JPH10289606A - Back light and liquid crystal display device therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate replacement work of a fluorescent lamp used for a back light without taking much trouble. SOLUTION: A light source unit 3 which involves a fluorescent lamp 12 and a lamp cover 13 for covering the fluorescent lamp 12 is provided, and the whole light source unit 3 is removably-attached onto a light guide unit 2. For the replacement of the fluorescent lamp 12, the whole light source unit 3 is replaced without only the fluorescent lamp 12 being replaced. It is thus possible to prevent the fluorescent lamp 12 from being broken due to external force at the time of replacing the fluorescent lamp 12, thereby facilitating the replacement work of the fluorescent lamp 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight and a liquid crystal display using the same.

[0002]

2. Description of the Related Art A backlight used in a liquid crystal display device or the like is a light guide plate for guiding light emitted from an incident surface to a light emitting surface, and a linear fluorescent lamp arranged at a position facing the incident surface of the light guide plate. And a lamp cover that covers the fluorescent lamp and guides light from the fluorescent lamp toward the incident surface of the light guide plate.

In such a backlight, when the fluorescent lamp burns out or its luminance is lowered due to its life, the fluorescent lamp is replaced. As a device and an invention for facilitating replacement of the fluorescent lamp, those described in Japanese Utility Model Laid-Open Publication No. Hei 6-88006 and Japanese Patent Laid-Open Publication No. Hei 8-152624 are known.

[0004]

However, the invention and the invention described in Japanese Utility Model Application Laid-Open No. Hei 6-88006 and Japanese Patent Application Laid-Open No. Hei 8-152624 described above all disclose a fluorescent lamp by covering the fluorescent lamp. The lamp is removed from the lamp cover, etc., and only the fluorescent lamp is replaced.

Here, the fluorescent lamp is very thin, and when the fluorescent lamp is attached to or detached from a lamp cover or the like, the fluorescent lamp may be damaged by the action of an external force.
If the fluorescent lamp is damaged, mercury and glass fragments will scatter,
It has a bad effect on the human body, or broken glass enters between the light guide plate and the liquid crystal display element to form a shadow on the liquid crystal display surface.

Therefore, the replacement of the fluorescent lamp must be performed carefully, and the replacement of the fluorescent lamp is troublesome. In some cases, a service person is called to replace the fluorescent lamp, and work using the liquid crystal display device is suspended until the service person comes.

[0007] Each user stores a new fluorescent lamp in preparation for replacement of the fluorescent lamp. However, since the fluorescent lamp is stored in a paper box, the fluorescent lamp is stored in a box when the fluorescent lamp is stored or transported. The fluorescent lamp may be damaged when external force is applied from outside.

Accordingly, an object of the present invention is to provide a backlight capable of easily replacing a fluorescent lamp and a liquid crystal display device using the same.

[0009]

According to a first aspect of the present invention, there is provided a light guide unit including a light guide plate formed in a flat rectangular shape and guiding incident light from an incident surface to a light emitting surface.
A light source unit that has a linear fluorescent lamp disposed at a position facing the incident surface of the light guide plate and a lamp cover that covers the fluorescent lamp and is detachably attached to the light guide unit. Prepare.

Therefore, when replacing the fluorescent lamp, not only the fluorescent lamp is replaced, but the entire light source unit including the fluorescent lamp and the lamp cover is replaced. Therefore, when the fluorescent lamp is replaced, the fluorescent lamp is damaged by an external force. In addition, the replacement work of the fluorescent lamp can be easily performed. Since the fluorescent lamp is stored and transported as a light source unit including a lamp cover, damage to the fluorescent lamp during storage and transport can be prevented.

According to a second aspect of the present invention, in the backlight according to the first aspect of the present invention, a hook provided at one end of the light guide knit; a fitting portion provided at the other end of the light source unit; A locking projection provided at one end of the optical unit and locking the hook; and a fitting portion provided at the other end of the light guide unit and fitting the fitting portion.

Therefore, the attachment of the light source unit to the light guide unit is performed by engaging the hook with the engaging projection and fitting the fitting portion of the light source unit to the fitting portion of the light guide unit. Therefore, attachment and detachment of the light source unit and the light guide unit can be performed without using a tool. Further, by locking the hook and the locking projection, the accuracy of the distance between the hook and the fitting part of the light source unit and the distance between the locking projection and the fitting part of the light guide unit are low. Also, the light source unit can be attached to the light guide unit satisfactorily. In addition, since the light source unit has a hook at one end and a fitting portion at the other end, the light guide unit is not mounted in the opposite direction, and the position of the power supply connector of the fluorescent lamp is inverted. It never happens.

According to a third aspect of the present invention, in the backlight according to the second aspect, the light source unit is provided rotatably around a locking portion between the hook and the locking projection. When the light source unit is rotated about the center, the fitting part of the light source unit and the fitting part of the light guide unit are fitted.

Therefore, the hook is locked to the locking projection, and the light source unit is rotated about the locking portion, so that the fitting portion of the light source unit and the fitting portion of the light guide unit are fitted. Then, the attachment of the light source unit to the light guide unit is completed.

According to a fourth aspect of the present invention, there is provided a liquid crystal display device according to any one of the first to third aspects, and a transmissive liquid crystal display element disposed on a light emitting surface of a light guide plate of the backlight. ;

Therefore, according to the liquid crystal display device of the present invention,
When the fluorescent lamp burns out or the brightness is reduced due to its life, not only the fluorescent lamp but also the light source unit is replaced as a whole, so that the replacement work of the fluorescent lamp can be easily performed without any trouble.

According to a fifth aspect of the present invention, there is provided a backlight according to any one of the first to third aspects, and a transmissive liquid crystal display disposed on a light emitting surface of a light guide plate of the backlight. A storage case for storing the backlight and the transmissive liquid crystal display element; a lid having an opening at a portion facing the transmissive liquid crystal display element and fitted to an outer peripheral portion of the storage case; A case; a plurality of fitting portions formed on the outer peripheral surface of the storage case; and a plurality of fitting portions formed on the inner peripheral surface of the lid case and resiliently fitted with the fitting portions. And;

Therefore, the backlight and the transmissive liquid crystal display element are housed in the storage case, and the lid case is fitted to the outer peripheral portion of the storage case. By resiliently fitting the fitting portion formed on the outer peripheral surface of the storage case, the liquid crystal display device can be assembled without using screws or tools. As a result, the assembling time of the liquid crystal display device is shortened, and it is not necessary to form a boss or the like for mounting a screw on the storage case or the lid case, thereby reducing the size of the liquid crystal display device.

[0019]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view of a backlight,
FIG. 2 is a perspective view showing an assembled state of the backlight, and FIG.
FIG. 1 is a vertical sectional front view showing a liquid crystal display device using this backlight.

First, the backlight 1 will be described.
The backlight 1 is configured by attaching two light source units 3 to a light guide unit 2.

The light guide unit 2 includes a light guide plate 4, a reflection sheet 5 and a diffusion sheet 6 formed in a flat rectangular shape, and a hook frame 7, a fitting frame 8, Is fixed.

The side surfaces of the two opposing sides of the light guide plate 4 are an incident surface 4a on which light is incident, and the surface of the light guide plate 4 is a light emitting surface 4b on which the incident light is guided and emitted. .
The reflection sheet 5 and the diffusion sheet 6 are pasted together with a double-sided tape or the like, the diffusion sheet 6 is pasted on the light emitting surface 4b which is the surface of the light guide plate 4, and the reflection sheet 5 is pasted on the back surface of the light guide plate 4. Have been. The hook frame 7 and the fitting frame 8 are formed in a substantially U-shaped cross section so as to sandwich the light guide plate 4, and the incident surface 4 a of the light guide plate 4 is formed.
Is fixed to the side surface orthogonal to. The fixing of the frames 7 and 8 to the light guide plate 4 is performed by inserting pins 11 into pin holes 9 formed in the frames 7 and 8 and pin holes 10 formed in the light guide plate 4. The reflection sheet 5 and the diffusion sheet 6 are also provided with the pins 11.
Is formed in the pin hole 10.

The light source unit 3 is disposed at a position facing the incident surface 4a and has a linear fluorescent lamp 12
And a lamp cover 13 for covering the fluorescent lamp 12 and holding the fluorescent lamp 12 so as to reflect the light emitted from the fluorescent lamp 12 to the incident surface 4a. At one end of the fluorescent lamp 12, a connector 14 is provided for connecting the fluorescent lamp 12 to a power supply unit.

The lamp cover 13 is formed in a substantially U-shaped cross section so as to sandwich the light guide unit 2, and a pair of hooks 15 is formed at one end thereof.
5 is locked by a pair of locking projections 16 formed at both ends of the hook frame 7. At the other end of the lamp cover 13, a pair of fitting holes 17 as fitting portions are formed, and these fitting holes 17 are formed as a pair of fitting portions formed at both end portions of the fitting frame 8. The fitting projection 18 is fitted.

Next, the liquid crystal display device 19 will be described. The liquid crystal display device 19 includes the backlight 1,
A transmissive liquid crystal display element 20 and a storage case 21 for accommodating the backlight 1 and the transmissive liquid crystal display element 20
And a lid case 22 fitted to the outer peripheral portion of the storage case 21. An opening 23 is formed in the cover case 22 at a portion facing the display surface of the transmissive liquid crystal display element 20. A plurality of fitting projections 24 as fitting parts are formed on the outer peripheral surface of the storage case 21, and a plurality of fitting concave parts 25 as fitting parts are formed on the inner peripheral surface of the lid case 22. Have been. By fitting the lid case 22 to the storage case 21, the fitting concave portion 25 and the fitting convex portion 2 are formed.
4 are resiliently fitted.

First, a procedure for assembling the backlight 1 in such a configuration will be described. The reflection sheet 5 and the diffusion sheet 6 are attached to the light guide plate 4, and the hook frame 7 and the fitting frame 8 are fitted to the light guide plate 4. Then, the pin holes 9 of the frames 7 and 8 and the pin holes 1 of the light guide plate 4 are formed.
By inserting the pin 11 by aligning it with 0,
The frames 7 and 8 are fixed to the light guide plate 4 and the light guide unit 2
Is assembled. Here, the frame 7 to the light guide plate 4,
By fixing the pin 8 with the pin 11 without using a screw, the fixing operation can be performed without using a tool. In addition, dust generated when the screw is tightened is not generated, and the dust does not adhere to the surface of the light guide plate 4 and appear as a shadow during liquid crystal display.

After assembling the light guide unit 2, the backlight 1 is assembled by attaching the light source unit 3 to the light guide unit 2. As shown in FIG. 2, the light source unit 3 is attached to the light guide unit 2 by hooking the hook 15 to the locking projection 16 and rotating the light source unit 3 in the direction indicated by the arrow around the locking portion. The fitting is performed by fitting the fitting hole 17 to the sightseeing projection 18. Therefore, attachment of the light source unit 3 to the light guide unit 2 can be easily performed without using a tool.

The attachment of the light source unit 3 to the light guide unit 2 is performed by engaging the hook 15 with the engaging projection 16 at one end of the light source unit 3. Even if a slight gap is generated between the lock member and the lock member, the locked state can be maintained. For this reason, hook 15
The distance between the fitting projection 17 and the locking projection 16 and the fitting projection 18
The distance between the light source unit 3 and the light source unit 3 can be favorably attached to the light guide unit 2 even if the accuracy is low.

The light source unit 3 has a hook 1 at one end.
5 is provided and the fitting hole 17 is provided at the other end, so that it is possible to prevent the light source unit 3 from being mounted in the light guide unit 2 in the opposite direction. Then, since the light source unit 3 is mounted in the opposite direction, the position of the connector 14 of the fluorescent lamp 12 becomes a position distant from the power supply unit, so that the light source unit 3 is not mounted again.

After assembling the backlight 1 by attaching the light source unit 3 to the light guide unit 2, the backlight 1 and the transmissive liquid crystal display element 20 are stored in a storage case 21. The liquid crystal display device 19 is assembled by fitting the lid case 22 to the outer peripheral portion. When the lid case 22 is fitted into the storage case 21, the opening 23 formed in the lid case 22 faces the display surface of the transmissive liquid crystal display element 20, and the opening 23
The display by the transmissive liquid crystal display element 20 is performed through the LCD.

When the lid case 22 is fitted into the storage case 21, a fitting projection 24 formed on the outer peripheral surface of the storage case 21 and a fitting concave portion 25 formed on the inner peripheral surface of the lid case 22 are formed. Are resiliently fitted. Therefore, the operation of assembling the liquid crystal display device 19 by covering the backlight 1 and the transmissive liquid crystal display element 20 with the storage case 21 and the lid case 22 can be performed without using screws or tools. Accordingly, the assembling time of the liquid crystal display device 19 is shortened, and the assembling work can be easily performed. Also, the storage case 21
It is not necessary to form a boss or the like for attaching a screw to the cover case 22 by protruding, so that the size of the liquid crystal display device 19 can be reduced.

Next, the replacement of the fluorescent lamp 12 when the fluorescent lamp 12 is burned out or the brightness is reduced due to its life will be described. When replacing the fluorescent lamp 12, the lid case 22 is removed from the storage case 21, the connection of the connector 14 is disconnected, and the transmissive liquid crystal display element 20 and the backlight 1 are taken out of the storage case 21. The light source unit 3 is removed from the light guide unit 2 by releasing the engagement between the fitting hole 17 and the fitting projection 18 and releasing the engagement between the hook 15 and the engagement projection 16. After the light source unit 3 including the fluorescent lamp 12 to be replaced is removed from the light guide unit 2, the prepared new light source unit 3 is attached to the light guide unit 2 by the above-described procedure. After assembling the backlight 1 by attaching the new light source unit 3 to the light guide unit 2, the backlight 1 and the transmissive liquid crystal display element 20 are stored in the storage case 21, and the lid case 22 is placed in the storage case 21. The liquid crystal display element 19 is assembled by fitting.

Here, when replacing the fluorescent lamp 12, not only the fluorescent lamp 12 is replaced, but the entire light source unit 3 in which the fluorescent lamp 12 to be replaced and the lamp cover 13 are integrated. Accordingly, the fluorescent lamp 12 is not damaged due to an external force acting on the fluorescent lamp 12 at the time of the replacement, and the replacement operation of the fluorescent lamp 12 can be easily performed. Further, since the fluorescent lamp 12 is stored and transported as the light source unit 3 in which the lamp cover 13 and the like are integrated, breakage of the fluorescent lamp 12 during storage and transport is prevented.

In the present embodiment, the light guide plate 4
The light guide unit 2 constituted by laminating the reflection sheet 5 and the diffusion sheet 6 and fixing the hook frame 7 and the fitting frame 8 to the light guide plate 4 has been described as an example. Instead of using the fitting 7 and the fitting frame 8, a light guide unit having a configuration in which a locking protrusion or a fitting protrusion is formed on the periphery of the light guide plate 4 may be used. With such a configuration, the number of parts is reduced, and the cost can be reduced.

[0035]

According to the backlight of the first aspect of the present invention, when replacing the fluorescent lamp, the entire light source unit including the fluorescent lamp and the lamp cover is replaced instead of replacing only the fluorescent lamp. It is possible to prevent the fluorescent lamp from being damaged by the action of an external force when replacing the lamp, and to easily replace the fluorescent lamp. Further, it is possible to prevent the fluorescent lamp from being damaged when the light source unit is stored or transported. Can be prevented.

According to the backlight of the second aspect, the light source unit and the light guide unit can be attached and detached without using a tool. Further, by locking the hook and the locking projection, the accuracy of the distance between the hook and the fitting part of the light source unit and the distance between the locking projection and the fitting part of the light guide unit are low. Also, the light source unit can be attached to the light guide unit satisfactorily. In addition, since the light source unit has a hook at one end and a fitting portion at the other end, it is possible to prevent the light guide unit from being mounted in the reverse direction, and the position of the power supply connector of the fluorescent lamp is reversed. It is possible to prevent re-attachment due to the situation.

According to the backlight according to the third aspect of the present invention, the light source unit is attached to the light guide unit by hooking the hook of the light source unit to the locking projection of the light guide unit.
Since the light source unit is rotated around the locking portion and the fitting portion of the light source unit is fitted to the fitting portion of the light guide unit, the light source unit can be easily attached to the light guide unit. You.

According to a fourth aspect of the present invention, there is provided a backlight according to any one of the first to third aspects, and a transmissive liquid crystal display disposed on a light emitting surface of a light guide plate of the backlight. The light source unit including the fluorescent lamp is replaced as a whole when the fluorescent lamp is burned out or the brightness is reduced due to its life, so that the replacement work of the fluorescent lamp can be easily performed without any trouble.

According to the liquid crystal display device of the present invention, when the lid case is fitted to the outer peripheral portion of the storage case storing the backlight and the transmission type liquid crystal display element, the inner peripheral surface of the lid case is formed. The fitting part formed on the outer case and the fitting part formed on the outer peripheral surface of the storage case resiliently fit and the storage case and the lid case are fixed, so the liquid crystal can be used without using screws or tools. The display device can be assembled, and the assembling time of the liquid crystal display device can be shortened. Further, since it is not necessary to form a boss or the like for mounting a screw on the storage case or the lid case, it is possible to reduce the size of the liquid crystal display device.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a backlight according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an assembled state of a backlight.

FIG. 3 is a longitudinal sectional front view showing a liquid crystal display device in which a lid case is fitted in a storage case in which a backlight and a transmissive liquid crystal display element are stored.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Back light 2 Light guide unit 3 Light source unit 4 Light guide plate 4a Incident surface 4b Light emitting surface 12 Fluorescent lamp 13 Lamp cover 15 Hook 16 Locking convex part 17 Fitting part 18 Fitting part 20 Transmissive liquid crystal display element 21 Storage case 22 Lid case 24 Fitting part 25 Fitting part

Claims (5)

[Claims] 1. A light guide unit including a light guide plate formed in a flat rectangular shape and guiding incident light from an incident surface to a light emitting surface;
A light source unit that has a linear fluorescent lamp disposed at a position facing the incident surface of the light guide plate and a lamp cover that covers the fluorescent lamp and is detachably attached to the light guide unit. A backlight, comprising: A hook provided at one end of the light source unit; a fitting portion provided at the other end of the light source unit; a locking projection provided at one end of the light guide unit and locking the hook. The backlight according to claim 1, further comprising: a fitting portion provided at the other end of the light guide unit and fitted with the fitting portion. 3. The light source unit is provided rotatably about a hook between a hook and a locking projection, and the light source is turned when the light source unit is rotated about the locking portion. The backlight according to claim 2, wherein the fitting part of the unit and the fitting part of the light guide unit are fitted. 4. A liquid crystal display comprising: the backlight according to claim 1; and a transmission type liquid crystal display element disposed on a light emitting surface of a light guide plate of the backlight. apparatus. 5. The backlight according to claim 1, a transmission type liquid crystal display element disposed on a light emitting surface of a light guide plate of the backlight, and the backlight and the transmission type liquid crystal display. A storage case for storing the element; a lid case having an opening at a portion facing the transmissive liquid crystal display element and fitted to an outer peripheral portion of the storage case; formed on an outer peripheral surface of the storage case. A liquid crystal display device comprising: a plurality of fitting portions; and a plurality of fitting portions formed on an inner peripheral surface of the lid case and resiliently fitted to the fitting portions. .