Image display and control method thereof

• US 20030016198A1
• Filed: 08/02/2002
• Published: 01/23/2003
• Est. Priority Date: 02/03/2000
• Status: Abandoned Application

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Tsujimoto, Hiroshi, Nagai, Yoshifumi
• Application Number:
  US10/182,828
• Publication Number:
  US 20030016198A1
• Time in Patent Office: Days
• US Class Current: 345/83
• CPC Class Codes: G09G 1/285 Interfacing with colour displays, e.g. TV receiver
• CPC Class Codes: G09G 2300/06 Passive matrix structure, i.e. with direct application of both column and row voltages to the light emitting or modulating elements, other than LCD or OLED
• CPC Class Codes: G09G 2310/027 Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters
• CPC Class Codes: G09G 2310/0272 Details of drivers for data electrodes, the drivers communicating data to the pixels by means of a current
• CPC Class Codes: G09G 2320/02 Improving the quality of display appearance
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/2014 by modulation of the duration of a single pulse during which the logic level remains constant
• CPC Class Codes: G09G 3/2077 by a combination of two or more gradation control methods
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]
• CPC Class Codes: G09G 3/3283 in which the data driver supplies a variable data current for setting the current through, or the voltage across, the light-emitting elements
• 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

An image display exhibiting high reproducibility by correcting variation in the chromaticity of light emitting elements and thereby uniforming the color tone of pixels, and a control method thereof. The image display comprises a display section (10) where light emitting elements of a plurality of color tones are arranged for each pixel, a drive section (50) for supplying the light emitting elements of each pixel with a drive current according to image data concerning the color tones, and a chromaticity correcting section (11) for distributing a specified part of drive current, supplied from the drive section (50) to a light emitting element corresponding to at least one of the color tones of each pixel, to a light emitting element corresponding to one or more other color tone of the pixel.

Claims

1. An image display apparatus comprising:

a display portion (10) including light emitting elements corresponding to a plurality of color tones disposed in each pixel;

a driving portion (50) supplying driving currents to the light elements corresponding to the plurality of color tones respectively in each pixel based on image data according to the plurality of color tones; and

a chromaticity correcting portion (11) distributing a predetermined part of the driving currents, which are supplied from the driving portion (50) to the light emitting elements corresponding to at least any one of the plurality of color tones in respective pixels, to the light emitting elements corresponding to at least one of the other plurality of color tones in the respective pixels.

2. The image display apparatus according to claim 1, wherein:

the chromaticity correcting portion (11) distributes the predetermined part of the driving current with adding to the driving currents, which are supplied from the driving portion (50) to the light emitting elements corresponding to at least one of the other plurality of color tones.

3. The image display apparatus according to claim 1, wherein:

the chromaticity correcting portion (11) distributes the predetermined part of the driving currents as the driving currents supplied to the light emitting elements corresponding to at least one of the other plurality of color tones during a predetermined divided one-image-frame period.

4. The image display apparatus according to any of claims 1 through 3, the image display apparatus further comprising a correcting data storing portion (32) storing chromaticity correcting data of each pixel according to the predetermined part of the driving currents, which are supplied from the driving portion (50) to the light emitting elements corresponding to at least any one of the plurality of color tones in respective pixels, to the light emitting elements corresponding to at least one of the other plurality of color tones in the respective pixels.

5. The image display apparatus according to claim 1, wherein,

the driving portion further comprising

a current supply portion (14) supplying a predetermined amount of current for each color tone, and

a luminance correcting portion (13) controlling the amount of current supplied from the current supply portion (14) to correct a dispersion of luminance in each dot corresponding to each color tone,

wherein,

the current controlled in each dot corresponding to each color tone in the luminance correcting portion (13) is supplied to the chromaticity correcting portion (11) as the driving current, whose driving period is controlled by a driving period based on the image data.

6. The image display apparatus according to claim 5, wherein:

the driving portion further comprising a driving period control portion (12) supplying the driving current, which is formed in a pulse driving current, to the chromaticity correcting portion (11),.

7. The image display apparatus according to claim 1, wherein:

the image display apparatus stores data to be necessary for controlling a predetermined amount of currents to be supplied for each color tones in the current supply portion (14),

pixel luminance correcting data to be necessary for correcting luminance in each dot corresponding to each color tone in the luminance correcting portion (13), and

chromaticity correcting data to be necessary for correcting chromaticity in each pixel according to the predetermined part of the driving currents, which are distributed to the light emitting elements in the respective pixels corresponding to at least one of the other plurality of color tones, of the light emitting elements corresponding to at least any one of the plurality of color tones.

8. The image display apparatus according to claim 4,

wherein:

the image display apparatus is composed of an image display unit displaying a display area, which is divided one image into a plurality of areas,

the correcting data storing portion (32) is installed in the image displaying unit,

the chromaticity correcting portion (11) is controlled directly based on the chromaticity correcting data stored in the correcting data storing portion (32).

9. The image display apparatus according to claim 5,

wherein:

the current supply portion (14) comprising a constant current driving portion controlling each light emitting element corresponding to each color tone individually,

the image display apparatus performs current control in each pixel for each light emitting element to emit a predetermined chromaticity with correcting a dispersion of chromaticity of each light emitting element.

10. An image display apparatus comprising:

a display portion (10) including light emitting elements corresponding to a plurality of color tones disposed in each pixel;

a plurality of first current driving portions (52), which are connected with the light emitting elements respectively, supplying main currents based on image data to be capable to perform driving control for light emitting elements individually; and

a second driving control portion (53) adding a correcting current, which corrects chromaticity of the light emitting element, to the other of light emitting elements,

wherein,

the second driving portion (53) adds the correcting currents for correcting chromaticity of the other light emitting elements to the main current for lighting each light emitting element corresponding to each color tone, so that each light emitting element is performed chromaticity correcting by adding the correcting current of at least one of the other light emitting elements to the main current.

11. The image display apparatus according to claim 10, wherein:

the second current driving portion (53) comprising

a plurality of second constant current driving portions (64) controlling to add the correcting current to the light emitting elements corresponding to each color tone, and

at least one of second current adjusting portions (65) connected with the second constant current driving portions (64).

12. The image display apparatus according to claim 11, wherein:

the second current driving portion adds the correcting current to the light emitting elements corresponding to each color tone in time-sharing.

13. The image display apparatus according to claim 11,

wherein:

the second current driving portion adds the correcting current to the light emitting elements corresponding to each color tone by a plurality of the second current adjusting portions (65) simultaneously.

14. The image display apparatus according to any of claims 10 through 13,

wherein,

the image display apparatus further comprising a lighting pulse generating portion (63) generating a lighting pulse to supply the main current based on the image data,

wherein,

the lighting pulse generating potion (63) outputs the lighting pulse for the light emitting elements corresponding to each color tone to the first current driving portions (52) and the second driving control portion (53) controlling supply of the correcting current for the light emitting elements corresponding to the other color tones,

the second driving control portion (53) supplies the correcting current, which is added to the light emitting elements corresponding to the other color tones, based on the lighting pulse for the light emitting elements corresponding to the color tone to be corrected their chromaticity.

15. The image display apparatus according to any of claims 10 through 14, wherein:

the first current driving portions (53) further comprising;

first constant current driving portions (60) performing driving control of the main currents to be supplied to the light emitting elements in each light emitting element individually,

a plurality of first current adjusting portions (61), which are connected with the first constant current driving portions (60) respectively, adjusting output currents of the first current driving portions (53), and

main current switches (62), which are connected with the first constant current driving portions (60) and the first current adjusting portions (61) in serial, controlling to supply the currents to the light emitting elements.

16. The image display apparatus according to claim 17, wherein:

the lighting pulse generating portion (63) generates the lighting pulse based on the image data received from a driving portion (50), and performs driving control of the main current in each first constant current driving portion (60) with outputting the lighting pulse to each main current switch (62) as an ON/OFF control signal.

17. The image display apparatus according to claim 16, wherein:

the lighting pulse generating portion (63) determines pulse width based on gradation data received from the driving portion (50),

the first constant current driving portion (60) supplies the main current to the light emitting element during the pulse valid period,

the lighting pulse according to the light emitting element to be corrected its chromaticity, which is generated in the lighting pulse generating portion (63), is input as a driving control signal to the second constant current driving portion (64) corresponding to the elements of the other color tones, and

a predetermined correcting current for correcting chromaticity is added to the main currents for the elements of the other color tones based on the second current adjusting portion (65).

18. The image display apparatus according to claim 10, wherein:

the current adjusting portion is a D/A converter for adjusting the current.

20. The image display apparatus according to claim 19, wherein:

the lighting pulse generating portions (63) controls lighting period with pulse-width-modulating gradation data based on a gradation reference clock.

21. The image display apparatus according to claim 19, wherein:

the second current adjusting D/A converter (65A) adds the correcting current during a driving period of the main current, which is supplied to the light emitting element to be corrected its chromaticity, to the other light emitting elements in the pixel of the light emitting element to be corrected its chromaticity, so as to adjust chromaticity balance with controlling the driving current of each light emitting element.

22. The image display apparatus according to claim 19, wherein:

the switch control portion (66) controls for ON/OFF of the plurality of correcting current switches by a chromaticity-correcting selecting signal.

19. An image display apparatus comprising:

a display portion (10) including light emitting elements corresponding to a plurality of color tones disposed in each pixel; and

a driving portion (50) supplying driving currents to the light elements corresponding to the plurality of color tones respectively in each pixel based on image data according to the plurality of color tones,

wherein,

the driving portion (50) includes

at least one of lighting pulse generating portions (63) generating lighting pulses controlling light emission of the light emitting elements respectively,

a plurality of main current switches being controlled ON/OFF by the lighting pulse generating portions (63),

at least one first current adjusting D/A converters (61) determining a main current supplied to each light emitting element via the main current switches

a plurality of correcting current switches for adjusting a correcting current,

a switch control portion (66) controlling ON/OFF of the plurality of correcting current switches, and

a second current adjusting D/A converter (65A) supplying the correcting current to each light emitting element via the correcting current switches,

wherein,

the correcting current to correct chromaticity of each light emitting element is added to the main current.

23. An image display apparatus comprising:

a display portion (10) including light emitting elements corresponding to a plurality of color tones disposed in each pixel, which is aligned in a matrix shape with m row and n column;

a correcting data storing portion (32) storing correcting data corresponding to each pixel respectively; and

a driving portion (50) correcting an image data, which is input thereto, based on the correcting data, and driving the display portion (10) to display by using the corrected image data;

wherein,

the driving portion (50) further includes

first constant current driving portions (60) performing constant current driving of the light emitting elements corresponding to the plurality of color tones in each pixel, and

a second constant current driving portion (64) performing chromaticity correcting of the light emitting elements in respective pixels corresponding to each color tone with supplying correcting currents to the light emitting elements in the respective pixels corresponding to the other plurality of color tones during a driving period of the light emitting elements corresponding to each color tone.

24. A control method for image displaying in multicolor with controlling amount of light emission A_R, A_G, A_B of light emitting elements L_R, L_G, L_B corresponding to a plurality of color tones R, G, B, which are disposed in each pixel in a display portion (10), based on image data D_R, D_G, D_B according to R, G, B, in each pixel,

wherein:

in light emission of at least one of the light emitting elements Li (i=R, G, B) based on the image data Di (i=R, G, B) in respective pixels, amount of light emission A′

k (k≠

i) of at least one of the other light emitting elements Lk (k≠

i) in the respective pixels based on amount of light emission Ai (i=R, G, B) of the light emitting element Li is added to amount of light emission Ak (k≠

i) of at least one of the other light emitting elements Lk based on the image data Dk (k≠

i), so as to control amount of light emission of the light emitting element Lk to Ak+A′

k.

25. A control method correcting luminance and chromaticity of an image display apparatus, which comprises a display portion (10) including light emitting elements corresponding to a plurality of color tones disposed in each pixel, and a driving portion (50) supplying driving currents to light emitting elements corresponding to the plurality of color tones respectively in each pixel based on an image data according to the plurality of color tones comprising:

a luminance-and-chromaticity calculating step calculating luminance and chromaticity of the light emitting elements corresponding to each of the plurality of color tones in the image display apparatus by a device detecting intensity of light emission;

a luminance-and-chromaticity deference calculating step calculating a deference of luminance and chromaticity by comparing luminance, chromaticity of the light emitting elements corresponding to each of the plurality of color tones and reference luminance, reference chromaticity;

a correcting step correcting luminance and chromaticity of each pixel to the reference luminance and the reference chromaticity by controlling the driving current, which is supplied from the driving portion (50) to the light emitting elements in each pixel corresponding to each of the plurality of color tones, based on the deference of luminance and chromaticity in the luminance-and-chromaticity deference calculating step;

a correcting-data storing step that correcting data according to control of the driving current, which is supplied to the light emitting elements corresponding to each of the plurality of color tones in the correcting step, is stored to the image display apparatus in each pixel.