A locally dimmed display device

Abstract

The application discloses a local dimming display device, which comprises MxN display units, each of which comprises KxL pixels; brightness adjustment signal lines, each of which is connected with a row or column of display units, and the pixels in the same display unit are connected with the same brightness adjustment signal line; a data unit connected with the display units through the brightness adjustment signal lines; a driving unit connected between the data unit and the brightness adjustment signal lines; and an address module and an addressing module in each display unit, wherein the addressing module is used for comparing whether the address stored in the address module matches the input address, so that the circuit area is saved, the circuit is simplified, and the light energy efficiency of display is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a display device with local dimming. BACKGROUND

[0002] Currently, different display technologies have different ways of local brightness adjustment. For example, some displays use full array local dimming technology, which controls the brightness of each pixel by setting an independent light bar in the display area, or uses edge-lit technology, in which the light bar is only located at the edge of the screen. Such displays require each individually set light bar to be connected to an external unit through a lead wire. For liquid crystal displays (LCD) and other large displays, the circuit is set on the bottom TFT substrate, and the substrate has a large area, so it is convenient to set the light bar and the interconnection lead wire. However, for Micro LED displays, due to the limitations of semiconductor manufacturing processes, it is difficult to adjust the backlight brightness by the conventional method of setting the light bar and the lead wire. SUMMARY

[0003] To solve the above technical problems, the present application provides a display device with local dimming, comprising:

[0004] MxN display units, each display unit comprising KxL pixels, N, M, K, and L being natural numbers greater than or equal to 1;

[0005] brightness adjustment signal lines, each group of brightness adjustment signal lines being connected to a row / column of display units, and the pixels in the same display unit being connected to the same brightness adjustment signal line;

[0006] a data unit for providing an address count signal and generating a brightness adjustment signal synchronized with the address count signal according to brightness adjustment data;

[0007] a driving unit connected between the data unit and the brightness adjustment signal lines;

[0008] Each display unit further comprises:

[0009] an address module for addressing the display unit and storing the address;

[0010] an addressing module for selecting a display unit with a matching address according to the address count signal;

[0011] a switch module connected between the display unit and the brightness adjustment signal line; when the address stored in the address module is the same as the input address, the switch module connects the brightness adjustment signal line and the display unit.

[0012] Optionally, the driving unit comprises:

[0013] a sampling module, receiving the brightness adjustment signal through a brightness adjustment signal line;

[0014] a digital-to-analog conversion module, processing the sampling data;

[0015] a conversion module, converting the data into a current signal.

[0016] Optionally, the display device comprises a logic circuit layer of a silicon substrate, an interconnection layer on the logic circuit layer, and a pixel layer on the interconnection layer.

[0017] The address unit, the data unit, the switch module, and the addressing unit are located on the logic circuit layer.

[0018] The brightness adjustment signal line is located on the interconnection layer, and the data bus comprises an interconnection plug perpendicular to the display surface.

[0019] Optionally, the address module, the addressing module, and the switch module of the display unit are located on the logic circuit layer of a vertical surface mapping area of a pixel array of the display unit.

[0020] Optionally, the driving unit is located in a peripheral area of a pixel area of the logic circuit layer.

[0021] Optionally, the addressing module comprises:

[0022] a counter, configured to count the clock signal;

[0023] a comparator, configured to compare the count value of the counter with the address of the display unit stored in the address unit, and select the display unit when the count result is the same as the address of the display unit.

[0024] Optionally, the display device is a silicon-based micro display.

[0025] Optionally, each pixel is further connected with an image data line, and the brightness adjustment signal line and the image data line control the pixel circuit simultaneously, so that the image data display is completed at the same time of the brightness adjustment.

[0026] Compared with the prior art, the display device of the present application has the following advantages: the pixels of the display device are divided into a plurality of display units, the address module and the addressing module are arranged in the display unit, the switch module is arranged in the display unit, the data unit and the driving unit are arranged in the peripheral area of the display unit, the brightness adjustment signal is sent to the unit with the matching address according to the addressing, the local brightness is adjusted, the circuit area is saved by sharing the driving unit, the process complexity is greatly simplified while the local dimming is realized, and the reliability of the device is improved. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1A structure schematic diagram of a display device according to an embodiment of the present application;

[0028] Figure 2 A connection schematic diagram of a display unit of a display device structure according to an embodiment of the present application;

[0029] Figure 3 A cross-sectional schematic diagram of a display device structure according to an embodiment of the present application;

[0030] Figure 4 A working timing diagram of a display device according to an embodiment of the present application;

[0031] Figure 5 A working timing diagram of a data unit of a display device according to an embodiment of the present application. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, so that the advantages and characteristics of the present application can be more easily understood by those skilled in the art, and the protection scope of the present application can be more clearly and definitely defined. Obviously, the described embodiments of the present application are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0033] In the present application, unless otherwise specified, "or" means "and / or". In addition, the use of the terms "comprise", "comprising", "include", "including" and "including" and other forms is not limiting. In addition, unless specifically stated otherwise, terms such as "element" or "component" encompass both elements and components containing a single unit and elements and components containing more than one unit.

[0034] Silicon-based LED / OLED is widely used in virtual reality, augmented reality near-eye display field, especially in augmented reality (AR, Augmented Reality) / virtual reality (VR, Virtual Reality) head-mounted display device. The area of silicon-based LED / OLED is very small, and the limitation of silicon substrate semiconductor process is very strict to the complexity of circuit and lead. Therefore, the silicon-based LED / OLED has few local brightness adjustment functions. With the application of silicon-based LED / OLED display device in near-eye display equipment, the brightness of the display substrate determines the user experience. In the process of using the silicon-based LED / OLED display device, the internal resistance of the light emitting element will change, which is easy to cause the brightness of the display substrate to be uneven, so the demand for local brightness adjustment is increasing, but the brightness adjustment method of the traditional liquid crystal display. The display screen is usually provided with a control signal for each pixel, and the brightness and color display are realized by controlling each pixel, but the circuit of this way is complex, and the area of the display screen is large, and the setting of the light source is not suitable for the silicon-based LED / OLED display device.

[0035] Figure 1 The display device structure diagram of an embodiment of the present application is shown in the figure. Figure 1 The display device of the present application comprises:

[0036] MxN display units 100, each display unit 100 comprising KxL pixels, N, M, K, L are natural numbers greater than or equal to 1; address module 200, address unit for addressing display unit and storing address; addressing module 400, for selecting display unit with matching address according to address count signal; switch module 430 connected between display unit and brightness adjustment signal line; when the address stored in the address module and the input address are the same, the switch module connects the brightness adjustment signal line and the display unit.

[0037] Brightness adjustment signal line, each group of brightness adjustment signal line corresponds to a row / column display unit, and the pixels in the same display unit are connected to the same brightness adjustment signal line;

[0038] Data unit 300, connected to display unit through brightness adjustment signal line, for providing brightness adjustment signal for display unit 100;

[0039] Drive unit 120, connected between data unit and brightness adjustment signal line, for processing data and providing brightness adjustment for pixels in display unit.

[0040] The following will be described in combination with specific examples. In the present embodiment, a display device is first partitioned into 32x32 display units, i.e. the display units are arranged in an array, 32 rows and 32 columns respectively, each display unit comprising 10 pixels 110, i.e. M is 32x32 and N is 10. Each group of brightness adjustment signal lines is connected to a row / column of display units, and the pixels in the same display unit are connected to the same brightness adjustment signal line; the display units 100 are connected to a data unit 300 through the brightness adjustment signal lines.

[0041] The data unit 300 provides an address count signal according to a clock signal CLK. In the present embodiment, as shown in FIG. 2, the address count signal ADDR_A ccout is the same as the clock signal CLK. The data unit synchronizes the input brightness adjustment data with the address count signal, and generates brightness adjustment data signals synchronized with the address count signal. The specific circuit implementation can comprise a latch, which stores the brightness adjustment data BJData_in internally and updates the output brightness adjustment signal BJData_out at the rising edge of the address count signal (i.e. the clock signal). The display unit further comprises an addressing unit 400 and an address unit 200, the address unit being used for addressing the display unit and storing the address, the input end of the addressing unit 400 being connected to the address count signal output end of the data unit. Figure 5

[0042] Specifically, in the present embodiment, the 10 pixels in the same display unit are connected to the brightness adjustment signal line connected to the display unit 100. The 10 pixels in the same display unit are connected to the same address module and addressing module. Specifically, as shown in FIG. 3, the addressing module 400 comprises a counter 410 for counting the address count signal (in the present embodiment, the clock signal), e.g. counting 1 per cycle; a comparator 420 for comparing the count value of the counter 410 with the address of the display unit 100 stored in the address module 200. When the count result is the same as the address of the display unit 100, the comparison module sends a gating enable signal EN to the switch module, selects the display unit 100, and the display unit 100 receives the brightness adjustment signal of the data unit 300. In other embodiments, the display unit can further comprise a clock module for providing a clock signal. The switch module can be a MOS switch. Figure 2

[0043] ​​In the embodiment, the driving unit 120 is also included, in which each display unit is connected to the same driving unit. The driving unit includes a sampling module 121, which samples the brightness adjustment signal when the display unit address and the count value match, and considers the display unit as the target unit; a digital-analog conversion module (CDAC) 122, which converts the sampled data into an analog signal; and a conversion module 123, which converts the data into a current signal, and then sends the current signal to the display unit through the brightness adjustment signal line. In the embodiment, the conversion module is a MOS tube.

[0044] In the conventional display screen, because each display unit 100 includes 10 pixels 110, each pixel in the same display unit 100 needs to be connected to a data bus for controlling the on-off change from the external data unit 300 and a gate line from the external control unit, and a total of 10-bit data buses S0, S1,..., S9 are needed for the control of each pixel through decoding, which obviously occupies a large display screen area.

[0045] In another application of the inventor, an addressing and local brightness adjustment device is provided, and the present application further optimizes the device, so that the driving unit is arranged at the periphery of the display area and is shared, thereby reducing the display area occupancy and saving the area and providing the light efficiency of the pixel display.

[0046] In addition, each display unit of the present application only needs one brightness adjustment signal line to realize the local dimming of the display screen, and the transmission of the brightness adjustment signal to which display unit 100 depends on the selection of the display unit 100 with the matched address. The selected display unit can be adjusted in brightness through the addressing method, and because the addressing module and the address module are arranged in the corresponding display unit, the wiring is further greatly saved, and the brightness of the pixels in the display unit can be adjusted by directly sending the address to the addressing module or opening the switch module when the required address is found. The present application greatly simplifies the complexity of the circuit and saves the cost.

[0047] In the embodiment, specifically, Figure 3As shown, the display device includes a logic circuit layer 510 of a silicon substrate, an interconnection layer 520 on the logic circuit layer, and a pixel layer 530 on the interconnection layer; the address unit, the data unit, and the addressing unit are located on the logic circuit layer 510; the brightness adjustment signal line is located on the interconnection layer 520, and the data bus includes an interconnection plug perpendicular to the display surface. Specifically, the address module, the addressing module, and the switch module of the display unit are located on the logic circuit layer of the vertical surface mapping area of the pixel array of the display unit. The data unit and the driving unit are located in the peripheral area of the corresponding pixel area of the logic circuit layer. Since the display device type in the embodiment is a silicon-based micro display, the MicroLED / OLED is adopted on the silicon substrate, in other words, it is necessary to form the pixel layer on the logic circuit of the silicon substrate. Due to the very limited area, in the semiconductor process, due to the very small size of the device, too many leads will bring parasitic effects, and yield problems. Therefore, the application sets the address unit, the data unit, and the addressing unit on the logic circuit layer, sets a smaller number of brightness adjustment signal lines on the interconnection layer, and further reduces the interconnection wires by setting the circuit of the addressing module and the address module at the corresponding position of the display unit. The address module, the switch module, and the addressing module are located at the corresponding position of each display unit of the logic circuit layer; the driving unit is located in the peripheral area of the corresponding pixel area of the logic circuit layer, and each display unit shares one driving unit. Therefore, the number and length of the leads are further reduced. The local brightness adjustment of the display device is realized, the reliability of the device is improved, and the manufacturing process is simplified.

[0048] The working timing shown below will be described in detail. Figure 4 The working timing shown below will be described in detail.

[0049] Firstly, the counter 410 obtains the clock signal CLK, and starts counting when the rising edge of the clock arrives. When the count value of the counter is transmitted to the comparator 420, the comparator 420 compares the display unit address and the count value. When the comparison result is equal, it is considered that the display unit is the target unit, and an enable signal EN is generated. The switch module 430 obtains the enable signal EN, and if the enable signal is valid, the switch module is closed to connect the data unit and the display unit, so that the data in the data unit 300 is transmitted to the display unit through the bus for display. Figure 2 As shown, when EN1 is valid, the bus data is transmitted to the first display unit, and then transmitted to the pixels in the display unit, so as to achieve the purpose of local dimming.

[0050] Specifically, taking the first display unit as an example: first set an initial address n1, when the counter counts to n1, the comparator will generate an enable signal EN1, when the EN1 signal is pulled high, the switch module is closed, the first display unit and the data unit are turned on, the brightness adjustment signal is sent to the driving unit, the sampling module receives the brightness adjustment signal through the brightness adjustment signal line, the digital-analog conversion module converts the sampling data into an analog signal; the conversion module converts the data into a current signal and sends it to the pixel for display, so that the bus data at this time can be sent to the pixel of the first display unit, the data of the first display unit is transmitted in a clock cycle, and the transmission is completed. The count value changes, EN1 is pulled down, so as to change the display of the display screen. Since the enable signal is pulled down, the display unit is closed, so that the brightness adjustment data can be maintained in the display unit. Here, only the first display unit is taken as an example, and the light adjustment of each subsequent display unit is the same.

[0051] In the embodiment, each pixel is also connected with an image data line, and the brightness adjustment signal line and the image data line control the pixel circuit at the same time, so that the image data display is completed at the same time of brightness adjustment. For example, the brightness adjustment signal line is connected with the image data line, and the brightness adjustment signal is superimposed on the image data for display. The specific superimposition method can be known to those skilled in the art. The present application superimposes the brightness data on the image data, so that no additional background light device is needed, only the existing pixel is used to realize the local dimming function, and the circuit is simple and has very strong practicability.

[0052] The above is only the preferred embodiment of the present application, and does not limit the implementation and protection scope of the present application. Those skilled in the art should realize that any equivalent replacement and obvious change made according to the present application and drawings should be included in the protection scope of the present application.

Claims

1. A locally dimmed, silicon-based microdisplay device, characterized by, The display device comprises: a silicon substrate comprising a logic circuit; an interconnection layer on the logic circuit layer, a pixel layer on the interconnection layer, the pixel layer comprising an array of pixels; MxN display units, each display unit comprising KxL pixels, N, M, K, L being natural numbers greater than or equal to 1; brightness adjustment signal lines, each group of brightness adjustment signal lines being connected to a row / column of display units, the pixels in the same display unit being connected to the same brightness adjustment signal line; a data unit for providing an address count signal and generating a brightness adjustment signal synchronized with the address count signal according to brightness adjustment data; the data unit providing the address count signal according to a clock signal, the address count signal being the same as the clock signal; the data unit synchronizing the input brightness adjustment data with the address count signal to generate a brightness adjustment data signal synchronized with the address count signal, storing the brightness adjustment data in the internal and updating the output brightness adjustment signal at the rising edge of the address count signal; a driving unit connected between the data unit and the brightness adjustment signal lines; each display unit further comprising: an address module for addressing the display unit and storing the address; an addressing module for selecting the display unit with the matching address according to the address count signal; a switch module connected between the display unit and the brightness adjustment signal line; when the address stored in the address module is the same as the input address, the switch module connects the brightness adjustment signal line with the display unit; each display unit being connected to the same driving unit, the driving unit comprising: a sampling module receiving the brightness adjustment signal through the brightness adjustment signal line; a digital-to-analog conversion module processing the sampling data; a conversion module converting the data into a current signal; and then sending the current signal to the display unit through the brightness adjustment signal line; each pixel further being connected to an image data line, the brightness adjustment signal line and the image data line simultaneously controlling the pixel circuit, the image data display being completed at the same time of the brightness adjustment.

2. The display device according to claim 1, wherein: the address module, the data unit, the switch module and the addressing module are located on the logic circuit layer; the brightness adjustment signal lines are located on the interconnection layer, and the data bus comprises interconnection plugs perpendicular to the display surface.

3. The display device according to claim 2, wherein: the address module, the addressing module and the switch module of the display unit are located on the logic circuit layer corresponding to the pixel array vertical surface mapping area.

4. The display device according to claim 3, wherein: the driving unit is located on the peripheral area of the logic circuit layer corresponding to the pixel area.

5. The display device according to claim 4, wherein the addressing module comprises: a counter for counting the clock signal; a comparator for comparing the count value of the counter with the address of the display unit stored in the address unit, and selecting the display unit when the count result is the same as the address of the display unit.

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