JPH07264358A - Reader - Google Patents

Abstract

(57) [Abstract] [Purpose] An original reading system that is driven intermittently that enables high-quality image reading. [Structure] In the steady conveyance state of the original 1, the moving amount is constant and normal reading is performed. When some restrictions occur and the reading is stopped and the conveyance is stopped, the image reading is stopped immediately before the slowdown. At the same time when the conveyance is stopped, a reverse rotation signal is sent to the conveyance motor 8 to return the conveyance amount of the document 1 by a fixed amount. This returns a preset amount according to the slow-down and slow-up characteristics of the carry motor 8 from the position where the reading of the original 1 is stopped and the next reading is started. When the original 1 is ready to be read again, the reading position of the original 1 is returned by the amount conveyed by the slowdown and the amount conveyed by the slowup, and the original 1 is in the normal conveying state. When to start reading again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reading device which is applied to a facsimile, a copying machine, a scanner or the like to read a document by intermittently driving the document.

[0002]

2. Description of the Related Art Conventionally, there is a reduction optical system as shown in FIG. 16 as a sheet-through type document reading apparatus used in facsimiles, copying machines, scanners and the like.

FIG. 16 is a schematic view of an optical system of a conventional document reading apparatus. 1 is a document, 2 is a contact glass on which the document 1 is placed, 3 is a light source extending in the longitudinal direction for illuminating the document 1, and
Reference numeral 4 is a reflection mirror that bends the optical path to downsize the entire apparatus, 5 is a white reference correction plate (hereinafter referred to as a shading plate) that corrects the lens cos 4th power law of the white output waveform, and 6 is the reflected light of the original 1. An image forming lens 7 is a line CCD (hereinafter, referred to as CCD) of an image pickup device which converts optical information into an electric signal. Although not shown, an IC such as an A / D converter intervenes before the voltage waveform output from the CCD 7 is transferred to the image processing system.

In recent years, facsimiles, copiers, scanners and the like have been widely used in offices and homes, and high image quality and high reliability are required. Furthermore, in order to reduce the restraint time for the user, it is necessary to read the document at high speed as much as possible. In particular, in order to satisfy the requirement of reading a document at high speed, the processing system after the reading must be heavily loaded. For example, in a facsimile or the like, in order to process the document information in a short time, the receiving side must be able to follow the speed, and the line speed for transmitting the image data must be high.

Since the functions of other models are affected as described above, many conditions are attached to perform high-speed processing, and the range is limited. Therefore, it is common practice to store the data in the internal memory once before transmitting it, and then transmit it.However, in order to store a large amount of image data at one time, a large storage memory or line buffer is required. And the like must be installed, which leads to an increase in the cost of the machine and is limited to high-end machines and the like, which is not practical.

Therefore, in order to keep the expensive memory and line buffer to the minimum necessary, attention is paid to the reading of an original by intermittent driving. It is possible to operate without using the memory as much as possible by the intermittent drive that can read the document in small steps according to the communication speed, the receiving capability of the other party, and the processing speed.

A document feeding motor used in a reading system of a reading device which is driven intermittently is a stepping motor or the like which is easy to control, and a transitional state of rising from a stationary state to a target steady state (hereinafter, slow speed). The time of a transient state (hereinafter referred to as slow down) from the steady state to the stop is a relatively short time. The most popular facsimile currently has a reading linear density of 200 dpi, and it is safe to judge that the stepping motor slow-up and slow-down times are insignificant at this linear density, which affects image quality. It wasn't a level.

[0008]

However, in recent years, the reading device having such a structure is required to have a high image quality.
The linear density of pi is a necessary item, and the conventional slow-up and slow-down characteristics of motors have a problem that the image is significantly affected.

FIG. 17 shows a graph of a document conveyance amount and its operation in a conventional reading method of intermittently driving a document. As shown in FIG. 17, when reading an original with an image sensor such as a CCD, if the original is conveyed in a steady state within one accumulation time between accumulation pulses, the original should always be read at regular intervals. However, when the document is started or stopped, the transport amount becomes smaller than the steady state due to the slow-up and slow-down characteristics of the motor.

Therefore, when intermittent driving is performed at 400 dpi,
The image of the read part is shrunk from the original image before and after the still state where the reading of the document is temporarily stopped. There is a problem that the shrinking interval occurs in proportion to the available line buffer and the amount of accumulated memory.

The present invention solves the above-mentioned problems of the prior art, and avoids the image shrinkage phenomenon that occurs in an unsteady state of rising and falling of document conveyance in an intermittently driven document reading system. It is an object of the present invention to provide a reading device that obtains high-quality images.

[0012]

In order to achieve this object, the present invention provides a light source for illuminating a document surface, a lens for focusing reflected light on the document surface, and document information of the reflected light. In a reading device having a reduction optical system including a line CCD and intermittently driving reading of a document, the document can be transported in a direction opposite to the transport direction of the document.
Further, it is characterized by further comprising a conveying means for returning the read position of the document by a preset amount while the conveyance for reading is started again from the stationary state where the reading is once stopped.

Further, there is provided a reduction optical system including a light source for illuminating the original surface, a lens for forming an image of reflected light from the original surface, and a line CCD for reading original information of the reflected light, and the original document. In a reading device that intermittently drives reading of a document, the document can be conveyed to a conveying unit that conveys the document in a direction opposite to the document conveying direction, and the conveyance starts again for reading from a stationary state where the reading is temporarily stopped. In addition, a conveyance motor for returning the read position of the document by a preset amount during the operation is provided.

Further, there is provided a reduction optical system including a light source for illuminating the original surface, a lens for forming an image of reflected light on the original surface, and a line CCD for reading original information of the reflected light. In a reading device that intermittently drives the reading of a document, a conveyance roller that is connected to a conveyance motor as a conveyance unit that conveys the original document and a reading state that is connected to the conveyance roller and is in a stationary state in which the reading is temporarily stopped are read again. A reverse rotation motor is provided for returning the read position of the document by a preset amount while the conveyance is started.

Further, there is provided a reduction optical system including a light source for illuminating the original surface, a lens for forming an image of reflected light on the original surface, and a line CCD for reading original information of the reflected light, and the original document. In the reading device that intermittently drives the reading of the document, the document can be conveyed in a direction opposite to the conveying direction of the document, and the document is read while the document is temporarily stopped and the document is conveyed again for reading. It is characterized in that it is provided with a reverse conveyance roller connected to a reverse rotation motor for returning the reading position by a preset amount and for conveying the original document in the reverse direction.

Further, there is provided a reduction optical system including a light source for illuminating the original surface, a lens for forming an image of reflected light from the original surface, and a line CCD for reading original information of the reflected light, and the original document. In the reading device that intermittently drives the reading of the document, the reading unit is moved, the optical path of the reflected light is changed, and the reading of the document is started while the reading state is temporarily stopped and conveyance for reading is started again. It is characterized by comprising a driving means for returning the position to be moved by a preset amount.

Further, there is provided a reduction optical system including a light source for illuminating the original surface, a lens for forming an image of the reflected light of the original surface, and a line CCD for reading the original information of the reflected light. In a reading device that intermittently drives the reading, while driving the block on which the lens and the line CCD are integrally mounted, and starting the conveyance for the reading again from the stationary state where the reading is temporarily stopped. In addition, it is characterized by further comprising drive means for returning the read position of the document by a preset amount.

Further, there is a reduction optical system including a light source for illuminating the document surface, a lens for forming reflected light from the document surface, and a line CCD for reading document information of the reflected light, and the document. In the reading device that intermittently drives the reading of the document, the position where the document is read is driven while the block on which the lens is placed is driven and the conveyance is started again for reading from the stationary state where the reading is temporarily stopped. Is provided with a driving means for returning the amount of the predetermined amount by a preset amount.

Further, there is provided a reduction optical system including a light source for illuminating the original surface, a lens for forming an image of the reflected light of the original surface, and a line CCD for reading the original information of the reflected light. In a reading device that intermittently drives reading, the block for mounting the line CCD and the peripheral circuit in which the line CCD is mounted is driven, and the conveyance starts again for reading from a stationary state where the reading is temporarily stopped. In the meantime, a driving means for returning the read position of the document by a preset amount is provided.

Further, there is a reduction optical system including a light source for illuminating the surface of the original, a lens for forming reflected light from the surface of the original, and a line CCD for reading original information of the reflected light. In a reading device for intermittently driving the reading of a document, a group of reflecting mirrors intervening in the optical path and at least one angle of the reflecting mirror group are driven, and the reading is conveyed again from a stationary state where the reading is temporarily stopped. It is characterized by further comprising drive means for returning the original reading position by a preset amount during the start of.

[0021]

According to the above construction, the conveying means is capable of conveying the original in the opposite direction, the conveying motor is also capable of conveying in the opposite direction to the original, or it is connected to the conveying roller. When a reverse rotation motor or a reverse rotation motor that conveys in the reverse direction and a reverse conveyance roller that is connected to this reverse rotation motor cause some restrictions, and when reading is stopped and conveyance is stopped, image reading is performed immediately before the slowdown. At the same time as stopping and stopping the conveyance, the original is conveyed in the opposite direction. The amount of conveyance of the original document is returned from a position at which the reading is started next time the reading of the original document is stopped to a preset amount according to the characteristics of the slowdown and slowup of the conveyance motor. When the original can be read again, the original reading position is returned by the amount conveyed by the slowdown and the amount conveyed by the slowup, and the original is in the normal conveying state. When to start reading again.

Driving means for moving a part of the reading unit to change the optical path of reflected light, or driving means for driving a block on which the lens and the line CCD are integrally mounted.
Alternatively, driving means for driving the block on which the lens is mounted, or driving means for driving the block on which the line CCD and the peripheral circuit mounting the line CCD are mounted, or a group of reflection mirrors interposed in the optical path, and this reflection Some limitation is caused by the driving means for driving the angle of at least one of the mirror groups, and when the reading is stopped and the conveyance is stopped, the image reading is stopped immediately before the slowdown, the reading is stopped, and at the same time, the driving means. Changes the reading position by changing the optical path of the reflected light from the document. The amount of change is returned by a preset amount from the position of the next reading start after the reading of the original document is stopped, according to the characteristics of the slowdown and slowup of the transport motor. When the original can be read again, the original reading position is returned by the amount conveyed by the slowdown and the amount conveyed by the slowup, and when the original is in the normal conveying state. Start reading again.

[0023]

Embodiments will be described in detail below with reference to the drawings. Here, in the conventional example shown in FIG. 16 and the drawings, corresponding members are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 is a graph of the amount of document conveyed and an explanatory diagram of its operation in the reading method of intermittently driving a document according to the first embodiment of the present invention, FIG. 2 is its timing chart, and FIG. 3 is a block diagram of the reading device. Shows. In FIG. 3, 1 is a document, 4 is a reflection mirror, 6 is a lens, 7 is a CCD, 8 is a conveyance motor such as a stepping motor for conveying the document, 9
Is a carrying roller for carrying the driving force of the carrying motor 8 by a belt, a gear and the like, and carrying the document 1.

In the steady conveyance state of the document 1, the amount of conveyance of the document 1 within the reading and accumulating time is constant, so that the normal reading is performed and the image information is accumulated in the memory or the line buffer. When the memory is exhausted or the condition of the receiving party causes some limitation, the reading of the document 1 is stopped and the conveyance is stopped.

At this time, since there is a slowdown of the carry motor 8, the image reading is stopped immediately before the slowdown starts. At the same time when the conveyance is stopped, a reverse rotation signal is sent to the conveyance motor 8 to return the conveyance amount of the document 1 by a predetermined amount. This is because the conveyance motor 8 slows down from the position of the next reading start after the reading of the original 1 is stopped,
A preset amount is returned according to the characteristics of the slow-up.

When the data in the memory can be received and the other party can receive the data, and the original 1 can be read again, the reading position of the original 1 can be the same as the position conveyed by the slow down and the slow up. The amount of the conveyed amount has been returned, and when the original 1 is in a sufficiently steady conveying state, the reading is started again. The position at this time becomes the next reading start position.

FIG. 4 is a block diagram of the reading apparatus according to the second embodiment of the present invention, and FIG. 5 is a timing chart. 8 is a conveying motor, 9 is a conveying roller, and 10 is an original 1 in the reverse conveying direction. It is a reverse rotation motor. In addition to the transport motor 8 for transporting the original document, a reverse rotation motor 10 for transporting in the opposite direction is provided to transmit the driving force to the transport roller 9. Normally, the reverse motor 10 is turned off, and can rotate freely.

The operation in the steady conveyance state is the same as in the first embodiment, and the reading of the original 1 is stopped immediately before the slowdown. Immediately after the conveyance is stopped, the energization of the conveyance motor 8 is turned off, the reverse rotation motor 10 is excited and rotated in the reverse direction,
A preset amount is returned in the opposite direction to the original conveyance direction. As a result, the next reading position is returned to the original position including the slow-down and slow-up transport amounts.

When the reading is ready, the reverse motor 10 is deenergized, the excitation is stopped, and the conveying motor 8 is excited again. Similar to the first embodiment, the reading of the document 1 is started from the next reading position where the reading is stopped.

FIG. 6 is a schematic view of a document table of a third embodiment of the present invention, FIG. 7 is a block diagram of a reading device, 10 is a reverse rotation motor,
Reference numeral 10a is a reverse conveyance roller that conveys the original 1 by the driving force of the reverse rotation motor 10. In addition to the drive system including the transport motor 8 for transporting the document and the transport roller 9, a drive system including a reverse rotation motor 10 that rotates in the opposite direction to the transport motor 8 and a reverse transport roller 10a is provided. Normally, the reverse motor 10 is turned off, and can rotate freely.

The third embodiment is a reverse rotation motor 10 of the second embodiment.
The operation is the same as that of the second embodiment except that the reverse conveying roller 10a is provided.

FIG. 8 is a timing chart of the fourth embodiment of the present invention, FIG. 9 is a block diagram of the reading device, 11 is a drive motor, 12 is a drive means which is moved by the drive force of the drive motor 11, Reference numeral 12a is a block for mounting the lens 6 and the CCD 7. Lens 6 and CCD that form part of the reading unit
The block 12a in which 7 is integrated is fixedly installed on a driving means such as a feed screw which is vertically movable.

The operation in the steady conveyance state is the same as in the first embodiment, and the reading of the original 1 is stopped immediately before the slowdown. Immediately after the reading is stopped, the block 12a is moved by the driving motor 11 and the driving means 12 by a certain amount so that the reading position is in the direction opposite to the document conveying direction. This is based on the characteristics of the slowdown and slowup of the conveyance motor 8 from the next reading start position of the document 1.
It is a preset amount. As a result, the next reading position becomes a position at which reading can be started when conveyance is started and the steady state is reached.

When the reading becomes possible, the slowdown of the feeding motor 8 starts and the feeding state becomes sufficiently steady, and then the reading of the original 1 is started again. Further, the block 12a returns to the original position after the reading of the document 1 is completed and before the next document 1 is conveyed.

FIG. 10 is a schematic view of a reading apparatus according to the fifth embodiment of the present invention, and FIG. 11 is an enlarged view of a part thereof. 11 is a driving motor, 12 is a driving means, and 12b is a lens 6 mounted thereon. It is a block to do. The block 12b on which the lens 6 forming a part of the reading unit is placed is fixedly installed on the driving means 12 such as a vertically movable feed screw.

The operation in the steady conveyance state is the same as in the first embodiment, and the reading of the original 1 is stopped immediately before the slowdown. Immediately after the reading is stopped, the block 12b is moved by a certain amount by the driving motor 11 and the driving means 12.
The optical path at the reading position up to now was s1, but by moving the lens 6 of the block 12b, the CCD 7
The optical path of the reading position which is incident on is shifted to s2. Similar to the fourth embodiment, the next reading position is a position where reading can be started when conveyance is started and a steady state is reached.

When the reading becomes possible, the slowdown of the feeding motor 8 starts and the feeding state becomes sufficiently steady, and then the reading of the original 1 is started again. Further, the lens 6 is returned to the original position after the reading of the original 1 is completed and before the next original is conveyed.

FIG. 12 is an enlarged view of a part of the reading device according to the sixth embodiment of the present invention, in which 11 is a driving motor, 12 is driving means, and 12c is a CCD 7 and a peripheral circuit in which the CCD 7 is mounted.
This is a block on which (hereinafter referred to as a circuit) is placed. A block 12c on which a circuit forming a part of the reading unit is placed is fixed and installed on a driving means 12 such as a vertically movable feed screw.

The operation in the steady conveyance state is the same as in the first embodiment, and the reading of the original 1 is stopped immediately before the slowdown. Immediately after the reading is stopped, the block 12c is moved by a certain amount by the drive motor 11 and the drive means 12.
The optical path of the scan line up to now was s1, but by moving the CCD 7 of the block 12c, the CCD
The optical path of the reading position incident on 7 moves to s2. Similar to the fourth embodiment, the next reading position is a position where reading can be started when conveyance is started and a steady state is reached.

When the reading becomes possible, the slowdown of the feeding motor 8 starts, the feeding state becomes sufficiently steady, and then the reading of the original 1 is started again. Further, the CCD 7 is returned to the original position after the completion of reading the original and before the next original is conveyed.

FIG. 13 is a block diagram of the reading apparatus of the seventh embodiment of the present invention, FIG. 14 is an enlarged view of a part thereof, FIG. 15 shows a timing chart, 11 is a drive motor, 13 is a belt, a gear, etc. Is a rotation driving means for transmitting the driving force of the driving motor 11 to move the rotation angle of the reflection mirror 4, and 13a is a rotation shaft provided on the side surface of the reflection mirror 4.

A rotary shaft 13a is provided on the side surface of the reflection mirror 4 that folds back the optical path of the reflected light of the original 1, and drive means 13 for transmitting the rotation of the drive motor 11 is provided. Be able to change the angle.

The operation in the steady conveyance state is the same as in the first embodiment, and the reading of the original 1 is stopped immediately before the slowdown. Immediately after the reading is stopped, the drive motor 11 rotates the reflecting mirror 4 about the rotating shaft 13a by a certain amount. The optical path of the reading position so far was s1, but
By rotating the reflection mirror, the optical path at the reading position is s
I will move to 2. Similar to the fourth embodiment, the next reading position is a position where reading can be started when conveyance is started and a steady state is reached.

When the reading becomes possible, the slowdown of the feeding motor 8 starts and the feeding state becomes sufficiently steady, and then the reading of the original 1 is started again. Also, when scanning a document or before the next document is conveyed,
The angle of the reflection mirror is returned to the original position.

[0046]

As described above, according to the first, second, third and fourth aspects of the present invention, the original is conveyed in the direction opposite to the conveying direction, and is conveyed from the original reading stop position. The scanning position is returned by the amount of slow-down and slow-up transport of the motor, and scanning is not started until the next transport reaches a steady state. Therefore, image shrinkage can be prevented, and high-quality images can be read even if the document is intermittently driven.

According to the fifth, sixth, seventh, eighth and ninth aspects, by changing the optical path of the reflected light of the document,
From the original scan stop position, return the scanning position by the transport motor slowdown and slowup transport amounts,
Moreover, the reading is not started until the next conveyance is in the steady state. Therefore, it is possible to prevent the image from shrinking, and it is possible to read a high-quality image even if the document is driven intermittently.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a graph of a document conveyance amount and its operation in a reading method of intermittently driving a document according to a first embodiment of the present invention.

FIG. 2 is a timing chart of the first embodiment of the present invention.

FIG. 3 is a configuration diagram illustrating a reading device according to a first embodiment of the invention.

FIG. 4 is a configuration diagram showing a reading device according to a second embodiment of the invention.

FIG. 5 is a timing chart of the second embodiment of the present invention.

FIG. 6 is a schematic view showing a document table according to a third embodiment of the present invention.

FIG. 7 is a configuration diagram showing a reading device according to a third embodiment of the present invention.

FIG. 8 is a timing chart of the fourth embodiment of the present invention.

FIG. 9 is a configuration diagram showing a reading device according to a fourth embodiment of the invention.

FIG. 10 is a schematic diagram showing a reading device according to a fifth embodiment of the present invention.

FIG. 11 is an enlarged view showing a part of the reading device according to the fifth embodiment of the present invention.

FIG. 12 is an enlarged view showing a part of the reading device according to the sixth embodiment of the present invention.

FIG. 13 is a configuration diagram showing a reading device according to a seventh embodiment of the present invention.

FIG. 14 is an enlarged view showing a part of the reading device according to the seventh embodiment of the present invention.

FIG. 15 is a timing chart of the seventh embodiment of the present invention.

FIG. 16 is a schematic diagram showing an optical system of a conventional document reading apparatus.

FIG. 17 is an explanatory diagram showing a graph of a document conveyance amount and its operation in a conventional reading method of intermittently driving a document.

[Explanation of symbols]

1 ... Original, 2 ... Contact glass, 3 ... Light source, 4
... Reflecting mirror, 5 ... Shading plate, 6 ... Lens, 7 ... CCD, 8 ... Conveying motor, 9 ... Conveying roller, 10 ... Reversing motor, 10a ... Reverse conveying roller, 11 ...
Drive motor, 12 ... Drive means, 12a, 12b, 12c ... Block, 13 ... Rotation drive means, 13a ... Rotation shaft.

Claims (9)

[Claims] 1. A reduction optical system comprising a light source for illuminating a document surface, a lens for forming reflected light from the document surface, and a line CCD for reading document information of the reflected light, and a document. In a reading device that intermittently drives the reading of the document, the document can be conveyed in a direction opposite to the conveying direction,
Further, the reading apparatus is provided with a conveyance unit that returns the reading position of the document by a preset amount while the conveyance for reading is started again from the stationary state where the reading is temporarily stopped. 2. A reduction optical system comprising a light source for irradiating a document surface, a lens for forming reflected light of the document surface, and a line CCD for reading document information of the reflected light, and a document. In a reading device that intermittently drives reading of a document, the document can be conveyed to a conveying unit that conveys the document in a direction opposite to the document conveying direction, and the conveyance starts again for reading from a stationary state where the reading is temporarily stopped. A reading device comprising a conveyance motor for returning the read position of the original document by a preset amount while scanning. 3. A reduction optical system including a light source for illuminating a document surface, a lens for forming reflected light from the document surface, and a line CCD for reading document information of the reflected light, and a document. In a reading device that intermittently drives the reading of a document, a conveyance roller that is connected to a conveyance motor as a conveyance unit that conveys the original document and a reading state that is connected to the conveyance roller and is in a stationary state in which the reading is temporarily stopped are read again. A reading device comprising a reverse rotation motor for returning a position where the original is read by a preset amount while conveyance is started. 4. A reduction optical system including a light source for illuminating a document surface, a lens for focusing reflected light on the document surface, and a line CCD for reading document information of the reflected light, and a document. In a reading device that intermittently drives the reading of the document, the document can be conveyed in a direction opposite to the conveying direction,
Further, while the reading is temporarily stopped, the document is conveyed in the opposite direction by being connected to a reverse motor for returning the reading position of the document by a preset amount while the conveyance is started for the reading again. A reading device comprising a reverse conveying roller. 5. A reduction optical system including a light source for illuminating a document surface, a lens for forming reflected light from the document surface, and a line CCD for reading document information of the reflected light, and a document. In the reading device that intermittently drives the reading of the document, the reading unit is moved, the optical path of the reflected light is changed, and the reading of the document is started while the reading state is temporarily stopped and conveyance for reading is started again. A reading device comprising a driving means for returning the position to be moved by a preset amount. 6. A reduction optical system including a light source for illuminating a document surface, a lens for focusing reflected light on the document surface, and a line CCD for reading document information of the reflected light, and a document. In a reading device that intermittently drives the reading, while driving the block on which the lens and the line CCD are integrally mounted, and starting the conveyance for the reading again from the stationary state where the reading is temporarily stopped. In addition, the reading device further includes a driving unit that returns the read position of the document by a preset amount. 7. A reduction optical system including a light source for illuminating a document surface, a lens for focusing reflected light on the document surface, and a line CCD for reading document information of the reflected light, and a document. In the reading device that intermittently drives the reading of the document, the position where the document is read is driven while the block on which the lens is placed is driven and the conveyance is started again for reading from the stationary state where the reading is temporarily stopped. A reading device provided with a driving unit for returning the amount by a preset amount. 8. A reduction optical system including a light source for illuminating a document surface, a lens for forming reflected light from the document surface, and a line CCD for reading document information of the reflected light, and a document. In a reading device that intermittently drives reading, the block for mounting the line CCD and the peripheral circuit in which the line CCD is mounted is driven, and the conveyance starts again for reading from a stationary state where the reading is temporarily stopped. The reading device is provided with a driving unit for returning the read position of the original document by a preset amount while being read. 9. A reduction optical system including a light source for irradiating a document surface, a lens for focusing reflected light on the document surface, and a line CCD for reading document information of the reflected light, and a document. In a reading device for intermittently driving the reading of a document, a group of reflecting mirrors intervening in the optical path and at least one angle of the reflecting mirror group are driven, and the reading is conveyed again from a stationary state where the reading is temporarily stopped. A reading device comprising driving means for returning the original reading position by a preset amount while the scanning is started.