JPH02150181A - Image pickup device - Google Patents

Abstract

PURPOSE:To make the title device suitable for an asynchronous input/output by providing an image pickup element obtained with successively laminating a light transmitting substrate, a transparent electrode, a first electrode patterned to an optical semiconductor island, an aeolotropic solid electrolyte, and second electrodes, an image pickup means, a means to irradiate beams on the optical semiconductor, etc. CONSTITUTION:The image pickup element obtained by successively laminating light transmitting substrate 101, a transparent electrode 102, optical semiconductors 103 and 104, a first electrode 105 patterned to an island, an aeolotropic solid electrolyte 106, and second electrodes 107 is provided. When light passed through an image pickup lens 305 irradiates the optical semiconductors 103 and 104, a voltage in proportion to the illumination light is generated at an optical battery 113. At the time of the image pickup, since the transparent electrode 102 and the second electrode 107 are short-circuited, the generated voltage charges a secondary battery 114, and the pattern of the illumination light is converted into the voltage pattern of the secondary battery. The charge can be held for a period in a range from a several hours to several hundred hours depending the types of the solid electrolytes. Thus, when the light is once inputted, it is stored, and repeatedly read. Thus, the image pickup device suitable for the asynchronous operation can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an imaging device that converts a two-dimensional optical image into an electrical signal and stores the electrical signal after the conversion.

Conventional technologyAlthough it is commonly used as a conventional imaging device, CO
D (Charge Coupled Device
). This is to read signal charges induced in a silicon photodiode to the outside using a CCD shift register.

Problems to be Solved by the Invention However, although the CCD image pickup device is suitable for repeatedly outputting a television signal at a fixed period, it is not suitable for outputting at a random period. The reason for this is that when the cycle becomes long, a dark current due to heat causes a white level output to be output even when no light hits it. Approximately 1 at room temperature
The limit is seconds to several seconds.

It is also not suitable to capture an optical image if it is only illuminated for a short time. This is because the CCD's charge disappears when it is used for measurement, that is, it does not have a memory function. There are two ways to deal with this: one is to have a huge amount of external image memory and record everything, and the other is to record only the necessary images while determining whether or not the desired optical image is present.

The former has the disadvantage that the configuration is too large, and the latter has the disadvantage that control is complicated. As described above, the CCD is an image sensor that is not suitable for non-periodic operation.

In view of this, an object of the present invention is to provide an imaging device suitable for aperiodic input/output.

Means for Solving the Problems The present invention consists of sequentially stacking a light-transmissive substrate, a transparent electrode, a photosemiconductor or a photoconductor, a first electrode patterned in an island shape, an anisotropic solid electrolyte, and a second electrode. The present invention is characterized by comprising: an imaging device consisting of an optical semiconductor; a means for capturing an optical image on the optical semiconductor; and a means for irradiating the optical semiconductor or the photoconductor with a light beam scanned in the vertical and horizontal directions. It is an imaging device.

Effect of the present invention With the above-described configuration, the following operation is performed during imaging.When an optical semiconductor is irradiated with light having an energy larger than the band gap of the optical semiconductor material through a light-transmitting substrate, excitation occurs in the conduction band of the optical semiconductor. Electrons and, in the valence band, holes are generated. At this time, when the transparent electrode and the second electrode are electrically short-circuited, a specific electrochemical reaction occurs at the first electrode and the second electrode due to the action of these electrons and holes, and this reaction causes the first electrode and the second electrode to The voltage between the two electrodes changes. The voltage between the first electrode and the second electrode corresponds to the electromotive voltage of the secondary battery constituted by the first electrode, the solid electrolyte, and the second electrode, and is maintained as it is even after the light irradiation is stopped.

In other words, the two-dimensional pattern of the irradiated light is converted into the two-dimensional pattern of the secondary battery.

During readout, the optical semiconductor is irradiated with a narrowly focused light beam to make only that part of the optical semiconductor electrically conductive, thereby extracting the voltage between the first and second electrodes to the outside via the transparent electrode. Do it by doing this.

Erasing is performed by discharging the secondary battery voltage between the first electrode and the second electrode by applying a voltage opposite to that during imaging between the transparent electrode and the second electrode.

Also, in the case of a photoconductor, since its resistance is inversely proportional to the irradiation light, a similar effect can be obtained by appropriately charging the secondary battery with a writing power source.

Embodiment FIG. 1 shows a configuration diagram of an imaging apparatus in a first embodiment of the present invention. In FIG. 1, reference numeral 100 denotes an imaging device formed by sequentially laminating a light-transmitting substrate, a transparent electrode, a photosemiconductor or a photoconductor, a first electrode patterned in an island shape, an anisotropic solid electrolyte, and a second electrode 107. The element 200 is a signal processing circuit of the imaging cord 100. Details will be described later. 30
0 is a laser oscillator that generates a light beam, 301 is a focusing lens, and 302 is a laser beam that vertically scans (low speed side scanning)
A galvanometer 303 scans the laser beam horizontally (
304 is an image sensor 100;
305 is an imaging lens.

In the configuration shown in FIG. 1, during imaging, the reflecting mirror 304 is fixed at an angle indicated by a dotted line, and the optical image created by the imaging lens 305 is focused on the imaging element 100. During reading and erasing, the reflecting mirror 304 is fixed at the angle shown by the solid line, and the image sensor 100 is irradiated with vertically and horizontally scanned laser light.

Next, the inside of the image sensor 100 will be explained with reference to FIGS. 2 and 3. FIG. 2 shows a cross-sectional view of the image sensor 100, where 101 is a light-transmitting substrate made of glass or the like, 102 is a transparent electrode made of indium/tin, etc., 103 is P-type amorphous silicon, and 104 is I-type amorphous silicon. Amorphous silicon, 105 is a first electrode patterned into an island shape, 106
is an anisotropic solid electrolyte, 107 is a second electrode, and 108 is a protective film.

Note that incident light during imaging and laser light during readout are irradiated from the transparent substrate 101 side. In addition to the above, optical semiconductors include Si, Zn5e, ZnTe, CdS, C
dSe, CdTe, A IXGal-XAs (0≦X≦
1), GaAs1-XPX (0≦X≦1), A I
Sb, InP, MoS2. MoSe2゜WS2
, "vVs e2. MXI n S2 (M=Cu or Ag, O<X<1>, MXI nSe2 (M=Cu
Or Ag, O<X<1), etc. can be used, and these P type, N type, or P-I, N-I, P-I-
An N-junction type can be selected.

The solid electrolyte material is RbC1-CuC1-CuI
crystalline and glassy copper ion conductive solid electrolytes of CuI-Cu20-Mo03 series, or Rb
I-AgI-based or AgI-A g20-B2O2-based crystalline or glassy silver ion conductive solid electrolytes can be used.

FIG. 3 shows a plan view of the image sensor 100. In FIG. 3, the same numbers as in FIG. 2 indicate the layers. 109 is the extraction electrode part of the transparent electrode 102, and 110 is the second electrode 10.
7 shows the extraction electrode section.

FIG. 3 shows an example in which the first electrodes are formed into islands in 6 columns horizontally and 6 rows vertically.

Next, FIG. 4 shows the inside of the signal processing circuit 200 and the image sensor 10.
0 is shown in the equivalent circuit. In Fig. 4, 201a and 201
202 is an amplifier for impedance conversion, and 203 is an erasing power supply. Reference numeral 113 in FIG. 4 is a photovoltaic cell composed of optical semiconductors 102 and 103 formed between the transparent electrode 102 and the first electrode 105 in FIG. 2, and the electromotive force is proportional to the irradiated light. Reference numeral 114 in FIG. 4 is a secondary battery in which the first electrode 105 and anisotropic solid electrolyte 106 in FIG. 2 are replaced by a second electrode 107. Since the first electrodes are independent from each other, there are as many sets of photovoltaic cells and secondary batteries connected in series as islands. In the example of FIG. 3, there are 36 (6×6).

The operation of the imaging apparatus of this embodiment configured as described above will be explained below with reference to FIG. 5.

First, FIG. 5(a) shows the principle of operation during imaging.

Light passing through the imaging lens 305 passes through the optical semiconductors 103 and 104.
The transparent electrode 102 and the second electrode 103 are short-circuited during imaging, so the generated voltage is applied to the secondary battery 114.
This means that the irradiated light pattern is converted into the voltage pattern of the secondary battery. This charged charge can be maintained for several hours to several hundred hours, although it varies depending on the type of solid electrolyte.

Next, FIG. 5(b) shows the operating principle at the time of reading. At the time of reading, the reflecting mirror 304 shown in FIG. 1 is switched to irradiate laser light of a constant intensity. This laser beam is scanned vertically and horizontally along the pattern of the island-shaped first electrode 105, and only one island is irradiated at a certain moment. Since the transparent electrode 102 and the second electrode 103 are connected to the amplifier 202, the voltage difference between the photovoltaic cell 113 and the secondary battery 114, which are irradiated with laser light, becomes an input to the amplifier 202.

Since the voltage of the photocell 113 is constant for the laser beam, that is, the voltage is constant, it is possible to read the voltage of the secondary battery 114 that is proportional to the irradiation light during imaging. Since the photovoltaic cells of other elements that are not hit by the laser beam are equivalent to being open, they will not be affected.Also, if the input current of the amplifier 202 is set to about the leakage current of the secondary battery 114, the secondary battery 11 due to this readout
Since the voltage drop of 4 is negligible, reading may be performed any number of times or for a long period of time.

Next, FIG. 5(c) shows the principle of operation during erasing.

When erasing, a voltage opposite to that used during imaging is applied externally.
Since the optical semiconductor 113 in this case is equivalent to a forward bias diode, the charge of the secondary battery 114 is discharged. At this time, the voltage of the external erasing voltage 03 needs to be higher than the forward voltage of the diode-operated photovoltaic cell 113.

As described above, according to this embodiment, long-term storage is possible by charging the secondary battery with the induced voltage of the optical semiconductor. This way, once there is an optical input, it is memorized,
An imaging device suitable for non-periodic operation that can be read out any number of times can be obtained.

Furthermore, although the explanation has been made using a 6×6 matrix in FIG. 3, since no matrix driving is performed, there is basically no restriction on the number of elements. This limit is determined by the laser beam diameter or the S/N ratio of the reduction in readout current due to the subdivision of the secondary battery.

It is possible to integrate a large number of elements within this range.

FIG. 6 shows a cross-sectional view of an imaging element used in an imaging device according to a second embodiment of the present invention.

In the second embodiment, the photovoltaic cell of the first embodiment is replaced with a photoconductor. In FIG. 6, reference numeral 115 is a photoconductor, and since the rest is the same as in FIG. 2, it is designated by the same number. The photoconductor 115 is made of amorphous silicon, Si, Zn.
5e, ZnTe, CdS, CdS e, Cd
T e etc. can be used.

FIG. 7 shows an equivalent circuit of the image sensor shown in FIG. 6 and a corresponding signal processing circuit. In FIG. 7, parts having the same functions as those in FIG. 4 are given the same numbers and their explanations are omitted. In FIG. 7, 116 is the resistance of the photoconductor 115 shown in FIG. 6, which is inversely proportional to the irradiated light. Then, as in the first embodiment, the first electrode 1
05 are independent from each other, there are as many sets of resistors and secondary batteries connected in series as islands. Reference numeral 204 indicates a write power supply during imaging, and 205 indicates a power supply during erasing.

The operation of the imaging apparatus of the second embodiment configured as described above will be explained below with reference to FIG. 8.

First, FIG. 8(a) shows the principle of operation during imaging.

The light passing through the imaging lens 305 is irradiated onto the photoconductor 115, resulting in a resistance 116 that is inversely proportional to the irradiated light. During imaging, the write power supply 204 is connected, so this resistor 11
6, the secondary battery 114 is charged, and the pattern of the irradiated light is converted into the voltage pattern of the secondary battery as in the first embodiment.

Next, FIG. 8(b) shows the operating principle at the time of reading. As in the first embodiment, when reading, the reflecting mirror 304 in FIG.
, and irradiate the laser beam with a certain intensity. Since only the photoconductor that is irradiated with the laser light is short-circuited, the voltage of the secondary battery 114 that is proportional to the irradiation light during imaging can be read out. Since the other elements are in an open state, there is no influence. Next, FIG. 8(C) shows the principle of operation during erasing.

Erasing is performed by applying a voltage opposite to that during imaging from the power supply 205 and simultaneously irradiating light to short-circuit the photoconductor 116 and discharge the secondary battery 114.

This light may also be used as a laser light during readout. In this case, partial erasure becomes possible. In the case of total erasing, there is no need to scan, so a separate light source may be used to erase all at once. Also, if you can set a longer erasing time, please set the power supply to 20
It is also possible to simply short-circuit without using 5.

As described above, according to this embodiment, by charging the secondary battery as in the first embodiment, long-term storage becomes possible. Photoconductors have the advantage of offering a wider range of options than photovoltaic cells in terms of light absorption wavelength and intensity.

Note that although laser light was used for reading in the first and second embodiments, coherent light such as a laser is not a necessary condition, and light of a constant intensity is sufficient, and ordinary lamp light can be used. be.

As described in detail, according to the present invention, it is possible to obtain an imaging device that can cope with imaging of phenomena that occur intermittently and output with random cycles, and has great practical effects.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an imaging device according to a first embodiment of the present invention, FIG. 2 is a sectional view of an imaging device of the same embodiment, FIG. 3 is a plan view of an imaging device of the same embodiment, and FIG. 4 5(a) to (C) are equivalent circuit diagrams of the image sensor and signal processing circuit of the same example.
is an explanatory diagram of the operation of the same embodiment, FIG. 6 is a sectional view of an image sensor used in an imaging device according to another embodiment of the present invention, and FIG. 7 is an equivalent circuit diagram of the image sensor and signal processing circuit of the same embodiment. , FIGS. 8(a) to 8(C) are explanatory diagrams of the operation of the same embodiment. 100...Image sensor, 101...Light transparent substrate, 1
02... Transparent electrode, 103.104... Optical semiconductor,
105... First electrode, 106... Anisotropic solid electrolyte, 107... Second electrode, 200... Signal processing circuit,
300... Laser oscillator, 302... Galvanometer, 303... Rotating polygon mirror, 305... Imaging lens. Name of agent: Patent attorney Shigetaka Awano (1 person) O5

Claims (3)

[Claims] (1) An imaging device formed by sequentially stacking a light-transmissive substrate, a transparent electrode, an optical semiconductor, an islanded first electrode, an anisotropic solid electrolyte, and a second electrode, and capturing an optical image on the optical semiconductor. An imaging device comprising: means for irradiating the optical semiconductor with a light beam scanned in a vertical direction and a horizontal direction. (2) An imaging device comprising a light-transmissive substrate, a transparent electrode, a photoconductor, an islanded first electrode, an anisotropic solid electrolyte, and a second electrode laminated in sequence, and an optical image formed on the photoconductor. An imaging device comprising: means for imaging; and means for irradiating the photoconductor with a light beam scanned in vertical and horizontal directions. (3) An imaging device according to claim 2, further comprising means for irradiating the photoconductor with light of a constant intensity.