Patent Publication Number: US-2011062332-A1

Title: Charge-Coupled Device Monitor and Lighting Device Thereof

Description:
PRIORITY CLAIM 
     The present application claims priority to Taiwan Patent Application No. 098216868, filed Sep. 11, 2009, which is incorporated by reference in its entirety. 
     FIELD OF THE INVENTION 
     The present invention relates to a charge-coupled device monitor and lighting device thereof, especially relates to a charge-coupled device monitor producing light with an infrared light emitting diode and lighting device thereof. 
     BACKGROUND OF THE INVENTION 
     Charge-coupled device (CCD) tells an image with the electrons raised by impacting photons in compliance with Photoelectric effect. Therefore, monitors using a charge-coupled device inevitably need additional lighting device configured nearby to compensate insufficient light coming from environment in night time. Current charge-coupled device monitor mostly adopts halogen lamps as the light source of the lighting device, however, due to the various defects the halogen lamps have, for example: the environmental consciousness violating elements, halogen, contained in the halogen lamps, great power consumption, short lifetime, poor assembly strength leading to fragility and raised maintenance difficulty, a new model of the lighting device is needed to develop. 
     For all kinds of industrial light source, light emitting diode (LED) is a cold light illuminator, with the natures of power saving, lower consumption, short time to work, halogen free and long life time. Since 20 contraries, the technical barrier of the blue LED is broken through, multi-colored and high-brightness LED is invented to be broadly applied to all kinds of products, such as displays, projectors and lighting devices, etc. Thus the lighting source attracting the most attentions to replace halogen lamps is LED to be a modern lighting source adopting in the charge-coupled device monitor. However, current technologies for fabrication and assembly process limit the emitting angle LED capable to provide, hence the projecting profile is narrowed and the conformity of the illuminance is effected. A lot of LEDs have to be configured to maintain the illuminance to desired level, however, this will cause the problem of huge power consumption. The power still cannot be saved. 
     Therefore, a charge-coupled device monitor in compliance with environmental consciousness uses reliable and long-lifetime lighting device is still in needs. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a light guiding unit to change the projecting profile of the infrared light emitting diode. A more variable projecting profile shape is provided to solve the problems of narrowed projecting angle or great power consumption induced by configuring more infrared light emitting diode in the conventional art. 
     Another object of the present invention is to apply the LED in charge-coupled device monitor, and through a light guiding unit to form at least one straight edge in the projecting profile to accumulate the projecting profiles of LEDs in a limited number to construct various light patterns. Hence, only fewer LEDs required to sustain the illuminance in a desired standard with the environmental-consciousness-compliant, reliable and long-lifetime lighting device. 
     According to an aspect of the invention, a lighting device is provided, comprising: an infrared light emitting diode, receiving a power to emit a light; and a light guiding unit, positioned on another side of the infrared light emitting diode, changing the projecting profile of the light to a predetermined projecting profile comprising at least one straight edge. 
     According to another aspect of the invention, a charge-coupled device monitor is provided, comprising: at least one lighting device, comprising an infrared light emitting diode, an electrical conducting unit and a light guiding unit, wherein the infrared light emitting diode receives a power to emit a light, the electrical conducting unit is positioned on a side of the infrared light emitting diode, electrically connecting to the infrared light emitting diode to provide the power, the light guiding unit is positioned on a side of the infrared light emitting diode, changing the projecting profile of the light to a predetermined projecting profile, and the predetermined projecting profile comprises at least one straight edge; at least one charge-coupled unit, receiving the light emitted by the lighting device in the predetermined projecting profile, transforming the light to at least one electrical signal; and a processing unit, electrically connecting the charge-coupled unit, transferring an image according to the electrical signal. 
     The lighting device may optionally comprise an electrical conducting unit positioned on a side of the infrared light emitting diode, electrically connecting to the infrared light emitting diode to provide the power. 
     The infrared light emitting diode is preferred to be the light source for the charge-coupled device monitor in night time. The predetermined projecting profile may be a distribution shape of the light in some distance, and it is preferred to be chosen from one of the following shapes comprising square like, rectangle and polygon, wherein square is the best in some embodiments. Hence, the conformity of the light projecting from the light guiding unit is promoted and the angle of the projecting profile is increased. 
     The assembly type of the light guiding unit and electrical conducting unit according to the present invention is not limited to Lumileds Luxeon assembly, surface mount assembly, Plastic Leaded Chip Carrier (PLCC) assembly, other types of assembly may be adopted in the present invention as well. The light guiding unit may have great transparency, and the electrical conducting unit may have great electrical conduction with the preference of comprising two electrode electrically connecting to the cathode and anode of the power, and connecting to the two ends of the LED(s) to provide the power. 
     The light guiding unit may be exemplified as a total internal reflection lens, which is made by any materials with great transparency, such as but is not limited to epoxy, acrylic or crystallized glass. Additionally, the light guiding unit also may be implemented with an integrated structure, monocoque, or the structure constructed by several parts. The light guiding unit may optionally further comprises a light entering area and a light exiting area, wherein the light entering area may be positioned beside the infrared light emitting diode in some embodiments. After the light enters the light guiding unit from light entering area, the light could be projected from the light exiting area with the predetermined projecting profile. The light entering area and light exiting area are preferred to have great transparency. In some embodiments, the light exiting area may comprise at least one flange and a convex lens forming within the flange, and within the flange and convex lens, at least one groove may be optionally formed. For the curvature radius of the convex lens, in some embodiments, it is better to be in the range of 5 to 5.3 mm; for the curvature radius of the groove, it may be in the range of 11 to 11.9 mm, whereas better in the range of 11.15 to 11.4 mm. Moreover, the diameter of the light exiting area may be in the range of 10.8 to 11.8 mm, and the distance between the infrared light emitting diode to the top of the convex lens may be in the range of 10.8 to 12 mm for example, or correspond to the focus of the convex lens in some embodiments. 
     For enhancing the thermal diffusivity, in some embodiments, it is preferred to position a buffer between the infrared light emitting diode and the light entering area, or a heat sink on the electrical conducting unit to couple to the infrared light emitting diode. However, it is not limited to such elements stated here, other elements with similar function can be adopted as well. 
     On the other hand, for enhancing light utilization efficiency, a reflective cup may be optionally positioned in the electrical conducting unit, and in one embodiment, the reflective cup is positioned next to the infrared light emitting diode for example. The light emitted from the side or near the bottom of the infrared light emitting diode is able to reflect to the light guiding unit. 
     The light guiding unit changes the projecting profile of the infrared light emitting diode to the shape comprising at least one straight edge, and expands the projecting angle of the light emitted by the infrared light emitting diode. Therefore, less number of LED(s) is needed to sustain illuminance in a required standard in the present invention, and power consumption is lowered, meanwhile, a lighting device in compliance with environmental consciousness and power saving is provided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which: 
         FIG. 1  shows a side view of a lighting device according to an embodiment of the present invention. 
         FIG. 2  shows a top view of the lighting device shown in  FIG. 1 . 
         FIG. 3  shows a cross-sectional view of the lighting device shown in  FIG. 1  along the AA line. 
         FIG. 4  shows a top view of the lighting device shown in  FIG. 1  after removing the light guiding unit. 
         FIG. 5  shows a 2-D distribution of illumination of a lighting device according to an embodiment of the present invention. 
         FIG. 6  shows a side view of a lighting device according to another embodiment of the present invention. 
         FIG. 7  shows a charge-coupled device monitor of an embodiment of the present invention. 
         FIG. 8  shows a systematic view of the charge-coupled device monitor shown in  FIG. 7 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Elements drawn are not necessarily in a true scale, however, similar symbols or reference number usually refer to similar elements. 
     Please refer to  FIGS. 1-4 , wherein  FIG. 1  shows a side view of a lighting device according to an embodiment of the present invention,  FIG. 2  shows a top view of the lighting device shown in  FIG. 1 ,  FIG. 3  shows a cross-sectional view of the lighting device shown in  FIG. 1  along the AA line, and  FIG. 4  shows a top view of the lighting device shown in  FIG. 1  after removing the light guiding unit. The lighting device  1  comprises an infrared light emitting diode  11 , a electrical conducting unit  12 , a light guiding unit  13 , a buffer  14  and a reflective cup  15 . The electrical conducting unit  12  is positioned at a side of the infrared light emitting diode  11 , while the light guiding unit  13  is positioned at another side of the infrared light emitting diode  11 . The assembly structure of the infrared light emitting diode  11  is formed by the electrical conducting unit  12  and the light guiding unit  13 . In the present embodiment, the electrical conducting unit  12  and the light guiding unit  13  are connected to each other in a compact manner, and a receiving space is formed therein for receiving the infrared light emitting diode  11 . 
     When the infrared light emitting diode  11  is powered by electricity, an infrared light is emitted. It is because that when the two ends of the LED is powered by electricity, among the pn junction between the p-type semiconductor and n-type semiconductor coupled to each other, a lot of electronic-hole pairs will be reconciled, and at this time, residual power will be released in photons manner to emit light. The electrical conducting unit  12  and the infrared light emitting diode  11  provide the required power to the infrared light emitting diode  11  to emit the light by electrically connection. In the present embodiment, the electrical conducting unit  12  comprises two electrodes  121 ,  122  and a base  123 . The electrodes  121 ,  122  has great electric conduction and electrically connect to cathode and anode of an external power (not shown) respectively. On the base  123 , at least one circuit is formed to electrically connect to the electrodes  121 ,  122  and the infrared light emitting diode  11 . Thus a route for the external power to the infrared light emitting diode  11  is produced. 
     The light guiding unit  13  has great transparency, and it is preferred to be formed integrated into a monocoque or constructed by multiple parts. The light guiding unit  13  comprises a light entering area  131  and a light exiting area  135 , wherein the light entering area  131  is next to the infrared light emitting diode  11 , for example: the light entering area  131  is positioned above the infrared light emitting diode  11 , and the light exiting area  135  is positioned on an end farer away from the infrared light emitting diode  11 . So, after the light enters the light guiding unit  13  from the light entering area  131 , the light guiding unit  13  will guide the direction of the light, whereas when the light is emitted from the light exiting area  135 , the light guiding unit  13  changes the projecting profile of the light to a predetermined projecting profile. The predetermined projecting profile may be a distribution shape of the illuminance of the light in some distance, having at least one straight edge. Therefore, the projecting profile is friendly to be accumulated. In the present embodiment, the light guiding unit  13  is exemplified as a total internal reflection lens to product a total internal reflection effect upon the light entering the light guiding unit  13  when the light contacts with the sidewall of the light guiding unit  13 , so the proportion of the light emitting from the light exiting area  135  is increased. The material of the light guiding unit  13  can be any material with great transparency, such as any of epoxy, acrylic or crystallized glass. 
     The light exiting area  131  comprises at least one flange  132  and a convex lens  133  formed within the flange  132 . Between the flange  132  and convex lens  133 , at least one groove  134  is optionally formed. Because the appearance of the light guiding unit  13  will effect the optical effects of the projecting profile, so height H 1  of the lighting device  1 , diameter D 1 , D 2  of the light exiting area  135 , curvature radius R 1  of the top of the convex lens  133 , curvature radius R 2  of the side of the convex lens  133  and curvature radius R 3  of the groove  134  are all important parameters. The height H 1  of the lighting device  1  can be in the range of 14 to 14.4 mm, the distance between the infrared light emitting diode  11  to the top of the convex lens  133  corresponds to the focus of the convex lens  133 , the diameter D 1 , D 2  of the light exiting area is in the range of 10.8 to 11.8 mm, and preferably, the diameter D 1 , D 2  of the light exiting area  135  is in the range of 11 to 11.6 mm. On the other hand, the curvature radius R 1 , R 2  of the convex lens  133  is better to be in the range of 5 to 5.3 mm, the curvature radius R 3  of the groove  134  is in the range of 11 to 11.9 mm, and preferably, the curvature radius R 3  of the groove  134  is in the range of 11.15 to 11.4 mm. The buffer  14  is positioned between the infrared light emitting diode  11  and the light entering area of the light guiding unit  13  to enhance the thermal dissipation of the infrared light emitting diode  11 . The buffer  14  can be chosen from the materials with great heat conduction and transparency, such as: silicon, to reduce the light covering effect for the light emitted from the infrared light emitting diode  11 . 
     The reflective cup  15  is positioned in the electrical conducting unit  12 , and the reflective cup  15  is positioned next to the infrared light emitting diode  11 . The surface of the reflective cup  15  is smooth, so the reflective cup  15  is able to reflect the light emitted from the side or the bottom of the infrared light emitting diode  11  to the light guiding unit  13 . The light utilization efficiency of the infrared light emitting diode  11  is hence promoted. 
     When the light is emitted in the predetermined projecting profile via the light exiting area  131  of the light guiding unit  13 , because the predetermined projecting profile comprises at least one straight edge, variable shapes of projecting profiles can be provided, and preferably, those with wider projecting angle. The conformity of the light projected by the light guiding unit is promoted with a great effect in projecting profile accumulation as well. Please refer to  FIG. 5  which shows a 2-D distribution of illumination of a lighting device according to an embodiment of the present invention. As shown in  FIG. 5 , in the present embodiment, the predetermined projecting profile tends to a square. Several lighting device  1  can accumulate their projecting profiles in an array, circle or other way to arrange to form a large illuminating device. When achieving illuminance in the same standard with multiple lighting device to construct a illuminating device, according to the present embodiment, the projecting profile of the lighting device is changed to the predetermined projecting profile for projecting the light from the light guiding unit  13 , the number of the lighting device required is less then that constructed by conventional LEDs. So the power consumption is reduced. 
     Please refer to  FIG. 6 , which shows a side view of a lighting device according to another embodiment of the present invention. For illustrate in a simple but clear manner, the same in the both embodiments do not illustrate again. In the present embodiment, the electrical conducting unit  22  of the lighting device  2  is further positioned a heat sink  224  on the place corresponding to the infrared light emitting diode  21  to couple to the infrared light emitting diode  21 . The heat dissipation of the infrared light emitting diode  21  is enhanced. Additionally, in the present embodiment, the height H 1  of the lighting device  2  is 14.20 mm, the diameter D 1 , D 2  of the light exiting area 135 is 11.65 mm, the curvature radius R 1  of the top of the convex lens  133  is 4.67 mm, the curvature radius R 2  of the side of the convex lens  133  is 5.74 mm and the curvature radius R 3  of the groove  134  is 11.20 mm. 
     Please refer to  FIG. 7  and  FIG. 8 , wherein  FIG. 7  shows a charge-coupled device monitor of an embodiment of the present invention, and  FIG. 8  shows a systematic view of the charge-coupled device monitor shown in  FIG. 7 . The charge-coupled device monitor  100  comprises at least one lighting device  3 , at least one charge-coupled unit  5  and a processing unit  7 . The processing unit  7  electrically connects to the charge-coupled unit  5 . The lighting device  3  can be any one of the lighting device implemented in the previous embodiments. For example, the lighting device  3  comprises an infrared light emitting diode, an electrical conducting unit and a light guiding unit. Here, for clarity, only differences between the present embodiment and previous embodiment are illustrated. The charge-coupled unit  5  corresponds to the lighting device  3  to receive the light emitted by the lighting device  3  in the predetermined projecting profile. When the Photoelectric effect occurs, the light is transformed to at least one electrical signal. After the processing unit  7  receives the electrical signal, an image is transferred according to the electrical signal for watching through a display panel. In the present embodiment, the lighting device  3  can be a LED to emit infrared for the charge-coupled device monitor  100  to be applied in night time. 
     Hence, as stated above, the projecting profile of the infrared light emitting diode is changed by the light guiding unit to have at least one straight edge. So the accumulation of the projecting profiles is easy to apply to lessen the number of required infrared light emitting diode to sustain illuminance in some standard to reduce power consumption. Thus a lighting device in compliance with environmental consciousness and power saving is provided. Besides, charge-coupled device monitors with such infrared light emitting diode and light guiding unit are able to provide an infrared light emitting diode in compliance with environmental consciousness and long lifetime, so the reliability is promoted. 
     Although the present invention has been explained by the embodiments shown in the drawings described above, it should be understand to the ordinary skilled person in the art that the present invention is not limited to the embodiments, but rather that various changes or modifications thereof are possible without departing from the spirit of the invention. Accordingly, the scope of the invention shall be determined only by the appended claims and their equivalents.