Liquid crystal display device

• US 6,111,559 A
• Filed: 02/07/1996
• Issued: 08/29/2000
• Est. Priority Date: 02/28/1995
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Motomura, Kensuke, Nagatsu, Yoshihide, Tsuchida, Susumu
• Primary Examiner(s): Liang, Regina
• Application Number:
  US08/598,022
• Time in Patent Office: 1,665 Days
• Field of Search: 345/102, 345/98, 345/87, 345/147, 345/77, 345/211, 345/212, 345/67, 349/61, 349/62, 349/63, 349/65, 349/69, 349/70
• US Class Current: 345/102
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• 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 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: H04N 5/70 Circuit details for electroluminescent devices

Abstract

A liquid crystal display apparatus having an amplitude detecting unit for detecting an amplitude of a supplied video signal; a liquid crystal display for displaying an image on a main surface based on the video signal; a backlight for giving off light with a luminance which can be freely set from the back surface of the liquid crystal display to the main surface; and a luminance setting unit for variably setting the luminance of the backlight based on the amplitude detected by the amplitude detecting unit.

Claims

1. A liquid crystal display apparatus comprising:

amplitude detecting means receiving an input video signal for detecting an amplitude level of the input video signal;

an amplifier for amplifying the input video signal and having an amplification rate which can be freely set;

a liquid crystal display for displaying an image on a main surface thereof based on the input video signal;

a backlight for emitting a light from a back surface of the liquid crystal display to the main surface of the liquid crystal display, the light having a luminance which is set variably; and

intensity setting means for lowering the luminance of the light from the backlight when the amplitude level detected by the amplitude detecting means is equal to or less than a predetermined level and for variably setting the amplification rate of the amplifier based on the amplitude detected by the amplitude detecting means.

2. A liquid crystal display apparatus comprising:

amplitude detecting means for detecting an amplitude of an input video signal;

an amplifier for amplifying the input video signal and having an amplification rate which can be freely set;

a liquid crystal display for displaying an image on a main surface thereof based on an amplified input video signal from the amplifier;

a backlight for emitting a light from a back surface of the liquid crystal display to the main surface, the light having a luminance which is set variably; and

intensity setting means for variably setting the luminance of the light from the backlight and the amplification rate of the amplifier based on the amplitude detected by the amplitude detecting means.

3. A liquid crystal display apparatus comprising:

time counting means receiving an input video signal for counting a continuous time during which a signal level of the input video signal is at a non-signal level;

a liquid crystal display for displaying an image on a main surface thereof based on the input video signal;

a backlight for emitting a light from a back surface of the liquid crystal display to the main surface, the light having a luminance which is set variably; and

luminance setting means for lowering the luminance of the light from the backlight when the continuous time counted by the time counting means is equal to or longer than a predetermined time.

4. A liquid crystal display apparatus comprising:

transitory signal detecting means receiving an input video signal for detecting a transitory state of the input video signal at the time of selection of a station;

a liquid crystal display for displaying an image on a main surface thereof based on the video signal;

a backlight for emitting a light from a back surface of the liquid crystal display to the main surface, the light having a luminance which is set variably; and

luminance setting means for lowering the luminance of the light from the backlight when the transitory state corresponding to the selection of the station is detected by the transitory signal detecting means, so that the liquid crystal display displays a black screen.