Display apparatus

• US 20050062710A1
• Filed: 09/17/2003
• Published: 03/24/2005
• Est. Priority Date: 09/17/2003
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Hitachi Displays Limited (Japan Display Incorporated)
• Inventors: Kasai, Naruhiko, Awakura, Hiroki, Satou, Toshihiro
• Granted Patent: US 7,202,842 B2
• Time in Patent Office: Days
• US Class Current: 345/99
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0861 with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
• CPC Class Codes: G09G 2320/0223 Compensation for problems related to R-C delay and attenuation in electrodes of matrix panels, e.g. in gate electrodes or on-substrate video signal electrodes
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2330/02 Details of power systems and of start or stop of display operation
• CPC Class Codes: G09G 3/2014 by modulation of the duration of a single pulse during which the logic level remains constant
• CPC Class Codes: G09G 3/2081 with combination of amplitude modulation and time modulation space and time error diffusion G09G3/2066
• CPC Class Codes: G09G 3/3225 using an active matrix
• CPC Class Codes: G09G 3/3291 in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements

Abstract

The present invention comprises: a display unit having a plurality of display elements arranged in a matrix; a drive voltage generating circuit for generating a drive voltage for driving the plurality of display elements; a dataline drive circuit for generating a signal voltage according to display data, the signal voltage being for controlling the amount of current in a supply line of the drive voltage; a scanline drive circuit for selecting one or more of the plurality of display elements which is to be driven; and a pixel light emission control circuit for controlling a light emission time period of each display element according to a distance measured along a current path from the drive voltage generating circuit to the display element.

Claims

1. A display apparatus comprising:

a display unit including a plurality of display elements arranged in a matrix;

a drive voltage generating circuit-for generating a drive voltage for driving said plurality of display elements;

a dataline drive circuit for generating a signal voltage according to display data, said signal voltage being for controlling the amount of current in a supply line of said drive voltage;

a scanline drive circuit for selecting one or more of said plurality of display elements which is to be driven; and

a control circuit for controlling a light emission time period of each display element according to-a distance measured along a current path from said drive voltage generating circuit to said each display element.

2. The display apparatus as claimed in claim 1, wherein said plurality of display elements exhibit a same luminance-level when they emit light if said display data is set to a same value.

3. The display apparatus as claimed in claim 1, further comprising:

a cutoff circuit for cutting off a supply of said drive voltage to said plurality of display elements according to a control signal from said control circuit.

4. The display apparatus as claimed in claim 1, wherein said control circuit increases said light emission time period with increasing distance of said each display element from said drive voltage generating circuit.

5. The display apparatus as claimed in claim 4, further comprising:

a detection circuit for detecting said amount of current in said supply line of said drive voltage;

wherein said control circuit increases increment of said light emission time period with increasing amount of current in said supply line of said drive voltage.

6. The display apparatus as claimed in claim 4, wherein said control circuit increases increment of said light emission time period with increasing gray scale value of said display data.

7. The display apparatus as claimed in claim 4, further comprising:

a detection circuit for detecting a luminance level of said plurality of display elements when they emit light;

wherein said control circuit increases increment of said light emission time period as said luminance level increases at said drive voltage.

8. The display apparatus as claimed in claim 1, wherein said control circuit inserts black display data into said display data and controls either a timing or a time of said insertion of said black display data, or both, so as to control said light emission time period.

9. The display apparatus as claimed in claim 1, wherein said control circuit inserts additional display data into said display data and controls either a timing or a time of said insertion of said additional display data or both, said additional display data having a luminance level lower than that of said display data.

10. A display apparatus comprising:

a display unit including a plurality of display elements arranged in a matrix;

a drive voltage generating circuit for generating a drive voltage for driving said plurality of display elements;

a dataline drive circuit for generating a signal voltage according to display data, said signal voltage being for controlling the amount of current in a supply line of said drive voltage; and

a scanline drive circuit for selecting one (or more) of said plurality of display elements which is to be driven;

wherein a light emission time period of each display element varies according to a location of said each display element.

11. The display apparatus as claimed in claim 10, further comprising:

a control circuit for controlling said light emission time period according to said location.

12. The display apparatus as claimed in claim 10, wherein when said plurality of display elements exhibit a same luminance level at a time of emitting light, said light emission time period of said each display element varies according to said location.

13. The display apparatus as claimed in claim 10, wherein a light emission time period of a display element in an upper row is shorter than that of a display element in a lower row, said display element in said upper row and said display element in said lower row being among said plurality of display elements.

14. The display apparatus as claimed in claim 10, wherein a light emission time period of a display element in a lower row is shorter than that of a display element in an upper row, said display element in said lower row and said display element in said upper row being among said plurality of display elements.

15. The display apparatus as claimed in claim 10, wherein a light emission time period of a display element in a left column is shorter than that of a display element in a right column, said display element in said left column and said display element in said right column being among said plurality of display elements.

16. The display apparatus as claimed in claim 10, wherein a light emission time period of a display element in a right column is shorter than that of a display element in a left column, said display element in said right column and said display element in said left column being among said plurality of display elements.