Full-color LED device control method

Abstract

The invention discloses a full-color LED device control method, a device is composed of a plurality of pixel points, and each pixel point is composed of a single chip without a color conversion material. The single chip emits blue light under high current density, emits green light under medium current density, and emits red light under low current density. The current is adjusted through a pulse width modulation (PWM) method to achieve different colors, the duty ratio is adjusted to achieve different brightness, and finally single-chip full-color display of each pixel point is achieved. Full-color light emitting is achieved on a single chip without color conversion materials, compared with multiple times of transfer of LED chips with different colors, only one time of transfer is needed, the problems of process complexity and high cost of multiple times of transfer are solved, displayed space pixels are improved, and integration of Micro LED chips can be achieved in batches. On the other hand, the LED device is stable in light emitting performance and high in reliability, and the problems of instability, toxicity and the like of color conversion materials do not exist.

Description

technical field [0001] The invention relates to the field of semiconductor materials, in particular to a method for controlling a full-color LED device. Background technique [0002] As a unique display, Micro LED display technology can be applied to smart glasses, smart phones, VR / AR, head-mounted displays, head-up displays, etc., and has received extensive attention in the industry. Compared with traditional LCD and OLED, MicroLED has the advantages of self-illumination, low power consumption, high resolution, high brightness and long service life. and breaking point. [0003] At present, there are mainly three types of Micro LED display technologies. The first is the most widely studied chip mass transfer technology. First, the chips of the first color are transferred to the integrated substrate, and then the chips of the second color are transferred to the integrated substrate. On the substrate, the last color is transferred to the same substrate, and the three colors ...

AI Technical Summary

Problems solved by technology

[0003] At present, there are three main types of Micro LED display technologies. The first is the most extensively researched chip mass transfer technology. First, the chip of the first color is transferred to the integrated substrate, and then the chip of the second color is transferred to the integrated substrate. On the substrate, finally transfer the last color to the same substrate, and the three colors are mixed to achieve full-color display. In this method, the second and third chip transfer processes are easy to affect the transferred chips, and multiple transfers are easy. Damage to integrated substrates and various components, mass production has not yet been achieved

The second method is to transfer short-wavelength monochromatic LED chips to the integrated substrate in batches at one time, and then coat red and green quantum dot conversion materials on each chip, and use high-energy photons radiated by short-wavelength monochromatic LED chips to excite red and green. Quantum dot conversion materials realize full-color display. However, in this scheme, quantum dot conversion materials will become unstable under high temperature, high humidity or other conditions, and some quantum dot conversion materials are also toxic to a certain extent, which is not conducive to display. It will also bring certain harm to human body and environment

The third method is also to transfer each chip to the integrated substrate in batches at one time, but it can only display monochrome pixels and cannot achieve full-color display.

However, their method of realizing single-chip full-color requires different chips in space. For example, the first chip is modulated to red light, the second chip is modulated to yellow light, and the third chip is modulated to blue light. 3 chips are completed, so the pixel spatial resolution is lower, and the packaging volume is larger, which is not conducive to Micro-LED integration

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