DISPLAY DEVICE AND DISPLAY METHOD

• US 20150325165A1
• Filed: 06/07/2013
• Published: 11/12/2015
• Est. Priority Date: 07/06/2012
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: MORI, Tomohiko, TOMIZAWA, Kazunari, HASEGAWA, Makoto, YOSHIDA, Yuichi
• Granted Patent: US 9,704,428 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 2300/0465 Improved aperture ratio, e.g. by size reduction of the pixel circuit, e.g. for improving the pixel density or the maximum displayable luminance or brightness
• CPC Class Codes: G09G 2300/0876 Supplementary capacities in pixels having special driving circuits and electrodes instead of being connected to common electrode or ground; Use of additional capacitively coupled compensation electrodes
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2320/028 by changing the viewing angle properties, e.g. widening the viewing angle, adapting the viewing angle to the view direction
• CPC Class Codes: G09G 3/2025 the sub-frames having all the same time duration
• CPC Class Codes: G09G 3/2074 using sub-pixels
• CPC Class Codes: G09G 3/2077 by a combination of two or more gradation control methods
• CPC Class Codes: G09G 3/2081 with combination of amplitude modulation and time modulation space and time error diffusion G09G3/2066
• CPC Class Codes: G09G 3/3614 Control of polarity reversal in general
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3655 Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors

Abstract

A display device is disclosed, along with a display method capable of displaying an input image having a resolution higher than the resolution of a display panel without degradation in display quality. The display device is a display device for displaying an image with each frame divided into two sub-frames. In the display device, a bright sub-pixel and a dark sub-pixel in each pixel are interchanged every sub-frame, and an input signal has a vertical resolution twice that of a display panel. The display device displays an image corresponding to the input signal by making the sub-frames different from each other in a voltage supplied to each pixel.

Claims

1. A display device for displaying an image with each frame divided into m sub-frames, m being an integer not less than 2, wherein

each of pixels in a display unit has a first sub-pixel and a second sub-pixel different in luminance from each other,

the first sub-pixel and the second sub-pixel in each pixel each switch between display of a high-luminance image and display of a low-luminance image for every one of the sub-frames,

an input signal input from an outside to the display device has a vertical resolution different from a vertical resolution of a display panel, and

the display device displays an image corresponding to the input signal by making the sub-frames different from each other in a voltage to be supplied to each pixel.

2. The display device according to claim 1, comprising:

a control unit which outputs display signals in first to m-th ones of the sub-frames to the display unit, wherein

the first sub-pixel and the second sub-pixel are connected to a single data signal line and a single scanning signal line and are connected to storage capacitor lines different from each other, and

the control unit produces a luminance difference between the first sub-pixel and the second sub-pixel by level-shifting a storage capacitor line signal which is supplied to the storage capacitor line corresponding to the first sub-pixel and a storage capacitor line signal which is supplied to the storage capacitor line corresponding to the second sub-pixel in directions different from each other and changing the level-shift direction for each of the storage capacitor line signals within the frame, and inverting a voltage polarity of a display signal every frame cycle and making the sub-frames different from each other in a voltage of the display signal.

3. The display device according to claim 1, wherein

each frame is divided into two sub-frames,

the first sub-pixels and the second sub-pixels are each arranged in a row direction and are alternately arranged in a column direction, and

the vertical resolution of the input signal is twice the vertical resolution of the display panel.

4. The display device according to claim 2, wherein

if each frame is divided into two sub-frames,

the sub-frames within the frame are different from each other in the level-shift direction for the storage capacitor line signal given to each of the storage capacitor lines, and a last one of the sub-frames of the frame and a first one of sub-frames of a succeeding frame are equal to each other in the level-shift direction for the storage capacitor line signal given to the storage capacitor line.

5. The display device according to claim 4, wherein

only the first sub-pixel is lighted for grayscale levels between not lower than one at which luminance of a display signal is a minimum and lower than one at which luminance is 0.5, and

the first sub-pixel and the second sub-pixel are lighted for the grayscale level, at which luminance of a display signal is 0.5, or a higher grayscale level.

6. The display device according to claim 5, wherein

if the display unit displays a grayscale level of 0 to a grayscale level of 255,

the grayscale level, at which luminance is 0.5, is a grayscale level of 186.

7. The display device according to claim 2, wherein

the storage capacitor line signal given to each of the storage capacitor lines is not level-shifted during writing of a signal voltage to a pixel electrode which, together with the storage capacitor line, forms a capacitor and is level-shifted in a positive direction or a negative direction with respect to a reference voltage in synchronization with or after an end of the writing.

8. The display device according to claim 7, wherein

one of the storage capacitor lines which, together with one of two included in each pixel of the pixel electrodes, forms a capacitor and one of the storage capacitor lines which, together with the other, forms a capacitor are opposite to each other in storage capacitor line signal level-shift direction.

9. The display device according to claim 7, wherein

one of the pixel electrodes which is included in one of two adjacent in a scanning direction of the pixels and one of the pixel electrodes which is included in the other each form a capacitor together with a single one of the storage capacitor lines.

10. The display device according to claim 1 or 2, wherein

each of the pixels is composed of four types of color pixels displaying colors different from each other, and

each of the four types of color pixels includes the first sub-pixel and the second sub-pixel.

11. The display device according to claim 10, wherein

the four types of color pixels are a red pixel displaying red, a green pixel displaying green, a blue pixel displaying blue, and a yellow pixel displaying yellow, and the color pixels in this order are repeatedly arranged in a row direction.

12. A display method for displaying an image with each frame divided into m sub-frames, m being an integer not less than 2, wherein

each of pixels in a display unit has a first sub-pixel and a second sub-pixel different in luminance from each other,

the first sub-pixel and the second sub-pixel in each pixel each switch between display of a high-luminance image and display of a low-luminance image for every one of the sub-frames,

an input signal input from an outside to a display device has a vertical resolution different from a vertical resolution of a display panel, and

an image corresponding to the input signal is displayed by making the sub-frames different from each other in a voltage to be supplied to each pixel.

13. The display method according to claim 12, comprising:

an output step of outputting display signals in first to m-th ones of the sub-frames to the display unit, wherein

the first sub-pixel and the second sub-pixel are connected to a single data signal line and a single scanning signal line and are connected to storage capacitor lines different from each other, and

the output step includes producing a luminance difference between the first sub-pixel and the second sub-pixel by level-shifting a storage capacitor line signal which is supplied to the storage capacitor line corresponding to the first sub-pixel and a storage capacitor line signal which is supplied to the storage capacitor line corresponding to the second sub-pixel in directions different from each other and changing the level-shift direction for each of the storage capacitor line signals within the frame, and inverting a voltage polarity of a display signal every frame cycle and making the sub-frames different from each other in a voltage of the display signal.

14. The display method according to claim 12, wherein

each frame is divided into two sub-frames,

the first sub-pixels and the second sub-pixels are each arranged in a row direction and are alternately arranged in a column direction, and

the vertical resolution of the input signal is twice the vertical resolution of the display panel.