JP3248976B2 - Image reading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus used for a facsimile, a copying machine, a scanner and the like.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 13, a white roller 6 is rotatably provided on a reading surface 5 of a contact sensor 4 having a light source 1, a lens 2, and a photoelectric conversion element 3 such as a CCD image sensor. A separation unit 7 is provided upstream of the sensor 4,
Discharge rollers 8 and 9 are disposed downstream of the contact sensor 4 so as to be in contact with each other, and the reflected light from the white roller 6 is input by the contact sensor 4 to perform shading correction, and then separated and sent by the separation unit 7. The image of the document 10 is used as the contact sensor 4
There is an image reading device that reads the image by using the image reading device.

In such an image reading apparatus, since the original 10 is pulled out by the white roller 6 against the load of the separation section 7, the friction coefficient of the white roller 6 is increased, and the white roller 6 is pressed against the contact sensor 4. You need to increase your power.
As a result, the load torque of the white roller 6 increases until the document 10 reaches the white roller 6, so that the white roller 6 must be driven by a motor with a large output.
In the process of transporting the original 10 by the white roller 6, the image surface of the original 10 is pressed against the reading surface 5 (transparent cover glass) of the contact sensor 4 by the white roller 6, so that the reading surface 5 becomes dirty. A white roller 6 is attached to the dirty reading surface 5.
Is pressed, the white roller 6 itself becomes dirty, and as a result,
Proper shading correction cannot be performed, and the image quality deteriorates.

In view of the above, Japanese Patent Application Laid-Open No. 58-242 discloses
A proposal as disclosed in Japanese Patent Publication No. 68 has been made. Hereinafter, the contents are shown in FIG. 14 and FIG. Portions having the same structure as the portions described in FIG. 13 are denoted by the same reference numerals, and description thereof is omitted. That is, transport rollers 11 and 12 for transporting the document 10 are provided between the close contact sensor 4 and the separation unit 7. Auxiliary rollers 6a having a large outer diameter are provided at both ends of the white roller (rubber roller) 6. By bringing these auxiliary rollers 6a into contact with both sides of the reading surface 5 of the contact sensor 4, the reading surface 5 and the white roller 6, a gap s is secured. Therefore, the load torque of the white roller 6 is reduced, and the stain on the reading surface 5 is reduced. In addition, as described in Japanese Utility Model Laid-Open No. 2-68565, there is a configuration in which a plurality of small-diameter portions are formed on the outer periphery of a platen roller in contact with a contact sensor, and the small-diameter portions are white.

There is also a proposal as disclosed in Japanese Patent Application Laid-Open No. 58-24269. Hereinafter, the contents are shown in FIG. That is, transport rollers 11 and 12 for transporting the document 10 are provided between the close contact sensor 4 and the separation unit 7. The white roller (document pressing roller) 6 is rotatably held by a metal fitting 13 that rotates about the axis of the discharge roller 9. Therefore, by rotating the metal fitting 13 upward to separate the white roller 6 from the contact sensor 4,
The reading surface 5 of the white roller 6 and the contact sensor 4 can be cleaned.

Further, there is a proposal disclosed in Japanese Patent Application Laid-Open No. 3-97363. In this proposal, as shown in FIG. 17, a white synthetic paper 25 is stuck on the inner surface of a translucent white polyester film 24, a weight 26 by a roller is placed on the white synthetic paper 25, and the original is Is described on the reading surface of the contact sensor 4.

[0007]

In the apparatus shown in FIGS. 14 and 15, since the original 10 is pulled out of the separation section 7 by the conveying rollers 11 and 12, the pressing force of the auxiliary roller 6a against the contact sensor 4 can be reduced. Since the white roller 6 that rotates integrally with the auxiliary roller 6a is floating above the reading surface 5, the load torque of the white roller 6 can be reduced. However, the gap s varies due to the manufacturing error of each part, and the thickness of the document 10 is not constant, so that the document 10 may not be able to be brought into close contact with the reading surface 5 of the contact sensor 4. Image quality is poor. Instead of the white roller 6, it is actually open flat 2-685.
Even if a platen roller described in Japanese Patent Application Publication No. 65-65 is used, since the platen roller is substantially the same as the white roller 6, the above problem cannot be solved.

FIG. 16 shows a white roller 6.
However, since the white roller 6 is in contact with the original 10 only by its own weight of the metal fitting 13 and the white roller 6, if the hardness of the white roller 6 is high, a sufficient nip amount cannot be obtained. Insufficient transport force of 10. If the rotation of the metal fitting 13 is not smooth due to manufacturing variations or the like, the nip amount is further affected. Further, since the white roller 6 is pressed against the reading surface 5 until the document 10 arrives, when the hardness of the white roller 6 is low, the load torque of the white roller 6 increases. In FIG. 17, the polyester film 24 can simply press the original by the close contact sensor, but does not have a function of transporting the original.

[0009]

According to the first aspect of the present invention,
A contact sensor whose reading surface is opposed to the document conveying path is provided, and a flexible belt that presses the reading surface of the contact sensor with its own elasticity only by its own elasticity with a predetermined length in the document conveying direction is rotatably provided. , Forming the belt with a transparent elastic body,
At least the inside of this belt faces the reading surface of the contact sensor.
A white reference member was provided in which the opposite side was colored white .

[0010] According to a second aspect of the invention, in the image reading apparatus according to claim 1 Symbol mounting, the friction coefficient on the outer peripheral surface of the belt to form a lower coating.

According to a third aspect of the present invention, in the image reading apparatus according to the first or second aspect , a rotating member driven by a driving portion and a flexible belt pressed against the rotating member are provided. A high friction portion was formed on at least one of the body and the belt at a contact portion between the two.

The invention according to claim 4 is the invention according to claim 1, 2, or
3. In the image reading apparatus described in 3, the regulating means for regulating the movement of the belt in the width direction is provided.

According to a fifth aspect of the present invention, in the image reading apparatus of the fourth aspect, a high friction portion is formed integrally with the regulating means.

The invention according to claim 6 is the invention according to claim 1, 2 or
In the image reading device described in Item 4, a rotating body is formed by fitting a cylindrical white reference member and a cylindrical high friction member around the outer periphery of a roller body that is long in the width direction of the belt.

[0015]

According to the first aspect of the present invention, the reflected light from the white reference member can be input to the contact sensor through the transparent belt, and the white reference member can be prevented from being stained by the belt. Shading correction can be performed stably.

According to the second aspect of the present invention, since the friction coefficient of the reading surface of the contact sensor and the belt that presses the original can be reduced, the fluctuation in the load torque of the belt can be reduced and the belt can be driven by a motor having a small torque. It becomes possible.

According to the third aspect of the present invention, the friction coefficient of the contact portion between the rotating member and the belt can be increased by the high friction portion. The feed amount can be determined accurately.

According to the fourth aspect of the present invention, since the movement of the belt in the width direction can be restricted by the restricting means, the document can be conveyed accurately.

According to the fifth aspect of the invention, the rotation of the rotating body is reliably transmitted to the belt by the high friction portion, and the movement in the width direction of the belt can be restricted by the restricting means. By integrally forming the means, the number of parts and the number of assembling steps can be reduced and cost can be reduced.

[0020] According to a sixth aspect of the invention, it can be reliably transmitted to the belt rotation of the rotary member by the high friction member, also the shading correction by inputting the reflected light from the white reference member in contact sensor It can be carried out. Since the rotating body having the property of enhancing the rotation transmission efficiency and the reference for shading correction is formed by the roller body, the high friction member, and the white reference member, the material of the roller body which is the main part of the rotating body can be widely covered. And cost can be reduced.

[0021]

An embodiment of the present invention will be described with reference to FIG. The same parts as those described in the conventional example are denoted by the same reference numerals, and description thereof is omitted (the same applies hereinafter). A flexible belt 14 is provided to face the reading surface 5 of the contact sensor 4. Transport rollers 11 and 12 for transporting a document are disposed upstream of the contact sensor 4, and discharge rollers 8 and 9 are disposed downstream of the contact sensor 4. Belt 14
Is held between rotating bodies 15 and 16. Either of these rotating bodies 15 and 16 is connected to a motor (not shown) as a driving unit. In addition, belt 1
A guide member 17 is provided inside of 4. Belt 1
Reference numeral 4 is in contact with the reading surface 5 of the close contact sensor 4 with a sufficient nip amount L in the document conveyance direction only by its own elasticity.

In such a configuration, the original is supplied in the direction of the arrow, is transported leftward by the transport rollers 11 and 12, and is further transported by the belt 14 which is rotated by the rotating motion of the rotating bodies 15 and 16. In this process, the image of the document is read by the contact sensor 4. The read original is discharged to the left by discharge rollers 8 and 9.

At this time, the belt 14 comes into contact with the reading surface 5 of the contact sensor 4 and the original with a sufficient nip amount L due to its own elasticity. , And the original can be transported reliably. Also, if the original is on the reading surface 5
The belt 14 contacts the fixed reading surface 5 until the nip portion between the belt 14 and the belt 14 is reached. However, the belt 14 contacts the reading surface 5 with only its own elasticity and a light load, so that the load torque is reduced. Can be smaller. Thus, the rotating bodies 15 and 16 can be driven by the motor having a small torque. Further, since the pressing force of the belt 14 against the document is small, the ink of the image of the document hardly adheres to the reading surface 5, and therefore, the dirt on the reading surface 5 and the belt 14 can be reduced.

Further, the material and hardness of the belt 14 are selected,
The load torque of the belt 14 is further reduced by selectively subjecting the outer peripheral surface of the belt 14 to unevenness or embossing to change the surface shape of the belt 14 or change the surface roughness to lower the friction coefficient. Is possible.

Further, the belt 14 receives a force on the downstream side when it is driven, but the position of the belt 14 can be stabilized by the guide member 17 disposed inside the belt 14, whereby The function and the document conveying function can be further improved.

Although not shown, a large number of feed holes are formed on both sides of the belt 14 at equal intervals, and projections engaging with these feed holes are arranged on the outer periphery of the rotating body 15 to thereby provide the rotating body. It is also possible to rotate the belt 14 with only 15.

Next, another embodiment of the present invention will be described with reference to FIG. This embodiment is the same as the configuration of the above-described example except that a gap s corresponding to the thickness of the document is opened and the rotating body 15 is opposed to the reading surface 5.

In such a configuration, the position of the belt 14 can be stabilized by the rotating body 15 disposed inside the belt 14, so that the original pressing action and the original feeding action can be further improved. It becomes possible. In this case, the guide member 17 used in FIG. 1 can be omitted.

Here, referring to FIG. 1 and FIG.
The invention described in 1 will be described. The invention according to claim 1 is
The belt 14 is formed of a transparent material.
By providing a white reference member in which at least one surface facing the reading surface 5 of the contact sensor 4 is colored white, reflected light from the white reference member is input to the contact sensor 4 through the transparent belt 14. Can be. The white reference member can be used by coloring the guide member 17 in FIG. 1 or the rotating body 15 in FIG. In this case, the white guide member 17 and the rotator 15 are located at the upper part of the document conveying path, and the guide member 17 and the rotator 1
Since the belt 14 exists between the document 5 and the document, the white guide member 17 and the rotating body 15 can be prevented from being stained. Therefore, when the shading correction is performed by inputting the reflected light from the guide member 17 or the rotating body 15 to the contact sensor 4 before the reading operation is started, the guide member 17 or the rotating body 15 is prevented from being stained. In addition, the shading correction can be stably performed. When the belt 14 becomes dirty, only the belt 14 needs to be replaced.

Next, a modification Katachirei of the present invention will be described with reference to FIG. In this modification, a hollow roller 18 is provided in contact with the reading unit 5 of the contact sensor 4. The hollow roller 18 is connected to an input shaft 1 connected to a motor as a driving unit.
9, a cylindrical shaft 20 for holding the input shaft 19, and a contact sensor 4 having a predetermined nip amount L with respect to the document transport direction.
And a plurality of elastic portions 22 connecting between the inner periphery of the pressure contact surface 21 and the cylindrical shaft 20. Is hollow 2
3 are formed.

In such a configuration, since the pressure contact surface 21 and the elastic portion 22 can be elastically bent, the hollow roller 18 can be formed by the elasticity of the hollow roller 18 by its own elasticity with a sufficient nip amount L and a light load. Can be pressed against the reading surface 5. The effect of this is shown in FIGS.
The operation of the belt 14 is the same. Further, since the original can be pressed by the hollow roller 18 driven by the motor, the number of parts can be reduced.
By making the outer periphery of the press contact surface 21 white, it is possible to use the outer periphery of the press contact surface 21 as a white reference surface for shading correction.

Further, the invention according to claim 2 will be described. According to a second aspect of the invention, FIG. 1, the belt 1 shown in FIG. 2
4. A film having a low friction coefficient is formed on the outer peripheral surface of the hollow roller 18 shown in FIG. This coating is formed by means such as coating or laminating a material having a low coefficient of friction such as Teflon. Therefore, belt 1
4. The load torque fluctuation of the hollow roller 18 can be reduced, and the hollow roller 18 can be driven by a motor having a small torque. In addition, since the outer surface of the transparent belt 14 and the hollow roller 18 can be prevented from being stained by this coating, when the guide member 17 in FIG. 1 and the rotating body 15 in FIG. The transmittance of the reflected light from the reference member to the contact sensor 4 can be improved, and
Shading correction can be accurately performed, and the gradation can be faithfully expressed. Even when the outer periphery of the hollow roller 18 in FIG. 3 is white, dirt on the outer periphery can be prevented by the coating, so that accurate shading correction can be performed.

Furthermore, a description will be given of a first embodiment of the invention of claim 3 according to FIGS. 4-6. A gear 27 is fixedly fitted to one end of the rotating body 15 provided inside the belt 14, and a transmission belt 29 is provided between the gear 27 and a driving gear 28 driven by a motor (not shown). It is wound. The two rotating bodies 16 arranged on the same axis parallel to the rotating body 15 are urged toward the rotating body 15 by a spring 30, and both sides of the belt 14 are pressed against the rotating body 15 by the rotating body 16.

As shown in FIG. 5, the rotating body 15 has a shaft 31 having one end fixedly fitted with the gear 27 and a high friction fixedly fitted to the shaft 31 facing the rotating body 16. It consists of two cylindrical high friction members 32 as parts. These high friction members 32 are formed of a material having a high friction coefficient such as rubber. In addition, as shown in FIG.
A white reference member 33 having at least a lower white surface is attached to a lower surface of the guide member 17 provided inside the fifth member 5.

In such a configuration, the rotation of the motor is transmitted to the rotating body 15 via the drive gear 28, the transmission belt 29, and the gear 27. Further, since the belt 14 is sandwiched between the high friction member 32 of the rotating body 15 and the rotating body 16 urged by the spring 30, the torque of the rotating body 15 can be transmitted to the belt 14 reliably. . Therefore, the feed amount of the document 10 can be accurately determined.

When reading the image of the document 10, the reflected light from the white reference member 33 is input to the contact sensor 4, and shading correction is performed based on the input.

Furthermore, a description will be given of a second embodiment of the invention of claim 3 according to FIG. In this embodiment, the belt 14
The two ring-shaped high friction members 34 as high friction portions are fixed to the inner peripheral surface of the member by means of adhesion or welding. The individual positions of these high friction members 34 are indicated by phantom lines, and the positions oppose the rotating body 16.

Accordingly, the belt 14 can be pressed against the rotating body 15 via the high friction member 34 with a high frictional force. As a result, the rotation of the rotating body 15 is
Can be transmitted reliably.

It should be noted that high friction portions may be formed on both the inner peripheral surface of the belt 14 and the outer periphery of the rotating body 15.

[0040] further described with reference to an embodiment of the invention of claim 4 according to FIGS. A ring-shaped stopper 35 is fixed to the inner periphery of both ends of the belt 14 by means such as adhesion or welding. When the positions of the stoppers 35 fixed to the belt 14 are indicated by phantom lines, these stoppers 35
Is set to L1, and the effective length excluding the shaft portions at both ends of the rotating body 15 is set to L2, which is slightly smaller than L1. Therefore, as shown in FIG.
The movement in the width direction is allowed by the value L3, which is the difference between L2 and L2. That is, the belt 14 is formed by the stoppers 35 and both end surfaces 36 of the rotating body 15 facing these stoppers 35.
A regulating means 37 for regulating the movement in the width direction is formed.

In such a configuration, since the movement of the belt 14 in the width direction can be restricted by the contact between the stopper 35 and the both end surfaces 36 of the rotating body 15, the original 10 can be accurately conveyed. Although not shown, members that abut against both side edges of the belt 14 may be fixedly provided, and these members may be used as a regulating unit that regulates the movement of the belt 14 in the width direction. In this case, by forming the members abutting on both side edges of the belt 14 with a material having a low friction coefficient, the load at the time of rotation of the belt 14 and the rotating body 15 can be reduced.

[0042] further described with reference to an embodiment of the invention of claim 5 according to FIG. 10. In this embodiment, stoppers 35 are fixed to the inner circumferences of both ends of the belt 14 and these stoppers 3
5 and both end surfaces 36 of the rotating body 15 form a regulating means 37 for regulating the movement of the belt 14 in the width direction.
The high friction member 34 protruding inward with a dimension of L4 is integrally formed on the stopper 35. These high friction members 34 are pressed against the outer peripheral surface of the rotating body 15.
Further, a regulating member 38 is fixedly provided opposite to both side edges of the belt 14 as regulating means for regulating the movement of the belt 14 in the width direction L3 or more.

In such a configuration, the high friction member 34
, The belt 14 can be pressed against the rotating body 15 with a high frictional force. Thereby, the rotation of the rotating body 15 can be reliably transmitted to the belt 14. Further, the movement of the belt 14 in the width direction can be restricted by the contact between the stopper 35 and the both end surfaces 36 of the rotating body 15. Of course, the movement in the width direction of the belt 14 can also be restricted by the contact between the both side edges of the belt 14 and the restriction member 38. Further, by integrally forming the stopper 35 and the high friction member 34 which constitute the regulating means 37, the number of parts and the number of assembling steps can be reduced, and the cost can be reduced. Note that, in order to reduce the load when the belt 14 and the rotating body 15 rotate, the regulating member 38 is formed of a material having a low friction coefficient.

[0044] further described with reference to an embodiment of the invention of claim 6 according to FIGS. In this embodiment, a rotating body 40 is formed by fixedly fitting a cylindrical white reference member 39 and a cylindrical high friction member 34 to the outer periphery of a roller body 38 that is long in the width direction of the belt. It is.

In such a configuration, the high friction member 34
Accordingly, the rotation of the rotating body 40 can be transmitted to the belt 14 reliably. Further, shading correction can be performed by inputting the reflected light from the white reference member 39 to the contact sensor 4. Furthermore, if the rotating body is formed of one material having a desired coefficient of friction and elasticity in order to make the contact friction with the belt 14 white for shading correction, the rotating body is made of an expensive material such as silicon rubber. According to the present embodiment, the rotating body 40 having the property of improving the rotation transmission efficiency and having the reference for shading correction is constituted by the roller body 38, the high friction member 34, the white reference member 39, and the like. Therefore, the material of the roller body 38 which is the main part of the rotating body 40 can be selected from a wide range to reduce the cost. Further, as shown in FIG.
By increasing the thickness of the high friction member 34 by a value of s from the thickness of the belt, the white reference member 39 can be prevented from being stained by being rubbed by the belt 14.

[0046]

According to the first aspect of the present invention, the belt is formed of a transparent elastic body, and a white reference member having at least one surface facing the reading surface of the contact sensor is colored white inside the belt. Therefore, the reflected light from the white reference member can be input to the contact sensor through the transparent belt, and the white reference member can be prevented from being stained by the belt, so that the shading correction can be stably performed. It has effects such as being able to.

According to the second aspect of the present invention, since a film having a low coefficient of friction is formed on the outer peripheral surface of the belt or the hollow roller, the belt or the hollow roller can be driven by a motor having a small torque by reducing the load torque fluctuation. It has the effect of being able to do it.

According to a third aspect of the present invention, there is provided a rotating body driven by a driving section and a flexible belt pressed against the rotating body, and at least one of the rotating body and the belt is brought into contact with both. Since the high friction portion located in the portion is formed, the friction coefficient of the contact portion between the rotating body and the belt can be increased by the high friction portion, whereby the torque of the rotating body can be reliably transmitted to the belt and the original can be transmitted. This has the effect that the feed amount can be accurately determined.

According to the fourth aspect of the present invention, since the regulating means for regulating the movement of the belt in the width direction is provided, the movement of the belt in the width direction can be regulated by the regulating member so that the original can be conveyed accurately. It has the effect of saying

According to the fifth aspect of the present invention, since the regulating means is formed integrally with the high friction portion, the rotation of the rotating body is reliably transmitted to the belt by the high friction portion, and the movement of the belt in the width direction is regulated by the regulating means. It is possible to regulate, and furthermore, by integrally forming the regulating means in the high friction portion, it is possible to reduce the number of parts and the number of assembling steps, thereby achieving effects such as cost reduction.

According to the sixth aspect of the present invention, a rotating body is formed by fitting a cylindrical white reference member and a cylindrical high friction member on the outer periphery of a roller body that is long in the width direction of the belt. The rotation of the rotating body can be reliably transmitted to the belt by the friction member, and the shading correction can be performed by inputting the reflected light from the white reference member to the contact sensor, and the rotation transmission efficiency is further improved. Since the rotating body having the properties and the reference for shading correction is formed by the roller body, the high friction member, and the white reference member, the material of the roller body which is the main part of the rotating body is selected from a wide range and the cost is reduced. This has the effect that down can be achieved.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of the invention described in claim 1 ;

[2] according to claim 1 is a front view showing another embodiment of the invention of claim 2 Symbol placement.

3A and 3B show a modified example of the present invention, in which FIG. 3A is a front view, and FIG. 3B is a perspective view of a hollow roller.

4 is a perspective view showing a first embodiment of the invention of claim 3, wherein.

FIG. 5 is a perspective view of a rotating body.

FIG. 6 is a partial front view.

7 is an exploded perspective view of a belt showing a second embodiment of the invention of claim 3, wherein.

FIG. 8 is an exploded perspective view of a regulating means showing one embodiment of the invention according to claim 4 ;

FIG. 9 is a vertical sectional side view of the regulating means.

10 is a vertical sectional side view of the regulating means and the high friction member showing an embodiment of claim 5, wherein.

FIG. 11 is an exploded perspective view showing an embodiment of the invention described in claim 6 .

FIG. 12 is a vertical sectional side view.

FIG. 13 is a front view showing a first conventional example.

FIG. 14 is a front view showing a second conventional example.

FIG. 15 is a side view of a part thereof.

FIG. 16 is a front view showing a third conventional example.

FIG. 17 is a front view showing a fourth conventional example.

[Explanation of symbols]

 4 Adhesion sensor 5 Reading surface 10 Document 14 Belt 15 Rotating body, white reference member 17 White reference member (guide member) 18 Hollow roller 19 Input shaft 21 Press-contact surface 22 Elastic portion 32 High friction portion 33 White reference member 34 High friction portion, High friction member 38 Roller body 39 White reference member 40 Rotating body

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B65H 5/02

Claims (6)

(57) [Claims] A flexible belt that has a contact sensor whose reading surface faces a document conveyance path and presses the reading surface of the contact sensor with a predetermined length in the document conveyance direction only by its own elasticity. The belt is rotatable, and the belt is
Formed of a conductive material and at least adhered to the inside of this belt
One side facing the reading surface of the sensor is white colored white
An image reading apparatus comprising a reference member . 2. An image according to claim 1 Symbol mounting, characterized in that the coefficient of friction on the outer peripheral surface of the belt to form a lower film reader. 3. A rotator driven by a drive unit and a flexible belt pressed against the rotator are provided, and at least one of the rotator and the belt is located at a contact portion between the two. part image reading apparatus according to claim 1 or 2, characterized in that the formation. 4. The image reading apparatus according to claim 1, 2 or 3, wherein in that a regulating means for regulating the width direction of movement of the belt. 5. The image reading apparatus according to claim 4 , wherein a high friction portion is formed integrally with said regulating means. 6. A rotating body formed by fitting a cylindrical white reference member and a cylindrical high friction member around the outer periphery of a roller body that is long in the width direction of the belt . 2 or
5. The image reading device according to 4 .