JPS5866915A - Method and device for recording and reproducing of picture - Google Patents

Abstract

PURPOSE:To obtain a picture recording and reproducing device which can reproduce colors faithfully without any change in color tones owing to spectral characteristics of an electrooptic element by using the electrooptic element which does not produce any working sound and permits miniaturization for the diaphragm of an image pickup optical system. CONSTITUTION:A lens barrel section 1 is mounted exchangeably in a camera body 11. An image pickup optical system 2, a diaphragm 3 of an electrooptic element such as EC element, and an aperture controlling circuit 4 which selects and controls the aperture diameter of said diaphragm 3 according to control inputs are contained in the section 1. Also an intrinsic information generating means 5 which is programmed and set beforehand with the spectral characteristics of the diaphragm 4 and a correction signal generating circuit 6 which generates the correction signal conforming to the program contents of the means 5 according to the information on the aperture value from the circuit 4 are contained. The light by the system 2 is conducted through the diaphragm 3 to an eyepiece shutter 9 from a finder optical system 8 with a half mirror 7 and is also conducted to a photoelectric converter 10 consisting of an image pickup tube or a solid-state image sensing element such as CCD so that pictures are imaged on the photodetecting plane of the converter 10.

Description

[Detailed Description of the Invention] The present invention relates to an image recording/reproducing method and apparatus, and
When recording and reproducing Mjh images or still images after converting them into electrical signals, an electro-optical element such as an electrochromic element (hereinafter referred to as an element) or a liquid crystal element (hereinafter referred to as a W element) is used in the first optical system. The present invention relates to an improvement for correcting a change in hue of an image due to spectral characteristics of the electro-optical element due to a change in aperture value when used as an aperture value.

Conventionally, the use of an electro-optical element such as the above-mentioned Ni-element or Bo-element as an aperture of an imaging optical system has been disclosed, for example, in Japanese Patent Application Laid-Open No. 55-166616 and Japanese Patent Application Laid-Open No. 56-9718. % Kaisho 56-21114. Japanese Patent Publication No. 56-22417. This method has already been proposed in various publications such as %KOKAI Publication No. 56-78818 and JP-A-56-47021. These electro-optical device diaphragms have many advantages, such as being able to be miniaturized and producing no operating noise. At that time, it exhibits so-called spectral characteristics in which the transmittance varies depending on the wavelength of light. For example, gray elements transmit more (transmit) short wavelength light,
The resulting image will look more bluish than it actually is. A particular problem in this case is that the influence of the spectral characteristics of the light shielding part on the color tone of the image also changes as the area of the light shielding part changes due to changes in the aperture value. These electro-optical devices were not suitable as apertures for image recording devices that use complex salt films such as cine cameras.On the other hand, images from an imaging optical system are converted into electrical signals by photoelectric conversion elements such as image pickup tubes, CCDs, and MO8 type image sensors. Magnetic recording cameras and video cameras that record after converting to A mechanical aperture mechanism is installed in the imaging optical system, which is operated by an automatic exposure device, but in addition to making the camera larger and more complex as a handheld camera, there is also the problem that the operating noise becomes a nuisance. Ta.

This invention converts a moving image or a still image into an electrical signal and then records or records/reproduces it (hereinafter simply referred to as recording/reproducing) using the electro-optical element, which can be configured to be structurally compact and does not generate operating noise. An image recording/reproducing method and apparatus capable of being used as an aperture of an imaging optical system of an apparatus for performing image processing, and at the same time correcting the spectral characteristics of transmitted light through the electro-optical element aperture to obtain faithful color reproducibility in a reproduced image. In other words, in this invention, an electro-optical element such as an electrochromic element or a liquid crystal element is used as an aperture of an imaging optical system, and image information photographed by this imaging optical system is converted into an electrical signal. When recording/reproducing after the image is recorded, a correction signal is obtained according to the aperture value of the electro-optical element diaphragm, and a change in color tone according to the aperture value due to the spectral characteristics of transmitted light of the electro-optic element diaphragm is eliminated. The electric signal of the image information is corrected by the correction signal, and in this case, the correction is performed prior to recording by a correction signal generation circuit that generates the correction signal in the recording device and a correction circuit that performs the correction operation. The conventional reproducing device is used as is. On the other hand, when correction is to be performed on the reproducing device side, the recording device is equipped with the correction signal generating circuit and the image obtained by converting the correction signal into the electrical signal. The reproduction apparatus is provided with a recording circuit that records the information on the recording medium together with the information, and the reproduction apparatus is equipped with a correction circuit that corrects the reproduced image information using a correction signal in the read signal from the recording medium.

For example, in the case of an element, its spectral transmittance characteristic is as shown in curve a in Figure 1 (and the spectral sensitivity of the human eye is as shown in the curve t). However, since its spectral transmittance characteristic has a peak on the shorter wavelength side as shown by curve a in Figure 1, the transmitted light has a bluish tinge.This EC element The aperture due to the ring-shaped EC element B, as illustrated in FIG.
, C, and D patterns are common, and when this aperture is used, the area ratio of the transmitting part (decolored part) and the light blocking part (colored part) changes depending on the aperture value, and therefore the spectral characteristic shown by the curve aK Therefore, the mixing ratio of each color in the light transmitted through the entire aperture changes, resulting in a change in the color tone of the transmitted light depending on the aperture value.

In this invention, the change in color tone is electrically corrected based on the aperture value with respect to the spectral characteristics of the light transmitted through the electro-optical element diaphragm, so the color reproducibility of the finally obtained reproduced image has extremely high fidelity. , a system configuration in which a noiseless electro-optical element diaphragm that can be made smaller and lighter is incorporated into the optical system of a camera can be realized without any problems in a device that converts an image into an electrical signal and then records and reproduces it.

Next, this invention will be explained with reference to the drawings showing an embodiment of the present invention. FIG. 3 is a block diagram showing the configuration of an image recording device according to an embodiment of the present invention.
The lens barrel section (1) K is equipped with an IK that is replaceable, and the lens barrel section (1) K is equipped with an imaging optical system (2) and an electro-optical element diaphragm (3) such as a p-element.
), an aperture control circuit 14) that switches and controls the aperture diameter of the electro-optical element aperture (8) by control input, and an aperture 14).
A unique information generating means 15) whose spectral characteristics are programmed in advance; and a unique information generating means according to the aperture value information from the aperture control circuit (4); generates a correction signal in accordance with the program contents of 6); and a correction signal generation circuit (6). Imaging optical system (2) K is guided from the radar optical system (8) to the eyepiece shutter (9) and is also guided to a photoelectric conversion element aO consisting of a rotating image element such as an image pickup tube or CCD, where photoelectric conversion is performed. An image is formed on the light-receiving surface of the element garden. +13 is an automatic exposure circuit, which is installed inside the camera body (
or inside the lens barrel section (1), which generates an exposure control output based on the brightness of the subject, provides control input to the aperture control circuit (4), and controls the control circuit [1].
The storage time, that is, the shutter time, of the photoelectric conversion element r1a is controlled via the photoelectric conversion element r1a and the drive circuit a-. In this case, the new program exposure method is used, but it makes no difference whether it is aperture priority, shutter priority, or manual exposure. In the case of a television camera, since the shutter time is constant, the control circuit [13] and the drive circuit am can be made into a simple constant-speed drive circuit and separated from the automatic exposure circuit υ. As mentioned above, the correction signal generation circuit (6) performs correction based on the spectral quadrature programmed in advance in response to the aperture value information from the aperture control circuit (4). This correction signal is sent to the correction circuit 09.

The image information formed on the light-receiving surface of the photoelectric conversion element αG is converted into an electric signal by the charging conversion element filK and sent to the image processing circuit OeK, where color correction is performed in response to correction input from the correction circuit αS. Recording circuit Q after being applied
? 1K, and is recorded on a recording medium (2) such as a magnetic disk or bubble memory. The image information recorded on this recording medium (company) becomes image information that has been corrected so as to eliminate the color tone change according to the aperture value due to the spectral characteristics of the transmitted light of the optical system aperture (3). Therefore, when reproducing the image, it is possible to visualize it using a normal reproduction device and achieve faithful color reproduction.

In the example shown in Fig. 6, the lens barrel section (1) is treated as a so-called interchangeable lens, and a unique information generating circuit (5) in which color characteristic information specific to each interchangeable lens is programmed is installed in the lens barrel section. However, in the case of a camera with a fixed lens, a color information generating circuit corresponding to the aperture value may be provided within the camera body.

4 and 5.6 are block diagrams showing another embodiment of the present invention, in which FIG. 4 is a recording device, FIG. 5 is a playback device used in combination with the recording device, and FIG. 6M is a modified example of the playback device. are shown respectively. In FIG. 4, the same reference numerals as in FIG. 3 have the same meanings, so their explanation will be omitted. In the example of FIG. 4, there is no correction circuit 4 in the example of FIG. 6, and the correction signal from the correction signal generation circuit (6) is transferred to the recording circuit a71.
Vc is set to 5K so that it is simultaneously recorded on the recording medium @ along with the image information. In other words, in this example, the camera does not have a means for correcting the image information to be recorded, but the correction signal is recorded on the recording medium together with the image information so that it can be corrected using the correction signal during playback. be.

Therefore, as shown in FIG. 5, a playback device combined with this camera a11 includes a reading circuit (II) that reads image information and a correction signal from a recording medium, and a reading circuit (II) that reads an image signal from the read image information. An image signal generation circuit ■ that generates an image signal and a reproduction line n that reproduces and visualizes the image signal,
Furthermore, a correction circuit (■) for correcting image information in the image signal generation circuit (2) using the correction signal discriminated by the reading circuit o9 is provided in the form of an adapter, or as a built-in correction circuit as shown in Fig. 6. However, in each of the above-mentioned embodiments, still images are recorded.
Although we have explained playback, recording and recording of moving images like on a VTR is also important.
The same applies to reproduction, however, in the case of a VTR, since the television camera has a white balance circuit, this can be used in place of the correction circuit α9 in the example of FIG. 3 to perform correction prior to recording.

As described above, according to this invention, when an image is converted into an electrical signal and then recorded or played back, an electro-optical element that does not generate operating noise and can be miniaturized is used in the aperture of the imaging optical system. Furthermore, it is possible to obtain an image recording/reproducing apparatus that can reproduce faithful colors without any change in color tone due to its spectral characteristics.

[Brief explanation of drawings]

Figure 1 is a diagram showing the spectral transmittance characteristics of an electrochromic element and the spectral sensitivity characteristics of the human eye. Figure 2 is a configuration diagram showing an example of an aperture using an electrochromic element.
FIG. 4 is a block diagram showing the configuration of an image recording device according to one embodiment of the present invention, FIG. 4 is a block diagram showing the configuration of an image recording device according to another embodiment of the invention, and FIG. FIG. 6 is a block diagram showing an example of a reproducing device combined with the previous recording device, and FIG. 6 is a block diagram showing another example of the reproducing device. (1); Lens barrel section, (2): Imaging optical system e 131
'tit, pneumatic optical element aperture, 141: aperture control circuit, [51: unique information generation circuit, [61: correction signal generation circuit, αG: photoelectric conversion element, αD: camera body, @
: automatic exposure circuit, [3: control circuit, aa: drive circuit, αS: correction circuit, Ql: image processing circuit, part: recording circuit, 38: recording medium, 01: reading circuit, cio
: Image signal generation circuit, 211 : Reproduction circuit. 2Z: Correction circuit. Agent Patent Attorney Tomo Sato

Claims (2)

[Claims] (1) An electro-optical element such as an electrochromic element or a liquid crystal element is used as an aperture of an imaging optical system, and when image information photographed by this imaging optical system is converted into an electrical signal and then recorded or reproduced, the electro-optical element The electric signal of the image information is converted into the correction signal so as to obtain a correction signal corresponding to the aperture value of the image information, and to eliminate a change in color tone depending on the aperture value due to the spectral characteristics of transmitted light of the electro-optical element. Image information recording and correction characterized by
How to play. (2) An electro-optical element such as an electrochromic element or a liquid crystal element is used as an aperture of an imaging optical system, and image information photographed by the imaging optical system is converted into an electrical signal by a photoelectric conversion element and then recorded. A correction signal generation circuit that generates a correction signal according to the aperture value of the number of electro-optical elements, and a color tone change according to the aperture value due to the spectral characteristics of the negative light transmitted by the number of the electro-optical elements. An image recording device characterized by comprising a 10M positive circuit that corrects the electric signal output from the photoelectric conversion element using the correction signal before recording the electric signal. In a combination of a recording device and a reproducing device, an electro-optical element is used as an aperture of an imaging optical system, and the image information photographed by the imaging optical system is converted into an electrical signal by a photoelectric conversion element, and then recorded and reproduced. The apparatus includes a correction signal generation circuit that generates a correction signal according to the aperture value of the number of electro-optic elements, and records both the image information converted into an electric signal by the photoelectric conversion element and the correction signal on a recording medium. and a recording circuit, the reproducing device selectively converts image information in the read signal from the recording medium so as to eliminate a change in color tone depending on the aperture value due to the spectral characteristics of transmitted light of the electro-optical elements. An image recording/reproducing device comprising a correction circuit that performs correction using a correction signal in a read signal.