A source driving circuit, a display device and a control method thereof

Abstract

The application discloses a source driving circuit, a display device and a control method thereof. The source driving circuit comprises a serial-parallel conversion module, a buffer module, a digital-analog conversion module and an output module. The serial-parallel conversion module is used for converting received serial display data corresponding to each row of pixels into parallel display data corresponding to the row of pixels. The buffer module is used for buffering the parallel display data. The digital-analog conversion module is used for converting digital signals corresponding to data lines in the parallel display data into analog signals. The output module is connected between the digital-analog conversion module and the corresponding multiple data lines. A detection module is used for detecting whether the parallel display data is preset gray scale data. If the parallel display data is the preset gray scale data, the digital-analog conversion module is closed, and the output module applies a preset voltage approximate to a common electrode voltage to each data line connected thereto. If the parallel display data is non-preset gray scale data, the digital-analog conversion module is opened, and the output module transmits corresponding analog signals to each data line connected thereto.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a source driving circuit, a display device and a control method thereof. BACKGROUND

[0002] In the prior art, when a display screen displays a picture, all original driving circuits in the display screen simultaneously output alternating analog data voltages.

[0003] For example, the display screen displays a picture, and the picture features that most of the picture is a black picture, and only a region corresponding to a source driving circuit is a non-black picture. At this time, the source driving circuit corresponding to the non-black picture outputs an analog data voltage corresponding to the non-black picture, and other source driving circuits output analog data voltages corresponding to black pictures. At this time, the amplitude of the analog data voltage corresponding to the black picture is still constantly switched, and the alternating switching of the analog voltage generates a certain power consumption, and the value of the power consumption is only to generate the black picture, which makes the power consumption of the display screen high.

[0004] Therefore, how to reduce the power consumption of the display screen becomes a technical problem to be solved. SUMMARY

[0005] Embodiments of the present application provide a source driving circuit, a display device and a control method thereof, to solve the technical problem of high power consumption of the display screen in the prior art.

[0006] In a first aspect, to solve the above technical problem, the present application provides a source driving circuit, comprising:

[0007] A serial-parallel conversion module is configured to convert received serial display data corresponding to each row of pixels into parallel display data corresponding to the row of pixels.

[0008] A buffer module is connected to an output end of the serial-parallel conversion module, and is configured to buffer the parallel display data.

[0009] A digital-analog conversion module is connected to an output end of the buffer module, and is configured to convert a digital signal corresponding to a data line in the parallel display data into an analog signal.

[0010] An output module is connected between the digital-analog conversion module and a plurality of data lines corresponding thereto.

[0011] a detection module, an input end of the detection module being connected with the cache module, a first output end of the detection module being connected with the digital-analog conversion module, and a second output end of the detection module being connected with the output module, the detection module being configured to detect whether the parallel display data is preset gray scale data; if the parallel display data is the preset gray scale data, the digital-analog conversion module is closed, and the output module is configured to apply a preset voltage to each data line connected with the output module; if the parallel display data is non-preset gray scale data, the digital-analog conversion module is opened, and the output module is configured to transmit a corresponding analog signal to each data line connected with the output module; wherein a voltage difference between the preset voltage and a common electrode in the display panel after the preset voltage is loaded into a pixel unit in the display panel is approximately 0.

[0012] In a possible implementation, the detection module comprises:

[0013] a detector, connected with the cache module, the detector being configured to detect whether data corresponding to each data line in the parallel display data is the preset gray scale data;

[0014] a controller, a control end of the controller being connected with an output end of the detector, a first output end of the controller being connected with an enable end of the digital-analog conversion module, and a second output end of the controller being connected with an enable end of the output module, the controller being configured to, when data corresponding to each data line in the parallel display data is the preset gray scale data, control the digital-analog conversion module to be closed, and output a first indication signal to the output module, the first indication signal being configured to instruct the output module to output the preset voltage; and when at least one of the parallel display data is non-preset gray scale data, control the digital-analog conversion module to be opened, and output a second indication signal to the output module, the second indication signal being configured to instruct the output module to output the analog signal.

[0015] In a possible implementation, the detector comprises:

[0016] a comparator, connected with the cache module, the comparator being configured to compare data corresponding to each data line in the parallel display data with data corresponding to the preset gray scale;

[0017] a multiplier, connected between the comparator and the controller, the multiplier being configured to perform multiplication operation on a comparison result of data corresponding to each data line in the parallel display data and the preset gray scale data, to determine whether the data corresponding to each data line in the parallel display data is the same as the preset gray scale data, and transmit a multiplication result to the control end of the controller.

[0018] In a possible implementation, the comparator further includes a comparator control terminal configured to receive a comparator control signal, and the comparator control signal is configured to control the opening or closing of the comparator.

[0019] In a possible implementation, the multiplier further includes a multiplier control terminal configured to receive a multiplier control signal, and the multiplier control signal is configured to control the opening or closing of the multiplier.

[0020] In a possible implementation, the cache module includes:

[0021] A first-stage cache connected to the output terminal of the serial-parallel conversion module, and configured to receive and cache, asynchronously, data corresponding to each data line in the parallel display data converted from the serial display data.

[0022] A second-stage cache connected between the first-stage cache and the digital-analog conversion module, and configured to cache, synchronously, data corresponding to each data line in the parallel display data for reading by the digital-analog conversion module.

[0023] In a possible implementation, the input terminal of the detector is connected to the output terminal of the first-stage cache.

[0024] In a possible implementation, the preset voltage is a sum of a common electrode voltage and a compensation voltage.

[0025] In a possible implementation, the detection module further includes:

[0026] A latch connected between the detector and the digital-analog conversion module, and configured to latch detection results of all lines in each frame to determine whether the digital-analog conversion module is opened when displaying a next frame of picture; if the digital-analog conversion module is opened when displaying the next frame of picture, the output module outputs an analog signal, and if the digital-analog conversion module is closed when displaying the next frame of picture, the output module outputs the preset voltage.

[0027] In a possible implementation, the preset gray scale includes a 0 gray scale.

[0028] In a second aspect, an embodiment of the present application provides a display device, including:

[0029] A timing control board;

[0030] A source drive circuit board including a plurality of source drive circuits as described in the first aspect, and the source drive circuits are configured to receive serial display data corresponding to the source drive circuits respectively and sent by the timing control board.

[0031] The display panel is configured to receive analog signals or preset voltages sent by the plurality of source driving circuits from the source driving circuit board, wherein the analog signals are converted from corresponding serial display data by corresponding source driving circuits.

[0032] In a third aspect, the embodiments of the present application provide a control method of the display device according to the second aspect, comprising:

[0033] Converting serial display data corresponding to each row of pixels received by each source driving circuit into parallel display data and buffering;

[0034] Detecting whether the buffered parallel display data is preset gray scale data;

[0035] If yes, controlling the corresponding source driving circuit to close digital-to-analog conversion and apply a preset voltage to the data line connected thereto; wherein the voltage difference between the pixel unit loaded into the display panel and the common electrode in the display panel is approximately 0;

[0036] If no, controlling the corresponding source driving circuit to open digital-to-analog conversion, converting digital signals corresponding to each data line in the parallel display data into analog signals, and transmitting the analog signals to the corresponding data line.

[0037] In a possible implementation, the display device further comprises:

[0038] After starting to receive control data corresponding to serial display data of the first row of each frame of picture, and before starting to receive the serial display data of the first row, the comparator in the source driving circuit is set to be opened;

[0039] Before opening the controller in the source driving circuit, the multiplier is set to be opened;

[0040] After receiving serial display data corresponding to the current row of pixels, the controller in the source driving circuit is opened, and the multiplication result output by the multiplier is provided to the digital-to-analog conversion module in the source driving circuit; before the output module transmits the analog data or the preset voltage to the data line, the controller is closed.

[0041] In a possible implementation, the display device further comprises:

[0042] When working in the energy-saving mode, the comparator and the multiplier are set to be opened;

[0043] When working in the non-energy-saving mode, the comparator and the multiplier are set to be closed. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 A schematic diagram of the display device provided by the embodiments of the present application for partial display;

[0045] Figure 2 The analog data signal corresponding to the region of the source driving circuit for displaying non-black picture is shown in the schematic diagram. Figure 1

[0046] Figure 3 The analog data signal corresponding to the region of the source driving circuit for displaying black picture is shown in the schematic diagram.

[0047] Figure 4 The structural schematic diagram of the source driving circuit provided by the embodiment of the present application is shown in the schematic diagram.

[0048] Figure 5 The structural schematic diagram of another source driving circuit provided by the embodiment of the present application is shown in the schematic diagram.

[0049] Figure 6 The structural schematic diagram of another source driving circuit provided by the embodiment of the present application is shown in the schematic diagram.

[0050] Figure 7 The structural schematic diagram of the comparator provided by the embodiment of the present application is shown in the schematic diagram.

[0051] Figure 8 The structural schematic diagram of another source driving circuit provided by the embodiment of the present application is shown in the schematic diagram.

[0052] Figure 9 The structural schematic diagram of another source driving circuit provided by the embodiment of the present application is shown in the schematic diagram.

[0053] Figure 10 The structural schematic diagram of another source driving circuit provided by the embodiment of the present application is shown in the schematic diagram.

[0054] Figure 11 The structural schematic diagram of the display device provided by the embodiment of the present application is shown in the schematic diagram.

[0055] Figure 12 The flow chart of the control method of the display device provided by the embodiment of the present application is shown in the schematic diagram.

[0056] Figure 13 The timing relationship in the source driving circuit provided by the embodiment of the present application is shown in the schematic diagram.

[0057] Figure 14 The analog data signal outputted by the display device provided by the embodiment of the present application when performing local display is shown in the schematic diagram.

[0058] Reference signs:

[0059] ​Serial-parallel conversion module 1, cache module 2, digital-analog conversion module 3, output module 4, detection module 5, input end 5a of the detection module, first output end 5b of the detection module, second output end 5c of the detection module, detector 51, controller 52, control end 52a of the controller, first output end 52b of the controller, second output end 52c of the controller, comparator 511, multiplier 512, first sub-comparator 5111, first-stage cache 21, second-stage cache 22, latch 53. DETAILED DESCRIPTION

[0060] The embodiment of the present application provides a source driving circuit, a display device and a control method thereof, so as to solve the technical problem of high power consumption of a display screen in the prior art.

[0061] In order to make the above object, features and advantages of the present application more obvious and easy to understand, the present application will be further described below with reference to the drawings and embodiments. However, the example embodiments can be implemented in various forms, and should not be understood as being limited to the embodiments described herein; on the contrary, these embodiments are provided so that the present application is more comprehensive and complete, and the concept of the example embodiments is fully conveyed to those skilled in the art. The same reference signs in the drawings represent the same or similar structures, so repeated description thereof will be omitted. The expressions of position and direction described in the present application are described with reference to the drawings, but changes can also be made as needed, and the changes are included in the protection scope of the present application. The drawings of the present application are only used to illustrate the relative positional relationship and do not represent the true proportions.

[0062] It should be noted that specific details are set forth in the following description in order to provide a thorough understanding of the present application. However, the present application can be practiced in a variety of ways other than those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below. The subsequent description of the specification is a preferred embodiment for implementing the present application, and is intended to illustrate the general principles of the present application, rather than to limit the scope of the present application. The protection scope of the present application is defined by the appended claims.

[0063] The display device generally comprises a display panel, a timing control board and a source driving circuit;

[0064] The source driving circuit is responsible for converting the digital data signal sent by the timing control board into an analog data signal capable of driving the display panel pixel unit to display, and the output channel thereof corresponds to one data line in the display panel, that is, each channel corresponds to one data line.

[0065] Typically, one source driver circuit corresponds to 720, 960, or 966 channels. The number of channels in a display panel is greater than or equal to the number of channels in one source driver circuit. Generally, display devices use multiple source driver circuits combined with the display panel.

[0066] In display devices, to ensure that the liquid crystal molecules of the pixel unit are not polarized, the voltage applied to the liquid crystal molecules must be switched symmetrically between positive and negative values. However, since the analog data voltages sent to the pixel unit by the source driving circuit are all positive, a common electrode voltage (denoted as Vcom) is usually introduced to achieve positive and negative symmetry of the voltage values ​​on the liquid crystal molecules. That is, one analog data voltage is higher than Vcom and the other is lower than Vcom. It should be noted that due to the influence of the switching voltage of the thin-film transistor controlling the pixel unit, the two voltage values ​​output by the source driving circuit are not symmetrical about Vcom.

[0067] Display panels are divided into normally black mode and normally white mode. In normally black mode, the liquid crystal molecules do not have a voltage applied and do not deflect, so the panel is opaque and displays a black state. In normally white mode, on the other hand, a voltage is applied to display a black state. Normally black mode is more widely used because of its normal black characteristics and is now the mainstream mode. In practical applications, in order to make the brightness change continuously and regularly with the gray level and to release the charge stored in the pixel unit, normally black mode display panels usually do not use no voltage as the lowest gray level (denoted as L0). Instead, a small voltage value is applied, resulting in very low brightness.

[0068] In existing technology, under any display screen, all source drive circuits of the display device simultaneously output alternating analog data voltages. For example... Figure 1 The diagram shown illustrates a partial display using a display device according to an embodiment of the present invention. The display device includes a display panel 1', a source driving circuit 2', and a timing control board 3'. The display panel 1' is to perform a partial display, such as... Figure 1 The diagram shows that only the area corresponding to one source driver circuit 2' displays a non-black image, while the areas corresponding to other source driver circuits 2' display a black image (i.e., the lowest grayscale). Figure 2 The image shows the source driver circuit for displaying a non-black screen at the output. Figure 1 A schematic diagram of the analog data signal corresponding to an image containing white areas, such as... Figure 3 The diagram shows the analog data signal of the area corresponding to the source drive circuit that displays a black screen. Among them, Figure 2 and Figure 3 The example shown uses the data signal of the source drive circuit corresponding to the non-black screen area as an example, where the polarity is the same within one frame and opposite between frames. L255+ and L255- represent different polarity levels corresponding to grayscale 255, and L0+ and L0- represent different polarity levels corresponding to grayscale 0.Figure 2 and Figure 3 The data signal corresponding to the display area of the source driving circuit in the Nth frame to the N+2th frame is shown. Figure 3 As shown, the amplitude of the analog data voltage corresponding to the black screen needs to be switched constantly, and the alternative switching of the analog voltage will generate a certain power consumption, but the value of this power consumption is only to produce a black screen. The inventor found that this is basically the same as the picture when the display panel itself does not work (i.e. long black mode), and it can be considered that this power consumption is wasted.

[0069] It should be noted that, Figure 1 In the display panel of the application, the display area outside the white area is black, Figure 1 In order to show the display area corresponding to different source driving circuits, the picture displayed by the display panel is semi-transparently processed.

[0070] To solve the above problems, the embodiments of the application improve the following solutions, which will be described in detail below in conjunction with the drawings.

[0071] Please refer to Figure 4 A structure schematic diagram of a source driving circuit provided by the embodiments of the application. The source driving circuit comprises:

[0072] A serial-parallel conversion module 1, configured to convert the serial display data corresponding to each row of pixels received into parallel display data corresponding to the row of pixels; the digital data signal received by the serial-parallel conversion module 1 from the timing control board comprises control data (which can be denoted as C) and display data, the signal mode of the digital data signal is serial mode, and the transmission mode is one row at a time (i.e. after transmitting one row, the next row is transmitted). In order to facilitate description, the display data in the display data received by the serial-parallel conversion module 1 is referred to as serial display data. The serial-parallel conversion module 1 converts the serial display data into parallel display data and transmits it to the next module.

[0073] A buffer module 2 connected to the output end of the serial-parallel conversion module 1, the buffer module 2 is configured to buffer the parallel display data; the output end of the serial-parallel conversion module 1 can be directly connected to the buffer module 2 or coupled to the buffer module 2 through other elements.

[0074] A digital-analog conversion module 3 connected to the output end of the buffer module 2, the digital-analog conversion module 3 is configured to convert the digital signal corresponding to the data line in the parallel display data into an analog signal;

[0075] An output module 4 connected between the digital-analog conversion module 3 and the corresponding plurality of data lines;

[0076] The detection module 5, the input end 5a of the detection module 5 is connected with the buffer module 2, the first output end 5b of the detection module 5 is connected with the digital-analog conversion module 3, the second output end 5c of the detection module 5 is connected with the output module 4, and the detection module 5 is used for detecting whether the parallel display data is preset gray scale data; if the parallel display data is preset gray scale data, the digital-analog conversion module 3 is closed, and the output module 4 applies a preset voltage to each data line connected therewith; if the parallel display data is non-preset gray scale data, the digital-analog conversion module 3 is opened, and the output module 4 transmits a corresponding analog signal to each data line connected therewith; wherein the voltage difference between the preset voltage loaded into the pixel unit in the display panel and the common electrode in the display panel is approximately 0.

[0077] In some embodiments, the preset gray scale can be a gray scale less than or equal to 5, such as 0 gray scale.

[0078] For example, the source drive circuit provided by the embodiment of the present application is used for displaying Figure 1 When the display area corresponding to the source drive circuit 2' containing white color in the display panel is displayed, the source drive circuit provided by the embodiment of the present application detects Figure 1 When the parallel display data corresponding to each pixel row except the row where the white color area is located is detected, the detection result is all preset gray scale data, at this time, the detection module 5 in the source drive circuit provided by the embodiment of the present application controls the digital-analog conversion module 3 to stop digital-analog conversion, which can save the power consumption consumed by the digital-analog conversion module 3; at the same time, the detection module 5 makes the output module 4 load the preset voltage to the pixel electrode of the corresponding row of pixel units, instead of loading the data voltage of the preset gray scale as in the prior art, so that when the pixel unit is driven to display the color corresponding to the preset gray scale by using the source drive circuit provided by the embodiment of the present application, the voltage difference between the pixel electrode of the corresponding row of pixel units and the common electrode is almost zero, the liquid crystal molecules do not deflect, and the corresponding pixel unit is in black state, which is equivalent to displaying black color in the view of the user, so that when the display panel displays the color corresponding to the preset gray scale, it does not need to apply the data voltage of the data corresponding to the preset gray scale as in the prior art (such as Figure 2 ), but applies a voltage similar to the voltage of the common electrode, which is a fixed value and no longer needs to be switched, so that the power consumption of the display panel can be effectively saved.

[0079] In the embodiments provided by the present application, since the source driving circuit in the present application adds the detection module 5 compared with the source driving circuit in the prior art, and the input end 5a of the detection module 5 is connected with the buffer module 2, the first output end 5b of the detection module 5 is connected with the digital-analog conversion module 3, and the second output end 5c of the detection module 5 is connected with the output module 4, the detection module 5 detects whether each row of parallel display data is non-preset gray scale data, when it is determined that the data is preset gray scale data, the digital-analog conversion module 3 is closed, so that the digital-analog conversion module 3 stops working, and the output module 4 applies a preset voltage to each data line connected therewith, so that not only the power consumption of the source driving circuit can be effectively saved, but also the output module does not need to load data signals representing black pictures with opposite polarities alternately on each data line as in the prior art, so that the power consumption of the alternately loaded signals is further saved; and when it is determined that the parallel display data is non-preset gray scale data, the digital-analog conversion module 3 is opened, so that the digital-analog conversion module 3 converts the parallel data signals into analog signals corresponding to the data lines and provides the analog signals to the output module 4, so that the output module 4 transmits the analog signals to the data lines. When the above source driving circuit is applied to the display device, when the display device performs local display, since the source driving circuit for displaying the preset gray scale corresponding picture does not need to perform digital-analog conversion, and for the pixel unit displaying the preset gray scale corresponding color, the preset voltage loaded on the display panel by the output module 4 is a fixed voltage, so that the power consumption of the display device can be effectively saved.

[0080] In some embodiments, the preset voltage is the sum of the common electrode voltage and the compensation voltage.

[0081] The preset voltage can be generated by an external circuit and provided to the source driving circuit, or generated internally by the source driving circuit, and how to generate the preset voltage is not limited herein. For example, the preset voltage can be generated by the common electrode voltage (Vcom) and the half analog reference voltage division.

[0082] The calculation formula of the compensation voltage is:

[0083] V c = (V gh -V gl )×C gs / (C gs +C st +C lc ) (1);

[0084] wherein, V c is the compensation voltage, V gh and V gl are the turn-on and turn-off voltages of the thin film transistor respectively, and V gh > 0, V gl < 0, which can be set by an external circuit and does not change in actual use after being set, so that Vgh and V gl is a fixed value; C gs is a fixed value, and the source electrode is connected with the corresponding pixel electrode; C st is a fixed value; C lc is a fixed value; and the compensation voltage (Vc) is also a fixed value and is positive.

[0085] It should be understood that the pixel voltage input into the pixel unit is affected by the switching of the on and off voltages of the thin film transistor, and a voltage drop equivalent to the compensation voltage is generated, so that the actual voltage applied to the pixel electrode of the pixel unit is (preset voltage-compensation voltage), and the voltage difference between the pixel electrode and the common electrode voltage Vcom is 0, so that the liquid crystal molecules in the pixel unit are not affected by the electric field force and do not deflect, and remain in the black state.

[0086] Please refer to Figure 5 Another structural diagram of a source drive circuit provided by the embodiment of the present application is shown in the figure, and the source drive circuit includes a detection module 5.

[0087] A detector 51 is connected with the buffer module 2, and the detector 51 is used to detect whether the data corresponding to each data line in the parallel display data is all preset gray scale data.

[0088] A controller 52, a control end 52a of the controller 52 is connected with an output end of the detector 51, a first output end 52b of the controller 52 is connected with an enable end of the digital-analog conversion module 3, and a second output end 52c of the controller 52 is connected with an enable end of the output module 4, and the controller 52 is used to control the digital-analog conversion module 3 to be closed when the data corresponding to each data line in the parallel display data is all preset gray scale data, and output a first indication signal to the output module 4, and the first indication signal is used to instruct the output module 4 to output a preset voltage; and when at least one of the data in the parallel display data is not preset gray scale data, the controller 52 controls the digital-analog conversion module 3 to be opened, and outputs a second indication signal to the output module 4, and the second indication signal is used to instruct the output module 4 to output an analog signal.

[0089] In the embodiment provided by the application, the detector 51 is arranged in the detection module 5 to detect whether the data corresponding to each data line in the parallel display data is all the preset gray scale data, and the detection result is transmitted to the controller 52; when the controller 52 determines that the data corresponding to each data line in the parallel display data is all the preset gray scale data according to the detection result, the controller controls the digital-to-analog conversion module 3 to be closed and outputs the first indication signal indicating that the preset voltage is output to the output module 4; when the controller 52 determines that at least one of the data in the parallel display data is not the preset gray scale data according to the detection result, the controller controls the digital-to-analog conversion module 3 to be opened and outputs the second indication signal indicating that the analog signal is output to the output module 4, so that the detection module 5 can control the working state of the digital-to-analog conversion module 3 and the signal output by the output module 4 by detecting the parallel display data.

[0090] Referring to Figure 6 Another structure diagram of the source driving circuit provided by the embodiment of the application is provided, wherein the detector 51 comprises:

[0091] The comparator 511 is connected with the buffer module 2, and is used to compare the data corresponding to each data line in the parallel display data with the data corresponding to the preset gray scale.

[0092] The multiplier 512 is connected between the comparator 511 and the controller 52, and is used to multiply the comparison result of the data corresponding to each data line in the parallel display data with the data of the preset gray scale to determine whether the data corresponding to each data line in the parallel display data is the same as the data of the preset gray scale, and transmit the multiplication result to the control end 52a of the controller 52.

[0093] Referring to Figure 7 A structure diagram of the comparator provided by the embodiment of the application is provided, and the comparator 511 comprises:

[0094] The plurality of first sub-comparators 5111 correspond to the plurality of data lines in the parallel display data one by one, and the first sub-comparator 5111 is used to compare the digital data of the corresponding data line with the data of the preset gray scale (such as the data corresponding to 0 gray scale), if the same, it is determined that the digital data of the corresponding data line is the data of the preset gray scale, if different, it is determined that the digital data of the corresponding data line is the data of the non-preset gray scale, the first sub-comparator 5111 transmits the comparison result to the multiplier 512, the multiplier 512 performs product operation on the comparison results to obtain the multiplication result, and transmits the multiplication result to the control end 52a of the controller 52.

[0095] In some embodiments, the comparator 511 further comprises a comparator control terminal for receiving a comparator control signal, the comparator control signal being used to control the comparator 511 to be turned on or turned off. The multiplier 512 further comprises a multiplier control terminal for receiving a multiplier control signal, the multiplier control signal being used to control the multiplier 512 to be turned on or turned off; the controller 52 further comprises a controller control terminal 52a for receiving a controller control signal, the controller control signal being used to control the controller 52 to be turned on or turned off, and the comparison result of the comparator 511 is transmitted to the digital-to-analog conversion module 3 when the controller 52 is turned on, and the comparison result is not transmitted to the digital-to-analog conversion module 3 when the controller 52 is turned off.

[0096] In the embodiments provided by the present application, by setting the comparator control terminal, the multiplier control terminal and the controller control terminal for the comparator 511, the multiplier 512 and the controller 52 respectively, whether the comparator 511, the multiplier 512 and the controller 52 work can be controlled by inputting the corresponding control signals to the comparator 511, the multiplier 512 and the controller 52, and when the source driving circuit provided by the present application is applied to a display device, the display device can be set to an energy-saving mode or a normal working mode by the control signals, wherein the energy-saving mode is a state (also can be called a working state) in which the comparator 511, the multiplier 512 and the controller 52 are all turned on, and the normal mode is a state (also can be called a non-working state) in which the comparator 511, the multiplier 512 and the controller 52 are all turned off.

[0097] Please refer to Figure 8 Another structure schematic diagram of a source driving circuit provided by an embodiment of the present application is shown in the figure. The buffer module 2 comprises:

[0098] The first-stage buffer 21 is connected to the output terminal of the serial-to-parallel conversion module 1, and is used to asynchronously receive and buffer the data corresponding to each data line in the serial display data converted into parallel display data; the first-stage buffer asynchronously buffers the data received asynchronously until the last data in the parallel display data is buffered, and then synchronously transmits all the data in the parallel display data to the second-stage buffer 22.

[0099] The second-stage buffer 22 is connected between the first-stage buffer 21 and the digital-to-analog conversion module 3, and is used to synchronously buffer the data corresponding to each data line in the parallel display data for the digital-to-analog conversion module 3 to read.

[0100] A plurality of groups of parallel display data corresponding to a plurality of rows of pixels can be stored in the second-stage buffer 22, and the digital-to-analog conversion module 3 reads the next group of parallel display data from the second-stage buffer 22 after completing the digital-to-analog conversion of a group of parallel display data, so that the situation of missing data due to the digital-to-analog conversion module 3 failing to convert in time can be prevented.

[0101] In the embodiment provided by the present application, since the serial-parallel conversion module 1 converts the serial data in the serial display data into the data in the parallel display data one by one, the data in the parallel display data output by the serial-parallel conversion module 1 is not output at the same time, at this time, the first-stage buffer 21 connected with the serial-parallel conversion module 1 can asynchronously buffer the data in the parallel display data output by the serial-parallel conversion module 1, and then synchronously output the data in the parallel display data to the second-stage buffer 22; the second-stage buffer 22 is arranged between the first-stage buffer 21 and the digital-analog conversion module 3 to buffer the parallel display data corresponding to multiple rows of pixels, so that the data loss can be prevented.

[0102] Please refer to Figure 9 The structure schematic diagram of another source driving circuit provided by the embodiment of the present application is shown in FIG. 4. The input end of the detector 51 is connected with the output end of the first-stage buffer 21.

[0103] Please refer to Figure 10 The structure schematic diagram of another source driving circuit provided by the embodiment of the present application is shown in FIG. 4. The source driving circuit further comprises, in the detection module 5:

[0104] The latch 53 is connected between the detector 51 and the digital-analog conversion module 3, and is used to latch the detection results of all rows of each frame to determine whether the digital-analog conversion module 3 is started when displaying the next frame of picture; wherein, if the digital-analog conversion module 3 is started when displaying the next frame of picture, the output module 4 outputs the analog signal, and if the digital-analog conversion module 3 is closed when displaying the next frame of picture, the output module 4 outputs the preset voltage.

[0105] For example, after the latch 53 stores the detection results of all rows of each frame and determines that the frame is the picture corresponding to the preset gray scale, it can be determined that the next frame of picture will also display the picture corresponding to the preset gray scale, at this time, the digital-analog conversion module 3 can be directly closed during the display time of the next frame of picture, and the output module 4 can always output the preset voltage during the display time of the next frame.

[0106] The control signal output by the latch 53 can be merged into a signal by a AND gate (or an OR gate) to be transmitted to the digital-analog conversion module 3 and the transmission module 4; of course, the AND gate / OR gate can also be arranged in the digital-analog conversion module 3 and the output module 4.

[0107] Based on the same inventive concept, the embodiment of the present application provides a display device, as shown in Figure 11 The structure schematic diagram of the display device provided by the embodiment of the present application is shown in FIG. 5, which comprises:

[0108] a timing control board 100;

[0109] The source drive circuit board 200 comprises a plurality of source drive circuits as described above, and is configured to receive serial display data corresponding to the plurality of source drive circuits respectively from the timing control board 100.

[0110] The display panel 300 is configured to receive analog signals or preset voltages transmitted by the plurality of source drive circuits from the source drive circuit board 200, wherein the analog signals are converted from the serial display data corresponding to the plurality of source drive circuits respectively.

[0111] The display device can be a liquid crystal display, a liquid crystal display screen, a liquid crystal television, a mobile phone, a tablet computer, a notebook computer, or the like.

[0112] Based on the same inventive concept, the embodiment of the present application provides a control method of a display device, wherein the display device can refer to the structure of the display device described above, and will not be described here again, please refer to Figure 12 The control method of the display device provided by the embodiment of the present application comprises the following steps:

[0113] Step S10: converting the serial display data corresponding to each row of pixels received by each source drive circuit into parallel display data and buffering;

[0114] Step S11: detecting whether the buffered parallel display data is preset gray scale data;

[0115] Step S12: if yes, controlling the corresponding source drive circuit to close digital-to-analog conversion and apply a preset voltage to the data line connected thereto; if no, controlling the corresponding source drive circuit to open digital-to-analog conversion, converting the digital signal corresponding to each data line in the parallel display data into an analog signal, and transmitting the analog signal to the corresponding data line; wherein the voltage difference between the preset voltage and the common electrode in the display panel after being loaded into the pixel unit in the display panel is approximately 0.

[0116] In the embodiment provided by the present application, by letting each source drive circuit detect whether the parallel display data corresponding to each row of pixels received by itself is preset gray scale data, and stopping digital-to-analog conversion and applying a preset voltage to the corresponding connected data line when the parallel display data is preset gray scale data, the power consumption of the display device during local display can be effectively reduced.

[0117] In some embodiments, when the comparator in the source driving circuit has a comparator control end, the multiplier has a multiplier control end, and the controller has a controller control end, their respective control signals are called comparator control signal, multiplier control signal, and controller control signal. These control signals are pulse signals composed of a first level and a second level, the first level is used to turn on the comparator, the multiplier, and the controller, and the second level is used to turn off the comparator, the multiplier, and the controller. When the comparator control signal, the multiplier control signal, and the controller control signal turn on the comparator, the multiplier, and the controller, the display device works in the energy-saving mode; and when the comparator control signal, the multiplier control signal, and the controller control signal turn off the comparator, the multiplier, and the controller, the display device works in the non-energy-saving mode.

[0118] When the display device works in the energy-saving mode, the control method of the display device further comprises:

[0119] After starting to receive the control data corresponding to the first row of serial display data of each frame of picture, and before starting to receive the first row of serial display data, the comparator in the source driving circuit is set to be turned on;

[0120] Before turning on the controller in the source driving circuit, the multiplier is set to be turned on;

[0121] After receiving the serial display data corresponding to the current row of pixels, the controller in the source driving circuit is turned on, and the multiplication result output by the multiplier is provided to the digital-to-analog conversion module in the source driving circuit; before the output module transmits the analog data or the preset voltage to the data line, the controller is turned off.

[0122] Please refer to Figure 13 The timing relationship diagram in the source driving circuit provided by the embodiments of the present application is shown.

[0123] The signal received by the source driving circuit is a digital data signal, the digital data signal includes control data (denoted as C) and display data (i.e. serial display data), the time length required for receiving the control data is T1, and the time length for receiving the serial display data is T2, T1 < T2.

[0124] The buffer control signal is used to control the storage of the parallel display data in the first-stage buffer to the second-stage buffer, and the buffer control signal is turned on for storage at the rising edge.

[0125] The release signal is used to control the output module to output the analog data or the preset voltage to the data line in the display panel, and the release signal is turned on for release at the falling edge and turned off for release at the rising edge.

[0126] From Figure 13It can be seen that the comparator control signal jumps from the second level to the first level (i.e. the comparator is turned on) after the control data corresponding to the first line of serial display data of each frame of picture is received, and before the first line of serial display data is received, and is kept on continuously; the multiplier control signal jumps from the second level to the first level (i.e. the multiplier is turned on) before the controller is turned on, and is kept on continuously; after the parallel display data corresponding to the current line of pixels is stored in the second-stage buffer (i.e. the rising edge of the buffer control signal), the controller control signal jumps from the second level to the first level (i.e. the controller is turned on), and before the analog data corresponding to the parallel display data of the current line of pixels is transmitted to the data line (i.e. the falling edge of the release signal), the controller control signal jumps from the first level to the second level (i.e. the controller is turned off).

[0127] In the embodiment provided by the application, the comparator in the source driving circuit is set to be turned on after the clock and control data corresponding to the first line of serial display data of each frame of picture is received, and before the first line of serial display data is received, so that each data in the serial display data can be compared, and meanwhile the multiplier can avoid not collecting all comparison results.

[0128] The multiplier is set to be turned on before the controller is turned on, so that the multiplier can avoid collecting the comparison results corresponding to the next line of pixels, and ensure that the output module correctly outputs corresponding signals.

[0129] Please refer to Figure 14 The analog data signal diagram output by the display device provided by the embodiment of the application when performing partial display.

[0130] Suppose the display device displays a picture in Figure 1 , and the content displayed partially in Figure 1 is a white picture and the rest is a black picture, in the embodiment provided by the application, the preset gray scale is 0 gray scale (corresponding to black color), as shown in Figure 14 , the signal output by the source driving circuit when displaying the picture corresponding to the preset gray scale is a preset voltage (Vco), and the preset voltage is approximately the common voltage signal (Vcom), so as to approximately not apply electricity to the liquid crystal molecules, and the liquid crystal molecules will not rotate, so as to present a black state; the signal output by the source driving circuit when displaying a white picture (the gray scale is 255, i.e. a picture corresponding to a non-pre-set gray scale) is composed of the preset voltage and the analog signal (L255+ / L255-) corresponding to the gray scale of 255, i.e. the preset voltage is output when displaying the black region in the picture corresponding to the non-pre-set gray scale, and the analog signal with the gray scale of 255 is output when displaying the white region in the picture corresponding to the non-pre-set gray scale, so as to maximize the power consumption when displaying the picture corresponding to the preset gray scale.

[0131] While the preferred embodiments of the application have been described, additional variations and modifications can be made to these embodiments by those skilled in the art once they have the benefit of the present disclosure without departing from the spirit and scope of the application. Accordingly, it is intended that the appended claims include all such modifications and variations as fall within the scope of the present application.

[0132] It is apparent that those skilled in the art can make various changes and modifications to the application without departing from the spirit and scope of the application. It is therefore intended that the present application cover all such changes and modifications that are within its scope.

Claims

1. A source driving circuit, characterized in that, include: The serial-to-parallel conversion module is used to convert the serial display data corresponding to each row of pixels into parallel display data for the corresponding row of pixels. A caching module is connected to the output of the serial-to-parallel conversion module, and the caching module is used to cache the parallel display data; A digital-to-analog converter module is connected to the output of the cache module. The digital-to-analog converter module is used to convert the digital signals corresponding to the data lines in the parallel display data into analog signals. The output module is connected between the digital-to-analog converter module and the corresponding multiple data lines; A detection module is included, with its input connected to the buffer module, its first output connected to the digital-to-analog converter module, and its second output connected to the output module. The detection module is used to detect whether the parallel display data is data at a preset grayscale level. If the parallel display data is data at the preset grayscale level, the digital-to-analog converter module is turned off, and the output module applies a preset voltage to each connected data line. If the parallel display data is data at a different grayscale level, the digital-to-analog converter module is turned on, and the output module transmits a corresponding analog signal to each connected data line. The preset voltage, after being applied to the pixel units in the display panel, has a voltage difference approximately zero between it and the common electrode in the display panel. The detection module includes: A detector, connected to the cache module, is used to detect whether the data corresponding to the data lines in the parallel display data are all data of the preset grayscale. The controller has its control terminal connected to the output terminal of the detector, its first output terminal connected to the enable terminal of the digital-to-analog converter module, and its second output terminal connected to one enable terminal of the output module. The controller is configured to: control the digital-to-analog converter module to turn off and output a first indication signal to the output module when all data lines in the parallel display data correspond to the preset grayscale; and control the digital-to-analog converter module to turn on and output a second indication signal to the output module when at least one data line in the parallel display data does not correspond to the preset grayscale. The second indication signal is used to instruct the output module to output the analog signal.

2. The source drive circuit as described in claim 1, characterized in that, The detector includes: A comparator, connected to the cache module, is used to compare the data corresponding to each data line in the parallel display data with the data corresponding to the preset grayscale. A multiplier, connected between the comparator and the controller, is used to perform a multiplication operation on the comparison result between the data corresponding to each data line in the parallel display data and the data of the preset grayscale, so as to determine whether the data corresponding to each data line in the parallel display data is the same as the data of the preset grayscale, and transmits the multiplication result to the control terminal of the controller.

3. The source drive circuit as described in claim 2, characterized in that, The comparator also includes a comparator control terminal, which is used to receive a comparator control signal and to control the comparator to be turned on or off.

4. The source drive circuit as described in claim 3, characterized in that, The multiplier also includes a multiplier control terminal, which is used to receive a multiplier control signal, and the multiplier control signal is used to control the multiplier to turn on or off.

5. The source drive circuit as described in any one of claims 2-4, characterized in that, The caching module includes: The first-stage buffer is connected to the output of the serial-to-parallel conversion module. The first-stage buffer is used to asynchronously receive and buffer the data corresponding to each data line in the serial display data converted into the parallel display data. The second-stage buffer is connected between the first-stage buffer and the digital-to-analog conversion module. The second-stage buffer is used to synchronously buffer the data corresponding to each data line in the parallel display data for the digital-to-analog conversion module to read.

6. The source drive circuit as described in claim 5, characterized in that, The input of the detector is connected to the output of the first-order buffer.

7. The source drive circuit as described in any one of claims 1-4, characterized in that, The preset voltage is the sum of the common electrode voltage and the compensation voltage.

8. The source drive circuit as described in any one of claims 2-4, characterized in that, The detection module also includes: A latch, connected between the detector and the digital-to-analog converter module, is used to latch the detection results of all lines in each frame to determine whether the digital-to-analog converter module is turned on when the next frame is displayed; wherein, if the digital-to-analog converter module is turned on when the next frame is displayed, the output module outputs an analog signal, and if the digital-to-analog converter module is turned off when the next frame is displayed, the output module outputs the preset voltage.

9. The source drive circuit as described in any one of claims 1-4, characterized in that, The preset grayscale includes 0 grayscale.

10. A display device, characterized in that, include: Timing control board; The source driver circuit board includes a plurality of source driver circuits as described in any one of claims 2-4; The source drive circuit is used to receive serial display data sent by the timing control board, which corresponds to the plurality of source drive circuits respectively. The display panel is used to receive analog signals or preset voltages sent by the plurality of source driving circuits from the source driving circuit board. The analog signals are obtained by converting corresponding serial display data by the corresponding source driving circuit.

11. A control method for the display device according to claim 10, characterized in that, include: The serial display data corresponding to each row of pixels received by each source driver circuit is converted into parallel display data and buffered. Check whether the cached parallel display data is the preset grayscale data; If so, the corresponding source drive circuit is controlled to turn off the digital-to-analog conversion and a preset voltage is applied to the data line connected to it; wherein, the voltage difference between the preset voltage and the common electrode in the display panel after being applied to the pixel unit in the display panel is approximately 0; If not, control the corresponding source drive circuit to enable digital-to-analog conversion, convert the digital signal corresponding to each data line in the parallel display data into an analog signal, and transmit it to the corresponding data line.

12. The control method as described in claim 11, characterized in that, Also includes: After receiving the control data corresponding to the first line of serial display data of each frame, and before receiving the first line of serial display data, the comparator in the source drive circuit is set to be enabled. The multiplier is set to on before the controller in the source drive circuit is turned on; After receiving the serial display data corresponding to the current row of pixels, the controller is turned on and the multiplication result output by the multiplier is provided to the digital-to-analog converter module in the source driver circuit. The controller is turned off before the output module transmits analog data or the preset voltage to the data line.

13. The control method as described in claim 12, characterized in that, Also includes: When operating in energy-saving mode, the comparator and the multiplier are set to be enabled; When operating in non-energy-saving mode, the comparator and the multiplier are set to be off.

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