CN112712772A

CN112712772A - LED display adjusting circuit

Info

Publication number: CN112712772A
Application number: CN202011635905.8A
Authority: CN
Inventors: 刘召军; 吕志坚; 何先顺; 陈锐; 黄利将; 盘福波; 叶嘉豪
Original assignee: Shenzhen Stan Technology Co Ltd
Current assignee: Shenzhen Stan Technology Co Ltd
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2021-04-27

Abstract

The embodiment of the invention discloses an LED display adjusting circuit, which comprises: the device comprises a driving module, a photoelectric conversion module and a data processing module; the driving module is connected with the LED chip; the photoelectric conversion module is connected with the LED chip and is connected with the driving module through the data processing module; the photoelectric conversion module is used for converting the optical signal of the LED chip into an electric signal; the data processing module is used for processing the electric signal to generate a regulating signal; the driving module is used for adjusting the luminous intensity of the LED chip according to the adjusting signal. The embodiment of the invention realizes the adjustment of the light-emitting brightness of the LED chips, so that the light-emitting brightness of each LED chip in the LED array is the same, and the light-emitting uniformity of the Micro-LED display device is improved.

Description

LED display adjusting circuit

Technical Field

The embodiment of the invention relates to the technical field of semiconductors, in particular to an LED display adjusting circuit.

Background

Micro Light-Emitting diodes (Micro-LEDs) have self-luminous display characteristics, are all-solid-state LEDs, have long life, high brightness, low power consumption, small size, and ultra-high resolution, can be applied to extreme environments such as high temperature or radiation, and are planned as a new generation of display technology by more and more manufacturers.

The Micro-LED display device usually drives the Micro-LED chip array to emit light through a driving chip, namely after the driving chip is electrified, a driving signal is sent to the Micro-LED chip array to drive the Micro-LED chip to emit light as required. However, the light-emitting parameters required by each LED chip are not completely the same, which causes the uneven light-emitting brightness of the LED chips when the LED chip array emits light, and affects the quality of the Micro-LED display device.

Disclosure of Invention

In view of this, the embodiment of the present invention provides an LED display adjusting circuit to adjust the light emitting brightness of an LED chip and improve the light emitting uniformity of a Micro-LED display device.

The embodiment of the invention provides an LED display adjusting circuit, which comprises: the device comprises a driving module, a photoelectric conversion module and a data processing module; the driving module is connected with the LED chip; the photoelectric conversion module is connected with the LED chip and is connected with the driving module through the data processing module;

the photoelectric conversion module is used for converting the optical signal of the LED chip into an electric signal;

the data processing module is used for processing the electric signal to generate a regulating signal;

the driving module is used for adjusting the luminous intensity of the LED chip according to the adjusting signal.

Furthermore, the driving module is further configured to drive the LED chip to emit light according to a driving signal, and the driving module includes a signal receiving circuit, a signal holding circuit and an adjusting circuit, where the signal receiving circuit is connected to the signal holding circuit, the signal holding circuit is connected to the adjusting circuit, and the adjusting circuit is connected to the LED chip.

Furthermore, the signal receiving circuit comprises a first NMOS transistor and a second NMOS transistor, a gate of the first NMOS transistor is connected to a gate of the second NMOS transistor and is configured to receive a row driving signal, a drain of the first NMOS transistor is configured to receive a first column driving signal, and a drain of the second NMOS transistor is configured to receive a second column driving signal.

Further, the first column driving signal and the second column driving signal are opposite signals.

Further, the signal holding circuit comprises a first PMOS tube, a second PMOS tube, a third NMOS tube and a fourth NMOS tube;

the grid electrode of the first PMOS tube, the grid electrode of the third NMOS tube, the drain electrode of the second PMOS tube and the drain electrode of the fourth NMOS tube are connected;

the grid electrode of the second PMOS tube, the grid electrode of the fourth NMOS tube, the drain electrode of the first PMOS tube and the drain electrode of the third NMOS tube are connected;

the grid electrode of the third NMOS tube is connected with the source electrode of the first NMOS tube, and the grid electrode of the fourth NMOS tube is connected with the source electrode of the second NMOS tube;

the drain electrode of the first PMOS tube is connected with the drain electrode of the third NMOS tube, and the drain electrode of the second PMOS tube is connected with the drain electrode of the fourth NMOS tube;

the source electrode of the first PMOS tube and the source electrode of the second PMOS tube are both connected with the anode of the working power supply;

and the source electrode of the third NMOS tube and the source electrode of the fourth NMOS tube are both connected with the negative electrode of the working power supply.

Furthermore, the adjusting circuit comprises a third PMOS tube and a fourth PMOS tube, the grid electrode of the third PMOS tube is used for receiving adjusting signals, the source electrode of the third PMOS tube is connected with the anode of the working power supply, the drain electrode of the third PMOS tube is connected with the source electrode of the fourth PMOS tube, the grid electrode of the fourth PMOS tube is connected with the grid electrode of the third NMOS tube, and the drain electrode of the fourth PMOS tube is connected with the LED chip.

Further, the photoelectric conversion module comprises a control switch and a photosensitive diode, the photosensitive diode is used for converting the light signal of the LED chip into an electrical signal, and the control switch is used for transmitting the electrical signal to the data processing module according to a control signal.

Further, the control switch is a fifth NMOS transistor, a gate of the fifth NMOS transistor is used for receiving and controlling the control signal, a source of the fifth NMOS transistor is connected to the photodiode, and a drain of the fifth NMOS transistor is connected to the gate of the second NMOS transistor.

Further, the anode of the photodiode is connected to the cathode of the LED chip, and the cathode of the photodiode is connected to the source of the fifth NMOS transistor.

Further, the data processing module is a comparator, and the comparator compares the electric signal with a reference signal to generate an adjustment signal.

The LED display adjusting circuit provided by the embodiment of the invention realizes the adjustment of the light-emitting brightness of the LED chips through the driving module, the photoelectric conversion module and the data processing module, so that the light-emitting brightness of each LED chip in the LED array is the same, and the light-emitting uniformity of the Micro-LED display device is improved.

Drawings

Fig. 1 is a schematic diagram of an LED display adjusting circuit according to an embodiment of the present invention;

fig. 2 is a schematic diagram of an LED display adjusting circuit according to a second embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

Before discussing exemplary embodiments in more detail, it should be noted that some exemplary embodiments are described as processes or as depicted as flowcharts. Although a flowchart may describe the steps as a sequential process, many of the steps can be performed in parallel, concurrently or simultaneously. In addition, the order of the steps may be rearranged. A process may be terminated when its operations are completed, but may have additional steps not included in the figure. Processing may correspond to, a function, a procedure, a subroutine, a subprogram, and so on.

Furthermore, the terms "first," "second," and the like may be used herein to describe various orientations, actions, steps, elements, or the like, but the orientations, actions, steps, or elements are not limited by these terms. These terms are only used to distinguish one direction, action, step or element from another direction, action, step or element. The terms "first", "second", etc. are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "plurality", "batch" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

Example one

Fig. 1 is a schematic diagram of an LED display adjusting circuit according to an embodiment of the present invention, which is applicable to the technical field of Micro-LEDs.

As shown in fig. 1, a LED display adjusting circuit according to a first embodiment of the present invention includes: the driving module 100 is connected with the data processing module 300 and the LED chip 400 (i.e., Micro-LED chip), and the photoelectric conversion module 200 is connected with the LED chip 400 and the data processing module 300.

When the LED display adjusting circuit operates, the driving module 100 first drives the LED chip 400 to emit light. The photoelectric conversion module 200 converts the optical signal of the LED chip 400 into an electrical signal and inputs the electrical signal to the data processing module 300. The data processing module 300 processes the received electrical signal to generate a regulation signal, and the regulation signal is used for regulating the light emitting brightness of the LED chip 400. The data processing module 300 transmits the adjustment signal to the driving module 100, and the driving module 100 adjusts the brightness of the LED chip 400 according to the adjustment signal.

Further, when the brightness of each LED chip 400 in the LED chip array is adjusted, the LED light emission brightness of each LED chip 400 may be compared with the average light emission brightness of the LED chip array. When the LED light emission luminance of the LED chip 400 is higher than the average light emission luminance of the LED chip array, a luminance reduction adjustment signal is generated. When the LED luminance of the LED chip 400 is lower than the average luminance of the LED chip array, a luminance boost adjustment signal is generated.

Further, the driving module 100 further includes a signal receiving circuit 110, a signal holding circuit 120, and an adjusting circuit 130. The signal receiving circuit 110 is connected to the signal holding circuit 120, the signal holding circuit 120 is connected to the adjustment circuit 130, and the adjustment circuit 130 is connected to the LED chip 400. The signal receiving circuit 110 is configured to receive a driving signal, which is used to drive the LED chip 400 to emit light. The signal receiving circuit 110 receives the driving signal and transmits the driving signal to the signal holding circuit 120. The signal hold circuit 120 may hold the driving signal for a period of time while transmitting the driving signal to the adjustment circuit 130. The adjusting circuit 130 transmits a driving signal to the LED chip 400, thereby causing the LED chip 400 to emit light. Meanwhile, the adjusting circuit 130 is further configured to receive an adjusting signal output by the data processing module 300, and adjust the light emitting brightness of the LED chip 400 through the adjusting signal.

Example two

Fig. 2 is a schematic diagram of an LED display adjusting circuit according to a second embodiment of the present invention, which is a further refinement of the first embodiment. As shown in fig. 2, an LED display adjusting circuit according to a second embodiment of the present invention includes: a driving module 100, a photoelectric conversion module 200 and a data processing module 300.

The driving module 100 includes a signal receiving circuit 110, a signal holding circuit 120, and a regulating circuit 130. The signal receiving circuit 110 includes a first NMOS transistor NMOS1 and a second NMOS transistor NMOS 2. The gate of the first NMOS transistor NMOS1 and the gate of the second NMOS transistor NMOS2 are connected to receive the row driving signal row, the drain of the first NMOS transistor NMOS1 is used to receive the first column driving signal Datan, and the drain of the second NMOS transistor NMOS2 is used to receive the second column driving signal Data _ n. In this embodiment, a row driving signal Rown, a first column driving signal Datan, and a second column driving signal Data _ n are driving signals of the LED chip 400, the row driving signal Rown is a driving signal of an nth row where the LED chip 400 is located in the LED chip array, the first column driving signal Datan is a driving signal of an nth column where the LED chip 400 is located in the LED chip array, and the second column driving signal Data _ n is an opposite signal of the first column driving signal Datan.

The signal holding circuit 120 comprises a first PMOS transistor PMOS1, a second PMOS transistor PMOS2, a third NMOS transistor NMOS3 and a fourth NMOS transistor NMOS 4; the grid electrode of the first PMOS tube PMOS1, the grid electrode of the third NMOS tube NMOS3, the drain electrode of the second PMOS tube PMOS2 and the drain electrode of the fourth NMOS tube NMOS4 are connected; the grid electrode of the second PMOS tube PMOS2, the grid electrode of the fourth NMOS tube NMOS4, the drain electrode of the first PMOS tube PMOS1 and the drain electrode of the third NMOS tube NMOS3 are connected; the grid electrode of the third NMOS transistor NMOS3 is connected with the source electrode of the first NMOS transistor NMOS1, and the grid electrode of the fourth NMOS transistor NMOS4 is connected with the source electrode of the second NMOS transistor NMOS 2; the drain electrode of the first PMOS tube PMOS1 is connected with the drain electrode of the third NMOS tube NMOS3, and the drain electrode of the second PMOS tube PMOS2 is connected with the drain electrode of the fourth NMOS tube NMOS 4; the source electrode of the first PMOS transistor PMOS1 and the source electrode of the second PMOS transistor PMOS2 are both connected with the positive electrode VDD of the working power supply; the source electrode of the third NMOS transistor NMOS3 and the source electrode of the fourth NMOS transistor NMOS4 are both connected with the negative electrode VSS of the working power supply.

The adjusting circuit 130 comprises a third PMOS transistor PMOS3 and a fourth PMOS transistor PMOS4, a gate of the third PMOS transistor PMOS3 is used for receiving an adjusting signal Iref, a source of the third PMOS transistor PMOS3 is connected with a positive electrode of a working power supply, a drain of the third PMOS transistor PMOS3 is connected with a source of the fourth PMOS transistor PMOS4, a gate of the fourth PMOS transistor PMOS4 is connected with a gate of the third NMOS transistor NMOS3, and a drain of the fourth PMOS transistor PMOS4 is connected with the LED chip 400.

The photoelectric conversion module 200 includes a control switch and a photodiode PD, and the control switch is a fifth NMOS transistor NMOS 5. The gate of the fifth NMOS transistor NMOS5 receives the control signal Row _ PD, the drain thereof is connected to the gate of the second PMOS transistor PMOS4 of the driving module 100, and the source thereof is connected to the cathode of the photodiode PD. The positive electrode of the photodiode PD is connected to the negative electrode of the LED chip 400.

In this embodiment, the data processing module 300 is a comparator. The Row driving signal Row, the first column driving signal Datan, the second column driving signal Data _ n and the control signal Row _ PD can all be generated by the FPGA circuit, wherein the first column driving signal Datan is converted into the second column driving signal Data _ n by the inverter.

The working principle of the embodiment is as follows: the driving module 100 receives a row driving signal row, a first column driving signal Datan and a second column driving signal Data _ n generated by the FPGA circuit, and drives the LED chip 400 to emit light. The photodiode PD provided at the cathode of the LED chip 400 senses the luminance of the LED chip 400, and converts the optical signal of the LED chip 400 into an electrical signal. Meanwhile, the FPGA circuit generates a control signal Row _ PD to be input to the gate of the fifth NMOS transistor NMOS5, so that the drain and the source of the fifth NMOS transistor NMOS5 are turned on, and the converted electrical signal is output to the data processing module 300. The data processing module 300 is an ADC (Analog-to-Digital Converter) circuit, which is substantially a comparator, and compares the electrical signal with the reference signal, and outputs the difference value as a regulating signal Iref to the gate of the third PMOS transistor PMOS3 of the regulating circuit 130, thereby regulating the light emitting brightness of the LED chip 400. In this embodiment, the reference signal is an electrical signal corresponding to the average luminance of the LED chip array.

Further, in the LED display adjusting circuit shown in fig. 2, when the row driving signal row is 0, the EN signal remains in the original state, which is 0 or 1. When the row driving signal row is equal to 1, the first column driving signal Datan and the second column driving signal Data _ n are transmitted to the signal holding module 120, so that the EN signal follows the second column driving signal Data _ n. When the row driving signal Rown is equal to 1, the first column driving signal Datan is equal to 1, and the second column driving signal Data _ n is equal to 0, EN is equal to 0, the fourth PMOS transistor PMOS4 is turned on, and the first column driving signal Datan and the adjusting signal Iref together control the state of the LED chip. The larger the voltage (VDD-Iref) of the adjusting signal Iref is, the larger the current flowing through the LED chip is, the larger the brightness of the LED chip is, so that the brightness of the LED chip can be adjusted by changing the adjusting signal Iref.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An LED display conditioning circuit, comprising: the device comprises a driving module, a photoelectric conversion module and a data processing module; the driving module is connected with the LED chip; the photoelectric conversion module is connected with the LED chip and is connected with the driving module through the data processing module;

2. The LED display conditioning circuit of claim 1, wherein the driving module is further configured to drive the LED chip to emit light according to a driving signal, the driving module comprising a signal receiving circuit, a signal holding circuit, and a conditioning circuit, the signal receiving circuit being connected to the signal holding circuit, the signal holding circuit being connected to the conditioning circuit, and the conditioning circuit being connected to the LED chip.

3. The LED display conditioning circuit of claim 2, wherein the signal receiving circuit comprises a first NMOS transistor and a second NMOS transistor, a gate of the first NMOS transistor and a gate of the second NMOS transistor are connected and configured to receive a row driving signal, a drain of the first NMOS transistor is configured to receive a first column driving signal, and a drain of the second NMOS transistor is configured to receive a second column driving signal.

4. The LED display conditioning circuit of claim 3, wherein the first column drive signal and the second column drive signal are opposite signals.

5. The LED display conditioning circuit of claim 3, wherein the signal holding circuit comprises a first PMOS transistor, a second PMOS transistor, a third NMOS transistor, and a fourth NMOS transistor;

6. The LED display adjusting circuit of claim 5, wherein the adjusting circuit comprises a third PMOS transistor and a fourth PMOS transistor, a gate of the third PMOS transistor is used for receiving an adjusting signal, a source of the third PMOS transistor is connected with a positive electrode of a working power supply, a drain of the third PMOS transistor is connected with a source of the fourth PMOS transistor, a gate of the fourth PMOS transistor is connected with a gate of the third NMOS transistor, and a drain of the fourth PMOS transistor is connected with the LED chip.

7. The LED display conditioning circuit of claim 6, wherein the photo-conversion module comprises a control switch and a photodiode, the photodiode is configured to convert the LED chip optical signal into an electrical signal, and the control switch is configured to transmit the electrical signal to the data processing module according to a control signal.

8. The LED display conditioning circuit of claim 7, wherein the control switch is a fifth NMOS transistor, a gate of the fifth NMOS transistor is configured to receive the control signal, a source of the fifth NMOS transistor is connected to the photodiode, and a drain of the fifth NMOS transistor is connected to the gate of the second NMOS transistor.

9. The LED display conditioning circuit of claim 8, wherein an anode of the photodiode is connected to a cathode of the LED chip, and a cathode of the photodiode is connected to a source of the fifth NMOS transistor.

10. The LED display conditioning circuit of any of claims 1-9, wherein the data processing module is a comparator that compares the electrical signal to a reference signal to generate a conditioning signal.