Abstract:
The present invention provides a photosensor testing device with a built-in light source and a tester provided with said device, which has a base and an upper cover disposed above the base, characterized in that the upper cover is equipped with at least one light emitting diode (LED) assembly used as a light source for a photosensor under test to undergo testing operation. Therefore, the components such as high intensity discharge lamps and optical processing devices are unnecessary any more, reducing the bulk volume of the testing device and its related cost. Besides, the testing process would be speeded up and the testing accuracy could be improved, as well as the time consumed in replacing the light source would be saved.

Description:
FIELD OF THE INVENTION 
   The present invention relates to a photosensor testing device, more particularly to a photosensor testing device with a built-in light source. 
   BACKGROUND OF THE INVENTION 
   Photosensors such as charge coupled device (CCD) or complementary metal oxide semiconductor (CMOS) and the like have been widely applied in mobile phones, safety monitoring systems, or industrial tester. As a result, there is increasing demand for testing the photosensors. Because most photosensors comprises a large number of cells of array, the spatial uniformity of a photosensor depends on whether each cell could have the same response to the light beams with the same intensity or not. Whether the responses to the light beams with different wavelengths for each cell are the same or not would determine whether a photosensor could achieve white balance or not. And the speeds of the responses to incident light beams for each cell would determine the response speed of a photosensor. That is to say, these are the optical properties which determine the quality of a photosensor. 
   In order to obtain the spatial uniformity and white balance data of a photosensor, as illustrated in  FIGS. 1 and 2 , the traditional tester  1  for testing photosensors includes a high intensity discharge lamp  10 , an optical processing device  11  and a light detecting device. The high intensity discharge lamp  10  is used to provide light beams with different wavelengths to the optical processing device  11 , after homogenizing the light via the color wheel  110  in the optical processing device  11  and the subsequent optical lens module, projecting the homogeneous light after this treatment onto the loading seat  12 . The homogeneous light passes through the aperture  121  in the upper cover  120 , illuminating a photosensor under test  13 , such as a CMOS chip. Each cell in the photosensor under test  13  senses the incident intensities and then the corresponding sense signals by its conversion would be outputted to a control device (not shown) via a plurality of leads  122  electrically connected to the photosensor, thus obtaining the testing results. The operations such as classification (shipping inspection), reduction of the pixels and gray scales of defectives within the acceptable range (serve as sub-quality products), and the like are performed according to the testing results. 
   However, the traditional tester  1  for testing photosensors needs to be equipped with the above high intensity discharge lamp  10 , optical processing device  11 , loading seat  12  and the like. In particular, the optical processing device occupies a large space, leading to a relatively high cost. Furthermore, halogen bulbs are often used as the high intensity discharge lamp  10  so that it would become a serious defect in those tests, which require stable-wavelength light sources, due to the drifts and unstable wavelength values of each wavelength component in the above halogen bulb light sources. In addition, frequent replacement of the bulbs also results in relatively higher cost due to their great consumption. 
   SUMMARY OF THE INVENTION 
   An objective of the present invention is to provide a photosensor testing device with a built-in light source and a tester provided with said device, whereby reducing the bulk volume of the tester. 
   Another objective of the present invention is to provide a photosensor testing device with a built-in light source and a tester provided with said device in order to lower the total cost of the tester. 
   Another objective of the present invention is to provide a built-in light source using light emitting diode assembly for the provision of a testing device with emitted light at stable wavelength and with a long-life light source. 
   Another objective of the present invention is to provide a photosensor testing device with a built-in LED assembly allowing for speeding up the testing process. 
   Therefore, the present invention provides a photosensor testing device with a built-in light source provided for testing a photosensor under test, which comprises a base and an upper cover. The above base is equipped with a loading portion, wherein an accommodating space for receiving said photosensor under test is arranged on said loading portion, wherein at least one light emitting diode assembly is mounted inside said upper cover. The upper cover is disposed above said base and allowable to be opened or closed relative to said base. When said photosensor under test is placed into the accommodating space and the upper cover is closed relative to said base, the light emitting diode assembly would be activated and project light beams on the surface of said photosensor under test to undergo a testing process. 
   The present invention also provides a tester provided for testing a photosensor under test, comprising a power supply, a photosensor testing device and a controller, wherein the photosensor testing device includes a base equipped with a loading portion on which an accommodating portion for receiving said photosensor under test is arranged; and an upper cover disposed above said base and allowed to be opened or closed relative to said base, wherein at least one light emitting diode assembly is mounted inside said upper cover. Said controller includes a processor which could conduct arithmetic operations according to its built-in programs. This controller could turn on the power supply under control, activating the light emitting diode assembly in said photosensor testing device to provide a light source for the photosensor under test, which senses the light source and then the corresponding signals by its conversion would be sent to said controller to commence the corresponding process. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above-mentioned and other technical contents, features, and effects of the present invention are clearly illustrated in the following detailed description of the preferred embodiments in coordination with the reference drawings. 
       FIG. 1  is a schematic front view of a conventional photosensor testing system; 
       FIG. 2  is an enlarged partial structural view illustrating the testing device of  FIG. 1 ; 
       FIG. 3  is a schematic structural diagram illustrating a preferred embodiment of the testing device according to the present invention; 
       FIG. 4  is a partial top view of the base of  FIG. 3 , illustrating the surface of the base of the testing device; 
       FIG. 5  is a schematic structural diagram illustrating another preferred embodiment of the testing device according to the present invention; 
       FIG. 6  is a structural block diagram illustrating a tester with the testing device according to the present invention; and 
       FIG. 7  is a schematic structural diagram of another preferred embodiment according to the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   As shown in  FIGS. 3 and 4 , a preferred embodiment of the testing device  2  according to the present invention comprises a base  20 , an upper cover  21 , and at least one light emitting diode assembly  22 . 
   The base  20  is equipped with a loading portion  200 , in this embodiment, a square accommodating space  23  for receiving a photosensor under test, such as a CMOS or a CCD chip, is formed on the loading portion  200 . However, the accommodating space  23  also could be a cave or any well-known caging structure else without limitation of the above shape. 
   Referring to  FIG. 4  at the same time, in this embodiment, the loading portion  200  is provided with a plurality of metal leads  24  uniformly around the bottom wall which forms the accommodating space  23 . These metal leads are allowed to electrically connect with the electric contacts of photosensor under test  3 , and the metal leads  24  are parallel arranged on the loading portion  200  extending away from the photosensor under test  3  to the position near the peripheral wall of base  20 . In this manner, the photosensor  3  could be driven by the electric energy of the tester then converting the measured light beams into the electric output signals. 
   The upper cover  21  is disposed above the base  20  via a pivot and allowed to be opened or closed relative to the base  20 . The upper cover  21  is inwardly caved at the face facing the base  20  to form a cave  210 , and the white light emitting diode assembly  22  of this embodiment is mounted inside the cave  210 . 
   In the actual testing process, the upper cover  21  is set in an open state (as shown in dashed line) first, and the photosensor under test  3  is placed into the accommodating space  23  of the base. The upper cover  21  is then closed and the photosensor under test  3  is pressed downward until its electric contacts connected to those leads  24 . Subsequently, the light emitting diode assembly  22  is activated to emit light, projecting the light beams on the surface of the photosensor under test  3  through an optical component such as a liquid crystal plate  25 . Each sensing unit (i.e. cell, not shown) of the photosensor under test  3  receives the image data via the liquid crystal plate  25  and then the corresponding sense signals by its conversion would be sent to the controller through the leads  24  thus followed by the operations such as compensation, classification (shipping inspection), reduction of the pixel numbers and gray scales of sub-quality products, and the like according to the testing results. 
   Since the technology for driving a light emitting diode assembly  22  to emit light is relatively mature, the control of luminous intensity, image fringes, patterns and the like is all readily accessible. Furthermore, the LED assembly could emit light at stable wavelength to provide a light source with an ideal light beam, thereby improving the testing accuracy. 
   To change the luminous signal of a light source activated and controlled by the power supply is more convenient and rapid than the conventional technique of mechanical control by rotating a color wheel. This would not only significantly reduce the volume of the tester, but also obviously shorten the testing time, thus increasing the testing efficiency. 
     FIG. 5  shows another preferred embodiment according to the present invention, where this embodiment mainly differs from the previous in that the upper cover  21  is connected to a manipulator  40  driven by a pneumatic cylinder  4 , so that the pneumatic cylinder  4  enables the manipulator  40  to interlock the upper cover  21  moving up and down. The upper cover  21  is pressed downward to a testing position after the photosensor under test being placed into the base  20 , and opened up after the testing. 
   Needless to say, it should be easily realized by those skilled in the art that the optical component of the previous embodiment is not necessary. The light source used in the present invention exhibits higher stability, and therefore, when the pre-calibration is performed, a photosensor sample with the best performance is placed in the loading portion to measure the patterns of the light beam emitted by each chip illuminating the photosensor under test and then stored in the memory device  9 . As a result, in use of the tester  8  provided with the photosensor testing device  2  according to the present invention, as shown in  FIG. 6 , after the power supply  5  is provided to enable the photosensor testing device  2 , the measurement signal from the photosensor testing device  2  would be inputted into the controller  60 . Then, the controller  60  compares this signal with the data pre-stored in the memory device  9  and displays the related information on the display device  7 . 
   In this embodiment, the controller  60  is exemplary as a computer unit including a processor, which could conduct arithmetic operations according to its built-in programs so as to input the corresponding instructions or data; the power supply  5  receives the corresponding voltage outputted by the controller  60  to control the on/off and brightness of the light emitting diode assembly  22  in the photosensor testing device  2 . The memory device  9  is intended to record the brightness distribution data on the loading portion  200  illuminated by the light source and allow the processor in the controller  60  to compare these with the data measured by the photosensor under test  3 . The display device  7 , such as a liquid crystal display, is provided for displaying the testing data to operators. 
   By means of the above configuration, the light emitting diode assembly  22  is mounted inside the upper cover  21  of the photosensor testing device  2 , thus reducing the bulk volume of the photosensor testing device  2  and greatly lowering the manufacturing cost. Also, the light emitting diode assembly  22  shows the variations in its intensity and wavelength of light under control and the stable wavelength characteristics, which advantageously meet various testing requirements, and the testing process is more easily controlled as well as would be speeded up and its accuracy could be improved effectively. Furthermore, the light emitting diode assembly  22  has longer life so that it is unnecessary to replace the light source and the cost would be considerably lowered. 
   It is understood to use light source as shown in  FIG. 7 , the third preferred embodiment according to the present invention. LED chips/dies  221 ′,  222 ′,  223 ′ with three colors of red, green and blue by color light separation are arranged to serve as light sources and activated to emit light respectively or shoot in mixed-light depending on requirements, besides the structures of base  20 ′, upper cover  21 ′, accommodating space  23 ′, leads  24 ′ and the like as same as those in the foregoing embodiments. It should be readily realized by those skilled in the art that the structures disclosed by the present invention merely show less uniformity of illumination, hence, if unnecessary to evaluate each cell in specific patterns when testing, an optical component would be further installed between the light emitting diode chips/dies  221 ′,  222 ′,  223 ′ and the photosensor under test  3  for diffusing and homogenizing the light beams from those light emitting diode chips/dies  221 ′,  222 ′,  223 ′, as shown in this embodiment. Here, for example, a light-homogenizing device  25 ′ is adopted as an optical component for diffusing the projecting light beams and uniformly projecting them onto the photosensor under test  3 . No doubt conventional optical devices such as an optical lens module may also be used. 
   What has been described above are the preferred embodiments of the present invention only, it is not intended to limit the scope of practice of the present invention, in principle, simple equivalent changes and modifications made according to the claims and specification should be included within the scope of the claims.