JPH02213268A - Image reader - Google Patents

Abstract

PURPOSE:To exactly read a document image by providing a first guiding member arranged in the downstream side of a document side guiding member with regard to an image reading direction, a second guiding member arranged in the upstream side of the document side guiding member, and a horizontal shift preventing means. CONSTITUTION:A second guide roll 13 being a second guiding member is provided on the respective positions corresponding to control members 20a and 20b among moving members 10, and in the position of the upstream side of a third guiding roll 14 with regard to an image reading direction A. A fixed roll 11 being a first guiding member is provided on a position corresponding to the control member 20b of this side in the moving member 10, and on the position of the downstream side of a third guide roll 14 with regard to the image reading direction A. As for a horizontal dislocation preventing means for preventing the horizontal dislocation of the fixed roll 11, the V-groove of the fixed roll 11 and the columnar control member 20b fitted thereto are used.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image reading device used in electrophotographic devices such as copying machines and facsimile machines.

According to Japanese Patent Application Laid-open No. 63-198040, a third guide section (corresponding to the document side guide member of the present application), a first guide section, and a third guide section are provided on a moving member disposed below the document table. An image reading device is shown in which two guide parts (corresponding to the first guide member and the second guide member of the present application, respectively) are arranged. An image reading means consisting of a lens array and a reading element is provided on the moving member, and by moving this moving member in the image reading direction along the document mounting table, the image of the original on the document mounting table is read. I try to read the whole area.

In this conventional device, the first guide section is disposed downstream of the second guide section in the image reading direction, and the first guide section is constituted by a fixed roller having substantially no elastic system. There is.

Since the first guide portion is a fixed roller, the movable member is prevented from tilting downward when the movable member is moved in the image reading direction.

However, in this conventional device, no measures have been taken to prevent each guide section from shifting in the lateral direction with respect to the image reading direction. There was a risk that the image would be skewed in the lateral direction, and as a result, the position of the read image would also deviate from its normal position.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image reading device that can accurately read original images.

hand to do The above problem is solved by the following image reading device.

A transparent document placement table on which a document is placed; a movable member that is disposed opposite to the document placement surface of the document placement table and is equipped with an image reading means; Fixedly placed on the side.

A document side regulating member provided along the document placing table, a moving member side regulating member fixedly arranged at a position farther from the moving member when viewed from the document placing table, and a moving member side regulating member fixedly arranged on the moving member and applied to the document side regulating member. and a moving member side guide member that is fixedly arranged on the moving member and applied to the moving member side regulating member.

In an image reading device in which a moving member is moved in an image reading direction along a document placing table while maintaining a constant distance between an image reading means and a document placing table by a moving member side guide member and a document side guide member. .

The moving member side guide member has a first guide member disposed downstream of the document side guide member in the image reading direction, and a second guide member disposed upstream of the document side guide member. I am.

The second guide member is pressed against the movable member side regulating member by the elastic member, the first guide member is fixed to the movable member, and the first guide member is further prevented from moving in the lateral direction with respect to the image reading direction. An image reading device characterized by being provided with a lateral shift prevention means for preventing.

It is.

In the above configuration, the document-side regulating member may be the document placing table itself, or may be a separate member from the document placing table itself.

There are two moving member side regulating members corresponding to both sides of the document placement table.
The film may be left in some places, or only one may be provided at approximately the center of the moving member.

The first guide member and the second guide member serve as the document side guide member and the moving member side guide member.

Either of them may be constructed using a rotatable member such as a roller, or may be constructed using a non-rotatable member simply attached to a document table or the like.

The lateral shift prevention means is a means for mechanically preventing the first guide member from shifting in the lateral direction with respect to the image reading direction. ■This can be achieved by fitting a roller with grooves to a rod with a circular cross section, or fitting a sliding bearing to a rod with a circular cross section.

While the second office moving member (10, 50) moves in the image reading direction (A), the reading means (17) on the moving member and the M document mounting table (1
5) is always kept constant by the document side guide member (third guide roller 14), first guide member (fixed roller 11), and second guide member (second guide roller 13).

As the second guide member presses the movable member toward the document mounting table, the movable member attempts to rotate about the document-side guide member. As a result, the fitting of the lateral displacement prevention means provided in conjunction with the first guide member is ensured,
There will be no side shift.

Garden garden FIG. 1 is a perspective view of an image reading device according to an embodiment.

In the figure, a moving member 10 is disposed below a document mounting table 15 made of transparent glass. The original is placed on the original placing table 15 with the image surface facing downward, that is, facing the direction of the moving member 10 . Moving member 1
0, an image reading means 1 is arranged. In the embodiment, an image reading means is constituted by a reading member 17 and a lens array 16 that guides a light image of an image to the reading member. As shown in FIGS. 6 and 7, the reading member 17 includes a plurality of reading elements 6 such as CCDs arranged on a substrate 5,
It is constructed by covering the top with a cover glass 7.

Supports 2 of a predetermined height are provided on both sides of the lens array 16 on the moving member 10, and a third guide roller 14 as a document-side guide member is provided at the upper end thereof. These third guide rollers are rotatable relative to the support column 2. Moreover, these third guide rollers 14
As shown in the drawings and FIG. 3, it is in contact with the lower surface of the document placement table 15, that is, the surface opposite to the document placement surface. The third guide roller 14 is provided to ensure that the distance between the document placement table 15 and the reading member 17 is always maintained at the conjugate length of the lens array 16. Therefore, the third guide roller 14
The member to be hit by is not the original platen 15 itself,
As shown in FIG. 4, it is also possible to make contact with a regulating member 42 that is separate from the original table 15 but fixed to the document table 15.

Below the moving member 10, two regulating members 20a and 20b are arranged along the original table 15. As shown in FIG. The rear regulating member 20a has a flat plate shape, and the front regulating member 20b has a columnar shape.

A motor 22 is disposed on the back side of the document table 15. Two wires 21a and 21b are hung around a pulley 23 attached to the output shaft of the motor 22. One wire 21a connects two pulleys 24a and 24 on the back side.
The hook is passed through b and is connected to the back side plate 10a of the support member 10 by a stopper 25, as shown in FIG.

The other wire 21b is passed through four pulleys 24a, 24b, 24c, and 24d on the back side and the front side, and is attached to a stopper on the side plate 10b on the front side of the support member 10, as shown in FIG. 25.

When the motor 22 operates and the pulley 23 rotates, the wire 2
1a and 21b are wound up and moved, thereby moving the moving member 10 in the direction of arrow A in the figure or in the opposite direction. The image reading means 1 reads the original image while the moving member 10 is being moved in six directions. Below this A
This direction is called the image reading direction.

A second guide roller 13 as a second guide member is disposed at a position of the movable member 10 corresponding to the regulating members 20a and 20b and upstream of the third guide roller 14 with respect to the image reading direction A. It is set up. These guide rollers 13 are pushed downward, that is, in the direction of the respective regulating members 20a and 20b, by compression springs 12 as elastic members, as shown in FIGS. 2 and 5. In other words, the third guide roller 14 is moved by these second guide rollers 13 to the document placing table 15 . In some cases, it is pressed against the document side regulating member 42.

An auxiliary roller 3 is provided at a position corresponding to the rear regulating member 20a of the movable member 10 and downstream of the third guide roller 14 in the one-image reading direction A. As shown in FIG. 5, the auxiliary roller 3 is pushed downward by the compression spring 4, that is, in the direction of the regulating member 20a. Therefore, the guide roller 14 is pressed against the original table 15 etc. by the auxiliary roller 3.

A fixed roller 11 as a first guide member is provided at a position corresponding to the regulating member 20b on the front side of the movable member 10 and downstream of the third guide roller 14 in the image reading direction A. . The fixed roller 11 is as shown in FIG.

The shaft 11a is supported by the movable member 10 so as to be rotatable but not displaceable. The fixed roller 11 is the eighth
As shown in the figure, a V-groove is provided, and the V-groove fits into the cylindrical regulating member 20b.

With the above configuration, when the movable member 10 moves in the image reading direction A in FIG.
is always pressed against the document placing table 15 etc. by the two second guide rollers 13 and the auxiliary roller 3, so that the distance between the document placing table 15 and the reading member 17 is always maintained at the conjugate length of the lens array 16. Therefore, the image can be read with high precision over the entire area of the document image.

Also, a roller on the downstream side with respect to the image reading direction A.

In this embodiment, assuming that the auxiliary roller 3 and the fixed roller 11 are both biased by springs and movable up and down like the auxiliary roller 3, the movable member 10 is moved in the image reading direction. When moving to A, each roller 3
The movable member 10 may vibrate up and down due to the frictional resistance between the control member 11 and each of the regulating members 20a and 20b, and as a result, there is a possibility that image reading accuracy may deteriorate. Specifically, there is a risk that what should normally be a single straight line may become serrated. In contrast, in this embodiment, one of the rollers on the downstream side is the fixed roller 11, so vertical vibration of the movable member 10 is prevented.

Furthermore, in this embodiment, only one roller 11 among the four rollers 3.11.13.13 provided on the moving member 10 is a fixed roller, and the rest are all elastically biased rollers. ing. In other words, only one of the rollers on both sides of the moving member 10 is a fixed roller. If the rollers on both sides are fixed rollers, if the accuracy of each component is poor, for example, if the movable member 10 is bent in the direction perpendicular to the image reading direction A, one of the rollers may be fixed. In this embodiment, at least one roller,
That is, the auxiliary roller 3 and the second guide roller 13 on the back side
Since both rollers are elastically biased, there is no need to worry about uneven contact.

Furthermore, in this embodiment, since the fixed roller 11 is fitted into the regulating member 20b, while the movable member 10 is moving in the image reading direction A, it is prevented from shifting in the direction perpendicular to the image reading direction A, that is, in the direction B in FIG. Can be done.

As can be understood especially by looking at FIG. 2, the moving member 10 is moved by the second guide roller 13 to the third guide roller 1-4.
As a result, the fixed roller 11 is pressed against the regulating member 20b with an appropriate force. Thereby, the fitting between the two is reliably maintained.

In the embodiment shown in FIG. 1, the first guide member is constituted by a fixed roller 11, and a cylindrical shape that fits into a V-groove of the fixed roller 11 and a cylindrical shape that fits into the V-groove of the fixed roller 11 is used as a lateral displacement prevention means for preventing lateral displacement of the fixed roller 11. A regulating member 20b was used. However, instead of the fixed roller 11, a sliding bearing 26 shown in FIGS. 9 and 10 may be used. This sliding bearing 26 is rotatably fixed to the moving member 10 by a pin 27. This sliding bearing 26 is connected to the cylindrical regulating member 20
b, and prevents the moving member 10 from tilting and from shifting in the lateral direction.

FIG. 11 shows a moving member 50 used in another embodiment.
It shows. The only difference between this moving member 50 and the moving member 10 shown in FIG. 1 is that a second guide roller 13 as a second guide member is provided corresponding to the cylindrical regulating member 20b. , flat regulation member 20a
It is not provided in a position corresponding to At the position corresponding to the flat regulation member 20a, there is a direction A in which the image is read.
The spring 4 is located at approximately the same position as the third guide roller 14.
The moving member 10 is the same as the moving member 10 shown in FIG. 1 except that it is provided with an auxiliary roller 3 that is pressed by a roller.

Also in this device, the fixed roller 11 is pressed against the regulating member 20b by the second guide roller 13, and the V groove of the fixed roller 11 is firmly fitted into the regulating member 20b, so that the displacement of the moving member 50 in the lateral force direction is prevented. Prevented.

In addition, in FIG. 11, the flat regulating member 20a and the auxiliary roller 3 on the back side are removed, and the fixed roller 11 and the second guide roller 13 are arranged at approximately the center position of the movable member 50.
Corresponding to this, the cylindrical regulating member 20b may also be installed at approximately the center position. According to this configuration, the movable member 50 includes two of the fixed roller 11 and the second guide roller 13.
It will be supported from below only by the point. Even in this case, the two third guide rollers 14
(Fig.) etc. at two points, the relationship between the moving member 50 and the original table 15 will not become unstable.

By the way, the shape, material, etc. of the third guide roller 14 are not limited to any particular material, but if a material that is too hard is used, a problem arises in that the sliding noise becomes too loud. Therefore, it is better to make the third guide roller 14 by covering the ball bearing 18 with a rubber layer 19 as shown in FIG. 12. With this configuration, the noise during movement can be suppressed to below moderate level. . but,
Since the distance from the reading means 17 must be kept constant, the amount of deformation of the rubber layer 19 when it hits the document table 15 is preferably 0.2 nm or less.

FIG. 13 is a graph showing the relationship between the rubber deformation amount 1 generated sound and the rubber hardness when the rubber layer is 1 cm and the outer diameter is 12+m. As can be seen from this graph, it is desirable to set the rubber hardness to 30' (JIS-A) or higher.

According to the present invention, the second guide member (13) is located upstream of the document side guide member (14), and the first guide member (11) is located upstream of the document side guide member (14).
) is located on the downstream side of the document-side guide member, so the movable member (10, 50) is moved to the document placing table (1) by the second guide member.
When pushed in the direction 5), the movable member is urged in the direction to rotate around the document side guide member. As a result, the lateral displacement preventing means provided in conjunction with the first guide member is securely fitted, and lateral displacement of the movable member can be reliably prevented. This allows the image reading means (, 1) on the moving member to accurately read the original image.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of one embodiment, FIG. 2 is a side view taken in the direction of the arrow ■ in FIG. is a side sectional view taken along the line ■-■ in FIG. 1, FIGS. 6 and 7 are views showing an example of the image reading means, and FIGS. 8 to 10 are views showing specific examples of the first guide member. 11 is a perspective view showing the main parts of another embodiment, FIG. 12 is a side sectional view of an example of the document side guide member, and FIG. 13 is a graph showing experimental results regarding the document side guide member. be. 15... Original placing table 1... Image reading means 10.50... Moving member 15.42... Original side regulating member 20a, 20b... Moving member side regulating member 14... Third guide Roller (document side guide member) 11...Fixed roller (first guide member) 13...Second guide roller (
2nd guide member) Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 8 Fig. 9 Fig. 10

Claims (1)

[Claims] A transparent document placing table on which a document is placed; a movable member disposed opposite to the document placing surface of the document placing table and equipped with an image reading means; a document-side regulating member that is fixedly arranged closer to the document placing table than the member and provided along the document placing table; a moving member side regulating member that is fixedly arranged at a position farther from the document placing table than the moving member; The moving member side guide member has a document side guide member that is fixedly arranged on the moving member and is applied to the document side regulating member, and a moving member side guide member that is fixedly arranged on the moving member and is applied to the moving member side regulating member. In an image reading device that moves the movable member in the image reading direction along the document platform while maintaining a constant distance between the image reading means and the document platform by the document side guide member and the document side guide member, the movable member described above is provided. The side guide member has a first guide member disposed downstream of the document side guide member in the image reading direction, and a second guide member disposed upstream of the document side guide member, The second guide member is pressed against the movable member side regulating member by the elastic member, the first guide member is fixed to the movable member, and the first guide member is further prevented from moving in the lateral direction with respect to the image reading direction. An image reading device characterized by being provided with a lateral shift prevention means for preventing.