Display device

• US 8,643,635 B2
• Filed: 12/26/2007
• Issued: 02/04/2014
• Est. Priority Date: 12/27/2006
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Arasawa, Ryo, Miyake, Hiroyuki
• Primary Examiner(s): Nguyen, Jimmy H
• Application Number:
  US11/964,564
• Publication Number:
  US 20080211800A1
• Time in Patent Office: 2,232 Days
• Field of Search: 345/211, 345/204, 345 76-104
• US Class Current: 345/211
• CPC Class Codes: G09G 2300/0857 Static memory circuit, e.g. flip-flop
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2330/028 Generation of voltages supplied to electrode drivers in a matrix display other than LCD
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/3258 with pixel circuitry controlling the voltage across the light-emitting element
• CPC Class Codes: G09G 5/00 Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators image data processing or generation, in general G06T

Abstract

A display device is driven through no wire cable such as an FPC, and a display image is continuously held for a certain period of time by storing an image signal received from a wireless communication device so that the display image can be held even when the display device is out of communication range with the wireless communication device. A display device includes at least a pixel circuit having an SRAM (static random access memory) circuit, a circuit which controls the pixel circuit, an antenna circuit, a circuit which generates a demodulation signal, a circuit which rectifies a wireless signal, a circuit which generates first voltage, a charge circuit which stores second voltage, a charge control circuit, a voltage supply control circuit, and a circuit which controls the charge control circuit and the voltage supply control circuit.

Claims

1. A display device comprising:

a display portion;

a pixel circuit in the display portion, the pixel circuit including an SRAM circuit;

a signal line control circuit;

a scanning line control circuit;

a first circuit configured to control the pixel circuit;

an antenna circuit;

a second circuit configured to generate a demodulation signal from a wireless signal received by the antenna circuit;

a third circuit configured to rectify the wireless signal received by the antenna circuit;

a fourth circuit configured to generate a first voltage from a voltage rectified by the third circuit;

a charge circuit configured to store a second voltage from the voltage rectified by the third circuit;

a charge control circuit configured to control charging of the second voltage to the charge circuit;

a voltage supply control circuit connected to the charge circuit;

a fifth circuit configured to control the charge control circuit and the voltage supply control circuit; and

a sixth circuit configured to determine whether the first voltage and the second voltage are supplied, compare levels of the first voltage and the second voltage with each other when the first voltage and the second voltage are supplied, and select the higher of the first voltage and the second voltage as a selected voltage,

wherein the voltage supply control circuit is configured to supply the second voltage to the sixth circuit,

wherein one of the first voltage and the second voltage selected in the sixth circuit is supplied to the signal line control circuit and the scanning line control circuit, and

wherein the sixth circuit comprises a storage capacitor and the storage capacitor is configured to compensate voltage supply to the first circuit in a period when voltage is not supplied to the first circuit which occurs when voltage selected in the sixth circuit is supplied to the first circuit.

2. The display device according to claim 1, wherein the third circuit is electrically connected to both the fourth circuit and the fifth circuit.

3. The display device according to claim 1, wherein the second circuit includes a first demodulation circuit and a second demodulation circuit, and the first demodulation circuit is configured to supply the demodulation signal generated in the first demodulation circuit to the first circuit, and the second demodulation circuit is configured to supply the demodulation signal generated in the second demodulation circuit to the charge control circuit.

4. The display device according to claim 1, wherein one of the first voltage and the second voltage selected in the sixth circuit is supplied to the first circuit.

5. The display device according to claim 1, wherein the fifth circuit includes a voltage comparison circuit.

6. The display device according to claim 1, wherein the fifth circuit includes a counter circuit.

7. A display device comprising:

a pixel circuit having an SRAM circuit formed over a substrate;

a signal line control circuit;

a scanning line control circuit;

an antenna circuit formed over the substrate;

a signal processing circuit including a rectifier circuit and a control portion over the substrate, the rectifier circuit configured to rectify a wireless signal received by the antenna circuit; and

a power generation portion formed over the substrate, the power generation portion including;

a constant voltage circuit configured to generate a first voltage from an output of the rectifier circuit;

a charge circuit configured to store a second voltage from the output of the rectifier circuit;

a charge control circuit configured to control charging of the second voltage to the charge circuit;

a voltage supply control circuit connected to the charge circuit;

a circuit configured to control the charge control circuit and the voltage supply control circuit; and

a voltage selection circuit configured to determine whether the first voltage and the second voltage are supplied, compare levels of the first voltage and the second voltage with each other when the first voltage and the second voltage are supplied, and select the higher of the first voltage and the second voltage as a selected voltage,

wherein one of the first voltage and the second voltage selected in the voltage selection circuit is supplied to the signal line control circuit, and the scanning line control circuit, and

wherein the voltage selection circuit comprises a storage capacitor and the storage capacitor is configured to compensate voltage supply to the control portion in a period when voltage is not supplied to the control portion which occurs when voltage selected in the voltage selection circuit is supplied to the control portion.

8. The display device according to claim 7, wherein the signal processing circuit further includes a first demodulation circuit.

9. The display device according to claim 8, wherein the power generation portion further includes a second demodulation circuit.

10. A display device comprising:

a pixel circuit including an SRAM circuit;

a signal line control circuit;

a scanning line control circuit;

an antenna circuit;

a signal processing circuit including a control portion and a rectifier circuit, the rectifier circuit configured to rectify a wireless signal received by the antenna circuit; and

a power generation portion including;

a constant voltage circuit configured to generate a first voltage from an output of the rectifier circuit;

a charge circuit configured to store a second voltage from the output of the rectifier circuit;

a charge control circuit configured to control charging of the second voltage to the charge circuit;

a voltage supply control circuit connected to the charge circuit;

a circuit configured to control the charge control circuit and the voltage supply control circuit; and

a voltage selection circuit configured to determine whether the first voltage and the second voltage are supplied, compare levels of the first voltage and the second voltage with each other when the first voltage and the second voltage are supplied, and select the higher of the first voltage and the second voltage as a selected voltage to be supplied to the signal line control circuit and the scanning line control circuit,

wherein one of the first voltage and the second voltage selected in the voltage selection circuit is supplied to the signal line control circuit and the scanning line control circuit, and

wherein the voltage selection circuit comprises a storage capacitor and the storage capacitor is configured to compensate voltage supply to the control portion in a period when voltage is not supplied to the control portion which occurs when voltage selected in the voltage selection circuit is supplied to the control portion.

11. The display device according to claim 10, wherein the signal processing circuit further includes a first demodulation circuit.

12. The display device according to claim 10, wherein the power generation portion further includes a second demodulation circuit.