JPH04129969A - Picture forming device - Google Patents

Abstract

PURPOSE:To save a driving source, to reduce a noise and to simplify a control circuit by providing constitution such that a conveying means for conveying a transcription material to an intermediate tray and a switch back means for performing both-side transcription are driven by a single transmitting means. CONSTITUTION:Constitution is provided such that conveying means 30, 31, 38 to an intermediate tray 37 and a switch back means 27 are driven by a single transmitting means. Based on this constitution, a picture is formed in a transcription material P, and then the picture-formed transcription material P is discharged to the outside of a device l. The transcription material P, after the picture is formed, is discharged to the intermediate tray 37, and the transcription material P is refed frown the intermediate tray 37 to form a picture overlapped again in the concerned transcription material P. The transcription material P, after a picture is formed, is discharged to the intermediate tray 37 via the switch back means 27 and refed from the intermediate tray 37 to from a picture again on a reverse side of the transcription paper P.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to an image forming apparatus such as a copying machine capable of double-sided and multiple copying, and more specifically to transfer paper conveyance of an image forming apparatus capable of double-sided and multiple copying. Regarding the mechanism.

(Old Conventional Technology) In the past, an image was formed by transferring an image formed in an image forming section of a copying machine to transfer paper, and then the image was formed again on the back side of the transfer paper on which the image was formed. Many image forming apparatuses have been proposed that can perform double-sided copying or multiple copying in which another image is formed on the same side of a transfer sheet on which an image has been formed and then combined.This type of image forming apparatus An example will be explained based on FIG. 5. Copying machine 1
has an optical system 2 that illuminates and scans an original (not shown), and an image forming section 3 consisting of a photosensitive ram 5 and the like onto which a light image reflected from the original is projected. 1-By depositing toner on the electrostatic latent image formed on the photosensitive ram 5, a 1 henna image corresponding to the Ll original is formed on the photosensitive ram 5.

The paper feed section 6 includes a plurality of paper feed tables 8, 9, 10, 11 . . . each containing transfer paper 1) of different sizes. ．． There are twelve
is sent to the photosensitive drum 5. One henna image on the ram 5 is transferred onto the transfer paper P by the photosensitive member 1 in the transfer section 13, and further sent to the fixing device 15 by the conveyance section 14, where the one hener image is fixed. In the case of copying or normal one-sided copying, the transfer paper P is sent to the paper discharge section 18 by a pair of feed rollers 16 and 17, and 431 sheets are delivered.

When making 11 double-sided copies on transfer paper (■), use flapper 19.
The transfer ar (p is the feed roller pair 1.6.21
It is guided to a conveyance path 22 between the two. At this time, when the transfer paper is detected by the sensor 40, the reversing roller pair 27 begins to rotate in the direction of the arrow 39. Furthermore, the flapper 23 below the feed roller pair 21 rotates in the direction of arrow 24 from the position shown in the figure, and the transfer paper P is guided to the conveyance path 25. When it is detected that the rear end of the transfer paper P has passed the sensor 26 provided near the flapper 23, the pair of reversing rollers 27 reverses the direction of the transfer paper P.
is sent into the discharge section 29 through the conveyance path 28. In the discharge section 29, a plurality of discharge roller pairs 30.31 and flappers 32.33 are provided, so that a plurality of discharge ports 34,
35 and 36 respectively. Note that each flapper 32, 33 is rotated by the operation of a solenoid (not shown) to open the discharge port 34, 35.

The paper feed section 6 is provided with a plurality of detection sections (not shown) that detect the paper size. Transfer paper P is discharged from three types of discharge ports 34, 35, and 36 according to the paper size detected by this detection section. For example, the size of rolling paper P or A
3. At the end of B4, flapper 3 is activated by the operation of the solenoid.
Turn clockwise in Figure 2 to open the discharge port 34.

ll:11 The transfer paper P sent into the output section 29 is delivered to the output section 29.
It is discharged to intermediate 1 to lay 37 arranged below. Also, the size of the transfer paper is A4. One more when B5 is in portrait mode
Two solenoids are activated, and the flapper 33 rotates clockwise in the figure to open the discharge I] 35. and discharge section 29
The transferred paper P is sent from the discharge port 35 to the intermediate tray 37.
, is discharged. Size of transfer paper P or A4. When B5 is oriented horizontally, none of the solenoids "1" is activated, and the transfer paper P advances in the discharge section 29 to the leading end and is discharged from the discharge port 36 to the intermediate layers 1 to 37.

When performing multiple copies on transfer paper P, transfer paper P is double-sided:
It is sent to the conveyance path 22 in the same manner as the 1-bee. In the case of multiple copies, the lower flapper 23ζJ remains at position 1 (as shown in FIG. It is loaded onto the intermediate tray 37.

The transfer paper P re-fed from the intermediate tray 37 is transferred to the fixing device 15 after the 1-toner image is transferred again to the surface on which the image has already been formed.
The image is fixed and then discharged from the paper discharge section 18 to the outside of the apparatus.

In such a conventional image forming apparatus, during double-sided copying, the transfer paper P on which an image has been formed once in the image forming section 3 is reversed by a pair of reversing rollers 27, passes through a conveyance path 25, a passage 28, and a discharge section 29, and then is transferred to an intermediate sheet P. The paper is stored and stacked on the 1-ray 37, and is then re-fed to form an image again. At this time, the pair of discharge rollers 30, 31, and 38 of the discharge section 29 are driven by a main body drive source (not shown), and rotate while the apparatus is in operation.

(C) Problems to be Solved by the Invention However, in the conventional example, the ejection rollers 30, 31, 38, etc. of the ejection section 29 do not need to operate except during duplex/multiple copying. The problem was that they were constantly operating with the same driving source, which caused noise.

Therefore, it would be possible to drive the discharge section 29 independently using another motor or the like, but the device for controlling the motor would be complicated, increasing costs and requiring extra space. The problem is that it becomes necessary.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide an image forming apparatus that is simple and can reduce noise by providing a transmission means for operating the conveyance means and switchback means to the intermediate 1-lay when necessary. That is.

(-') Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances. The transferred transfer material (■)) is sent to the image forming section (13) again, and an intermediate l-ray (
37), and change the conveyance direction of the transfer material (P) to the back 1
Switchback means (27) for forming an image on n1
An image forming section W? (]-), conveyance means (3o 31.38) to the intermediate 1 lay (37)
) and the switchback means (27) are driven by the same transmission means (60).

The transmission means (60) includes two input shafts (45g, 46g) that always rotate in the same direction;
g) through two switching means (45° 46), an output shaft (30S) rotating in the same direction and connected to the conveying means (30, 31, 38), and the switchback means (2
7) and an output shaft (27s) that switches the direction of rotation.

Further, the transmission means (60) includes an output shaft (30s) that rotates in the same direction, and an output shaft (20s) that switches the rotation direction.
One-way mechanism (4s) that absorbs the rotation difference between
5o, 46o).

(E) Function Based on the above configuration, (1) After forming an image on the transfer material (P), the transfer material (P) on which the image has been formed is discharged to the outside of the apparatus (1). In addition, after forming an image on the transfer material (P),
The transfer material (P) is fed again from the intermediate tray (37), and is again superimposed on the transfer material (P) to form an image. In addition, after forming an image on the transfer material (P), it is discharged to the intermediate tray (37) via the switchback means (27), and the transfer material (P) is re-fed from the intermediate tray (37). Then, an image is formed on the back side of the transfer material (P) again.

In said zero operation, the transmission means (60) does not actuate the transport means (30° 31.38) to the intermediate tray (37) and the switchback means (27). At the time of said zero action, the transmission means (60) is connected to the conveyance means (30, 31, 38) to the intermediate tray (37) and the switchback means (
27) in the same direction. At the time of the zero action, the conveying means (30, 31, 38) operate in the same direction,
The switchback means (27) performs an intermediate reversal operation.

In addition, two input shafts (45g, 46g) of the transmission means (60)
g) are rotationally driven in the same direction, and the conveying means (30, 3)
,, 38) always rotate in the same direction, and the output shaft (27S) connected to the switchback means (27) switches the direction of rotation midway through.

Furthermore, the one-way mechanism (45o, 460) absorbs the difference in rotation between the output shaft (30s), which always rotates in the same direction, and the output shaft (27s), which changes the rotational direction midway.

Note that the symbols in the parentheses are illustrative and do not limit the structure of the present invention in any way.

(f) Example Hereinafter, the present invention will be described in detail with reference to the drawings.

A general description of the copying machine embodying the present invention is omitted in this embodiment since it overlaps with the description given with reference to FIG. 5 in the section of the prior art. Also in this example, the fifth
The same reference numerals are used for the same members as those used in the figures.

Next, this embodiment will be described in detail with reference to FIGS. 1 to 3.

The power transmission device 60 transmits rotational force from another drive source (not shown) to the timing pulley 52 via the timing heald 53, and connects the shaft 518, the gear 51, and the twin gear gear 50.
g, -1i' gears 50 and timing bells 1 to 49, gears 45g and 4 respectively installed in the clutch 45.46.
Rotational force is transmitted to 6g. In addition, a shaft 51 to which a timing pulley 52 and a gear 51 are fixed to support plates 41 and 44 fixed to the main body of the device 1. s, 1 child gear 50.50g
The shafts 45s and 46s are rotatably supported. And clutch 45.46 each shaft 4.5s
, 46s are rotatably supported.

In addition, they are attached to timing pulleys 45ρ, 46p or shafts 45s, 46s via one-way clutches 45o, 46o, and these timing pulleys 45p, 46p
A timing pulley 48 is driven via a timing held 47 stretched over a shaft 30 supported by a support plate 41.
A timing pulley 30p and a timing pulley 31p are fixed to the front side of the shaft 30s, and a timing pulley 31p is fixed to the opposite side of the shaft 30s.
, a timing held 43 is attached to 38p. The shafts 303, 318, 388 are supported by the support plate 42, and the shafts 30s, 31s, 38S are connected to the discharge drive roller 3.
0a, 31a, and 38a are being investigated.

] 1 In addition, a shaft 27s is pivotally supported on the support plate 41, and this shaft 27s
and the timing pulley 57 attached to the shaft 46s.
, 56, the timing bell 1-58 is stretched, and gears 55 and 54 attached to the shaft 27s and the shaft 45s, respectively, are meshed with each other.

Furthermore, the timing belt 49 rotates in the direction of the arrow in FIG. The timing pulley 47 is rotated in the direction of arrow B via either timing pulley 45p or 46p, and the shaft 30s is rotated in the direction of arrow B.
It is designed to rotate in the direction. And axis 30s
A discharge roller 30a attached to the transfer paper P is configured to discharge the transfer paper P.

Also, when the clutch 45 is connected to the shaft 45s, the shaft 45s
, gear 54, and gear 55, the shaft 27S is rotated in the direction of arrow C, and at this time, the shaft 46s is rotated through timing bells 1 to 58.
However, the one-way clutch 46o causes it to idle, and the timing bells 1 to 47 prevent it from going against the timing pulley 46p, which is rotating in the opposite direction.

Further, when the clutch 46 is connected to the shaft 46s, the shaft 27s is rotated in the direction opposite to the arrow C via the timing pulley 56, timing belt 58, and timing pulley 57.
At this time, the shaft 45s rotates in the opposite direction to the timing pulley 45p via the gears 55 and 54, but is caused to idle by the one-way clutch 45o.

Therefore, when the clutch 46 is turned on, the reversing roller 27a rotates in the direction of arrow 39 in FIG.
When the switch is turned on, the reversing roller 27a pulls the transfer paper P onto the switch.

Next, the operation of this embodiment will be explained.

Since the general operation has been described in the prior art section, it will be omitted, and the operation of the discharge section 29 and the pair of reversing rollers 27 will be explained here.

When copying machine 1 is instructed to make a one-sided copy, the signal causes the third
Both clutches 45 and 46 shown in the figure are not turned on. Therefore, the rotational force is input to the power transmission device 60 from another drive source (not shown) via the timing belt 53, or the shaft 45s,
46s does not rotate because clutches 45 and 46 are disengaged. That is, the discharge rollers 30, 31, 38 and the reversing roller 27 are stationary.

Next, when the copier 1 is instructed to make multiple copies, the flapper 19
rotates in the direction of arrow 20, undergoes primary transfer on two sides,
When the transfer paper P having the fixed image is ejected from the fixing device 15 and its leading edge is detected by the sensor 40, the flapper 23 assumes the position shown in FIG. 1 and the clutch 46 is turned on. , discharge rollers 30a, 31
a, 38a rotates in the direction of arrow B, and the reversing roller 27a rotates in the direction of arrow 39.

Then, the transfer paper P is guided by a flapper 19.23, and is discharged by a feed roller 21, a discharge roller 30a, etc., and then transferred to an intermediate layer 37 through one of the discharge rollers 34, 35, and 36.
ul is released.

Note that since the transfer paper P is not detected by the sensor 26, the clutch 46 remains on until the transfer paper P is ejected.

Next, when the copying machine 1 is instructed to perform double-sided copying, the flapper 20
rotates in the direction of arrow 20, and when the sensor 40 detects the leading edge of the transfer paper P discharged from the fixing device 15, the flapper 2 rotates in the direction of arrow 20.
At the same time, the clutch 46 is turned on and the discharge rollers 30a, 31a, 38a are rotated in the direction of arrow B.
The reversing roller 27a rotates in the direction of the arrow 39.
Rotate in the direction. And the transfer paper P has a flapper 19.2
3, the feed rollers 1.6, 21. The transfer paper P is conveyed to the conveyance path 25 by the reversing roller 27 . Then, when the trailing edge of the transfer paper P0' is detected by the sensor 26,
The clutch 46 is turned off, the clutch 45 is turned on, and the roller 27a of the reversing roller 27 rotates in the opposite direction as indicated by the arrow 24, and the flapper 23 rotates in the opposite direction as indicated by the arrow 24. 31a and 38a are arrow B
Continue rotating in direction. As a result, the transfer paper P is switched and guided from the conveyance path 25 to 28 by the flapper 23, and is discharged from either the discharge port 34 or 35. Then, the discharge rollers 30, 31, 38 and the reversing roller 27 stop.

Further, the discharge ports 34, 35, and 36 receive a transfer paper size signal from one of the cassettes 8, 9, 10, 11, and 12, and a corresponding solenoid is activated by the flapper 32.
33 is opened or closed.

Next, another embodiment will be described with reference to FIG.

FIG. 4 is an explanatory diagram showing the length of the transfer paper P and the length of the conveyance path.

The length of the conveyance path from sensor 40 to sensor 26. , the length of the conveyance path from the sensor 26 to the roller 38a 3,
The length of the transfer paper P(1), , P2) is 4, the preceding transfer paper is Pl, and the following transfer paper is P2. Then, between the length of the transfer paper P1 or the transport path L and the reversal movement ρ, make sure that the leading edge of the next transfer paper P2 is not detected by the sensor 40 (in other words, the roller 27 a When it is necessary for the sensor 26 to reverse the roller 27a, the sensor 40 inputs an instruction to rotate the roller 27a in the normal direction, which is not possible.Furthermore, the transfer sheets P and P2 interfere with each other in the vicinity of the sensor 26. That is, the conveyance pitch of the transfer paper P1 and P2 >L.+2ρ, the conveyance path and the sensor 26,
40 positional relationships must be set.

That is, in the case of the embodiment described above in which the one-way clutches 45o and 46o are provided, this condition is satisfied.

Next, if only the one-way clutch 450 is provided and 46o is removed, the roller 30a will be closed only during the reverse rotation of the roller 27a.
Since 31a and 38a are configured to rotate, the transfer paper P
, and P2 are equal to or larger than L O+2ρ10, 1 or more.

That is, this is the present embodiment, and is an embodiment in which the pitch of the transfer sheets P1 and P2 is 7°+2ρ+L, or less.

By doing this, when the leading edge of the transfer paper P is detected by the sensor 40, the flapper 2 is activated by the signal from the sensor 40.
At the same time, the clutch 46 is turned on and the roller 27a rotates in the direction of the arrow 39. Then, the transfer paper P is conveyed to the conveyance path 25. When the rear end of the transfer paper P is detected by the sensor 26, the signal causes the flapper 23 to rotate in the direction opposite to the arrow 24, and the clutch 45 is turned on, causing the roller 27a to move in the direction indicated by the arrow 24.
The rollers 30a and 31a rotate in the opposite direction to 9.
, 38a are rotated by the one-way clutch 45o in the direction of arrow B, and the transfer paper P is conveyed from the conveyance path 25 to 28.
It is discharged to either of the discharge ports 34, 35, and 36.

That is, since the one-way clutch 46o is not provided in this embodiment, even if the clutch 46 is turned on, the timing bell 1 is not activated.
The rollers 30a, 31a, 3 are removed from the timing pulley 47 by rotating the roller 27a in the direction of the arrow 39 via the
Do not rotate 8a. And clutch 45
is turned on, the one-way clutch 45o causes the rollers 30a, 31a, and 38a to rotate.

In this embodiment, the one-way clutch 468 is removed and the operating time of the rollers 30, 3], 38 is reduced by increasing the conveyance pitch of the transfer paper P by increasing the conveyance path length.
Noise is reduced to cost 1.

In this embodiment (and other embodiments), in the case of multiple copying, it is preferable to turn on the clutch 45 from the control stand of the device (even if the clutch 46 is turned on by the sensor 40, the one-way clutch 46o is not activated). (Therefore, rollers 30a, 31a, and 38a do not rotate).

(1.) As described in detail, according to the present invention, the conveyance means for conveying the transfer material to the intermediate tray and the switchback means for double-sided copying are driven by the same transmission means. Therefore, since the duplex/multiple copying operation is performed using a transmission means from another drive source, the drive source can be saved. In addition, by operating the transmission means, only the transport and reversing rollers necessary for single-sided copying, multiple copying, and double-sided copying are driven, so unnecessary rollers are not operated, reducing the noise generated. It's coming hard. Furthermore, the control circuit can be simplified by controlling with a one-way clutch or the like.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional side view showing an intermediate 1 lay transfer means and a switchback transfer means showing an embodiment of the present invention, Fig. 2 is a side view showing its power transmission system, and Fig. 3 is a plan development thereof. 4 are explanatory views of other embodiments, and FIG. 5 is a longitudinal sectional side view of a conventional copying machine. DESCRIPTION OF SYMBOLS 1... Image forming device (copying machine), 13... Image forming section (transfer section), 27... Switchback means (reversing roller pair), 27s, 30s... Output shaft (output for switching rotation) shaft, output shaft rotating in the same direction),
30, 31. 38... Conveyance means (discharge roller pair), 37... Intermediate tray 45.46... Switching means (clutch) 45g, 46g... Input shaft (gear) 60... Transmission means (Power transmission device) P...Transfer material (transfer paper)

Claims (1)

[Scope of Claims] 1. The transfer material on which the image has been formed is sent to the image forming section again, and an intermediate tray is provided for forming an image on the transfer material again, and an image is formed on the back side by switching the conveying direction of the transfer material. 1. An image forming apparatus comprising: a switchback means for transporting the intermediate tray; and a switchback means for transporting the intermediate tray and the switchback means. 2. The transmission means includes two input shafts that always rotate in the same direction, an output shaft that rotates in the same direction and is connected to the conveyance means from the input shaft via two switching means, and the switchback. an output shaft connected to the means for switching the rotation direction;
The image forming apparatus according to claim 1, having the following. 3. The image forming apparatus according to claim 2, wherein the transmission means is provided with a one-way mechanism for absorbing a rotation difference between the output shaft rotating in the same direction and the output shaft switching the rotation direction.