Display device and portable terminal

• US 7,659,892 B2
• Filed: 03/14/2006
• Issued: 02/09/2010
• Est. Priority Date: 03/17/2005
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Tanada, Yoshifumi, Yamazaki, Shunpei
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): TORRES RUIZ, JOHALI ALEJANDRA
• Application Number:
  US11/374,431
• Publication Number:
  US 20060209060A1
• Time in Patent Office: 1,428 Days
• Field of Search: 363/204, 363/206, 363/211, 363/213, 345/13, 345/15, 345/74, 345/78, 345/95, 345/211
• US Class Current: 345/211
• CPC Class Codes: G06F 3/147 using display panels
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: G09G 2330/02 Details of power systems and of start or stop of display operation
• CPC Class Codes: G09G 2380/06 Remotely controlled electronic signs other than labels

Abstract

In order to increase the continuous operating time of a display device driven by a battery or the like, and a portable information terminal using the same, the volume and weight of the battery are increased. Thus, there arises a trade-off between the increased capacity of the battery and the portability of the device/terminal. Therefore, the invention provides a display device with portability ensured, which is capable of operating continuously for long periods and a portable information terminal using the same. In the display device, TFTs and an RFID tag are formed over the same insulating substrate. The RFID tag detects signals from a reader/writer, and generates DC power based on the signals. While the RFID tag is detecting signals, the display device is driven by the DC power generated in the RFID tag.

Claims

1. A portable terminal comprising:

a battery for supplying a first DC power for driving a part of or the entire circuits;

a resonant circuit comprising a coil and a capacitor for inducing AC power by bringing the resonant circuit into a resonant state, the coil and the capacitor being connected in parallel;

a power source circuit for generating a second DC power for driving a part of or the entire circuits by rectifying the AC power; and

a selector circuit for selecting the first DC power or the second DC power,

wherein the selector circuit selects the first DC power when the resonant circuit is not in the resonant state and selects the second DC power when the resonant circuit is in the resonant state.

2. The portable terminal according to claim 1, further comprising a display portion.

3. A portable terminal comprising:

a display device for displaying images by controlling multiple pixels arranged in matrix comprising a resonant circuit and a selector circuit; and

a battery for supplying a first DC power for driving a part of or the entire circuits

wherein the selector circuit selects the first DC power when the resonant circuit is not in a resonant state and selects a second DC power when the resonant circuit is in the resonant state, and

wherein the resonant circuit comprises;

a coil and a capacitor for inducing AC power by bringing the resonant circuit into the resonant state, the coil and the capacitor being connected in parallel, and

a power source circuit for generating the second DC power for driving a part of or the entire circuits by rectifying the AC power.

4. The portable terminal according to claim 3, wherein the multiple pixels, the resonant circuit, the power source circuit and the selector circuit are formed over the same insulating substrate.

5. The portable terminal according to claim 3, wherein the multiple pixels, the power source circuit and the selector circuit comprise thin film transistors, and are provided over an insulating substrate formed of glass or plastic.

6. The portable terminal according to claim 3, wherein each of the multiple pixels comprises a liquid crystal element or a self-luminous element.

7. The portable terminal according to claim 3, wherein the display device further comprises a source driver and a gate driver for controlling the multiple pixels.

8. The portable terminal according to claim 7, wherein the multiple pixels, the resonant circuit, the power source circuit, the selector circuit, the source driver and the gate driver are formed over the same insulating substrate.

9. The portable terminal according to claim 7, wherein the multiple pixels, the power source circuit, the selector circuit, the source driver and the gate driver comprise thin film transistors, and are provided over an insulating substrate formed of glass or plastic.