Display device and electronic device

Patent metadata

Field	Value
Publication number	US-2015310814-A1
Application number	US-201314443446-A
Country	US
Kind code	A1
Filing date	Nov 14, 2013
Priority date	Nov 22, 2012
Publication date	Oct 29, 2015
Grant date	—

Abstract

A display device disclosed includes a liquid crystal panel ( 6 ), and an image optimization circuit ( 4 ) for switching, in accordance with an update frequency of image data, between (i) a first mode in which a liquid crystal driver ( 7 ) is driven at a first driving frequency and (ii) a second mode in which the liquid crystal driver ( 7 ) is driven at a second driving frequency lower than the first driving frequency. The display device can therefore be used even in a case where a transmission path for image data is limited and optimally display high-resolution image data with reduced electric power consumption.

First claim

1 . A display device comprising:
a display panel including a plurality of active elements; a driving circuit for driving scanning signal lines and data signal lines both of which are included in the display panel; and an image processing circuit section for supplying image data and a control signal to the driving circuit, the image processing circuit section including: an image optimization circuit for switching, in accordance with an update frequency of the image data, between (i) a first mode in which the driving circuit is driven at a first driving frequency and (ii) a second mode in which the driving circuit is driven at a second driving frequency lower than the first driving frequency, in a case where the driving circuit is driven in the first mode,
the image optimization circuit, in a case where the image data to be transmitted via a transmission path provided between the image processing circuit section and the driving circuit has a data amount that exceeds a maximum transmission capacity for one frame period, carrying out first image data processing for reducing the data amount of the image data so that the image data is transmitted via the transmission path within the one frame period while the driving circuit is driven in the first mode, and
the driving circuit, in accordance with an image restoration control signal transmitted from the image optimization circuit, carrying out second image processing for restoring, for display, the image data that has been subjected to the first image data processing,
in a case where the driving circuit is driven in the second mode,
the image optimization circuit transmitting a control signal for causing the driving circuit to be driven at the second driving frequency so that the image data is transmitted via the transmission path within one frame period while the driving circuit is driven in the second driving mode.

2 . The display device as set forth in claim 1 , wherein:
the driving circuit is driven in the first mode in a case where a motion image is displayed on the display panel; and the driving circuit is driven in the second mode in a case where a still image is displayed on the display panel.

3 . The display device as set forth in claim 1 , wherein:
the image optimization circuit carries out the first image data processing by removing image data of a first pixel adjacent to a second pixel in the display panel; and the driving circuit carries out the second image data processing by using image data of the second pixel as the image data of the first pixel.

4 . The display device as set forth in claim 1 , wherein:
in a case where the driving circuit is switched from the first mode to the second mode, the display device displays, on the display panel a plurality of times, an identical image with use of immediately previously updated image data.

5 . The display device as set forth in claim 1 , wherein the second driving frequency of the second mode is set so as to decrease stepwise.

6 . The display device as set forth in claim 1 , wherein, in a case where the driving circuit is driven in the first mode, the display panel is driven on a basis of column inversion driving.

7 . The display device as set forth in claim 1 , wherein, in a case where the driving circuit is driven in the second mode, the display panel is driven on a basis of dot inversion driving.

8 . The display device as set forth in claim 1 , wherein:
in a case where the driving circuit is driven in the first mode, the display panel is driven on a basis of column inversion driving; in a case where the driving circuit is driven in the second mode, the display panel is driven on a basis of dot inversion driving; and the image optimization circuit carries out gamma correction with respect to the image data so as to approximate, to each other, (i) a first gamma curve for a case in which the display panel is driven on the basis of the column inversion driving and (ii) a second gamma curve for a case in which the display panel is driven on the basis of the dot inversion driving.

9 . The display device as set forth in claim 1 , wherein, in a case where the first mode is switched to the second mode, the data amount of the image data increases stepwise.

10 . The display device as set forth in claim 1 , wherein:
each of the plurality of active elements includes an oxide semiconductor layer.

11 . The display device as set forth in claim 10 , wherein the oxide semiconductor layer is a semiconductor layer containing at least one element selected from indium, gallium, and zinc.

12 . An electronic device comprising a display device as set forth in claim 1 .

Assignees

• Sharp Kk

Inventors

• Umekida Tetsuya
• Maeda Kenji
• Watanabe Tatsuo
• Natsumi Masayuki
• Sato Yuichi
• Takayama Kazuya

Classifications

• G09G2320/103

  Detection of image changes, e.g. determination of an index representative of the image change · CPC title

• G09G3/3696

  Generation of voltages supplied to electrode drivers · CPC title

• G09G2330/021

  Power management, e.g. power saving · CPC title

• G09G2310/0229

  De-interlacing · CPC title

• G09G2310/0224

  Details of interlacing · CPC title