JPH0787555B2 - Imaging device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high resolution image pickup device, and more particularly to an image pickup device having a high resolution such as a memory function.

(Prior Art) A video signal obtained by picking up an optical image of a subject with an image pickup device is easy to edit, trim, and other image signal processing, and a reversible recording member that can erase a recorded signal is used. Although it has the feature that recording and reproduction can be performed easily by using it, the image pickup device that has been generally used conventionally for generating a video signal has a photoelectric conversion unit in the image pickup element by an image pickup lens. 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 unit of the image sensor, and the electrical image information is converted into a serial video signal on the time axis. It is well known that various image pickup tubes and various solid-state image pickup devices have been conventionally used as the above-mentioned image pickup device in the configuration of an image pickup apparatus in which the image pickup device can be output.

(Problems to be solved by the invention) In recent years, in response to a growing demand for high-quality and high-resolution reproduced images, new types of television systems such as EDTV and HDTV have been proposed. It is well known that this has been done.

By the way, in order to obtain a high-quality / high-resolution reproduced image, an image pickup device capable of generating a video signal capable of reproducing a high-quality / high-resolution reproduced image is required. In an image pickup device in which an image pickup tube is used as an image pickup element, there is a limit to the miniaturization of the electron beam diameter in the image pickup tube, so that it is not possible to expect high resolution due to the miniaturization of the electron beam diameter. Since the target capacity of the tube increases in correspondence with the target area, it is not possible to realize high resolution by increasing the target area. Further, for example, in the case of a moving image pickup device, high resolution is required. As a result, the frequency band of the video signal becomes several tens of MHz to several hundreds of MHz or more, which causes 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 points will be specifically described as follows. That is, in order to generate a video signal capable of reproducing a high-quality and high-resolution reproduced image by an image pickup apparatus in which an image pickup tube is used as an image pickup element, the electron beam diameter in the image pickup tube is reduced or the target is reduced. It is conceivable to use a large area as the electron beam diameter because there is a limit to the miniaturization of the electron beam diameter of the image pickup tube due to the performance of the electron gun of the image pickup tube and the structure of the focusing system. There is a limit to the increase in resolution due to the miniaturization, and if an attempt is made to obtain high resolution by increasing the area of the target after using an imaging lens with a large image size, the increase in the target area The decrease in the high-frequency signal component in the output signal of the image pickup tube due to the increase in the target capacity of the image pickup tube causes the S / N of the image pickup tube output signal to decrease significantly. , By imaging device using a camera tube is not possible to satisfactorily generate a video signal as capable of reproducing the high image quality and high resolution of the reproduced image.

Further, in order to reproduce a high-quality and high-resolution reproduced image by an image pickup apparatus using a solid-state image pickup element as an image pickup element, it is necessary to use a solid-state image pickup element having a large number of pixels. Many solid-state imaging devices have a high clock frequency for driving them (for example, the frequency of a clock for driving a solid-state imaging device in the case of a video camera is several hundred MHz), and are targeted for driving. Since the capacitance value of the circuit that is used increases with the increase in the number of pixels, such a solid-state imaging device is practical from the present condition that the limit of the clock frequency of the solid-state imaging device is 20 MHz. It cannot be configured as a thing.

As described above, in the conventional image pickup apparatus, it is difficult for the image pickup element used for its configuration to generate a video signal that can reproduce a high-quality / high-resolution reproduced image, and It has not been possible to easily provide an imaging device capable of generating a video signal capable of reproducing a reproduced image of high image quality and high resolution.

In addition, the image sensor used in the conventional image capturing apparatus corresponds to a new optical image of the subject after the electric signal generated by photoelectrically converting the optical information to be recorded is transmitted as a video signal. The image pickup device itself does not have a function of storing electric signals generated corresponding to sequential subject images. When it is necessary to record the electrical information signal obtained by the method, the video signal generated by the imaging device is recorded using, for example, a magnetic recording device. However, since it is useful in various respects that the captured contents are recorded,
The appearance of a device having a memory function in the imaging device itself has been long awaited.

(Means for Solving Problems) In the present invention, a photoconductive layer member having a transparent electrode attached to one surface thereof and a surface of the photoconductive layer member to which the transparent electrode is not attached are opposed to each other. Light composed of an electrode provided as an electrode, a charge storage layer member movable between the electrode and the photoconductive layer member, and a power supply connected between the transparent electrode and the electrode. -A charge conversion unit,
An optical image of the subject is formed on the imaging surface of the light-charge conversion unit from the transparent electrode side of the light-charge conversion unit by an imaging lens, and the subject is formed on the charge storage layer member in the light-charge conversion unit. Means for forming a charge image corresponding to the optical image of the charge storage layer, and a portion for forming the charge image on the charge storage layer member on which the charge image corresponding to the optical image of the subject is formed, (EN) An image pickup device provided with a means for moving to a charge image and a means for generating a video signal by reading a charge image corresponding to an optical image of a subject in a charge image reading section.

(Examples) Hereinafter, specific contents of the image pickup apparatus of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a perspective view for explaining the configuration principle and operation principle of the image pickup apparatus of the present invention, and FIGS. 2 and 3 show a schematic configuration of an embodiment of the image pickup apparatus of the present invention. It is a block diagram.

In FIG. 1, Et is a transparent electrode, E is an electrode, PCL is a photoconductor layer member, CML is a charge storage layer member, Vc is a power source, and each of the above-mentioned components constitutes a photo-charge conversion unit PCCA. Therefore, a predetermined electric field is generated between the transparent electrode Et and the electrode E by the power source Vc connected between the transparent electrode Et and the electrode E.

The light-to-charge conversion unit PCCA is housed in a dark box having an appropriate structure so that unnecessary external light does not strike the photoconductor layer member PCL.

The transparent electrode Et in the photo-charge conversion unit PCCA is a transparent electrode having a spectral transmission characteristic such that light in the wavelength band of optical information to be imaged can be transmitted (for example,
ITO), and as a photoconductor layer member PCL described above, when a high-definition optical image is given to one of its end faces, under the application of an electric field of appropriate strength, A photoconductor material (for example, amorphous silicon) having a characteristic capable of generating a high-definition charge image on the other end surface is used. Further, the charge storage layer member CML is made of a material having a high insulation resistance value (for example, a silicon resin) such that the charge image adhered and formed on the surface of the charge storage layer member CML can remain in the same pattern for a long period of time. The one used is used.

The charge storage layer member CML described above has a disk shape,
It may be in any shape such as a tape shape or a sheet shape, but in any case, the above charge storage layer member CML is transferred in the direction of arrow X in the figure in a predetermined transfer mode. It is designed to be done.

An optical image of a subject is formed on the imaging surface of the light-to-charge conversion unit PCCA by the imaging lens 1 provided in front of the transparent electrode Et in the light-to-charge conversion unit PCCA, The light-to-charge conversion unit PCCA is the imaging lens 1
The charge storage layer member CM provides a charge image corresponding to the optical image of the subject formed on the imaging surface of the light-to-charge conversion unit PCCA by the
Although the operation of forming L is performed, the above-mentioned conversion operation from the optical image to the charge image in the photo-charge conversion section PCCA is performed as follows.

That is, when the light flux that has entered the transparent electrode Et side of the photo-charge conversion unit PCCA through the imaging lens 1 passes through the transparent electrode Et of the photo-charge conversion unit PCCA and enters the photoconductor layer member PCL, photoconduction Since the electric resistance value of the body layer member PCL changes according to the light quantity of the light beam incident on it, the photoelectric layer member PCL
The electric resistance value of each part of the image changes according to the light amount of each part of the subject.

Then, the transparent electrode Et and the electrode E in the light-to-charge conversion unit PCCA are
As described above, since a predetermined voltage is applied by the power source Vc, the charge storage layer member CML provided so as to face the above-mentioned photoelectric layer member PCL has a photoelectric layer. The charge corresponding to the state of change in the electric resistance value of the member PCL is attached, and the charge storage layer member CM
In L, a charge image corresponding to the optical image of the subject is formed.

The charge storage layer member CML having a charge amount corresponding to the light amount of each portion in the optical information to be recorded such as the optical information of the subject given to the photoconductor layer member PCL of the photo-charge conversion unit PCCA The above-described charge image generated in the state of being attached to the surface of the recording medium is recorded when the optical information to be recorded is simultaneously given to the entire surface of the photoconductor layer member PCL via the imaging lens 1. The entire two-dimensional charge image corresponding to the entire two-dimensional optical information targeted is simultaneously generated, and the optical information targeted for recording is applied to the entire surface of the photoconductor layer member PCL. When sequentially given by the flying spot scanner, the entire charge image corresponding to the optical information to be recorded is sequentially generated, but in any of the above cases , One complete charge image corresponding to the entire optical information to be recorded is a photoconductor layer member. After being brought into a state of being generated on the end surface of the PCL, the surface of the charge storage layer member CML is separated from the surface of the photoconductor layer member PCL described above as necessary, and then the surface of the charge storage layer member CML. The position where the region 2 to which the one complete charge image 2 corresponding to the entire optical information to be recorded in the above is attached does not face the end face of the photoconductor layer member PCL. After moving to, the imaging operation of the next subject is performed.

As described above, complete charge images 2 can be sequentially deposited on the surface of the charge storage layer member CML. Then, as described above, the complete one-by-one charge image 2 sequentially attached to the surface of the charge storage layer member CML shows each portion in the optical information to be recorded, which is given to the photoconductor layer member PCL. Since the charge image has a charge amount corresponding to the light amount of, the charge image has a high resolution corresponding to that of the photoconductor layer member PCL having a sufficiently high resolution. When read by the reading means having, a video signal capable of reproducing a reproduced image with extremely high definition can be generated.

In the charge storage layer member CML on which the charge image corresponding to the optical image of the object is formed in the light-charge conversion unit PCCA, the charge image reading portion RA is the portion where the charge image 2 is formed in the charge storage layer member CML. The charge image 2 is transferred to the charge image reading section RA, and the charge image 2 corresponding to the optical image of the object is detected by electrostatic detection means, optical detection means, or other charge detection means. It is possible to easily generate a video signal capable of reproducing a reproduced image of high image quality and high resolution.

When the image pickup apparatus of the present invention is implemented as a color image pickup apparatus, each primary color image separated into three primary colors by a three-color separation optical system having a well-known configuration is imaged by the image pickup apparatus having the above-described first configuration. You can do it like this. Further, in carrying out the present invention, one surface of the charge storage layer member CML is opposed in such a manner that it is separated from the end surface of the photoconductive layer member PCL in the photo-charge conversion section PCCA by a minute distance. The charge storage layer member CML may be provided in such a manner as described above, in which case the surface of the charge storage layer member CML and the photoconductive layer member PCL are
By the discharge between the charge storage layer member CML and the end surface of the charge storage layer, a charge image corresponding to the optical image of the subject is formed on the surface of the charge storage layer member CML.

The reading of the amount of charge from the portion where the charge image 2 is formed in the charge storage layer member CML is performed by the charge image reading unit RA, but in the embodiment shown in FIG. 2, the charge image reading unit is used. As the RA, one configured to electrostatically detect the charge image 2 corresponding to the optical image of the subject is used, and in the embodiment shown in FIG. As the reading unit RA, one that is configured to optically detect the charge image 2 corresponding to the optical image of the subject is used.

First, the charge image reading section RA in the embodiment shown in FIG. 2 will be described. In FIG. 2, 3 is a needle electrode for electric charge detection, 4 is a switch, 5 is a field effect transistor, 6 is a resistance, and 7 is a detection force terminal. The electric charge image shown in FIG. The reading unit RA detects the charge in the charge storage layer member CML with high resolution by electrostatic induction by the charge detection needle electrode 3 provided close to the charge image 2 in the charge storage layer member CML. Is applied to the gate of the field effect transistor 5, and the voltage appearing across the resistor 6 connected between the source of the field effect transistor 5 and the ground is sent to the detection output terminal 7. The switch 4 is a reset switch for discharging unnecessary electric charges accumulated in the gate due to a leak of the field effect transistor 5, and a switching element such as a field effect transistor is used as the switch 4 in implementation.

In FIG. 2, the needle electrode 3 for charge detection is shown as a single needle, but in the implementation, a multi-needle electrode configured by arranging a large number of needle electrodes as a needle electrode for charge detection is used. it can. When a multi-needle electrode is used as the charge detection needle electrode, when the single-needle charge detection needle electrode 3 is used to detect the charge distribution of the charge image in the charge storage layer member CML, The required two-dimensional mechanical scanning means is not required, and the two-dimensional charge image read operation can be performed by the one-dimensional mechanical scanning only in the sub-scanning direction.

If a multi-needle electrode arranged two-dimensionally is used,
No mechanical scanning means is required. Fine formation of many needle electrodes can be easily realized by applying LSI process technology.

Next, the charge image reading section RA in the embodiment shown in FIG. 3 will be described. In FIG. 3, Er is an electrode in contact with the surface of the charge storage layer member CML opposite to the surface on which the charge image 2 is formed, and the above-mentioned charge storage layer member CML is sandwiched between the electrodes. A dielectric mirror in the charge image reading head RH is located at a position facing the charged electrode Er.
DML is located.

The charge image reading head RH described above is an element that converts a charge image into an optical image.
For example, a light modulation material layer member PML (for example, lithium niobate having an electro-optical effect, or a layer of a nematic liquid crystal having an electric field scattering effect, which has a characteristic that the state of light can be changed by an applied voltage). It is possible to use a structure in which the dielectric mirror DML is provided on one surface of the (light modulation material layer) and the transparent electrode Etr is provided on the other surface.

Then, a charge pattern is applied to the side of the dielectric mirror DML in the charge image reading head RH, and
When light is incident from the other surface of the light modulation material layer member PML, the incident light passes through the light modulation material layer member PML and is reflected by the dielectric mirror DML, and the reflected light is again light modulation material layer member PML. After passing through, the light is emitted from the surface of the light modulation material layer member PML on the incident side, but the light state of the emitted light (the angle of the polarization plane in the above example) is the light of the incident light. The state (the angle of the plane of polarization in the case of the above example) has changed corresponding to the amount of charges in the above-mentioned charge image.

Therefore, for example, the light emitted from the laser light source 10 (or the light source 10 using a halogen lamp) is passed through the polarizer 11 to form a linearly polarized light flux (when the light source 10 is a laser light source, the polarizer 11 is Optical deflector after use)
Make it incident on 12.

The light deflector 12 emits the light beam incident on it in a state in which it is deflected in two directions orthogonal to each other like a raster drawn on a display of a television device.

The light beam emitted from the optical deflector 12 in the above-described state is made into parallel light by the collimator lens 13 which makes incident light parallel light and outputs the parallel light, and the parallel light beam is made incident on the beam splitter 9. It

The light beam incident on the beam splitter 9 is condensed by the lens 8 and then incident on the charge image reading head RH. On the side of the dielectric mirror DML in the charge image reading head RH described above, a charge storage layer member CML that stores recorded information in the form of a charge image.
Since the charge image forming surfaces of the charge image reading heads face each other, an electric field due to the charge image of the charge storage layer member CML is applied to the light modulation material layer member PML of the charge image reading head RH via the above-mentioned dielectric mirror DML.

Therefore, when light is incident from the transparent electrode Etr side of the charge image reading head RH, the incident light is emitted from the light modulation material layer member PML.
Of the light emitted from the charge image reading head RH, which is reflected by the dielectric mirror DML and passes through the light modulation material layer member PML again, and the light is emitted from the surface of the transparent electrode Etr. The state (the angle of the polarization plane in the above example) is the light state of the incident light (the angle of the polarization plane in the above example) is the charge amount of the charge image in the charge storage layer member CML. It has been changed corresponding to.

As described above, the emitted light from the charge image reading head RH depends on the charge amount of the charge image in the charge storage layer member CML in which the incident light on the charge image reading head RH stores the record information in the form of a charge image. And the amount of rotation of the polarization plane is changed, and the collimator lens 13 described above is in the state of parallel light.

Therefore, when the above-mentioned emitted light from the charge image reading head RH passes through the lens 8 and the beam splitter 9 and then enters the condenser lens 14, the light flux condensed by the condenser lens 14 is always the same. Focus on the position.

Therefore, the light condensed by the condensing lens 14 described above is passed through the wavelength plate 15 for adjusting the amount of light and the analyzer 16 for converting the rotation amount of the polarization plane into the change in brightness. When the photoelectric converter 17 is arranged at the position of the condensing point of the condenser lens 14, the charge storage layer member CML is removed from the photoelectric converter 17 described above.
A video signal whose amplitude changes in accordance with the amount of charges in each part of the two-dimensional charge image in is obtained.

As described above, the video signal output from the photoelectric converter 17 is
This corresponds to the charge amount distribution in the two-dimensional charge image having high definition in the charge storage layer member CML. Therefore, for example, when a laser beam having a diameter of 1 micron is used as the reading beam,
It can generate video signals with high resolution of 1000 lines / 1mm.

(Effects of the Invention) As is clear from the above description, the image pickup device of the present invention has a photoconductive layer member having a transparent electrode attached to one surface thereof, and a transparent material in the photoconductive layer member. Between the electrode provided opposite to the surface on which the electrode is not attached, the charge storage layer member movable between the electrode and the photoconductive layer member, and the transparent electrode and the electrode. A light-to-charge conversion section composed of a power source connected to the light-source, means for forming a charge image corresponding to the optical image of the object on the charge storage layer member in the light-to-charge conversion section, and Means for moving the charge image forming portion of the charge storage layer member on which the charge image corresponding to the image is formed to the charge image reading section, and means for moving the charge image reading section to the optical image of the object in the charge image reading section. The charge image that is being read In addition to a normal optical image, the image pickup apparatus of the present invention includes a character, a figure, a pattern, coded optical information, and other arbitrary light. Information can be picked up and recorded as optical information to be picked up, and in addition, in the image pickup apparatus of the present invention, a complete charge can be formed by sequentially adhering to the surface of the charge storage layer member. Since the image is a charge image having a charge amount corresponding to the light amount of each part in the optical information to be recorded on the photoconductor layer member, the charge image has a sufficiently high definition. It requires a high degree of definition corresponding to the body layer member, and as described above, it is a perfect layer that is sequentially deposited on the surface of the charge storage layer member.
It is possible to easily generate a video signal capable of reproducing a high-quality and high-resolution reproduced image from each charge image by, for example, electrostatic reading means or optical reading means. In the image pickup device of the invention, at the same time as the image pickup of the optical information to be imaged, the optical information is recorded. According to the present invention, the above-mentioned conventional problems can be solved well, Further, the present invention can be suitably applied to an electronic still camera and a camera-integrated recording / reproducing apparatus.

[Brief description of drawings]

FIG. 1 is a perspective view for explaining the configuration principle and operation principle of the image pickup apparatus of the present invention, and FIGS. 2 and 3 are block diagrams of an embodiment of the image pickup apparatus of the present invention. Et, Etr …… Transparent electrode, E …… Electrode, PCL …… Photoconductor layer member, CML …… Charge storage layer member, Vc …… Power supply, PCCA ……
Light-to-charge converter, 1 ... Imaging lens, 2 ... Charge image, RA
... Readout section for charge image, 3 ... Needle electrode for charge detection, 4
... switch, 5 ... field effect transistor, 6 ... resistance, 7 ... detection force terminal, Er ... electrode, RH ... charge image reading head, DML ... dielectric mirror, PML ... optical modulation material Layer member, 10 ... Laser light source (or light source using halogen lamp), 11 ... Polarizer, 12 ... Optical deflector, 13 ... Collimator lens, 9 ... Beam splitter, 8 ... Lens, 14 ... … Condenser lens, 15 …… Wave plate for adjusting light intensity, 16
…… Analyzer, 17 …… Photoelectric converter,

Front page continuation (72) Inventor Asakura, 3-12 Moriya-cho, Kanagawa-ku, Yokohama, Kanagawa Japan Victor Company of Japan (72) Masato Furuya 3--12, Moriya-cho, Kanagawa-ku, Yokohama Japan Victor Co., Ltd. (56) References JP-A-58-225772 (JP, A)

Claims (1)

[Claims] 1. A photoconductive layer member having a transparent electrode attached to one surface thereof, and an electrode provided opposite to the surface of the photoconductive layer member to which the transparent electrode is not attached. A charge-storage layer member movable between the electrode and the photoconductive layer member, and a light-charge conversion unit configured by a power source connected between the transparent electrode and the electrode,
An optical image of the subject is formed on the imaging surface of the light-charge conversion unit from the transparent electrode side of the light-charge conversion unit by an imaging lens, and the subject is formed on the charge storage layer member in the light-charge conversion unit. Means for forming a charge image corresponding to the optical image of the charge storage layer, and a portion for forming the charge image on the charge storage layer member on which the charge image corresponding to the optical image of the subject is formed, Image pickup device including means for moving the electric charge image corresponding to the optical image of the subject in the electric charge image reading section and generating a video signal.