JPH03190696A - Picture image forming device - Google Patents

Abstract

PURPOSE:To prevent the deterioration, etc., due to the ripple and folding of a form and heating by providing a means controlling the driving of a discharging means so as to discharge the form out of the device, after forming a punching hole, by temporarily stopping the from under discharging in the state of the end side thereof being faced to a punching part based on the detection signal transmitted from a detection means. CONSTITUTION:When a detection means S detects the tip or rear end of a form, a driving control means C temporarily stops the form under discharging in the state of the rear end side thereof being faced to a punching part 7, based on the detection signal transmitted from the detection means S. In this state the punching part 7 forms a punching hole at the vicinity of the rear end of the form. Consequently, there is no risk of the form which was temporarily stopped for the punching hole formation being brought into contact with the other part of a form transfer part 4 arranged at the upper stream side of the punching hole 7.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an image forming apparatus, and more particularly, to a punching mechanism for automatically forming punch holes for binding in sheets after image formation. The present invention relates to an image forming apparatus equipped with the following.

<Prior art and problems to be solved by the invention> Conventionally, an electrostatic latent image formed on the surface of a photoreceptor is visualized, then transferred to paper and subjected to image processing, and the paper after image processing is heated. As an image forming device that forms an image on the surface of paper using the so-called Carlson process, which fixes the image on the surface of the paper through a fixing process, it automatically punches holes for binding in conjunction with the operation of the device. Various types of paper have been proposed that have a punching function for forming them on paper.

The above-mentioned image forming apparatuses having a punching function can be roughly divided into two types: those that form punch holes in advance on paper before image processing, and those that form punch holes on paper after image processing and fixing processing. However, when punching holes in paper before image processing, there is a risk that paper dust generated during punch hole formation may have an adverse effect on the formed image, so currently,
Types in which punch holes are formed in paper after image processing and fixing processing are becoming common.

Image forming apparatuses that form punch holes in paper after image processing and fixing generally have a stopper in contact with the leading edge of the paper, or a discharge roller for discharging the paper from the apparatus. After the paper is stopped in the paper transport section by temporarily stopping the paper with the leading edge of the paper sandwiched between the edges, the leading edge of the paper is removed by a perforating section consisting of a punch blade and a punch die into which the punch blade is introduced. It is configured to form a punch hole nearby.

However, in the above-mentioned apparatus, when the paper is stopped, if the rear end of the paper is caught in the constantly rotating conveyance roller of the ejection path, there is a risk that the paper may be wrinkled or folded. In addition, if the paper is stopped with the trailing edge of the paper caught in the fixing device that heats the paper and fixes the transferred image, the part of the paper caught in the fixing device There is a risk that the product may be heated more than necessary and deteriorate in quality.

Therefore, in order to prevent the above-mentioned wrinkles, folds, deterioration due to heat, etc., as shown in FIG. 7, a punch blade X1a and a punch die
A punching mechanism
An image forming apparatus is provided with a retention section Z that curves and retains the paper P as shown by the dotted chain line in the figure, between the perforation mechanism X and the constantly rotating conveyance roller Y2. has been proposed (see Japanese Unexamined Patent Publication No. 140755/1983). Note that the reference numeral X4 in the drawing indicates a sensor for detecting the leading end of the paper P, causing the stopper X2 to protrude as shown by the black arrow in the drawing, and stopping the rotation of the discharge roller X3.

According to the above-mentioned image forming apparatus, in the case of a large-sized paper P such that when the leading end of the paper P is stopped by the stopper X2 and the discharge roller X3, the trailing end is caught between the transport rollers Y2, As the transport roller Y2 rotates, the rear end of the paper P is pushed out and is retained in the retention section Z in a curved state without wrinkles or folds, as shown by the dashed line in the figure. .

However, in order to prevent wrinkles or folds from occurring in the paper retained in the retention section 2, it is necessary to curve the paper gently as shown in the figure, and the retention section 2 must be bent in the vertical direction as well as in the conveyance direction of the paper. Since this requires a large space, there is a problem in that the image forming apparatus cannot be downsized.

The present invention has been made in view of the above circumstances, and
It is an object of the present invention to provide an image forming apparatus that can prevent wrinkles and folds of paper, deterioration due to heat, etc., and that does not require a large space and can be miniaturized.

Means for Solving the Problems> In order to solve the above problems, an image forming apparatus of the present invention has the following features:
an image processing section, a paper transport section that supplies paper to the image processing section, performs fixing processing on the image-processed paper in a fixing processing section, and then discharges the paper out of the apparatus by an ejection means; and a leading edge or trailing edge of the paper. a detection means for detecting; a perforation section which is disposed downstream of the fixing processing section of the paper transport section and forms a punch hole on the trailing edge side of the paper; and when forming the punch hole by the perforation section; Based on the detection signal from the detection means, the paper being ejected is temporarily stopped with its trailing edge facing the perforation section, and after the punch holes are formed, the paper is ejected out of the device. It is characterized by comprising a drive control means for controlling the drive of the means.

<Operation> According to the image forming apparatus of the present invention having the above configuration, when the detection means detects the leading edge or trailing edge of the paper, the drive control means, based on the detection signal from the sensing means,
The paper being ejected is temporarily stopped with its trailing edge side facing the perforation section, and the punching section forms a punch hole near the rear end of the paper, so the paper is paused to form the punch hole. There is no possibility that the paper will come into contact with other parts of the paper transport section that are arranged upstream of the perforation section.

<Embodiments> Hereinafter, an image forming apparatus of the present invention will be described in detail with reference to drawings showing embodiments.

FIG. 1 shows the entirety of a copying machine as an embodiment of the image forming apparatus of the present invention. This copying machine includes a casing 1 having a document placement plate 11 and a document presser 12 on the top. optical system 2, image processing section 3, first paper transport section 4,
Second paper transport section 5, intermediate tray 6, and punching section 7
It is equipped with

The optical system 2 is composed of a light source 21, mirrors 22, 23, 24, an optical element 25, and a mirror 26, and uses the light source 21 to expose an original (not shown) set on the original placing plate 11. , mirrors 22, 23, 24, optical elements 25,
and a mirror 26 for guiding the image to the image processing section 3.

The image processing section 3 includes a charging charger 32, a developing device 33, a transfer charger 34, a separation charger 35, and a cleaner 36 arranged in this order around a photosensitive drum 31 that rotates in one direction. . In the image processing section 3, the charging charger 3
By guiding the reflected light from the original onto the surface of the photoreceptor drum 31, which is uniformly charged by 2, an electrostatic latent image corresponding to the original image is formed, and this electrostatic latent image is converted into a toner image by the developing device 33. After the toner image is transferred to the surface of the paper P by the transfer charger 34 and the paper P is peeled off from the surface of the photoreceptor drum 31 by the separation charger 35, the toner remaining on the surface of the photoreceptor drum 31 is removed. One cycle of image processing is completed by collecting it with the cleaner 36.

The first paper transport section 4 includes paper feed rollers 41a, 41b, 4
1c, paper feed paths 42a, 42b, 42c.

Registration roller 43, conveyance roller 44, conveyance belt 45
, a heat fixing device 46, a conveyance roller 47, and a pair of ejection rollers 48 as ejection means.

Paper feed rollers 41a, 41b, 41c are paper feed cassettes 13a, 13 that are removably attached to the side of casing 1.
The paper P is fed in one by one from the cooking bypass 14 or b.

The registration rollers 43 and the conveyance rollers 44 feed the paper P fed from the paper feed cassettes 13a, 13b or the squishing bypass 14 to the image forming section 3 in synchronization with the rotation of the photosensitive drum 31.

The thermal fixing device 46 fixes the toner image on the surface of the paper P by applying heat and pressure to the paper P on which the image has been formed by the image forming section 3 .

As shown by the broken line in FIG. 2, the discharge roller 48 is connected to an independent discharge drive system G that is separate from the drive system of the copying machine. Since punch holes are formed by the section 7 on the trailing edge side of the paper P, the drive control means C controls the ejection drive system G so that the trailing edge side of the paper P faces the punching section 7. The drive is controlled so that it is temporarily stopped in the state where it is. Therefore, when punching holes are formed, the paper P is temporarily stopped with the trailing end side being pinched by the discharge roller 48 and the leading end side being pushed out from the casing 1. There is no risk of contact with the conveying roller 47 and the thermal transfer device 46, which are arranged upstream of the transfer roller 7 and are constantly rotating.

The ejection drive system G includes a stepping motor G1 whose rotation is controlled based on a signal from the drive control means C, a gear G5 attached to the lower roller of the pair of ejection rollers 48, and the stepping motor G1. Rotate gear G5
A plurality of gears G2 to G4 are provided. In addition,
The stepping motor G1 can rotate not only in the direction of discharging the paper P out of the apparatus, but also in the opposite direction, and as described later, the stepping motor G1 can rotate the paper P in the direction opposite to the above direction. It is also used to rotate in both forward and reverse directions.

As shown in FIG.
It branches off from a switching claw 49 provided between a transport roller 47 and a discharge roller 48 of the paper transport section 4 and is connected to a registration roller 43 via an intermediate tray 6.

This second paper conveyance section 5 branches from a switching pawl 49 and a first half 5a that guides the paper P to the intermediate tray 6, and a switching pawl 52 that is provided in the middle of this first half 5a. It includes an inversion section 5b that inverts the paper P and then guides it to the intermediate tray 6, and a rear half section 5c that extends from the paper refeed roller 53 disposed at one end of the intermediate tray 6 to the registration roller 43. The first half 5a is a guide path 50a.

50b, 50c, conveying rollers 51a, 51b, and switching claw 52, and the reversing portion 5b includes guide paths 50d, 50.
e, includes a conveyance roller 51c, and the latter half 5c includes a refeed roller 53, conveyance rollers 54a, 54b +
54 C% and paper feed paths 55a, 55b, and 55c. Of the second paper conveyance unit 5, the conveyance roller 51a is driven by the stepping motor G1 of the discharge drive system G, as described above. That is, the conveyance roller 51a is provided with a timing belt G6, a gear G7. The rotation of stepping motor G1 is transmitted via G8.

In order to form an image on the paper P only once using the electrostatic copying machine of this embodiment, the paper P on which the image has been formed in the image forming section 3 is transported by the first paper transport section 4. , the receiver is discharged onto the tray 15.

When forming an image on the same sheet of paper P twice or more using the electrostatic copying machine, switch the switching claw 49 as shown by the dashed line in FIG. The paper P on which an image has been formed is transported to the second paper transport section 5, stored once in the intermediate tray 6, and then transported to the image forming section 3.
Image formation is performed again. To form a second image on the same side of the paper P, the paper P on which the image has been formed is transported to the intermediate tray 6 through the first half 5a of the second paper transport section 5, and then the second half It is conveyed to the image forming section 3 again through the portion 5C. At this time, the conveyance roller 51a
It rotates in the same direction as the other conveyance rollers 51b. To form a second image on the opposite side of the paper P, the paper P on which the -degree image has been formed is carried into the first half 5a of the second paper transport section 5, and then the first half 5a is conveyance roller 51a
is rotated in the opposite direction, the paper P is carried into the reversing section 5b from the switching claw 52, passing through this reversing section 5b,
The sheet is conveyed to the intermediate tray 6 in a reversed state, and then conveyed to the image forming section 3 again through the latter half portion 5c.

The perforation section 7 is disposed between the switching claw 49 and the discharge roller 48 of the first paper conveyance section 4, and is
As shown in Figures (at to (C)), a pair of punch blades 72.72 are held movably up and down by a holder 71, and a coil spring 73.73 holds the punch blades 72.72 in the raised position. A punch dia 4 that receives the punch blade 72.72, and a cam 75.7 that pushes down the punch blade 72.72 to form a punch hole in the paper P.
5.

Further, below the punch diamond 4, punch blades 72 and 72 are provided.
A collection box 76 is arranged to collect punched waste PI (see FIG. 4(C)) of the punched holes.

As shown in FIG. The punch blade 72 is inserted into the upper surface of the lower horizontal frame 71a of the holder 71. At the same time, a bushing 71c to which a coil spring 73 is fitted is attached to the lower surface of the horizontal frame 71a.
Paper holder F for pressing and fixing the paper to the punch dial 4
is attached with its tip end elastically abutting against the upper surface of the punch diamond 4.

The punch blade 72 has a cutting edge 72b at the lower end, and is made of a cylindrical body whose upper end comes into contact with the cam 75.
and the bushing 71c, and the flange 7
A coil spring 73 is interposed between the bushing 71c and the bushing 71c, and is inserted into the insertion holes of the upper and lower horizontal frames 71a and 71b so as to be able to move up and down, and is held in the raised position by the coil spring 73.

The punch diameter 4 has a through hole 74a into which the punch blade 72.72 is introduced at a position corresponding to the punch blade 72.72.
, 74a (Fig. 4 (ω~ (in October, only one side arranged in the direction perpendicular to the page is shown) was formed,
It is constituted by a plate that also serves as a lower guide plate for the paper conveying section 4.

As shown in FIG. 3, the pair of cams 75.75 are attached to a rotating shaft 75a, and by rotating this rotating shaft 75a by the drive system of the copying machine, the pair of cams 75, 75, as shown in FIG. As shown in ~(C), the punch blade 72.72 is brought into contact with the upper end of the punch blade 72.72, and the punch blade 72.72 is pushed down to form a punch hole in the paper P.

In addition, in the above-mentioned perforation part, in order to ensure that the pressing force of the punch blade 72 by the cam 75 is efficiently applied in the moving direction of the punch blade 72 when the rotation shaft 75a is rotated, as shown in FIG. As shown in a), the axis of the rotating shaft 75H is shifted from the axis of the punch blade 72 by a distance α in the horizontal direction.

Further, the pair of cams 75.75 are connected to the pair of punch blades 7.
In order to speed up the timing of forming the punch holes in the paper P according to 2.72 and reduce the load on the rotating shaft 75a and the drive system, the solid lines in Fig. 3 and the dashed-dotted lines in Fig. 2 are used. As shown, they are attached to the rotating shaft 75H with their phases shifted from each other.

Further, as shown in FIG. 3, a third cam 75' is provided between the pair of cams 75 and 75 of the rotating shaft 75a so as to correspond to the three punch holes of the American standard.
are arranged at an intermediate phase between the cams 75 and 75 on both sides. In order to form three punch holes in the paper P using this third cam 75', the holder 71 may be provided with three punch blades. Further, in order to form four or more punch holes in the paper P, it is sufficient to configure a rotating shaft to which a corresponding number of cams are attached and the same number of punch blades as the cams.

In addition, in the copying machine of this embodiment, among the above-mentioned perforations 7,
The parts other than the cam 75 and 75 are shown in FIG. 2 so that they can be pulled out from the casing 1 as a whole by being rotated about the rotation axis U1 together with the discharge roller 48 and the switching claw 49. As shown by the two-dot chain line, unit U
It is configured as. And a paper jam
When this occurs, as shown in FIG. 3, this unit U is rotated to release the cooperation between the cam 75 and the punch blade 72, to free the punch blade 72, and to release the inside of the device. By exposing the paper, jam removal can be easily performed. Furthermore, when processing the scraps P1 in the collection box 76, the unit U may be rotated to take out the collection box 76.

As shown in FIGS. 2 and 5, on the front surface of the unit U, there is a window U2 fitted with a transparent plate made of synthetic resin or the like, in order to check the amount of scraps in the collection box 76.
is provided.

By the way, the window may be arranged on the front surface of the casing 1. In that case, the unit U interposed between the front plate of the casing 1 on which the window is formed and the collection box 76
It is sufficient to provide a notch approximately the same size as the window in each member such as the side plate of the window.

As described above, the sensor S serving as a detection means is disposed between the heat fixing device 46 and the conveyance roller 47 of the first paper conveyance section 4, and has the function of detecting the trailing edge of the paper P. ,
It also has the function of detecting paper jams. That is, when the paper P is sent out from the heat fixing device 46, the arm S1 is tilted down as shown by the dashed line in FIG. As shown, the arm S1 stands up again, and at this time the rear end of the paper P is detected. In addition, - the sensor S which has been overturned
If the arm S1 does not stand up after a predetermined period of time, it is determined that there is a paper jam.

In the copying machine of this embodiment, which consists of the above-mentioned parts,
In the punch hole forming mode, the paper P that has been subjected to image processing and fixing is ejected from the thermal fixing device 46, and the sensor S
When detecting the trailing edge of the paper P, the drive control means C
However, based on this detection signal, stepping motor G1
The rotation of the paper P is stopped, and the drive of the discharge roller 48 is temporarily stopped with the rear end side of the paper P facing the perforation part 7.

Next, when a punch hole is formed near the rear end of the paper P by the punching section 7, the drive control means C rotates the stepping motor G1 to drive the ejection roller 48 again to form the punch hole. The subsequent paper P is discharged onto the tray 15 by a receiver outside the apparatus. In addition, as the drive control means C, the sixth
As shown in the figure, an electromagnetic clutch provided between one of the shafts J1 of the drive system of the copying machine and one roller 48b of the pair of ejection rollers 48, based on a signal from the sensor S, It is also possible to use a controller including a control unit C1 that connects and connects the clutch K.

Note that the timing for temporarily stopping the paper P after the sensor S detects the trailing edge of the paper P is, for example, when timing is started when the sensor S detects the trailing edge of the paper P, and the timing is measured for a predetermined period of time. It is controlled by a timer that outputs a signal, and a pulse counter that converts the rotation of the discharge roller 48, etc. into pulses using a rotary encoder, counts the pulses, and outputs a signal when the pulses have been counted a predetermined number of times.

In addition, by using a timer or pulse counter that has an adjustment function that can adjust the set clock time until outputting the above-mentioned signal and the set count of pulses as an adjustment means in the drive control means, for example, in the case of a timer, the setting Adjust the counting time within an appropriate range from 0 seconds, and in the case of a pulse counter, adjust the set pulse count value within an appropriate range from 0, and after the sensor S detects the trailing edge of the paper P. , the timing until the discharge roller 48 is stopped may be adjustable. Note that the above-mentioned timing adjustment may be performed by, for example, operating means such as a selection switch provided on the operation panel of the copying machine.

In the copying machine of this embodiment having the above configuration, when punching holes are formed, the ejection roller 48 is stopped with the rear end side of the paper P facing the perforation part 7, and the paper P is punched by the perforation part 7. Since the punched hole is formed near the rear end, there is no risk that the paper P will come into contact with the constantly rotating conveyance roller 47, thermal transfer device 46, etc., which are arranged upstream of the punched part 7. Wrinkles, folds, and deterioration due to heat are prevented. Therefore, the perforation section 7 can be placed close to other members of the first paper conveyance section 4, such as the conveyance roller 47 and the thermal transfer device 46.

In addition, when the drive control means is provided with the above-mentioned adjustment means, by adjusting the timing until the paper P is temporarily stopped by this adjustment means, the paper P is formed near the trailing edge of the paper P. It becomes possible to change the position of the punch hole in various ways.

Note that the image forming apparatus of the present invention is not limited to the above embodiment.

For example, in the illustrated embodiment, a sensor S provided in the paper transport section 4 is used as the detection means. but,
The above-mentioned detection means determines the length of the paper P based on the paper size data input in advance, such as the type of paper feed cassette into which the paper P was supplied, and uses the data on the length of the paper P and the data set in advance. In addition, the position of the trailing edge of the paper P, that is, the distance from the trailing edge of the paper P to the punching unit 7, is calculated and detected by arithmetic processing from the data on the distance from the registration roller 43 to the punching unit 7. Detection means may be provided. The data on the distance from the trailing edge of the paper P to the perforation section 7 detected by the detection means may be, for example, data on a predetermined number of pulses or a predetermined clock time for setting the timing to temporarily stop the paper P. This is manually applied to the drive control means and used to control the discharge roller 48 by the drive control means.

Further, the drive control means detects the front end of the paper P by the sensor S, and controls the ejection roller 48 based on the relationship between the signal and the length of the paper P to perforate the rear end of the paper P. It is also possible to temporarily stop the camera while facing the section 7.

In the illustrated embodiment, the ejecting roller 48 is used as the ejecting means, but the ejecting means can also be constituted by a belt.

Further, in the illustrated embodiment, the bunch blade 72 or the cam 75 is used to move the blade up and down, but the blade may be moved up and down by a solenoid or the like.

The arrangement of the ejection means, the detection means, and the perforation is not limited to the illustrated embodiment.

The perforation section 7 includes the optical system 2, the image forming section 3, the first and second
The paper conveyance units 4, 5, intermediate tray 6, etc. may be placed in a separate casing that is attached externally to the casing 1 in which the paper conveyance units 4, 5, intermediate tray 6, etc. are placed.

Although the illustrated embodiment shows a copying machine as an example of an image forming apparatus, the configuration of the present invention can be applied to other image forming apparatuses such as a laser beam printer.

In addition, various design changes can be made without changing the gist of the present invention.

<Effects of the Invention> The image forming apparatus of the present invention is configured as described above, and when punch holes are formed, the paper is transported a predetermined distance after the detection means detects the leading edge or trailing edge of the paper. At this point, the drive control means stops the ejecting means with the trailing edge of the paper facing the perforating section, and the punching section forms punch holes near the trailing edge of the paper, so that the paper is ,
There is no risk of contact with other parts of the paper conveying section disposed upstream of the perforation, and wrinkles, folds, deterioration due to heat, etc. are prevented. Therefore, in the image forming apparatus of the present invention, the perforation section can be placed close to other parts of the paper transport section, and the image forming apparatus does not require a large space and can be downsized.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing the configuration of a copying machine as an embodiment of the image forming apparatus of the present invention, FIG. Figure 3 is a perspective view showing a state in which the unit in which the perforation etc. are arranged in the above embodiment is rotated to expose the inside, and Figure 4 (a)
1~(C1 is a cross-sectional view showing the procedure for forming punch holes by the punching section used in the above embodiment, FIG. 5 is a perspective view showing the unit in a closed state, and FIG. 6 is a view of the discharge means. FIG. 7 is a perspective view showing a modified example of the drive control means for controlling the drive, and FIG. 7 is a schematic cross-sectional view showing a conventional drilling mechanism. FIG. 2 S...sensor (detection means), C... drive control means,
3... Image processing unit, 4... First paper transport unit,
7... Perforation section, 46... Fixing processing section, 48
...Discharge roller (discharge means).

Claims (1)

[Claims] 1. An image processing unit that visualizes the electrostatic latent image formed on the surface of the photoconductor and then transfers it to paper; paper is supplied to this image processing unit, and the paper after image processing is fixed in a fixing processing unit a paper transport unit that discharges the paper out of the apparatus by a discharge unit after processing; a detection unit that detects a leading edge or a trailing edge of the paper; and a paper transport unit disposed downstream of the fixing processing unit of the paper transport unit,
A perforation part that forms a punch hole on the rear end side of the paper; and when the punch hole is formed by the perforation part, the paper being ejected is placed in the rear end side of the perforation part based on a detection signal from the detection means. 1. An image forming apparatus comprising: a drive control means for controlling a drive of a discharging means so as to temporarily stop the sheet facing the paper and discharge the sheet out of the apparatus after forming a punch hole.