CN101727850A - Source driver device and display device provided with same - Google Patents

Abstract

A source driver device and a display device having the same are provided. The source driver apparatus includes a gamma voltage generator having a storage device and a plurality of gamma DACs, a data DAC coupled to the gamma voltage generator, and a receiver for receiving input display data from a data bus, for parsing the input display data to transmit the generated display data to the data DAC, for transmitting a plurality of gamma data signals to the storage device, wherein each of the gamma DACs receives a plurality of gamma data signals from the storage device to generate a plurality of reference voltage signals based on the corresponding gamma data signal, wherein the data DAC is coupled to the receiver for receiving the generated display data according to the plurality of reference voltage signals generated by the gamma DACs and for generating a driving voltage signal based on the generated display data, for driving the display panel.

Description

A source driver device and a display device provided with the source driver

technical field

The invention relates to a driving device, in particular to a source driver and a display device provided with the source driver.

Background technique

In general, a liquid crystal display (LCD) can be used to display images, wherein the digital data signal of the image is converted into an analog data signal to control the liquid crystal material of the LCD panel. In addition, some different gamma reference voltages are necessary as inputs to the DAC during the DAC process.

A conventional liquid crystal display device usually includes a gate driving circuit, a source driving circuit and a gamma reference voltage generator. The liquid crystal display panel includes a plurality of gate lines disposed along a fixed interval in a first direction, and a plurality of data lines disposed along a fixed interval in a second direction perpendicular to the gate line, thereby forming a The pixel area is located in a matrix array at each intersection of the gate line and the data line.

The gate driving circuit sequentially accesses the gate lines to activate corresponding pixels of the LCD panel. The source drive circuit externally converts the input red, green, and blue digital image data signals into analog data signals, and outputs the converted analog image data signals to each of the plurality of data lines to excite pixels in the pixel area . This action is generally referred to as a scanning process. In order to convert red, green and blue digital image data signals into analog data signals, the reference voltage output of the gamma reference voltage generator is used to perform digital-to-analog conversion, thereby generating a liquid crystal driving voltage. In each scanning period of the scanning process, the generated liquid crystal driving voltage is applied to a plurality of data lines of the liquid crystal display panel.

The gamma reference voltage generator includes a plurality of resistors connected in series between a first power supply terminal Vdd and a second power supply terminal Vss. Therefore, multiple gamma reference voltages are supplied to a source driver integrated circuit (IC) to generate multiple sets of gray scale voltages for the DAC. Therefore, some operational amplifier integrated circuits must be additionally configured in the liquid crystal display device to avoid the voltage drop of the reference voltage caused by the load effect. As a result, the driving of the liquid crystal display panel is broken. Furthermore, in order to generate multiple sets of gamma reference voltages, it usually requires quite a lot of resistors and operational amplifiers to be incorporated into the LCD device, which is usually on the printed circuit board of the LCD device.

Since the conventional gamma voltage generating device requires additional resistors and operational amplifiers on the printed circuit board, the manufacturing cost of the liquid crystal display device increases. Besides, the increase of required space on the printed circuit board also hinders the simplification of the liquid crystal display device.

Contents of the invention

The invention describes a source driver device and a display device with the source driver device.

A feature of the present invention is a source driver device for driving a display panel, including a gamma voltage generator, having a storage element and a plurality of gamma digital-to-analog converters, a data digital-to-analog converter, coupled Connected to the gamma voltage generator, and a receiver to receive input display data from a data bus for parsing the input display data to transmit the generated display data to the data digital-to-analog converter, and to transmit multiple the gamma data signal to the storage element, wherein each gamma digital-to-analog converter of the plurality of gamma digital-to-analog converters receives a plurality of gamma data signals from the storage element to generate multiple gamma data signals based on the corresponding gamma data signal a reference voltage signal, and wherein the data digital-to-analog converter is coupled to the receiver to receive the generated display data, which is based on a plurality of reference voltage signals generated by the gamma digital-to-analog converter, and generates a display based on the generated A driving voltage signal of data is used to drive the display panel.

Another feature of the present invention is a display device, including a display panel, and a source driver, the source driver has a gamma voltage generator, which has a storage element, a plurality of gamma digital-to-analog converters and a a voltage divider, a data digital-to-analog converter coupled to the gamma voltage generator, and a receiver to receive input display data transmitted along a data bus for parsing the input display data to transmit the generated display a data-to-data digital-to-analog converter for transmitting a plurality of gamma data signals to a storage element, wherein the storage element is coupled to a receiver and receives and stores a plurality of gamma data signals, wherein the plurality of gamma digital-to-analog converters Coupled to the storage element to receive a plurality of gamma data signals for generating a plurality of reference voltage signals based on the plurality of gamma data signals, and wherein the voltage divider is coupled to the gamma digital-to-analog converter for generating a plurality of reference voltage signals based on the gamma data signals A plurality of gamma voltage signals of a plurality of reference voltage signals, the data digital-to-analog converter is coupled to the receiver to receive the generated display data, and according to the plurality of gamma voltage signals received from the voltage divider, based on the The generated display data of the display panel is driven to generate a driving voltage signal.

In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments are specifically cited below and described in detail with reference to the accompanying drawings.

Description of drawings

Features, characteristics and embodiments of the present invention are described in the associated drawings, in which:

1 is a schematic circuit diagram of an exemplary source driver according to an embodiment; and

FIG. 2 is a schematic circuit diagram of another exemplary source driver according to another embodiment.

Description of reference symbols

10: Gamma voltage generator

101: Receiver

103: storage element

105-1-105-n: Gamma Digital to Analog Converter

111: Data digital to analog converter

20: Gamma voltage generator

201: Receiver

203: storage element

205-1-205-n: Gamma Digital to Analog Converter

207-1-207-n: Operational Amplifiers

209: Voltage divider

211: Data digital to analog converter

r(1)-r(n): Gamma data signal

Vr1-Vrn: reference voltage signal

Vg1-Vgm: Gamma voltage signal

Vd: driving voltage signal

Detailed ways

FIG. 1 is a schematic circuit diagram of an exemplary source driver according to an embodiment. In FIG. 1 , a source driver for driving a display panel can be configured to include a receiver 101 , a gamma voltage generator 10 and a digital-to-analog converter 111 . The gamma voltage generator 10 may include a storage element 103 and a plurality of gamma digital-to-analog converters 105-1-105-n. The receiver 101 can receive data from a data bus, and can analyze the data to send display data to the data DAC 111 and gamma data signals r(1)-r(n) to the storage element 103 . The storage element 103 can be coupled to the receiver 101 and can receive and store the gamma data signals r(1)-r(n). For example, the storage element 103 here may include a static random access memory, a dynamic random access memory and a synchronous dynamic random access memory. A plurality of gamma digital-to-analog converters 105-1-105-n can be coupled to the storage element 103, and can respectively receive the gamma data signals r(1)-r(n), for generating gamma based on the corresponding received gamma The reference voltage signals Vr1-Vrn of the horse data signals r(1)-r(n).

Furthermore, for example, the gamma digital-to-analog converters 105-1-105-n may be resistive digital-to-analog converters (resistive DAC, R-DAC), and each resistive digital-to-analog converter includes a plurality of resistors. Furthermore, the number n may range from approximately 6 to 20, for example with respect to the gamma data signals r(1)-r(n).

In FIG. 1 , the data digital-to-analog converter 111 can be coupled to the receiver 101 to receive the display data signal from the receiver 101, and can generate the driving voltage signal Vd based on the display data signal and the reference voltage signal Vr1-Vrn to drive the Display panel.

The gamma data signals r(1)-r(n) are preferably sent to the receiver 101 during a vertical blanking time interval (VBI). The input data supplied to the receiver 101 via a data bus can be transmitted via Reduced Swing Differential Signaling (RSDS) to output gamma data signals r(1)-r(n) and display data. For example, the gamma data signals r(1)-r(n) may be digital signals, such as Transistor-Transistor Logic (TTL) signals, and may be transmitted during a vertical blanking period. Alternatively, the gamma data signals r(1)-r(n) can be sent to the receiver 101 during a horizontal blanking time interval (HBI). Furthermore, the gamma data signals r(1)-r(n) can be sent to the receiver 101 before a start pulse signal is sent to a source driver. The start pulse signal indicates that the source driver starts to receive display data.

FIG. 2 is a schematic circuit diagram of another exemplary source driver according to another embodiment. In FIG. 2 , a display device such as a liquid crystal display device with a gamma source driver can be configured to include a receiver 201 , a gamma voltage generator 20 and a digital-to-analog converter 211 . The gamma voltage generator 20 may include a storage element 203 , a plurality of gamma digital-to-analog converters 205 - 1 - 205 - n , a plurality of operational amplifiers 207 - 1 - 207 - n and a voltage divider 209 .

The receiver 201 can receive data signals from a data bus and analyze data signals to transmit display data to the data DAC 211 , and can transmit gamma data signals r(1)-r(n) to the storage element 203 . The storage element 203 can be coupled to the receiver 201, and can receive and store the gamma data signals r(1)-r(n). The gamma digital-to-analog converters 205-1-205-n can be coupled to the storage element 203, and can respectively receive the gamma data signals r(1)-r(n) to generate corresponding gamma data signals based on r (1)-r(n) reference voltage signal Vr1-Vrn.

In FIG. 2, the operational amplifiers 207-1-207-n can be coupled between the gamma digital-to-analog converters 205-1-205-n and the voltage divider 209 to boost the generated reference voltage signal Vr1- Vrn is generated by gamma digital-to-analog converters 205-1-205-n. The operational amplifiers 207-1-207-n can reduce the reference voltage signals Vr1-Vrn generated from the gamma DACs 205-1-205-n to avoid the voltage drop of the reference voltage.

The voltage divider 209 may include, for example, a non-linear digital-to-analog converter coupled to operational amplifiers 207-1-207-n for generating gamma voltage signals Vg1-Vgm based on reference voltage signals Vr1-Vrn, where m greater than n. In addition, the voltage divider 209 can be configured as a resistor string and can be used to insert the reference voltage signals Vr1-Vrn. The data digital-to-analog converter 211 can be coupled to the receiver 201 to receive display data, and to the voltage divider 209 to receive the generated gamma voltage signals Vg1-Vgm to generate a driving voltage signal Vd based on the display data, For driving the display panel.

In FIG. 2, the storage element 203 can be coupled to the receiver 201, and can receive and store the gamma data signals r(1)-r(n). The storage element 203 here may include, for example, a static random access memory, a dynamic random access memory, and a synchronous dynamic random access memory.

A plurality of gamma digital-to-analog converters 205-1-205-n can be coupled to the storage element 203, and can respectively receive the gamma data signals r(1)-r(n), for generating gamma based on the corresponding received gamma The reference voltage signals Vr1-Vrn of the horse data signals r(1)-r(n). Furthermore, for example, the gamma DACs 205-1-205-n can be resistive DACs, and each resistive DAC includes a plurality of resistors. In addition, for example, regarding the gamma data signals r(1)-r(n), the number n may range from approximately 6 to 20.

According to the above embodiments, the gamma source driver can be assembled on a semiconductor integrated circuit chip, wherein each element of the gamma source driver can be integrated in the integrated circuit chip.

According to the above embodiments, the gamma data signal is preferably transmitted to the receiver 201 during the vertical blanking period. In addition, the input display data input to the receiver 201 can be transmitted via reduced-swing differential signal data, and can be transmitted to the receiver 201 to output gamma data signal and display data. The gamma data signal can be digital and can be a transistor-transistor logic (TTL) signal and can also be transmitted during vertical blanking.

While the present invention has been described with reference to preferred embodiments, it is to be understood that the invention is not limited to the detailed description thereof. Alternatives and modifications have been suggested in the previous description, and those skilled in the art may also use other alternatives and modifications. In particular, according to the device structure of the present invention, all combinations of components that are substantially the same as those of the present invention to achieve substantially the same results as the present invention will not depart from the scope of the present invention. Therefore, all these alternatives and modifications are within the category defined by the claims of the present invention and their equivalents.

Claims (21)

1. A source driver device for driving a display panel, the source driver device comprising: A gamma voltage generator having a storage element and a plurality of gamma digital-to-analog converters; a data digital to analog converter coupled to the gamma voltage generator; and a receiver for receiving input display data from a data bus, for parsing the input display data to transmit generated display data to the data digital-to-analog converter, and for transmitting gamma data signals to the storage element; wherein each of the gamma digital-to-analog converters receives the plurality of gamma data signals from the storage element for generating a plurality of reference voltage signals based on the corresponding gamma data signals; and Wherein the DAC is coupled to the receiver to receive the generated display data according to the generated plurality of reference voltage signals generated by the gamma DAC, and generate a display data based on the generated A driving voltage signal of the generated display data is used to drive the display panel. 2. The source driver device as claimed in claim 1, further comprising a plurality of operational amplifiers, wherein each of the operational amplifiers is coupled to one of the gamma digital-to-analog converters for boosting the plurality of reference voltages Signal. 3. The source driver device as claimed in claim 1, further comprising a voltage divider coupled to the plurality of gamma DACs for interpolating the reference voltage signal. 4. The source driver device of claim 3, wherein the voltage divider comprises a resistor string. 5. The source driver device of claim 1, wherein the plurality of gamma DACs comprise a resistive DAC comprising a plurality of resistors. 6. The source driver device as claimed in claim 1, wherein the display panel comprises a liquid crystal display. 7. The source driver device as claimed in claim 1, wherein the storage element comprises one of a static random access memory element, a dynamic random access memory element and a synchronous dynamic random access memory element. 8. The source driver device of claim 1, wherein the plurality of gamma data signals are transmitted to the receiver during a vertical blanking time. 9. The source driver device of claim 1, wherein the plurality of gamma data signals are transmitted to the receiver during a horizontal blanking time. 10. The source driver device of claim 1, wherein the plurality of gamma data signals are transmitted before a start pulse is supplied to the source driver device. 11. The source driver device of claim 1, wherein the input display data comprises a reduced-swing differential signal. 12. The source driver device of claim 1, wherein the plurality of gamma data signals comprise transistor-transistor logic signals. 13. A display device comprising: a display panel; and a source driver, comprising: A gamma voltage generator comprising a storage element, a plurality of gamma digital-to-analog converters and a voltage divider; a data digital to analog converter coupled to the gamma voltage generator; and a receiver for receiving input display data transmitted along a data bus, for parsing the input display data to transmit generated display data to the data digital-to-analog converter, and for transmitting gamma data signals to the storage element, wherein the storage element is coupled to the receiver and receives and stores the plurality of gamma data signals; wherein the plurality of gamma digital-to-analog converters are coupled to the storage element to receive the plurality of gamma data signals for generating a plurality of reference voltage signals based on the plurality of gamma data signals; and Wherein the voltage divider is coupled to the gamma digital-to-analog converter for generating multiple gamma voltage signals based on the multiple reference voltage signals, and the data digital-to-analog converter is coupled to the receiver to receive The generated display data, and according to the plurality of gamma voltage signals received from the voltage divider, are used to generate a driving voltage signal based on the generated display data for driving the display panel. 14. The display device as claimed in claim 13, wherein the display device is a liquid crystal display device. 15. The display device of claim 13, wherein the input display data comprises reduced-swing differential signals, and the plurality of gamma data signals comprise transistor-transistor logic signals. 16. The display device as claimed in claim 13, wherein the source driver is a semiconductor integrated circuit chip, and the gamma voltage generator, the storage element, the plurality of gamma digital-to-analog converters, the voltage divider The device, the digital-to-analog converter and the receiver are integrated on the semiconductor integrated circuit chip. 17. The display device of claim 13, wherein the storage element comprises one of a static random access memory element, a dynamic random access memory element, and a synchronous dynamic random access memory element. 18. The display device as claimed in claim 13, wherein the source driver further comprises a plurality of operational amplifiers connected between the plurality of gamma DACs and the voltage divider. 19. The display device of claim 13, wherein the plurality of gamma data signals are transmitted to the receiver during a vertical blanking time. 20. The display device of claim 13, wherein the plurality of gamma data signals are transmitted to the receiver during a horizontal blanking time. 21. The display device of claim 13, wherein the plurality of gamma data signals are transmitted before a start pulse is supplied to the source driver device.

Images