JPH0923314A - Original illuminaire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the reflected image of a solid object more bright to approach nature by arranging a diffuse reflecting means in a position facing the illuminated position of an original even at the time of illuminating the solid object or the like whose surface is metallic. SOLUTION: Illuminating light emitted from a light source 4 is reflected by a main reflector 5 and a counter reflector 6 and is condensed on an original 2 placed on a platen glass 3. A diffuse reflecting plate 8 is illuminated directly from the light source 4 or by reflected light from the original 2. The original 2 placed on the platen glass 3 is uniformly illuminated by diffused light. In comparison with conventional blackened plate, the original 2 is only illuminated by diffused light from the diffuse reflecting plate 8 to increase the proportion of diffuse reflected light from the original 2. Consequently, the brighter reflected image of the solid object is obtained even if the solid object whose surface is metallic is illuminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document illuminating device used for copying machines, facsimiles, image scanners, etc., and more particularly to a document illuminating device suitable for digital color copying machines, color facsimiles and the like.

[0002]

2. Description of the Related Art Conventionally, as a document illumination device of this type,
For example, as shown in FIG. 6, by using a main reflector 12 and a counter reflector 13 provided around a light source 11, the light source 1
Original 2 placed on platen glass 15 with light from 1
0, and the reflected light image from the original 20 is imaged on a photoconductor or an image sensor (not shown) by the imaging optical system 14 through the slit 16a of the case 16 to copy or read the image of the original 20. Some are configured to do. In such a document illuminating device, the surface of the case 16, the lamp cover 17, etc. is usually blackened. This is to prevent disturbance of the reflected light image of the document 20 caused by stray light, that is, illumination light or light reflected from the document 20 that is reflected unnecessarily by the case 16, the lamp cover 17, or the like.

[0003]

However, in order to create, for example, an advertisement or a product sample by using such a document illuminating device, a three-dimensional object having a metallic surface such as a watch, a jewel, or a printed circuit board is used. When illuminating or illuminating a three-dimensional original having a step such as a laminated original, there is a problem that the reflection image of the three-dimensional object is read darker than it looks.

This cause is due to the following two reasons. (1) Since the ratio of diffused reflected light on the surface of a metal surface is lower than that of a normal original, less reflected light travels in the optical axis direction of the imaging optical system than a normal original. It gets dark. (2) The image of the surrounding objects is reflected on the metal surface, and the image of the black portion for preventing stray light is reflected on the surface, which makes it dark.

Therefore, the present invention has been made to solve the above-mentioned problems of the prior art, and its object is to provide a three-dimensional object surface even when a three-dimensional object whose surface is metallic is illuminated. Document illumination device that can increase the proportion of diffusely reflected light at the same time and reduce the reflection of the image of the black member on the surface of the three-dimensional object to prevent stray light, making the reflected image of the three-dimensional object brighter and closer to a natural appearance. To provide.

[0006]

A document illuminating apparatus according to the present invention includes a platen glass for supporting a document, an illuminating unit for illuminating the document, and a photoreceptor or an image sensor for the image of the document. In an image reading apparatus having an image forming optical system for forming an image on the upper surface, the direct light illuminated by the illumination means or the reflected light reflected by another member is diffusely reflected and mounted on the platen glass. The diffuse reflection means for uniformly illuminating the placed document is arranged at a position facing the illumination position of the document.

Further, according to the present invention, the diffusive reflecting means can be moved back and forth as required, so that it is possible to switch between the state in which the diffusive reflecting means is used and the state in which the diffuse reflecting means is not used according to the type of the original. You may.

[0008]

According to the present invention, the direct reflection of light illuminated by the illumination means or the reflection of light reflected by another member is diffused and reflected to uniformly illuminate the original placed on the platen glass. The means is arranged at a position facing the illumination position of the original document, and the original placed on the platen glass is uniformly illuminated by using the diffuse reflection means.

Therefore, even when a three-dimensional object whose surface is metallic is illuminated, the three-dimensional object is illuminated by the uniform diffused light from the diffuse reflection means, so the diffused reflected light on the surface of the three-dimensional object increases. It is possible to brighten the reflection image of a three-dimensional object.

Further, by reflecting the image of the diffuse reflection means on the surface of the three-dimensional object, the proportion of the image of the blackened lamp cover or case can be reduced,
It is possible to make the image reflected on the surface of the three-dimensional object brighter.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiment.

FIG. 1 shows an embodiment of a document illuminating device according to the present invention.

In FIG. 1, reference numeral 1 denotes an original illuminating device according to this embodiment. The original illuminating device 1 illuminates a platen glass 3 for placing an original 2 and an original 2. The light source 4, a main reflector 5 for condensing the light emitted from the light source 4 on the original 20 on the platen glass 3, and the light emitted from the light source 4 are reflected on the original 20 on the platen glass 3. And an image forming optical system 7 for forming a reflected light image from the original 2 on a photoconductor or an image sensor (not shown).
And a diffuse reflector 8 as a diffuse reflector for illuminating the original 2 with diffuse illumination light.

Here, the light source 4 and the main reflector 5 are used.
With respect to the counter reflector 6, the imaging optical system 7, and the platen glass 3, the same ones as those used in the conventional document illumination device are used.

In the original illuminating device 1, the case 9 in which the light source 4, the main reflector 5 and the like are normally arranged and the surface of the lamp cover 10 of the light source 4 are blackened. This is to prevent the disturbance of the reflected light image of the original 2 caused by the stray light, that is, the illumination light or the reflected light from the original 2 which is reflected unnecessarily by the case 9, the lamp cover 10, or the like.

By the way, in this embodiment, the direct light illuminated by the illumination means or the reflected light reflected by another member is diffused and reflected to uniformly illuminate the original placed on the platen glass. The diffuse reflection means is arranged at a position facing the illumination position of the original.

That is, in this embodiment, a thin plate of white acrylic resin is arranged on both sides of the slit 9a of the case 9 as the diffuse reflection plate 8 constituting the above-mentioned diffuse reflection means. Incidentally, this diffuse reflection means 8
As other than the white acrylic resin thin plate shown in the above embodiment, conventionally known diffuse reflection means, for example, white, silver or light color plastic, a member such as paper, or white on the surface of the constituent members, Silver or light paint,
It is also possible to use those coated with a pigment, opal glass, a ceramic plate, a quartz plate, a rough polished surface of a metal plate, a sintered body of silica, alumina, BaSo _4, or the like.

The location of the diffuse reflection means 8 is
A position where the image of the diffuse reflection plate 8 is reflected on the surface of the original 2 is preferably illuminated by the light source 4 or by the reflected light from the original 2. In this embodiment, as described above, the diffuse reflection plates 8 are arranged on both sides of the slit 9a on the case 9 for making the reflected image from the original 2 incident on the imaging optical system 7.

In the document illuminating apparatus according to this embodiment having the above-described structure, the ratio of the diffusely reflected light on the surface of the three-dimensional object is determined even when a three-dimensional object whose surface is metallic is illuminated as follows. In addition to increasing the number, it is possible to reduce the reflection of the image of the black member on the surface of the three-dimensional object against stray light, and to make the reflected image of the three-dimensional object brighter and closer to the natural appearance.

That is, in the document illuminating device 1 according to this embodiment, as shown in FIG. 1, the illumination light emitted from the light source 4 is reflected by the main reflector 5 and the counter reflector 6 and placed on the platen glass 3. It is condensed on the placed document 2. Further, the diffuse reflection plate 8 is illuminated by the light source 4 directly or by the reflected light from the original 2, and uniformly illuminates the original 2 placed on the platen glass 3 with the diffused light. Therefore, as compared with the conventional blackening treatment, since the original 2 is illuminated by the diffused light from the diffuse reflector 8, the ratio of the diffused reflected light from the original 2 can be increased, and the surface is Even when a metallic three-dimensional object is illuminated, a brighter reflection image of the three-dimensional object can be obtained.

When a three-dimensional object whose surface is metallic is illuminated, the image of the diffuse reflection plate 8 is projected on the surface of the three-dimensional object to reduce the reflection of the image of the black member on the surface of the three-dimensional object. The reflected image can be brightened.

Therefore, according to the above embodiment, even when a three-dimensional object having a metallic surface is illuminated as the original document 2, the read image of the original document 2 looks brighter and more natural than in the conventional document illuminating device. It is possible to get closer to you.

Embodiment 2 FIGS. 2 and 3 show another embodiment of the present invention. The same parts as those of the above-mentioned embodiment are designated by the same reference numerals. The reflecting means can be moved back and forth, and the diffuse reflecting means can be switched to be used or not be used.

Referring to FIG. 2, the original illuminating device 1 according to the second embodiment has a platen glass 3 for supporting an original 2.
A light source 4 for illuminating the original 2, a main reflector 5 for condensing the light from the light source 4 onto the original 2 on the platen glass 3, an opposing reflector 6, and an image of the original 2 which is not shown in the drawing. An image forming optical system 7 for forming an image on a body or an image sensor, a diffuse reflector 30 for illuminating the original 2 with diffuse illumination light, and a moving mechanism 31 for moving the diffuse reflector 30 are provided. There is. Although not shown in the figure, a switch for switching the mode between the metal surface and the normal document is provided on the control panel of the copying machine or the facsimile using the document illuminating device 1.

Here, the light source 4 and the main reflector 5 are
With respect to the counter reflector 6, the imaging optical system 7, and the platen glass 3, the same ones as those used in the conventional document illumination device are used. Further, as the diffuse reflection plate 8, the same diffuse reflection means as described in the first embodiment is used.

FIG. 3 shows a moving mechanism of the diffuse reflection plate viewed from the platen surface side. The diffuse reflection plate 30 is slidable in the arrow direction along rails 32 attached to both sides. An arm 33 bent in a dogleg shape is rotatably attached to the center of the diffuse reflection plate 30. The other end of the arm 33 is fixed to the rotation shaft of the speed reducer 34, and the motor 35 is provided at the tip of the speed reducer 34.
Is attached. Thus, by rotating the motor 35, the arm 33 is rotated via the speed reducer 34, and the diffuse reflection plate 30 is moved back and forth in the arrow direction.

Further, the moving mechanism 31 for moving the diffuse reflection plate 30.
As described above, the case 9 of the original illuminating device 1 to which is attached is subjected to the blackening treatment for antireflection. Further, the case 9 is provided with a reflection image from the original 2.
A slit 9a for entering the imaging optical system 7 is opened.

Normally, the diffuse reflection plate 30 is retracted to a position hidden by the reflectors 5 and 6 when viewed from the platen surface (position shown by a dotted line in FIG. 3). Therefore, the black case 9 is visible from the platen surface.

When the original 2 such as a document is illuminated for reading, the reading operation of the original 2 is performed with the diffuse reflection plate 30 retracted to the retracted position. This can prevent stray light when reading the original 2 as usual.

On the other hand, in the case of illuminating and reading a three-dimensional object having a metal surface as the original 2, the metal surface is selected by the mode change switch on the control panel (not shown). As a result, the motor 35 operates and the diffuse reflection plate 30
Is moved to a position (a position indicated by a solid line in FIG. 3) which is directly illuminated from the light source 4 or illuminated by reflected light from the original 2. By reading the original 2 in this state, the original 2 can be uniformly illuminated by the diffused light from the diffuse reflection plate 30. Further, since the diffuse reflection plate 30 is reflected on the surface of the document 2, the reflected image of the document 2 can be made brighter and closer to the appearance.

After the reading of the original 2 is completed, the mode selector switch is automatically or manually switched to the normal original side, and the diffuse reflection plate 30 is retracted as shown by the broken line in FIG.

In this embodiment, although the diffuse reflection plate 30 is retracted by the mode selector switch, only one of the protrusions can be selected. The amount of protrusion may be set in several stages, or any amount of protrusion may be selected.

The other structure and operation are the same as those of the above-mentioned embodiment, and the description thereof will be omitted.

Embodiment 3 FIG. 4 and FIG. 5 show another embodiment of the present invention. The same parts as those of the above embodiment are designated by the same reference numerals and explained. By forming the reflecting means not in the form of a flat plate but in an upward convex shape or a downward convex shape as required, it becomes possible to diffuse and illuminate the original 2 more uniformly and efficiently by the diffuse reflection plate 8. ing.

The other structure and operation are the same as those of the above-mentioned embodiment, and the description thereof will be omitted.

[0036]

As described above, according to the present invention,
In the case of illuminating a three-dimensional object whose surface is metallic as described above, by illuminating the original with diffused light by the diffuse reflection means, and by reflecting the diffuse reflection means on the original surface, the reflection image from the original is Brighter and more visible.

The addition of the present invention to a document illuminating device can be performed easily and at low cost, and its effect is extremely great in performing high-quality image reading and copying.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a document illumination device according to the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of a document illumination device according to the present invention.

FIG. 3 is a plan configuration diagram showing a main part of the embodiment shown in FIG.

FIG. 4 is a configuration diagram showing a third embodiment of a document illumination device according to the present invention.

FIG. 5 is a configuration diagram showing a modified example of the third embodiment of the document illumination device according to the present invention.

FIG. 6 is a configuration diagram showing a conventional document illumination device.

[Explanation of symbols]

1 Original illumination device, 2 originals, 3 platen glass, 4
Light source, 5 main reflectors, 6 opposing reflectors, 7
Imaging optical system, 8 Diffuse reflector.

Claims (1)

[Claims] 1. A platen glass for supporting a document, an illuminating unit for illuminating the document, and an image forming optical system for forming an image of the document on a photoconductor or an image sensor. In the image reading apparatus having the above, the diffuse reflection means for diffusely reflecting the direct light illuminated by the illumination means or the reflected light reflected by another member to uniformly illuminate the document placed on the platen glass. Is disposed at a position facing the illumination position of the document.