CA2046358C - Liquid crystal display - Google Patents
Liquid crystal displayInfo
- Publication number
- CA2046358C CA2046358C CA002046358A CA2046358A CA2046358C CA 2046358 C CA2046358 C CA 2046358C CA 002046358 A CA002046358 A CA 002046358A CA 2046358 A CA2046358 A CA 2046358A CA 2046358 C CA2046358 C CA 2046358C
- Authority
- CA
- Canada
- Prior art keywords
- pixel
- liquid crystal
- crystal display
- capacitance
- tft
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired - Fee Related
Links
Classifications
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
- G09G3/3607—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels
-
- 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
-
- 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
- G02F1/1343—Electrodes
- G02F1/134309—Electrodes characterised by their geometrical arrangement
- G02F1/134345—Subdivided pixels, e.g. for grey scale or redundancy
-
- 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
- G02F1/136213—Storage capacitors associated with the pixel electrode
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/2007—Display of intermediate tones
- G09G3/2074—Display of intermediate tones using sub-pixels
Abstract
To provide a liquid crystal display having a uniform display characteristic the invention permits the channel width of a thin film transistor driving each pixel to be changed in proportion to the size of each pixel electrode.
Description
~ JA9-90-004 1 2046358 LIQUID ~Ys~AL DISPLAY
The invention relates to an active matrix typed liquid crystal display using thin film transistors (thereafter referred to as TFT) as switching elements, and more particularly, to a liquid crystal display for displaying half tone by an area gradation method.
The development of a liquid crystal display serving as a man-machine interface has been recently advanced actively following the progress of office automation. In particular, the development of an active matrix typed liquid crystal display has been active. In the liquid crystal display, the area gradation method which is based on a combination of on/off of a plurality of pixels of different display size, is employed as a method for displaying half tone. A liquid crystal display on which half tone is displayed by the method is disclosed, for example, in PUPA No.62-182717.
The invention will be more clearly understood from the following description taken in conjunction with the appended drawings wherein:
FIG.l is a schematic equivalent circuit diagram showing one picture element in a liquid crystal display as one embodiment of the invention.
FIG.2 shows a structure of a TFT shown in FIG.l.
FIG.3 is a schematic equivalent circuit diagram showing one picture element in a liquid crystal display as other embodiment of the invention.
FIG.4 is a diagram showing a principle of the area gradation method.
J~9-90-004 2 2 Og 63 5 8 -Now, as shown in FIG.4, when one picture element consists of four pixels A, B, C, and D whose area ratio is different, it is possible to display 16 levels of gradation.
In this case, formerly, each TFT driving a pixel has a structure wherein the ratio (W/L) of channel width (W) to channel length (L) is the same. However, a pixel capacitance (CLc) of a liquid crystal pixel forming as a load depends on the size of each pixel used. This has caused the following problems.
In a conventional liquid crystal display shown above, a problem exists in that TFT's having the same capability in driving each pixel, data can be written in a short period of time for a pixel of small area and on the other hand, it takes a long period of time to write data for a pixel of large area, and therefore, a writing characteristic of each pixel depends on a pixel capacitance (CLc) proportional to the area of each pixel.
It will be appreciated also that a problem exists in that the same leakage current flowing through a TFT driving each pixel, the speed of leakage is high for a pixel of small area and it is low for a pixel of large area, and therefore, a holding characteristic of each pixel depends on a pixel capacitance (CLc) proportional to the area of the pixel.
It will be appreciated also that a problem exists in that a voltage, what is called "punch-through voltage" (~Vcell), showing a voltage drop in a gate driving voltage applied to a pixel through the capacitance (CGs) between a gate electrode and a source electrode of the above each TFT
depends upon each pixel as shown below and an optimum driving voltage applied to each pixel of different size differs from each other.
cell VG ( CLC/CGC
~ JA9-90-004 3 2046358 (where VG is a gate driving voltage of TFT, CLc is a pixel capacitance, and CGs is a capacitance between a gate electrode and a source electrode of a TFT) It will be finally appreciated that these problems in a TFT
driving each subpixel as sho~n above cause a flicker to be produced on a display screen.
The invention is practiced to solve these problems and for the purpose of providing a liquid crystal display having a uniform display characteristic that a display screen is free from flickering by equalizing a "punch-through voltage" for every pixel and by equalizing a writing characteristic and a holding characteristic of each subpixel.
A liquid crystal display concerning the invention permits the channel width of a TFT driving each pixel to be changed in proportion to the size of each pixel electrode.
The channel width of each TFT driving a plurality of pixels can be changed so as to be proportional to the size of the pixel electrodes.
FIG.l is a schematic equivalent circuit diagram showing a liquid crystal display according to one embodiment of the invention. FIG.2 shows a structure of a TFT. In the figure, gate lines 40a and 40b are connected to each of the gate electrodes of TFT s 20 and 22 and TFT s 21 and 23, respectively. Data lines 30a and 30b are connected to each of the drain electrodes of the TFT s 20 and 21 and the TFT
22 and 23, respectively. Subpixel electrodes 10, 11, 12, 13, and 14 have pixel capacitances CLc8, CLc4, CLc2, and CLcl, respectively. Each source electrode of the TFT s 20, 21, 22, and 23 are connected to pixel capacitances CLc8, CLc4, CLc2, and CLcl, respectively. A pixel capacitance being proportional to the size of a pixel electrode, the ratio of the subpixel capacitances CLc8, CLc4, CLc2, and CLcl will be 8:4:2:1. Also, the TFT's 20, 21, 22, and 23 have the specific capacitances CGs8, CGs4, CGs2, and C
~ JA9-90-004 4 2 04 6 358 between a gate electrode and a source electrode, respectively.
The operations of the circuit are as follows: .
When gate signals are se~uentially applied to the gate lines 40a and 40b and a gate line 40c from a gate driver (not shown), the TFT s 20, 22, 21, and 23 are driven in this order and, at the same time, data signals are applied to the data lines 30a and 30b and a data line 30c from a data driver (not shown) and data is written into the pixels 10, 11, 12, and 13. In this case, a picture element is composed of four pixels. Since the ratio of pixels 10, 11, 12, and 13 in size is 8:4:2:1, one picture element will be displayed by 16 levels of gradation.
Now, if the channel width W of the TFT s shown in FIG.2 is changed in proportion to the size of the pixel electrodes, the capacitance CGs between the gate electrode and the source electrode of the TFT, and 1/ON resistance RON and 1/OFF resistance RoFF of the TFT change in proportion to the channel width W of the TFT and, therefore, a punch-through voltage (~Vcell) and a writing characteristic and a holding characteristic of the pixels shown above can be obtained from the following:
1. PUNGH-THROUGH VOLTAGE
CGs GLc+CGs G .. (1) l+
GS
(where VG is a gate driving voltage of TFT, CLc is a pixel capacitance, and CGs is a capacitance between gate electrode and source electrode of TFT) In the expression (1), CGs changing in proportion to the size of the pixel electrodes, CLc / CGs is constant and the ~,~JA9-90-004 5 2 0 4 6 3 5 8 punch-through voltage (~VceLl) is equalized without respect to the size of the pixel electrodes so that a flicker is not produced.
The invention relates to an active matrix typed liquid crystal display using thin film transistors (thereafter referred to as TFT) as switching elements, and more particularly, to a liquid crystal display for displaying half tone by an area gradation method.
The development of a liquid crystal display serving as a man-machine interface has been recently advanced actively following the progress of office automation. In particular, the development of an active matrix typed liquid crystal display has been active. In the liquid crystal display, the area gradation method which is based on a combination of on/off of a plurality of pixels of different display size, is employed as a method for displaying half tone. A liquid crystal display on which half tone is displayed by the method is disclosed, for example, in PUPA No.62-182717.
The invention will be more clearly understood from the following description taken in conjunction with the appended drawings wherein:
FIG.l is a schematic equivalent circuit diagram showing one picture element in a liquid crystal display as one embodiment of the invention.
FIG.2 shows a structure of a TFT shown in FIG.l.
FIG.3 is a schematic equivalent circuit diagram showing one picture element in a liquid crystal display as other embodiment of the invention.
FIG.4 is a diagram showing a principle of the area gradation method.
J~9-90-004 2 2 Og 63 5 8 -Now, as shown in FIG.4, when one picture element consists of four pixels A, B, C, and D whose area ratio is different, it is possible to display 16 levels of gradation.
In this case, formerly, each TFT driving a pixel has a structure wherein the ratio (W/L) of channel width (W) to channel length (L) is the same. However, a pixel capacitance (CLc) of a liquid crystal pixel forming as a load depends on the size of each pixel used. This has caused the following problems.
In a conventional liquid crystal display shown above, a problem exists in that TFT's having the same capability in driving each pixel, data can be written in a short period of time for a pixel of small area and on the other hand, it takes a long period of time to write data for a pixel of large area, and therefore, a writing characteristic of each pixel depends on a pixel capacitance (CLc) proportional to the area of each pixel.
It will be appreciated also that a problem exists in that the same leakage current flowing through a TFT driving each pixel, the speed of leakage is high for a pixel of small area and it is low for a pixel of large area, and therefore, a holding characteristic of each pixel depends on a pixel capacitance (CLc) proportional to the area of the pixel.
It will be appreciated also that a problem exists in that a voltage, what is called "punch-through voltage" (~Vcell), showing a voltage drop in a gate driving voltage applied to a pixel through the capacitance (CGs) between a gate electrode and a source electrode of the above each TFT
depends upon each pixel as shown below and an optimum driving voltage applied to each pixel of different size differs from each other.
cell VG ( CLC/CGC
~ JA9-90-004 3 2046358 (where VG is a gate driving voltage of TFT, CLc is a pixel capacitance, and CGs is a capacitance between a gate electrode and a source electrode of a TFT) It will be finally appreciated that these problems in a TFT
driving each subpixel as sho~n above cause a flicker to be produced on a display screen.
The invention is practiced to solve these problems and for the purpose of providing a liquid crystal display having a uniform display characteristic that a display screen is free from flickering by equalizing a "punch-through voltage" for every pixel and by equalizing a writing characteristic and a holding characteristic of each subpixel.
A liquid crystal display concerning the invention permits the channel width of a TFT driving each pixel to be changed in proportion to the size of each pixel electrode.
The channel width of each TFT driving a plurality of pixels can be changed so as to be proportional to the size of the pixel electrodes.
FIG.l is a schematic equivalent circuit diagram showing a liquid crystal display according to one embodiment of the invention. FIG.2 shows a structure of a TFT. In the figure, gate lines 40a and 40b are connected to each of the gate electrodes of TFT s 20 and 22 and TFT s 21 and 23, respectively. Data lines 30a and 30b are connected to each of the drain electrodes of the TFT s 20 and 21 and the TFT
22 and 23, respectively. Subpixel electrodes 10, 11, 12, 13, and 14 have pixel capacitances CLc8, CLc4, CLc2, and CLcl, respectively. Each source electrode of the TFT s 20, 21, 22, and 23 are connected to pixel capacitances CLc8, CLc4, CLc2, and CLcl, respectively. A pixel capacitance being proportional to the size of a pixel electrode, the ratio of the subpixel capacitances CLc8, CLc4, CLc2, and CLcl will be 8:4:2:1. Also, the TFT's 20, 21, 22, and 23 have the specific capacitances CGs8, CGs4, CGs2, and C
~ JA9-90-004 4 2 04 6 358 between a gate electrode and a source electrode, respectively.
The operations of the circuit are as follows: .
When gate signals are se~uentially applied to the gate lines 40a and 40b and a gate line 40c from a gate driver (not shown), the TFT s 20, 22, 21, and 23 are driven in this order and, at the same time, data signals are applied to the data lines 30a and 30b and a data line 30c from a data driver (not shown) and data is written into the pixels 10, 11, 12, and 13. In this case, a picture element is composed of four pixels. Since the ratio of pixels 10, 11, 12, and 13 in size is 8:4:2:1, one picture element will be displayed by 16 levels of gradation.
Now, if the channel width W of the TFT s shown in FIG.2 is changed in proportion to the size of the pixel electrodes, the capacitance CGs between the gate electrode and the source electrode of the TFT, and 1/ON resistance RON and 1/OFF resistance RoFF of the TFT change in proportion to the channel width W of the TFT and, therefore, a punch-through voltage (~Vcell) and a writing characteristic and a holding characteristic of the pixels shown above can be obtained from the following:
1. PUNGH-THROUGH VOLTAGE
CGs GLc+CGs G .. (1) l+
GS
(where VG is a gate driving voltage of TFT, CLc is a pixel capacitance, and CGs is a capacitance between gate electrode and source electrode of TFT) In the expression (1), CGs changing in proportion to the size of the pixel electrodes, CLc / CGs is constant and the ~,~JA9-90-004 5 2 0 4 6 3 5 8 punch-through voltage (~VceLl) is equalized without respect to the size of the pixel electrodes so that a flicker is not produced.
2 WRITING C~ARACTERISTIC
A write time ToN can be defined as follows:
ON ON CLC - - - - - - .. .. ~2) (where RON is ON resistance of TFT and CLc is a pixel capacitance.) In the expression (2), if the channel width W of the TFT's is changed in proportion to the size of the pixel electrodes, that is, the pixel capacitance CLc, the time ~ON
required for writing to the liquid crystal pixel will be constant since the ON resistance RON varies inversely proportional to the channel width W. That is, the write time is the same for any pixel of different size of the pixel electrodes and thus a flicker will not be produced.
A write time ToN can be defined as follows:
ON ON CLC - - - - - - .. .. ~2) (where RON is ON resistance of TFT and CLc is a pixel capacitance.) In the expression (2), if the channel width W of the TFT's is changed in proportion to the size of the pixel electrodes, that is, the pixel capacitance CLc, the time ~ON
required for writing to the liquid crystal pixel will be constant since the ON resistance RON varies inversely proportional to the channel width W. That is, the write time is the same for any pixel of different size of the pixel electrodes and thus a flicker will not be produced.
3. HOLDING CHARACTERISTIC
A hold time IOFF for the li~uid crystal pixel based on a leakage current of the TFT can be obtained from the following:
OFF ROFF CLC - - - - - - - - (3) (where RoFF is OFF resistance of TFT and CLc is a pixel capacitance.) In the expression (3), if the channel width W of the TFT is changed in proportion to the pixel capacitance CLc, a hold time IOFF will be constant without respect to the size of the pixel electrode since the the OFF resistance RoFF of the TFT varies inversely proportional to the channel width W of the TFT. Accordingly, a data holding characteristic of ~JA9-90-004 6 2046358 liquid crystal is equalized for any pixel having the electrodes of different size.
Further, as shown in FIG.3, also if each pixel capacitance CLc shown in FIG.1 and each compensation capacitance Cs are connected in parallel, the same relation as in FIG.l can be established by replacing CLc with (CLc~Cs) in the above expression to take the same effect as in the embodiment shown in FIG.1.
According to the invention, the channel width of each TFT
driving each pixel, as described above, is changed in proportion to the size of each pixel electrode to equalize the influence of a gate driving voltage (punch~through voltage) on the potential of the pixel electrode, to keep a constant write time for the liquid crystal pixel and a constant hold time for the liquid crystal pixel, regardless of the size of the pixel electrode (that is, CLc), and thus to prevent a display screen from flickering.
A hold time IOFF for the li~uid crystal pixel based on a leakage current of the TFT can be obtained from the following:
OFF ROFF CLC - - - - - - - - (3) (where RoFF is OFF resistance of TFT and CLc is a pixel capacitance.) In the expression (3), if the channel width W of the TFT is changed in proportion to the pixel capacitance CLc, a hold time IOFF will be constant without respect to the size of the pixel electrode since the the OFF resistance RoFF of the TFT varies inversely proportional to the channel width W of the TFT. Accordingly, a data holding characteristic of ~JA9-90-004 6 2046358 liquid crystal is equalized for any pixel having the electrodes of different size.
Further, as shown in FIG.3, also if each pixel capacitance CLc shown in FIG.1 and each compensation capacitance Cs are connected in parallel, the same relation as in FIG.l can be established by replacing CLc with (CLc~Cs) in the above expression to take the same effect as in the embodiment shown in FIG.1.
According to the invention, the channel width of each TFT
driving each pixel, as described above, is changed in proportion to the size of each pixel electrode to equalize the influence of a gate driving voltage (punch~through voltage) on the potential of the pixel electrode, to keep a constant write time for the liquid crystal pixel and a constant hold time for the liquid crystal pixel, regardless of the size of the pixel electrode (that is, CLc), and thus to prevent a display screen from flickering.
Claims (10)
1. In a liquid crystal display having a plurality of pixel electrodes of different sizes, and a plurality of thin film transistors each of which is connected to a corresponding one of said pixel electrodes, each thin film transistor having a gate channel width, the improvement comprising:
the gate channel width of said each thin film transistor being proportional to area of said pixel electrode.
the gate channel width of said each thin film transistor being proportional to area of said pixel electrode.
2. In a liquid crystal display having a plurality of pixel electrodes of different sizes, and a plurality of thin film transistors each of which is connected to a corresponding one of said pixel electrodes, each thin film transistor having a gate channel width, the improvement comprising:
the gate channel width of said each thin film transistor being proportional to capacitance of said pixel.
the gate channel width of said each thin film transistor being proportional to capacitance of said pixel.
3. A liquid crystal display according to claim 2 wherein said capacitance comprises capacitance of an electrode of said pixel.
4. A liquid crystal display according to claim 3 wherein said capacitance further comprises a compensation capacitor associated with said pixel.
5. In a liquid crystal display including at least one display element having a plurality of pixels of different sizes and a thin film transistor for driving each of said pixels, each thin film transistor having a gate channel width, the improvement comprising:
the gate channel width of each thin film transistor being proportional to capacitance of its respective pixel.
the gate channel width of each thin film transistor being proportional to capacitance of its respective pixel.
6. A liquid crystal display according to claim 5 wherein there are four pixels in each display element.
7. A liquid crystal display according to claim 6 wherein the pixels have areas related by successive powers of a predetermined number.
8. A liquid crystal display according to claim 7 wherein the number is 2.
9. A liquid crystal display according to claim 5 wherein said capacitance comprises capacitance of an electrode of said pixel.
10. A liquid crystal display according to claim 9 wherein said capacitance further comprises a compensation capacitor associated with said pixel.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17972790A JPH06100757B2 (en) | 1990-07-09 | 1990-07-09 | Liquid crystal display |
| JP179,727 | 1990-07-09 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2046358A1 CA2046358A1 (en) | 1992-01-10 |
| CA2046358C true CA2046358C (en) | 1994-10-25 |
Family
ID=16070816
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002046358A Expired - Fee Related CA2046358C (en) | 1990-07-09 | 1991-07-05 | Liquid crystal display |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US5235448A (en) |
| EP (1) | EP0466377B1 (en) |
| JP (1) | JPH06100757B2 (en) |
| CA (1) | CA2046358C (en) |
| DE (1) | DE69110206T2 (en) |
Families Citing this family (30)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5402141A (en) * | 1992-03-11 | 1995-03-28 | Honeywell Inc. | Multigap liquid crystal color display with reduced image retention and flicker |
| KR100218584B1 (en) * | 1994-09-21 | 1999-09-01 | 모리시타 요이찌 | Liquid crystal display device and driving method thereof |
| US5606437A (en) * | 1995-03-31 | 1997-02-25 | Rockwell International | Direct drive split pixel structure for active matrix liquid crystal displays |
| TW491959B (en) * | 1998-05-07 | 2002-06-21 | Fron Tec Kk | Active matrix type liquid crystal display devices, and substrate for the same |
| JP3308498B2 (en) * | 1998-07-31 | 2002-07-29 | 富士通株式会社 | LCD panel |
| US6278502B1 (en) | 1998-09-28 | 2001-08-21 | International Business Machines Corporation | Pixel capacitor formed from multiple layers |
| EP1069463A3 (en) * | 1999-07-15 | 2004-08-04 | Alps Electric Co., Ltd. | Active matrix type liquid crystal display |
| KR100593314B1 (en) * | 2000-07-24 | 2006-06-26 | 엘지.필립스 엘시디 주식회사 | liquid crystal display device |
| JP2002333870A (en) * | 2000-10-31 | 2002-11-22 | Matsushita Electric Ind Co Ltd | Liquid crystal display device, el display device and drive method therefor and display pattern evaluation method of subpixel |
| KR100780714B1 (en) * | 2001-10-29 | 2007-11-30 | 엘지.필립스 엘시디 주식회사 | Licuid crystal display device |
| TWI287132B (en) * | 2001-11-23 | 2007-09-21 | Chi Mei Optoelectronics Corp | A liquid crystal display having reduced flicker |
| US6897908B2 (en) * | 2001-11-23 | 2005-05-24 | Chi Mei Optoelectronics Corporation | Liquid crystal display panel having reduced flicker |
| JP3698365B2 (en) * | 2002-08-29 | 2005-09-21 | インターナショナル・ビジネス・マシーンズ・コーポレーション | Array substrate inspection apparatus and inspection method |
| US7453531B2 (en) * | 2003-11-22 | 2008-11-18 | Lg Display Co., Ltd. | LCD driving device having plural TFT channels connected in parallel with either increasing channel widths or decreasing channel distances from central part to edges of the device |
| CN100367336C (en) * | 2004-07-13 | 2008-02-06 | 友达光电股份有限公司 | Method for improving current driving type display picture homogeneous degree |
| DE602005012140D1 (en) * | 2004-11-10 | 2009-02-12 | Magink Display Technologies | CONTROL CHART FOR A CHOLESTERIC LIQUID CRYSTAL DISPLAY ELEMENT |
| GB0520763D0 (en) * | 2005-10-12 | 2005-11-23 | Magink Display Technologies | Cholesteric liquid crystal display device |
| KR20070078522A (en) * | 2006-01-27 | 2007-08-01 | 삼성전자주식회사 | Display device and liquid crystal display |
| US20070229722A1 (en) * | 2006-04-03 | 2007-10-04 | Wen-Hsiung Liu | Pixel structure and liquid crystal display panel thereof |
| WO2007118332A1 (en) * | 2006-04-19 | 2007-10-25 | Ignis Innovation Inc. | Stable driving scheme for active matrix displays |
| JP5116359B2 (en) * | 2007-05-17 | 2013-01-09 | 株式会社半導体エネルギー研究所 | Liquid crystal display |
| JP2008304659A (en) * | 2007-06-07 | 2008-12-18 | Hitachi Displays Ltd | Display device |
| JP2011158563A (en) * | 2010-01-29 | 2011-08-18 | Hitachi Displays Ltd | Liquid crystal display device |
| JP2010152384A (en) * | 2010-02-10 | 2010-07-08 | Seiko Epson Corp | Electro-optical device and electronic apparatus |
| TWI461807B (en) * | 2010-07-08 | 2014-11-21 | Hannstar Display Corp | Pixel structure of in-cell touch display panel and method of forming the same |
| CN106125408A (en) * | 2016-08-31 | 2016-11-16 | 京东方科技集团股份有限公司 | The driving method of array base palte, display device and display device |
| US10504930B2 (en) * | 2016-11-18 | 2019-12-10 | Hannstar Display Corporation | Reflective liquid crystal display panel |
| CN108072991A (en) * | 2016-11-18 | 2018-05-25 | 南京瀚宇彩欣科技有限责任公司 | It is totally reflected liquid crystal display panel |
| CN108227321B (en) * | 2016-12-22 | 2021-05-18 | 南京瀚宇彩欣科技有限责任公司 | Total reflection liquid crystal display panel |
| CN111583865B (en) * | 2020-06-12 | 2021-11-26 | 京东方科技集团股份有限公司 | Display panel, display device and method for determining channel width-length ratio of switching device |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5688193A (en) * | 1979-12-19 | 1981-07-17 | Citizen Watch Co Ltd | Display unit |
| JPS60188924A (en) * | 1984-03-09 | 1985-09-26 | Citizen Watch Co Ltd | Display device |
| JPS6227716A (en) * | 1985-07-29 | 1987-02-05 | Fuji Photo Film Co Ltd | Light valve for meshed-dot formation |
| JPS62182717A (en) * | 1986-02-06 | 1987-08-11 | Nec Corp | Liquid crystal display device |
| JPH0713715B2 (en) * | 1987-01-22 | 1995-02-15 | ホシデン株式会社 | Color liquid crystal display device |
| JPS6488722A (en) * | 1987-09-30 | 1989-04-03 | Toshiba Corp | Water level controller |
| US4840460A (en) * | 1987-11-13 | 1989-06-20 | Honeywell Inc. | Apparatus and method for providing a gray scale capability in a liquid crystal display unit |
| WO1989004505A1 (en) * | 1987-11-13 | 1989-05-18 | Honeywell Inc. | Apparatus and method for providing a gray scale in liquid crystal flat panel displays |
| JPH01179915A (en) * | 1988-01-11 | 1989-07-18 | Canon Inc | Liquid crystal element |
| JPH02165125A (en) * | 1988-12-20 | 1990-06-26 | Seiko Epson Corp | Display device |
-
1990
- 1990-07-09 JP JP17972790A patent/JPH06100757B2/en not_active Expired - Lifetime
-
1991
- 1991-07-01 DE DE69110206T patent/DE69110206T2/en not_active Expired - Fee Related
- 1991-07-01 EP EP91305936A patent/EP0466377B1/en not_active Expired - Lifetime
- 1991-07-05 CA CA002046358A patent/CA2046358C/en not_active Expired - Fee Related
- 1991-07-08 US US07/727,014 patent/US5235448A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| EP0466377A3 (en) | 1992-09-02 |
| US5235448A (en) | 1993-08-10 |
| CA2046358A1 (en) | 1992-01-10 |
| JPH06100757B2 (en) | 1994-12-12 |
| DE69110206D1 (en) | 1995-07-13 |
| DE69110206T2 (en) | 1995-12-07 |
| EP0466377A2 (en) | 1992-01-15 |
| JPH0466918A (en) | 1992-03-03 |
| EP0466377B1 (en) | 1995-06-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2046358C (en) | Liquid crystal display | |
| KR100443219B1 (en) | Active matrix device and display | |
| US8031287B2 (en) | Display panel and liquid crystal display including the same | |
| CN1381034A (en) | Display and recorded medium | |
| JP2008225142A (en) | Electrooptical device, driving circuit, and electronic equipment | |
| KR100440360B1 (en) | LCD and its driving method | |
| CN102460557A (en) | Pixel circuit and display device | |
| US7355575B1 (en) | Matrix panel display apparatus and driving method therefor wherein auxiliary signals are applied to non-selected picture elements | |
| KR100188113B1 (en) | Liquid crystal display device | |
| JPH05224626A (en) | Liquid crystal display device | |
| KR100612991B1 (en) | Liquid crystal display | |
| JPH02216121A (en) | Liquid crystal display device | |
| US20130106824A1 (en) | Data signal line driving circuit, display device, and data signal line driving method | |
| KR20100060578A (en) | Liquid crystal panel and liquid crystal display device having the same | |
| JP3245733B2 (en) | Liquid crystal display device and driving method thereof | |
| KR20030012668A (en) | Liquid crystal display | |
| KR100658063B1 (en) | In plane switching mode tft-lcd improving activation style | |
| CN107422558B (en) | Liquid crystal panel and driving method thereof | |
| CN100489633C (en) | Thin film transistor array substrate | |
| KR930003679B1 (en) | Active matrix lcd | |
| KR960014652B1 (en) | Operating method of tft lcd with adding capacitor | |
| JPS63261228A (en) | Driving method for liquid crystal display device | |
| KR100495806B1 (en) | Bi-directional value added liquid crystal display device | |
| JPH0764516A (en) | Active matrix liquid crystal display device | |
| JPS63266490A (en) | Driving of active matrix type liquid crystal panel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |