Thin film panel, driving device, and liquid crystal display having the same

• US 7,876,304 B2
• Filed: 03/06/2006
• Issued: 01/25/2011
• Est. Priority Date: 03/08/2005
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Ki-Chan
• Primary Examiner(s): Mengistu; Amare
• Assistant Examiner(s): ZHOU, HONG
• Application Number:
  US11/369,119
• Publication Number:
  US 20060202947A1
• Time in Patent Office: 1,786 Days
• Field of Search: 345/87, 345/207, 345/102, 345/204, 345/690, 250214 A-214 C
• US Class Current: 345/102
• CPC Class Codes: G02F 1/13312 Circuits comprising photodetectors for purposes other than feedback
• CPC Class Codes: G02F 1/13318 Circuits comprising a photodetector
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: G09G 3/3614 Control of polarity reversal in general
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3696 Generation of voltages supplied to electrode drivers

Abstract

A thin film panel, a driving device, and a liquid crystal display having the thin film panel and the driving device are provided. The thin film panel includes a first panel, a second panel, and an illumination sensor, wherein the illumination sensor includes a plurality of color filters formed on the first panel and a plurality of photo sensors formed on the second panel opposed to the plurality of color filters.

Claims

1. A display panel comprising a first panel, a second panel, an illumination sensor and a determination unit,

wherein the illumination sensor includes:

a plurality of color filters disposed on a peripheral area of the first panel, the peripheral area of the first panel surrounding a display area of the first panel; and

a plurality of photo sensors disposed on a peripheral area of the second panel corresponding to the peripheral area of the first panel, at least two photo sensors of the plurality of photo sensors opposing at least two different color filters of the plurality of color filters,

wherein the plurality of photo sensors generate a plurality of output voltages, respectively,

at least two of the plurality of output voltages are responsive to intensities of light which pass through the at least two different color filters,

the determination unit outputs a first control signal based on the plurality of output voltages, and

the determination unit includes a lookup table in which magnitudes of the plurality of output voltages corresponding to the at least two different color filters are classified based on spectral characteristics of an external light.

2. The display panel of claim 1, wherein the plurality of color filters includes at least two of a red filter, a green filter and a white filter.

3. The display panel of claim 2, wherein resistance of the at least one of the photo sensors varies depending upon light energy which passes through the at least one of the color filters.

4. The display panel of claim 2, wherein the at least one of the photo sensors includes:

a substrate;

a first insulating layer formed on the substrate;

a semiconductor layer formed on the first insulating layer;

first and second electrodes formed on the semiconductor layer; and

a second insulating layer formed on the first and second electrodes.

5. The display panel of claim 4, wherein the second panel is a thin film transistor panel including a plurality of gate lines and data lines, the first and second electrodes of each photo sensor formed within a same layer of the second panel as the data lines.

6. The thin film panel of claim 4, wherein the first and second electrodes are interdigitated.

7. The display panel of claim 6, wherein the semiconductor layer includes amorphous silicon.

8. The display panel of claim 7, wherein the illumination sensor is formed on an edge of the thin film panel.

9. The display panel of claim 1, wherein the first panel is a common electrode panel including a common electrode and the second panel is a thin film transistor panel including a plurality of thin film transistors and pixel electrodes.

10. The display panel of claim 1, wherein the plurality of output voltages of the plurality of photo sensors are respectively proportional to energy of an ambient light source incident to the illumination sensor.

11. The display panel of claim 1, wherein the determination unit receives the plurality of output voltages directly from the at least one of the photosensors.

12. A liquid crystal display comprising a thin film panel having first and second panels and an illumination sensor integrated on the thin film panel, a gray voltage generator which generates a plurality of gray voltages in a unit of three colors, a determination unit and a signal controller,

wherein the illumination sensor includes:

a plurality of color filters disposed on a peripheral area of the first panel, the peripheral area of the first panel surrounding a display area of the first panel; and

a plurality of photo sensors disposed on a peripheral area of the second panel corresponding to the peripheral area of the first panel, at least two photo sensors of the plurality of photo sensors opposing at least two different color filters of the plurality of color filters,

wherein the illumination sensor outputs a plurality of sensing signals respectively based on intensities of light which pass through the at least two different color filters,

the determination unit compares the plurality of sensing signals with each other and outputs first control signals based on a result of comparing the plurality of sensing signals with each other,

the signal controller outputs second control signals based on the first control signals, the second control signals comprising a third control signal supplied to the gray voltage generator,

the third control signal is generated based on the light intensities which pass through the at least two different color filters, and

the determination unit includes a lookup table in which magnitudes of the plurality of sensing signals corresponding to the at least two different color filters are classified based on spectral characteristics of the external light.

13. The liquid crystal display of claim 12, wherein the plurality of color filters include at least two of a red filter, a green filter and a white filter.

14. The liquid crystal display of claim 12, wherein each of the at least two photo sensors includes:

a substrate;

a first insulating layer formed on the substrate;

a semiconductor layer formed on the first insulating layer;

first and second electrodes formed on the semiconductor layer; and

a second insulating layer formed on the first and second electrodes.

15. The liquid crystal display of claim 14, wherein the second panel is a thin film transistor panel including a plurality of gate lines and data lines, the first and second electrodes of each photo sensor formed within a same layer of the second panel as the data lines.

16. The liquid crystal display of claim 14, wherein the first and second electrodes are interdigitated.

17. The liquid crystal display of claim 12, wherein the illumination sensor includes first and second resistors connected in series between an input voltage and a ground voltage.

18. The liquid crystal display of claim 17, wherein the first resistor is a variable resistor of which resistance varies depending upon an external light and the second resistor is a constant resistor with constant resistance.

19. The liquid crystal display of claim 18, further comprising an output terminal connected to a node between the variable resistor and the constant resistor, the output terminal outputting the sensing signals.

20. The liquid crystal display of claim 19, wherein the plurality of sensing signals are respectively proportional to energy of the external light.

21. The liquid crystal display of claim 20, further comprising:

pixels; and

a backlight unit which supplies internal light to the thin film panel,

wherein the pixels include pixels of three colors.

22. The liquid crystal display of claim 21, wherein the second control signals further comprise a fourth control signal supplied to the backlight unit.

23. The liquid crystal display of claim 22, wherein the fourth control signal is generated based on brightness of the external light.

24. The liquid crystal display of claim 23, wherein the illumination sensor outputs the plurality of sensing signals corresponding to energy of light passing through the at least two different color filters formed on the first panel.

25. The liquid crystal display of claim 24, wherein the plurality of color filters are selected from a red filter, a green filter, a blue filter, and a white filter.

26. The liquid crystal display of claim 25, wherein the illumination sensor includes first to third sensors, and

wherein the first to third sensors include the red filter, the green filter, and the white filter, respectively.

27. The liquid crystal display of claim 26, wherein the determination unit outputs the first control signal for controlling the backlight unit based on the sensing signal output from the second sensor.

28. The liquid crystal display of claim 12, wherein the liquid crystal display is any one of a transmissive type, a reflective type, and a transflective type.

29. The liquid crystal display of claim 12, wherein the determination unit receives the plurality of sensing signals directly from the illumination sensor.