Display with supplemental lighting system

• US 4,754,275 A
• Filed: 12/09/1987
• Issued: 06/28/1988
• Est. Priority Date: 06/07/1985
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Gomez, Fernando, Abbaticchio, Mark J.
• Primary Examiner(s): Brigance, Gerald L.
• Application Number:
  US07/132,628
• Time in Patent Office: 202 Days
• Field of Search: 340/825.44, 340/756, 340/763, 340/765, 340/311.1, 455/154, 455/159
• US Class Current: 340/7.51
• CPC Class Codes: G02F 1/1336 Illuminating devices
• CPC Class Codes: G02F 2201/58 Arrangements comprising a monitoring photodetector
• CPC Class Codes: G08B 5/225 Display details
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• 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 device has a single switch that transfers a stored message to a liquid crystal display and simultaneously activates a supplemental display lighting system. The supplemental lighting system is inhibited, however, when circuitry senses that ambient light conditions are sufficient to illuminate the display.

Claims

1. A selective call radio paging receiver, comprising in combination:

means for receiving a paging signal that includes a message;

means for storing a received message;

means for displaying a stored message;

a light source for illuminating said displaying means;

a switch electrically coupled to said storing means and having first and second positions;

means for sensing ambient light intensity; and

driver circuitry electrically coupled to said switch, to said ambient light sensing means, and to said light source;

said radio paging receiver being constructed and arranged such that when said switch is moved from said first to said second position, a stored message is transferred from said storing means to said displaying means and said light source is activated if the intensity of ambient light, as sensed by said ambient light sensing means, is below a predetermined threshold level.

2. The display apparatus of claim 1, wherein said driver circuitry includes a first transistor, the collector of said first transistor being coupled to said light source;

and

said ambient light sensing means includes a phototransistor coupled to the base of said first transistor.

3. The display apparatus of claim 2, wherein said driver circuitry further includes a second transistor, the base of said second transistor being coupled to said switch and the collector of said second transistor being coupled to said base of said first transistor.