US 2003/0112378 A1 · Image display apparatus, light quantity control method, and storage medium storing program thereof

Abstract

A light quantity control by a user can be synchronized to an automatic light quantity control depending on a luminance level of an input video signal. An image display apparatus partially passes or reflects a light from a light source which can control light quantity and displays an image based on a video signal externally input, and has a predetermined scope of an output level corresponding to a scope of control of light quantity of the light source, and includes: a light quantity control unit having a predetermined scope of an output level corresponding to the scope of control of the light quantity of the light source, and for outputting a reference signal at a level arbitrarily set by a user; an APL detection circuit for detecting the average luminance level for one frame (or one field) of the video signal, and outputting an amplification coefficient depending on the detected average luminance level; a multiplier circuit for multiplying the amplification coefficient by a reference signal, and outputting a control signal which is the multiplication result; and a power circuit for controlling the light quantity of the light source according to the control signal.

Claims13

Dependent claims

An image display apparatus which has a light source whose quantity can be controlled, and displays an image based on a video signal externally input after partially passing through or reflecting a light from the light source, comprising:

light quantity control means having a predetermined scope of an output level corresponding to a scope of control of light quantity of the light source, and for outputting a reference signal at a level arbitrarily set by a user;
level control means for detecting an average brightness of the displayed image according to the video signal, and for controlling a level of the reference signal output from said light quantity control means depending on the detected brightness;
and
control means for controlling light quantity of the light source according to the signal controlled by said level control means.

1 more element

An light quantity control method for use with an image display apparatus which has a light source whose quantity can be controlled, and which displays an image based on a video signal externally input after partially passing through or reflecting a light from the light source, comprising:

a first step of generating a reference signal at a level arbitrarily set by a user from a scope of a predetermined level corresponding to a scope of control of light quantity of said light source;
a second step of detecting average brightness of said displayed image according to said video signal;
a third step of controlling a level of the reference signal generated in said first step depending on the average brightness detected in said second step;
and
a fourth step of controlling light quantity of the light source according to the signal whose level is controlled in said third step.

2 more elements

A storage medium storing a program used to direct a computer to execute an light quantity control method for use with an image display apparatus which has a light source whose quantity can be controlled, and which displays an image based on a video signal externally input after partially passing through or reflecting a light from the light source, comprising:

a first step of generating a reference signal at a level arbitrarily set by a user from a scope of a predetermined level corresponding to a scope of control of light quantity of said light source;
a second step of detecting average brightness of said displayed image according to said video signal;
a third step of controlling a level of the reference signal generated in said first step depending on the average brightness detected in said second step;
and
a fourth step of controlling light quantity of said light source according to the signal whose level is controlled in said third step.

2 more elements

Dependencies are inferred from the claim text.

Image display apparatus, light quantity control method, and storage medium storing program thereof

Life of this patent

Image display apparatus, light quantity control method, and storage medium storing program thereof

Life of this patent

Abstract

Claims13