JPH09101577A - Lighting equipment for copiers - Google Patents

Abstract

(57) Abstract: An illumination device for a copying machine that illuminates a document surface from two directions, is easy to install, and is easy to partially adjust the amount of light radiated on the document surface. A lighting device is provided. A copying machine that irradiates a sheet original 24 with light from a light source 26 and forms reflected light from the sheet original on a photosensitive drum 31 via a lens 28 to form an electrostatic latent image, A counter reflection plate 30 is provided on the opposite side of the lens optical axis a from the light source 26 so that a sheet original can be irradiated from a direction different from the light source, and the counter reflection plate 30 is made of a rubber magnet and has a high reflectance. The film layer was formed. Further, a plurality of cutout portions 30c are formed in the lateral direction of the opposing reflecting plate 30 to form a plurality of reflecting pieces 30d, and each reflecting piece can be moved in the lateral direction on the mounting member 29.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating device used for scanning a sheet original in an electronic copying machine, and more particularly to an illuminating device for illuminating an original from two different directions.

[0002]

2. Description of the Related Art In an electronic copying machine, a sheet original is sent onto a contact glass, and light from a linear light source such as a fluorescent lamp is emitted from the lower side of the contact glass to receive reflected light from the original with a lens. An electrostatic latent image of the original is formed on the rotating photosensitive drum by the lens.

In this case, if the original is illuminated only from one direction, and if the original has irregularities such as a bonded portion, a shadow is formed in accordance with the irregularities, and this is reflected in the copy.

Therefore, a method in which the original is illuminated from two directions so that no shadow is formed is disclosed in Japanese Utility Model Laid-Open No. 56-17285.
No. 4 is proposed.

This will be described with reference to FIG. 3. In this lighting device, a first reflecting plate 1 and a second reflecting plate 2 are arranged so as to face each other, and these two reflecting plates are connected by a bottom surface 3 U. A channel-shaped condensing reflector 4 is used. The light source 5 made of a fluorescent lamp is arranged on the bottom surface 3 near the first reflector 1. Light from the light source 5 and the first reflection plate 1 irradiates the document surface 6 from the first direction, and light from the second reflection plate 2 irradiates the document surface 6 from the second direction, and the document surface 6 irradiates from two directions. become.
The light reflected from the document surface 6 passes through an opening 7 formed in the bottom surface 3 of the condensing reflection plate 4 and reaches a mirror 8, where it is reflected and is reflected and reflected by an in-mirror lens 9 to be a photoconductor. The image reaches the drum 10 and forms a document image.

FIG. 4 is a diagram showing the details of the condenser reflector 4. In this known example, a large number of notches 2a are further formed in the lateral direction of the second reflector 2 to form the second reflector 2. The reflecting plate 2 is made up of a large number of small reflecting pieces 2b, and the angle of each reflecting piece 2b is changed so that the amount of light irradiated on the original surface can be partially adjusted.

However, with the above construction, the first reflector 1 and the second reflector are in a substantially fixed relationship, and when one position is determined, the other position is automatically determined.
Although it is possible to correct the unevenness of light quantity, the first reflector and the second reflector
It is difficult to change the light intensity ratio of the entire reflector. Moreover, since it is attached while positioning, it is difficult to attach. Also, it takes time to adjust each reflecting piece 2b when the condensing reflecting plate 4 is attached, and each time the fluorescent lamp of the light source 5 is replaced, the reflecting piece must be adjusted again. But it was very troublesome.

[0008]

SUMMARY OF THE INVENTION In the present invention, the document surface is
It is an object of the present invention to provide an illuminating device for a copying machine that irradiates light from different directions, in which the ratio of the amount of light from both directions can be freely changed and which is easy to install.

Another object of the present invention is to provide an illuminating device which can easily partially adjust the amount of light applied to the document surface.

[0010]

To achieve the above object, the present invention illuminates a sheet original with light from a light source, and forms reflected light from the sheet original on a photosensitive drum through a lens. In an illuminating device of a copying machine that creates an electrostatic latent image by providing a counter reflection plate on the opposite side of the lens optical axis from the light source, it is possible to irradiate a sheet original from a direction different from the light source. The plate is characterized in that a film layer having a high reflectance is formed on a base material made of a rubber magnet, and the counter reflection plate is attracted to a mounting member made of a magnetic material.

Further, the reflectance of the opposing reflecting plate and the reflectance of the magnetized surface of the mounting member may be made different, or the light source may be a rod-shaped fluorescent lamp, and the entire width in the longitudinal direction of the fluorescent lamp is a circle. An opening is provided in a part of the circumference, and the direction of the opening is arranged to be displaced from the center of the scanning exposure toward the counter reflecting plate side, or a plurality of cutouts are formed in the lateral direction of the counter reflecting plate. To form a plurality of reflecting pieces, each reflecting piece can be moved in the lateral direction on the mounting member, or the high reflectance film layer is a satin-finished structure, or the mounting member It can be a lens holder.

An ordinary light source is arranged on one side of the optical axis of the lens,
On the opposite side of the optical axis, a counter reflecting plate that reflects the light of the light source is provided. The sheet original is irradiated with illumination light from both the light source and the counter reflecting plate at different angles. The counter reflecting plate is independent of the light source and can be attracted to a mounting member such as a lens holder by magnetic force, so that the mounting is easy and the positioning is determined independently of the light source.

If the reflectances of the counter reflecting plate and the mounting member are made different, the ratio of the light amount from the light source to the light amount from the counter reflecting plate can be changed by moving the counter reflecting plate in the lateral direction. By making the difference between the two light amounts small, the shadow of the pasted portion of the document cannot be formed.

If a small reflecting piece is formed in a comb shape by forming a notch in the opposing reflecting plate, it is possible to correct partial unevenness in light quantity.

A cover is attached to the entire width of the fluorescent lamp as a light source in the longitudinal direction so that a part of the circumference of the cover is irradiated with an original from the opening, and the center of irradiation is closer to the counter reflector than the center of scanning exposure. By shifting them, it becomes easy to reduce the difference in light amount between the light source and the counter reflection plate.

If the counter reflecting plate is made of satin, the influence of the notch portion does not have to appear. If the mounting member also serves as the lens holder, the number of parts does not have to be increased.

[0017]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a main part of a copying machine provided with the illumination device of the present invention. In the figure, reference numeral 21 is a contact glass, and the sheet original document 24 is transported in the direction of the arrow by the transport rollers 22 and 23 provided on both sides.

The sheet original 24 will be out of focus when the original is wavy on the scanning surface (the upper surface of the contact glass 21) 21a. To prevent this, the sheet roller 24 is pressed by the white roller 25 to correct the wavy. Drive while being run.

Reference numeral 26 denotes a light source, which is a rod-shaped fluorescent lamp, has a cover 26a so as to cover the entire width in the longitudinal direction, and emits light from an opening 26b provided in a part of the circumference of the cover. The sheet original 24 is illuminated from two directions on the scanning surface 21a by the light source 26 as described below.

That is, the first illumination direction is the direct light emitted from the opening 26b of the light source 26. The second illumination direction is due to the reflected light from the counter reflection plate 30 provided on the mounting member 29. The mounting member 29 also serves as a lens holder for supporting the lens 28, and the light source 26 and the counter reflecting plate 30 are arranged on both sides of the optical axis a of the lens 28. The 24 scanning exposure centers can be illuminated from different directions.

The light reflected from the sheet original 24 is reflected by the lens 2
An image is formed on the photoconductor drum 31 via 8 to form an electrostatic latent image. The lens 28 uses a Selfoc lens array. The lens 28 is fixed to the mounting member 29 at a predetermined position by a fastening means such as an adhesive so that the original image is focused on the surface of the photosensitive drum 31.

FIG. 2 is a view showing the details of the counter reflection plate 30. The counter reflection plate 30 serving as the second illumination is formed by forming a high reflectance film layer 30b on a base material 30a made of a rubber magnet. The film layer 30b is formed in white or silver by aluminum vapor deposition. Is.

As shown in FIG. 2, the counter reflecting plate 30 has a comb shape having a large number of notches 30c in the lateral direction, and the counter reflecting plate is composed of a large number of reflecting pieces 30d. There is. When the reflecting piece 30d is formed into a satin-finished shape and is irregularly reflected, it is possible to reduce the influence of uneven illuminance due to the cutout portion 30c.

Since the mounting member 29 is made of a magnetic material such as iron or nickel alloy, and the counter reflecting plate 30 is attracted to the mounting member 29 by magnetic force, it is easy to use without using screws or the like at the fastening portion. Can be assembled into. The reflectance of the mounting surface of the counter member 30 of the mounting member 29 is equal to that of the counter reflecting plate 3.
It is lower than 0. Therefore, the counter reflector 3
By moving the entire 0 at once in the lateral direction (the direction of the arrow in FIGS. 1 and 2), the brightness of the scanning exposure center of the sheet original 24 can be adjusted.

The partial reflection of the illuminance is controlled by the counter reflection plate 30.
Can be easily adjusted by partially moving up and down in the lateral direction as shown by the alternate long and short dash line in FIG. At this time, since the notch 30c is provided in the counter reflection plate 30,
Even if the counter reflecting plate 30 is partially moved up and down in the lateral direction, the counter reflecting plate 30 does not float up or wavy from the magnetized surface, and it is easily adjusted without using fastening screws and tools. You can

The direction of the opening 26b of the light source 26 is oriented slightly toward the counter reflecting plate 30 side from the center of the scanning exposure of the sheet original 24, and the ratio of the light amounts of the first illumination and the second illumination is 1.
So that the illuminance difference is reduced so that the shadow due to the bonded original is less likely to occur.

In the above description, the reflectance of the mounting surface of the opposing reflecting plate of the mounting member is set lower than the reflectance of the mounting of the opposing reflecting plate. The same effect can be obtained even if the reflectance of is reduced. Further, if it is not necessary to correct the partial illuminance unevenness, the notch 30c may not be formed. Even in that case, it is possible to change the ratio of the amount of light from the light source to the amount of light from the counter reflecting plate side by moving the counter reflecting plate 30 in the lateral direction.

[0028]

According to the present invention as described above,
Since a rubber magnet is used for the opposing reflector and the magnetic member is attached to the attaching member made of a magnetic material, the assembling can be facilitated.

If the reflectances of the counter reflecting plate and the magnetized surface of the mounting member are made different, the illuminance can be adjusted by moving the entire counter reflecting plate.

If a plurality of cutouts are formed in the opposing reflecting plate to form a plurality of small reflecting pieces, it is possible to adjust partial illumination unevenness and prevent floating due to waviness that is likely to occur in the case of a single plate. .

Since the direction of the opening of the fluorescent lamp is directed from the scanning exposure center toward the counter reflecting plate side, the difference between the direct light emitted from the fluorescent lamp and the reflected light from the counter reflecting plate which is irradiated on the original scanning surface. Is smaller, and the generation of shadows can be effectively prevented.

If the film layer having high reflectance is satin-finished, uneven illumination can be reduced. Further, if the mounting member is also used as the lens holder, it is not necessary to increase the number of parts.

[Brief description of the drawings]

FIG. 1 is a side view showing a main configuration of a lighting device of a copying machine according to the present invention.

2A and 2B are views of a counter reflecting plate, FIG. 2A is a front view, and FIG.

FIG. 3 is a diagram showing a configuration of a main part of a conventional lighting device that illuminates from two directions.

FIG. 4 is a perspective view of a conventional condenser reflector.

[Explanation of symbols]

 21 Contact Glass 21a Scanning Surface 24 Sheet Manuscript 26 Light Source 28 Lens 29 Mounting Member (Lens Holder) 30 Opposing Reflector 30a Base Material 30b Film Layer 30c Cutout 30d Reflecting Piece a Optical Axis

Claims (6)

[Claims] 1. An illumination device of a copying machine, which irradiates a sheet original with light from a light source and forms reflected light from the sheet original on a photosensitive drum through a lens to form an electrostatic latent image. A counter reflection plate is provided on the opposite side of the lens optical axis from the light source so that the sheet original can be irradiated from a direction different from the light source, and the counter reflection plate is provided with a high reflectance film layer on a base material made of a rubber magnet. An illuminating device for a copying machine, characterized in that it is formed and constructed, and the opposing reflecting plate is adsorbed to a mounting member made of a magnetic material. 2. The illumination device for a copying machine according to claim 1, wherein the reflectance of the counter reflector is different from the reflectance of the magnetized surface of the mounting member. 3. The fluorescent lamp according to claim 1 or 2, wherein the light source is a rod-shaped fluorescent lamp, and an opening is provided in a part of the circumference of the fluorescent lamp over the entire width in the longitudinal direction, and the direction of the opening is scanned. An illumination device for a copying machine, which is directed to a position displaced from the center of exposure to the side of the opposing reflector. 4. The counter reflection plate according to claim 1, wherein a plurality of cutout portions are formed in a lateral direction of the counter reflection plate to form a plurality of reflection pieces, and each counter reflection plate is partially attached to the attachment. An illumination device for a copying machine, characterized in that the members are displaced in the lateral direction. 5. The illumination device for a copying machine according to claim 1, wherein the film layer having high reflectance has a satin finish. 6. The illumination device for a copying machine according to claim 1, wherein the mounting member is a lens holder.