JPH0664235U - Panel display - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] The light from the back light source is guided to the liquid crystal display part like the conventional transmissive panel display device while the light is shielded from the front of the user to improve the display contrast. Provided is a greatly improved panel display device. [Structure] Between the liquid crystal display section B and the back light source 13, a striped pattern sheet 3 composed of a transparent layer 1 and a light shielding layer 2 is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a panel display device, and more particularly to a panel display device having a transmissive liquid crystal display unit.

[Prior art]

Various display systems have been proposed, which apply a mechanism of causing a change in a liquid crystal state by an electric signal and converting it into optical information. For example, a DS (dynamic scattering) method, which is a display method that applies the dynamic scattering effect of a nematic liquid crystal with a negative dielectric anisotropy, or a cholesteric liquid crystal with a positive dielectric anisotropy is used, and a cholesteric liquid crystal is applied by applying an electric field. PC (Phase Change) method, which is a display method that applies the effect of phase transition from a negative phase to a nematic phase, a memory type method that is a method that uses cholesteric liquid crystal with negative dielectric anisotropy, and a phase transition effect. There is a white tailor type guest-host method that utilizes liquid crystal alignment changes.

The electrode shape includes a segment type and a matrix type, which are classified into a transmissive display, a reflective display, and a projection display due to the difference in the basic configuration of the liquid crystal display. In addition, the reflector plate in the display device is used to efficiently reflect ambient light and improve the visibility of the liquid crystal display part, and the transmissive diffuser plate is used in the dashboard instruments of automobiles. It is used to increase the visibility by uniformly and efficiently diffusing the light from the backlight (back light source) into the liquid crystal display.

[Problems to be solved by the device]

However, when the above-mentioned display device is intended to be used on a table, it is necessary to make the display device small and thin, and therefore the light of the back light source is directly visible and the liquid crystal display becomes cloudy / transparent. Alternatively, when represented by the gradation, there is a drawback that display characteristics are deteriorated because the contrast of the display unit is low. In particular, the panel display device that does not use a polarizing plate in order to improve the light utilization efficiency and obtain a bright display characteristic has a drawback that the tendency becomes strong.

The present invention solves the above-mentioned conventional problem. Even though the light from the rear light source is blocked from the front of the user, the liquid crystal display section has the same function as the conventional panel display device. An object of the present invention is to provide a panel display device that guides light from a rear light source and greatly improves the contrast of the display section.

[Means for Solving the Problems]

The inventor pays attention to the direction of the light emitted from the back light source, and alternates a transparent layer configured to guide the light in a predetermined direction uniformly and a light shielding layer that does not scatter the light to the user side. A laminate having a striped pattern in which the layers are integrated is formed by alternating a light-transmitting layer and a light-shielding layer by, for example, "A method for producing an antiglare sheet having an inclined laminated surface" described in JP-A-1-187503. In a panel display device comprising a striped sheet laminated in multiple layers and comprising the above-mentioned liquid crystal display unit and a back light source for illuminating the liquid crystal display unit, the above-mentioned striped pattern is provided between the liquid crystal display unit and the back light source. We have succeeded in greatly improving the display contrast, which has been a problem in the past, by providing a light-shielding / light-guide plate consisting of pattern sheets, and have reached the present proposal.

Hereinafter, the panel display device of the present invention will be described in detail. Materials used for the transparent (transparent) layer portion and the light shielding layer portion, which are the constituent elements of the striped sheet used in the panel display device of the present invention, will be described. Any known transparent material can be used as the transparent material, but when plastic is used, it is transparent among polyvinyl chloride, polyethylene, polypropylene, polyvinyl acetate, cellulose derivatives, silicone rubber, etc. It is desirable that it has excellent properties. Further, it may or may not use a diluent such as water, toluene, tetrahydrofuran, or cellosolve, or may have the property of exhibiting fluidity when heated and solidifying when cooled.

As the light-shielding material, various pigments such as iron oxide black, carbon black, and titanium black, various dyes and pigments such as aniline black, calcium carbonate, clay, diatomaceous earth, alumina, fumes are added to the above-mentioned transparent materials. One or a mixture of two or more kinds of various fillers such as high quality silica and precipitated silica, metal powder, carbon fiber, natural fiber, synthetic fiber, and short fiber powder such as metal wire may be used.

With respect to these light-shielding materials, it is desirable that, when formed on the light-shielding layer, the light from the light source on the surface has a spectral reflectance of 0 to 25% in the range of 400 nm to 700 nm. In such a case, it is desirable to use a pigment such as carbon black and to set the spectral reflectance to 10% or less in the range of light from a light source of 400 nm to 700 nm. This is because the smaller the spectral reflectance, the more the contrast can be improved. Alternatively, similarly, it is desirable that the light transmittance of the light source in the light shielding layer is in the range of 400 nm to 700 nm and the spectral transmittance is also 0 to 25% for the same reason. Any color other than black may be used as long as it satisfies either of these conditions. When forming thin films such as transparent layers and light-shielding layers, transfer heat-resistant films as necessary, such as untreated or blasted polyethylene terephthalate film (hereinafter abbreviated as PET film). It may also be effective in production when used as a film.

[0012] Next, the method for forming a transparent layer and a light-shielding layer and a method for producing an alternating multiple layered stack by repeating the steps will be described more specifically. 1) A liquid silicone coater is coated on a carrier for transportation. After coating with-, a silicone rubber plate formed by using a mold is arranged on this surface, an adhesive layer is printed on the surface of this rubber plate, and the process is repeated to laminate; 2) A method of coating liquid silicone on a carrier for transport with a coater, then topping the silicone raw material with a calendar roll on this surface, and stacking it repeatedly; 3) Transport After applying liquid silicone on the carrier for coating with a coater, liquid silicone is again coated on this surface with a coater, and then an adhesive layer is printed on the surface. Repeated lamination method: 4) Sheeting of silicon raw material on a carrier for transportation This surface again other hand silicone - down raw topping, then the method of laminating repeatedly the same; and the like.

Laminates obtained by these methods are appropriately cured (solidified) under pressure heating or under pressure to be integrated into an alternating multiple layer laminate, but the light transmittance of the material and the thickness of the light-shielding thin film are uneven. If the problem occurs, it can be solved by reducing the ratio of the light shielding material portion to the whole. By slicing with a known knife blade, rotary blade, etc. in a direction crossing the stacking plane in a stacking body of alternating multiple layers obtained at a predetermined inclination angle, a striped pattern with alternating multiple layers of a light shielding layer and a transparent layer according to the present invention is obtained. -Got is obtained.

Next, the method of supporting (reinforcing) this striped sheet is basically the same as the method used for the conventional antiglare sheet, but 1) the striped sheet It is integrated with a transparent film, sheet, plate (particularly glass plate) or the like on at least one surface of the sheet via an adhesive or the like. 2) At least one surface (entire or part: the same applies hereinafter) of the striped sheet is integrated with the transmission diffusion plate via an adhesive (including an adhesive). 3) It is attached to at least one surface of the striped sheet with an adhesive or the like with the back surface of the liquid crystal display to be integrated. Alternatively, it is realized by any combination of 1), 2) and 3).

Regarding the adhesive, specifically, a highly transparent liquid silicone adhesive or adhesive, a highly transparent double-sided tape, a rubber adhesive, an acrylic adhesive, etc. There is no limitation on the kind as long as it is excellent in heat resistance, but a transparent liquid silicone-based adhesive having excellent heat stability, light resistance and shock resistance is particularly useful.

As for transparent films, sheets and plates, for example, hard or semi-rigid vinyl chloride resin, ethyl cellulose, cellulose acetate diacetate, cellulose acetate butyrate, acrylic resin, styrene. A resin, a polycarbonate resin, a thermoplastic resin such as polyethylene or polypropylene, or a blend thereof, or a material such as glass may be used, and there is no particular limitation as long as it is excellent in transparency. Therefore, films, sheets and plates made of polycarbonate resin, which has excellent heat resistance and punching processability, are used.

Regarding the transparent diffusion plate, various fillers such as calcium carbonate, clay, diatomaceous earth, alumina, fumed silica, and precipitated silica are added to the above-mentioned transparent materials, glass fiber, short fiber powder such as natural fiber and synthetic fiber. It is also possible to use a material in which one or more kinds of white pigments such as zinc white, titanium dioxide, titanium white, and lead white are mixed, and a permeation diffusing agent is mixed.

Alternatively, a film, sheet, or plate made of the above-mentioned transparent material, on the surface of which various fillers, various pigments, dyes and the like are dispersed in a transparent vehicle, is screen-printed and coated. -A coated or spray-coated transmission diffusion layer may be provided. The coloring is optional, but it is desirable that the contrast of the display portion is not significantly lowered.

The back light source is not particularly limited, and may be a fluorescent lamp such as an incandescent lamp or a neutral white color, or a thin electroluminescence (EL) panel, a light emitting diode or the like that emits visible light. There is no problem even if natural light such as sunlight is used by guiding light using an optical fiber. However, note that the color rendering of the light source may be important when performing color display.

Regarding the liquid crystal display used in the present invention, the above-mentioned DS (dynamic scattering) method, PC (phase change) method, memory type, white Taylor type guest-host method, etc. may be used. There is no particular limitation on the shape of electrodes that apply an electric signal to the enclosed liquid crystal body. It may be selected from segment type, matrix type and the like according to the purpose. It does not matter whether the display is negative or positive.

In a panel display device comprising a liquid crystal display unit of such a liquid crystal display body and a back light source for illuminating the liquid crystal display unit, the above-mentioned striped pattern stripe is provided between the liquid crystal display unit and the back light source. By providing a light-shielding / light-guiding plate made of a cathode, the contrast of the liquid crystal display can be greatly improved. The striped sheets may be placed directly or may be placed apart from each other as long as they are placed between the liquid crystal display section and the back light source.

Next, an example of the panel display device having the above configuration will be described with reference to the drawings. As shown in FIG. 1, A is an example of the structure of a light-shielding / light-conducting plate having a striped sheet used in the present invention. B illustrates a liquid crystal display in which a cholesteric liquid crystal having a positive dielectric anisotropy is used for display.

The striped sheet 3 composed of the transparent layer 1 and the light shielding layer 2 has a predetermined angle so that the light emitted from the back light source 13 and scattered by the transmission diffusion plate 6 is not leaked in the normal direction. It is sliced into thin pieces and is integrated with the transparent film 5 via the transparent adhesive 4. Such a light-shielding / light-guide plate A does not scatter light in the normal direction and within the light-shielding range unless there is an object that scatters light on the user side, but it is caused by the transparent layer 1 and the light-shielding layer 2. Within the light guide range, the light of the back light source 13 is continuously guided through the transmissive diffusion plate 6.

Now, in the liquid crystal display B, when the switch 10 is turned on and the electric field of the AC power supply 11 is applied between the transparent electrodes 7 a and 7 b provided on the glass substrate 12, the liquid crystal substance between them is applied. Changes to a nematic phase and forms a homeotropic structure 9 in which the molecules are aligned in the direction of the electric field, resulting in a transparent state. The user can see the light-shielding / light-guide plate A directly, but since it is in the light-shielding state, there is no light scattering and it is dark , The part to which the electric field is not applied is still in the focal conic structure 8 of the cholesteric phase, and thus is in a turbid state, which scatters the light guided by the transparent layer 1 and is therefore visually recognized as bright. The difference in contrast allows the user to clearly recognize the difference. FIG. 2A shows a perspective view when no electric field is applied, and FIG. 2B shows a perspective view when an electric field is applied.

FIG. 3 is a vertical sectional view showing another embodiment of the panel display device according to the present invention. 3 (a) is a panel display device having a light-shielding / light-guide plate in which a transparent diffusion layer 14 is provided on one side of a transparent film 5, and FIG. 3 (b) is a transparent film on each surface of the striped pattern sheet 3. 5. A panel display device obtained by laminating a liquid crystal display body B, and FIG. 3C shows a panel display device obtained by laminating a transmissive diffusion plate 6 and a liquid crystal display body E on each surface of the striped sheet 3. FIG. 3D shows a panel display device in which a transparent film 5 having a transmissive diffusion layer 14 provided on each surface of a striped pattern sheet 3 and a liquid crystal display B are bonded together. B, a panel display device in which a light blocking / light guiding plate is provided between the back light source 13 and the back light source 13.

[0024]

【Example】

 Hereinafter, the present invention will be described in various ways with reference to preferred embodiments, but the present invention is not limited to these embodiments, and improvements and improvements can be added without departing from the spirit of the invention. Of course.

Silicone rubber compound, SE1188u [trade name of Toray Dow Corning Silicone Co., Ltd.] 100 PHR and peroxide vulcanizing agent C-2 [trade name of Shin-Etsu Chemical Co., Ltd.] 2 PHR For the transparent layer 1 and a silicone rubber compound KE981u [trade name of Shin-Etsu Chemical Co., Ltd.] 100 PHR, a black colorant KE-Color-BB [same as above] 30 PHR peroxide vulcanizing agent C-8 [Same as above] 1. The raw material for the light-shielding layer 2 consisting of 5 PHR was made into a sheet shape by using a roll, and the sheets were alternately laminated and bonded, and heated at 160 ° C./20 hours under the condition of 4 kg / cm ^2. A laminated body was obtained by pressing.

As shown in FIG. 4, the transparent layer 1 has an O.V. It was formed into a film with a thickness of 120 mm. A visible angle of 2r = 60 degrees and an inclination angle of I ^' = 24 degrees were set to eliminate the light transmitted in the normal direction of the striped sheet, and a knife blade was used so that the thin slice thickness W = 0.36 mm. The sliced results are shown in FIG.

Next, on both sides of the striped sheet 3, 50 PHR of each of liquid silicone KE1934A [trade name of Shin-Etsu Chemical Co., Ltd.] and KE1934B [same as above], and primer AP-1 [. Same as above] An adhesive 4 consisting of 1 PHR was applied to a thickness of 0.03 mm by a screen printing machine, and a transparent film 5 made of a polycarbonate film having a thickness of 0.3 mm was used as a transmission diffusion plate 6. 0.4 mm thick Makrofol LT natural [trade name of Bayer Co., Ltd.] was attached to the coated surface of each adhesive 4, and a load of 10 g / cm ² , O.I. Degassing was performed under the condition of 1 Torr / 30 seconds, and curing and integration were performed by heat treatment at 120 ° C./2 hours to obtain a light-shielding / light-guide plate A integrated with the transmission diffusion plate 6. The panel display device according to the present invention shown in FIG. 5 was obtained by providing this in the middle of the liquid crystal display B in which the cholesteric liquid crystal having positive dielectric anisotropy is enclosed and the back light source 13.

[0028]

[Effect of device]

 The panel display device according to the present invention further improves the display contrast as compared with the conventional panel display device in which the light-shielding / light-guide plate A is not provided. can do.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an example of a panel display device according to the present invention.

2A and 2B show a panel display device of the present invention, wherein FIG. 2A is a perspective view when an electric field is not applied, and FIG. 2B is a perspective view when an electric field is applied.

FIG. 3 is a vertical cross-sectional view showing another embodiment of the panel display device according to the present invention.

FIG. 4 relates to a panel display device of the present invention, (a) is a vertical cross-sectional view of a laminate comprising a transparent layer 1 and a light shielding layer 2, and (b) is a slice of the laminate at a predetermined angle I ^′. Model diagram of
(C) is a partial cross-sectional view of the striped sheet.

FIG. 5 is a vertical sectional view showing an embodiment of a panel display device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Transparent layer 2 ... Light-shielding layer 3 ... Stripe sheet 4 ... Adhesive 5 ... Transparent film 6 ... Transmission diffusion plate 7a, 7b ... Transparent electrode 8. ..Focalconic structure of cholesteric phase 9 ... Homeotropic structure of nematic phase 10 ... Switch 11 ... AC power supply 12 ... Glass substrate 13 ... Back light source 14 ... Transmission diffusion layer A・ ・ ・ Shading / light guide plate B ・ ・ ・ Liquid crystal display

Claims (1)

[Scope of utility model registration request] 1. A panel display device comprising a liquid crystal display unit and a back light source for illuminating the liquid crystal display unit, wherein a light-shielding / light guide plate having a striped pattern sheet is provided between the liquid crystal display unit and the back light source. A panel display device characterized by the following.