JPH04148751A - Image reading device - Google Patents

Abstract

PURPOSE:To reduce the overall height of a reading device by forming pressing means with a flexible sheet so that a document sheet does not lift or vibrate but is brought into tight contact with a reading portion. CONSTITUTION:A document sheet is brought into tight contact with reading means 105 by means of document sheet pressing means comprising a flexible sheet 106a, and a flexible member 110b (a sponge rubber piece) for pressing the flexible sheet, and means 110a for pressing the flexible member 110b. This makes the pressing means of a flat structure to reduce the overall height of the entire device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an image information reading device used in a facsimile machine or the like, and in particular, the present invention relates to an image information reading device used in a facsimile machine, etc. The present invention relates to an image reading device that reads information.

[Prior Art] In reading devices such as facsimile machines, when reading image information of a document with a reading section such as a contact sensor, the document may rise or shake from the reading line of the reading section. In order to prevent the image information from becoming blurred due to the scanning, a pressure roller is placed at a position facing the reading section. Configured to read.

Here, the pressure roller is used to bring the original into close contact with the reading line of the reading unit, and for this reason, it is mainly made of rubber material so that the original can be brought into close contact regardless of the unevenness of the surface of the reading unit. A rubber roller consisting of is used.

Furthermore, the surface of the pressure roller is white because it is read by a reading unit before reading the image information of the original, and the read data is a reference color when reading the image information of the original.

That is, a white rubber roller is used as the pressure roller.

[Problems to be Solved by the Invention] However, when using a pressure roller, there is a space for arranging the pressure roller on the reading section, a gear, etc. for rotating the pressure roller in the same direction as the conveyance roller, etc. This requires a space for arranging the drive system, which has the disadvantage of increasing the overall height of the entire device.

In addition, if a pressure roller with a small diameter is used in order to reduce the overall height of the entire device, the curvature of the roller will increase, and the reflected light that is emitted from the light source of the reading section, reflected off the roller surface, and enters the reading section will be reduced. In order to reliably guide the light to the photoelectric conversion element of the reading section, it is necessary to improve the assembly accuracy of the reading section, the pressing roller, etc., which has the disadvantage of increasing costs and reducing productivity.

Furthermore, the pressure roller must have a high coefficient of friction against the original and a low coefficient of friction against the glass surface of the reading section to ensure reliable conveyance of the original. The disadvantage is that it is difficult to select a material that has

[Object of the Invention] The present invention has been made to solve the problems of the prior art described above, and its purpose is to reduce the overall height of the entire device and to guide reflected light to the reading section. It is an object of the present invention to provide a reading device equipped with a document pressing means that does not require high assembly accuracy and allows easy selection of material for the pressing means.

[Means and effects for solving the problem] A typical means of the present invention for solving the above problems is as follows: In an image reading device that reads image information by bringing a document into close contact with a reading means, the document is flexible. The document is brought into close contact with the reading means by a document pressing means having a flexible sheet, a flexible member for pressing the flexible sheet, and a means for pressing the flexible member.

In the means of the present invention, since the pressing means for pressing the original is a flexible sheet, it is possible to have a planar structure than before. Therefore, the overall height of the entire device can be reduced.

In addition, when reading the surface of the pressing means with the reading means, since the surface is flat, the reflected light reflected from the surface of the pressing means is used, unlike when a white rubber roller with a small diameter is used as the pressing means in the past. High assembly precision is not required to lead to the reading means.

Furthermore, the pressing means does not have a conveyance function, and there is no need to consider the coefficient of friction against the document and the reading means, unlike conventional white rollers - this makes it easier to select the material for the pressing means.

In addition, a polyester film or the like can be used as the flexible sheet, a sponge rubber or the like can be used as the flexible member for pressing it, and a weight can be used as the means for pressing the flexible member. It is also possible to use a pressing force due to weight or a spring.

[Embodiment] Next, an embodiment in which the reading device of the present invention is applied to a facsimile machine will be described with reference to the drawings.

FIG. 1 is an enlarged sectional view of a reading system portion of a facsimile machine, and FIG. 2 is a sectional view of the entire facsimile machine.

First, the general structure of the entire apparatus will be described with reference to FIG. 2. A document tray 101 extending diagonally upward and to the right from the apparatus main body 1 is capable of stacking a plurality of documents S. An optical reading system 100 for reading image information of a document S conveyed from the document tray 101 is arranged on the top surface of the apparatus main body 1, and a thermal head 201 is located at the lower left of the apparatus main body 1.
A recording system 200 including a cutter 203 and a cutter 203 is arranged. Further, an operation panel is arranged on the top surface of the optical reading system 100. The optical reading system 100 includes a document tray 1
01 is separated one by one by the separation roller 103 that is in pressure contact with the separation pressing piece 102, and then the document S stacked on the paper feed roller 1
The document S is conveyed to a contact sensor (contact type image sensor) 105 by a paper feed roller 104a or the like that is in pressure contact with the document S, and the image information of the document S is read while being pressed by a pressing means 106 to bring the document S into close contact with the contact type image sensor. Thereafter, the document S is ejected onto the recording cover by the ejecting roller 107a that is in pressure contact with the ejecting roller 107b.

The contact image sensor 105 uses an LE as a light source.
Light is irradiated from D105a onto the image information surface of the document S, and the reflected light reflected from the image information surface is sent to the contact image sensor 105.
Image information is read by forming an image on the photoelectric conversion element 105b configured on the top surface, and the read image information is transferred to the recording section of another machine in facsimile mode, or to the own device in copy mode. The units above the upper document guide 108, which guides the top surface of the document S, are configured to be openable and closable around a fulcrum 109, and are designed to prevent document jams. This is to facilitate processing and maintenance of the contact type image sensor and ADF.

Note that the document tray 101 has a slider 101 that can slide in a direction perpendicular to the conveyance direction of the document S (width direction of the document S).
A is provided so that both sides of the document S stacked on the document tray 101 can be aligned by the slider 101a.

Further, the recording system 200 drives a thermal head 201 based on an image signal from the contact image sensor 105, and the heating element thereof generates heat. The thermal head 201 is pressed from behind by a spring, and the platen roller 202 rotates in synchronization with the image signal, so image information is formed at a predetermined position on the recording paper S° (Thermal head 201 When printing is completed, the recording paper S' is conveyed by a predetermined amount by the platen roller 202, and the recording paper S' is conveyed by a predetermined amount by the cutter 20.
3, and again by the platen roller 202.
The series of operations is completed by returning the recording paper until the leading edge approaches the recording position of the thermal head 201.

In the facsimile mode, the image information is formed using the image signal sent from the other party's facsimile machine rather than the image signal from the contact type image sensor 105 described above.

Next, the optical reading system 100 will be described in detail with reference to the enlarged sectional view of FIG.

The pressing means 106 shown in FIG.
06a, one end of which is fixed onto the upper document guide plate 108 with a metal fitting 106b having a U-shaped cross section and a screw 106c.

The flexible sheet 106a is made of polyester film or the like, and presses the original S onto the reading line (photoelectric conversion element) 105b of the contact type image sensor 105.

Further, the surface of the flexible sheet 106a is read by the contact image sensor 105, and this read data is used as a reference color when reading the image information of the document S, such as a narrow document or a transparent document. In this case, it becomes the background color, so it is desirable that it be white.

An area of the flexible sheet 106a corresponding to the reading position is bonded to a weight 110a on the back side via a sponge rubber 110b. This weight 110a is made by bending a sheet metal, and its end portion is locked to the upper document guide 108 so as to be movable in the vertical direction.

The weight 110a and the sponge rubber 110b are pressed with a width of 10 mm centered on the reading position. A central portion of the flexible sheet 106a facing the reading line 105b protrudes in a slightly curved manner, and is movable in the vertical direction toward the inner surface of the central portion of the upper document guide 108. In addition, the weight of a weight 110a placed parallel to the reading line 105b acts on the reading line 105b. In this embodiment, the weight of this weight 110a is 40g.
It is set to about.

It is desirable that the sponge rubber 1lob interposed between the weight 110a and the flexible sheet 106a bends by about 0.5 to 1 mm when the above-mentioned weight is applied to the entire surface.

As in this embodiment, when the contact image sensor 105 does not have a short focus coupling lens, the depth of field is only about 50μ layers, and the flatness of the reading line 105b of the contact image sensor is ±150μ. In the case of variations, it is practically impossible to configure the weight with only a rigid body, but as in this example, a material (sponge rubber 110b) that is flexible in the pressing direction is used as the rigid weight 11O.
By interposing it between the weight 110a and the flexible sheet 106a, the weight of the weight 110a and the elasticity of the flexible sheet 106a allow even a contact type image sensor with poor flatness to be lifted off the reading line 105b. , to prevent it from shaking. Then, at this reading line 106b, the front IC! Light is emitted from the LED 105a, and the reflected light reflected from the image information surface forms an image on the photoelectric conversion element 105b, and the image information of the document S is read.

In this way, when the flexible sheet 106a is used instead of the conventional pressure roller (white rubber roller), in addition to being able to bring the original S into close contact with the reading line 105b with a lower load than the pressure roller, the pressing means 106 can be made flat to reduce the overall height of the entire device.

Furthermore, when obtaining reference color data for reading the image information of the document S by reading the surface of the flexible sheet 106a, it is possible to The reflected light reflected from the surface of the adhesive sheet 106a is transferred to the photoelectric conversion element 105 of the contact image sensor 105.
High assembly accuracy is not required to lead to b.

Further, since the sponge rubber 110b is interposed between the weight member 110a and the flexible sheet 106a, even if the contact image sensor 105 is a sensor with a small depth of field without a short focus lens, and the reading position is 105
Even if the flatness of b is poor, it is possible to reliably press the image information surface of the document against the reading position 105b of the contact image sensor 105.

Further, since the document S is not conveyed by the pressing means 106, there is more freedom in selecting the material of the flexible sheet 106a compared to a conventional pressing roller, and the selection is easy.

(Other Embodiments) In the embodiments described above, the case where the present invention is applied to a facsimile machine is shown, but the present invention may also be applied to a photographic machine or other image reading device.

In addition, in the above embodiment, the weight is 110 m, the sponge rubber is 11 m, and the weight is 110 m.
0b, an example was given in which the flexible sheets 106a were all glued together, but they do not necessarily have to be glued together, and the same effect can be obtained even if they are separated and combined. .

[Effects of the Invention] As described above, the present invention uses a pressing means made of a flexible sheet to press the original against the reading section of the reading means and bring it into close contact with the reading section of the reading means to prevent it from lifting or shaking. , the pressing means can be formed planar, and therefore the overall height of the entire device can be reduced.

Furthermore, since the pressing means is flat, higher assembly precision is not required to guide the reflected light to the reading section than with conventional pressing means having a curved surface.

In addition, since a flexible member is interposed in the pressing direction between the weight of the pressing means and the flexible sheet, the adhesion is improved, making it suitable for contact type image sensors with a small depth of field. is also available.

Further, since the pressing means itself does not have a conveying function, material selection is not difficult as in conventional pressing rollers, and can be easily selected.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an optical reading system in a facsimile machine embodying the present invention. FIG. 2 is an enlarged sectional view of the reading system of FIG. 1. 104... Paper feed roller pair, 107... Paper ejection roller pair, 105... Close contact type image sensor, 105a...
LED array, 105b...reading line (reading position)
Gatsu photoelectric conversion element, 106a... flexible sheet, 11
0a... Weight, 110b... Sponge rubber (flexible member). Agent Patent Attorney Sumihira Yamashita

Claims (2)

[Claims] (1) In an image reading device that reads image information by bringing a document into close contact with a reading means, the document is placed between a flexible sheet, a flexible member that presses the flexible sheet, and a flexible member that presses the flexible sheet. An image reading device characterized in that the document is brought into close contact with the reading device by means of a document pressing device having a pressing device. (2) The image reading device according to claim 1, wherein the means for pressing the flexible member is a weight member.