Patent Application
20070236566
The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of different embodiments of the present invention. In the drawings, like reference numerals designate corresponding parts throughout various views, and all the views are schematic.
Reference will now be made to the drawings to describe various embodiments of the present invention in detail.
Referring to
The scalar board 31 includes an ADC 311, a TMDS unit 312, a multiplexer 313, a scalar 314 having a matrix-converting circuit 316, and a first LVDS unit 315.
The ADC 311 receives an analog RGB signal from an external circuit (not shown), converts the analog RGB signal to a digital RGB signal, and transmits the digital RGB signal to the multiplexer 313. The TMDS unit 312 receives a digital RGB signal from another external circuit (not shown), and encodes the digital RGB signal for the multiplexer 313. That is, the liquid crystal display 3 is capable of selectively receiving analog RGB signals or digital RGB signals. The multiplexer 314 receives a digital RGB signal from either the ADC 311 or the TMDS unit 312, and transmits the digital RGB signal to the scalar 314 having the matrix-converting circuit 316. The matrix-converting circuit 316 converts the RGB signal to a YCbCr signal. In the expression YCbCr, Y represents a luminance of a red, a green or a blue sub-pixel of a liquid crystal panel 325 of the liquid crystal module 32, Cb represents chroma of the color blue, and Cr represent chroma of the color red. The first LVDS unit 315 receives the YCbCr signal from the matrix-converting circuit 316, and converts the YCbCr signal to an LVDS signal.
The liquid crystal module 32 includes a second LVDS unit 321, a T-con 322, a signal driving circuit 323 having an inverse-matrix-converting circuit 327, and a scanning driving circuit 324.
The second LVDS unit 321 of the liquid crystal module 32 receives the LVDS signal from the first LVDS unit 315 of the scalar board 31, and converts the LVDS signal back to the corresponding YCbCr signal. The T-con 322 receives the YCbCr signal from the second LVDS unit 321, and transmits the YCbCr signal to the signal driving circuit 323. The T-con 322 also generates a control signal for the scanning driving circuit 324. The inverse-matrix-converting circuit 327 of the signal driving circuit 323 converts the YCbCr signal back to the corresponding RGB signal. The scanning driving circuit 324 and the signal driving circuit 323 cooperatively drive the liquid crystal panel 325 to display images.
The liquid crystal display 3 includes the matrix-converting circuit 316, which converts the RGB signal requiring a large amount of bandwidth to the YCbCr signal. In general, the YCbCr signal requires a small amount of bandwidth. When the YCbCr signal is sampled at 4:2:0 or 4:1:1, an amount of signal flow of the liquid crystal display 3 can be reduced to half that of a conventional liquid crystal display, as calculated according to standards defined by the International Telecommunication Union (ITU). In an alternative embodiment, when the YCbCr signal is sampled at 4:2:2, an amount of the signal flow of the liquid crystal display 3 can be reduced to one-third of that of a conventional liquid crystal display. Therefore unlike conventional liquid crystal displays, the liquid crystal display 3 can use low-cost components having smaller capacities for signal transmittance. Thus, an overall cost of the liquid crystal display 3 can be reduced.
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The ADC 811 receives an analog RGB signal from an external circuit (not shown), converts the analog RGB signal to a digital RGB signal, and transmits the digital RGB signal to the multiplexer 813. The TMDS unit 812 receives a digital RGB signal from another external circuit (not shown), and encodes the digital RGB signal for the multiplexer 813. That is, the liquid crystal display 8 is capable of selectively receiving analog RGB signals or digital RGB signals. The multiplexer 813 receives a digital RGB signal from either the ADC 811 or the TMDS unit 812, and transmits the digital RGB signal to the scalar 814. The scalar 814 reduces a frequency of the digital RGB signal to a desired value. The first LVDS unit 815 receives the digital RGB signal from the scalar 814, generates an LVDS signal according to the digital RGB signal, and transmits the LVDS signal to the liquid crystal module 82.
The liquid crystal module 82 includes a second LVDS unit 821, a T-con 822, a signal driving circuit 823, a scanning driving circuit 824, an overdrive circuit 84, and a liquid crystal panel 825.
The second LVDS unit 821 of the liquid crystal module 82 receives the LVDS signal from the first LVDS unit 815 of the scalar board 81, and converts the LVDS signal back to the corresponding RGB signal. The T-con 822 receives the RGB signal from the second LVDS unit 821, and transmits the RGB signal to the signal driving circuit 823. The T-con 822 also generates a control signal for the scanning driving circuit 824.
The overdrive circuit 84 includes an M-con 841, a memory 842, a signal processing unit 843, a matrix-converting circuit 845, and an inverse-matrix-converting circuit 846. The matrix-converting circuit 845 receives the RGB signal from the T-con 822, generates a first frame YCbCr signal, and transmits the first frame YCbCr signal to the M-con 841. The first frame YCbCr signal can be sampled at 4:2:2, 4:2:0, or 4:1:1. The M-con 841 stores the first frame YCbCr signal to the memory 842, reads the first frame YCbCr signal from the memory 842, and transmits the first frame YCbCr signal to the signal processing unit 843 together with a next frame YCbCr signal. The signal processing unit 843 transmits the two frames of YCbCr signals to the inverse-matrix-converting circuit 846. The inverse-matrix-converting circuit 846 receives the two frames of YCbCr signals, converts the two frames of YCbCr signals back to the corresponding RGB signals, and transmits the RGB signals to the signal driving circuit 823. The scanning driving circuit 824 and the signal driving circuit 823 cooperatively drive the liquid crystal panel 825 to display images. The liquid crystal display 8 has advantages similar to those described above in relation to the liquid crystal display 3.
An exemplary method of transmitting RGB signals in a liquid crystal display includes: receiving and transmitting the RGB signals; converting the RGB signals to YCbCr signals, and transmitting the YCbCr signals; and converting the YCbCr signals back to the RGB signals. In this exemplary method, the liquid crystal display can for example be any of the above-described liquid crystal displays 3, 5, 6, 7 or 8.
It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit or scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 95112471 | Apr 2006 | TW | national |
