CN1567060A - Liquid crystal display unit and its thin backlight module - Google Patents

Abstract

A liquid crystal display unit and its thin backlight module, wherein the liquid crystal display unit includes a backlight module and a liquid crystal panel, wherein the liquid crystal panel is set on the backlight module, and the backlight module includes a frame, a light guiding plate and a prism sheet, the frame is used for the liquid crystal panel to set in, the light guiding plate is set in the frame, and form a first protruding part on it, and form a gap by forming the first protruding part, the prism sheet is set between the liquid crystal panel and the light guiding plate, and have a second protruding part, by making the second protruding part locate in the gap of the light guiding plate, in order to position the prism sheet on the light guiding plate.

Description

Liquid crystal display unit and its thin backlight module

technical field

The invention relates to a liquid crystal display unit and its backlight module, in particular to a liquid crystal display unit with a thin backlight module.

Background technique

In the liquid crystal display unit of a general liquid crystal display, a backlight module is used as a light source, and in the backlight module, a prism sheet plus a pattern design of a light guide plate is often used to achieve desired optical properties.

As shown in FIG. 1a, components in a known backlight module are assembled vertically on each optical film, or glued in the gaps between components to form spacers and then stacked.

Specifically, in the frame 11 of the known liquid crystal display unit 10, a reflective sheet 12, a light guide plate 13, a diffusion sheet 14, a prism sheet 15, and a liquid crystal panel 16 are sequentially arranged from bottom to top, and the flexible panel connected to the liquid crystal panel 16 The circuit board 17 extends to the bottom of the reflection sheet 12 around the outside of the frame 11 .

However, the known backlight module is prone to cause the following problems:

1. Restrict the design of the geometric shape of the backlight module: limited by the current attainable manufacturing technology of the prism sheet (thickness, enhancement effect), the design of the thickness of the entire backlight module cannot meet the customer's requirements, and it is likely to lose the order;

2. The positioning method of the prism sheet is not easy: as shown in Figure 1b, in the known backlight module, the prism sheet 15 will grow positioning wings 151 on the left and right sides (only one is shown in Figure 1b), so that the operator can process and positioning/fixing the prism sheet 15, but this design may cause the prism sheet 15 to be in the same row on the light incident side and the light exit side due to the deformation/rotation of the prism sheet 15 in the z direction (that is, the direction perpendicular to the paper surface) The luminance of three points (nine-point luminance measurement) causes large variations, or worse, dark/bright bands;

3. Design reverse work problem: use double-sided tape as the spacer between components. In addition to the reverse work problem when the good rate is not good, you must also consider the light absorption and scattering effects of the double-sided tape itself. Optical properties are unstable;

4. Product reliability: The positioning wings on both sides of the known design of the prism sheet are fixed, and in the case of asymmetrical positions, after the high-low temperature cycle test, it is easy to cause the backlight module point due to thermal stress/residual stress. When it is bright, the streak phenomenon occurs on it;

5. Backlight module assembly: Due to the existence of positioning wings on both sides, it is extremely difficult to design automatic/semi-automatic assembly;

6. Since the flexible circuit board 17 is provided with a plurality of electronic components 171 , the higher components often increase the overall thickness of the liquid crystal display unit.

Contents of the invention

In order to overcome the above disadvantages, the object of the present invention is to provide a liquid crystal display unit whose thickness can be reduced.

The purpose of the present invention is to provide a backlight module, which can still accurately position the optical components in the backlight module in the case of thinning.

According to the present invention, a thin backlight module is provided, the backlight module includes: a frame, a light guide plate and a prism sheet, the light guide plate is arranged in the frame, and a first protrusion is formed on it to The prism sheet has a second protruding part, wherein the second protruding part is located in the notch of the light guide plate, so as to position the prism sheet on the light guide plate.

In a preferred embodiment, an inclined surface is formed on the first protrusion, and the inclined surface is adjacent to the prism sheet.

In another preferred embodiment, a groove is formed on the frame, and a first side wing corresponding to the groove is formed on the light guide plate, and the light guide plate can be fixed in the frame by placing the first side wing in the groove.

In another preferred embodiment, the second protruding portion is formed on the prism sheet in the extending direction of the prisms.

In another preferred embodiment, the thin backlight module further includes a light source disposed in the frame and adjacent to the first protruding portion of the light guide plate.

In addition, the light source can be a light emitting diode.

In another preferred embodiment, the thin backlight module further includes a diffusion sheet, and the diffusion sheet is arranged between the prism sheet and the light guide plate.

In addition, a groove is formed on the frame, and a second side wing corresponding to the groove is formed on the diffusion sheet, and the diffusion sheet can be fixed in the frame by placing the second side wing in the groove.

In another preferred embodiment, the thin backlight module further includes a reflective sheet, which is pasted on the light guide plate and located on different sides of the light guide plate from the prism film system.

In addition, the liquid crystal display unit also includes a double-sided adhesive, which is arranged between the light guide plate and the reflective sheet, and is used to paste the reflective sheet on the light guide plate.

In the present invention, a liquid crystal display unit is provided, the liquid crystal display unit includes a backlight module and a liquid crystal panel, wherein the liquid crystal panel is arranged on the backlight module, and the backlight module includes: a frame, a light guide plate and a prism sheet , the frame is used for setting the liquid crystal panel therein, the light guide plate is arranged in the frame, and a first protrusion is formed on it, and a gap is formed by forming the first protrusion, the prism sheet is arranged on the liquid crystal panel and the light guide plate There is a second protruding part between them, and the prism sheet is positioned on the light guide plate by making the second protruding part located in the notch of the light guide plate.

In another preferred embodiment, the frame forms a stepped portion on a side not adjacent to the light guide plate.

In addition, the liquid crystal display unit further includes one, the flexible circuit board is arranged on the liquid crystal panel, and has a plurality of electronic components on it, and some of the electronic components are located in the step portion.

In addition, the liquid crystal display unit also includes a buffer, which is arranged between the flexible circuit board and the frame, and the buffer can be a sponge.

In another preferred embodiment, the liquid crystal display unit further includes a light-shielding tape, and the light-shielding tape is arranged between the prism sheet and the liquid crystal panel.

Description of drawings

Figure 1a is a sectional view of a known liquid crystal display unit;

Figure 1b is a front view of a known backlight module;

Fig. 2a is an exploded view of the liquid crystal display unit in the first embodiment of the present invention;

Figure 2b is a front view of the backlight module in Figure 2a;

Figure 2c is a cross-sectional view of the assembled liquid crystal display unit in Figure 2a;

Figures 3a, 3b, and 3c are side views, front views, and front views of the light guide plate in Figure 2a, respectively;

Fig. 4a is an exploded view of the liquid crystal display unit in the second embodiment of the present invention; and

Fig. 4b is a cross-sectional view of the assembled liquid crystal display unit in Fig. 4a.

Explanation of symbols of attached parts and components:

10 liquid crystal display unit

11 frames

12 reflectors

13 light guide plate

14 diffusers

15 prism sheet

151 positioning wing

16 LCD panels

17 flexible circuit board

171 Electronic components

20 liquid crystal display units

21 backlight module

211 frame

211a groove

212 light guide plate

212a first protrusion

212b gap

212c bevel

212d First Wing

213 diffuser

213a Second Wing

214 prism sheet

214a second protrusion

215 reflector

216 double-sided tape

217 light sources

22 LCD panel

23 blackout tape

24 flexible circuit board

20' LCD display unit

211' frame

211b Step Department

24' flexible circuit board

241 Electronic components

25 cushioning parts

Detailed ways

In order to make the above and other objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is specifically cited below, which is described in detail with reference to the accompanying drawings.

first embodiment

Figures 2a, 2b, and 2c show the first embodiment of the liquid crystal display unit of the present invention. In this embodiment, the liquid crystal display unit 20 includes a backlight module 21 and a liquid crystal panel 22, wherein the liquid crystal panel 22 is arranged on the backlight The backlight module 21 includes a frame 211 , a light guide plate 212 , a diffusion sheet 213 , two prism sheets 214 and a reflective sheet 215 .

The frame 211 can be used for disposing the liquid crystal panel 22 therein, and is preferably made of plastic; in addition, the frame 211 has several grooves 211a formed around its inner side for clamping the light guide plate 212 or the diffusion sheet 213 .

The light guide plate 212 is arranged in the frame 211, and as shown in Figures 3a, 3b, and 3c, a first protruding portion 212a is formed thereon, and a notch 212b is formed by forming the first protruding portion 212a, the notch 212b can be used to improve the optical characteristics and accept the prism sheet 214; again, an inclined surface 212c is formed on the first protrusion 212a, and the inclined surface 212c can be adjacent to the prism sheet 214, that is to say, by means of the inclined surface 212c of the first protrusion 212a , the prism sheet 214 can be placed, thereby reducing the thickness of the backlight module 21; moreover, a plurality of first side wings 212d are formed on the side of the light guide plate 212, and these first side wings 212d correspond to the grooves 211a of the frame 211. The first side wing 212d is placed in the groove 211a to fix the light guide plate 212 in the frame 211 .

Furthermore, it should be understood that the light source 217 of the backlight module 21 is arranged in the frame 211 and adjacent to the first protruding portion 212a of the light guide plate 212, as shown in FIG. The light source 217 can be effectively utilized on the flat horizontal end face of the light plate 212; again, the z-axis height of the inclined surface 212c of the first protruding portion 212a of the above-mentioned light guide plate 212 is related to the profile height and effective light emitting area of the light source 217, while the inclined surface The slope of 212c is related to the size of the notch 212c; in addition, the light source 217 can be a light emitting diode (LED).

The diffusion sheet 213 is arranged between the prism sheet 214 and the light guide plate 212, and several second side wings 213a corresponding to the groove 211a of the frame 211 can be formed thereon, by placing the second side wings 213a in the groove 211a , the scattering sheet 213 can be fixed in the frame 211 .

Two prism sheets 214 are arranged between the liquid crystal panel 22 and the diffusion sheet 213, and one of the prism sheets 214 is formed with a second protruding portion 214a. The prism sheet 214 is positioned on the light guide plate 212, so that positioning wings need not be grown around the prism sheet 214 as in the prior art; In the extending direction of the prism, there is no need to worry about whether the strength of the prism sheet 214 will be weakened due to the formation of the second protruding portion 214a, and at the same time, the optical quality will not be affected.

The reflective sheet 216 is pasted on one side of the light guide plate 212 by means of a double-sided adhesive tape 217 , that is, the reflective sheet 216 and the prism sheet 214 are respectively located on different sides of the light guide plate 212 .

In addition, the liquid crystal display unit 20 is usually provided with a light-shielding tape 23 between the prism sheet 214 and the liquid crystal panel 22, as shown in FIG. Panel 21 is connected.

With the above structure, the liquid crystal display unit of this embodiment has the following advantages:

1. The design of the thinner backlight module can make the appearance of the entire liquid crystal display unit lighter and thinner, which is conducive to the increase of market share;

2. Reduce the design of the positioning wings of the prism sheet, thereby not only reducing the design cost (the cost of reverse work in the mold and assembly), but also minimizing the effect of stress caused by the known positioning wings;

3. Utilize the structural design designed on the light guide plate and other components to replace the known adhesive material and reduce the design amount of the side positioning wings, so as to avoid the adverse influence of the connecting adhesive material on the optics of the backlight module;

4. Reduce the thermal stress concentration that may occur during the temperature cycle test, resulting in optical variation;

5. Eliminating the positioning wings on the side of the prism sheet makes it easier to design automated assembly equipment to reduce costs.

second embodiment

Figures 4a and 4b show the second embodiment of the liquid crystal display unit of the present invention. In this embodiment, the liquid crystal display unit 20' includes a backlight module 21', a liquid crystal panel 22 and a flexible circuit board 24'; Note that in this embodiment, the same components as those of the first embodiment are assigned the same symbols, and descriptions thereof are omitted.

The difference between this embodiment and the first embodiment is that the frame 211' of the backlight module 21' forms a stepped portion 211b on its outer side (that is, the side not adjacent to the light guide plate 212), thereby connecting with the liquid crystal panel 21. In the flexible circuit board 24 , some of the electronic components 241 with a relatively high height can be located in the stepped portion 211 b, so as to reduce the overall thickness of the liquid crystal display unit 20 ′.

In addition, the liquid crystal display unit 20' can also include a buffer member 25, which is arranged between the flexible circuit board 24' and the frame 211', thereby preventing the liquid crystal display unit 20' from falling and vibration/shock tests. At this time, the assembly 241 and the frame 211 ′ are crushed and damaged due to external force, and the buffer member 25 can be a sponge.

In addition to obtaining the same advantages as the first embodiment, this embodiment also allows the higher components on the flexible circuit board to be designed to flash into the side of the frame, so that the overall thickness of the liquid crystal display unit can be reduced.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can certainly make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, The scope of protection of the present invention shall be defined by the scope of claims of the patent application.

Claims (25)

1. A thin backlight module, comprising: a frame; a light guide plate, the light guide plate is arranged in the frame, and a first protrusion is formed thereon, wherein the light guide plate forms a notch by forming the first protrusion; and A prism sheet, the prism sheet has a second protruding part, wherein the second protruding part is located in the notch of the light guide plate, so as to position the prism sheet on the light guide plate. 2. The thin backlight module as claimed in claim 1, wherein a slope is formed on the first protruding portion, and the slope is adjacent to the prism sheet. 3. The thin backlight module according to claim 1, wherein a groove is formed on the frame, and a first side wing corresponding to the groove is formed on the light guide plate, by placing the first side wing The groove is used to fix the light guide plate in the frame. 4 . The thin backlight module as claimed in claim 1 , wherein the second protruding portion is formed on the prism sheet along the extending direction of the prisms. 5. The thin backlight module according to claim 1, further comprising: A light source is arranged in the frame and adjacent to the first protrusion of the light guide plate. 6. The thin backlight module as claimed in claim 5, wherein the light source is a light emitting diode. 7. The thin backlight module according to claim 1, further comprising: A diffusion sheet, the diffusion sheet is arranged between the prism sheet and the light guide plate. 8. The thin backlight module according to claim 7, wherein a groove is formed on the frame, and a second side wing corresponding to the groove is formed on the diffusion sheet, by placing the second side wing on the In the groove, the scattering sheet can be fixed in the frame. 9. The thin backlight module according to claim 1, further comprising: A reflective sheet, the reflective sheet is pasted on the light guide plate, and is located on different sides of the light guide plate from the prism sheet. 10. The liquid crystal display unit according to claim 9, further comprising: A double-sided adhesive, the double-sided adhesive is arranged between the light guide plate and the reflective sheet, and is used to paste the reflective sheet on the light guide plate. 11. A liquid crystal display unit, comprising: a backlight module; and a liquid crystal panel, the liquid crystal panel is arranged on the backlight module; Wherein the backlight module includes: a frame, the frame is used for the liquid crystal panel to be arranged therein; a light guide plate, the light guide plate is arranged in the frame, and a first protrusion is formed thereon, wherein the light guide plate forms a notch by forming the first protrusion; and A prism sheet, the prism sheet is arranged between the liquid crystal panel and the light guide plate, and has a second protrusion, wherein the second protrusion is located in the notch of the light guide plate, so as to position the prism sheet on the the light guide plate. 12. The liquid crystal display unit as claimed in claim 11, wherein a stepped portion is formed on a side of the frame not adjacent to the light guide plate. 13. The liquid crystal display unit according to claim 12, further comprising: A flexible circuit board, the flexible circuit board is arranged on the liquid crystal panel, and has a plurality of electronic components on it, and some of these electronic components are located in the step part. 14. The liquid crystal display unit according to claim 13, further comprising: A buffer, the buffer is arranged between the flexible circuit board and the frame. 15. The liquid crystal display unit as claimed in claim 14, wherein the buffer member is a sponge. 16. The liquid crystal display unit as claimed in claim 11, wherein a slope is formed on the first protruding portion, which is adjacent to the prism sheet. 17. The liquid crystal display unit according to claim 11, wherein a groove is formed on the frame, and a first side wing corresponding to the groove is formed on the light guide plate, by placing the first side wing The groove is used to fix the light guide plate in the frame. 18. The liquid crystal display unit as claimed in claim 11, wherein the second protruding portion is formed on the prism sheet along the extending direction of the prisms. 19. The liquid crystal display unit according to claim 11, wherein the backlight module further comprises: A light source is arranged in the frame and adjacent to the first protrusion of the light guide plate. 20. The liquid crystal display unit as claimed in claim 19, wherein the light source is a light emitting diode. 21. The liquid crystal display unit according to claim 11, wherein the backlight module further comprises: A diffusion sheet, the diffusion sheet is arranged between the prism sheet and the light guide plate. 22. The liquid crystal display unit as claimed in claim 21, characterized in that: a groove is formed on the frame, and a second side wing corresponding to the groove is formed on the diffusion sheet, by placing the second side wing In the groove, the scattering sheet can be fixed in the frame. 23. The liquid crystal display unit according to claim 11, wherein the backlight module further comprises: A reflective sheet, the reflective sheet is pasted on the light guide plate, and is located on different sides of the light guide plate from the prism sheet. 24. The liquid crystal display unit according to claim 23, wherein the backlight module further comprises: A double-sided adhesive, the double-sided adhesive is arranged between the light guide plate and the reflective sheet, and is used to paste the reflective sheet on the light guide plate. 25. The liquid crystal display unit according to claim 11, further comprising: A light-shielding tape, the light-shielding tape is arranged between the prism sheet and the liquid crystal panel.

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