JPH0225509B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an illumination device in a copying machine.

2. Description of the Related Art Conventionally, for example, the following technology is known regarding an illumination device for exposing the surface of a document in an electrophotographic copying machine or the like.

Prior Art 1 A lighting device that uses a plurality of filaments connected in a single glass tube as a light source.

With this technology, the position accuracy of each filament enclosed in the glass tube is not very accurate, so although it is necessary to adjust the position of each filament individually, it is not possible to do so. The disadvantage is that the misalignment is accumulated together with the installation error of the tube itself, resulting in misalignment of the filament from the focal point of the reflecting shade, resulting in uneven illumination due to poor focusing.

Also, with current technology, it is not possible to produce lamps with long tube lengths and low power consumption, and the illumination width is _A3, longitudinal size,
B It is currently impossible to perform exposure of ₄ longitudinal sizes with a single tube and with low power (approximately 130w).

Prior Art 2 This lighting device adopts the idea of an integrating sphere, and its outline is shown in FIG. In this example,
Since the light source 1 is a small light bulb, it is difficult to achieve positional accuracy with respect to the other individual light sources arranged linearly in the direction penetrating the plane of the paper.In order to cover this, the reflective shade 2 is made of a diffuse reflection surface. .

As a result, the illumination efficiency has become extremely poor due to reflection attenuation, light leakage loss, and the like. By the way, according to the trial calculation results, a lighting efficiency of only 5 to 6% can be obtained.

The present invention has been made by focusing on the drawbacks of the above-mentioned conventional techniques in illumination devices, and an object of the present invention is to provide an illumination device for a copying machine that can correctly position a light source at the focal position of a reflector. .

The present invention will be explained in detail below.

A lighting device according to the present invention includes: a light source configured to extend linearly in any one direction; and a reflecting plate whose reflecting surface that reflects light from the light source is formed of a curved surface having a focal point. reflective side plates or the like are disposed opposite to each other with the light source in between in the direction of linear spread of the light source, and are on the at least one side reflective plate and pass through the focal point. A feature is that a reference hole for aligning the light source is formed at a position orthogonal to the imaginary line.

For example, when the filament of a light source lamp is deviated from the focal point of the reflector, the variation in the amount of light that occurs on the light condensing surface is examined, and the graph shown in FIG. 2 is obtained. This graph shows the amount of light when there is no positional shift.
The relationship between the amount of deviation and the amount of light is normalized and shown as 100%.

As can be seen from this graph, the larger the filament misalignment, the more the light intensity tends to decrease.

Therefore, in the present invention, as shown in FIG. By irradiating light with stronger directivity, such as a laser beam, it is possible to align, for example, the filament F of the light source 4 on a predetermined reference position space.

When adjusting the position of the light sources, for example, if highly directional light is irradiated from the reference hole 300 of one side reflection plate 3, 3' to the reference hole 300' of the other reflection side 300, the filament F of each light source 4 is If the center is not aligned, the light will be blocked. Therefore, each light source 4 may be moved and adjusted in an appropriate direction so that the light can pass through.

In FIGS. 3 to 6, reference holes 300, 3
The formation position of 00' is on the side reflecting plates 3, 3', and is a portion penetrated by the imaginary line L passing through the focal point of the curved surface of the reflecting plate 5. The reflecting plate 5 consists of, for example, three parts. One of them is the first reflecting section, and the curved surface is a part of a circle, the center of this circle is called the first focal point, and the line L passes through this first focal point. The other two are a second reflecting section and a third reflecting section, each of which is a part of an ellipse, and focuses the light focused at the first focal point onto a second focal point O (see FIG. 5). In addition, side reflector plate 3
is provided to return light from outside the longitudinal region of the slit into the region.

Although the reference hole is shown as a circle in the above example, it is not limited to this shape, and may be rectangular or other shapes, and is determined taking into consideration the shape of the filament, etc.

In addition, the reference holes 300 and 300' are connected to each side of the reflector plate 3,
3', but it may be formed only on one of the reflective side plates.

If the outer diameter of the filament F is D, and the tolerance for positional deviation required to achieve the required degree of convergence is δ, then the diameter of the reference holes 300, 300' is Dr
is set as Dr=D+2δ (see FIG. 4).

Next, a specific example of adjusting the positional deviation of the filament F of each light source will be described while looking through the reference hole 300.

Referring to FIG. 9, the light source 4 is fixed to a support 6 made of a heat-resistant insulator, and two terminals 7 and 8 are protruding from it.

Next, reference numeral 9 designates a light source first mounting plate made of a hard insulator such as a glass epoxy print material, and holes 70 and 80 are formed in portions corresponding to the terminals 7 and 8. Also, 2 of this light source first mounting plate 9
Two elongated holes 10 and 11 are formed in each ear.

A flexible printed board 12 for power supply is superimposed and fixed on the first light source mounting plate 9, and when the light source 4 is attached, power is applied to the terminals 7 and 8 through the conductor 13. There is.

This first light source mounting plate 9 further includes a second light source mounting plate 1 which is an L-shaped piece, as shown in FIGS. 7 and 8.
It is attached to one of the bent surfaces of 4 with screws 10B and 11B through elongated holes 10 and 11, etc.

On the other hand, two elongated holes 15 and 16 are formed in the other bent surface of the second light source mounting plate 14.
Through these elongated holes 15, 16, screws 15B, 1
6B, the light source second mounting plate 14 is attached to the illumination system bracket 17 (see FIG. 7).

According to this configuration, n sets of light sources 4 are arranged linearly on the illumination system bracket 17.

Therefore, the position adjustment of the light source 4 is as follows.
Loosen the screws 10B and 11B and attach the light source first mounting plate 9.
By moving the imaginary line L, it is possible to adjust the movement in the X direction (see Fig. 5) within the perpendicular plane, and by loosening the screws 15B and 16B and moving the light source second mounting plate 14. It can be moved and adjusted in the Y direction (see FIG. 5), which is orthogonal to the X direction within the same plane.

Furthermore, by forming each of the elongated holes 10, 11, 15, 16, etc. larger than the corresponding screw diameter, the first light source mounting plate 1 can be attached to the second light source.
The light source second mounting plate 14 can be rotated on the mounting plate 14 and the light source second mounting plate 14 can be rotated on the illumination system bracket 17 to correct the inclination of the longitudinal axis of the filament F with respect to the imaginary line L. It becomes possible to do so. In this case, since the flexible printed board 12 is flexible and bends freely, there will be no problem during adjustment. In connection with this, the arrangement pitch P (see FIG. 9) of the n light source first mounting plates 9 fixed on the flexible printed board 12 is set in such a way as to ensure the adjustment allowance due to the above-mentioned rotation. It is preferable to make the pitch longer than the regular pitch between light sources (for example, 2 to 3 mm).

As shown in FIG. 6, this flexible printed board 12 has a power supply part for the reciprocating member and a lamp mounting part integrated into one, and when performing slit exposure scanning, it flexes while maintaining a constant radius and becomes an illumination device. This use is effective in that sense as it follows the current flow and supplies power.

According to the present invention, a curved surface with high light collection efficiency can be applied to the reflecting plate, and the whole can be accurately positioned by positioning the highly efficient small lamp-shaped light sources individually linearly in a certain longitudinal direction. Therefore, the illumination efficiency can be improved, and by applying the principles of the present invention, even a light source with a long tube length can be accurately positioned. However, when using a light source with a long tube length, it is a prerequisite that the positional accuracy of the filament within the tube is high.

As in the embodiment illustrated above, when a plurality of light sources, for example, miniature halogen lamps, are used, in order to make the illuminance distribution uniform in the condensing part, the individual light sources are arranged on the imaginary line L. light source 4
It goes without saying that considerations should be made, such as making the coil length of the filament of the light source located on the outside shorter than the coil length of the filament of the light source located in the center.

Furthermore, as a consideration regarding the uniformity of the illuminance distribution, it is also effective to individually change the size and position of the mounting holes 18 of the light sources 4 formed in the reflection plate 5. For example, the holes are made larger or more numerous at the center of the line L, and the holes are made smaller and narrower toward the periphery.

Although the embodiments have been described using an example of an illumination device for an exposure optical system, it goes without saying that the present invention can be implemented in other illumination devices used in copying machines, such as erase lamps.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a lighting device according to the prior art, FIG. 2 is a graph showing the influence of filament positional deviation on the amount of light on the light collecting surface, and FIG. 3 is a front view of the lighting device according to the present invention. , FIG. 4 is a partially enlarged view of the filament seen from the reference hole, FIGS. 5 and 6 are side views of the illumination device according to the present invention, and FIG. 7 is a perspective view of the illumination device according to the present invention. 8 and 9 are exploded perspective views of essential parts of the same figure. 3, 3'... Side reflecting plate, 300, 300'... Reference hole, 4... Light source, 5... Reflecting plate.

Claims (1)

[Scope of Claims] 1. An illumination device for a copying machine in which a plurality of light sources each having a filament are arranged on a straight line including the focal point of a reflecting plate whose reflecting surface is a curved surface having a focal point, An illumination device for a copying machine, which has a reflective side plate on the side, and a reference hole for position adjustment for aligning the filament on the straight line is provided at a portion of the reflective side plate that intersects with the straight line.