JPH06324539A - Copying device - Google Patents

Abstract

PURPOSE:To prevent a document conveying failure by driving either a contact glass or a guide member according to the direction of conveyance, thus automatically varying the relation between the position of the contact glass and that of the guide member. CONSTITUTION:Each of guide plates 43 and 44 has an upper plate-shaped portion guiding a document 18 and forming an inclined face that gets higher in the direction for conveying the document 18, and the right end of the guide plate 43 is in a position higher than a contact glass 12A opposite thereto and the left end of the guide plate 44 is in a position lower than the contact glass 12A opposite thereto, so that a difference of height is formed therebetween. When the document 18 is conveyed rightwards under these conditions, the possibility of the end of the document entering the gap between the contact glass 12A and the guide plate 43 and the gap between the contact glass 12A and the guide plate 44 is slight even if it is curled, so no document conveying failure occurs.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, and in particular,
The present invention relates to a copying apparatus in which a document is reciprocally conveyed on a guide member, a contact glass provided in the middle of the guide member is passed through, and slit exposure is performed while the document is conveyed.

[0002]

2. Description of the Related Art Generally, in a slit exposure type copying apparatus, an original is exposed in the vicinity of the center of a contact glass while the original is conveyed in a fixed direction, a copy is formed, and the original is discharged. .

In this type of copying apparatus, various measures have been taken in the original conveying path so that the original can stably pass through a predetermined conveying path. For example, as disclosed in Japanese Utility Model Laid-Open No. 60-1076, an inclined surface that rises in the moving direction of the original is formed on the end surface of the contact glass on the original input side, and the original is guided by this inclined surface. Configured.
Also, as disclosed in Japanese Utility Model Publication No. 63-70755,
A tongue portion extending toward the contact glass is formed on the guide member facing the original entry side end surface of the contact glass,
The tongue is configured to guide the document.

[0004]

By the way, in order to continuously form a plurality of copies from one original, it is generally necessary to repeat the exposure of the original. In the slit exposure type copying apparatus, since the original is exposed while being conveyed, it is necessary to reciprocate the original in order to repeat the exposure operation. However, when transporting a document back and forth,
Problems in transportation are likely to occur. That is, a problem is unlikely to occur when the document is conveyed in the forward direction, but when it is conveyed in the backward direction, the document comes out of the normal path and is conveyed abnormally (jam).
It often becomes. In particular, when the original is curled, due to the influence of the inclined surface of the contact glass and the tongue portion of the guide member, defective conveyance of the original is likely to occur during the backward movement as shown in FIG.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to suppress the occurrence of document conveyance failure in a copying machine which conveys a document back and forth.

[0006]

In order to solve the above problems, according to the present invention, an original is reciprocally conveyed on a guide member, and the original is conveyed through a contact glass provided in the middle of the guide member. In a copying apparatus which performs slit exposure while moving: movable supporting means for movably supporting at least one of the guide member and the contact glass; direction identifying means for identifying a document transport direction; and interlocking with switching of the document transport direction. Driving at least one of the guide member and the contact glass, and positioning the guide member at a position facing the contact glass above the contact glass at the upstream end side of the contact glass, and at the downstream end side of the contact glass at the contact end. Driving means for positioning the guide member at a position facing the glass below the glass;
To provide.

[0007]

According to the present invention, the direction identifying means identifies the carrying direction of the document, and the driving means drives the contact glass or the guide member in accordance with the carrying direction, and the positional relationship between the contact glass and the guide member. Change automatically. As a result, it is possible to suppress the occurrence of document conveyance failure in both the forward direction conveyance and the backward direction conveyance.

For example, when the leading edge of the original curls downward, the leading edge of the original enters the gap between the contact glass and the guide member, or the leading edge of the original hits the stepped portion between the contact glass and the guide member. As shown in 2, there is a high possibility that a document conveyance failure will occur. However, in the present invention, the guide member at a position facing the contact glass is positioned above the contact glass at the upstream end side of the contact glass, and at the downstream end side of the contact glass at the downstream end side of the contact glass according to the conveyance direction of the document. Since the guide member at the position opposite to that is positioned below,
A step with a high front and a low tip is formed between the contact glass on the upstream side and the guide member, and a step with a high front and a low tip is formed between the contact glass on the upstream side and the guide member. It is extremely unlikely that the leading edge of the original is abutted against these steps and that the leading edge of the original enters the gap.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the overall construction of a copying apparatus according to an embodiment. This will be described with reference to FIG. A contact glass 12 is provided on the top of the main body housing 10 while being covered with a cover 11. In front of and behind this contact glass 12, a document feeding roller 1 which constitutes a document feeding device.
3, 14, 15 and document discharge rollers 16, 17 are provided. The document 18 is exposed on the contact glass 12 while being conveyed in the forward direction, and an optical image obtained by the exposure of the document 18 is formed on the drum-shaped photoconductor 22. Since it is necessary to expose the document 18 to form each copy image, when a plurality of copies are to be continuously formed, the specified number of copies of the document 18 is used for the contact glass 12. The above reciprocating conveyance is performed, and the exposure is performed during each forward conveyance. The reciprocating conveyance of the document 18 is realized by the forward and reverse rotations of the document conveying rollers 14 and 15 and the document discharging rollers 16 and 17. When the exposure is completed, the document 18 is discharged to the tray 19.

A white backup plate 20 is provided on the contact glass 12 so as to be vertically movable. On the other hand, below the contact glass 12,
A light-collecting photoconductor array 23 is provided to form an image of the original 18 on the contact glass 12 illuminated by the lamp 21 on the photoconductor 22. Around the drum-shaped photoconductor 22, a charging charge necessary for carrying out the electrophotographic process.
Jar 24, developing device 25, transfer charger 26, separation charger 27, cleaning device 28, and charge eliminating charger.
Ja 29 is provided.

The roll paper 30 is fed by the feed rollers 31 and 32, and is fed by the registration roller 33 so as to come into contact with the surface of the photoconductor 22 at a predetermined timing, and the transfer charger 26 operates. As a result, the toner image formed on the photoconductor 22 is transferred and separated from the photoconductor 22 by the action of the separation charger 27. Then, after being conveyed to the fixing device 35 by the conveyor belt 34 and fixed, the discharge roller 3
The sheet is discharged onto the tray 37 by 6. The roll paper 30 is
Depending on the length designated in advance, it is cut by the cutter 38 or the length of the document read by the document length reading mechanism.

FIG. 3 shows the structure of the main part of the document transport mechanism. This will be described with reference to FIG. Contact glass 12A
Before and after the guide plate 43, 4 which is swingably supported.
4, document transport rollers 14 and 15 and document discharge roller 1
6, 17 are provided. The document feeding roller 14 and the document discharging roller 16 are connected to a driving mechanism driven by an electric motor, and are rotationally driven in forward and reverse directions. When the document feeding roller 14 and the document discharging roller 16 rotate in the counterclockwise direction (the direction of the solid arrow in the figure), the document 18 is transported in the right direction (forward feeding direction: AR1). When the exposure is repeated a plurality of times, the document feeding roller 14 and the document discharging roller 16 are driven in the clockwise direction to feed the document 18 to the left (reverse feeding direction: AR2) to a predetermined reference. After returning to the position, the document 18 is conveyed again in the forward conveyance direction and exposure is performed.

One end of each of the two guide plates 43 and 44 is engaged with the connecting rod 45. This connecting rod 45 is
A solenoid 47 is connected to one end and a tension coil spring 46 is connected to the other end. When the solenoid 47 is deenergized, the force of the spring 46 causes the connecting rod 45
Is positioned at a predetermined position on the right side. In that state, the guide plates 43 and 44 are positioned in the state shown by the solid line in FIG. 3, respectively. That is, in the guide plates 43 and 44, the upper plate-shaped portions that guide the document 18 form slopes that become higher in the document transport direction (right side), and the position of the right end of the guide plate 43 is different from that. The position is higher than the contact glass 12A facing each other, and the position of the left end of the guide plate 44 is lower than the contact glass 12A facing the contact glass 12A, and a step is formed between them. Therefore, when the document 18 is conveyed rightward (forward conveyance direction) in this state,
Even if the leading edge of the document 18 is curled, the document 18
Has a gap between the contact glass 12A and the guide plate 43, and the contact glass 12A and the guide plate 4
There is a very small possibility that it will get into the gap between the sheet and the sheet 4, and no document conveyance failure will occur.

When the solenoid 47 is biased, the pulling force of the solenoid 47 positions the connecting rod 45 at a predetermined position on the left side. In that state, the guide plates 43 and 44 are positioned in the state shown by phantom lines in FIG. That is, the guide plates 43 and 44 are
The upper plate-shaped portion that guides 8 forms slopes that become higher in the document conveying direction (left side), and the right end position of the guide plate 43 is lower than the contact glass 12A facing it, and The position of the left end of the plate 44 is higher than the contact glass 12A facing it,
A step is formed between them. Therefore, when the original document 18 is conveyed in the leftward direction (returning conveyance direction) in this state, even if the leading end (left end) of the original document 18 has a curl, the leading end of the original document 18 has the contact glass 12A and the guide plate. The possibility of entering the gap between the contact glass 12A and the guide plate 44 is extremely small,
Document feeding failure does not occur.

However, in order to suppress the document conveyance failure, it is necessary to switch the inclination of the guide plates 43 and 44 according to the document conveyance direction. Of course, if the number of copies is one, the document is conveyed only in the forward direction, so it is not necessary to switch the inclination of the guide plates 43 and 44. Guide plate 4
An optical sensor 48 for detecting the position of the document 18 is installed above the sheet 3.

FIG. 5 shows the configuration of an electric circuit for controlling the document feeding mechanism shown in FIG. Referring to FIG. 5, the sensor unit SU and the pulse generator PG are connected to the input of the document conveyance control unit FC, the driver DV is connected to the output, and the communication terminal is connected to the system control unit SC. A solenoid 47, a clutch unit CL, and an electric motor M1 are connected to the driver DV. The sensor unit SU includes an optical sensor 48 that detects the position of the document 18. The electric motor M1 is a drive source for the document transport roller 14 and the document discharge roller 16.
The clutch unit CL includes various clutches for turning on / off the driving of the document feeding roller 14 and the document discharging roller 16 and switching the driving direction. The system control unit SC controls the entire copying machine, and exchanges various information with the document conveyance control unit FC.

FIG. 6 shows the contents of the operation of the document feeding control unit FC shown in FIG. This will be described with reference to FIG. When the power is turned on, initialization is performed, and then in step 62, the original start instruction from the system control unit SC is awaited.
When the original start instruction arrives, the next step 63 starts the conveyance of the original (forward conveyance). Next step 6
In step 4, the optical sensor 48 waits for detection of the trailing edge of the document (tail edge in the transport direction). When the trailing edge of the document is detected, it is checked in the next step 65 whether the exposure is completed. That is, the number of copies specified in advance by the operator and the number of exposures of the document (the number of times the document is conveyed in the forward direction)
And are compared, and if they match, it is considered that the exposure has been completed.

In the case of copying one sheet, the process proceeds from step 65 to 6F, but in the case of copying multiple sheets, the process proceeds from step 65 to step 66 after the first exposure. In step 66, a predetermined time T1 is set in the internal timer and the timer is started. Next step 67
Then, wait until the time T1 of the timer reaches the time over. When T1 reaches the time over, the routine proceeds to the next step 68. In this embodiment, when the time T1 reaches the time over in step 67, the rear end of the document 18 passes through the exposure position (center) on the contact glass 12A and is further advanced to a predetermined position. In addition, the time T1 is set. In step 68, the conveyance of the document is stopped and the solenoid 47 is energized. Thereby, the guide plate 43
And 44 are switched from the state shown by the solid line in FIG. 3 to the state shown by the virtual line.

In the next step 69, the conveyance of the original document in the reverse direction (reverse conveyance direction) is started. In the following step 6A, the optical sensor 48 waits until the rear end (right end) of the document is detected. When the trailing edge of the document is detected, a predetermined time T2 is set in the internal timer and the timer is started. In the next step 6C, it waits until the time T2 of the timer reaches the time over. When T2 reaches the time over, the process proceeds to the next step 6D. In this embodiment, when the time T2 reaches the time over in step 6C, the right end of the document 18 passes through the exposure position (center) on the contact glass 12A and further advances to a predetermined reference position. As described above, the time T2 is set. In step 6D, the conveyance of the document is stopped and the solenoid 47 is deenergized. As a result, the guide plates 43 and 44 are switched again from the state shown by the phantom line in FIG. 3 to the state shown by the solid line.

In the next step 6E, a transport preparation completion signal is output to the system control unit SC. In response to this signal, the system control unit SC prepares for the next copy cycle and outputs the document start instruction to the document transport control unit FC again at a predetermined timing. Therefore,
The document conveyance control unit FC repeatedly executes the processing from step 62. When the completion of exposure is detected in step 65, after waiting for the completion of the document discharge in step 6F, the document conveyance is stopped in the next step 6G, and the process returns to step 62 again.

In the above embodiment, the inclinations of the guide plates 43 and 44 provided on both the input side and the output side of the contact glass 12A are switched according to the document conveying direction. When the trailing edge of the document is controlled so as to stop between the exit side end of the contact glass 12A and the exposure section (center) during conveyance in the forward direction, the conventional guide plate 44 can be used instead. Good. For that purpose, the time T1 may be appropriately adjusted.

FIG. 4 shows the structure of the document feeding mechanism in another embodiment. This will be described with reference to FIG. In this embodiment, the contact glass 12B is swingably supported around a fulcrum a, and the guide plates 41 and 42 at both ends thereof are fixed. Further, one end of the lever 51 rotatably supported is in contact with a part of the contact glass 12B, and the other end of the lever 51 is connected to the plunger of the solenoid 52. A tension coil spring 53 is engaged with the plunger. Therefore, by energizing / deactivating the solenoid 52, the lever 51
Can be moved to change the inclination of the contact glass 12B. The rotation fulcrum a of the contact glass 12B is the upper end of the holder 54 of the converging photoconductor array 23.

In the deenergized state of the solenoid 52, the lever 51 is rotated clockwise to a predetermined position by the force of the spring 53, and the contact glass 12B is positioned at the inclined position shown by the solid line in FIG. In this state, the upper surface of the contact glass 12B forms an inclined surface whose height increases as the document 18 advances in the forward transport direction (AR1). In addition, the guide plate 41 and the contact glass 12
In the portion facing B, the height of the contact glass 12B is lower than that of the guide plate 41.
The height of the contact glass 12B is higher than that of the guide plate 42 in a portion where the guide glass 42 and the guide plate 42 face each other.

In the energized state of the solenoid 52, the lever 51 rotates counterclockwise to a predetermined position by the pulling force of the solenoid 52, and the contact glass 12B is positioned at the position of inclination shown by the phantom line in FIG. It In this state, the upper surface of the contact glass 12B forms a slope whose height increases as it moves in the backward transport direction (AR2) of the document 18. Further, in the portion where the guide plate 41 and the contact glass 12B face each other, the height of the contact glass 12B is higher than that in the guide plate 41, and in the portion where the contact glass 12B and the guide plate 42 face each other, the contact glass 12B contacts more than the guide plate 42. The height of the glass 12B is low.

Therefore, as in the case of the above-described embodiment, when the document 18 is conveyed in the forward conveyance direction (AR1), the solenoid 52 is deenergized to reduce the possibility of document conveyance failure. Therefore, when the document 18 is conveyed in the backward conveyance direction (AR2), the solenoid 52 is biased to reduce the possibility of document conveyance failure. Further, as shown in FIG. 4, by arranging the holder 54 that determines the rotation fulcrum a of the contact glass 12B in the vicinity of the converging photoconductor array 23, the upper and lower sides of the contact glass 12B in the slit exposure section 55 can be adjusted. The amount of movement in the direction can be minimized, and the swing of the contact glass 12B can be prevented from adversely affecting the reading of the original image.

[0026]

As described above, according to the present invention, the direction identifying means identifies the conveying direction of the original document, and the driving means drives the contact glass or the guide member in accordance with the conveying direction, and the contact glass is detected. Since the positional relationship with the guide member is automatically changed, even if the leading edge of the document is curled, document conveyance failure occurs in both the forward direction conveyance and the backward direction conveyance. Can be suppressed.

[Brief description of drawings]

FIG. 1 is a front view showing the overall configuration of a copying apparatus according to an embodiment.

FIG. 2 is a front view showing a conventional document transport mechanism.

FIG. 3 is a front view showing a document feeding mechanism of the embodiment.

FIG. 4 is a front view showing a document feeding mechanism of another embodiment.

FIG. 5 is a block diagram showing a main part of an electric circuit according to an embodiment.

FIG. 6 is a flowchart showing the operation of the document conveyance control unit.

[Explanation of symbols]

10: Main body housing 11: Cover 12, 12A, 12B: Contact glass 13, 14, 15: Original transport roller 16, 17: Original discharge roller 18: Original 19: Tray 20: Backup plate 21: Lamp 22: Drum-shaped photoconductor 23: Light-collecting photoconductor array 24: Charging charger 25: Developing device 26: Transfer charger 27: Separation charger 28: Cleaning device 29: Static elimination charger 30: Roll paper 31, 32: Paper feed roller 33: Registration roll
LA 34: Conveyor belt 35: Fixing device 36: Ejecting roller 37: Tray 38: Cutter 41, 41A, 42, 42A: Guide plate 43, 44: Guide plate 45: Continuous rod 46, 53: Tension coil spring 47 , 52: Solenoid 51: Lever 54: Holder 55: Slit exposure unit

Claims (5)

[Claims] 1. A copying apparatus in which an original is reciprocally conveyed on a guide member, a contact glass provided in the middle of the guide member is passed through, and slit exposure is performed while the original is conveyed. At least one of the guide member and the contact glass is driven in conjunction with a movable supporting means for movably supporting at least one of them; a direction identifying means for identifying a conveyance direction of a document; On the upstream end side of the contact glass, the guide member at a position opposed to the contact glass is positioned above, and on the downstream end side of the contact glass, the guide member at a position opposed to the contact glass is positioned below. Drive means;
A copying machine characterized by being provided with. 2. The copying apparatus according to claim 1, wherein the movable supporting means rotatably supports the contact glass. 3. The guide member includes a plurality of oscillating members respectively arranged at positions facing both ends of the contact glass, and the movable supporting means supports the plurality of oscillating members, respectively. 2. The copying apparatus according to claim 1, wherein the driving unit moves each of the plurality of swing members in association with switching of a document conveying direction. 4. When the document is forwardly transported, the document transport is stopped while the document rear end passes through the slit exposure section and the document is present on the contact glass, and then the document is backwardly transported. The copying apparatus according to claim 1, further comprising a transport control unit that controls the copying. 5. A displacement control means for controlling the driving means to move the contact glass or the guide member when it is detected that the trailing edge of the original has passed through the slit exposure section when the number of copies is plural. The copying apparatus according to claim 1.