Method of color image enlargement in which each RGB subpixel is given a specific brightness weight on the liquid crystal display

• US 5,821,913 A
• Filed: 12/14/1995
• Issued: 10/13/1998
• Est. Priority Date: 12/14/1994
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Mamiya, Johji
• Primary Examiner(s): Saras, Steven J.
• Assistant Examiner(s): Bell, Paul A.
• Application Number:
  US08/572,554
• Time in Patent Office: 1,034 Days
• Field of Search: 345/88, 345/89, 345/127, 345/128, 345/130, 345/132, 345/147, 345/149, 345/22, 345/23, 345/150, 345/152, 345/153, 345/155, 358/451, 358/525, 358/521, 382/298, 382/299, 382/300, 382/301, 395/139
• US Class Current: 345/88
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2320/028 by changing the viewing angle properties, e.g. widening the viewing angle, adapting the viewing angle to the view direction
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 2340/0414 Vertical resolution change
• CPC Class Codes: G09G 2340/0421 Horizontal resolution change
• CPC Class Codes: G09G 2340/0457 Improvement of perceived resolution by subpixel rendering
• CPC Class Codes: G09G 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607

Abstract

A method and apparatus is provided for displaying an enlarged image on a liquid crystal display apparatus capable of displaying colors, and in particular, a liquid crystal display method and apparatus that can enlarge an image at an arbitrary ratio and display the outline of the enlarged image smoothly. On a display panel of a color liquid crystal display apparatus in which display dots each comprising an array of three subpixels displaying red (R), green (G), and blue (B) are arranged in a matrix, three pieces of raw-direction original display brightness data to be displayed in three subpixels are extended and subjected to predetermined weights of brightness to form enlarged display brightness data. This data is sequentially output to the subpixels to extend the original image in the raw direction of the display panel before display.

Claims

1. A liquid crystal display method for displaying an enlarged image on a display panel of a color liquid crystal display apparatus in which display dots each comprising a subpixel displaying red (R), a subpixel displaying green (G), and a subpixel displaying blue (B) placed in this order are arranged in a matrix, characterized by the steps of:

forming six pieces of enlarged display brightness data arranged in the order of R-G-B-R-G-B, G-B-R-G-B-R, or B-R-G-B-R-G and to which weights of brightness of 1/3, 2/3, 1, 1, 2/3, 1/3! are applied, respectively, based on three pieces of raw-direction original display brightness data to be displayed in the three subpixels comprising one of said display dots; and

sequentially outputting said enlarged display brightness data to the six subpixels to enlarge the original image in the raw direction of said display panel.

2. A liquid crystal display method according to claim 1 characterized in that:

said weighting and addition of brightness are carried out after said original display brightness data is subjected to gamma (Γ

) conversion so as to be converted from gradation data to brightness data.

3. A liquid crystal display method according to claim 2 characterized in that:

after said weighting and addition of brightness, the data is subjected to gamma reverse (Γ

-1) conversion so as to be converted from brightness data to gradation data.

4. A liquid crystal display method according to claim 3 characterized in that:

said gamma reverse conversion is executed by selecting among a plurality of gamma conversion tables corresponding to changes in the visual angle.

5. A liquid crystal display method for displaying an enlarged image on a display panel of a color liquid crystal display apparatus in which display dots each comprising a subpixel displaying red (R), a subpixel displaying green (G), and a subpixel displaying blue (B) placed in this order are arranged in a matrix, characterized by the steps of:

forming first enlarged display brightness data comprising six pieces of enlarged display brightness data arranged in the order of R-G-B-R-G-B in the raw direction and to which weights of brightness of 1/3, 2/3, 1, 1, 2/3, 1/3! are applied, respectively, based on three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting a first display dot;

forming second enlarged display brightness data comprising six pieces of enlarged display brightness data arranged in the order of G-B-R-G-B-R in the raw direction and to which weights of brightness of 1/3, 2/3, 1, 1, 2/3, 1/3! are applied, respectively, based on three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting a second display dot adjacent to said first display dot;

forming third enlarged display brightness data comprising six pieces of enlarged display brightness data arranged in the order of B-R-G-B-R-G in the raw direction and to which weights of brightness of 1/3, 2/3, 1, 1, 2/3, 1/3! are applied, respectively, based on three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting a third display dot adjacent to said second display dot;

adding said first to third enlarged display brightness data to each other to combine them in data regions of the same color to which weights of brightness of 1/3 and 2/3 are applied, respectively, and

sequentially outputting to the subpixels said enlarged display brightness data formed by combination to enlarge the original image 4/3 times in the raw direction of said display panel.

6. A liquid crystal display method for displaying an enlarged image on a display panel of a color liquid crystal display apparatus in which display dots each comprising a subpixel displaying red (R), a subpixel displaying green (G), and a subpixel displaying blue (B) placed in this order are arranged in a matrix, characterized by the steps of:

enlarging three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting a first display dot, to six pieces of first enlarged display brightness data including single-color data at one end the brightness of which is reduced to half and two pieces of data of two other colors at the other end the brightness of which is reduced to half;

enlarging three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting a second display dot adjacent to said first display dot, to six pieces of second enlarged display brightness data including at one end, two pieces of data of the same two colors as in the other end of said first enlarged display brightness data the brightness of which is reduced to half and at the other end, one piece of data of the same color as in the one end of said first enlarged display brightness data the brightness of which is reduced to half;

adding the two pieces of data at the other end of said first enlarged display brightness data to the two pieces of data at the one end of said second enlarged display brightness data, or the data at the one end of said first enlarged display brightness data to the data at the other end of said second enlarged display brightness data to combine said first and second enlarged display brightness data, and sequentially repeating this sequence of operations; and

thereby sequentially outputting to the subpixels said enlarged display brightness data formed by combination to enlarge the original image 3/2 times in the raw direction of said display panel.

7. A liquid crystal display method for displaying an enlarged image on a display panel of a color liquid crystal display apparatus in which display dots each comprising a subpixel displaying red (R), a subpixel displaying green (G), and a subpixel displaying blue (B) placed in this order are arranged in a matrix, comprising the steps of:

forming first enlarged display brightness data comprising six pieces of enlarged display brightness data arranged in the order of R-G-B-R-G-B, G-B-R-G-B-R, or B-R-G-B-R-G in the raw direction and to which weights of brightness of 1/2, 1, 1, 1, 1/2, 1/2! are applied, respectively, based on three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting a first display dot;

forming second enlarged display brightness data comprising six pieces of enlarged display brightness data arranged in the order of G-B-R-G-B-R, B-R-G-B-R-G, or R-G-B-R-G-B in the raw direction and to which weights of brightness of 1/2, 1/2, 1, 1, 1, 1/2! are applied, respectively, based on three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting a second display dot adjacent to said first display dot, the fifth and sixth pieces of said first enlarged display brightness data corresponding in color to the first and second pieces of said second enlarged display brightness data, respectively;

adding the fifth and sixth pieces of said first enlarged display brightness data to the first and second pieces of said second enlarged display brightness data, respectively to combine said first and second enlarged display brightness data, and

sequentially outputting to the subpixels said enlarged display brightness data formed by combining to enlarge the original image 3/2 times in the raw direction of said display panel.

8. A liquid crystal display method for displaying an enlarged image on a display panel of a color liquid crystal display apparatus in which display dots each comprising a subplxel displaying red (R), a subpixel displaying green (G), and a subpixel displaying blue (B) placed in this order are arranged in a matrix, comprising:

a first step of forming first enlarged display brightness data comprising six pieces of enlarged display brightness data arranged in the order of R-G-B-R-G-B in the raw direction and to which weights of brightness of 1/3, 2/3, 1, 1, 2/3, 1/3! are applied, respectively, based on three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting a first display dot;

a second step of forming second enlarged display brightness data comprising six pieces of enlarged display brightness data arranged in the order of G-B-R-G-B-R in the raw direction and to which weights of brightness of 1/3, 2/3, 1, 1, 2/3, 1/3! are applied, respectively, based on three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting a second display dot following said first display dot;

a third step of forming third enlarged display brightness data comprising six pieces of enlarged display brightness data arranged in the order of B-R-G-B-R-G in the raw direction and to which weights of brightness of 1/3, 2/3, 1, 1, 2/3, 1/3! are applied, respectively, based on three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting a third display dot following said second display dot;

a fourth step of forming supplementary enlarged display brightness data comprising five pieces of data arranged in the order of R-G-B-R-G, G-B-R-G-B, or B-R-G-B-R and to which weights of brightness of 1/3, 2/3, 1, 2/3, 1/3! are applied, respectively, based on three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting a fourth display dot positioned at one of the following four positions;

before said first display dot;

between said first and second display dots;

between said second and third display dots; and

after said third display dot;

a fifth step of adding said first to fourth enlarged display brightness data to each other to combine them in data regions of the same color to which weights of brightness of 1/3 and 2/3 are applied, respectively, and

sequentially outputting to said subpixels said enlarged display brightness data formed by sequentially repeating said first to fifth steps to enlarge the original image (M+1)/M times in the raw direction of said display panel, where M is a natural number and M/≧

4.

9. A liquid crystal display method for displaying an enlarged image on a display panel of a color liquid crystal display apparatus in which display dots each comprising a subpixel displaying red (R), a subpixel displaying green (G), and a subpixel displaying blue (B) placed in this order are arranged in a matrix, comprising:

at least one first step of forming first enlarged display brightness data comprising six pieces of enlarged display brightness data arranged in the order of R-G-B-R-G-B in the raw direction and to which weights of brightness of 1/3, 2/3, 1, 1, 2/3, 1/3! are applied, respectively, based on three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting at least one first display dot;

at least one second step of forming second enlarged display brightness data comprising six pieces of enlarged display brightness data arranged in the order of G-B-R-G-B-R in the raw direction and to which weights of brightness of 1/3, 2/3, 1, 1, 2/3, 1/3! are applied, respectively, based on three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting at least one second display dot following said at least one first display dot;

at least one third step of forming third enlarged display brightness data comprising six pieces of enlarged display brightness data arranged in the order of B-R-G-B-R-G in the raw direction and to which weights of brightness of 1/3, 2/3, 1, 1, 2/3, 1/3! are applied, respectively, based on three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting at least one third display dot following said at least one second display dot;

at least one fourth step of forming supplementary enlarged display brightness data comprising seven pieces of data arranged in the order of R-G-B-R-G-B-R, G-B-R-G-B-R-G, or B-R-G-B-R-G-B and to which weights of brightness of 1/3, 2/3, 1, 1, 1, 2/3, 1/3! are applied, respectively, based on three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting at least one fourth display dot positioned at one of the following three positions;

before said at least one first display dot;

between two of said display dots that are adjacent to each other; and

after said at least one third display dot;

a fifth step of adding said first to fourth enlarged display brightness data to each other to combine them in data regions of the same color to which weights of brightness of 1/3 and 2/3 are applied, respectively, and

sequentially outputting to said subpixels said enlarged display brightness data formed by sequentially repeating said first to fifth steps to enlarge the original image M/N times in the raw direction of said display panel, where M and N are natural numbers and M≧

N+2.

10. A liquid crystal display method for displaying an enlarged image on a display panel of a color liquid crystal display apparatus in which display dots each comprising a subpixel displaying red (R), a subpixel displaying green (G), and a subpixel displaying blue (B) placed in this order are arranged in a matrix, comprising:

at least one first step of forming first enlarged display brightness data comprising six pieces of enlarged display brightness data arranged in the order of R-G-B-R-G-B in the raw direction and to which weights of brightness of 1/3, 2/3, 1, 1, 2/3, 1/3! are applied, respectively, based on three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting at least one first display dot;

at least one second step of forming second enlarged display brightness data comprising six pieces of enlarged display brightness data arranged in the order of G-B-R-G-B-R in the raw direction and to which weights of brightness of 1/3, 2/3, 1, 1, 2/3, 1/3! are applied, respectively, based on three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting at least one second display dot following said at least one first display dot;

at least one third step of forming third enlarged display brightness data comprising six pieces of enlarged display brightness data arranged in the order of B-R-G-B-R-G in the raw direction and to which weights of brightness of 1/3, 2/3, 1, 1, 2/3, 1/3! are applied, respectively, based on three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting at least one third display dot following said at least one second display dot;

at least one fourth step of forming supplementary enlarged display brightness data comprising eight pieces of data arranged in the order of R-G-B-R-G-B-R-G, G-B-R-G-B-R-G-B, or B-R-G-B-R-G-B-R and to which weights of brightness of 1/3, 2/3, 1, 1, 1, 1, 2/3, 1/3! are applied, respectively, based on three pieces of raw-direction original display brightness data to be displayed in three subpixels constituting at least one fourth display dot positioned at one of the following three positions;

before said at least one first display dot;

between two of said display dots that are adjacent to each other; and

after said at least one third display dot;

a fifth step of adding said first to fourth enlarged display brightness data to each other to combine them in data regions of the same color to which weights of brightness of 1/3 and 2/3 are applied, respectively, and

sequentially outputting to said subpixels said enlarged display brightness data formed by sequentially repeating said first to fifth steps to enlarge the original image M/N times in the raw direction of said display panel, where M and N are natural numbers and M≧

N+2.

11. A liquid crystal display method for enlarging the number of lines of an original image by a ratio of (1+M/N) to produce an enlarged image, where M and N are natural numbers, comprising the steps of:

converting each successive line of the original image into a group of line constituents of the enlarged image, the first and last lines of the original image being both converted into groups of three line constituents weighted M/2N, 1, M/2N! and remaining lines of the original image being converted into successive groups of two line constituents weighted 1-((2n-1)M/2N), (2n+1)M/2N! where n is a natural number; and

adding the last line constituent of a group to the first line constituent of a next successive group to form a display line of the enlarged image.

12. A liquid crystal display method for displaying an enlarged image on a display panel of a color liquid crystal display apparatus in which display dots each comprising a subpixel displaying red (R), a subpixel displaying green (G), and a subpixel displaying blue (B) placed in this order are arranged in matrix, characterized by the steps of:

forming six pieces of first enlarged display brightness data (1/3) RL0, (2/3) GL0, (1) BL0, (1) RL0, (2/3) GL0, (1/3) BL0! by weighting and enlarging in the raw direction, three pieces of raw direction original display brightness data RL0 (red) GL0 (green), BL0 (blue)!, where RL0, GL0 and BL0 are three subpixels constituting a first display dot;

forming six pieces of second enlarged display brightness data (1/3) GL1, (2/3) BL1, (1) RL1, (1) GL1, (2/3) BL1, (2/3) RL1! by weighting and enlarging in the raw direction, three pieces of raw direction original display brightness data RL1, GL1, BL1, where RL1, GL1 and BL1! are three subpixels constituting a second display dot adjacent to said first display dot;

forming six pieces of third enlarged display brightness data (1/3) BL2, (2/3) RL2, (1) GL2, (1) BL2, (2/3) RL2, (1/3) GL2! by weighting and enlarging in the raw direction, three pieces of raw direction original display brightness data RL2, GL2, BL2! , where RL2, GL2 and BL2 are three subpixels constituting a third display dot adjacent to said second display dot;

adding the fifth and sixth pieces of said first enlarged display brightness data (2/3) GL0, (1/3) BL0! to the first and second pieces of said second enlarged display brightness data (1/3) GL3, (2/3) BL1!, respectively, to combine said first and second enlarged display brightness data;

adding the fifth and sixth pieces of said second enlarged display brightness data (2/3) BL1, (1/3) RL1! to the first and second pieces of said third enlarged display brightness data (1/3) BL2, (2/3) RL2!, respectively, to combine said second and third enlarged display brightness data;

adding the fifth and sixth pieces of said third enlarged display brightness data (2/3) RL2, (1/3) GL2! to first and second pieces of a next, enlarged display brightness data (1/3) RLX, (2/3) GLX!, respectively, where RLX and GLX are two subpixels of a next display dot adjacent to said third display dot, to combine said third and next enlarged display brightness data, and sequentially repeating this sequence of operations; and

thereby sequentially outputting to the subpixels said enlarged display brightness data formed by combination to enlarge the original image 4/3 times in the raw direction of said display panel.