KR100666961B1 - Back light apparatus - Google Patents

Abstract

A backlight unit is provided to minimize the brightness variation of light applied to an object to be tested, thereby accurately identifying defects of the object to be tested, by partially controlling the reflective amount of light reflected from a reflective plate. A light source(110) emits a light to an object to be tested. A reflective plate(120) reflects the light emitted from the light source to the object to be tested. A brightness controlling member(130) is provided on the reflective plate. The brightness controlling member partially controls the amount of light reflected from the reflective plate, thereby making the brightness of light applied to the object to be tested uniform. The brightness controlling member corresponds to brightness holes, which are formed in the reflective plate.

Description

Back light device {BACK LIGHT APPARATUS}

1 is a perspective view showing a conventional backlight device,

2 is an exploded perspective view illustrating a backlight device according to a first embodiment of the present invention;

3 is a plan view illustrating a backlight device according to a first embodiment of the present invention;

4 is a cross-sectional view taken along line AA ′ of FIG. 3;

5 is a plan view showing another embodiment of the luminance correction hole of the backlight device according to the first embodiment of the present invention;

6 is a plan view showing another embodiment of the luminance correction hole of the backlight device according to the first embodiment of the present invention;

7 is an exploded perspective view showing a backlight device according to a second embodiment of the present invention;

8 is an enlarged view illustrating main parts of the backlight device according to the second embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

110: light source 111: connector

112: fixing part 120: reflecting plate

130,140: luminance correction means (130: luminance correction hole, 140: luminance correction sheet)

150: case 151: inlet

152: discharge port 160: suction fan

170: discharge fan 180: cooling fan

The present invention relates to a backlight device, and more particularly, to enable accurate inspection of an inspected object by improving the uniformity of the luminance of the inspected object, and to increase the deviation of the luminance due to heat by discharging heat quickly and effectively. The present invention relates to a backlight device for preventing damage to an object under test or peripheral parts.

In general, a device for inspecting a defect generated in a test object such as an LCD (liquid crystal display) panel is a method for diffusing, scattering, reflecting, or reflecting light collided with a test object or a defect present in the test object by irradiating light to the test object. The backlight device, which is an important element, is provided to allow defects to be detected in an inspected object such as an LCD panel by transmission.

When described with reference to the accompanying drawings, a backlight device used for inspection equipment such as a conventional LCD panel as follows.

1 is an exploded perspective view showing a backlight device according to the prior art. As shown, the conventional backlight device 10 is installed to be arranged in parallel by the case 11 and the lamp support base 12 in the case 11, a plurality of lamps for emitting light toward the test subject Circulating air 13 for cooling, through a reflecting plate 14 provided below the lamp 13 and reflecting light emitted from the lamp 13, and an opening 11a formed in the case 11; It includes a fan 15 to make. In addition, a stabilizer 16 is provided inside the case 11.

In the backlight device 10 according to the related art, light emitted by the lamp 13 passes through the upper plate 2 through the diffusion plate 1 and is irradiated to an object under test such as an LCD panel. At this time, the light emitted from the lamp 13 is reflected by the reflecting plate 14 and irradiated to the object under test.

Although the conventional backlight device 10 requires high luminance for accurate inspection, the luminance variation of the light irradiated to the object under test is inevitably generated according to the characteristics or arrangement of the lamp 13. In the subject under test, the luminance deviation between the central portion and the edge portion exceeded 25%.

To explain in detail the reason why the luminance deviation inevitably occurs, first, in the conventional backlight device 10, the color of the components including the case 11 is usually black, which is a black characteristic that absorbs light well. As a result, the luminance of the light irradiated onto the inspected object is lower in the edge portion closer to the case 11 than in the center portion.

In addition, the fan 15 is installed on the side surface of the case 11 in order to discharge heat of the high temperature lamp 13 provided in the case 11, but the fan 15 is located near the center of the case 11. By not properly dissipating heat to the outside, the temperature of the lamp 13 disposed at the center of the case 11 is higher than the temperature of the lamp 13 disposed at the edge of the case 11. Therefore, the lamp 13 disposed at the center of the case 11 has a high brightness due to the high temperature due to the characteristic of the lamp 13 that the brightness increases as the temperature increases, and conversely, the lamp disposed at the edge of the case 11. (13) has a low luminance due to a low temperature.

That is, due to the color difference of the case 11 and the temperature difference of the lamp 13 disposed inside the case 11, the luminance of light provided to the inspected object is lower near the edge than the reference, and near the center. There was a problem that the luminance deviation of the light irradiated to the subject to be increased further increases.

As such, since the luminance deviation of the light irradiated onto the inspected object has a large value, inspection of a specific part of the inspected object is not performed properly, which makes it difficult to accurately determine a defect of the inspected object, thereby bringing a defective inspector to normal. Many problems are caused in the inspection work such as determining or inspecting a normal inspected object as defective by causing an error of the inspection equipment.

In particular, since the LCD panel inspection equipment is used in a dark room, the color of most of the main body is black, so it absorbs light emitted from the lamp 13 to further increase the luminance deviation for the inspected object. The luminance uniformity of is further required.

In order to solve this problem, the desired brightness uniformity is maintained by dividing the plurality of lamps 13 into several areas by adjusting the brightness of each area, but a short length lamp is used for each area division. As a result, not only a large number of lamps 13 are required, but also the number of ballasts 16 is increased, which greatly increases the size of the equipment, the power used, the number of lamp replacements, and the like, and generates high heat. Has many problems.

In addition, the conventional backlight device 10 is limited by the distance to the inspected object for accurate inspection of the inspected object, so that heat is easily transferred and bent to the inspected object, resulting in a defect due to deformation, and high temperature to the surrounding components. This adversely affects the accuracy of inspection work and the equipment utilization rate. In order to solve this problem, the fan 15 is provided, but the heat for the central part in the case 11 is not properly discharged to the outside, and the heat is more difficult to dissipate due to the obstacle of the internal air flow, especially the reflector 14. It was.

By solving these problems, it is necessary to develop a backlight device that can minimize the effects of high temperature while maintaining high luminance.

In addition, the current backlight device has a problem in that the luminance deviation is further increased when corresponding to the enlargement equipment, but due to such equipment characteristics, the luminance uniformity of the inspected object is further required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to improve the uniformity of luminance of an object to be precisely inspected, and to discharge heat quickly and effectively. The present invention provides a backlight device that prevents an increase in luminance deviation due to damage and damage to an object or a peripheral part.

In the backlight device for illuminating the subject under test, the present invention provides a light source for emitting light to the subject, a reflector for reflecting light emitted from the light source to the subject, and a reflecting plate. And luminance correction means for partially correcting the light reflection amount of the reflecting plate so that the luminance of the light irradiated onto the inspected object is uniform.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

2 is an exploded perspective view showing a backlight device according to a first embodiment of the present invention. As shown, the backlight device 100 according to the present invention is installed in the inspection equipment for inspecting defects present in the inspected object, such as an LCD panel, and irradiates light to the inspected object, thereby rotating, scattering, reflecting, and transmitting light. A device for detecting defects present in an object under various properties, comprising: a light source 110 for emitting light, a reflecting plate 120 for reflecting light, and luminance correction means 130 provided at the reflecting plate 120 ).

The light source 110 has a long lifespan, a light emitting diode (also called "LED"), a cold cathode fluorescent lamp (also called "CCFL") with low noise and heat emission, or high brightness. Hot Cathode Fluorescent Lamps (also called "HCFLs") that can be implemented, or External Electrode Fluorescent Lamps (also called "EEFLs") that have high brightness uniformity with high brightness can be used. In this embodiment, a linear fluorescent lamp was used.

The light sources 110 are arranged in plural in parallel by terminals not shown at both ends thereof connected by the connector 111.

The reflecting plate 120 reflects the light emitted from the light source 110 to the object under test, and is positioned to be adjacent to one side of the light source 110, for example, the lower side. In addition, the reflector plate 120 may be made of stainless steel or aluminum, and a reflecting film may be stacked on an upper surface of the reflector 120 to efficiently reflect light emitted from the light source 110.

Meanwhile, the case 150 is provided to install the light source 110 and the reflector plate 120.

The case 150 has a plurality of fixing posts 153 vertically formed inside the case 150 so that the light source 110 and the reflecting plate 120 are installed, and the reflecting plate 120 and the light source are mounted on the fixing post 153. The connector 111 of 110 is fixed with a bolt or screw not shown. In addition, the reflective plate 120 and the connector 111, the fixing hole 121 and the fixing portion 112 are formed in order to be fixed to the fixing post 153, such as bolts or screws. Meanwhile, the case 110 is provided with a plurality of ballasts 154 inside.

The luminance correction means 130 is provided in the reflector 120 to partially correct the amount of light irradiated from the light source 110 and reflected from the reflector 120 so that the luminance of the light irradiated onto the object under test is uniform.

The luminance correction means 130 is a luminance correction hole formed in the reflector 120 in the present embodiment shown in FIGS. 2 and 3 to pass light.

The luminance correction hole 130 is formed in the reflector 120 so that the luminance of the light reaching the inspected object is higher than the surroundings, and is partially reflected by the light from the light source 110. Reduce

Luminance correction hole 130 is made of a plurality of for adjusting the light reflectance portion of the efficient reflecting plate 120, and due to the structural characteristics according to the arrangement of the light source 110, considering that the central portion is higher luminance than the edge. 2 and 3, the densely distributed toward the center from the edge of the reflector 120, or as shown in Figure 5, the diameter or width increases from the edge of the reflector 120 toward the center, As shown in FIG. 6, the gap is formed toward the center from the edge of the reflector 120.

On the other hand, the case 150 is formed in the inlet 151 in the high temperature portion generated due to the temperature difference generated by the characteristics and arrangement of the light source 110, and the discharge port 152 in the low temperature portion, respectively. In this embodiment, since the side facing the side of the light source 110 in the case 150 is higher than the side where the connector 111 for electrically and mechanically connecting the light source 110 is located, the case 150 is a light source. A plurality of suction ports 151 are formed on the side facing the side of 110, and a plurality of discharge holes 152 are formed on the side where the connector 111 is located.

Inlet 151 and outlet 152 of case 150 is provided with a suction fan 160 and a discharge fan 170 to suck and release air, respectively. That is, as shown in Figure 3, the suction fan 160 to suck the outside air through the suction port 151 to pass through the hot portion in the case 150, the discharge fan 170 is heated inside Air is discharged to the outside through the outlet 152 through the low temperature portion.

Meanwhile, a cooling fan 180 may be further included to efficiently lower the temperature in the case 150 through direct cooling of the light source 110 and the central portion of the case 150.

The cooling fan 180 is installed on the bottom surface of the case 150 to be adjacent to the luminance correction hole 130 to blow air for cooling the light source 110 through the luminance correction hole 130. Therefore, as shown in FIG. 4, the air blown by the cooling fan 180 is directly blown to the light source 110 through the luminance correction hole 130 to thereby suppress the increase in temperature due to the light source 110 to the maximum. In addition, it is not affected by the flow of air by the reflector 120, thereby improving the cooling efficiency in the case 150, particularly for the central portion.

In addition to the cooling fan 180, various blowing means such as an air nozzle for injecting air by pumping force or pressure may be used to blow air through the luminance correction hole 130.

Referring to the operation of the backlight device 100 according to the first embodiment of the present invention having such a structure as follows.

The light emitted from the light source 110 and the light reflected from the reflecting plate 120 are irradiated onto the inspected object for inspecting the inspected object such as an LCD panel, and at this time, formed at a position corresponding to a high luminance portion of the inspected object. The light emitted from the light source 110 passes through the luminance correction hole 130 to partially correct the reflection amount of the reflecting plate 120, thereby making the luminance of the light irradiated onto the inspected object uniform.

In addition, as shown in FIG. 3, the suction fan 160 sucks the outside air through the suction port 151 to directly heat the high temperature portion of the case 150, that is, the portion where the heat is emitted from the light source 110. The high temperature portion is primarily cooled by passing through the air, and the heated air inside the discharge fan 170 passes through the low temperature portion, that is, the connector 111 connection part with less heat emission from the light source 110, to allow the room to cool. The low temperature portion is secondarily cooled by releasing to the outside through the outlet 152. This reduces the temperature deviation between the hot portion and the low temperature portion of the case 150, thereby minimizing the luminance variation of the light source 110 caused by the nonuniformity of the temperature.

As shown in FIG. 4, the air blown by the cooling fan 180 is blown directly to the light source 110 through the luminance correction hole 130, thereby rapidly increasing the temperature due to the light source 110. In addition, the reflection plate 120 does not interfere with the flow of air so that the cooling efficiency is excellent in the case 150, particularly in the center portion.

In addition, the luminance correction hole 130 is formed to be densely distributed from the edge of the reflector 120 toward the center, or to increase in diameter or width, or to have a smaller gap, thereby resulting in a center due to structural characteristics such as the arrangement of the light source 110. It can effectively solve the problem of high brightness of the part.

7 is an exploded perspective view illustrating a backlight device according to a second embodiment of the present invention. As shown, the backlight device 200 according to the second embodiment of the present invention includes the light source 110, the reflector 120, and the luminance correction means 140 similarly to the first embodiment 100. In addition, the case 150 further includes a suction fan 160 and a discharge fan 170. Therefore, the same parts as those of the first embodiment 100 will be omitted, and the difference will be described in detail.

The luminance correction means 140 according to the present embodiment is a luminance correction sheet attached to the reflector 120 to absorb light.

The luminance correction sheet 140 is preferably manufactured in black to absorb light, and may be manufactured in a relatively thick shape such as a plate as well as a thin shape such as a film, and the planar shape is circular, elliptical, polygonal, Straight lines and curvatures can be mixed outside. In addition, the luminance correction sheet 140 may have an adhesive layer on the attachment surface so as to be detachably attached to the reflective plate 120.

Luminance correction sheet 140 is made of a plurality in order to effectively adjust the light reflection amount of the reflector 120, like the luminance correction hole 130 (shown in Figures 2 and 3, etc.) of the previous embodiment, Due to the structural characteristics according to the arrangement, the central portion has a higher luminance than the edge, so that the central portion is more densely distributed from the edge of the reflector 120 to the center, the diameter or width thereof is increased, or the gap is smaller.

On the other hand, not only the second embodiment 200 of the present invention but also the brightness correction means 130 and 140 according to the previous embodiment 100 are formed so as to satisfy the luminance uniformity within a predetermined deviation as well as the brightness required for the inspected object. Standard, number, location, etc. of the brightness correction means 130, 140 provided on the reflecting plate 120 to attach to the brightness correction means provided on the reflecting plate 120 by using a computer program capable of simulating brightness and brightness deviation ( The proper size, number, location, etc. of the 130, 140 are obtained first, and the reflecting plate 120 on which the luminance correction means 130, 140 based on such data is actually provided is used for the inspection equipment. Finally, the size, number, and position of the reflector 120 of the luminance correction means 130 and 140 are obtained according to the measured values.

Referring to the operation of the backlight device 200 according to the second embodiment of the present invention having such a structure is as follows.

As shown in FIG. 8, the light emitted from the light source 110 is reflected by the reflecting plate 120 and irradiated to the object under test, but the light reaching the luminance correcting sheet 140 is absorbed to thereby absorb the light of the reflecting plate 120. The reflection amount is partially adjusted or corrected. Accordingly, the luminance correction sheet 140 is provided at a position corresponding to a portion having a relatively high luminance in the inspected object, thereby reducing the amount of light irradiated to a portion having a relatively high luminance in the inspected object, thereby reducing the luminance of the light irradiated onto the inspected object as a whole. Make it uniform.

As described above, the backlight device according to the present invention can easily partially compensate for the light reflection amount of the reflecting plate, thereby minimizing the luminance deviation of the light irradiated onto the test object inevitably generated by the characteristics or arrangement of the light source, thereby providing excellent luminance uniformity. In this way, the number of light sources, power consumption, maintenance costs, etc. are reduced, and the inspection equipment can accurately determine defects of the inspected object, thereby effectively determining whether the inspected object is defective.

In addition, even if the inspection equipment requires high brightness, the heat generated from the light source is released quickly and effectively without stagnation in the device, thereby minimizing deformation due to temperature, thereby maintaining the quality of the inspected object. And prevents peripheral parts from being damaged by heat or causing errors.

What has been described above is only one embodiment for implementing the backlight device according to the present invention, and the present invention is not limited to the above-described embodiment, and as claimed in the following claims, the gist of the present invention Without departing from the scope of the present invention, any person having ordinary skill in the art will have the technical spirit of the present invention to the extent that various modifications can be made.

Claims (11)

delete In the backlight device for illuminating the subject for inspection, A light source for emitting light to the test object, A reflector for reflecting light emitted from the light source to the object under test; And a luminance correction means provided in the reflecting plate to partially correct the light reflection amount of the reflecting plate to make the luminance of the light irradiated onto the inspected object uniform. The brightness correction means, A luminance correction hole formed in the reflector to pass light Backlight device characterized in that. In the backlight device for illuminating the subject for inspection, A light source for emitting light to the test object, A reflector for reflecting light emitted from the light source to the object under test; And a luminance correction means provided in the reflecting plate to partially correct the light reflection amount of the reflecting plate to make the luminance of the light irradiated onto the inspected object uniform. The brightness correction means, A luminance correction sheet attached to the reflector to absorb light Backlight device characterized in that. The method of claim 2, The luminance correction hole, It is made up of a plurality, the densely distributed toward the center from the edge of the reflecting plate Backlight device characterized in that. The method of claim 2, The luminance correction hole, It is composed of a plurality, the diameter or width of the increase toward the center from the edge of the reflecting plate Backlight device characterized in that. The method of claim 2, The luminance correction hole, It is made of a plurality, the gap is smaller toward the center from the edge of the reflecting plate Backlight device characterized in that. The method of claim 2 or 3, A case in which the light source and the reflecting plate are installed, and a suction port is formed at a high temperature part and a discharge port is formed at a low temperature part, respectively, generated due to a temperature difference; A suction fan and a discharge fan installed in the case to respectively suck and discharge air through the suction port and the discharge port, respectively. Backlight device further including. The method of claim 2, A cooling fan installed adjacent to the luminance correction hole to blow air for cooling to the light source through the luminance correction hole; Backlight device further including. The method of claim 3, wherein The luminance correction sheet, It is made up of a plurality, the densely distributed toward the center from the edge of the reflecting plate Backlight device characterized in that. The method of claim 3, wherein The luminance correction sheet, It is composed of a plurality, the diameter or width of the increase toward the center from the edge of the reflecting plate Backlight device characterized in that. The method of claim 3, wherein The luminance correction sheet, It is made of a plurality, the gap is smaller toward the center from the edge of the reflecting plate Backlight device characterized in that.

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