JP3364316B2 - Reader - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reading device which is applied to an image forming apparatus such as a copying machine or a facsimile and reads image information of an original using a contact image sensor.

[0002]

2. Description of the Related Art In a conventional scanner (reading device), C
Although a CD image sensor or a contact image sensor is used, in a book-compatible scanner that reads document image information while the document is fixed, the contact image sensor has a smaller outer thickness than the CCD image sensor. This has the advantages that the drive system is greatly simplified and adjustment is almost unnecessary, and that "distortion" due to the reduction optical system does not occur in the read image.

However, the contact image sensor is
Although it has the above-mentioned advantages, there is a problem that if the support structure is not accurate, the optimum focus is not stable and accurate image information cannot be read.

In the image scanner disclosed in Japanese Patent Laid-Open No. 3-276958, a distance regulating mechanism is interposed between a carriage base on which a contact image sensor is mounted and a contact glass, and the contact image sensor with respect to a reading reference surface of the contact glass. The positional relationship (focus) of is made constant.

[0005]

As a method of keeping the focus of the contact-type image sensor constant, it is effective to press the contact-type image sensor in pressure contact with a contact glass through some means.

However, in a reading apparatus which is equipped with an automatic document feeder (ADF) and is capable of reading an original by using the ADF and an original by the book-corresponding scanner function, and having different reading positions for reading both originals. If both reading positions are installed on the same contact glass, there is no problem in moving the contact image sensor in the pressure contact state.

However, when both reading positions are installed on the same contact glass, the conveying roller cannot be installed below the upper surface of the glass in the ADF, which makes it impossible to reduce the size, and as shown in FIG. When the guide body 1 for guiding the conveyance of the document is simply placed on the contact glass 2,
As shown by the chain double-dashed line, in the portion of the conveyance path 3 that faces the contact glass 2, the guide body 1 tends to project in the conveyance path 3 on the downstream side of the conveyance and the conveyance failure of the document is likely to occur. Therefore, in order to eliminate the transport obstacle, as shown in FIG. 6, a portion of the contact glass 2 on which the guide body 1 is installed is cut to form a recess 4, and a lower portion of the guide body 1 is formed in the recess 4. It is necessary to devise such a device as to prevent the transportation obstacle 3 from being formed in the transportation path 3.

On the other hand, if independent contact glasses are provided at both reading positions, the contact glass is pressed by the gap control mechanism of the contact image sensor due to a step formed at the boundary between the installation positions of both contact glasses. The smooth movement is disturbed and an impact is generated, and there is a possibility that the contact type image or the distance regulation mechanism may be damaged by repeated operation.

It is an object of the present invention to provide a reading device which uses a contact image sensor and can stably read an image for a long period of time.

[0010]

In order to achieve the above-mentioned object, a reading apparatus of the present invention has an AD which has a moving original contact glass in the original reading portion and which automatically conveys the original.
F, a document mounting contact glass, which is provided at a position different from that of the ADF, and on which a document is mounted, and reciprocates below the document mounting contact glass for reading a document, and during automatic document transportation, a contact image sensor for document reading by the mobile and fixed state to the contact glass for movement document, the contact with the contact glass or the document placement glass platen for the moving document with both the contact glass and the contact image sensor A spacer that holds the interval constant, a pressing member that presses the contact image sensor against the moving document contact glass or the document mounting contact glass via the spacer, the ADF in the contact image sensor and the document mounting. When moving between the contact glass for mounting, the spacer can contact the moving area of the spacer. Characterized by comprising a et apart separating member.

Further, the separating member is composed of a driving unit for moving the contact type image sensor up and down and a driving source.

Further, the drive source of the separating member is a motor for rotationally driving the drive portion.

Further, the drive source of the separating member is a solenoid device for linearly moving the drive portion by electromagnetic action.

Further, the separating member is a protrusion that moves the contact image sensor in the spacer separating direction.

Further, an ADF which has a moving original contact glass in the original reading portion and which automatically conveys the original,
The original placing contact glass, which is provided at a position different from the ADF, and on which the original is placed, reciprocates between the original placing contact glass for reading the original and the moving original for automatic original feeding. A contact type image sensor that moves to the contact glass and reads the document in a fixed state, and a constant distance between both contact glasses and the contact type image sensor by contacting the moving document contact glass or the document mounting contact glass. And a pressing member that presses the contact image sensor against the moving original contact glass or the original placing contact glass via the spacer, and the ADF and the original placing contact in the moving area of the spacer. It is characterized in that it is provided with a thin plate material covering a boundary portion with the glass.

[0016]

The reading device according to the present invention having the above-described structure is provided with the ADF and the original placing contact glass for reading the original in a fixed state, and the original placing contact glass is provided on the original reading portion of the ADF. Since independent contact glass for moving originals is provided, it is possible to read two types of original information, sheet-like originals and book-like originals.
It is provided with the contact glass to F itself desorption as a unit facilitates handling.

The reading of the document information can be performed by a common contact image sensor, and at the time of reading, the distance between the contact image sensor and the both contact glasses is kept constant by the spacer, so that the optimum focal length is maintained. .

Moreover, AD in the contact image sensor
Even if there is a moving obstacle such as a boundary or a step in the moving area between F and the document placing contact glass, the contact image sensor moves with the spacer separated from the portion, so that the contact image The sensor and the spacer can be prevented from being damaged or dimensionally displaced, and the optimum focal length can be maintained for a long period of time without being impacted.

As the separating means for separating the spacer from the movement obstructing portion, it is conceivable to use a motor or a solenoid device as a driving source, or to provide a separating projection at the movement obstructing portion without using the driving source.

By providing a thin plate material at the boundary between the ADF and the document mounting contact glass, the spacer can be smoothly moved even at the boundary, and the impact on the contact image sensor and the spacer can be suppressed at low cost. It

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front sectional view showing a schematic configuration of a first embodiment of the present invention, FIG. 2 is a side sectional view of the first embodiment of FIG. 1, 11 is an apparatus main body, 12 is an upper portion of the apparatus main body 11. An original placing contact glass, which is fixed on the original and placed on the upper surface,
Reference numeral 13 denotes an automatic document feeder (AD
F), 14 is a traveling body that reciprocates between the document mounting contact glass 12 and the lower surface of the ADF 13, 15 is a contact image sensor mounted on the traveling body 14, and 16 is a guide shaft that guides the movement of the traveling body 14. Is.

The ADF 13 includes a paper feed roller 21 for sequentially feeding the originals stacked on the original table 20, and a plurality of conveying roller pairs 22.
And a guide plate 23 that forms a conveyance path for guiding the conveyance of documents.
And a unit pair composed of a moving original contact glass 24 and the like installed on the conveyance path of the original read portion, which facilitates attachment and detachment with respect to the apparatus main body 11 and handling.

As shown in FIG. 2, one side of the traveling body 14 is supported by the guide shaft 16, and the other side of the apparatus main body 11 is supported.
A guide projection (26) slidably mounted on a rail body (25) provided on the base is formed. Further, an end portion of a wire 27 for towing the traveling body 14 to move it in a predetermined direction is fixed to a side portion of the traveling body 14 on the guide shaft 16 side. Wire 27
It is wound around a pulley 28 and moved by the rotation of a motor 29 that drives the pulley 28.

The contact-type image sensor 15 moves on the lower surface of the original placing contact glass 12 or AD
The document is optically read in a known manner by stopping on the lower surface of the moving document contact glass 24 of F13.
A roller 30, which is a spacer, is rotatably provided above the contact image sensor 15. Further, on both sides of the contact type image sensor 15, a shaft 31 which is erected on the traveling body 14 is provided.
In response to the elastic force of the push-up spring 32, which is a pressing member provided in
The roller 30 may be replaced with the contact glass 12 for placing the original.
An overhanging piece 33 that presses against the moving original contact glass 24 is provided.

A rack 35 is fixed to a side portion of the contact type image sensor 15 in the longitudinal direction, a drive motor 36 is provided on the traveling body 14, and an output shaft of the drive motor 36 is meshed with the rack 35 to provide a contact type image. A pinion gear 37 having a partly toothless shape for moving the sensor 15 downward is fixed. The rack 35
The drive unit for driving the pinion gear 37 and the drive motor 36 as a drive source constitute a separating member for separating the roller 30 from the document mounting contact glass 12 or the lower surface of the ADF 13.

In the first embodiment having the above-mentioned structure, when reading an original placed on the original placing contact glass 12,
The roller 30 is elastically contacted with the lower surface of the original placing contact glass 12 by the elastic force of the push-up spring 32, and the contact body image sensor 15 of the traveling body 14 is separated from the original placing contact glass 12 by the roller 30. The guide shaft
16 Guided by the rail body 25, the wire 27 pulls to travel in a predetermined direction. The document is read by the contact image sensor 15 during this traveling.

When the reading of the original placed on the original placing contact glass 12 is shifted to the reading of the original by the ADF 13, the drive motor 36 is operated to rotate the pinion gear 37. The rotated pinion gear 37 meshes with the rack 35 to move the contact image sensor 15 downward. By this movement, the roller 30 is separated from the original placing contact glass 12.

The roller 30 is the contact glass 12 for placing the original.
The moving body 14 is moved in the direction of the ADF 13 in a state of being separated from, and the contact image sensor 15 is positioned on the lower surface of the moving original contact glass 24 of the ADF 13. In this state, the engagement between the pinion gear 37 and the rack 35 is released. Then,
Roller 30 is in elastic contact with the lower surface of the moving original contact glass 24 to hold the distance between the contact image sensor 15 and the moving original contact glass 24 to be constant. Thereafter, when the ADF 13 is operated, the original is conveyed to the moving original contact glass 24, and the moving original is read by the contact image sensor 15 in a fixed state.

In the case of shifting from the reading of the original by the ADF 13 to the reading of the original by the original placing contact glass 12, the drive motor 36 is operated to rotate the pinion gear 37 and mesh with the rack 35 as described above. Let roller 30
Is moved away from the ADF 13, and the running body 14 is transferred to the original placing contact glass 12.

As described above, the original placing contact glass
When the traveling body 14 and the contact image sensor 15 are moved between the ADF 13 and the ADF 13, the roller 30 exists in the moving area by separating from the contactable portion in the moving area between the document placing contact glass 12 and the ADF 13. It is possible to prevent the roller 30 from being damaged due to a boundary, a step, or the like, or to generate vibration at the time of transfer to transmit an impact to the contact-type image sensor 15 to cause an adverse effect. , 24 and contact image sensor 15
By maintaining a constant interval between and, the depth of focus of the contact image sensor 15 can be stabilized, and good document reading can be performed.

FIG. 3 is a front sectional view of an essential part of the second embodiment of the present invention. In the following description, FIG.
Members corresponding to those described with reference to FIG. 2 are designated by the same reference numerals, and detailed description thereof is omitted.

In the second embodiment, the separating member is driven by a solenoid device 41 for moving the plunger 40 in and out by electromagnetic action, and the plunger 40 and the contact type image sensor 15 so as to be lowered by the plunger 40. The drive unit is a projecting arm portion 42 projecting to the side, and the contact type image sensor 15 and the roller 30 are mounted on the original document as in the first embodiment by turning on / off the solenoid device 41. The contact glass 12 for mounting or the ADF 13 is lowered with relatively low noise.

FIGS. 4 (a) and 4 (b) are front sectional views for explaining the structure and operation of the main part of the third embodiment of the present invention. A protrusion 46, which is a separating member, is provided at the boundary 45 between the contact glass 12 and the ADF 13 where the contact glass 12 and the ADF 13 are installed. The rollers 30 are prevented from coming into contact with each other to prevent the roller 30 from being damaged or impacted at the boundary portion 45 when the traveling body 14 moves.

Unlike the first and second embodiments, the third embodiment does not require an electric drive source such as a motor or a solenoid device or an electric control system, and has a simple structure.
Since the roller is vertically moved in the same manner as in the second embodiment, it is advantageous in terms of cost and space saving.

FIG. 5 is a front sectional view of an essential part of the fourth embodiment of the present invention. In the fourth embodiment, a thin portion is formed so as to cover a boundary portion 45 between the document placing contact glass 12 and the ADF 13. A sheet 50, which is a plate material, is attached, and the roller 30 of the contact image sensor 15 is always in contact with the document mounting contact glass 12 and the ADF 13 when the traveling body 14 is moved.
The transition of the roller 30 in the above is smoothed by the presence of the sheet 50, the impact received at the boundary portion 45 is made as small as possible, and the outer periphery of the roller is protected.

In the fourth embodiment, impact can be prevented from being applied to the contact image sensor 15 and the roller 30 at a low cost, and the roller 30 can be prevented from being damaged.

[0038]

As described above, in the reading apparatus of the present invention, according to the first aspect of the present invention, the ADF is a unit body provided with the contact glass for placing a document and the contact glass for a moving document independent of the contact glass for placing the document. In addition, it can be easily attached and detached and handled, and it has a simple structure in which reading is performed on both contact glasses with a common contact image sensor. Furthermore, the distance between both contact glasses and the contact image sensor is increased. The spacer that keeps the constant contact is separated by the separating member so that it does not come into contact with the boundaries, steps, etc. existing in the moving area between both contact glasses, so that no impact is applied to the spacer when the contact type image sensor moves Prevents damage and dimensional deviation from occurring in the image sensor or spacer, and maintains the optimum focal length for a long period of time. It can be performed good image reading.

According to the second, third, and fourth aspects of the present invention, the contacting / separating operation with respect to the contactable portion of the spacer is ensured by the separating member for moving the contact type image sensor up and down by using the motor or the solenoid device as a driving source. You can do it.

According to the fifth aspect of the present invention, the contact image sensor can be moved in the spacer separating direction by using the protrusion, and the separating member has a simple structure and is provided at low cost.

According to the sixth aspect of the present invention, the same effect as that of the first aspect of the invention can be obtained, and by covering the boundary portion between the ADF and the document mounting contact glass with a thin plate material, the boundary portion is covered. The spacer can be moved smoothly, the structure is simple and low-cost, and the impact on the spacer and the contact image sensor can be suppressed, and the optimum focal length can be maintained for a long period of time, and good image reading can be performed.

[Brief description of drawings]

FIG. 1 is a front sectional view showing a schematic configuration of a first embodiment of a reading device of the present invention.

FIG. 2 is a side sectional view of the first embodiment of FIG.

FIG. 3 is a front sectional view of a main part in a second embodiment of the present invention.

FIG. 4 is a front sectional view for explaining a configuration and an operation of a main part in a third embodiment of the present invention.

FIG. 5 is a front sectional view of a main part in a fourth embodiment of the present invention.

FIG. 6 is an explanatory diagram for explaining a problem of the conventional reading device.

[Explanation of symbols]

12 ... Original placement contact glass, 13 ... ADF (automatic document feeder), 14 ... Traveling body, 15 ... Adhesive image sensor, 21 ... Paper feeding roller, 22 ... Conveying roller pair, 23 ... Guide plate, 24 ... Contact glass for moving documents , 30 ... Roller (spacer), 31 ... Shaft, 32 ... Push-up spring (pressing member),
35 ... Rack (drive unit), 36 ... Drive motor (drive source),
37 ... Pinion gear (driving part), 40 ... Plunger (driving part), 41 ... Solenoid device (driving source), 42 ... Projecting arm part
(Driving part), 45 ... boundary part, 46 ... protrusion (separating member),
50 ... Sheet (thin plate material).

Claims (6)

(57) [Claims] 1. An original document having a moving original contact glass at a portion to be read, and an automatic original document conveying section for automatically conveying the original document, and an original document placed at a position different from the automatic original document conveying section. Contact type that reciprocates between the placing contact glass and the lower side of the original placing contact glass for reading the original, and moves to the moving original contact glass during automatic original feeding to read the original in a fixed state The image sensor, a spacer that contacts the contact glass for moving originals or the contact glass for placing originals and keeps a constant gap between both contact glasses and the contact image sensor, and the contact image sensor via the spacer. A pressing member for pressing the moving original contact glass or the original placing contact glass,
A reading device, comprising: a separating member that separates the spacer from a contactable portion in a moving area of the contact type image sensor when the automatic document conveying section and the document mounting contact glass are moved. 2. The reading device according to claim 1, wherein the separating member is composed of a drive unit and a drive source for moving the contact-type image sensor up and down. 3. The reading device according to claim 2, wherein the drive source of the separation member is a motor that rotationally drives the drive unit. 4. The reading device according to claim 2, wherein the drive source of the separation member is a solenoid device that linearly moves the drive unit by electromagnetic action. 5. The reading apparatus according to claim 1, wherein the separating member is a protrusion that moves the contact image sensor in the spacer separating direction. 6. An automatic document feeder having a moving document contact glass in a document reading portion, and an automatic document feeder for automatically feeding the original, and an original placed on a position different from the automatic document feeder, and on which the original is placed. Contact type that reciprocates between the placing contact glass and the lower side of the original placing contact glass for reading the original, and moves to the moving original contact glass during automatic original feeding to read the original in a fixed state image sensor and, a spacer for holding a distance in contact with the contact glass or the document placement glass platen for the moving document with both the contact glass and the contact image sensor constant, the contact type image sensor via a spacer of this A pressing member for pressing the moving original contact glass or the original placing contact glass
A reading device, comprising: a thin plate member covering a boundary portion between the automatic document feeder and a document mounting contact glass in a moving region of the spacer.