JPS6356528B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image recording/reproducing method and apparatus, and in particular, when converting moving images or still images into electrical signals and then recording/reproducing them, an electrochromic element (hereinafter referred to as (called EC element)
The present invention relates to an improvement for correcting a change in the hue of an image due to the spectral characteristics of the electro-optical element that accompanies a change in the aperture value when an electro-optical element such as a liquid crystal element (hereinafter referred to as an LC element) is used as an aperture.

Conventionally, the use of electro-optical elements such as the above-mentioned EC elements and LC elements as an aperture of an imaging optical system has been disclosed, for example, in Japanese Patent Application Laid-Open Nos. 166616-1982 and 1983-
This method has already been proposed in various publications such as JP-A No. 9718, JP-A No. 56-21114, JP-A No. 56-22417, JP-A No. 56-78818, and JP-A No. 56-47021. These electro-optical device apertures have various advantages, such as being able to be miniaturized and not producing operating noise. At that time, it exhibits so-called spectral characteristics in which the transmittance varies depending on the wavelength of light. For example, an EC element transmits more short-wavelength light, making the resulting image look more bluish than it actually is.
In this case, a particular problem is that as the area of the light-shielding area changes due to changes in the aperture value, the influence of the spectral characteristics of the light-shielding part on the tone of the image also changes. These electro-optical elements are not suitable as apertures for image recording devices that use silver halide films, such as cameras and cine cameras. On the other hand, in magnetic recording cameras and video cameras, which convert images from an imaging optical system into electrical signals using a photoelectric conversion element in an image pickup tube, CCD, or MOS image sensor, and then record the images, it is necessary to control the amount of light and control the field of view. In order to obtain artistic effects by changing depth, blur, etc., or to increase the depth of field as much as possible,
A mechanical diaphragm mechanism is installed in the imaging optical system and operated by these automatic exposure devices, but in addition to making it larger and more complex as a handheld camera, there is also the problem that the operating noise becomes a nuisance. .

This invention records or records/reproduces (hereinafter simply referred to as "record/reproduce") the electro-optical element, which can be structurally compact and does not generate operating noise, after converting a moving or still image into an electrical signal. 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. is intended to provide.

That is, 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 and then recorded and reproduced. At this time, a correction signal corresponding to the aperture value of the electro-optical element diaphragm is obtained, and an electric signal of the image information is obtained so as to eliminate a color tone change according to the aperture value due to the spectral characteristics of transmitted light of the electro-optic element diaphragm. is corrected by the correction signal, and in this case, when correction is performed prior to recording, the recording apparatus is equipped with a correction signal generation circuit that generates the correction signal and a correction circuit that performs the correction operation. , the existing reproduction device is used as is, and on the other hand, when correction is performed on the reproduction device side, the recording device is equipped with the correction signal generation circuit and the correction signal, along with the image information converted into the electric signal, on the recording medium. The reproduction apparatus is provided with a correction circuit for correcting reproduced image information using a correction signal in a read signal from the recording medium. For example, in the case of an EC element, its spectral transmittance characteristic is as shown by curve a in FIG. 1, and the spectral sensitivity of the human eye is as shown by curve b. Even when colored, the EC element does not act as a complete light shield and allows a few percent of light to pass through, but its spectral transmittance characteristics have a peak on the shorter wavelength side, as shown by curve a in Figure 1. Therefore, the permeation hole becomes bluish. this
Apertures using EC elements generally have a ring-like pattern of EC elements A, B, C, and D, as shown in Fig. The area ratio of the colored area) and the light shielding area (colored area) changes, and as a result, due to the spectral characteristics shown in curve a, the mixing ratio of each color in the light transmitted through the entire aperture changes, and this changes depending on the aperture value. This results in a change in the color tone of the transmitted light.

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 images into electrical signals and then records and reproduces them.

Next, this invention will be explained with reference to the drawings of the embodiments.
FIG. 3 is a block diagram showing the configuration of an image recording apparatus according to an embodiment of the present invention. Reference numeral 1 denotes a lens barrel section, which is replaceably attached to the camera body 11. An imaging optical system 2, an electro-optical element aperture 3 such as an EC element, and the electro-optical element aperture 3
an aperture control circuit 4 that switches and controls the aperture diameter of the aperture according to control input; a unique information generating means 5 in which the spectral characteristics of the aperture 4 are programmed in advance; and a unique information generator 5 that generates unique information according to aperture value information from the aperture control circuit 4. Generating means 5
and a correction signal generation circuit 6 that generates a correction signal in accordance with the program contents. Imaging optical system 2
The light is guided through the aperture 3 by the half mirror 7 from the finder optical system 8 to the eyepiece shutter 9, and is also guided to the photoelectric conversion element 10 consisting of a rotating imaging device such as an image pickup tube or CCD. An image is formed on the light-receiving surface of the 12
is an automatic exposure circuit, which is provided inside the camera body 11 (or inside the lens barrel section 1), generates an exposure control output based on the brightness of the subject, and provides control input to the aperture control circuit 4, as well as The storage time, that is, the shutter time, of the photoelectric conversion element 10 is controlled via the control circuit 13 and the drive circuit 14. In this case, the so-called 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 14 can be made simple with constant speed drive output and can be separated from the automatic exposure circuit 12. As mentioned above, the correction signal generation circuit 6 generates a correction signal based on the spectral characteristics programmed in advance in the unique information generation means 5 in response to the aperture value information from the aperture control circuit 4, and this correction signal is used for correction. The signal is sent to circuit 15. The image information formed on the light-receiving surface of the photoelectric conversion element 10 is converted into an electrical signal by the photoelectric conversion element 10 and sent to the image processing circuit 16, where it receives correction input from the correction circuit 15 and changes the color. After the correction is applied, the recording circuit 17 records the data on a recording medium 18 such as a magnetic disk or a bubble memory. This recording medium 1
The image information recorded in 8 is the electro-optical element diaphragm 3.
This is image information that has been corrected to eliminate the color tone change according to the aperture value due to the spectral characteristics of transmitted light, and therefore, when reproducing it, it is necessary to visualize it with a normal reproduction device and reproduce it with fidelity. This allows for excellent color reproduction.

In the example shown in FIG. 3, the lens barrel section 1 is treated as a so-called interchangeable lens, and a unique information generating circuit 5 in which unique color characteristic information is programmed for each interchangeable lens is built into the lens barrel section. In the case of a camera with a fixed lens, a color information generation circuit corresponding to the aperture value may be provided within the camera body.

4 and 5 and 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. 6 is a modification of the playback device. Examples are given for each. Fourth
In the figure, the same reference numerals as in FIG. 3 have the same meanings, so their explanation will be omitted. In the example of FIG. 4, the correction circuit 15 in the example of FIG. 3 is not provided, and the correction signal from the correction signal generation circuit 6 is simultaneously recorded on the recording medium 18 by the recording circuit 17 together with the image information. In other words, in this example, camera 1
This device does not have a means for correcting the image information to be recorded in the recording medium, but a correction signal is recorded on the recording medium together with the image information so that correction can be performed using the correction signal during reproduction. Therefore, as shown in FIG. 5, for example, a reproduction device combined with this camera 11 includes a reading circuit 19 that reads image information and correction signals from a recording medium 18, and a reading circuit 19 that generates an image signal from the read image information. An image signal generation circuit 20;
Reproduction circuit 21 that reproduces and visualizes the image signal
In addition, a correction circuit 22 for correcting image information in an image signal generation circuit 20 using a correction signal discriminated by a reading circuit 19 is provided in the form of an adapter, or a correction circuit 22 is provided in a built-in format as shown in FIG. It uses things such as

In each of the above-mentioned embodiments, the recording and playback of still images have been described, but the same applies to the recording and playback of moving images such as on a VTR. However, in the case of a VTR, the television camera has a white balance circuit. Since there is a correction circuit 1 of the example in Fig. 3,
5 could be used to make corrections prior to recording.

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

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the spectral transmittance characteristics of an electrochromic element and the spectral sensitivity characteristics of the human eye, Fig. 2 is a configuration diagram showing an example of an aperture using an electrochromic element, and Fig. 3 is a diagram showing the spectral sensitivity characteristics of the human eye. Block diagram illustrating the configuration of an image recording device according to an embodiment, No. 4
The figure is a block diagram showing the configuration of an image recording apparatus according to another embodiment of the present invention, FIG. 5 is a block diagram showing an example of a reproducing apparatus combined with the recording apparatus shown in the previous figure, and FIG. FIG. 3 is a block diagram showing another example. 1: Lens barrel section, 2: Imaging optical system, 3: Electro-optical element aperture, 4: Aperture control circuit, 5: Unique information generation circuit, 6: Correction signal generation circuit, 10: Photoelectric conversion element, 11: Camera body , 12: automatic exposure circuit, 13: control circuit, 14: drive circuit, 15: correction circuit, 16: image processing circuit, 17: recording circuit,
18: Recording medium, 19: Reading circuit, 20: Image signal generation circuit, 21: Reproduction circuit, 22: Correction circuit.

Claims (1)

[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 image information photographed by the imaging optical system is converted into an electrical signal and then recorded and reproduced. In doing so, a correction signal corresponding to the aperture value of the electro-optical element aperture is obtained, and the image information is electrically adjusted so as to eliminate color tone changes according to the aperture value due to the spectral characteristics of transmitted light of the electro-optical element aperture. An image information recording/reproducing method characterized in that a signal is corrected by the correction signal. 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 the image information photographed by this 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 electro-optical element aperture, and a correction signal generating circuit that generates a correction signal according to the aperture value of the electro-optic element aperture, and the photoelectric generator that generates a correction signal according to the aperture value of the electro-optic element aperture, and a correction signal generating circuit that generates a correction signal according to the aperture value of the electro-optical element aperture; An image recording apparatus comprising: a correction circuit that corrects the electric signal output from the conversion element using the correction signal prior to recording the electric signal. 3 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 the image information photographed by this imaging optical system is converted into an electrical signal by a photoelectric conversion element, and then recorded and reproduced. In the combination of a recording device and a reproducing device, the recording device includes a correction signal generation circuit that generates a correction signal according to the aperture value of the electro-optical element aperture, and a correction signal generating circuit that generates a correction signal according to the aperture value of the electro-optical element aperture, and an image that is converted into an electric signal by the photoelectric conversion element. The reproducing device includes a recording circuit that records both information and the correction signal on a recording medium, and the reproducing device is configured to record the information and the correction signal together on a recording medium, and the reproducing device is configured to record the correction signal so as to eliminate the color tone change depending on the aperture value due to the spectral characteristics of transmitted light of the electro-optic element aperture. An image recording/reproducing apparatus comprising a correction circuit that corrects image information in a read signal from a recording medium using a correction signal in the read signal.