JP2773061B2 - Reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reading apparatus such as a facsimile apparatus using a contact type image sensor having a small depth of field.

[0002]

2. Description of the Related Art In general, a reading device such as a facsimile device has a lens and a CCD because it is unitized and can be reduced in size and weight, and maintenance and handling are easy. Instead of being equipped with a configured reduction optical system, a contact type image sensor is often used. However, a short focus imaging lens usually used as a contact image sensor, for example, a SELFOC lens (trade name) has a shallow subject depth of about ± 0.3 mm, and reading outside this range is difficult. Therefore, in a reading apparatus using a contact type image sensor such as a selfoc lens, it is necessary to bring the document surface into close contact with the contact type image sensor, and for example, the one shown in FIG. 3 is known.

FIG. 3 shows a reading device in a facsimile machine. A document reading section A is provided with a document insertion port 51, and a document 52 is inserted through the document insertion port 51 to separate a pair of separation rollers 53, 53. The document 52 is separated one by one by 54, and the separated document 52 is sent to a contact image sensor 58 that is in close contact with a rotating roller 57 by feeding roller pairs 55 and 56 to read image information. , 60 so as to be discharged out of the apparatus.

A contact type image sensor 58 for reading image information of the document 52 is in close contact with a rotary roller 57 made of an elastic material such as a rubber material. As a close contact means, as shown in FIG. 4 in particular, a close contact type image sensor 58 is attached to a holding member 61, and is disposed so as to be rotatable around a rotation fulcrum 61a of the holding member 61. , A torsion spring 62 is attached. Therefore, the torsion spring 62 exerts a rotational force F 'in the counterclockwise direction of FIG. At this time, the rotation fulcrum 61 a is provided at a position far away from the reading surface 58 a of the contact image sensor 58, and as a result, the force of pressing the reading surface 58 a of the contact image sensor 58 perpendicularly to the rotating roller 57. Is a pressing force Fy 'which is a component of the rotating force F', and the pressing force Fy '
57 are formed in close contact with each other. Note that x of the rotational force F '
The component force Fx 'of the component does not act as a force for pressing the contact image sensor 58 against the rotating roller 57, and is a useless force.

[0005]

However, according to the above-mentioned prior art, the rotation fulcrum 61a of the holding member 61 is far away from the reading position (for example, the distance L ₁ from the rotation axis center to the reading position in FIG. 4). (= 45 mm and the angle θ with respect to the document conveying surface = 30 degrees), there is a problem that the space of the reading unit becomes considerably large.

The rotation of the holding member 61 in the rotating direction of the holding member 61 is caused by the deformation of the rotating roller 57 formed of an elastic body such as a rubber material, the action of a component force Fx 'not directed to the axis of the rotating roller 57, and the like. The variation angle β appears as a deviation amount x as shown in FIG. 5, and as a result, a floating amount y of the document is generated, and the reading accuracy is reduced. This is particularly problematic when reading with high gradation. For example, when a perfect contact image sensor (self contact lensless contact image sensor) is used, the deviation amount x is about ± 0.2 mm and the floating amount y is 0.05.
When it becomes mm or more, the MTF is divided by 30%, and it is difficult and problematic to read 64 gradations.

Further, in FIG. 4, the direction of rotation of the rotational force F 'is not oriented in the direction of the axis of the rotating roller 57, and the angle .alpha.'
The force for pressing the rotating roller 57 is Fy 'because the displacement is large, and in order to obtain the predetermined pressing force Fy ", it is necessary to press the rotating roller 57 with a larger rotating force F". However, there is a problem in that the reaction force of the torsion spring generating the strong rotation force F ″ deforms the frame or the like that forms the rotation fulcrum 61a of the holding member 61, and as a result, the reading position may shift.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a reading apparatus which can efficiently press the contact type image sensor and is reduced in size. It was done.

[0009]

A representative means for solving the above-mentioned problems and applied to the embodiments described below is a document conveying means for conveying a document, and a contact means for reading image information of the document in a contact state. A reading unit having a type image sensor and a rotating roller provided at a position facing the sensor, and a holding member for bringing the original into close contact with a predetermined reading position of the contact type image sensor, the contact type image sensor A rotation fulcrum of the holding member to which is attached is provided on the roller shaft of the document conveying means near the reading means,
A concave groove is provided in a part of the holding member to be fitted with a shaft of the rotating roller.

[0010]

According to the present invention, as described above, the rotation fulcrum of the holding member for holding the close contact type image sensor is provided on the roller shaft of the document conveying means disposed near the reading means, and the fulcrum is used as the center of rotation. As a result, the reading means can be pressed efficiently, and the size of the reading device can be further reduced. In addition, by providing a concave groove portion that fits with the shaft portion of the rotating roller in a part of the holding member, it is possible to prevent the positional displacement between the contact image sensor and the rotating roller, and to always maintain the optimal reading position relationship. Can be kept.

[0011]

Next, an embodiment in which the above means is applied to a facsimile machine will be described by way of example.

[First Embodiment] FIG. 1 is an explanatory view of the principle showing the state of close contact of the reading unit, and FIG. 2 is a cross-sectional view of the reading unit in which a facsimile apparatus according to the present invention is partially cut and shown. First, the overall configuration of the apparatus will be described with reference to FIG. 2. Reference numeral 1 denotes an apparatus main body. In order to make the entire apparatus compact, its upper surface cover 1a is attached to the front part of the apparatus main body 1 (the left end in FIG. 2). An inclined surface is formed so as to become gradually lower.
A document reading unit 2 is provided on the front side of the apparatus main body 1. The document reading unit 2 has a document insertion slot 3 and a document guide 5 slidable in the width direction of the document 4 in the document insertion slot 3. Is provided.

A separation roller 7 is provided between the document feed path of the document reading section 2, ie, the document insertion port 3 and a document discharge port 6 provided at a part (above the inclined surface) of the upper cover 1a.
a separating section 7 that separates the originals 4 sent one by one from the original guide 5 with the original surface facing down, and a separating section 7 having a pressing piece 7b pressed by the separating roller 7a. A feeding unit 8 including a pair of feeding rollers 8a and 8b for feeding the separated document 4, and a contact image sensor 9 as reading means for reading image information of the document 4 conveyed from the feeding unit 8. A rotating roller 10 that faces the upper surface of the contact image sensor 9 and conveys the document 4 while closely contacting the reading position 9 a on the upper surface; and a pair of discharges that discharge the read document 4 from the document discharge port 6. A discharge unit 11 including rollers 11a and 11b is provided.

The contact-type image sensor 9 is a short-focus imaging lens having a very shallow depth of field. In the case of the facsimile mode, an image information signal read from the document 4 is copied to a recording unit of another machine. In the mode, the data is transmitted to its own recording unit (not shown) provided on the rear side (right side in FIG. 2) 12 of the apparatus main body 1.

Next, the configuration of the close contact state between the close contact type image sensor 9 of the document reading section 2 and the rotating roller 10 will be described.
This will be described in detail with reference to FIG. The close contact type image sensor 9 located between the feeding unit 7 and the discharging unit 11 is integrally attached to the holding member 13. The holding member is formed in an L shape, and has a rotation fulcrum 13a at one end and a concave groove 13b at the other end. Rotating fulcrum 13 of the holding member 13
a is the feed roller 8 near the contact type image sensor 9;
By attaching the torsion spring 14 to the roller shaft of FIG. 1A and attaching the torsion spring 14 to the roller shaft, a rotational force F acts on the holding member 13 in the counterclockwise direction in FIG. As described above, the rotation fulcrum 13a is positioned near the contact type image sensor 9 (for example, the distance L ₂ = 20 from the center of the rotation axis to the reading position in FIG. 1).
mm and the angle φ with the document transport surface = 15 degrees), and the distance from the reading position 9a to the rotation fulcrum 13a is minimized by providing the roller with a deviation angle α in the rotation direction of the holding member 13. To a minimum. As a result, the rotational force F of the holding member 13 is a component force of the y component and is substantially equal to the pressing force Fy acting toward the center of the rotating roller 10. As a result, the useless component force Fx of the x component becomes extremely small.
It is possible to ensure the close contact of the document 4 with the minimum necessary rotation force F.

Further, a bearing 10a of the rotating roller 10 is fitted in the concave groove 13b of the holding member 13, and the reading position 9a of the contact type image sensor 9 and the center of the rotating roller 10 are fitted by this fitting relationship. It is configured to match automatically. The shaft 15 is attached to a frame or side plate (not shown) with a degree of freedom (play) of about 0.5 mm, and when the bearing 10a is fitted into the concave groove 13b of the holding member 13. Contact image sensor 9 and rotating roller 10
Is configured to be accurately performed.
The CS roller 10 is formed of an elastic material such as a rubber material in order to improve the adhesion to the reading position 9a.

[Other Embodiments] In the above-described first embodiment, the shaft center on the feed roller side is used as the rotation fulcrum of the holding member, but the same effect can be obtained by providing this rotation fulcrum on the discharge roller side. It is clear that The same effect can be obtained by using a guide member, for example, a plate-like member, instead of the rotating roller.

[0018]

As described above, according to the present invention, by providing the rotation fulcrum of the holding member on the roller axis of the document conveying means near the contact type image sensor, the contact type image which is in the rotation direction of the holding member is provided. The sensor pressing direction is
For example, since the roller is oriented substantially in the axial direction of the rotating roller serving as the pressed member, it is possible to adhere the document with an efficient pressing force. Further, a concave groove is provided in a part of the holding member integrally formed with the contact image sensor, and the bearing of the rotating roller is fitted into the groove, so that the reading position of the contact image sensor and the rotating roller can be changed. Can be prevented, and accurate reading can be performed, and the optimum reading positional relationship can always be maintained. Further, since the axis of the roller in the vicinity of the contact type image sensor is used as the rotation fulcrum of the holding member, there is no need to provide a special member for the rotation fulcrum, and the most compact and inexpensive reading device is configured. be able to.

[Brief description of the drawings]

FIG. 1 is a principle explanatory diagram showing a configuration of a reading unit in a state of close contact in the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a reading unit by partially cutting the facsimile apparatus according to the present invention.

FIG. 3 is a cross-sectional view showing a configuration of a reading unit by partially cutting a conventional facsimile machine.

FIG. 4 is a principle explanatory view showing a configuration of a conventional reading unit in a contact state.

FIG. 5 is an explanatory diagram showing a relationship between a shift amount of a reading position of a reading unit and a floating amount of a document in a conventional facsimile apparatus.

[Explanation of symbols]

F is a rotational force, Fx and Fy are component forces, 1 is a main body of the apparatus, 2 is a document reading section, 3 is a document insertion slot, 4 is a document, 6 is a document discharge port, 8 is a feeding section, and 8a and 8b are feeding sections. Feed roller, 9 is a contact image sensor, 9a is a reading position, 10 is a rotating roller,
11 is a discharge unit, 11a and 11b are discharge rollers, 13 is a holding member,
13a is a rotation fulcrum, 13b is a concave groove, 14 is a torsion spring, and 15 is a shaft.

Claims (1)

(57) [Claims] A reading unit having a contact type image sensor for reading image information of the document in a contact state, and a rotating roller provided at a position facing the sensor; A holding member for bringing the document into close contact with a predetermined reading position of the image sensor, and a rotation fulcrum of the holding member to which the contact image sensor is attached is provided on a roller shaft of the document conveying means near the reading means. A reading device provided with a concave groove portion which is fitted to a shaft portion of the rotating roller in a part of the holding member.