JP2851342B2 - Document cassette - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention always provides an accurate and stable state to a reading engineering system when a document cassette holding a document carrying image information is subjected to an image reading process. The present invention relates to a document cassette that allows a document to be positioned by using a document cassette.

[Prior Art] For example, in the fields of printing and plate making, image scanning, reading and reproducing in which a film original is created by electrically processing image information carried on a document for the purpose of streamlining work processes, improving image quality, etc. The system is widely used.

In this case, in the image reading apparatus constituting the image scanning reading and reproducing system, the read document is substantially accommodated in a cassette, and the illumination light source is energized while conveying the cassette in the sub-scanning direction through the document table. I do. That is, illumination light is emitted in the main scanning direction, whereby the image information carried on the read original is read two-dimensionally.

The present applicant has already developed various types of such an image reading apparatus and an original reading cassette, and has applied for a patent.

In this case, the document cassette has a pair of support plates at least one of which is formed of a transparent material, and light reflected or transmitted from the document via the transparent support plate is provided in the reading unit. The image information is read by being photoelectrically converted by an optical / electrical conversion element such as a CCD.

In the optical system provided in the reading unit, the focal length for the original is based on the position of the lower surface of the cassette frame of the original cassette. Therefore, the thickness of the cassette frame to which the support plate is attached and the thickness of the support plate must be accurately secured with an accuracy of about several tens of microns.

[Problems to be Solved by the Invention] Therefore, when attempting to manufacture this type of original cassette in a lot, it is practical to produce the same cassette frame thickness, support plate thickness, etc. in tens of microns. It is unavoidable that the quality varies. If the thickness or the like is non-uniform in this manner, the optical system constituting the reading unit cannot ensure a good focal length with respect to the document, causing a focus shift or a magnification shift. As a result, the disadvantage that the image resolution is deteriorated is exposed.

An object of the present invention is to always maintain a constant focal length of an optical system in an image reading apparatus with respect to a document, regardless of the thickness of a cassette frame, the thickness of a support plate, and the like.
An object of the present invention is to provide a document cassette capable of accurately and precisely reading image information carried on a document.

[Means for Solving the Problems] In order to solve the above problems, a document cassette according to the present invention is arranged on a rotary table having an opening between a light source and an image reading unit, and carries image information. In a document cassette used in an image reading apparatus configured to obtain image information by receiving light from the light source transmitted through the sheet-shaped document to be received by the image reading unit, the sheet-shaped document is placed, A transparent support plate for positioning the sheet-shaped document in the optical axis direction of the light with respect to the image reading unit; and a cassette frame defining an opening for fixing the support plate. The plate is set to a size that allows direct contact with a cassette support provided on the rotary table, and the sheet-shaped document is positioned with reference to the cassette support.

[Operation] In the document cassette according to the present invention, the cassette support provided on the rotary table in the image recording apparatus directly contacts the support plate that forms the document cassette and has a highly accurate smooth surface. The lower surface position of the support plate becomes a reference position in the focus direction of the optical system, and accurate and precise image reading can be performed.

Next, a preferred embodiment of a document cassette according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a document using the document cassette according to the present invention;
1 shows an image reading apparatus 10 for reading image information preferably carried on a film. A cassette attaching / detaching portion 14 is formed at one upper end side of the housing 12 constituting the image reading apparatus 10, and the cassette is inserted into the housing 12 through the cassette attaching / detaching portion 14.
The introduction of the cassette 20 and the extraction of the cassette 20 from the inside of the housing 12 are performed.

Here, the cassette 20 has a frame 22 formed in a substantially rectangular shape, and V-shaped grooves 24a, 24a are formed on both sides of the frame 22 in the transport direction.
4b is formed, a light transmitting member on the frame 22,
For example, a glass plate 26 is attached. At one end of the frame 22, a glass plate 28, which is also a light-transmitting member, is swingably supported via a hinge member 30, and the glass plate 28 and the glass plate 26 hold the document S to be read. (See FIGS. 4 and 5).

In this case, as will be understood from FIG.
Is larger in area than the glass plate 28, and the end surface of the glass plate 26 is firmly attached to the side wall defining the concave portion 32 formed in the frame 22 via an adhesive or the like. deep. Accordingly, as will be described later, when reading an image, the rotating bodies 422a and 422b provided on the rotary table 302 are directly
6 can be held horizontally by contacting it.

A cassette insertion port 40 is provided near the cassette mounting / dismounting section 14, and a locking mechanism 50 is provided near the cassette insertion port 40.
And a linear solenoid 52 constituting
One end of a locking member 58 is swingably connected to the linear solenoid 52. Therefore, the other end of the locking member 58 enters the cassette insertion port 40 under the driving action of the linear solenoid 52, and a new cassette 20 is erroneously loaded into the housing 12 from the cassette insertion port 40. Can be prevented.

One end of the transport mechanism 100 is disposed near the locking mechanism 50, and the other end of the transport mechanism 100 extends above a rotary table 302 having an opening described later. As shown in FIG. 1, the transport mechanism 100 includes a frame 102, and one end of the frame 102 has a plurality of rods 104 along the transport direction.
Are fixed in an upright state, and a guide roller 106 engaged with one V-shaped groove 24a of the cassette 20 is supported on the rod 104. Similarly, a guide roller 110 that engages with the other V-shaped groove 24b of the cassette 20 via a plurality of rods 108 in the transport direction is provided on the other end side of the frame 102.

A rotary drive source 114 is fixed to the frame 102, and one end of a timing belt 118 is engaged with a pulley 116 which is mounted on a drive shaft of the rotary drive source 114. The timing belt 118 rotationally drives the roller pair 120, the first conveying roller group 122, and the second conveying roller group 124 via a pulley 116 engaged with the timing belt 118 and a rotational force transmitting means 119 including a gear train. The first conveying roller group 122 has a plurality of rotating shafts 130 that rotate via a rotating force transmitting means 119, and is separated from the rotating shafts 130 by a predetermined distance so as to engage with the upper surface of the frame 22 of the cassette 20. A pair of transport rollers 132 are mounted on the shaft. On the other hand, the second transport roller group 124
Similarly, it has a plurality of rotating shafts 136 engaged with the rotating force transmitting means 119, and a pair of conveying rollers 138 are respectively mounted on the rotating shafts 136, and the conveying rollers 138 are displaceable mechanisms (not shown) including cams. It is configured to be able to move up and down freely via the.

First and second transport roller group 1 constituting transport mechanism 100
A document table 200 is disposed below the reference numerals 22 and 124 via a sub-scanning mechanism 202 so as to be able to advance and retreat in the sub-scanning direction (the direction of arrow A). The sub-scanning mechanism 202 includes a rotary drive source 204, and a ball screw 206 is connected to the rotary drive source 204.
Is fitted to a nut member 208 fixed to one side of the document table 200, and both sides of the document table 200 are
Held at 10.

The document table 200 is provided with a trimming mechanism 250 for moving the cassette 20 forward and backward in a trimming direction, that is, a direction orthogonal to the sub-scanning direction (the direction of arrow A). The trimming mechanism 250 includes a rotary drive source 25 attached to the document table 200.
2, and one end of a ball screw 254 is connected to the rotary drive source 252. The ball screw 254 extends in the trimming direction, and is fitted to a nut member (not shown) provided on the trim table 256, and the other end is supported by the document table 200. A set of guide bars 260 extending in the trimming direction and parallel to each other is fixed to the document table 200, and the trim table 256 is supported by the guide bars 260.

An opening 262 having a relatively large diameter is formed in the trim base 256, and guide rollers 264a and 264b are supported near the opening 262 on the same straight line as the guide rollers 106 and 110 constituting the transport mechanism 100. Is done. Furthermore, a rotation mechanism 300 for rotating the cassette 20 by a predetermined angle on the trim base 256,
A cassette positioning mechanism 400 according to the present embodiment for positioning and holding the cassette 20 on a rotary table 302 constituting the rotation mechanism 300 is provided.

A gear train is connected to a rotation drive source (not shown) constituting the rotating mechanism 300, and the gear train is
The rotating table 302 is supported by support rollers 310a, 310b and 312a, 312b provided on a trim base 256, while being engaged with a ring-shaped gear 318 fixed to 302.

The cassette positioning mechanism 400 includes an actuator, for example, a rotary drive source 402 fixed to the lower surface side of the trim base 256, and a cam plate 404 is engaged with a rotary shaft of the rotary drive source 402 (FIGS. 1 to 3). (See FIG. 3). The rotary table 302 is at an angular position for attaching and detaching the cassette 20, and the cam plate 40
4 is provided with a lock means 405 that can be engaged. The locking means 405 includes a slide member 406,
A rack 408 is integrally formed with 6. A coil spring 410 is engaged with the end of the slide member 406, and the slide member 406 is constantly urged toward the cam plate 404 through the elastic force of the coil spring 410.

The pinion 412 meshes with the rack 408, and this pinion 412
One end of the locking plate 414 is engaged with the locking plate 4
14 is bent on the way, and the elastic member 416 is attached to the other end. Therefore, when no external force acts on the slide member 406, the locking plate 414 swings vertically upward under the elasticity of the coil spring 410, and the end surface of the cassette 20 is pressed by the elastic member 416. On the other hand, when the cam plate 404 engages with the slide member 406, the locking plate 414 swings in the horizontal direction, and the elastic member 416 retracts inside the turntable 302.

In the present embodiment, the slide member 406 is
Although the slide member 406 is configured to be pressed by the cam plate 404 connected to the 02, the slide member 406 may be pressed by a rod (not shown) that is connected to a linear solenoid and can move forward and backward.

As shown in FIG. 2, a stopper 418 is fixed to the rotary table 302 so as to face the elastic member 416, and elastic members 420a and 420b engaged with the end of the cassette 20 are provided on the end surface of the stopper 418. Is provided. Lock plate 4 on rotary table 302
A plurality of rotating bodies 422a and 422b, which are a plurality of cassette supporting bodies, are provided between the stopper 14 and the stopper 418 and engage with the bottom surface of the glass plate 26 constituting the cassette 20. In this case, the fixed shafts 424a and 424b that support the rotating bodies 422a and 422b are mounted directly on the upper surface 302a of the rotary table 302, thereby accurately securing the height position of the cassette 20 with respect to the rotary table 302. (See FIG. 4).

Guide means 425 capable of positioning and holding the cassette 20 in the optical axis direction (described later) is provided on the rotary table 302. The guide means 425 includes a rod 426 supported in a direction perpendicular to the outside of the rotating body 422a.
Is configured to be able to move up and down through the resilience of a coil spring 428, and a guide roller 430 is supported on the upper end thereof. On the other hand, outside the rotating body 422b, a plurality of rods 43
The rod 431 is vertically oriented, and the rod 431 moves up and down under the resilient action of the coil spring 432 and swings around the pin 436 via the resilient force of the coil spring 434. The guide roller 438 is supported at the end.

The light source 450 constituting the transmission illumination mechanism in the housing 12 is indicated by an arrow A
The image reading unit 500 is provided to extend in a main scanning direction substantially orthogonal to the direction, and an image reading unit 500 that photoelectrically reads the illumination light L derived from the light source 450 is provided below the light source 450.

The image reading unit 500 includes a bracket 502, which is engaged with a ball screw 504 extending in the optical axis direction (the direction of arrow I in FIG. 1) and connected to the ball screw 504. It is configured to be able to advance and retreat in the optical axis P direction under the driving action of the rotary drive source 506. A turntable 510 is supported on an upper portion of the bracket 502 via a support shaft 508, and a belt 514 that engages with a rotation drive source 512 fixed to the bracket 502 is stretched on the turntable 510. A plurality of imaging lenses 516 are arranged on the turntable 510 at equal angular intervals while being accommodated in the holder 518.

Also, the optical axis P is attached to the bracket 502 in parallel with the ball screw 504.
A ball screw 520 is supported extending in the direction, and a rotation drive source 522 is connected to an end of the ball screw 520,
The movable base 526 is engaged with the ball screw 520. A holder 528 is attached to the movable table 526, and the first CCD 530a, the second CCD 530b, and the third CCD 530 into which the illumination light L split in three directions by a prism (not shown) is introduced.
c is provided. At this time, the first CCD 530a to the third CCD 5
Reference numeral 30c photoelectrically reads the color image information carried on the read original S as image information corresponding to each of R, G, and B colors.

The image reading apparatus incorporating the document cassette according to the present embodiment is basically configured as described above, and the operation thereof will be described next.

When the cassette 20 containing the desired document S to be read is inserted into the cassette insertion opening 40 from the cassette attaching / detaching portion 14, the leading end of the cassette 20 is nipped by the roller pair 120, and the rotation drive source 114 is driven. Is done. For this reason, pulley 11
6. The roller pair 120, the first conveying roller group 122, and the second conveying roller group 124 are integrally driven to rotate via the timing belt 118 and the rotational force transmitting means 119. Accordingly, the cassette 20 having the frame 22 sandwiched between the roller pairs 120 is transferred to the first transport roller group 122 side, and the first transport roller group 122
Are formed on the upper surface of the frame 22, and V-shaped grooves 24 formed on both sides of the frame 22 are formed.
The guide rollers 106 and 110 are fitted to a and 24b, and the cassette 20 moves to the second transport roller group 124 side.

The leading end of the cassette 20 abuts and is supported by the stopper 418 under the guide action of the transport rollers 138 constituting the second transport roller group 124 and the guide rollers 430 and 438 constituting the guide means 425 provided on the rotary table 302. After that, the rotation drive source 1
The drive of 14 stops. Here, a rod 426 supporting the guide roller 430 is urged toward the rotary table 302 via a coil spring 428, and the guide roller 438 is connected to the rotary table 302 and the guide via a coil spring 432 and a coil spring 434. It is urged to the roller 430 side. Therefore, the cassette 20 is
Both sides are resiliently supported by 0 and 438, and the glass plate 26 is pressed against the rotating bodies 422a and 422b to rotate the rotating table 302.
However, the height position, that is, the position in the optical axis P direction is adjusted.

Next, the rotation drive source 402 constituting the cassette positioning mechanism 400 is driven, the cam plate 404 is rotated by a predetermined angle, and its small diameter portion faces the slide member 406 constituting the lock means 405 (see FIG. 3). . For this reason, the slide member 406 is displaced toward the cam plate 404 through the elastic force of the coil spring 410, and the pinion 412 meshing with the rack 408 provided on the slide member 406 rotates and locks. The plate 414 swings vertically upward, and the cassette 20 is pressed toward the stopper 418 by the elastic member 416. by this,
The cassette 20 is positioned and held with respect to the rotary table 302 in a direction substantially orthogonal to the direction of the optical axis P.

In addition, as is well known, generally, the accuracy of the smooth surface of the glass plate 26 can be easily ensured. Therefore, in the present invention, in view of this point, the lower surface of the glass plate 26 is directly
The rotating bodies 422a and 422b are brought into contact with each other to hold the cassette 20. Therefore, if the focal position of the optical system is set to correspond to the lower surface of the glass plate 26, image information can be read with high accuracy.

After the cassette 20 is positioned and held with respect to the rotary table 302, the displacement mechanism 140 is driven to drive the second transport roller group 124
Is separated from the cassette 20.

Next, the rotating mechanism 300 is driven as necessary to adjust the angular position of the read original S held in the cassette 20. In addition, the trimming mechanism 250 is driven as necessary to trim the read original S. That is, the trim base 256 is displaced in a direction substantially orthogonal to the sub-scanning direction under the driving action of the rotary drive source 252, whereby the trimming operation of the read original S is mechanically performed.

After the cassette 20 is positioned with respect to the document table 200, the rotation drive source 204 constituting the sub-scanning mechanism 202 is driven, and the document table 200 is moved via the guide bar 210 under the rotation of the ball screw 206. The light source 450 is energized while being conveyed in the sub-scanning direction (the direction of arrow A). Therefore, when the illumination light L derived from the light source 450 passes through the read original S in the main scanning direction, the color image information carried on the read original S is extracted as an optical signal, and the image as the optical signal is extracted. Each of the CCDs 530a to 530c receives information via a predetermined imaging lens 516 which is previously arranged on the optical axis P under the action of the rotary drive source 512.
Is irradiated. As a result, the color image information as the optical signal corresponds to each of R, G and B colors,
It is read photoelectrically by 30a to 530c. During this time, the document table 200 is being conveyed in the sub-scanning direction in the direction of arrow A, and the read document S is two-dimensionally illuminated by the illumination light L, its color image information is taken out, and all are read by the respective CCDs 530a to 530c. become.

In this case, the cassette 20 is positioned on the rotary table 302 in the optical axis P direction via the guide means 425, and is also positioned in the direction substantially orthogonal to the optical axis P direction by the guide means 425 and the lock means 405. I have. For this reason, it is possible to read the image information carried on the read document S stored in the cassette 20 with high accuracy.

After the reading operation of the read original S is completed, the sub-scanning mechanism 202
The document table 200 under the action of the rotary drive source 204 constituting the
After the movement in the direction opposite to the direction, the trimming mechanism 250 and the rotating mechanism 300 are driven as necessary, and the rotary table 302 is positioned at the position where the cassette 20 is attached / detached. Here, while driving the displacement mechanism 140 to cause the transport rollers 138 constituting the second transport roller group 124 to abut on the upper surface of the frame 22 of the cassette 20, the rotation drive source 402 constituting the cassette positioning mechanism 400 Under the driving action, the large diameter side of the cam plate 404 is engaged with the slide member 406, and the locking plate 414 is
Away from the rotary table 302.

Therefore, the pulley 116 is rotated in the opposite direction to that described above under the driving action of the rotary drive source 114 constituting the transport mechanism 100, and the second transport roller group 124 and the first transport roller 124 are rotated via the timing belt 118 and the rotational force transmitting means 119. Roller group 122 and roller pair 12
0 to drive the cassette 20 so that the cassette
Derived from 4 outward. At this time, if the locking member 58 is detached from the cassette insertion port 40 under the action of the locking mechanism 50 in advance, the cassette 20 is carried out through the cassette insertion port 40 to the outside.

As described above, in this embodiment, the size of the glass plate 26 is set to a size that directly contacts the rotating bodies 422a and 422b. Are held by the rotating bodies 422a and 422b, and the reference position in the focal direction of the imaging lens 516 constituting the image reading device 10 is the lower surface position of the glass plate.

As a result, the focal position of the read document S is maintained in a good state despite the variation in the thickness of the frame 22, so that a defocus and a double image deviation can be avoided, and an image with excellent resolution can be obtained. Can be

Incidentally, in the image reading apparatus configured so that the operator manually sets the cassette 20, in place of the rotating bodies 422a and 422b provided on the rotary table 302 of the previous embodiment, a projection-shaped cassette receiver is provided. What is necessary is just to provide the support plate 112 so as to be able to directly contact, and to directly place the lower surface of the glass plate 26 on this cassette receiver.

[Effects of the Invention] As can be understood from the above description, in the document cassette according to the present invention, the rotating body in the image reading apparatus or the support plate made of a gas plate or the like for holding the read document directly with respect to the cassette receiver is directly connected. Contact is possible.

Therefore, in the optical system in the image reading apparatus, the lower surface position of the support plate can be used as a reference position to read the image information carried on the document.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image reading apparatus, FIG. 2 is a schematic perspective view of a cassette positioning mechanism incorporated in the apparatus of FIG. 1, FIG. 3 is an explanatory view of locking means and an actuator constituting the cassette positioning mechanism, FIG. 4 is a longitudinal sectional view showing an engagement relationship between the cassette positioning mechanism and the cassette, and FIG. 5 is a perspective explanatory view of the cassette. 10 Image reading device 14 Cassette attaching / detaching section 20 Cassette 26, 28 Glass plate 100 Transport mechanism 140 Displacement mechanism 200 Document table 202 Subscanning mechanism 250 Trimming mechanism 300 Rotating mechanism 400 Cassette positioning mechanism 402 Rotating drive source 405 Locking means 414 Locking plates 422a, 422b Rotating body 425 Guide means 430, 438 Guide roller 450 Light source 500 …… Image reading unit

Claims (1)

(57) [Claims] An image reading unit receives light from the light source, which is disposed on a rotary table having an opening between a light source and an image reading unit and which has passed through a sheet-like document carrying image information. A document cassette used in an image reading apparatus configured to obtain image information by positioning the sheet-shaped document and positioning the sheet-shaped document in the optical axis direction of the light with respect to the image reading unit; And a cassette frame defining an opening for fixing the support plate, the support plate having a size capable of directly contacting a cassette support provided on the rotary table. Wherein the sheet-shaped document is positioned with reference to the cassette support.