CN102194394A - Data insertion circuit applied to display device - Google Patents

Abstract

A data insertion circuit applied to a display device comprises: a signal source, a switch unit, a control unit. The signal source is used for providing a video driving signal. The switching unit has an output node coupled to a channel of the display device, a first input node coupled to the signal source, and a second input node coupled to a control voltage for data insertion, and is configured to selectively output the video driving signal or the control voltage to the output node. When the display device is in a normal mode, the control unit controls the switch unit to transmit the video driving signal to the display device, and when the display device is in a data insertion mode, the control unit controls the switch unit to transmit the control voltage to the display device.

Description

Data insertion circuit applied to display device

technical field

The invention relates to a data insertion circuit, in particular to a data insertion circuit applied to a display device.

Background technique

In a display device, motion blur (motion blur) technology is often applied to insert a black/gray image between two continuous moving images to enhance the picture quality. With the help of this type of motion blur technology, images in motion appear smoother to the naked eye. In a traditional display device (for example: a liquid crystal display panel), the motion blur technology is often implemented in a timing controller chip (timing controller, TCON), and the timing control chip is usually used as a display module (for example: a display card) Interface with a display driver. However, in order to realize the motion blur, the timing control chip must operate at a higher frequency to correctly input data to the LCD panel, thus resulting in higher power consumption and poorer system performance.

Contents of the invention

In view of this, the present invention provides a new data insertion circuit that enables the timing control chip to operate at a lower frequency and insert motion blur data from an external source, so that the Improve performance.

According to an embodiment of the present invention, a data insertion circuit applied to a display device is provided. The data insertion circuit includes a signal source, a switch unit and a control unit. The signal source is used to provide a video driving signal. The switch unit has an output node coupled to a channel of the display device, a first input node coupled to the signal source, and a second input node coupled to a control voltage for data insertion, The switch unit is used for selectively outputting the video driving signal or the control voltage to the output node. The control unit is coupled to the switch unit. When the display device is in a normal mode, the control unit controls the switch unit to transmit the video driving signal to the display device, and when the display device is in a data insertion mode, the control unit controls the switch unit to transmit the video drive signal control voltage to the display device.

According to another embodiment of the present invention, a data insertion circuit applied to a display device is provided. The data insertion circuit includes a first signal source, a second signal source, a first switch unit, a second switch unit, a multiplexer unit and a control unit. The first signal source and the second signal source are respectively used to provide a first video driving signal and a second video driving signal. The first switch unit has an output node, a first input node coupled to the first signal source, and a second input node coupled to a first control voltage for data insertion, the first The switch unit is used for selectively outputting the first video driving signal or the first control voltage to the output node of the first switch unit. The second switch unit has an output node, a first input node coupled to the second signal source, and a second input node coupled to a second control voltage for data insertion, the second switch The unit is used to selectively output the second video driving signal or the second control voltage to the output node of the second switch unit, wherein a voltage level of the first control voltage is different from a voltage level of the second control voltage voltage level. The multiplexer unit has a control node for receiving a control signal, a first input node coupled to the output node of the first switch unit, a first input node coupled to the output node of the second switch unit A second input node, a first output node coupled to a first channel of the display device, and a second output node coupled to a second channel of the display device, the multiplexer unit is used according to the control signals to alternately output the first control voltage and the second control voltage to the first channel and the second channel of the display device. The control unit is coupled to the first switch unit, the second switch unit and the multiplexer unit. When the display device is in a normal mode, the control unit controls the first switch unit to transmit the first video drive signal to the multiplexer unit, and controls the second switch unit to transmit the second video drive signal to the multiplexer unit The multiplexer unit, and controlling the multiplexer unit to respectively transmit the first video drive signal and the second video drive signal to the first channel and the second channel of the display device; and when the display device is in a In the data insertion mode, the control unit controls the first switch unit to transmit the first control voltage to the multiplexer unit, and controls the second switch unit to transmit the second control voltage to the multiplexer unit.

Description of drawings

FIG. 1 is a schematic diagram of a data insertion circuit implemented in a display device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a first-type data insertion circuit implemented in a display device according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of a second-type data insertion circuit implemented in a display device according to another embodiment of the present invention.

FIG. 4 is a schematic diagram of a data insertion circuit implemented in a display device according to another embodiment of the present invention.

FIG. 5 is a schematic diagram of a dual-channel data insertion circuit implemented in a display device according to an embodiment of the present invention.

FIG. 6 is a schematic diagram of a dual-channel data insertion circuit implemented in a display device according to another embodiment of the present invention.

FIG. 7 is a schematic diagram of signal timing when a full grayscale image is inserted through a data insertion circuit shown in FIG. 6 according to an embodiment of the present invention.

FIG. 8 is a schematic diagram of a dual-channel data insertion circuit implemented in a display device according to another embodiment of the present invention.

[Description of main component symbols]

100, 200, 300, 400, 500, 600 display devices

110, 210, 310, 410 Data insertion circuit

111, 511a, 511b, 611a, 611b signal source

112, 512a, 512b, 612a, 612b switch unit

113, 413, 613 control unit

114, 514a, 514b, 614a, 614b buffer

120 channels

130, 430 Power source

415 Control voltage supply unit

510, 610 Dual-channel data insertion circuit

520a, 620a even channel

520b, 620b odd channels

615 Multiplexer Unit

Vc Control Voltage

Vc1 The first control voltage

Vc2 Second control voltage

Vd Video drive signal

Vd1 The first video drive signal

Vd2 Second video drive signal

Vref1 The first reference voltage

Vref2 Second reference voltage

TP1 System Clock

POL control signal

All_Grey_EN, Veven, Vodd, VDIFF signal

VCOM common mode voltage

N1, NA The first input node

N2, NB Second input node

NC third input node

ND The fourth input node

N3 output node

N _CTRL control node

Detailed ways

Please refer to FIG. 1 , which is a schematic diagram of a data insertion circuit 110 implemented in a display device 100 according to an embodiment of the present invention. The data insertion circuit 110 has a signal source 111 , a switch unit 112 and a control unit 113 . The signal source 111 provides a video driving signal Vd to the switch unit 112 . The switch unit 112 has an output node N3 coupled to a channel 120 of the display device 100, a first input node N1 coupled to the signal source 111, and a first input node N1 coupled to the signal generated by the switch unit 112 for data insertion. A second input node N2 of the control voltage Vc, in addition, the switch unit 112 selectively outputs the video driving signal Vd or the control voltage Vc to the output node N3. Please note that the channel 120 can be an odd channel or an even channel corresponding to a specific pixel in the display device 100 , for example, an even channel of a specific pixel on a display panel. When the display device 100 is in a normal mode, the control unit 113 controls the switch unit 112 to transmit the video drive signal Vd to the display device 100; however, when the display device 100 is in a data insertion mode (data insertion mode), The control unit 113 controls the switch unit 112 to transmit the control voltage Vc to the display device 100 .

However, in practice, the data insertion circuit usually needs an interface to drive a channel of a display device, so the switch unit introduced in the present invention also needs a buffer to enhance its driving ability to transmit data, more specifically That said, the data insertion circuits disclosed herein can be classified into two broad categories. Please refer to FIG. 2 and FIG. 3 together with FIG. 1 . FIG. 2 is a schematic diagram of a first-type data insertion circuit 210 implemented in a display device 200 according to an embodiment of the present invention, and FIG. 3 is implemented in a display device 300 according to another embodiment of the present invention. A schematic diagram of a second type data insertion circuit 310 of FIG. In FIG. 2 , an additional buffer 114 (eg, an operational amplifier with a negative feedback mechanism) is introduced between the switching device 112 and the signal source 111 to drive the channel 120 . In this example, when the display device 200 is in the normal mode, the control unit 113 will control the switch device 112 to sequentially transmit the video driving signal Vd to the display device 200 through the buffer 114 and the channel 120; and when the display device 200 is in the In the data insertion mode, the control unit 113 controls the switch device 112 to transmit the control voltage Vc to the display device 200 . In addition, during the data insertion mode, the output terminal of the buffer 114 sees a high impedance load.

In FIG. 3 , a newly added buffer 114 is disposed in a data insertion circuit 310 between a switch device 112 of a display device 300 and a signal source 111 . In this example, when the display device 300 is in the normal mode, the control unit 113 will control the switch device 112 to sequentially transmit the video driving signal Vd to the display device 300 through the buffer 114 and the channel 120; and when the display device 300 is in the During the data insertion mode, the control unit 113 will control the switch device 112 to transmit the control voltage Vc to the display device 300 through the buffer 114 and the channel 120 in sequence. In addition, during the data insertion mode, the output terminal of the signal source 111 will see to an open-circuited load.

Please note that the control voltage Vc provided by the control unit 113 may be a fixed supply voltage (for example: a time-invariant voltage) provided by the display device 100 , 200 or 300 , the display device 100 , 200 or 300 A common mode voltage (common voltage, VCOM), or an external voltage with any potential provided by a power source 130 externally connected to the data insertion circuit 110, 120 or 130, that is, the control voltage Vc can be based on different requirements And apply different design methods. For example, for a normally white/black (normally white/black) liquid crystal display panel, when a completely black image is to be inserted, the control unit 113 will pass a supply voltage, a reference ground voltage or display device A common-mode voltage of 100, 200 or 300 is used to obtain the control voltage Vc; and when an arbitrary grayscale image is to be inserted, a correction is added to the common-mode voltage of the display device 100, 200 or 300 through the control unit 113 Voltage to get the control voltage Vc.

When a constant voltage is continuously applied to a channel of a pixel in a display panel, the display panel may therefore become less and less sensitive to voltage changes, resulting in reduced service life of the display panel and failure. Thus, when inserting a full black/random grayscale image, the applied voltage needs to be modified somewhat to protect the display panel. Please refer to FIG. 4 , which is a schematic diagram of a data insertion circuit 410 implemented in a display device 400 according to another embodiment of the present invention. Compared with FIG. 1 , the data insertion circuit 410 in the display device 400 further includes a control voltage supply unit 415 . The control voltage supply unit 415 is coupled between the switch unit 112 and the control unit 413 for receiving a first reference voltage Vref1 and a second reference voltage Vref2 and providing the control voltage Vc. When the display device 400 is in the data insertion mode, the control unit 413 controls the control voltage supply unit 415 to alternately output the first reference voltage Vref1 and the second reference voltage Vref2 as the control voltage Vc, for example, the first reference voltage Vref1 and the second reference voltage Vref2 The second reference voltage Vref2 can be VCM0+VDIFF0 and VCM0-VDIFF0 respectively, wherein VCM0 is a common-mode voltage value of the display device 400, and DIFF0 is an arbitrary voltage value that is not zero. Therefore, these two voltages are alternately applied to the channels. 120 to insert an arbitrary grayscale image, so as to avoid damage to the display device 400 .

In practice, for a display device (for example: a liquid crystal display panel), each pixel on the liquid crystal display panel needs to be driven through a pair of channels (that is, an odd channel and an even channel) . For a normally white LCD panel, during data insertion mode, one of the odd channel and the even channel needs to be driven by the supply voltage, while the other needs to be driven by the ground voltage. For example, please refer to FIG. 5 , which is a schematic diagram of a two-channel data insertion circuit 510 implemented in a display device 500 according to an embodiment of the present invention. When the display device 500 is in the normal mode, a control unit 513 controls the switch units 512a and 512b to transmit the video driving signals Vd1 and Vd2 generated by the signal sources 511a and 511b respectively to an even channel 520a through the buffers 514a and 514b respectively. with an odd channel 520b. When the display device 500 is in the data insertion mode, the control unit 513 controls the switch units 512a and 512b to transmit the control voltages Vc1 and Vc2 to the even channel 520a and the odd channel 520b through the buffers 514a and 514b respectively.

If there is a constant voltage difference between the odd and even channels, it may cause damage to the display device and thus shorten its service life. In view of this, the present invention further provides a method to prolong the service life of the display device. Please refer to FIG. 6 , which is a schematic diagram of a two-channel data insertion circuit 610 implemented in a display device 600 according to another embodiment of the present invention. Part of the components in the display device 600 are very similar to the corresponding components in the display device 500 , and further descriptions are omitted here. It can be seen from the figure that the display device 600 further includes a multiplexer unit 615 . In this embodiment, the multiplexer unit 615 has a control node N _CTRL for receiving a control signal POL, a first input node NA coupled to the output node N3 of the first switch unit 612a through the buffer 614a, A second input node NB coupled to the output node N3 of the second switch unit 612b through the buffer 614b, a first output node NC coupled to the even channel 620a of the display device 600, and an odd channel coupled to the display device 600 A second output node ND of the channel 620b. The multiplexer unit 615 alternately outputs the first control voltage Vc1 and the second control voltage Vc2 to the even channel 620 a and the odd channel 620 b of the display device 600 according to the control signal POL.

Please refer to FIG. 7 to understand the operation details of the data insertion circuit 610 shown in FIG. 6 . FIG. 7 is a schematic diagram of signal timing when a full-grayscale image is inserted through the data insertion circuit 610 shown in FIG. 6 according to an embodiment of the present invention, wherein TP1 is a system clock of the data insertion circuit 610, and All Gray EN is used for A signal for triggering the control signal 613 , VCOM is a common mode voltage of the display device 600 , Veven and Vodd are signals received by the even channel 620 a and the odd channel 620 b respectively. Before a time point T1, the display device 600 is in the normal mode, the even channel 620a and the odd channel 620b receive signals from the signal sources 611a and 611b respectively, and the multiplexer unit 615 is equivalently during the normal mode Transparent and useless. When the display device 600 enters the data insertion mode, the signal All_Grey_EN rises, and the forced switching devices 612 a and 612 b transmit signals from the control unit 613 to the multiplexer unit 615 . Since an arbitrary grayscale image is inserted, the control unit 613 will send the voltage VCM±VDIFF to the multiplexer unit 615, wherein VDIFF is a signal that can be adjusted arbitrarily, and is used to represent a grayscale voltage of the inserted grayscale image. Flat (gray level). At a time point T2, the multiplexer unit 615 detects that the control signal POL has changed sign, so the multiplexer unit 615 switches the output signals. In this way, all grayscale images can be inserted smoothly without causing damage to the display device 600 and affecting its service life.

It should be noted that the architecture shown in FIG. 6 is only for illustration and is not intended to limit the scope of the present invention. For example, the multiplexer unit 615 can also be disposed between the control unit 613 and the switch units 612a, 612b as shown in FIG. 8 , and this design change also falls within the scope of the present invention.

To sum up, the present invention provides a data insertion device that can insert motion blur data from an external source without making major changes to the structure. In this way, a timing control chip for a display device can consume less system resources and achieve better performance.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the present invention.

Claims (10)

1. A data insertion circuit applied to a display device, comprising: a signal source for providing a video driving signal; A switch unit having an output node coupled to a channel of the display device, a first input node coupled to the signal source, and a second input node coupled to a control voltage for data insertion , the switch unit is used to selectively output the video driving signal or the control voltage to the output node; and A control unit, coupled to the switch unit, wherein: When the display device is in a normal mode, the control unit controls the switch unit to transmit the video driving signal to the display device; and When the display device is in a data insertion mode, the control unit controls the switch unit to send the control voltage to the display device. 2. The data insertion circuit according to claim 1, further comprising: A buffer is coupled between the output node of the switch unit and the channel of the display device. 3. The data insertion circuit as claimed in claim 1, wherein the display device is a liquid crystal display panel, and the control voltage is a common mode voltage of the liquid crystal display panel. 4. The data insertion circuit as claimed in claim 1, further comprising: a control voltage supply unit, coupled to the switch unit and the control unit, for receiving a first reference voltage and a second reference voltage; Wherein when the display device is in the data insertion mode, the control unit controls the control voltage supply unit to alternately output the first reference voltage and the second reference voltage as the control voltage. 5. The data insertion circuit as claimed in claim 4, wherein the display device is a liquid crystal display panel, the first reference voltage is a common supply voltage of the liquid crystal display panel, and the second reference voltage is a common supply voltage of the liquid crystal display panel A common ground voltage. 6. The data insertion circuit as claimed in claim 4, wherein the display device is a liquid crystal display panel, the first reference voltage is between a common supply voltage and a common mode voltage of the liquid crystal display panel, and the second The reference voltage is between a common ground voltage of the liquid crystal display panel and the common mode voltage. 7. A data insertion circuit applied to a display device, comprising: A first signal source, used to provide a first video driving signal; a second signal source for providing a second video driving signal; A first switch unit has an output node, a first input node coupled to the first signal source, and a second input node coupled to a first control voltage for data insertion, the first The switch unit is used to selectively output the first video driving signal or the first control voltage to the output node of the first switch unit; A second switch unit has an output node, a first input node coupled to the second signal source, and a second input node coupled to a second control voltage for data insertion, the second The switch unit is used to selectively output the second video driving signal or the second control voltage to the output node of the second switch unit, wherein a voltage level of the first control voltage is different from that of the second control voltage a voltage level; A multiplexer unit having a control node for receiving a control signal, a first input node coupled to the output node of the first switch unit, a first input node coupled to the output node of the second switch unit A second input node, a first output node coupled to a first channel of the display device, and a second output node coupled to a second channel of the display device, the multiplexer unit is used according to the control signal to alternately output the first control voltage and the second control voltage to the first channel and the second channel of the display device; and A control unit, coupled to the first switch unit, the second switch unit and the multiplexer unit, wherein: When the display device is in a normal mode, the control unit controls the first switch unit to transmit the first video drive signal to the multiplexer unit, and controls the second switch unit to transmit the second video drive signal to the multiplexer unit The multiplexer unit, and controlling the multiplexer unit to respectively transmit the first video driving signal and the second video driving signal to the first channel and the second channel of the display device; and When the display device is in a data insertion mode, the control unit controls the first switch unit to transmit the first control voltage to the multiplexer unit, and controls the second switch unit to transmit the second control voltage to the multiplexer unit multiplexer unit. 8. The data insertion circuit as claimed in claim 7, further comprising: a first buffer coupled between the output node of the first switch unit and the first input node of the multiplexer unit; and A second buffer is coupled between the output node of the second switch unit and the second input node of the multiplexer unit. 9. The data insertion circuit as claimed in claim 7, wherein the display device is a liquid crystal display panel, the first control voltage is a common supply voltage of the liquid crystal display panel, and the second reference voltage is the liquid crystal display panel A common ground voltage. 10. The data insertion circuit as claimed in claim 7, wherein the display device is a liquid crystal display panel, the first control voltage is between a common supply voltage and a common mode voltage of the liquid crystal display panel, and the second The control voltage is between a common ground voltage of the liquid crystal display panel and the common mode voltage.

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