JPH01260706A - Linear light source and long cylindrical lens - Google Patents

Abstract

PURPOSE:To enable the width of irradiation to be wide as well as to enable illumination intensity to be maintained high by using a resin molded product wherein both locking projections which are engaged with locking sections provided in advance for the side walls of a support frame body and wing sections which come in contact with the top sections of the side walls of the frame body are interchangeably provided for the side surfaces of the product. CONSTITUTION:A long cylindrical lens 4 is formed with a resin molded product roughly in a semi-cylindrical form, which is fixed onto a frame body 3 in such a way as to be positioned above photo diodes 2, and is fixed by fixing holes 34 so that the direction of its ridge is in parallel with the lining-up direction of the photo diodes 2. Locking projections 42 composed of small projection sections which are engaged with locking sections 35 and wing sections 43 coming in contact with the top sections of the side walls 32 of the frame body 3 are interchangeably provided for the both sides of the long cylindrical lens 4 at regular intervals. And the locking projections 42 and the wing sections 43 are arranged in such a way that the respective lower surfaces of them are aligned with a straight line. This constitution enables the width of irradiation to be wide, thereby enabling a linear light source to be obtained, which is high in illumination intensity and can maintains optical characteristics excellent for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION A) Industrial Application Field The present invention relates to a linear light source using a light emitting diode and a rod-shaped lens for the linear light source.

BACKGROUND ART In recent years, light emitting diodes have begun to be used as linear light sources for illuminating originals, replacing fluorescent lamps and the like. As shown in Japanese Patent Application Laid-open No. 60-230621, etc.,
Light emitting diodes are arranged in one to several rows on a long substrate,
A rod-shaped lens is supported above it.

The most commonly used rod-shaped lens is a glass cylindrical lens (round rod). This is used because it is long but durable, makes it easy to maintain a constant distance between the lens and the light emitting diode, maintains high transparency of the lens, and is easy to obtain.

However, with the glass rod-shaped lens, it is difficult to adjust the illumination width and illumination intensity on the illumination surface. That is, after determining the distance from the lens to the illumination surface of the original, etc., 0.5 to L 2 f
The diameter of the rod-shaped lens and the distance from the light emitting diode are determined so as to obtain a predetermined illumination width of approximately f, but if the illumination width is made wider, the illuminance will decrease. Generally, the illumination width is 1.0 to 5 to facilitate the installation work of the linear light source and reading element.
．． 0111, it is required to be as wide as possible. As a result, the illuminance was close to the allowable limit, and every time the specifications changed slightly, the diameter of the glass rod-shaped lens and the height of the supporting frame had to be redesigned, resulting in poor productivity.

C) Problems to be Solved by the Invention Therefore, we considered molding a rod-shaped lens with a resin that allows the lens to have relatively free curvature. However, the diameter (or thickness) of a rod-shaped lens is at most 10 nm, but the length is 80~5 nm.
It is long at 00m1, and it is not possible to create a joint in the middle. For this reason, resin rod-shaped lenses tend to form a layered interface where resin flow during molding becomes a pattern on the surface, which is undesirable because it causes uneven illumination. Furthermore, if the conditions deteriorate further, air bubbles may enter the lens, the surface may become rough, cloudy, etc., resulting in a decrease in brightness (i), which is inconvenient, and predetermined optical properties cannot be obtained. In addition, even with rod-shaped lenses that do not have such problems, light-emitting diodes generate heat when turned on, causing expansion and contraction in the substrate and frame, whereas elongated resin does not have the power to correct this, and the rod-shaped lens does not fit into the frame. It has been difficult to maintain a constant optical position relationship with respect to the illumination surface because it has fallen into the body or become detached from the frame due to warping.

2) Means for Solving the Problems The present invention has been made in consideration of the above-mentioned points. A resin molded product is used which has interlocking protrusions and wing portions that contact the top of the side wall of the crushed body alternately on the side surface.

Further, the present invention provides a rod-shaped lens for such a linear light source, which has a substantially semicylindrical shape as a whole, has locking protrusions consisting of small protrusions on both sides, and wing portions consisting of large protrusions arranged in a substantially straight line, and has a substantially semi-cylindrical lens in the approximate center. A resin molded product is used in which a resin injection gate treatment section is provided.

E) Function: As a result, the rod-shaped lens can have a freely adjustable curvature, has excellent transparency, has a wide illumination width, and can maintain high illuminance. Furthermore, the linear light source has good assembly workability and yield, is robust, and furthermore maintains good optical properties for a long period of time.

Embodiments will be described in detail below with reference to FIGS. 1 and 2.

(v) Example In these figures, (11 is a long board, for example, the width is 4.
It is made of a glass epoxy resin substrate with a length of 350 fins, has a printed pattern (conductive foil) on the front or back sides, and preferably has a light-reflective white paint applied to the outermost layer of the surface, excluding the wiring area. . (2) are light emitting diodes placed and fixed in a line on the substrate (1) and wired, for example, in the shape of a dice with each side of 0.2 to 0.4 m. From GaP, GaAsP, etc., 5n
arranged at intervals. (3) is a frame fixed to the substrate (1) with a bottle c31) whose tip is welded, and a light-reflective side wall C33 along the row of light-emitting diodes (2) and a frame body that connects the light-emitting diodes (2) from 1 to The light emitting diode (2) is surrounded by a low-height partition reflective surface divided into several sections, and there are fixing holes at both ends for fixing the rod-shaped lens.
The top of the side wall C32 has a retaining part (
) is the default.

(4) is a rod-shaped lens fixed to the frame (3) so as to be positioned above the light-emitting diode (2).It is a resin molded product with a substantially semicylindrical shape, and the direction of the ridge line is the same as that of the light-emitting diode (2). It is fixed with a fixing hole (b) so as to be parallel to the alignment direction of 2). The portion (4υ) to be inserted into the fixing hole (2) is preferably of a shape different from the approximate center of the rod-shaped lens, such as a semicircular cross section, in order to prevent the rod-shaped lens from vertically warping and from shifting laterally. Rod-shaped lens (4
) has a locking protrusion (6) consisting of a small protrusion that fits into the locking part (G), and a wing portion consisting of a large protrusion that abuts the top of the side wall Gz of the frame (3). G13 are provided alternately at regular intervals. This locking protrusion (c) and wing part (4)
3 is arranged so that the lower surface is in a straight line, but the central part of the rod-shaped lens ■On one side, there is a resin injection gate treatment part where the paris that occurs due to the provision of a resin injection gate in the mold during resin molding is treated. Because of (c), the locking protrusion is 0z
Neither wing section 03 is provided.

Such a rod-shaped lens (4) is made of, for example, an injection molded product of heat-resistant acrylic resin, and can be prevented from fogging by providing a resin injection gate flat in the lower part of the center of the rod and in the same row as the locking protrusion and wing portion. It is possible to mass-produce transparent rod-shaped lenses without bubbles or resin flow marks. In addition, to fix the rod-shaped lens (4) to the frame (3), use the deflection of both to insert and fit either one end or both ends of the rod-shaped lens (4) into the fixing hole 04). Just go. For this purpose, an inclined portion (35
1) to make it easier for the locking protrusion 0z to enter, and the locking part (
C) A recess (352) is partially provided on the lower outer surface of the side wall C.
It is more preferable if 32 has elasticity.

Specifically, the rod-shaped lens (4) has a length of 350n.
height! 51+1 width 3.0M and radius of curvature 2. ,ON
The lower side of the lens is flat or has a sufficiently larger radius of curvature than the upper side.

Then, a reference straight section is provided at a position of 0.6 ff with respect to the substantially flat part on the lower side, and a height of 0.3 ff is placed on the reference straight section.
ff length Z5ff protrusion amount 0.25 ff locking protrusion (
6) and height 0.7M length 4. Oa protrusion amount 1.0 fl (
Z) Wing parts 0J are provided at a pitch of 20 ff, with 16.15 pieces on each side and 14.14 pieces on each side on the other side. Then, the resin injection gate processing section (the grip has a height of 0
．． It is provided in 5MM2O3. In particular, in order to avoid leaving any traces of resin flow, a substantially flat part is provided below the center throat of the circular arc part at a short position (k (the radius of one circular part)), and from the approximately flat part to the reference line. The resin injection gate may be provided at a position where the height (11) is approximately equal to or higher than the height of the center (C).

In the above example A, the height (!,) is greater than the center height! ,=0,
Only IB is expensive. It is preferable that the molding is finished to a Hikari 7 mirror finish, and a surface treatment such as collicoat treatment is applied.

In this example, the minimum width ZOff length is 32 at 5 fins away.
High-intensity wide illumination with a minimum illuminance of 10,001 ux can be performed over 0M.

g) As described above, a rod-shaped lens with good production yield and excellent optical properties can be obtained, and the linear light source is easy to assemble and has good adhesion between the rod-shaped lens and the frame, making it sturdy and stable during illumination. We have been able to provide a linear light source that can be used over a wide area, with high illuminance, and which can maintain good optical properties for a long period of time.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a linear light source according to an embodiment of the present invention, and Figure 2 (a
) and (b) are cross-sectional views of the rod-shaped lens, and (C) of the same figure is a side view. (1) Inner board, (2)...Light emitting diode, (3)...
... Frame, C11l... Pin, (3z... Side wall, (
To)...Partition reflective surface, (B)...Fixing hole, (G)
... Locking part, (4) ... Rod-shaped lens, (6) ...
Locking protrusion, (43...wing part, (44)...center part of lens, (c)...resin injection gate processing part. Applicant: Sanyo Electric Co., Ltd. and one other representative: Patent attorney Takuji Nishino (1 other person)

Claims (1)

[Claims] 1) A long substrate, a plurality of light emitting diodes arranged and fixed on the substrate, and a side wall along the row of the light emitting diodes and fixed on the substrate. and a rod-shaped lens fixed to the frame so as to be positioned above the light-emitting diodes, the rod-shaped lens having a ridge line parallel to the row of light-emitting diodes, the rod-shaped lens is located above the light-emitting diodes. A linear light source characterized by being made of a resin molded product having a locking protrusion that fits into a locking portion provided in advance on a side wall, and a wing portion that abuts the top of the side wall of a frame body. 2) The linear light source according to claim 1, wherein the locking protrusions and wing portions of the rod-shaped lens are provided alternately and substantially linearly on both sides of the rod-shaped lens. 3) A rod-shaped lens made of a resin molded product having a substantially semicylindrical shape, in which a plurality of locking protrusions consisting of small protrusions and wing portions consisting of large protrusions are arranged in a substantially straight line on both sides of the rod-shaped lens. What is claimed is: 1. A rod-shaped lens for a linear light source, characterized in that a resin injection gate processing section is provided on a straight line of the resin injection gate processing section and approximately at the center of the rod-shaped lens. 4) The cross section of the rod-shaped lens has an arcuate portion upward, and has a substantially flat portion facing the light emitting diode at a position shorter than 1/2 of the radius of the arcuate portion below the center of the arcuate portion. 4. The rod-shaped lens for a linear light source according to claim 3, wherein the resin injection gate processing portion is provided at a position substantially equal to or higher than the height of the center of the circular arc portion.