JPH01286685A - Image pickup device - Google Patents

Abstract

PURPOSE:To obtain an optical image without any shading by composing the title device so that the whole of a reproduced optical image can be simultaneously read from a first photo-photo converting element and the read reproduced optical image can be given to a second photo-photo converting element as writing light. CONSTITUTION:Writing light WL1 image-forms the optical image of a copy device on a photo-photo covering element PPC1. On the other hand, reading light incident side of the element PPC1 is wholey irradiated by the reading light RL1. The light RL1 as the incident light to the element PPC1 proceeds according to the route of a transference electrode Et2 a photo modulating member PML a dielectric mirror DML, reflects on the mirror DML, and returns to the electrode Et2. Since the refractive index of a crystal to compose the member PML changes according to an electric field, the reflected light of the light RL1 includes picture information. Consequently, the reproduced optical image corresponding to the optical image becomes the incident light as writing light WL2 from the element PPC1 to a photo-photo converting element PPC2. Therefore, no shading exists in the optical image to be written to the element PPC2. A charge pattern formed on this element PPC2 is read by reading light RL2.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an imaging device, and particularly to an imaging device with 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 to generate video signals have the characteristic that they can be easily used for recording and reproducing. The formed optical image of the subject is converted into electrical image information corresponding to the optical image of the subject by the photoelectric conversion section of the image sensor, and the electrical image information is converted into a serial video signal on the time axis. As is well known, various image pickup tubes and various solid-state image pickup devices have been conventionally used as the above-mentioned image pickup devices in the configuration of image pickup devices. Furthermore, as the demand for high-quality, high-resolution playback images has increased in recent years, new television systems such as so-called EDTV and HDTV have been proposed, as is well known. It is.

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 it is not possible to achieve high resolution by miniaturizing the electron beam diameter; Since the target capacity of an image pickup tube increases in proportion to the target area, it is impossible to achieve higher resolution by increasing the target area. Due to this, the frequency band of the video signal increases from several tens of 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 be reproduced.

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 It is conceivable to use a large area one as an image pickup tube, but the performance of the electron gun of the image pickup tube.

Also, there is a limit to the miniaturization of the electron beam diameter of the image pickup tube due to the structure of the focusing system, so there is a limit to increasing the resolution by miniaturizing the electron beam diameter.

When trying to obtain high resolution by increasing the area of the target while using an imaging lens with a large captured image size, the output signal of the image pickup tube will increase due to the increase in the target capacity of the image pickup tube due to the increase in the target area. Due to the decrease in high-frequency signal components at
As a result, some imaging devices using an image pickup tube are unable to generate a good video signal that can reproduce high-quality, high-resolution reproduced images.

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 clock frequency for driving them becomes higher (for example, in the case of a video camera, the clock frequency for driving 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. Since the capacitance value of the circuits used in solid-state imaging devices has increased due to the increase in the number of pixels, such solid-state imaging devices are not practical given the current situation where the clock frequency limit for solid-state imaging devices is said to be 20 MHz. It is considered that it cannot be constituted as a thing.

In this way, conventional imaging devices have been unable to reproduce high-quality, high-resolution playback images and generate clear video signals in good condition due to the presence of an essential image sensor for their configuration. , measures to improve this were sought.

The present applicant company provides an imaging device capable of solving the above-mentioned problems by first providing at least a photoconductive layer member, a dielectric mirror, and a light modulating material layer member between two transparent electrodes. For example, using a light-to-light conversion element PPC whose schematic structure is shown in FIG. 4, an imaging device whose schematic structure is illustrated in the block diagram of FIG. 5 has been proposed.

First, in FIG. 4, 1 and 2 are glass plates, 3.4 are transparent electrodes, 5 and 6 are terminals, and 7 is a photoconductive layer member.
8R reflects light in the wavelength range of the readout light RL, and
A dielectric mirror having wavelength selectivity that can transmit light in the wavelength range of the erasing light EL, and the dielectric mirror 8R having this wavelength selectivity is, for example, a multilayer film of a 5i02 thin film and a TiO2 thin film. A dichroic filter constructed by the above method can be used.

In the previously proposed light-to-light conversion element PPC shown in FIG. Since the body mirror 8R is used, it is possible to make the erasing light EL enter from the incident side of the readout light RL in the light-to-light conversion element PPC, and therefore, it is possible to make the erasing light EL enter from the incident side of the readout light RL in the light-to-light conversion element PPC. It also becomes easy to install an optical system such as an imaging lens on the incident side.

The optical information writing operation for the previously proposed light-to-light conversion element PPC having the configuration shown in FIG. , the movable contact of the changeover switch SW is switched to the fixed contact WR side by a changeover control signal supplied to the input terminal 11 of the changeover control signal in the changeover switch SW,
A voltage of g10 is applied between the two ends of the photoconductive layer member 7 so that an electric field is applied between both ends of the photoconductive layer member 7, and the writing light WL is made incident from the glass plate 1 side in the light-to-light conversion element PPC. carried out by

That is, when the writing light WL incident on the light-to-light conversion element PPC when writing optical information passes through the glass plate 1 and the transparent electrode 3 and reaches the photoconductive layer member 7, the photoconductive layer member 7 is Since the electrical resistance value changes in accordance with the optical image caused by the incident light that has reached it, at the interface between the photoconductive layer member 7 and the dielectric mirror 8R having wavelength selectivity, the light that has reached the photoconductive layer member 7 A charge image corresponding to the optical image created by the incident light is generated.

The optical information written in the form of an optical image by the incident light and a corresponding charge image as described above is transferred to the light-light conversion element P.
To play from a PC, the movable contact of the changeover switch SW should be switched to the fixed contact WR side, and the voltage of the power supply 10 should be applied between the transparent electrodes 3 and 4 via the terminal 5.6. This can be done by projecting readout light RL of a constant light intensity from a light source (not shown) from the glass plate 2 side.

That is, the photoconductive layer member 7 in the light-to-light conversion element PPC on which optical information has been written by incident light as described above.
Since a charge image corresponding to the optical image caused by the incident light reaching the photoconductive layer member 7 is generated at the interface between the photoconductive layer member 7 and the wavelength-selective dielectric mirror 8R, The light modulating material layer member 9 (for example, lithium niobate single crystal 9), which is provided in series with the dielectric mirror 8R having wavelength selectivity, has an electric field with an intensity distribution corresponding to the optical image created by the incident light. It is in a state of participation.

Since the refractive index of the lithium niobate single crystal 9 changes depending on the electric field due to the first-order electro-optic effect, the photoconductivity described above is applied when an electric field with an intensity distribution corresponding to the optical image of the incident light is applied. The refractive index of the lithium niobate single crystal 9, which is provided in series with the dielectric mirror 8R having wavelength selectivity with respect to the layer member 7, changes from light to light by writing optical information using the incident light as described above. At the interface between the photoconductive layer member 7 and the wavelength-selective dielectric mirror 8R in the conversion element PPC, a charge image is generated corresponding to an optical image caused by the incident light that reaches the photoconductive layer member 7. Be what you are.

Therefore, when the readout light RL is projected onto the glass plate 2 side, the readout light RL projected onto the glass plate 2 side as described above changes from the transparent electrode 4 to the lithium niobate single crystal 9 to the wavelength selectivity. dielectric mirror 8R→.

The above-mentioned readout light RL is a dielectric mirror 8 having wavelength selectivity that reflects light in the wavelength range of the readout light and transmits light in the wavelength range of the erasing light.
It is reflected by R and returns to the glass plate 2 as reflected light. However, since the refractive index of the lithium niobate single crystal 9 changes depending on the electric field due to the primary electro-optic effect, the reflected light of the readout light RL is niobium. Due to the primary electro-optic effect of the lithium oxide single crystal 9, the image information is included in accordance with the intensity distribution of the electric field applied to the lithium niobate single crystal 9, and reproduction corresponding to the optical image by the incident light on the glass plate 2 side is performed. Produces an optical image.

In the reproducing operation of the light-to-light conversion element PPC as described above, the readout light RL projected from the glass plate 2 side is transmitted through the transparent electrode 4 → lithium niobate single crystal 9 → dielectric having wavelength selectivity. The readout light advances toward the photoconductive layer member 7 as shown by the body mirror 8R→, but before it reaches the photoconductive layer member 7, the readout light is processed by the dielectric mirror 8R having wavelength selectivity. By being reflected, it follows an optical path such as lithium niobate single crystal 9 → transparent electrode 4 → glass plate 2, so that the above-mentioned readout light RL reaches the photoconductive layer member 7 and is affected by the written incident light. There is no adverse effect on the charge image.

In this way, the previously proposed light-to-light conversion element PPC shown in FIG.
In this case, the writing operation is performed by making the writing light WL enter from the glass plate 1 side.

The optical image is reproduced by making the readout light RL incident on the glass plate 2 side, but the information written in the previously proposed light-to-light conversion element PPC shown in FIG. 4 is erased as follows. can.

That is, when erasing the information written in the previously proposed light-to-light conversion element PPC shown in FIG. By the switching control signal supplied to the signal input terminal 11, the movable contact of the changeover switch SW is switched to the fixed contact E side, and the transparent electrodes 3 and 4 are electrically short-circuited, and the transparent electrodes 3 and 4 are electrically short-circuited. 4 to the same potential so that no electric field is applied between both ends of the photoconductive layer member 7, and then light-
The erasing light EL is made incident on the glass plate 2 side of the light conversion element.

As mentioned above, the erasing light EL incident on the glass plate 2 side of the light-light conversion element PPC is transmitted through the glass plate 2 → transparent electrode 4 → lithium niobate single crystal 9 → dielectric mirror with wavelength selectivity.
It reaches the photoconductive layer member 7 through a path such as 8R→photoconductive layer member 7, and the erasing light EL lowers the electrical resistance value of the photoconductive layer member 7, thereby improving the wavelength selectivity of the photoconductive layer member 7. The charge image formed on the interface with the dielectric mirror 8R is erased.

In this way, the previously proposed light-to-light conversion element PPC shown in FIG.
In the write operation, the charge image formed on the interface between the photoconductive layer member 7 and the wavelength-selective dielectric mirror 8R is transferred from the readout light incident side of the light-to-light conversion element PPC to the light-to-light conversion element. Since erasing is performed by the erasing light incident on the PPC, it is possible to use an imaging device configured such that an imaging optical system is provided on the side where the writing light WL is incident, and other devices where the writing light WL is The present invention has the advantage that it can be easily applied to an apparatus having a configuration in which it is difficult to provide an input device for erasing light on the incident side.

FIG. 5 is a perspective view of an imaging device constructed using a light-to-light conversion element PPC having the configuration described with reference to FIG. 4, and the symbol PPC in FIG. Although a light conversion element is shown, in the light-to-light conversion element PPC shown in FIG.
The surface side of the glass plate 1 on which the writing light WL is incident is designated by the drawing code 1, and the drawing code R is shown in FIG.
The surface side of the glass plate 2 on which the reading light RL indicated by L and the erasing light EL indicated by the drawing symbol EL are incident is designated by the drawing symbol 2, and is shown in FIGS. 4 and 5. The light that exists
Although the correspondence relationship with the photoconversion element PPC is clarified,
In FIG. 5, specific illustrations and descriptions of other constituent parts of the light-to-light conversion element PPC are omitted to simplify the illustration.

In Fig. 5, O is the subject and L is the photographic lens.

BSI and BS2 are beam splitters, PSr is a light source of readout light RL (for example, a flying spot scanner using a laser beam can be used as the light source of readout light PSr, and in the following description, the light source of readout light is As PSr, a flying spot scanner using a laser beam is used), PSe is a light source of erasing light EL, PLP is a polarizing plate, and PD is a photodetector, as illustrated in Fig. 5. In an imaging device configured using a light-to-light conversion element PPC, an optical image of a subject 0 is transmitted to a glass plate 1 as writing light to the light-to-light conversion element PPC by an imaging lens L.
It is incident from the side.

The first . second transparent electrode 3,
4, the voltage of the power source 10 is applied through a changeover switch SW in which the movable contact is switched to the fixed contact WR side as shown in FIG.

In the light-light conversion element PPC, light corresponding to the optical image of the subject O is applied to the glass plate 1 side via the photographing lens L.
By a writing operation similar to the writing operation already described with reference to FIG. A charge image corresponding to the optical image created by the incident light that reaches the area is generated.

As described above, the light in which a charge image corresponding to the optical image by the writing light is generated at the interface between the photoconductive layer member 7 of the light-to-light conversion element PPC and the wavelength-selective dielectric mirror 8R. 1st in the photoconversion element PPC. In a state where the voltage of the power supply 10 is applied between the second transparent electrodes 3 and 4 via the changeover switch SW, the light emitted from the readout light source PSr configured as a laser beam flying spot scanner is The readout light RL of the interference light is transferred to the beam splitter BSI.
When the light is transmitted through the beam splitter BS2, reflected by the beam splitter BS2, and projected from the glass plate 2 side of the light-to-light conversion element PPC, as already described with reference to FIG. The readout light RL is transmitted through the second transparent electrode 4→
The process progresses from the lithium niobate single crystal 9 to the dielectric mirror having wavelength selectivity 8R.

The readout light RL described above is reflected by a dielectric mirror 8R having wavelength selectivity capable of reflecting light in the wavelength range of the readout light and transmitting light in the wavelength range of the erasing light, and is reflected by the dielectric mirror 8R toward the glass plate 2. However, since the refractive index of the lithium niobate single crystal 9 changes depending on the electric field due to the first-order electro-optic effect, the reflected light of the readout light RL reflects the electro-optic effect of the lithium niobate single crystal 9. This includes image information according to the intensity distribution of the electric field applied to the lithium niobate single crystal 9, and a reproduced optical image corresponding to the optical image created by the incident light is generated on the glass plate 2 side. When a flying spot scanner using a laser beam is used as the light source PSr of RL, the light-light conversion element PPC
Since the reproduced optical image appearing on the glass plate 2 side is constructed by flying spot scanning, the light of the reproduced optical image is transmitted to the beam splitter BS2, the polarizing plate PL,
By passing through P and being applied to the photodetector PD, a video signal corresponding to the optical image of the subject 0 is output from the photodetector PD.

In order to generate a video signal by performing a writing operation and a reading operation of images of different subjects at each predetermined time length on the time axis in the imaging device shown in FIG. Before a new optical image of the object is written every predetermined length of time, it is necessary to erase the charge image corresponding to the previously written optical image.

The above-mentioned erasing operation in the imaging device is performed during a predetermined time before new optical images are written one after another on the time axis, and it is performed in the video signal output from the photodetector PD. This is performed in correspondence with the vertical blanking period (in Fig. 6, the display of 1v is one vertical scanning period, and the period indicated as erasure in Fig. 6 is the erasure performed during the vertical blanking period). Period, 6th
The period indicated as readout in the figure is for the light-to-light conversion element P.
(This is the period during which the reproduced optical image is read out from the PC.)
Corresponding to the vertical blanking period in the video signal output from the photodetector PD, as already described with reference to FIG. By the switching control signal supplied to the switching control signal input terminal 11, the movable contact of the changeover switch SW is switched to the fixed contact E side, and the transparent electrodes 3 and 4 are electrically short-circuited and the transparent electrode 3.4 to the same potential so that no electric field is applied between both ends of the photoconductive layer member 7, and erase light E from the light source PSe of the erase light.
The erasing light EL is emitted from the beam splitter BS.
The light is made to enter from the glass plate 2 side of the light-to-light conversion element PPC via I and BS2.

The erasing light EL incident on the glass plate 2 side of the light-to-light conversion element PPC as described above reaches the photoconductive layer member 7 through the path already described with reference to FIG. The electrical resistance value of the conductive layer member 7 is reduced, and the charge image formed on the interface between the photoconductive layer member 7 and the wavelength selective dielectric mirror 8R is erased.

(Problems to be Solved by the Invention) Incidentally, in the previously proposed imaging device illustrated in FIG. - While an erasing operation is performed on the photoconversion element PPC.

A reading operation is performed on the light-to-light conversion element PPC during a period other than the period in which the above-mentioned erasing operation is performed, and an optical image from a subject is always written into the light-to-light conversion element PPC. Therefore, the video signal outputted from the imaging device and having a time-series signal form has shading.

That is, as mentioned above, the amount of charge of the charge image corresponding to the optical image of the subject read out in each vertical scanning period is the same from the time when the erase operation is performed to the time when the next erase operation is performed. It is in a state where it increases as time passes due to the writing light that is continuously incident on the
The charge image described above is read out by scanning with readout light during the period from the time when an erasing operation is performed to the time when the next erasing operation is performed, and is made into a time-series video signal. The amplitude of the video signal obtained by reading out gradually increases with the passage of time from the time when the charge image was erased by the previous erasing operation.

The shading that occurs in the video signal due to the above-mentioned causes can be solved, for example, by separating the period for writing optical information to the light-to-light conversion element PPC and the period for reading out the charge image from the light-to-light conversion element PPC. However, such a solution has the disadvantage that the signal to be read out is small due to the short exposure time, and also has the disadvantage that, for example, the erasing, writing, reading, and
Each operation period is arbitrarily set so that each operation of erasing, writing, and reading is performed on the light-to-light conversion element, and a video signal is read out from the light-to-light conversion element to generate a video signal based on a charge image. It is also possible to use a memory such as a frame memory to convert the image signal into a video signal of a predetermined standard television system, thereby obtaining a video signal free from the above-mentioned shading. When realizing high-resolution moving image imaging using such means, the deflection frequency, the frequency of the video signal, etc. become extremely high, so it is difficult to implement even if a conventional frame memory is used.

(Means for Solving the Problems) The present invention provides a first light-to-light conversion system comprising at least a photoconductive layer member, a dielectric mirror, and a light modulating material layer member between two transparent electrodes. means for providing optical image information of the object on the writing light incident side of the element; and means for causing readout light having a wide cross-sectional area to be incident on the readout light incident side of the first light-to-light conversion element; The above-mentioned first light is placed on the writing light incident side of the second light-to-light conversion element, which is configured to include at least a photoconductive layer member, a dielectric mirror, and a light modulating material layer member between transparent electrodes. - means for providing a reproduced optical image read out from the first light-to-light conversion element in a period shorter than the writing period of the light-to-light conversion element; and the above-described second light-to-light conversion.

An imaging device is provided, comprising means for inputting readout light onto the readout light incident side of the element and reading optical image information corresponding to an optical image given thereto from a second light-to-light conversion element. It is something.

(Example) Hereinafter, specific contents of the imaging device of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a block diagram of an embodiment of the imaging device of the present invention, FIG. 2 is a side view showing an example of the configuration of a light-light conversion element used in the imaging device shown in FIG. It is a timing chart for explaining operation.

In FIG. 1, PPCl is the first light-to-light conversion element, PP
C2 is a second light-to-light conversion element, which is the first light-to-light conversion element described above.
Second light-to-light conversion element ppct.

The PPC 2 may have a configuration as illustrated in FIG. 2, respectively.

In Figure 1, 1. Second light-light conversion element PPC
Although the description of the specific configuration of PPC2 is omitted, in (,) of FIG. 2 illustrating the first light-to-light conversion element PP1 shown in FIG. 1, Etl, E
t2 is a transparent electrode, PCL is a photoconductive layer member, and DML is a first
A dielectric mirror with wavelength selectivity that can reflect light in the wavelength range of the reading light RLI and transmit light in the wavelength range of the erasing light EL. For example, a thin film of S i O2 and T
A dichroic filter composed of a multilayer film including a thin film of iO2 can be used. Further, PML in FIG. 2(a) is a light modulating material layer member (for example, lithium niobate single crystal), and the light modulating material layer member PML made of the lithium niobate single crystal described above is a lithium niobate single crystal. The refractive index of changes depending on the electric field due to the first-order electro-optic effect.

The first light-to-light conversion element PPCl having the configuration illustrated in FIG. 2(a) has the same configuration as the light-to-light conversion element PPC already described with reference to FIG. , the first light-light conversion element P having the configuration illustrated in FIG. 2(a).
PCl write operation, read operation, erase operation, etc.
This is the same as the case of the light-to-light conversion element PPC already described with reference to the figures.

In addition, during the write operation, read operation, erase operation, etc. of the light-to-light conversion element PPC, the changeover switch SWI in FIG. 2(a) and the changeover switch SW2 in FIG. 2(b), which will be described later, are as follows. It is used in the same switching manner as the changeover switch SW shown in FIG. 4 described above.

Next, the second light-to-light conversion element PP shown in FIG.
In FIG. 2(b) illustrating Etl,
Et2 is a transparent electrode, DMLb is a dielectric mirror having wavelength selectivity that transmits light in the wavelength range of writing light and light in the wavelength range of erasing light, and reflects light in the wavelength range of reading light, PCPML. is a light modulating material layer member having both a photoconductive effect and a first-order electro-optic effect (for example, a member composed of bismuth silicate (BS○)), I
L is an insulating film, and the second light-to-light conversion element PPC2 shown in FIG. 2(b) is a first light-to-light converter having the configuration shown in FIG. The structure is such that the functions of the photoconductive layer member PCL and the light modulating material layer member PML in the conversion element PPC1 can be achieved by one light modulating material layer member PCPML. Note that the second light-to-light conversion element PPC2 may also be configured using a light modulating material layer member made of a lithium niobate single crystal.

In FIG. 1, WLI is writing light that is incident on the first light conversion element PPC1, and this writing light WLI forms an optical image of the subject 0 on the first light-to-light conversion element PPCl by the imaging lens L1. Ru.

The first light-to-light conversion element PPC is caused by the writing light WLI incident on the first light-to-light conversion element PPCl.
A charge image corresponding to the optical image of the subject ○ is formed at the boundary between the photoconductive layer member PCL and the dielectric mirror DML at l.

BSI is a first beam splitter, and this first beam splitter BSI is a light source PSr of the first read light.
The first readout light RLI is emitted from L and is expanded by lens L2 to become readout light having a large cross-sectional area.
is reflected to the read-out light incident side of the first light-to-light conversion element PPCl, and simultaneously irradiates the entire surface of the read-out light incident side of the first light-to-light conversion element RLI.

Readout light R incident on the first light-light conversion element PPCl
LI is the transparent electrode Et2 shown in FIG. 2(a).
→Light modulating material layer member PML using lithium niobate single crystal
The light travels as → dielectric mirror DML →, is reflected by dielectric mirror DML, and returns as light modulating material PML made of lithium niobate single crystal → transparent electrode Et2.

Since the refractive index of the lithium niobate single crystal constituting the light modulating material layer member PML changes depending on the electric field due to the first-order electro-optic effect, the reflected light of the readout light RLI reflects the first-order electricity of the lithium niobate single crystal. The optical effect includes image information corresponding to the intensity distribution of the electric field applied to the lithium niobate single crystal, and the first light-to-light conversion element PPCl generates a reproduced optical image corresponding to the optical image created by the incident light. The light passes through the first beam splitter BSI and then enters the writing light incident side of the second light-to-light conversion element PPC2 as the second writing light WL2 via the wavelength plate WLPI and the polarizer ANI. Ru.

As described above, the readout light RLI of the first light-to-light conversion element PPCl has such a large cross-sectional area that it can simultaneously irradiate the entire surface of the first light-to-light conversion element PPCl on the input side of the readout light. , first light-to-light conversion element PPCl
The entire reproduction target image is simultaneously read out from the
The write light WL2 is supplied to the light-to-light conversion element PPC2 as the second write light WL2.

Therefore, the entire reproduced optical image is simultaneously read out from the first light-to-light conversion element PPCl and the optical image written to the second light-to-light conversion element PPC2 naturally has no shading. Further, the readout period from the first light-to-light conversion element PPCl can be set arbitrarily, but even if the readout period is short, if the intensity of the readout light used for the readout is made sufficiently large, The optical image read from the first light-to-light conversion element PPCl and written to the second light-to-light conversion element PPC2 can be easily made sufficiently bright.

The second writing light WL2 supplied to the second light-to-light conversion element PPC2 as described above has a photoconductive effect in the second light-to-light conversion element PPC2 shown in FIG. 2(b). A second writing is performed on the boundary between the pcpML and the insulating film IL, such as a light modulating material layer member (for example, a member made of bismuth silicate (BSO)) that has both the primary electro-optic effect and the primary electro-optic effect. A charge image corresponding to the optical image by the light WL2 is formed.

The charge image formed on the second light-to-light conversion element PPC2 is read out by the readout light RL2, which is emitted from the light source PSr2 of the second readout light RL2 and then deflected in the vertical and horizontal directions by the optical deflector PDEF. be exposed. In FIG. 1, the second readout light RL2 emitted from the optical deflector PDEF is transmitted through the second beam splitter BS2 and is transferred from the readout light incident side of the second light-to-light conversion element PPC2 to the second readout light RL2. The light is input to the light-to-light conversion element PPC2.

The second readout light RL2 incident on the second light-to-light conversion element PPC2 is transmitted through the transparent electrode Et2→insulating film IL→light modulating material layer having both a photoconductive effect and a primary electro-optic effect. A member (for example, a member made of bismuth silicate (BSO)) PCPML → dielectric mirror DML → reaches the dielectric mirror DML, and then the second readout light RL2 passes through the dielectric mirror DML. The light is reflected and passes through the PCPML and the insulating film IL again, such as a light modulating material layer member (for example, a member made of bismuth silicate (BSO)) that has both a photoconductive effect and a primary electro-optic effect. The light then enters the beam splitter BS2 from the transparent electrode Et2 side, and this light is a reproduced optical image corresponding to the optical image of the subject ○ described above.

The reproduced optical image read out from the second light-to-light conversion element PPC2 is supplied to the photodetector PD via the wavelength plate WLP2, polarizer AN2, and lens L4, where it is photoelectrically converted, and sent from the photodetector to an output terminal. A time-series video signal is sent to 12.

The signal form of the video signal sent to the output terminal 12 as described above is determined by the length and width (vertical and horizontal) of the optical deflector PDEF described above.
By setting the respective deflection frequencies (vertical and horizontal) in a predetermined manner, a video signal conforming to a desired standard system can be obtained.

TPO is based on the above-mentioned 1. Second light-light conversion element PPCl
, a control signal generation circuit for performing write operations, read operations, erase operations, etc. in the PPC2 at predetermined timings, and a light source of erase light shown as block PSe in FIG. The timing of the operation in is also performed using the control signal generated by the control signal generating circuit PG.

Figure 3 is 1. Second light-light conversion element PPCl.

This is a chart illustrating the timing of a write operation, a read operation, an erase operation, etc. in the PPC2, and is a chart (
a) is a vertical synchronizing signal period in the first light-to-light conversion element PPCl, and (b) in FIG. 3 is a write operation, a read operation (reading operation), This is a chart illustrating the timing of the erasing operation, etc., and (c) of FIG.
This is the vertical synchronization signal period in PC2, and (d) in FIG. 3 is a chart illustrating the timing of write operation, read operation (read operation), erase operation, etc. in the second light-to-light conversion element PPC2. .

(Effects of the Invention) As is clear from the detailed explanation above, at least the light guide fI! between the two transparent electrodes of the present invention! means for providing optical image information of a subject on the writing light incident side of a first light-to-light conversion element configured to include a layer member, a dielectric mirror, and a light modulating layer member; The light-to-light conversion element includes means for causing readout light having a wide cross-sectional area to be incident on the readout light incident side, and at least a photoconductive layer member, a dielectric mirror, and a light modulating material layer member between two transparent electrodes. On the writing light incident side of the second light-to-light conversion element configured as shown in FIG. means for providing a reproduced optical image obtained by the second light-to-light conversion element; Since the imaging device is equipped with means for reading out corresponding optical image information, in the imaging device of the present invention, the readout light RLI of the first light-to-light conversion element ppct is the same as that of the first light-to-light conversion element PPC: It has a large cross-sectional area so that the entire surface on the incident side of the first readout light can be irradiated simultaneously, and the entire reproduced image is simultaneously read out from the first light-to-light conversion element PPCl, and it is transferred to the second readout light. light-light conversion element P
Since it is supplied to PC2 as second write light WL2,
Naturally, there is no shading in the optical image written to the second light-to-light conversion element PPC2, and the reading period from the first light-to-light conversion element PPCl may be set arbitrarily. Even if the readout period is short, if the intensity of the readout light used for the readout is made sufficiently large, the light is read out from the first light-to-light conversion element PPCl and transferred to the second light-to-light conversion element ppcz. The optical image written on the PPC2 can be easily made sufficiently bright, and furthermore, the second light-to-photo conversion element PPC2 can read out the charge image in any readout manner, so that the optical image written on the PPC2 can be read out in accordance with the desired scanning standard. Therefore, it is possible to easily generate a video signal. According to the present invention, the above-mentioned conventional problems can be satisfactorily solved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the imaging device of the present invention, FIG. 2 is a side view showing an example of the configuration of a light-light conversion element used in the imaging device shown in FIG. FIG. 4 is a side view of a previously proposed light-to-light conversion element, FIG. 5 is a perspective view showing a schematic configuration of an imaging device, and FIG. 6 is a time chart for explaining operation. PPCl...first light-light conversion element, PPC2...
Second light-light conversion element, Eta, Et2...transparent electrode, PCL...photoconductive layer member, DML...reflects light in the wavelength range of the first readout light RL1, and erases light EL A dielectric mirror having wavelength selectivity that can transmit light in the wavelength range of , DMLb... transmits light in the wavelength range of writing light and light in the wavelength range of erase light, and also A dielectric mirror with wavelength selectivity that reflects the light of ), IL...insulating film, PSrl...light source of first read light, WLPI.

Claims (1)

[Claims] Optical image information of a subject is provided on the writing light incident side of the first light-to-light conversion element, which is configured to include at least a photoconductive layer member, a dielectric mirror, and a light modulating material layer member between two transparent electrodes. means for causing readout light having a wide cross-sectional area to be incident on the readout light incident side of the first light-to-light conversion element; and at least a photoconductive layer member and a dielectric material between the two transparent electrodes. On the writing light incident side of the second light-to-light conversion element, which is configured to include a mirror and a light modulating material layer member, for a period shorter than the writing period of the first light-to-light conversion element described above. means for providing a reproduced optical image read out from the first light-to-light conversion element; and a means for providing a reproduced optical image read out from the first light-to-light conversion element; An imaging device comprising means for reading out an optical image given to it from a conversion element and corresponding optical image information.