JPH02306762A - Method and apparatus for reading both sides of original - Google Patents

Abstract

PURPOSE:To eliminate the need for a page memory, to reduce the cost and to improve the operability by providing a stationary read unit reading a side opposite to a movement read unit. CONSTITUTION:A main body 1 provided with a transparent original platen 2, an original retainer 3 provided with a carrier belt 5 covering the original platen, a stationary read unit 7 reading the opposite side of the moving read unit, an automatic paper feeder 8 and a stacker 6 while clipping a read part formed with the stationary and moving read units 7, 4 are arranged to the apparatus. That is, the stationary read unit 7 for automatic paper supply and the flat bed type moving read unit 4 are provided, one side is read by the stationary read unit 7 and the other side is read by the moving read unit 4. Thus, the sequential read of both sides of an original is implemented without using a page memory independently of the relation of the vertical direction of the original and the paper feeding direction, the device cost is reduced and the operability is improved.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a document reading device that inputs two-dimensional information on the surface of a document to an image sensor through a lens and obtains an electrical signal through photoelectric conversion. The present invention relates to a double-sided reading device that is capable of reading both the front and back sides of a document with the following operations.

(Prior Art) Conventionally, devices having various structures as shown in FIGS. 11 to 13 have been proposed as double-sided reading devices. In the first conventional example shown in FIG.
First turning drum 72, intermediate passage 73, second turning drum 7
4 and a discharge path 75 to the stacker 6, and is equipped with a light source 12, a lens 13, and a one-dimensional image sensor 14 at a fixed position facing the turning drum 72, 74.
and second fixed reading units h7a and 7b are provided respectively, and the two-dimensional information on the surface of the document is read by the first fixed reading unit by main scanning by the image sensor and sub-scanning by moving the document.
? In a, the information on the back side is read by the second fixed reading unit 7b.

In the second conventional example shown in FIG. 12, information on the document surface is extracted as optical information using a light source 22 and a reflecting mirror 23 mounted on a first carrier 21 that runs along a transparent document table 2.
The first and second mirrors have a structure in which images are formed on a one-dimensional image sensor 28 provided at a fixed position via a movable mirror 25, 26 mounted on the carrier 24 and an imaging lens 27 provided at a fixed position.
A mobile reading unit 4a, 4b is provided on the apparatus main body 1 side and the document holder 3 side, respectively, and both sides of the document placed on the document table 2 are read by sub-scanning by simultaneous or sequential movement of the carriers 21 and 21. It is something.

A third conventional example shown in FIG. 13 is provided with a feed heald 5, an automatic paper feeder 8, and a stacker 6 for transporting the original on the transparent document table 2, and the document fed onto the document table is transferred in the same manner as in FIG. In an apparatus for reading with a mobile reading unit 4, a reversing drum 76, a holding roller 77, 78 and a V-shaped guide 79 are used.
The device is equipped with a reversing device 80 consisting of a reversing device 80, which feeds the document from the automatic paper feeder 8 onto the transparent document table 2 using the rollers 32, 33, 81 and the belt 5, and operates the movable reading unit 4 to read the front surface. Next, the original is reversely fed, guided to the reversing device 80, reversed 180 degrees, and sent onto the transparent original table 2 again to read the back side.The belt 5 and rollers 82 and 83 transfer the read original into the stacker 6 It is of a structure that discharges water.

(Problem to be Solved by the Invention) However, in the above-mentioned first conventional example, the sub-scanning direction of the document (
the length of the first and second reading units 7a (in the feeding direction);
7b, it is necessary to provide a page memory in the document reading device to temporarily store the read information on the front or back side, which poses a problem that the cost of the device becomes extremely high.

In addition, in the second conventional example, page memory can be eliminated by sequentially operating the first reading unit 4a and the second reading unit 4b, but automatic document feeding is completely impossible, and the document cover is closed. There is a problem in that operability is deteriorated due to the increased size and weight.

In addition, in the third conventional example, paper jams are likely to occur in the curved path in the reversing device 80, and thick paper etc. cannot be reversed, so the paper thickness of documents that can be automatically read or double-sided scanned is limited to a narrow range. There is a problem.

This invention was made in view of the problems of the conventional devices as described above, and it does not require page memory, has no bends in the document path, allows both automatic sheet feeding reading and manual insertion reading, and is low cost. The objective is to obtain a document reading device that is inexpensive and has excellent operability.

(Means for Solving the Problems) A double-sided document reading device of the present invention includes a main body 1 provided with a transparent document table 2, a document holder 3 provided with a feed belt 5 covered with the document table, and a movable reading unit 4 including a carrier 21 that is driven to move along a document table; and a movable reading unit disposed on the document entry side or discharge side of the feed belt.

A fixed reading unit 7 for reading the opposite side of the sheet, and an automatic paper feeder 8 and a stacker 6 are arranged with a reading unit formed by the fixed and movable reading unit 7.4 sandwiched therebetween. It is.

Further, the method for reading both sides of a document according to the present invention using the device configured as described above includes an operation of reading one side of the document with the fixed reading unit 7 while moving the fed document, and placing the document on the transparent document table 2. After positioning, move reading unit 4
an operation of reading the other side of the document while moving the first carrier 21 in a direction away from the fixed reading unit 7;
An operation in which the first carrier 21 of the movable reading unit 4 is held fixed at a position apart from the fixed reading unit 7 and the document is moved while the movable reading unit 4 reads the other side of the document, or the movable reading unit 4 A direction in which the first carrier 21 of the movable reading unit 4 is moved to a position away from the fixed reading unit 7 and the original is positioned on the transparent document table 2, and then the first carrier 21 of the movable reading unit 4 approaches the fixed reading unit 7. This is characterized in that the operation is performed sequentially in combination with the operation of reading the other side of the document while moving the document.

(Function) The device with the above configuration has a fixed reading unit 7 for automatic paper feeding.
and a so-called flatbed type mobile reading unit 4, and one side is read by a fixed reading unit and the other side by a moving reading unit, so that both sides of the document can be read in a rational sequential operation. In addition, it is possible to form a document path substantially linearly, and it is possible to automatically read thick paper, etc., and it is also possible to read one side of books, etc. by manual insertion. Furthermore, by making the original guide 11 of the fixed reading section a transparent guide, it is possible to read transparent originals, and by combining the line memory and the above-mentioned multiple reading methods, it is possible to read the original no matter what direction the original is inserted. Data can be output as a proper serial signal.

(Embodiment) FIG. 1 is a side view showing a first embodiment of the device of this invention. In the figure, 1 is a main body having a transparent document platen 2 on the top surface, 3 is a document holder, the main body 1 has a built-in movable reading unit 4 having the same structure as the conventional one, and the document holder 3 is the same as the third conventional example. A feeding heald 5 with a similar structure is built-in. Photoelectric sensors A and D for detecting the original are provided at the paper entry end of the feed belt 5 and at the paper ejection side end of the document table.
is installed.

On the other hand, a fixed reading unit is located close to the paper entry side of the document table 2 and includes a transparent document guide 11, an illumination lamp 12, a rod lens 13, a -dimensional image sensor 14, and paper feed rollers 15 and 16 before and after the document guide 11. 7 is provided. The transparent document guide 11 is disposed on the same plane as the transparent document table 2, and a linear document path is formed between them.
1 can read a transparent original by moving it directly below the transparent original guide 11. Photoelectric sensors B and C for detecting a document are provided before and after the paper feed roller 15 on the paper entry side.

An automatic document feeder 8 is arranged on the paper entry side of the fixed reading unit 7 . This automatic paper feeder has a known structure and includes a paper feed tray 31 for stacking and storing documents, a pickup roller 32, and a pair of separation rollers 33.

The separation roller pair 33 separates the topmost sheets of the plurality of documents that have entered the nip portion of the separation roller pair 33 by rotating an upper roller 33a in the paper feeding direction and a lower roller 33b rotating in the counter-feeding direction. Only one sheet is allowed to pass. The pick-up roller 32 and the separation roller pair 33 are connected to the paper feed roller 15.1 of the fixed reading unit via an electromagnetic clutch 34 (FIG. 2).
6, and when the electromagnetic clutch is released, it becomes in a free rotation state.

The paper feed table 31 of the automatic paper feed device needs to be installed at an angle so that the leading edges of the stacked documents are aligned in the paper feed direction, but as long as this requirement is satisfied, it should be installed as much as possible. It is mounted horizontally to prevent large bends from forming in the document path between the automatic paper feeder and the fixed reading unit.

The above device has a plurality of operation modes, and the operation of each mode will be described below with reference to the drive block diagram of FIG. 2 and the flowchart of each mode.

In the first operation mode shown in FIGS. 3(a) and 3(b), automatic paper feeding is started by rotating the roller drive motor 41 with the clutch 34 in the ON state, and when sensor B detects the leading edge of the document, The clutch 34 is turned OFF, the pink up roller 32 and the separation roller pair 33 are in a free rotation state, and when the document has been further fed by a distance 1i1e (Fig. 1), a reading start command is given to the fixed reading unit 7, and the sensor A is activated. When the leading edge of the original is detected, the belt drive motor 42 starts rotating, and when the sensor B detects the passage of the trailing edge of the original and the original has been further advanced by a distance e, a command is given to the fixed reading unit 7 to finish reading. give. Through the above operations, the fixed reading unit 7 reads the front surface of the document. The roller and heald drive motors 41 and 42 continue to rotate, and when the sensor A detects the passage of the trailing edge of the document, the rotation of the roller drive motor 41 is stopped, and when the document has been further advanced by a distance a. The rotation of the belt drive motor 42 is stopped. With the above operations, the original is positioned on the transparent original platen 2.

Next, a normal rotation command is given to the carrier drive motor 43, and at the same time, a reading start command is given to the movable reading unit 4, and when the first carrier 21 has moved by the paper length, a reading end command is given, and at the same time, a reading end command is given to the carrier drive motor 43. Reversing the situation, Carrier 21.24 returned to the home position. With this operation, the back side of the document is read. The paper length can be detected by detecting the amount of rotation of the roller drive motor 41 from when sensor B or A is turned on until it is turned off. Then, a rotation command is given to the roller drive motor 41 and the belt drive motor 42,
After sensor D detects the passage of the trailing edge of the document, a further distance d
A stop command is given to the belt drive motor 42 after the document has been fed for the same amount of time. With this operation, the scanned original is ejected to the stacker 6, and feeding of the next original is started. By repeating the above operations, the originals on the paper feed table 31 are sequentially read.

According to the above operation mode, the front and back sides of the document are read in the main scanning direction shown by arrows P and Q in FIG. 6, and in the sub-scanning direction shown by R and S in FIG. If this reading mode is used in orthogonal directions, both the front and back sides of the document will be read from left to right and from top to bottom. However, if the top and bottom of the document match the document feeding direction, in the first operation mode, the front side of the document is read from top to bottom and from right to left, and the back side is read from top to bottom and from right to left. The data is read upside down from left to right, and a page memory must be provided to invert one page's worth of data. Therefore, in such a case, the next second or third operation mode is selected.

In the second operation mode shown in FIG. 4, the first carrier 21 is first moved to the sensor D position. and the first
After reading the front surface in the same procedure as in the mode (steps 61 to 62 in FIG. 3), the belt drive motor 42 continues to rotate even after sensor A detects the trailing edge of the document. When the leading edge of the document is detected by sensor D, carrier 2
1 is fixed, a reading start command is given to the movable reading unit 4, and when the sensor D detects the trailing edge of the document, the reading is finished, and a drive command is given to the roller drive motor 41 to feed the next document. The belt drive motor 42 is stopped when the document has been further transported by a distance d.

In addition, in the third operation mode shown in FIG.
1 is first moved to the position of sensor D, and the front side is read in the same manner as in the first mode (steps from 61 to 62 in Fig. 3), and then sensor D detects the front edge of the document. At this point, the belt drive motor 42 is stopped, the carrier drive motor 43 is started to reverse, and a reading start command is given to the movable reading unit 4, and when the first carrier 21 has moved by the paper length, the movable reading unit 4 is started.
At the same time, the carrier drive motor 43 is rotated forward to return the first carrier 21 to the position of the sensor D. After that, the first operation mode is 63 to 6.
Similarly to steps up to step 4 (FIG. 3(b)), a rotation command is given to the roller drive motor 41 and the belt drive motor 42, and after the sensor D detects the passage of the trailing edge of the document, the document is further moved by a distance d. After the belt drive motor 42 has been sent, the belt drive motor 42 is stopped.

According to the second and third operation modes, when the top and bottom of the document match the document feeding direction as shown in FIG. 7, both the front and back sides of the document can be read from top to bottom. becomes. Note that since the scanning direction of the image sensor 14.28 is constant, in the device shown in the figure, the main scanning direction P of the document surface is from the right to the left of the document in the second and third operation modes, which is reversed. This problem can be solved by providing a line memory 44 in the device and inverting the read data on the front surface line by line, which can be solved with a small capacity memory, which increases the cost of the device and delays signal processing. Never. Note that the second mode and third mode are as follows:
It is sufficient to have either one of the operating modes, and if the paper feeding accuracy of the feeding belt 5 becomes a problem due to slippage, the third operating mode may be selected.

FIGS. 8 and 9 show a second embodiment of the device according to the invention, in which a fixed reading unit 7 and a movable reading unit 4 are shown.
This aims to reduce costs by using a common image sensor and imaging lens. Hereinafter, only the parts different from the first embodiment will be explained.

In this second embodiment, the lens holder 51 on which the image sensor 28 and the imaging lens 27 are mounted is placed on the carrier 2.
1, and can be positioned between a moving reading position M and a fixed reading position N using, for example, a stamping motor and a ball screw. As shown in FIG. 9, the holding plate 52 of the mirror 26 on the lower side of the second carrier 24 is pivoted to the third carrier with a pin 53, and is held by a spring 54 at the position shown by the solid line in the figure. has been done. On the other hand, the holder 51 is provided with a protrusion 55 facing the mirror holding plate 52, and when the second carrier 24 is at the home position shown in the figure and the holder 51 is moved to the fixed reading position N, the protrusion 55 is attached to the mirror holding plate 52. The holding plate 52 is pushed to lower the mirror 26 to the position shown by the imaginary line in FIG.

The optical path of the fixed reading unit 7 is formed by mirrors 56 and 57 fixed to the document holder 3 and a mirror 58 fixed to the main body l, and the image sensor 28 at the fixed reading position WN collects information on the document passing through the transparent document guide 11. to form an image. At this time, the lower mirror 26 of the second carrier is laid down as described above, and does not block the optical path.

The device of this second embodiment is also capable of reading operations in the first, second, and third modes, as in the first embodiment.
As shown in FIG. 10, only the movement of the holder 51 is performed between fixed reading (front side reading) and moving reading (back side reading).

(Effects of the Invention) According to the apparatus and method of the present invention described above, both sides of a document can be sequentially read without using a page memory, regardless of the relationship between the top and bottom directions of the document and the paper feeding direction. This makes it possible to reduce the cost of the device. In addition, since the problem of increasing the weight of the document holder does not occur, the operability of flatbed scanning by manual insertion is not deteriorated, and it is possible to read documents by manual insertion, including notes, etc., and automatically feed sheet documents. All reading operations including single-sided reading and double-sided reading are possible. Furthermore, since there is no bending in the paper path, it is possible to automatically read documents that are difficult to bend, such as thick paper, and there is an effect that a compact, multifunctional, and low-cost document reading device can be provided.

[Brief explanation of drawings]

1 to 5 are diagrams showing a first embodiment of the present invention, in which FIG. 1 is a cross-sectional view showing the main parts of the device, FIG. 2 is a block diagram showing the main drive system, and FIG. a). (b) is a flowchart showing the first reading method, FIG. 4 is a flowchart showing the second reading method, and FIG. 5 is a flowchart showing the third reading method.
It is a flow chart showing a reading method. Figures 6 and 7 show the vertical direction of the original and the paper feeding force, Figure 8 is a sectional view of the entire device, Figure 9 is an enlarged side view of the second carrier, and Figure 10 shows only the main parts. FIG. 11th
1 to 13 are cross-sectional views showing first to third conventional examples. In the figure, 1: Main body 2: Transparent document table 3: Document holder 4: Mobile reading unit 5: Feed belt
6: Stacker 7: Fixed reading unit 8: Automatic paper feeder 11: Transparent document guide 12: Illumination lamp 13: Rosodo lens 14: Image sensor 21: First carrier
22: Light source 24: Second carrier 27: Lens 28: Image sensor 31: Paper feed tray 44 second line memory

Claims (5)

[Claims] (1) A main body (1) equipped with a transparent document table (2), and a document holder (1) equipped with a feed belt (5) that covers the document table (2).
3), and a carrier (2) that is driven to move along the document table.
1), and a fixed reading unit (7) disposed on the document entry side or ejection side of the feed belt and reading the opposite side of the mobile reading unit.
), an automatic paper feeder (8), and a stacker (6) are arranged with a reading section formed by the fixed and movable reading units (7) and (4) interposed therebetween. (2) A line memory (44) for inverting bit information for one read line read by the image sensor (14) or (28) in either the fixed reading unit (7) or the movable reading unit (4). A double-sided reading device according to claim 1, further comprising: a. (3) In the double-sided reading device according to claim 1 or 2,
The fixed reading unit (
Step 7) reads one side of the document, positions the document on the transparent document table (2), and then moves the document to the mobile reading unit (4).
) A method for reading both sides of a document, characterized by sequentially performing an operation of reading the other side of the document while moving the carrier (21) of the device in a direction away from the fixed reading unit (7). (4) In the double-sided reading device according to claim 1 or 2,
The fixed reading unit (7) reads one side of the document while moving the document, and the movable reading unit (4)
Holding the carrier (21) in a fixed position away from the fixed reading unit (7) and moving the document while reading the other side of the document with the movable reading unit (4) is performed sequentially. A method for reading both sides of a manuscript. (5) In the double-sided reading device according to claim 1 or 2,
The fixed reading unit (
7) to read one side of the document, and move the carrier (21) of the movable reading unit (4) to the fixed reading unit (
7), position the original on the transparent document platen (2), and then move the original to a position away from the
) A method for reading both sides of a document, characterized by sequentially performing an operation of reading the other side of the document while moving the carrier (21) of the device in a direction approaching a fixed reading unit (7).