EP0622954A2
Expired / Lapsed
EP
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Method and device for recording information, and method for measuring the transmittance of liquid crystals, which is applied to recording information
Assignee: Dai Nippon Printing Co Ltd
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Filing: 1994-04-27
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Granted: —
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Expires: 2014-04-27
Abstract
Abstract The invention provides a system in which a photoelectric sensor having a transparent electrode and a photoconductive layer formed on a transparent substrate in this order is opposed to a liquid crystal recording medium having a transparent electrode and a polymer dispersion type of liquid crystal layer formed on a transparent substrate in this order, and voltage is applied between both the electrodes for exposure to image-carrying light, so that the liquid crystals are oriented to record the information. In this system, the transmittance of the liquid crystal recording medium, the current flowing through the photoelectric sensor or liquid crystal recording medium, the conductivity of the unexposed portion of the photoelectric sensor, and the transmittance of the liquid crystal layer at a dark portion are measured, or the voltage applied on the liquid crystal recording medium is estimated by monitoring the current flowing through the liquid crystal recording medium, so that the applied voltage and the duration of the applied voltage can be controlled. Before recording the information, the optimal applied voltage and the optimal duration of the applied voltage can thus be preset to make it possible to obtain images of high quality.
Inventors
- 👤 Masato C/O Dai Nippon Printing Co. Ltd. Okabe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 15:27
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/30; C; C09; C09K; C09K19/00; C09K19/04
Claims Analysis
Total Claims: 59
Claim 1
Independent Claim
153 words
A method for recording information by opposing a photoelectric sensor to a liquid crystal recording medium with an air layer located therebetween, said photoelectric sensor having a photoconductive layer formed on a transparent electrode and said liquid crystal recording medium in which a polymer dispersion type of liquid crystal layer having liquid crystals dispersed and fixed in resin is formed on an electrode, and applying voltage between both the electrodes simultaneously with exposure to image-carrying light, thereby recording the image on said liquid crystal recording medium, characterized in that the resistivity of said liquid crystal recording layer and/or the conductivity of said photoelectric sensor in a dark place are measured prior to recording the image, and the voltage to be applied between both said electrodes is preset on the basis of the measurements of the resistivity of said liquid crystal recording layer and/or the conductivity of said photoelectric sensor in a dark place.
Claim 2
Dependent Claim
65 words
A method according to Claim 1, characterized in that the resistivity of said liquid crystal recording medium is found from a change-with-time in the current flowing through said liquid crystal recording layer, said current being measured by forming an electrode on the surface of said liquid crystal recording layer and applying voltage on said liquid crystal recording layer via a capacitor having a given capacity.
Claim 3
Dependent Claim
63 words
A method according to Claim 1 or 2, characterized in that the conductivity of said photoelectric sensor in a dark place is found from the value of the current flowing through said photoelectric sensor, said current being measured by forming an electrode on the surface of said photoconductive layer and applying voltage on said photoelectric sensor via a capacitor having a given capacity.
Claim 4
Dependent Claim
32 words
A method according to Claim 1, 2, 3, characterized in that the conductivity of said photoelectric sensor is determined on the basis of the resistivity of said liquid crystal recording layer measured.
Claim 5
Independent Claim
40 words
A method according to any one of Claims 1 to 4, characterized in that the conductivity of said photoelectric sensor is determined on the basis of a current value corresponding to a capacity change of said liquid crystal recording layer.
Claim 6
Independent Claim
146 words
A device for recording information wherein a photoelectric sensor having a transparent electrode and a photoconductive layer formed on a transparent substrate in this order is opposed to a liquid crystal recording medium having a transparent electrode and a polymer dispersion type of liquid crystal recording layer formed on a transparent substrate in this order, and voltage is applied between both the electrodes for exposure to image-carrying light, so that liquid crystals are oriented to record the information, characterized by including a means for measuring the conductivity of an unexposed portion of said photoelectric sensor and a means for measuring the resistivity of said liquid crystal recording medium, and characterized in that the voltage to be applied between the electrodes of said photoelectric sensor and said liquid crystal recording medium is preset on the basis of the measurements obtained by said conductivity and resistivity measuring means.
Claim 7
Independent Claim
126 words
A method for recording information by opposing a photoelectric sensor to a liquid crystal recording medium with an air layer located therebetween, said photoelectric sensor having a photoconductive layer formed on a transparent electrode and said liquid crystal recording medium in which a polymer dispersion type of liquid crystal layer having liquid crystals dispersed and fixed in resin is formed on an electrode, and applying voltage between both the electrodes simultaneously with exposure to image-carrying light, thereby recording the image on said liquid crystal recording medium, characterized in that the conductivity of an unexposed portion of said photoelectric sensor is measured to determine the duration of the voltage applied between said photoelectric sensor and said liquid crystal recording medium on the basis of the resulting measurement.
Claim 8
Dependent Claim
27 words
A method according to Claim 7, characterized in that voltage is applied between said electrodes for said determined duration of the applied voltage to record the information.
Claim 9
Independent Claim
137 words
A method for recording information using a liquid crystal recording medium in which a photoelectric sensor, a polymer dispersion type of liquid crystal layer and an electrode are formed on at least an electrode in this order or in which a photoelectric sensor, a dielectric middle layer, a polymer dispersion type of liquid crystal layer and an electrode are formed on an electrode in this order, by applying voltage between both the electrodes simultaneously with exposure to image-carryng light through the photoelectric sensor of the liquid crystal recording medium, thereby recording the information on the polymer dispersion type of liquid crystal layer, characterized in that the conductivity of an unexposed portion of said photoelectric sensor is measured, and the duration of the voltage applied between both said electrodes is determined on the basis of the resulting measurement.
Claim 10
Dependent Claim
28 words
A method according to Claim 9, characterized in that voltage is applied on between said electrodes for said determined duration of the applied voltage to record the information.
Claim 11
Independent Claim
143 words
A method for measuring the transmittance of a liquid crystal recording medium having a transparent electrode and a polymer dispersion type of liquid crystal layer formed on a transparent substrate in this order by locating the liquid crystal recording medium in opposition to a photoelectric sensor having a transparent electrode and a photoconductive layer formed on a transparent substrate in this order and applying voltage between both the electrodes for exposure to image-carrying light, so that the liquid crystals are oriented to record the image, characterized in that a part of the surface of said photoconductive layer or said liquid crystal layer is provided with a reflecting layer, and the incident light passing through said liquid crystal recording medium is reflected by said reflecting layer, so that the transmittance of said liquid crystal recording medium can be measured by detecting the reflected light.
Claim 12
Dependent Claim
20 words
A method according to Claim 11, characterized in that said reflecting layer is formed on the exposed or unexposed portion.
Claim 13
Independent Claim
110 words
A method for recording information by opposing a photoelectric sensor having a transparent electrode and a photoconductive layer formed on a transparent substrate in this order to a liquid crystal recording medium having a transparent electrode and a polymer dispersion type of liquid crystal layer formed on a transparent substrate in this order, and applying voltage between both the electrodes for exposure to image-carrying light, so that the liquid crystals are oriented to record the information, characterized in that the transmittance of said liquid crystal recording medium is monitored, and the duration of the applied voltage is controlled on the basis of the transmittance of said liquid crystal recording medium.
Claim 14
Dependent Claim
29 words
A method according to Claim 13, characterized in that when the difference in transmittance between the exposed and unexposed portions reaches a maximum, the application of voltage is stopped.
Claim 15
Dependent Claim
59 words
A method according to Claim 13 or 14, characterized in that the area to be monitored is irradiated with light in a quantity corresponding to an average quantity of light of the image to detect the transmittance of said liquid crystal layer, and the duration of the applied voltage is controlled on the basis of the thus detected transmittance.
Claim 16
Dependent Claim
60 words
A method according to Claim 13, 14, or 15, characterized in that the area to be monitored is irradiated with light in a quantity corresponding to the maximum quantity of light of the image to detect the transmittance of said liquid crystal layer, and the duration of the applied voltage is controlled on the basis of the thus detected transmittance.
Claim 17
Independent Claim
44 words
A method according to any one of Claims 13 to 16, characterized in that the transmittance of said liquid crystal layer at a dark portion is detected, and the duration of the applied voltage is controlled on the basis of the thus detected transmittance.
Claim 18
Dependent Claim
20 words
A method according to Claim 17, characterized in that gradation is controlled by controlling the duration of the applied voltage.
Claim 19
Independent Claim
133 words
A device for recording information by opposing a photoelectric sensor having a transparent electrode and a photoconductive layer formed on a transparent substrate in this order to a liquid crystal recording medium having a transparent electrode and a polymer dispersion type of liquid crystal layer formed on a transparent substrate in this order, and applying voltage between both the electrodes for exposure to image-carrying light, so that the liquid crystals are oriented to record the information, characterized by including a transmittance monitor for irradiating a given area of said liquid crystal recording medium with light and detecting the reflected light to measure the transmittance of said liquid crystal recording medium, and characterized in that the duration of the applied voltage is controlled on the basis of the value detected by said transmittance monitor.
Claim 20
Dependent Claim
43 words
A device according to Claim 19, characterized in that a part of the surface of the photoelectric sensor to be exposed to light is provided with a mask, and the transmittance of the area shielded by said mask from the light is measured.
Claim 21
Dependent Claim
38 words
A device according to Claim 20, characterized in that a reflecting layer is formed on the masked surface of said photoelectric sensor opposite to said liquid crystal recording medium or the surface of said liquid crystal recording medium.
Claim 22
Dependent Claim
39 words
A device according to Claim 19 or 20, characterized in that said reflecting layer is formed on the surface of said photoelectric sensor opposite to said liquid crystal recording medium or the surface of said liquid crystal recording medium.
Claim 23
Dependent Claim
29 words
A device according to Claim 21 or 22, characterized in that said reflecting layer has the spectral properties of reflecting light with the wavelength lying in a visible region.
Claim 24
Independent Claim
29 words
A device according to Claims 21 or 22, characterized in that said reflecting layer has the spectral properties of reflecting light with the wavelength lying in a ultraviolet region.
Claim 25
Dependent Claim
36 words
A device according to Claim 22, 23, or 24, characterized in that an optical system is provided for irradiating the area provided with said reflecting layer with light in a quantity corresponding to the image information.
Claim 26
Dependent Claim
38 words
A device according to Claim 25, characterized in that said optical system is comprised of a half mirror for separating a part of said image-carrying light and a lens element for condensing the light from said half mirror.
Claim 27
Dependent Claim
33 words
A device according to Claim 25 or 26, characterized in that said optical system is one separate from the exposure system for emitting light corresponding to the quantity of light of the subject.
Claim 28
Independent Claim
118 words
A method for recording information by opposing a photoelectric sensor having a transparent electrode and a photoconductive layer formed on a transparent substrate in this order to a liquid crystal recording medium having a transparent electrode and a polymer dispersion type of liquid crystal layer formed on a transparent substrate in this order, and applying voltage between both the electrodes for exposure to image-carrying light, so that the liquid crystals are oriented to record the information, characterized in that the current flowing through said liquid crystal recording medium is monitored to estimate the voltage applied on said liquid crystal recording medium, and the duration of the applied voltage is controlled on the basis of the thus estimated voltage.
Claim 29
Dependent Claim
32 words
A method according to Claim 28, characterized in that the duration of the applied voltage is controlled on the basis of the voltage of the unexposed portion estimated by monitoring the current.
Claim 30
Dependent Claim
84 words
A method according to Claim 28 or 29, characterized in that an electrode is formed on a part of said photoconductive layer, and an electric circuit element corresponding to said liquid crystal recording layer is connected to said electrode, so that when the voltage is applied, the current flowing through said electric circuit element is monitored to estimate the voltage applied on said liquid crystal recording layer, and the duration of the applied voltage is controlled on the basis of the thus estimated voltage.
Claim 31
Independent Claim
154 words
A method for recording information by using an information recording medium in which a transparent electrode, a photoconductive layer and a liquid crystal recording layer are formed on a transparent substrate with a transparent electrode formed on said liquid crystal recording layer, or an integral type of information recording medium in which a transparent electrode, a photoconductive layer, a dielectric middle layer and a liquid crystal recording layer are formed on a transparent substrate in this order and an additional transparent electrode is provided, and applying voltage between both electrodes of said information recording medium for exposure to image-carrying light, so that the liquid crystals are oriented to record the information, characterized in that the current flowing through said liquid crystal recording medium is monitored to thereby estimate the voltage applied on said liquid crystal recording medium, and the duration of the applied voltage is controlled on the basis of the thus estimated voltage.
Claim 32
Dependent Claim
85 words
A method according to Claim 31, characterized in that an electrode is formed on part of said photoconductive layer, and an electric circuit element corresponding to said liquid crystal recording layer and dielectric middle layer is connected to said electrode, so that when the voltage is applied, the current flowing through said electric circuit element is monitored to estimate the voltage applied on said liquid crystal recording layer, and the duration of the applied voltage is controlled on the basis of the thus estimated voltage.
Claim 33
Dependent Claim
83 words
A method according to Claim 31, characterized in that an electrode is formed on a part of said dielectric middle layer, and an electric circuit element corresponding to said liquid crystal recording layer is connected to said electrode, so that when the voltage is applied, the current flowing through said electric circuit element is monitored to estimate the voltage applied on said liquid crystal recording layer, and the application of the voltage is stopped when the thus estimated voltage reaches the threshold voltage.
Claim 34
Independent Claim
128 words
A device for recording information by opposing a photoelectric sensor having a transparent electrode and a photoconductive layer formed on a transparent substrate in this order to a liquid crystal recording medium having a transparent electrode and a polymer dispersion type of liquid crystal layer formed on a transparent substrate in this order, and applying voltage between both the electrodes for exposure to image-carrying light, so that the liquid crystals are oriented to record the information, characterized by including a current-monitoring resistance connected between a power source for applying voltage between both said electrodes and said information recording medium, and a control means for monitoring the current flowing through said liquid crystal layer from the voltage applied on said resistance to control the duration of the applied voltage.
Claim 35
Dependent Claim
38 words
A device according to Claim 34, characterized in that a mask is formed on a part of the surface of said photoelectric sensor to be exposed to light, and the current value of the masked area is measured.
Claim 36
Dependent Claim
37 words
A device according to Claim 35, characterized in that the electrode of said photoelectric sensor or said liquid crystal recording medium at the masked area is formed separately from the electrode of the portion exposed to light.
Claim 37
Dependent Claim
39 words
A device according to Claim 34, 35, or 36, characterized in that an electric circuit element corresponding to said liquid crystal recording layer is connected in series with a circuit comprised of a photoelectric sensor and a current-monitoring resistance.
Claim 38
Independent Claim
42 words
A device according to any one of Claims 34 to 37, characterized in that a current-measuring circuit connected with a current-monitoring resistance is connected with a power source for applying a bias voltage corresponding to the discharge voltage of an air gap.
Claim 39
Independent Claim
55 words
A device according to any one of Claims 34 to 38, characterized in that an electrode is formed on a part of the surface of said liquid crystal recording layer, and voltage is applied on said liquid crystal recording layer to measure the current, thereby measuring the electric properties of said liquid crystal recording layer.
Claim 40
Independent Claim
123 words
A device for recording information by using an integral type of information recording medium in which a transparent electrode, a photoconductive layer, a dielectric middle layer and a liquid crystal recording layer are formed on a transparent substrate in this order and an additional transparent electrode is provided, and applying voltage between both the electrodes for exposure to image-carrying light, so that the liquid crystals are oriented to record the information, characterized by including a current-monitoring resistance connected between a power source for applying voltage between both said electrodes and said information recording medium, and a control means for monitoring the current flowing through said liquid crystal layer from the voltage applied on said resistance to control the duration of the applied voltage.
Claim 41
Dependent Claim
44 words
A device according to Claim 40, characterized in that characterized in that an electric circuit element corresponding to said liquid crystal recording layer and said dielectric middle layer is connected in series with a circuit comprised of a photoelectric sensor and a current-monitoring resistance.
Claim 42
Independent Claim
110 words
A method for recording information by opposing a photoelectric sensor having a transparent electrode and a photoconductive layer formed on a transparent substrate in this order to a liquid crystal recording medium having a transparent electrode and a polymer dispersion type of liquid crystal layer formed on a transparent substrate in this order, and applying voltage between both the electrodes for exposure to image-carrying light, so that the liquid crystals are oriented to record the information, characterized in that the current flowing through said liquid crystal recording medium is measured to thereby monitor the behavior of said liquid crystal recording layer and so control the duration of the applied voltage.
Claim 43
Dependent Claim
38 words
A method according to Claim 42, characterized in that the application of the voltage is stopped at the time when the voltage of the unexposed portion is estimated to reach the threshold of said liquid crystal recording medium.
Claim 44
Dependent Claim
45 words
A method according to Claim 42 or 43, characterized in that the time at which the contrast between the light and dark portions reaches a maximum is monitored from the change-with-time of the current of the exposed portion to stop the application of the voltage.
Claim 45
Dependent Claim
48 words
A method according to Claim 42 or 43, characterized in that the time at which the contrast between the light and dark portions reaches a maximum is monitored from the change-with-time of the current difference between the exposed and unexposed portions to stop the application of the voltage.
Claim 46
Independent Claim
69 words
A method according to any one of Claims 42 to 45, characterized in that the area to be measured in terms of current is irradiated with light of a given intensity, and the application of the voltage is stopped when the difference in the integral value of the current between the exposed and unexposed portions reaches the quantity corresponding to the capacity change of said liquid crystal recording medium.
Claim 47
Independent Claim
46 words
A method according to any one of Claims 42 to 46, characterized in that the behavior of said liquid crystal recording medium at the exposed portion is monitored by the differentiation of the current value of the unexposed portion to control the application of the voltage.
Claim 48
Independent Claim
65 words
A method according to any one of Claims 42 to 47, characterized in that an electrode is formed on the surface of the liquid crystal recording layer of said liquid crystal recording medium, and voltage is applied on said liquid crystal recording medium prior to recording the information, so that the resistance value of said liquid crystal recording medium is measured from the current value.
Claim 49
Independent Claim
49 words
A method according to any one of Claims 42 to 48, characterized in that an electrode is formed on the surface of the photoconductive layer of said photoelectric sensor, and voltage is applied on said photoelectric sensor prior to recording the information, so that the current value is measured.
Claim 50
Independent Claim
121 words
A device for recording information by opposing a photoelectric sensor having a transparent electrode and a photoconductive layer formed on a transparent substrate in this order to a liquid crystal recording medium having a transparent electrode and a polymer dispersion type of liquid crystal layer formed on a transparent substrate in this order, and applying voltage between both the electrodes for exposure to image-carrying light, so that the liquid crystals are oriented to record the information, characterized by including a current-monitoring resistance connected between a power source and said photoelectric sensor, and a control means for monitoring the value of the current flowing through a circuit from the voltage applied on said resistance to control the duration of the applied voltage.
Claim 51
Dependent Claim
38 words
A device according to Claim 50, characterized in that a mask is formed on a part of the surface of said photoelectric sensor to be exposed to light, and the current value of the masked area is measured.
Claim 52
Dependent Claim
39 words
A device according to Claim 50 or 51, characterized in that the electrode of said photoelectric sensor or said liquid crystal recording medium at the masked area is formed separately from the electrode of the portion exposed to light.
Claim 53
Dependent Claim
39 words
A device according to Claim 51 or 52, characterized in that a current-monitoring area is formed on the portion to be exposed to light, and current-monitoring resistances are connected to the masked area and the portion exposed to light.
Claim 54
Dependent Claim
39 words
A device according to Claim 53, characterized in that the values of the current-monitoring resistances connected to the masked area and the portion exposed to light are preset at those for correcting the difference in area between said electrodes.
Claim 55
Dependent Claim
32 words
A device according to Claim 53 or 54, characterized in that an optical system is provided for irradiating the current-monitoring area of said photoelectric sensor exposed to a given quantity of light.
Claim 56
Dependent Claim
45 words
A device according to Claim 54 or 55, characterized in that an electrode to be formed on the photoelectric sensor or said liquid crystal recording medium at the current-monitoring area of said photoelectric sensor exposed to light is separated from the portion exposed to light.
Claim 57
Dependent Claim
41 words
A device according to Claim 54, 55 or 56, characterized in that said optical system is comprised of a half mirror for separating a part of said image-carrying light and a lens element for condensing the light from said half mirror.
Claim 58
Independent Claim
36 words
A device according to any one of Claims 54 to 57, characterized in that said optical system is one separate from the exposure system for emitting light corresponding to the quantity of light of the subject.
Claim 59
Independent Claim
60 words
A device according to any one of Claims 50 to 58, characterized in that a spacer is located between said photoelectric sensor and said liquid crystal recording medium to keep the air gap constant, and a current-detecting electrode is formed on a part of said photoelectric sensor or said liquid crystal recording medium on which said spacer is not found.
References Cited (Backward Citations)
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