TWM548274U - Inspection equipment of printed circuit board - Google Patents

Description

Printed circuit board testing equipment

The present invention relates to a detection device for a panel, and more particularly to a detection device for a printed circuit board that can quickly and accurately detect a surface state.

Modern life is full of various electronic devices. Printed circuit boards (PCBs) located inside these electronic devices, although rarely mentioned, play an extremely important role. In addition to fixing various electronic components, printed circuit boards can provide current connections between electronic components in a predetermined manner. Therefore, whether it is Single-Sided Boards, Double-Sided Boards, or Multi-Layer Boards, in order to accurately mount these electronic components in their respective preset positions, The detection of printed circuit boards has become a very important task.

For manufacturers of printed circuit boards, it is a must-have product monitoring operation to carry out various inspection items to ensure quality control to prevent shipment of defective printed circuit boards to downstream manufacturers. Among various inspection items, surface flatness detection of printed circuit boards is an important test item in the quality control of printed circuit boards. If the surface of the brushed circuit board is not flat, it may cause problems in subsequent component processing, and even the final electronic device products will appear such as noise, contact is not Good and so on. However, the proliferation of printed circuit boards with market demand has made the number of printed circuit boards to be detected quite large, and the efficiency of conventionally manipulating optical instruments has been overwhelmed. The existing flat flaw detection methods are mostly changed to Automated Optical Inspection (AOI). Among the conventional techniques, the most widely used method is to use the straight-through characteristics of the laser beam to detect the printed circuit board.

The first figure is a schematic diagram of a conventional printed circuit board inspection apparatus. Referring to the first figure, the detection apparatus 100 of the prior art is provided with laser devices 160 on both sides of the stage 120. The laser device 160 has a laser light generator and a laser light receiver on each side of the carrying platform 120. The laser light generator can produce a laser beam 162, and the laser beam 162 transmits a straight line to the laser light receiver on the opposite side. The direction of the laser beam 162 described above is perpendicular to the direction of travel of the stage 120. When the printed circuit board 140 to be tested is placed on the stage 120 and moved along the direction of travel 122 of the stage, the printed circuit board 140 to be tested will pass through the laser beam 162 described above. Because the printed circuit board 140 to be tested has a certain thickness, when the printed circuit board 140 to be tested passes the laser beam 162 along the traveling direction 122, the printed circuit board 140 to be tested will block part of the laser beam 162. Under normal conditions, since the thickness of the printed circuit board 140 to be tested is uniform, when the printed circuit board 140 to be tested passes the laser beam 162, the height of the blocked laser beam 162 should also be completely uniform. In other words, if the surface of the printed circuit board 140 to be tested is not a flat surface but has a raised curved surface, the information obtained by the laser receiver will show that the laser beam 162 blocked by the printed circuit board 140 to be tested is At some point, there are occlusion signals at different heights. In this way, it can be determined whether the surface of the printed circuit board 140 to be tested has a curved surface. Because the curved surfaces on these printed circuit boards will likely cause There is an error in the process of installing electronic parts. Therefore, it is an important test item to pick out the printed circuit board with curved surface by inspection.

In the above detection process, if the upper surface (detection surface) of the printed circuit board 140 to be tested has a convex curved surface, the laser device 160 detects that the interception signal of the laser beam 162 is different, and further knows that The upper/detection surface of the printed circuit board 140 is not a complete horizontal plane. However, if the upper/detection surface of the printed circuit board 140 to be tested has a concave curved surface or a wavy surface, the laser beam 162 detected by the laser device 160 will not intercept the signal. The difference, in other words, the printed circuit board detecting apparatus 100 may mistake the printed circuit board 140 to be tested having a concave curved surface as the printed circuit board to be tested without any curved surface.

In the detection of printed circuit boards, AOI is selected as the detection method in order to complete the inspection process more quickly, more accurately, and more stably. If there is a risk of misjudgment in the test results, it will not only increase the labor cost and time cost of the re-inspection. If the counterfeit goods are produced to downstream manufacturers, it will be more likely to cause huge compensation and loss of goodwill. Therefore, although the above-described printed circuit board detecting apparatus 100 has been widely used in the industry, the possibility of misjudgment of the above-described printed circuit board detecting apparatus 100 still has many uncertainties and risks for the printed circuit board detecting process.

In view of the above background, in order to meet the industrial requirements, the present invention provides a detecting device for a printed circuit board, and the detecting device of the printed circuit board can not only quickly detect the curvature of the surface of the board, but also effectively avoid the occurrence of false positives. .

One of the objects of the present invention is to provide a detection device for a printed circuit board, which can effectively reduce the incidence of false positives by comprehensive image signal capture, thereby achieving the effect of avoiding repeated inspections.

Another object of the present invention is to provide a testing device for a printed circuit board. By comprehensively capturing the design of the surface image to be tested, the detecting device of the printed circuit board according to the present invention can achieve the effect of quickly completing the detecting process.

Another object of the present invention is to provide a detecting device for a printed circuit board, which can further reduce the detection time by the detecting device of the printed circuit board according to the present invention by simultaneously detecting the design of the multi-array printed circuit board.

Another object of the present invention is to provide a detecting device for a printed circuit board, which can realize a printed circuit board according to the prior art by a simple optical principle and selection of an optical device. The detection device is more cost effective and easier to operate.

In accordance with the foregoing objects, the present specification provides a test apparatus for a printed circuit board including a carrier, a reference mark, a light source, an image capture device, and a processor. The above-mentioned carrier can be used to carry the printed circuit board to be tested. The detecting device of the above printed circuit board can detect a printed circuit board to be tested at a time, and can also detect a plurality of printed circuit boards to be tested at a time. The above reference mark is disposed above the above-mentioned carrier. The above reference mark may be a repeating unit of a plurality of geometric figures. The light source is disposed obliquely above the carrier. The light source described above may be a light source or a light-emitting device that produces a point source effect. The light source described above illuminates the reference mark in a non-orthoscopic manner and produces a reference mark projection on the stage and the printed circuit board to be tested. The image capturing device is disposed above the carrying platform for capturing a reference mark projected on the carrying platform and the printed circuit board to be tested Shadow. The processor is connected to the image capturing device, and can be used to calculate an image signal captured by the image capturing device to obtain surface information of the printed circuit board to be tested.

100‧‧‧Printed circuit board testing equipment

120‧‧‧Loading station

122‧‧‧The direction of travel of the carrying platform

140‧‧‧Printed circuit board to be tested

160‧‧‧ Laser device

162‧‧‧Laser beam

200‧‧‧Printed circuit board testing equipment

220‧‧‧Printed circuit board to be tested

240‧‧‧ reference mark

240'‧‧‧ reference mark projection

260‧‧‧Light source

280‧‧‧Image capture device

300‧‧‧Printed circuit board testing equipment

320‧‧‧First printed circuit board to be tested

325‧‧‧Second printed circuit board to be tested

340‧‧‧ reference mark

340'‧‧‧First reference mark projection

340'‧‧‧second reference mark projection

360‧‧‧First light source

365‧‧‧second light source

380‧‧‧First image capture device

385‧‧‧Second image capture device

1 is a schematic diagram of a detection device of a printed circuit board of a prior art; a second diagram is a schematic diagram of a detection device of a printed circuit board according to an embodiment of the present invention; and a third diagram is a specific embodiment of the present invention A schematic diagram of a test device for a printed circuit board.

The invention is directed to a detection device for a printed circuit board. In order to thoroughly understand the present invention, detailed steps and compositions thereof will be presented in the following description. Obviously, the implementation of the present invention is not limited to the specific details familiar to those skilled in the art. On the other hand, well-known components or steps are not described in detail to avoid unnecessary limitations of the present invention. The preferred embodiments of the present invention will be described in detail below, but the present invention may be widely practiced in other embodiments, and the scope of the present invention is not limited, and the scope of the following patents shall prevail. .

According to an embodiment of the present specification, a detecting apparatus for a printed circuit board is disclosed. The second drawing is a schematic view of a detecting apparatus 200 for a printed circuit board according to this embodiment. The above-described printed circuit board detecting apparatus 200 includes a carrying table, reference numerals 240, a light source 260, an image capturing device 280, and a processor. Printed above The board inspection apparatus 200 can be used to perform surface inspection of a printed circuit board. The above-mentioned carrying platform, not shown in the figure, can be used to carry the printed circuit board 220 to be tested.

The above reference mark 240 is disposed above the above-mentioned stage. According to this embodiment, the above reference numeral 240 may be a repeating unit of a plurality of geometric figures. In a preferred example according to this embodiment, the reference numeral 240 may be a plurality of straight lines. In another preferred embodiment according to the present embodiment, the reference mark 240 may be a mesh profile formed by two sets of lines intersecting each other. In still another preferred example according to this embodiment, the reference numeral 240 may be a plurality of reference points.

The light source 260 is disposed above the support platform. According to the design of the present invention, the light source 260 may be a light source or a light-emitting device capable of generating a point light source effect, such as a surface light source or a line light source with a grating, a concentrating element, a light guiding element, or other conventional techniques. A combination of techniques known to produce point source effects is well known. In accordance with the design of the present embodiment, the light source 260 illuminates the reference mark 240 in a non-projective manner and produces a reference mark projection 240' on the stage and the printed circuit board 220 to be tested. In a preferred embodiment in accordance with the present embodiment, the light source 260 can illuminate the reference mark 240 at an angle of incidence of about 10 to 85 degrees to produce a reference mark projection 240'.

The image capturing device 280 is disposed above the carrying platform. The image capturing device 280 can capture the image signal projected by the reference mark projection 240' on the carrying platform and the printed circuit board 220 to be tested. The processor is not shown in the figure and is connected to the image capturing device 280. The processor can be used to calculate the image signal captured by the image capturing device 280 to obtain surface information of the printed circuit board 220 to be tested.

According to this embodiment, when performing the detection, a standard sample (Golden sample) may be placed on the above-mentioned carrying platform to perform image capturing. Light source 260 illuminates reference mark 240 and produces a reference mark projection 240' of the standard template on the carrier and standard template. At this time, the image capturing device 280 can capture the image signal V ₀ of the reference mark projection 240 ′ of the standard template from above, and transmit the image signal V ₀ to the processor for recording. Next, the printed circuit board 220 to be tested is placed on the above-mentioned stage. After the light source 260 illuminates the reference mark 240 and forms the reference mark projection 240 ′ of the printed circuit board to be tested on the carrying platform and the printed circuit board 220 to be tested, the image capturing device 280 can extract the reference of the printed circuit board 220 to be tested from above. The image signal V _{1 of the} projection 240' is marked and the image signal V _{1 is} transmitted to the processor described above. The processor can determine whether the printed circuit board 220 to be tested has an abnormal surface different from the standard template by calculating the image signals V ₀ and V ₁ after the background data has been filtered first. More preferably, according to the embodiment, the processor can determine the position of the abnormal curved surface of the printed circuit board 220 to be tested by filtering out the calculation results of the image signals V ₀ and V ₁ after the background data.

In a preferred example according to this embodiment, the reference mark 240 may include a set of first reference marks and a set of second reference marks. According to the present example, the first reference mark and the second reference mark may be two sets of geometric figures having an angle of not zero or 180 degrees with each other, for example, two sets of lines that are not parallel to each other. In a preferred embodiment according to the present example, the reference mark 240 may be a mesh profile formed by two sets of straight lines. According to the example, the image capturing device 280 captures the image signal of the reference mark shadow generated by the two sets of reference marks, and transmits the image signal to the processor for calculation and analysis, in addition to determining whether the printed circuit board 220 to be tested is abnormal. In addition to the curved surface, a 3D model of the surface of the printed circuit board 220 to be tested can be created. As a result, it will further help reduce the automatic optical inspection (AOI). Misjudgments that can be generated and other analyses.

According to another embodiment of the present specification, a detecting apparatus for a printed circuit board is disclosed. According to the present specification, the above printed circuit board detecting apparatus can simultaneously perform detection of a plurality of sets of brushed circuit boards. In the present embodiment, the detection of only two printed circuit boards is performed as a representative description. The third figure is a schematic view of a detecting apparatus 300 for a printed circuit board according to this embodiment. The above-described printed circuit board detecting apparatus 300 includes a carrying platform, a reference mark 340, a first light source 360, a first image capturing device 380, a second image capturing device 385, and a processor. The above-described printed circuit board detecting apparatus 300 can be used for surface detection of a plurality of sets of printed circuit boards. The above-mentioned carrying platform, not shown in the figure, can simultaneously carry the first printed circuit board 320 to be tested and the second printed circuit board 325 to be tested.

The above reference mark 340 is disposed above the above-mentioned stage. According to this embodiment, the above reference mark 340 may be a repeating unit of a plurality of geometric figures. In a preferred example according to this embodiment, the reference numeral 340 may be a plurality of straight lines. In another preferred example according to the present embodiment, the reference mark 340 may be a mesh profile formed by two sets of lines intersecting each other. In still another preferred example according to the embodiment, the reference mark 340 may be a plurality of points.

The first light source 360 is disposed obliquely above the carrier. According to the design of the present invention, the first light source 360 may be a light source or a light-emitting device that can generate a point light source effect. According to the design of the embodiment, the first light source 360 illuminates the reference mark 340 in a non-projective manner, and generates reference marks on the carrying platform and the first printed circuit board 320 to be tested and the second printed circuit board 325 to be tested. Projections 340' and 340". In a preferred example according to this embodiment, the first light source 360 may illuminate the reference mark 340 with an incident angle of about 10 to 85 degrees to generate a reference. The test marks 340' and 340" are marked.

The first image capturing device 380 and the second image capturing device 385 are respectively disposed above the first to-be-tested printed circuit board 320 and the second to-be-tested printed circuit board 325. The first image capturing device 380 and the second image capturing device 385 respectively capture the reference mark projection 340' projected on the carrying platform and the first to-be-tested printed circuit board 320 and the second printed circuit board 325 to be tested. 340" image signal. The processor, not shown in the figure, is connected to the first image capturing device 380 and the second image capturing device 385. The processor can be used to calculate the first image capturing device 380 and the second The image signal captured by the image capturing device 385 is used to obtain surface state information of the first to-be-tested printed circuit board 320 and the second to-be-tested printed circuit board 325.

According to the embodiment, when the detection is performed, the two standard templates are first transported on the loading platform, and the first image capturing device 380 and the second image capturing device 385 respectively capture the image signal V of the reference mark projected by the standard template. ₀ and V ₀ ', and the image signals V ₀ and V ₀ ' are transmitted to the above processor. Then, the first printed circuit board 320 to be tested and the second printed circuit board 325 to be tested are transported by the above-mentioned carrier. The first light source 360 illuminates the reference mark 340 and generates reference mark shadows 340' and 340" on the first printed circuit board 320 to be tested and the second printed circuit board 325, respectively. The first image capturing device 380 and the second image The capturing device 385 captures the image signals V ₁ and V ₁ ' of the reference mark projections 340 ′ and 340 ′ of the first to-be-tested printed circuit board 320 and the second to-be-tested printed circuit board 325 , respectively, and the image signal V ₁ and V ₁ ' is transferred to the processor. The processor can respectively obtain the first circuit board 320 to be tested by calculating the image signals V ₀ and V ₁ after filtering the background data and the image signals V ₀ ′ and V ₁ ′ after filtering the background data, respectively. The surface information of the second printed circuit board 325 to be tested further determines whether the first printed circuit board 320 to be tested and the second printed circuit board 325 to be tested have an abnormal surface different from the standard template.

In a preferred example of the present embodiment, the detecting device 300 of the printed circuit board may further include a second light source 365. The second light source 365 is disposed obliquely above the loading platform as shown in the third figure. The second light source 365 may be a light source or a light emitting device that can generate a point light source effect. According to the present example, the first light source 360 and the second light source 365 may be disposed obliquely above the first printed circuit board 320 to be tested and the second printed circuit board 325 to be tested, respectively. The first light source 360 and the second light source 365 both illuminate the reference mark 340 in a non-projective manner, and generate a reference mark projection 340 on the carrying platform, the first printed circuit board 320 to be tested and the second printed circuit board 325 to be tested. According to the design of the present example, the first light source 360 and the second light source 365 can be set to be turned on. For example, the first image capturing device 380 is used to capture the first printed circuit board 320 to be tested. video signal V _1, only the first light source irradiating the reference numerals 360 and 340 generate the carrier on the stage reference mark and the projection of the first printed circuit board 320 under test and a second printed circuit board 325 under test. For use in a second image When the capturing device 385 captures the image signal V ₁ ' of the second printed circuit board 325 to be tested, only the second light source 365 illuminates the reference mark 340 and is on the carrying platform and the first printed circuit board 320 to be tested and the second to be tested. A reference mark projection is generated on the printed circuit board 325. Thus, the first image capturing device 380 and the second image capturing device 385 can obtain clearer image signals. In an embodiment according to the present example, in order The first light source 360 and the second light source 365 illuminate the reference mark 340 and generate a reference mark projection on the carrying platform and the first printed circuit board 320 to be tested and the second printed circuit board 325 to be tested, and the first image capturing device 380 and the first The second image capturing device 385 can capture the image signals V ₁ and V ₁ ', and V ₂ and V ₂ '. wherein the first light source 360 illuminates the reference mark 340, and the carrier and the first printed circuit to be tested A reference mark projection is generated on the board 320 and the second printed circuit board 325 to be tested, and the image signals respectively captured by the first image capturing device 380 and the second image capturing device 385 are V ₁ and V ₁ '; The light source 360 illuminates the reference mark 340, and the reference mark projection is generated on the carrying platform and the first printed circuit board 320 to be tested and the second printed circuit board 325 to be tested. The first image capturing device 380 and the second image capturing device 385 respectively The captured image signals are V ₂ and V ₂ '. The processor compares the image signals V ₀ and V ₁ , V ₀ and V ₂ after filtering the background data, respectively, to obtain a more detailed first test to be tested. Circuit board 320 surface information. Similarly, the processors are compared separately In addition to the video signal V and ₀ V after background information ₁ ', V ₀ and V _2', the second test result in more detailed information about the surface of the printed circuit board 325 of.

In another preferred embodiment of the present embodiment, the detecting device 300 of the printed circuit board may further include a second light source. The second light source is disposed obliquely above the loading platform. The second light source may be a point source or a light-emitting device that produces a point source effect. According to the present example, the first light source 360 and the second light source may be disposed obliquely above the first printed circuit board 320 to be tested and the second printed circuit board 325 to be tested, respectively. The first light source 360 and the second light source both illuminate the reference mark 340 in a non-projective manner, and generate a reference mark projection 340 on the carrying platform, the first printed circuit board 320 to be tested and the second printed circuit board 325 to be tested 325. According to the design of the present example, the first light source 360 and the second light source may be set to be turned on in turn. For example, the first image capturing device 380 is used to capture the image signal of the first printed circuit board 320 to be tested. V _1, the second light source illuminates only the tag 340 described above with reference to the carrier and to generate a reference mark projected on the test station and the first printed circuit board 320 and the second printed circuit board 325 under test; to be used in the second image capturing When the device 385 captures the image signal V ₁ ' of the second printed circuit board 325 to be tested, only the first light source 360 illuminates the reference mark 340 and is printed on the carrying platform and the first printed circuit board 320 to be tested and the second to be tested. A reference mark projection is generated on the circuit board 325. When the standard template is detected, the reference mark 340 is illuminated by the second light source, and is generated on the stage and the first printed circuit board 320 to be tested and the second printed circuit board 325 to be tested. After the test marker projection, so that a first image capturing device 380 to capture the template is placed in a standard position of the first printed circuit board under test 320 is a video signal V _0; a first light source 360 is irradiated to the reference numerals 340, the carrier After the reference mark projection is generated on the first and second printed circuit boards 320 to be tested, the second image capturing device 380 is captured by the second image capturing device 380 to be placed at the position of the second printed circuit board 325 to be tested. The image signal of the standard template is V ₀ '. When the printed circuit board to be tested is tested, the reference mark 340 is illuminated by the second light source, and the carrier and the first printed circuit board 320 to be tested and the second printed circuit board 325 are to be tested. A reference mark projection is generated, the image signal captured by the first image capturing device 380 to the first printed circuit board 320 to be tested is V ₁ ; the reference light 340 is illuminated by the first light source 360, and the first to be tested is printed on the carrier and the first to be tested. A reference mark projection is generated on the circuit board 320 and the second printed circuit board 325 to be tested, and the image signal captured by the second image capturing device 385 is V ₁ '. The processor compares the image signal V ₀ after filtering the background data. and V _1, A first printed circuit board under test to obtain information about the surface 320. The surface information processor than the video signal V ₀ after filtering out background information 'and V _1', to obtain the second printed circuit board 325 under test.

In summary, the present specification discloses a detecting device for a printed circuit board. The above-mentioned printed circuit board detecting apparatus includes a carrying platform, a reference mark, a light source, an image capturing device, and a processor. The above-mentioned carrier can be used to carry the printed circuit board to be tested. According to the design of the present specification, the above detection device of the printed circuit board can be After detecting a printed circuit board to be tested, it is also possible to detect a plurality of printed circuit boards to be tested at a time. The above reference mark is disposed above the above-mentioned carrier. The above reference mark may be a repeating unit of a plurality of geometric figures. The light source is disposed obliquely above the carrier. The light source described above may be a light source or a light-emitting device that produces a point source effect. The light source described above illuminates the reference mark in a non-orthoscopic manner and produces a reference mark projection on the stage and the printed circuit board to be tested. The image capturing device is disposed above the carrying platform for capturing a reference mark projection projected on the carrying platform and the printed circuit board to be tested. The processor is connected to the image capturing device, and can be used to calculate an image signal captured by the image capturing device to obtain surface information of the printed circuit board to be tested. According to the design of the present specification, in addition to the effect of quickly detecting the curvature of the surface of the board body, the detecting device of the above printed circuit board can simulate the surface 2D of the surface of the board to be tested by projecting light and shadow, and even Class 3D model, which effectively avoids misjudgment of the curvature of the surface of the board. In other words, the present specification provides a detection device that can simultaneously improve the detection rate and effectively avoid the occurrence of false positives, while reducing the cost of the detection device and facilitating the operation of the user.

Obviously, the present invention may have many modifications and differences as described in the above embodiments. It is therefore to be understood that within the scope of the appended claims, the invention may be The above are only the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention; any equivalent changes or modifications made without departing from the spirit of the present invention should be included in the following patent application. Within the scope.

200‧‧‧Printed circuit board testing equipment

220‧‧‧Printed circuit board to be tested

240‧‧‧ reference mark

240'‧‧‧ reference mark projection

260‧‧‧Light source

280‧‧‧Image capture device

Claims (10)

A detecting device for a printed circuit board, comprising: a carrying platform for carrying a printed circuit board to be tested; a plurality of reference marks, wherein the reference mark is disposed above the carrying platform; and a light source, wherein the light source is disposed on the carrying platform Incliningly above, the light source illuminates the reference mark in a non-projective manner, and generates a reference mark projection on the carrying platform and the printed circuit board to be tested; an image capturing device, wherein the image capturing device is disposed on the carrying platform Above; and a processor, the processor is coupled to the image capturing device. A detecting device for a printed circuit board according to the first aspect of the invention, wherein the reference mark is a repeating unit of a plurality of geometric figures. A detecting device for a printed circuit board according to the first aspect of the invention, wherein the reference numeral is a plurality of straight lines. A detecting device for a printed circuit board according to claim 1, wherein the reference mark comprises a set of first reference marks and a set of second reference marks, and the first reference mark and the second reference mark may have each other A set of two geometric figures that are not zero or 180 degrees. A detecting device for a printed circuit board according to the first aspect of the invention, wherein the reference mark is a mesh profile formed by two sets of straight lines. The apparatus for detecting a printed circuit board according to the first aspect of the invention, wherein the light source is a point light source or a light-emitting device capable of generating a point light source effect. The apparatus for detecting a printed circuit board according to the first aspect of the invention, wherein the light source illuminates the reference mark at an incident angle of about 10 to 85 degrees to generate the reference mark projection. A detecting device for a printed circuit board, comprising: a carrying platform for carrying a first printed circuit board to be tested and a second printed circuit board to be tested; a plurality of reference marks, wherein the reference mark is disposed above the carrying platform; a first light source and a second light source, wherein the first light source and the second light source are respectively disposed obliquely above the carrying platform, and the first light source and the second light source respectively illuminate the reference mark in a non-projective manner, and The first display image projection and the second reference mark projection are generated by the first test substrate and the second test printed circuit board; the first image capture device and the second image capture device, the first An image capturing device and a second image capturing device are respectively disposed above the carrying platform; and a processor, wherein the processor is respectively connected to the first image capturing device and the second image capturing device. A detecting device for a printed circuit board according to item 8 of the patent application, wherein the above A reference mark is a repeating unit of a plurality of geometric figures. The apparatus for detecting a printed circuit board according to the eighth aspect of the invention, wherein the first light source and the second light source are point light sources or light emitting devices capable of generating a point light source effect.