JPH0524706B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an imaging device such as a video camera or a still image camera (shutter camera), and particularly to an imaging device having high resolution.

(Prior art) A video signal obtained by capturing an optical image of a subject with an imaging device is easily edited, trimmed, and other image signal processing, and a recording member having reversibility that can erase the recorded signal is used. However, imaging devices that have been commonly used in the past to generate video signals are capable of performing photoelectric conversion in the image sensor using an imaging lens. The optical image of the object formed on the image sensor is converted into electrical image information corresponding to the optical image of the object by the photoelectric conversion section of the image sensor, and the electrical image information is converted into a serial image on the time axis. It has a configuration that can be output as a signal, and it is well known that various image pickup tubes and various solid-state image pickup devices have been used as the above-mentioned image pickup devices in the configuration of imaging devices. be.

(Problem to be solved by the invention) In recent years, as the demand for high-quality and high-resolution reproduced images has increased, new television systems such as so-called EDTV and HDTV have been proposed. As is well known, this has been the case.

By the way, in order to obtain high-quality and high-resolution reproduced images, an imaging device that can generate a video signal that can reproduce high-quality and high-resolution reproduced images is required. In an imaging device that uses an image pickup tube as an image pickup element, there is a limit to miniaturization of the electron beam diameter in the image pickup tube, so high resolution cannot be expected by miniaturization of the electron beam diameter, and Since the target capacity of the tube increases in proportion to the target area, it is impossible to achieve higher resolution by increasing the target area. At the same time, the frequency band of the video signal ranges from several + MHz to several hundred MHz or more, which poses a problem in terms of S/N.
It is difficult to generate a video signal that can reproduce a high-resolution reproduced image.

The above point will be specifically explained as follows. In other words, in order to generate a video signal that can reproduce high-quality, high-resolution images using an image pickup device that uses an image pickup tube as an image sensor, it is necessary to miniaturize the electron beam diameter in the image pickup tube and to However, there is a limit to miniaturizing the electron beam diameter of the image pickup tube due to the performance of the electron gun in the image pickup tube and the structure of the focusing system. There is a limit to increasing resolution through miniaturization, and if you use an imaging lens with a large image size and try to obtain high resolution by increasing the target area, the target area will increase. Due to the increase in the target capacity of the image pickup tube, the high-frequency signal component in the output signal of the image pickup tube decreases, and the S/N ratio of the image pickup tube output signal decreases significantly. Depending on the device, it is not possible to adequately generate a video signal that can reproduce a high-quality, high-resolution reproduced image.

In addition, in order to reproduce high-quality, high-resolution images using an imaging device that uses a solid-state image sensor as an image sensor, it is necessary to use a solid-state image sensor with a large number of pixels; As more and more solid-state image sensors are driven, the frequency of the clock used to drive them becomes higher (for example, in the case of a video camera, the frequency of the clock used to drive the solid-state image sensor is several hundred MHz), and the frequency of the clock used to drive the solid-state image sensor becomes higher. As the capacitance value of the circuit increases with the increase in the number of pixels, such solid-state imaging devices are limited by the frequency limit of the clock of the solid-state imaging device.
Given the current state of the clock, which is said to be 20MHz, it is thought that it cannot be constructed as a practical device.

In this way, conventional imaging devices are able to achieve high image quality and
It was not possible to generate a good video signal that would allow reproduction of high-resolution images, and an improvement measure was required.

(Means for Solving the Problems) The present invention provides an imaging lens for a light-to-light conversion element configured to include at least a photoconductive layer member and a light modulating material layer member between two transparent electrodes. means for forming an optical image of a subject by using light; means for reading optical image information corresponding to the optical image of the subject using light from the light-to-light conversion element; An imaging device comprising a means for inputting the read optical information into a light-to-charge conversion element comprising at least a photoconductive layer member and a charge storage layer member; A means for forming an optical image of a subject using an imaging lens on a light-to-light conversion element configured with a conductive layer member and a light modulation layer member; a means for reading optical image information corresponding to an optical image of a subject using a light-to-charge conversion element comprising at least a photoconductive layer member and a charge storage layer member; The object of the present invention is to provide an imaging device including a means for causing a reference light for forming a fluorogram to be incident on the element along with optical information read out from the light-to-light conversion element.

(Example) Hereinafter, specific contents of the imaging device of the present invention will be described in detail with reference to the accompanying drawings. 1 to 3 are block diagrams showing a schematic configuration of an embodiment of the imaging device of the present invention, and FIG. 4 is a block diagram of a light-to-light conversion element used in the configuration of the imaging device of the present invention. FIG. 5 is a side sectional view for explaining the construction principle of a light-to-charge conversion element used in the construction of the imaging device of the present invention.

In Fig. 1, O is the object, 1 is the imaging lens,
2 is an optical shutter provided when the imaging device is configured as a shutter camera, PPCE is a light-to-light conversion element, 4 is a beam splitter, and 5 is an optical shutter.
It is a light source of readout light used to read out the optical image information from the light conversion element PPCE as optical information of single wavelength light, and this light source 5 can be a laser light source or any other light source {source of electromagnetic radiation}. can be used. Furthermore, electromagnetic radiation refers to light in a broad sense, that is, the entire spectrum of radiation called electromagnetic waves (γ
It is well known that the term refers to radiation in the range from radiation such as X-rays and X-rays to long-wave radio waves.

Also, 6 and 9 are lenses, 7 is a polarizing plate (if the light source described above is a light source that can emit the required single wavelength light, the polarizing plate 7 is not necessary), 8 is an analyzer, and PCCE
is a light-charge conversion element.

In the imaging device shown in FIG.
is imaged. It goes without saying that when the imaging device is configured as a shutter camera, an optical image of the subject O is formed on the light-to-light conversion element PPCE by the imaging lens 1 with the optical shutter 2 open. Nor.

As the light-light conversion element PPCE, a spatial modulation element such as a liquid crystal optical modulator, a photoconductive Pockels effect element, a microchannel optical modulator, or an element constructed using a photochromic material is used. can. Note that the light-to-light conversion element PPCE can be selectively used depending on the purpose, whether it has a memory function or one without a memory function.

FIG. 4 is a side sectional view showing the principle of construction of a light-to-light conversion element PPCE that can be used as a light-to-light conversion element PPCE, and the light-to-light conversion element shown in FIG.
In PPCE, Et1 and Et2 are transparent electrodes, PCL is a photoconductive layer member, and DML is a dielectric mirror (a dielectric mirror with wavelength selection characteristics that transmits writing light and erasing light and reflects readout light). PML is a light modulating material layer member such as a lithium niobate single crystal, Lw is a writing light, Lr is a reading light, Le is an erasing light, Vb is a power supply, and SW is a changeover switch. The above-mentioned changeover switch SW switches its movable contact v to the fixed contact wr side when the writing light Lw is made incident on the light-to-light conversion element PPCE and when the readout light is made incident on the light-to-light conversion element PPCE. When the erasing light Le is incident on the light conversion element PPCE, its movable contact v is switched to the fixed contact e side.

Transparent electrode Et1 in light-light conversion element PPCE,
In a state where the voltage of the power supply Vb is applied to Et2 via the movable contact v and the fixed contact wr of the switch SW, the writing light Lw corresponding to the optical image of the object is transmitted to the light-to-light conversion element PPCE. When the light passes through the transparent electrode Et1 and enters the photoconductive layer member PCL, the electrical resistance value of the photoconductive layer member PCL changes in accordance with the optical image of the subject incident thereon.

Therefore, a charge image corresponding to the optical image of the object is generated at the boundary between the photoconductive layer member PCL and the dielectric mirror DML. This charge image is the transparent electrode Et in the light-light conversion element PPCE.
1 and Et2 are at the same potential via the movable contact v and fixed contact e of the switch SW, when the light -
Erasing light Le from the transparent electrode Et2 side of the light conversion element PPCE
It can be erased by making it incident.

In other words, in the erase mode, the light-light conversion element
Erasing light Le incident from the transparent electrode Et2 side of PPCE
is a light modulating material layer member PML and a dielectric mirror (a dielectric mirror with wavelength selection characteristics that allows writing light and erasing light to pass through and reflects read light)
When the photoconductive layer member PCL passes through the photoconductive layer member PCL and enters the photoconductive layer member PCL, the electrical resistance value of the photoconductive layer member PCL decreases due to the above-mentioned erasing light Le, and the photoconductive layer member PCL reaches the boundary with the dielectric mirror DML in the photoconductive layer member PCL. The charge image in the area is erased.

Furthermore, the charge image corresponding to the optical image of the subject occurring at the boundary between the photoconductive layer member PCL and the dielectric mirror DML is
Light is transmitted through the movable contact v and fixed contact Wr of SW.
In a state where the voltage of the power supply Vb is applied to the transparent electrodes Et1 and Et2 in the light-to-light conversion element PPCE, the light-to-light conversion element It can be read out as an optical image from the transparent electrode Et2 side of PPCE.

That is, in the read mode, the read light Lr incident from the transparent electrode Et2 side of the light-to-light conversion element PPCE is transmitted through the light modulating material layer member PML, passes through the dielectric mirror (writing light and erasing light is passed, and is read out). A dielectric mirror with wavelength selective characteristics that reflects light reaches the DML, where it is reflected and passes through the light modulating material layer member PML again to form a light-light conversion element.
The readout light is emitted from the transparent voltage Et2 side of the PPCE, but after reciprocating within the light modulating material layer member PML as described above, the readout light emitted from the transparent electrode Et2 side of the light-light conversion element PPCE is as described above. Photoconductive layer material
Since the plane of polarization is changed by the electric field caused by the charge image corresponding to the optical image of the object generated at the boundary between the PCL and the dielectric mirror DML, the emitted light must be passed through the analyzer. Therefore, the light emitted from the analyzer becomes an optical image showing the same change in light amount as the optical image of the subject.

By using single wavelength light as the readout light described above, a reproduced image with sufficiently high resolution can be obtained.

Therefore, in the imaging device shown in the first figure, the transparent electrode Et1 of the light-to-light conversion element PPCE is
Writing light due to the optical image of the object O incident on the side
Lw is converted into a charge image at the boundary between the photoconductive layer member PCL and the dielectric mirror DML in the light-light conversion element PPCE, and the charge image is is emitted from the light-to-light conversion element PPCE as single wavelength optical information whose information content corresponds to the optical image of the subject. 1st
In the illustrated example, the single wavelength readout light
Lr is light source 5 → lens 6 → polarizer 7 → beam splitter 4 → transparent electrode of light-light conversion element PPCE Et
The light enters the light-to-light conversion element PPCE through the optical path No. 2.

Then, the single wavelength light information whose information content corresponds to the optical image of the subject emitted from the light-to-light conversion element PPCE is transferred from the beam splitter 4 to the analyzer 8.
→Lens 9 (which may be configured as a reduction optical system)→Light-to-charge conversion element
The image is formed on PCCCE and recorded on the photo-charge conversion element PCCCE.

In the description of the embodiments so far, the light-to-light conversion element PPCE used in the imaging device is a dielectric material that has wavelength selective characteristics that allows writing light and erasing light to pass through, and allows reading light to be reflected. The light to be used in carrying out the present invention is
As the photoconversion element PPCE, if the photoconductive layer member in the light-to-photoconversion element PPCE has no sensitivity to the readout light and the photoconductive layer member can reflect the readout light, a dielectric layer may be used. Of course, the light-light conversion element PPCE having a configuration without a body mirror may also be used.

In addition, in the description of the examples, the light-light conversion element
Although it is assumed that single-wavelength optical information is read out from the PPCE, it goes without saying that the embodiment may be implemented so that optical information other than single-wavelength information is read out from the light-to-light conversion element PPCE.

FIG. 5 is a side sectional view showing one example of the structure of the photo-charge conversion element PCCE, and the photo-charge conversion element PCCE shown in FIG. It has a laminated structure of a storage layer member CML and an electrode E. As the charge storage layer member CML, a material having a sufficiently high insulation resistance value, such as silicosine resin or polyester, is used to retain the charge image applied thereto for a long period of time. It's fine.

In FIG. 5, since a power supply Vc is connected between the transparent electrode Et and the electrode E in the photo-charge conversion element PCCE, the recording light Lc is incident on the transparent electrode Et side and the photoconductive layer member PCL is When the electrical resistance value changes in a manner corresponding to the distribution of the light amount of the recording light Lc described above, the value of the photoconductive layer member PCL changes in a manner corresponding to the distribution of the light amount of the recording light Lc described above. A charge image corresponding to the pattern of change in electrical resistance value is generated at the boundary between the photoconductive layer member PCL and the charge storage layer member CML. Further, the charge image can be erased by setting the transparent electrode Et and the electrode E to the same potential and injecting the erasing light from the transparent electrode Et side.

The above-described photo-charge conversion element PCCE may be moved in a predetermined movement manner by a drive mechanism (not shown). That is, when the imaging device operates in the shutter camera operation mode, after the optical shutter 2 is opened for a predetermined period of time and then closed, the light-to-charge conversion element PCCE is If the imaging device is operating in the operating mode as a video camera, each image is recorded while remaining stationary for a predetermined period of time. After that, the photo-charge conversion element PCCE
Intermittent feeding may be performed to rapidly transfer one frame (one image), and the aforementioned photo-charge conversion element PCCE
As the intermittent transfer mechanism, a mechanism similar to a well-known transfer mechanism used in movie shooting machines may be adopted. In addition, the light-charge conversion element shown in FIG.
The PCCE may be in the form of a tape, disk, sheet, or any other form.

The imaging device of the embodiment shown in FIG. 1 described above has the following features:
A signal processing function or a photoelectric conversion function may be added. For example, the single wavelength optical information emitted from the light-to-light conversion element PPCE shown in FIG. 1 is sent to the beam splitter 4. Alternatively, the signal may be sent to a signal processing device via another beam splitter, and the signal processing device may perform various signal processing such as editing, trimming, and optical amplification based on the optical image information incident thereon. (As the signal processing device, one configured using a controllable spatial modulation element, a reversible parallel memory, a controllable parallel functional element, a controllable functional coupling element, etc. may be used. (optical parallel signal processing may be performed by a signal processing device that has been used).

Next, the imaging device shown in FIG.
The single-wavelength optical information emitted from the optical conversion element PPCE is reflected by another beam splitter 14 provided in the optical path following the beam splitter 4, and the optical information is transmitted through the lens 15 to the photoelectric converter 16 (photoelectric As the converter 16, a two-dimensional sensor, 1
This is an example of a configuration in which an electrical signal in a predetermined signal form is output from a photoelectric converter 16 (a dimensional sensor, a photodiode, etc. can be selectively used), and 10 in FIG. Laser light source used as a light source, 11
12 is a beam splitter, 13 is a wave plate for optically setting bias, 14 is a beam splitter, 15 is a lens, and 16 is a photoelectric converter. .

In the image pickup device shown in the second diagram, the optical image information reflected by the half prism 14 may be directly projected onto a monitor screen so that the optical image to be recorded on the photo-charge conversion element PCCE can be monitored. It is.

The imaging device shown in FIG. 3 is a block diagram of another embodiment of the present invention in which recording and reproduction of optical image information in the photo-charge conversion element PCCE is performed by the fluorography method. In FIG. 3, O is an object, 1 is an imaging lens, 2 is an optical shutter provided when the imaging device is configured as a shutter camera, PPCE is a light-to-light conversion element, and in FIG. 3, 18 is a lens, PCCE is a photo-charge conversion element.

In the imaging device shown in FIG.
However, if the imaging device is configured as a shutter camera, an optical shutter 2
When the camera is open, the optical image of the subject O is captured by the imaging lens 1.
Needless to say, the image is formed on the light-to-light conversion element PPCE by .

Reference numeral 19 is used for the light used as readout light for the light-to-light conversion element PPCE, for imaging a fluorogram for the light-to-charge conversion element PCCE, and for reproducing a wavefront from the light-to-charge conversion element PCCE. A light source that emits coherent light, such as a semiconductor laser.

The light that is used both for reading out the optical image from the light-to-light conversion element PPCE and for photographing the fluorogram is
The light is supplied from the light source 19 to the light-to-light conversion element PPCE through the path of the light source 19 → half mirror 20 → concave lens 22 → light-to-light conversion element PPCE. As a result, light-
An optical image corresponding to the optical image of the object appears on the light conversion element PPCE, and the optical image is applied to the lens 18 as a signal wave in the fluorography method, so that the lens 18 converts the light into
The image is formed on the charge conversion element PCCE. The coherent light emitted from the light source 19 described above is supplied to the light-to-charge conversion element PCCE from the light source 19 → half mirror 20 → concave lens 21 → the light-to-charge conversion element PCCE. A fluorogram corresponding to the optical image of the object appearing on the output side of the light-to-light conversion element PPCE is formed and recorded.

In this way, according to the imaging device shown in the third figure, the optical image of the subject O is recorded as a fluorogram on the photo-charge conversion element PCCE.

The photo-charge conversion element PCCE may be moved in a predetermined manner by a drive mechanism (not shown). In that case, if the imaging device shown in the third figure is operating in the shutter camera operation mode, the optical shutter 2
is opened for a predetermined period of time and then closed, the photo-charge conversion element PCCE is moved by one frame (one image), and the imaging device is set in the operation mode as a video camera. When operating in Intermittent feeding such as transport is performed. In addition, the above-mentioned light-charge conversion element
As the intermittent transfer mechanism of the PCCE, a mechanism similar to a well-known transfer mechanism used in movie shooting machines may be adopted.

Note that the information recorded as a charge image on the photo-charge conversion element PCCE by the image pickup apparatus of the embodiment shown in FIGS.
The transparent electrode Et and the electrode E in the PCCE are brought into a state of the same potential, and a needle-like electrode, multi-needle electrode, etc. is brought close to the transparent electrode Et side in the photo-charge conversion element PCCE, and the information recorded as a charge image is Alternatively, the transparent electrode Et and the electrode E in the photo-charge conversion element PCCE may be set at the same potential, and the transparent electrode and the light modulator may be read out on the transparent electrode Et side of the photo-charge conversion element PCCE. The dielectric mirror side of the information reading head, which has a laminated structure of the material layer member and the dielectric mirror, is brought close to each other, and the reading light is incident from the transparent electrode side of the information reading head to perform the information reading described above. The light incident on the head passes through the transparent electrode → light modulating material layer member →
The light emitted from the transparent electrode in the information reading head is applied to the analyzer again through the path of dielectric mirror→light modulating material layer member→transparent electrode, and the light-
Reproducing the optical image as an optical image having a light amount pattern corresponding to the charge amount pattern of the charge image in the charge conversion element PCCE, or photoelectrically converting the optical image obtained as described above into an electrical signal. Therefore, it is possible to read out information with high definition.

In addition, when the imaging device of the present invention is configured as a color image imaging device, an optical color separation striped filter having a known configuration is arranged in front of the transparent electrode Et1 in the light-to-light conversion element PPCE in each embodiment. do it.

(Effects of the Invention) As is clear from the above detailed description, the imaging device of the present invention has a light source including at least a photoconductive layer member and a light modulating material layer member between two transparent electrodes. means for forming an optical image of a subject on the light conversion element using an imaging lens;
means for reading optical image information corresponding to an optical image of a subject using light from the light-to-light conversion element; an imaging device comprising a means for causing light to enter a light-to-charge conversion element comprising a member; and at least a photoconductive layer member and a light modulating material layer member between two transparent electrodes. A means for forming an optical image of a subject using an imaging lens on a light-to-light conversion element, and reading optical image information corresponding to the optical image of the subject using light from the light-to-light conversion element. a light-to-charge conversion element comprising at least a photoconductive layer member and a charge storage layer member; and an optical signal read out from the light-to-light conversion element to the light-to-charge conversion element. Since the imaging device is equipped with a means for inputting reference light for forming a fluorogram as well as information, in the imaging device of the present invention, the photoconductive layer member in the light-to-light conversion element PPCE is
By reading out the charge image corresponding to the optical image of the object generated at the boundary of the PCL with a readout light, a reconstructed image with sufficiently high resolution is obtained.
This can be recorded on the light-to-charge conversion element PCCE, and the optical information emitted from the light-to-light conversion element PPCE can be recorded on the photoelectric converter (or a two-dimensional sensor as required).
(one-dimensional sensor, photodiode, etc. can be selectively used), the photoelectric converter may output an electrical signal in a predetermined signal form, and furthermore, the optical image information in the photo-charge conversion element PCCE may be outputted from the photoelectric converter. Recording and reproduction may be performed by a fluorography method, and furthermore, a photoelectric charge conversion element may be used.
The information recorded in the PCCE as a charge image is obtained by setting the transparent electrode Et and the electrode E in the photo-charge conversion element PCCE to the same potential state, and installing a needle-like electrode and a multi-needle electrode on the transparent electrode Et side of the photo-charge conversion element PCCE. By bringing electrodes close together, information recorded as a charge image can be read out electrostatically, or by optical
Transparent electrode Et and electrode E in charge conversion element PCCE
are at the same potential, and the photo-charge conversion element PCCE
The dielectric mirror side of the information reading head in a laminated structure of the transparent electrode, the light modulating material layer member, and the dielectric mirror is brought close to the transparent electrode Et side of the information reading head. The light incident on the information reading head described above is read out again through the path of transparent electrode → light modulating material layer member → dielectric mirror → light modulating material layer member → transparent electrode. The light emitted from the transparent electrode in the optical head is applied to an analyzer and reproduced as an optical image having a light amount pattern corresponding to the charge amount pattern of the charge image in the photo-charge conversion element PCCE, or as described above. By photoelectrically converting the obtained optical image into an electrical signal, it is possible to read out high-definition information.According to the present invention, the above-mentioned conventional drawbacks can be satisfactorily solved. It is possible to provide an imaging device that can capture a high-resolution reproduced image.

[Brief explanation of the drawing]

1 to 3 are block diagrams showing the schematic configuration of an embodiment of the imaging device of the present invention, and FIG.
The figure shows the light used in the configuration of the imaging device of the present invention.
FIG. 5 is a side sectional view for explaining the construction principle of a light conversion element. FIG. O... Subject, 1... Imaging lens, 2... Optical shutter provided when the imaging device is configured as a shutter camera, PPCE... Light-light conversion element, 4, 14... Half prism, 5... ...Light source of readout light used when reading optical image information from the light-light conversion element PPCE as optical information of single wavelength light, 6, 9, 15, 18... Lens, 7... Polarizing plate, 8 ...Analyzer, PCCE...Photo-charge conversion element, Et, Et1, Et2...Transparent electrode, PCL...Photoconductive layer member, DML...Dielectric mirror, PML...
Light modulating material layer member, Lw...writing light, Lr...reading light, Le...erasing light, Vb...power supply, SW...changeover switch, CML...charge storage layer member, 16...
...Photoelectric converter (as the photoelectric converter 16, a two-dimensional sensor, a one-dimensional sensor, a photodiode as required), 10... Laser light source used as a light source of readout light, 11... Light source of erasing light 12...beam splitter, 13...wave plate for setting optical bias, 19...light sources 19, 20...half mirror, 21, 22→concave lens.

Claims (1)

[Scope of Claims] 1. A light source comprising at least a photoconductive layer member and a light modulating material layer member between two transparent electrodes.
means for forming an optical image of a subject on the light conversion element using an imaging lens; and means for reading optical image information corresponding to the optical image of the subject using light from the light-to-light conversion element. An imaging device comprising means for causing optical information read from the light-to-light conversion element to enter a light-to-charge conversion element comprising at least a photoconductive layer member and a charge storage layer member. 2. A light source comprising at least a photoconductive layer member and a light modulating material layer member between two transparent electrodes.
means for forming an optical image of a subject on the light conversion element using an imaging lens; and means for reading optical image information corresponding to the optical image of the subject using light from the light-to-light conversion element. , a light-to-charge conversion element comprising at least a photoconductive layer member and a charge storage layer member, and optical information read from the light-to-light conversion element to the light-to-charge conversion element; , and means for also inputting a reference light for forming a fluorogram.