IMAGE DISPLAY APPARATUS AND METHOD FOR CONTROLLING THE SAME

• US 20150002556A1
• Filed: 06/26/2014
• Published: 01/01/2015
• Est. Priority Date: 06/28/2013
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Kimoto, Tatsuya
• Granted Patent: US 9,741,295 B2
• Time in Patent Office: Days
• US Class Current: 345/690
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2380/08 Biomedical applications
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
• 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

Abstract

An image display apparatus includes a display unit to display an image based on image data on a screen including a plurality of areas, a light emitting unit to individually control emission brightness for each area, a calculation unit to calculate emission brightness of an image displayed on the screen for each area based on the image data, a measurement unit disposed opposing the screen and to measure a characteristic value relating to display characteristics of the display unit, and a control unit to determine whether emission brightness of a first area opposing the measurement unit is lower than a first value when the measurement unit measures the characteristic value and to set the emission brightness to a value equal to or greater than the first value when the emission brightness of the light emitting unit for the first area is lower than the first value.

Claims

1. An image display apparatus comprising:

a display unit configured to display an image based on image data on a screen including a plurality of areas;

a light emitting unit capable of individually controlling emission brightness for each of the areas;

a calculation unit configured to calculate emission brightness of an image displayed on the screen for each of the areas based on the image data;

a measurement unit disposed opposing the screen, and configured to measure a characteristic value relating to display characteristics of the display unit; and

a control unit configured to determine whether emission brightness of a first area opposing the measurement unit is lower than a first value when the measurement unit measures the characteristic value, and to set the emission brightness to a value equal to or greater than the first value in a case where the emission brightness of the light emitting unit on the first area is lower than the first value.

2. The image display apparatus according to claim 1, wherein, when the measurement unit measures the characteristic value, the control unit sets the emission brightness of the light emitting unit so that the emission brightness for the first area is equal to or greater than the first value and equal to or lower than a second value, in a case where the emission brightness for the first area is less than the first value.

3. The image display apparatus according to claim 2, wherein the second value is a value obtained by dividing maximum brightness of the light emitting unit set in advance by 250.

4. The image display apparatus according to claim 2, wherein the second value is a value obtained by dividing maximum brightness of the light emitting unit set in advance by 100.

5. The image display apparatus according to claim 1, wherein, when the measurement unit measures the characteristic value, the control unit controls the emission brightness for the first area to gradually rise, in a case where the emission brightness for the first area is lower than the first value.

6. The image display apparatus according to claim 1, wherein the control unit controls the emission brightness of the first area, which has been raised to reach or exceed the first value, to gradually fall in response to the measurement unit finishing measuring the characteristic value.

7. The image display apparatus according to claim 1, wherein, when the measurement unit measures the characteristic value, the control unit raises emission brightness for a second area adjacent to the first area, in a case where the emission brightness for the first area is lower than the first value.

8. The image display apparatus according to claim 1, wherein the first value is a lower limit value of emission brightness at which the measurement unit can measure the characteristic value.

9. The image display apparatus according to claim 1, wherein the display characteristics are at least one of gamma characteristics, color characteristics, and brightness characteristics.

10. The image display apparatus according to claim 1, wherein the characteristic value is at least one of a chromaticity value and a brightness value.

11. A method for controlling an image display apparatus that includes a display unit configured to display an image on a screen including a plurality of areas based on image data and a light emitting unit capable of independently controlling emission brightness for each of the areas, the method comprising:

calculating emission brightness of an image displayed on the screen for each of the areas based on the image data;

measuring a characteristic value relating to display characteristics of the display unit by using a measurement unit disposed opposing the screen;

determining whether emission brightness for a first area opposing the measurement unit is lower than a first value when the measurement unit measures the characteristic value; and

setting the emission brightness to a value that is equal to or greater than the first value in a case where the emission brightness of the light emitting unit for the first area is lower than the first value.

12. The method for controlling the image display apparatus according to claim 11, wherein when the measurement unit measures the characteristic value, the emission brightness of the light emitting unit is set so that the emission brightness for the first area is equal to or greater than the first value and equal to or lower than a second value, in a case where the emission brightness for the first area is lower than the first value.

13. The method for controlling the image display apparatus according to claim 12, wherein the second value is a value obtained by dividing maximum brightness of the light emitting unit set in advance by 250.

14. The method for controlling the image display apparatus according to claim 12, wherein the second value is a value obtained by dividing maximum brightness of the light emitting unit set in advance by 100.

15. The method for controlling the image display apparatus according to claim 11, wherein when the measurement unit measures the characteristic value, the emission brightness for the first area is controlled to gradually rise, in a case where the emission brightness for the first area is lower than the first value.

16. The method for controlling the image display apparatus according to claim 11, wherein the emission brightness for the first area, which has been raised to reach or exceed the first value, is controlled to gradually fall in response to the measurement unit finishing measuring the characteristic value.

17. The method for controlling the image display apparatus according to claim 11, wherein when the measurement unit measures the characteristic value, emission brightness for a second area adjacent to the first area is raised, in a case where the emission brightness for the first area is lower than the first value.

18. The method for controlling the image display apparatus according to claim 11, wherein the first value is a lower limit value of emission brightness at which the measurement unit can measure the characteristic value.

19. The method for controlling the image display apparatus according to claim 11, wherein the display characteristics are at least one of gamma characteristics, color characteristics, and brightness characteristics.

20. The method for controlling the image display apparatus according to claim 11, wherein the characteristic value is at least one of a chromaticity value and a brightness value.