JPH0816769B2 - Document feeder - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a document feeding device that conveys a document to an exposure position and discharges the document from the exposure position after completion of the document exposure.

(Prior Art) Conventional document feeding apparatus, for example, in a document circulating apparatus that separates and conveys documents one by one from a mounting table, stops them at a predetermined position, discharges them from the exposure position after exposure, and returns them to the mounting table, As a technique for stopping at a predetermined position, for example, a method in which a claw is put out at the tip of the stop position of the document on the platen glass and abutted against the claw, or the rear end of the document is detected by a detection means on the document conveyance path However, there is a method of stopping the transportation drive and stopping the transportation after a predetermined time has passed after the detection.

In particular, the former case has a drawback that the configuration is large, and the latter has a drawback that the accuracy of the stop position of the document becomes poor when the document conveying speed is increased.

(Object of the Invention) An object of the present invention is to eliminate the above-mentioned drawbacks of the conventional example and to provide a document feeding apparatus capable of stopping the document at the exposure position quickly and accurately.

In order to achieve the above-mentioned object, the present invention comprises a conveying unit that conveys a document to an exposure position and discharges the document from the exposure position after the exposure of the document, a motor that drives the conveyance unit, and a bipolar terminal of the motor. First braking means for braking the conveying means by electrically short-circuiting, second braking means for braking the conveying means by an electromagnetic brake, and the first braking means for stopping the document at the exposure position. Control means for controlling the first and second braking means at a timing such that the braking means first performs braking, and then the second braking means superimposes braking on the first braking means. The present invention provides a document feeding device characterized by having:

(Description of Embodiments) Hereinafter, a specific description will be given based on the drawings. FIG. 1 is a vertical cross-sectional view showing a schematic configuration of an example of a double-sided document circulating device according to the present invention.

Reference numeral 1 is a document placing table, 2 is a paper feed belt drive shaft, and 2a is a paper feed belt driven shaft, between which a paper feed belt 3 is hung, and is rotating in the direction of arrow C in the figure. Reference numeral 4 is a separation belt drive shaft, and 4a is a separation belt driven shaft, on which a separation belt 5 is attached, and it rotates in the direction of arrow D in the figure. The document placing table 1 with the paper feeding belt 3 and the separating belt 5.
The plurality of sheet-shaped stacked originals placed on is separated from the lowermost one by one. Reference numeral 6 is a conveying roller, and 6a and 6b are rollers which are in pressure contact with the conveying roller 6, respectively. Further, 9, 10, 11 are also conveying rollers, and 9a, 10a, 11a are conveying rollers 9, 10, 11 respectively.
It is a roller that presses against. Further, 7 is a conveyor belt drive roller located on the left side of the platen glass 12 disposed on the upper surface plate of the main body of the copying machine, and 7a is a conveyor belt driven roller located on the right side of the platen glass 12 between them. A belt 8 is attached to the.

The lower surface of the suspension belt 8 is in close proximity to or in contact with the upper surface of the platen glass 12. Further, reference numerals 13 to 17 are reflection type optical sensors arranged at required places of the document circulation path (paper path) to detect the leading edge or trailing edge of the document. or,
Reference numeral 20 is a reflection type optical sensor ES for detecting a document placed on the document placing table 1, 19 is a reflection type sensor (recycle sensor) RS for detecting one circulation of the document stack, and the partition arm 22 is a pulse motor. The document is stopped on the bundle of documents by 21 and at that time the recycle sensors RS, 19 are turned on. Then, the document is fed separately from the bottom document and the trailing edge of the last document is separated by the partition arm 22.
After passing through the partition arm 22, the recycle sensor R
It is a mechanism that turns off the position of S, 19.

FIG. 2 is a schematic cross-sectional rear view showing the drive unit. In the figure, reference numeral 80 is a motor M2, and 81 is a motor gear for transmitting the driving force to the paper feed belt drive shaft 2 and the separation belt drive shaft 4 through a gear 96. 82 is a motor M1, 83 is a motor pulley, and 86 is 2
Drive transmission from the belt 87 to the belt 88 is performed by the stepped pulley. Also, 89 is a two-stage pulley, which is integrated, and the belt
The driving force is transmitted from 88 to the belt 90, so that the driving force is always transmitted to the driving roller 7 of the conveyor belt 8 through the pulley 91. Further, 93 is a disc having a two-stage pulley 89 and a notch groove 94 for rotating one body, and the amount of movement of the belt 8 can be detected by a photoelectric sensor 95. Reference numeral 92 is an electromagnetic brake BK, which enables the belt 8 to be stopped instantaneously when turned on.

Further, 97 is a motor M3, 98 is a gear, 99 is a pulley, 100, 101,
A belt 102 transmits the driving force to the conveying rollers 6, 9, 10, 11. Further, 103 is a notch groove 104 which is rotated by one with the pulley 99.
It is a disk with
It is possible to detect the rotation amounts of 0 and 11, that is, the amount of conveyance movement of the document. Reference numeral 23 is a switching claw for switching whether the original on the platen glass 12 is conveyed toward the conveyance roller 6 or the conveyance roller 9 by the fulcrum 106.
It is performed by SL, 107.

 Next, the operation of the double-sided document circulating device will be described.

(I) Single-sided original copy In FIG. 1, a plurality of sheet-shaped single-sided originals arranged in page order are placed on the original placing table 1 with the first page facing upward. The placed originals are separated and fed one by one from the bottom by the paper feed belt 3 and the separation belt 5, and the fed originals pass through the paper path Ia and are conveyed to the platen glass by the conveyance belt 8.
12 The original is fed with the image side facing down. When the rear end of the document is detected by the sensors S2, 14, the counting of the number of the cutout grooves 94 of the disc 93 (FIG. 2) is started from that point, and the motors M1, 82 are turned on after counting a predetermined count. At the same time, the electric brake is turned on by the drive control circuit 130 of the motors M1 and 82, which will be described later, and the electromagnetic brakes BK and 92 are turned on, and the rotational drive of the conveyor belt 8 is instantaneously stopped.
As a result, the original is automatically set to the predetermined set position on the surface of the platen glass 12 at the set position.

When the original is positioned on the platen glass 12 in this manner, the copying operation is started and one exposure scan is performed, and the copied copy paper is stored in a paper discharge tray (not shown). After the exposure of the original, the
It is discharged through VIIa and VIa. At the same time, the next original is fed in parallel by the above-mentioned operation and positioned and set on the platen glass 12.

This parallel operation is simply an operation of circulating the original document, and since the reverse of the original document is not performed for the previous original document and the next original document, it is referred to as a normal discharge normal feeding operation. Then, the normal feeding and normal feeding operation is sequentially performed, and one circulation of the set originals is detected by the recycle sensor RS, 19, and the end of the circulation is sent to the copying machine main body to count the number of copies. The above operation is repeated until the set number of copies is reached, and the required number of copies are stored in the discharge tray (not shown) of the copying machine.

(Ii) Double-sided original copy If the number of originals on the original placing table 1 is three, the originals placed on the original placing table 1 are in the page order as shown in FIG. 3, and the originals are placed after copying. Also becomes the same as the first set as shown in FIG. These operations will be described.

First, the 5th and 6th page originals are conveyed to the platen glass 12, then the motors M1, 82, M3, 97 (Fig. 2) are reversely rotated and, at the same time, the solenoids SL, 107 are turned off to switch the discharge route. The original is conveyed by being held by the conveyance rollers 9 and 9a through the paper paths IIIa and IVa. If the sensor S4,16 detects the trailing edge of the document, the motor M3,97 is stopped.
After a lapse of a certain time, the motors M3 and 97 are rotated in the normal direction, and the document passes through the paper paths Va and VIa and is transported by the transport rollers 10, 10a, 11, and 11a. When the sensors S5 and 17 detect the trailing edge of the document, the motors M3 and 97 are stopped, after a certain time the motors M3 and 97 are rotated in the reverse direction again, the motors M1 and 82 are rotated in the normal direction, and the solenoid SL is rotated. , 107 is turned on, and the original passes through the paper path VIIa and is gripped by the belt 8 and conveyed. And sensor S
When the trailing edge of the document is detected by 3,15, the number of the cutout grooves 94 of the disk 93 (FIG. 2) is started to be counted from that point, and the motor M1, 82 is turned off after counting the predetermined number of counts. At the same time, the electric brakes of the motors M1 and 82 are turned on, the electromagnetic brakes BK and 92 are turned on, and the driving of the conveyor belt 8 is instantaneously stopped to set the original. As described above, the sheet feeding operation in which the original on the original placing table 1 is inverted and set on the platen glass 12, that is, the reverse sheet feeding operation (hereinafter referred to as the anti-feed operation) is first performed.

Then, the main body of the copying machine starts the copying operation of the sixth page of the document, starts one exposure scanning, and stores the copied copy paper in the paper discharge tray (not shown). 6 after the exposure of the original
The exposed original of the page is subjected to a pulling and repeating operation for positioning and setting the fifth page of the original on the platen glass 12 downward through the paper paths IIIa, IVa, Va, VIa, VIIa (this operation is performed). Hereinafter referred to as pulling repeat operation).

After that, the main body of the copying machine starts the copying operation of the fifth page of the original, and stores the copy paper in the paper discharge tray (not shown).

After the exposure of the original on the fifth page, the original on the platen glass 12 passes through the paper paths VIIa and VIa, and the fifth roller faces upward on the original placed on the original placing table 1 by the transport rollers 11 and 11a. Is discharged (this operation is hereinafter referred to as normal discharge operation).
From a certain time during the normal discharging operation, the above-described anti-feeding operation of the next original having pages 4 and 3 is performed in parallel with the normal discharging operation, and the fourth page is turned downward on the platen glass 12. The positioning is set (the operation of performing the normal discharging operation and the anti-charging operation in parallel is hereinafter referred to as the anti-discharging normal feeding operation). After that, the above-mentioned copying operation is performed a necessary number of times, and finally the copy sheets are arranged in the page order and stored in a paper discharge tray (not shown), and the originals are not changed in the initial set state as shown in FIG. The document is discharged to the document table 1 and copying from the double-sided document is completed.

FIG. 4 is a schematic control circuit diagram for performing the above-described sequence operation.

In FIG. 4, a well-known one-chip microcomputer (hereinafter referred to as a microcomputer) 120 having a built-in ROM, RAM, etc.
The input port I _{1 of the} microcomputer 120
Each sensor signal is input to I ₇ and interrupt terminals iNT1, iNT
2 is the transport clock and sensor output from the sensor 105
The belt clock signal output from BC, 95 is input.

On the other hand, the driver is connected to the output ports O ₁ , O _{4 to} O ₈ of the microcomputer 120.
D1 to ID6 are connected, and each load can be driven through the drivers D1 to D6. Especially output ports O ₄ , O
_{From 5} onward, M3FWD, M3RE is used so that the transport motor M3, 97 can be rotated forward and backward.
V is output and rotated in the directions of arrow → and in FIG. 1, respectively. A drive control circuit 130, which will be described later, is connected to the output ports O ₂ and O ₃ , and forward / reverse rotation of the belt drive motors M1 and 82 and electric brake control are performed via the drive control circuit 130.

The I / O terminal of the microcomputer 120 is connected to the main body of the copying machine,
The above-mentioned copying operation start signal, original document exposure end signal, original circulation end signal, etc. are transmitted and received to match the operations of the double-sided original circulation device and the copying machine main body. The reading of these input signals or the turning on / off of the load are controlled according to a program stored in the ROM in the microcomputer 120.

FIG. 5 is a detailed diagram of a circuit for controlling the drive of the belt drive motors M1, 82.

In FIG. 1, the motor M is rotated so as to rotate in the direction of arrow →.
Microcomputer 12 to drive 1,82 (hereinafter referred to as forward rotation)
0 output port O ₃ to M1, CHG = "H", O ₂ to M1, ON = "H"
Is output, and inverter Q45 output is output by M1, CHG = "H" =
Transistor Q41 when output becomes "L" and inverter Q46 output = "H"
Turns off, and the output of the inverter Q47 = "H" turns on the transistor Q43. In addition, M1, ON = "H" for inverter
When Q48 output = "H", inverter Q49 output = "L" turns on transistor Q42, and inverter Q50 output = "L" turns off transistor Q44. As a result, the current flows in the direction of →, and Moko M1, 82 rotates in the forward direction.

On the other hand, when driving the motors M1, 82 to rotate in the direction of the arrow in Fig. 1 (hereinafter, reverse rotation) M1, CH
Microcomputer 120 outputs G = "L", M1, ON = "H", and M1, CHG =
With "L", inverter Q45 output = "H", inverter Q46 output = "L" turns on transistor Q41, and inverter Q47 output = "L" turns off transistor Q43. Furthermore, when M1, ON = "H", the inverter Q48 output = "L" and the inverter Q49 output = "H", the transistor Q42 turns off,
Inverter Q50 output = "H" turns on transistor Q44. As a result, the current flows in the direction of, and the motors M1, 82 rotate in reverse.

Next, to apply the electric brake to the motor M1, 82, use M1,
Regardless of CHG level, by setting M1, ON = "L", inverter Q48 input = "L", inverter Q48 output = "L", and inverter Q46 output = "H" turns off transistor Q41.
Inverter Q47 output = "H" turns on transistor Q43, inverter Q49 output = "H" turns transistor Q42 off, and inverter Q50 output = "H" turns transistor Q44 on, so both ends of motors M1 and 82 are ground lines. The motor M1, 82 is electrically braked and stops instantly.

Next, the operation of the double-sided document circulating device (hereinafter referred to as RDF) of the present invention will be described with reference to the general flow chart of FIGS. 6 and 7 and the detail flow chart of FIGS.

FIG. 6 is a general flow chart for a single-sided original copy operation, and FIG. 7 is a general flow chart for a double-sided original copy operation. In the single-sided original copy operation in FIG. 6, first, a normal feeding SUB (step 100) described later is executed to execute the original placing table 1.
One original is separated from the original bundle placed on the tray, fed, and passed through the conveyance paths Ia to IIa (Fig. 1).
The operation of stopping at the predetermined position is performed, and then a copying operation start signal is sent to the copying machine main body, and the copying machine starts the copying operation and starts the exposure. On the other hand, the RDF executes a recycling SUB (step 500) in order to detect the circulation of the document bundle (step 500) and stops the partition arm 22 from rotating on the document bundle and waits until the exposure of the copying machine main body is completed (step 200). When the exposure ends, the normal discharge S described later
UB (step 300) is executed so that the original document on the platen glass 12 passes through the conveying paths IIa to VIIa to VIa and is again placed on the upper side of the partition arm 22 on the original document stack placed on the original document table 1. After that, this operation is repeated and the recycle SUB (step50
In (0), when the partition arm 22 falls from the original due to its own weight, the copying machine is informed that the circulation of the original is completed, and the operation ends, and as a result, a set of copy sets is completed in the discharge tray of the copying machine. .

On the other hand, in FIG.
(Step 100) and pull repeat SUB (step 400) are executed to transfer the original from the original placing table 1 to the conveyance paths Ia to IIa to IIIa to IVa to Va to VI.
After passing through a to VIIa to IIa, the platen glass 12 is stopped at a predetermined position. At this time, the original is placed so that the back surface of the original placed on the original placing table 1 comes to the platen glass 12 side.
At 0, the main body of the copying machine is instructed to perform the back side copy operation of the original. Next, when the exposure of the copying operation is completed, pull again and repeat SUB
(Step 400) is executed to feed the originals IIa-IIIa-IVa-Va
~ VI ~ VIIa ~ IIa, stop again at a predetermined position on the platen glass 12, and this time the surface of the original is the platen glass.
It is installed so that it comes to the 12 side, and in step 200 the copying machine main body issues a command to perform the surface copying operation of the originals, and at the same time executes the recycle SUB to stop the rotation of the partition arm 22 on the original bundle (step 500). Normal discharge SUB at the end of exposure
(Step 300) is executed, and the original is returned to the upper side of the partition arm 22 of the original placing table 1 in the same set state as before the original is circulated on both sides. After that, this operation is repeated, and a set of copy sets is completed by the end of one cycle described above.

Next, the operation executed by each SUB will be described in detail. In FIG. 8, the normal feed SUB is executed by first turning on the separation motor M2,80 to separate one document from the document stack placed on the document mounting table 1 from below, and the conveyance rollers 6,6a. Wait until the leading edge of the original arrives at the paper feed sensor S1,13 arranged upstream (step 101). The originals separated by the arrival of the leading edge are fed by the feeding rollers 6,6a to the feeding motor M3,9.
7FWD is turned on to rotate the conveying rollers 6, 6a in the direction of the solid line arrow, and waits until the leading edge of the document arrives at the paper feed sensor S2, 14 between the conveying rollers 6, 6a and the belt roller 7 ( ste
p102). Separation motor to prevent the second document from being continuously separated even if the document was sent to the conveyance path normally when the leading edge arrived.
Outputs M1, CHG = "H", M1 of the microcomputer 120 to turn off the belt drive motors M1 and 82 to turn the belt rollers 7 in the direction of arrow → in order to turn off the M2 and 80, and further to feed to the conveyance path IIa. , ON
It is turned on and stands by until the trailing edge of the document is detected by the above-described paper feed sensor S2, 14 with the leading edge of the document fed into the belt 8 (step 103). Set the rear edge of the document to the paper feed sensor S2,14
Is detected, the registration counter [RGCN1] which is operated by the clocks of the photoelectric sensors BC and 95 to stop the document at a predetermined position on the platen glass 12 is started, and the photoelectric sensors BC and 95 are input one clock at a time. Every time [R
GCN1] is counted, and the process waits until [RGCN1] ends (step 104). At the end of [RGCN1], the original is platen glass
Assuming that the vehicle has arrived near the prescribed position on 12, electromagnetic brake B
At the same time when the K and 92 are turned on, the belt drive motor M1 and 8 described above
By turning off M1 and ON to apply the electric brake of 2, the belt drive is instantly stopped and accurate document positioning can be performed, as described later. In addition, the drive of the transport motor M3,97 is also M3,
Stop at 97FWD off.

This operation ensures that one original is
Stop in place above.

On the other hand, in FIG. 9, the execution of the twist-back SUB is as follows. First, the switching solenoids SL and 107 are turned off to feed the original document on the platen glass 12 to the conveying paths IIIa to IVa, the switching claw 23 is lifted, and the conveying path is changed. To rotate 7 in the direction of the dotted arrow, turn on the belt drive motors M1, 82, that is, M1, CHG = "L" M1, ON
The transport motors M3 and 97 are turned on, that is, M3REV is turned on in order to rotate 9,9a in the direction of the dotted arrow. Manuscripts are transported from transport path IIIa to I
In the state of entering Va, the conveyance is continued until the reversal sensor S4, 16 detects the trailing edge of the document (step 401). At the time of detection of the trailing edge, i.e., the belt drive motors M1, 82 and the transport motors M3, 97 are turned off by turning M1, 82 ON off, M3, 97 REV off, the document is supported by the transport rollers 9, 9a, and the trailing edge is the reverse sensor. It is located between S4, 16 and the transport rollers 9, 9a, and is stopped while the standby interval timer is being timed (step 402). Then, the document is transported in the reverse direction and fed to the transport paths Va to VIa. Turn on the feed motors M3, 97 to rotate the feed rollers 9, 9a and 10, 10a, 11, 11a in the direction of the solid arrow, that is, turn on the M3, 97FWD and reverse the originals from the feed path Va to VIa. Continue feeding until the sensor S5,17 detects the trailing edge of the document (ste
p403). Immediately at the time of detection of the trailing edge, M3,97FWD is turned off to turn off the feeding motor M3,97, and the originals are fed by the feeding rollers 10,10a, 11,
It is supported by 11a and its rear end is positioned between the reversing sensors S5, 17 and the transport rollers 10, 10a, and is stopped while the interval timer is being timed (step 404).

Next, the document transport direction is reversed again and the transport paths VIIa to IIa
To rotate the conveyor rollers 10,10a, 11,11a, 6,6b in the direction of the dotted arrow to turn on the conveyor motors M3,97, that is, M3REV, and rotate the belt roller 7 in the direction of the solid arrow. In order to do so, the belt drive motors M1, 82 are turned on, that is, M1, CHG = "H" M1, ON is turned on. The front end of the document is fed into the belt 8 and waits until the rear end is detected by the paper discharge sensors S3, 15 in the conveyance path IIIa (step 405).

When the trailing edge is detected, the registration counter [RGCN2] is started to stop the original at a predetermined position on the platen glass 12, and the clock pulse of the photoelectric sensor 95 causes [RGCN2].
Time is measured until [CN2] ends (step 406). (RGCN2)
At the end, it is assumed that the original has arrived near the predetermined position on the platen glass 12, the electromagnetic brakes BK and 92 are turned on, and at the same time, the above-mentioned belt drive motors M1 and 82 are electrically braked. Further, the driving of the belt 8 is instantaneously stopped, and the original can be accurately positioned. The driving of the transport motors M3, 97 is also stopped by turning off M3, 97 REV, and the switching solenoids SL, 107 are turned off. By this operation, the front and back sides of the original are securely pulled back and stopped at a predetermined position on the platen glass 12.

In FIG. 10, the normal exhaust SUB is executed by the platen glass 12
In order to rotate the belt roller 7 in the direction of the dotted line arrow in order to feed the upper document to the transport paths VIIa to VIa, the belt drive motors M1, 82 are turned on, that is, M1, CHG = "L", M1, ON are turned on, Further, the conveying motors M3, 97 are turned on, that is, M, in order to rotate the conveying rollers 6, 6b, 10, 10a, 11, 11a in the direction of arrow →.
3FWD is turned on and solenoids SL, 107 are turned on. In the state in which the original has entered the conveyance path VIa, the process waits until the paper ejection sensors S3, 15 detect the rear end of the original (step 301). When the trailing edge is detected, the paper discharge counter [EJCN] is started and the clock output of the photoelectric sensor 105 is counted until the end of [EJCN] (step 302). (EJC
At the end of [N], the document leaves the transport rollers 11 and 11a and is returned to the upper side of the document stack on the document table 1.
7FWD off M1, ON is turned off to stop the driving, and the sheet discharge is completed (step 303).

Further, in FIG. 11, the recycle SUB is performed by first separating the originals at a predetermined position on the platen glass 12 to the partition arm 22 above the remaining originals on the original placing table 1.
Rotate the pulse motor 21 once to stop the rotation (step 501) When one cycle of the document is completed, the partition arm 22 falls by its own weight and it is detected that the recycle sensors RS and 19 are turned on, and the one cycle completion signal is copied. Output to the machine (step50
2).

 By this operation, one circulation of the document can be surely detected.

FIGS. 12 to 14 show that when the original of the embodiment of the present invention is stopped at a predetermined position on the platen glass 12, the belt drive motors M1 and 82 are turned off by the output of the microcomputer 120, and the original is actually the platen glass. FIG. 12 shows the delay time until the belt 8 stops, and FIG. 12 shows a case where the belt drive motor M1, 82 is electrically braked, and the belt 8 is delayed by T ₁ hour until it stops. On the other hand, in FIG. 13, when the belt drive motor M1, 82 is off, the drive device for the belt 8 has inertia, but when the electromagnetic brake BK, 92 is applied to the drive device, there is a delay of T ₂ hours until it stops. The delay time T ₂ ′ of the operation of the mechanical part of the electromagnetic brake is added, and the time T ₂ -T ₂ ′ until it stops due to the mechanical part operation delay is dependent on the speed at the time of coupling during the operation of the electromagnetic brake. It is caused by slippage. Further, FIG. 14, which is an embodiment of the present invention, shows that when the belt drive motor M1, 82 is turned off, the electric brake is applied, and during the operation delay of the electromagnetic brake BK, 92, the speed of the belt drive device is reduced to some extent. Since the 92 and 92 are combined, the above-mentioned slip amount becomes smaller, and stops at T ₃ hours. Then, T ₃ <T ₂ and T ₃ <T ₁ , and the electromagnetic brake
The stop variation due to the slippage of BK, 92 is reduced, and a reliable stop position can be obtained.

As another embodiment of the present invention, there is a method shown in FIG.
That is, in FIG., The driver D5 in a way that the drive of the electromagnetic brake BK, 92 carried out 'from the driver D5, D5' output ports O _7, O ₇ of the microcomputer 120 through the one applying rated power of the electromagnetic brake BK, 92 Then (hereinafter referred to as BK), D5 'is applied with a voltage equal to or higher than the rated power supply (hereinafter referred to as BKOVER) (for example, double the rating) and driven by D5' to form the electromagnetic brake BK, 92. That is, the driving timing is shown in FIG.
First drive BKOVER with a pulse, then electromagnetic brake B
By continuously driving K and 92, only the response time is shortened, and after the electromagnetic brake is connected, the electromagnetic brake BK and 92 operate at the rated value. As a result, as shown in FIG. 16, since the coupling time T ₂ ″ of the electromagnetic brake together with the belt drive motor and the electric brakes of M1 and 82 is short, it can be stopped in an extremely short time.

In this embodiment, the electromagnetic brake BK, 92 and the belt drive motor M
Although the electric brake of 1,82 is applied, as another embodiment, the electromagnetic brake BK, 92 may be applied first and the electric brake of the belt drive motor M1,82 may be applied during the coupling time. The stopping accuracy of is obtained.

(Effect) As described above, according to the present invention, the first braking means for braking by electrically short-circuiting the bipolar terminals of the motor for driving the conveying means when stopping the original at the exposure position. The first and second braking means are controlled at such a timing that the second braking means, which first applies the braking and then the electromagnetic means brakes the conveying means, superimposes the braking operation on the first braking means. , When the speed of the conveying means is reduced to a certain extent by the braking force of the first braking means, the braking forces of the first and second braking means are applied to minimize the variation in stoppage due to the slip of the second braking means. Hold it down to
The original can be stopped at the exposure position accurately and quickly.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a double-sided document circulating apparatus embodying the present invention, FIG. 2 is a cross-sectional rear view showing a drive unit, FIG. 3 is a side view showing a document placed state, and FIG. Circuit diagram, FIG. 5 is a drive control circuit diagram, FIGS. 6 and 7 are general flow charts, FIGS. 8 to 11 are detail flow charts, and FIGS. 12 to 14 are time when an original is stopped on a platen glass. A diagram, FIG. 15 is a control circuit diagram of another embodiment, FIG. 16 is a diagram showing the timing of FIG. 15, and FIG. 17 is a diagram showing the time when the original is stopped on the platen glass. 1 ... original placing table, 8 ... belt, 12 ... platen glass, 14 ... paper feed sensor S ₂ , 82 ... belt drive motor M1,
92 …… electromagnetic brake BK, 95 …… sensor BC, 120 …… microcomputer, 130 …… drive control circuit.

Continuation of front page (51) Int.Cl. ⁶ Identification number Reference number in the office FI Technical indication location G03G 15/00 107 (72) Inventor Takahata, 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Mamoru Tanaka 3167 Yamamiya-cho, Kofu-shi, Yamanashi Japan Precision Engineering Co., Ltd. (72) Inhito Umeda 3167 Yamamiya-cho, Kofu-shi, Yamanashi Japan Precision Engineering Co., Ltd. (56) References JP-A-57-85746 (JP, A) JP-A-55-52037 (JP, A) JP-A-49-43710 (JP, A) JP-A-53-53378 (JP, A) JP-A-58-58575 (JP, A) Actually opened Sho 58-103065 (JP, U) Japanese Patent Sho 51-3996 (JP, B1)

Claims (1)

[Claims] 1. An electrically short-circuiting means for conveying an original document to an exposure position and discharging the original document from the exposure position after the exposure of the original document, a motor for driving the conveying means, and bipolar terminals of the motor. A first braking means for braking the conveying means by means of: a second braking means for braking the conveying means by means of an electromagnetic brake; and a first braking means for stopping the original at the exposure position first. Control means for controlling the first and second braking means at a timing such that braking is performed and then the second braking means superimposes on the first braking means to perform braking. Document feeding device.