Panel drive device and display device

This application is a National Phase Entry of PCT International Application No. PCT/CN2017/081872, which was filed on Apr. 25, 2017, and claims priority to Chinese Patent Application No. 201610389582.6, which was filed on Jun. 3, 2016, the content of which is incorporated by reference in the entirety.

The present disclosure relates to the field of display technologies, and particularly to a panel drive device and a display device.

An existing thin-film-transistor liquid-crystal display (TFT-LCD) device usually includes a panel drive device, which includes an interface module and a voltage conversion module. Particularly, the interface module receives a first voltage from a power module, outputs a second voltage, and then provides the voltage conversion module with the second voltage through wires of a printed circuit board. Due to voltage losses in transmission cables of the interface module, the second voltage output by the interface module is usually lower than the first voltage received by the interface module. Because of voltage losses in the wires of the printed circuit board, the third voltage actually received by the voltage conversion module is usually lower than the second voltage output by the interface module. Correspondingly, the third voltage actually received by the voltage conversion module is usually lower than the first voltage received by the interface module.

In this case, since the third voltage received by the voltage conversion module is relatively low, the voltage conversion module might operate abnormally or the output voltage of the voltage conversion module might be abnormal, causing the TFT-LCD device to operate abnormally. The situation gets worse especially when the load of the panel drive device is heavy.

An embodiment of the present disclosure provides a panel drive device and a display device, which are able to compensate for the voltage losses in the transmission cables as well as in the wires of the printed circuit board, so that a third voltage signal received at an input end of the voltage conversion module equals to a first voltage signal received at an input end of the interface module, thereby avoiding abnormal operations of the liquid crystal panel.

According to one aspect of the present disclose, a panel drive device is provided, where the panel drive device includes an interface module, a voltage conversion module and a compensation module. The interface module includes a first input end and a first output end. The voltage conversion module includes a second input end and a second output end. The first output end is coupled with the second input end. A voltage signal at the first input end is a first voltage signal, a voltage signal at the first output end is a second voltage signal, a voltage signal at the second input end is a third voltage signal and a voltage signal at the second output end is a fourth voltage signal. The compensation module is configured to generate a compensation voltage signal according to the third voltage signal and apply the compensation voltage signal to the first input end or the first output end, so that a value of the third voltage signal equals to a value of the first voltage signal.

According to an exemplary embodiment, the compensation module includes a first resistor, a differential amplifier circuit and a conversion unit. A first end of the first resistor receives the third voltage signal and a second end of the first resistor is grounded. Two input ends of the differential amplifier circuit are coupled with the two ends of the first resistor respectively, and an output end of the differential amplifier circuit is coupled with the conversion unit.

According to an exemplary embodiment, the compensation module includes a first resistor, a second resistor, a differential amplifier circuit and a conversion unit. A first end of the first resistor receives the third voltage signal and a second end of the first resistor is grounded via the second resistor. Two input ends of the differential amplifier circuit are coupled with the two ends of the first resistor respectively, and an output end of the differential amplifier circuit is coupled with the conversion unit.

According to an exemplary embodiment, the differential amplifier circuit includes a differential amplifier, a third resistor, a fourth resistor, a fifth resistor and a sixth resistor. One end of the third resistor is coupled with the first end of the first resistor, while the other end of the third resistor is coupled with a first input end of the differential amplifier; one end of the fourth resistor is coupled with the second end of the first resistor, while the other end of the fourth resistor is coupled with the a second input end of the differential amplifier; one end of the fifth resistor is grounded, and the other end of the fifth resistor is coupled with the first input end of the differential amplifier; one end of the sixth resistor is coupled with the second input end of the differential amplifier, while the other end of the sixth resistor is coupled with an output end of the differential amplifier.

According to an exemplary embodiment, in the differential amplifier circuit, a ratio of a resistance of the fifth resistor to a resistance of the third resistor equals to a ratio of a resistance of the sixth resistor to a resistance of the fourth resistor.

According to an exemplary embodiment, the conversion unit is configured to multiply a difference value between a reference voltage of an output voltage of the differential amplifier and the output voltage of the differential amplifier by a preset coefficient, to obtain a value of the compensation voltage signal.

According to an exemplary embodiment, the panel drive device further includes a timing controller configured to receive a first control signal from the interface module, receive the fourth voltage signal from the voltage conversion module and output a second control signal.

According to an exemplary embodiment, the panel drive device further includes a gate drive circuit configured to receive the second control signal from the timing controller and output a gate drive signal.

According to an exemplary embodiment, the panel drive device further includes a gamma circuit configured to receive the fourth voltage signal from the voltage conversion module, receive a data signal from the interface module and output a gamma voltage signal.

According to an exemplary embodiment, the panel drive device further includes a source drive circuit configured to receive the fourth voltage signal from the voltage conversion module, receive the gamma voltage signal from the gamma circuit and output a source drive signal.

According to another aspect of the present disclosure, a display device is also provided, which includes a panel drive device according to any one of the abovementioned exemplary embodiments.

In order to make the technical solutions according to the embodiments of the present disclosure or the prior art more apparent, the accompanying drawings, which are to be used in the description of the embodiments or the prior art, will be briefly described. Obviously, the drawings mentioned below just illustrate some embodiments of the present disclosure, and on the basis of these drawings other drawings can be obtained by those skilled in the art without any inventive effort.

FIG. 1 is a structural block diagram of a panel drive device according to a first embodiment of the present disclosure;

FIG. 2 is a circuit diagram of a compensation module according to an embodiment of the present disclosure;

FIG. 3 is a circuit diagram of a compensation module according to another embodiment of the present disclosure;

FIG. 4 is a structural block diagram of a panel drive device according to a second embodiment of the present disclosure;

FIG. 5 is a structural block diagram of a panel drive device according to a third embodiment of the present disclosure;

FIG. 6 is a structural block diagram of a panel drive device according to a fourth embodiment of the present disclosure.

In order to make the objects, technical solutions, and advantages of the embodiments of the disclosure more apparent, the technical solutions according to the embodiments of the present disclosure will now be described clearly and fully with reference to the drawings in the embodiments of the disclosure, and apparently the embodiments described below are only a part but not all of the embodiments of the disclosure. Based upon the embodiments here of the disclosure, all the other embodiments which can occur to those skilled in the art without any inventive effort shall fall into the scope of the disclosure.

In addition, as used herein, the term “a plurality of” is intended to refer to two or more than two unless otherwise indicated, and the terms such as “first” and “second” are only used to distinguish between different components or operations and are not used to limit the components or operations.

FIG. 1 illustrates a structural block diagram of a panel drive device 10 according to a first embodiment of the present disclosure.

As illustrated in FIG. 1 , the panel drive device 10 according to the first embodiment of the present disclosure can include an interface module 11 , a voltage conversion module 12 and a compensation module 13 .

Particularly, the interface module 11 can receive a first voltage signal V 1 from a power module at an input end of the interface module 11 , and output a second voltage signal V 2 to the voltage conversion module 12 from an output end of the interface module 11 . Due to transmission losses of cables in the interface module 11 , a value of the second voltage signal V 2 is usually lower than a value of the first voltage signal V 1 .

The voltage conversion module 12 can receive the second voltage signal V 2 from the interface module 11 via wires of a printed circuit board. Due to voltage losses in the wires of the printed circuit board, the voltage signal received at the input end of the voltage conversion module 12 is a third voltage signal V 3 , and a value of the third voltage signal V 3 is usually lower than the value of the second voltage signal V 2 . Correspondingly, the value of the third voltage signal V 3 is lower than the value of the first voltage signal V 1 . The voltage conversion module 12 is configured to convert the third voltage signal V 3 into a fourth voltage signal V 4 through a boosting circuit or a buck circuit.

The compensation module 13 can generate a compensation voltage signal Vc according to the third voltage signal V 3 and output the compensation voltage signal Vc to the input end of the interface module 11 , so that the value of the third voltage signal V 3 equals to the value of the first voltage signal V 1 .

In this way, by outputting the compensation voltage signal Vc to the input end of the interface module 11 , the panel drive device 10 according to the embodiment of the present disclosure, is able to compensate for losses in the transmission cables and in the wires of the printed circuit board, so that the value of the third voltage signal V 3 received by the voltage conversion module 12 equals to the value of the first voltage signal V 1 , thereby avoiding abnormal operations of the liquid crystal panel.

In order to make the value of the third voltage signal V 3 equals to the value of the first voltage signal V 1 , if the value of the third voltage signal V 3 is different from a reference voltage of the third voltage signal V 3 , the compensation voltage signal Vc should be generated correspondingly to compensate at the input end of the interface module 11 .

FIG. 2 illustrates a circuit diagram of a compensation module according to an embodiment of the present disclosure.

As illustrated in FIG. 2 , the compensation module 13 can include a first resistor R 1 , a differential amplifier circuit 131 and a conversion unit 132 . A first end of the first resistor R 1 receives the third voltage signal V 3 , a second end of the first resistor R 1 is grounded via a second resistor R 2 . Then a voltage at the second end of the first resistor R 1 is V 3 *R 2 /(R 1 +R 2 ), and a voltage difference between the two ends of the first resistor R 1 , ΔV, equals to V 3 *R 1 /(R 1 +R 2 ). Two input ends of the differential amplifier circuit 131 are coupled with the two ends of the first resistor R 1 respectively. An output end of the differential amplifier circuit 131 is coupled with the conversion unit 132 , and outputs an output voltage Vo based on the voltage difference between the two ends of the first resistor R 1 , i.e. the output voltage Vo is a multiple of V 3 *R 1 /(R 1 +R 2 ).

As illustrated in FIG. 2 , the differential amplifier circuit 131 includes a differential amplifier AMP, a third resistor R 3 , a fourth resistor R 4 , a fifth resistor R 5 and a sixth resistor R 6 . One end of the third resistor R 3 is coupled with the first end of the first resistor R 1 , and the other end of the third resistor R 3 is coupled with a first input end of the differential amplifier AMP. One end of the fourth resistor R 4 is coupled with the second end of the first resistor R 1 , and the other end of the fourth resistor R 4 is coupled with a second input end of the differential amplifier AMP. One end of the fifth resistor R 5 is grounded, and the other end of the fifth resistor R 5 is coupled with the first input end of the differential amplifier AMP. One end of the sixth resistor R 6 is coupled with the second input end of the differential amplifier AMP, and the other end of the sixth resistor R 6 is coupled with an output end of the differential amplifier AMP.

As illustrated in FIG. 2 , the first input end of the differential amplifier AMP is a non-inverting input end (+) of the differential amplifier AMP and the second input end of the differential amplifier AMP is an inverting input end (−) of the differential amplifier AMP. It should be noted that, according to exemplary embodiments of the present disclosure, the first input end of the differential amplifier AMP can also be the inverting input end (−) of the differential amplifier AMP, while the second input end of the differential amplifier AMP can also be the non-inverting input end (+) of the differential amplifier AMP.

As illustrated in FIG. 2 , in order to simplify the calculation of the output voltage of the differential amplifier AMP, it is supposed that a ratio of a resistance of the fifth resistor R 5 to a resistance of the third resistor R 3 equals to a ratio of a resistance of the sixth resistor R 6 to a resistance of the fourth resistor R 4 , and then the output voltage Vo of the differential amplifier AMP is:

Suppose that the value of the first voltage signal V 1 received at the input end of the interface module 11 is 3.3 V, the value of the second voltage signal V 2 output at the output end of the interface module 11 is 3.2 V, the value of the third voltage signal V 3 received at the input end of the voltage conversion module 12 is 3.1 V, R 1 =R 2 , and R 6 =6*R 4 , then the output voltage Vo of the differential amplifier is two times greater than the value of the third voltage signal V 3 according to the formula (1). Then, the reference voltage of the third voltage signal V 3 is set as 3.3 V, and a reference voltage of the output voltage Vo of the differential amplifier is 9.9 V, whereas the actual output voltage of the differential amplifier is 3*3.1V, i.e. the actual output voltage of the differential amplifier is 9.3 V.

Then a value of the compensation voltage signal Vc can be set by the conversion unit 132 to be a product of a preset first coefficient k 1 and a difference value between the reference voltage of the output voltage of the differential amplifier and the output voltage Vo of the differential amplifier, i.e., the value of the compensation voltage signal Vc can be set to be k 1 *(9.9−9.3) V=k 1 *0.6V, where the first coefficient k 1 can be obtained through a priori method. For example, the first coefficient k 1 can be set as ⅓, and then the value of the compensation voltage signal is 0.2 V.

By outputting the compensation voltage signal Vc to the input end of the interface module 11 , the sum of the compensation voltage signal Vc and the first voltage signal V 1 can be applied to the input end of the interface module 11 , so that the voltage at the input end of the interface module 11 is 3.5V. In this way, according to the abovementioned attenuation rule, the value of the second voltage signal V 2 at the output end of the interface module 11 is 3.4 V, and the value of the third voltage signal V 3 at the input end of the voltage conversion module 12 is 3.3V, equivalent to the value of the first voltage signal V 1 .

FIG. 3 illustrates a circuit diagram of a compensation module according to another embodiment of the present disclosure.

Different from FIG. 2 , the second end of the first resistor R 1 in FIG. 3 is grounded directly. Then the embodiment of the compensation module 13 illustrated by FIG. 3 can be considered as a special case of the compensation module 13 illustrated by FIG. 2 when the resistance of the second resistor is 0. Then the voltage difference between the two ends of the first resistor R 1 , ΔV, equals to V 3 .

As illustrated in FIG. 3 , in order to simplify the calculation of the output voltage of the differential amplifier AMP, it is supposed that a ratio of the resistance of the fifth resistor R 5 to the resistance of the third resistor R 3 equals to a ratio of the resistance of the sixth resistor R 6 to the resistance of the fourth resistor R 4 , and then the output voltage Vo of the differential amplifier is:

Suppose that the value of the first voltage signal V 1 received at the input end of the interface module 11 is 3.3 V, the value of the second voltage signal V 2 output at the output end of the interface module 11 is 3.2 V, the value of the third voltage signal V 3 received at the input end of the voltage conversion module 12 is 3.1 V, and R 6 =6*R 4 , then the output voltage Vo of the differential amplifier is five times greater than the value of the third voltage signal V 3 according to the formula (2). Then, the reference voltage of the third voltage signal V 3 is set as 3.3 V, and the reference voltage of the output voltage Vo of the differential amplifier is 6*3.3V=19.8V, whereas the actual output voltage of the differential amplifier is 6*3.1V, i.e. the actual output voltage of the differential amplifier is 18.6V.

Then the value of the compensation voltage signal Vc can be set by the conversion unit 132 to be a product of a preset second coefficient k 2 and the difference value between the reference voltage of the output voltage of the differential amplifier and the output voltage Vo of the differential amplifier, i.e., the value of the compensation voltage signal Vc can be set to be k 2 *(19.8−18.6) V=k 2 *1.2V, where the second coefficient k 2 can be obtained through a priori method. For example, the second coefficient k 2 can be set as ⅙, and then the value of the compensation voltage signal Vc is 0.2 V.

By outputting the compensation voltage signal Vc to the input end of the interface module 11 , the sum of the compensation voltage signal Vc and the first voltage signal V 1 can be applied to the input end of the interface module 11 , so that the voltage at the input end of the interface module 11 is 3.5V. In this way, according to the abovementioned attenuation rule, the value of the second voltage signal V 2 at the output end of the interface module 11 is 3.4 V, and the value of the third voltage signal V 3 at the input end of the voltage conversion module 12 is 3.3V, equivalent to the value of the first voltage signal V 1 .

FIG. 4 illustrates a structural block diagram of a panel drive device according to a second embodiment of the present disclosure.

As illustrated in FIG. 4 , the panel drive device according to the second embodiment of the present disclosure includes an interface module 11 , a voltage conversion module 12 and a compensation module 13 .

Different from FIG. 1 , in FIG. 4 , the compensation voltage signal Vc generated by the compensation module 13 is applied to the output end of the interface module 11 , so that the value of the third voltage signal V 3 equals to the value of the first voltage signal V 1 .

In this way, by applying the compensation voltage signal Vc to the output end of the interface module 11 , the panel drive device 10 according to the embodiment of the present disclosure, is able to compensate for losses in the transmission cables and in the wires of the printed circuit board, so that the value of the third voltage signal V 3 received by the voltage conversion module 12 equals to the value of the first voltage signal V 1 , thereby avoiding abnormal operations of the liquid crystal panel.

The methods for generating the compensation voltage signal Vc by the compensation module 13 has been described above, and thus will not be repeated again.

When the compensation module 13 illustrated in FIG. 2 is applied to the panel drive device 20 illustrated in FIG. 4 , suppose that the value of the first voltage signal V 1 received at the input end of the interface module 11 is 3.3 V, the value of the second voltage signal V 2 output at the output end of the interface module 11 is 3.2 V, the value of the third voltage signal V 3 received at the input end of the voltage conversion module 12 is 3.1 V, R 1 =R 2 , and R 6 =6*R 4 , then the output voltage Vo of the differential amplifier is two times greater than the value of the third voltage V 3 according to the formula (1). Then, the reference voltage of the third voltage signal V 3 is set as 3.3 V, and the reference voltage of the output voltage Vo of the differential amplifier is 9.9 V, whereas the actual output voltage of the differential amplifier is 3*3.1V, i.e. the actual output voltage of the differential amplifier is 9.3 V.

Then a value of the compensation voltage signal Vc can be set by the conversion unit 132 to be a product of a preset third coefficient k 3 and a difference value between the reference voltage of the output voltage of the differential amplifier and the output voltage Vo of the differential amplifier, i.e., the value of the compensation voltage signal Vc can be set to be k 3 *(9.9−9.3) V=k 3 *0.6V, where the third coefficient k 3 can be obtained through a priori method. For example, the third coefficient k 3 can be set as ⅓, and then the value of the compensation voltage signal Vc is 0.2 V.

By applying the compensation voltage signal Vc to the output end of the interface module 11 , the sum of the compensation voltage signal Vc and the second voltage signal V 2 can be applied to the output end of the interface module 11 , so that the voltage at the output end of the interface module 11 is 3.4V. In this way, according to the abovementioned attenuation rule, the value of the third voltage signal V 3 at the input end of the voltage conversion module 12 is 3.3V, equivalent to the value of the first voltage signal V 1 .

When the compensation module 13 illustrated in FIG. 3 is applied to the panel drive device 20 illustrated in FIG. 4 , suppose that the value of the first voltage signal V 1 received at the input end of the interface module 11 is 3.3 V, the value of the second voltage signal V 2 output at the output end of the interface module 11 is 3.2 V, the value of the third voltage signal V 3 received at the input end of the voltage conversion module 12 is 3.1 V, and R 6 =6*R 4 , then the output voltage Vo of the differential amplifier is five times greater than the value of the third voltage signal V 3 according to the formula (2). Then, the reference voltage of the third voltage signal V 3 is set as 3.3 V, and the reference voltage of the output voltage Vo of the differential amplifier is 19.8 V, whereas the actual output voltage of the differential amplifier is 6*3.1V, i.e. the actual output voltage of the differential amplifier is 18.6 V.

Then a value of the compensation voltage signal Vc can be set by the conversion unit 132 to be a product of a preset fourth coefficient k 4 and a difference value between the reference voltage of the output voltage of the differential amplifier and the output voltage Vo of the differential amplifier, i.e., the value of the compensation voltage signal Vc can be set to be k 4 *(19.8−18.6) V=k 4 *1.2V, where the fourth coefficient k 4 can be obtained through a priori method. For example, the fourth coefficient k 4 can be set as ⅙, and then the value of the compensation voltage signal Vc is 0.2 V.

By applying the compensation voltage signal Vc to the output end of the interface module 11 , the sum of the compensation voltage signal Vc and the second voltage signal V 2 can be applied to the output end of the interface module 11 , so that the voltage at the output end of the interface module 11 is 3.4V. In this way, according to the abovementioned attenuation rule, the value of the third voltage signal V 3 at the input end of the voltage conversion module 12 is 3.3V, equivalent to the value of the first voltage signal V 1 .

FIG. 5 illustrates a structural block diagram of a panel drive device according to a third embodiment of the present disclosure.

Different from FIG. 1 , in FIG. 5 , the panel drive device 30 can further include a timing controller 14 and a gamma circuit 15 .

Particularly, the timing controller 14 can receive a first control signal Sc 1 from the interface module 11 , receive a fourth voltage signal V 4 from the voltage conversion module 12 and output a second control signal Sc 2 . The timing controller 14 according to the embodiments of the present disclosure is the same as a timing controller in the prior art, and thus will not be described in detail herein.

Particularly, the gamma circuit 15 can receive a fourth voltage signal V 4 from the voltage conversion module 12 , receive a data signal Data from the interface module 11 and output a gamma voltage signal Vg. The gamma circuit 15 according to the embodiments of the disclosure is the same as a gamma circuit in the prior art and thus will not be described in detail herein.

FIG. 6 illustrates a structural block diagram of a panel drive device according to a fourth embodiment of the present disclosure.

Different from FIG. 5 , the panel drive device 40 can further include a gate drive circuit 16 and a source drive circuit 17 .

Particularly, the gate drive circuit 16 can receive a second control signal Sc 2 from the timing controller 14 , and output a gate drive signal Sg to a liquid crystal panel. The gate drive circuit 16 according to the embodiments of the present disclosure is the same as a gate drive circuit in the prior art, and thus will not be described in detail herein.

Particularly, the source drive circuit 17 can receive the fourth voltage signal V 4 from the voltage conversion module 12 , receive the gamma voltage signal Vg from the gamma circuit 15 , and output a source drive signal Ss to the liquid crystal panel. The source drive circuit 17 according to the embodiments of the present disclosure is the same as a source drive circuit in the prior art, and thus will not be described in detail herein.

Based on the same inventive conception, exemplary embodiments of the present embodiments further provide a display device, which includes a panel drive device according to any one of the abovementioned embodiments.

By applying the compensation voltage signal Vc to the input end or the output end of the interface module 11 , the display device according to embodiments of the present disclosure, is able to compensate for losses in the transmission cables and in the wires of the printed circuit board, so that the value of the third voltage signal V 3 at the input end of the voltage conversion module 12 equals to the value of the first voltage signal V 1 at the input end of the interface module 11 , thereby avoiding abnormal operations of the liquid crystal panel.

It should be noted that the display device according to the embodiments of the disclosure can be any product or component with a display function, such as a display panel, electronic paper, a mobile phone, a tablet, a television, a laptop, a digital photo frame or a navigator.

Described above are only some of the embodiments of the present disclosure, to which the scope of the present disclosure is not limited, any change or replacement that can be thought of easily by those skilled in the art within the technical scope disclosed by the present disclosure should fall into the scope of the present disclosure. Therefore, the scope of the present disclosure is defined by the scope claimed by the claims.