JPH0432846Y2 - - Google Patents

Description

[Detailed Description of the Invention] (A) Field of Industrial Application The present invention relates to a document reading device equipped with an automatic document feeder.

(b) Prior art Conventionally, in a document reading device equipped with an automatic document feeder, positioning of a fed document is performed using, for example,
As seen in Japanese Patent No. 58-55373, this is accomplished by bringing one end of the document into contact with a retractable claw provided on a document mounting table. That is, as shown in FIGS. 4 and 5, the contact glass 4
Pulley 4 is placed so that it is close to and opposite to the entire upper surface of
An endless belt 43 is stretched between 1 and 42. When the pulley 41 is rotationally driven, the endless belt 43 is interlocked, and a document inserted from the right side in the figure is fed between the contact glass 40 and the endless belt 43.

On the other hand, the positioning pawl 44 is located close to the pulley 42.
is provided. The positioning pawl 44 is slidable in the vertical direction relative to the contact glass 40 by fitting a guide pin 46 into a diagonal elongated hole 45 provided therein. Normally, the positioning pawl 44 is held in a state protruding from the upper surface of the contact glass 40 by the force of the spring 47, and when pulled in the direction of the arrow in the figure, the positioning pawl 44 slides downward.

The document fed by the drive of the endless belt 43 is positioned by the leading end of the document coming into contact with the positioning pawl 44 .

By the way, when positioning a document like this,
Since the endless belt 43 is driven even after the document contacts the positioning claw 44, the leading edge of the document may be bent. Further, if the document slips between the document and the endless belt 43, accurate positioning cannot be performed.

(c) Purpose of the invention The purpose of the invention is to accurately position the original without causing any bending in the original, and to accurately place the optical system reading section in a standby state.

(d) Structure of the invention The present invention feeds the original while being in contact with the placing glass by a document feeding unit equipped with an endless belt that is driven to run in a predetermined direction, and after feeding, the original is placed on the placing glass as described above. In a document reading device that reads a document with an optical system reading section movably provided below,
one of the optical element and the light receiving element is attached to the document feeding section, and the other is attached to the optical system reading section,
In the document standby state, the light-emitting element and the light-receiving element are in positions facing each other, and when the document fed as the document feeding section is driven is fed to the position facing the light-emitting element and the light-receiving element. The document reading device is characterized in that it is configured to stop driving the document feeding section.

(E) Embodiment FIGS. 1 and 2 are a schematic side view and a block diagram showing an embodiment of the present invention.

The first pulse motor 1 rotates the rollers 4a and 4b, and the second pulse motor 2 rotates the roller 5. An endless belt 6 for conveying a document stretched between a pair of rollers 5 is interlocked by a second pulse motor 2.

The original 8 set on the original setting table 7 is placed on the first
By driving the second pulse motors 1 and 2, the sheet is separated into one sheet by the brake piece 9 and conveyed onto the mounting glass 10. When the electromagnetic clutch 11 is energized, both rollers 4a, 4b rotate; otherwise only roller 4b rotates. Here, it is assumed that the fed document 8 is set face down.

The document that has been read is transferred to the second pulse motor 2.
The document is discharged onto the document discharge table 12 by the endless belt 6 which is interlocked with the document.

The third pulse motor 3 drives a first drive section 13 and a second drive section 14, and these drive sections 13 and 14 are pulled by wires 17 and 18 via a fixed pulley 15 and a movable pulley 16. drive.

The first drive unit 13 includes a light emitting element 19 and a fluorescent lamp 20.
and a first mirror 21, and a second drive unit 14.
has a movable pulley 16 and a second mirror 22,
When the fluorescent lamp 20 lights up, the mounting glass 1
0, the image information of the original is first reflected by the first mirror 21, then reflected by the second mirror 22, and transmitted to the lens 2.
3 and is converted into an electrical signal by a CCD drive circuit 24 having a CCD. Here, if the amount of movement of the first drive section 13 is 1, the amount of movement of the second drive section 14 is 1/
2, and the distance 25 of the optical axis is always constant.

Furthermore, when the first drive unit 13 is in a standby state (the position shown in FIG. 1), a light receiving element 26 is disposed above the mounting glass 10 facing the light emitting element 19.

Next, the block circuit diagram shown in FIG. 2 will be explained.

The main control circuit 30 receives a start signal a from the outside.
A signal b from the light receiving element 26 is inputted to give commands to each part. The binarization circuit 31 gives a read timing i to the CCD drive circuit 24, inputs an analog signal j, converts it into a digital signal l, and uses a predetermined clock k for the period of the read instruction signal h from the main control circuit 30. Write to image memory 32. The fluorescent lamp lighting circuit 33 turns on/off the fluorescent lamp 20 based on the signal c from the main control circuit 30. The first to third motor drive circuits 34 to 36 are connected to the main control circuit 30.
It operates by each pulse signal d, e, f from.
The electromagnetic clutch 11 is ON/OFF controlled by a signal g.

The operation of this embodiment will be described below with reference to the timing chart shown in FIG.

When a start signal a is received from the outside with the original 8 placed on the original setting table 7, the main control circuit 30 turns on the clutch 11 (signal g), causing the first and second motor drive circuits 34 and 35 to The first and second pulse motors 1,
Drive 2. As a result, the original 8 is separated into one sheet by the brake piece 9 and conveyed by the rollers 4a, 4b, and 5. Here, the signals d and e are slowed up and slowed down to improve the responsiveness of the pulse motor.

When a predetermined pulse signal d or e is applied, the clutch 11 is turned off (signal g). This is the point at which the document reaches a position where it can be transported by the rollers 5, and by turning off the clutch 11, the trailing edge of the transported document passes through the brake piece 9, preventing the next document from being transported successively. It is.

The original is further conveyed by the endless belt 6 while being in contact with the placing glass 10, and when its tip reaches the position where the light emitting element 19 and the light receiving element 26 face each other, the light of the light emitting element 19 is blocked by the original and the light of the light receiving element is blocked. Signal b becomes low level. At this point, the driving of the first and second pulse motors 1 and 2 is stopped (signals d and e), so that the original is accurately placed at the reading position.

Next, for the reading process, first turn on the fluorescent lamp 20.
(signal c) and by applying a pulse signal f (accurate pulse) to the third pulse motor 3, the first and second drive sections 13 and 14 are driven rightward in FIG. The control circuit 30 is a binarization circuit 31
A read instruction signal h is given to. Binarization circuit 3
1 is the period of the read instruction signal h, the CCD drive circuit 24
The input analog signal j is converted into a digital signal l
is converted into and written into the image memory 32.

When the reading is completed, the fluorescent lamp 20 is turned off (signal c), and a pulse signal f (inverted pulse) is given to the third pulse motor 3 to place the first and second drive units 13 and 14 in the standby position (first (Figure). At the same time, by applying a pulse signal e to the second pulse motor 2, the endless belt 6 is interlocked and the original is ejected. Here, such document ejection speed is determined by the speed of the first and second drive units 1.
It is assumed that the speed of return to the standby state position in steps 3 and 14 is sufficiently faster. Therefore, the first and second drive parts 1
3 and 14 progress toward the standby state position, and when the light emitting element 19 attached to the first drive unit 13 and the light receiving element 26 above the mounting glass 10 face each other, the output of the light receiving element 26 Signal b becomes high level. As a result, by stopping the driving of the third pulse motor 3, the first and second driving sections 13,
14 will be accurately returned to the standby position.

Note that the present invention can also be applied to a copying machine by arranging a photosensitive drum in place of the CCD drive circuit 24 and providing a paper feeding mechanism.

(f) Effects of the invention According to the invention, the original can be automatically fed to the original reading position accurately without causing any bending of the original, and the optical system reading section can be accurately positioned to the standby state. be able to.

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention,
Figure 1 is a schematic side view, Figure 2 is a block diagram, and Figure 3 is a schematic side view.
The figure is a timing chart. 4 and 5 show a conventional example, with FIG. 4 being a side view and FIG. 5 being a front view of the main parts. 6... Endless belt, 13... First drive section, 14... Second drive section, 19... Light emitting element, 2
6... Light receiving element.

Claims (1)

[Scope of utility model registration request] A document feeding section equipped with an endless belt that is driven to run in a predetermined direction feeds the document while being in contact with the placement glass, and after being fed, the document is provided movably below the placement glass. In a document reading device that reads a document by an optical reading section, one of a light emitting element and a light receiving element is attached to the document feeding section and the other to the optical reading section, and the light emitting element and the light receiving element are installed in the document feeding section and the other is attached to the optical system reading section. The element and the light-receiving element are located at opposing positions, and when the document fed as the document feeding section is driven reaches the position where the light-emitting element and the light-receiving element face each other, the document feeding section A document reading device characterized in that it is configured to stop driving.