Image display apparatus

• US 7,928,969 B2
• Filed: 12/20/2007
• Issued: 04/19/2011
• Est. Priority Date: 12/25/2006
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.), Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.), Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Yamano, Akihiko, Ebisawa, Hisafumi, Yui, Hideaki
• Primary Examiner(s): Mengistu; Amare
• Assistant Examiner(s): Sadio; Insa
• Application Number:
  US11/961,756
• Publication Number:
  US 20080150842A1
• Time in Patent Office: 1,216 Days
• Field of Search: 345/204, 345/690
• US Class Current: 345/204
• CPC Class Codes: G09G 2310/0275 Details of drivers for data electrodes, other than drivers for liquid crystal, plasma or OLED displays, not related to handling digital grey scale data or to communication of data to the pixels by means of a current
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 3/22 using controlled light sources

Abstract

There is provided an image display apparatus having: display devices; a spacer; and a drive circuit. The drive circuit has a first correction circuit that corrects inputted data to make it linear with luminance and a second correction circuit. The second correction circuit has a calculation circuit for calculating an evaluation value and an adjustment circuit. The evaluation value relates to suppression effect that the spacer suppresses an influence on the light emission of a predetermined emitting region due to the inputted image data by driving non-corresponding display devices and is calculated by using the electric charge signal after converting a luminance signal into an electric charge signal. The adjustment circuit calculates an adjustment value that refers to a property of a phosphor based on the luminance signal and dynamically calculates the correction value by using the evaluation value and the adjustment value.

Claims

1. An image display apparatus comprising:

a plurality of pixels having an electron-emitting device and a light emitting region that emits light when an electron emitted from the electron-emitting device enters therein, respectively;

a spacer for maintaining a space between the electron-emitting device and the light emitting region;

a first conversion circuit for converting an image signal;

a second conversion circuit for converting output of the first conversion circuit;

a correction value calculation circuit for calculating a correction value on the basis of output of the second conversion circuit;

a correction value adjustment circuit for adjusting the correction value on the basis of output of the first conversion circuit and outputting the adjusted correction value; and

a correction value addition circuit for correcting output of the first conversion circuit by the adjusted correction value;

wherein the first conversion circuit performs conversion such that a linearity between output of the first conversion circuit and a luminance to be displayed becomes higher than a linearity between the image signal and the luminance to be displayed;

the second conversion circuit is a circuit such that a linearity between output of the second conversion circuit and the amount of electron to be emitted is higher than a linearity between output of the first conversion circuit and the amount of electron to be emitted;

the spacer is located on a position where an electron directed from a light emitting region of a first pixel toward a light emitting region of a second pixel is blocked;

the correction value calculation circuit calculates a correction value corresponding to the second pixel on the basis of the output corresponding to the first pixel in the output of the second conversion circuit; and

the correction value is a value that can reduce a difference between a luminance of the second pixel and a luminance of a pixel that is located separately from the spacer further than the second pixel.

2. An image display apparatus comprising:

a plurality of pixels having an electron-emitting device and a light emitting region that emits light when an electron emitted from the electron-emitting device enters therein, respectively;

a first conversion circuit for converting an image signal;

a second conversion circuit for converting output of the first conversion circuit;

a correction value calculation circuit for calculating a correction value on the basis of output of the second conversion circuit;

a correction value adjustment circuit for adjusting the correction value on the basis of output of the first conversion circuit and outputting the adjusted correction value; and

a correction value addition circuit for correcting output of the first conversion circuit by the adjusted correction value;

wherein the first conversion circuit performs correction such that a linearity between output of the first conversion circuit and a luminance to be displayed becomes higher than a linearity between the image signal and the luminance to be displayed;

the second conversion circuit performs correction such that a linearity between output of the second conversion circuit and the amount of electron to be emitted becomes higher than a linearity between output of the first conversion circuit and the amount of electron to be emitted;

the plurality of pixels includes a first pixel and a second pixel located in the vicinity of the first pixel, and a distance between the first pixel and the second pixel is one that a reflection electron from the first pixel reaches the second pixel;

the correction value calculation circuit calculates a correction value corresponding to the second pixel on the basis of the output corresponding to the first pixel in the output of the second conversion circuit; and

the correction value is a value that can correct increase of the luminance of the second pixel due to the light emission of the second pixel generated by the reflection electron from the first pixel.

3. An image display apparatus comprising:

a plurality of display devices having corresponding light emitting regions, respectively, and displaying an image by making the light emitting regions emit light;

a spacer for preventing the light emission of the predetermined light emitting region caused by driving of a display device corresponding to the light emitting region other than a predetermined light emitting region; and

a drive circuit for outputting a drive signal to drive the display device on the basis of the inputted image data;

wherein the drive circuit has a first correction circuit for obtaining a luminance signal by correcting the inputted image data so as to be brought close to a signal that is linear with respect to the luminance, and a second correction circuit for outputting the corrected drive signal;

the second correction circuit has an evaluation value calculation circuit for calculating an evaluation value that evaluates a suppression effect that the spacer suppresses an influence on the light emission of a predetermined light emitting region due to the inputted image data, the influence being caused by driving of the display device corresponding to the light emitting region other than the predetermined light emitting region, and an adjustment circuit;

the evaluation value calculation circuit converts the luminance signal into an electric charge signal showing an electric charge amount that is necessary for obtaining a luminance that is designated by a luminance signal by correcting the luminance signal so as to be brought close to a signal that is linear with respect to the electric charge amount and then, calculates the evaluation value that evaluates the suppression effect by using the electric charge signal; and

the adjustment circuit calculates an adjustment value that refers to a property of a phosphor of the display device on the basis of the luminance signal and dynamically calculates a correction value corresponding to the drive signal using the evaluation value and the adjustment value.

4. An image display apparatus according to claim 3,

wherein the second correction circuit has a correction value addition circuit for adding the correction value to the luminance signal that is a correction target.

5. An image display apparatus according to claim 3,

wherein the adjustment circuit outputs a value that is obtained by adjusting the evaluation value by the adjustment value as a correction value.

6. An image display apparatus according to claim 3,

wherein, the larger the luminance that is indicated by the luminance signal, the adjustment circuit carries out calculation so that the adjustment value is made smaller.

7. An image display apparatus according to claim 3,

wherein the display device has an electron-emitting device and a predetermined light emitting region that is arranged at a space from the electron-emitting device and emits light by irradiation with an electron to be emitted from the electron-emitting device;

the spacer is an electron blocking member for preventing an electron originated with an electron emitted from an electron-emitting device in the vicinity of the electron-emitting device corresponding to a predetermined light emitting region from being irradiated on the predetermined light emitting region by blocking the electron emitted from an electron-emitting device in the vicinity of the electron-emitting device corresponding to the predetermined light emitting region; and

the evaluation value in the evaluation value calculation circuit is a value that is obtained by evaluating the blocking amount that the spacer blocks the electron emitted from the electron-emitting device in the vicinity of the electron-emitting device corresponding to the predetermined light-emitting region from being irradiated to the predetermined light emitting region.

8. An image display apparatus comprising:

a plurality of display devices having corresponding light emitting regions, respectively, and displaying an image by making the light emitting region emit light;

a spacer for preventing the light emission of a predetermined light emitting region caused by driving of a display device corresponding to the light emitting region other than the predetermined light emitting region; and

a drive circuit for outputting a drive signal to drive the display device on the basis of the inputted image data;

wherein the drive circuit has a first correction circuit for obtaining an electric charge signal by correcting the inputted image data so as to be brought close to a signal that is linear with respect to the electric charge amount; and

a second correction circuit for outputting the corrected drive signal;

the second correction circuit has a calculation circuit for calculating an evaluation value that evaluates a suppression effect that the spacer suppresses an influence on the light emission of a predetermined light emitting region due to the inputted image data, the influence being caused by driving of the display device corresponding to the light emitting region other than the predetermined light emitting region, and an adjustment circuit;

the calculation circuit calculates the evaluation value that evaluates the suppression effect by using the electric charge signal; and

the adjustment circuit converts the electric charge signal into a luminance signal by correcting the electric charge signal so as to be brought close to a signal that is linear with respect to the luminance, calculates an adjustment value that refers to a property of a phosphor of the display device on the basis of the luminance signal, and dynamically calculates a correction value corresponding to the drive signal using the evaluation value and the adjustment value.

9. An image display apparatus according to claim 8,

wherein the second correction circuit has a correction value addition circuit for adding the correction value to the electric charge signal that is a correction target.

10. An image display apparatus according to claim 8,

wherein the adjustment circuit outputs a value that is obtained by adjusting the evaluation value by the adjustment value as a correction value.

11. An image display apparatus according to claim 8,

wherein, the larger the luminance that is indicated by the luminance signal is, the adjustment circuit carries out calculation so that the adjustment value is made smaller.

12. An image display apparatus according to claim 8,

wherein the display device has an electron-emitting device and a light emitting region that is arranged at a space from the electron-emitting device and emits light by irradiation with an electron to be emitted from the electron-emitting device;

the spacer is an electron blocking member for preventing an electron originated with an electron emitted from an electron-emitting device in the vicinity of the electron-emitting device corresponding to a predetermined light emitting region from being irradiated on the predetermined light emitting region by blocking the electron emitted from an electron-emitting device in the vicinity of the electron-emitting device corresponding to the predetermined light emitting region; and

the evaluation value in the evaluation value calculation circuit is a value that evaluates the blocking amount that the spacer blocks the electron emitted from the electron-emitting device in the vicinity of the electron-emitting device corresponding to the predetermined light-emitting region from being irradiated to the predetermined light emitting region.