Display apparatus and method of driving the same

Patent metadata

Field	Value
Publication number	US-9417732-B2
Application number	US-201113187826-A
Country	US
Kind code	B2
Filing date	Jul 21, 2011
Priority date	Oct 4, 2010
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

A display apparatus includes a display panel, a backlight unit, a backlight control circuit, sensors, a read-out circuit and a sensor auxiliary circuit. The display panel includes pixels and displays an image. The backlight unit includes a first light source which emits a first light in a infrared light range. The backlight control circuit controls a brightness of the first light source. The sensors sense an external signal and outputs first sensing signals. The read-out circuit outputs the first sensing signals as second sensing signals. The sensor auxiliary circuit compares a maximum value and a minimum value of the second sensing signals and provides a brightness control signal to the backlight control circuit based on the compared difference to control the brightness of the first light source.

First claim

What is claimed is:

1. A display apparatus comprising:
a display panel comprising a plurality of pixels, wherein the display panel displays an image;
a backlight unit comprising a first light source which emits a first light in an infrared light range, the backlight unit providing the first light to the display panel;
a backlight control circuit which controls a brightness of the first light source;
a plurality of sensors which senses an external signal corresponding to the first light reflected by an object on the display panel and outputs a plurality of first sensing signals;
a read-out circuit which stores the plurality of first sensing signals and outputs a plurality of second sensing signals during a predetermined time period; and
a sensor auxiliary circuit which receives the plurality of second sensing signals, compares a maximum value and a minimum value in the plurality of second sensing signals and provides a brightness control signal to the backlight control circuit based on the compared difference to control the brightness of the first light source to prevent reduced sensing capability of the plurality of sensors as time lapses,
wherein the sensor auxiliary circuit comprises:
a data selector which receives the plurality of second sensing signals and outputs the maximum value and the minimum value;
a comparator which compares a difference between the maximum value and the minimum value with a predetermined reference value, outputs a first control signal when the difference between the maximum value and the minimum value is greater than or equal to the reference value, and outputs a second control signal when the difference between the maximum value and the minimum value is less than the reference value; and
a control signal generator which outputs a first brightness control signal in response to the first control signal to maintain the brightness of the first light source and outputs a second brightness control signal in response to the second control signal to increase the brightness of the first light source.

2. The display apparatus of claim 1 , wherein the plurality of sensors comprise:
a visible light sensor which senses light in the visible light range; and
an infrared light sensor which senses light in the infrared light range.

3. The display apparatus of claim 2 , wherein the visible light sensor and the infrared light sensor are alternately arranged between two adjacent pixels as viewed from a top plan view.

4. The display apparatus of claim 1 , wherein the display panel comprises:
a first substrate; and
a second substrate comprising a plurality of color filters and disposed opposite to the first substrate,
wherein the plurality of sensors is disposed inside the second substrate.

5. The display apparatus of claim 1 , wherein the backlight control circuit increases the brightness of the first light source using a pulse-width modulation method.

6. The display apparatus of claim 1 , wherein the backlight control circuit increases the brightness of the first light source using a pulse-amplitude modulation method.

7. The display apparatus of claim 1 , further comprising a timing controller which receives the plurality of second sensing signals from the read-out circuit and provides the plurality of second sensing signals to the sensor auxiliary circuit in response to a sensor test signal, wherein the sensor test signal is provided from an external device or generated from the timing controller.

8. The display apparatus of claim 7 , wherein the sensor auxiliary circuit is included in the timing controller.

9. The display apparatus of claim 1 , further comprising a scan driver which sequentially applies a scan signal to the plurality of sensors,
wherein the display panel further comprises:
a plurality of scan lines which sequentially receives the scan signal; and
a plurality of read-out lines which receives the plurality of first sensing signals from the plurality of sensors.

10. The display apparatus of claim 1 , wherein the read-out circuit comprises:
a plurality of operational amplifiers, wherein each of the plurality of operational amplifiers receives a corresponding first sensing signal of the plurality of first sensing signals from a corresponding read-out line of the plurality of read-out lines and compares the corresponding first sensing signal to a predetermined reference voltage to output a difference between the first sensing signal and the reference voltage as a corresponding second sensing signal when the first sensing signal is greater than the reference voltage;
a read-out part which sequentially outputs the plurality of second sensing signals in response to a plurality of switching signals; and
a shift register which sequentially provides the plurality of switching signals to the read-out part.

11. The display apparatus of claim 1 , wherein the backlight unit further comprises a second light source which emits a second light in a visible light range, and the backlight unit provides the second light to the display panel.

12. The display apparatus of claim 1 , wherein the read-out circuit outputs the plurality of first sensing signals as the plurality of second sensing signals.

Assignees

• Kim Heetae
• Jang Hyeonyong
• Yang Byungchoon
• Kim Dongkwon
• Lee Young-Keun
• Kim Ho-Young
• Samsung Display Co Ltd

Inventors

• Kim Heetae
• Jang Hyeonyong
• Yang Byungchoon
• Kim Dongkwon
• Lee Young-Keun
• Kim Ho-Young

Classifications

• G09G2360/145

  the light originating from the display screen · CPC title

• G09G2320/0633

  by amplitude modulation of the brightness of the illumination source · CPC title

• G06F3/0421 Primary

  by interrupting or reflecting a light beam, e.g. optical touch-screen · CPC title

• G09G2320/045

  Compensation of drifts in the characteristics of light emitting or modulating elements · CPC title

• G06F3/0412 Primary

  Digitisers structurally integrated in a display · CPC title