JPH0682683U - Retroreflector and display device using the same - Google Patents

Abstract

(57) [Summary] [Purpose] To make it easy to manufacture using general inexpensive materials and to increase the intensity of reflected light. [Structure] In the retroreflector 10, a large number of cylinders 12 made of a transparent solid such as glass or plastic are arranged in close contact with each other on a substrate 16 in parallel, and the cylinders are placed between each cylinder. Light reflection film 14 covering almost half of the side surface
Is a structure in which is interposed. The light reflecting film may be a metal film such as aluminum vacuum-deposited on the surface of the cylinder, or a metal foil or a plastic film on which a metal is vapor-deposited. On the surface where the cylinders of this retroreflector are arranged,
A display device can be configured by installing a transparent plate on which characters, figures, or symbols are written via an air layer.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a retroreflector and a display device using the retroreflector. More specifically, the present invention relates to a retroreflector in which a large number of cylinders made of a transparent solid are used as light reflecting elements and are regularly arranged. Is. This retroreflector is used in, for example, reflective sheets and reflective cloths for traffic signs, advertising boards, stickers, and reflectors for bicycles.

[0002]

[Prior art]

 For traffic signs and road signs, retroreflectors (eg sheets, cloths, tapes, etc.) using spherical glass beads with a diameter of a few microns to a few millimeters are used. They utilize the property that minute glass beads act as a spherical lens and the reflected light returns to the direction of the incident light source, that is, retroreflectivity.

Examples thereof are described in “Glass Handbook” edited by Sakuhana et al. (Asakura Shoten Publishing Co., Ltd.), pages 275 to 278. For example, as shown in FIG. 5, there is a reflection sheet having a structure in which a transparent resin 32 having a large number of glass beads 30 embedded therein is superposed on an aluminum vapor deposition film (reflection film) 34 and bonded by an adhesive 36. The incident light a from the front and the incident light c from the oblique direction are reflected by the aluminum vapor deposition film 34 to become reflected lights b and d, respectively, and return to the direction of the incident light source. As another example, as shown in FIG. 6, there is an open type reflective cloth in which about half of the glass beads 40 are exposed. In this case, half of the glass beads 40 are exposed and fixed to the base fabric 44 via the paint 42. The incident light a from the front and the incident light c from the oblique direction are reflected by the rear surface (boundary with the paint 42) of the glass beads 40, respectively, and become reflected lights b and d to return to the direction of the incident light source. .

These glass beads are obtained by passing glass powder or particles through a high-temperature atmosphere to remelt them, and shaping them into spherical shapes by utilizing surface tension, or by injecting molten glass with high-pressure air or high-temperature gas. Alternatively, it is manufactured by a method of forming into a spherical shape by dispersing with a centrifugal force.

[0005]

[Problems to be solved by the device]

 In the structure using these glass beads, in order to prevent unevenness, glass beads of uniform particle size should be evenly dispersed in a plane and the positional deviation in the thickness direction should be suppressed as much as possible. I won't. Therefore, the manufacturing process is considerably complicated and the cost is high. Also, in this structure, the glass beads are fixed with resin or paint, so that the glass beads are necessarily dispersed appropriately, and the planar array density of the reflective elements (glass beads) is low, so that the reflected light Will also be less intense.

Further, in the conventional structure, in the case of the structure in which the glass beads are embedded in the transparent resin, the refractive index of the glass has to be particularly high in order to have a refractive index difference from the transparent resin. Therefore, the glass composition becomes special, the devitrification becomes very high, and the chemical durability is lowered.

An object of the present invention is to solve the above-mentioned problems of the prior art, easy to manufacture, high intensities of reflected light, and a retroreflector which can be constructed by using a general inexpensive material, and the retroreflector. Is to provide a display device using.

[0008]

[Means for Solving the Problems]

 According to the present invention, a large number of cylinders made of a transparent solid material are closely arranged in parallel with each other on a base material, and between the cylinders and the base material, a light beam covering approximately half of the side surface of the cylinder is provided. It is a retroreflector with a reflective film interposed. As the transparent solid material, glass or plastics is used. The shape of the base material is not limited to a flat surface, and may be a curved surface such as a cylindrical shape or a spherical shape. The light reflecting film may be a metal film such as aluminum directly vacuum-deposited on the surface of the cylinder, a metal foil such as an aluminum foil, or a plastics film such as a metal such as aluminum or chrome deposited.

The light reflection film may be provided on the surface of the base material on which the cylinder is arranged, but it is preferable to provide the light reflection film on the surface of the cylinder arranged in a raft-shaped surface facing the base material by the method as described above. Of course, in these cases, a layer that blocks light should not be interposed between the transparent cylinder and the light reflecting film.

Further, the present invention uses the retroreflector as described above, and installs a transparent body on which characters, figures, or symbols are written on the surface on which the cylinders are arranged, through an air layer. It is a display device. To arrange the transparent body on the retroreflector through the air layer, a known technique such as inserting a honeycomb plate or a spacer may be used. The transparent body, or the characters, symbols, or figures may be colored.

[0011]

[Action]

 In the retroreflector of the present invention, when light is incident from a direction perpendicular to the axial direction of the transparent cylinder, the incident light is reflected by the light reflecting film on the surface of the cylinder on the base material side, and is directed toward the incident light source. Return. That is, in the present invention, the phenomenon that has conventionally occurred in glass beads occurs only when the incident light direction in the transparent cylinder is perpendicular to the axis of the cylinder. In other words, the retroreflector of the present invention has a directivity in the retroreflection property. Therefore, for example, when the retroreflector of the present invention is used for a traffic sign or the like, it is desirable to install it so that the axis of the cylinder is perpendicular to the ground. Then, at night, for example, light that is substantially parallel to the ground, such as the headlights of a car, is reflected back toward the light source by the retroreflector and returns.

The retroreflector according to the present invention has a higher arrangement density of the reflective elements (transparent cylinders), and thus a higher intensity of reflected light, as compared with a conventional reflector using glass beads. Therefore, the refractive index of the material such as glass may be lower than that of the conventional one.

When a transparent plate on which characters and the like are written is placed on the surface of such a retroreflector via an air layer, the characters and the like written on the transparent member can be clearly recognized. By arranging the air layer therebetween, a large difference in refractive index can be secured between the transparent body and the air layer, and between the air layer and the retroreflector, and good retroreflection characteristics are exhibited.

[0014]

【Example】

 1 and 2 are a perspective view and a sectional view showing an embodiment of a retroreflector according to the present invention. In this retroreflective body 10, a large number of cylinders 12 made of a transparent solid material are closely arranged in parallel with each other on a substrate 16, and between the cylinders 12 arranged in a raft shape and the substrate 16. Is a structure in which a light-reflecting film 14 is provided so as to cover almost half of the side surface of the cylinder 12. Here, the light reflection film 14 is formed on the surface of the cylinder 12, and the light reflection film 14 is attached to the substrate 16 using the adhesive 18.

Glass or plastics is used as the transparent solid material. Specifically, for example, a glass or plastic filament is preferable. Generally, a glass or plastic fiber is formed by twisting a plurality of filaments, but when used in the present invention, it must be one filament. The light reflecting film 14 may be a metal film such as aluminum directly vacuum-deposited on the surface of the cylinder.

In the retroreflector of the present invention, when light is incident from a direction perpendicular to the axial direction of the cylinder 12, the incident light is reflected by the light reflection film 14 on the surface of the cylinder 12 on the side of the substrate 16 and enters. Reflects in the direction of the light source. That is, in the present invention, the phenomenon that has conventionally occurred in glass beads occurs only when the incident light direction is a direction perpendicular to the axis of the cylinder 12. Since the retroreflective property is directional in this way, when using the retroreflector of the present invention for traffic signs, for example, it is desirable to install so that the axis of the cylinder is perpendicular to the ground. . For example, at night, light traveling almost parallel to the ground, such as a headlight of an automobile, is reflected by the retroreflector in the direction of the light source.

The retroreflector according to the present invention has a high arrangement density of the reflective elements (transparent cylinders) (continuous in the axial direction of the cylinder, and a diameter larger than that of a conventional reflector using glass beads). Since they are in close contact with each other in the direction), the intensity of the reflected light becomes high. For this reason, the refractive index of materials such as glass and plastic may be lower than in the past.

The shape of the base material used in the present invention is not limited to a flat surface, and may be a curved surface such as a cylindrical shape or a spherical shape depending on the use condition. In addition to the above-mentioned structure, the light reflecting film may be a metal foil such as an aluminum foil, or a plastic film on which a metal such as aluminum or chromium is deposited. When these foils or films are adhered to the substrate via a plastic or elastic layer of appropriate thickness, and transparent cylinders arranged in a raft pattern are pressed onto them, the above foils or films deform and become transparent. The shape follows the surface of the cylinder. This has the same effect as if a light-reflecting film were applied directly to the semicircular surface of the cylinder on the substrate side.

Further, the light reflection film may be provided on the surface of the base material on which the cylinder is arranged by a method such as vacuum deposition of a metal such as aluminum or chromium, but the surface of the cylinder facing the substrate as described above is used. It is preferable to attach it by the method. Of course, in these, a layer that blocks light should not be interposed between the column and the light reflection film.

3 and 4 are a perspective view and a sectional view showing an embodiment of a display device using a retroreflector according to the present invention. This is one in which the retroreflector 10 as described above is used, and the transparent plate 24 on which characters, figures, or symbols 22 are written is placed on the surface on which the cylinders are arranged, via the air layer 20. Is. Although not shown, the air layer 20 may be interposed, for example, by inserting a honeycomb plate, a spacer, or the like therebetween. The transparent plate 26 and the characters, figures, or symbols 22 written on it may be colored.

As described above, when the transparent plate 24 on which characters or the like are written is placed on the surface of the retroreflector 10 through the air layer 20, the characters or the like written on the transparent plate 24 can be clearly recognized by the reflected light. . By arranging the air layer 20 between them, a large difference in refractive index can be secured between the transparent plate 24 and the air layer 20, and between the air layer 20 and the retroreflector 10, whereby good retroreflection is achieved. May exhibit characteristics.

Hereinafter, a prototype of the retroreflector according to the present invention will be described. (Prototype Example 1) A commercially available aluminum foil with an adhesive tape was wound around a paper tube having a diameter of 5 cm by double winding and fixed. Next, a nylon bevel thread having a diameter of 0.3 mm was tightly wound around the above paper cylinder by hand, and both ends of the bevel thread were adhesively fixed. Furthermore, a small amount of a low-viscosity adhesive (for example, an isocyanate-based instant adhesive or an ultraviolet light curable adhesive) was used for fixing. At this time, make sure that the adhesive does not fill the gusset thread. The tubular body produced in this manner exhibited a vivid glow when irradiated with light from the axial direction of the tubular body.

Example 2 A monofilament of E-glass having a diameter of 23 μm was tightly and tightly wound around a paper cylinder having a diameter of about 30 mm using a winding jig, and both ends of the filament were wrapped around the paper cylinder. It was fixed with cellophane adhesive tape. The winding jig used here includes an E-glass supply drum and a drive drum that holds the paper cylinder, and the feed speed in the axial direction of the paper cylinder can be adjusted according to the rotation speed of the drive drum. It is a structure like this. Further, a cellophane adhesive tape was attached and fixed at one location along the axial direction of the paper cylinder. Next, this cylindrical body was placed in a vacuum vapor deposition apparatus, and aluminum was vapor-deposited on the entire surface of the cylindrical body. Further, spray the adhesive on the entire surface of the tubular body, place it on the veneer board, cut along the axial direction of the tubular body with the part fixed with cellophane adhesive tape, and then on the veneer board. It was developed and adhered and fixed. The plate-shaped body manufactured in this manner exhibited recursive reflection.

[0024]

[Effect of device]

 As described above, the retroreflector according to the present invention can be easily manufactured by using an inexpensive material such as ordinary E glass or a plastic filament as compared with the conventional glass beads. Although this retroreflector has retroreflectivity only in one direction such as the horizontal direction, it is often used in traffic signs for automobiles or pedestrians, advertising devices illuminated from one direction, and the like. In this case, a sufficiently satisfactory effect can be obtained.

Further, in the retroreflector according to the present invention, the intensity of the reflected light becomes higher because the density of the cylinders (reflection elements) is higher than that of the conventional reflector using glass beads. As a result, the refractive index of the glass and other materials that make up the cylinder may be lower than that of conventional glass beads, expanding the range of material selection and enabling the use of cheaper materials. .

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a retroreflector according to the present invention.

FIG. 2 is a sectional view thereof.

FIG. 3 is a perspective view showing an embodiment of a display device using a retroreflector according to the present invention.

FIG. 4 is a sectional view thereof.

FIG. 5 is a cross-sectional view of a conventional reflection sheet.

FIG. 6 is a cross-sectional view of a conventional reflective cloth.

[Explanation of symbols]

 10 Retroreflector 12 Cylinder 14 Light Reflecting Film 16 Substrate 18 Adhesive 20 Air Layer 22 Characters, Figures, or Symbols 24 Transparent Plate

Claims (2)

[Scope of utility model registration request] 1. A number of cylinders made of a transparent solid material,
Retroreflective reflections characterized in that they are arranged in parallel and in close contact with each other on a base material, and a light-reflecting film is provided between each cylinder and the base material so as to cover almost half of the side surface of the cylinder. body. 2. The retroreflector according to claim 1, wherein a transparent body on which characters, figures, or symbols are written is placed on the surface on which the cylinder is arranged, with an air layer interposed therebetween. Characteristic display device.