JPH03163585A - Manufacture of side illumination type display panel - Google Patents

Abstract

PURPOSE:To eliminate a printing process or a transfer process and to improve productivity by providing a transfer layer having a display layer simultaneously with a molding process. CONSTITUTION:The transfer layer 5 is provided simultaneously with the molding process of a transparent resin plate 9 by using a transfer foil having the transfer layer 5 consisting of at least the display layer 3 on a base sheet 1 having release characteristics a metallic mold 10 having a recessed and projecting part 12 inside and a metallic mold 11 where the transfer foil is mounted. Therefore, a light reflecting recessed and projecting part 8 is formed on the back surface of the transparent resin plate 9 being a molded article by copying ruggedness formed on the inside of the metallic mold. Simultaneously, the transfer layer 5 is transferred on the surface of the plate 9 so that the illumination required part of the display layer corresponds and coincides with the recessed and projecting part 8 on the back surface. Thus, the printing process and the transfer process are eliminated and the productivity is improved.

Description

[Detailed description of the invention] [Industrial application field]

This invention is widely used in indicators for home appliances, audio equipment, automobiles, etc., and relates to a method for manufacturing a side-illuminated display panel having a display portion such as display characters, display scales, and marks. ．．

[Conventional technology]

Conventionally, side-illuminated display panels have been used as follows. Light is incident from the side of a transparent resin substrate made of acrylic or the like with a light-reflecting uneven portion on the back side, and by utilizing the internal reflection effect of the acrylic plate, the incident light is reflected by the light-reflecting uneven portion and the surface is The reflected light illuminates the display section. Furthermore, since the amount of reflected light can be adjusted by adjusting the density of the light-reflecting uneven portions, the unevenness becomes denser as the distance from the light source increases, making it possible to uniformly illuminate each display section. This method allows display panels to be illuminated brightly, uniformly, and clearly even with one or two small-capacity light bulbs, and also allows for thinner and lighter display devices, which are more important than display panels and light bulbs. ．． Conventionally, a method for manufacturing a side-illuminated display panel having a display pattern portion such as display characters, display scales, marks, etc. has been as follows. First, a display pattern is printed in multiple colors as necessary by screen printing on the surface of a transparent resin substrate that has been shaped into a predetermined shape using acrylic or the like to have a light-reflecting uneven portion on the back surface. The method involved printing and forming a light-shielding portion in other locations, or transferring a transfer foil onto the surface of the transparent resin substrate by means such as heating and pressing.

[Problem to be solved by the invention]

However, such conventional methods involve the step of forming a transparent resin substrate having light-reflecting irregularities on one surface;
Two major steps are required, including a printing step for forming a display portion on the formed transparent resin substrate and a transfer step, which is time-consuming and significantly reduces productivity. Further, since the shape of the transparent resin substrate is limited to a surface shape suitable for printing, that is, a surface shape such as a flat surface or a cylindrical side surface, it is difficult to support products with various shapes such as three-dimensional shapes.

[Means to solve the problem]

In order to solve the above problems, this invention is constructed as follows. That is, the method for manufacturing a side-illuminated display panel of the present invention includes a transfer foil formed on a base sheet in which a transfer layer having a Hitotsubashi layered display layer having a transparent portion on the entire surface has releasability, and a light-reflecting uneven portion. First, a transfer foil is placed between mold A and mold B using a mold A that has an uneven part to shape the cavity and a mold B that shapes the cavity together with the mold A. By placing mold A and mold B together and injecting transparent resin into the formed cavity, the transfer layer of the transfer foil is brought into close contact with the front surface and the uneven portions are copied onto the back surface. A molded product having a light-reflecting uneven portion formed thereon was molded, and after cooling and solidifying, the mold was opened, the molded product was taken out, and the base sheet was peeled from the molded product. In addition, a transfer layer including a display layer having a light-shielding part and a light-transmitting part is formed on a releasable base sheet, and the light-transmitting layer is used to form a light-reflecting uneven part. Mold A has an uneven part formed in the same pattern as that of Mold A, and Mold B forms a cavity together with Mold A.
First, the transfer foil is positioned between the molds A and B so that the pattern of the transparent part thereof corresponds to the pattern of the uneven parts of the mold 8, and Molds A and B are closed, and a transparent resin is injected into the formed cavity to create a molded product with a transfer layer of transfer foil tightly attached to the front surface and a light-reflecting uneven portion formed on the back surface. After molding and cooling to solidify, the mold was opened, the molded product was taken out, and the base sheet was peeled off from the molded product. Further, the transparent portion of the transfer foil may be made of an ultraviolet-sensitive luminescent material. Further, the transparent portion of the transfer foil may be made of an infrared-sensitive luminescent material. This invention will be explained in more detail below with reference to the drawings. FIG. 1 is a sectional view showing one step of the method for manufacturing a side-illuminated display panel of the present invention. Figures 2 and 4 are cross-sectional views showing one embodiment of the transfer foil used in the present invention. 3rd, 5th
The figure is a sectional view showing one embodiment of a side-illuminated display panel obtained by the manufacturing method of the present invention. 1 is a base sheet, 2 is a release layer, 3 is a display layer, 30 is a transparent part, 3l is a light shielding part, 4 is an adhesive layer, 5 is a transfer layer, 6 is a transfer foil, 7 is a display panel, 8 is a light reflection 9 is a transparent resin substrate, 10 is a mold A, 11 is a mold B, and 12 is an uneven portion, respectively. First, the transfer Fg 7 used in this invention will be explained (see Figures 2 and 4). As the base sheet, a plastic film such as polyester, polypropylene, vinyl chloride, polyethylene, etc. is used. Transfer layers 5 such as a release layer 2, a display layer 3, and an adhesive layer 4 are sequentially provided on this base sheet l. Release layer 2 is the base sheet}
This is a layer for peeling off the transfer [5] from 1, and is made of thermoplastic resin, natural rubber, rubber, etc. The transparent portion 30 of the display layer 3 may be provided on the entire surface with the same ink using colored transparent ink, colorless transparent ink, ink made of an ultraviolet-sensitive luminescent material, an infrared-sensitive luminescent material, etc. (See Figure 2), the type of ink may be partially changed. Colored and transparent ink is made by dispersing transparent pigments or dyes into colorless and transparent ink made by appropriately diluting transparent Gokai resin with a solvent. Light-shielding ink is made by diluting Gokai resin appropriately with a solvent and dispersing opaque pigments (eg carbon plaque, titanium oxide, etc.). The UV-sensitive ink is made by diluting Hei resin appropriately with a solvent and dispersing fluorescent pigments or phosphorescent pigments. Infrared-sensitive inks are inks containing dispersed dyes that convert infrared rays into visible light. Further, in order to make the contrast stand out, the display layer 3 may provide a light-shielding portion 3l using light-shielding ink or a vapor deposited film in a portion of the display layer 3 that does not require illumination other than the light-transmitting portion 30 as described above. (See Figure 4). In this case, the pattern of the transparent portion 30 and the pattern of the uneven portion l2 of the mold AlO must match. The adhesive layer 4 is formed on the entire surface of the display layer 3, and is used to adhere each of the layers at the same time as the transparent resin substrate 9 is formed. As the adhesive layer 4, a heat-sensitive or pressure-sensitive resin suitable for the surface material such as the transparent resin substrate 9 is used as appropriate. For example, if the transparent resin substrate 9 is made of acrylic resin, acrylic resin is used, and if polycarbonate resin is used, epoxy resin is used. The release layer 2, display layer 3, and adhesive layer 4 are each formed by a conventional printing method such as a gravure printing method, a screen printing method, a flexographic printing method, a reverse coating method, or a roll coating method. Next, we will explain the mold used in the method of forming and simultaneously decorating a molded product using the transfer foil 6, as well as the method of simultaneously forming and transferring the transparent resin substrate 9 using the simultaneous molding and decorating method. Let us explain this as an example. That is, the mold AIO has a predetermined pattern of uneven portions 12 formed on its inner surface. These irregularities are copied onto the inside of one surface of the molded product and become the light reflecting irregularities 8. A transfer M6 is placed between this mold AIO and a normal mold Bll, and the transfer is performed simultaneously with molding. When the transfer foil 6 is long, the transfer foil M6 wound into a roll is fed into the mold AlO and the mold Bll using a foil feeding device for the preforming device. Then, the transfer foil 7 is positioned with respect to the uneven portion 12 of the mold AIO. In particular, when the display layer 3 of the transfer foil 6 is provided with the light-transmitting portion 30 and the light-shielding portion 31, the light-transmitting portion 30 and the uneven portion 12 must be positioned. After the mold is closed, the molten resin is injected (Figure 1). The molding resin used at this time includes, for example, acrylic resin,
It is best to use a resin with a high refractive index and high internal reflectance, such as polycarbonate resin, or a light-harvesting plastic made by adding fluorescent pigments to these resins to further increase the light-gathering efficiency on the sides. The shape of the product obtained in this way is: - Since various shapes can be obtained by changing the shape of the mold, the shape of the display panel is not limited. After cooling and solidifying, wait for the mold to open, and then peel off the base sheet 1 to obtain a perfect product and complete the cylindrical simultaneous transfer process. In this way, the side-illuminated display panel is fully equipped (3rd
, see Figure 5). At least one power source that emits not only visible light but also ultraviolet rays, infrared rays, etc. depending on the material of the transparent portion 30 of the display layer 3 is disposed on the side surface of the side-illuminated display panel manufactured in this manner. This causes the light section 30 to emit light.

[Effect]

This invention uses a transfer foil having a transfer layer consisting of at least a display layer on a releasable base sheet, a mold having an uneven portion on its inner surface, and a mold on which the transfer foil is placed. A transfer layer is applied at the same time as the board is prepared. Therefore, the unevenness formed on the inner surface of the mold is copied onto the back surface of the transparent resin plate that is the molded product, forming a light-reflecting uneven area, and at the same time, the necessary illumination portion of the display layer is formed on the surface of the transparent resin substrate. The transfer layer is transferred so that it corresponds to the light-reflecting unevenness on the back side. When the display layer has a light-transmitting part and a light-blocking part, it is necessary to accurately align the pattern of the light-transmitting part and the pattern of the light-reflecting uneven part, but since we are using a simultaneous transfer device, Their positioning can be done accurately.

【effect】

This invention provides a transfer foil in which a transfer layer including a display layer is shaped on a releasable base sheet, a mold having an uneven portion in a cavity, and a transfer foil placed on the mold. A configuration in which a transfer layer of transfer foil is provided at the same time as the molding of a transparent resin substrate using a mold to produce a display panel having a light-reflecting uneven portion on the back surface and a decoration on the front surface. did. Therefore, since the transfer layer having the display layer is provided at the same time as the molding process, the printing process or transfer process that was conventionally required separately can be omitted, thereby increasing productivity. In addition, since the transfer is performed simultaneously with molding, it is easy to decorate or shape transparent resin substrates of any shape, and as a result, products with a wide variety of display panel shapes can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one step in the method for manufacturing a side-illuminated display panel of the present invention. Figures 2 and 4 are cross-sectional views showing one embodiment of the transfer foil used in the present invention. 3rd, 5th
The figure is a sectional view showing an example of a side-illuminated display panel obtained by the manufacturing method of the present invention. DESCRIPTION OF SYMBOLS 1... Base sheet, 2... Peeling layer, 3... Display layer, 30... Transparent part, 3l... Light shielding part, 4... Adhesive layer, 5... Transfer layer, 6... Transfer foil, 7... Display panel, 8... Light reflecting uneven portion, 9... Transparent resin substrate,
10... Mold A, 11... Mold B1 12... Uneven portion.

Claims (1)

[Scope of Claims] 1. A transfer foil formed on a base sheet having a releasable transfer layer, one of which is a display layer having a transparent portion on the entire surface;
First, a transfer foil is placed between mold A and mold B using a mold A having an uneven part for forming a light reflecting irregular part and a mold B forming a cavity together with mold A. Place it on the
By closing mold A and mold B and injecting a transparent resin into the formed cavity, the transfer layer of the transfer foil is brought into close contact with the front surface, and the uneven portions are copied onto the back surface. 1. A method for manufacturing a side-illuminated display panel, comprising: molding a molded product having light-reflecting uneven parts, opening the mold after cooling and solidifying, taking out the molded product, and peeling a base sheet from the molded product. 2. A transfer foil formed on a base sheet in which a transfer layer having a releasable property is formed of a display layer having a light-shielding part and a light-transmitting part, and the light-transmitting part to form a light-reflecting uneven part. First, using a mold A having a concave-convex portion formed in the same pattern as the pattern of Place the mold A and the mold B between the molds A and B by positioning them so as to correspond to the pattern of the uneven parts of the mold A.
The mold is closed, and a transparent resin is injected into the formed cavity to form a molded product with the transfer layer of the transfer foil in close contact with the surface and light-reflecting uneven parts formed on the back surface.After cooling and solidifying, the mold is A method for manufacturing a side-illuminated display panel, comprising opening the molded product, taking out the molded product, and peeling a base sheet from the molded product. 3. The method for manufacturing a side-illuminated display panel according to claim 1 or 2, wherein the transparent portion of the transfer foil is made of an ultraviolet-sensitive luminescent material. 4. The method for manufacturing a side-illuminated display panel according to claim 1 or 2, wherein the transparent portion of the transfer foil is made of an infrared-sensitive luminescent material.