JPH08123157A - Original exposing and scanning device - Google Patents

Abstract

PURPOSE: To clearly project image light from an original placed on a platen glass and also from the original carried along the platen glass to a light receiving body. CONSTITUTION: A mirror carriage 60 is constituted of a mirror carriage main body part 63 and a mirror supporting frame 64 movably supported in parallel with the platen glass 10 with respect to the main body part 63, and mirrors 61 and 62 are fixed to the mirror supporting frame. The frame 64 is provided with an abutting lever 64a passing through the main body part 63, and is pressed against the main body part by a compression spring 65. When the main body part 63 stands still at a specified position in order to expose and scan the original carried along the platen glass 10, the abutting part 64b abuts on the main body frame 80 of this exposing and scanning device, the frame 64 moves on a lens side, and focus is diverged upward. Thus, the image light from the original carried in a state where it is floated from the platen glass 10 can be clearly projected on a lens.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document exposure scanning device for exposing and scanning a document surface to obtain image light, and in particular, a document laid on a platen glass and a document conveyed along the platen glass. Both of them relate to an original document exposure scanning device capable of performing exposure scanning to obtain image light.

[0002]

2. Description of the Related Art As an original exposure / scanning device used in a copying machine, an image scanner, a facsimile, etc., an original placed on a platen glass and an original tray are placed.
It is known that an image light can be obtained by exposing and scanning both of the originals which are transferred one by one on the platen glass.

Such an original document exposure scanning device is equipped with an exposure means for exposing the original document surface and a first mirror, and a lamp carriage which can run along a platen glass, a second mirror and a third mirror. An original feeding device for carrying a mirror carriage that travels in the same direction as the lamp carriage, a lens, and an original placed on an original tray by rollers to feed the originals one by one onto the platen glass and transfer the original along the platen glass. It has and. In this document exposure device, a document laid on the platen glass is exposed and scanned by a lamp carriage traveling along the platen glass. Also, the documents placed on the document tray are
The document feeder passes the platen glass one by one,
Exposure scanning is performed by a stationary lamp carriage. The above-mentioned document feeder is provided with a roller around which an elastic member is wound around a peripheral surface thereof like the device described in Japanese Utility Model Laid-Open No. 61-176546, and by rotating this roller, the document is placed on a platen glass. There are things such as transferring while pressing. In this way, when the original is placed on the platen glass or is conveyed by the original feeder, the reflected light (image light) from the original surface obtained by the exposure scanning is the first light of the lamp carriage. Reflected on mirror 1
Further, the light is reflected by the second mirror and the third mirror of the mirror carriage, and an image is formed on a light receiving body such as an image sensor or a photoconductor through a lens.

In such an original document exposure scanning device, the optical path length is set so that the reflected light of the original document on the upper surface of the platen glass forms an image on the photoreceptor, and the apparatus is placed on the platen glass. A platen cover is provided to bring the original into close contact with the platen glass. In addition, the optical path length from the upper surface of the platen glass to the lens is constantly maintained by running the mirror carriage at a speed half that of the lamp carriage.

In the above-described document exposure scanning device, a book or a document having a large thickness is placed on the platen glass and exposed and scanned, and a large number of documents of the same size are placed together at a predetermined position. However, it is possible to carry out exposure scanning by feeding one by one by the document feeding device, and it is possible to perform exposure scanning quickly without the need to open and close the platen cover that covers the platen glass and replace the document.

[0006]

However, in the above-described conventional document exposure scanning apparatus, when the document is transferred while being pressed against the platen glass, the ink of the document and stains attached to the document adhere to the platen glass, May cause defects such as black streaks. Further, there is a drawback that the document is easily damaged due to friction with the platen glass. On the other hand, if the original is not pressed against the platen glass, the original rises from the platen glass and passes through, so the optical path length from the original to the lens increases and the reflected light from the original is accurately imaged on the photoreceptor. However, there is a problem that a clear image cannot be obtained.

The present invention has been made in view of the above problems, and an object thereof is to always project a clear image on a photoreceptor without contaminating the platen glass or adversely affecting a document. An object is to provide a document exposure scanning device.

[0008]

In order to solve the above problems, the invention as set forth in claim 1 sets a platen glass on which a document is laid and a document so that the document surface passes over the platen glass. A document placed on a platen glass, which is equipped with a document feeding device that moves and moves one by one, an exposure unit that exposes the document surface, and a first mirror that reflects the reflected light (image light) from the document surface. Is exposed and scanned while traveling along the document surface, and with respect to the document passing on the platen glass, the lamp carriage that exposes and scans the document surface that passes while being stationary is reflected by the first mirror. A mirror carriage that mounts a second mirror and a third mirror that reflect image light and guides the image light to a photoreceptor, and that runs in conjunction with the lamp carriage; and a mirror carriage that is supported on the optical path of the reflected light. In document exposure scan device having a lens for forming on the photoreceptor image light from,
When the lamp carriage stops at a position where the original moving on the platen glass is exposed and scanned, the second and third mirrors mounted on the mirror carriage are moved to the imaging lens side by a predetermined amount. A mirror shift means is provided.

According to a second aspect of the present invention, in the document exposure / scanning apparatus according to the first aspect, the mirror carriage has a mirror carriage main body portion that travels in the same direction as the lamp carriage, a second mirror, and Third
And a mirror support frame which is fixedly supported by the mirror carriage body and is supported so as to be movable in the optical path direction with respect to the mirror carriage main body section. An urging means for urging to the side opposite to the optical path direction, and an urging means for urging the mirror support frame against the urging force of the urging means toward the imaging lens side when performing exposure scanning while the mirror carriage is stopped. And a contact member.

According to a first aspect of the present invention, there is provided a mirror shift means for moving the second mirror and the third mirror to the image forming lens side with respect to the mirror carriage when the lamp carriage stands still and performs exposure scanning. The optical path from the upper surface of the platen glass to the lens is shortened by a predetermined amount as compared with the time of traveling exposure scanning. The shortened optical path is preferably about ½ of the distance that the conveyed document floats from the platen glass. Further, either the entire mirror carriage may be moved to the light receiving body side, or only the mirror may be moved.

In the urging means according to the second aspect, an elastic body such as a spring or rubber is used by being interposed between the main body of the mirror carriage and the member supported by the mirror support frame or the mirror support frame. You can Furthermore, the contact member according to claim 2 is
The shape, size, etc. can be selected as appropriate, and the frame or the like of the document exposure scanning device can also be used.

[0012]

In the document exposure / scanning apparatus according to the first aspect, when the document placed on the platen glass is exposed and scanned, the lamp carriage travels along the platen glass, and the mirror carriage interlocks with the platen glass. The optical path length from the upper surface of the platen glass to the lens is kept constant. On the other hand, when exposing and scanning a document that is moved and moved on the platen glass by the document feeding device, the lamp carriage moves to a predetermined position and stands still. The mirror carriage also interlocks with the lamp carriage and stops at a predetermined position. At this time, the second and third mirrors are moved to the imaging lens side by a predetermined amount by the mirror shift means. That is, the mirror is shifted so that the optical path length from the upper surface of the platen glass to the lens becomes shorter than that during traveling of the lamp carriage. Therefore, the position where the image projected onto the photoreceptor by the lens is in focus is slightly above the upper surface of the platen glass, and even if the original is lifted above the platen glass and exposed and scanned, it is reflected from the original surface. The light is sharply imaged on the photoreceptor.

In the document exposure apparatus according to the second aspect of the present invention, normally, the urging means urges the mirror support frame to the side opposite to the photoreceptor, and the second mirror and the third mirror are mirrors. It moves together with the carriage body. Therefore, the mirror carriage works in conjunction with the lamp carriage, and when the original on the platen glass is exposed and scanned, the distance from the upper surface of the platen glass to the lens is maintained at a predetermined amount. On the other hand, when the document feeder moves the document and the lamp carriage reaches a position where the document passing through the platen glass is exposed and scanned while the document is stationary, the contact member contacts the mirror support frame, and the biasing means applies the force. The mirror support frame is pushed out to the imaging lens side against the force. Therefore, the second mirror and the third
Is arranged so as to approach the light receiver, and the optical path of the image light after reaching the lens after being reflected by the first mirror is shortened. Therefore, even if the original is exposed and scanned while floating from the platen glass and the optical path of the image light until reaching the first mirror increases, the increased optical path is offset by the movement of the mirror, and the image light is appropriate. It is incident on the lens with a long optical path length.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the document exposure scanning device according to the invention described in claim 1 or 2 will be specifically described below with reference to FIGS. FIG. 1 is a schematic sectional view showing a document exposure scanning device of this embodiment. The document exposure / scanning apparatus of this embodiment includes a platen glass 10 fitted and fixed on the upper part of the main body, and a platen glass 10 hinged on the upper part of the main body.
A platen cover 20 that covers the document D laid on it from above and presses it against the platen glass 10, and a document D ′ placed on the platen cover 20 are conveyed one by one in the direction of arrow A shown in the figure. Then, a document carriage 40 that passes over the platen glass 10, an exposure lamp 51 that exposes the document surface, and a first mirror 52 are mounted, and a lamp carriage 5 that is supported so as to run along the platen glass 10.
0, a second mirror 61 and a third mirror 62, and a mirror carriage 60 that is supported so as to run in the same direction as the lamp carriage 50, a first mirror 52 and a second mirror 61 from the document surface. , An image forming lens 70 for forming an image of the image light guided through the third mirror 62 on the light receiving body.

As shown in FIG. 2, the document feeding device 40 has a slit-shaped opening 42 in the main scanning direction at the bottom of a conveyance path 41 for conveying the document D ', and above the opening 42. A document passing through the sheet directly faces the platen glass 10. Further, the conveyance rollers 43, 4 are provided on both sides.
Each pair of documents 3 is provided, and the documents placed on the document tray 30 are moved one by one in the direction of the arrow A shown in FIG. 2, pass through the opening 42, and then are fed onto the document tray 30. It is like this. The lamp carriage 50 travels along the platen glass 10 while traveling along the platen glass 10.
The document D laid on the sheet is exposed by the exposure lamp 51, and the reflected light (image light) from the document D is reflected by the first mirror 52. Also, the document feeder 40
A document that is moved below the opening 42 and passes above the opening 42 is exposed under the opening 42 while remaining stationary.

The mirror carriage 60 is supported so as to be movable in the same direction as the lamp carriage 50, and is supported so as to be movable in a direction parallel to the platen glass 10 with respect to the mirror carriage main body 63. And a mirror support frame 64. The mirror carriage body 63 has a box-like shape with an open side surface on the lamp carriage 50 side (right side in the drawing).
The lamp carriage 50 travels at half the speed. The mirror support frame 64 allows the image light reflected by the first mirror 52 to enter the second mirror 61 and the image light from the second mirror 61, and reflects the image light to the lens 70 in parallel with the platen glass 10. It supports the third mirror 62. Further, the mirror support frame 64 penetrates the side surface of the mirror carriage main body 63 which is not released,
The contact rod 64a is provided so as to protrude toward the main body frame 80 of the exposure scanning device which is a contact member. The tip of the contact rod 64a is a disc-shaped contact portion 64b, and the contact rod 64a is provided with a pressing spring 65, which is a biasing means, between the contact portion 64b and the carriage body 63. The mirror support frame 64 is wound so that both ends are in contact with each other, and the mirror support frame 64 is biased toward the mirror carriage main body 63 side.

In the present embodiment having the above-mentioned structure, the document D is laid on the platen glass 10 with the document surface facing down,
When the platen cover 20 is covered from above and the document exposure scanning device is operated, the lamp carriage 50 runs along the platen glass 10 in the direction of arrow B shown in the figure, and the exposure lamp 51 exposes the document D. At this time, the pressing spring 65
Always presses the contact portion 64b to the left side in the drawing and urges the mirror support frame 64a toward the mirror carriage body 63, so that the mirror support frame 64 moves together with the mirror carriage body 63. The image light from the document surface which is in close contact with the upper surface of the platen glass is reflected by the first mirror 52, the second mirror 61 and the third mirror 62 in this order, and is guided to the imaging lens 70. At this time, the mirror support frame 63, together with the mirror body 64, is 1 / th of the lamp carriage 50.
Since the vehicle is traveling at the speed of 2, the image light always passes through the lens with a constant optical path length, and then is incident on the photoreceptor.

On the other hand, when the document D'placed on the document tray 30 is exposed and scanned, the lamp carriage 50 stands still below the opening 42 of the document feeder 40 as shown in FIG. At the same time, the mirror carriage body 63 also stands still at a predetermined position. At this time, the contact portion 64b of the mirror support frame 64 that has moved together with the mirror carriage main body portion 63 strikes the main body frame 80 of the exposure scanning device, and the mirror support frame 64 has the conveyance path width W (from the upper surface of the platen glass to the upper portion thereof). 1/4 of the distance to the wall of the road, the same hereafter)
Only the lens moves to the image forming lens 70 side and stops. as a result,
The distance from the first mirror 52 to the second mirror 61,
The distance from the third mirror 62 to the lens 70 is shortened by 1/4 of the transport path width W, respectively. Therefore, when the document placed on the platen glass is scanned, if the upper surface of the platen glass is in focus, the platen glass is in focus above the platen glass by ½ of the transport path width W when the document is stationary. .

After that, the conveying rollers 43 rotate, and the originals are fed into the conveying path 41 one by one, and when they successively pass over the opening 42, they are exposed by the exposure lamp 51 of the stationary lamp carriage 50 and the original surface. The reflected light (image light) from is reflected in order by the first mirror 52, the second mirror 61, and the third mirror 62, and is imaged on the photoreceptor by the imaging lens 70. At this time, the document passing through the transport path 41 passes through the transport path while moving up and down, but the focus of the optical system is substantially in the center of the transport path, and the reflected light from the traveling document is reflected on the photoreceptor. A clear image is formed.

FIG. 3 is a graph showing the relationship between the distance from the upper surface of the platen glass 10 of the document to be exposed and scanned and the state of the image on the photoreceptor when the image light obtained from the document is incident. . A curve A shows a case where the exposure scanning is performed while the mirror support frame 64 is not moved with respect to the mirror carriage and is supported on the side far from the lens. At this time,
The focus of the optical system matches the upper surface of the platen glass.
Since the original document laid on the platen glass 10 is pressed by the platen cover 20, the distance from the upper surface of the platen glass 10 is 0, and the image on the photoreceptor is in the best condition. On the other hand, when the original document feeding device 40 moves the original document to perform exposure scanning while shifting the mirror support frame 64 without shortening the optical path, the original document moves up and down in the conveyance path 41, and the optical path of the image light is maximum. Thus, the width W of the conveyance path is increased. As a result, the image on the photoreceptor will be partially improper in the vicinity.

However, when the mirror support frame 64 is moved to the lens 70 side by the above operation, the first mirror 52 is moved.
The optical path until it enters the lens 70 after being reflected by
The focus of the optical system will be above the upper surface of the platen glass. As a result, as shown by the curve B, the image on the photoreceptor is in a good state from to. Particularly, in the present embodiment, the mirror support frame 64 is moved to the imaging lens 70 side by 1/4 of the transport path width W, and the focus is adjusted to ½ of the transport path width W above the upper surface of the platen glass. Therefore, even if the document in the transport path 41 moves up and down in a large range, an image in a good state can be formed on the photoconductor.

[0022]

In the document exposure / scanning apparatus according to the first or second aspect of the present invention, the mirror shift means causes the second mirror and the third mirror to scan the document transported on the platen glass. Since the mirror is moved to the light receiving body side, the optical path length from the upper surface of the platen glass to the imaging lens is shortened, and the optical system is in a state of being focused above the upper surface of the platen glass. Therefore, it is possible to project a clear image on the photoreceptor even if the original is transported in a floating state without being pressed by the platen glass. Further, since the document to be transferred can be conveyed without being pressed on the platen glass, the document is not damaged or ink or dirt on the document does not adhere to the platen glass, and image defects such as black streaks are prevented. Can be prevented.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an original exposure scanning device which is an embodiment of the invention described in claim 1 or claim 2.

FIG. 2 is a schematic cross-sectional view of the document exposure scanning device of FIG. 1, showing a state in which a document transported on a platen glass is exposed and scanned.

FIG. 3 is a diagram showing a state of an image incident on a light receiving body when an original conveyed by an original feeding device is exposed and scanned in the original exposure scanning device of FIG.

[Explanation of symbols]

 10 Platen Glass 20 Platen Cover 30 Document Tray 40 Document Feeding Device 50 Lamp Carriage 60 Mirror Carriage 63 Mirror Carriage Main Body 64 Mirror Support Frame 65 Pressing Spring 70 Lens 80 Main Frame of Exposure Scanner

Claims (2)

[Claims] 1. A platen glass on which a document is laid, a document feeding device for moving and moving the document one by one such that the document surface passes over the platen glass, an exposing unit for exposing the document surface, and a document surface. For a document mounted with a first mirror that reflects the reflected light (image light) of, and placed on the platen glass, the document that is exposed and scanned while traveling along the document surface and passes on the platen glass Is equipped with a lamp carriage that exposes and scans the surface of the document passing therethrough in a stationary state, a second mirror and a third mirror that reflect the image light reflected by the first mirror and guide it to a light receiver. An original exposure scanning device having a mirror carriage that runs in conjunction with the lamp carriage, and a lens that is supported on the optical path of the reflected light and forms an image of the image light from the mirror onto a light receiving body. When the lamp carriage stops at a position for exposing and scanning an original moving on the platen glass, the second mirror and the third mirror mounted on the mirror carriage are moved toward the imaging lens by a predetermined amount. A document exposure scanning device, characterized in that it is provided with a mirror shift means for moving the document only. 2. The document exposure scanning apparatus according to claim 1, wherein the mirror carriage fixedly supports a mirror carriage main body that travels in the same direction as the lamp carriage, a second mirror and a third mirror, A mirror support frame movably supported with respect to the mirror carriage main body in the optical path direction, and the mirror shift means attaches the mirror support frame to the opposite side of the mirror carriage main body in the optical path direction. Urging means for urging, and an abutting member for pushing the mirror support frame toward the imaging lens side against the urging force of the urging means when performing exposure scanning while the mirror carriage is stopped. Characteristic exposure scanning device.