Portable radio equipment with a display back-lighting function

• US 5,337,073 A
• Filed: 07/13/1992
• Issued: 08/09/1994
• Est. Priority Date: 11/09/1988
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Tsunoda, Hideyuki, Nishiyama, Toshirou
• Primary Examiner(s): Oberley, Alvin E.
• Assistant Examiner(s): Saras, Steven J.
• Application Number:
  US07/911,385
• Time in Patent Office: 757 Days
• Field of Search: 340/781, 340/784, 340/811, 340/805, 340/825.44, 340/825.81, 315/169.1, 315/169.3, 313/507-510, 350/345, 345/76, 345/77, 345/78, 345/79, 345/80, 345/81, 345/102, 345/207
• US Class Current: 345/102
• CPC Class Codes: G02F 1/133604 with lamps
• CPC Class Codes: G02F 2201/58 Arrangements comprising a monitoring photodetector
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/12 using electroluminescent elements
• 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: H04M 1/22 Illumination; Arrangements for improving the visibility of characters on dials
• CPC Class Codes: H05B 44/00 Circuit arrangements for operating electroluminescent light sources for operating light emitting diodes H05B45/00
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

Portable radio equipment having a display for displaying a message and an illuminating device for back-lighting the display. The illuminating device has a function of back-lighting the display and a function of sensing illumination on the surface of the display. Implemented by an electroluminescent lamp, the illuminating device back-lights the display surely and, yet, without wasteful consumption of power.

Claims

1. Portable radio equipment having a display for displaying a message, comprising:

illuminating means comprising an electroluminescent lamp, having a function of back-lighting the display and a function of sensing illumination on a display surface of the display;

first driver means for driving said illuminating means to sense illumination on the display surface of the display;

second driver means for driving said illuminating means to cause said illuminating means to emit light;

switching means for selecting either one of an illumination sense mode wherein said illuminating means senses illumination and a back-light mode wherein said illuminating means emits light; and

control means for controlling said first and second driver means and said switching means to select either one of said illumination sense mode and said back-light mode, wherein said control means comprises;

a first and second input port connected to said first driver means and said switching means;

an output port connected to said switching means and said second driver means;

a timer having an input terminal connecting to said first input port;

an AND gate having one input terminal connecting to an output terminal of said timer and the other input terminal connecting to said second input port;

an inverter having an input terminal connecting to said first input port; and

a D-type flip-flop having a C terminal connecting to an output terminal of said AND gate, an R terminal connecting to an output terminal of said inverter, and a Q terminal connecting to said output port.

2. A control device for use with portable radio equipment having a display for displaying a message and illuminating means comprising an electroluminescent lamps, having a function of back-lighting said display and a function of sensing illumination on a display surface of said display for controlling said illuminating means, said control device comprising:

first driver means for driving said illuminating means to sense illumination on the display surface of the display;

second driver means for driving said illuminating means to cause said illuminating means to emit light;

switching means for selecting either one of an illumination sense mode wherein said illuminating means senses illumination and a back-light mode wherein said illuminating means emits light; and

control means for controlling said first and second driver means and said switching means to select either one of said illumination sense mode and said back-light mode, wherein said control means comprises;

a first and second input port connected to said first driver means and said switching means;

an output port connected to said switching means and said second driver means;

a timer having an input terminal connecting to said first input port;

an AND gate having one input terminal connecting to an output terminal of said timer and the other input terminal connecting to said second input port;

an inverter having an input terminal connecting to said first input port; and

a D-type flip-flop having a C terminal connecting to an output terminal of said AND gate, an R terminal connecting to an output terminal of said inverter, and a Q terminal connecting to said output port.