JP4232417B2 - Backlight unit, electro-optical device, electronic apparatus, and method for manufacturing backlight unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a backlight unit used in a portable small-sized television, a pager, a wall-mounted television, a notebook computer, an electro-optical device of a portable game machine, and the like, a light guide unit therefor, and an electro-optical device including the backlight unit About.
[0002]
[Background]
In recent years, thin and light liquid crystal display devices have been widely used in display units of portable small-sized televisions, pagers, wall-mounted televisions, notebook computers, portable game machines, and all other electronic devices, and the demand for these devices is increasing. There is a tendency.
[0003]
A reflective liquid crystal display device, which is light, thin, and has low power consumption, does not have a light source unit, and performs display visual recognition using only external light. However, in consideration of use in various environments including outdoors and dark places at night, a reflective liquid crystal display device having a front light type backlight unit and a transmission having an edge light type or area light type backlight unit. Type liquid crystal display devices and transflective liquid crystal display devices have also been developed.
[0004]
The area light type backlight unit is a type in which a light source is arranged directly below a surface light source. An advantage of the area light type backlight unit is that, for example, a large number of cold cathode fluorescent lamps can be arranged in a plane, so that a surface light source with high luminance can be constructed. However, there is a problem that luminance spots and chromaticity spots accompanying the deterioration of the lamp are easily recognized and the backlight unit becomes thick.
[0005]
The edge light type backlight unit is a type in which a light source is arranged on a side surface, and is designed to uniformly guide light to a display unit with a light guide (for example, Patent Document 1, Patent). Reference 2). The advantage of the above-mentioned edge light type backlight unit is that a very uniform surface light source can be obtained.For example, even when a plurality of cold cathode fluorescent lamps are used, luminance unevenness or It is mentioned that a chromaticity spot is hard to be visually recognized.
[0006]
As described above, the edge light type backlight unit is provided with the light guide. In the light guide, it is important that light incident from a light source such as a cold cathode fluorescent lamp or LED (light emitting diode) is uniformly emitted from the entire emission surface while light is guided into the light guide. It is.
[0007]
Therefore, the optical design of the light source and the light guide is one of important development items because it greatly affects the display quality of electro-optical devices such as liquid crystal display devices.
[0008]
[Patent Document 1]
JP 2001-52520 (Page 6, FIG. 4)
[Patent Document 2]
JP 2002-133907 (5th page, FIG. 1)
[Problems to be solved by the invention]
In electro-optical devices such as liquid crystal display devices, development of various portable devices has been promoted, and demands for higher brightness, thinner thickness, and lower power consumption are increasing. Since the liquid crystal display device itself does not emit light, in general, a configuration in which a backlight unit is arranged in the liquid crystal display device is often employed so that the display can be seen in a dark place.
[0009]
The backlight unit includes an area light type backlight unit and an edge light type backlight unit used in a transmissive liquid crystal display device and a transflective liquid crystal display device, and a front light type backlight unit used in a reflective liquid crystal display device. Etc. The light emitted from the backlight unit is transmitted through the liquid crystal display device, so that the display of the liquid crystal display device can be seen even in a dark place.
[0010]
The edge light type backlight unit described above is provided with a light guide. The function of the light guide is to emit light uniformly from the entire emission surface while guiding light incident from the light source into the light guide.
[0011]
Originally, it is ideal that 100% of the light incident from the light source is emitted to the emission surface on the liquid crystal display panel side while guiding the inside of the light guide. However, at present, this is not realized, and in most cases, light is partly from the end of the light guide that is not on the liquid crystal display panel side, that is, the gap between the light guide and the holder that holds the light guide. It will be emitted. This is because the light guide and the holder holding the light guide are molded as individual parts, and finally the light guide and the holder are fitted in the assembly stage. That is, since there is an air layer in the gap between the light guide and the holder, light incident on the light guide from the light source partially leaks from the end of the light guide to the air layer. Therefore, the conventional light guide unit has a problem that the light use efficiency is not improved.
[0012]
SUMMARY An advantage of some aspects of the invention is that it provides an electro-optical device with high display quality by using a light guide unit that improves light use efficiency of a light source.
[0013]
[Means for Solving the Problems]
The backlight unit of the present invention includes a light guide, a light source disposed to face an incident end face of the light guide, a substrate on which the light source is mounted, A holder disposed at an edge of the light guide, and The light guide is formed smaller than the thickness of the holder, an incident end surface of the light guide is formed away from the holder, and an end surface other than the incident end surface of the light guide is the holder. The light source is disposed between the incident end face of the light guide and the holder, and the substrate on which the light source is mounted is surrounded by one surface of the light guide and the holder Built into the confined space . In the conventional technique, light incident on the light guide from the light source may partially leak into the air layer that exists in the gap between the light guide and the holder. However, by using the integrated light guide unit, light that has partially leaked does not leak, so the light utilization rate by the light guide is improved.
[0014]
In the light guide unit, the light guide and the holder can be integrally formed by, for example, multicolor molding or insert molding means.
[0015]
In one mode of the light guide unit, the material of the holder is different from the material of the light guide. The light guide material is made of, for example, a transparent resin such as a polymethyl methacrylate (PMMA) resin or a polycarbonate (PC) resin.
[0016]
In another aspect of the light guide unit, the holder can be made of a resin material having high reflection characteristics with respect to wavelength dispersion of a light source. By using a material having a high reflection property as the material of the holder, when the light emitted from the light source reaches the interface between the light guide and the holder, the light is guided again inside the light guide. It exits from the exit surface of the body. Therefore, the light use efficiency of the light guide unit is improved.
[0017]
In still another embodiment of the light guide unit, the resin material is mixed with, for example, titanium oxide. The resin material can have a high reflection characteristic of 95% or more, for example, by mixing a certain proportion of titanium oxide.
[0018]
In another aspect of the present invention, the backlight unit can include the light guide unit and a light source. By mounting the light guide unit on the backlight unit, a high-luminance backlight unit with high light utilization efficiency can be provided.
[0019]
In one aspect of the backlight unit, the light source is disposed at an end face where the light guide and the holder are not integrated, for example, between the light guide and the holder.
[0020]
In another aspect of the backlight unit, the light source may be, for example, an LED (light emitting diode).
[0021]
The electro-optical device may include the backlight unit and an electro-optical display panel disposed at a position where the light emitted from the backlight unit is emitted. The electro-optic display panel is, for example, a liquid crystal panel, such as STN (Super Twisted Nematic) mode, TFT-LCD (Thin Film Transistor-Liquid Crystal Display) mode, TFD-LCD (Thin Film Dynode-Liquid Crystal Display) mode, and the like. May be used.
[0022]
Furthermore, according to the present invention, an electronic apparatus can be configured by including the electro-optical device as a display unit.
[0023]
Further, the present invention is a method for manufacturing a backlight unit comprising a light guide, a light source disposed to face the incident end face of the light guide, and a holder disposed at an edge of the light guide, A first step of molding a resin material into the holder; and after the first step, An incident end face of the light guide is formed apart from the holder, and end faces other than the incident end face are integrated with the holder. A second step of forming the light guide so as to After the second step, the light source includes a third step of disposing the light source between the incident end face of the light guide and the holder. In the second step, the light guide The substrate is formed to be smaller than the thickness of the holder, and in the third step, a substrate on which the light source is mounted is incorporated into a space surrounded by one surface of the light guide and the holder. By using the integrated light guide unit, light that has partially leaked does not leak, so the light utilization rate by the light guide improves. The manufacturing method of the light guide unit may be, for example, a manufacturing method using a dedicated two-color molding machine having two cylinders, or a manufacturing method using two injection molding machines.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below with reference to the drawings.
[0025]
The present embodiment relates to a light guide unit and a backlight unit that can efficiently use light from a light source. Hereinafter, although this embodiment is described in detail, the scope of the present invention is not limited to the examples described below.
[0026]
[Embodiment]
The present embodiment relates to a light guide unit and a backlight unit installed below a liquid crystal display device. In this embodiment, in order to prevent an air layer from intervening between the light guide in the backlight unit and the holder for holding the light guide, integrated molding is performed by an injection molding method such as a two-color molding method. It is characterized by doing.
[0027]
(Two-color molding method)
Two-color molding is a kind of injection molding method.
[0028]
First, the injection molding will be described below.
[0029]
Injection molding is the most widely used method for plastic molding. The most important tool in the injection molding method is an injection mold. In other words, an injection molding machine is used to perform injection molding, and a plastic molded product having a desired shape is manufactured by a mold attached to the heart of the injection molding machine.
[0030]
The injection molding machine includes a mechanism that melts and injects a plastic material, a mechanism that opens and closes a mold, and a mechanism that controls driving thereof. A general process of the injection molding method will be described. First, granular or pelletized plastic material falls from the hopper to the heating cylinder. The material plasticized by the shearing action by the rotation of the screw is accumulated on the nozzle side, and the screw moves backward in the cylinder and measures the required amount. The plasticized material is then injected into the mold by rapid advancement of the screw. When cooling is completed, the mold is opened, the molded product is taken out, and the process is completed.
[0031]
Next, two-color molding (multicolor) molding will be described below.
[0032]
Two-color (multicolor) molding is a method of simultaneously molding letters, numbers, symbols, etc. of different colors on an injection molded product, for example. The above two-color (multicolor) molding method requires two or more injection molding machines or a dedicated two-color (multicolor) molding machine having two or more cylinders, and the mold also rotates, A special mold that expands is required.
[0033]
In the present embodiment, a light guide unit produced by a dedicated two-color molding machine having two cylinders will be described. However, the present embodiment is not limited to a dedicated two-color molding machine having two cylinders, and for example, integral molding may be performed by using two or more injection molding machines. .
[0034]
(Backlight unit structure)
The backlight unit 100 to which the light guide unit of the present invention is applied will be described. Fig.1 (a) shows the top view of the backlight unit 100 to which the light guide unit of this invention is applied. FIG. 1B is a cross-sectional view of the backlight unit AA ′ shown in FIG. FIG. 3C is a cross-sectional view of the backlight unit BB ′ shown in FIG.
[0035]
As shown in FIG. 1, the backlight unit 100 is roughly composed of a light guide 1, a holder 2, an LED (light emitting diode) 3 that operates as a light source, a reflection film (not shown), and the like. Although not shown, the LED 3 is connected to a control circuit for lighting each LED 3.
[0036]
In addition, as shown in FIG. 3C, the light guide unit 200 includes a light guide 1 and a holder 2.
[0037]
This embodiment will be described in detail using an edge light system. However, the application of the light guide unit of the present invention is not limited to the edge light system, and can be used for a front light system, for example.
[0038]
The backlight unit 100 has an LED 3 attached to one end face of the light guide 1. In addition, a plurality of light diffusing portions made up of large and small depressions are formed on the surface of the light guide 1. The light guide 1 is made of a transparent resin such as polymethyl methacrylate (PMMA) resin or polycarbonate (PC) resin. Polymethylmethacrylate resin is a representative polymer material with excellent transparency, its photoelastic coefficient and birefringence are relatively small, and the residual stress and flow orientation during molding have little effect on the optical properties of the molded product. . Polycarbonate resin is a material having a relatively high heat resistance with a glass transition temperature of 145 ° C.
[0039]
When each LED emits light by the control circuit in a state where the LED 3 is provided at one end portion of the light guide body 1, light incident from the LED 3 from one end portion of the light guide body 1 is guided through the light guide body and externally. The light is evenly emitted. That is, incident light from the LED 3 is emitted to the surface of the light guide 1 and can irradiate the liquid crystal display panel with light.
[0040]
In the prior art, the light guide and the holder are injection molded as separate parts. And finally, it is commercialized by fitting the light guide to the holder in the assembly stage. However, in the conventional technology as described above, an air layer is interposed in the gap between the light guide and the holder. Therefore, the light incident from the end face of the light guide is guided through the inside of the light guide, and most of the light is emitted to the exit surface of the light guide, but some light is emitted from the end face of the light guide. There is a disadvantage that it ends up. Therefore, the conventional technique has a problem in light utilization efficiency.
[0041]
In the light guide unit 200, the light guide 1 and the holder 2 are integrally formed by multicolor molding, for example, two-color molding. That is, the light guide unit can uniformly emit all the light to the liquid crystal display panel side while guiding the light incident from the LED 3 into the light guide. Therefore, unlike the prior art, an air layer is not interposed in the gap between the light guide and the holder that holds the light guide, so that part of the light is not emitted from the end face of the light guide. In short, the utilization efficiency of the light incident from the LED 3 into the light guide body is improved.
[0042]
Moreover, the material of the light guide 1 and the material of the holder 2 use different materials. As described above, the light guide 1 is made of a transparent resin such as polymethyl methacrylate (PMMA) resin or polycarbonate (PC) resin. In addition, as the material of the holder 2 of the present embodiment, a resin material having high reflection characteristics with respect to wavelength dispersion of the light source is used. For example, a base resin material, for example, a resin material having a high reflection characteristic in which a titanium oxide powder or the like is mixed with a polycarbonate resin at a certain ratio is used. The reflection characteristic of the resin material shows a high value of 95% or more.
[0043]
Incident light from the LED 3 guides the inside of the light guide, exits from the exit surface of the light guide, and irradiates the liquid crystal display panel. Or the incident light is reflected at the interface between the light guide 1 and the holder 2 because the material of the holder 2 is a resin material having high reflection characteristics, and again guides the inside of the light guide. The liquid crystal display panel arranged on the surface of the light guide can be irradiated. In short, by using the backlight unit 100, the light utilization efficiency of the LED 3 is further improved.
[0044]
In the light guide unit 200, the light guide 1 and the holder 2 are integrated, and the resin material of the holder 2 has high reflection characteristics. Therefore, the light emitted from the LED 3 in the backlight unit 100 does not leak partly through the gap between the light guide and the holder that holds the light guide. The light is reflected at the interface, guided inside the light guide again, and finally emitted from the surface of the light guide 1. That is, the backlight unit 100 can efficiently use the incident light from the LED 3 and irradiate the liquid crystal display panel.
[0045]
Therefore, the present invention can provide the backlight unit 100 with high light utilization efficiency.
[0046]
(Backlight unit manufacturing method)
FIG. 2 is a manufacturing process of the backlight unit 100 according to the present embodiment, and shows details of manufacturing the light guide unit 200 by the injection molding machine. FIGS. 3A, 3 </ b> B, and 3 </ b> C are diagrams of main manufacturing steps of the light guide unit 200. 3A and 3B are cross-sectional views of a mold that is an important tool of an injection molding machine. FIG. 3C illustrates a light guide unit 200 manufactured by injection molding, and corresponds to a cross-sectional view of the backlight unit BB ′ illustrated in FIG.
[0047]
The manufacturing process of the backlight unit 100 can be roughly divided into three processes. The process Pa is a manufacturing process of the light guide unit 200, the process Pb is a manufacturing process of the substrate on which the LED 3 is mounted, and the process Pc is an assembly process of the substrate on which the light guide unit 200 and the LED 3 are mounted. .
[0048]
Details of the process Pa corresponding to the important process of the present invention, that is, the manufacturing process of the light guide unit 200 will be described below.
[0049]
A manufacturing process of the light guide unit 200 by injection molding of a two-color molding method using a dedicated two-color molding machine having two cylinders will be described. However, the manufacturing method of the light guide unit 200 is not limited to a manufacturing method using a dedicated two-color molding machine having two cylinders. For example, the light guide unit 200 can be integrated by using two injection molding machines. Molding may be performed.
[0050]
The manufacturing process of the light guide unit 200 by the injection molding machine shown in FIG. 2 will be described for the case where an inline screw type injection molding machine is used.
[0051]
In step Pa1, mold closing is performed. In other words, the mold is closed after confirming that the mold is at a low pressure and that there is no foreign matter. This mold is formed of a fixed mold 51 and a rotary mold 52. Next, in step Pa2, the mold is clamped at a high pressure so as not to open at the injection pressure.
[0052]
In step Pa3, a resin material corresponding to the material of the holder 2 in the first cylinder is injected into the mold at high pressure and high speed, and injection is performed. In step Pa4, the pressure in the injection cylinder is kept high. Next, in step Pa5, the pressure in the first cylinder is lowered to solidify the resin material in the mold. As shown in FIG. 3A, the holder 2 is formed by the above steps Pa3 to Pa5.
[0053]
After the holder 2 is molded, the rotary die 52 of the mold rotates in step Pa6.
[0054]
In step Pa7, a resin material corresponding to the material of the light guide 1 in the second cylinder is injected into the mold at high pressure and high speed and then injected. In step Pa8, the pressure in the second cylinder is kept high. Next, in step Pa9, the pressure in the injection cylinder is lowered to solidify the plastic in the mold. By the steps Pa7 to Pa9, the light guide 1 is formed as shown in FIG. 3B, and the light guide 1 and the holder 2 are integrated as shown in FIG. 3C. 200 is formed. In the light guide unit 200, a space for incorporating a substrate on which an LED as a light source is mounted is formed by a mold.
[0055]
Next, at step Pa10, the mold is opened, and at step Pa11, the light guide unit 200 is removed from the mold.
[0056]
In the process Pc, the light guide unit 200 molded in the process Pa and the LED mounting board mounted in the process Pb are assembled, and the backlight unit 100 according to the present invention is manufactured.
[0057]
In the light guide unit 200 according to the present embodiment, the light guide 1 and the holder 2 are integrated, and the material of the holder 2 also has high reflection characteristics. In short, unlike the prior art, a portion of light does not occur from the gap between the light guide and the holder that holds the light guide. Therefore, the light incident on the light guide 1 from the LED 3 that is the light source of the backlight unit 100 is reflected when reaching the interface between the light guide 1 and the holder 2, and is guided again inside the light guide. It exits from the exit surface of the body 1. That is, the backlight unit 100 can efficiently use incident light from the light source and irradiate the liquid crystal display panel.
[0058]
Therefore, the present invention can provide the backlight unit 100 with high light utilization efficiency.
[0059]
(Liquid crystal display device)
FIG. 4 shows a cross-sectional view of a liquid crystal display device 400 using this embodiment. The liquid crystal display device 400 is roughly composed of a liquid crystal display panel 300 and a backlight unit 100.
[0060]
First, the configuration of the liquid crystal display panel 300 will be described.
[0061]
Transparent electrode films 5a and 5b are respectively formed on the surfaces of insulating substrates 4a and 4b such as glass, and an alignment film (not shown) for aligning liquid crystal molecules in a certain direction is further provided. The two insulating substrates 4a and 4b are pasted with a sealing material 11 so that the transparent electrode films 5a and 5b are opposed to each other while keeping a certain distance by a spacer (not shown). The liquid crystal material 6 is sealed in the gap between the two insulating substrates 4a and 4b, whereby the liquid crystal layer 6 is sandwiched between the two insulating substrates 4a and 4b. Further, polarizing plates 7a and 7b and retardation plates 8a and 8b are attached to the outside of the insulating substrates 4a and 4b, respectively, and the liquid crystal display panel 300 is formed by these.
[0062]
Note that a switching element or the like may be formed on the insulating substrate 4a, and color filters 9a, 9b and 9c, a protective film 10 and the like may be formed on the insulating substrate 4b.
[0063]
When a voltage is applied to the transparent electrode films 5a and 5b, the arrangement of the liquid crystal molecules sandwiched between them changes, and the transmission of light from the backlight unit 100 along with the directions of the absorption axes of the polarizing plates 7a and 7b. The opaqueness is controlled, and a desired display can be obtained.
[0064]
As described above, in the backlight unit 100 according to the present embodiment, the light guide 1 and the holder 2 are integrated, and the material of the holder 2 also has high reflection characteristics. In short, unlike the prior art, a portion of light does not occur from the gap between the light guide and the holder that holds the light guide. The incident light from the LED 3 is reflected when reaching the interface between the light guide and the holder, is guided again inside the light guide, and is emitted from the exit surface of the light guide. That is, the backlight unit 100 can efficiently use the incident light from the LED 3 and irradiate the liquid crystal display panel 300.
[0065]
Therefore, the backlight unit 100 of this embodiment can provide the liquid crystal display device 400 that is bright and has high display quality.
[0066]
[Method of manufacturing liquid crystal display panel]
Next, a method for manufacturing the liquid crystal display panel 300 shown in FIG. 4 will be described with reference to FIG. FIG. 5 is a flowchart showing a manufacturing process of the liquid crystal display panel 300.
[0067]
First, a substrate 4a is manufactured (step S1), a transparent conductive film 5a is formed by sputtering, and patterning is performed by a photolithography method to form a transparent electrode film 5a (step S2). Further, an alignment film (not shown) is formed on the transparent electrode film 5a, and a rubbing process is performed (step S3).
[0068]
On the other hand, the substrate 4b is manufactured (step S4). Further, a transparent conductive film 5b is formed on the overcoat layer 10 provided on the color filter red 9a, the color filter green 9b, and the color filter blue 9c by sputtering, and patterning is performed by photolithography. A transparent electrode film 5b is formed (step S5). Thereafter, an alignment film made of polyimide resin or the like (not shown) is formed on the transparent electrode film 5b, and a rubbing process or the like is performed (step S6).
[0069]
And the said board | substrate 4a and the board | substrate 4b are bonded together through the sealing material 11, and a panel structure is comprised (process S7). The substrate 4a and the substrate 4b are bonded to each other with a substantially prescribed substrate interval by a spacer (not shown) distributed between the substrates.
[0070]
Thereafter, the liquid crystal 6 is sealed from an opening (not shown) of the sealing material 11, and the opening of the sealing material is sealed with a sealing material such as an ultraviolet curable resin (step S8). After the main panel structure is completed in this way, the phase difference plates 8a and 8b and the polarizing plates 7a and 7b are attached to the outer surface of the panel structure as necessary by a method such as sticking (step S9), as shown in FIG. The liquid crystal display panel 300 is completed.
[0071]
[Electronics]
FIG. 6 is a schematic configuration diagram showing the overall configuration of the present embodiment. The electronic apparatus shown here includes the liquid crystal display device 400 and a control unit 410 that controls the liquid crystal display device 400. Here, the liquid crystal display device 400 is conceptually divided into a panel structure 400A and a drive circuit 400B formed of a semiconductor IC or the like. Further, the control means 410 includes a display information output source 411, a display information processing circuit 412, a power supply circuit 413, and a timing generator 414.
[0072]
The display information output source 411 includes a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), a storage unit such as a magnetic recording disk or an optical recording disk, and a tuning circuit that tunes and outputs a digital image signal. The display information is supplied to the display information processing circuit 412 in the form of an image signal of a predetermined format based on various clock signals generated by the timing generator 414.
[0073]
The display information processing circuit 412 includes various well-known circuits such as a serial-parallel conversion circuit, an amplification / inversion circuit, a rotation circuit, a gamma correction circuit, and a clamp circuit, and executes processing of input display information to obtain image information. To the drive circuit 400B together with the clock signal CLK
Supply. The driving circuit 400B includes a scanning line driving circuit, a data line driving circuit, and an inspection circuit. The power supply circuit 413 supplies a predetermined voltage to each of the above-described components.
[0074]
Next, specific examples of electronic devices to which the liquid crystal display device according to the present invention can be applied will be described with reference to FIG.
[0075]
First, an example in which the liquid crystal display device according to the present invention is applied to a display unit of a portable personal computer (so-called notebook personal computer) will be described. FIG. 7A is a perspective view showing the configuration of this personal computer. As shown in the figure, the personal computer 510 includes a main body 512 having a keyboard 511 and a display 513 to which the liquid crystal display device according to the present invention is applied.
[0076]
Next, an example in which the liquid crystal display device according to the present invention is applied to a display unit of a mobile phone will be described. FIG. 7B is a perspective view showing the configuration of the mobile phone. As shown in the figure, a cellular phone 520 includes a plurality of operation buttons 521, a receiving part 522, a mouthpiece 523, and a display unit 524 to which the liquid crystal display device according to the present invention is applied.
[0077]
Note that, as an electronic device to which the liquid crystal display panel according to the present invention can be applied, in addition to the personal computer shown in FIG. 7A and the mobile phone shown in FIG. Monitor direct-view video tape recorders, car navigation devices, pagers, electronic notebooks, calculators, word processors, workstations, videophones, POS terminals, digital still cameras, etc.
[0078]
[Modification]
The electro-optical device of the present invention is not limited to a passive matrix type liquid crystal display panel, but also an active matrix type liquid crystal display panel (for example, a TFT (thin film transistor) or a TFD (thin film diode)) as a switching element. ) Can be applied in the same manner. In addition to the liquid crystal display panel, the present invention is applied to various electro-optical devices such as an electroluminescence device, an organic electroluminescence device, a plasma display device, an electrophoretic display device, and a field emission display (field emission display device). It is possible to apply similarly.
[Brief description of the drawings]
FIG. 1A is a plan view of a backlight unit according to the present invention.
(B) A sectional view of a backlight unit according to the present invention is shown.
FIG. 2 shows a backlight unit manufacturing process according to the present invention.
FIG. 3 is a cross-sectional view of the light guide unit according to the present invention during the manufacturing process.
FIG. 4 is a cross-sectional view showing a structure of a liquid crystal display device to which the present invention is applied.
FIG. 5 is a diagram showing a manufacturing process of a liquid crystal display panel to which the present invention is applied.
FIG. 6 illustrates a structure of an electronic device using a liquid crystal display device to which the present invention is applied.
FIG. 7 illustrates an example of an electronic device including a liquid crystal display device to which the present invention is applied.
[Explanation of symbols]
1 Light guide
2 Holder
3 LED
51 Fixed type
52 Rotating type
100 backlight unit
200 Light guide unit
300 LCD panel
400 Liquid crystal display device

Claims (8)

A light guide;
A light source disposed to face the incident end face of the light guide;
A substrate on which the light source is mounted;
A holder disposed at an edge of the light guide, and
The light guide is formed smaller than the thickness of the holder, an incident end surface of the light guide is formed away from the holder, and an end surface other than the incident end surface of the light guide is the holder. Is integrated with
The light source is disposed between the incident end face of the light guide and the holder;
A backlight unit, wherein a substrate on which the light source is mounted is incorporated in a space surrounded by one surface of the light guide and the holder . Material of the holder, a back light unit according to claim 1, characterized in that different from the material of the light guide. The holder, the wavelength dispersion of the light source, the backlight unit according to claim 1 or 2, characterized in that it is made of a resin material having a high reflection characteristic. The backlight unit according to claim 3 , wherein the resin material is mixed with titanium oxide. The light source, the backlight unit according to any of claims 1 to 4, characterized in that it comprises an LED. The backlight unit according to any one of claims 1 to 5 ,
An electro-optical device comprising: an electro-optical display panel disposed at a position where light emitted from the backlight unit is emitted. An electronic apparatus comprising the electro-optical device according to claim 6 as a display unit. A method for manufacturing a backlight unit comprising a light guide, a light source disposed opposite to an incident end face of the light guide, and a holder disposed at an edge of the light guide,
A first step of molding the resin material in the holder,
After the first step, the incident end face of the light guide, with formed apart from the holder, the end surface other than the incident end face, the shaping of the light guide body so as to integrate with the holder Two steps;
A third step of disposing the light source between the incident end surface of the light guide and the holder after the second step;
In the second step, the light guide is formed smaller than the thickness of the holder,
The method of manufacturing a backlight unit, wherein in the third step, a substrate on which the light source is mounted is incorporated in a space surrounded by one surface of the light guide and the holder.

Images