Display device

• US 9,548,039 B2
• Filed: 02/03/2014
• Issued: 01/17/2017
• Est. Priority Date: 12/27/2006
• Status: Active Grant

• 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:
  US14/170,671
• Publication Number:
  US 20140146034A1
• Time in Patent Office: 1,079 Days
• Field of Search: 345 76-104, 345/204, 345/211, 345/212
• US Class Current: 1/1
• 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 first circuit configured to control the pixel circuit;

a first antenna circuit configured to receive a first electromagnetic wave with a first wavelength;

a second antenna circuit configured to receive a second electromagnetic wave different from the first electromagnetic wave;

a second circuit configured to generate a first demodulation signal from the first electromagnetic wave received by the first antenna circuit;

a third circuit configured to rectify the first electromagnetic wave received by the first antenna circuit;

a fourth circuit configured to rectify the second electromagnetic wave received by the second antenna circuit;

a fifth circuit configured to generate a first voltage from an output of the third circuit;

a sixth circuit configured to generate a second demodulation signal from the second electromagnetic wave received by the second antenna circuit;

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

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

a voltage supply control circuit;

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

an eighth circuit configured to select one of the first voltage and the second voltage,

wherein the voltage supply control circuit is configured to supply the second voltage to the eighth circuit, and

wherein the eighth 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 eighth circuit is supplied to the first circuit.

2. The display device according to claim 1, wherein the second antenna circuit has a different shape from the first antenna circuit.

3. The display device according to claim 1, wherein the first electromagnetic wave is a wireless signal from a reader/writer and the second electromagnetic wave is randomly generated outside.

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

5. The display device according to claim 1, wherein the seventh circuit includes a counter circuit.

6. The display device according to claim 1, wherein the first antenna circuit and the second antenna circuit are provided over a substrate.

7. A display device comprising:

a pixel circuit having an SRAM circuit over a substrate;

a first antenna circuit configured to receive a first electromagnetic wave with a first wavelength;

a second antenna circuit configured to receive a second electromagnetic wave different from the first electromagnetic wave;

a control portion over the substrate;

a first rectifier circuit configured to rectify the first electromagnetic wave received by the first antenna circuit;

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

a second rectifier circuit configured to rectify the second electromagnetic wave received by the second antenna circuit;

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

a charge control circuit configured to control charging of the second voltage to the charge 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 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 the selected voltage is supplied to the control portion.

8. The display device according to claim 7, wherein one of the first voltage and the second voltage selected in the voltage selection circuit is supplied to a signal line control circuit and a scanning line control circuit.

9. The display device according to claim 7, further comprising:

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

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

10. The display device according to claim 7, further comprising a first demodulation circuit and a second demodulation circuit.

11. The display device according to claim 7, wherein the first electromagnetic wave is a wireless signal from a reader/writer and the second electromagnetic wave is randomly generated outside.

12. The display device according to claim 7, wherein the first antenna circuit and the second antenna circuit are provided over the substrate.

13. A display device comprising:

a pixel circuit having an SRAM circuit over a substrate;

a signal line control circuit and a scanning line control circuit over the substrate;

a first antenna circuit configured to receive a first electromagnetic wave with a first wavelength;

a second antenna circuit configured to receive a second electromagnetic wave different from the first electromagnetic wave;

a signal processing circuit including a first rectifier circuit and a control portion over the substrate, the first rectifier circuit configured to rectify the first electromagnetic wave received by the first 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 first rectifier circuit;

a second rectifier circuit configured to rectify the second electromagnetic wave received by the second antenna circuit;

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

a charge control circuit configured to control charging of the second voltage to the charge 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 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 the selected voltage is supplied to the control portion.

14. The display device according to claim 13, 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.

15. The display device according to claim 13, wherein the power generation portion further comprises:

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

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

16. The display device according to claim 13,

wherein the signal processing circuit further comprises a first demodulation circuit, and

wherein the power generation portion further comprises a second demodulation circuit.

17. The display device according to claim 13, wherein the first electromagnetic wave is a wireless signal from a reader/writer and the second electromagnetic wave is randomly generated outside.

18. The display device according to claim 13, wherein the first antenna circuit and the second antenna circuit are provided over the substrate.