Display device with optical input function

• US 20060033729A1
• Filed: 08/03/2005
• Published: 02/16/2006
• Est. Priority Date: 08/10/2004
• Status: Active Grant

• Current Assignee: Japan Display Central Incorporated (Japan Display Incorporated)
• Original Assignee: Toshiba Mobile Display Company Limited (Japan Display Incorporated)
• Inventors: Nakamura, Takashi, Yoshida, Masahiro, Nagaoka, Kazutaka
• Granted Patent: US 7,602,380 B2
• Time in Patent Office: Days
• US Class Current: 345/207
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/042 by opto-electronic means

Abstract

A display device includes a plurality of scanning lines, a plurality of signal lines, a plurality of pixel circuits and sensor circuits, a signal line drive circuit and scanning line drive circuit which drive the plurality of pixel circuits, and a precharge circuit and sensor control circuit which drive the sensor circuits. A filter subjects image data to an interpolation process to compensate for a gradation value of an output. In a signal processing section, the area of a light receiving area is calculated and it is determined that a light source is set in contact with a display screen.

Claims

1. A display device with an optical input function comprising:

a plurality of scanning lines arranged in parallel,

a plurality of signal lines arranged to intersect with the plurality of scanning lines,

a plurality of pixel portions arranged at intersecting portions between the plurality of scanning lines and the plurality of signal lines,

photosensor portions provided at least one for each or every preset number of the plurality of pixel portions,

a pixel drive section which drives the plurality of pixel portions via the plurality of scanning lines and the plurality of signal lines,

a sensor drive section which drives the photosensor portions, and

an output processing section which includes an interpolation filter which is supplied with outputs of the photosensor portions and compensates for gradation values of images supplied from the photosensor portions.

2. The display device with the optical input function according to claim 1, wherein the output processing section includes an A/D converter which generates digital image data based on photosensing signals of the photosensor portions.

3. The display device with the optical input function according to claim 2, wherein the interpolation filter rearranges gradation values of the digital image data items corresponding to a preset one of the pixel portions and at least one pixel portion which lies near the above pixel portion in one of ascending and descending orders and sets a gradation value having a specified order as a gradation value of the preset pixel portion.

4. The display device with the optical input function according to claim 3, wherein the specified order is dynamically variable.

5. The display device with the optical input function according to claim 2, wherein the interpolation filter rearranges gradation values of the digital image data items corresponding to a preset one of the pixel portions and at least one pixel portion which lies near the above pixel portion in one of ascending and descending orders and sets a gradation value having an intermediate order as a gradation value of the preset pixel portion.

6. The display device with the optical input function according to claim 2, wherein the A/D converter copes with 1-bit data and the digital image data is 1-bit digital image data.

7. A display device with an optical input function comprising:

a plurality of scanning lines arranged in parallel,

a plurality of signal lines arranged in parallel to intersect with the plurality of scanning lines,

a plurality of pixel portions arranged at intersecting portions between the plurality of scanning lines and the plurality of signal lines,

a plurality of photosensor portions arranged at the intersecting portions between the plurality of scanning lines and the plurality of signal lines,

a pixel drive section which drives the plurality of pixel portions via the plurality of scanning lines and the plurality of signal lines,

a sensor drive section which drives the photosensor portions,

an operation processing section which is supplied with outputs of the photosensor portions and derives information of an area of a light receiving area on the display screen by use of photosensing signals when light from a tip end of a light source is illuminated on the display screen, and

a determining section which determines that the light is input when the information of the area of the light receiving area lies within a preset parameter setting range.

8. The display device with the optical input function according to claim 7, wherein the determining section includes operating means for comparing the information of the area of the light receiving area with a specified area reference value and calculating a deviation amount thereof from the reference value, and contact determining means for determining that the light source means is set in contact with the display screen when the deviation amount from the reference value is smaller than a specified deviation amount threshold value.

9. The display device with the optical input function according to claim 7, wherein the determining section includes operating means for calculating a deviation amount of the area of the light receiving area with time, and contact determining means for determining that the light source means is set in contact with the display screen when the deviation amount with time is smaller than a specified threshold value of the deviation amount with time.

10. The display device with the optical input function according to claim 7, wherein the determining section includes operating means for calculating degree of roundness of the area of the light receiving area based on the area and peripheral length of the light receiving area, and contact determining means for determining that the light source means is set in contact with the display screen when the degree of roundness is larger than a specified threshold value of the degree of roundness.

11. The display device with the optical input function according to claim 7, wherein the information of the area of the light receiving area is a plurality of information items which include first area information obtained by use of an output of a median filter and second area information obtained by use of an output of a compression filter and the parameters include a square value of peripheral length derived based on a difference between the first and second area information items and a multiplication value obtained by multiplying the peripheral length by a variable coefficient.

12. The display device with the optical input function according to claim 8, wherein the area reference value is set based on an area of an opening portion of a tip end of the light source.

13. The display device with the optical input function according to claim 8, further comprising calibration means for previously calculating and storing the area reference value.

14. The display device with the optical input function according to claim 8, further comprising calibration means for previously calculating and storing the deviation amount threshold value.

15. The display device with the optical input function according to claim 9, further comprising calibration means for previously calculating and storing the threshold value of the deviation amount with time.

16. The display device with the optical input function according to claim 10, further comprising calibration means for previously calculating and storing the threshold value of the degree of roundness.

17. A display device with an optical input function comprising:

a plurality of scanning lines arranged in parallel,

a plurality of signal lines arranged to intersect with the plurality of scanning lines,

a plurality of pixel portions arranged at intersecting portions between the plurality of scanning lines and the plurality of signal lines,

photosensor portions at least one of which is provided for each or every preset number of pixel portions,

a pixel drive section which drives the plurality of pixel portions via the plurality of scanning lines and the plurality of signal lines,

a sensor drive section which drives the photosensor portions,

an output processing section which includes an interpolation filter which is supplied with outputs of the photosensor portions to compensate for gradation values of images obtained from the photosensor portions,

an operation processing section which is supplied with an output of the output processing section and derives information of an area of a light receiving area on the display screen by use of photosensing signals when light from a tip end of a light source is illuminated on the display screen, and

a determining section which determines that the light is input when the information of the area of the light receiving area lies within a preset parameter setting range.

18. The display device with the optical input function according to claim 17, wherein the output processing section includes an A/D converter which generates digital image data based on photosensing signals of the photosensor portions, the interpolation filter is supplied with an output of the A/D converter and performs a filtering process to rearrange gradation values of the digital image data items corresponding to a preset one of the pixel portions and at least one pixel portion which lies near the above pixel portion in one of ascending and descending orders and set a gradation value having a specified order as a gradation value of the preset pixel portion, and the determining section includes at least one of the following means (a), (b) and (c), that is,

(a) operating means for comparing the information of the area of the light receiving area with a specified area reference value and calculating a deviation amount from the reference value and contact determining means for determining that the light source means is set in contact with the display screen when the deviation amount from the reference value is smaller than a specified threshold value of the deviation amount,

(b) operating means for calculating a variation amount of the area of the light receiving area with time and contact determining means for determining that the light source means is set in contact with the display screen when the variation amount with time is smaller than a specified threshold value of the variation amount with time, and

(c) operating means for calculating degree of roundness of the light receiving area based on the area and peripheral length of the light receiving area and contact determining means for determining that the light source means is set in contact with the display screen when the degree of roundness is larger than a specified threshold value of the degree of roundness.