LIGHT SOURCE CONTROL APPARATUS, IMAGE DISPLAY APPARATUS AND LIGHT SOURCE CONTROL METHOD

• US 20130063500A1
• Filed: 09/11/2012
• Published: 03/14/2013
• Est. Priority Date: 09/14/2011
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: OKA, Kiyohiro, MAKINO, Wataru
• Granted Patent: US 9,813,683 B2
• Time in Patent Office: Days
• US Class Current: 345/690
• CPC Class Codes: H04N 9/3155 for controlling the light source light source control per se H05B35/00 – H05B47/00; control of an illumination source for displays in general G09G3/3406

Abstract

There is provided a light source control apparatus including an image change determination unit that determines presence or absence of at least one of a change of an image signal and the image signal, and a light source controller that reduces luminous output of a light source at a predetermined decreasing rate when the image change determination unit determines at least one of no change of the image signal and absence of the image signal.

Claims

1. A light source control apparatus, comprising:

an image change determination unit that determines presence or absence of at least one of a change of an image signal and the image signal; and

a light source controller that reduces luminous output of a light source at a predetermined decreasing rate when the image change determination unit determines at least one of no change of the image signal and absence of the image signal.

2. The light source control apparatus according to claim 1,

wherein the light source controller maintains the luminous output of the light source in a state of being reduced by a fixed amount.

3. The light source control apparatus according to claim 2,

wherein the light source controller again reduces the maintained luminous output of the light source at a predetermined decreasing rate.

4. The light source control apparatus according to claim 3,

wherein the light source controller reduces the luminous output of the light source up to a predetermined lower limit at the decreasing rate.

5. The light source control apparatus according to claim 2,

wherein when the image change determination unit determines one of the change of the image signal and presence of the image signal while the luminous output is reduced or the reduced luminous output is maintained, the light source controller restores the luminous output of the light source to initial luminous output.

6. The light source control apparatus according to claim 1,

wherein the decreasing rate is 5 W/s or less.

7. The light source control apparatus according to claim 2,

wherein the luminous output reduced by the fixed amount is 85% to 90% of the luminous output of a luminous output mode set by a user.

8. The light source control apparatus according to claim 1,

wherein the image change determination unit determines presence or absence of at least one of the change of the image signal and the image signal in accordance with a histogram of the number of pixels corresponding to each brightness of a frame based on the image signal.

9. The light source control apparatus according to claim 8,

wherein the image change determination unit determines presence or absence of at least one of the change of the image signal and the image signal based on a difference between the histogram and a histogram corresponding to a past image signal.

10. An image display apparatus, comprising:

a light source; and

a light source control apparatus, including an image change determination unit that determines presence or absence of at least one of a change of an image signal and the image signal and a light source controller that reduces luminous output of the light source at a predetermined decreasing rate when the image change determination unit determines at least one of no change of the image signal and absence of the image signal.

11. A light source control method, comprising:

determining presence or absence of at least one of a change of an image signal and the image signal; and

reducing luminous output of a light source at a predetermined decreasing rate when at least one of no change of the image signal and absence of the image signal is determined in the image change determination step.