (not shown), the photographing switch is turned on. When the camera control circuit 50 confirms that the photographing switch is turned on, the photographing operation is started. The output video is transferred to the recording unit 51 by the camera control circuit 50, and is recorded on a recording medium by the recording unit control circuit. When the photographer releases the photographing button (not shown), the photographing switch is turned off, and when the camera control circuit 50 confirms that the photographing switch is turned off, the photographing operation is stopped and the camera returns to the standby state again. Video recording is sequentially performed by repeating the above-described shooting operation procedure.

In the present embodiment, the physical property filter 4 is provided in the vicinity of the diaphragm device 3, but may be located at any position in the optical path of the photographing optical system 1, and the light transmittance of the physical property filter 4 is 4 It can be fixed to one of the states (I to IV), but this state may be any number. Further, the color correction of each state of the physical property filter 4 may be performed not only at the time of manual white balance but also at the time of auto white balance so that an output image of a more accurate color balance may be obtained. May be switched not only manually but also automatically according to the brightness of the subject.

The sensor 5 of the present embodiment directly detects the light transmittance of the physical property filter 4 by a photo interrupter or the like and controls the physical property filter 4 to be in each state. When a physical filter whose light transmittance is determined is used, an applied voltage detecting circuit of the physical filter 4 is provided instead of the sensor 5 as in the present embodiment, and the light transmitting state of the physical filter 4 is changed. It may be used as a detecting means, and the sensor 5 does not need to directly detect the light transmittance of the physical property filter 4.

Since the physical property filter 4 has a large maximum light transmittance and no polarization component, an electrochromic (EC) element is suitable.

In the present embodiment, the color signal correction amount stored in the color signal correction amount storage circuit
For each of the states I to IV, the R region, G region, B
The video signal correction amount of the region is stored, but this may further subdivide the light wavelength, for example, store the video signal correction amount for each light wavelength of 10 nm, and perform finer color correction of the video signal, In addition, the Cy region of the light wavelength (light wavelength 40
0-600 nm), Mg region (light wavelength 400-500n)
m and 600 to 700 nm), Ye region (500 to 700 nm)
nm) may be stored, and color correction of the video signal may be performed.

As described above, the Cy region, the Mg region,
By storing the video signal correction amount in the Ye region and correcting the video signal, it is possible to obtain an effect that color correction can be easily performed in a video camera using an imaging device having a complementary color filter.

As described above, the stored video signal correction amount may be in any form as long as color correction of the video signal can be performed.
By storing the video signal correction amounts of the R, G, and B regions and correcting the video signals, it becomes easier to perform color correction in a video camera using an imaging device having a pure color filter or a video camera having a color separation prism. The effect is obtained.

(Second Embodiment) FIG. 7 shows a second embodiment of the present invention.
This will be described with reference to FIGS.

FIG. 7 is a schematic block diagram of a main part of a video camera according to a second embodiment of the present invention, FIG. 8 is a block diagram of a main part showing a circuit configuration of the video camera shown in FIG. 7, and FIG. FIG. 4 is an explanatory diagram showing a correction amount map of a video signal stored in a color signal correction amount storage circuit of a video camera.

In the reference numerals shown in FIG. 7, the same blocks as those in the first embodiment shown in FIG. 1 are indicated by the same reference numerals. Reference numeral 14 denotes a temperature sensor for detecting the temperature in the vicinity of the physical property filter 4. The video camera of the second embodiment shown in FIG.
1 differs from the video camera of the first embodiment shown in FIG.

FIG. 8 differs from the first embodiment shown in FIG. 2 in that a temperature detecting circuit 53 is provided and the circuit is electrically connected to a color signal correction circuit. Also, a flowchart for controlling the aperture operation, a flowchart for controlling the operation of the physical property filter, and an explanatory diagram of the spectral transmission characteristic of the physical property filter are the same as those in FIGS.

Next, the operation of the video camera according to the second embodiment will be described.

The operation of the video camera according to the present embodiment differs from the operation of the video camera according to the first embodiment in the portion of the video signal correction operation. Therefore, in the description of the present embodiment, only the video signal correction operation will be described, and description of other operations will be omitted.

The spectral transmission physical properties of the physical filter 4 of the video camera shown in FIG. 7 in the normal temperature region are as shown in FIG. 5, but even if the average light transmittance of the physical filter 4 in the normal temperature region is the same. The spectral transmission properties in the low temperature region (i) and the high temperature region (iii) are different from those in the normal temperature region (ii). That is, at the time of manual white balance, not only when the light transmission state of the physical property filter 4 is different, but also when the video camera of this embodiment has a different operating temperature environment of the video camera, that is, when the temperature of the physical property filter 4 is different. Is changed. Here, in order to detect the temperature of the physical property filter 4 more accurately, the temperature sensor 14 is used.
Are disposed near the physical property filter 4. Then, as shown in FIG. 9, the color signal correction amount is a color signal for each light wavelength (R, G, B) in each light transmission state (I-III) and each temperature state (i-iii) of the physical property filter 4. Each is stored in the correction amount storage circuit. Then, the sensor 5 and the temperature sensor 14 detect the light transmission state and the temperature region of the physical property filter 4, and store the correction amount of each light wavelength (R, G, B) corresponding to the detected state in the color signal correction amount shown in FIG. It is read from the circuit and the video signal is corrected.

For example, if the light transmission state is state III and the temperature region is i, the correction amount of the video signal is the light wavelength R region,
C _Ri , C _Gi , and C _Bi for the G region and the B region, respectively. Further, in the present embodiment, the physical property filter 4 is provided near the stop device 3 as in the first embodiment, but it may be located at any position in the optical path of the photographing optical system 1. The light transmittance of No. 4 can be fixed to four states (I to IV), but this state may be any number. In addition, color correction of each state of the physical property filter 4 may be performed not only at the time of manual white balance but also at the time of automatic white balance so that an output image of a more accurate color balance may be obtained. May be switched not only manually but also automatically according to the luminance of the subject.

The sensor 5 according to the present embodiment directly detects the light transmittance of the physical property filter 4 by a photo interrupter or the like and controls the physical property filter 4 to be in each state. When a physical filter whose light transmittance is determined is used, an applied voltage detecting circuit of the physical filter 4 is provided instead of the sensor 5 as in the present embodiment, and this is used to detect the light transmission state of the physical filter 4. The sensor 5 may not be used for directly detecting the light transmittance of the physical property filter 4.

Since the physical property filter 4 has a large maximum light transmittance and no polarization component, an electrochromic (EC) element is suitable.

In the present embodiment, the color signal correction amount stored in the color signal correction amount storage circuit is based on the video signal in the R, G, and B regions of the light wavelength for each of the states I to IV of the physical property filter 4. Although the correction amount is stored, the light wavelength may be further subdivided, for example, a video signal correction amount for each light wavelength of 10 nm may be stored, and finer color correction of the video signal may be performed. Cy region (light wavelength 400 ~
600 nm), Mg region (light wavelengths of 400 to 500 nm and 600 to 700 nm), Ye region (light wavelengths of 500 to 70 nm)
0 nm) may be stored to correct the video signal.

With this configuration, the Cy region, the Mg region,
By storing the video signal correction amount in the Ye region and correcting the video signal, an effect is obtained in that a video camera using an image sensor having a complementary color filter can easily perform color correction.

The video signal correction amount stored as described above may be in any form as long as color correction of the video signal can be performed. The video signal correction amounts for the R, G, and B regions are stored, and the video signal is corrected, so that color correction can be easily performed in a video camera using an imaging device having a pure color filter or a video camera having a color separation prism. Is obtained.

Further, in this embodiment, the temperature range is from i to
Although it is divided into iii, it goes without saying that this can be divided into any number.

(Third Embodiment) FIG. 1 shows a third embodiment of the present invention.
This will be described with reference to FIGS.

FIG. 10 is a schematic block diagram of an essential part of an interchangeable lens type video camera according to a third embodiment of the present invention.
FIG. 1 is a main block diagram showing a circuit configuration of the video camera shown in FIG.

A flowchart for controlling the operation of the diaphragm device, a flowchart for controlling the operation of the physical filter, an explanatory diagram of the spectral transmission characteristics of the physical filter, and an output image correcting operation are the same as those in the first embodiment, and therefore description thereof will be omitted.

A shown in FIG. 10 is a camera body unit,
B is a lens unit. Reference numeral 21 denotes a photographing optical system, and reference numeral 22 denotes an image pickup device, which comprises, for example, a CCD or the like. 23
Is a diaphragm device capable of mechanically adjusting the aperture diameter.

Reference numeral 24 denotes a physical property filter, which is a liquid crystal element or an electrochromic (EC) element (for example, a thin film of a transition metal oxide (IrOx, Ta ₂ O ₅ ,
WO ₃ ). The property filter 24 has an effect of controlling the light transmittance of the filter by applying a voltage as is known. A sensor 25 detects the light transmittance of the physical property filter 24. 26 is an electronic viewfinder,
Reference numeral 27 denotes an eyepiece for enlarging and observing an image displayed on the electronic viewfinder 26.

Reference numeral 28 denotes a switch for switching the light transmittance of the physical property filter 24. In this embodiment, four switches are provided. 29 is a power switch of the video camera, 30 is the optical axis of the photographing optical system 21, 31 is the maximum effective light flux of the photographing optical system 21, 32 is a switch for switching between automatic white balance and manual white balance, and 33 is a manual white balance adjustment knob. is there.

Reference numeral 34 denotes a camera mount, and 35 denotes a lens mount. The camera mount 34 and the lens mount 35
The camera body unit A and the lens unit B are mechanically connected. Reference numeral 36 denotes an electric contact pin, which is provided near the camera mount 34 of the camera body unit A. An electrical contact 37 is provided near the lens mount 35 of the lens unit B. Further, when the camera body unit A and the lens unit B are mechanically connected by the camera mount 34 and the lens mount 35, the electric contact pins 36 and the electric contacts 37 are in contact.

The camera body unit A shown in FIG.
Has a recording section 51 and a power supply 52 electrically connected to the camera control circuit 50, and the lens unit B has a lens control circuit 53.

The image sensor 22, the electronic viewfinder 26, the switch 28, the power switch 29, the white balance changeover switch 32, and the adjustment knob 33 are electrically connected to the camera control circuit 50, respectively. Further, the diaphragm device 23, the physical property filter 24, and the sensor 25 are electrically connected to the lens control circuit 53, respectively.
Further, the camera control circuit 50 and the lens control circuit 53 are electrically connected via the electric contact pin 36 and the electric contact 37. Signal transmission (communication) between the camera body unit A and the lens unit B is performed via the camera control circuit 50 and the lens control circuit 53.

Next, the operation of the video camera of this embodiment will be described.

When the camera body unit A and the lens unit B are connected and the power switch 29 of the video camera is operated and the power is turned on, the diaphragm device 23 is controlled so that the amount of light incident on the image sensor 22 becomes appropriate. Adjust the aperture diameter. Further, the position of the switch 28 is detected, and the light transmittance of the physical property filter 24 is adjusted so that the light transmittance becomes a state corresponding to the position. At this time, the control information of the aperture device 23 and the control information of the physical property filter 24 are transmitted from the exposure control circuit and the camera control circuit shown in FIG. 11 to the aperture control circuit and the physical property filter control circuit via the lens control circuit, respectively (communication). ) Is done.

Here, in the video camera of the present embodiment, the light transmittance of the physical property filter 24 can be selected from four by the switch 28. In addition, the physical property filter 24
FIG. 5 shows the spectral characteristics of the respective light transmittances (state I to state IV).

The state I shown in FIG.
In the state II, the average light transmittance in the visible light region (wavelength: 400 to 700 nm) is half the average light transmittance in the state I, and in the state III, the average light transmittance is half. A state の of the state I and a state IV are states in which the average light transmittance is ８ of that of the state I. In this embodiment, the light transmittance of the physical property filter 24 is detected by a sensor 25 including a photo interrupter or the like.
Is controlled to have a predetermined light transmittance.

Further, as shown in FIG. 5, the spectral transmission characteristics of the physical property filter 24 are not flat in the visible light region, and each state of the light transmittance of the physical property filter 24 (state I
To state IV) in the R region (wavelength 600 to 700 n)
m), G region (wavelength 500 to 600 nm), and B region (wavelength 400 to 500 nm) have different light transmittance ratios (color balance).

However, the camera automatically adjusts the white balance of the image signal when the white balance is in the auto mode, so that even if the light transmission state of the physical filter 24 changes, the output image is hardly affected. However,
When the white balance is in the manual mode, if the light transmittance of the physical filter 24 changes, the color balance changes, so that the color (color balance) of the output image changes.

Therefore, in this embodiment, when the white balance is in the manual mode, the sensor 25 and the switch 28
Further, the current light transmission state (states I to IV) of the physical property filter 24 is detected, and color correction (color balance correction) of the video signal is performed according to the state. This color correction amount is stored in the color signal correction amount storage circuit for each state (I to IV), and the color correction of the video signal is performed by the color signal correction circuit. This control flow is the same as in the first embodiment shown in the flowchart of FIG. Here, the control information of the color correction amount is also transmitted (communicated) from the color signal correction amount storage circuit to the color signal correction circuit via the lens control circuit and the camera control circuit.

In the above manner, the color-balanced video is then displayed on the electronic viewfinder 26 via the camera control circuit 50 and observed by the photographer through the eyepiece 27. This state is referred to as a standby state.

Here, when the photographer presses a photographing button (not shown), the photographing switch is turned on. When the camera control circuit confirms that the photographing switch is turned on, the photographing operation is started. The output video is transferred to the recording unit by the camera control circuit, and is recorded on the recording medium by the recording unit control circuit. Then, the photographer presses a shooting button (not shown).
When the button is released, the photographing switch is turned off. When the camera control circuit 50 confirms that the photographing switch is turned off, the photographing operation is stopped, and the camera returns to the standby state again. Video recording is sequentially performed by repeating the above-described shooting operation procedure.

In this embodiment, the physical property filter 24 is provided in the vicinity of the diaphragm device 23, but may be located at any position in the optical path of the photographing optical system 21 in the lens unit B. It may be provided inside. Further, a physical property filter control circuit, a light transmittance detection circuit, and a color signal correction amount storage circuit may be provided in the camera body unit A. Further, a switch 28 for switching the light transmittance of the physical property filter 24 may be provided in the lens unit B.

Although the light transmittance of the physical property filter 24 can be fixed to four states (I to IV), any number of states may be used. The color correction of each state of the physical property filter 24 may be performed not only at the time of manual white balance but also at the time of automatic white balance so that an output image of a more accurate color balance may be obtained. May be switched not only manually but also automatically according to the brightness of the subject.

The sensor 25 of this embodiment directly detects the light transmittance of the physical property filter 24 with a photo interrupter or the like and controls the physical property filter 24 to be in each state. When a physical filter whose light transmittance is determined is used, an applied voltage detecting circuit for the physical filter 24 is provided instead of the sensor 25 as in the present embodiment, and this is used to detect the light transmission state of the physical filter 24. The sensor 25 may not be a device that directly detects the light transmittance of the physical property filter 24.

Since the physical property filter 24 has a large maximum light transmittance and no polarization component, an electrochromic (EC) element is suitable.

In the present embodiment, the color signal correction amount stored in the color signal correction amount storage circuit corresponds to the R, G, and B regions of the light wavelength for each of the states I to IV of the physical property filter 24. Although the video signal correction amount is stored, the light wavelength may be further subdivided, for example, the video signal correction amount for each light wavelength of 10 nm may be stored, and finer color correction of the video signal may be performed. Cy wavelength region (light wavelength 400 to 600 nm), Mg region (light wavelength 400 to 5 nm)
00 nm and 600 to 700 nm), Ye region (light wavelength 5
(00 to 700 nm), and the color correction of the video signal may be performed.

By storing the video signal correction amounts of the above-described Cy area, Mg area, and Ye area and correcting the video signal, it becomes easier to perform color correction in a video camera using an imaging device having a complementary color filter. The effect is obtained.

The video signal correction amount thus stored is
Any form may be used as long as the color correction of the video signal can be performed.
Color correction is performed in a video camera using an imaging device having a pure color filter or a video camera having a color separation prism by storing the video signal correction amounts of the R, G, and B regions and correcting the video signal. The effect of becoming easy is obtained.

In the case of using a physical filter whose spectral transmission characteristic changes depending on the environmental temperature in this embodiment,
A temperature sensor for detecting the temperature in the vicinity of the physical filter 24 is provided as in the embodiment, and the color signal correction amount storage circuit stores the light transmission state of the physical filter and the color signal correction amount for each environmental temperature as shown in FIG. The image signal may be stored, and the video signal may be corrected based on the light transmission state and the operating temperature of the physical filter.

The light transmission state of the physical filter such as the light transmittance (spectral transmission characteristic) for each light wavelength region of the physical filter 24 is transferred from the lens unit B to the camera body unit A instead of the output image correction amount of the image sensor. Transmission (communication)
The video signal may be corrected by the color signal correction circuit based on the information.

[0081]

As described above, according to the present invention,
A diaphragm device, and a physical filter capable of adjusting light transmittance,
In a video camera that adjusts the amount of light incident on an image sensor by using the diaphragm device and the physical property filter, the physical property filter is used in a plurality of predetermined light transmission states, and a predetermined color signal is used regardless of the light transmission state of the physical property filter. Since the output signal of the image sensor is corrected so as to obtain the following, the image is less affected by the spectral transmission characteristics of the physical property filter, and an image with good color reproducibility can be obtained. That is, there is an effect that a video camera having a small and high-performance incident light amount adjusting device can be obtained.

Further, unlike the conventional art, there is no need to attach an ND filter to the diaphragm blades constituting the diaphragm device, and there is no need to insert and remove the ND filter in the optical path of the photographing optical system. There is an effect that a video camera capable of obtaining a high-quality aperture effect can be provided.

Further, according to the present invention, since the storage circuit for the output image correction amount of the image pickup device is provided, it is not necessary to calculate the correction amount when correcting the output image, and the output image can be easily corrected. There is an effect that can be.

Further, according to the present invention, in an interchangeable lens type video camera, the output image correction amount of the image pickup device or the light transmission state of the property filter according to the property filter in the interchangeable lens is communicated from the interchangeable lens to the camera body. Therefore, the present invention has an effect that it can be applied to an interchangeable lens type video camera.

Further, according to the present invention, when the spectral transmission characteristic of the physical filter used changes according to the use environment temperature, the color correction of the output image of the image pickup device is performed by the light transmission state of the physical filter and the environment temperature. Since this is performed, there is an effect that a video camera which is hardly affected by the light transmission state of the physical property filter and the environmental temperature and can obtain a shot image with good color reproducibility can be provided.

Further, according to the present invention, since the output image correction amount of the image sensor for each light wavelength region is stored,
There is an effect that stored information can be reduced and color correction of an output image can be easily performed.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a main part of a video camera according to a first embodiment.

FIG. 2 is a main block diagram showing a circuit configuration of the video camera of the first embodiment.

FIG. 3 is a flowchart for controlling the operation of the aperture device of the first embodiment.

FIG. 4 is a flowchart for controlling the operation of the physical property filter according to the first embodiment.

FIG. 5 is an explanatory diagram of a spectral transmission characteristic of a physical property filter.

FIG. 6 is a flowchart for controlling an output video correction operation of the first embodiment.

FIG. 7 is a schematic block diagram of a main part of a video camera of a second embodiment.

FIG. 8 is a main block diagram illustrating a circuit configuration of a video camera according to a second embodiment.

FIG. 9 is an explanatory diagram showing a correction amount map of a video signal stored in a color signal correction amount storage circuit of the video camera of the second embodiment.

FIG. 10 is a schematic block diagram of a main part of an interchangeable lens type video camera according to a third embodiment.

FIG. 11 is a main block diagram illustrating a circuit configuration of a video camera according to a third embodiment.

[Explanation of symbols]

 1, 21 shooting optical system 2, 22 image sensor 3, 23 aperture device 4, 24 physical filter 5, 25 sensor 6, 26 electronic viewfinder 7, 27 eyepiece 8, 28 switch 9, 29 power switch 10, 30 optical axis 11, 31 Maximum effective light flux 12, 32 White balance changeover switch 13, 33 Adjustment knob 14 Temperature sensor 34 Camera mount 35 Lens mount 36 Electric contact pin 37 Electric contact 50 Camera control circuit 51 Recording unit 52 Power supply 53 Lens control circuit A Camera body Unit B Lens unit

Claims (5)

[Claims] 1. An imaging optical system having, in an optical path, a diaphragm means for mechanically adjusting an opening area of an optical path, a physical filter for adjusting a light transmission state, and an imaging means on an imaging surface of the imaging optical system. In the video camera, the amount of light incident on the imaging unit is adjusted by the diaphragm unit and the physical property filter, and at least a white balance adjusting unit having a manually operable mode and a light transmission state detecting unit of the physical property filter are provided. The physical property filter is used in a plurality of predetermined light transmission states, and at least when the white balance adjustment unit is in a manually operable mode, a predetermined color signal is obtained by an output of the light transmission state detection unit. A video camera comprising a correction unit for correcting an output signal (video signal) of an imaging unit. 2. The video camera according to claim 1, wherein
A video camera comprising a storage unit for storing an output signal correction amount (video signal correction amount) of the imaging unit based on an output of the light transmission state detection unit. 3. A video camera according to claim 1 or 2, wherein said video camera comprises an interchangeable lens unit and a camera body unit, and has an interchangeable photographic optical system. Communication means for communicating to the camera body unit the light transmission state of the physical property filter or the correction amount of the output signal of the imaging means when at least the white balance adjustment means is in a manually operable mode; A video camera comprising: 4. The video camera according to claim 1, wherein said light transmission state detecting means is provided when said ambient temperature detecting means and at least said white balance adjusting means are in a manual operable mode. A video camera, comprising: a correction unit that corrects an output signal of the imaging unit so that a predetermined color signal is obtained based on an output and an output of the environmental temperature detection unit. 5. The video camera according to claim 2, further comprising storage means for storing an output signal correction amount of the image pickup means in which an output signal correction amount for each light wavelength is stored. And a video camera.