Charging circuit, charging method, display screen and electronic equipment

Abstract

The invention discloses a charging circuit, a charging method, a display screen and electronic equipment, and belongs to the technical field of display. The charging circuit comprises 2m voltage sources, a first switching circuit and 2m second switching circuits, each second switching circuit corresponds to one voltage source, the input end of each second switching circuit is connected with the corresponding voltage source, and the output end of each second switching circuit is connected with the voltage input end of the pixel driving circuit through the first switching circuit. The first switch circuit is turned on when the connected voltage source is selected and turned off after the turn-on time is up, and the second switch circuit is configured to be turned on when the connected voltage source is selected. According to the invention, the problem that a huge number of pixel circuits cannot be charged in a short time in the prior art is solved, and meanwhile, the space occupation of the charging circuit is reduced.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a charging circuit for charging a pixel driving circuit, a charging method of the charging circuit, a display screen having the charging circuit, and an electronic device having the display screen. Background Art

[0002] With the continuous development of display technology, OLED and other types of display screens are widely used in mobile phones, computers, etc. Figure 1 As shown, in the display screen, the pixel driving circuit is arranged at the intersection of the scanning lines arranged in the row direction to supply the control signal and the data lines arranged in the column direction to supply the data signal, so as to drive the pixel unit to display the image. In the pixel driving circuit, the capacitor C and the light-emitting element L are important components. During the image display process, the capacitor C needs to be charged so that the capacitor C can control the light-emitting element L to emit light during the light-emitting stage.

[0003] At present, the following scheme is usually adopted to charge the capacitor in the pixel driving circuit: first, the ramp voltage is divided into two n segment, n is the color depth of the pixel; finally, an n-bit counter is used to count to control the charging time of all data lines, that is, when the counter counts to the grayscale value of a certain line (the grayscale value range is 0 to 2 n -1) is equal, the data line will stop charging. For example, a display screen with a resolution of 3840×3840 is used for detailed description. In specific implementation, it is necessary to charge the R, G, and B of a row of 3840 pixels at the same time, so one ramp voltage needs to charge 11520 lines at the same time. When charging, first divide the 4.7V~3.1V ramp voltage into 1024 (2 n , n is the pixel color depth, here n = 10), and then a 10-bit counter is used to control the charging time of all data lines. The counter can count from 0 to 1023 (2 n -1). When the counter reaches a grayscale value equal to that on a certain line, the data line will stop charging. When the counter completes counting, all the more than 10,000 lines will complete the charging of the corresponding voltage.

[0004] However, charging with only one ramp voltage will bring the following problems: the time available for charging each data line is very short and cannot reach the predetermined target value; and the charging circuit is relatively complex or difficult to implement.

[0005] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0006] The object of the present invention is to provide a charging circuit, which can solve the problem that the prior art cannot charge a large number of pixel circuits in a short time, and reduce the space occupied by the charging circuit.

[0007] To achieve the above object, an embodiment of the present invention provides a charging circuit, which is applied to a pixel driving circuit. The pixel driving circuit is configured at a point where a scanning line arranged in a row direction to supply a control signal and a data line arranged in a column direction to supply a data signal intersect each other. The charging circuit includes:

[0008] 2 m A voltage source, the 2 m A voltage source is formed by evenly segmenting the ramp voltage, m≥1;

[0009] The first switch circuit and 2 m second switch circuits, each second switch circuit corresponds to a voltage source, and the input end of each second switch circuit is connected to the corresponding voltage source, and the output end is connected to the voltage input end of the pixel driving circuit through the first switch circuit; wherein,

[0010] The first switch circuit is configured to be turned on when the connected voltage source is selected, and the turn-on time is determined according to the grayscale value of the pixel;

[0011] The second switch is configured to be turned on when the connected voltage source is selected and to be turned off after a turn-on time is reached, where the turn-on time is determined according to the grayscale value of the pixel.

[0012] In one or more embodiments of the present invention, the on-time is determined according to the grayscale value of the pixel, including:

[0013] Determine the time limit parameter according to the grayscale value of the pixel;

[0014] The time it takes for the counter to count from zero to the time limit parameter is the on-time.

[0015] In one or more embodiments of the present invention, determining the time limit parameter according to the grayscale value of the pixel includes:

[0016] Convert the grayscale value of the pixel into n-bit binary, where n is the color depth of the pixel;

[0017] The decimal value corresponding to the low nm bits of the binary number is used as the time limit parameter.

[0018] In one or more embodiments of the present invention, the voltage source is selected according to the grayscale value of the pixel and includes:

[0019] Convert the grayscale value of the pixel into n-bit binary, where n is the color depth of the pixel;

[0020] Select the corresponding voltage source according to the decimal value corresponding to the high m bits of the binary number.

[0021] In one or more embodiments of the present invention, when the first switch circuit and the second switch circuit are turned on, the starting value of the selected voltage source is input into the pixel driving circuit.

[0022] In one or more embodiments of the present invention, the first switch circuit is configured to be turned on when the connected voltage source is selected, comprising:

[0023] The first switch circuit is controlled to be turned on by a switch signal.

[0024] In one or more embodiments of the present invention, the pixel driving circuits corresponding to the pixels in the same column share the charging circuit.

[0025] In one or more embodiments of the present invention, the first switch circuit and / or the second switch circuit each includes a switch.

[0026] An embodiment of the present invention provides a charging method, comprising the following steps:

[0027] Get the grayscale value corresponding to the pixel;

[0028] Selecting a voltage source for charging according to the grayscale value, and controlling a second switch circuit corresponding to the voltage source to be turned on;

[0029] The on-time of the first switch circuit is determined according to the grayscale value, the first switch circuit is controlled to be on, and the first switch circuit is controlled to be off when the on-time is reached.

[0030] An embodiment of the present invention provides a display screen, comprising the charging circuit described above.

[0031] An embodiment of the present invention provides an electronic device, including the display screen mentioned above.

[0032] Compared with the prior art, the present invention can solve the problem that the prior art cannot charge a large number of pixel circuits in a short time, and can reduce the space occupied by the charging circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the display screen circuit structure;

[0034] Figure 2 is a schematic diagram of the charging circuit structure according to an embodiment of the present invention;

[0035] Figure 3is a schematic diagram of a ramp voltage according to an embodiment of the present invention;

[0036] Figure 4 is a flow chart of a charging method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation modes.

[0038] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.

[0039] like Figure 2 As shown, a charging circuit according to a preferred embodiment of the present invention is used to charge a pixel driving circuit, which can solve the problem that the prior art cannot charge a large number of pixel circuits in a short time, and at the same time reduce the space occupied by the charging circuit. The pixel driving circuit here is used to drive the corresponding pixel unit to display an image. The pixel driving circuit is configured at the intersection of the scanning lines arranged in the row direction to supply control signals and the data lines arranged in the column direction to supply data signals. Figure 1 In the pixel driving circuit, the capacitor C is an important component thereof, and the capacitor C can be used to store charge to control the light emitting element L to emit light during the light emitting stage. The charging circuit of the present invention can increase the charging time of the capacitor to meet the charging time requirement.

[0040] Specifically, the charging circuit includes 2 m A voltage source 10, a first switch circuit 20 and a m A second switch circuit 30, m≥1. Wherein, 2 m The voltage source 10 is formed by averaging the ramp voltage segments, and 2 m The voltage sources 10 have corresponding numbers, where the ramp voltage is as follows: Figure 3 As shown, the ramp voltage includes a ramp voltage that changes from small to large and a ramp voltage that changes from large to small. In addition, m can be determined according to actual needs. The actual demand refers to how many times the charging time is extended. For example, in order to extend the charging time by 16 times, m is 4 at this time, that is, the ramp voltage can be evenly divided into 16 voltage segments (i.e., voltage source 10), and each voltage segment can be charged at the same time, and finally the charging time is extended by 16 times to achieve a sufficient charging time.

[0041] like Figure 2As shown, each second switch circuit 30 corresponds to a voltage source 10, and the input end of the second switch circuit 30 is connected to the corresponding voltage source 10, and the output end is connected to the voltage input end of the pixel driving circuit through the first switch circuit 20, as shown in FIG. Figure 2 As shown, 2 m The voltage sources 10 are respectively denoted as voltage source U1 to voltage source U2 m , the first switch circuit 20 is denoted as the first switch circuit Kc, 2 m The second switch circuits 30 are respectively denoted as second switch circuits K1 to K2 m The second switch circuit K1 corresponds to the voltage source U1, an input end of which is connected to the voltage source U1, and an opposite end is connected to the voltage input end of the pixel driving circuit through the first switch circuit Kc.

[0042] Further, the first switch circuit 20 is configured to be turned on when the connected voltage source 10 is selected, and the time of the conduction is the time taken by the counter to count from zero to the time limit parameter. The time limit parameter here is determined according to the grayscale value of the pixel. The on or off of the first switch circuit 20 is controlled by a corresponding switch signal, such as inputting a switch signal through an external control circuit to control the on or off of the first switch circuit 20. Further, the time limit parameter is determined by the following steps: first convert the grayscale value of the pixel into n-bit binary, where n is the color depth of the pixel, such as 8 bits or 10 bits, etc. When a 10-bit color depth is used, the corresponding grayscale value range is 0 to 1023. When the grayscale value of a certain pixel is 10'h66 (10 represents the color depth, h66 represents the hexadecimal number 66), it is converted into a 10-bit binary number of 0001100110. Finally, the decimal value corresponding to the low nm-bit binary number is used as the time limit parameter. As described above, the decimal value 38 corresponding to the lower 6 (nm=10-4) bits of the binary number is used as the time limit parameter.

[0043] The second switch circuit 30 is configured to be turned on when the connected voltage source 10 is selected, so that the selected voltage source 10 can be input into the pixel driving circuit. The voltage source 10 here is selected according to the grayscale value of the pixel. In the specific implementation, the voltage source 10 is selected by the following steps: First, the grayscale value of the pixel is converted into n-bit binary, where n is the color depth of the pixel, such as 8 bits or 10 bits, etc. When a 10-bit color depth is used, the corresponding grayscale range is 0 to 1023. When the grayscale value of a certain pixel is 10'h66 (10 represents the color depth, and h66 represents the hexadecimal number 66), it is converted into a 10-bit binary number of 0001100110. Finally, the voltage source 10 with the corresponding number is selected according to the decimal value corresponding to the upper m-bit binary number. As described above, the second voltage segment is selected according to the decimal value 1 corresponding to the upper 4-bit (m=4) binary number, that is, the second voltage source 10 is selected.

[0044] In this embodiment, the first switch circuit 20 and the second switch circuit 30 each include a switch. Of course, in other embodiments, the first switch circuit 20 and / or the second switch circuit 30 may also include a plurality of switches connected in series, and the plurality of switches cooperate to realize the conduction or disconnection of the first switch circuit 20 and / or the second switch circuit 30.

[0045] The following takes the pixel color depth as 10, the slope voltage range as 4.7 to 3.1, the first switch circuit 20 and the second switch circuit 30 each including a switch (the switch in the first switch circuit 20 is denoted as the first switch, and the switch in the second switch circuit 30 is denoted as the second switch), and the slope voltage is divided into 16 segments as an example, and the working principle of the charging circuit described in the present invention is described in detail.

[0046] Combination Figure 2 As shown, the charging circuit includes 16 voltage sources 10, which are respectively denoted as U1 to U16. The 16 voltage sources 10 are formed by evenly dividing the ramp voltage (4.7 to 3.1) into 16 sections. At the same time, the charging circuit also includes 1 first switch and 16 second switches, which are respectively denoted as the first switch Kc and the second switch K1 to K16. Among them, one end of the second switch K1 is connected to the voltage source U1, and the opposite end is connected to the pixel driving circuit corresponding to the pixel in the first row of a certain column through the first switch Kc to charge the capacitor C therein, that is, one end of the second switch K1 is connected to the voltage source U1, and the opposite end is connected to the first switch Kc to form a connection point A, which is further connected to the pixel driving circuit corresponding to the pixel in the first row of a certain column through the first switch Kc. One end of the second switch K2 is connected to the voltage source U2, and the opposite end is connected to the connection point A. By analogy, one end of the second switch K16 is connected to the voltage source U16, and the opposite end is connected to the connection point A.

[0047] When charging the pixel driving circuit, the grayscale value of the pixel is first determined, for example, the grayscale value of the pixel is 10′h20.

[0048] Secondly, after the grayscale value of the pixel is determined, it is further determined according to the grayscale value which voltage source 10 is selected for charging. After the voltage source 10 for charging is determined, the corresponding second switch is closed. In specific implementation, first, the grayscale value of the pixel is converted into a 10-bit binary, such as the grayscale value 10'h20 converted into a 10-bit binary is 0000100000. Finally, the corresponding voltage source 10 is selected according to the decimal value corresponding to the upper 4-bit binary number. As described above, the first voltage source 10 is selected according to the decimal value 0 corresponding to the upper 4-bit (m=4) binary number, that is, the voltage source U1 (voltage range is 4.7~4.6V) is selected. After the voltage source U1 is determined to be selected, the second switch K1 corresponding to the voltage source U1 is further closed, while the remaining second switches K2~K16 are not closed because their corresponding voltage sources 10 are not selected. After the second switch K1 is closed, the first switch Kc is further controlled to be closed. At this time, the voltage provided to the capacitor in the pixel driving circuit is 4.7V.

[0049] After the voltage source 10 is determined, the parameter value is further determined according to the grayscale value to determine the charging time. In the specific implementation, the grayscale value of the pixel is first converted into a 10-bit binary number, such as converting the above grayscale value 10'h20 into a 10-bit binary number is 0000100000. Finally, the decimal value corresponding to the lower 6-bit binary number is used as the parameter value. As mentioned above, the decimal value 32 corresponding to the lower 6 (nm=10-4)-bit binary number is used as the parameter value. After determining the parameter value, the counter is turned on. When the counter counts from 0 to 32, the first switch Kc is disconnected to end charging. At this time, the voltage of the capacitor is calculated by the following formula:

[0050] (1) When V1 is greater than V0,

[0051]

[0052] Wherein, V1 is the starting value in the selected voltage segment, V0 is the ending value in the selected voltage segment, and x is the decimal number corresponding to the low nm bits of the grayscale value of the pixel;

[0053] (2) When V1 is less than V0,

[0054]

[0055] Therefore, the voltage of the capacitor at this time is 4.7-(4.7-4.6)*(32 / 63)≈4.65V.

[0056] Since the pixel driving circuits corresponding to all pixels in the same column share the same charging circuit, one charging circuit can control the charging of the pixel driving circuits in the same column of all rows. After the above process, the capacitors of the pixels in the first row are fully charged. When scanning the second row, the process is repeated again to charge the capacitors in the second row.

[0057] like Figure 4 As shown, a charging method according to a preferred embodiment of the present invention, based on the above-mentioned charging circuit, can solve the problem that the prior art cannot charge a large number of pixel circuits in a short time, and reduce the space occupied by the charging circuit. Specifically, the charging method includes the following steps:

[0058] First, obtain the grayscale value corresponding to the pixel;

[0059] Secondly, a voltage source 10 for charging is selected according to the grayscale value, and a second switch circuit 30 corresponding to the voltage source 10 is controlled to be turned on;

[0060] Finally, the on-time of the first switch circuit 20 is determined according to the grayscale value, and the first switch circuit 20 is controlled to be turned off when the on-time arrives.

[0061] Specifically, in a specific implementation, the following steps can be used to select the voltage source 10 for charging according to the grayscale value: First, the grayscale value of the pixel is converted into n-bit binary, where n is the color depth of the pixel, such as 8 bits or 10 bits. For example, when a 10-bit color depth is used, the corresponding grayscale range is 0 to 1023. When the grayscale value of a certain pixel is 10'h66 (10 represents the color depth, and h66 represents the hexadecimal number 66), it is converted into a 10-bit binary number of 0001100110. Finally, the voltage source 10 with the corresponding number is selected according to the decimal value corresponding to the upper m-bit binary number. As described above, the second voltage segment is selected according to the decimal value 1 corresponding to the upper 4-bit (m=4) binary number, that is, the second voltage source 10 is selected.

[0062] Further, the on-time is determined according to the grayscale value of the pixel, specifically, the time limit parameter is determined according to the grayscale value of the pixel; the time taken by the counter to count from zero to the time limit parameter is the on-time. The time limit parameter here can be determined by the following steps: first, the grayscale value of the pixel is converted into n-bit binary, where n is the color depth of the pixel, such as 8 bits or 10 bits, etc. When a 10-bit color depth is used, the corresponding grayscale value range is 0 to 1023. When the grayscale value of a certain pixel is 10'h66 (10 represents the color depth, h66 represents the hexadecimal number 66), it is converted into a 10-bit binary number of 0001100110. Finally, the decimal value corresponding to the lower nm-bit binary number is used as the time limit parameter. As mentioned above, the decimal value 38 corresponding to the lower 6 (nm=10-4)-bit binary number is used as the time limit parameter.

[0063] The following takes the case where the pixel color depth is 10, the slope voltage range is 4.7 to 3.1, the first switch circuit 20 and the second switch circuit 30 both include a switch (the switch in the first switch circuit 20 is denoted as the first switch, and the switch in the second switch circuit 30 is denoted as the second switch), and the slope voltage is divided into 16 segments as an example, and the charging method described in the present invention is described in detail.

[0064] like Figure 2 As shown, the specific structure of the charging circuit is detailed in the above description and will not be repeated here.

[0065] When charging the pixel driving circuit, the grayscale value of the pixel is first determined, for example, the grayscale value of the pixel is 10′h20.

[0066] Secondly, after the grayscale value of the pixel is determined, it is further determined according to the grayscale value which voltage source 10 is selected for charging. After the voltage source 10 for charging is determined, the corresponding second switch is closed. In specific implementation, first, the grayscale value of the pixel is converted into n-bit binary, where n is the color depth of the pixel, such as 8 bits or 10 bits, etc. For example, the grayscale value 10'h20 converted into 10-bit binary is 0000100000. Finally, the voltage source 10 with the corresponding number is selected according to the decimal value corresponding to the upper m-bit binary number, such as selecting the corresponding voltage source 10 according to the decimal value corresponding to the upper 4-bit binary number. As described above, the first voltage source 10 is selected according to the decimal value 0 corresponding to the upper 4-bit (m=4) binary number, that is, the voltage source U1 (voltage range is 4.7~4.6V) is selected. When the voltage source U1 is determined to be selected, the second switch K1 corresponding to the voltage source U1 is further closed, while the remaining second switches K2 to K16 are not closed because their corresponding voltage sources 10 are not selected.

[0067] Finally, after the second switch K1 is closed, the first switch Kc is further controlled to be closed, and the voltage provided to the capacitor in the pixel driving circuit is 4.7V. The parameter value is further determined according to the grayscale value to determine the closing time of the first switch Kc, thereby controlling the charging time. In the specific implementation, the grayscale value of the pixel is first converted into a 10-bit binary. For example, the grayscale value 10'h20 converted into a 10-bit binary is 0000100000. Finally, the decimal value corresponding to the lower 6 binary digits is used as the time limit parameter. As mentioned above, the decimal value 32 corresponding to the lower 6 (nm=10-4) binary digits is used as the time limit parameter. After determining the time limit parameter, the counter is turned on. When the counter counts from 0 to 32, the first switch Kc is disconnected to end the charging.

[0068] The present invention also discloses a display screen, including scan lines arranged in a row direction to supply control signals, data lines arranged in a column direction to supply data signals, a pixel driving circuit disposed at the intersection of the scan lines and the data lines, and a charging circuit for charging the pixel driving circuit. The charging circuit is described above in detail and will not be described here one by one. Since the display screen has the charging circuit described above, it can solve the problem that the prior art cannot charge a large number of pixel circuits in a short time, and reduce the space occupied by the charging circuit.

[0069] The present invention also discloses an electronic device, including the above-mentioned display screen, which can solve the problem that the prior art cannot charge a large number of pixel circuits in a short time and reduce the space occupied by the charging circuit. The electronic device here includes but is not limited to mobile phones, tablet computers, etc.

[0070] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A charging circuit applied to a pixel driving circuit, wherein the pixel driving circuit is arranged at a point where a scanning line arranged in a row direction to supply a control signal and a data line arranged in a column direction to supply a data signal intersect each other, characterized in that: The charging circuit comprises: 2 m A voltage source, the 2 m A voltage source is formed by evenly segmenting the ramp voltage, m≥1; The first switch circuit and 2 m second switch circuits, each second switch circuit corresponds to a voltage source, and the input end of each second switch circuit is connected to the corresponding voltage source, and the output end is connected to the data input end of the pixel driving circuit through the first switch circuit; wherein, The first switch circuit is configured to be turned on when the connected voltage source is selected and turned off after the on-time is reached, and the on-time is determined according to the grayscale value of the pixel; The second switch is configured to be turned on when a connected voltage source is selected, and the voltage source is selected according to a grayscale value of a pixel.

2. The charging circuit according to claim 1, characterized in that: The on-time is determined according to the grayscale value of the pixel and includes: Determine the time limit parameter according to the grayscale value of the pixel; The time it takes for the counter to count from zero to the time limit parameter is the on-time.

3. The charging circuit according to claim 2, characterized in that: Determining the time limit parameter according to the grayscale value of the pixel includes: Convert the grayscale value of the pixel into n-bit binary, where n is the color depth of the pixel; The decimal value corresponding to the low nm bits of the binary number is used as the time limit parameter.

4. The charging circuit according to claim 1, characterized in that: The voltage source is selected according to the grayscale value of the pixel and includes: Convert the grayscale value of the pixel into n-bit binary, where n is the color depth of the pixel; Select the corresponding voltage source according to the decimal value corresponding to the high m bits of the binary number.

5. The charging circuit according to claim 1, characterized in that: When the first switch circuit and the second switch circuit are turned on, the initial value of the selected voltage source is input into the pixel driving circuit.

6. The charging circuit according to claim 1, characterized in that: The first switch circuit is configured to be turned on when the connected voltage source is selected, comprising: The first switch circuit is controlled to be turned on by a switch signal.

7. The charging circuit according to claim 1, characterized in that: The pixel driving circuits corresponding to the pixels in the same column share the charging circuit.

8. The charging circuit according to claim 1, characterized in that: The first switch circuit and / or the second switch circuit each includes a switch.

9. A charging method based on the charging circuit according to any one of claims 1 to 8, characterized in that: The steps include: Get the grayscale value corresponding to the pixel; Selecting a voltage source for charging according to the grayscale value, and controlling a second switch circuit corresponding to the voltage source to be turned on; The on-time of the first switch circuit is determined according to the grayscale value, the first switch circuit is controlled to be on, and the first switch circuit is controlled to be off when the on-time is reached.

10. A display screen, characterized in that: The charging circuit comprises the charging circuit according to any one of claims 1 to 8.

11. An electronic device, characterized in that: Includes the display screen as claimed in claim 10.

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