Method of displaying a pixel of an image on a screen based on a location of the pixel on the screen

Patent metadata

Field	Value
Publication number	US-9679541-B2
Application number	US-201514707531-A
Country	US
Kind code	B2
Filing date	May 8, 2015
Priority date	Dec 8, 2014
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

A display system and a method of displaying an image are hereby presented. The display system is arranged to display an image on a screen which has at least one useful screen area which is intended to be seen by a user and at least one non-useful screen area which the user cannot see. The display device comprises a bandwidth saver unit arranged to determine a location on the screen of a current pixel to be displayed. If the pixel is located in a non-useful screen area of the screen, then the fetching from a data memory of a pixel value is inhibited by the bandwidth saver unit with respect to this pixel, and a replacement, fixed pixel value is passed to a data processing unit for further processing.

First claim

What is claimed is:

1. A display system arranged to display an image on a screen having useful screen areas intended to be seen by a user and non-useful screen areas not visible by the user, comprising:
a data memory to store pixels values of the image to be displayed;
a data processing unit to control the display of pixels on the screen; and
a memory access controller coupled to the data processing unit, the memory access controller to determine whether a pixel to be processed by the data processing unit to be displayed on the screen belongs to a useful screen area or to a non-useful screen area of the screen, and if the pixel belongs to a non-useful screen area, to inhibit a pixel value associated with said pixel from being fetched from the data memory to the data processing unit and to force said pixel with a fixed value to be processed by the data processing unit;
wherein the memory access controller further to implement a memory table storing at least one binary data associated with a pixel of the image which defines whether said pixels belongs to a useful screen area of the screen or to a non-useful screen area of the screen; and
wherein the memory access controller comprises:
at least one counter whose output value defines a position on the screen of a current pixel to be displayed;
at least one comparator arranged to compare the position of said current pixel with the useful screen areas defined in the table; and,
a control unit arranged to inhibit the fetching of the pixel value associated with the current pixel from the data memory to the data processing unit and to force said current pixel with the fixed value.

2. The system of claim 1 , wherein the fixed value corresponds to a black pixel when displayed on the screen.

3. The system of claim 1 , wherein the memory access controller further to implement a memory table storing at least one binary data associated with one rectangular zone or a plurality of rectangular zones defining a useful screen area.

4. The system of claim 3 , wherein each rectangular zone is defined, in the memory table, by:
an offset value corresponding to the number of pixels between the first pixel of a line of pixels on the screen, and the first pixel of said line which belongs to the rectangular zone; and
a width, in number of pixels, between the first and the last pixel of the line of pixels of the rectangular zone, associated with a number of lines for which the corresponding offset/width couple is set.

5. An integrated circuit comprising a display system as claimed in claim 1 .

6. An integrated circuit as claimed in claim 5 , comprising at least one of: one or more processing cores; on-chip memory; a display control unit.

7. A display arrangement, comprising a display system as claimed in claim 1 and a display connected to the display system, the display being directly driven by the display system.

8. A display arrangement as claimed in claim 7 , wherein the display is part of a driver information system of a self-propelled vehicle.

9. A display arrangement as claimed in claim 8 , wherein the driver information system is a dashboard.

10. A method of displaying an image comprising:
controlling, by a data processing unit, the display of pixels of the image on a screen having useful screen areas intended to be seen by a user and non-useful screen areas not visible by the user;
determining, by a memory access controller, whether at least one pixel to be processed by the data processing unit for display on the screen belongs to a useful screen area or to a non-useful screen area of the screen and, if the pixel belongs to a non-useful screen area, said memory access control unit inhibiting the fetching to the data processing unit of a value associated with the current pixel from a data memory storing pixels values of the image to be displayed; and
forcing said pixel with a fixed value for the purpose of the processing by the data processing unit;
wherein the memory access controller comprising at least one counter, at least one comparator and a control unit, and wherein the method further comprises:
identifying a position on the screen of a current pixel to be displayed, performed by the counter whose output value defines said position;
comparing the position of said pixel with the useful screen areas defined in the table, performed by the comparator; and
inhibiting the fetching of the value associated with the pixel from the memory to the data processing unit and forcing said pixel with the fixed value.

11. The method of claim 10 , wherein the fixed value corresponds to a black pixel on the screen.

12. The method of claim 10 , wherein the method further comprises the phase of implementing, by the memory access control unit, a memory table storing at least one binary data associated with a pixel of the image which defines whether said pixels belongs to a useful screen area of the screen or to a non-useful screen area of the screen.

13. The method of claim 10 , wherein the method further comprises the phase of implementing, by the memory access control unit, a memory table storing at least one binary data associated with one rectangular zone or a plurality of rectangular zones for defining a useful screen area.

14. The method of claim 13 , wherein the method further comprises the phase of defining each rectangular zone, in the memory table, by:
an offset between the first pixel of the line on the screen, and the first pixel of a line of pixels in the rectangular zone; and
a width, in number of pixels, between the first and the last pixel of the line in the rectangular zone, associated with a number of lines for which the corresponding offset/width couple is set.

15. A non-transitory computer program product comprising one or more stored sequences of instructions that are accessible to a processor and which, when executed by the processor, cause the processor to:
control a display of pixels of the image on a screen having useful screen areas intended to be seen by a user and non-useful screen areas not visible by the user;
determine whether at least one pixel to be processed by the data processing unit for display on the screen belongs to a useful screen area or to a non-useful screen area of the screen and, if the pixel belongs to a non-useful screen area, said memory access control unit inhibiting the fetching to the data processing unit of a value associated with the current pixel from a data memory storing pixels values of the image to be displayed; and
force said pixel with a fixed value for the purpose of the processing by the data processing unit;
identify a position on the screen of a current pixel to be displayed;
compare the position of said pixel with the useful screen areas defined in a table; and
inhibit the fetching of the value associated with the pixel from the memory to the data processing unit and forcing said pixel with the fixed value.

16. The non-transitory computer program product of claim 15 , wherein the fixed value corresponds to a black pixel on the screen.

17. A display system arranged to display an image on a screen having useful screen areas intended to be seen by a user and non-useful screen areas not visible by the user, comprising:
a data memory to store pixels values of the image to be displayed;
a data processing unit to control the display of pixels on the screen; and
a memory access controller coupled to the data processing unit, the memory access controller to determine whether a pixel to be processed by the data processing unit to be displayed on the screen belongs to a useful scre

Assignees

• Aubineau Vincent
• Mckenna Daniel
• Staudenmaier Michael Andreas
• Nxp Usa Inc

Inventors

• Aubineau Vincent
• Mckenna Daniel
• Staudenmaier Michael Andreas

Classifications

• G09G5/14

  Display of multiple viewports · CPC title

• G09G2330/021

  Power management, e.g. power saving · CPC title

• G09G5/395 Primary

  Arrangements specially adapted for transferring the contents of the bit-mapped memory to the screen (G09G5/399 takes precedence) · CPC title

• G06T15/40

  Hidden part removal · CPC title

• G09G5/363

  Graphics controllers · CPC title