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

Abstract

The invention discloses a MicroLED micro-display chip with multiple interfaces and over-temperature control, and relates to the technical field of display chips, which comprises the following steps: step 1, the MicroLED micro-display chip comprises a CMOS (Complementary Metal-Oxide-Semiconductor Transistor) driving circuit and provides multiple interfaces; 2, adopting a sapphire or silicon-based substrate as a light-emitting layer of the MicroLED chip, wherein a GaN layer is grown on the light-emitting layer; step 3, enabling the MicroLED driver to be a silicon-based CMOS (Complementary Metal Oxide Semiconductor) driving circuit; 4, the CMOS driving circuit can provide current input; and step 5, the MicroLED display chip comprises a temperature sensor. And the driving current of a single pixel is set to be 150 uA to 2.35 mA, and the standard current is 1.95 mA, so that the brightness of the MicroLED is remarkably improved. In order to prevent the driving integrated circuit from being damaged, a temperature monitoring circuit is designed. The temperature of the circuit can be continuously checked through the over-temperature detection function, whether the temperature reaches a specific level or not is checked, and if the temperature is higher than the specific level, the driving IC closes the corresponding half area, so that all sections of the half area enter a RESET state. A pixel and power supply diagnosis function is added, and the effect of a display picture is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of display chips, and in particular to a MicroLED micro display chip with multiple interfaces and over-temperature control. Background Art

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

[0003] 1. High brightness and efficiency: MicroLED displays are able to provide ultra-high brightness and long life, which is very important for display devices that are readable in sunlight. The high brightness and efficiency of MicroLED make it perform well in HDR displays.

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

[0005] 3. Low power consumption: MicroLED displays have relatively low power consumption, which is a significant advantage for mobile devices as other devices rely heavily on battery power.

[0006] 4. High contrast and color performance: MicroLED displays have high contrast and wide color gamut, which can provide richer colors and deeper blacks, which are critical to improving image quality and user experience.

[0007] 5. Fast response time: The response time of MicroLED display is faster than that of LCD and OLED, which is very helpful in reducing motion blur and improving dynamic image quality.

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

[0009] 7. Long life cycle: MicroLED displays have a longer lifespan than OLED displays, 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 expanded to large displays while maintaining high resolution and image quality, which is very beneficial for large-size applications such as TVs and public displays.

[0011] 9. Environmental adaptability: MicroLED displays are able to operate in a variety of 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 production and reducing subsequent repair processes. CMOS inverters are used to directly drive MicroLEDs. By comparing the simulation results of NMOS, PMOS and CMOS inverters driving MicroLEDs, it can be determined that CMOS is the best driving circuit.

[0013] As MicroLED technology matures, its application areas are becoming clearer. In actual application scenarios, such as portable projectors, automotive pixelated projection headlights, AR smart glasses and other products, in order to provide a better user experience, the brightness requirements for MicroLED display chips are getting higher and higher, and clear requirements are also put forward for the functions of CMOS drive circuits.

[0014] However, the current CMOS driver circuit design can only provide the voltage and current for MicroLED to light up its diode. As smart glasses and other electronic products with increasingly higher energy consumption and computing power requirements, including but not limited to automotive pixelated projection headlights, car head-up displays, portable projectors, etc., other necessary functions such as temperature control, image quality adjustment, frame buffering, brightness correction, etc., require additional chips to achieve. The additional chips not only increase the product size, increase the system cost, and increase the system energy consumption; more importantly, they weaken the system competitive advantage of MicroLED. At the same time, the existing CMOS driver design is not conducive to direct bonding with MicroLED in terms of structure, which increases the subsequent manufacturing cost.

[0015] At this stage, the display brightness of MicroLED display chips mostly stays between hundreds of thousands of nits and millions of nits, which cannot meet the high brightness requirements of projection products, resulting in problems such as low brightness of the projection screen and poor user experience. Summary of the invention

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

[0017] Step 1: The MicroLED micro display chip contains a CMOS driving circuit and provides a variety of interfaces. In a small effective display area, the MicroLED micro display chip can reach 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 2: The light-emitting layer of the MicroLED chip uses a sapphire or silicon-based substrate, including a grown GaN layer, wherein light emission is achieved by growing the GaN layer;

[0019] Step 3: MicroLED driver is silicon-based CMOS driver circuit;

[0020] Step 4: The CMOS driving circuit can provide current input;

[0021] Step 5: The MicroLED display chip contains a temperature sensor, which is used to achieve over-temperature control.

[0022] The multiple interfaces in step 1 include SPI, I 2 C. UART, RGB8 interface.

[0023] In step 1, the MicroLED display chip realizes brightness adjustment through the CMOS driving circuit.

[0024] In the step 1, the MicroLED display chip implements Gamma correction through a CMOS driving circuit.

[0025] In the step 1, the MicroLED display chip realizes analog dimming through the CMOS driving circuit, and conduction between the CMOS driving circuit and the MicroLED circuit is realized through bonding.

[0026] In step 2, the size of the sapphire or silicon-based substrate used is 4 inches, 8 inches or 12 inches.

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

[0028] In step 4, the current input provided by the CMOS driving circuit is 0.15uA for each pixel.

[0029] In step 5, the temperature sensor is used to implement over-temperature control.

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

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

[0032] 2. To prevent damage to the driver IC, a temperature monitoring circuit is designed. The over-temperature detection function can continuously check the temperature of the circuit to see if the temperature reaches a certain level. If the temperature is higher than this level, the driver IC will shut down the corresponding half-zone and put all its sections into the RESET state.

[0033] 3. Added pixel and power diagnosis functions to ensure the effect of the display picture. When the pixel array is activated, 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. Provides a variety of control interfaces for customers to choose from: I 2 C control, UART control, SPI control.

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

[0036] 6. Gamma correction is set. The MicroLED display chip of the present invention receives pixel data and interprets it as brightness information to calculate the PWM of each LED. Since the eye is more sensitive in a low-light environment 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 through analog dimming.

[0038] 8. A frame register is set up to increase cache storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The present invention is a schematic diagram of a single pixel unit structure of a flip-chip silicon-based LED chip capable of realizing planar arrangement and 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 region; 10-2, second electrode region; 10-3, third electrode region; 11, insulating layer; 12, eutectic layer; 13, CMOS driving circuit. DETAILED DESCRIPTION

[0041] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention are provided for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

[0042] For example, see Figure 1The present invention provides a technical solution: a MicroLED micro display chip with multiple interfaces and over-temperature control, step 1: the MicroLED micro display chip includes a CMOS driving circuit 13 and provides multiple interfaces, wherein in a smaller effective display area, the MicroLED micro display chip can reach a brightness of tens of millions of nits, and the CMOS driving circuit 13 is used to realize over-temperature control, white balance adjustment, Gamma correction and dimming;

[0043] Step 2: The light-emitting layer of the MicroLED chip uses a sapphire or silicon-based substrate 03, including a grown GaN layer, wherein light emission is achieved by growing the GaN layer;

[0044] Step 3: MicroLED driving is a silicon-based CMOS driving circuit 13;

[0045] Step 4: The CMOS driving circuit 13 can provide current input;

[0046] Step 5: The MicroLED display chip contains a temperature sensor, which is used to achieve over-temperature control.

[0047] In step 1, multiple interfaces include SPI, I 2 C. UART, RGB8 interface.

[0048] In step 1, the MicroLED display chip realizes brightness adjustment through the CMOS driving circuit 13 .

[0049] In step 1, the MicroLED display chip implements Gamma correction through the CMOS driving circuit 13.

[0050] In step 1, the MicroLED display chip realizes analog dimming through the CMOS driving circuit 13, and conduction between the CMOS driving circuit 13 and the MicroLED circuit is realized through bonding.

[0051] In step 2, the size of the sapphire or silicon-based substrate 03 is 4 inches, 8 inches or 12 inches.

[0052] In step 3, the size of the silicon-based CMOS driving circuit 13 is 4 inches, 8 inches or 12 inches.

[0053] In step 4, the current input provided by the CMOS driving circuit 13 is 0.15 uA for each pixel.

[0054] In step 5, the temperature sensor is used to achieve over-temperature control, white balance adjustment, gamma correction and dimming.

[0055] When used, the present invention realizes a MicroLED micro display chip with multiple interfaces and over-temperature control, such as Figure 1As shown, it is a single pixel unit structure diagram of a flip-chip silicon-based LED chip, which specifically includes 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, and a CMOS driving circuit 13. 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 driver integrated circuit, the MicroLED chip is designed with a temperature monitoring circuit. The over-temperature detection function can continuously check the temperature of the circuit to see if the temperature reaches a specific level. If the temperature is higher than this level, the CMOS driving circuit will turn off the corresponding half area, so that all its sections enter the RESET state.

[0056] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without creative work should fall within the scope of protection of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention are implemented according to the conventional means in the field unless otherwise specified and limited.

Claims

1. A MicroLED micro display chip with multiple interfaces and over-temperature control, characterized in that: The following steps are involved: Step 1: The MicroLED micro display chip includes a CMOS driving circuit (13) and provides multiple interfaces; Step 2: The light-emitting layer of the MicroLED chip uses a sapphire or silicon-based substrate (03), including growing a GaN layer; Step 3: MicroLED driving is a silicon-based CMOS driving circuit (13); Step 4: The CMOS driving circuit (13) can provide current input; Step 5: The MicroLED display chip contains a temperature sensor.

2. The MicroLED micro display chip with multiple interfaces and over-temperature control according to claim 1, characterized in that: In step 1, the multiple interfaces include SPI, I 2 C. UART, RGB8 interface.

3. The MicroLED micro display chip with multiple interfaces and over-temperature control according to claim 1, characterized in that: In the step 1, the MicroLED display chip realizes brightness adjustment through the CMOS driving circuit (13).

4. The MicroLED micro display chip with multiple interfaces and over-temperature control according to claim 1, characterized in that: In the step 1, the MicroLED display chip implements Gamma correction through the CMOS driving circuit (13).

5. The MicroLED micro display chip with multiple interfaces and over-temperature control according to claim 1, characterized in that: In the step 1, the MicroLED display chip implements analog dimming through the CMOS driving circuit (13), and conduction between the CMOS driving circuit (13) and the MicroLED circuit is achieved through bonding.

6. The MicroLED micro display chip with multiple interfaces and over-temperature control according to claim 1, characterized in that: In the step 2, the size of the sapphire or silicon-based substrate (03) is 4 inches, 8 inches or 12 inches.

7. The MicroLED micro display chip with multiple interfaces and over-temperature control according to claim 1, characterized in that: In the step 3, the size of the silicon-based CMOS driving circuit (13) is 4 inches, 8 inches or 12 inches.

8. The MicroLED micro display chip with multiple interfaces and over-temperature control according to claim 1, characterized in that: In step 4, the current input provided by the CMOS driving circuit (13) is 0.15uA for each pixel.

9. The MicroLED micro display chip with multiple interfaces and over-temperature control according to claim 1, characterized in that: In step 5, the temperature sensor is used to implement over-temperature control.

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