Display device and display control method

• US 9,368,051 B2
• Filed: 01/16/2014
• Issued: 06/14/2016
• Est. Priority Date: 01/25/2013
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Mizushiro, Kenji
• Primary Examiner(s): Spar, Ilana
• Assistant Examiner(s): Rayan, Mihir
• Application Number:
  US14/156,870
• Publication Number:
  US 20140210869A1
• Time in Patent Office: 880 Days
• US Class Current: 1/1
• CPC Class Codes: G09G 2310/06 Details of flat display driving waveforms
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 3/003 to produce spatial visual effects
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A display device includes a light modulation device, a light source, a light modulation device control section, and a light source control section. The light modulation device control section controls the light modulation device to select a plurality of scan lines of the light modulation device by K lines (K is an integer not smaller than 2), and write a data signal into the pixels corresponding to the selected scan lines in an image update period, and to select at least a part of the plurality of scan lines line by line, and then write the data signal into the pixels corresponding to the selected scan line in an image display period subsequent to the image update period. The light source control section sets a duty ratio in a part of the image display period to be higher than the duty ratio in another part of the image display period.

Claims

1. A display device comprising:

a light modulation device including a plurality of pixels disposed corresponding to respective intersections between a plurality of scan lines and a plurality of data lines;

a light source adapted to irradiate the light modulation device with light in accordance with pulse width modulation (PWM) control;

a light modulation device control section adapted to control the light modulation device to;

select the plurality of scan lines by K lines (K is an integer not smaller than

     2), and then write a data signal into the pixels corresponding to the selected scan lines in an image update period, the image update period being a period for updating an image to be displayed by the light modulation device from the previous frame to the present frame,

select at least a part of the plurality of scan lines, line by line, and then write the data signal into the pixels corresponding to the selected scan line in an image display period subsequent to the image update period,

write the data signal corresponding to a designated grayscale of the pixels corresponding to a first scan line of the plurality of scan lines in the image update period, and

select a second scan line, which is other than the first scan line of the plurality of scan lines, and then write the data signal corresponding to a designated grayscale of the pixels corresponding to the selected second scan line in a first display period in the image display period, and select the plurality of scan lines by K lines and then write the data signal into the pixels corresponding to the selected scan lines in a second display period subsequent to the first display period; and

a light source control section adapted to;

perform the PWM control of the light source so as to set a duty ratio in a part of the image display period to be higher than the duty ratio in another part of the image display period when the light modulation device is irradiated with the light with a predetermined luminance, and

set a duty ratio in a period from when writing of the data signal is performed in the first display period to when writing of the data signal is performed in the second display period to be higher than the duty ratio in the another part of the image display period.

2. The display device according to claim 1, wherein

the light source control section sets

the duty ratio in the another part of the image display period to 0% when the light modulation device is irradiated with the light with the luminance equal to and lower than a threshold value, and

the duty ratio in the part of the image display period to 100%, and the duty ratio in the another part of the image display period to be higher than 0% when the light modulation device is irradiated with the light with the luminance higher than the threshold value.

3. The display device according to claim 1, wherein

the light modulation device control section controls the light modulation device to:

write the data signal corresponding to a designated grayscale of the pixels corresponding to a first scan line of the plurality of scan lines in the image update period, and

select a second scan line, which is other than the first scan line of the plurality of scan lines, and then write the data signal corresponding to a designated grayscale of the pixels corresponding to the selected second scan line in a first display period in the image display period, and select the plurality of scan lines, line by line, and then write the data signal into the pixels corresponding to the selected one of the scan lines in a second display period subsequent to the first display period, and

the light source control section sets the duty ratio in the second display period to be higher than the duty ratio in the first display period.

4. The display device according to claim 3, wherein

when the light modulation device is irradiated with the light in the first display period, the light source control section temporally divides the first display period into a plurality of sub-periods, and sets the duty ratio so that the more posterior the sub-period is located on a time axis, the higher the duty ratio in the sub-period is.

5. The display device according to claim 1, wherein

the light modulation device control section controls the light modulation device to select the second scan line, and then write the data signal corresponding to a designated grayscale of the pixels corresponding to the selected second scan line in a third display period after the second display period in the image display period, and

the light source control section sets a duty ratio in a period from when writing of the data signal is performed in the third display period to when the third display period ends to be higher than the duty ratio in the another part of the image display period.

6. The display device according to claim 1, wherein

the light modulation device control section controls the light modulation device to write the data signal representing one of a left-eye image and a right-eye image in 3D image display, and

the light source control section sets a duty ratio in the image update period to 0%.

7. The display device according to claim 1, wherein

the light modulation device control section controls the light modulation device to write the data signal representing a 2D image, and

the light source control section sets a duty ratio in the image update period to be higher than 0% when the duty ratio in the image display period is 100%.

8. A display control method of a display device, comprising:

providing the display device with

a light modulation device including a plurality of pixels disposed corresponding to respective intersections between a plurality of scan lines and a plurality of data lines, and

a light source adapted to irradiate the light modulation device with light in accordance with pulse width modulation (PWM) control;

selecting the plurality of scan lines by K lines (K is an integer not smaller than

     2), and then writing a data signal into the pixels corresponding to the selected scan lines in an image update period, the image update period being a period for updating an image to be displayed by the light modulation device from the previous frame to the present frame;

selecting at least a part of the plurality of scan lines, line by line, and then writing the data signal into the pixels corresponding to the selected scan line in an image display period subsequent to the image update period;

writing the data signal corresponding to a designated grayscale of the pixels corresponding to a first scan line of the plurality of scan lines in the image update period;

selecting a second scan line, which is other than the first scan line of the plurality of scan lines, and then writing the data signal corresponding to a designated grayscale of the pixels corresponding to the selected second scan line in a first display period in the image display period, and selecting, the plurality of scan lines by K lines and then writing the data signal into the pixels corresponding to the selected scan lines in a second display period subsequent to the first display period;

performing the PWM control of the light source so as to set a duty ratio in a part of the image display period to be higher than the duty ratio in another part of the image display period when the light modulation device is irradiated with the light with a predetermined luminance; and

setting a duty ratio in a period from when writing of the data signal is performed in the first display period to when writing of the data signal is performed in the second display period to be higher than the duty ratio in the another part of the image display period.

9. A display device comprising:

a light modulation device including a plurality of pixels disposed corresponding to respective intersections between a plurality of scan lines and a plurality of data lines;

a light source adapted to irradiate the light modulation device with light in accordance with pulse width modulation (PWM) control;

a light modulation device control section adapted to control the light modulation device to;

select the plurality of scan lines by K lines (K is an integer not smaller than

     2), and then write a data signal into the pixels corresponding to the selected scan lines in an image update period, the image update period being a period for updating an image to be displayed by the light modulation device from the previous frame to the present frame, and

select the plurality of scan lines by L lines (L is an integer not smaller than 1 and not larger than K-1), and then write the data signal into the pixels corresponding to the selected scan lines in an image display period subsequent to the image update period,

write the data signal corresponding to a designated grayscale of the pixels corresponding to a first scan line of the plurality of scan lines in the image update period and

select a second scan line, which is other than the first scan line of the plurality of scan lines and then write the data signal corresponding to a designated grayscale of the pixels corresponding to the selected second scan line in a first display period in the image display period, and select the plurality of scan lines by K lines and then write the data signal into the pixels corresponding to the selected scan lines in a second display period subsequent to the first display period; and

a light source control section adapted to;

perform the PWM control of the light source so as to set a duty ratio in a part of the image display period to be higher than the duty ratio in another part of the image display period when the light modulation device is irradiated with the light with a predetermined luminance, and

set a duty ratio in a period from when writing of the data signal is performed in the first display period to when writing of the data signal is performed in the second display period to be higher than the duty ratio in the another part of the image display period.