US3855579A - Method of using an optic relay comprising an element of an electro-optical material and a photosensitive element - Google Patents

Method of using an optic relay comprising an element of an electro-optical material and a photosensitive element Download PDF

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Publication number
US3855579A
US3855579A US00323848A US32384873A US3855579A US 3855579 A US3855579 A US 3855579A US 00323848 A US00323848 A US 00323848A US 32384873 A US32384873 A US 32384873A US 3855579 A US3855579 A US 3855579A
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United States
Prior art keywords
voltage
electro
plate
image
relay
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Expired - Lifetime
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US00323848A
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English (en)
Inventor
M Grenot
J Pergrale
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US Philips Corp
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US Philips Corp
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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/03—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect
    • G02F1/05—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect with ferro-electric properties
    • G02F1/0533—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect with ferro-electric properties structurally associated with a photo-conductive layer

Definitions

  • Gllc 13/04 is Zero Application: Television Field of Search 340/173 LM, l73 L5 2 Claims, 1 Drawing Figure METHOD OF USING AN OPTIC RELAY COMPRISING AN ELEMENT OF AN ELECTRO-OPTICAL MATERIAL AND A PHOTOSENSITIVE ELEMENT
  • the present invention is related to the invention which forms the object of the US. Pat. 3,792,259 in the name of applicant. It relates more in particular to a method of using an optic relay described in the above patent application when in the manufacture of said relay a photosensitive element is included.
  • the method described consists in exposing the photosensitive layer in a uniform manner, for example, by means of a flash of light, and simultaneously removing the direct voltage applied between the two control electrodes.
  • said control electrodes are constituted by two transparent conductive layers deposited on the faces of the stack consisting of the plate of electro-optical material, the dielectric mirror and the photoconductive layer. Under the influence of the light, numerous pairs of electrons-holes are produced in the photoconductor the resistivity of which decreses considerable.
  • the phenomenon or erasing charges deposited on the electro-optical material may be made equal to a capacitor discharge via a resistor which may be non-linear, the capacitor being constituted by the plate of electrooptical material and the resistance being that of the photoconductive element.
  • the erased" state is obtained while the applied external voltage is zero.
  • the capacitive divider comprising in series on the one hand the capacity C constituted by the assembly plate of electro-optical material dielectric mirror and on the other hand the capacity C constituted by the photoconductive element causes a volt age equal to V C'/C C to appear at the terminals of the said plate, which voltage is sufficient to produce a uniform modulation to which a uniform background corresponds.
  • the method of using the optic relay according to the present invention endeavours to mitigate said inconvenience. It is remarkable in that, in order to erase a recorded image, the photosensitive layer is uniformly exposed and simultaneously a voltage -V having a sign opposite to that of the voltage V applied during the recording is applied between the control electrodes.
  • the value of V is such that when the voltage V is again applied for a new recording, the voltage which appears at the terminals of the useful capacity C of the assembly electro-optical material-dielectric mirror is zero. Said value of V is equal to C'/C V.
  • reference numeral 1 denotes a sheet of material which is transparent to the reading light and which serves to support the assembly of the relay
  • 2 is a conductive layer which is transparent to the reading light and permits the connection of the contact 3 deposited on the plate 4 of electro-optical material, for example, deuterated potassium biph osphate (KDP)
  • KDP deuterated potassium biph osphate
  • 5 is the multi-layer dielectric mirror permitting the reflection of the reading light emitted by the source 6.
  • the photoconductive layer is shown at 7, the conductive layer at 8 which is transparent to the erasing light 9 and permits the connection to the contact 10.
  • a direct voltage +V is applied between the electrodes 3 and 10.
  • the KDP is brought at a temperature near its 'Curie point (approximately 50C).
  • the assumed initial charging state of the plate corresponds to a non-uniform charge density which may originate, for example, from a first image erasing by projection with the aid of the light 9 in the presence of the applied potential +V.
  • the voltage V (C/C V) is applied between the electrodes 3 and 10 and the photosensitive layer is exposed with the aid ofa beam of uniform light 9 during a time which is sufficient for the assembly KDP-dielectric mirror to be charged to the voltage -V'.
  • the recording conditions of an image are while applying the voltage +V between the electrodes 3 and I0 and projecting an image on the photosensitive layer. Due to the capacity existing between the faces of the photosensitive layer, the various points of the assembly KDP-dielectric mirror are brought at potentials which vary between 0 for the non-exposed points and +V for the most exposed points.
  • V C'/C+C should read V line 62
  • C'/C V should read L Col. 2, line 33
  • V' (C'/C V) should read V' V)

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  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Ceramic Engineering (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Optics & Photonics (AREA)
  • Liquid Crystal (AREA)
  • Switches Operated By Changes In Physical Conditions (AREA)
  • Photo Coupler, Interrupter, Optical-To-Optical Conversion Devices (AREA)
  • Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
  • Optical Recording Or Reproduction (AREA)
  • Facsimile Scanning Arrangements (AREA)
US00323848A 1972-01-14 1973-01-15 Method of using an optic relay comprising an element of an electro-optical material and a photosensitive element Expired - Lifetime US3855579A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7201326A FR2167426B2 (ja) 1972-01-14 1972-01-14

Publications (1)

Publication Number Publication Date
US3855579A true US3855579A (en) 1974-12-17

Family

ID=9091963

Family Applications (1)

Application Number Title Priority Date Filing Date
US00323848A Expired - Lifetime US3855579A (en) 1972-01-14 1973-01-15 Method of using an optic relay comprising an element of an electro-optical material and a photosensitive element

Country Status (6)

Country Link
US (1) US3855579A (ja)
JP (1) JPS4881072A (ja)
CA (1) CA991299A (ja)
DE (1) DE2301233C3 (ja)
FR (1) FR2167426B2 (ja)
GB (1) GB1414894A (ja)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4731754A (en) * 1985-09-12 1988-03-15 The United States Of America As Represented By The Secretary Of The Navy Erasable optical memory material from a ferroelectric polymer
US4941735A (en) * 1989-03-02 1990-07-17 University Of Colorado Foundation, Inc. Optically addressable spatial light modulator
US5179533A (en) * 1989-07-31 1993-01-12 Radiant Technologies Read/write optical memory

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3740734A (en) * 1972-03-15 1973-06-19 Bell Telephone Labor Inc Coarse grain polycrystalline ferroelectric ceramic optical memory system

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3740734A (en) * 1972-03-15 1973-06-19 Bell Telephone Labor Inc Coarse grain polycrystalline ferroelectric ceramic optical memory system

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4731754A (en) * 1985-09-12 1988-03-15 The United States Of America As Represented By The Secretary Of The Navy Erasable optical memory material from a ferroelectric polymer
US4941735A (en) * 1989-03-02 1990-07-17 University Of Colorado Foundation, Inc. Optically addressable spatial light modulator
US5179533A (en) * 1989-07-31 1993-01-12 Radiant Technologies Read/write optical memory

Also Published As

Publication number Publication date
GB1414894A (en) 1975-11-19
JPS4881072A (ja) 1973-10-30
FR2167426B2 (ja) 1975-10-24
DE2301233A1 (de) 1973-08-09
FR2167426A2 (ja) 1973-08-24
DE2301233B2 (de) 1978-02-16
CA991299A (en) 1976-06-15
DE2301233C3 (de) 1978-10-12

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