JPH02238765A - Image reading device - Google Patents

Abstract

PURPOSE:To attain stable reading with high quality without increasing a load to a drive system carrying an original by providing a guide member regulating the original so as to keep a prescribed distance to the original from a read means at a position opposite to the read means. CONSTITUTION:A paper supply roller 2 and a paper discharge roller 9 are provided respectively at a carrier direction upperstream position and a carrier direction downstream position of a read position 4d as a carrier means. Then a guide member 5 regulating the original 1 in a way that the original face has a prescribed distance to the read position 4d is provided in an escaping way at a position opposite to a contact sensor 4 as a read means. Thus, the original 1 is surely carried without increasing the load of the drive system carrying the original 1. Moreover, dirt on the original 1 is not transferred to the guide member 5, correct white balance is taken and picture reading with high quality is maintained for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image reading device that closely reads an image of a document. [Prior Art] In general, the reading means of relatively small image reading devices such as facsimiles are made up of a lens and a CCD because they are unitized and can be made smaller, and they are easy to maintain and handle. Close-contact sensors are often used in the optical systems that are constructed. However, the self-occurring lens array normally used as this contact type sensor has a depth of field of ±0. The depth was as shallow as 3mm, and reading outside this range was difficult. Therefore, in the conventional image reading apparatus using a contact type sensor, it is necessary to bring the surface of the document into close contact with the contact type sensor, and an example of such an image reading apparatus is shown in FIG.

Here, 101 is a manuscript, and 102 is this manuscript 101
103 is a paper feed roller as a feeding means, 104 is a detection sensor for detecting the presence or absence of the original 101, 105 is a contact type sensor as a reading means,
106 is a reading position of this contact type sensor 105. 107 is a white roller as a discharging means, and 108 is a contact type sensor 105 attached to this white roller 107.
It is a spring that presses down. In the above configuration, when the original 101 is fed from between the original guide plates 102, this original 101
1 is fed between a contact type sensor 105 and a white roller 107 by a paper feed roller 103, and this contact type sensor 105 is brought into close contact with the document 101 by a panel 108, so that the image is read within the above-mentioned depth of field. At the same time, the original 10 is rotated by the white roller 107.
1 is the one to be discharged. The contact type sensor 105 uses the white color of the white roller 107 as a white reference, and corrects the output waveform of the read image to achieve white balance.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional example, the white roller 107 and the contact sensor 105 are not connected until the reading of the original 101 is completed and the next original 101 is read, or after the original 101 is read. Since the white roller 107 is in direct contact with
The load on the motor (not shown) driving the motor increases significantly. Here, in order to reduce the load on the motor, it is sufficient to lower the friction coefficient between the contact type sensor 105 and the white roller 107, but it is better to reduce the friction coefficient of the platen glass used on the surface of the contact type sensor 105. Although it is possible to lower the friction coefficient of the white roller 107, doing so would significantly reduce the document conveying ability of the white roller 107. The coefficient of friction between the contact type sensor 105 and the white roller 107 could not be lowered, and the load on the motor had no choice but to increase.

In addition, since the white roller 107 is constantly pressed against the contact sensor 105, dirt attached to the back side of the original 101 may be directly transferred to the roller surface, or
The dirt on the surface of the white roller 107 may be transferred indirectly through the sensor surface, resulting in deterioration of the whiteness of the white roller 107. Then, the contact type sensor 105 not only cannot properly maintain the white balance and deteriorate the quality of the image, but also causes the background to become dirty when reading an image of a highly transparent document 101 or a small document 101.
Since the roller surface must be cleaned frequently, it is also disadvantageous in terms of maintenance.

The present invention has been made to solve the problems of the prior art described above, and its purpose is to stably perform high-quality reading without increasing the load on the drive system that conveys the original. It is in. [Means for Solving the Problems] In order to achieve the above object, the present invention includes a conveyance means for conveying a document having image information, and an image of the document conveyed by the conveyance means at a predetermined reading position. In the image reading device, the conveying means has a feeding means and a discharging means at a position upstream in the conveying direction and a position downstream in the conveying direction of the reading position, respectively, A guide member is retractably provided at a position facing the means for regulating the document so that the surface of the document is maintained at a constant distance from the reading position.

[Function] A guide member is provided at a position opposite the reading means to regulate the original so that the original is kept at a certain distance from the reading means, so that a roller or the like can be pressed against the reading position of the reading means. Images can be read without any problems. Further, since the surface of the guide member does not directly contact the reading position and does not press the document, there is no risk of dirt from the document being transferred to the guide member.

[Example] A first example of the present invention is shown in Fig. 1(a). (b) to FIG. 4, and the configuration thereof will be explained.

1 is a document having image information, 2 is a paper feed roller that feeds the document 1, and 3 is a detection sensor that detects the edge of the document 1. 4 is a contact type sensor as a reading means, and LE
Consisting of a D array 4a, a SELFOC lens array 4b, and a light receiving element 4c, the reading position 4d
is equipped with a platen glass. 5 is a pressure spring 6
This is a guide member that restricts the original l to the reading position 4d of the contact type sensor 4, and this guide member 5 has a facing surface 5a corresponding to the reading position 4d of the contact type sensor 4, as shown in FIG. An oblong guide hole 5b is formed in the extended end of the facing surface 5a, and a guide lever 50 is further formed in the end. A white background portion 5d is formed on the opposing surface 5a, and guide spacers 5e are formed at three points in the vicinity of the white background portion 5d.
is installed protrudingly. 7 is a fixed shaft that engages with the guide hole 5b of the guide member 5 and rotatably supports the guide member 5;
9 is a document guide plate for easily guiding the document 1; 9 is a discharge roller for discharging the document 1; and 1O is a microswitch that detects the position of the guide lever 50 which is moved up and down by the cam 11. As shown in FIGS. 3 and 4, 12 is a drive motor, and this drive motor l2
The boot 4 attached to the rotating shaft l3 is connected to the discharge roller clutch pulley l7 and the cam clutch pulley 18 via the motor roller belt l5 and the motor cam belt l6.
The driving force is transmitted to each. Here, the paper ejection roller clutch pulley l7 is attached to a shaft 19 via a paper ejection roller clutch 17a, and a paper ejection roller pulley 20 is further attached to this shaft l9. The driving force is transmitted to the paper feed roller pulley 22 via the inter-boot belt 2l. Further, the cam clutch pulley 18 is attached to a shaft 23 via a cam clutch 18a, and a cam l1 for actuating the guide lever 50 of the guide member 5 is attached to this shaft 23.

By the way, the paper discharge roller clutch 17a provided on the paper discharge roller clutch pulley l7 and the cam clutch 18a provided on the cam clutch pulley l8 each have a one-way clutch structure, and the paper discharge roller clutch 17a has a one-way clutch structure. As shown in Figure 3, when the discharge roller clutch pulley l7 rotates in the direction of arrow C in the figure, the driving force is not transmitted to the shaft l9, but only when it rotates in the direction of arrow D in the figure. Communicate. Similarly, the cam clutch 18a transmits driving force to the shaft 23 only when the cam clutch boo IJ18 rotates in the direction of arrow E in the figure, and transmits the driving force when it rotates in the direction of arrow F in the figure. Don't communicate. That is, when the drive motor l2 rotates in the direction of arrow A in the figure (hereinafter referred to as forward rotation), the paper discharge roller clutch bobbin 17 rotates in the direction of arrow D in the figure, and the cam clutch bobbin l8 rotates in the direction of arrow D in the figure.
rotates in the direction of arrow F in the figure, the shaft 19 of the discharge roller clutch pulley l7 is driven, and the cam clutch pulley l7 is driven.
8 shaft 23 is not driven. Furthermore, when the drive motor l2 rotates in the direction of arrow B in the figure (hereinafter referred to as reverse rotation), the paper ejection roller clutch boolean 17 rotates in the opposite direction to the forward rotation described above.
The shaft 19 of the cam clutch boot 18 is not driven, and the shaft 2 of the cam clutch
Only 3 is driven.

Next, an example of the operation of this embodiment will be explained. First, when the main body of the apparatus is turned on or when the setting of the document l is detected, the drive motor 12 rotates in reverse. Then, the driving force of this drive motor l2 is transmitted to the shaft 23, and the cam 11 attached to this shaft 23 rotates, as shown in FIG.
As shown in b), this cam l1 pushes down the guide lever 5C of the guide member 5. And guide lever 50
When the guide lever 50 is pushed down by a predetermined amount by the cam l1, the microswitch lO in contact with the end of the guide lever 50 is turned on, and the drive motor l2 stops rotating. Here, the opposing surface 5a of the guide member 5 is maintained at a sufficient distance from the reading position 4d of the contact type sensor 4 (hereinafter referred to as a standby state). Therefore, when the next document 1 having image information is sent through the document guide plate 8, the drive motor l2 rotates in the forward direction, and the shaft l9
to drive. The rotation of this shaft l9 is transmitted to the paper ejection roller pulley 20 and also to the paper feed roller boob 922 via the inter-pulley belt 2l, and the paper ejection roller pulley 2o and the paper feed roller pulley 22 are attached to each other. The driving force is also transmitted to the paper discharge roller 9 and the paper feed roller 2, respectively. In other words, the leading edge of the original 1 sent from between the original guide plates 8 touches the detection sensor 3.
The paper is conveyed by the paper feed roller 2 until it is detected by the paper feed roller 2. Then, when the document l is further conveyed by a predetermined amount, the drive motor l2 changes the direction of rotation from forward rotation to reverse rotation. That is, when the rotation is in the forward direction, the document 1 is conveyed in a standby state, and when the rotation is changed to the reverse rotation, the conveyance of the document 1 is stopped and the rotation of the cam 11 is stopped, as shown in FIG. 1(a). Accordingly, the guide member 5 is pressed to the reading position 4d of the contact type sensor 4 by the pressing spring 6 (hereinafter referred to as the operating state). Further rotation of the cam l1 turns off the microswitch lO, and the drive motor 12 again changes its rotational direction from reverse rotation to forward rotation. Incidentally, in the above operating state, the facing surface 5a of the guide member 5 is pressed against the contact type sensor 4 via the guide spacer 5e provided protrudingly from the facing surface 5a, and the projection of the guide spacer 5e causes the document 1 to be A paper path portion P is formed when conveying and reading. That is, the thickness of the normal original 1 is 0. Since it is 3 mm or less, the flatness of the reading position 4d of the reading sensor 4 and the facing surface 5a of the guide member 5 is set to 0. In addition to keeping it below 1mm,
The protrusion amount of the guide baser 5e is set to 0. By setting it to about 4mm, it is 0. The paper path portion P is formed in the range of 3 mm to 0.5 mm, and the depth of field of the contact type sensor 4 is ±0.
Even if the depth is as shallow as 3 mm, reading is possible without any problems. When the detection sensor 3 detects the end of the document l sent to the paper bus section P by the paper feed roller 2, a predetermined amount of the document 1 is further read, and the document 1 is ejected by the paper ejection roller 9. The drive motor 12 then stops. Here, if the next document l exists, it enters the standby state again and repeats the above series of operations, and if document 1 is no longer available, it is ejected, and after a predetermined period of time, the device main body is This automatically turns off the power.

Therefore, in this embodiment, it is possible to achieve white balance by using the white background portion 5d formed on the facing surface 5a of the guide member 5 as a reference white color without using a white roller. Furthermore, the guide hole 5b formed in the guide member 5 is shaped like an ellipse so that its movement with respect to the fixed shaft 7 is not determined uniquely, so that the guide member 5 can be used as a contact type sensor 4. Good pressing is possible.

When the guide member 5 in this embodiment regulates the original l, it moves so as to extend the original 1 from the upstream side in the conveying direction of the reading position 4d to the position facing the reading means, as shown in FIGS. As shown in b), even if the document 1 has a curled or folded edge, it will not buckle. Further, by conveying the document 1 and moving the guide member 5 using the forward and reverse rotations of one motor, the apparatus can be made smaller and costs can be reduced.

Next, a second embodiment of the present invention is shown in FIG. 5, and the same parts as in the first embodiment will be described with the same reference numerals. The boob 14 of the drive motor l2 in this embodiment transmits driving force to the intermediate roller 25 via the belt 24, and the rim portion 26 of the intermediate roller 25 abuts the outer peripheral portion of the second paper ejection roller clutch boob 927. The driving force is then transmitted to the second paper ejection roller clutch boolean 27. The second paper discharge roller clutch pulley 27 is attached to the shaft 19 via a second paper discharge roller clutch 27a which has a one-way clutch structure similar to the paper discharge roller clutch 17a.

Therefore, it is possible to transport the document 1 even when the drive motor l2 rotates in the reverse direction.

The other configurations and functions are the same as those of the first embodiment, so their explanation will be omitted. In the embodiment described above, the guide member 5 is retracted by rotational movement, but it may be moved perpendicularly to the reading position 4d of the contact type sensor 4.

Further, the operation of the guide member 5 is not limited to the cam 11, and may be performed using a gear or the like.

[Effects of the Invention] As explained above, according to the present invention, an image can be read without pressing a roller or the like against the reading position of the reading means, so that the load on the drive system for conveying the document is not increased. Reliable transportation can be performed.

Additionally, by preventing dirt from the original from being transferred to the guide member, white balance can be maintained correctly and high-quality image reading can be maintained for a long period of time.

[Brief explanation of drawings]

Figure 1(a). (b) is a cross-sectional view showing the first embodiment of the present invention, FIG. 2 is a perspective view showing the main parts of FIG. 1, FIG. 3 is a side view showing the drive system of FIG. 1, and FIG. FIG. 3 is a top view of FIG. 3, FIG. 5 is a top view of the drive system in the second embodiment of the present invention, and FIG. 6(a). (b) is a sectional view showing an example of the operation of the present invention, and FIG. 7 is a sectional view showing a conventional example. Explanation of symbols 1...Document 2...Paper feed roller 3...Detection sensor 4...Contact type sensor 5...Guide member 6...Press spring 7...Fixed shaft 8...
Document guide plate 9...paper ejection roller lO...micro switch 11...cam l4...booley 15...motor roller belt 16...motor cam belt 17...t non-paper roller clutch booley 18...Cam clutch pulley 20...Paper discharge roller pulley 2]...Boob belt 22...Paper feed roller pulley 24...Belt 5a Fig. 2 Fig. 3 Fig. 6 (b) 7 figure

Claims (1)

[Scope of Claims] An image reading device comprising a conveying means for conveying a document having image information, and a reading means for closely reading an image of the document conveyed by the conveying means at a predetermined reading position, The conveying means has a feeding means and a discharging means at an upstream position in the conveying direction and a downstream position in the conveying direction of the reading position, respectively, and at a position facing the reading means, the document surface is at a certain distance from the reading position. An image reading device characterized in that a guide member for regulating the original document is retractably provided.