Display device

• US 5,945,972 A
• Filed: 11/27/1996
• Issued: 08/31/1999
• Est. Priority Date: 11/30/1995
• Status: Expired due to Term

• Current Assignee: Japan Display Central Incorporated (Japan Display Incorporated)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Itoh, Goh, Okumura, Haruhiko, Fujiwara, Hisao, Tsuchida, Katsuya
• Primary Examiner(s): Wu, Xiao
• Assistant Examiner(s): Frenel, Vanel
• Application Number:
  US08/758,014
• Time in Patent Office: 1,007 Days
• Field of Search: 345/98, 345/90, 345/91, 345/92, 345/93, 345/97, 345/100, 345/104, 345/173, 345/207
• US Class Current: 345/98
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2300/0814 used for selection purposes, e.g. logical AND for partial update
• CPC Class Codes: G09G 2300/0828 forming a digital to analog [D/A] conversion circuit
• CPC Class Codes: G09G 2300/0852 being a dynamic memory with more than one capacitor
• CPC Class Codes: G09G 2300/0857 Static memory circuit, e.g. flip-flop
• CPC Class Codes: G09G 2310/04 Partial updating of the display screen
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2330/022 in absence of operation, e.g. no data being entered during a predetermined time
• CPC Class Codes: G09G 2340/02 Handling of images in compressed format, e.g. JPEG, MPEG
• CPC Class Codes: G09G 2340/16 Determination of a pixel data signal depending on the signal applied in the previous frame
• CPC Class Codes: G09G 2360/142 the light being detected by light detection means within each pixel
• CPC Class Codes: G09G 3/20 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
• CPC Class Codes: G09G 3/2051 with use of a spatial dither pattern
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3659 the addressing of the pixel involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependant on signal of two data electrodes
• CPC Class Codes: G09G 5/08 Cursor circuits
• CPC Class Codes: G09G 5/14 Display of multiple viewports
• CPC Class Codes: G09G 5/34 for rolling or scrolling

Abstract

A display device includes a substrate, a plurality of pixels arranged in rows and columns on the substrate, and a plurality of signal lines for providing an image signal to the pixels on a column-by-column basis. Each of the pixels comprises a plurality of memory elements for storing image signals sent over a corresponding one of the signal lines, a selector for selecting one of the memory elements, and a display element for displaying a dot at a brightness corresponding to an image signal stored in the selected memory elements.

Claims

1. A display device comprising:

a substrate;

a plurality of pixels arranged in rows and columns on said substrate;

a plurality of signal lines for providing image signals to said plurality of pixels on a column by column basis;

a plurality of row address lines for providing row address signals to said plurality of pixels on a row-by-row basis; and

a plurality of rewrite signal lines for providing rewrite signals to said plurality of pixels on a column-by-column basis,

each of said plurality of pixels comprising;

a plurality of memory elements for retaining said image signals sent over said plurality of signal lines;

selection means for selecting one of said plurality of memory elements;

rewrite direction means connected to a corresponding one of said plurality of rewrite signal lines to receive a rewrite signals therefrom, said rewrite direction means being responsive to said rewrite signals to direct said plurality of memory elements to rewrite contents thereof; and

a display element for displaying a dot at a brightness corresponding to contents of a selected one of said plurality of memory elements;

wherein said selection means selects one of said plurality of memory elements when receiving a row address signal from a corresponding one of said plurality of row address lines and, at the same time, an image signal from a corresponding one of said plurality of signal lines, and

in a case where said rewrite direction means directs to rewrite said contents of said selected one of said plurality of memory elements, said image signal from said corresponding one of said plurality of signal lines is written into said selected one of said plurality of memory elements and one of said plurality of memory elements rewritten at the latest is selected, contents of which are provided to said display element for display.

2. The display device according to claim 1, further comprising:

a plurality of column address lines for providing column address signals to said plurality of pixels on a column-by-column basis;

a plurality of memory selection signal lines for providing selection signals for driving said selection means;

and a memory selection controller for driving said plurality of memory selection signal lines, said memory selection controller providing said selection signals for driving said selection means to said plurality of memory selection signal lines in synchronism with said row and said column address signals.

3. The display device according to claim 1, wherein, when a first image signal for one pixel in a previous frame is stored in one of said plurality of memory elements and a second image signal for a pixel in a current frame corresponding to said one pixel in the previous frame is substantially the same as said first image signal, said selection means selecting said one of said plurality of memory elements which stores said first image signal and provides said first image signal to said display element.

4. The display device according to claim 3, wherein said first image signal is a background image signal.

5. The display device according to claim 1, wherein an image signal stored in at least one of said plurality of memory elements is an image signal for an image other than a multiwindow image currently displayed.

6. The display device according to claim 1, wherein at least one of said plurality of memory elements retains data processed in a background by a host system for providing said image signals.

7. The display device according to claim 1, wherein said plurality of memory elements of each of said plurality of pixels have a storage capacity large enough to retain an image corresponding to more pixels than said plurality of pixels arranged on said substrate, and such an image is stored in said plurality of memory elements and displayed by being switched per substantially the number of said plurality of pixels on said substrate to thereby display said image corresponding to more pixels than said plurality of pixels on said substrate.

8. The display device according to claim 1, wherein said one of said plurality of memory elements rewritten at the latest is said selected one of said plurality of memory elements into which said image signal from said corresponding one of said plurality of signal lines.

9. A display device comprising:

a substrate;

a plurality of pixels arranged in rows and columns on said substrate; and

a plurality of signal lines for providing image signals to said plurality of pixels on a column-by-column basis,

each of said plurality of pixels comprising;

a plurality of memory elements for retaining said image signals sent over a corresponding one of said plurality of signal lines;

selection means for selecting one of said plurality of memory elements; and

a display element for displaying a dot at a brightness corresponding to contents of a selected one of said plurality of memory elements;

wherein said plurality of memory elements in each of said plurality of pixels form a first memory circuit including at least one memory element and a second memory circuit including of at least one memory element, said first memory circuit stores an image signal for a right eye and said second memory circuit stores an image signal for a left eye, and said selection means switches between said first and said second memory circuit at high speed to thereby provide a stereoscopic display.

10. A display device comprising:

a substrate;

a plurality of pixels arranged in rows and columns on said substrate;

a plurality of first signal lines arranged in said columns;

a plurality of second signal lines arranged in said columns, each of said second signal lines being paired with a respective one of said plurality of first signal lines;

a plurality of first control lines arranged in said columns;

a plurality of second control lines arranged in said columns, each of said second control lines being paired with a respective one of said plurality of first control lines,

a plurality of address lines arranged in said rows; and

a plurality of row control lines arranged in said rows, each of said row control lines being paired with a respective one of said plurality of address lines,

each of said plurality of pixels including;

a display element having a pixel electrode;

a first switch having a first conduction path, one end of said first conduction path being connected to a corresponding one of said plurality of first signal lines, conduction of said first conduction path being controlled by a corresponding one of said plurality of address lines;

a memory circuit having an input terminal and an output terminal, said input terminal being connected to the other end of said first conduction path and said memory circuit including at least one memory element;

a second switch having a second conduction path, one end of said second conduction path being connected to said output terminal of said memory circuit, conduction of said second conduction path being controlled by a corresponding one of said plurality of first control lines;

a third switch having a third conduction path, one end of said third conduction path being connected to the other end of said second conduction path, the other end of said third conduction path being connected to said pixel electrode, conduction of said third conduction path being controlled by a corresponding one of said plurality of row control lines;

a fourth switch having a fourth conduction path, one end of said fourth conduction path being connected to said pixel electrode, conduction of said fourth conduction path being controlled by said corresponding one of said plurality of row control lines;

a fifth switch having a fifth conduction path, one end of said fifth conduction path being connected to the other end of said fourth conduction path and the other end of said fifth conduction path being connected to a corresponding one of said plurality of second signal lines, conduction of said fifth conduction path being controlled by a corresponding one of said plurality of second control lines.

11. The display device according to claim 10, wherein said memory circuit includes at least two memory elements, a synchronizing signal input terminal to receive a synchronizing signal for selecting a desired one of said memory elements at data entry, and

a select signal input terminal to receive a select signal to select a desired one of said memory elements at data output.

12. The display device according to claim 11, wherein said memory circuit in each of said plurality of pixels stores at least two color signals, and said select signal is changed at regular intervals to thereby cause said display element to display an image at a gray level using said at least two color signals.

13. The display device according to claim 11, further comprising a data transfer line connected between said memory circuit and another memory circuit included in neighboring one of said plurality of pixels, said data transfer line allowing data retained in said memory circuit to be transferred to said memory circuit of said neighboring one of said plurality of pixels and vice versa.

14. The display device according to claim 13, wherein said data are color information which are able to be transferred from said memory circuit to said another memory circuit to effect spatial modulation.

15. A display device comprising:

a substrate;

a plurality of pixels arranged in rows and columns on said substrate;

a plurality of signal lines for providing an image signal to said plurality of pixels on a column-by-column basis;

a signal line driver for driving said plurality of signal lines;

first storage means for retaining an externally input image signal as a first record signal; and

a subtracter for producing a difference signal between said image signal at one point of time and said first record signal prior to said point of time which is retained in said first storage means and outputting said difference signal to said signal line driver,

said signal line driver outputting said difference signal as said image signal, and

each of said plurality of pixels including;

second storage means for storing a second record signal corresponding to said first record signal stored in said first storage means;

an adder for adding said second record signal stored in said second storage means and said difference signal; and

a display element for displaying a dot at a brightness corresponding to an output of said adder.

16. The display device according to claim 15, wherein said first storage means includes a plurality of first memory elements and a first selector for selecting one of said plurality of first memory elements, and wherein said second storage means includes a plurality of second memory elements and a second selector for selecting one of said plurality of second memory elements.

17. The display device according to claim 16, further comprising a select signal driver for driving said second selector on a basis of a result of selection by said first selector.

18. A display device comprising:

a substrate;

a plurality of pixels arranged in rows and columns on said substrate;

a plurality of address lines arranged in rows;

a plurality of signal lines arranged in columns;

a plurality of row scanning lines arranged in rows;

a plurality of column scanning lines arranged in columns;

a vertical scanner for driving each of said plurality of row scanning lines in sequence;

a horizontal scanner for driving each of said plurality of column scanning lines in sequence; and

operation means for performing operations on position data obtained through said vertical scanner and said horizontal scanner to obtain coordinate data at a pixel location that is specified by an external light signal,

each of said plurality of pixels comprising;

a first memory circuit selected by a corresponding one of said plurality of address lines for storing an image signal sent over a corresponding one of said plurality of signal lines;

a photoelectric conversion element for sensing presence or absence of said external light signal to produce a detect signal in the presence of said external light signal;

a second memory circuit selected by a corresponding one of said plurality of row scanning lines for storing said detect signal from said photoelectric conversion element and outputting said detect signal onto a corresponding one of said plurality of column scanning lines;

an OR circuit for taking a logical sum of said image signal retained in said first memory circuit and said detect signal retained in said second memory circuit to output a logical sum signal; and

a display element for displaying a dot at a brightness corresponding to said logical sum signal from said OR circuit.

19. The display device according to claim 18, wherein said first memory circuit includes a plurality of memory elements.

20. The display device according to claim 18, further comprising a digital-to-analog converter connected between said OR circuit and said display element.