Display device

• US 20030231160A1
• Filed: 02/26/2003
• Published: 12/18/2003
• Est. Priority Date: 06/13/2002
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Betsui, Keiichi, Yoshihara, Toshiaki, Makino, Tetsuya
• Granted Patent: US 7,019,762 B2
• Time in Patent Office: Days
• US Class Current: 345/102
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3651 using multistable liquid crystals, e.g. ferroelectric liquid crystals

Abstract

Color display is performed by adding data of a predetermined level to pixel data of each emission color inputted according to an image to be displayed and synchronizing an input of summed pixel data obtained by the addition with light emission timing of each of emission colors (R, G, B) from a back-light. Switching is performed between color display based on such summed pixel data and color display based on the original pixel data, according to ambient illuminance measured. Moreover, the predetermined level to be added is suitably selected based on ambient illuminace.

Claims

1. A field-sequential type display device for performing color display by switching a plurality of emission colors of a light source with passage of time and synchronizing light emission timing of each emission color with an input of pixel data of each emission color corresponding to an image to be displayed, comprising:

an adder unit for creating summed pixel data by adding addition data to pixel data of each emission color inputted according to the image to be displayed; and

a display unit for receiving an input of the summed pixel data from said adder unit and performing color display by synchronizing the light emission timing of each emission color with the input of the summed pixel data.

2. The display device of claim 1, further comprising a switching unit for performing switching between color display performed based on the pixel data inputted according to the image to be displayed and color display performed based on the summed pixel data obtained by said adder unit.

3. The display device of claim 2, further comprising:

a measuring unit for measuring ambient illuminance; and

a control unit for controlling switching performed by said switching unit, based on a result of measurement obtained by said measuring unit.

4. The display device of claim 1, further comprising:

a storage unit for storing a plurality of kinds of data of mutually different levels for use as the addition data; and

a selecting unit for selecting one kind of data from the plurality of kinds of data stored by said storage unit.

5. The display device of claim 2, further comprising:

a storage unit for storing a plurality of kinds of data of mutually different levels for use as the addition data; and

a selecting unit for selecting one kind of data from the plurality of kinds of data stored by said storage unit.

6. The display device of claim 4, further comprising:

a measuring unit for measuring ambient illuminance; and

a control unit for controlling selection performed by said selecting unit, based on a result of measurement obtained by said measuring unit.

7. The display device of claim 5, further comprising:

a measuring unit for measuring ambient illuminance; and

a control unit for controlling selection performed by said selecting unit, based on a result of measurement obtained by said measuring unit.

8. The display device of claim 1,

wherein the addition data is substantially white achromatic data.

9. The display device of claim 2,

wherein the addition data is substantially white achromatic data.

10. The display device of claim 4,

wherein the addition data is substantially white achromatic data.

11. The display device of claim 1, further comprising an intensity control unit for controlling intensities of the plurality of emission colors of the light source.

12. The display device of claim 2, further comprising an intensity control unit for controlling intensities of the plurality of emission colors of the light source.

13. The display device of claim 4, further comprising an intensity control unit for controlling intensities of the plurality of emission colors of the light source.

14. The display device of claim 1, further comprising a converting unit for creating converted pixel data by converting the inputted pixel data, according to the addition data,

wherein the addition data is added to the converted pixel data by said adder unit.

15. The display device of claim 2, further comprising a converting unit for creating converted pixel data by converting the inputted pixel data, according to the addition data,

wherein the addition data is added to the converted pixel data by said adder unit.

16. The display device of claim 4, further comprising a converting unit for creating converted pixel data by converting the inputted pixel data, according to the addition data,

wherein the addition data is added to the converted pixel data by said adder unit.

17. The display device of claim 1, further comprising a detecting unit for detecting whether a level of the pixel data to be inputted is not more than a predetermined level,

wherein, when the level of the inputted pixel data is not more than the predetermined level, addition of the addition data is not performed by said adder unit.