JP3201952B2 - Image reading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus (hereinafter, also referred to as "scanner") for reading character or graphic information on a paper medium as image information. The present invention relates to a self-propelled reading unit that can be used as a handy scanner or a flatbed scanner.

[0002]

2. Description of the Related Art A general-purpose image reading apparatus used as a general document input apparatus includes a flatbed scanner for reading an original placed on a transparent flat plate, and an ADF (automatic document feeder) for reading a sheet-like original while feeding it. ) There are scanners and handy scanners. Flatbed scanners are characterized by high reading accuracy and the ability to read bound documents such as books. on the other hand,
The ADF scanner can automatically feed a plurality of sheet-shaped originals and continuously read the same, and is generally smaller than a flatbed scanner. In addition, the handy scanner is simple and there is no limit on the length of the read document, but the read quality tends to deteriorate. Recently, ADF scanners that can automatically process documents and have a relatively small installation space are preferred.
However, the ADF scanner is inconvenient in that it cannot read a large document that cannot be inserted into the scanner or cannot read a book with a stitch.

As one means for solving this problem, A
ADF scanner that unitizes a part including an optical unit and a feed roller of a DF scanner (hereinafter, the unitized unit is referred to as a “handy unit”), and which can be used as a handy scanner by removing the unit. Has been advocated.

FIG. 21 shows an example of such a conventional ADF scanner, which comprises a base frame 1 and a handy unit 2 removably mounted thereon. The optical unit 3 is built in the handy unit 2, and a driven feed roller 42 is mounted on the handy unit 2. The optical unit 3
This is a reduction optical system including a light source lamp 34, three reflecting mirrors 31, an imaging lens 32, and a one-dimensional image sensor 33.

On the other hand, a paper feed table 15,
Pick (paper take-out) roller 43, paper separation pad 4
4. Drive side feed roller 41 and paper feed motor 45
The rotation of the paper feed motor 45 is transmitted to the pick roller 43 and the feed roller 41 via gear trains 46 and 47. In a normal apparatus, a clutch is interposed in a gear train 46 for driving the pick roller 43, and when a sheet is fed by the feed roller 41,
The pick roller 43 is set in a free rotation state.

The original on the paper feed table 15 is picked up by a pick roller 43.
The paper is separated and fed one by one by the paper separation pad 44 and the feed roller 41 and the driven side feed roller 4 are separated.
2 and read while being sent at a predetermined speed.
When reading a large manuscript or book, the handy unit 2 is detached from the base frame 1 and the driven side feed roller 42 is brought into contact with the manuscript surface and read by hand.

According to the above structure, the ADF scanner can be used as a handy scanner. However, since this type of conventional device has a structure in which the handy unit 2 is mounted on the base frame 1 on which the pick roller 43, the drive side feed roller 41, the paper feed motor and the like are mounted, the device becomes large and the number of parts increases. However, there was a problem that it became expensive.

On the other hand, as a small ADF scanner, FIG.
The following devices are known. This device omits the feed roller on the pick roller side and is called a two-roller type or the like. In the illustrated device, the pick roller 4
3 and the drive-side feed roller 41 are mounted on the upper unit frame 21, and the paper feed table 15, the separation pad 44, the feed-side driven feed roller 42 and the stacker 16 are mounted on the lower base frame 1. . The optical unit 3 includes a light source lamp 34, a rod lens array 3
The apparatus is downsized by adopting an erect equal-size type having a two-dimensional and one-dimensional image sensor 33.

In the ADF scanner, it is necessary to precisely regulate the paper speed at the time of reading the original on the feed roller side. When the paper is fed by the feed roller, the pick roller is freely rotated to loosen the paper. It is common to prevent slippage due to overload. When the next sheet is fed immediately after the previously fed sheet has passed through the pick roller, the sheet edge detection sensor PS cannot detect the sheet edge of each sheet, and the reading reference position cannot be set. . In an apparatus as shown in FIG.
These operations are performed by the clutch interposed in the gear train 46 for driving the pick roller.
In the roller type apparatus, a mechanism as shown in FIG. 23 is employed.

This mechanism includes a sleeve 7 having a pick roller shaft 431 provided with a claw 72 for engaging with the tip of a coil spring 71.
3 is mounted so that it cannot rotate relatively, a gear 74 is rotatably mounted on the shaft, and the sleeve 73 and the gear 74 are connected by a coil spring 71. The pick roller 43 has a peripheral speed slightly lower than that of the feed roller 41. It is designed to be driven at a slow speed. In the above mechanism, the pick roller 4
When the sheet 3 is driven by the sheet fed by the feed roller 41 and rotates faster than the roller shaft 431, the tip of the coil spring 71 and the claw 72 of the sleeve are separated from each other, and after the trailing end of the sheet is separated from the pick roller 43, the claw 72 and the coil spring 71 are separated. The pick roller stops until the leading edge of the sheet comes in contact with the sheet, and there is a gap between the previously fed sheet and the next fed sheet.

[0011]

[0008] As shown in FIG.
By removing the unit frame 21 of the second roller type ADF scanner miniaturized from the base frame 1, can be used as the handy scanner, it is thought as miniaturization is possible.

However, in order to use it as a handy scanner, it is necessary to reduce the weight of the handy unit. However, when the weight is reduced, the rigidity of the unit frame and the optical unit is apt to decrease. Deformation due to warpage during resin molding or the pressure of the feed roller, etc., even if the optical unit alone is adjusted for focus, optical axis, etc., reading line deviation due to optical axis deviation occurs when mounted on the device, There is a problem that reading quality is not stable, such as a change in optical path length and a change in reading magnification.

In order to avoid deformation of the frame, it is necessary to add a reinforcing rib or a reinforcing member to increase the rigidity of the entire apparatus.
As the size and weight of the device increase, especially the size and weight of the unit used as a handy scanner increase, the cost of the device increases and the operability when used as a handy scanner decreases.

Further, if a flatbed type image can be read by using the above-described handy unit of the ADF scanner or an independently used handy scanner, it is necessary to perform high-precision reading. It is very convenient when reading books.

The present invention has been made in order to solve such a problem. First, in order to realize a small and lightweight handy unit, a mounting structure of a highly accurate optical unit which is not affected by bending of a molded part or the like. Secondly, to obtain an ADF scanner which can use a handy unit as a small-sized self-propelled handy scanner having a simple structure, and thirdly, to use a handy scanner or a handy unit to obtain a flat bed type. It is an object of the present invention to provide a simple and inexpensive device capable of reading an image.

[0016]

According to a first aspect of the present invention, there is provided an image reading apparatus comprising: a base frame having a document path interposed therebetween;
Feed element 4 is attached to unit frame 21
In the document feed type image reading apparatus provided with the optical units 1 and 42 and the optical unit 3, the optical unit 3 is a unit frame 2
1, the optical unit 3 is rotatably supported around a support shaft 35 parallel to the read line L near both ends of the read line L, and the rotation of the optical unit 3 around the support shaft slides in the radial direction of the rotation. The unit frame 21 is regulated by support pairs 26 and 36 which are freely movable and cannot be relatively moved in the circumferential direction, and the unit frame 21 is supported by the base frame 1 at both ends in the reading line direction.

According to a second aspect of the present invention, there is provided the image reading apparatus according to the first aspect, wherein a feed element provided on the unit frame is driven by a paper feed motor provided in the unit frame. 41 and the unit frame 21 is the base frame 1
The unit frame 21 is detachably mounted on the unit and used as a handy scanner.

[0018]

According to a third aspect of the present invention, there is provided the image reading apparatus according to the second aspect, wherein the unit frame 21 has a pressing arm 61 which can be pulled out at both ends in the reading line direction and is urged in the retracting direction. A free-rotation roller 62 is attached to the tip of the pressure arm around an axis parallel to the reading line L, and the pressure is drawn to the upper surface of both sides of a transparent plate 51 having detachable legs 52. The flatbed reading is performed by bringing the free rotating roller 62 of the arm 61 into contact with the feed element 41 and making contact with the lower surface thereof.

The image reading apparatus according to the fourth aspect is the second aspect.
In the image reading apparatus described above, the unit frame 21 is provided with a pressing arm 61 that can be pulled out and is urged in the retreating direction at both ends in the reading line direction, and has a distal end of the pressing arm around an axis parallel to the reading line L. are freely rotating roller 62 is rotatably attached, is mounted to the proximal end of one 35 of the support pairs with pressure arm 61 including a shaft 35 according to claim 1, comprising a detachable leg 52 The flatbed reading is performed by bringing the free rotating roller 62 of the pressing arm 61 drawn out on the upper surface of both side edges of the transparent plate 51 and the feed element 41 into contact with the lower surface, and optically reading out the pressing arm 61 when the pressing arm 61 is drawn out. The reading line L of the unit 3 moves to the transparent plate 51 side, and the optical path length of the reading light is adjusted at the time of flatbed reading.

The image of claim 5, wherein the reading device includes a sensor PS for detecting the originals, the image reading apparatus according to claim 3 or 4 wherein ES is attached to the unit frame 21, the sensor with pressure arm 61 The transparent plate 51 is provided with a projection 53 which engages with the sensor described above.

According to a sixth aspect of the present invention, there is provided an image reading apparatus according to the second aspect.
In the image reading apparatus described above , a flat bed unit 5 having a space in which the unit frame 21 can be inserted below the rectangular transparent plate 51 and guide rails 56 disposed on both sides of this space is separately provided. A pinion 48 having a diameter smaller than the outer diameter of the feed roller 41 is mounted on the shaft of the feed roller 41 which is axially mounted on the feed roller 41. The rack 49 is provided on the lower surface of the transparent plate 51 of the bed unit so as to mesh with the pinion 48.

According to a seventh aspect of the present invention, there is provided an image reading apparatus according to the sixth aspect.
In the image reading apparatus described above , a pattern 57 that can be read by the optical unit 3 is provided on the lower surface of the transparent plate 51 of the flat bed unit and outside the document reading range in the width direction.

[0024] The image reading apparatus according to the eighth aspect is the sixth aspect.
Or the paper reading sensor PS for detecting the paper edge of the read original or the paper empty sensor ES for detecting the presence or absence of the original in the unit frame 21 in the image reading apparatus according to the seventh embodiment. At the home position 51 when reading the flatbed, a projection 53 is provided to engage with the sensor PS or ES.

The image reading apparatus according to the ninth aspect is the sixth aspect of the invention.
Or the paper reading sensor ES for detecting the paper end of the read original and the paper empty sensor ES for detecting the presence or absence of the original are mounted on the unit frame 21 in the image reading apparatus according to the seventh embodiment. A first projection 53 that engages with one of the sensors PS and ES is provided at a home position 51 when reading the flat bed, and a second projection 54 that engages with the other sensor is provided on the reading end side. Is what it is.

[0026] The image reading apparatus according to the tenth aspect is directed to the image reading apparatus.
6. The image reading apparatus according to 6 or 7, wherein the unit frame 21 is provided with a paper edge detection sensor PS for detecting the paper edge of the read document or a paper empty sensor ES for detecting the presence or absence of the document during automatic paper feed reading. Locking tools 67 and 68 are provided on the frame 1 to engage with the end of the flat bed unit 5 on the home position side. When reading the flat bed, the handy unit 2 is inserted into the guide rail 56 of the flat bed unit and the base is inserted. The frame 1 is mounted on the flatbed unit 5 with the upper surface facing the transparent plate 51, and the sensors PS and ES of the base frame 1 detect the home position of the handy unit 2 when reading the flatbed. It is.

[0027] The image reading apparatus according to the eleventh aspect is characterized in that:
The image reading apparatus according to any one of 6 to 10 , wherein the leg 52 of the flat bed unit 5 is foldable.

[0028]

According to the first and second aspects of the present invention, both longitudinal ends of the unit frame are positioned by the base frame, and the optical unit is mounted on the unit frame at both longitudinal ends. 3
Are not affected by the bending of the unit frame 21 in the longitudinal direction. Further, the optical unit 3 rotates around the support shaft near the reading line to release the bending and thermal deformation of the unit frame 21, so that the optical axis length does not change. Therefore, even if the rigidity of the optical unit 3 and the unit frame 21 is low, it is easy to maintain the accuracy of the optical system.

[0029]

In the apparatus according to the third and fourth aspects, the original is placed on the upper surface of the transparent plate 51, the pressing arm 61 of the unit frame is pulled out, and the transparent plate 51 is sandwiched between the feed element 41 and the free rotation roller 62. By driving the scanner 41, it is possible to inexpensively read a three-dimensional object, a book, a magazine, and the like, which cannot be read by the conventional handy scanner, similarly to the flatbed scanner.

The roller in the handy unit rotates together with the reading start command from the main body, and the handy unit runs on the lower surface of the transparent plate of the flatbed unit to read the original placed on the upper surface of the transparent plate.

In the apparatus according to the third aspect , the optical path length of the optical unit changes by the amount of the light passing through the transparent plate and the reading magnification in the main scanning direction changes in the minus direction. Correct with. For focusing, the optical system is a reduced optical system with a large depth of field, and the change in the optical path length is within the depth of field range.

On the other hand, according to the apparatus of the fourth aspect , it is possible to optically set the flatbed reading to the same conditions as those of the ADF reading and the handy reading without electrically correcting the reading magnification error. Image can be obtained.

According to the fifth aspect of the present invention, when the pressing arm 61 is retracted, the sensor PS advances at the time of reading the ADF and detects the leading and trailing edges of the sheet. Also, when reading the flatbed, the sensor PS retracts with the withdrawal of the pressing arm 61, moves without rubbing the transparent plate during the flatbed reading operation, and the sensor does not slide on the transparent plate. Since there is no slidable object (roller rotational movement), the transparent plate is not damaged, and the apparatus can be used in a good state for a long time. Also, the unit frame 21
To the home position of the projection 5 provided on the transparent plate.
3 can be detected.

According to the invention of claim 6 , by inserting the guide portion 66 of the unit frame 21 into the guide rail 56 of the transparent plate 51, the pinion 48 attached to the roller shaft meshes with the rack 49 on the back side of the transparent plate. . In response to a reading start command from the main body (handy reading and flatbed reading are also selected on the main body side), the feed roller 41 is driven, the handy unit travels along the back surface of the transparent plate, and reads the original placed on the transparent plate surface. As a result, it becomes possible to inexpensively read a bound document such as a three-dimensional object, a book, a magazine, and the like, which cannot be read by a conventional handy scanner, similarly to a flatbed type device.

The optical path length of the optical unit changes by an amount corresponding to the transparent plate, and the reading magnification in the main scanning direction changes in the minus direction. This is corrected by electrically interpolating data. For focusing, the optical system is a reduced optical system having a large depth of field, and the optical path length change is within the depth of field range.

According to the sixth aspect of the present invention, the reading range is widened by the negative reading magnification in the main scanning direction. Claim 7
A pattern 57 is provided in a portion outside the spread reading area in the main scanning direction as described above, and by recognizing the pattern 57, it is possible to determine whether the reading is a hand reading or a flat bed without adding a dedicated sensor. It is possible to automatically recognize whether it is reading.

According to the configuration of claim 8 , the position of the handy unit can be detected without adding a dedicated sensor to the flatbed unit 5.

According to the ninth aspect of the present invention, a prescan operation frequently performed in flatbed reading can be quickly performed without adding a dedicated sensor. That is, it is possible to inexpensively read the document by moving from the home position, performing pre-scanning of the document, waiting at the reading end side, and then performing the main scan by moving from the end side to the home position. Note that the data in the sub-scanning direction is reversed at the time of the main reading, but this can be solved by electrically reversing the data in the main body.

The invention of claim 11 is the invention of claims 6 to 10
In the invention of the above, the flat bed unit 5 when not in use
This is an improvement in the storage capacity of the device.

[0041]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an optical unit according to the present invention will be described with reference to FIGS. In the following description, the term “handy unit” is used, but the mounting structure of the optical unit of the present invention is not limited to a unit used as a handy scanner.

The driven rollers 42, 42 are mounted on the base frame 1 by being urged upward by leaf springs 421. Pick rollers, separation pads, a paper feed table, and the like are also mounted on the base frame 1, but are not shown in the drawing. The base frame 1 has a rectangular box shape that is long in the direction perpendicular to the paper surface of FIG. 1, and is provided with seats 11 and 12 spaced apart in the width direction (paper feed direction) on the upper surfaces at both ends in the longitudinal direction. The lock claw 13 and the lock spring 14 are provided to face each other.

The unit frame 21 of the handy unit
Is a frame having an inverted U-shaped cross section which is elongated in a direction perpendicular to the paper surface of FIG. The unit frame 21 includes connecting members 22 at both longitudinal ends thereof.
The lock pawls 13 and the lock springs 14 are placed on the receiving seats 11 and 12,
Are fixed in the engaged state. The seat 11 on one side of the seat fits into the recess on the bottom surface of the connecting member 22 to position the unit frame 21. The connecting member 22 is provided with a C-section groove 25 opened upward and a long hole 26 long in the sheet feeding direction.

The optical unit 3 is a unit provided with a resin (polycarbonate containing glass fiber, etc.) frame which is long in the direction perpendicular to the plane of FIG. 1 and has pins at right and left sides in the direction perpendicular to the plane of FIG. 35, 36 are provided, the first pin 35 is fitted in the C-section groove 25, and the second pin 36 is fitted in the elongated hole 26, and is held in the unit frame 21. The optical system of the optical unit 3 is a reduction optical system and includes four reflecting mirrors 31 for folding the optical path, and includes an imaging lens 32 and a one-dimensional image sensor 33.
Is built-in. The first pin 35 is provided in such a manner that the position of the original reading line L of the optical system in the paper feed direction coincides with the original reading line L.

The drive-side feed rollers 41 are attached to the unit frame 21 at a portion inside the connecting member 22. The drive-side feed roller 41 is driven by a paper feed motor mounted on the handy unit 2 side, but is not shown in the drawing. These drive mechanisms are mounted on the longitudinal end of the unit frame 21 (outside the optical unit).

The focus and the optical axis of the optical unit 3 are adjusted alone (in a state where the optical unit 3 is not mounted on the unit frame 21). On the other hand, since the unit frame 21 is an elongated molded product, when the unit frame 21 is made thin, distortion tends to occur, and the longitudinal central portion tends to bend upward due to the applied pressure of the driven feed roller 42.

In the structure of the present invention, since the longitudinal ends of the unit frame 21 are positioned by the base frame 1 and the optical unit 3 is mounted on the unit frame 21 at the longitudinal ends, the optical unit 3 is
It is not affected by the bending of the unit frame 21 in the longitudinal direction. Further, the optical unit 3 has the second pin 36 fitted to the unit frame 21 movably fitted along the elongated hole 26, so that even if the unit frame 21 is bent or thermally deformed, the optical axis The length does not change. Slot 2
The vertical distortion of 6 only slightly rotates the optical unit 3 around the first pin 35, so that the optical unit 3 is not deformed. Therefore, in the illustrated device, the first
By managing the positional relationship between the pin 35 and the seat 11 serving as a positioning reference for the unit frame 21,
Reading quality can be guaranteed.

Further, the lock spring 14 is expanded to
By turning the unit frame 21 rightward in FIG. 1 around the engagement portion with the base 3, the handy unit 2 can be easily removed from the base frame 1. Since two drive-side feed rollers 41 are present on the bottom surface of the detached handy unit 2, the detached handy unit can be used as a self-propelled handy scanner. Also, even when the ADF scanner is not used as a handy scanner, the assembly of the base frame 1 and the unit frame 21 as described above makes it possible to easily and accurately assemble the ADF scanner and position the components relative to each other. become able to.

In the configuration in which the handy unit 2 is made detachable, the configuration shown in FIGS.
Can be used to perform flat-bed reading. That is, in FIGS.
1, a pressing arm 61 rotatable downward around an axis perpendicular to the sheet of FIG. 1 in the folding direction, that is, the upper side of FIG. 1 (the lower side of FIG. 3). 1), and a free-rotation roller 62 is axially attached to the tip of the roller in a direction perpendicular to the plane of FIG. Two pressing arms 61 are mounted on both ends of the unit frame 21 so as to be folded outward.

When performing flatbed reading using the handy unit 2, a transparent plate 51 having detachable legs 52 is prepared. The width dimension of this transparent plate is slightly smaller than the longitudinal dimension of the unit frame 21, and the pressure arm 6
It is a dimension that fits inside 1. The hand-held unit 2 removed from the base frame 1 is turned upside down to raise the pressing arm 61, and the transparent plate 51 is inserted between the free rotation roller 62 and the unit frame 21. Then, a leg 52 is attached to the transparent plate 51 to support the transparent plate 51, and a document to be read is placed on the transparent plate 51.

The handy unit 2 is pressed against the lower surface of the transparent plate 51 by the urging force in the direction in which the pressing arm 61 is folded, and the drive-side feed roller 41 is
Abuts the lower surface of. Therefore, if a reading start signal is sent in this state, the feed roller 41 runs along the transparent plate 51 and reads the original on the transparent plate 51. This allows
It becomes possible to read an image of a three-dimensional object or a book, which could not be read by a conventional handy scanner, similarly to a flat bed type device at low cost.

When reading is performed by the method shown in FIGS. 3 and 4, the optical path length of the optical system changes by the thickness of the transparent plate, and the reading magnification in the main scanning direction shifts in the minus direction. Can be corrected by interpolating electrically read data. Also, the optical path length becomes longer by the interposition of this transparent plate, causing a focus shift. However, if an optical unit of a reduced optical system with a sufficiently long optical path length is used, the change in the optical path length will be within the range of the depth of field. And the defocus can be prevented.

When an optical system having a short optical path length is to be used,
When it is desired to prevent a change in the optical path length during flatbed reading, a structure as shown in FIG. 5 can be employed. That is, the first pin 35 described with reference to FIG. 1 is provided at the base end of the pressing arm 61, and the C-shaped groove 25 is provided on the optical unit 3 side, so that the pressing arm 61 swings around the fulcrum pin 63. Then, the reading line portion of the optical unit 3 moves up and down correspondingly. By moving the optical unit 3 forward and backward in the unit frame 21 in conjunction with the rotation of the pressing arm 61 in this manner, it is possible to avoid a change in the optical path length during flatbed reading.

The sheet edge detection sensor PS shown in FIG.
However, in the apparatus mounted on the handy unit 2 side, when performing the above flatbed reading, the sheet edge detection sensor rubs the transparent plate 51. In such a case, as shown in FIG. 6, the pressing arm 61 is extended to the opposite side of the fulcrum pin 63, and a paper end detection sensor PS is provided on the extended portion, so that the pressing force at the time of reading the flat bed is obtained. The paper end detection sensor PS can be retracted by using the rising operation of the pressure arm 61, thereby avoiding the sensor from rubbing the transparent plate 51 and avoiding damage to the sensor and the transparent plate. be able to.

In the case where the sheet edge detection sensor PS is provided on the handy unit 2 side as described above, the protrusions 53 and the like provided on the transparent plate 51 are detected by these sensors PS, so that the flatbed reading is performed. Can be performed by the same control as in the ADF reading.

FIGS. 7 and 8 show a two-roller type embodiment in which one of the rollers provided in the handy unit is a pick roller 43. FIG. In the two-roller type, one driven-side feed roller 42 is provided on the base frame 1, and the separation pad 4 is pressed against the pick roller 43.
4 is attached. The upper surface of the base frame 1 in FIG. 7 is slanted, and an upper extension thereof serves as a sheet feeding table.

The unit frame 21 of the handy unit
Is a lock claw 13 and a lock spring 1 similar to those shown in FIG.
4 and is fixed to the base frame 1. It is preferable that the optical unit 3 is also mounted in the same structure as in FIG. FIG. 7 shows a sheet end detection sensor PS and a paper empty switch ES for detecting the presence or absence of a sheet on the sheet supply table, all of which are mounted on the handy unit 2 side.

FIG. 7 shows a paper feed motor 45 for driving the feed roller 41 and the pick roller 43 and gear trains 46 and 47 of the rotation transmitting mechanism. The pick roller 43 rotates so that its peripheral speed is slightly lower than the peripheral speed of the feed roller 41.
In addition, a one-way clutch is interposed, and the pick roller 43 is pivotally mounted on the pick roller shaft 431 so as to freely rotate by a certain angle by engaging and disengaging the pin 432 and the projection 433 as shown in FIG.

In the above configuration, when used as an ADF scanner, the pin 432 and the projection 433 engage with each other at the position shown by the solid line in FIG. 9, and the pick roller 43 is driven to supply the paper. When the paper is fed by the feed roller, the peripheral speed of the feed roller is faster, so that the pick roller 43 rotates faster than its shaft 431, and the relative positional relationship between the pin 432 and the protrusion 433 is indicated by a dotted line in FIG. As shown. In this state, the pick roller 43 pushes the pin 432 to rotate the pick roller shaft 431 at a speed slightly higher than its original driving speed. This rotation is permitted by a one-way clutch interposed in the gear train 46.

When the trailing edge of the paper leaves the pick roller 43,
The rotation of the pick roller 43 stops, and the pick roller shaft 43
Numeral 1 returns to the original rotation speed, and after rotating from the position of the dotted line to the position of the solid line in FIG. 9, the pick roller 43 is driven.
That is, only during the period in which the pick roller 43 is stopped, an interval is opened between the trailing edge of the preceding sheet and the leading edge of the succeeding sheet,
The sheet edge detection sensor PS can reliably detect the leading edge of the sheet.

On the other hand, the handy unit 2 having such a structure
When the handheld scanner is detached from the base frame 1 and used as a handy scanner, the self-propelling of the handy scanner is performed by the drive side feed roller 41, and the pick roller 43 is always driven. That is, due to the presence of the clutch interposed in the gear train 46, even a very long document can be read as a handy scanner.
You.

In the structure shown in FIG. 7, the same structure as that shown in FIGS. 3 to 6 can be used to perform flat bed reading. However, FIGS. An embodiment in which the movement in the sub-scanning direction can be more accurately performed will be described.

In the embodiment shown in FIGS. 10 to 15, a pinion 48 is provided on the feed roller 42 of the handy unit. The outer diameter of the pinion 48 is slightly smaller than that of the feed roller 41. The longitudinal end of the unit frame 21 is not provided with a biasing arm or the like, and serves as a guide block 66 having a guide slit 65 at the base of the upper surface.

On the other hand, the transparent plate 51 has fixed legs 52 as shown in FIGS.
And a guide flange 55 is provided above the guide rail. Then, at a position facing the pinion 48,
A rack 49 is provided. The pinion 48 and rack 49 displace the teeth so that the PCD is as large as possible.

FIG. 15 shows a state where the handy unit 2 configured as described above is mounted on the transparent plate 51. The handy unit 2 has guide blocks 66 at both ends thereof.
Is guided by the guide rail 56 and the guide flange 55, and the pinion 48 meshes with the rack 49. By driving the feed roller 41 to rotate in this state, the pinion 48 rotates, and the handy unit 2 runs.

In the above configuration, the reading speed in the sub-scanning direction is lower than that in the ADF reading due to the small diameter of the pinion 48, which is corrected by electrically correcting the read data. As described above, the change in the reading magnification in the main scanning direction and the change in the optical path length can be solved by using electric means or an optical system having a long optical path length.

When the flatbed reading is performed in this manner, the reading range is expanded by the amount by which the reading magnification in the main scanning direction becomes a minus direction. Therefore, the portion outside the document reading range on the back side of the transparent plate 51 is shown in FIG. Pattern 5 as shown
By arranging 7 and recognizing it, it is possible to automatically recognize whether the reading state is the handy reading or the flatbed reading.

When the paper end detection sensor PS and the paper empty sensor ES are provided in the handy unit 2 as in the handy unit shown in FIG. 7, flatbed reading is performed using these sensors PS and ES. The fact that the home position of the handy unit 2 can sometimes be detected is the same as in the case of FIG.

When the guide structure of the handy unit as shown in FIG. 15 is adopted, the feed roller 41 is moved to the transparent plate 5 with a slight gap between the feed roller 41 and the transparent plate 51.
1 can be prevented from contacting, so that there is no need to provide a retreat mechanism for the sensor as shown in FIG. 6, which is rather convenient.

Since the sheet edge detection sensor PS and the paper empty sensor EP are usually mounted at positions shifted in the sheet width direction, the respective sensors are applied to both running ends of the transparent plate 51. Providing the projections 53 and 54 (see FIGS. 16 and 17) in contact with each other makes it possible to detect both running ends of the handy unit 2. In addition, it is not necessary to start running the handy unit one by one from the home position side, and it becomes possible to read efficiently.

When the paper end detection sensor PS and the paper empty switch EP are provided on the base frame 1 side, the handy unit 2 removed from the base frame 1 is mounted on the transparent plate 51 as shown in FIG. The base frame 1 is hooked to an end of the transparent plate 51 by a hook 6.
If it is set to be engaged at 7, 68, etc., the home position of the handy unit 2 at the time of flat bed reading can be detected by detecting the handy unit 2 by the paper empty switch ES and the paper end detection sensor PS. Becomes possible.

Also, the legs 52 of the flatbed are shown in FIG.
As shown in FIG. 19, the flatbed unit 5 can be foldable so that it is not in use.
Can be folded and stored.

When the flat bed unit 5 is constructed to be foldable in this manner, as a guide structure for the handy unit 2, a guide provided at an end of the unit frame 21 of the handy unit as shown in FIGS. By guiding the slit 65 with the guide flange 55 on the transparent plate side, the folded thickness of the flatbed unit 5 can be reduced. In this case, if the guide slit 65 of the handy unit is provided between the light source lamp 34 incorporated in the handy unit and the paper feed motor 45, the size in the longitudinal direction of the handy unit 2 is made as small as possible. It is possible to

[Brief description of the drawings]

FIG. 1 is a sectional view of a first embodiment.

FIG. 2 is a schematic perspective view of the apparatus of FIG.

FIG. 3 is a perspective view of a flatbed reading state.

FIG. 4 is a front view of a flatbed reading state.

FIG. 5 is a side view of another structure of the flatbed reading.

FIG. 6 is an enlarged side view showing a means for detecting a home position.

FIG. 7 is a side view of the second embodiment.

FIG. 8 is a schematic perspective view of a second embodiment.

FIG. 9 is an enlarged side view of the mounting structure of the pick roller.

FIG. 10 is a perspective view of a guide structure for reading a flatbed.

FIG. 11 is an enlarged view of a main part of FIG. 10;

FIG. 12 is a perspective view of a flatbed unit.

FIG. 13 is a front view of a guide unit of the flatbed unit.

FIG. 14 is a perspective view of the back side of the flatbed unit.

FIG. 15 is a front view of a flatbed reading state.

FIG. 16 is a side view showing a detection state of a home position.

FIG. 17 is a side view showing a detection state of a reading end.

FIG. 18 is a perspective view showing another example of detection of the home position.

FIG. 19 is an enlarged front view of a main part showing another example of the guide structure.

FIG. 20 is a perspective view of a unit having the guide structure of FIG. 19;

FIG. 21 is a side view of the first conventional example.

FIG. 22 is a side view of the second conventional example.

FIG. 23 is an exploded perspective view of a conventional pick roller mounting structure.

[Explanation of symbols]

 1 Base frame 3 Optical unit 21 Unit frame 24 Slot 35 Pin 36 Pin 41 Feed roller 42 Driven feed roller 43 Pick roller 45 Paper feed motor 51 Transparent plate 52 Leg 53 Projection 54 Projection 56 Guide rail 48 Pinion 61 Pressure arm with pressure 62 Free rotation roller 64 Extension part 66 Guide block 67 Hook 68 Hook 431 Pick roller shaft L Reading line PS Paper edge detection sensor ES Paper empty switch

Continuation of the front page (56) References JP-A-62-25559 (JP, A) JP-A-2-137467 (JP, A) JP-A-7-44605 (JP, U) JP-A-5-18168 (JP) , U) Fully open sho 64-16758 (JP, U) Fully open sho 63-92457 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 1/00-1/207

Claims (11)

(57) [Claims] 1. An original feed type comprising a unit frame (21) opposed to a base frame (1) of an image reading device with an original path interposed and having feed elements (41, 42) and an optical unit (3). In the image reading apparatus, the optical unit (3) is rotatably supported on the unit frame (21) around a support shaft (35) parallel to the reading line (L) near both ends of the reading line (L),
The rotation of the optical unit (3) around the support shaft is slidable in the radial direction of the rotation and is not movable relative to the circumferential direction.
(26,36) and unit frame (21)
Indicates the base frame (1) at both ends in the reading line direction.
An image reading apparatus, wherein the image reading apparatus is supported by. 2. A feed element provided on the unit frame (21) is a drive-side feed element (41) driven by a paper feed motor (45) built in the unit frame (21), and the unit frame (21) The image reading apparatus according to claim 1, wherein the image reading device is detachably provided on the base frame (1), and is used as a handy scanner by removing the unit frame (21). 3. The unit frame (21) has a read line.
Able to be pulled out at both ends in the direction and urged in the retracting direction
Arm (61), and a reading line
A free rotation roller (62) is mounted around an axis parallel to (L).
On both sides of a transparent plate (51) with removable legs (52)
The free rotating roller (62) of the pressing arm (61)
Abut the feed element (41) against the lower surface
3. The method according to claim 2, further comprising:
Image reading device. 4. The unit frame (21) has a read line.
Able to be pulled out at both ends in the direction and urged in the retracting direction
Arm (61), and a reading line
A free rotation roller (62) is mounted around an axis parallel to (L).
And one of the support pairs (3) including the support shaft (35) according to claim 1.
5) is attached to the base end of the pressure arm (61) and can be removed
Drawer on the upper surface of both sides of the transparent plate (51) equipped with a functional leg (52)
The free rotating roller (62) of the pressing arm (61)
With the feed element (41) in contact with the lower surface,
Optical unit when the pressure arm (61) is pulled out.
The reading line (L) of the knit (3) moves to the transparent plate (51) side and
The optical path length of the reading light is adjusted when reading the ratbed
The image reading device according to claim 2, wherein: 5. A sensor (PS, ES) for detecting a document is provided as a unit.
The frame according to claim 3 or 4, wherein the frame is mounted on a frame (21).
In the image reading device, the sensor controls the pressing arm (61).
An extension (6) that extends a short length beyond its pivot pin (63)
4), and the transparent plate (51) is engaged with the above sensor.
4. A projection according to claim 3, wherein said projection is provided.
Or the image reading device according to 4. 6. A unit frame below a rectangular transparent plate (51).
Room (21) has a space in which it can be inserted and
Flatbed unit (5) with inner rail (56)
Provided as a separate unit, a flange attached to the unit frame (21)
The diameter of the feed roller (41) is smaller than the outer diameter of the roller (41).
Of the unit frame (21)
Guided by the guide rail (56) at both ends in the direction of the line
Transparent plate of flatbed unit (51) with internal (66)
A rack (49) that meshes with the pinion (48) on the lower surface of the
3. The image reading device according to claim 2, wherein: 7. The transparent plate (51) of the flat bed unit.
The optical unit is located on the lower part of the document reading area
A contract with a pattern (57) that can be read in (3)
The image reading device according to claim 6. 8. A paper edge of a read original is detected at the time of automatic paper feed reading.
Paper edge detection sensor (PS) or document presence
Paper empty sensor (ES) in unit frame (21)
It is attached and when reading the flat bed of the transparent plate (51)
At the home position with the above sensor (PS) or (ES).
8. A mating projection (53) is provided.
Image reading device. 9. A paper edge of a read original is detected at the time of automatic paper feed reading.
Paper edge detection sensor (PS) and document presence
Paper empty sensor (ES) in unit frame (21)
It is attached and when reading the flat bed of the transparent plate (51)
And one of the above sensors (PS, ES)
A first projection (53) to be engaged is provided, and the other end is provided on the reading end side.
A second projection (54) that engages the sensor of
The image reading device according to claim 6. 10. A paper edge of a read original during automatic paper feed reading.
Paper edge detection sensor (PS) to detect
Paper empty sensor (ES) to the base frame (1)
It is attached and the flatbed is attached to the base frame.
Engagement that engages the home position end of the unit (5)
Tools (67, 68) are provided for reading flatbeds.
Guide the flatbed unit to the handy unit (2)
Insert the rail (56) and raise the base frame (1).
Flatbed unit (5) with the surface facing the transparent plate (51) side
On the base frame (1) and the sensor (PS, ES) on the base frame (1).
The handy unit (29)
7. A frame position is detected.
Or the image reading device according to 7. 11. The leg (52) of the flat bed unit (5).
11. The device according to claim 6, wherein the device is foldable.
2. The image reading device according to 1.