Micro LED micro display chip with multiple interfaces and over-temperature control

Abstract

This invention discloses a MicroLED microdisplay chip with integrated multiple interfaces and over-temperature control, relating to the field of display chip technology. The chip includes the following steps: Step 1: The MicroLED microdisplay chip includes a CMOS driving circuit and provides multiple interfaces; Step 2: The light-emitting layer of the MicroLED chip uses a sapphire or silicon substrate and includes a grown GaN layer; Step 3: The MicroLED driver is a silicon-based CMOS driving circuit; Step 4: The CMOS driving circuit can provide current input; Step 5: The MicroLED display chip includes a temperature sensor. The driving current for a single pixel is set to 150uA. ～ With a standard current of 1.95mA and a current of 2.35mA, the brightness of MicroLEDs is significantly improved. A temperature monitoring circuit was designed to prevent damage to the driver IC. The over-temperature detection function continuously monitors the circuit temperature to see if it reaches a specific level. If the temperature exceeds this level, the driver IC will shut down the corresponding half-region, putting all its segments into a RESET state. Pixel and power supply diagnostic functions have been added to ensure the quality of the displayed image.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display chip, and particularly relates to a MicroLED micro display chip with multiple interfaces and over-temperature control. BACKGROUND

[0002] MicroLED technology is a new type of display technology, which is praised as the next generation of display technology due to its excellent performance. It has the following characteristics:

[0003] 1. High brightness and efficiency: MicroLED display screens can provide ultra-high brightness and long life, which is very important for display devices that can be read under sunlight. The high brightness and efficiency of MicroLED make it perform well in HDR display.

[0004] 2. Small size and high pixel density: MicroLED micro display chip screens can maintain high pixels and high PPI on screen areas with a diagonal less than 1 inch, which is very important for near-eye display applications such as virtual reality and augmented reality.

[0005] 3. Low power consumption: The power consumption of MicroLED display screens is relatively low, which is a significant advantage for mobile devices that rely heavily on battery power.

[0006] 4. High contrast and color performance: MicroLED display screens have high contrast and wide color gamut, which can provide richer colors and deeper black, which is crucial for improving image quality and user experience.

[0007] 5. Fast response time: The response time of MicroLED display screens is faster than liquid crystal display and organic light-emitting diode, which is very helpful for reducing motion blur and improving dynamic image quality.

[0008] 6. Flexibility and transparency: MicroLED technology also has the potential to achieve flexible and transparent display, which is very promising for wearable devices and new display applications.

[0009] 7. Long life cycle: The life of MicroLED display screens is longer than that of OLED display screens, which is an important advantage for display devices that need to run for a long time without replacement.

[0010] 8. Scalability: MicroLED technology can be extended to large display screens while maintaining high resolution and image quality, which is very advantageous for large-size applications such as televisions and public display screens.

[0011] 9. Environmental adaptability: MicroLED display screens can work in various environmental conditions, including high and low temperature environments, which makes them suitable for a wide range of application scenarios.

[0012] The circuit design of MicroLED driving is a complex process involving multiple key technologies. Using MOS devices to drive MicroLED can achieve independent driving of each unit, thereby improving yield and reducing subsequent repair processes. CMOS inverters are used to directly drive MicroLED. By comparing the simulation results of NMOS, PMOS and CMOS inverter driving MicroLED, it can be determined that CMOS is the best driving circuit.

[0013] With the increasing maturity of MicroLED technology, its application fields are also gradually clear. Actual application scenarios, such as portable projectors, automotive pixelated projection headlamps, AR smart glasses and other products, require higher brightness of MicroLED display chips to provide better user experience, and clear requirements for the functions of CMOS driving circuits.

[0014] However, the current CMOS driving circuit design can only provide voltage and current for MicroLED to light up its diode. For smart glasses and other electronic products with increasing energy consumption and computing power requirements, including but not limited to automotive pixelated projection headlamps, vehicle head-up displays, portable projectors and other necessary functions such as temperature control, image quality adjustment, frame buffer, brightness correction, additional chips are needed to achieve them. Additional chips not only increase product size, improve system cost and increase system energy consumption; more importantly, they weaken the competitive advantage of MicroLED systems. At the same time, the existing CMOS driving design is not conducive to direct bonding with MicroLED in structure, increasing the cost of later manufacturing.

[0015] The current MicroLED display chip has a display brightness mostly between hundreds of thousands of nits and millions of nits, which cannot meet the demand of projection products for high brightness, resulting in low projection picture brightness and poor user experience. SUMMARY

[0016] To solve the above technical problems, the present application provides a MicroLED micro display chip with multiple interfaces and over-temperature control, comprising the following steps:

[0017] Step one: The MicroLED micro display chip contains a CMOS driving circuit and provides multiple interfaces. Within a smaller effective display area, the MicroLED micro display chip can achieve a brightness of tens of millions of nits. Through the CMOS driving circuit, over-temperature control, white balance adjustment, Gamma correction and dimming are achieved.

[0018] Step two: the MicroLED chip light emitting layer adopts sapphire or silicon substrate, and contains a grown GaN layer, wherein the light emission is realized by growing the GaN layer;

[0019] Step three: the MicroLED drive is a silicon-based CMOS drive circuit;

[0020] Step four: the CMOS drive circuit can provide current input;

[0021] Step five: the MicroLED display chip contains a temperature sensor to realize over-temperature control.

[0022] The various interfaces in step one include SPI, I2C, UART, RGB8 interface.

[0023] The MicroLED display chip in step one realizes brightness adjustment through the CMOS drive circuit.

[0024] The MicroLED display chip in step one realizes Gamma correction through the CMOS drive circuit.

[0025] The MicroLED display chip in step one realizes analog dimming through the CMOS drive circuit, and realizes the conduction of the CMOS drive circuit and the MicroLED circuit through bonding.

[0026] The size of the sapphire or silicon substrate in step two is 4 inches, 8 inches or 12 inches.

[0027] The size of the silicon-based CMOS drive circuit in step three is 4 inches, 8 inches or 12 inches.

[0028] The current input provided by the CMOS drive circuit in step four is 0.15mA per pixel.

[0029] The temperature sensor in step five is used to realize over-temperature control.

[0030] The beneficial effects of the present application are as follows:

[0031] 1. The driving current of a single pixel is set to 150uA-2.35mA, and the standard current is 1.95mA, which significantly improves the brightness of the MicroLED.

[0032] 2. To prevent damage to the drive integrated circuit, a temperature monitoring circuit is designed. Through the over-temperature detection function, the temperature of the circuit can be continuously checked to see if the temperature reaches a certain level. If the temperature is higher than the level, the drive IC will close the corresponding half area, so that all paragraphs enter the RESET state.

[0033] 3. Added pixel and power supply diagnosis function to ensure the effect of the display screen. When the pixel array is in the active state, the pixel can be automatically diagnosed by controlling the Vf voltage of the pixel and the power supply of the paragraph. The state machine will loop through all the pixels in the array to check each pixel.

[0034] 4. A variety of control interfaces are provided for customers to choose from: I2C control, UART control, SPI control.

[0035] 5. Added brightness calibration function, which can calibrate each pixel point to ensure uniform light output.

[0036] 6. Gamma correction is set. The MicroLED display chip of the application receives pixel data and interprets it as brightness information to calculate the PWM of each LED. Because the sensitivity of the eye is higher in low light environments, and vice versa, a gamma correction table is used to adjust the light output to achieve the best display effect.

[0037] 7. Improve PWM resolution by analog dimming.

[0038] 8. Frame registers are set to improve cache storage. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 is a single pixel unit structure schematic diagram of the flip-chip LED chip of the application which can realize planar arrangement full-color display.

[0040] In the figure: 01, filter layer; 02, protective layer; 03, substrate; 04, light blocking layer; 05, color conversion material; 06, first semiconductor layer; 07, light emitting layer; 08, second semiconductor layer; 09, transparent conductive layer; 10-1, first electrode area; 10-2, second electrode area; 10-3, third electrode area; 11, insulating layer; 12, eutectic layer; 13, CMOS driving circuit. DETAILED DESCRIPTION

[0041] The application will be further described in detail below in conjunction with the drawings and specific embodiments. The embodiments of the application are given for the purpose of example and description, and are not exhaustive or limit the application to the disclosed form. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are chosen and described to better illustrate the principles and practical application of the application, and to enable those of ordinary skill in the art to understand the application so as to design various embodiments with various modifications for specific purposes.

[0042] Example one, please refer to Figure 1The application provides a technical scheme: a MicroLED micro display chip with multiple interfaces and over-temperature control, step one: the MicroLED micro display chip contains a CMOS driving circuit 13 and provides multiple interfaces, wherein the MicroLED micro display chip can reach a brightness of ten million nits in a smaller effective display area, and over-temperature control, white balance adjustment, Gamma correction and dimming are realized through the CMOS driving circuit 13;

[0043] Step two: the MicroLED chip light-emitting layer adopts a sapphire or silicon substrate 03 and contains a grown GaN layer, wherein light emission is realized through the grown GaN layer;

[0044] Step three: the MicroLED driving is a silicon-based CMOS driving circuit 13.

[0045] Step four: the CMOS driving circuit 13 can provide current input.

[0046] Step five: the MicroLED display chip contains a temperature sensor and is used to realize over-temperature control.

[0047] The multiple interfaces in step one include SPI, I2C, UART, RGB8 interface.

[0048] The MicroLED display chip in step one realizes brightness adjustment through the CMOS driving circuit 13.

[0049] The MicroLED display chip in step one realizes Gamma correction through the CMOS driving circuit 13.

[0050] The MicroLED display chip in step one realizes analog dimming through the CMOS driving circuit 13, and the conduction of the CMOS driving circuit 13 and the MicroLED circuit is realized through bonding.

[0051] The sapphire or silicon substrate 03 in step two adopts a size of 4 inches, 8 inches or 12 inches.

[0052] The silicon-based CMOS driving circuit 13 in step three adopts a size of 4 inches, 8 inches or 12 inches.

[0053] The current input provided by the CMOS driving circuit 13 in step four is 0.15 mA per pixel.

[0054] The temperature sensor in step five is used to realize over-temperature control, white balance adjustment, Gamma correction and dimming.

[0055] In use, the application realizes a MicroLED micro display chip with multiple interfaces and over-temperature control, like Figure 1As shown, it is a single pixel unit structure diagram of the flip silicon-based LED chip, specifically including a filter layer 01, a protective layer 02, a substrate 03, a light blocking layer 04, a color conversion material 05, a first semiconductor layer 06, a light emitting layer 07, a second semiconductor layer 08, a transparent conductive layer 09, a first electrode area 10-1, a second electrode area 10-2, a third electrode area 10-3, an insulating layer 11, a eutectic layer 12, a CMOS driving circuit 13, wherein the high-brightness MicroLED micro display chip can realize over-temperature control, white balance adjustment, Gamma correction and dimming through the CMOS driving circuit 13, at the same time, the MicroLED display chip receives pixel data and interprets it as brightness information to calculate the PWM of each LED, in order to prevent damage to the driving integrated circuit, the MicroLED chip is designed with a temperature monitoring circuit, which can continuously check the temperature of the circuit through the over-temperature detection function, and check whether the temperature reaches a certain level. If the temperature is higher than the level, the CMOS driving circuit will close the corresponding half area, so that all paragraphs of it enter the RESET state.

[0056] Obviously, the embodiments described are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art and related fields without creative labor should belong to the protection scope of the present application. The structures, devices and operation methods not specifically described and explained in the present application are implemented according to the conventional means in the art, unless specifically described and limited.

Claims

1. A MicroLED microdisplay chip with integrated multiple interfaces and over-temperature control, characterized in that: The MicroLED microdisplay chip includes a CMOS driving circuit (13) and provides a variety of interfaces; The light-emitting layer of the MicroLED microdisplay chip uses a sapphire or silicon substrate (03) and includes a grown GaN layer; MicroLED driver is a silicon-based CMOS driver circuit (13). The CMOS driver circuit (13) can provide current input; The MicroLED microdisplay chip contains a temperature sensor; The various interfaces include SPI, I²C, UART, and RGB8 interfaces; The MicroLED microdisplay chip achieves analog dimming through the CMOS driving circuit (13), and the CMOS driving circuit (13) and the MicroLED circuit are connected through bonding; The temperature sensor is used to implement over-temperature control. If the temperature is higher than the level, the CMOS driving circuit will shut down the corresponding half-region.

2. The MicroLED microdisplay chip with integrated multi-interface and over-temperature control according to claim 1, characterized in that: The MicroLED microdisplay chip achieves brightness adjustment through a CMOS driving circuit (13).

3. The MicroLED microdisplay chip with integrated multiple interfaces and over-temperature control according to claim 1, characterized in that: The MicroLED microdisplay chip achieves Gamma correction through a CMOS driving circuit (13).

4. The MicroLED microdisplay chip with integrated multi-interface and over-temperature control according to claim 1, characterized in that: The sapphire or silicon substrate (03) is 4 inches, 8 inches or 12 inches in size.

5. The MicroLED microdisplay chip with integrated multi-interface and over-temperature control according to claim 1, characterized in that: The silicon-based CMOS driving circuit (13) is 4 inches, 8 inches or 12 inches in size.

6. The MicroLED microdisplay chip with integrated multi-interface and over-temperature control according to claim 1, characterized in that: The CMOS driving circuit (13) provides a current input of 0.15mA per pixel.

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