CN119300203B

CN119300203B - A method for detecting aging of organic light-emitting diodes based on pure optics

Info

Publication number: CN119300203B
Application number: CN202411397538.0A
Authority: CN
Inventors: 朱洪强; 吴泽邦; 尹开慧; 罗磊; 李妍彦; 汤仙童; 陈敬; 熊祖洪
Original assignee: Chongqing Normal University
Current assignee: Chongqing Normal University
Priority date: 2024-02-04
Filing date: 2024-02-04
Publication date: 2025-06-20
Anticipated expiration: 2044-02-04
Also published as: CN118053365A; CN119300203A; CN118053365B

Abstract

The invention relates to a method for detecting aging of an organic light emitting diode based on pure optics, which relates to the technical field of OLED detection, firstly, an OLED panel to be detected is placed in a specified test slot, the OLED panel is electrified, the current intensity between the anode and the cathode in the OLED panel is continuously refreshed, the light information emitted by each pixel in the OLED panel to be tested is enabled to penetrate through the corresponding filter layer, the photosensitive layer is derived behind the filter layer, the photosensitive layer is provided with a plurality of photosensitive units, and the photosensitive units are used for collecting light signals penetrating through the filter layer. The technology developed by the invention can ensure the production cost and thickness of the OLED panel, and has the effects of accurate detection result, no influence on the structure of the original display panel and low destructiveness.

Description

Method for detecting aging of organic light-emitting diode based on pure optics

Technical Field

The invention relates to the technical field of OLED detection, in particular to a detection method and a detection plate, and specifically relates to an OLED aging detection method and a detection plate.

Background

OLED (Organic Light-Emitting Diode), also known as Organic laser display, organic Light Emitting semiconductor. An OLED is a current-type organic light emitting device, which is a phenomenon of emitting light by injection and recombination of carriers, and the intensity of the light emission is proportional to the current injected. Under the action of an electric field, holes generated by the anode and electrons generated by the cathode of the OLED move, are respectively injected into the hole transport layer and the electron transport layer, and migrate to the light emitting layer. When the two meet at the light emitting layer, an energy exciton is generated, thereby exciting the light emitting molecule to finally generate visible light.

The OLED directly emits light by exciton flyback radiation of the light-emitting layer, so that the biggest advantage is that the contrast brightness of the OLED screen is superior to that of a traditional display screen, but the OLED screen has the defects that the quantity of excitons can be easily aged due to the influence of factors such as electron-hole transition and the like due to the fact that exciton flyback radiation emission photons are directly used as a light source, and the situation of a flask appears, so that chromatic aberration is generated and the use is influenced.

In the process of detecting, recycling or warranting an OLED screen, the screen burning condition of the OLED display screen needs to be objectively known, or whether the screen burning exists or not is needed. The aging detection method of the OLED pixel circuit comprises a data writing module, a driving module, a threshold compensation module, a light emitting unit, a sensing module and a first light emitting control module, wherein the driving module comprises a control end, a first end and a second end, and is configured to control driving current flowing through the first end and the second end for driving the light emitting unit to emit light, the data writing module is connected with the control end of the driving module, and is configured to write reference voltage into the control end of the driving module in a reset stage, write threshold compensation information into the second end of the driving module in a compensation stage, write data signal into the control end of the driving module in a data writing stage, the threshold compensation module is connected with the control end of the driving module and the second end of the driving module, the first end is configured to control current flowing through the first end and the second end for driving the light emitting unit to emit light, the threshold compensation module is connected with the first end and the second end of the light emitting unit in a reset stage, the threshold compensation module is configured to adjust the data signal in the first end and the light emitting unit is connected with the first end and the second end of the driving module in a reset stage, the first end of the light emitting unit is connected with the first end and the light emitting unit is configured to adjust the aging unit, the first light emitting control module is connected with a first voltage end and a first end of the driving module, and is configured to conduct the first voltage end with the first end of the driving module in a light emitting stage so as to write a first voltage into the first end of the driving module. The application of the scheme increases the production cost and reduces the application scene of the panel.

Or directly scanning and calculating the aging degree of each pixel point, for example, the invention disclosed by the patent publication No. CN105139790B discloses an OLED display aging detection method, which comprises the steps of identifying a first pixel point belonging to an original signal from all pixel points of a display signal according to the resolution of the original signal, wherein the display signal is obtained by carrying out image interpolation processing on the original signal according to the resolution of display equipment, obtaining an aging compensation value of each pixel point in the display signal, detecting the first pixel point, calculating to obtain the aging compensation value of the first pixel point, detecting a second pixel point except the first pixel point, and calculating to obtain the aging compensation value of the second pixel point according to the aging compensation value of the first pixel point through an image interpolation algorithm corresponding to the first pixel point adjacent to the second pixel point. The result obtained by the algorithm is obtained by means of a calculation program, and the detection value of each pixel is inaccurate.

Since the three primary colors of each pixel in an OLED are independent, the degree of aging of the exciplex in each pixel, although related to practical use, is also highly random and prone to error.

Disclosure of Invention

The invention provides a method for detecting the aging of an organic light-emitting diode based on pure optics, which has the advantages of accurate detection result, no influence on the structure of an original display panel and low destructiveness on the premise of ensuring the production cost and thickness of an OLED panel.

The technical scheme of the invention is as follows:

The method for detecting the aging of the organic light emitting diode based on pure optics comprises the steps of firstly placing an OLED panel to be detected in a specified test groove, electrifying the OLED panel, and continuously refreshing the current intensity between the anode and the cathode in the OLED panel, so that light information emitted by each pixel in the OLED panel to be detected penetrates through a corresponding filter layer, wherein a photosensitive layer is derived behind the filter layer, the photosensitive layer is provided with a plurality of photosensitive units, and the photosensitive units are used for collecting light signals penetrating through the filter layer.

As a further optimization of the scheme, the outer sides of the photosensitive units are connected with display units, each photosensitive unit comprises a plurality of photoreceptors, and each photoreceptor is optically isolated from all pixel points adjacent to one or more corresponding pixel points on the to-be-detected OLED panel.

As a further optimization of the scheme, each photosensitive unit comprises a photosensitive device, and each photosensitive device corresponds to a pixel point in the to-be-detected OLED panel.

When the OLED panel is electrified, a plurality of pixel points are selected as calibration points, strong current is applied, and the positions of the calibration points are determined on the photosensitive layer, so that the alignment of the OLED panel with the filter layer and the photosensitive layer is realized.

The utility model provides an OLED ageing testing board, includes filter layer and photosensitive layer, wherein the filter layer includes grating layer and liquid crystal layer, the liquid crystal layer is provided with the electrode, can change through the polarization direction of liquid crystal layer light beam, the light beam of grating layer side can pass through the liquid crystal layer with grating layer is to the photosensitive layer, the photosensitive layer is provided with a plurality of sensitization units, every sensitization unit can be with optical signal conversion to the signal of telecommunication.

As a further optimization of the scheme, the optical filter layer comprises two grating layers, the polarization directions of the two grating layers are different, and the liquid crystal layer is sandwiched between the two grating layers.

As a further optimization of the present solution, the unit includes a photoreceptor, which uses SOI as a substrate and is a photodiode with a lateral structure.

As a further optimization of the present solution, each of the photoreceptors includes a substrate, an isolation layer, and a functional layer including two electrode N-regions and P-regions, between which a multiplication region and an absorption region are provided.

As a further optimization of the scheme, the device further comprises a connecting layer, wherein the connecting layer is used for packaging the photosensitive layer, and each electrode in the photoreceptor is led out of the outer surface of the connecting layer and used as a pin of other test lines.

The working principle and the beneficial effects of the invention are as follows:

Selecting an OLED panel to be tested, placing the OLED panel to be tested in a vacuum environment, removing the outer package, butting the OLED panel with the detection plate, and adjusting pixel points to align corresponding photosensitive units in the photosensitive layer of the detection plate through the filter layer. Different currents are applied to the anode and the cathode of the OLED panel, so that the intensity of an optical signal which is supposed to be output by the primary color point in each element of the OLED panel is changed continuously. The polarization direction of the filter layer in the test board is changed according to the current signal applied to the OLED panel, so that the direction of light rays emitted to the photosensitive unit in the detection board is constant, and the current intensity output by the photosensitive unit can be changed according to the intensity of incident light of the photosensitive unit, so that the quality of the output light signal of the pixel point in the OLED panel is reflected.

Drawings

The invention will be described in further detail with reference to the drawings and the detailed description.

FIG. 1 is a flow chart of the present application;

Detailed Description

The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The OLED aging detection method comprises the steps of firstly placing an OLED panel to be detected in a specified test groove, electrifying the OLED panel, continuously refreshing the current intensity between the anode and the cathode in the OLED panel, enabling light information emitted by each pixel in the OLED panel to be detected to penetrate through a corresponding light filtering layer, deriving a photosensitive layer after the light filtering layer, enabling the light passing state of the light filtering layer to change along with the state of an electrical signal refreshed by the OLED panel to be detected, wherein the photosensitive layer is provided with a plurality of photosensitive units, the photosensitive units are used for collecting light signals passing through the light filtering layer, the outer sides of the photosensitive units are connected with display units, each photosensitive unit comprises a plurality of photoreceptors, each photoreceptor is optically isolated from all pixels adjacent to one or more pixels corresponding to the OLED panel to be detected, and each photoreceptor corresponds to one pixel in the OLED panel to be detected.

One photosensitive unit can cover a plurality of pixel points, which requires a higher precision photoreceptor, and a plurality of pixel points can be detected simultaneously, and when a problem area is detected, a single area is scanned by a smaller detection plate.

For the luminous organic material in each pixel point, gradual change current is input, and the output optical signal is also gradual change signal, so that an accurate interval of a spectrum of each pixel with problems can be obtained, and a basis can be provided for the design of the OLED panel at the later stage and the adjustment of the primary color position and the area.

The polarization angle of the filter layer of the detection plate can be adjusted, the voltage applied by the filter layer is related to the driving current intensity of the OLED, when the current applied by the luminous source in the OLED changes, the direction of the output light signal also changes, if the characteristics of the output light signal of each pixel are the same when the pixel point is normal, the light-sensitive unit can be excited normally after passing through the filter layer, if the pixel is aged, the luminous intensity deviates from the normal in the current change interval applied by a certain light source, so that the light intensity is weakened when the light-sensitive unit is processed by the filter layer, and the light intensity input into the light-sensitive unit is weakened, so that the light-sensitive unit cannot be excited.

When the OLED panel is electrified, a plurality of pixel points are selected as calibration points, strong current is applied, and the positions of the calibration points are determined on the photosensitive layer, so that the alignment of the OLED panel with the optical filter layer and the photosensitive layer is realized. The filter layer size is larger than the OLED panel size, and when the OLED panel is placed, the photosensitive units are aligned with corresponding pixels of the OLED panel.

The above function is to calibrate the positions of the OLED panel and the detection plate, and generally, the error is allowed to be about 10% of the pixel point after the alignment calibration. The shielding grating is used for ensuring that the optical signal of each pixel point and the adjacent pixel point are not interfered.

Embodiment 2, an OLED aging detection panel, includes filter layer and photosensitive layer, wherein the filter layer includes grating layer and liquid crystal layer, the liquid crystal layer is provided with the electrode, can change the polarization direction of passing through the liquid crystal layer light beam, the light beam of grating layer side can pass through the liquid crystal layer with the grating layer is to the photosensitive layer, the photosensitive layer is provided with a plurality of sensitization units, every sensitization unit can convert optical signal into the electrical signal. The optical filter layer comprises two grating layers, the polarization directions of the two grating layers are different, and the liquid crystal layer is sandwiched between the two grating layers. The unit comprises a photoreceptor which takes SOI as a substrate and is a photodiode with a transverse structure. Each photoreceptor comprises a substrate, an isolation layer and a functional layer, wherein the functional layer comprises an N region and a P region of two electrodes, and a multiplication region and an absorption region are arranged between the two electrodes. The device also comprises a connecting layer, wherein the connecting layer is used for packaging the photosensitive layer, and each electrode in the photoreceptor is led out of the outer surface of the connecting layer and used as other test circuit pins.

The arrangement of the grating layer and the liquid crystal layer in the filter plate can refer to the LCD screen principle, and the externally applied voltage of the liquid crystal layer can adjust the optical signals. And the light sensitive layer is arranged behind the grating, and the grating of the adjacent light sensitive layer plays a role in checking and filtering. The photosensitive layer adopts a structure of a transverse SOI substrate, so that the photoreceptor can be guaranteed to be completely paved on the photosensitive layer and corresponds to the pixel points of the OLED, each type of OLED panel with resolution corresponds to a corresponding detection plate, and after enough photons enter an absorption region, the carrier concentration between two electrodes on the functional layer of the photoreceptor can be increased, and therefore an avalanche unit is reduced, and the two electrodes can be conducted.

Meanwhile, two electrodes of each photosensitive unit are externally connected with a detection luminescent plate, each detection luminescent plate comprises a plurality of pixel points with single color, each pixel point is correspondingly and electrically connected with one sensing unit, a high potential is applied to one end of each sensing unit, one end of each pixel point is connected with one corresponding pixel point of the detection luminescent plate, and therefore problem pixels can be directly and intuitively reflected, and the problem pixels with various color changes are singly extracted.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the invention.

Claims

1. A method for detecting aging of organic light emitting diodes based on pure optics, firstly placing an OLED panel to be tested in a designated test slot, characterized in that the OLED panel is powered on, and the current intensity between the positive and negative electrodes in the OLED panel is continuously refreshed, so that the intensity of the light signal to be output by the primary color point in each element of the OLED panel is continuously changed, so that the light information emitted by each pixel in the OLED panel to be tested passes through the corresponding filter layer, and the light transmission state of the filter layer can change with the electrical signal state refreshed by the OLED panel to be tested, and a plurality of filter units are distributed on the filter layer plane, and each of the filter units covers a plurality of the OLED The pixel points of the panel, each of the filter units is surrounded by a light-isolating grating, the light-isolating grating vertically penetrates the filter layer, a photosensitive layer is derived from the filter layer, the photosensitive layer is provided with a plurality of photosensitive units, the photosensitive units are used to collect light signals passing through the filter layer, each of the photosensitive units includes a plurality of photoreceptors, the electrical indicators of each of the photoreceptors are collected, and the collected electrical indicators are analyzed to obtain the intensity of the light signal received by each photoreceptor, wherein each time the current signal applied to the OLED panel to be tested is refreshed, a group of electrical signal data groups output by the photoreceptors are obtained, and each of the electrical signal data groups is judged.

2. A method for detecting aging of organic light-emitting diodes based on pure optics according to claim 1, characterized in that an imaging unit is connected to the outside of the photosensitive unit, and each of the photoreceptors is optically isolated from all pixel points adjacent to one or more corresponding pixel points on the OLED panel to be tested.

3. The method for detecting aging of organic light-emitting diodes based on pure optics according to claim 2, characterized in that each of the photosensitive units includes a plurality of photoreceptors, and each photoreceptor corresponds to a pixel point in the OLED panel to be tested.

4. The method for detecting aging of organic light-emitting diodes based on pure optics according to claim 1, characterized in that the size of the filter layer is larger than the size of the OLED panel, and when placing the OLED panel, the photosensitive unit is aligned with the corresponding pixel of the OLED panel.

5. The method of detecting aging of organic light-emitting diodes based on pure optics according to claim 4 is characterized in that when the OLED panel is powered on, a number of pixel points are selected as calibration points, a strong current is applied, and the position of the calibration points is determined in the photosensitive layer to achieve alignment of the OLED panel with the filter layer and the photosensitive layer.

6. A method for detecting aging of an organic light-emitting diode based on pure optics according to any one of claims 1 to 5, characterized in that the filter layer comprises two grating layers and a liquid crystal layer, the liquid crystal layer is provided with electrodes capable of changing the polarization direction of a light beam passing through the liquid crystal layer, the two grating layers have different polarization directions, the liquid crystal layer is sandwiched between the two grating layers, and the light beam on the grating layer side can pass through the liquid crystal layer and the grating layer to project toward the photosensitive layer.

7. A method for detecting aging of organic light-emitting diodes based on pure optics according to claim 6, characterized in that the photosensitive unit comprises a photoreceptor, and the photoreceptor is based on SOI and is a photodiode with a lateral structure.

8. A method for detecting aging of organic light-emitting diodes based on pure optics according to claim 7, characterized in that each of the photoreceptors includes a substrate, an isolation layer and a functional layer, the functional layer includes two electrodes, an N region and a P region, and a multiplication region and an absorption region are arranged between the two electrodes.

9. A method for detecting aging of organic light-emitting diodes based on pure optics according to claim 8, characterized in that it also includes a connecting layer, wherein the connecting layer is used to encapsulate the photosensitive layer and lead out each electrode in the photoreceptor to the outer surface of the connecting layer to serve as other test circuit pins.