JPH0540515Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to a lighting device that uses light emitting diode lamps and is suitable for controlling lighting on a dot by dot basis.

B. Prior art In recent years, light emitting diode arrays have been increasingly used in electrophotographic devices such as plain paper copiers, especially in erase heads (illumination devices for charge removal).
etc., JP-A-60-140272 and JP-A-60
As shown in Japanese Patent No. 237474, a lighting device is used in which light emitting diode lamps are arranged in a line using a frame.

However, the light from a light-emitting diode lamp does not emit light only directly above the light-emitting diode (element), but instead is diffused by the lamp resin, so all the light-emitting diode lamps are lit to provide illumination in a linear manner. However, if the lighting is controlled for each light emitting diode lamp, that is, dot by dot, the edge of the illumination part will become blurred. On the other hand, as shown in FIG.
In other words, the light emitting diode lamp 31 is
4 and narrow down the optical path, the outline blur will no longer occur. However, in such an illumination device, on the illumination surface of the photosensitive drum, etc., in addition to the original dots d, the irradiated image is also emitted in a direction perpendicular to the dot row (on both sides of the dot row).
d' and d' appeared, forming a row of three dots, and the original dots did not have sufficient illuminance, which was inconvenient. This phenomenon was more pronounced with square lamps than with round lamps.

C. Problems to be Solved by the Invention In the present invention, it has been found that the above-mentioned double-sided irradiation image is caused by the fitting gap between the light-emitting diode lamp and the frame and reflections on the walls of the frame. Therefore, it is an object of the present invention to provide an illumination device that can provide a dot array with high illuminance and clear outline.

D. Means for solving the problem The present invention arranges the light emitting diode of the light emitting diode lamp on the surface side of the resin, that is, on the surface position where the length of the resin is shorter than 2/5, and houses the light emitting diode lamp in the frame. At the same time, a bottom plate made of a white resin molded product having a plurality of triangular protrusions facing the resin bottom of each light emitting diode lamp is inserted into the bottom of the frame.

E. Effect This allows the light emitting diode to be brought close enough to the light projection window of the frame body, and only the reflected light that is in approximately the same direction as the original light for the dots is emitted from the window, so that unnecessary light is emitted from the window. There is no irradiation image, and the dots have clear outlines depending on the light illuminance.

Embodiment FIG. 1 is a perspective view of a lighting device according to an embodiment of the present invention.
FIG. 2 is a sectional view of the main part. In these figures, numerals 1, 1, .
Preferably, it is connected to the driving element 3 on the substrate 2. Reference numeral 4 denotes a substantially ladder-shaped frame for housing the light-emitting diode lamps 1, 1, . At the bottom of the board 2
A bottom plate made of a white resin molded product inserted above the edge of the lead wire 1 of the light emitting diode lamp 1.
1, 11... and a plurality of triangular protrusions 52, 5 that face and preferably abut the bottom of the resin 12 of each light emitting diode lamp 1.
It has 2...

To explain more specifically, the light emitting diode lamp 1 has a surface (light emitting surface) of, for example, 2.0 mm in size.
A colorless transparent resin 12 in the shape of a rectangular parallelepiped with a size of 4.0 mm and a length of 5.0 mm is placed 1.4 to 1.5 mm from the surface.
GaP at a depth (1/2 to 2/5 the conventional distance)
Alternatively, a light emitting diode 13 made of GaAsP or the like is supported by lead wires 11, 11 with reflectors so as to be positioned therein. The size of the surface of the resin 12 is roughly determined by the specifications of the lighting device, and in the above example, the size of the dots is a square with a side of 2.0 mm and is arranged at a pitch of 2.5 mm. .

The light emitting diode lamps 1 are arranged in a ladder-like manner with the side walls 41, 41 of the frame 4.
It is regulated by 2,42... The frame body 4 has windows 43, 43... corresponding to the dots and one light emitting diode lamp 1, 1..., and the total length is 300 to 400 mm.
It is. The bottom plate 5 is a rod-shaped member with a length approximately equal to the total length of this window row and a height of about 2 mm and a width of 4 mm, and is made of, for example, a polyphenylene oxide resin molded product, and the triangular protrusions 52, 52, . . . The diameter is about 2mm. Since the triangular protrusions 52, 52, . . . are separated for each light emitting diode lamp 1, 1, . . ., there are the following advantages. First, light emitting diode 1
Even if 3 has a reflector, since it is covered with resin 12, some of the light will go to the bottom side, but the triangular protrusion 5
Since the devices 42, 42, . Then,
If the triangular protrusions 52, 52... are appropriately separated during assembly, the bottom plate 5 will have flexibility, so it can be inserted into the bottom of the frame 4 one after another from one end of the bow, making the work easier. Good. Furthermore, triangular protrusion 5
2, 52, . . . support the bottom of the light emitting diode lamp 1 that is about to come off, so that the position of the light emitting diode 13 is determined, and the light directed toward the bottom can be reflected forward.

The position of the light emitting diode 13 mentioned above is
The light image of the light emitting diode projected on the side wall etc. of the resin 12 should not be re-projected onto the substantially central part of the surface of the resin 12. The light emitting diode 13 may be located at a location close to . The material used as the resin 12 is an epoxy resin due to moldability, weather resistance, etc., and since the refractive index is approximately fixed, the position is restricted by the triangular protrusion 52, and there is light reflection, the resin 12 is It is sufficient to place it at a position closer to the surface that is shorter than 2/5 of the length of .

Effects of the invention As described above, the outline of the dot is made clear by the frame body, preventing undesired irradiation images and light leakage, and moreover, since the light source is positioned closer to the irradiation surface, a dot with high illuminance can be obtained. . Furthermore, even if there are many lamps, they can be fixed with the bottom plate, making assembly easy.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a lighting device according to an embodiment of the present invention.
FIG. 2 is a sectional view of a main part thereof, and FIG. 3 is a sectional view of a conventional illumination device and an image on an irradiation surface. 1, 1... Light emitting diode lamp, 12... Resin, 13... Light emitting diode, 4... Frame, 5...
...Bottom plate, 52, 52...triangular projection.

Claims (1)

[Scope of utility model registration request] A plurality of light emitting diode lamps covered with a translucent resin and having light emitting diodes arranged at positions shorter than 2/5 of the length of the resin, a substantially ladder-shaped frame for storing the light emitting diode lamps in an array, and a frame. and a bottom plate made of a white resin molded product having a plurality of triangular protrusions that are inserted into the bottom of the lamp and face the resin bottom of each light emitting diode lamp.