Signal processing apparatus, signal processing method, correction value generation apparatus, correction value generation method, and display apparatus manufacturing method

• US 20040227697A1
• Filed: 05/13/2004
• Published: 11/18/2004
• Est. Priority Date: 05/14/2003
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Mori, Tetsuzo
• Granted Patent: US 7,599,574 B2
• Time in Patent Office: Days
• US Class Current: 345/30
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: H04N 5/21 Circuitry for suppressing or minimising disturbance, e.g. moiré or halo

Abstract

A signal processing apparatus supplied with a signal obtained by performing orthogonal transform on a video signal corresponding to a plurality of pixels includes a correction circuit for correcting the orthogonal-transformed signal, by using correction values obtained by performing orthogonal transform equivalent to the orthogonal transform on measured values obtained by measuring nonuniformity of display characteristics of a display device, which performs display on the basis of a signal processed by the signal processing apparatus, and an inverse orthogonal transform device for performing inverse orthogonal transform on a signal corrected by the correction circuit and thereby obtaining a corrected video signal.

Claims

1. A signal processing apparatus comprising:

an orthogonal transform device for performing orthogonal transform on a video signal corresponding to a plurality of pixels;

a correction circuit for correcting the signal transformed by said orthogonal transform device, by using correction values obtained by performing orthogonal transform equivalent to the orthogonal transform on measured values obtained by measuring nonuniformity of display characteristics of a display device, which performs display on the basis of a signal processed by said signal processing apparatus; and

an inverse orthogonal transform device for performing inverse orthogonal transform on a signal corrected by said correction circuit and thereby obtaining a corrected video signal.

2. A signal processing apparatus supplied with a signal obtained by performing orthogonal transform on a video signal corresponding to a plurality of pixels;

, said signal processing apparatus comprising;

a correction circuit for correcting the orthogonal-transformed signal, by using correction values obtained by performing orthogonal transform equivalent to the orthogonal transform on measured values obtained by measuring nonuniformity of display characteristics of a display device, which performs display on the basis of a signal processed by said signal processing apparatus; and

an inverse orthogonal transform device for performing inverse orthogonal transform on a signal corrected by said correction circuit and thereby obtaining a corrected video signal.

3. A signal processing apparatus according to claim 2, wherein the input orthogonal-transformed signal is a signal transmitted from a transmitting subject of the signal in a state in which the signal has been subjected to orthogonal transform, or a signal readout from a medium for recording the signal in a state in which the signal has been subjected to orthogonal transform.

4. A signal processing method for processing a signal obtained by performing orthogonal transform on a video signal corresponding to a plurality of pixels, said signal processing method comprising:

a correction process for correcting the orthogonal-transformed signal, by using correction values obtained by performing orthogonal transform equivalent to the orthogonal transform on measured values obtained by measuring nonuniformity of display characteristics of a display device, which performs display on the basis of a signal processed by using said signal processing method; and

an inverse orthogonal transform process for performing inverse orthogonal transform on a signal corrected in said correction process and thereby obtaining a corrected video signal.

5. A signal processing method according to claim 4, further comprising a process for performing orthogonal transform on the video signal corresponding to the pixels.

6. A correction value generation apparatus for generating correction values in order to correct a signal obtained by performing orthogonal transform on a video signal corresponding to a plurality of pixels, so as to be capable of suppressing nonuniformity in display characteristics of a display apparatus, said correction value generation apparatus comprising:

a detector for detecting a display state of the display apparatus for a test video signal input thereto;

an orthogonal transform device for performing orthogonal transform equivalent to the orthogonal transform on a detected signal obtained from said detector for the test video signal; and

a circuit for generating correction values in order to suppress nonuniformity in the display characteristics on the basis of an output of said orthogonal transform device.

7. A correction value generation method for generating correction values in order to correct a signal obtained by performing orthogonal transform on a video signal corresponding to a plurality of pixels, so as to be capable of suppressing nonuniformity in display characteristics of a display apparatus, said correction value generation method comprising:

a detection process for detecting a display state of the display apparatus for a test video signal input thereto;

an orthogonal transform process for performing orthogonal transform equivalent to the orthogonal transform on a detected signal obtained from said detection process for the test video signal; and

a process for generating correction values in order to suppress nonuniformity in the display characteristics on the basis of a result of said orthogonal transform process.

8. A manufacture method of a display apparatus including a correction circuit for correcting a signal in a state in which a video signal corresponding to a plurality of pixels has been subjected to orthogonal transform, said manufacture method comprising:

a process for preparing a display apparatus so as to be capable of bringing the display apparatus into a display state;

a process for executing the correction value generation method according to claim 7;

and

a process for storing correction values obtained by said correction value generation method executing process in a storage device.