Image display device, image display method, and image display program

• US 20040080516A1
• Filed: 08/06/2003
• Published: 04/29/2004
• Est. Priority Date: 08/22/2002
• Status: Active Grant

• Current Assignee: BOE Technology Group Co., Ltd.
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Kurumisawa, Takashi, Ishida, Masanori, Murai, Kiyoaki
• Granted Patent: US 7,277,103 B2
• Time in Patent Office: Days
• US Class Current: 345/596
• CPC Class Codes: G09G 2340/0414 Vertical resolution change
• CPC Class Codes: G09G 2340/0421 Horizontal resolution change
• CPC Class Codes: G09G 2340/0428 Gradation resolution change
• CPC Class Codes: G09G 3/2014 by modulation of the duration of a single pulse during which the logic level remains constant
• CPC Class Codes: G09G 3/2022 using sub-frames
• 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 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/367 with a nonlinear element in series with the liquid crystal cell, e.g. a diode, or M.I.M. element
• CPC Class Codes: G09G 3/3688 suitable for active matrices only
• CPC Class Codes: G09G 5/227 Resolution modifying circuits, e.g. variable screen formats, resolution change between memory contents and display screen

Abstract

The invention provides an easy and simple method of converting the resolution of image data, which is capable of generating the high-resolution image data without incongruity, does not make a circuit in the display device complicated and does not increase the power consumption. This invention can include a portable terminal device, such as a mobile telephone or a PDA, that processes and displays image data transmitted from the outside. Image data with a plurality of grayscales can be displayed by controlling the display state of each pixel in a display unit in accordance with grayscale control pulses corresponding to the number of grayscales. For example, when a 64 grayscale display is performed, a grayscale level is defined using sixty four grayscale control pulses. Thus, it is possible to emit light from pixels in the display unit by sixty four grayscale levels. Further, the resolution converting device can generate pseudo-high-resolution image data obtained by increasing the number of pixels of original image data by n multiplication and by reducing the number of grayscales of the original image data to 1/n. When displaying the pseudo-high-resolution image data, the number of grayscale control pulses is changed to 1/n by a halftone controller. That is, in the pseudo-high-resolution image data, the number of grayscales is 1/n. Therefore, the number of grayscale control pulses used for halftone display may be 1/n in accordance with the number of grayscales. Therefore, the low-resolution image data can be displayed without incongruity by converting the resolution, also, it is possible to reduce power consumption of the display unit by the reduced amount of the number of grayscale levels pulses.

Claims

1. An image display device, comprising:

a display unit that displays image data;

a halftone controller that performs halftone display by controlling a display state of each pixel in the display unit by a number of grayscale control pulses corresponding to a number of grayscale levels of the image data;

a resolution conversion device that multiplies a number of pixels of original image data by n and generates pseudo-high-resolution image data with a number of grayscale levels of 1/n; and

a grayscale controlling device that controls the halftone controller to change the number of the grayscale control pulses to 1/n when displaying the pseudo-high-resolution image data.

2. The image display device according to claim 1, the resolution conversion device converting a pixel into one of n pixel patterns comprising 1 to n pixels of specific grayscale levels.

3. The image display device according to claim 2, the resolution conversion device converting one pixel into four pixel patterns with four pixels which have two pixels in each of the horizontal and vertical directions, constructed by doubling one pixel in each of the horizontal and vertical directions,

the four pixel patterns having a first pixel pattern comprising only one pixel of a specific grayscale level, a second pixel pattern comprising two pixels of the specific grayscale level, a third pixel pattern comprising three pixels of the specific grayscale level, and a fourth pixel pattern comprising four pixels of the specific grayscale level.

4. The image display device according to claim 1, the halftone controller comprising a pulse generator that generates the number of grayscale control pulses corresponding to the number of pieces of the image data, and a driver that applies a driving voltage to the pixels only for a period corresponding to the number of grayscale control pulses corresponding to the grayscale levels to be displayed.

5. The image display device according to claim 1, further comprising:

a receiver that receives a low-resolution image data having a number of pixels a and a number of grayscale levels b near a display area and high-resolution image data having a number of pixels a×

n and a number of grayscale levels b near the display area,

the grayscale controller controlling the halftone controller to set the number of the grayscale pulses to b/n when displaying the pseudo-high-resolution image data, and to set the number of the grayscale pulses to b when displaying the high-resolution image data.

6. An image display method to be executed in an image display device comprising a display unit that displays image data, the image display method comprising:

multiplying a number of pixels of original image data by n and generating pseudo-high-resolution image data with the number of grayscale levels of 1/n; and

performing halftone display by controlling a display state of each pixel in the display unit with a number of grayscale control pulses corresponding to the number of grayscale levels of the image data to be displayed, the number of the grayscale control pulses being 1/n when displaying the pseudo-high-resolution image data.

7. An image display program to be executed in an image display device comprising a display unit that displays image data, the image display program comprising:

multiplying a number of pixels of original image data by n and generating pseudo-high-resolution image data with a number of grayscale levels of 1/n; and

performing halftone display by controlling a display state of each pixel in the display unit with the number of grayscale control pulses corresponding to the number of grayscale levels of the image data to be displayed, the number of the grayscale control pulses being 1/n when displaying the pseudo-high-resolution image data.