JPH10112782A - Linear lighting body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a light guide lighting body with small lighting spots at a low cost with small power consumption and a high emission efficiency by providing a plurality of notches causing reflecting faces in a specific direction at a bottom side or a side face of a transparent light guide body. SOLUTION: The transmission body is made up of a container vessel 3 for a transparent light guide body 1 and a light source 2 placed at least one end in the X direction of the transparent light guide body 1 and a plurality of notches 4 acting like reflecting faces are provided to the bottom face or the side face of the transparent light guide body 1 in the X direction. The notches 4 provided to the bottom face or the side face of the transparent light guide body 1 have a function of reflecting a light introduced from the light source 2 into its projected curved face (light emission face). The light reflected in the reflection face of each notch 4 is collected by a lens action of the light emission face. The light not reaching the reflected face of each notch 4 among the lights made incident onto the transparent light guide body 1 is reflected in the bottom face, the side face and the end face and reaches the reflecting face of each notch 4 and emitted from the light emission face.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for illuminating a reading portion of a document, such as a document, such as a facsimile machine, a copying machine, and an inspection machine using a line CCD camera, and an inspection object, in a line.

[0002]

2. Description of the Related Art In facsimile machines, copiers and the like, an LED array in which light emitting diodes are linearly arranged is used as a light source. The original surface is illuminated by this LED array,
Characters and the like on the document surface are imaged into a sensor through an imaging optical system and detected. However, since the conventional LED array uses a large number of LEDs, there is a drawback that power consumption is large, a large amount of space is required, and the cost is high.
To solve this problem, Japanese Unexamined Patent Publication No. Hei 6-3528 proposes a rod-shaped illumination body. In this rod-shaped illumination body, light scattered and reflected by a light scattering surface provided at a position facing the light emission surface is emitted from the light emission surface.

[0003]

However, although this problem can be solved with this rod-shaped illuminator, the efficiency of irradiating a portion that needs to be illuminated to utilize the scattered light from the light-scattering surface is low, and the surface of the original is not illuminated. The problem is that the illuminance is low.
An object of the present invention is to provide a light guide illuminator that is low in cost, consumes little power, has high irradiation efficiency, and has few illumination spots.

[0004]

SUMMARY OF THE INVENTION The gist of the present invention is that one end (top) in the Z direction of a YZ section of a rectangular rod having a length in the X direction, a width in the Y direction, and a height in the Z direction. Comprises a transparent light guide 1 formed into a convex curve, a light source 2 disposed on at least one end face of the transparent light guide in the X direction, and a transparent light guide storage container 3. The convex curved surface formed by the convex curve is a light emitting surface, and is a linear illuminating body provided with a plurality of cutouts serving as reflective surfaces toward the X direction on the bottom surface or side surface of the transparent light guide. .

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION As the transparent light guide 1, a known plastic such as a polymethyl methacrylate resin or a polycarbonate resin, or an inorganic glass or the like is used. A convex curved surface is formed on the top surface of the transparent light guide,
This is the light emitting surface. In addition, this convex curved surface has a light collecting function.

As the light source 2, a known light source such as an LED is used. When the length of the transparent light guide is short, the light source is arranged only at one end in the X direction. Depending on the type of light source and the amount of light, about one to five light sources are arranged at one end.

The storage container 3 usually has an opening only on the convex curved surface (light emitting surface) side of the transparent light guide. A material having a light reflecting function or a material whose inner surface is processed to have a light reflecting function is used. It is preferable that the storage container has a size capable of storing the transparent light guide in close contact with the transparent light guide so that the transparent light guide exerts a light reflecting function. An opening for inserting a light source is provided at the end of the storage container on the side where the light source is arranged, as necessary.

The cutout provided on the bottom surface or side surface of the transparent light guide has a function of reflecting the light introduced from the light source to the convex curved surface (light emission surface). The light reflected on the reflecting surface of the cutout is collected by the lens function of the light emitting surface. Of the light incident on the transparent light guide from the light source, the light that does not reach the reflection surface of the notch portion is reflected by the bottom surface, side surface or end surface thereof, then reaches the reflection surface of the notch portion and emits light. Emitted from the surface.

The shape of the notch is not particularly limited as long as it has a light reflecting function. Typical examples include a triangular prism shape, a semi-circular column shape, a semi-elliptical column shape, and the like. still,
The triangular prism or the like is cut such that the top is on the upper side and the column (longitudinal) direction is the Y direction. A film-like material or a film-like material having a light reflecting function can be applied, laminated, or the like, as necessary, to the cutout portion.

[0010] A plurality of notches are provided in the X direction on the bottom surface or side surface of the transparent light guide.
As the distance from the light source increases, the center-to-center distance (pitch) of each adjacent cutout portion is preferably smaller.
With such a configuration, the difference between the amount of light reflected from the reflective surface at the notch located closer to the light source (hereinafter simply referred to as “reflective surface”) and the amount of light reflected from the reflective surface farther from the light source is reduced. can do. From the same viewpoint, it is preferable that the size of the notch (the area of the reflection surface) increases as the distance from the light source increases. When the notch has a triangular prism shape, the size can be increased by increasing the length of the triangular side or the length of the column.
When the light source is disposed only at one end in the X direction of the transparent light guide, in order to suppress the influence of the reflected light from the other end where the light source is not disposed, the light source is disposed near the end. It is preferable that the height, depth, and pitch of the cutout portions are appropriately reduced.

When the light is emitted in the direction of the central axis in the Z direction of the transparent light guide, the cutout is provided at the center of the bottom surface. When the light is emitted at a predetermined angle with respect to the center axis in the Z direction of the transparent light guide, the cutout portion is provided at a position other than the center of the side surface or the bottom surface. Preferably, it is provided at the bottom.

[0012]

The present invention will be described more specifically with reference to the following examples.

Example 1 An end of a polymethyl methacrylate rod having a length of 6 mm, a width of 2 mm and a length of 227 mm in the YZ section in the Z direction is defined by a curvature R = 1.
It was shaved at 5 mm. Next, the lowermost part of the side (the lower part of the XZ plane)
A vertex angle of 90 degrees at a position 6.5 mm from the end on the light source side;
Height (Z direction) 0.5mm, Depth (Y direction) 0.25m
An m-shaped notch having a triangular prism shape was provided. In the following, 64 cutout portions having the sizes shown in Table 1 were sequentially provided as shown in FIG. 3 to form a transparent light guide. Basically, as the distance from the light source increases, the pitch of the notch portion is reduced and the size of the notch portion is increased, but the position farthest from the light source, that is, near the other end surface of the transparent light guide In, the depth of the notch was slightly reduced to suppress the influence of light reflected from the end face.

The pitches of the cutout portions of the 26th and subsequent cutouts are all 3.00 mm.

[0015] This light guide is made to have an inner size of 6 mm x 2 mm x
The LED light source (CL-190Y manufactured by CITIZEN CORPORATION) is housed in a white case made of 227 mm polycarbonate resin.
G-CD) at one end of the light guide in the vertical direction (Z direction).

The X of the linear illuminator thus manufactured is
A detector was installed at a position 2 mm away from the light exit surface at the center in the Z direction in the Z direction, and the light amount distribution in the Y direction was measured, and the results in FIG. 6 were obtained. A detector is installed at a position 2 mm away from the light emitting surface of the linear illuminator in the Z direction and 0.7 mm away from the Y (left) direction. The light quantity distribution was measured, and the result of FIG. 7 was obtained.

[0017]

[Table 1]

[0018]

According to the linear illuminator of the present invention, it is possible to uniformly illuminate a document or the like. This illuminator has a small storage space, low power consumption, and can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is an external view of a transparent light guide used for a linear illuminator of the present invention. Arrows indicate light rays.

FIG. 2 is a YZ sectional view of the transparent light guide of FIG. 1;

FIG. 3 is a schematic XZ plane view of the linear illumination body of the present invention.

FIG. 4 is a schematic YZ cross-sectional view of the linear illumination body of the present invention.

FIG. 5 is a YZ sectional view of another transparent light guide of the present invention.

FIG. 6 is a measurement diagram of a light amount distribution in a Y direction according to the first embodiment.

FIG. 7 is an X-direction light amount distribution measurement diagram in the first embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent light guide 2 Light source 3 Storage container 4 Notch part 5 Convex curved surface (light emission surface)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuki Chiba 3816 Noboru Noto, Tama-ku, Kawasaki-shi, Kanagawa Mitsubishi Rayon Co., Ltd. No. 3-19 Inside Mitsubishi Rayon Co., Ltd.

Claims (6)

[Claims] 1. A transparent light guide in which one end (top) in the Z direction of a YZ cross section of a rectangular rod-shaped object having a length in the X direction, a width in the Y direction, and a height in the Z direction is formed into a convex curve. The transparent light guide comprises a light source (2) disposed on at least one end face of the transparent light guide in the X direction and a storage container (3) for the transparent light guide. A linear illuminator in which a convex curved surface to be formed is a light emitting surface, and a plurality of cutouts serving as reflection surfaces are provided in the X direction on the bottom surface or side surface of the transparent light guide. 2. The linear illuminator according to claim 1, wherein the pitch of the notch decreases as the distance from the light source increases. 3. The linear illuminator according to claim 1, wherein the size of the notch increases as the distance from the light source increases. 4. The linear illuminator according to claim 1, wherein the pitch of the notches decreases and the size of the notches increases as the distance from the light source increases. 5. The linear illuminating body according to claim 1, wherein a shape of the cutout portion is a triangular prism shape, a top of the triangle is on an upper side, and a column direction is the Y direction. 6. The linear illuminator according to claim 1, wherein the cutout portion is provided at a lowermost portion of the side surface.