ELECTRONIC BOOK

• US 20110032227A1
• Filed: 07/27/2010
• Published: 02/10/2011
• Est. Priority Date: 08/06/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: MIYAGUCHI, Atsushi
• Granted Patent: US 9,153,181 B2
• Time in Patent Office: Days
• US Class Current: 345/207
• CPC Class Codes: G09G 2310/0254 Control of polarity reversal in general, other than for liquid crystal displays
• CPC Class Codes: G09G 2320/0271 Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 2380/02 Flexible displays
• CPC Class Codes: G09G 2380/14 Electronic books and readers
• CPC Class Codes: G09G 3/035 for flexible display surfaces
• CPC Class Codes: G09G 3/344 based on particles moving in a fluid or in a gas, e.g. electrophoretic devices electrophoretic devices per se G02F1/167

Abstract

An object is to improve visibility without causing increases in device size and cost. Another object is to improve visibility and reduce the burden on a user without blocking external light when reflection of external light is high. An electronic book includes a display panel having an electrophoretic display element controllable by a pixel circuit of each pixel, and an illuminance sensor, and a display control portion having a circuit configured to correct an image signal for the electrophoretic display element to display a grayscale image in accordance with illuminance that is detected by the illuminance sensor.

Claims

1. An electronic book comprising:

a display panel comprising an electrophoretic display element and an illuminance sensor;

a display control portion comprising a circuit configured to correct an image signal for the electrophoretic display element to display a grayscale image in accordance with illuminance detected by the illuminance sensor; and

a pixel circuit operationally connected to the electrophoretic display element.

2. The electronic book according to claim 1, wherein the display control portion comprises a memory portion, a data input/output portion, an operation portion, and a power supply portion.

3. The electronic book according to claim 1, wherein the correction of a grayscale level of an image signal is a process for inverting a grayscale level of an image signal from black to white or from white to black.

4. An electronic book comprising:

a display panel comprising an electrophoretic display element and an illuminance sensor;

a display control portion comprising a grayscale correction circuit, an arithmetic circuit, and an image signal generation circuit; and

a pixel circuit operationally connected to the electrophoretic display element,

wherein the grayscale correction circuit controllable by the arithmetic circuit is configured to correct a grayscale level of an image signal to be input to the image signal generation circuit, for the electrophoretic display element to display a grayscale image in accordance with illuminance detected by the illuminance sensor.

5. The electronic book according to claim 4, wherein the display control portion comprises a memory portion, a data input/output portion, an operation portion, and a power supply portion.

6. The electronic book according to claim 4, wherein the correction of a grayscale level of an image signal is a process for inverting a grayscale level of an image signal from black to white or from white to black.

7. An electronic book comprising:

a display panel comprising an electrophoretic display element and an illuminance sensor;

a display control portion comprising a circuit configured to correct an image signal for the electrophoretic display element to display an enlarged character and a circuit configured to correct an image signal to display a grayscale image, in accordance with illuminance detected by the illuminance sensor; and

a pixel circuit operationally connected to the electrophoretic display element.

8. The electronic book according to claim 7, wherein the display control portion comprises a memory portion, a data input/output portion, an operation portion, and a power supply portion.

9. The electronic book according to claim 7, wherein the correction of a grayscale level of an image signal is a process for inverting a grayscale level of an image signal from black to white or from white to black.

10. An electronic book comprising:

a display panel comprising an electrophoretic display element and an illuminance sensor;

a display control portion comprising a grayscale correction circuit, an arithmetic circuit, a character enlargement circuit, and an image signal generation circuit; and

a pixel circuit operationally connected to the electrophoretic display element,

wherein the character enlargement circuit controllable by the arithmetic circuit is configured to correct an image signal to be input to the image signal generation circuit, for the electrophoretic display element to display an enlarged character in accordance with illuminance detected by the illuminance sensor, and

wherein the grayscale correction circuit controllable by the arithmetic circuit is configured to correct a grayscale level of an image signal to be input to the image signal generation circuit, for the electrophoretic display element to display a grayscale image in accordance with illuminance detected by the illuminance sensor.

11. The electronic book according to claim 10, wherein the display control portion comprises a memory portion, a data input/output portion, an operation portion, and a power supply portion.

12. The electronic book according to claim 10, wherein the correction of a grayscale level of an image signal is a process for inverting a grayscale level of an image signal from black to white or from white to black.