JPH0843817A - Illuminator and liquid crystal display device - Google Patents

Abstract

PURPOSE:To prevent photoirradiation amount from lowering and to prolong the life of the illuminator. CONSTITUTION:In this illuminator 14, a discharge tube 19 is disposed on the end face of a light transmission plate and housed in a reflector case 21; and further a conductive spring connecting body 22 consisting of a spring part having elasticity along the discharge tube 19, a locking part 21b locked in the reflector case, and an electrode connection part connected to be engaged with the electrode 19a of the discharge tube 19 is inserted in the reflector case; then the other end of the spring connecting body 22 is attached to a connector 23 to which a lead wire 24 is connected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an illuminating device comprising a combination of a long cylindrical fluorescent lamp and a light guide plate, and further to a liquid crystal display device equipped with this illuminating device.

[0002]

2. Description of the Related Art The structure of a conventional lighting device 1 will be described with reference to FIGS. FIG. 8 is an exploded perspective view of the backlight illumination device 1 mounted on the edge light type liquid crystal display device. Reference numeral 2 is a transparent light guide plate made of acrylic resin or the like, 3 is a discharge tube such as a cold cathode fluorescent tube or a hot cathode fluorescent tube arranged on an end face of the light guide plate 2, 4 is a reflector plate arranged on the back surface of the light guide plate 2, 5
Is a reflector for a discharge tube arranged outside the discharge tube 3, 6 is a diffuser plate, and these light guide plate 2, discharge tube 3 and the like are integrally housed in a housing 7 made of metal such as aluminum, zinc or steel plate. . In addition, the arrow in a figure is a storage or mounting direction. Then, a liquid crystal display panel (not shown) is provided on the diffusion plate 6 of the lighting device 1 to form a liquid crystal display device.

FIG. 6 shows the wiring of the discharge tube 3,
Lead wires 8 and 9 are connected to both ends of the discharge tube 3, and further connected to a terminal connector 10. Further, FIG. 7 is an enlarged sectional view of an essential part of both ends (H in FIG. 6) of the discharge tube 3.
An insulative rubber body 11 having a rectangular parallelepiped shape is fitted to both ends of the discharge tube 3, and the lead wire 9 is drawn out through a hole formed in a part of this. The lead wire 9 is connected to the soldering portion 12 of the discharge tube 3.

[0004]

However, since the lead wire 9 is connected to the discharge tube 3 by the soldering portion 12 in the illuminating device 1 having the above-mentioned structure, there are the following problems. . That is, since the connection is made by solder, the heat required for the connection is conducted to the bonding interface between the electrode of the discharge tube 3 and the main body glass, and the thermal influence thereof impairs the internal airtightness of the discharge tube 3 and reduces the amount of the atmosphere. Inflow, and as a result,
There has been a problem that the life of the discharge tube 3 is shortened as the light irradiation amount of the discharge tube 3 is reduced.

Moreover, the discharge tube 3 is assembled by the physical connection made through the soldering portion 12, and the lighting device 1 is assembled.
When excessive tension is applied to the lead wire 9 during the assembly of the liquid crystal display device of 1 or the assembly of the device at the customer's side, it acts on the bonding interface between the electrode of the discharge tube 3 and the main body glass, The internal airtightness of the discharge tube 3 was impaired, and similarly, the light irradiation amount of the discharge tube 3 was decreased and the life thereof was shortened.

Further, the number of steps for attaching the lead wire is increased due to the step of soldering the lead wire to the discharge tube 3. Alternatively, the total length of the lead wires 8 and 9 and the terminal connector 1
There are many types of liquid crystal display devices according to the customer's request, and the number of liquid crystal display devices according to each request increases, which increases the number of liquid crystal display device products, which lowers the manufacturing efficiency. There is a problem that the cost is reduced.

[0007]

According to a first aspect of the present invention, there is provided a light reflecting member on the other main surface of a light guide plate which emits light from one main surface, and an elongated light source is arranged on the end surface of the light reflecting member. An illumination device in which the elongated light source is delivered to a pair of reflector cases, the irradiation light of the elongated light source is reflected by the pair of reflector cases, and the reflected light is made incident on the end surface of the light guide plate. And a spring portion having elasticity, a locking portion that is locked to the reflector case,
A connector to which a lead wire is connected is connected to a conductive spring connecting body that is composed of an electrode connecting portion that engages and connects with an electrode of a long light source, and the conductive spring connecting body is connected to the inside of the pair of reflector cases. In addition to the above, the engaging portion is attached to the reflector case, the electrode connecting portion is engaged with the electrode of the elongated light source, and the spring portion is attached in a stretched state. To do.

According to claim 2, there is provided a liquid crystal display device in which a liquid crystal panel is arranged on one main surface of the illuminating device of claim 1.

[0009]

According to the illuminating device of the first aspect, the conductive spring connecting body including the spring portion, the locking portion, and the electrode connecting portion is inserted into the pair of reflector cases to which the elongated light source is delivered. , The conductive spring connector is connected to the connector to which the lead wire is connected to make an electrical connection with the outside, so that it is possible to obtain conduction simply by contacting the discharge tube electrode and the conductive spring connector. There is.

Therefore, by using the conductive spring connection body having such a structure, it is possible to maintain the contact pressure with the discharge tube electrode and to provide a stroke capable of absorbing the full length tolerance in manufacturing the discharge tube. Become. That is, the discharge tube has a tolerance of ± 0.8 mm with respect to the entire length, but within this range, the elasticity of the conductive spring connector is not impaired.

Moreover, with respect to the entire length of the discharge tube, the entire length of the conventional structure (a rectangular parallelepiped insulating rubber body 11 at both ends of the discharge tube 3) is used.
It is possible to construct the illuminating device with a size that does not exceed the mounting total length formed by fitting.

As described above, in the lighting device according to the first aspect, since the electrodes of the discharge tube and the lead wires are not connected by the soldering portion, the internal airtightness of the discharge tube is not impaired due to the thermal effect accompanying the discharge, and the discharge is prevented. The light irradiation amount of the tube does not decrease, and its life can be extended. Moreover, since the lead wire is not physically connected, the light irradiation amount of the discharge tube does not decrease and the life of the discharge tube can be extended.

Further, since the reflector case has both the reflecting function and the supporting function of the discharge tube, and the connector to which the lead wire is connected can be attached / detached, the reflector case itself can be easily attached / detached. Therefore, the lamp unit including the discharge tube can be easily replaced by the user from the display module equipped with the lighting device.

According to a second aspect of the present invention, there is provided a liquid crystal display device in which a liquid crystal panel is arranged on one main surface of the illuminating device of the first aspect. With this structure, the discharge tube of the illuminating device is irradiated with light. Since the amount does not decrease and the life is long, a high performance and highly reliable liquid crystal display device can be provided.

[0015]

EXAMPLE This example will be described below with reference to FIGS. FIG. 1 shows a 24 cm class (screen diagonal size:
10 is an explanatory view of a part of a black and white liquid crystal display device 13 in which a lighting device 14 is mounted so that the internal structure can be understood. 2 is a sectional view taken along the section line AA of FIG. 1, and FIG.
4 is an exploded perspective view of FIG. 4, FIG. 4 is a projection view of the conductive spring connector 22, and FIG. 5 is an enlarged view of a main part of the spring portion 22a of the conductive spring connector 22. Note that these figures show the lower right part of the front surface of the liquid crystal display device 13 (the lower part of the lighting device 14).
However, the upper right part of the liquid crystal display device 13 (upper part of the illuminating device 14) has a similar symmetrical structure, and is not shown in this example.

The liquid crystal display device 13 is equipped with an edge light type backlight illumination device 14,
Is a liquid crystal display panel, and 16 is an effective display area of the liquid crystal display panel 15. Reference numeral 17 denotes a transparent light guide plate such as polymethylmethacrylate having a thickness of 4 mm,
One main surface of the light guide plate 17 serves as a light emitting side, and a light reflecting member 18 formed by depositing silver on a PET sheet, for example, is provided on the other main surface thereof. 19 is this light guide plate 17
Is a discharge tube such as a cold-cathode fluorescent tube or a hot-cathode fluorescent tube having a tube diameter of 3.8 mm arranged on the end face of the.

Further, on the other main surface of the light guide plate 17, a large number of elements are densely distributed over substantially the entire surface as an adjusting means for planarly increasing the brightness with the light reflecting member 18, and the density is away from the light source 19. A printed pattern (not shown) containing glass beads exhibiting a white or milky white color which is changed in a manner that becomes higher along with it may be formed, whereby the brightness of the illuminating device 14 is increased and the light reflecting means 18 is used. More reflected light can be applied to the liquid crystal display panel 15 side. In addition, in order to increase the brightness, a light diffusing plate made of PC or PET may be provided on one main surface of the light guide plate 17, or a polycarbonate prism plate may be formed on the light diffusing plate.

The liquid crystal display panel 15 and the light guide plate 17
A display member such as the above and the lighting device 14 are housed in a casing 20 made of metal such as aluminum, zinc, or a steel plate. An attachment hole for attaching the liquid crystal display device 13 itself to another member such as a personal computer is shown as C in FIG. Note that FIG. 2 omits the housing 20.

Next, the lighting device 14 will be described. Discharge tube 19
Has been delivered to the pair of reflector cases 21. Specifically, the pair of reflector cases 21 includes a first reflector case 21a and a second reflector case 21b.
The discharge tube 19 is embedded between the two, and the discharge tube 19 irradiates the light guide plate 17 with light through an elongated opening formed on one side surface of the reflector case 21. There is. Since the reflector case 21 is manufactured by injection molding with a white resin such as polycarbonate or PBT, the discharge tube 1
Part of the light irradiation of 9 irradiates the inner surface of the reflector case 21, and the reflected light also goes to the light guide plate 17.

Further, the pair of reflector cases 21
A groove for burying the conductive spring connection body 22 is also provided inside the chamber in parallel with the groove for burying the discharge tube 19. As shown in FIG. 4, the conductive spring connector 22 has a spring portion 22 a having elasticity along the longitudinal direction of the discharge tube 19, a locking portion 22 b locked by the reflector case 21, and a discharge tube 19 of the discharge tube 19. An electrode connecting portion 22c to be connected so as to engage with the electrode 19a
And a connector connecting terminal 22d. Then, the conductive spring connecting body 22 is inserted into the pair of reflector cases 21, and the engaging portion 22b of the conductive spring connecting body 22 is inserted into the recess provided in the second reflector case 21b.
And the elasticity of the spring portion 22a,
The electrode contact portion 22c of the conductive spring connector 22 is connected to the discharge tube 19
It is connected so as to engage with the electrode 19a.

According to the conductive spring connector 22 having such a structure, it serves as a guide in the stroke direction within the reflector case 21, and further extends within the stroke range.
While absorbing the full length tolerance of the discharge tube 19,
Can be applied to the extent that it has a contact pressure necessary for conduction with the electrode 19a. In this embodiment, the discharge tube 19 has a tolerance of ± 0.8 mm with respect to its entire length, but within this tolerance range (interval B in FIG. 1), the elasticity of the conductive spring connector 22 is reduced. Is not damaged.

Further, the connector connecting terminal 22d of the conductive spring connecting body 22 has a protruding shape, and the connector connecting terminal 22d is mounted on the connector 23 embedded in the reflector case 21, and further the connector 23 is attached. It is electrically connected to the outside by a lead wire 24 via.

To assemble the lighting device 14 having the above-described structure, first, the discharge tube 19 is mounted on the second reflector case 21b, and then the engaging portion 2 of the conductive spring connector 22 is attached.
2b is locked and the electrode connection portion 22c of the conductive spring connection body 22 is connected so as to fit with the electrode 19a of the discharge tube 19. In such a mounted state, the spring portion 22
The conductive spring connector 22 itself is fixed in a state where a is extended. Then, the connector 23 to which the lead wire 24 is further connected is attached to the conductive spring connection body 22, and finally the first reflector case 21a is fitted to the second reflector case 21b.

Next, the structure of the conductive spring connector 22 will be described with reference to FIG. In the figure, (A) is a front view of the conductive spring connector 22, (B) is a top view, (C) is a left side view, and (D) is a rear view.

The conductive spring connector 22 is formed by pressing, for example, spring steel having a thickness of 0.35 mm. The electrode connecting portion 22c of the conductive spring connecting body 22 has, for example, a shape shown in E in the figure, and this shape is determined corresponding to the shape of the electrode 19a of the discharge tube 19 to be engaged.
The above E shape is determined because the shape of the electrode 19a of the discharge tube 19 is concave like a mortar.

The shape and size of the connector connecting terminal 22d of the conductive spring connector 22 are also determined by the corresponding connector 23.

Further, the spring portion 22 of the conductive spring connection body 22
a is a shape such that the contact pressure of the discharge tube 19 against the electrode 19a, the absorption of the full length tolerance of the discharge tube 19 and the space of itself are minimized. It is obtained by punching with a press.

The dimensions of the spring portion 22a will be described with reference to FIG. The spring portion 22a has a structure in which cantilever beams are continuous at an interval W3, and the allowable deformation amount per one stage of this beam is determined by the elastic modulus of the material, the cross section of the shape, and the applied load amount. Therefore, the conductive spring connector 22 created by the present inventor
For example, the material is SUS304CSP-
H and the thickness is 0.35 mm, the spacing W1, pitch P, spacing W3, and spacing W4 shown in FIG.
2 mm, 1.1 mm, 2.4 mm, and 3.0 mm, the spring constant of 27 can be obtained by connecting 19 basic stages.
A spring characteristic of 0 g / mm and an effective stroke of 2 mm was obtained.

By using the conductive spring connecting body 22 having the above-mentioned structure and characteristics, the electrode 19a of the discharge tube 19 is formed.
A suitable contact pressure was obtained, and the full length tolerance of the discharge tube 19 was sufficiently absorbed.

The present invention is not limited to the above embodiments, and various changes and improvements may be made without departing from the scope of the present invention.

[0031]

As described above, according to the lighting device of the first aspect, the conductive spring connection body including the spring portion, the locking portion, and the electrode connection portion is provided in the reflector case together with the elongated light source. Since this product is delivered and this conductive spring connector is attached to a connector to make an electrical connection to the outside, conduction can be obtained simply by contacting the discharge tube electrode and the conductive spring connector. With this configuration, since the electrodes of the discharge tube and the lead wires are not connected by the soldering portion, the internal airtightness of the discharge tube is not impaired due to the thermal effect, and the light irradiation amount of the discharge tube does not decrease. As a result, a high performance and highly reliable lighting device could be provided.

In the illuminating device of the present invention, since the reflector case itself can be easily attached and detached, not only when the long light source or the like is replaced, but also the long light source is replaced according to the application. In such a case, there is also an advantage that the user can easily replace it at any time and the range of use thereof is significantly expanded.

Further, since the liquid crystal display device according to the second aspect is equipped with this illuminating device, it has a long life and has excellent characteristics of high performance and high reliability.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a main part of a liquid crystal display device according to an example.

FIG. 2 is a cross-sectional view taken along the section line AA shown in FIG.

FIG. 3 is an exploded perspective view of the lighting device of the embodiment.

4A and 4B are projection views of a conductive spring connector used in the lighting device of the embodiment, where FIG. 4A is a front view and FIG. 4B is a top view.
(C) is a left side view and (D) is a rear view.

FIG. 5 is an explanatory view of a main part of a conductive spring connector.

FIG. 6 is an explanatory diagram showing wiring of a discharge tube mounted in a conventional lighting device.

FIG. 7 is a sectional view of a main part of a conventional lighting device.

FIG. 8 is an exploded perspective view of a conventional edge light type liquid crystal display device.

[Explanation of symbols]

 13 Liquid crystal display device 14 Illumination device 15 Liquid crystal display panel 17 Light guide plate 19 Discharge tube 21 Reflector case 22 Conductive spring connection body 22a Spring part 22b Engagement part 22c Electrode connection part 23 Connector

Claims (2)

[Claims] 1. A light reflecting member is provided on the other main surface of a light guide plate that emits light from one main surface, and a long light source is disposed on the end surface of the light guide plate, and the long light source is delivered to a pair of reflector cases. Then, the illumination light of the elongated light source is reflected by a pair of reflector cases, and the reflected light is made incident on the end face of the light guide plate. The illumination device has an elastic spring portion and a reflector case. A connector to which a lead wire is connected is connected to a conductive spring connecting body that includes a locking portion that locks to the electrode and an electrode connecting portion that engages and connects with the electrode of the elongated light source. The connector is inserted into the pair of reflector cases, the locking portion is locked to the reflector case, the electrode connecting portion is engaged with the electrode of the elongated light source, and the spring portion is further extended. I put it on Lighting equipment. 2. A liquid crystal display device in which a liquid crystal panel is arranged on one main surface of the illuminating device of claim 1.