JPS6291902A - Light guiding lens - Google Patents

Abstract

PURPOSE:To make the manufacturing cost of the titled lens inexpensive omitting a production of a vertical angle part of the titled lens with a good accuracy by losing the reflectance of a light at the vertical angle part of a prism. CONSTITUTION:The titled lens is formed by pouring polyethmethacrylate into a forming die in which an image side lens 4 of the titled lens and a side surface of the prism 2 are connected so as to a shape of an array. And the path of the light in the titled lens is shown by the arrow A. Namely, the light injects to an object side of the lens part 1 and then reflects on the surface and the another surface of said reflection surfaces 2b of the prism 2 positioned in front of the lens part 1 in order. And then, the light moves in the direction of the left side from the surface of the reflection surface 3b of the prism 3 and then reflects on the another surface thereof. And then, the reflected light is outgoing from the image side of the lens part 4, thereby projecting the image of the object at the prescribed position.

Description

[Detailed Description of the Invention] [Summary] A cylindrical or prismatic object-side lens section and an image-side lens section, located between the lens sections, and reflecting incident light on two surfaces not including the apex corner. It is a light guide lens consisting of at least two prisms.It is easy to manufacture because it uses prisms as a light reflecting means, and it reflects light without using the apex part of the prism, so it has a highly accurate apex part. There is no need for manufacturing, and an inexpensive product can be obtained.

Furthermore, since the object-side and image-side lens portions are diagonally located, when formed in an array, the lens portions do not come into contact with each other (light from adjacent lens portions does not enter, resulting in a good image).

[Industrial application field]

The present invention relates to a light guide lens that is part of a lens system used in facsimiles and LED printers.

Such a light guide lens allows the object image to be fixed at a certain distance. [Prior Art] A conventional light guide lens is shown in FIGS. 4(a) and 4(b). (8
Figure 1 is a side sectional view, and figure (b) is a view of figure 81 viewed from the direction of arrow Y.

In a conventional light guiding lens, (as shown in Figure 81, the object side lens part 1', which is a spherical surface into which light enters, and the image side lens part 4', which is also a spherical surface and which emits light, are shifted in the vertical direction. Reflecting surfaces 2' and 3'' for reflecting light are formed at the front of the object-side lens section 1' and the front of the image-side lens section 4', respectively. This reflective surface 2'.

3' is inclined so as to reflect light with an accuracy smaller than the critical angle, so it is necessary to provide a reflective film.

For this reason, a reflective film made of aluminum evaporation is applied.

Further, a needle surface 5' is formed between the two reflective surfaces 2' and 3' for inverting an image caused by reflected light.

A plurality of such lenses were connected together and used as a formed lens array.

[Problem that the invention sought to solve]

First, in conventional light guiding lenses, when formed in an array, the object side and image side lens parts come into contact with the adjacent object side and image side lens parts, so the incident light leaks into the adjacent lens part and is directed toward the object. It was not possible to project an accurate image.

In addition, since the Datsuha surface is formed so that its center is located at the center of the object side lens section in the XY direction in the figure, the incident light from the object side lens section passes through the apex corner of the Datsuha surface and reaches the image side lens section. Since the accuracy of the apex corner affects the projected image, it was necessary to manufacture the apex corner with high precision. Therefore, the manufacturing process has become complicated and the manufacturing cost has also increased.

[Means for solving problems]

In order to solve the above problems, the present invention includes a cylindrical or prismatic object-side lens portion into which light enters, and at least two prisms that totally reflect the light incident from the object-side lens portion by two surfaces sandwiching the apex portion. and a cylindrical or prismatic image-side lens portion that emits the light reflected by the prism, and the two prisms have their apex portions located on the outside, and a portion of the bottom surface that is orthogonal to each other. The object-side lens part and the image-side lens part are located perpendicularly to the bottom surface portions of the prisms that overlap and do not overlap with each other.

[Effect]

According to the above means, when formed in an array, the object side and image side lens parts are alternately positioned, so that they do not come into contact with adjacent object side and image side lens parts, and the center of the lens part and the apex corner of the prism are aligned. The projected image is not affected by the apex corner.

〔Example〕

The present invention will be described in detail below with reference to the drawings.

Fig. 1 is a perspective view of a light guide lens in a stand-alone state showing an embodiment of the present invention, and Figs. 2 (a), (b) (cl) indicate that the light guide lens in Fig. 1 is actually used in a facsimile machine, etc. FIG.

FIGS. 3(a), 3(b), and 3(c) are diagrams showing another embodiment similarly formed in an array shape.

In these FIGS. 1 to 3, 1 is the object-side lens part;
2 and 3 are prisms, and 2a and 3a are apex parts.

2b and 3b are reflective surfaces, 2c and 3C are bottom surfaces, and 4 is an image side lens portion.

2 and 3, (a) is a front view, (b) is a bottom view, and (C) is a side view.

First, the light guide lens of this embodiment in a stand-alone state will be explained with reference to FIG.

Approximately half of one side of each of the bottom surfaces 2c and 3c of the prisms 2 and 3 intersect at a right angle with respect to the longitudinal direction.

That is, the apex portions 2a and 3a each face outward, and the shape when viewed from above is an annular shape, and the object side and image side lens portions are located diagonally.

The object-side lens part 1, which is a rectangular prism, stands vertically on the part of the bottom surface 2C of the prism 2 that is not in contact with the prism 3, and the part of the bottom surface 3C of the prism 3 that is not in contact with the prism 2 is also provided with four square prisms. A prismatic image-side lens portion 4 is vertically erected.

Next, a light guiding lens arranged in an array will be explained with reference to FIG. 2 (al(bl(C)).

Normally, when used in a lens system of a facsimile machine or the like, a plurality of light guide lenses as described above are integrally formed in an array.

In this embodiment, polyethyl methacrylate is placed in the mold so that the image side lens 4 of the light guiding lens and the side surface of the prism 2 are connected to form an array as shown in Figures (a) and (b). Pour and form.

The movement of light in this light guide lens first enters the object-side lens section 1 as shown by arrow A, and then reaches one surface of the reflective surface 2b of the prism 2 located in front of it.

It is then reflected on the other surface, and then reflected on the reflective surface 3 of the prism 3.
(a) (b) Proceeds to the left in the figure and is reflected by the other surface by one surface of b, and the reflected light is emitted from the image side lens section 4 and projects an object image at a predetermined position.

FIG. 3 is a diagram showing a modification of the lens-shaped light guide lens shown in FIG. 2.

In this embodiment, one side surface of each of the object-side lens section 1 and the image-side lens section 4 is in contact with one side surface of each of the prisms 2 and 3, forming an array of light guiding lenses. Such a light guide lens has slightly better strength than the embodiment shown in FIG.

In both of these embodiments, the light guide lens (
Since the lens parts (single body) are not adjacent to each other and are connected, light from entering from an adjacent lens part does not occur.

Although polyethyl methacrylate was used as the material in these examples, polycarbonate was also used.

Polystyrene, poly-4-methylpentene-1, etc. may also be used.

〔effect〕

According to the present invention, since light is not reflected at the apex portion of the prism, it is not necessary to manufacture the apex portion with high precision, and manufacturing costs are reduced. Furthermore, when forming an array, adjacent lens portions are not adjacent to each other, so light from adjacent lens portions does not enter, resulting in a better projected image.

[Brief explanation of drawings]

Figure 1 is a diagram showing one example of the light guide lens of the present invention, Figure 2 is a diagram showing one example of the light guide lens of the present invention.
The figure shows a first embodiment in which the light guide lenses of the present invention are formed in an array, FIG. 3 shows a second embodiment in which the light guide lenses of the present invention are formed in an array, and FIG. 4 shows a conventional light guide lens. FIG. [Explanation of symbols] 1------Object side lens section, 2. 3------1.
prism. 2 a, 3 a---one vertex corner part, 2 b,
3b=---reflection surface. 2 c, 3 c---bottom surface, 4---image side lens section. Ordinance' and light guiding lens. Figure 1

Claims (2)

[Claims] (1) A cylindrical or prismatic object-side lens portion 1 into which light enters, and two surfaces 2b ( 3
b) consists of at least two prisms 2 and 3 that reflect the light so as to change by 180 degrees, and an image-side lens section 4 that is cylindrical or prismatic and that emits the light reflected by the prisms 2 and 3; The two prisms 2 and 3 have their apex portions 2a and 3a located on the outside, and their bottom surfaces 2c and 3c partially overlap each other so as to be perpendicular to each other, and the bottom surfaces of the prisms 2 and 3 do not overlap with each other. A light guiding lens characterized in that the object side lens section 1 and the image side lens section 4 are vertically arranged. (2) The light guide lens according to claim 1, wherein the prisms 2 and 3 do not use the apex portions 2a and 3a of the prisms 2 and 3 to reflect the incident light.