JP2001007979A - Document reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a document reader which stably read a picture while simplifying the constitution of a driving system for document carrying and read. SOLUTION: The document reader is comprised of a contact type document rear sensor 1, a counter roll 2 which is arranged so as to face the document read sensor 1, a paper supply roll 3, and a paper ejection roll. Rolls 2, 3, and 4 are connected through connection members like gear members so that they can be rotated and driven by a single driving source. The document read sensor 1 is normally biased downward by a spring 12, and in the document read, a lever part 14a of a solenoid 13 projects to energize the document sensor 1 upward through a link mechanism 13 at the reading of a document, and the lever 14a of the solenoid 14 is inserted and fitted and the document read sensor is energized downward by the spring 12 when not reading a document.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document reading apparatus for reading a document image by conveying a sheet-shaped document, and more particularly, to a document reading apparatus provided with a contact type document reading sensor and a document feeding section. It belongs to the technical field.

[0002]

2. Description of the Related Art Conventionally, a contact type document reading sensor for reading a document image in close contact with the document during the document conveying process by transporting a sheet-shaped document has been arranged, and a contact type document sensor for reading image information of the document has been provided. (Hereinafter referred to as a contact-type original reading device) is known.

In a conventional contact type document reading apparatus, a roller member used for conveying the document and fixing the height of the document when reading the document image is disposed to face the document reading section. The roller member is incorporated in a drive-side gear arrangement, and the position of the roller member is fixed.

In such a state, the roller member provided opposite to the original reading section is arranged so as to always contact the contact type original reading sensor in order to improve the accuracy of reading the original image. That is, while the document is being conveyed, it always rotates.

Therefore, between the time when the document is conveyed from the document table on which the document is placed to the document reading section and the time when the reading of the document is completed and the document is discharged to the document discharging section, the roller member is used. It will rotate while being in close contact with the contact type reading sensor, and the contact surface of the roller member will be worn,
The roller surface becomes dirty with the paper dust of the original or the powdery roller material when worn out, and depending on the material of the roller member, the reading surface of the close contact type reading sensor is worn out, and the paper dust of the original, the roller material, the sensor, etc. There was a problem that the material was stained by powdering.

Further, the positional relationship fluctuates due to the above-mentioned wear, and the reading position is not stabilized, so that the reading accuracy is lowered or the reading surface of the above-mentioned contact type reading sensor becomes dirty. This leads to various problems such as disappearance or the above-mentioned stain adhering to the document.

On the other hand, since the other transporting roller is disposed to face the driven roller, the load on the other transporting roller is relatively small, but the roller member is in close contact with the contact-type reading sensor that is not driven and rotated. Due to the rotation, there is also a problem that the load for driving the roller member increases.

Japanese Patent Laid-Open Publication No. Hei 8-70368 discloses a composite reading apparatus in which a document reading means is arranged in a vertical conveyance path, and a sensor using a spring member opposed to a contact type reading sensor for reading a document image. There is disclosed a technology in which a roller member movably held on the side is provided to reduce a load when the roller member is rotationally driven, and also to prevent a document from rising and a paper jam in a document reading unit.

Japanese Patent Application Laid-Open No. 7-38703 discloses that
The roller member provided to face the contact sensor for reading the original is divided into three parts in the axial direction, the central part of the central part is shaped like a drum, and the central part of the roller is connected to the original carrying roller at both axial ends. The connecting part is almost the same as the shape of the original transport roller, and the half of the peripheral surface of the central roller is a low friction surface and the other half is a high friction surface, so that the central roller It is disclosed that the load on the document reading unit is reduced, the document reading unit is supported by a spring, a spring clutch is built in the central roller, and the document is transported and separated using a ratchet and solenoid. There is disclosure of reducing the load on the central roller.

[0010] Further, JP-A-6-37978 discloses that
A document is read by pressing a roller facing the document reading unit as a cantilever reference white sheet on a member facing the document reading unit with a pressing member from the back surface of the white sheet near the document reading unit. Accordingly, a technique for improving the reading accuracy has been proposed.

[0011]

In the above-described prior art, a roller of a document reading section is made movable, and a clutch, a latch, a solenoid switch, and the like are provided so that the drive can be transmitted only when necessary in the document reading operation. Is used to constitute a roller unit for transporting the original and reading the original, which is effective in that the wear of the roller can be prevented and the load for driving the roller can be reduced.

However, in the above-mentioned prior art, the structure of the roller drive unit becomes complicated, the meshing accuracy of the gear arrangement to be driven is required, and there is a possibility that the driving speed becomes uneven in the transport speed and the reading speed. Was.

In the technique described in Japanese Patent Application Laid-Open No. 6-37978, the opposing rollers are eliminated, and the vicinity of the document reading portion in the white sheet can be pressed by the pressing member from the back surface with the pressing member to realize the reading operation of the document. When the thickness of the document changes, the pressing state of the pressing member fluctuates. In the worst case, the document may be jammed. Further, when the thickness of the document fluctuates, the conveyance force of the document also fluctuates, and the reading accuracy of the document changes. May be reduced.

The present invention has been made to solve these problems of the prior art, and an object of the present invention is to simplify the configuration of a drive system for carrying and reading a document while simplifying the structure. An object of the present invention is to provide a document reading device that performs a stable reading operation.

[0015]

An original reading apparatus according to the present invention is provided so as to face an original reading sensor for reading an original image in a close contact state or a substantially close contact state, and an original reading section in which the original reading sensor reads an original image. An opposing roller that inserts and conveys the original that has reached the original reading unit when the original is read by the original reading sensor, and is provided upstream of the original conveyance path where the original is conveyed from the original reading unit, A paper feed roller that conveys the document to the reading unit, and a discharge that is provided downstream of the document reading unit in the document conveyance path and conveys the document conveyed by the opposing roller further downstream of the document conveyance path. When reading an original, the original reading unit is in close contact with or substantially in contact with the opposed roller, and is separated from the opposed roller. To a single drive source via a connecting / disconnecting mechanism that can be held in each of the two states, and a connecting member having a rotating shaft coaxial with the rotating shaft of the facing roller, the paper feeding roller, and the paper discharging roller. And a drive mechanism for connecting and rotating the roller group.

According to this configuration, the document reading device includes the document reading sensor, the sheet feeding roller, the opposing roller, the sheet discharging roller, the separation / contact mechanism, and the driving mechanism, and includes the sheet feeding roller, the opposing roller, and the sheet discharging roller. The rollers are arranged so as to be able to be connected and driven by a single drive source such as a motor via a connecting member such as a gear coaxial with each rotation axis of the rollers. An opposing roller is disposed on an opposing surface of the original reading sensor across the original conveyance path, and the above-described rollers forming an original reading section for reading an original near the opposing portion are connected and driven. With this configuration, the opposing roller keeps a fixed positional relationship from the original conveying path for reading the original, while the original reading section of the original reading sensor comes into close contact with or substantially adheres to the opposite roller by the separating mechanism. State or
It is configured so that it can be held in two states of being completely separated from the opposing roller.

When the paper feed roller, the opposing roller, and the paper discharge roller are rotated by the single driving source via the connecting member, first, the placed original is fed to the paper feeder disposed at the most upstream side of the original transport path. The paper is fed by a roller and transported to an opposing roller provided downstream of the paper feed roller.

When reading an original, the original reading sensor needs to be in close contact or substantially close contact with the opposing roller in order to bring the original in close contact with the original. To avoid problems such as wearing out, applying excessive load to the drive source, fluctuating the reading position, generating stains with shaved powder, and soiling the back side of the original, when not reading the original Then, the opposing roller and the document reading unit are completely separated.

That is, at a predetermined timing, the document reading unit and the opposing roller are closely or substantially closely contacted, and the image of the document is read. When the reading of the document is completed, the document reading unit and the opposing roller are completely separated. After the reading of the document is completed, the document is further transported and discharged by a discharge roller provided downstream of the document reading unit.

Therefore, by making the original reading sensor and the opposing roller detachable from each other, the original reading sensor and the opposing roller are brought into close contact or almost in contact with each other only for a minimum necessary period.
Excessive load is required due to the contact and wear between the document reading sensor and the opposing roller, the opposing roller and the document reading section are shaved, the life is shortened, the reading position fluctuates, and inside the machine due to shaved powder And the problem of causing contamination of the original and the like can be avoided or reduced.

Also, in the conventional document reading apparatus, the opposing roller side facing the document reading section can be separated from and brought into contact with the document.
Although the mechanism of the opposing roller portion became complicated and the reading accuracy was reduced due to the reduction in the mechanism accuracy, according to this configuration, the structure of the drive system was simplified and the reduction in the mechanism accuracy was prevented. The problems caused by the friction between the document reading unit and the opposing roller can be solved or reduced.

The document reading apparatus according to the present invention is provided upstream of the document reading section in the document transport path, and detects a leading edge position of the document to start reading of the document in the document reading section. A reading start time detecting means for detecting a start time, wherein the separation / separation mechanism holds the document reading unit in a close contact state or a substantially close contact state with the opposed roller based on a detection result by the reading start time detecting means; You may comprise as possible.

According to this configuration, before the fed document arrives at the document reading unit, the leading edge position of the document is detected by the reading start timing detecting means, so that the image reading timing of the document is determined. The document reading unit and the opposing roller, which have been separated from each other, are kept in a close contact state or a substantially close contact state.

Accordingly, the reading start timing detecting means makes the original reading portion and the opposing roller come into close contact or almost in close contact with each other for a minimum period, so that unnecessary wear does not occur.
Wear of the document reading sensor and the opposing roller can be minimized.

Further, the original reading apparatus of the present invention is provided on the upstream side of the original transport path from the original reading section, and detects the leading edge position of the original to start reading the original in the original reading section. A reading start time detecting means for detecting a start time; and a storage means for storing transport time information required for transporting between the reading start time detecting means and the document reading section. The apparatus may be configured to be able to hold the separated state based on the transport time information and the detection result of the reading start timing detecting means.

According to this configuration, before the fed document reaches the document reading section, the leading edge position of the document is detected by the reading start timing detecting means, and the detected value at that time is stored in the storage means in advance. Based on the transport time information, the separated state is maintained after the contact state is continued for a predetermined time. Therefore, it is not necessary to newly provide a unit for detecting whether or not the rear end of the document has passed the document reading unit, and it is possible to determine the separation timing while preventing an increase in manufacturing cost. Note that the reading start timing detecting means may also be used as a jam detecting means for detecting that a document has jammed before the document reaches the reading position.

Further, since the timing of the separation state as well as the close contact state is determined, the time required for the original reading section and the opposing roller to come into close contact or substantially close contact can be minimized, and unnecessary wear does not occur. In addition, wear of the original reading sensor and the opposing roller can be minimized.

Further, in the original reading apparatus according to the present invention, the reading start timing detecting means can further detect the rear end position of the original, and the separation / contact mechanism includes the transport time information, the reading start timing detection Based on the detection result by the means, it may be configured so that the above-mentioned separated state can be maintained.

According to this configuration, before the trailing end position of the fed document reaches the document reading section, the reading start timing detecting means also detects the trailing end position of the document, and the detected value at that time is used. Based on this, the separating mechanism is set to the separated state. Therefore, it is not necessary to newly provide a unit for detecting whether or not the rear end of the document has passed the document reading unit, and it is possible to determine the separation timing while preventing an increase in manufacturing cost.

Since the passage of the trailing edge of the document can be reliably detected rather than the time information, the trailing edge of the document can be detected even when the leading edge of the document has slipped or the transport speed has changed after the leading edge has passed. The original reading unit can be reliably detected, and the document reading unit can be accurately separated.

In addition, since the timing of the separation state as well as the close contact state is determined, the time required for the original reading section and the opposing roller to come into close contact or substantially close contact can be minimized, and unnecessary wear does not occur. In addition, wear of the original reading sensor and the opposing roller can be minimized.

Further, in the original reading apparatus according to the present invention, the separating mechanism includes a solenoid, a link mechanism for performing the separating operation of the original reading sensor in conjunction with the solenoid, and an opposing roller. And a biasing means for biasing the opposite side.

According to this configuration, when the document reading section is separated from or brought into contact with the original, the solenoid is turned on / off at a predetermined timing to operate the link mechanism in conjunction with the solenoid. The document reading sensor urged in the reverse direction performs a separation / contact operation via the link mechanism. With this configuration, the separation / contact mechanism of the document reading unit of the document reading device can be realized with a low-cost and simple configuration.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall schematic sectional view of an original reading apparatus provided with an original reading section according to an embodiment of the present invention. The operation of conveying and reading an original will be described below.

On the right side of the drawing, a document placing table 5 is provided at a position communicating with the document conveying path, and a document S to be read is loaded on the document placing table 5. Is provided with a document detecting means (not shown) including a light emitting / receiving element for detecting the placed document S, a mechanical switch, and the like.

As will be described later, preferably, the original detecting means detects the size of the original in the conveying direction so that the original conveying time can be calculated. However, instead of the original detecting means, the size of the original in the conveying direction can be calculated. The document size may be specified or input by operating means (not shown).

Next, the original placing table 5 is detected by the original detecting means.
When an operator operates a reading operation instruction means (not shown) for detecting the presence of a document on the upper side and further including a key switch or the like for instructing the start of a document reading operation, a conveying roller 9 for conveying the document is provided. Starts rotating, and the originals on the original mounting table 5 are transported one by one in the direction of the pair of paper feed rollers 3 disposed to the left of the drawing with respect to the transport rollers 9.

The original S transported by the transport rollers 9 is
The position of the leading edge of a document and a contact type document reading sensor 1 described later
The timing at which the sheet is fed by the sheet feed roller 3 is adjusted so that the reading start position of the reading sensor 1 (hereinafter, abbreviated as the reading sensor 1) matches.

The document S fed by the paper feed roller 3 is adjusted by, for example, varying the rotation start timing of the paper feed roller 3, and the document S fed by the paper feed roller 3 further advances along the document feed path, and is read by the reading sensor. The document 1 is conveyed to a document reading position 6 (see FIG. 2), which is a position facing an opposing roller 2 provided so as to face the reading sensor 1 in the vertical direction.

Since the paper feed roller 3 has been adjusted in advance so that the leading edge position of the document and the image reading start position match, the original is moved from the leading edge position to the trailing edge position of the document.
Images on S are sequentially read by the reading sensor 1.
As shown by the broken line in the drawing, the original reading unit 10
Is composed of an opposing roller 2, a document reading sensor 1, and the like.

In this embodiment, the reading timing of the document S is adjusted by stopping the rotation of the paper feed roller 3. However, as described later, for example, as described later, the document S is located upstream of the document reading position 6 in the transport direction. Alternatively, a sensor or the like for detecting the leading edge of the document for detecting the leading edge position of the document may be provided to adjust the reading timing.

Since the position of the trailing edge of the original S varies depending on the size, the original reading device can be used with various original sizes by, for example, using the above-described sensor for detecting the leading edge of the original. The edge may be detected, or the size in the transport direction may be detected using the above-described document detection unit.

Here, in order to detect the leading edge and the trailing edge of the document S, the edge of the sensor detection value is set such that the sensor output of the document leading edge detection sensor changes from the ON state to the OFF state or from the OFF state to the ON state. By detecting, the leading end position and the trailing end position of the document can be detected.

For example, when the leading edge of the document S reaches the sensor for detecting the leading edge of the document, it is in the OFF state. When the leading edge of the document S reaches the sensor for detecting the leading edge of the document, the state changes to the ON state. The ON state is continued while the document passes through the sensor for detecting the leading edge of the document, and becomes OFF when the rear end position of the document passes the sensor for detecting the leading edge of the document.
It is possible to detect the leading edge position and the trailing edge position of the document. Note that the detection can be performed in the same manner even if the polarity in the ON state is reversed until the leading edge of the document S reaches the document leading edge detection sensor.

Next, after the image on the document S is sequentially read by the document reading sensor 1, the document is discharged and conveyed along a paper discharge unit paper guide 16 described later provided on the paper discharge side of the paper conveyance path. After being further conveyed from the paper discharge roller 4 located on the original conveying path on the left side of the original reading sensor 1,
The document S is discharged onto a discharge tray (not shown) provided downstream of the discharge roller 4 (not shown) in the document conveyance path.
Reading of a series of image information on the document S is completed.

Here, each of the transport roller 9, the feed roller 3, the facing roller 2, and the discharge roller 4 shown in FIG. 1, at least the feed roller 3, the facing roller 2, and the discharge roller 4
Are arranged in such a manner that they can mesh with and interlock with a gear member having a rotation axis coaxially with the rotation axis of each roller,
Driven by a common drive source, and a CP (not shown)
Drive control is performed by an information processing device such as U.

The gear member described above may be integrated with each roller and provided at an end on the drive side, or a separate gear member may be fixed to the drive side of each roller. . Further, the gear member may include not only a gear member having a rotation axis coaxially for each of the rollers, but also another gear member that meshes with each of the gears. Still further, these rollers may be interlocked via a belt member wound around each other.

The above-described document reading apparatus operates as a single unit such as a scanner, and also has a digital multifunction peripheral having, for example, an image reading section of a digital copying machine, an image reading section of a facsimile, copying, facsimile, and printer functions. It is needless to say that the present invention can be applied to various devices such as an image reading unit of a machine.

Next, the detailed operation of the document reading sensor 10 in the document reading section 10 of the document reading apparatus will be described in detail with reference to FIGS. FIG. 2 shows the image reading unit 10.
3 and FIG. 4 are state transition diagrams for explaining an image reading operation in the image reading unit 10.

FIG. 2 is a detailed partial cross-sectional view of the image reading unit 10, and a paper detecting sensor 11 not shown in FIG.
Spring 12, link mechanism 13, and solenoid 1
4. Discharge paper guides are provided.

In the preferred embodiment described below,
Spring 12, link mechanism 13, and solenoid 14
Thus, the separation / contact mechanism of the document reading sensor 1 is configured, but the present invention is not limited thereto, and the separation / contact mechanism may be configured by another method.

First, the paper detection sensor 11
Is provided to detect that the document S has been transported to the document reading position 6 near the document reading sensor 1.
It is arranged between the position of the paper feed roller 3 and the document reading position 6 on the document conveying path.

Incidentally, in FIG. 2, the paper detecting sensor
Is rotated in the conveyance direction of the document S, and the paper detection sensor 1
1 shows an embodiment in which the document S can be detected by an optical sensor or the like provided in the device 1, but the document is inserted and conveyed between the light emitting and receiving elements without using the actuator 15 to block light. Detection may be performed, or reflected light may be detected instead of insertion and conveyance.

Although the paper detection sensor is used to determine the close-contact separation timing of the document reading sensor 1, the paper detection sensor can also detect a document conveyance trouble or paper jam. It is possible to detect both the document conveyance trouble and the close-contact separation timing of the document reading sensor 1 without unnecessarily increasing the number of sensors.

Next, a spring 12 is connected to the bottom end of the original reading sensor 1 and reciprocates in two directions, that is, a direction in which the original detecting sensor 1 is substantially in contact with the opposing roller 2 and a direction in which the original detecting sensor 1 is separated, ie, the direction B in the drawing. More specifically, the upper end 12a of the spring 12 is connected to the lower end of the document detection sensor, and the lower end 12b of the spring 12 is connected to a housing of a document reading device (not shown).

The spring 12 normally acts to urge the original reading sensor 1 downward in the direction B in the drawing. The state shown in FIG. And the original reading sensor 1 is
It shows a state in which it is pushed up to the side.

It should be noted that, contrary to the above-described direction, normally, the state in which the spring 12 pushes up the original reading sensor 1 (the state shown in FIG. 2), and when the original reading sensor 1 separates from the opposing roller 2 in FIG. However, in this case, the original reading sensor 1 is always in a state of being close to or in contact with the opposing roller 2, and stress is applied to the opposing roller 2. It is preferable that the spring 12 is biased downward so that the document reading sensor 1 is separated from the opposing roller 2.

The document reading section 10 has a link mechanism 13
And the solenoid 14, the document reading sensor 1 is reciprocated in the direction B by the interaction with the spring 12 described above.

That is, the solenoid 14 is connected to a control circuit (not shown) and a power supply circuit (not shown).
4a is reciprocally movable in the direction A shown in the figure, and the tip 14b of the lever 14a is connected to the connection 13a of the link 13b arranged in the up and down direction of the link mechanism 13 to connect the shaft support 13c. When the link portion 13b rotates in the direction A about the axis, the link portion 13d provided so as to be substantially orthogonal to the link portion 13b is reciprocated in the direction D in FIG. The document reading sensor 1 reciprocates in the direction B in the drawing by rotating about the connection portion 13e with the document reading sensor 1 provided on the leading end side as an axis, and the spring 12 extends in the direction C in the drawing. I do.

In this way, the original reading sensor 1 is controlled by the interlocking of the spring 12, the link mechanism 13, and the solenoid 14 so as to be substantially in contact with and separated from the opposing roller. When reading, the original reading sensor 1 is held in a direction substantially in contact with the opposing roller, and when the original S is not read by the original reading sensor 1, the original reading sensor 1 can be operated to be separated from the opposing roller 2.

That is, the solenoid 14 can switch between the energized state and the deactivated state of the link mechanism 13 by a timing signal or the like from a control unit (not shown) of the document reading apparatus. The configuration is linked to the document reading sensor 1, and the movable state of the document reading sensor 1 (vertical direction B in the present embodiment) can be controlled by the energized and de-energized states of the solenoid 14.
The present invention can be configured with a simple and inexpensive configuration.

In FIG. 2, the path conveyed by the paper feed roller 3, the opposing roller 2, and the paper discharge roller 4 corresponds to a document conveying path, and includes a spring 12 and a link mechanism 1.
3 and the solenoid 14 constitute a separating mechanism.

Referring to FIGS. 3 and 4, the operation transition of the discharged image reading unit 10 from the time when the document S is fed from the document placing table 5 to the time when the document S is discharged through the discharge roller 4 will be described. This will be described below.

As described in the above description of FIG. 1, the feed roller 3, the opposing roller 2, and the discharge roller 4
Are connected by a connecting member such as a gear portion and are driven by a driving source such as a single motor to constitute a driving mechanism.
As shown in FIG. 4 and FIG. 4, the movable timings of these rollers 2, 3, and 4 are the same. The original S may be conveyed at the same time depending on the positions of the paper feed roller 3, the opposing roller 2, and the paper discharge roller 4, so that these rollers are connected and driven, and the original S is conveyed. It is needless to say that the peripheral speeds are adjusted so that there is no difference and no bending occurs.

First, FIG. 3A shows that the original S
At this point, the solenoid 14 is in the deenergized state, the lever portion 14a is in the retracted state, and the link portion 13b has moved to the right in the drawing. Since the link 13d is located below the shaft support 13c as the axis center, the original reading sensor 1 is held at the lower position, and the original reading sensor 1 and the opposing roller 2 In a state of being separated.

Next, FIG. 3B shows a state in which the document S has passed through the opposing portion of the paper feed roller and has begun to contact the actuator 15 of the paper detection sensor 11. Since the document S has not reached the document reading position 6 in the state where the sheet is detected, the state in which the opposing roller 2 and the document reading sensor 1 are separated from each other is maintained in the same manner as in FIG.

FIG. 3C shows a state in which the original S is inserted and conveyed between the original reading sensor 1 and the opposing roller 2 and an image on the original S is being read by the original reading sensor 1.

In the state of FIG. 3B, the sheet detection sensor 1
1 detects the leading edge of the document S, and a paper detection sensor 11
The distance between the original detection position and the original reading position 6 and the conveyance speed of the original S can be set using the design values or set at the time of shipment from the factory. The timing at which S reaches the document reading position 6 is determined based on the detection timing of the paper detection sensor 11, and the lever portion 14 a of the solenoid 14 is pulled out.
The document reading sensor 1 is moved upward through the link mechanism 13 and is brought close to or in contact with the opposing roller 2.

In this case, the timing at which the original reading sensor 1 comes into contact with or substantially comes into contact with the sheet detecting sensor 11
May be operated immediately from the detection timing of the sheet detection sensor 1, but depending on the arrangement state of the apparatus, the paper detection sensor 1
When the distance between the document reading position 1 and the document reading position 10 is long, or when the conveying speed of the document is slow even if the distance is short, the operation is performed after a lapse of a predetermined time from the detection timing of the paper detection sensor 11. By doing so, the state in which the document reading sensor 1 is in contact with or substantially in contact with the opposing roller 2 can be minimized. This also applies to the separation timing of the document reading sensor 1. The time interval of contact is determined from the relationship between the document conveying speed and the paper size, and the document reading sensor 1 is read only for that time. can do.

In this way, the leading edge position of the document S is matched with the document reading timing of the document detection sensor 1 at the document reading position 6, and as shown in FIG. The rear end is the actuator 15 of the paper detection sensor 8
The image reading of the document S is continued until the position of the document S is exceeded.

FIG. 4B shows a state immediately after the trailing end of the document S has passed the actuator 15 of the sheet detection sensor 8. Since the end has not reached, the document reading sensor 1 is not separated from the opposing roller 2 and maintains a state of contact or close proximity.

In the same manner as the setting of the document reading timing described above, the sheet detection sensor 11, the document reading position 6, and the document S
Since the transport speed relationship can be ascertained on the apparatus side, the document reading stop timing at which the rear end of the document S reaches the document reading position 6 from the timing at which the document S passes through the actuator 15 in FIG. Is possible.

Accordingly, as shown in FIG.
The document reading sensor 1 and the opposing roller 2 contacted or approached until the rear end of the document S reaches the document reading position. At the timing when the rear end of the document S reaches the document reading position, based on the timing at which the document S passes through the actuator 15. As shown in FIG. 4C, the lever 14a of the solenoid 14 is retracted so as to separate the original reading sensor 1 from the opposing roller 2.

The timing for separating the original reading sensor 1 is not based on the passage time, but when the paper detecting sensor 11 detects that the original state (state in which the actuator 15 returns to the original state), It may be determined that the rear end has passed the paper detection sensor 11 and the document reading sensor 1 may be separated immediately after that or more preferably after a predetermined time after passing the rear end.

In this case, no new sensor is required,
Since the passage of the trailing end of the document can be detected and the trailing end is actually detected, the separation timing can be reliably set, and the contact period can be shortened.

In the above-described embodiment, the paper detection sensor 11 is provided only on the upstream side of the document conveyance path. However, for example, a means for newly detecting discharge on the downstream side of the document reading position 6 is provided. May be provided. Further, the paper detection sensor 11 may be realized by a reflection type or transmission type optical sensor.

Further, in the above-described embodiment, the means for conveying the original at the original reading position 6 is constituted by the roller-shaped opposing roller 2. The conveyed belt means may be realized by being opposed to each other.

As described above, when the original S is the original reading sensor 1
Since the original reading sensor 1 can be brought into contact with or in proximity to the original during a period during which the original reading position 6 passes, the original reading sensor and the opposing roller 2 come into contact with or approach each other for a minimum period. The driving load generated between the rollers can be minimized.
And the abrasion of the original reading sensor 1 can be reduced.

[0079]

According to the present invention, there is provided an original reading apparatus for reading an original image in a close contact state or a substantially close contact state,
The document reading sensor is provided to face a document reading unit that reads a document image, and when reading the document by the document reading sensor, an opposing roller that inserts and conveys the document that has reached the document reading unit, A paper feed roller provided upstream of the document transport path where the document is transported and transporting the document to the document reading section, and a paper feed roller provided downstream of the document transport section than the document reading section, and the opposed roller A document reading device further comprising a discharge roller for conveying the conveyed document to the downstream side of the document conveyance path, wherein the document reading unit is brought into close contact or substantially close contact with the opposing roller when reading the document. A separation / contact mechanism that can be held in two states separated from the opposing roller, and a rotation axis coaxial with rotation axes of the opposing roller, the paper feed roller, and the paper discharge roller Through a connecting member having, it is characterized in that a drive mechanism for coupling rotational drive of the rollers by a single drive source.

Therefore, by making the original reading sensor and the opposing roller detachable from each other, the original reading sensor and the opposing roller are in close contact or almost in close contact with each other only for a minimum necessary period.
Excessive load is required due to the contact and wear between the document reading sensor and the opposing roller, the opposing roller and the document reading section are shaved, the life is shortened, the reading position fluctuates, and inside the machine due to shaved powder In addition, there is an effect that problems such as causing contamination of a document or a document can be avoided or reduced.

Further, in the conventional document reading apparatus, the opposing roller side facing the document reading section can be separated and brought into contact.
Although the mechanism of the opposing roller portion became complicated and the reading accuracy was reduced due to the reduction in the mechanism accuracy, this configuration was described above while simplifying the structure of the drive system and preventing the reduction in the mechanism accuracy. There is an effect that problems caused by friction between the document reading unit and the opposed roller can be solved or reduced.

According to the document reading apparatus of the present invention, the document reading section is provided upstream of the document reading section in the document transport path, and starts reading the document in the document reading section by detecting the leading edge position of the document. A reading start time detecting means for detecting a document reading start time, wherein the separation / contact mechanism is configured to bring the document reading portion into close contact state or substantially close contact state with the opposed roller based on a detection result by the reading start time detection means; The original reading unit and the opposing roller are in close contact or almost in close contact with each other only for a minimum period by the reading start timing detecting means, so that unnecessary wear does not occur. There is an effect that the wear of the document reading sensor and the opposing roller can be minimized.

Further, according to the document reading apparatus of the present invention, the document reading apparatus is provided on the upstream side of the document conveying path from the document reading section,
Reading start time detecting means for detecting a document reading start time at which the document reading section starts reading the document by detecting a leading edge position of the document; and transporting between the reading start time detecting means and the document reading section. Storage means for storing the transfer time information required for the reading, and the separation / contact mechanism is configured to be able to hold the separated state based on the transfer time information and the detection result by the reading start timing detecting means. It is not necessary to newly provide a means for detecting whether or not the rear end of the document has passed the document reading unit,
There is an effect that the separation timing can be determined while preventing an increase in manufacturing cost.

In addition, since the timing of the separation state as well as the close contact state is determined, the time required for the original reading section and the opposing roller to be in close contact or substantially close contact can be minimized, and unnecessary wear does not occur. Also, wear of the document reading sensor and the opposing roller can be minimized.

Further, according to the original reading apparatus of the present invention, the reading start timing detecting means can further detect the rear end position of the original. Based on the result of detection by the timing detecting means, it is characterized in that it can be held in the above-mentioned separated state, so a means for detecting whether or not the rear end of the document has passed the document reading section is newly provided. There is no need to provide, and there is an effect that the separation timing can be determined while preventing an increase in manufacturing cost.

Further, since it is possible to reliably detect that the trailing edge of the original has passed, it is possible to reliably detect the trailing edge of the original even when the leading edge of the original has passed and slipped due to the transport state or when the transport speed has changed. The document reading unit can be separated with high accuracy.

Furthermore, since the timing of the separation state as well as the close contact state is determined, the time required for the original reading section and the opposing roller to come into close contact or substantially close contact can be minimized, and unnecessary wear does not occur. Also, wear of the document reading sensor and the opposing roller can be minimized.

Further, in the original reading apparatus according to the present invention, the separating mechanism includes a solenoid, a link mechanism for operating the original reading sensor in conjunction with the solenoid, and an opposite roller. And a biasing means for biasing the document reading device in a direction opposite to the side. Therefore, there is an effect that the separation / contact mechanism of the document reading unit of the document reading device can be realized with a low-cost and simple configuration.

[Brief description of the drawings]

FIG. 1 is a schematic overall sectional view of a document reading apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part for describing a configuration of a document reading unit of the document reading apparatus according to the embodiment of the present invention.

FIG. 3 is a cross-sectional view of a main part for describing an operation transition of a document reading unit of the document reading apparatus according to the embodiment of the present invention.

FIG. 4 is an essential part cross-sectional view for explaining an operation transition of a document reading section of the document reading apparatus according to the embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 contact type original reading sensor (original reading sensor) 2 opposed roller 3 paper feed roller 4 discharge roller 5 original placing table 6 original reading position 9 transport roller 10 original reading section 11 paper detection sensor 12 spring 12 a upper end 12 b lower end 13 Link mechanism 13a, 13e Connection part 13b, 13d Link part 13c Shaft support part 14 Solenoid 14a Lever part 14b Lever tip part 15 Actuator 16 Discharge paper guide

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Keisuke Hara 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Takashi Goto 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka Sharp F term (reference) 2H076 BA15 EA14 3F343 FA02 FB01 GB01 GC01 GD01 JA01 JD08 JD33 LD04 LD11 LD24 5C062 AA02 AB02 AB32 AB33 AB35 AD01 AD06 BA00 5C072 AA01 BA02 BA13 DA25 EA07 NA01

Claims (5)

[Claims] A document reading sensor for reading a document image in a close contact state or a substantially close contact state; and a document reading sensor provided to face a document reading section for reading a document image. An opposing roller for inserting and transporting the document that has reached the document reading unit, and provided upstream of the document transport path where the document is transported relative to the document reading unit;
A paper feed roller for transporting a document to the document reading unit, provided on the downstream side of the document transport path from the document reading unit,
A document reading device further comprising a discharge roller for conveying the document conveyed by the opposing roller to a downstream side of the document conveying path; A separation / contact mechanism that can be held in each of two states of a separated state and a state separated from the opposing roller; and a rotation axis coaxial with the rotation axes of the opposing roller, the paper feed roller, and the paper discharge roller. And a drive mechanism for connecting and rotating the roller group by a single drive source via a connecting member provided therein. 2. A reading start provided at an upstream side of the document conveying path from the document reading section and detecting a leading edge position of the document to detect a document reading start time at which the document reading section starts reading the document. Timing detecting means, wherein the separation / contact mechanism is capable of holding the document reading portion in a close contact state or a substantially close contact state with the opposed roller based on a detection result by the reading start timing detecting means. The document reading device according to claim 1. 3. A reading start provided at an upstream side of the document conveying path from the document reading section and detecting a leading edge position of the document to detect a document reading start time at which the document reading section starts reading the document. Timing detecting means, and storage means for storing transport time information required for transporting between the reading start timing detecting means and the document reading section, wherein the separation mechanism includes the transport time information, 3. The document reading apparatus according to claim 1, wherein the separated state can be maintained based on a detection result by a start time detecting unit. 4. The reading start time detecting means can further detect a rear end position of the document, and the separating mechanism can hold the separated state based on a detection result by the reading start time detecting means. 3. The document reading apparatus according to claim 2, wherein: 5. The separation / contact mechanism includes a solenoid, a link mechanism that performs a separation / contact operation of the document reading sensor in conjunction with the solenoid, and biases the document reading sensor to a side opposite to the counter roller. 2. The document reading apparatus according to claim 1, further comprising an urging unit that performs the operation.