Micro light emitting diode display

Abstract

The utility model provides a kind of light emitting diode LED display and a kind of LED display.The light emitting diode LED display includes: multiple LED;At least one constant current driver;And at least one pixel local transistor, the cathode of LED is connected with each other, and it is turned on to ground via pixel local transistor.LED display includes: multiple pixels;And by three sections connection to the constant current driver and scan controller of pixel.LED cathode is connected with each other, and it is turned on to ground via pixel local transistor.In addition, in the first section, constant current driver is connected to pixel by second conductive layer, and scan controller is connected to pixel by first conductive layer;In the second section, constant current driver is connected to pixel by third conductive layer, and scan controller is connected to pixel by first conductive layer;In the third section, constant current driver is connected to pixel by fourth conductive layer, and scan controller is connected to pixel by first conductive layer.

Description

Technical Field

[0001] This utility model relates to a micro light-emitting diode display device for a micro light-emitting diode display. Background Technology

[0002] In existing technologies, the active matrix (AM) driving topology of traditional LED displays has relatively simple wiring connections, but it suffers from the following drawbacks: Under AM driving, the digital-to-analog converter (DAC) limits grayscale levels and has a slow response time. Furthermore, AM driving typically requires complex thin-film transistor (TFT) pixel local circuitry. Moreover, under AM driving, the luminance efficiency is relatively low due to the limited current supply capability of the TFT; additionally, the voltage-to-current conversion and current-to-luminance of the micro-LEDs are non-linear under AM driving, potentially leading to uneven color display. Simultaneously, under AM driving, the refresh rate of the display is usually limited by its frame rate, and power consumption is relatively high.

[0003] Passive matrix (PM) driving topologies have been developed for miniature / micro LED displays. For example, when using pulse width modulation (PWM) mode, the display's response time is faster than that of displays using AM drivers; furthermore, due to its constant current PWM mode, PM drivers can achieve better brightness linearity and color uniformity; and the power consumption of PM drivers may be lower than that of AM drivers. However, when PM drivers are used in COG displays, the wiring connections are relatively complex, and the width of the grounding path may be insufficient to carry large return currents. Utility Model Content

[0004] This summary is intended to introduce some concepts in a simplified form, which will be further elaborated in the detailed description below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended as a basis for determining the scope of the subject matter.

[0005] According to an exemplary embodiment, an LED display device is provided that addresses the technical problems of conventional AM and PM driving by achieving precise current control. Specifically, an exemplary embodiment utilizes a constant current source driver to drive the LED anode node and solves the return current metal density problem by using a pixel local transistor as a scan switch to connect the common cathode to ground.

[0006] Specifically, the device may include: a plurality of light-emitting diodes (LEDs); a constant current driver configured to be connected to the anodes of each LED; and a pixel local transistor configured to be connected to the cathodes of the LEDs. In an exemplary embodiment, the cathodes of the LEDs are interconnected and connected to ground via the pixel local transistor.

[0007] Furthermore, according to an exemplary embodiment, the LED display further includes a scan controller configured to connect to the gate of the pixel local transistor, such that the pixel local transistor acts as a scan switch. The LED display also includes a video controller configured to connect to the constant current driver and the scan controller, and to communicate with them via a predetermined protocol. In one exemplary embodiment, the pixel local transistor may be an amorphous silicon TFT, an indium gallium zinc oxide TFT, a low-temperature polycrystalline silicon TFT, and / or a silicon-based microintegrated circuit. Each LED may be a miniature light-emitting diode implemented using COG technology. The predetermined protocol may include a low-level protocol (LLP).

[0008] According to another exemplary embodiment, an LED display is provided. The LED display may include: a plurality of pixels; one or more constant current drivers configured to be connected to the pixels; and a scan controller configured to be connected to the pixels. The constant current drivers and the scan controller having a plurality of output terminals are configured to be connected to the pixels in a predetermined arrangement comprising three segments: a first segment, a second segment, and a third segment. In the first segment, the constant current driver is configured to be connected to the pixel through a second conductive layer, and the scan controller is configured to be connected to the pixel through a first conductive layer. In the second segment, the constant current driver is configured to be connected to the pixel through a third conductive layer, and the scan controller is configured to be connected to the pixel through the first conductive layer. In the third segment, the constant current driver is configured to be connected to the pixel through a fourth conductive layer, and the scan controller is configured to be connected to the pixel through the first conductive layer.

[0009] Furthermore, in one exemplary embodiment, in the first section, the scan controller may be configured to connect to the pixel through the first conductive layer and further through a first via. In the second section, the scan controller may be configured to connect to the pixel through the first conductive layer and further through a first via, a second conductive layer, and a second via. In the third section, the scan controller may be configured to connect to the pixel through the first conductive layer and further through a first via, a second conductive layer, a second via, a third conductive layer, and a third via.

[0010] Furthermore, in one exemplary embodiment, the LED display further includes a pixel local transistor configured to be disposed between the first conductive layer and the LED. The scan controller is configured to be connected to the gate of the pixel local transistor, such that the pixel local transistor acts as a scan switch. The pixel local transistor may be an amorphous silicon TFT, an indium gallium zinc oxide TFT, a low-temperature polycrystalline silicon TFT, and / or a silicon-based micro-IC. Each LED may be a miniature light-emitting diode implemented using COG technology. The LED display may also include a video controller configured to be connected to the constant current driver and the scan controller and to communicate with them via a predetermined protocol. The predetermined protocol may include the LED Link Protocol (LLP) and any LED controller system. Attached Figure Description

[0011] The advantages of the present invention will become clear in the following detailed description of exemplary embodiments, which should be considered in conjunction with the accompanying drawings.

[0012] Figure 1A This is a schematic diagram depicting an edge view (assuming it is a side view in the horizontal display direction) illustrating the arrangement of conductive layers in an exemplary embodiment.

[0013] Figure 1B This is a schematic diagram depicting a front view of the wire connection arrangement in an exemplary embodiment.

[0014] Figure 1C It is a schematic diagram depicting a front view of the wire connection arrangement in an exemplary embodiment, in which a scan controller is disposed in each segment and a constant current driver is disposed in each vertical pixel line.

[0015] Figure 1D This is a schematic diagram depicting a module in an exemplary embodiment where the vertical and horizontal wire connections are arranged to have a predetermined number of pixels.

[0016] Figure 2A This is a schematic diagram depicting the arrangement of the LED common cathode and pixel local transistors according to an exemplary embodiment.

[0017] Figure 2B This is a schematic diagram depicting a module in an exemplary embodiment where the common cathode arrangement of pixel local transistors is configured for a predetermined number of pixels. Detailed Implementation

[0018] Various aspects of this utility model are disclosed in the following description of specific embodiments and related drawings. Alternative embodiments may be designed without departing from the spirit or scope of this utility model. Furthermore, to avoid obscuring the relevant details of this utility model, well-known elements in the exemplary embodiments will not be described in detail or will be omitted. For ease of understanding, several terms used herein will be explained below.

[0019] In this document, the term "exemplary" means "used as an example, instance, or illustration." The embodiments described are merely illustrative and not limiting. It should be understood that the embodiments described herein are not necessarily superior to or more advantageous than other embodiments. The terms "embodiment of the present invention," "embodiment," or "utility invention" do not require that all embodiments of the present invention include the features, advantages, or modes of operation discussed.

[0020] Furthermore, many embodiments are described based on sequences of actions performed, for example, by computing device elements. It should be understood that the operations described herein can be performed by special-purpose circuitry (such as an application-specific integrated circuit (ASIC)), program instructions executed by one or more processors, or a combination of both. Moreover, these sequences of operations can be fully embodied in any form of computer-readable storage medium storing a corresponding set of computer instructions that, when executed, will cause the associated processor to perform the functions described herein. Therefore, aspects of this invention can be embodied in various forms, all of which are constructed within the scope of the claimed subject matter. Furthermore, for the embodiments described herein, their corresponding forms can be described, for example, as "logic circuitry configured to perform the actions."

[0021] Various exemplary implementations of a micro-LED display are disclosed based on exemplary embodiments and with general reference to the accompanying drawings. In exemplary embodiments, the technical problems of the prior art are overcome by using a constant current source driver to drive the LED anode node, enabling precise current control. Furthermore, exemplary embodiments address the return current metal density problem by using a pixel local transistor as a scan switch to connect the common cathode to ground. Simultaneously, in exemplary embodiments, high-resolution grayscale can be achieved using PWM. Since PWM may require high-frequency constant current control, a constant current source channel (CCSCH) can be used as the common cathode PWM control current source.

[0022] For reference Figure 1A and Figure 1B , Figure 1A and Figure 1BThe arrangement of wire connections is described, which can be exemplarily divided into three sections (126, 127, and 128). In an exemplary embodiment, four conductive layers (113, 115, 117, and 119) and three via layers (121, 123, and 124) may be provided. In an exemplary embodiment, the conductive layers (113, 115, 117, and 119) may include any type of metal or conductive layer. In the first section 126, the second conductive layer 115 may be a vertical wire, which is connected to the first conductive layer 113 (horizontal wire) through the first via 121, and then connected to the LED 105. In the second section 127, the third conductive layer 117 may be used as a vertical wire, and is connected to the first conductive layer 113 through the second via 123, the second conductive layer 115, and the first via 121, and then connected to the LED 105. In the third section 128, the fourth conductive layer 119 can be used as a vertical conductor and is connected to the first conductive layer 113 via the third through-hole 124, the third conductive layer 117, the third through-hole 124, the second conductive layer 115, and the first through-hole 121, and then connected to the LED 105. According to an exemplary embodiment, in the horizontal direction (scanning direction), the space of the first conductive layer 113 can be used for a pixel local transistor (scanning switch transistor) and its connection. Furthermore, in an exemplary embodiment, the pixel local transistor can be disposed between the first conductive layer 113 and the LED. Figure 1B In the diagram, the conductive layers (113, 115, 117, and 119) are shown as arrows to indicate the driving and / or scanning directions.

[0023] For reference Figure 1C and Figure 1D According to an exemplary embodiment, the scan controller 103 may be disposed in each segment, and the constant current driver 102 may be a plurality of constant current drivers arranged with a plurality of vertical pixel lines. Furthermore, in an exemplary embodiment, the arrangement of the aforementioned vertical and horizontal wire connections may be configured as modules having a predetermined number of pixels, each module being disposed in each division of the entire screen. For example, Figure 1D A display with modules I through IV is shown.

[0024] For reference Figure 2A , Figure 2A The cathode node of LED 105 is depicted connected to pixel local transistor 107. According to an exemplary embodiment, the cathode nodes of LED 105 can be connected to each other to form a common cathode and can be further connected to pixel local transistor 107. The current flowing through pixel local transistor 107 can be the total RGB current of LED 105, and the pixel local transistor 107 connected to LED 105 can be used as a scan switch. Therefore, in an exemplary embodiment, this scan switch can be shared with adjacent pixels on the same scan line.

[0025] According to an exemplary embodiment, a large conductive layer may exist beneath the LED 105 and the pixel local transistor 107, which serves as a common ground (GND). In an exemplary embodiment, the pixel local transistor 107 can conduct current from the LED 105 to the common ground layer. Furthermore, in an exemplary embodiment, the pixel local transistor 107 may be a TFT circuit, such as one or more transistors and / or a silicon-based micro-IC. According to an exemplary embodiment, although the relatively large total pixel current can be discharged to the large conductive layer ground through the individual pixel local transistors 107, only narrow signal lines are needed to control the gate of the pixel local transistor 107. Therefore, in an exemplary embodiment, the use of wide metal to carry the large return current of each scan switch can be avoided, and only narrow lines are needed to control the switch.

[0026] Still refer to Figure 2A , Figure 2A The pixel local transistor 107 is also depicted as being shared by adjacent pixels. According to an exemplary embodiment, the pixel local transistor 107 may be shared by adjacent LEDs 105, and therefore the pixel local transistor 107 may be shared by multiple pixels located in... Figure 2A The same scan line is shown. Therefore, a wide scan metal line for the return current may not be necessary. According to an exemplary embodiment, the number of PWM pulses in each scan cycle can be equal to the number of scans, so the frequency of the scan switch can be lower than the frequency of the CCSCH. For example, in a sixteen-scan design, the CCSCH needs to switch sixteen times in each scan cycle, which requires the channel speed to be sixteen times faster than the scan switch.

[0027] For reference Figure 2B According to an exemplary embodiment, the common cathode arrangement of the pixel local transistors 107 can be configured as modules for a predetermined number of pixels, with each module disposed in each division of the entire screen. According to an exemplary embodiment, for example, the constant current driver 102 can drive 320x180 pixels; therefore, a full HD display may require eighteen constant current drivers 102 at the top and another eighteen constant current drivers 102 at the bottom, but is not limited thereto. Additionally, in an exemplary embodiment, the scan controller 103 can control 180 scan lines; therefore, a full HD screen may require six scan controllers on the left and six scan controllers on the right, but the exemplary embodiment is not limited thereto.

[0028] According to an exemplary embodiment, the pixel local transistor 107 may be made of different types of thin-film transistor (TFT) devices, such as amorphous silicon TFT, indium gallium zinc oxide TFT, low-temperature polycrystalline silicon TFT, silicon-based micro-IC, but is not limited thereto. In an exemplary embodiment, the video controller 104 may be a video and timing control device, but its function is not limited thereto. According to an exemplary embodiment, the video controller 104 may receive video input signals from a video source, such as via a high-definition multimedia interface (HDMI), which may include a clock signal (CLK), video data, an enable signal, and / or a synchronization signal. Furthermore, in an exemplary embodiment, the function of the video controller 104 may be defined as follows. First, output video data and control data are transmitted to the constant current driver 102 via a predetermined protocol (e.g., low-level protocol (LLP)), and feedback data is received from the constant current driver 102. Then, the video controller 104 outputs a scan control signal to the scan controller 103. Still referring to Figure 2B In some cases, only one video controller can be used for the entire screen. However, in another exemplary embodiment, multiple video controllers may also be used.

[0029] According to an exemplary embodiment, the constant current driver 102 may include, but is not limited to, the following functions: First, it receives video and control data from the video controller 104 and transmits feedback data to the video controller 104. According to an exemplary embodiment, a frame buffer and / or a line buffer (not shown) may buffer the video data, and video processing may include gamma correction circuitry and calibration circuitry. Furthermore, in an exemplary embodiment, PWM pulses may be calculated and generated, and constant current pulses may be provided to the LED 105 based on these PWM pulses.

[0030] Additionally, in an exemplary embodiment, the scan controller 103 may include, but is not limited to, the following functions: First, the scan controller 103 receives and decodes a scan control signal from the video controller 104, and outputs a scan line voltage signal to the pixel local transistor 107. This scan line voltage signal is then transmitted to the next pixel local transistor 107.

[0031] The foregoing description and accompanying drawings illustrate the principles, preferred embodiments, and operating modes of this invention. However, this invention should not be construed as limited to the specific embodiments discussed above. Those skilled in the art will understand additional variations to the embodiments discussed above (e.g., features associated with certain configurations of this invention may be replaced as needed with any other configuration of this invention).

[0032] Therefore, the above embodiments should be considered illustrative rather than restrictive. Accordingly, it should be understood that those skilled in the art can make modifications to the embodiments without departing from the scope of the present invention as defined by the following claims.

Claims

1. A light-emitting diode (LED) display, characterized in that, Include: Multiple LEDs; At least one constant current driver configured to be connected to at least one anode of each LED; as well as At least one pixel local transistor configured to connect to the LED cathode, The cathodes of the LEDs are connected to each other and are connected to ground via the pixel local transistors.

2. The LED display as described in claim 1, characterized in that, It includes at least one scan controller connected to at least one gate of the pixel local transistor, such that the pixel local transistor acts as a scan switch during operation.

3. The LED display as described in claim 1, characterized in that, It includes at least one video controller connected to the constant current driver and the scan controller, and communicates with each other according to a predetermined protocol.

4. The LED display as described in claim 1, characterized in that, in, The pixel local transistor is at least one of the following: amorphous silicon TFT, indium gallium zinc oxide TFT, low-temperature polycrystalline silicon TFT, and silicon-based micro IC.

5. The LED display as described in claim 1, characterized in that, in, Each of the LEDs is a miniature light-emitting diode implemented using COG technology.

6. The LED display as described in claim 3, characterized in that, in, The pre-defined agreement includes LLP.

7. An LED display, characterized in that, include: Multiple pixels; At least one constant current driver is configured to be connected to the pixel; as well as At least one scan controller, configured to be connected to the pixel, in The constant current driver and the scan controller are connected to the pixel through a predetermined configuration including a first segment, a second segment, and a third segment. In the first segment, the constant current driver is connected to the pixel through a second conductive layer, and the scan controller is connected to the pixel through a first conductive layer. In the second section, the constant current driver is connected to the pixel through a third conductive layer, and the scan controller is connected to the pixel through a first conductive layer. In the third section, the constant current driver is connected to the pixel through a fourth conductive layer, and the scan controller is connected to the pixel through the first conductive layer.

8. The LED display as described in claim 7, characterized in that, in In the first segment, the scan controller is connected to the pixel through the first conductive layer and via a first via. In the second section, the scan controller is connected to the pixel through the first conductive layer, and via the first via, the second conductive layer, and the second via. In the third segment, the scan controller is connected to the pixel through the first conductive layer and via the first via, the second conductive layer, the second via, the third conductive layer, and the third via.

9. The LED display as described in claim 7, characterized in that, It includes at least one pixel local transistor disposed between the first conductive layer and the LED.

10. The LED display as described in claim 9, characterized in that, in, The scan controller is connected to at least one gate of the pixel local transistor, such that the pixel local transistor acts as a scan switch during operation.

11. The LED display as described in claim 9, characterized in that, in, The pixel local transistor is at least one of the following: amorphous silicon TFT, indium gallium zinc oxide TFT, low-temperature polycrystalline silicon TFT, and silicon-based micro IC.

12. The LED display as claimed in claim 7, characterized in that, in, Each pixel is a miniature light-emitting diode implemented using COG.

13. The LED display as described in claim 7, characterized in that, It includes at least one video controller configured to connect to the constant current driver and the scan controller, and to communicate with each other via a predetermined protocol.

14. The LED display as described in claim 13, characterized in that, in, The pre-defined agreement includes LLP.

15. The LED display as claimed in claim 7, characterized in that, in, The first conductive layer, the second conductive layer, the third conductive layer, and the fourth conductive layer are conductive paths selected from wires, inkjet-printed conductive tape, or metal strips.

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