JPH02299365A - Reader - Google Patents

Abstract

PURPOSE:To prevent jamming by moving an original contact face of a pressing means in the original carrier direction when the original tip rushes into a press contact part between the depression means and a sensor. CONSTITUTION:In the case of reading an original 2, when a motor is driven, originals 2 separated one by one each at a separator means 3 are carried to a read means 5 by a carrier means 4. In this case, since a pressing roller 5b is driven, the original tip is not in contact with the pressing part between a read sensor 5a and the roller 5b. A friction force FS between a sensor face and the original 2 is smaller than an original carrying force FR with the roller 5b, no jamming takes place and the original is surely discharged to a discharge tray 12.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a reading device such as a facsimile machine, a copying machine, or an image reader, and more particularly to a reading device using a contact line sensor.

<Prior Art> Today, office automation equipment such as facsimile machines and copying machines that are widely used are desired to be downsized, and various developments have been made in response to this demand. Under these circumstances, a reading device using a contact type line sensor that does not require an optical system is effective in reducing the size of the facsimile machine and the like.

Since the contact type line sensor generally has a shallow focal point temperature, it is necessary to include a means for pressing the read document into contact with the sensor. In particular, when using a fully contact type line sensor that directly reads images with a light receiving element without using a single focus imaging lens array, the depth of focus is extremely shallow, several tens of microns, so the distance between the line sensor and the original must be kept sufficiently close. A means of adhesion is essential.

Therefore, conventionally, as shown in FIG.
A pressure roller 51 serving as a conveyance means and a contact type line sensor 52 are pressed together by a spring 53, and a document 50 is placed between them.
It is configured so that it passes through. That is, the separation roller 54
The document 50 is separated one by one by a separation pad 55 and is conveyed by a pressing roller 51 rotating in the direction of the arrow, and the image is read by a line sensor 52.

In general, in a configuration using a contact type line sensor, the part facing the sensor on the reading line is white to generate a reference signal during reading and as a lining when reading thin or transparent originals. There is a need.

Therefore, conventionally, the pressure roller 51 is made white.

<Problems to be Solved by the Invention> In the reading device using the contact type line sensor, if the contact between the original 50 and the line sensor 52 is not good, the image will be out of focus and the quality of the read image will deteriorate.

Therefore, the pressure roller 51 that presses against the line sensor 52
It is necessary to make the spring 53 soft and to increase the strength of the spring 53.

However, since the pressing roller 51 is white, if the pressing roller 51 is made soft or the pressing force with the line sensor 52 is increased, the roller surface becomes dirty 8 and there is a risk that the standard white color cannot be maintained.

Furthermore, as the dirt is transferred to the line sensor 52, the sensor 52 itself becomes more likely to become dirty, and there is a possibility that the reading accuracy may be reduced.

Therefore, it is necessary to use a material for the press roller 51 that is soft and resistant to dirt as much as possible, but generally speaking, the more resistant the material is to dirt, the lower the coefficient of friction on the surface tends to be.

However, when considering the feeding accuracy of the document 50, the friction coefficient of the pressure roller 51 must be high to obtain a reliable document conveyance force. There are issues such as the image being stretched.

That is, in order to prevent the pressure roller 51 from becoming dirty, a material with a low coefficient of friction must be selected, and in order to obtain a conveying force, a material with a high coefficient of friction must be selected.

Therefore, as shown in FIG.
A non-rotating pressing member 56 is pressed against the sensor 52, and the document 50 is conveyed by conveying rollers 57 disposed before and after the sensor 52, and the document conveying means and the pressing means are constructed as separate members. .

However, in the configuration shown in FIG. 8, since the pressing member 56 does not rotate, it becomes a load on the document conveyance, and there is a risk that the leading edge of the document may get caught in the pressure contact portion between the pressing member 56 and the sensor 52, resulting in a jam. There is.

It is thought that this jam occurs more noticeably when the document is thin and has a weak texture. However, if the pressure spring 53 is weakened for this purpose, there is a risk that reading will be out of focus as described above.

The present invention is intended to solve the above-mentioned conventional problems, and its purpose is to be able to reliably transport a document, to bring the document into close contact with a close-contact type line sensor, and further to press the document. It is an object of the present invention to provide a reading device in which a material that is not easily soiled can be selected as a member.

Means for Solving the Problems> Typical means according to the present invention for solving the above problems include a conveyance means for conveying a document, and a contact type for reading the document conveyed by the conveyance means. It has a line sensor and a pressing means that is configured independently of the conveyance means and presses the conveyed document against the contact type line sensor, and moves the document contacting surface of the press means in the document conveyance direction. The present invention is characterized in that the document conveying force of the pressing means is smaller than the document conveying force of the conveying means.

Effects> In the above means, jamming can be prevented by moving the document contacting surface of the pressing means in the document conveyance direction when the leading edge of the document enters the pressure contact portion between the pressing means and the sensor.

In addition, since the document conveying force of the pressing means is made smaller than that of the conveying means, the friction coefficient of the pressing means can be reduced, it can be made of a material that is resistant to staining, and the document can be reliably conveyed by the conveying means. .

<Embodiment> Next, an embodiment of the present invention in which the above means is applied to a facsimile machine will be described.

[First example]

FIG. 1 is an explanatory cross-sectional view of a facsimile machine comprising a reading device A and a recording device B according to a first embodiment.

The configuration of the reading device A includes a separating means 3 for separating the originals 2 loaded on the original placing table 1 one by one, a transport means 4 for transporting the originals 2 separated by the separating means 3,
A reading means 5 for reading the image of the transported document 2 is arranged.

The separation means 3 includes a separation roller 3a rotating in the direction of arrow a.
When the separating roller 3a rotates, the original 2 stacked on the original placing table I is separated.
The structure is such that one of the uppermost layers is separated and supplied.

The conveying means 4 is made of a material with a high coefficient of friction such as rubber, and includes a drive roller 4a that is rotated in the direction of the arrow by a motor (not shown), and a driven roller 4b that is in pressure contact with the drive roller 4a and rotates as a result.

In this embodiment, the pair of rollers 4a, 4b and the original 2
By setting the friction coefficient μ to approximately 1.7 and applying approximately 1 to 2 kg as a pressing force, a document conveying force of 2 is obtained, and the document 2 held between both rollers 4a and 4b is The structure is such that it can be transported without slipping.

The reading means 5 is composed of a reading sensor 5a made of a contact type line sensor and a pressing roller 5b serving as a pressing means.
The reading sensor 5a is pressed against the pressing roller 5b by a spring 5c so that both are pressed against each other with a predetermined pressing force. The pressing roller 5b is configured to be rotatable in the direction of arrow C by a motor (not shown).

The pressure roller 5b is made of a soft white rubber material with a hardness of about 20 to 50 degrees, and contains several percent to several tens of percent of resin so that its surface is hard to get dirty. As a result, the surface of the pressure roller 5b is less likely to get dirty, even though the pressure roller 5b has good adhesion to the reading sensor 5a.

Further, the pressure roller 5b has a friction coefficient μ2 with respect to the original 2.
is smaller than the friction coefficient μm of the conveying means 3, approximately 0.5
5, and by applying a pressing force of 1 kg, the document conveying force when the press roller 5b rotates in the direction of arrow C is approximately 550 g, which is set smaller than the document conveying force by the conveying means 3, and is substantially In this case, the pressing roller 5b does not have the ability to convey the original.

Furthermore, the friction coefficient μ of the original contact surface (reading surface) of the reading sensor 5a with respect to the original 2 is set to about 0.4, which is smaller than the friction coefficient μ of the pressing roller 5b. Therefore, when the original 2 passes through the reading means 5, as shown in FIG.
is smaller than the document conveyance force F by the pressure roller 5b, so that the document 2 does not jam at this portion. Incidentally, since the document contacting surface of the sensor 5a is generally made of glass, the frictional force F will not become larger than the conveyance force F even if the frictional coefficient μ8 is made as small as possible.

The configuration of the recording device B includes a heat-sensitive sheet 6 that develops color when heated.
The sheet roll 6a which is wound into a roll is attached to the holder 7.
The sheet 6 is conveyed by a platen roller 8 rotating in the direction of arrow d, and an image is recorded by selectively heating the sheet 6 with a thermal head 9 that generates heat according to the read information.

After recording, the sheet 6 is cut from the trailing edge of the image by a cutter IO, and is also discharged from the apparatus by a discharge roller 11.

Next, the document reading operation of the facsimile machine having the above configuration will be explained.

When reading the original 2, when a motor (not shown) is driven, the original 2 separated one by one by the separating means 3 is transferred to the conveying means 4.
and is transported to the reading means 5. At this time, the pressure roller 5b
Since the leading edge of the document rotates, the leading edge of the document does not come into contact with the pressure contact portion between the reading sensor 5a and the pressing roller 5b, and as described above, the relationship of frictional force F<conveying force F exists, so that The paper is reliably discharged onto the discharge tray 12 without jamming.

Since the original 2 is pressed by the relatively soft pressing roller 5b, it comes into complete contact with the reading sensor 5a, and the original information is reliably read by the sensor 5a. Furthermore, since the pressing roller 5b is made of a material with a low coefficient of friction, it is not easily soiled even when pressed against the original 2, maintains the reference white color, and does not reduce reading accuracy.

The information read by the reading sensor 5a as described above is transmitted to the recording device of another facsimile machine in the facsimile mode, and to the own recording device B in the copy mode.

In the above embodiment, a rubber roller containing resin was used as the material of the pressure roller 5b, but the material of the pressure roller 5b does not need to be limited to this. It may be configured as shown in FIG.

The pressure roller 5d shown in FIG. 3 has an elastic member 5d made of rubber, urethane, etc. on the roller shaft 5dl! is fixed in the form of a roller, and a thin white film 5ds is adhered to the surface of this elastic member 5dz. This white film 5ds is made of, for example, Teflon (
(registered trademark) sheet, polyester film, etc. with a low coefficient of friction. By adhering such a white film 5ds, it is possible to make it much more difficult to get dirty than when using a rubber roller.

Furthermore, instead of adhering the white film 5d, it is also effective to construct the elastic member 5d2 from white rubber and to coat its surface with a thin layer of Teflon or the like.

[Second example]

Next, a second embodiment of the reading device will be described with reference to FIG. Incidentally, the same parts as in the first embodiment are given the same reference numerals and the explanation will be omitted.

In this reading device, the conveying means 4 is the reading means 5.
A pair of front conveyance rollers 4c arranged before and after the.

4d and a pair of rear conveyance rollers 4e and 4f.

Further, the pressure roller 5e of the reading means 5 is provided with an elastic member 5eg made of rubber, urethane, etc. on the roller shaft 5e, and this elastic member 5e! A notch 5es is provided in a part. Further, a thin white film 5e4 made of Teflon or the like is adhered to the surface of the elastic member 5ez other than the notch 5ei.

Further, the length of the arc other than the notch of the pressing roller 5e is the fourth
It is set to be sufficiently longer than the distance l from the reading line L to the pair of rear conveyance rollers 4e and 4f shown in the figure.

Note that the conveyance rollers 4c, 4e, and the pressure roller 5e.

The relationship between the coefficient of friction between the reading surface of the sensor 5a and the document 2 is the same as in the first embodiment.

Here, drive control of the reading device having the above configuration will be explained. Note that the front and rear conveyance rollers 4c, 4 of this reading device
e is configured to be rotated by the drive of a conveyance motor (stepping motor), and the press roller 4e is configured to be rotated by the drive of the press motor, and each of the motors is controlled by a control system 42I as shown in FIG. The drive is controlled as shown in the flowchart (b).

In the block diagram of FIG. The signal is sent to a motor driver 17 that drives the transport motor 15 and the press motor 16, and a sensor driver 18 that drives the reading sensor 5a, thereby driving each member.

In FIG. 5, 19 is a data bus, 20 is an interface control signal, 21 is a motor control signal, and 22 is a sensor control signal.

Next, the document feeder 1 controlled by the control system will be described with reference to the flowchart in FIG. 5 (bl).

First, in the initial state, the pressing roller 5e is in a state with the notch 5e3 facing downward. When reading is started in this state, the transport motor is driven and the front transport roller pair 4C14d rotates to move the document 2.
is transported, and when the leading edge of the document reaches reading line L, the transport motor stops driving and temporarily interrupts document transport (S
t-33).

In this state, the pressing motor is driven, and as shown in FIG. 6(B), the pressing roller 5e rotates in the direction of the arrow e, causing the notch
When the end portion 5es of the os comes into pressure contact with the original 2, the transport motor is driven again to transport the original 2 and start reading (34 to 37). At this time, the front and rear transport roller pair 4c,
4d, 4e, 4f and the pressure roller 5e are set to rotate at the same circumferential speed.

Next, as shown in FIG. 6(C), when the leading edge of the document 2 is conveyed to the nip position of the pair of rear conveyance rollers 4d, the pressing motor stops, and from then on the document 2 is transferred to the pair of front and rear conveyance rollers 4c, 4d,
4e, 4( (58-S9).

At this time, the pressure roller 5e has stopped rotating, but as described above, the length of the arc of the pressure roller 5c is longer than the distance l, so the arc portion is maintained in a state where it presses the document 2. is conveyed in close contact with the reading sensor 5a. Further, even if the pressing roller 5e has stopped rotating, the leading edge of the document 2 is already nipped by the pair of rear conveyance rollers 4e and 4f, so that it is conveyed without jamming.

Then, as shown in FIG. 6(D), when the trailing edge of the document passes through the plain line L and the conveyance and reading of the document 2 is completed, the press motor rotates a predetermined amount to return the press roller 5e to the initial state, and the conveyor The motor stops after conveying the original 2 by distance #β (SIO~512).

It should be noted that whether or not the leading edge of the document has been conveyed to the reading position in step S2 and whether the leading edge of the document has been conveyed to the pair of rear conveying rollers 4e and 4f in step S8 are as follows.
For example, it can be detected by counting the number of pulses that drive the transport motor. This is step S
The same goes for detecting whether the cutout end 5e5 of the pressure roller 5e is in pressure contact with the document 2 in step 5.

In this embodiment, the original 2 is transported by the front and rear transport rollers 4c, 4.
d, 4e, and 4f, the conveying force is approximately twice that of the first embodiment.
Since the surface is made of a material with a low coefficient of friction such as Teflon (registered trademark) film, even if the pressing roller 5e is in the presentation state, it does not impose a load on the conveyance of the original 2.

<Effects of the Invention> As described above, in the present invention, the document contacting surface of the pressing means for pressing the document against the contact type line sensor is movable in the document conveying direction, so that the document does not come into contact with the pressure portion between the sensor and the pressing device. There is no jam when entering.

Further, the II friction coefficient of the pressing means is 11! of the conveying means! Since the coefficient of friction is smaller than the coefficient of friction, the document can be transported reliably, and the pressing means can be made of a material that is hard to stain and is made of a soft material, thereby making it possible to reliably bring the document into close contact with the sensor and prevent out-of-focus. This makes it possible to prevent deterioration in reading quality.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a cross-sectional explanatory diagram of a first embodiment in which the present invention is applied to a facsimile machine, Fig. 2 is an explanatory diagram of the relationship of force applied to a document in a reading section, and Fig. 3 is an explanatory diagram of a first embodiment in which the present invention is applied to a facsimile machine. 4 is an explanatory diagram of a reading device according to the second embodiment; FIG. 5 is an explanatory diagram of another embodiment of the pressure roller; FIG. 5 is a block diagram of a control system according to the second embodiment; fbl is a document conveyance procedure Flowchart, Figure 6 (A
) to (D) are explanatory diagrams showing the document conveyance procedure, and FIGS. 7 and 8 are explanatory diagrams of the prior art. Reference numeral 1 denotes a document mounting table, 2 a document, 3 a separation means, 3a a separation roller, 3b a separation pad, 4 a conveyance means, 4a a drive roller, 4b a driven roller, and 4c. 4d is a front conveyance roller; 4e and 41 are rear conveyance rollers; 5 is a reading means; 5a is a reading sensor; 5b, 5d. 5e is a pressure roller, 5c is a spring, 6 is a thermal sheet, 6a is a roll, 7 is a holder, 8 is a platen roller,
9 is a thermal head, 10 cutter 111 is a discharge roller, and 12 is a discharge tray.

Claims (1)

[Scope of Claims] A conveyance means for conveying a document; a contact type line sensor for reading the document conveyed by the conveyance means; and a contact type line sensor configured independently of the conveyance means, and configured to read the document conveyed by the conveyance means. a pressing means for pressing the contact type line sensor, the document contacting surface of the pressing means is configured to be movable in the document conveying direction, and the document conveying force of the pressing means is applied to the document conveying force of the conveying means. A reading device characterized by being smaller than the force.