JP3387785B2 - Display backlight - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight of a display device which illuminates a display panel for displaying an image from its back surface.

[0002]

2. Description of the Related Art In recent years, as a display device for displaying images such as characters and characters, a display device using a backlight, which has been announced for the purpose of making the device thinner and lighter, has been widely used. Specific examples of the display device using this backlight include a liquid crystal display device that displays an image on a liquid crystal display panel to which liquid crystal is applied.

Such a liquid crystal display device is a conventional display (display device) having low power consumption, light weight, and space saving.
It has unique features and is used in a variety of products due to the increase in product strength due to the development of peripheral technology.

Further, the liquid crystal display device performs matrix display and is classified into an active matrix system and a simple matrix system as its structure. Among them, an active matrix system using a thin film transistor as a switch for each pixel is used.
Since a matrix type liquid crystal display device can obtain a clear image display without crosstalk, it is used for a display of a notebook type personal computer, a display for EWS and the like, and is rapidly expanding the market.

In such a liquid crystal display device, an edge-light type backlight is mainly used due to a demand for low power consumption and compactness, and its sectional structure is shown in FIG.

In this type of backlight, the light emitted from the lamp 1 is reflected by the reflector 2 and is incident on the end face of the light guide 3 formed of a transparent acrylic resin or the like, and the incident light is guided. It is used as a light source of the liquid crystal display device for the display panel 6 by uniformly emitting from the front surface of the light guide body and irradiating it from the back surface of the display panel 6 by the reflection pattern 4 and the reflection plate 5 arranged on the back surface of the body 3. It is a thing.

At this time, the light emitted from the lamp 1 is prevented from leaking through the gaps between the respective members and the irradiation efficiency of the display panel 6 is prevented from decreasing, and the light is uniformly incident on the light guide body 3 without loss. A structure has been devised and utilized in which a back cover 7 having a pressing effect is attached with a sheet metal or the like to eliminate gaps between the respective parts. Further back cover 7
A high-voltage insulating sheet 8 is provided between and to insulate the high-voltage circuit portion of the lamp 1.

On the other hand, notebook type personal computers
Functionality is important, and the screen size of the PC is 10 "
The sizes above are the mainstream. Further, from the viewpoint of energy saving, even in a desktop type personal computer, a liquid crystal display device has come to be used as a display unit thereof as a display with low power consumption, space saving, and a small amount of heat generation.

The liquid crystal display devices used for these devices currently have screen diagonal dimensions of 30 cm (12.1 ") to 35 cm.
It is shifting to (14 "). Therefore, the backlight size used for the liquid crystal display device exceeds 30 cm diagonally. Also, because of the slimness of the notebook PC body, a thin liquid crystal module is required. It is required, and currently, the thing whose thickness is 10 mm or less is predominant.

[0010]

However, in the conventional backlight as described above, although the structure of the backlight is incorporated in the size of the liquid crystal display device described above, a large screen of the liquid crystal display device and In order to satisfy the demand for thinning, it is necessary to increase the size of the backlight and reduce the thickness of the backlight.

Therefore, the back cover 7 for pressing the reflector 2 has a long dimension and a small thickness, and it is difficult to obtain a structure for ensuring rigidity.
Further, as shown in FIG. 4, since the reflector 2 at this time is bent and used along the lamp 1, the toughness of the material forming the reflector 2 exerts a stress to push up the back cover 7, and the back cover 7 causes Due to insufficient pressing, a gap is left between the light guide 3 and the reflector 5 or between the reflector 5 and the reflector 2, and light leaks from this gap, and as a result, As shown in FIG. 5, there is a problem in that a portion 10 of reduced brightness or uneven brightness occurs, a display defect occurs on the display panel, and the display quality is deteriorated.

In order to avoid these, as shown in FIG. 6, the rear cover 7 is provided with a reinforcing diaphragm 11 or the like to increase the rigidity, and to secure the rigidity to press down against the force of the reflector 2 swelling. However, since the reinforcing diaphragm 11 of the back cover 7 requires a space in the thickness direction, it has a problem that it is difficult to obtain a thin concept structure.

The present invention solves the above-mentioned problems of the prior art, and due to the lack of pressure on the reflector due to the increase in size and thickness of the display device, the reflector floats from the light guide body due to its reaction force, and thus the gap is generated. (EN) Provided is a backlight for a display device, which can prevent the light leakage of the display device, prevent uneven brightness and decrease in brightness in the display panel of the display device, and can improve the display quality without increasing the number of constituent members.

[0014]

In order to solve the above-mentioned problems, in the backlight of the display device of the present invention, a high voltage insulating sheet provided by bending so as to hit a reflector in the display device has a bent portion. The feature of the present invention is that the reflector is always pressed by the portion that hits the reflector due to the stress of opening.

As described above, due to the lack of pressure on the reflector due to the increase in size and thickness of the display device, light leakage from the gap generated by the reflector floating from the light guide due to its reaction force is eliminated, and the display panel of the display device is eliminated. It is possible to prevent uneven brightness and decrease in brightness in the display, and it is possible to improve the display quality without increasing the number of constituent members.

[0016]

A backlight of a display device according to claim 1 of the present invention is provided for illuminating the display panel of the display device from the back side thereof, and the illumination lamp and the lamp lighting device are provided. Backlight of a display device including a high-voltage circuit, an insulating sheet that insulates and protects the high-voltage circuit, and a reflector that reflects light from the lamp and allows the light to enter a light guide disposed on the back surface of the display panel. In the above, the insulating sheet is bent and arranged so that the sheet surface contacts the reflector so as to eliminate a gap between the insulating sheet and the reflector.

According to a second aspect of the backlight of the display device, the insulating sheet according to the first aspect is configured such that an electric circuit for driving the display panel is included inside the bent sheet surface.

According to the above structure, the high-voltage insulating sheet provided in the display device by being bent so as to hit the reflector constantly presses the reflector at the part that hits the reflector due to the stress of opening the bent part.

Hereinafter, the backlight of the display device according to the embodiment of the present invention will be specifically described with reference to the drawings. It should be noted that components having the same operation as that of the conventional example will be described with the same reference numerals.

FIG. 1 is a sectional view of a display device showing the structure of the backlight of the present embodiment, and FIG. 2 is a sectional view of the display device showing the arrangement of electric circuit parts for driving the display. In the structure of the backlight of this display device, as shown in FIG. 1, a bent portion M1 is provided in a portion of the high-voltage insulating sheet 8 that contacts the reflector 2. At this time, the bent portion M
With respect to the bending of No. 1, due to the characteristics of the material of the high-voltage insulating sheet 8, the bending portion M1 still has a stress to open even if it is bent by 180 °.

If the stress for opening the high-voltage insulating sheet 8 by assembling in this state is utilized, the back cover 7 is pushed up by the stress that the reflector 2 tends to be straightened, the reflector 2 is lifted, and a gap with the light guide 3 is formed. Even if a gap is formed between the light guide 3 and the reflector 5, the bent high-voltage insulating sheet 8 can always press the reflector 2 against the light guide 3.

With the above operation, no gap is generated between the backlight constituent members such as the reflector 2, the light guide 3 and the reflector 5. Further, as shown in FIG. 2, the high-voltage insulating sheet 8 has an FPC inside the bent portion M1.
The electric circuit unit 9 configured to drive the display panel 6 and the like can be wrapped, and the electric circuit unit 9 is configured to also serve as insulation protection for the front and back.

Here, the bent portion M of the high-voltage insulating sheet 8
1 may be bent in any direction as long as it can generate a stress that presses the reflector 2, and may be arbitrarily determined by each display size and configuration.

In this way, the high-voltage insulating sheet 8 is provided with the bent portion M1 and the reflector 2 is constantly pressed by utilizing the stress to open the bending, so that the reflector 2
The reaction force of 2 causes the reflector 2 and the like to float above the light guide body 3 to prevent a light leakage due to the formation of a gap.

With the above structure, due to the lack of pressure on the reflector due to the large-sized and thin display device,
It is possible to prevent light leakage from the gap generated by the reflector floating from the light guide due to its reaction force, and prevent uneven brightness and decrease in brightness in the display panel of the display device, and improve display quality without increasing the number of components. Can be improved.

In the above embodiment, the high-voltage insulating sheet 8 is bent so that its bent portion M1 is located outside the liquid crystal module, but it may be bent inside the liquid crystal module. Well, the same effect can be obtained.

[0027]

As described above, according to the present invention, the high-voltage insulating sheet provided in the display device by being bent so as to hit the reflector is always reflected at the part that hits the reflector due to the stress of opening the bent part. Can be held down.

Therefore, due to the lack of pressure on the reflector due to the increase in size and thickness of the display device, light leakage from the gap generated by the reflector floating from the light guide due to its reaction force is eliminated, and the display panel of the display device is eliminated. It is possible to prevent uneven brightness and decrease in brightness, and it is possible to improve display quality without increasing the number of constituent members.

[Brief description of drawings]

FIG. 1 is a sectional view of a display device showing a structure of a backlight according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a display device showing an arrangement of electric circuit parts in the same embodiment.

FIG. 3 is a sectional view of a display device showing a structure of a conventional backlight.

FIG. 4 is a sectional view of a display device showing a defective state in the conventional example.

FIG. 5 is a sectional view of a display device showing another defective state in the conventional example.

FIG. 6 is a cross-sectional view of a display device showing the configuration of the defect countermeasure in the conventional example.

[Explanation of symbols]

1 lamp 2 reflector 3 Light guide 4 reflection pattern 5 reflector 6 Display panel 7 Back cover 8 High voltage insulation sheet 9 Electric circuit section

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshinori Yasuda 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-10-125124 (JP, A) 75739 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) F21V 8/00 601 G02F 1/335

Claims (2)

(57) [Claims] 1. A lamp for lighting, a high voltage circuit for lighting the lamp, an insulating sheet for insulating and protecting the high voltage circuit, the lamp being provided for illuminating a display panel of the display device from the back surface, and the lamp. In a backlight of a display device comprising a reflector for reflecting light from a light guide member arranged on the back surface of the display panel, the insulating sheet, the sheet surface of which is a gap between the reflector and A backlight for a display device, which is bent and arranged so as to come into contact with the reflector so as to be lost. 2. The backlight of a display device according to claim 1, wherein the insulating sheet is configured to include an electric circuit for driving the display panel inside the bent sheet surface.