JPS62154950A - Original image reader - Google Patents

Abstract

PURPOSE:To reduce the cost, size, and weight of an original reader capable of being switched between two modes of a fixed and a mobile original by constituting the reader by using only a single mode as a driving source. CONSTITUTION:When a start signal for a mobile original read is sent from a console panel, the CCW rotation of a pulse motor 12 is transmitted to an automatic feeder part by a pulley 14a and a gear 14b and an original 11 is fed to a readout roller 11. When there is a mode switching command, the pulse motor 12 enters n1-step CW rotation and an image sensor 1 moves from a state shown in a figure (d) to (e). At this time, a hook 24 moves to C-D by the step of a groove 23 and then the pulse motor 12 is put in CCW rotation to allow the hook 24 to move in the groove 23 to D-E-A and come out of the groove 23 finally. The CCW rotation is carried on and then the image sensor 1 reaches a position 1a, so that an original fixed readout stand-by state is entered.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a drive means for an image sensor scanning mechanism and a document feeding mechanism in a document image reading device.

[Background of the invention]

A document image reading device (hereinafter referred to as an image reading device) using the above-described image sensor, which is the object of the present invention, is used, for example, as an input device for an image file system, an electronic copy device connected to a printer, or a facsimile transmission device. It is used in a wide range of applications such as document reading units, and in recent years, these functions have been further integrated to connect image reading devices, processing units, and printers, making the processing units more versatile. Systems for processing are also provided. By the way, the image reading device in such a system has a fixed original reading method for reading thick originals such as books, and a system that automatically reads multiple sheet originals while continuously feeding them for facsimile transmission etc. In many cases, it is required to have both functions of the original moving scanning method.

A device having the above two functions will be explained using the example shown in FIG. 5. In the figure, numeral 1 is an image sensor unit, which incorporates a light source such as a fluorescent lamp and an image sensor. This image sensor unit 1 has bezel bearings (not shown) attached to both ends thereof, and is capable of sliding on a pair of sleeves 2m and 2b on both sides fixed to the main body of the apparatus. That is, the drive boos IJ 4a, 4b rotatably attached to the main body of the device and the idler goolie 5m, 5bK wires 3m, 3b are routed and fixed near the bearing of the image sensor 1 1-, z? The rotation of the motor 12m is transmitted through the drive shaft 6.
.

4b allows the image sensor 1 to slide along the stem shafts 2a, 2bK.

According to the above, the image sensor 1 is slid from the 1 m position in FIG. 5 to the positions Ib and le, or is kept stopped, and performs a predetermined image reading operation.

Note that 9 is an autofeeder unit for the sheet-like original 11, and 10 is an original reading roller.The originals loaded on the autofeeder unit 9 are separated one by one by the power of a pulse motor 12b and fed to the reading roller 10. It becomes a trap so that it is ejected in the direction of the arrow. Reference numeral 7 denotes a document table (glass) on which a document 8 such as a book is fixedly placed, and the image sensor unit 1 includes:
By sliding under the document table 7, scanning for image reading of a fixed document is performed.

To explain the operation of the device having the above configuration, when the target document is a book or the like, the document 8 is set on the document table 7, and the operation knob (or Specify fixed document reading mode in the host unit connected to the device. As a result, the image sensor starts moving in the direction from 1a to 1b by the pulse motor 12jL in response to a start signal given from the control section according to a predetermined procedure and timing. Image sensor 1
performs main scanning in its longitudinal direction, and sub-scans up to 91b by the movement while transmitting an image signal for each read line.

On the other hand, when a sheet-like original is to be processed, the original is set on the auto feeder 9 and the operation panel is set to the moving original reading mode, and the image sensor 1 is moved and stopped at the moving original reading position 1e'J. . Next, the υ pulse motor 12b is rotated in response to a start signal given from the control unit, and the originals are separated and read one by one), fed by a roller Lot, read by the image sensor 1, and then discharged to the discharge path. .

However, in such an example, since two motors are used, two motor driver series are required in the electric circuit, making the device expensive. It was also a factor that hindered the

[Purpose of the invention]

The present invention uses a common single motor as a driving source in a document reading device that has two modes of fixed reading and moving reading of documents as described above, thereby reducing cost, miniaturization, and
An object of the present invention is to provide an image reading device that can be reduced in weight, and in particular, a drive mechanism thereof.

[Summary of the invention]

The features of the document reading device according to the present invention, which has been made to achieve the above object, include: a document table for placing a document; and a sheet document reading position provided on one side of the document table. , an automatic document feeding mechanism that feeds and discharges sheet-like originals; and an automatic document feeding mechanism that faces the document table in the vertical direction and moves across the range of the document table, or further reaches the sheet-like document reading position as necessary. an image sensor unit for reading a document image, an image sensor unit movement drive mechanism that causes the image sensor unit to move, and a driving force transmitted to both the automatic document feeding mechanism and the image sensor unit movement drive mechanism. A fixed document reading mode includes a forward and reverse rotation type motor device connected through a system and shared as a drive source, and a drive control means for the motor device, and reads a document placed on the document table. , Image Sensor Units)
The document image reading device is provided with a two-mode selection of a moving document reading mode in which reading is performed at a sheet-like document reading position, and the movement of the image sensor unit is locked when the image sensor unit is moved to the sheet-like document reading position. In addition, a driving force transmission system connecting the image sensor unit moving drive mechanism and the motor device is provided with a driving force transmission release means for idling and releasing the driving force when the image sensor unit is locked. This is because it has a unique structure.

The locking means in the above configuration is, for example, a cam mechanism that is a combination of a grooved cam and a cam follower that fits into the cam mechanism to move the image sensor unit into the sheet document reading position (advance) and move it out (forward). It can be configured by using a known cam mechanism that has the function of restraining the image sensor unit from moving backward when it moves backward (reverse) and releasing the constraint when it moves forward or backward; however, electromagnetic locking means, etc. may also be used.

Further, the driving force transmission canceling means provided in the driving force transmission system connecting the image sensor moving drive mechanism and the motor device is, for example, a belt rotated by a pulley, which is connected to the driven side (that is, the image sensor side). It is possible to easily configure the locking mechanism by providing the above-mentioned locking means such that the rotation of the locking mechanism is stabilized when a high torque load is applied, but the present invention is not particularly limited to such a configuration. .

[Embodiments of the invention]

The present invention will be described in detail below based on an example of an outline of the configuration of an apparatus, which is an embodiment, shown in FIGS. 1-4 of the drawings.

In these figures, 1 is an image sensor unit, which has a built-in fluorescent lamp light source focusing optical system and a contact type line image sensor (none of which are shown), which illuminates the document with a light source and uses its reflection. The structure is such that the light passes through the focusing optical system and is read by an image sensor. The image sensor has a number of elements arranged in a row in the longitudinal direction corresponding to the reading width of the original image, and reads one line of image in the width direction of the original in one main scan. It is constructed as a single piece, and has beveled bearings attached to both ends thereof, and is capable of sliding on stationary shirts (2a, 2b) fixed to the main body of the device. Drive boob IJ4a still rotatably mounted on the device body,
4b and idler pulleys 5a, 5b, wires 3a, 3b are routed, respectively.
, 3b are arranged near the bearing of the image sensor unit 1.

The drive units IJ 4a and 4b are fixed to the same drive shaft 6, and as the drive shaft 6 rotates forward and reverse, the image sensor unit 1 moves up to 2m.

2b, and can slide between 1a to 1b to icO shown in the figure. Note that 1c indicates a reading position of a sheet-like original.

A mechanism for reading a document such as a book in the apparatus of this example has the following configuration. In other words, 7 is the original platen glass,
The height is set so that the surface thereof becomes the focal position of the image sensor 1. Reference numeral 8 indicates a fixed document to be read, such as a book, which is read by being placed on the document table glass 7 with the reading surface facing down. In the fixed original reading mode, the image sensor 1 performs sub-scanning while sliding from 1a to 1b, and transfers the data of each main-scanning line to the processing section.

Further, a mechanism for reading a sheet-like original has the following configuration. That is, 9 is an auto feeder unit (automatic document feeding mechanism), and one or a plurality of sheet documents are placed on the document M with the reading side facing down. Then, the auto feeder feeds the sheet-like original 11 from the bottom.
The sheets are read one by one and sent to the roller 210, and then discharged in the direction of the arrow in the figure. In this moving original reading mode, the image sensor 1 is stopped at position 1c, reads the fed original 11, and transfers data. Note that each setting of the fixed original reading mode and the moving original reading mode described above can be made using the operation panel (not shown) on the device.
Alternatively, the device is provided so as to perform the operation in response to a command from a host (not shown) to which the device is connected.

The configuration described above is substantially the same as that described in the conventional example device shown in FIG. structure to give.

Specifically, it is a drive mechanism that has a function of switching the driving force of the motor from either the image sensor 1 or the auto feeder 9 to the other in relation to the movement of the position of the image sensor 1, and its structure will be described below. and an example of the operation will be explained in detail.

FIG. 2 is an explanatory diagram of the drive mechanism section 1, 1L bottom, in the figure,
The clockwise rotation of the shaft will be described as CW, and the counterclockwise rotation will be described as CCW.・! The rotation of the motor 12 is controlled by the timing pulleys 14a and 1 through the belt 13.
5. A gear 14b is fixed to the timing pulley 141L, a gear 30b, and a pulley 30.
m, the rotation is transmitted to the reading roller 10 of the auto feeder section via the belt 31 and the pulley 10a. The drive shaft 16 is fixed to the pulley 15 by one end.
The other end is connected via a spring clutch 17 to the drive shaft 6 for sliding the image sensor. This four-knolling clutch 17 transmits the CW of the drive shaft 16a to the drive shaft 6, but does not transmit CCW.

The timing pulley 18 has a built-in one-way clutch, the inner ring of which is fixed to the drive shaft 16, and the CCV of the drive shaft 16.
Only Goo IJ 1 BK is transmitted. 19 is a timing belt, 20 is a timing seat IJ19 & on one end, and a 7 (or U) boo' on the other end.
This is a shaft to which J21a is fixed. Reference numeral 22 is a seven-shaped (or U-shaped) pulley fixed to the drive shaft 6, and a round belt 21 is stretched between the pair of V-shaped pulleys 21a and 22. The tension of the round belt 21 is set so that it will slip between the pulleys at a certain torque between the drive torque of the i4 motor and the torque required to convey the image sensor 1. The above constitutes a driving force transmission canceling means provided in the middle of the transmission system. As described above, the image sensor unit 1 is slid along the shafts 2m and 2b as the drive shaft 6 rotates.

Next, a mechanism for stopping the image sensor at position 1c in FIG. 1 when in the moving document reading mode will be explained.

As shown in FIGS. 3(a) and 3(b) K, a groove 23 is carved on the right side surface of the image sensor 1 in FIG. In the figure, 23m indicates the right side surface of the image sensor 1, and 23b indicates the bottom surface of the groove.

Further, a bent end portion (hook portion) 24b of an L-shaped hook 24 is fitted into this groove 23 so that it can move along the slope and stepped portion formed at a predetermined position on the groove bottom surface 23b. There is. That is, the hook 24 is pivotally supported at the rear end by a pivot 24aK so as to be able to rotate in a plane perpendicular to the fixed part of the device main body, and the tip bent part 24b is moved to the groove bottom surface 24b by the spring force of the spring 26. It is designed to be pushed by

In this example, the groove 23 has a heart-shaped loop portion as shown in the figure, and a bent portion 24b at the tip of the hook 24 when the image sensor 1 is moved from the position 1b in FIG. 1 to the IC position. In order to specify the movement path of the hook tip near bent portion 24b to be inserted and to stop the hook from being dislocated, A step B-E and a sloped bottom surface connected to the step B-E are provided, and FIG. 3(b) shows that the hook tip bent portion 24b crosses the step B-E in the order of movement. The shapes of the bottom surfaces of the grooves 23 are sequentially shown in cross section. That is, the hook tip near bent portion 24b inserted from the introduction path (actually, the image sensor having the groove 23 is moved) reaches point A in FIG.
(see Figure 4(b)), enter the route on the upper side of the diagram with a gentler inclination angle and climb over step B (see Figure 4(c)).
Next, as the image sensor 1 moves back, the hook tip bent portion 24b climbs over the stepped portion C and engages with the recessed portion of the heart-shaped loop, thereby locking the return movement (Fig. 4(a) )reference).

After this, if forward movement force is applied to the image sensor 1 again,
The near bent portion 24b of the hook tip moves to C-D and climbs over the stepped portion (see Fig. 4 (,)), and then the image sensor 1 is given a force to move back, causing the hook tip to bend. The DE movement of the portion 24b, the overcoming of the stepped portion E, and the removal of the portion 24b from the lead-out path (see FIG. 4(f)) are performed.

In the figure, 27 is a shielding plate attached to the image sensor 1, and 28 is an optical sensor fixedly provided to the main body of the device, and is installed to detect when the shielding plate 27 has come to a predetermined position fK. It is being

Further, 29 indicates a reading axis of the image sensor 1.

Next, the operation of the image reading device of the above embodiment will be explained.

First, a document to be read is placed on the document table glass 7, a fixed document reading mode is designated on an operation panel (not shown), and a reading start signal is sent. Then, a shielding plate (not shown) attached to the image sensor 1 shields an optical sensor (not shown) attached near the portion 1a in FIG. The pulse motor 12 rotates in the CW force direction. This rotation is transmitted to the drive shaft 16 via the pulley 15, and further transmitted to the drive shaft 6 via the spring clutch 17, so that the image sensor 1 begins to move from 11 to the direction 1b. Note that the reading cycle of the image sensor 1 is synchronized with the driving frequency of the pulse motor 12. That is, if one step of the master pulse motor corresponds to one line of sub-scanning, one line of image signal is sent every one step, and when two steps correspond to one line, the image signal is sent to the VC every two steps.
The image signal for one line is transferred to the processing section.

In this example, if it becomes necessary to stop the image sensor 1 during image reading (for example, if the reading device is forced to temporarily interrupt the reading operation due to complicated processing by the connected host) is determined by a signal from a control circuit (not shown).
) The tp pulse motor 12 is decelerated and stopped. At this time, the image sensor 1 generates inertial movement, and if this is left unattended, the next time the reading operation is restored, the image sensor 1 causes inertia movement, which causes the problem that the image corresponding to the inertia movement is lost.However, in the mechanism of this example, , when the pulse motor starts to decelerate, that is, when the relative rotational speed of the drive shaft 16 drops to that of the drive shaft 6, the one-way clutch built into the pulley 18 engages, and the belt 19, pulley 20, belt 21, and pulley 22 are engaged. Since the deceleration of the drive shaft 16 is transmitted to the drive shaft 6 through the drive shaft 6, the image sensor 1 is able to completely follow the deceleration of the pulse motor 12. There isn't.

As described above, the image sensor 1 travels while reading images, and finally reaches near the reading end position fib. Then, the shielding plate 27 attached to the image sensor 1 shields an optical sensor (not shown) provided near the main body lb, so that the pulse motor is decelerated and rotated to a stop, and the image sensor 1 is stopped at the position 1b. Ru. If image sensor 1 recovers from 1b to 1&, pulse motor 1
2 should be rotated CCW. In this case, the one-way clutch 75 built into the pulley 18 engages, and the rotation of the drive shaft 16 is transmitted to the drive shaft 6 as described above.
The sensor 1 is conveyed in the direction of 1a, and the shielding plate shields the optical sensor near the main body 1a, thereby decelerating and stopping the cell motor 12.

As described above, a fixed document such as a book shown in FIG. 1(b) is read. At this time, the rotation is also transmitted to the auto feeder section, but this does not cause any particular trouble.

Next, the moving document reading mode will be explained.

In this mode, a sheet original is set on the auto feeder 9, and the moving original reading mode is designated.

When the fixed original reading mode is switched to the moving original reading mode, the image sensor 1 moves from 1& in the direction 1b and further towards the IC due to the CW rotation of the pulse motor 12. Then, the image sensor 1 is shown in FIG. 4(b).
When the image sensor l is moved to the position shown in FIG. After the shielding plate 27 of the image sensor 1 shields the optical sensor 28 attached near the IC position of the main body, the pulse motor 12 is stopped when the pulse motor 12 is stopped when the pulse motor 12 moves further to the right by n□ steps. c.
). During this time, the hook 24 moves from A to B according to the slope of the bottom surface of the groove 23, and then the pulse motor 12
By reversing and rotating ■W, image sensor 1 becomes the fourth
The position shown in figure (d) is reached.

Note that in this example, there are only a few steps during this time, but the second
Pulley 14a and gear 14b shown in the figure, and gear 3
The rotation is transmitted to the autofeeder section via the 0bf-receiver 30IL, and the first page of the document loaded on the autofeeder is fed in a minute amount toward the reading roller 10.

Next, when the pulse motor 12 is reversed in the CCW direction, the hook 24 climbs over the step C and is locked at the position shown in FIG. 4(d), and cannot move further to the left.

The position at which the image sensor 1 stops coincides with the position where the reading axis 29 of the image sensor 1 reaches the IC position in FIG.

Further, the drive shaft 16 rotates in the CCW direction, and its power is transmitted to the pulley 20 via the pulley 18 and belt 19. At this time, the image sensor 1 is
Since the drive shaft 6 and the pulley 22 are locked in the C position, the drive shaft 6 and the pulley 22 cannot rotate CC'w, and the rubber belt 21
will continue to lag between pulley 20 and pulley 22.

In the above state, when you send the start signal for movement W, document reading, and take-out from the operation panel, the CC of the nozzle motor 12 is
The W rotation is transmitted to the autofeeder section by the pulley 14a and gear 14b, and the document 11 is fed to the reading roller 11. In this example, an optical sensor (not shown) is installed between the auto feeder 9 and the reading roller 10, and when this sensor detects the leading edge of the original 11, the leading edge of the original is directly above the image sensor IC. , that is, the reading start position is reached. After this,
The image is read and its signal is transferred to the processing section in synchronization with the transmission pulse of the pulse motor as described above.

When multiple sheets of originals are set, when the reading of the previous page is completed, the previous page is ejected in the direction of the arrow in Fig. 1(b), and at the same time, the next page is ejected by the auto feeder section. Further, as described above, an optical sensor (not shown) detects the leading edge of the document, leading to the following reading operation.

Through the above steps, the moving original is read.

Next, the operation of shifting from the moving original reading mode to the fixed original reading mode will be described.

When a mode switching command is given, the pulse motor 12 rotates CW in the aforementioned n1 steps. Then, the image sensor 1 moves from the state shown in FIG. 4(d) to (.).

At this time, the hook 24 advances to C-D due to the step in the groove 23, and then by rotating the pulse motor 12 CCW, the hook 24 further advances inside the $ 23 to D-E-A, and eventually moves from the groove 23 to C-D. It comes off. Further continue the CC'w rotation K
The horizontal pulley sensor 1 reaches the 1& position, and the original is in fixed reading standby mode.

Note that the timings for moving the image sensor 1, locking the stop, or driving the auto feeder section, and for normal rotation, stop, and reverse rotation of the smoke 12 as described above are as follows.
It is given by an electronic control device (generally a microcomputer) (not shown) based on signals from each optical sensor, etc. or commands input to the operating panel, and these are designed using known electronic circuit technology. It is something that can be configured.

In the above embodiment, a fluorescent lamp was used as the light source and a contact type image sensor was used in the reading section. It goes without saying that various modified aspects can be adopted, such as using a sensor or using a DCC thermomotor or the like as a driving source.

〔Effect of the invention〕

As described above, the image reading device of the present invention has a simple structure and uses only a single motor as the driving source, and constitutes a document reading device capable of switching between two modes, fixed document mode and moving document mode. As a result, it is possible to reduce the cost, size, and weight of the device.
Its usefulness is enormous.

[Brief explanation of drawings]

Figures 1 (Ta) and (b) show an overview of the configuration of an image reading device according to the present invention - an example, Figure 2 is a perspective view showing a part of its drive mechanism, and Figures 3 (a) and ( b) is a detailed view showing the image sensor engaging means; FIGS. 4(a) to (f)
) is an explanatory diagram of the operation of the image sensor, Figure 5 (a) monovalent)
1 is a diagram illustrating an example of a general configuration of a conventional image reading device; FIG. 1: Image sensor unit, 2a, 2b: Stereo shaft, 3a, 3b: Driving wire, 4a, 4b: Driving pulley, 6: Drive shaft, 7: Original table, 9: Auto feeder, 10: Reading roller, 12: No? Luss motor, 15: ff1a)'l'-9, 16: Drive shaft,
17 Spring clutch, 23: Image sensor locking groove, 24: Hook. Awn A Rin Seatm

Claims (1)

[Claims] A document table for placing a document; an automatic document feeding mechanism for feeding and discharging sheet documents to a sheet document reading position provided on one side of the document table; an image sensor unit for reading an original image, which is provided so as to be movable across the range of the original table, or further to the original reading position on the sheet as needed; and this image sensor unit is caused to perform the movement. An image sensor unit moving drive mechanism, a forward and reverse rotation type motor device connected to both the automatic document feeding mechanism and the image sensor unit moving drive mechanism via a drive force transmission system and used commonly as a drive source, and the motor device. drive control means, and is capable of selecting two modes: a fixed document reading mode in which the document placed on the document table is read, and a moving document reading mode in which the image sensor unit is read at the sheet document reading position. The document image reading device is provided with a locking means for locking the movement of the image sensor unit when the image sensor unit is moved to a sheet document reading position, and the image sensor unit moving drive mechanism and the motor device are connected to each other. A document image reading device characterized in that the connected driving force transmission system is provided with a driving force transmission release means for idling and releasing the driving force when the image sensor unit is locked.