Timing controller, liquid crystal display having the same, and method of driving liquid crystal display

• US 8,605,026 B2
• Filed: 06/23/2008
• Issued: 12/10/2013
• Est. Priority Date: 10/18/2007
• Status: Expired due to Fees

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Ko, Hyun-seok, Kim, Myeong-su
• Primary Examiner(s): BOYD, JONATHAN A
• Application Number:
  US12/143,992
• Publication Number:
  US 20090102776A1
• Time in Patent Office: 1,996 Days
• Field of Search: 345/99, 345/100
• US Class Current: 345/99
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2330/06 Handling electromagnetic interferences [EMI], covering emitted as well as received electromagnetic radiation
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A liquid crystal display includes a first timing controller for receiving image signals in synchronization with a first clock signal and outputting representative image signals in synchronization with a second clock signal, the frequency of the second clock signal being lower than the frequency of the first clock signal; and circuitry for controlling luminance of light-emitting blocks of the liquid crystal display in response to the representative image signals.

Claims

1. A liquid crystal display comprising:

a plurality of light-emitting blocks whose respective luminances are individually controllable in response to supplied and respective luminance control signals;

a plurality of display blocks each having two or more pixels and each corresponding to a respective light-emitting block;

a first timing controller structured and coupled for receiving image signals in synchronization with a supplied first clock signal, the received image signals corresponding to pixels of the display blocks, and for generating and outputting a data control signal corresponding to the image signals and representative image signals that are representative of luminances of respective ones of the display blocks where the representative image signals are output in synchronization with a second clock signal, the frequency of the second clock signal being lower than the frequency of the first clock signal;

luminance control circuitry structured and coupled for controlling luminance of the light-emitting blocks of the liquid crystal display in response to the generated representative image signals;

a second timing controller for outputting backlight data signals corresponding to the representative image signals;

a plurality of backlight drivers for controlling luminance of light-emitting blocks in response to the backlight data signals; and

a data driver outputting data signals to the plurality of display blocks in response to the data control signal;

wherein the first timing controller comprises;

a memory;

a representative-value generator for receiving the image signals, generating the representative image signals, and writing the representative image signals to the memory in synchronization with the first clock signal; and

a serializer for reading the representative image signals from the memory in synchronization with the second clock signal, and serially outputting the read representative image signals to the second timing controller.

2. The liquid crystal display of claim 1, wherein the first timing controller serially outputs the representative image signals to the second timing controller in synchronization with the second clock signal.

3. The liquid crystal display of claim 1,

wherein the generated representative image signals are representative of at least one of average and maximum brightness values of image signals received for the respective display blocks.

4. The liquid crystal display of claim 3, wherein the first timing controller is configured to generate and output the representative image signals by:

writing the representative image signals to a memory in synchronization with the first clock signal;

reading the representative image signals from the memory in synchronization with the second clock signal; and

serially outputting the representative image signals read out from the memory to the second timing controller.

5. The liquid crystal display of claim 4, wherein each representative image signal comprises a plurality of bits, and the serializer comprises:

a plurality of latch units for reading the representative image signals from the memory in synchronization with the second clock signal and storing the read representative image signals; and

a plurality of transfer units for performing bit-by-bit output of the representative image signals stored in the respective latch units.

6. The liquid crystal display of claim 5, wherein the serializer further comprises a multiplexer that serially transmits output bits of the transfer units.

7. The liquid crystal display of claim 3, wherein the first timing controller comprises:

a representative-value generator for receiving the image signals in synchronization with the first clock signal, and generating the representative image signals that correspond to the respective display blocks;

a plurality of latch units for storing the representative image signals; and

a transfer unit for performing bit-by-bit output of the representative image signals stored in the latch units, the bit-by-bit output being performed in synchronization with the second clock signal.

8. A timing controller for use in an image display device, the image display device having a backlighting unit subdivided into a plurality of light-emitting blocks and a display panel subdivided into a plurality of display blocks, the timing controller comprising:

a representative-value generator structured and coupled for receiving a supplied plurality of image signals in synchronization with a supplied first clock signal and for generating therefrom a plurality of representative image signals that are each respectively representative of a respective collection of luminances to be provided by a corresponding one of the light-emitting blocks and a corresponding one of image display blocks of the image display device; and

a serializer for serially outputting the representative image signals in synchronization with a second clock signal, the frequency of the second clock signal being lower than the frequency of the first clock signal.

9. The timing controller of claim 8, further comprising a memory;

wherein the representative-value generator writes the representative image signals to the memory in synchronization with the first clock signal, and the serializer reads the representative image signals from the memory in synchronization with the second clock signal.

10. The timing controller of claim 9, wherein each representative image signal comprises a plurality of bits, and the serializer comprises:

a plurality of latch units for reading the respective representative image signals from the memory in synchronization with the second clock signal and storing the read representative image signals; and

a plurality of transfer units for performing bit-by-bit output of the representative image signals stored in the respective latch units.

11. The timing controller of claim 10, wherein the serializer further comprises a multiplexer for serially transmitting the output bits of the transfer units.

12. The timing controller of claim 8, wherein the serializer comprises:

a plurality of latch units for storing the respective representative image signals; and

a transfer unit for performing bit-by-bit output, in synchronization with the second clock signal, of the representative image signals stored in the respective latch units.

13. A method of driving a liquid crystal display where the display includes a liquid crystal display panel (LCD panel) and a plurality of individually controllable light-emitting blocks structured and disposed for providing respective lights of controlled brightnesses to the LCD panel, the method comprising:

receiving image signals in synchronization with a first clock signal, the image signals representing luminances of pixels within display blocks of the LCD panel, where the display blocks are positioned so as to be respectively illuminated by respective ones of the individually controllable light-emitting blocks;

generating and outputting a data control signal corresponding to the received image signals;

generating and outputting representative image signals in synchronization with a second clock signal, the frequency of the second clock signal being lower than the frequency of the first clock signal;

controlling luminance of the light-emitting blocks in response to the representative image signals; and

generating and outputting data signals in response to the data control signal to the LCD panel.

14. The method of claim 13 wherein controlling luminance of the light-emitting blocks in response to the representative image signals comprises:

providing backlight data signals corresponding to the representative image signals; and

controlling luminance of the light-emitting blocks in response to the backlight data signals.

15. The method of claim 14, wherein the outputting of the representative image signals in synchronization with the second clock signal comprises outputting the representative image signals in as serial signals that are synchronized to the second clock signal.

16. The method of claim 14, wherein the LCD panel is subdivided into a regular matrix of display blocks which correspond to the respective light-emitting blocks, and the representative image signals are representative values of image signals provided to the respective display blocks.

17. The method of claim 16, wherein the outputting of the representative image signals in synchronization with the second clock signal comprises:

generating the representative image signals that correspond to the respective display blocks;

writing the representative image signals to a memory in synchronization with the first clock signal;

reading the representative image signals from the memory in synchronization with the second clock signal; and

serially outputting the read representative image signals.

18. The method of claim 17, wherein each representative image signal comprises a plurality of bits, and the serially outputting of the representative image signals comprises:

storing the read representative image signals in latch units; and

outputting, one bit at a time, the representative image signals stored in the latch units.

19. The method of claim 16, wherein the outputting of the representative image signals in synchronization with the second clock signal comprises:

generating the representative image signals that correspond to the respective display blocks;

storing the respective representative image signals in latch units; and

in synchronization with the second clock signal, performing bit-by-bit output of the representative image signals stored in the latch units.