JP2017103168A - Backlight and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a backlight and a display device capable of fixing members stably and capable of narrowing a frame.SOLUTION: A backlight 3 includes: a light guide plate 10 for emitting light from a light source 9 into a predetermined direction; an optical sheet 11 for adjusting intensity distribution of the light emitted from the light guide plate 10; a back surface housing 14 in which the light source 9 is arranged, which has a placement surface for placing the light guide plate 10 and the optical sheet 11 from the back surface side, and which has a back surface housing step part 22 which is predetermined at least at one side other than the side on which the light source 9 is arranged out of the outer periphery of the placement surface; a front surface housing 13 which is positioned by the back surface housing step part 22, which accommodates the light source 9, the light guide plate 10, and the optical sheet 11 from the front surface side and which has an opening in which the light emitted from the optical sheet 11 passes; and a light shielding/backlight fixing tape 17 in which at least the front surface housing 13 covers the place positioned by the back surface housing step part 22, and in which the back surface housing 14 and the front surface housing 13 are fixed.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a backlight and a display device including the backlight.

  In recent years, with the spread of information electronic devices, thin and lightweight display devices are variously used as displays for mobile phones or personal computers, various devices used in industrial applications, in-vehicle display devices, handy terminals or advertisement display devices. Used in the field.

  In addition, with the expansion of the fields in which display devices are used, for example, in amusement equipment, a plurality of small display devices are operated in addition to the main display device, and the small display devices are connected to display an image integrally. Increasingly, it is used for productions that impact viewers. In addition, in-vehicle display devices are often provided with switches and the like around the display device in consideration of design, and it is required to narrow the frame of the display device.

  In order to narrow the frame of the display device, it is necessary to simplify the constituent members of the display device by making them as thin as possible. However, it has been difficult to ensure the vibration resistance and impact resistance of the display device in order to make the constituent members thin and simplified.

  Conventionally, a technique for fixing a side surface of a liquid crystal panel and a side surface of a backlight unit with a fixing member including a plate (plate member) and an adhesive layer applied to one surface of the plate (for example, has been disclosed (for example, Patent Document 1).

JP 2014-126585 A

  In patent document 1, it is the technique regarding the display apparatus mounted in the portable information terminal, and a use environment does not assume severe conditions compared with an industrial use, a vehicle-mounted use, or an amusement etc., and is a vibration resistance with respect to a display apparatus. Properties and impact resistance are not so demanded. Therefore, even a display device in which the side surface of the liquid crystal panel and the side surface of the backlight unit are fixed by a fixing member composed of a plate (plate-like member) and an adhesive layer applied to one surface of the plate can be handled. is there.

  However, in Patent Document 1, since the constituent members of the display device are fixed with a member having an adhesive or a double-sided tape or the like, the adhesive deteriorates over time when used for a long time under a severe temperature environment. As a result, the adhesive strength of the pressure-sensitive adhesive or the double-sided tape is remarkably lowered, and the constituent members of the display device are decomposed. Therefore, it is not sufficient to rely only on the adhesive strength of the pressure-sensitive adhesive in a display device used in a severe use environment or temperature environment.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a backlight and a display device capable of stably fixing members and capable of narrowing the frame.

  In order to solve the above problems, a backlight according to the present invention includes a light source, a light guide plate that emits light from the light source in a predetermined direction, and an optical that adjusts the intensity distribution of the light emitted from the light guide plate. The sheet and the light source are disposed, and the light guide plate and the optical sheet have a placement surface on which the light guide plate and the optical sheet are placed from the back side, and are determined in advance on at least one side of the outer periphery of the placement surface other than the side on which the light source is placed. A rear housing having a positioning portion, a front housing having a light source, a light guide plate, and an optical sheet that are positioned by the positioning portion and having an opening through which light emitted from the optical sheet passes. And a first fixing tape that covers at least a position where the front casing is positioned by the positioning portion and fixes the rear casing and the front casing.

  According to the present invention, the backlight includes a light source, a light guide plate that emits light from the light source in a predetermined direction, an optical sheet that adjusts an intensity distribution of the light emitted from the light guide plate, and a light source. And a back surface having a placement surface on which the light guide plate and the optical sheet are placed from the back side, and having a positioning portion predetermined on at least one side of the outer circumference of the placement surface other than the side where the light source is arranged Positioned by a housing, a positioning portion, a light source, a light guide plate, and an optical sheet are accommodated from the front side, and a front housing having an opening through which light emitted from the optical sheet passes, and at least the front housing is positioned. Since the first fixing tape that covers the portion positioned by the section and fixes the rear housing and the front housing is provided, the member can be stably fixed and the frame can be narrowed.

It is a disassembled perspective view which shows an example of a structure of the display apparatus by Embodiment 1 of this invention. It is a top view which shows an example of a structure of the backlight by Embodiment 1 of this invention. It is a figure which shows an example of the AA cross section of FIG. It is an enlarged view of the a part of FIG. It is an enlarged view of the b section of FIG. It is a figure which shows another example of the AA cross section of FIG. It is an enlarged view of the c section of FIG. It is an enlarged view of the d section of FIG. It is a figure which shows an example of the shape of the front housing | casing and back housing | casing by Embodiment 2 of this invention. It is sectional drawing which shows an example of a structure of the display apparatus by Embodiment 3 of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  In addition, in each figure shown below, what attached | subjected the same code | symbol shall show a substantially the same component.

<Embodiment 1>
FIG. 1 is an exploded perspective view showing an example of the configuration of a display device 1 according to Embodiment 1 of the present invention. In the following description, it is assumed that the display device 1 is a liquid crystal display device.

  As shown in FIG. 1, a display device 1 includes a display element 2, a backlight 3 that irradiates the display element 2 from the back, and a housing 4 that houses the display element 2 and the backlight 3 and has an opening. And a circuit board 5. Hereinafter, each component will be described in detail.

<Display element 2>
The display element 2 includes a transmissive or transflective liquid crystal display panel that applies the birefringence of liquid crystal, and includes a first substrate 6 and a second substrate 7. On the first substrate 6, a color filter, a light shielding layer, a counter electrode, and the like are formed on an insulating substrate such as glass. On the second substrate 7, a thin film transistor (hereinafter referred to as TFT) serving as a switching element, a pixel electrode, and the like are formed on an insulating substrate such as glass.

  In addition, the display element 2 includes a spacer (not shown) that keeps a distance between the first substrate 6 and the second substrate 7, and a sealing material that bonds the first substrate 6 and the second substrate 7 (see FIG. A liquid crystal (not shown) sandwiched between the first substrate 6 and the second substrate 7, a sealing material (not shown) for sealing the liquid crystal injection port, An alignment film (not shown) for aligning the liquid crystal, and a polarizing plate (shown on the surface of the first substrate 6 on the casing 4 side and on the surface of the second substrate 7 on the backlight 3 side) And a driving IC (Integrated) disposed on the outer peripheral portion of the second substrate 7 or a tape-like wiring material (TCP: Tape Carrier Package, COF: Chip On Film, etc.) connected to the outer peripheral portion. Circuit) 8 etc. are provided.

<Backlight 3>
The backlight 3 has a light source 9 that emits light, a light guide plate 10 that has an emission surface that receives light emitted from the light source 9 from the side surface and propagates to the front surface, and a counter-emission surface that is the opposite surface of the emission surface; An optical sheet 11 that controls the intensity distribution and spread of the light emitted from the light guide plate 10, a reflection sheet 12 that returns the light that has escaped from the non-emission surface of the light guide plate 10 back to the light guide plate 10, and each of these members (light source) 9, a light guide plate 10, an optical sheet 11, and a reflection sheet 12).

  The light source 9 is provided with a point light source of RGB (Red: Red, Green: Green, Blue: Blue), an LED (Light Emitting Diode) of an emission color other than RGB, or a fluorescent tube lamp (not shown). . When a point light source is used as the light source 9, a general glass epoxy resin base or a flexible flat cable may be used as a light source substrate for mounting the point light source. In order to enhance, a metal or ceramic based material such as aluminum may be used.

  The light guide plate 10 is made of transparent acrylic resin, polycarbonate resin, glass, or the like, and emits light from the light source 9 from the emission surface. At least one of the exit surface and the opposite exit surface of the light guide plate 10 has a scattering dot pattern or a prism shape that emits light and adjusts the intensity distribution and exit direction of the light within the surface.

  The optical sheet 11 is disposed on the emission surface of the light guide plate 10 and adjusts the intensity distribution and the emission angle of the light emitted from the light guide plate 10. In the example of FIG. 1, three optical sheets 11 are shown. However, a lens sheet for condensing light, a diffusion sheet for uniforming light, or a visual field for adjusting luminance in the viewing angle direction. A necessary number of corner adjustment sheets or the like may be arranged according to the purpose.

  The front housing 13 has an opening through which light emitted from the optical sheet 11 passes, and the display element 2 is positioned and held on the outer peripheral portion on the upper surface side (display element 2 side). In addition, as a material of the front housing | casing 13, resin materials, such as metals, such as aluminum, stainless steel, and iron, PC (Polycarbonate: Polycarbonate), ABS (Acrylonitrile Butadiene Styrene: Acrylonitrile butadiene styrene), can be used.

  The rear housing 14 has a placement surface on which the light source 9 is positioned and held (arranged), and the light guide plate 10 and the optical sheet 11 are placed from the back side. In addition, as a material of the back housing | casing 14, in order to conduct the heat | fever emitted from the light source 9 efficiently, it is desirable to use a metal with high heat conductivity. In particular, if aluminum or aluminum alloy having high thermal conductivity is used, the heat generated by the light source 9 can be efficiently radiated and the heat can be prevented from being accumulated inside the backlight 3.

  Note that the front housing 13 and the back housing 14 are generally fixed to each other by a hook structure or screwing, and hold the other components of the backlight 3, the display element 2, the circuit board 5, and the like. However, the front housing 13 and the back housing 14 may be integrated.

<Case 4>
The housing 4 is a frame-shaped member that holds the display element 2, the backlight 3, a touch panel (not shown), a protective member (not shown), and the like. The housing 4 is made of a thin metal or resin molded product, and is fixed to the backlight 3 by a claw-like fixing structure or screwing. In addition, the housing | casing 4 may be formed integrally and may be comprised by combining a some member. Further, attachment portions (screws, attachment holes, etc.) to the final product may be provided on the side surface, front surface, back surface, peripheral portion, or the like of the housing 4.

<Circuit board 5>
The circuit board 5 controls the display element 2 and the light source 9 with electrical input / output signals. Further, the circuit board 5 is usually formed with a copper pattern on glass epoxy or the like, and electronic components are mounted on the surface by soldering. The circuit board 5 is disposed and fixed mainly on the back side (the side on which light is not emitted) of the display device 1, but is FPC (Flexible) in which wiring is formed on a film-like base material connected to the display element 2. A configuration may be adopted in which electronic components are mounted on a printed circuit). Further, in order to protect the circuit board 5 from external pressure or static electricity, a protective cover (not shown) made of a metal such as aluminum, stainless steel, or galvanized steel sheet, or a thin film resin such as PET (Polyethylene Terephthalate). May be attached. When a metal protective cover is used, a resin such as PET is disposed on the circuit board 5 side of the protective cover in order to avoid electrical contact with the circuit board 5 or electronic components disposed on the circuit board 5. It is desirable to apply insulation measures by sticking a sheet made of metal.

<Touch panel>
A touch panel (not shown) is connected to the end by converting information on position coordinates input from the outside (user) into an electric signal by a circuit provided with a transparent electrode formed on a transparent substrate. It is transmitted to the control circuit of the final product through the output wiring section. As the output wiring portion, an FPC is used because of the degree of freedom of connection due to its thinness and flexibility. However, different materials or structures may be used as long as they have equivalent functions or characteristics. The touch panel is equipped with a protective member (not shown) made of a transparent material such as glass or plastic on the front side in order to prevent damage, deformation, wear, or dirt due to pressure or contact from the input side. Also good. Printing can be added to the periphery of the front surface or back surface of the protective member depending on light shielding or design purposes.

  Next, a characteristic structure of the display device 1 will be described.

  FIG. 2 is a plan view showing an example of the configuration of the backlight 3.

  As shown in FIG. 2, a light source arrangement side 15 is provided on at least one side of the backlight 3. The light source arrangement side 15 may be provided on a plurality of sides in order to achieve a desired luminance specification, and is not limited to one side.

  FIG. 3 is a diagram illustrating an example of the AA cross section of FIG. 2. 4 is an enlarged view of part a in FIG. 3, and FIG. 5 is an enlarged view of part b in FIG.

  As shown in FIGS. 3 to 5, if a BM width 16 that is a width of a BM (Black Matrix) provided in the display element 2 is a narrow frame of 1 mm, for example, a backlight is included in the BM width 16. It can be confirmed that the frame 19 is accommodated (the inner end of the frame 3 of the backlight 3 is located outside the inner end of the BM). Further, the light shielding / backlight fixing tape 17 (first fixing tape) includes a front housing 13, an optical sheet 11, a light guide plate 10, a reflection sheet 12, and a light source 9 (not shown here) that are constituent members of the backlight 3. 1), the rear housing 14 and the double-sided tape 18 are held and fixed.

  As shown in FIG. 4, the double-sided tape that attaches and fixes the backlight 3 and the display element 2 to the display element 2 side of the light shielding / backlight fixing tape 17 that fixes the constituent members of the backlight 3. 20 is provided. The double-sided tape 20 is desirably made of a black material so that light from the backlight 3 is not transmitted and reflected. Similarly, the light shielding / backlight fixing tape 17 uses a tape having a function of shielding the light from the backlight 3, and in order to shield the light emitted from the end of the optical sheet 11, It is necessary to arrange so as to overlap the end (extend to the inside of the opening of the front housing 13 so as to overlap with a part of the optical sheet 11 in plan view).

  The front case wall thickness 21 of the front case 13 corresponds to the thinnest thickness (for example, 0.5 mm) that can be molded in white with high reflection efficiency when a resin molded product is used, for example, in order to realize a narrow frame. A resin molded product is applicable. Note that the thinnest thickness that can be molded is not limited here because there is a possibility of further thinning due to future technological advances.

  As shown in FIG. 5, it can be confirmed that the front housing 13 and the light guide plate 10 are fixed by the double-sided tape 18. The purpose of using the double-sided tape 18 is that the light from the light source 9 propagates through the light guide plate 10 and is efficiently reflected on the front case 13, and the front case 13 and the light guide plate 10 are attached and fixed. This is to improve the rigidity of the backlight 3.

  The rear casing 14 is provided with a rear casing step portion 22 (positioning portion) having a step at one end, which is one of the features of the first embodiment. When each component of the backlight 3 is fixed with the light shielding / backlight fixing tape 17, the front casing 13 is hooked (positioned) and fixed to the rear casing step 22 so that it can be firmly fixed. It becomes. That is, the front housing 13 is positioned by the rear housing step 22 and accommodates the light source 9, the light guide plate 10, and the optical sheet 11 from the front. Further, the light shielding / backlight fixing tape 17 covers the position where the front housing 13 is positioned by the rear housing stepped portion 22, and fixes the rear housing 14 and the front housing 13. In addition, as a processing method of the back surface housing level | step difference part 22, the crushing process at the time of the press process by a metal mold | die, the cutting process by a machine, etc. are mentioned.

  Next, another example of the configuration of the backlight 3 will be described.

  FIG. 6 is a diagram illustrating another example of the AA cross section of FIG. 2. 7 is an enlarged view of a portion c in FIG. 6, and FIG. 8 is an enlarged view of a portion d in FIG. Below, a different part from the structure of the backlight 3 shown to FIGS. 3-5 is demonstrated, and description is abbreviate | omitted about the same part.

  As shown in FIGS. 6 to 8, the backlight 3 and the display element 2 are provided above the front casing frame 23 (projecting portion) of the front casing 13 (on the surface of the front casing frame 23 on the display element 2 side). And a front case double-sided tape 26 is provided. The front casing frame 23 overlaps the outer periphery of the optical sheet 11 in plan view. The front casing double-sided tape 26 is desirably made of a black material so that light from the backlight 3 is not transmitted and reflected.

  The front case frame width 25 of the front case frame 23 is desirably 1 mm or less so that the BM width 16 or less of the display element 2 is obtained. The optical sheet 11 is accommodated inside the front casing frame width 25.

  The backlight fixing tape 24 is realized by holding and fixing the constituent members of the backlight 3 and using a tape or the like having a function of blocking light from the backlight 3.

  From the above, according to the first embodiment, the members constituting the backlight 3 can be stably and firmly fixed and the frame can be narrowed even under severe use environment or temperature environment. Become.

  In the above description, the light shielding / backlight fixing tape 17 (see FIGS. 3 to 5) and the backlight fixing tape 24 (see FIGS. 6 to 8) have been described using a tape having a light shielding function. It is not limited. For example, it is possible to further strengthen the rigidity of the backlight 3 by sticking or applying an adhesive material to a thin spring steel material or the like in addition to the tape and fixing it.

  The configuration of the side facing the light source arrangement side 15 (AA cross section in FIG. 2) has been described above, but the same configuration is applied to all sides where the light source 9 is not arranged. That is, the back housing 14 has the back housing step 22 on at least one side of the outer periphery of the mounting surface other than the side where the light source 9 is disposed.

<Embodiment 2>
In the first embodiment, the case where the front casing 13 is hooked on the rear casing step 22 of the rear casing 14 has been described. However, the present invention is not limited to this. In the second embodiment of the present invention, as shown in FIG. 9, comb-shaped comb-tooth portions are formed at the respective ends of the front housing 13 and the back housing 14. Other configurations are the same as those in the first embodiment, and thus description thereof is omitted here.

  As shown in FIG. 9, the front housing convex portion 27 constituting the comb tooth portion (second comb tooth portion) of the front housing 13 is the comb tooth portion (first comb tooth portion) of the rear housing 14. It is possible to fit in the rear housing recess 28 constituting the.

  From the above, according to the second embodiment, the members constituting the backlight 3 can be fixed more firmly than the first embodiment.

<Embodiment 3>
In the first embodiment, the case where the front housing 13 and the light guide plate 10 are bonded and fixed with the double-sided tape 18 has been described. However, the present invention is not limited to this. In Embodiment 3 of the present invention, as shown in FIG. 10, the light guide plate 10 includes a light guide plate main body 30, and a light guide plate white molded portion integrally molded with the light guide plate main body 30 and white (two-color molding). 29. Other configurations are the same as those in the first embodiment, and thus description thereof is omitted here.

  As shown in FIG. 10, the light guide plate 10 accommodates the optical sheet 11 by forming a light guide plate white molding portion 29 (protruding portion) in a portion corresponding to the outer periphery of the mounting surface of the back housing 14. Has a recess. The light shielding / backlight fixing tape 17 (second fixing tape) fixes the rear housing 14 and the light guide plate 10.

  From the above, according to the third embodiment, in addition to the effects of the first embodiment, the double-sided tape 18 used in the first embodiment is not necessary, and therefore the number of parts or the cost can be reduced. It becomes.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

  DESCRIPTION OF SYMBOLS 1 Display apparatus, 2 Display element, 3 Backlight, 4 Housing | casing, 5 Circuit board, 6 1st board | substrate, 7 2nd board | substrate, 8 Driving IC, 9 Light source, 10 Light guide plate, 11 Optical sheet, 12 Reflection Sheet, 13 Front case, 14 Back case, 15 Light source arrangement side, 16 BM width, 17 Shading / backlight fixing tape, 18 Double sided tape, 19 Backlight frame, 20 Double sided tape, 21 Front case wall thickness, 22 Back housing recess, 23 Front housing frame, 24 Backlight fixing tape, 25 Front housing frame width, 26 Front housing double-sided tape, 27 Front housing projection, 28 Rear housing recess, 29 Light guide plate white molding part 30 Light guide plate body.

Claims (8)

A light source;
A light guide plate that emits light from the light source in a predetermined direction;
An optical sheet for adjusting the intensity distribution of the light emitted from the light guide plate;
The light source is disposed, and has a placement surface on which the light guide plate and the optical sheet are placed from the back side, and the outer circumference of the placement surface is previously provided on at least one side other than the side on which the light source is arranged. A back housing having a defined positioning portion;
A front case that is positioned by the positioning unit, accommodates the light source, the light guide plate, and the optical sheet from the front side, and has an opening through which light emitted from the optical sheet passes;
A first fixing tape that covers at least a portion where the front case is positioned by the positioning unit and fixes the back case and the front case;
With a backlight.   The backlight according to claim 1, wherein the positioning part is a step part having a step. The positioning portion is a first comb tooth portion formed in a comb tooth shape,
2. The backlight according to claim 1, wherein the front housing includes a comb-shaped second comb-tooth portion formed so as to be fitted to the first comb-tooth portion. The opening is opened so that the optical sheet is exposed,
The said 1st fixing tape is extended to the inner side of the said opening part so that it may overlap with a part of said optical sheet by planar view, The any one of Claim 1 to 3 characterized by the above-mentioned. Back light.   4. The backlight according to claim 1, wherein the front housing has a protruding portion that overlaps with the outer periphery of the optical sheet in plan view. 5. A light source;
A light guide plate that emits light from the light source in a predetermined direction;
An optical sheet for adjusting the intensity distribution of the light emitted from the light guide plate;
A rear housing having a placement surface on which the light source is placed and the light guide plate and the optical sheet are placed from the back side;
A second fixing tape for fixing the rear housing and the light guide plate;
With
The said light guide plate has a recessed part which accommodates the said optical sheet by forming a protrusion part in the part corresponding to the outer periphery of the said mounting surface, The backlight characterized by the above-mentioned.   The light guide plate includes a light guide plate main body, and a light guide plate white molded portion molded in white, which is the protruding part integrally formed with the light guide plate main body. Backlight. The backlight according to any one of claims 1 to 7,
A display element disposed on the backlight;
A display device comprising:

Images