JPH063384Y2 - Original illumination device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is a document illuminating device for illuminating a document and reading or recording the information thereof, in particular, an illumination for condensing light on the document using a reflecting member It relates to the device.

[Prior art]

 FIG. 6 is a sectional view showing a conventional document illumination device.

Reference numeral 1 denotes a tubular lamp for illuminating an original, and the light emitted from this lamp is condensed on the reading position P in a slit shape by the reflectors 5 and 6, and is placed on the transparent original glass 2. The placed document 3 is slit-exposed.

Reference numeral 4 is a light-shielding portion that blocks unnecessary light.

As shown in Japanese Patent Publication No. 60-15052, the reflection plate refracted in multiple stages as shown in FIG. 6 is reflected by the light source and the reflection plate formed by the curvature of an ellipse or the like. It has an advantage of being able to stably illuminate the illuminated portion even if the plate is misaligned to some extent.

However, the above-mentioned reflecting plate is provided by bending one flat plate, and it is difficult to process the reflecting surfaces of the mirror so that the reflecting surfaces of the mirror intersect each other with a sharp edge. The vicinity has a gentle curvature.

FIG. 5 schematically shows how the light rays in FIG. 6 are reflected, including the reflection near the bending line.

In this way, originally, the light flux A for illuminating the original substantially uniformly,
In addition to B, the light flux C is condensed on the surface of the original from a surface having a curvature near the bending line, and the illuminance distribution on the original has a peak C ′. Although this drawing schematically shows one bending, the number of peaks C ′ increases as the number of bending lines increases, and the illuminance distribution has a ripple in the scanning direction.

On the other hand, when reading a document, the document is not always kept at the same distance as the illumination device, and the position of the light beam changes due to the bending of the glass due to the weight of the document, the original warp of the glass, or the floating. However, the distribution with ripples in the sub-scanning direction has a drawback that the amount of light is unstable and causes deterioration of reading and recording image quality.

For example, CCD (Change Coupled Dev)
When a document is read by an element having a short light receiving width in the scanning direction, such as ice), it is easily affected by changes in ripples, and in particular, a plurality of channels are arranged in a zigzag pattern in the scanning direction of the document. The scaled one has a drawback in that the amount of light slightly changes between the channels, and the connection between channels appears in the image.

[Purpose of device]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the conventional problems described above and to provide an original illuminating device in which ripples caused by the curvature of the refraction portion are removed.

[Outline of device]

The present invention for achieving the above object includes a light source for illuminating an original,
In a document illuminating device having a plurality of reflecting members each having a flat surface portion for reflecting the light from the light source, each of the reflecting members has a refracting portion for supporting itself, and a plurality of reflecting members are provided. One of the members is characterized in that the refracting portion of one reflecting member is covered by the flat portion of the other reflecting member.

[Example of device]

 Hereinafter, the present invention will be described with reference to the drawings.

In addition, the same numbers are assigned to members having the same function.

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 6 shows a structure in which the reflecting members 5 and 6 are divided into reflecting members 5A, 5B, 6A, 6B and 6C each having a flat reflecting surface. In the embodiment shown in FIG. 1, each reflecting member has a refracting portion for fixing, but the reflecting surface is
It consists of only one plane, and the refraction part is not involved in the slit exposure. The refracting portion of the plane mirror 5A is covered with the plane mirror 5B, so that the influence of the unevenness of the light amount due to the refracting portion is surely prevented. The plane mirrors 5A and 5B are fixed by the same screw, and the plane mirrors 6A, 6B and 6C are fixed by the same screw.

In addition, the end surface 5C of the bent portion composed of a plurality of plane mirrors
Is provided so as not to intersect the light ray 1C traveling from the light source to the edge 5d.

As a result, the adverse effect of the reflection on the end surface 5C does not occur.
This also applies to the other refraction portions.

FIG. 2 shows the condensed state of the luminous flux of FIG. 1 on only one side. The luminous fluxes A and B emitted from the light source 1 are reflected by the divided reflecting members 5A and 5B, respectively, and illuminate the document. Since the refraction portion has no curvature, no ripple is generated at the bent portion as shown in FIG. 5 of the conventional example.

FIG. 3 shows another embodiment of the present invention, in which the reflector 5 on the opposite side of the lamp with respect to the reading position P is provided by dividing, and the ripple of the ripple which appears remarkably when the reflecting surface is close to the original reading position P is shown. This shows the case where it is effective for removal.

FIG. 4 is also another embodiment of the present invention, in which the reflection plate 6 on the same side as the lamp with respect to the reading position P is provided in a divided manner.
It shows the case that is effective when the light quantity from the B and 6C sides is sufficiently large.

As described above, when there is one reflecting plate, this may be divided, and when there are a plurality of reflecting plates, it is preferable to divide at least the reflecting plate having the largest light intensity or the reflecting plate which is close to the original.

The reflection original has been described above, but it goes without saying that the same applies to a transparent original.

Further, as the light source, a fluorescent lamp, a halogen lamp, an LED array or the like can be used.

[Effect of device]

As described above, according to the present invention, it is possible to provide a gentle illuminance distribution in the document scanning direction even if the reflecting member has a refracting portion for supporting, and thereby the positional relationship of the document is changed. Also, it is possible to supply stable image information without the light amount changing drastically. Further, even if a CCD array provided in a zigzag pattern is used as the light receiving member, uneven light amount between the arrays is prevented,
A correct image can be read.

[Brief description of drawings]

 FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is an explanatory view of the embodiment of the present invention, FIGS. 3 to 4 are views showing other embodiments, and FIG. Explanatory drawing, FIG. 6 is a sectional view of a conventional example. In the figure, 1 ... Light source 2 ... Platen glass 3 ... Original 4 ... Light-shielding plate 5, 6 ... Reflector

Claims (1)

[Scope of utility model registration request] 1. A document illuminating device having a light source for illuminating an original document and a plurality of reflecting members each having a flat surface portion for reflecting light from the light source, wherein the reflecting members support each other. The original document illuminating device is characterized in that the refracting portion of one of the plurality of reflecting members is covered with the flat portion of the other reflecting member.