JP4336699B2 - Backlight device and control method - Google Patents

Description

  The present invention relates to a backlight device and a control method, and more particularly to a backlight device used in a liquid crystal panel lighting inspection device and a backlight control method.

  A liquid crystal display (LCD) device is generally disposed in an LCD panel and includes a driving circuit that is operated by a microprocessor to display an image on the LCD panel.

  In the LCD panel, a lighting inspection is performed at the final stage of the manufacturing process. Such a lighting inspection apparatus for an LCD panel uses a probe unit to send an electrical signal to each of the data line and the gate line of the LCD panel to drive the driving circuit of the LCD panel. Note that a single liquid crystal display cannot emit light for image display. For this reason, in order to irradiate light through a liquid crystal display, an LCD panel needs a light source. Accordingly, the LCD device includes a backlight device that emits light from the back side of the LCD panel.

  FIG. 1 is an exploded perspective view illustrating a conventional backlight device. As shown in the figure, a conventional backlight device 10 is provided with a case 11 and a plurality of lamps 13 installed in the case 11 so as to be arranged in parallel by a lamp base 12 and emitting light toward an object to be inspected. It includes a reflector 14 installed under the lamp 13 and reflecting light emitted from the lamp 13, and a fan 15 for circulating air for cooling through an opening 11 a formed in the case 11. A ballast 16 is installed inside the case 11.

In such a conventional backlight device 10, the light emitted by the lamp 13 passes through the upper plate 2 through the diffusion plate 1 and is irradiated onto an object to be inspected such as an LCD panel. Here, the light emitted from the lamp 13 is reflected by the reflecting plate 14 and is applied to the object to be inspected.
Korean Patent Application Publication No. 2002-21076

However, in the conventional backlight device using the lamp 13 as a fluorescent lamp, a luminance deviation inevitably occurs.
That is, in the backlight device 10, the color of the components including the case 11 is normally black. Since black color absorbs light emitted from the lamp 13 in terms of characteristics, the luminance of the light applied to the object to be inspected is lower at the edge portion that is the end portion of the case 11 than at the central portion of the case 11.

  Further, a fan 15 is installed on the side surface of the case 11 for discharging the heat of the high temperature lamp 13 provided inside the case 11. However, the fan 15 transfers heat existing near the center in the case 11 to the outside. Since it is difficult to discharge, the temperature of the lamp 13 arranged near the center inside the case 11 becomes higher than the temperature of the lamp 13 arranged near the edge inside the case 11. Therefore, because of the characteristics of the lamp 13, the brightness increases as the temperature increases. Therefore, the lamp 13 disposed near the center inside the case 11 increases in temperature and brightness, and conversely, near the edge inside the case 11. The lamp 13 arranged in the lower temperature and the luminance is lowered.

Despite the occurrence of such a luminance deviation, there has conventionally been no method for compensating for such luminance non-uniformity.
In addition, the lamps 13 which are fluorescent lamps arranged side by side in the horizontal direction have their luminance at the end of the fluorescent lamps lowered by repeated turn-on and turn-off operations, and the brightness of each fluorescent lamp is reduced. Since the brightness is not constant, there is a problem that luminance deviation occurs.

  Further, since the lamp 13 has a non-constant life, it needs to be replaced, but there is a difficulty in that the backlight 10 must be disassembled every time. In addition, it is difficult to attach and remove the lamp 13, and the lamp 13 made of a weak material is easily broken during the operation. Therefore, the handling is not easy, and the operator takes a lot of time and labor to replace the lamp. There was a disadvantage.

  To deal with these problems, halogen lamps with relatively constant brightness and heat resistance are often used. However, there is still a problem with heat and the size is large, so the arrangement in the backlight unit is difficult. There was a problem that it was not easy.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a backlight that can be replaced quickly and locally when a part of the backlight device is abnormal. To provide an apparatus.

Another object of the present invention is to provide a backlight device and a control method that can achieve uniform luminance.
Still another object of the present invention is to provide a backlight device capable of reducing a luminance deviation.

  Still another object of the present invention is to provide a backlight device capable of simplifying components.

The backlight device according to the present invention includes a case, a base substrate installed inside the case, and an LED unit assembled as a module on the base substrate.
A backlight control method according to the present invention includes a step of dividing a base substrate on which a modularized LED unit is assembled into a plurality of arbitrary regions, and a step of sensing the luminance value of each of the divided regions for each region. And determining a luminance difference between the luminance value and a preset reference luminance value for each region, and adjusting the luminance value for each region based on the luminance difference.

  In the backlight device according to the present invention, when a plurality of LED units modularized on the base substrate are assembled, when some of the LED units are abnormal, it is possible to replace the LED units locally and quickly. Work can be performed in a short time and easily.

  Further, in the backlight device and the backlight control method according to the present invention, since the brightness of each of the plurality of LED units modularized is individually controlled, the brightness is uniformed among the plurality of LED units, This increases the accuracy of the inspection and improves the reliability of the product.

  Further, in the backlight device according to the present invention, among the plurality of LED units that are modularized and individually controlled, the LED unit arranged at the edge of the base substrate has high luminance, so that the luminance deviation is reduced. be able to.

Further, in the backlight device according to the present invention, the LED unit has a plurality of small LEDs arranged adjacent to each other, so that the luminance deviation can be reduced.
Further, in the backlight device according to the present invention, the reflecting plate is integrally provided on the block substrate of the LED unit on which the plurality of LEDs are arranged. Therefore, simplification of components can be achieved.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.
2 is an exploded perspective view of a backlight device according to an embodiment of the present invention, FIG. 3 is an assembled front view of the backlight device according to an embodiment of the present invention, and FIG. 4 is a side view of FIG. FIG. 5 is a first assembly example showing an assembly structure of an LED unit and a base substrate according to an embodiment of the present invention, and FIG. 6 is an enlarged perspective view showing a portion A of FIG. It is.

  As shown in FIGS. 2 and 3, the backlight device includes a case 100, a modularized LED unit 110 that is installed inside the case 100 and emits light toward the object to be inspected, and a plurality of units 110. It includes a base substrate 120 installed and a plurality of fans 102 that circulate air in the case 100 for cooling. Here, the case 100 has a substantially quadrangular shape with an upper part opened and a housing space provided therein, and a plurality of ballasts 101 are installed on the inner lower surface.

  A plurality of openings 102a are formed in the first side surface of the case 100 along the longitudinal direction, and a fan 102 is attached to each opening 102a. Note that the fan 102 may be installed on the second side surface of the case 100 facing the first side surface, or on both side surfaces (first and second side surfaces) thereof.

  As shown in FIG. 4, a plurality of power supply units 104 are formed on the third side surface of the case 100. A plurality of heat radiating holes 106 for releasing heat are also formed on the third side surface.

In such a case 100, the base substrate 120 and the LED unit 110 assembled as a module on the base substrate 120 are housed together.
The base substrate 120 is substantially the same as the shape inside the case 100 and is accommodated in the case 100 with a smaller size. A control unit 127 (see FIG. 13) for supplying the voltage applied through the power supply unit 104 to the LED unit 110 is formed on the base substrate 120 as a circuit pattern. The control unit 127 controls each LED unit 110 described below.

  As shown in FIG. 6, the LED unit 110 is formed in a square plate material shape, and a plurality of LEDs 112 that are soldered onto the block substrate 111 and electrically connected to the block substrate 111 provided with a reflecting plate. It is comprised including.

Here, the block substrate 111 may have a reflecting plate function by coating or the like, and in some cases, a separate reflecting plate (not shown) may be integrally installed.
A luminance sensor 116 capable of sensing luminance is further provided on the block substrate 111.

  The modularized LED units 110 are adjacent to each other on the base substrate 120, and a plurality of LED units 110 are assembled and arranged on the base substrate 120. Hereinafter, a first assembly example of the LED unit 110 and the base substrate 120 will be described in detail.

  In the first assembly example shown in FIGS. 5 and 6, a plurality (for example, two) of plugs 113 electrically connected to the respective LEDs 112 are formed on the lower surface of the LED unit 110, and correspond to the plurality of plugs 113. A plurality of (for example, two) socket portions 121 are arranged on the base substrate 120 at the position.

  Therefore, the plug 113 of the LED unit 110 is securely connected to the socket portion 121 of the base substrate 120, and the LED unit 110 and the base substrate 120 are electrically connected and assembled in a state in which separation is prevented.

Thus, each different LED unit 110 is assembled adjacent to the base substrate 120.
FIG. 7 is a perspective view showing another assembly structure (second assembly example) of the LED unit 110 and the base substrate 120, and FIG. 8 is an enlarged perspective view showing a portion B of FIG. FIG. 9 is an enlarged perspective view of a portion C in FIG.

In the second assembly example shown in FIGS. 7 to 9, the LED unit 110 and the base substrate 120 are assembled by the locking means.
As for the locking means, hanging hooks 114 are formed on both side ends of each LED unit 110, and a plurality of mounting portions 122 that are partitioned in a predetermined direction are formed on the base substrate 120. Hanging grooves 122a are formed at intervals of the size of the LED unit 110 along the longitudinal direction of the side surface.

  The hanging rod 114 normally protrudes, and is formed so that a spring (not shown) installed in the internal space can be compressed and slidably moved toward the internal space. The hanging groove 122a forms a constant space inside.

  When assembling the LED unit 110 to the mounting portion 122 of the base substrate 120, the user first holds the hooks 114 on both side ends of the LED unit 110 and slides them inside the LED unit 110. Is mounted on the mounting portion 122. Then, when the user removes the hook 114 held by the user, the hook 114 protrudes to the outside of the LED unit 110 due to the restoring force of the spring, and the protruding hook 114 is inserted into the hook groove 112a. Therefore, the LED unit 110 is assembled to the base substrate 120 in a state in which the LED unit 110 is prevented from being detached upward.

  In this way, each other LED unit 110 having locking means is assembled to the base substrate 120. Then, a substantially flat electrical connection terminal is installed on the lower surface of the LED unit 110 and the mounting portion 122 of the base substrate 120 corresponding thereto, so that the LED unit 110 and the base substrate 120 are electrically connected. It has become.

10 is a perspective view showing still another assembly structure (third assembly example) of the LED unit 110 and the base substrate 120, and FIG. 11 is an enlarged perspective view showing a portion D of FIG. is there.
In the third assembly example shown in FIGS. 10 and 11, a plurality of slide grooves 124 are formed in a predetermined direction on the base substrate 120 so as to be separated by a predetermined distance, and the lower surface of the LED unit 110 corresponds to the slide grooves 124. A slide projection 115 having a shape to be formed is formed. As a result, the plurality of LED units 110 are slidably connected to the base substrate 120 along the slide grooves 124 of the base substrate 120.

  Then, a substantially flat connection terminal (not shown) is installed on the slide groove 124 of the base substrate 120 corresponding to the slide protrusion 115 of the LED unit 110, and the LED unit 110 and the base substrate 120 are electrically connected. Connected.

  On the other hand, stopper means is further installed in the slide groove 124 to prevent the LED unit 110 assembled by the slide mechanism from being detached, and this stopper means includes a hook portion 125 disposed at the insertion opening of the slide groove 124. .

The hook portion 125 protrudes along the internal space of the slide groove 124 and can protrude due to the restoring force of the spring 126.
When the LED unit 110 is assembled to the base substrate 120, the hook portion 125 of the slide groove 124 formed in the base substrate 120 is pushed, and the LED unit 110 is gradually slid and inserted. Of the plurality of LED units 110 inserted into one slide groove 124, the LED unit 110 located at the forefront (position close to the insertion slot) touches the protruding hook portion 125 to prevent separation from the slide groove 124. Is done.

  A plurality of LED units 110 that are modularized as described above are arranged on the base substrate 120 adjacent to each other on the base substrate 120 and can be attached or detached depending on the assembly structure. it can.

It is also possible to assemble so that one modularized LED unit 110 can be attached to and detached from the base substrate 120.
A method for controlling the LED unit 110 assembled in a modular manner on the base substrate 120 configured as described above will be described in more detail.

FIG. 12 is a flowchart of a backlight control method according to an embodiment of the present invention, and FIG. 13 is a schematic block diagram illustrating a control structure of the LED unit 110.
As shown in FIGS. 12 and 13, in step 200, the control unit 127 divides the base substrate 120 on which the LED unit 110 of the module is assembled into arbitrary regions.

  Here, an external power source is applied to the base substrate 120 to which the LED unit 110 of the module is mounted through the power supply unit 104, and the control unit 127 of the base substrate 120 that receives the power supply through the power supply unit 104, The luminance control of each LED unit 110 assembled in a modular manner becomes possible.

As a result, the base substrate 120 on which the plurality of LED units 110 are arranged adjacent to each other is divided into arbitrary regions (see FIG. 3).
Arbitrary area division can be one LED unit 110, and preferably, the area is divided into areas including several LED units 110.

  Next, in step 210, the control unit 127 senses luminance for each divided area. Specifically, the control unit 127 senses the luminance with the luminance sensor 116 provided in each LED unit 110, and totals the measured luminance value of each LED unit 110 for each divided area.

Next, in step 220, the control unit 127 determines the difference between the brightness value (total value) sensed for each region and the set reference brightness value.
The control unit 127 is preset with a luminance value corresponding to one LED unit 110 or a luminance value for each region as a reference luminance value, and the luminance value sensed for each region by this reference luminance value. Judge the difference.

  Then, the control unit 127 adjusts the luminance value for each region in step 230 or step 240. Specifically, the control unit 127 raises the voltage applied to the LED unit 110 having a low luminance value and raises the magnitude of the luminance value to the reference luminance value in a region where the luminance value is lower than the reference luminance value. (Step 230).

  Further, the control unit 127 reduces the magnitude of the luminance value to the reference luminance value by reducing the voltage applied to the LED unit 110 having a high luminance value in the region where the luminance value is higher than the reference luminance value. (Step 240).

Accordingly, each LED unit 110 assembled on the base substrate 120 is maintained at a uniform brightness through the control unit 127.
As a more efficient method of uniform brightness control, the brightness of the LED unit 110 arranged at the edge of the base substrate 120 is higher than that of the central LED unit 110 based on the characteristics of the LED units 110 that are modularized and controlled. It is desirable to install a tall one.

As described above, the modularized LED unit 110 is very useful because it can be locally replaced when some of the LED units 110 are abnormal.
The embodiments of the present invention have been described in detail above. However, the present invention is not limited to these embodiments, and those skilled in the art to which the present invention pertains do not depart from the spirit and scope of the present invention. Can be modified or changed.

1 is an exploded perspective view showing a backlight device according to the prior art. 1 is an exploded perspective view of a backlight device according to an embodiment of the present invention. 1 is an assembled front view of a backlight device according to an embodiment of the present invention. FIG. 4 is a side view of FIG. 3. It is the perspective view which showed the assembly structure of the LED unit and base substrate by a 1st assembly example. It is the perspective view which expanded and showed the A section of FIG. It is the perspective view which showed the assembly structure of the LED unit and base substrate by the 2nd assembly example. It is the perspective view which expanded and showed the B section of FIG. It is the perspective view which expanded and showed the C section of FIG. It is the perspective view which showed the assembly structure of the LED unit and base substrate by the 3rd assembly example. It is the perspective view which expanded and showed the D section of FIG. 3 is a flowchart illustrating a backlight control method according to an embodiment of the present invention. It is a schematic block diagram which shows the control structure of the LED unit by one Embodiment of this invention.

Explanation of symbols

100 Case 101 Ballast 102 Fan 104 Power supply unit 110 LED unit 111 Block substrate 112 LED
113 Plug 114 Hanging hook 115 Slide protrusion 120 Base substrate 121 Socket portion 122 Mounting portion 122a Hanging groove 124 Slide groove 125 Hook portion 126 Spring

Claims (10)

In the backlight device,
Case and
A base substrate installed inside the case;
A plurality of LED units assembled adjacent to each other on the base substrate and detachably installed ,
A plug is formed on the lower surface of each LED unit,
A socket part into which the plug is inserted is formed on the base substrate at a position corresponding to the plug,
The backlight device, wherein each LED unit and the base substrate are electrically connected .   The backlight device according to claim 1, wherein the base substrate further includes a control unit that controls luminance of the LED unit. 2. The backlight according to claim 1, wherein each of the plurality of LED units is modularized, and an LED unit disposed at an edge of the base substrate among the plurality of LED units has high luminance. Equipment . The LED unit is
A block substrate provided with a reflector;
A plurality of LEDs arranged on the block substrate;
The backlight device according to claim 1, comprising: The backlight device according to claim 1, wherein the LED unit further includes a luminance sensor . In the backlight device,
Case and
A base substrate installed inside the case;
A plurality of LED units assembled adjacent to each other on the base substrate and detachably installed,
A backlight device further comprising a locking means for fixing each LED unit to the base substrate . The locking means is
Hanging hooks formed on both ends of the LED unit;
A hanging groove formed on the base substrate and locked to the hanging hook,
The backlight device according to claim 6, comprising: In the backlight device,
Case and
A base substrate installed inside the case;
A plurality of LED units assembled adjacent to each other on the base substrate and detachably installed,
A plurality of slide grooves formed on the base substrate and spaced apart from each other by a predetermined distance;
A slide protrusion formed on the lower surface of each LED unit, wherein each LED unit is attached to the base substrate by inserting the slide protrusion of each LED unit into one of the plurality of slide grooves. , The slide protrusion,
A backlight device comprising: 9. The backlight device according to claim 8, wherein stopper means are respectively disposed in the plurality of slide grooves of the base substrate . The stopper means includes
The backlight device according to claim 9, further comprising a hook portion that is disposed at each insertion opening of the plurality of slide grooves and is provided so as to protrude by a restoring force of a spring .

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