A fixture for testing the light spot of a COB-LED light source and a method for testing the light spot of a COB-LED light source

Abstract

A fixture for testing the light spot of a COB-LED light source and a method for testing the light spot of a COB-LED light source. Relating to the field of optical testing. The testing method is simple and the testing cost is low. A fixture for testing the light spot of a COB-LED light source, comprising a base and an upper cover covering the base, the base being provided with a light source display hole, an LED chip being fixed on the base and a light-emitting portion of the LED chip being placed in the light source display hole; the upper cover comprising an upper cover base, the upper cover base being provided with a shielding portion for shielding the light source display hole. A testing method for testing the light spot of a COB-LED light source, comprising a fixture selection step, a partitioning step, a testing step, and a calculation step. There is no need to use a variety of instruments for testing, and the testing steps are simple.

Description

Technical Field

[0001] The invention relates to the field of optical testing, and in particular to a fixture for testing a COB-LED light source spot and a method for testing a COB-LED light source spot. Background Art

[0002] With the continuous development of science and technology, the LED application market has gradually matured; because COB has good heat dissipation performance, low cost and can be personalized, the application of COB in lighting has also become a trend. The COB (COB light source, or high-power integrated surface light source) currently produced is generally a blue light chip plus phosphor and then covered by a transparent colloid on a substrate to form an LED chip (that is, the LED chip referred to in this case). Users have higher and higher demands for product stability and reliability; then the quality requirements of the produced COB also increase accordingly. In the COB preparation process, there is an uneven distribution of phosphor in both the static process and the phosphor sedimentation process; the uneven distribution of phosphor in the static process is not obvious, while the uneven distribution of phosphor in the phosphor sedimentation process is more obvious; the uneven distribution of phosphor causes the COB light source to produce light spots.

[0003] At present, the instruments used to test this phenomenon are: COA (spatial spectral distribution photometer), near-field distribution photometer, and far-field distribution photometer. Among them, COA adopts a unique dark box design, which is specially used for accurate testing of spatial light intensity distribution (light distribution performance), spatial color distribution, average color and color non-uniformity, and total luminous flux of LED packages (including integrated packages). Test the spatial color uniformity of the light source with rated current. Near-field distribution photometer is used for near-field measurement of small light sources (such as LEDs, etc.), which can obtain the near-field brightness distribution of the light source. The light model of the light source can be established through the algorithm, and the total luminous flux, the illumination distribution at any position in the space, and the far-field light intensity distribution can be calculated. The far-field distribution photometer usually includes a mechanical structure (turntable) for supporting and positioning the light source to be measured and a photometric detector. According to the requirements of CIE70, the distance between the light source and the detector needs to be far enough during measurement (generally, the measurement distance is required to be at least 5 times the maximum light-emitting surface of the LED light source). The market methods for testing COB light source spots all require these instruments. For small test quantities and low-precision tests, the test costs are high and the test methods are complex. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a fixture for testing a COB-LED light source spot and a method for testing a COB-LED light source spot with a simple testing method and low testing cost.

[0005] The objective of the present invention is achieved by adopting the following technical scheme: a fixture for testing the light spot of a COB-LED light source, comprising a base and an upper cover covering the base, the base being provided with a light source display hole, an LED chip being fixed on the base and a light-emitting portion of the LED chip being placed in the light source display hole; the upper cover comprising an upper cover base, the upper cover base being provided with a shielding portion for shielding the light source display hole.

[0006] The light source display hole is a circular hole.

[0007] The shielding portion is a fan-shaped hole arranged on the upper cover base, and the center of the fan-shaped hole is coaxial with the center of the light source display hole.

[0008] The base is provided with at least one pair of wire outlet holes, the pair of wire outlet holes are symmetrically arranged on both sides of the light source display hole, and the upper cover is provided with through holes corresponding to the wire outlet holes.

[0009] The base is provided with a receiving groove for receiving the LED chip, and the light source display hole is provided at the bottom of the receiving groove;

[0010] The accommodating groove is used to accommodate the base of the LED chip, the base is embedded in the accommodating groove and the light emitting part is embedded in the light source display hole.

[0011] A method for testing the light spot of a COB-LED light source includes a fixture selection step, and the test is performed after being clamped by the fixture used for testing the light spot of a COB-LED light source. The appropriate fixture is selected for testing according to the model of different LED chips;

[0012] Partitioning step, dividing the light-emitting surface of the LED chip into several areas for easy testing and comparison;

[0013] Testing steps: each block is tested separately by the test probe of the integrating sphere, and each color coordinate data is recorded;

[0014] Calculation step: import the test results into the software for calculation, compare and distinguish whether the LED chip is qualified according to the calculation results, and complete.

[0015] The partitioning steps are:

[0016] The light-emitting part placed in the light source display hole is evenly divided into four 90-degree fan-shaped areas starting from the center of the light source display hole, and numbered respectively.

[0017] The test steps are:

[0018] Pass one end of the test probe through the outlet hole on the upper cover and then through the corresponding hole on the base to fix the fixture;

[0019] The light-emitting part of the LED chip is displayed outside through the regional display hole to emit light. After the cover is closed, the light-emitting part is displayed outside through the fan-shaped hole, and other areas are blocked;

[0020] The color coordinate values ​​of the four sector-shaped areas are measured respectively, and each area is tested multiple times and the color coordinate data of each area is recorded.

[0021] The calculation steps are:

[0022] Calculate the average value of the color coordinate data of each area, take the average value of the color coordinates of each area to calculate the total average value of the four areas, take the difference between the average value of the four areas and the total evaluation mean, take the largest difference among the four differences and compare it with the standard value to determine whether the LED chip is qualified.

[0023] Compared with the prior art, the beneficial effect of the present invention is that when the clamp of the present invention is used, it is only necessary to close the upper cover on the base, and the entire light spot testing process can be completed by rotating the upper cover to expose different light-emitting surfaces of the light-emitting part, and the clamp has a simple structure, a simple manufacturing process and a relatively simple method of use.

[0024] The method of the present invention only needs to use a single fixture and an integrating sphere to complete the test, and does not need to use multiple instruments for testing. The test steps are simple, less data is recorded, and it is convenient and fast. In addition, the average value is taken after multiple tests during the test process, so the test accuracy is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic diagram of the base structure in the present invention,

[0026] Figure 2 yes Figure 1 AA section view;

[0027] Figure 3 It is a structural schematic diagram of the upper cover in the present invention;

[0028] Figure 4 yes Figure 3 BB cross-sectional view;

[0029] Figure 5 It is a state diagram of the present invention;

[0030] In the figure: 1. light source display hole; 2. upper cover base; 3. fan-shaped hole; 4. wire outlet hole; 5. receiving groove. DETAILED DESCRIPTION

[0031] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0032] The present invention Figure 1-5 As shown, a fixture for testing the light spot of a COB-LED light source comprises a base and an upper cover covering the base, wherein the base is provided with a light source display hole 1, an LED chip is fixed on the base and the light-emitting part of the LED chip is placed in the light source display hole 1; the upper cover comprises an upper cover base 2, and a shielding part for shielding the light source display hole 1 is provided on the upper cover base 2. When testing is required, the LED chip is placed on the desktop, the light source display hole 1 of the base is aligned with the light-emitting part, the upper cover is covered on the base, and the shielding part shields part of the light-emitting part, which is convenient for subsequent testing.

[0033] The light source display hole 1 is a circular hole. The shielding portion is a fan-shaped hole 3 provided on the upper cover base 2, and the center of the fan-shaped hole 3 is coaxial with the center of the light source display hole 1. When testing different areas of the same light-emitting portion, since the center of the fan-shaped hole 3 is coaxial with the center of the light source display hole 1, the center of the circle is always coaxial during the rotation of the upper cover, and the light-emitting portion is accurately divided, making the detection result more accurate and reliable.

[0034] The base is provided with at least one pair of outlet holes 4, which are symmetrically arranged on both sides of the light source display hole 1, and the upper cover is provided with through holes corresponding to the outlet holes 4. The base is directly covered on the LED chip, and during detection, the test probe of the integrating sphere is directly inserted from the through hole on the upper cover, passes through the outlet holes 4, contacts with the LED chip, and fixes the LED chip while performing detection.

[0035] The base is provided with a receiving groove 5 for receiving the LED chip, and the light source display hole 1 is provided at the bottom of the receiving groove 5; the receiving groove 5 is used to receive the base of the LED chip, and the base is embedded in the receiving groove 5 and the light emitting part is embedded in the light source display hole 1. In order to prevent the base from floating during the detection process, a receiving groove 5 adapted to the base of the LED chip is provided on the base, so that the LED chip can be completely embedded in the receiving groove 5, and the base will not float due to the thickness of the base of the LED chip, so that the entire fixture is clamped more firmly, and repeated adjustment is not required, thereby improving the test accuracy.

[0036] A method for testing the light spot of a COB-LED light source includes the steps of selecting a fixture, and testing after being clamped by the right fixture. The appropriate fixture is selected for testing according to the model of different LED chips; the base is directly covered on the LED chip, the light-emitting part of the LED chip is embedded in the light source display hole 1, and then the upper cover is covered.

[0037] Partitioning step: divide the light-emitting surface of the LED chip into several blocks for easy testing and comparison; divide the circular light-emitting surface of the entire COB from the center of the circle into four fan-shaped areas with an angle of 90°, and number them as 1# area, 2# area, 3# area and 4# area in a clockwise direction.

[0038] In the test procedure, each block is tested separately through the test probe of the integrating sphere, and the test results of each block are recorded; before the test, one end of the integrating sphere test probe passes through the through hole on the upper cover, and then through the outlet hole 4 on the base to fix the light spot test fixture. Then the integrating sphere test probe is aligned with the positive and negative electrode pads of the LED chip to be tested to fix the test material. The light-emitting part of the LED chip to be tested is displayed through the light source display hole 1. After the upper cover is closed, the "1# area of ​​the light-emitting part is displayed outside through the fan-shaped hole 3 to emit light, and other areas are blocked.

[0039] Use the function of the integrating sphere to test the photoelectric parameters. It is necessary to perform multiple tests to obtain the average value. Take three tests as an example. Perform the first test on area 1#. After the first test is completed, perform the second test after an interval of 10s. After the second test is completed, perform the third test after an interval of 10s. In this way, the data of the three tests are recorded in the computer connected to the integrating sphere. After the test of area 1# is completed, rotate the upper cover of the fixture 90° clockwise to make area 2# appear outside and other areas blocked; perform the same steps as area 1# to test the photoelectric parameters and record them. Similarly, test areas 3# and 4# and record the data.

[0040] Calculation step: import the test results into the software for calculation, compare and distinguish whether the LED chip is qualified according to the calculation results, import the test data into Excel, extract the color coordinates x and y data for processing. The processing steps are: calculate the average value of the three x and y values ​​measured in each area and record them as Xp and Yp, that is, the average value of area 1# is recorded as X1 and Y1, the average value of area 2# is recorded as X2 and Y2, the average value of area 3# is recorded as X3 and Y3, and the average value of area 4# is recorded as X4 and Y4. Then calculate the total average value of the Xp and Yp values ​​of the four areas and record it as X and Y, and then take the maximum difference between the average value of each area and the total average value of the four areas as ΔX and ΔY and record them. If ΔX < 0.007 and ΔY < 0.0025, it is qualified, otherwise it is judged as unqualified.

[0041] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A fixture for testing the light spot of a COB-LED light source, comprising a base and an upper cover covering the base, characterized in that: The base is provided with a light source display hole, the LED chip is fixed on the base and the light emitting part of the LED chip is placed in the light source display hole; The upper cover comprises an upper cover base, and the upper cover base is provided with a shielding portion for shielding the light source display hole; The light source display hole is a circular hole, the shielding portion is a fan-shaped hole provided on the upper cover base, and the center of the fan-shaped hole is coaxial with the center of the light source display hole; When testing different areas of the same luminous part, since the center of the fan-shaped hole is coaxial with the center of the light source display hole, the center is always coaxial during the rotation of the upper cover. The entire light spot test process can be completed by rotating the upper cover to expose different luminous surfaces of the luminous part.

2. A fixture for testing the light spot of a COB-LED light source according to claim 1, characterized in that: The base is provided with at least one pair of wire outlet holes, the pair of wire outlet holes are symmetrically arranged on both sides of the light source display hole, and the upper cover is provided with through holes corresponding to the wire outlet holes.

3. The fixture for testing the light spot of a COB-LED light source according to claim 1, characterized in that: The base is provided with a receiving groove for receiving the LED chip, and the light source display hole is provided at the bottom of the receiving groove; The accommodating groove is used to accommodate the base of the LED chip, the base is embedded in the accommodating groove and the light emitting part is embedded in the light source display hole.

4. A method for testing the light spot of a COB-LED light source, characterized in that: The method comprises the step of selecting a fixture, wherein the test is performed after being clamped by a fixture for testing the light spot of a COB-LED light source as described in any one of claims 1 to 3, and a suitable fixture is selected for the test according to the models of different LED chips; Partitioning step, dividing the light-emitting surface of the LED chip into several areas for easy testing and comparison; Testing steps: each block is tested separately by the test probe of the integrating sphere, and each color coordinate data is recorded; Calculation step: import the test results into the software for calculation, compare and distinguish whether the LED chip is qualified according to the calculation results, and complete.

5. A method for testing a COB-LED light source spot according to claim 4, characterized in that: The partitioning step is: starting from the center of the light source display hole, the light-emitting part placed in the light source display hole is evenly divided into four 90-degree fan-shaped areas, and numbered respectively.

6. A method for testing a COB-LED light source spot according to claim 4, characterized in that: The test steps are: passing one end of the test probe through the outlet hole on the upper cover and then through the corresponding hole on the base to fix the fixture; The light-emitting part of the LED chip is displayed outside through the regional display hole to emit light. After the cover is closed, the light-emitting part is displayed outside through the fan-shaped hole, and other areas are blocked; The color coordinate values ​​of the four sector-shaped areas are measured respectively, and each area is tested multiple times and the color coordinate data of each area is recorded.

7. The method for testing the light spot of a COB-LED light source according to claim 5, characterized in that: The calculation steps are: calculating the average value of the color coordinate data of each area, taking the average value of the color coordinates of each area to calculate the total average value of the four areas, taking the difference between the average value of the four areas and the total evaluation mean, taking the largest difference among the four differences and comparing it with the standard value to determine whether the LED chip is qualified.

Images