JPH0614558Y2 - Image reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an image reading device, and more particularly to an image reading device in which a plurality of line image sensors are arranged in a staggered manner in the sub-scanning direction.

[Conventional technology]

Conventionally, in this type of image reading apparatus, as shown in FIG. 3, for example, a document (not shown) is pressed against the platen glass 32 by pressing a single film-shaped document holder attached to a guide plate 36. It was done by member 37.

[Problems to be solved by the device]

In the above-described conventional image reading apparatus, since the original is pressed against the original platen glass 32 by the single film-like original pressing member 37, the front side (see FIG. 3) as viewed in the sub-scanning direction. And the right side) of the line image sensors 35a and 35c, and the strength of the document pressing member 37 when pressing the document at the reading position A,
Reading position B by the line image sensor 35b arranged on the rear side (left side in FIG. 3) when viewed from the sub-scanning direction.
When comparing the strength of the strain of the document pressing member 37 when pushing the document with, the reading position B is considerably inferior to the reading position A, and the document floats at the reading position B, and the line image sensor There is a problem that the image may not be clearly read by 35b. In particular, in the case of a thick original or a corrugated original, this problem becomes remarkable.

SUMMARY OF THE INVENTION In view of the above points, an object of the present invention is to provide an image reading apparatus capable of clear reading of an image without floating even in the case of a thick original or a corrugated original.

[Means for Solving the Problems]

The image reading device of the present invention is an image reading device in which a plurality of line image sensors are arranged in a staggered manner in the sub-scanning direction, and a guide plate arranged in the main scanning direction and the line image sensor attached to the guide plate. A film-shaped first document pressing member which presses the document correspondingly, and the first line image sensor which is attached to the guide plate and which is on the rear side of the line image sensor when viewed from the sub-scanning direction. It is characterized in that it is provided with a film-shaped second original document pressing member for pressing the original document via the original document pressing member.

[Action]

In the image reading apparatus of the present invention, the guide plate is arranged in the main scanning direction, and the film-shaped first document holding member is attached to the guide plate to hold the document corresponding to the line image sensor, and the film-shaped second document holding member. An original pressing member is attached to the guide plate and presses the original through the first original pressing member corresponding to the line image sensor on the rear side of the line image sensor when viewed from the sub-scanning direction.

〔Example〕

 Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing the structure of an image reading apparatus according to an embodiment of the present invention. In the image reading apparatus of this embodiment, the document table includes a front document table 11, a document glass plate 12, and a rear document table 13.

Inside the front-side document table 11, a plurality of front-side feed rollers 51 are attached to a rotary shaft 51 a so as to be exposed on the upper surface of the front-side document table 11. In addition, a paper stopper 52 is provided in the front-side document table 11 to support the spindle 5.
It is rotatably supported by 2a and has a solenoid 5 at one end.
It is connected to the plunger of No. 3 and is arranged such that the other end (tip) of the plain is projected on the upper surface of the front side document table 11 by the elastic tension of the coil spring 54. Note that reference numeral 55
Reference numerals 56 and 56 respectively denote paper position sensors.

The platen glass 12 has an upper surface on the front side platen 11
Is arranged so as to be slightly lower than the upper surface of the original, and on the lower surface side of the original table glass 12, the left and right ends of the original (not shown) are located on the front side (the right side in FIG. 1) when viewed from the sub-scanning direction. Two line image sensors 15a and 15c are arranged so as to correspond to the central portion, and one line image sensor is arranged on the rear side (left side in FIG. 1) when viewed from the sub-scanning direction so as to correspond to the central portion of the document. 15b is arranged. That is, the three line image sensors 15a, 15b and 15c are arranged in a staggered pattern in the sub-scanning direction.

Further, a guide plate 16 is arranged on the upper surface side of the platen glass 12 with a slight gap so that the longitudinal direction is the main scanning direction. As shown in FIG. 2, the guide plate 16 is on the front side when viewed from the sub-scanning direction (the diagonally upper left side when viewed in FIG. 2).
A first bent portion 16a that is slightly tilted is provided, and a second bent portion 16b that is slightly tilted due to a cut is formed in the middle when viewed from the sub-scanning direction. A base end of a white, smooth and elastic first original document pressing member 17 made of, for example, a film of polyester resin is attached to the first bent portion 16a, and a free end of the first original document pressing member 17 is It extends from the guide plate 16.
In addition, the second bent portion 16b has a second smooth and elastic second white film made of a polyester resin or the like.
The original end of the original pressing member 18 is attached, and the free end of the second original pressing member 18 extends from the guide plate 16. The first document pressing member 17 and the second document pressing member 18 are selected to have appropriate thickness according to the strength of the material to be formed.

The rear document table 13 is arranged such that its upper surface is slightly lower than the upper surface of the document table glass 12, and a plurality of rear feed rollers 6 are provided in the rear document table 13.
The rotary shaft 6 so that 1 is exposed on the upper surface of the rear document table 13.
It is attached to 1a. Reference numeral 62 indicates a paper position sensor.

On the other hand, a front side pinch roller 71 is rotatably attached to a shaft 71a supported by a crank 72 so as to face the front side feed roller 51 in an upper cover (not shown) of the image reading device. , The crank 72 is a shaft 74 installed between the inner frames 21.
It is rotatably attached to a and is urged clockwise (as viewed in FIG. 1) by a coil spring 73 so that the plain is brought into contact with the front side pinch roller base 74 and stopped. The front side pinch roller base 74 is also rotatably attached to the shaft 74a, and a front side cam pin 75 is planted at one end of the front side pinch roller base 74. The front side cam pin 75 is a rear surface of the cam member 90. It is inserted in the cam groove 91 (not shown) on the side (see FIG. 1).

In addition, the rear feed roller 6 is provided in the upper cover.
1, a rear side pinch roller 81 is rotatably attached to a shaft 81a that is rotatably supported by a crank 82, and the crank 82 is rotatably attached to a shaft 84a that is installed between the inner frames 21. The plain 83 is urged in the counterclockwise direction (see FIG. 1) by the ridges 83, and the plain is brought into contact with the rear side pinch roller base 84 and stopped. The rear side pinch roller base 84 is also rotatably attached to the shaft 84a.
A rear side cam pin 85 is planted at one end of 4, and the rear side cam pin 85 is inserted into a cam groove 91 on the front side (see FIG. 1) of the cam member 90.

The cam member 90 is fixed to the rotary shaft 92 that is provided between the inner frames 21, and the cam grooves 91 are formed on both surfaces thereof as described above.

Further, the lock lever 2 is provided outside the inner frame 21.
2 is biased in the counterclockwise direction (as viewed in FIG. 1) and the shaft 22a
The lock lever 22 is rotatably supported, and the tip claw of the lock lever 22 is adapted to engage with a locking pin 31 that is erected on the side frame 3. In FIG. 1, reference numeral 23 indicates a support shaft that rotatably supports the upper cover with respect to the document table.

Next, the operation of the image reading apparatus of this embodiment having the above structure will be described.

In the initial state, the front side pinch roller 71 is at a position separated from the front side feed roller 51, and similarly, the rear side pinch roller 81 is at a position separated from the rear side feed roller 61. Further, the paper stopper 52 is
The tip is projected on the upper surface of the front document table 11.

From this initial state, when a document is placed on the front side document table 11 and fed in until the leading edge of the document comes into contact with the paper stopper 52, the paper position sensors 55 and 56 set the size of the document at a predetermined position. Is detected.

Next, when a reading start instruction button (not shown) is operated from the state of setting the original, the plunger of the solenoid 53 is actuated against the contraction elastic force of the coil spring 54, and the paper stopper 52 is rotated about the shaft 52a. It rotates clockwise (as viewed in FIG. 1) and retracts from the position where the front end of the paper stopper 52 projects to the upper surface of the front document table 11.

Further, the front side feed roller 51 and the rear side feed roller 61 start to rotate, and at the same time, the cam member 90 also rotates, and the action of the cam groove 91 and the cam pin 75 causes the front side pinch roller base 74 to move the shaft 74a. Rotate clockwise around the front pinch roller 71
Is elastically contacted with the front feed roller 51 by the elastic force of the coil spring 72. Therefore, the original is pinched by the front side pinch roller 71 and the front side feed roller 51, and the original is fed into the image reading apparatus as the front side feed roller 51 rotates.

A document passing on the platen glass 12 has line image sensors 15a and 15c on the front side when viewed from the sub-scanning direction.
At the reading position A by, the first document pressing member 17 holds the image and prevents it from floating, and the line image sensors 15a and 15c read the image clearly. Further, at the reading position B by the line image sensor 15b on the rear side when viewed from the sub-scanning direction, the line image sensor 15 is prevented from being lifted by being pressed by the first document pressing member 17 and the second document pressing member 18.
The image is clearly read by b.

When the leading edge of the document reaches the rear-side document table 13, the paper position sensor 62 detects the leading edge of the document.

Next, by the action of the cam groove 91 and the cam pin 85, the rear side pinch roller base 84 rotates counterclockwise around the shaft 84a, and the rear side pinch roller 81 causes the coil spring 83.
Is elastically contacted with the rear side feed roller 61. Therefore, the document is nipped by the rear side pinch roller 81 and the rear feed roller 61, and the document is sent out of the image reading apparatus as the rear feed roller 61 rotates.

The operation timings of the front side pinch roller 71 and the rear side pinch roller 81 are set so that the front side pinch roller 71 rises as soon as the rear side pinch roller 81 lowers in order to prevent the slack of the document. There is.

[Effect of device]

As described above, according to the present invention, a film-shaped first document pressing member that is attached to the guide plate and presses the document corresponding to the line image sensor, and a rear side when attached to the guide plate when viewed from the sub scanning direction. By providing a film-shaped second document pressing member that presses the document via the first document pressing member corresponding to the line image sensor on the side, even in the case of a thick document or a corrugated document, etc. The effect is to prevent the original from floating and to enable clear reading of the image.

Further, since the document is prevented from floating with an extremely simple configuration including the first document pressing member and the second document pressing member, when the document is prevented from floating by using a roller or the like. Compared with the above, there is an effect that maintenance such as cleaning and replacement can be easily performed.

[Brief description of drawings]

FIG. 1 is a sectional view showing the construction of an image reading apparatus according to an embodiment of the present invention, FIG. 2 is a perspective view of the guide plate in FIG. 1 seen from the bottom side, and FIG. 3 is a conventional image reading apparatus. It is sectional drawing which shows the principal part of an apparatus. In the figure, 12 ... Original platen glass, 15a, 15b, 15c ... Line image sensor, 16 ... Guide plate, 16a ... First bent portion, 16b ... Second bent portion, 17 ... A first document pressing member, 18 ... A second document pressing member.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References Japanese Patent Laid-Open No. 2-61632 (JP, A) Japanese Patent Laid-Open No. 2-287342 (JP, A) Actual Opening Flat 1-147564 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. An image reading apparatus in which a plurality of line image sensors are arranged in a staggered manner in a sub-scanning direction, a guide plate arranged in the main scanning direction, and a guide plate attached to the guide plate corresponding to the line image sensor. A film-shaped first original pressing member for pressing an original, and the first original pressing member which is attached to the guide plate and corresponds to a line image sensor on the rear side of the line image sensor when viewed from the sub-scanning direction. An image reading apparatus, comprising: a film-shaped second document pressing member that presses a document through the sheet.