Automatic contrast control of display device

• US 6,002,386 A
• Filed: 11/10/1997
• Issued: 12/14/1999
• Est. Priority Date: 11/08/1996
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Gu, Sung-Jin
• Primary Examiner(s): Mengistu, Amare
• Assistant Examiner(s): LEWIS, DAVID LEE
• Application Number:
  US08/966,537
• Time in Patent Office: 764 Days
• Field of Search: 345/6, 345/112, 345/127, 345/147, 348/647, 348/648
• US Class Current: 345/690
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 5/10 Intensity circuits
• CPC Class Codes: H04N 17/045 Self-contained testing apparatus
• CPC Class Codes: H04N 21/42202 environmental sensors, e.g. for detecting temperature, luminosity, pressure, earthquakes
• CPC Class Codes: H04N 21/4318 by altering the content in the rendering process, e.g. blanking, blurring or masking an image region image enhancement or restoration in general G06T5/00
• CPC Class Codes: H04N 21/44218 Detecting physical presence or behaviour of the user, e.g. using sensors to detect if the user is leaving the room or changes his face expression during a TV program methods or arrangements for recognising human body or animal bodies or body parts G06V40/10; methods or arrangements for acquiring or recognising human faces, facial parts, facial sketches, facial expressions G06V40/16; methods or arrangements for recognising movements or behaviour G06V40/20; arrangements for identifying users in broadcast systems H04H60/45
• CPC Class Codes: H04N 5/57 Control of contrast or brightness

Abstract

An automatic contrast control circuit for a display device includes a distance detector installed on a front panel of the display device, for detecting a distance existing between a user and the front panel and generating a distance signal representative of the detected distance; and a micro-computer for outputting a contrast gain control signal based on the distance signal output from the distance detector, and outputting on screen display (OSD) data indicative the contrast gain signal. A display control panel is provided on the display device to permit user input of an automatic contrast control (ACL) function and an OSD function. The distance detector includes a light emitting unit for emitting light from the display device, and a light receiving unit for receiving the light reflected from the user to detect the distance between the user and the front panel of the display device. Thus, The contrast of the display device is controlled automatically, depending on the proximity of the user to the display screen, to offer enhanced eye protection.

Claims

1. An automatic contrast control circuit for a display device, comprising:

a distance detector, installed on a front panel of the display device, for detecting a distance between a user and the front panel of the display device and generating a distance signal indicative of the detected distance between the user and the front panel;

a controller for generating a contrast gain control signal to automatically control contrast of an image provided on the display device in accordance with the distance signal, and generating on-screen display data indicative the contrast gain control signal;

a first function selection means for enabling an automatic contrast control function, and generating a signal representative of the selected function for output to said controller to activate operation of said distance detector and generation of said contrast gain control signal; and

a second function selection means for enabling an on-screen display function, and generating a signal representative of the selected function for output to said controller to activate an on-screen display of the contrast gain control signal.

2. A method for automatic contract control of a display device using a distance detector installed on a front panel of the display device, said method comprising the steps of:

detecting a distance existing between a user and the front panel of the display device;

determining whether a detected distance is less than a reference distance, said reference distance corresponding to thirty (30)cm; and

generating a contrast gain control signal reflective of the detected distance, when the detected distance is less than the reference distance, and automatically controlling the contrast of an image on the display device, and activating an on screen display of the contrast gain control signal.