Light emitting module testing apparatus

• US 9,247,626 B2
• Filed: 07/17/2014
• Issued: 01/26/2016
• Est. Priority Date: 10/16/2013
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Sun Ki
• Primary Examiner(s): WHITE, DYLAN C
• Application Number:
  US14/334,337
• Publication Number:
  US 20150102728A1
• Time in Patent Office: 558 Days
• Field of Search: 315/151, 315/149, 315/152
• US Class Current: 1/1
• CPC Class Codes: F21W 2102/00 Exterior vehicle lighting devices for illuminating purposes
• CPC Class Codes: G01J 1/08 Arrangements of light sources specially adapted for photometry standard sources, also using luminescent or radioactive material
• CPC Class Codes: G01J 2001/4247 for testing lamps or other light sources
• CPC Class Codes: G01M 11/065 details about the image analysis
• CPC Class Codes: G01R 31/2635 Testing light-emitting diodes, laser diodes or photodiodes
• CPC Class Codes: G01R 31/44 Testing lamps
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/14 using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 47/20 Responsive to malfunctions or to light source life; for protection

Abstract

A light emitting module testing apparatus includes a sensing unit and a controller. The sensing unit includes a photodiode array sensing light emitted from a light emitting module serving as a test object. The controller generates luminance information based on light sensed by the sensing unit, and sets an operating condition of the light emitting module serving as the test object by comparing the generated luminance information with a pre-set reference range. The light emitting module testing apparatus thereby senses luminance of light emitted from the light emitting module serving as a test object, and sets the operating condition of the light emitting module to have an appropriate luminance.

Claims

1. A light emitting module testing apparatus, comprising:

a sensing unit including a photodiode array sensing light emitted from a light emitting module serving as a test object before being included in a lighting device; and

a controller generating luminance information based on light sensed by the sensing unit, and setting an operating condition of the light emitting module serving as the test object by comparing the generated luminance information with a reference luminance profile identifying, at each of a plurality of respective locations, a respective pre-set reference range of luminance for the respective location.

2. The light emitting module testing apparatus of claim 1, wherein the operating condition of the light emitting module set by the controller is a current value applied by a driving unit provided in the light emitting module to a light source provided in the light emitting module.

3. The light emitting module testing apparatus of claim 2, wherein the photodiode array comprises first to n^th photodiodes where n is a natural number greater than or equal to 2.

4. The light emitting module testing apparatus of claim 3, wherein the luminance information generated by the controller is a luminance profile including information regarding luminance of light sensed at locations of each of the first to n^th photodiodes.

5. The light emitting module testing apparatus of claim 4, wherein the reference luminance profile comprises a maximum reference luminance profile identifying an upper limit of the luminance for each of the plurality of respective locations and a minimum reference luminance profile identifying a lower limit of the luminance for each of the plurality of respective locations.

6. The light emitting module testing apparatus of claim 5, wherein when the luminance profile generated by the controller has a region exceeding the maximum reference luminance profile, the controller sets the operating condition of the light emitting module so as to decrease the current value applied by the driving unit provided in the light emitting module to the light source provided in the light emitting module.

7. The light emitting module testing apparatus of claim 5, wherein when the luminance profile generated by the controller has a region lower than the minimum reference luminance profile, the controller sets the operating condition of the light emitting module so as to increase the current value applied by the driving unit provided in the light emitting module to the light source provided in the light emitting module.

8. The light emitting module testing apparatus of claim 5, wherein when a difference between a maximum value of the luminance profile generated by the controller and a minimum value of the luminance profile generated by the controller for a respective location is greater than a difference between the maximum reference luminance profile and the minimum reference luminance profile for the respective location, the controller determines that the light emitting module is defective.

9. The light emitting module testing apparatus of claim 5, wherein at least one of the maximum reference luminance profile and the minimum reference luminance profile has a linear shape.

10. The light emitting module testing apparatus of claim 5, wherein at least one of the maximum reference luminance profile and the minimum reference luminance profile has a curved shape.

11. The light emitting module testing apparatus of claim 5, wherein the sensing unit comprises first to m^th photodiode arrays each including first to n^th photodiodes, where m is a natural number greater than or equal to 2, and

the luminance information generated by the controller is a single average luminance profile derived by averaging first to m^th luminance profiles respectively obtained by the first to m^th photodiode arrays.

12. The light emitting module testing apparatus of claim 1, wherein the sensing unit is disposed to be positioned directly above a main light emitting surface of the light emitting module.

13. The light emitting module testing apparatus of claim 1, wherein the photodiode array comprises first to n^th photodiodes where n is a natural number greater than or equal to 2, and

the sensing unit comprises a bar-like light receiving part in which the photodiode array is disposed.

14. The light emitting module testing apparatus of claim 1, wherein the sensing unit comprises first to m^h photodiode arrays each including first to n^th photodiodes and first to m^th bar-like light receiving parts in which the first to m^th photodiode arrays are respectively disposed, where n and m are natural numbers greater than or equal to 2.

15. A light emitting module testing apparatus, comprising:

a sensing unit including a photodiode array sensing light emitted from a light emitting module serving as a test object before being included in a lighting device, the light emitting module having a light source and having a driving unit providing a pre-selected current to drive the light source; and

a controller generating luminance information based on light sensed by the sensing unit, and comparing the luminance information with a reference luminance profile identifying, at each of a plurality of respective locations, a respective pre-set reference range of luminance for the respective location to set the pre-selected current value applied by the driving unit provided in the light emitting module to the light source such that the luminance information of light emitted from the light emitting module serving as the test object satisfies the reference luminance profile.

16. A light emitting module testing apparatus, comprising:

a sensing unit including a plurality of photodiodes disposed on a substrate for sensing, at locations of each of the plurality of photodiodes, light emitted from a light emitting module serving as a test object before being included in a lighting device; and

a controller coupled to the sensing unit, generating a luminance profile including, for each respective location of a plurality of locations of the photodiodes, luminance information of light sensed at the respective location, and generating a control signal based on comparing the luminance information of light sensed at each respective location with a reference luminance profile identifying, at each of a plurality of respective locations, a respective pre-set luminance range for the respective location.

17. The light emitting module testing apparatus of claim 16, wherein each photodiode of the plurality of photodiodes is connected to a respective transistor, and the controller receives an electrical signal from each respective transistor connected to a photodiode of the plurality of photodiodes indicative of luminance of light sensed at the location of the respective photodiode.

18. The light emitting module testing apparatus of claim 16, wherein the controller generates the luminance profile by averaging, for each of a plurality of locations of photodiodes, luminance information of light sensed by photodiodes at or proximate to the respective location, and generates the control signal based on comparing the averaged luminance information of light sensed at each location with the reference luminance profile identifying the respective pre-set luminance range for the respective location.

19. The light emitting module testing apparatus of claim 18, wherein the reference luminance profile identifying the respective pre-set luminance range for each respective location of the plurality of respective locations includes different luminance ranges for different ones of the locations of the photodiodes.

20. The light emitting module testing apparatus of claim 16, wherein the sensing unit is disposed to be positioned directly above a main light emitting surface of the light emitting module.