LED display apparatus and LED displaying method

• US 5,995,070 A
• Filed: 05/22/1997
• Issued: 11/30/1999
• Est. Priority Date: 05/27/1996
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Kitada, Takashi
• Primary Examiner(s): Hjerpe, Richard A.
• Assistant Examiner(s): LANEAU, RONALD
• Application Number:
  US08/861,533
• Time in Patent Office: 922 Days
• Field of Search: 345/83, 345/102, 345/82, 345/515, 345/516, 379/61, 348/468
• US Class Current: 345/83
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 2340/0457 Improvement of perceived resolution by subpixel rendering
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]

Abstract

Image display apparatus and method with an LED matrix device. Each dot of the device is composed of one red LED, one blue LED and two green LEDs. When data displayed in a 16×16 dot matrix is displayed by reducing the data to a 8×8 dot matrix, 2×2 dots of the 16×16 matrix are grouped into one unit composed of 2×2 dots arrayed in a matrix. Four data, i.e., data obtained by extracting upper-left data from all the units, data obtained by extracting upper-right data, data obtained by extracting lower-left data, data obtained by extracting lower-right data, respectively, from all the dot units, are successively displayed on a time division basis with deviation corresponding to a half dot relative to one another. Image of smooth contour can be generated even with a small-scale LED display apparatus having a small number of dots and low resolution.

Claims

1. An LED display apparatus, comprising:

(a) an LED panel comprising a number of dots, each of said dots comprising a plurality of neighboring color LEDs, said LEDs being arranged in a repeating regular pattern in said panel;

(b) a display data storage means for storing display data comprising a plurality of data pieces greater in number than said number of dots, said plurality of data pieces being stored in blocks equal in number to said number of dots, each of said blocks being divided into a number of sections;

(c) a pixel data read-out means for reading out from said display data storage means pixel data, comprising a plurality of said data pieces, for all of said dots according to a read-out address signal identifying corresponding ones of said sections within each of said blocks;

(d) a read-out operation counting means for counting a number of said pixel data that said read-out means reads out from said storage means;

(e) an address determining means for providing said read-out address signal to said read-out means, said address determining means changing said address signal to identify a different one of said sections of said blocks in response to an output from said counting means indicating that said number of said pixel data read out by said read-out means is equal to said number of said blocks; and

(f) an LED control means for changing a combination of said neighboring LEDs according to said one of said sections identified by said address determining means and driving said combination of said LEDs to display on said panel said pixel data read out by said read-out means.

2. An LED display apparatus according to claim 1,

further comprising:

display change-over means for controlling an address determining method to be adopted in said address determining means on the basis of a display mode.

3. An LED display apparatus according to claim 2,

wherein said display change-over means samples a display change-over signal indicating a display mode on a frame-by-frame basis.

4. An LED apparatus according to claim 1, wherein said number of dots of said LED panel are arranged in an m×

n matrix, said blocks are arranged in an m×

n matrix and said plurality of data pieces of said display data are arranged in a p×

q matrix, each p×

q matrix of said data pieces comprising a frame and said p×

q matrix being larger than said m×

n matrix.

5. An LED apparatus according to claim 4, wherein said neighboring color LEDs are arranged in a two-by-two matrix comprising one red LED, one blue LED and two green LEDs, and said LED control means energizes different combinations of said red, blue and green LEDs in accordance with different ones of said sections identified by said read-out address signal.

6. An LED apparatus according to claim 4, wherein said sections are arranged in a two-by-two matrix and said read-out address signal identifies locations in said two-by-two matrix, whereby upper-left data, upper-right data, lower-left data and lower-right data are displayed in said m×

n matrix of dots in said display panel successively on a time-division basis with a predetermined deviation relative to one another a plurality of times within a same said frame.

7. An LED display apparatus, comprising:

(a) an LED panel comprising a number of dots, each of the dots comprising a plurality of neighboring color LEDs, said LEDs being arranged in a repeating regular pattern in said panel;

(b) averaging means for (i) receiving display data comprising a plurality of data pieces greater in number than said number of dots and (ii) generating averaged data from said data pieces by averaging predetermined combinations of said data pieces;

(c) a display data storage means for storing said averaged data in blocks equal in number to said number of dots, each of said blocks being divided into a number of sections;

(d) a pixel data read-out means for reading out from said storage means pixel data, comprising said averaged data stored in said blocks, for all of said dots according to a read-out address signal identifying corresponding ones of said sections within each of said blocks;

(e) a read-out operation counting means for counting a number of said pixel data that said read-out means reads out from said storage means;

(f) an address determining means for providing said read-out address signal to said read-out means, said address determining means changing said address signal to identify a different one of said sections of said blocks in response to an output from said counting means indicating that said number of said pixel data read out by said read-out means is equal to said number of said blocks; and

(g) an LED control means for changing a combination of said neighboring LEDs according to said identified one of said sections and driving said combination of said LEDs to display on said panel said pixel data read out by said read-out means.

8. An LED apparatus according to claim 7, wherein said number of dots of said LED panel are arranged in an m×

n matrix, said blocks are arranged in an m×

n matrix and said plurality of data pieces of said display data are arranged in a p×

q matrix, each p×

q matrix of said data pieces comprising a frame and said p×

q matrix being larger than said m×

n matrix.

9. An LED apparatus according to claim 8, wherein said neighboring color LEDs are arranged in a two-by-two matrix comprising one red LED, one blue LED and two green LEDs, and said LED control means energizes different combinations of said red, blue and green LEDs in accordance with different ones of said sections identified by said read-out address signal.

10. A method of displaying display data on a dot-matrix type LED display device including an LED panel comprising a number of dots, each of said dots comprising a plurality of neighboring color LEDs, said LEDs being arranged in a repeating regular pattern in said panel, said display data comprising a plurality of data pieces greater in number than said number of dots, said method comprising:

(a) storing in a storage means said display data such that said plurality of data pieces are stored in blocks equal in number to said number of dots, and dividing each of said blocks into a number of sections;

(b) reading out from said storage means pixel data, comprising a plurality of said data pieces of said display data, for all of said dots according to a read-out address signal identifying corresponding ones of said sections within each of said blocks;

(c) counting a number of said pixel data that are read out from said storage means in step (b);

(d) changing said address signal to identify a different one of said sections of said blocks in response to a determination in step (c) that said number of said pixel data read out is equal to said number of said blocks; and

(e) changing a combination of said neighboring LEDs according to said one of said sections identified in step (d) and driving said combination of said LEDs to display on said panel said pixel data read out in step (b).

11. A method according to claim 10, wherein said sections are arranged in a two-by-two matrix and said read-out address signal identifies locations in said two-by-two matrix, whereby upper-left data, upper-right data, lower-left data and lower-right data are displayed in said m×

n matrix of dots in said display panel successively on a time-division basis with a predetermined deviation relative to one another a plurality of times within a same said frame.

12. A method of displaying display data on a dot-matrix type LED display device including an LED panel comprising a number of dots, each of said dots comprising a plurality of neighboring color LEDs, said LEDs being arranged in a repeating regular pattern in said panel, said display data comprising a plurality of data pieces greater in number than said number of dots, said method comprising:

(a) generating averaged data from said data pieces by averaging predetermined combinations of said data pieces of said display data;

(b) storing in a storage means said averaged data in blocks equal in number to said number of dots, and dividing each of said blocks into a number of sections;

(c) reading out from said storage means pixel data, comprising said averaged data stored in said blocks, for all of said dots according to a read-out address signal identifying corresponding ones of said sections within each of said blocks;

(d) counting a number of said pixel data read out from said storage means in step (c);

(e) changing said address signal to identify a different one of said sections of said blocks in response to a determination in step (d) that said number of said pixel data read out is equal to said number of said blocks; and

(f) changing a combination of said neighboring LEDs according to said one of said sections identified in step (e) and driving said combination of said LEDs to display on said panel said pixel data read out in step (c).