Color/black-and-white switchable portable terminal and display unit

• US 7,038,641 B2
• Filed: 01/08/2004
• Issued: 05/02/2006
• Est. Priority Date: 05/24/2000
• Status: Expired due to Term

• Current Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Hitachi, Ltd.
• Inventors: Hiyama, Ikuo, Tsumura, Makoto, Hirota, Shouichi, Oouchi, Takayuki
• Primary Examiner(s): Awad, Amr A.
• Assistant Examiner(s): Shapiro, Leonid
• Application Number:
  US10/752,508
• Publication Number:
  US 20040140972A1
• Time in Patent Office: 845 Days
• Field of Search: 345 82- 83, 345 87- 88, 345/90, 345/92, 345/102, 345211-213, 345/76
• US Class Current: 345/83
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0056 for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G09G 2300/023 Display panel composed of stacked panels
• CPC Class Codes: G09G 2300/0434 Flat panel display in which a field is applied parallel to the display plane
• CPC Class Codes: G09G 2300/0456 with a reflective area and a transmissive area combined in one pixel, such as in transflectance pixels
• CPC Class Codes: G09G 2300/046 with an emissive area and a light-modulating area combined in one pixel
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0852 being a dynamic memory with more than one capacitor
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/027 Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 2320/062 Adjustment of illumination source parameters
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2330/02 Details of power systems and of start or stop of display operation
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2330/022 in absence of operation, e.g. no data being entered during a predetermined time
• CPC Class Codes: G09G 2340/0428 Gradation resolution change
• CPC Class Codes: G09G 2340/0435 Change or adaptation of the frame rate of the video stream
• CPC Class Codes: G09G 2340/14 : Solving problems related to the presentation of information to be displayed
• CPC Class Codes: G09G 2360/144 : the light being ambient light
• 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 3/2011 : by amplitude modulation
• 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 3/3225 : using an active matrix
• CPC Class Codes: G09G 3/3233 : with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3258 : with pixel circuitry controlling the voltage across the light-emitting element
• CPC Class Codes: G09G 3/3406 : Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3611 : Control of matrices with row and column drivers
• CPC Class Codes: G09G 3/3648 : using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 5/028 : Circuits for converting colour display signals into monochrome display signals
• CPC Class Codes: H04W 52/027 : by controlling a display operation or backlight unit
• CPC Class Codes: Y02D 30/70 : in wireless communication networks

Abstract

A display unit has a brightness equal to that in a conventional black-and-white reflection type and the power consumption is small at a standby time, and bright color display of high quality can be produced and power consumption is small at the time of use. An information device having this display unit, such as a portable phone, also is provided. The display unit has a color light emitting means, a reflecting mean of external light and a light polarizing state modulating means. The display unit has a driving method switching means for switching color light emitting display and reflection display by on/off control of the light emitting means and switching control of a driving method of a display element.

Claims

1. A display device comprising:

colored-light emitting means for emitting colored light to effect a colored light-emitting display;

reflection means for reflecting external light to effect a monochromatic reflection display;

light polarizing state modulating means for modulating a polarizing state of the colored light;

a colored signal processing section for processing a received image signal to effect driving of image display on the colored light-emitting display, and a monochromatic signal processing section for processing the received image signal to effect driving of image display on the monochromatic reflection display; and

switching means for selecting lighting according to one of the colored light emitting means for a color display mode and the reflection means for a monochromatic display mode, and for selecting processing and driving according to one of the colored signal processing section for the color display mode and the monochromatic signal processing section for the monochromatic display mode, on a basis of the received image signal;

wherein the colored light emitting means comprises an organic LED layer, the reflection means comprises an anode of the organic LED layer, and the light polarizing state modulating means comprises a polarizing plate, a phase difference plate and a liquid crystal layer.

2. A display device according to claim 1, comprising a common electrode which functions as both an electrode operating the organic LED and an electrode operating the liquid crystal layer, the electrodes being operable at substantially a same electric potential.

3. A display device according to claim 2, wherein common wiring of the common electrode is arranged between the organic LED and the liquid crystal layer.

4. A system comprising:

at least one of;

a casing, an antenna, a speaker, an input key, a microphone, a camera, a battery, an infrared interface, and operating system (OS) software; and

,

a display device including;

colored-light emitting means for emitting colored light to effect a colored light-emitting display;

reflection means for reflecting external light to effect a monochromatic reflection display;

light polarizing state modulating means for modulating a polarizing state of the colored light;

a colored signal processing section for processing a received image signal to effect driving of image display on the colored light-emitting display, and a monochromatic signal processing section for processing the received image signal to effect driving of image display on the monochromatic reflection display; and

switching means for selecting lighting according to one of the colored light emitting means for a color display mode and the reflection means for a monochromatic display mode, and for selecting processing and driving according to one of the colored signal processing section for the color display mode and the monochromatic signal processing section for the monochromatic display mode, on a basis of the received image signal;

wherein the colored light emitting means comprises an organic LED layer, the reflection means comprises an anode of the organic LED layer, and the light polarizing state modulating means comprises a polarizing plate, a phase difference plate and a liquid crystal layer.

5. A system according to claim 4, comprising a common electrode which functions as both an electrode operating the organic LED and an electrode operating the liquid crystal layer, the electrodes being operable at substantially a same electric potential.

6. A display device according to claim 5, wherein common wiring of the common electrode is arranged between the organic LED and the liquid crystal layer.