WO2001053887A2 - An active matrix electro-optic display - Google Patents

An active matrix electro-optic display Download PDF

Info

Publication number
WO2001053887A2
WO2001053887A2 PCT/GB2001/000152 GB0100152W WO0153887A2 WO 2001053887 A2 WO2001053887 A2 WO 2001053887A2 GB 0100152 W GB0100152 W GB 0100152W WO 0153887 A2 WO0153887 A2 WO 0153887A2
Authority
WO
WIPO (PCT)
Prior art keywords
active matrix
optic display
matrix electro
electro
semiconductor material
Prior art date
Application number
PCT/GB2001/000152
Other languages
French (fr)
Other versions
WO2001053887A3 (en
Inventor
Paul William Herbert Surguy
Original Assignee
Central Research Laboratories Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Central Research Laboratories Limited filed Critical Central Research Laboratories Limited
Publication of WO2001053887A2 publication Critical patent/WO2001053887A2/en
Publication of WO2001053887A3 publication Critical patent/WO2001053887A3/en

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof  ; Multistep manufacturing processes therefor
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
    • H01L29/76—Unipolar devices, e.g. field effect transistors
    • H01L29/772—Field effect transistors
    • H01L29/78—Field effect transistors with field effect produced by an insulated gate
    • H01L29/786—Thin film transistors, i.e. transistors with a channel being at least partly a thin film
    • H01L29/78645—Thin film transistors, i.e. transistors with a channel being at least partly a thin film with multiple gate
    • H01L29/78648—Thin film transistors, i.e. transistors with a channel being at least partly a thin film with multiple gate arranged on opposing sides of the channel
    • 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 
    • G02F1/13—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 liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
    • G02F1/1362—Active matrix addressed cells
    • G02F1/1368—Active matrix addressed cells in which the switching element is a three-electrode device
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof  ; Multistep manufacturing processes therefor
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
    • H01L29/76—Unipolar devices, e.g. field effect transistors
    • H01L29/772—Field effect transistors
    • H01L29/78—Field effect transistors with field effect produced by an insulated gate
    • H01L29/786—Thin film transistors, i.e. transistors with a channel being at least partly a thin film
    • H01L29/78603—Thin film transistors, i.e. transistors with a channel being at least partly a thin film characterised by the insulating substrate or support
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof  ; Multistep manufacturing processes therefor
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
    • H01L29/76—Unipolar devices, e.g. field effect transistors
    • H01L29/772—Field effect transistors
    • H01L29/78—Field effect transistors with field effect produced by an insulated gate
    • H01L29/786—Thin film transistors, i.e. transistors with a channel being at least partly a thin film
    • H01L29/78681—Thin film transistors, i.e. transistors with a channel being at least partly a thin film having a semiconductor body comprising AIIIBV or AIIBVI or AIVBVI semiconductor materials, or Se or Te
    • 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 
    • G02F1/13—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 liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/133305—Flexible substrates, e.g. plastics, organic film
    • 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 
    • G02F1/13—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 liquid crystals, e.g. single liquid crystal display cells
    • G02F1/137—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 liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
    • G02F1/139—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 liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on orientation effects in which the liquid crystal remains transparent
    • G02F1/141—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 liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on orientation effects in which the liquid crystal remains transparent using ferroelectric liquid crystals

Definitions

  • This invention relates to active matrix electro-optic displays, and particularly, though not exclusively, to ferroelectric liquid crystal displays.
  • Figure 1 shows a schematic cross section and plan view of a cadmium selenide transistor device
  • Figure 2 shows a schematic cross section of an active matrix display device according to the invention.
  • Liquid crystal displays having a thin film transistor (TFT) on each picture element are well known.
  • Analogue liquid crystal displays such as twisted nematic LCDs using cadmium selenide (CdSe), or similar high mobility amorphous /low temperature deposition process material, as the semiconductor material in the thin film transistor have been described in US 5,650637 and US 5,365,079.
  • CdSe or CdTe can be sputtered down as an amorphous layer at low temperatures (compared to polycrystalline silicon) but can achieve better mobilities than the equivalent low temperature amorphous silicon. This means that a much wider variety of substrates can be used (including plastic). However because the CdSe or CdTe is sputtered and not annealed (to keep the processing temperature low), the control of the grain size and grain boundaries are not good. This leads to a variation of about 0.5V in the threshold voltage of transistor made from the sputtered CdSe or CdTe on large substrates suitable for display applications. This makes CdSe or CdTe transistors made in this way impossible to manufacture if they are to be used with an analogue responding liquid crystal devices.
  • Ferroelectric liquid crystal displays can be made to be binary or bistable. This means they can be used for digital (binary) applications.
  • a transistor is incorporated into the display matrix then only polycrystalline silicon (which is deposited at high temperature) is able to switch fast enough to enable high-resolution digital colour sequential displays to be produced.
  • polycrystalline silicon cannot be processed at low enough temperatures for plastic substrates.
  • One way of making cadmium selenide transistors suitable for use in the present invention is described in the paper by M J Lee, S W Wright, C P Judge and P K Roberts in the Proceedings of the International Display Conference held in Monterey in 1994, page 138
  • Figure 1(a) shows a schematic cross section of such a CdSe transistor.
  • a substrate 1 made from a substantially optically transparent plastics material such as PEN (polyethylene naphthalate) having a glass transition temperature of PEN (polyethylene naphthalate)
  • a bottom gate electrode 2 is deposited on the substrate by sputtering and selective removal.
  • the gate electrode metal is aluminium although other metals such as nichrome may be used as an alternative.
  • An insulating layer 3 such as silicon dioxide is then sputtered on top of the substrate and gate electrode assembly.
  • the silicon dioxide may be deposited by photochemical decomposition.
  • Source and drain electrodes (4, 5) are then deposited on the silicon dioxide layer and selectively removed. In the present embodiment these electrodes are transparent to light and comprise ITO, but aluminium or nichrome can be used as alternative materials.
  • the CdSe layer (6) is then deposited by sputtering.
  • An insulative silicon dioxide layer (7) is then deposited on top of the semiconductor layer. It is preferably deposited in the same vacuum system, without breaking vacuum between deposition steps. This is then patterned and etched in the usual way, and a top gate electrode (8) is deposited and patterned.
  • Figure 1(b) shows a plan view of the device before the top gate electrode is provided.
  • the gate electrodes 2 and 8 are opaque, to minimise light induced currents in operation.
  • Figure 2 shows how the TFT device is incorporated into an active matrix
  • FLC display This shows a schematic cross section of a ferroelectric LC display pixel, having a thin film transistor (9) as described above, and a pair of transparent substrates 1, each having a transparent electrode 11 and an alignment layer 10.
  • the column electrode 12 is electrically connected to the gate of the TFT, whilst the row electrode 13 is connected to the drain. Electrodes 11 and 13 have an electrically insulative layer therebetween (not shown).
  • the cavity between the two substrates is filled with a bistable electro-optic material 14, such as a ferroelectric liquid crystal.
  • a particularly relevant application that requires plastic (i.e. low process temperature) substrates and needs the colour sequential approach, as well as the monochrome bistable capability, are the displays in the next generation of portable communications equipment. These require low power and colour "video" capability.
  • Conventional colour filter displays mostly require back illumination in order to be viewable, and this is not compatible with low power requirements.
  • the colour sequential approach however allows colour "video” pictures to be viewed, but once they have been viewed the display can automatically switch to bistable mode, where the displays consumes no power, but is only able to displays static monochrome pictures or text using reflected available light. This approach allows optimum power consumption as the display uses zero power (if used in reflection) in standby mode or when transmitting or receiving calls /data and consumes power only when the display is viewed.
  • An additional advantage of using high mobility semiconductor materials such as cadmium selenide or cadmium telluride with digital FLC materials is the fact that you can fabricate integrated column and row driver circuits on a glass or plastics substrate. If an analogue liquid crystal device was being made, the column drivers would be analogue. Cadmium selenide or other II-VI materials cannot be used for analogue column drivers as the threshold voltage of the transistors is too variable to construct the digital to analogue converters. Such semiconductor materials can however be used for the row driver circuits, as these are digital even for analogue LC devices.
  • LCDs based on CdSe or CdTe transistors are able to produce good quality high- resolution displays, but together they can produce high-resolution digital colour sequential displays. This is not an obvious combination since low temperature CdSe has generally been abandoned for LCD application because of the difficulty in controlling the threshold voltage.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Ceramic Engineering (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Computer Hardware Design (AREA)
  • Chemical & Material Sciences (AREA)
  • Nonlinear Science (AREA)
  • Liquid Crystal (AREA)
  • Materials Engineering (AREA)
  • Mathematical Physics (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Optics & Photonics (AREA)
  • Devices For Indicating Variable Information By Combining Individual Elements (AREA)

Abstract

An active matrix electro-optic display comprises a matrix of ferroelectric liquid crystal pixels, each pixel being driven in use by a thin film transistor (9) consisting of or including a layer (14) of CdSe or CdTe semiconductor material carried by a substrate (1) consisting of a plastics material. The semiconductor material is amorphous or polycrystalline, and is deposited and subsequently processed only at temperatures lower than the glass transition temperature of the substrate.

Description

AN ACTIVE MATRIX ELECTRO-OPTIC DISPLAY
This invention relates to active matrix electro-optic displays, and particularly, though not exclusively, to ferroelectric liquid crystal displays.
According to one aspect of the invention there is provided a liquid crystal display as specified in claims 1 - 8.
Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which:-
Figure 1 shows a schematic cross section and plan view of a cadmium selenide transistor device, and
Figure 2 shows a schematic cross section of an active matrix display device according to the invention.
Liquid crystal displays having a thin film transistor (TFT) on each picture element are well known. Analogue liquid crystal displays such as twisted nematic LCDs using cadmium selenide (CdSe), or similar high mobility amorphous /low temperature deposition process material, as the semiconductor material in the thin film transistor have been described in US 5,650637 and US 5,365,079.
Displays using ferroelectric liquid crystals with amorphous or polycrystalline silicon TFTs are also well known. However, the combination of using a II- VI semiconductor material such as CdSe and a bistable electro-optic material such as a ferroelectric liquid crystal (FLC) material has not previously been described. US 4,930,875 discloses a passive driver circuit using CdSe transistors.
The inventor believes that there has been a prejudice in the art against using II- VI semiconductor TFTs, because such materials have in practice variable threshold voltages which makes using them for reliable manufacture impossible. It is possible to manufacture a ferroelectric LC display which is built using TFTs, (made from amorphous or polycrystalline silicon) that can be operated at sufficiently fast (lOus) line addressing times, to be able to use the colour sequential technique with analogue greyscale. This technique generates colour in an image by displaying 3 time separated red, green and blue images that are rapidly displayed sequentially to produce the effect to the eye of a single image with full colour in it. The advantage of this technique being that the colour is generated by a set of rapidly flashing red green and blue lamps or other light sources which illuminate the monochrome FLC display. This is cheaper than incorporating a colour filter into the display.
II-VI Semiconductor materials such as CdSe or CdTe can be sputtered down as an amorphous layer at low temperatures (compared to polycrystalline silicon) but can achieve better mobilities than the equivalent low temperature amorphous silicon. This means that a much wider variety of substrates can be used (including plastic). However because the CdSe or CdTe is sputtered and not annealed (to keep the processing temperature low), the control of the grain size and grain boundaries are not good. This leads to a variation of about 0.5V in the threshold voltage of transistor made from the sputtered CdSe or CdTe on large substrates suitable for display applications. This makes CdSe or CdTe transistors made in this way impossible to manufacture if they are to be used with an analogue responding liquid crystal devices.
Ferroelectric liquid crystal displays can be made to be binary or bistable. This means they can be used for digital (binary) applications. Currently when used as a passive matrix LCD (no transistors on the display) they cannot be addressed sufficiently fast to be able to produce high-resolution displays that use the colour sequential effect, and use digital (time dithered) greyscale. If a transistor is incorporated into the display matrix then only polycrystalline silicon (which is deposited at high temperature) is able to switch fast enough to enable high-resolution digital colour sequential displays to be produced. However, polycrystalline silicon cannot be processed at low enough temperatures for plastic substrates. However, it has been realised by the present inventor that using transistors made from low temperature CdSe technology, the required speed can be achieved AND at low processing temperature compatible with plastic substrates. One way of making cadmium selenide transistors suitable for use in the present invention is described in the paper by M J Lee, S W Wright, C P Judge and P K Roberts in the Proceedings of the International Display Conference held in Monterey in 1994, page 138.
Figure 1(a) shows a schematic cross section of such a CdSe transistor. A substrate 1 made from a substantially optically transparent plastics material such as PEN (polyethylene naphthalate) having a glass transition temperature of
120°C. Other materials such as for example polycarbonate or polyimide or PES or PET can be used as alternative materials. A bottom gate electrode 2 is deposited on the substrate by sputtering and selective removal. In the present embodiment the gate electrode metal is aluminium although other metals such as nichrome may be used as an alternative. An insulating layer 3 such as silicon dioxide is then sputtered on top of the substrate and gate electrode assembly. As an alternative the silicon dioxide may be deposited by photochemical decomposition. Source and drain electrodes (4, 5) are then deposited on the silicon dioxide layer and selectively removed. In the present embodiment these electrodes are transparent to light and comprise ITO, but aluminium or nichrome can be used as alternative materials. The CdSe layer (6) is then deposited by sputtering. An insulative silicon dioxide layer (7) is then deposited on top of the semiconductor layer. It is preferably deposited in the same vacuum system, without breaking vacuum between deposition steps. This is then patterned and etched in the usual way, and a top gate electrode (8) is deposited and patterned. Figure 1(b) shows a plan view of the device before the top gate electrode is provided. The gate electrodes 2 and 8 are opaque, to minimise light induced currents in operation.
Figure 2 shows how the TFT device is incorporated into an active matrix
FLC display. This shows a schematic cross section of a ferroelectric LC display pixel, having a thin film transistor (9) as described above, and a pair of transparent substrates 1, each having a transparent electrode 11 and an alignment layer 10. The column electrode 12 is electrically connected to the gate of the TFT, whilst the row electrode 13 is connected to the drain. Electrodes 11 and 13 have an electrically insulative layer therebetween (not shown). The cavity between the two substrates is filled with a bistable electro-optic material 14, such as a ferroelectric liquid crystal.
This approach enables the following display capabilities to be realised in a single display: 1. Plastic displays (Arising from the low processing temperature)
2. Low (no) power monochrome reflective displays (arising from the FLC properties)
3. High resolution "video" digital colour displays (arising from the combination of CdSe or CdTe or other II-VI material and FLC)
A particularly relevant application that requires plastic (i.e. low process temperature) substrates and needs the colour sequential approach, as well as the monochrome bistable capability, are the displays in the next generation of portable communications equipment. These require low power and colour "video" capability. Conventional colour filter displays mostly require back illumination in order to be viewable, and this is not compatible with low power requirements. The colour sequential approach however allows colour "video" pictures to be viewed, but once they have been viewed the display can automatically switch to bistable mode, where the displays consumes no power, but is only able to displays static monochrome pictures or text using reflected available light. This approach allows optimum power consumption as the display uses zero power (if used in reflection) in standby mode or when transmitting or receiving calls /data and consumes power only when the display is viewed. An additional advantage of using high mobility semiconductor materials such as cadmium selenide or cadmium telluride with digital FLC materials is the fact that you can fabricate integrated column and row driver circuits on a glass or plastics substrate. If an analogue liquid crystal device was being made, the column drivers would be analogue. Cadmium selenide or other II-VI materials cannot be used for analogue column drivers as the threshold voltage of the transistors is too variable to construct the digital to analogue converters. Such semiconductor materials can however be used for the row driver circuits, as these are digital even for analogue LC devices.
Integrated row and column driver circuits are deposited at the same time as the TFT matrix, so that using integrated drivers provides cost and space savings, particularly advantageous for low-power portable devices. In summary, neither passive matrix ferroelectric LCDs, nor conventional
LCDs based on CdSe or CdTe transistors are able to produce good quality high- resolution displays, but together they can produce high-resolution digital colour sequential displays. This is not an obvious combination since low temperature CdSe has generally been abandoned for LCD application because of the difficulty in controlling the threshold voltage.
Finally, the priority document GB 0001254.2, especially the drawings, is incorporated herein by reference.

Claims

1. An active matrix electro-optic display, comprising a matrix of pixels each having a plurality of stable, optically distinguishable states, each pixel being driven in use by a semiconductor device (9) consisting of or including a layer of II-VI semiconductor material carried by a substrate (1).
2. An active matrix electro-optic display, as claimed in claim 1 in which the semiconductor device consists of or includes a thin film transistor.
3. An active matrix electro-optic display, as claimed in claim 1 in which the substrate consists of or includes a plastics material.
4. An active matrix electro-optic display as claimed in any preceding claim in which the II-VI semiconductor material is CdS or CdSe or CdTe.
5. An active matrix electro-optic display as claimed in any preceding claim in which the II-VI semiconductor material is amorphous or polycrystalline and which has been deposited and/or subsequently processed only at temperatures lower than the glass transition temperature of the substrate.
6. An active matrix electro-optic display as claimed in any preceding claim in which the electro-optic material consists of a ferroelectric liquid crystal material.
7. An active matrix electro-optic display as claimed in any preceding claim in which the said layer of II-VI semiconductor material includes integrated column and row drivers.
8. An active matrix electro-optic display as claimed in any preceding claim in which the active areas of the transistors in the layer of II-VI semiconductor material are masked by opaque layers in operation.
PCT/GB2001/000152 2000-01-21 2001-01-16 An active matrix electro-optic display WO2001053887A2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB0001254A GB0001254D0 (en) 2000-01-21 2000-01-21 An active matrix electro-optic display
GB0001254.2 2000-01-21

Publications (2)

Publication Number Publication Date
WO2001053887A2 true WO2001053887A2 (en) 2001-07-26
WO2001053887A3 WO2001053887A3 (en) 2001-12-06

Family

ID=9883997

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2001/000152 WO2001053887A2 (en) 2000-01-21 2001-01-16 An active matrix electro-optic display

Country Status (2)

Country Link
GB (1) GB0001254D0 (en)
WO (1) WO2001053887A2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7508466B2 (en) 2005-11-14 2009-03-24 Cree, Inc. Laser diode backlighting of LC display with at least one diode generating light beam having divergence angle and with display panel having beam spreader to increase divergence
WO2012093360A1 (en) * 2011-01-04 2012-07-12 Ecole Polytechnique Federale De Lausanne (Epfl) Semiconductor device

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4431271A (en) * 1979-09-06 1984-02-14 Canon Kabushiki Kaisha Display device with a thin film transistor and storage condenser
US4461071A (en) * 1982-08-23 1984-07-24 Xerox Corporation Photolithographic process for fabricating thin film transistors
EP0296663A1 (en) * 1987-06-18 1988-12-28 Koninklijke Philips Electronics N.V. Display device
US4930875A (en) * 1986-02-17 1990-06-05 Canon Kabushiki Kaisha Scanning driver circuit for ferroelectric liquid crystal device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4431271A (en) * 1979-09-06 1984-02-14 Canon Kabushiki Kaisha Display device with a thin film transistor and storage condenser
US4461071A (en) * 1982-08-23 1984-07-24 Xerox Corporation Photolithographic process for fabricating thin film transistors
US4930875A (en) * 1986-02-17 1990-06-05 Canon Kabushiki Kaisha Scanning driver circuit for ferroelectric liquid crystal device
EP0296663A1 (en) * 1987-06-18 1988-12-28 Koninklijke Philips Electronics N.V. Display device

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
CROSSLAND WILLIAM A ET AL: "Transmissive analogue SLM using a chiral smectic liquid crystal switched by CdSe TFTs" LIQUID-CRYSTAL DEVICES AND MATERIALS;SAN JOSE, CA, USA FEB 25-27 1991, vol. 1455, 1991, pages 264-273, XP000997176 Proc SPIE Int Soc Opt Eng;Proceedings of SPIE - The International Society for Optical Engineering 1991 Publ by Int Soc for Optical Engineering, Bellingham, WA, USA *
H.HIRAI ET AL.: "Tellurium thin-film transistor deposited on polyester film having plasma polymerized films on double-layered gate insulators" APPLIED PHYSICS LETTERS, vol. 50, no. 13, 30 March 1987 (1987-03-30), pages 818-820, XP002164215 *
LEE M J ET AL: "Cadmium selenide TFTs and circuits prepared by sputtering" CONFERENCE RECORD OF THE 1994 INTERNATIONAL DISPLAY RESEARCH CONFERENCE AND INTERNATIONAL WORKSHOPS ON ACTIVE-MATRIX LCDS AND DISPLAY MATERIALS, PROCEEDINGS OF 1994 INTERNATIONAL WORKSHOP ON ACTIVE-MATRIX LCDS (AMLCD), MONTEREY, CA, USA, 10-13 OCT. 1, pages 138-141, XP000997274 1994, Santa Ana, CA, USA, SID, USA *
T.P.BRODY: "Active-matrix TFTs are in trouble. Cadmium selenide is the answer" INFORMATION DISPLAY, vol. 8, no. 2, February 1992 (1992-02), pages 5-9, XP000990688 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7508466B2 (en) 2005-11-14 2009-03-24 Cree, Inc. Laser diode backlighting of LC display with at least one diode generating light beam having divergence angle and with display panel having beam spreader to increase divergence
WO2012093360A1 (en) * 2011-01-04 2012-07-12 Ecole Polytechnique Federale De Lausanne (Epfl) Semiconductor device
US9608101B2 (en) 2011-01-04 2017-03-28 Ecole Polytechnique Federale De Lausanne (Epfl) Semiconductor device

Also Published As

Publication number Publication date
WO2001053887A3 (en) 2001-12-06
GB0001254D0 (en) 2000-03-08

Similar Documents

Publication Publication Date Title
CN102763156B (en) Liquid crystal indicator and electronic installation
KR101848684B1 (en) Liquid crystal display device and electronic device
KR100462133B1 (en) Display apparatus
US6771247B2 (en) Display and method of driving display
US5056895A (en) Active matrix liquid crystal liquid crystal light valve including a dielectric mirror upon a leveling layer and having fringing fields
US8144102B2 (en) Memory element and display device
KR100426980B1 (en) Electro-optical device, method for fabricating the same, and electronic apparatus
KR101541474B1 (en) Method for driving liquid crystal display device
CN101276087B (en) Liquid crystal display device
US9501985B2 (en) Method for driving liquid crystal display device
CN107577080B (en) Transparent display panel and transparent display device
TWI603312B (en) Method for driving liquid crystal display device
WO2003096112A1 (en) Bistable liquid crystal device with picture electrodes having comb structure
EP1246159A2 (en) Active matrix display device with faster static memory circuit implemented at pixel level
US4770501A (en) Optical modulation device and method of driving the same
JP2001184015A (en) Driving method for display device
US5748268A (en) Quasi-tiled active matrix display
JP2004126199A (en) Display circuit structure for liquid crystal display
WO2001053887A2 (en) An active matrix electro-optic display
US20180033359A1 (en) Semiconductor device and electronic device
JP2009104050A (en) Liquid crystal display device
JPS63101832A (en) Active matrix liquid crystal display device
JPS614021A (en) Driving method of liquid crystal element
JP3668115B2 (en) Display device
JP2006178031A (en) Electro-optical device and electronic equipment

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A2

Designated state(s): JP US

AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
AK Designated states

Kind code of ref document: A3

Designated state(s): JP US

AL Designated countries for regional patents

Kind code of ref document: A3

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase in:

Ref country code: JP