Color/mono switched display

• US 20030197674A1
• Filed: 04/19/2002
• Published: 10/23/2003
• Est. Priority Date: 04/19/2002
• Status: Active Grant

• Current Assignee: Kopin Corporation
• Original Assignee: Kopin Corporation
• Inventors: Herrmann, Frederick P.
• Granted Patent: US 7,057,668 B2
• Time in Patent Office: Days
• US Class Current: 345/102
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 2360/18 Use of a frame buffer in a display terminal, inclusive of the display panel
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: H04N 9/3108 by using a single electronic spatial light modulator
• CPC Class Codes: H04N 9/3114 by using a sequential colour filter producing one colour at a time

Abstract

A color sequential display operative in one of two alternate modes. The first mode is a color sequential mode in which primary color images are displayed in successive frames while respective background light sources are simultaneously flashed on the display. The second mode is a monochrome mode in which the luminance Y signal is displayed in successive frames along with flashes of background white light.

Claims

1. A color sequential display system operable in a monochrome mode comprising:

a) a video signal source which generates a composite video signal containing a luminance signal Y_s and primary color signals R_s, B_s, and G_s;

b) a light source adapted to flash light of each of the primary colors R, B, or G or a white light W;

c) a display optically coupled to the light source, said display having an array for displaying (i) an image of the R_s, B_s, and G_s signals in succession at a rate of 150-240 Hz in a color sequential mode or (ii) displaying an image of the luminance signal Y_s in succession at a rate of 50-60 Hz in a monochrome mode; and

d) a control for the light sources which, in the color sequential mode, flashes light of each of the primary colors in synchronism with the respective image display of the R_s, B_s &

G_s signals and in the monochrome mode, flashes the white light or light of all of the primary colors simultaneously in synchronism with the display of the luminance signal Y_s.

2. The system of claim 1 wherein the light sources comprises R, B and G and white LEDs.

3. The system of claim 1 in which the display is an active matrix display.

4. The system of claim 1 in which M is 50 Hz or greater and N is at least 3 times M.

9. The method of claim 1 wherein the light sources comprises R, B and G and white LEDs.

10. The method of claim 1 in which the display is an active matrix display.

12. The system of claim 1 wherein the light sources comprises R, B and G and white LEDs.

13. The system of claim 1 in which the display is an active matrix display.

5. A color sequential display system comprising:

a) a source of composite video signals having luminance and color components;

b) a light source comprising a plurality of light emitting devices adapted to emit one each of the primary colors and white light;

c) a sequential color circuit coupled between the source and a display to generate a plurality of color images in temporal sequence, the sequential color circuit controlling a sequence of colored image frames formed on the display from the luminance part of the composite video signal; and

d) a monochrome circuit alternatively coupled between the display and light source which in a first mode (i) simultaneously generates each of the primary colors or in a second mode (ii) generates only a white color.

6. The system of claim 5 wherein the light emitting devices comprise red, green t and blue and white LEDs.

7. The system of claim 5 wherein the display comprises an active matrix display.

8. A method of operating a color sequential display system in a monochrome mode comprising:

a) receiving a composite video signal containing a luminance signal Y_x and primary color signals R_s, B_s, and G_s;

b) generating light of each of the primary colors R, B, or G and a white light W;

c) displaying (i) an image of the R_s, B_s, and G_s signals in succession at a rate of N cycles per second in a color sequential mode or (ii) displaying an image of the luminance signal YS in succession at a rate of M cycles per second in a monochrome mode; and

d) in the color sequential mode flashing light of each of the primary colors in synchronism with the respective image display of the R_s, B_s &

G_s signals and in the monochrome mode, flashing the white light or light of all of the primary colors simultaneously in synchronism with the display of the luminance signal Y_s.

11. A color sequential display system operable in a monochrome mode comprising:

a) an interface for receiving a composite video signal containing a luminance signal Y_s and primary color signals R_s, B_s, and G_s;

b) a light source coupled to the display and optically adapted to generate light of each of the primary colors R, B, or G and a white light W;

c) said display having an array for displaying (i) an image of the R_s, B_s, and G_s signals in succession at a rate of N cycles per second in a color sequential mode or (ii) displaying an image of the luminance signal Y_s in succession at a rate of M cycles per second in a monochrome mode; and

d) a control for the light sources which, in the color sequential mode, flashes light of each of the primary colors in synchronism with the respective image display of the Rs, B_s &

G_s signals and in the monochrome mode, flashes of the white light or light of all of the primary colors simultaneously in synchronism with the display of the luminance signal Y_s.