JP2744686B2 - Image forming device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrostatic copying machine or a laser beam printer, and more particularly, to additional information for recording additional information on paper by thermal transfer. Recording means, and / or
Alternatively, the present invention relates to an image forming apparatus provided with a punching means for forming a punch hole for binding in a sheet.

<Problems to be Solved by the Related Art and the Invention> Conventionally, in addition to an image forming function of visualizing an electrostatic latent image formed on the surface of a photoreceptor into a toner image and transferring the toner image to a paper, An image forming apparatus having an additional information recording function of recording additional information such as the number of pages and date using a thermal head and a thermal transfer ribbon (for example, see JP-A-59-77).
No. 459) and an image forming apparatus having a punching function of forming a punch hole for binding in a sheet (for example, see Japanese Patent Application Laid-Open No. 58-140755).

However, in the above-described image forming apparatus, the additional information recording position and the punch hole forming position are deviated from the appropriate positions due to an assembly error during manufacturing and an operation error during use, and the additional information and the punch hole may overlap with the formed image. Conversely, the additional information and punch holes may protrude from the edge of the sheet.

Therefore, in order to adjust the recording position of the additional information and the formation position of the punch holes to the correct positions, fine adjustment of the attachment position of the additional information recording means and the punching means, or a return switch for detecting the end of the sheet. However, it is necessary to repeat the fine adjustment by opening the apparatus, close the apparatus, and perform the test, which is troublesome.

The present invention has been made in view of the above circumstances, and easily fine-tunes a recording position of additional information and a forming position of a punch hole without finely adjusting a mounting position of an additional information recording unit or a punching unit. It is an object of the present invention to provide an image forming apparatus capable of performing the following.

<Means for Solving the Problems> In order to solve the above problems, the image forming apparatus of the present invention uses a thermal transfer ribbon for a sheet that has passed through an image processing unit and a fixing unit along a sheet conveying path. Additional information recording means for recording additional information using a thermal head,
And an image forming apparatus provided with at least one of punching means for forming a punch hole for binding to the sheet, wherein the sheet is provided at an outlet of the fixing means on a sheet conveying path, and is provided with a sheet ejected from the fixing means. A detection switch for detecting the trailing end; input means for inputting a displacement amount for displacing the additional information recording position and / or the punch hole forming position on the sheet; reference value setting means for setting a predetermined reference value; Means for reading the reference value from the reference value setting means when there is an input from the input means, and changing the reference value by the input displacement amount; and A control means for operating the additional information recording means or the perforating means when a time corresponding to the reference value changed by the reference value changing means has elapsed.

<Operation> In the image forming apparatus of the present invention having the above configuration, when the input means inputs a displacement amount for displacing the additional information recording position and / or the punch hole forming position on the sheet, the reference value is changed. The reference value is changed by the displacement amount by the means. For example, if the reference value "50" is 51,5
It is changed so that it increases to the number corresponding to the input displacement amount up to 2,53… 99, or the reference value “50” decreases to the number corresponding to the input displacement amount up to 49,48,…, 00 Be changed. After the trailing edge of the conveyed sheet is detected by the trailing edge detection switch, when a time corresponding to the changed reference value has elapsed,
The additional information recording means or the perforation means is operated by the control means.

Embodiment Hereinafter, an image forming apparatus according to the present invention will be described with reference to the drawings showing an electrostatic copying machine as an embodiment.

As shown in FIG. 8, the electrostatic copying machine of this embodiment is
An optical system 11, an image processing unit 12, a fixing unit 13, a paper transport unit 14, an additional information storage unit T, and a punching unit P are provided in a casing 1 having a document placing plate 10 on which a document is placed. ing.

The optical system 11 forms an image of the original placed on the original placing plate 10 on the surface of the photosensitive body 12a of the image processing unit 12, and forms an electrostatic latent image corresponding to the original image on the photosensitive body 12a. Formed.

The image processing unit 12 visualizes the electrostatic latent image into a toner image, and transfers the toner image to the paper surface.

The fixing means 13 heats and presses the toner image transferred onto the paper surface to fix it on the paper surface.

The paper transport unit 14 is configured to send the paper sent from the manual paper feed unit 15a or the paper feed cassettes 15b and 15c to the image processing unit 12,
After sequentially passing through the fixing means 13, the additional information recording means T, and the perforating means P, the paper is discharged onto the discharge tray 16 by the discharge rollers 14a, 14a.

As shown in FIG. 3, the piercing means P includes a lower horizontal frame P3.
a holder P3 whose lower surface also serves as an upper guide plate of the transport path Pa of the paper P, a punch blade P1 held up and down by the holder P3, and a coil spring holding the punch blade P1 at an ascending position. P4, a punch die P5 also serving as a lower guide plate of the transport path Pa, and a cam P2 for pushing down the punch blade P1 to form a punch hole in the paper P.

The holder P3 is formed of a frame having a substantially U-shaped cross section in which an insertion hole through which the punch blade P1 is inserted is formed in upper and lower horizontal frames P3a and P3b. A punch blade P1 is inserted through the upper surface of the lower horizontal frame P3a of the holder P3, and bushs P3c, P3c to which a coil spring P4 is fitted are attached.

The punch blade P1 has a cutting edge P2b at a lower end portion, and is formed of a cylindrical body whose upper end portion is in contact with the cam P2. P3
c and the flange P2a and the bush P3c.
The upper and lower horizontal frames with the coil spring P4 interposed between
It is vertically movably inserted into the insertion holes of P3a and P3b, and is held at the raised position by the coil spring P4.

The punch die P5 is located at a position corresponding to the punch blade P1.
It is constituted by a plate having a through hole P5a into which the punch blade P1 is introduced.

The cam P2 is attached to the rotating shaft P2a. By rotating the rotating shaft P2a, the cam P2 comes into contact with the upper end of the punch blade P1 and pushes down the punch blade P1 to form a punch hole in the paper P. It is made to let.

The perforating means P is disposed between the additional information recording means T and the discharge rollers 14a, 14a as shown in FIGS. 4 and 5, and is provided after the sheet passing through the additional information recording means T. A plurality of binding holes are punched at the end.
As shown in FIG. 6, the perforating means P is arranged on a unit U which can rotate outside the casing 1 around a lower end axis U1 as shown in FIG. Unit U
Is rotated outward of the casing 1, the engagement between the punch blade 1 and the cam P2 is released, and the punch blade P1 is in a free state. Jam processing becomes easy. Further, when the unit U is rotated outward of the casing 1, the additional information recording means T at the back thereof is exposed, so that maintenance of the additional information recording means T is facilitated.

The additional information recording means T is, as shown in FIG. 7, a casing 2, a ribbon cassette 3 which is detachably attached to the casing 2 and houses a band-shaped thermal transfer ribbon R therein, and a rotatable casing 2. , A thermal head 5 supported by the support member 4, and a thermal head moving means 9 for pushing the thermal head 5 in the direction of a platen roller 7 opposed to the paper path. And

The casing 2 is composed of a box 21 having an open top and this box
21 comprises side plates 22a and 22b fixed to both ends. Side plate 2
2a and 22b have a substantially triangular shape, and are directly or indirectly attached to the copying machine main body 1 by a support shaft 24 at the lower end. The casing 2 is rotatable about the support shaft 24 between a set position shown by a two-dot chain line in FIG. 6 and an open position shown by a solid line in FIG. 6 where the ribbon cassette 3 can be taken out.

The ribbon cassette 3 is composed of a body 31, a delivery reel 32 around which a thermal transfer ribbon R is rotatably attached to the body 31, and a take-up reel 33, and the thermal transfer ribbon delivered from the delivery reel 32. R is taken up by the take-up reel 33. Body 31 is 3 reels
An opening 31 a is provided between the casing 2 and the casing 21.
The bottom plate 21a has an opening 23 that matches the opening 31a. The thermal head 5 has an opening 31 as shown in FIG.
The thermal transfer ribbon R protrudes below the casing 2 through the opening a and the opening 23 so as to contact the sheet on the platen roller 7.

In the box 21 of the casing 2, the ribbon cassette 3, driving means 6 for driving the take-up reel 33 of the ribbon cassette 3 to take up the thermal transfer ribbon R, and loading the ribbon cassette 3 into the casing 2. A lock member 8 for holding the mounted state is provided.

The driving means 6 has a motor 61 and a torque limiter mechanism 62 for transmitting the driving force of the motor 61 to the take-up reel 33. When the ribbon cassette 3 is attached to the casing 2, a connection shaft (not shown) at the end of the torque limiter mechanism 62 is engaged with the take-up reel 33.

The lock member 8 includes a shaft 81 and an L-shaped member 82 that is rotatable about the shaft 81. An end 82 a of the L-shaped member 82 is applied to one side 31 a of the body 31 of the ribbon cassette 3. The ribbon cassette 3 is attached to and maintained at a predetermined position by contact with the ribbon cassette 3, thereby preventing the ribbon cassette 3 from falling off.

The thermal head 5 includes a plurality of minute resistors, and energizes the resistors facing the pattern of the additional information to be recorded to generate heat, melt the thermal transfer ribbon R and transfer the ribbon to the paper, The additional information is recorded in. The thermal head 5 has a thermistor S as a temperature sensor for measuring the temperature of the thermal head 5.
Is built-in.

The support member 4 includes a support shaft 41 having both ends rotatably attached to the side plates 22a and 22b, a plate 42 having a lower end fixed to a center portion of the support shaft 41, and a thermal head 5 mounted thereon. It consists of. The support member 4 has a recording position where the thermal head 5 is pressed against the thermal transfer ribbon R (see FIG. 4) and a retract position where the thermal head 5 is retracted so that the ribbon cassette 3 can be taken out of the casing 1 (see FIG. 4). (See FIG. 7 and FIG. 7).

The support member 4 is provided with a thermal head moving means 9.
By this, the position is moved between the position recording / retreat position and the release position (see FIG. 5) located between the positions. The release position is such that when the mode in which additional recording is not performed is selected, the thermal transfer ribbon R is retracted from the path of the sheet, and the thermal transfer ribbon R contacts the sheet heated by the fixing unit 13 by mistake.
This is set to prevent the paper from being stained.

The thermal head moving means 9 includes a shaft 91, a bias roller 92,
It is constituted by a bias spring 93, leaf springs 94 and 95, and a tension spring 96.

Both ends of the shaft 91 are directly or indirectly supported by the casing 1. The bias roller 92 has a shaft 91 that is elongated
The biasing spring 93 is disposed in the elongated hole 92a. By the action of the biasing spring 93, the biasing roller 92 is biased and rotated with respect to the rotation of the shaft 91.

The leaf spring 94 has one end 94a attached to the support shaft 41 and the other end 94b extending in the radial direction of the support shaft 41, and
, And presses the casing 2. The leaf spring 94 urges the shaft 41 to rotate so that the thermal head 5 can smoothly move from the recording position to the release position by the reaction force against the pressing.

One end 95a of the plate spring 95 is attached to the support shaft 41, and the other end 95b extends in the radial direction of the support shaft 41 and can be pressed against the biasing roller 92.

The tension spring 96 is disposed between the plate 42 and the casing 13a of the fixing unit 13, and connects the plate 42 to the casing 13a.
Pull in the direction close to.

When additional recording is not performed, the biasing spring 93 is located at the upper right of the shaft 91 as shown in FIG.
No pressing force is generated between 92 and the leaf spring 95. Therefore, the support member 4 is rotationally urged clockwise by the tensile force of the tension spring 96 and the reaction force of the leaf spring 94, and the thermal head 5 is located at the release position.

On the other hand, when the mode for performing additional recording on the sheet is selected, the bias spring 93 is disposed at the lower left of the shaft 91 by rotating the shaft 91 half a turn as shown in FIG. As a result, the leaf spring 95 is pressed by the bias roller 92, and the shaft
Since the plate 41 is rotated counterclockwise in FIG. 4 mainly against the reaction force of the leaf spring 94 against the bottom plate 21a, the plate 42 fixed to the shaft 41 rotates counterclockwise. Then, the thermal head 5 is moved to the recording position. When the sheet is discharged from the fixing unit 13, the sheet turns over the limit switch 13b at the exit of the fixing unit 13. On the basis of the signal from the limit switch 13b, the discharge rollers 14a, 14a and the platen roller 7 slow down the paper conveyance speed to a speed at which the additional information recording means T can perform recording. The additional information is recorded on the sheet by the means T.

When the casing 2 is rotated from the set position to the open position, the support member 4 is urged to rotate clockwise by the tensile force of the tension spring 96, and the thermal head 5 moves to the retracted position. Therefore, maintenance of the additional information recording means T such as removal of the ribbon cassette 3 can be easily performed.

FIG. 1 shows the electrical configuration of the above-mentioned electrostatic copying machine.

As shown in the figure, an operation panel C, a main motor M1, a step motor M2, a thermal head 5, a thermistor S, a head lifting / lowering clutch K, and a motor 61 of a driving device 6 are connected to a CPU 100 via an input / output interface 101. It is connected.

The main motor M1 drives the image processing unit 12, the fixing unit 13, the paper transport unit 14, and the like.

The step motor M2 drives the discharge rollers 14a, 14a and the platen roller 7 separately from the above components. That is, as described above, the step motor M2 drives the discharge rollers 14a, 14a and the platen roller 7 during the additional information recording.
Can be reduced to such an extent that the additional information recording means T can perform recording. Further, the step motor M2 can stop the rotation of the discharge rollers 14a, 14a and the platen roller 7 with the rear end of the sheet facing the punch blade P1 when the punch hole is formed by the perforated portion P. it can.

The head lifting clutch K is for connecting the shaft 91 of the thermal head moving means 9 to a power transmission mechanism from the main motor M1 and rotating the shaft 91 to raise and lower the thermal head 5. is there.

The CPU 100 is further connected to various drive mechanisms constituting the copying machine via the input / output interface 101, but since it has no particular relation to the features of this embodiment,
It is omitted in FIG.

The control ROM 102, the font ROM 103, and the RAM 104 are connected to the CPU 100 as recording means. Control ROM1
02 is a read-only memory in which a control program of the electrostatic copying machine is stored. The font ROM 103 is a read-only memory in which character data is stored in advance. When a specific character or numeral is recorded by the additional information recording means T, the specific character or numeral is read from the font ROM 103 and stored in the buffer area 104a of the RAM 104.

Next, the control operation of the additional information recording means T and the punching means P will be described with reference to FIG. 2 showing the relationship between the operation timings of the additional information recording means T and the punching means P.

The discharge rollers 14a, 14a and the platen roller 7 are driven by the stepping motor M2 as described above, and have a mechanism capable of changing the speed. On the other hand, the image processing unit 1
2. The fixing unit 13, the paper transport unit 14, and the like are driven by the main motor M1, and their speeds are constant and do not change.

If neither the additional information recording means T nor the perforating means P is selected to operate, the sheet coming out of the fixing means 13 is conveyed at the same speed by the discharge rollers 14a, 14a and discharged to the discharge tray 16. In this case, the step motor M2 is rotated at 300 mm / sec.

On the other hand, when the operation of the additional information recording means T and / or the perforating means P is selected, the rotation speed of the step motor M2 is changed as described below.

First, when the sheet is discharged from the fixing means 13 and the rear end of the sheet has passed through the limit switch 13b at the exit of the fixing means 13, as shown in FIG.
Switches from on to off. Therefore, if the additional information recording means T or the perforating means P is operated after a predetermined time with reference to the off edge of the limit switch 13b, the additional information is recorded inside a predetermined dimension from the trailing edge of the paper, or Punch holes can be made.

Now, if perforation means P is actuated selected, after a time t ₁ from the off-edge detection of the limit switch 13b, and the step motor M2 is stopped (FIG. 2 B). At this time, the trailing edge of the sheet stops, for example, at a position 10 mm upstream of the punch blade P1. While the paper is stopped, the cam P2 is rotated once by a cam motor (not shown) (FIG. 2C). Thereby, a punch hole can be formed 10 mm inward from the trailing edge of the sheet.
Thereafter, when the step motor M2 is rotated at a speed of, for example, 198 mm / sec (FIG. 2B), the discharge roller 14 is thereby rotated.
The sheets a and 14a rotate, and the sheet is discharged to the discharge tray 16.

Then, if the additional information recording means T is activated selected, time from off-edge detection of the limit switch 13b t ₂
Thereafter, the step motor M2 is stopped (FIG. 2D). At this time, the trailing edge of the sheet is, for example, on the upstream side of the platen roller 7.
Stops at 20mm. After the stop of the step motor M2, the clutch K for head lifting and lowering is turned on, and the shaft 91 of the thermal head moving means 9 is rotated to lower the thermal head 5 to the recording position shown in FIG. 4 (E in FIG. 2). ). Further, the motor 61 of the additional information recording means T is turned on to feed the ink ribbon R (FIG. 2F).

Then, in this state, the step motor M2 is intermittently driven one step at a time, for example, for 80 steps, and the additional information is recorded line by line by the thermal head 5 every time the step motor M2 stops intermittently (FIG. 2). D).

In this case, since the recording of the additional information is performed at the rear end of the copy sheet, a part of the copy sheet does not remain in the fixing unit 13, and a part of the copy sheet is heated by the heat of the fixing unit 13. There is no worry about deformation or burning.

When the recording of the additional information is completed by operating the step motor M2 for 80 steps, the step motor M2 is temporarily stopped. Then, the head lifting clutch K is turned off (FIG. 2E). Thus, the thermal head 5 is raised by the reaction force of the leaf spring 94. The rotation of the motor 61 is continued during and after the thermal head 5 is raised, and the ink ribbon R fed out during printing is wound up. Therefore, the ink ribbon R does not remain stuck to the sheet, and the ink ribbon R does not cause unnecessary loosening (FIG. 2F).

Thereafter, the step motor M2 is rotated at, for example, 198 mm / sec. As a result, the sheet is discharged to the discharge tray 16 by the discharge rollers 14a, 14a (FIG. 2D).

In order to displace the additional information recording position by the additional information recording means T and / or the punch hole formation position by the punching means P, the additional information recording position or the punch hole is selected from the control program stored in the control ROM 102. It is sufficient to select a mode for displacing the formation position.

If you select the mode to displace the additional information recording position,
00 indicating the additional information recording position is displayed on the display C2 of the operation panel C.
A number from ~ 99 is displayed. This number is initially displayed as "50". This is because the reference position (for example, the position 20 mm from the trailing edge of the paper described above) is the center axis (=
This is because 50) is preset in the control ROM 102 as the reference value setting means. Then, a range of 25 mm in the front-back direction in the paper transport direction is equally divided into 100, and the reference value 50 is 00 to 9
It can be changed in the range of 9.

When the copier is operated in this state, a test image in which copying and recording of additional information are performed is obtained. By looking at the test image, it is determined which direction and how much the additional information recording position is displaced. I do.

Then, the user operates the input key C1 of the operation panel C to change the numerical value displayed on the display C2. In order to displace the additional information recording position further upstream than the reference position, the input key C1 may be operated to reduce the numerical value displayed on the display C2. On the other hand, to displace the additional information recording position downstream from the reference position,
By operating C1, the numerical value displayed on the display C2 may be increased. If the numerical value changes by 1, the additional information recording position will be shifted by 0.25 mm.
It can be obtained by calculation according to the distance for displacing the additional information recording position.

When the copier is operated again after setting the values, CPU1
00, depending on the amount of change in numerical value, shown in FIG. 2, by changing the time t ₂ from the off-edge detection of the limit switch 13b to the step motor M2 stops, to displace the additional information recording position. Looking at the test image obtained in this state, it is determined whether or not the additional information recording position has been correctly displaced. Then, when the additional information recording position is correctly displaced,
The mode for displacing the additional information recording position is ended. If the additional information recording position is not correctly displaced, the numerical value may be set again.

When the mode for displacing the punch hole forming position is selected, the display C2 indicates the punch hole forming position on the display C2.
Is displayed. This number is the reference position (for example,
Center value (= 10mm from the trailing edge of paper)
Is a numerical value obtained by equally dividing a range of 25 mm in the front-back direction into 100 in the sheet conveyance direction.

When the copying machine is operated in this state, a test image on which copying and punching have been performed is obtained, and by looking at the test image, it is determined in which direction and how much the punch hole forming position is displaced.

Then, the user operates the input key C1 of the operation panel C to change the numerical value displayed on the display C2. To displace the punch hole formation position further upstream than the reference position,
By operating the input key C1, the numerical value displayed on the display C2 may be reduced. On the other hand, in order to displace the punch hole formation position downstream from the reference position, that is, toward the trailing edge of the sheet, the input key C1 may be operated to increase the numerical value displayed on the display C2. When the numerical value changes by 1, the punch hole formation position becomes 0.
Since it will be shifted by 25 mm, how much the numerical value is displaced depends on the distance to displace the punch hole formation position,
It can be obtained by calculation.

When the copier is operated again after setting the values, CPU1
00, depending on the amount of change in numerical value, shown in FIG. 2, by changing the time t ₁ from the off-edge detection of the limit switch 13b to the step motor M2 stops, to displace the forming positions of the punch holes. By looking at the test image obtained in this state, it is determined whether or not the formation position of the punch hole has been correctly displaced. If the formation position of the punch hole is correctly displaced, the mode for displacing the formation position of the punch hole ends. If the formation position of the punch hole is not correctly displaced, the numerical value may be set again.

As described above, according to this embodiment, the numerical value displayed on the display C2 can be changed only by operating the input key C1, thereby displacing the additional information recording position and / or the punch hole forming position. Can be.

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

For example, in the above embodiment, both the additional information recording position by the additional information recording means T and the punch hole forming position by the punching means P can be displaced. However, the image forming apparatus of the present invention It may be one that can displace only one of them.

Further, the image forming apparatus of the present invention may have only one of the additional information recording unit T and the punching unit P.

If the additional information recording means T can record the additional information on the paper by the thermal head and the thermal transfer ribbon,
The present invention is not limited to the embodiment shown in the drawings, and various conventionally known structures can be employed.

The punching means P is not limited to the embodiment shown in the drawings as long as a punch hole can be formed in a sheet by a punch blade, and various conventionally known structures can be adopted.

Although the illustrated embodiment shows an electrostatic 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.

<Effect of the Invention> The image forming apparatus of the present invention is configured as described above, and receives an input of a displacement amount for displacing an additional information recording position and / or a punch hole forming position on a sheet from an input unit. At this time, the reference value is changed by the reference value changing means by the displacement amount. After the trailing edge of the conveyed sheet is detected by the sheet trailing edge detection switch, the control unit operates the additional information recording unit or the punching unit when a time corresponding to the changed reference value has elapsed. Therefore, additional information recording or punch hole formation can be performed inside a desired size from the rear end of the sheet. That is, the position at which the additional information is recorded and / or the position at which the punch holes are formed can be adjusted with respect to the paper transport direction. Therefore, the image forming apparatus of the present invention can easily fine-tune the recording position of the additional information and the forming position of the punch hole without finely adjusting the mounting position of the additional information recording means and the punching means, the mounting position of the limit switch, and the like. It can be adjusted.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an electric configuration of an electrostatic copying machine as one embodiment of the image forming apparatus of the present invention, and FIG. 2 shows operation timings of the additional information recording means and the punching means in the above embodiment. FIG. 3 is a cross-sectional view of the perforating means in the above embodiment, FIGS. 4 to 6 are cross-sectional views showing the periphery of the additional information recording means in the above embodiment, and FIG. 7 is a perspective view of the additional information recording means. FIG. 8 is a schematic diagram showing the internal configuration of the electrostatic copying machine. T: additional information recording means, P: punching means, 100: CPU (control means), C1: input means.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-22797 (JP, A) JP-A-59-77459 (JP, A) JP-A-63-109449 (JP, A) JP-A-62 148939 (JP, A) JP-A-63-173071 (JP, A) JP-A-63-253961 (JP, A) JP-A-62-148938 (JP, A) JP-A-63-89874 (JP, A) JP-A-63-137873 (JP, A) JP-A-62-16169 (JP, A) JP-A-2-183272 (JP, A) JP-A-2-291159 (JP, A) JP-A-1-79048 (JP, U) Japanese Utility Model Showa 63-14255 (JP, U)

Claims (1)

(57) [Claims] An additional information recording means for recording additional information on a sheet which has passed through an image processing section and a fixing means along a sheet conveying path by using a thermal transfer ribbon and a thermal head, and said sheet In an image forming apparatus provided with at least one of punching means for forming a punch hole for binding in a sheet, a trailing end of a sheet discharged from the fixing means is provided at an exit of the fixing means on a sheet conveying path. Input means for inputting a displacement amount for displacing an additional information recording position and / or a punch hole forming position on a sheet; reference value setting means in which a predetermined reference value is set; Is read from the reference value setting means, the means for changing the reference value by the input displacement amount, and the paper trailing edge detection switch is used to detect the trailing edge of the sheet. After being, during the time corresponding to the changed reference value by the reference-value change means, an image forming apparatus, characterized in that it comprises a control means for operating the additional information recording means or drilling means.