JPH04137675A - Light emitting diode array - Google Patents

Abstract

PURPOSE:To obtain a projecting light having a large light quantity adapted for a dielectric light source and a clear contour without using a lens with small number of components by condensing a light irradiated from a light emitting diode element via a light focusing hole of a reflecting surface by the inner surface to increase the quantity of the light, and converting it to a projecting light of a predetermined shape by a frame itself. CONSTITUTION:A case 13 is composed of a black (light absorbing color) member, and light focusing holes 14 are provided at positions corresponding to the positions of LED pellets 12 of the case 13. The pellet 12 is exposed externally from the bore side of the hole 14. The inner surface of each hole 14 is mirror-finished, and a reflecting surface 15 is formed on the same surface. A light X irradiated from the pellet 12 is propagated to an emitting port 14a while condensing, i.e., increasing in the light quality by the pyramidal shape of the hole 14 and the reflection of the surface 15. The light is converted to a predetermined shape, i.e., a square projecting light by the case itself (black) and externally irradiated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a light emitting diode array used as a light source for weight removal in a copying machine.

(Prior Art) Some copying machines are designed to prevent redundant parts from turning into black images during enlargement/reduction by exposing the photosensitive drum surface from a static eliminating light source.

A light emitting diode array (hereinafter referred to as LE) is used as the light source for weight removal.
D array) is used.

By the way, the light source for static elimination is required to have a sufficiently large amount of light for exposure, and to have a shape of the projection light so that the boundary between the copied area and the redundant area is a straight line with no positional deviation. Ru.

Conventionally, in this type of LED array, as shown in FIG.
A structure is used in which a black case 3 (frame body) is formed with a hole 3a having a rectangular shape in the plane direction and a straight shape in the side direction at the ED pellet position, and a rod-shaped lens 4. was.

In detail, on the side of the board 2 where the LED pellet 1 is located,
A case 3 is installed so that the ED pellet 1 is exposed through the hole 3a, and a rod-shaped lens 4 is installed on the case 3.

According to this LED array, the black hole 3a forms a rectangular projection light, and the lens 4 condenses the light emitted from the LED pellet 1 to increase the amount of light.

However, according to this LED array, if each LED pellet 1 up to the area indicated by symbol g lights up due to copying with reduction, for example, a part of the light from the LED pellet 1 will be specularly reflected inside the lens 4. However, it may progress to areas that are not lit. In such a case, the fifth
In the figure, a phenomenon occurs in which the light of the LED pellet 1 is emitted to the outside from an area that is not lit, as indicated by the symbol A.

When such a phenomenon occurs, there is a problem in that the light emitted from different parts erases portions that should not be erased during copying, which is not good in terms of the performance of the copying machine.

Therefore, an LED array constructed without using the lens 4, which causes trouble, has been proposed.

As shown in FIG. 6, this is a white first case 5 in which a light focusing hole 5a having a rectangular shape in the plane direction and a tilter shape in the direction of the side part is formed on the substrate 2 at the position of the LED pellet. and a window portion 6a corresponding to the light emission side opening of the light focusing hole 5a.
It has a structure in which it is combined with a flat, black second case 6 having a shape.

For details, please refer to the sides N and L of the board 2 where the LED pellet 1 is located.
The first case 5 is installed so that the ED pellet 1 or the light focusing hole 5a is exposed, and the second case 6 is installed on the side surface of the case 5 on the light emission side so that the openings overlap each other. .

According to this LED array, at the white light focusing hole 5a, L
The light emitted from the ED pellet 1 is condensed to increase the amount of light, and is narrowed down to a rectangular projection light by a black window 6a.

(Problems to be Solved by the Invention) However, this LED array requires two cases to be mounted on the board 2. Therefore, costs increase due to an increase in the number of parts. Furthermore, LED arrays require high assembly accuracy, but as the number of parts increases and the structure becomes more complex as described above, it becomes difficult to maintain assembly accuracy.

Moreover, in order to become three parts, the first case 5 and the second case
At the boundary with Case 6, diffused reflection occurs as shown by arrow B. This light turbulence makes the linear boundary between the exposed areas of the photosensitive drum and the unexposed areas, that is, the outline of the projected light, unclear, resulting in a copy in which the same areas are blurred. . Therefore, it is not very good as a light source for static elimination.

This invention was made with attention to these circumstances,
The objective is to provide a light emitting diode array that can obtain projection light with a large amount of light and clear contours without using lenses and with a small number of parts.

(Another Means for Solving the Problems) In order to achieve the above object, the present invention includes an elongated substrate on which light emitting diode elements are linearly arranged, and a tapered shape at a portion corresponding to the position of the light emitting diode elements. a member having a light focusing hole and provided on a side surface of the substrate where the light emitting diode element is located so that the light emitting diode element is exposed from the small diameter side of the light focusing hole;
and a reflective surface formed on the inner surface of the light focusing hole of this member to form a light emitting diode array.

(Function) According to the light emitting diode array of the present invention, the light emitted from the light emitting diode elements is condensed by the light convergence hole whose inner surface is a reflective surface to increase the amount of light, and the frame body itself can project a predetermined shape. Focused on light.

Here, since there is only one frame as a component other than the board on which the light emitting diode element is mounted, there are no boundaries where light is disturbed (diffuse reflection) as in the conventional case, and projection light with a clear outline is obtained. be able to.

Therefore, it is possible to meet the requirements necessary for a light source for weight removal without using a lens. Moreover, since the number of parts is small, it is easy to maintain assembly accuracy.

(Example) The present invention will be described below based on the example shown in FIGS. 1 to 3. Figure 2 shows an LE to which this invention is applied.
D array is shown, 11 is a strip-shaped substrate on which a large number of LED pellets 12 are linearly arranged, and 13 is the LED of the substrate 11.
It is an elongated case (member) installed along the arrangement of the LED pellets 12 on the side where the pellets 12 are located.

The case 13 is entirely made of a black (light absorbing color) member. Further, a light focusing hole 14 is provided in a portion of the case 13 corresponding to each LED pellet position. As shown in FIGS. 1 and 4, the light focusing hole 14 has a rectangular shape when viewed from the plane, and a tapered hole shape when viewed from the side perpendicular to the rectangular shape. .

The LED pellet 12 is exposed to the outside from the small diameter side of the light focusing hole 14. Also, this light focusing hole 1
Each inner surface of 4 has a mirror finish, and a reflective surface 15 is formed on the same surface.

When the LED array assembled in this way is turned on,
Each LED bellet 12 emits light.

The light X emitted from these LED pellets 12 travels to the exit port 14a while condensing, that is, while increasing the amount of light, due to the truncated pyramid shape of the light focusing hole 14 and reflection from the elongated projection surface]5. Then, this light is focused by the case itself (black) into a predetermined shape, that is, a rectangular projection light,
It emits to the outside.

Here, since the case 13 is not made of two parts as in the conventional case, the LED array does not have a boundary portion that would disturb the contour of the projected light.

Therefore, projection light with a large amount of light and a clear outline can be obtained. In other words, it can meet the requirements necessary for a light source for weight removal.

Moreover, since no lens is used, the case 13 is the only component other than the board 11 on which the LED bullet 12 is mounted, so the number of components is small and assembly precision can be easily maintained.

Note that each ridgeline 14a on the LED pellet side of the light focusing hole 14
Then, a flat portion 15 is formed as shown in FIG.
The light X may also be reflected in this portion. In this way, the amount of light can be increased at the four corners of the rectangular exit port 14b of the light focusing hole 14, resulting in the effect that copies can be made with clearer boundaries.

[Effects of the Invention] As described above, according to the present invention, projection light having a large amount of light and a clear outline can be obtained with a small number of parts and without using a lens.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention, FIG. 1 is an enlarged sectional view showing the structure around the light focusing hole of the LED array, FIG. 2 is a sectional view of the LED array, 3 is a plan view of the light focusing hole seen from the direction of arrow A in FIG. 1; FIG. 4 is a plan view of the light focusing hole which is the main part of another embodiment of the present invention;
5 and 6 are cross-sectional views showing different conventional LED arrays. 11... Substrate, 12... Light emitting diode element, 13
...Case (member), 14...Light focusing hole, 14a.
- Output port, 15... reflective surface. Figure Figure Figure Figure 11... Ink work cloth, 12... Light emitting diode element 1
3...7-su (broken i-go).

Claims (1)

[Claims] an elongated substrate on which light emitting diode elements are linearly arranged; and a tapered light focusing hole in a portion corresponding to the position of the light emitting diode elements, and a side surface of the substrate on which the light emitting diode elements are located. The light emitting diode device is characterized by comprising a member provided such that the light emitting diode element is exposed from the small diameter side of the light focusing hole, and a reflective surface formed on the inner surface of the light focusing hole of this member. Light emitting diode array.