JPS59178442A - Image forming device - Google Patents

Abstract

PURPOSE:To confirm an image forming range, and to reduce image forming errors by displaying a picture formable range on an original placing plate. CONSTITUTION:A relation of an original placing place 2 and a moving mechanism for moving an optical system 3 is shown in the figure. A scale 61 for showing a copiable length corresponding to an original of various sizes is provided on the original placing plate 2 of the upper face of a body 1, and also, as for the first carriage 411 for supporting an exposure lamp 4, a scale 62 for showing a copiable length on the original placing plate 2 is provided on its upper part (namely, the lower part of the original placing plate 2). These scales 61, 62 show, for instance, a length of ''A4'' and ''A5'' sizes.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image forming apparatus such as a copying machine with a fixed document table.

[Technical background of the invention]

For example, a copying machine with a document table identification type moves an optical system such as an exposure rung and a mirror back and forth along a fixed document table, and makes copies by exposing and scanning the document set on the document table. This is what we do.

[Problems with back handling techniques]

However, in the above-mentioned apparatus, since the range that can be photographed is unknown, copying errors may be made and copies may be made in vain.

[Objective of the Invention J This Origin] was made in view of the above circumstances, and its purpose is to provide an image forming apparatus that can confirm the image forming range and reduce errors in forming both edges. There is a particular thing.

[Kishun of invention]

This invention is configured so that the range in which image formation is possible can be displayed on a JA manuscript table.

[Embodiment J of the Invention An embodiment of the invention will be described below with reference to the drawings.

FIG. 1 schematically shows an image forming apparatus, such as a copying machine, according to the present invention. That is, 1 is a main body of a copying machine, and a document table (transparent glass) 2 is fixed to the upper surface of the main body 1 to support a document. The optical system 3 set on the document table 2 reciprocates in the direction of arrow a along the lower surface of the document table 2, and is exposed and scanned during each forward movement. In this case, mirror 6.7 moves at half the speed of mirror 5 so as to keep the optical path length constant. The light reflected from the original by the scanning of the optical system and the light reflected from the original by the light irradiation of the continuous exposure lens 4 are reflected by the mirrors 5, 6. '7, passes through the variable magnification lens block 8, is further reflected by the mirror 9, and is guided to the photoreceptor drum 1o, so that the image of the original document is formed on the surface of the photoreceptor drum 10. ing. The home position of the optical system 3 is a fulcrum 52 which will be described later.
It is near the right edge of the drawing.

The photosensitive drum 1θ rotates in the direction of arrow C, and the surface is first charged by the charger 11, and then the document group is exposed to slit light to form a blank group. This electrostatic latent image is electrified by the adhesion of toner by the developing device 2.

- The paper (driven hoe forming body) P is delivered from the selected upper paper feed cassette 13 or lower paper feed cassette 14 to the feed roller 15 or rr! , 16, and pass through the paper guide path J7 or 18 to a pair of registration rollers 19.
and is sent to the transfer section by this pair of rollers 19. Here, each of the above paper feed cassettes 13
14 is removably provided at the lower right end of the main body 1, and either one can be selected from an operation panel (not shown). Note that each of the paper feed cassettes 13 and 14 has a force sensor size detection switch 30.
1,302, the cassette size is detected.

The detection switches 3ol and 302 are constituted by sensitive microswitches that are turned on and off in accordance with the insertion of cassettes of different sizes.

Thus, the paper P sent to the transfer section is transferred to the transfer charger 2.
By coming into close contact with the front surface of the photoreceptor drum 1o at the portion 0, the toner image on the photoreceptor drum lo is transferred by the action of the charger 2o.

The transferred paper P is peeled off from the photoreceptor drum 10 by the action of the peeling charger 2 and conveyed on the conveyor belt 22, and sent to a pair of fixing rollers 23 as a fixing device provided at the end of the conveyor belt 22. , the transferred image is fixed by passing through this.

After fixing, the paper P is discharged to the outside of the main body 1 by a pair of paper discharge rollers 24. After the photosensitive drum 10 has been transferred, the charge is removed by the charger 26, the residual toner on the surface is removed by the cleaner 27, and the afterimage is erased by the charge removal run f28, so that the drum returns to its initial state. ing. Note that 29 is a cooling fan for preventing the temperature inside the main body 1 from rising.

Here, a paper transport path 51 is formed by the transport roller pair 19, the transport belt 22, the paper ejection roller pair 24, and a guide plate (not shown) appropriately arranged between them.
A photoreceptor drum 1o and a transfer charger 20 are arranged in the middle of this conveyance path 51, and the above-mentioned pair of constant rollers 2 are arranged at the terminal end.
3 is arranged like this.

Furthermore, as shown in FIG.
It can be separated into two parts.

One end of the upper unit 11 is rotatably supported by the lower unit 72 via a support shaft (fulcrum) 52, and serves as an opening control function. Further, the main body 1 which can be separated into the upper and lower units '1eJ2 in this manner is provided with an opening/closing mechanism 53 that opens and closes the upper unit 11 with respect to the lower unit 12. If the paper P gets stuck in the paper conveyance path 5 for some reason,
Most of the paper conveyance path 51 can be opened, and the tied paper P can be easily removed. Furthermore, when the optical system 3 is opened, the Baum position of the optical system 3 is near the fulcrum 52, so the opening/closing moment is small and the optical system 3 is prevented from falling.

On the other hand, on the discharge side of the discharge roller pair 24.
The paper P discharged from this dart 15°24.24 is introduced into the introduction path 151. The paper P introduced into the introduction path 151 is conveyed via a pair of feed rollers 152 and 152 while being held between conveyor pels 153 and 153 provided on the bottom side of the main body 1. The sheet P is then reversed by the reversing path 154 and then sent to the registration rollers 19.

FIG. 3 shows the operation panel, including a copy key 131 for issuing a command to start copying, and a numeric keypad 132 for setting the number of copies, etc.
, an indicator 133 for displaying the number of sheets, etc., a vibration setting device 134 for setting the copy density, an upper cassette selection key 135 for selecting the upper feeding cassette 13, and its indicator light (LED).
136, lower cassette selection key 137 for selecting the lower paper feed cassette 14 and its indicator light (LED) 138, valley cassette paper size indicator 139', J4θ, division key 141 for specifying division copying and its indicator light ( L
ED) 142, a touch release key 143 for canceling split copying and its indicator light 144, a double-sided key 14 for specifying double-sided copying
5 and its indicator light (LED) 146, release key to cancel double-sided copying = 147 and its indicator light (t, go
) J 4 g.

FIG. 4 shows an example of the configuration of a drive source for each drive section of the copying machine configured as described above, and is composed of the following motors. That is, numeral 31 is a lens motor, which is a holder for moving the position of the lens block 8 for changing the magnification. When the motor 31 and Vu sequentially expose the first range and the second range on the document table 2, the first
100 times for the range and 1 for the second range
．． The position of the lens block 8 is moved so that the magnification is increased by 0.02 times. Reference numeral 32 denotes a mirror motor for changing the distance (optical path length) between the mirror 5 and mirror 6.7 for varying magnification.

A scanning motor 33 is a motor for moving the exposure run 4, mirror 5, and mirror 6.7 for scanning the original. A shutter motor 34 is a motor for moving a shutter (not shown) for adjusting the charging width of the photosensitive drum 10 by the charger 11 during zooming. 35 is a developing motor, which is connected to the developing device 12;
This is a motor for driving the developing roller, etc. 36
A drum motor is a motor for driving the photosensitive drum 10. 37 is a fixing motor, which connects the paper transport path 22, the pair of fixing rollers 23, and the pair of paper ejection rollers 24.
This is a motor for driving. A paper feeding motor 38 is a motor for driving the delivery rollers 15 and 16. Reference numeral 39 denotes a built-in motor, which is a motor for driving the pair of registration rollers 19. A fan motor 40 is a motor for driving the cooling fan 29.

FIG. 5 shows a moving mechanism for moving the optical system 3 back and forth. That is, the mirror 5 (and the exposure lamp 4) is supported by the first carriage 41, the mirror 6.7 is supported by the second carriage 4-2, and these carriages 41, . 412 is the guide rail 421, 42
2, and can freely move in parallel in the direction of arrow a. Thus, the four-phase nozzle smoke 33 drives the pulley 43. An endless belt 45 is stretched between the 7° pulley 43 and the idle pulley 44.
One end of a first carriage 411 that supports the mirror 5 is fixed in the middle. On the other hand, the guide portion 46 of the rail 422 of the second carriage 412 that supports the mirror 6.7 has two pulleys 47 spaced apart in the axial direction of the rail 422.
47 is rotatably provided, and these pulleys 47,
A wire 48 is stretched between the wires 47 and 47.
One end is fixed to the fixing part 49, and the other end is fixed to the upper surface fixing part 49 via a coil spring 50.

In addition, a first carriage 41 is provided in the middle of the wire 48.
One end of 1 is fixed. As the nozzle motor 33 rotates, the belt 45 rotates and the first barrel 411 moves, and the second barrel 412 also moves accordingly. At this time, pulleys 47, 47
acts as a movable pulley, so the second gear carriage 412 moves in the same direction at half the speed of the first carriage 411. In addition, 1. 2nd Old Man 41,. 41
The direction of movement in step 2 is controlled by switching the rotation direction of the pulse motor 33.

The first carriage 411 is set at a position that is the sum of the length of the paper P in the feeding direction and the deceleration distance of the carriage 411 itself, in accordance with the paper size of the selected paper feed cassette.

6 and 7 show the relationship between the document table 2 and the moving mechanism for moving the optical system 3. FIG. That is, the document table 2 on the top surface of the main body 1 is provided with a scale 6 indicating the length that can be copied according to the document size of each glaze. Also,
The first carriage 411 that supports the exposure run f4 is provided with a scale 62 on the upper part (below the original platen 2) that indicates the length of the original platen 2 that can be copied. The scales 61 and a 62 are designed to indicate the length of 1-A4 size J ['A5 size J]. Also, the first carriage 4)! An auxiliary display section 63 for displaying the copy range 14 of the original is fixed to a part of the ground glass section 21 provided outside the copy range of the document table 2. This auxiliary display section 63 is as shown in FIG. J, ) 65 and a lens 66. Note that the scale 62 is set at a position that matches the length of the paper in the feeding direction in accordance with the paper size of the selected paper feed cassette.
Ri & 62 t on the scale 62 indicates its position.

It is smaller than or the same as the distance W.

FIG. 10 shows the overall control circuit, showing the main processor group 7 and the main processor group 1. Second sub-processor group 72, 7
．． It is mainly composed of 9. 2. The main processor group 7 includes an operating panel 74 and various raccoon switches and sensors, such as the cassette size detection switches 301 and 30.
2, the high voltage transformer 76 which detects the input from the input device 75 such as 2, and drives the various transformers, the static eliminator 28, and the platen renoids 27 of the cleaner 27.
a1 The heater 23a1 of the fixing roller 23, the exposure run 4, and each of the motors 31 to 40 are controlled to perform the above-described copying operation. Among the motors 31 to 4o, the motors 35, 37, 40 and the toner motor 72 that supplies toner to the machine 12 are connected to the main processor via a motor driver 78. - 34 are controlled by the first sub-processor group 72 via a pulse motor driver 79, and
6, 38, and 39 are controlled by the second subgrocer group 73 via the pulse motor driver 80. Further, the exposure rung 4 is controlled by the main processor $-71 via the lamp regulator 81, and the heater 23a is controlled by the main processor group 71 via the heater control section 82. Then, commands to drive and stop each motor are sent from the main processor group 7 to the first and second sub-processor groups 72.73, and from the first and second sub-processor groups 72.73 to the main processor l? A status indicating whether each motor is driven or stopped is sent to i71. Furthermore, position information from a position sensor 83 that detects the initial positions of the motors 31 to 34 is input to the first sag grosser group 72.

FIG. 11 shows an example of the configuration of the main processor group 7. That is, No. 9 is a Wanchizo microcomputer (hereinafter simply referred to as a microcomputer), and an operation A? (not shown) is performed via an input/output port 92. Performs key human power detection and various display controls for the network. Also, microcomputer 91
is expanded by input/output ports 93-96. The input/output port 93 is connected to a high voltage transformer 76, motor driver 78, lamp regulator 81, and other outputs, and the input/output port 94 is connected to a size switch for detecting the paper size and its input.
The input/output port 95 is connected to a copying condition setting switch, its purchasing input, and the like. The input/output port 96 is for an option. FIG. 12 shows an example of the configuration of the first sag processor group 72. That is, 101 is a microcomputer, which is connected to the main processor group 7. 102 is a programmable interval timer for controlling the phase switching interval time of the nogle motor, and when a set value is set from the microcomputer 101, the count value is set based on the set value.
When the count is out, an end pulse is output to the interrupt line of the microcomputer 10. A reference clock signal is input to the timer 102. Furthermore, the microcomputer 101 receives position information from the position sensor 83 and is connected to input/output ports 103 and 104.

The motors 3 to 34 are connected to the input/output port 104 via the pulse motor driver 79. The input/output port 03Fi is used for outputting status signals of each pulse motor to the main processor group 7.

FIG. 13 shows an example of the configuration of the second sub-processor group 73. That is, 111 is a microcomputer, which is connected to the main processor group 71. Reference numeral 112 is a programmable interval timer for controlling the phase switching interval time of the GLS motor, which counts based on the set value set by the microcomputer 121;
When the count is out, a termination pulse is output. This termination pulse is latched by the latch circuit 113, and its output is supplied to the interrupt line of the microcomputer 111 and the input/output port input line.

The input/output ports 1 and 4 are connected to the microcomputer 111, and the motors 36.3B, 39 are connected to the input/output port 114 via a motor driver 80.

Figure 14 shows the pulse motor control circuit. 7, Ikaka, -F121 (I/O port 104 in Figure 1-1□L)
, 114) is equipped with a pulse motor driver 122 (corresponding to
A pulse motor 123 (equivalent to the pulse motor driver 79, 80 in Fig. '9') is connected to the pulse motor driver 122.
(equivalent to 6°38.39) windings A, A, B, and B are connected.

Figure 15 shows the speed control method of a pulse motor.
The figure (a) shows the speed curve of the pulse motor, and the figure (b) shows the phase switching interval. As is clear from this figure,
At first, the phase switching interval is long, gradually becomes shorter, then becomes evenly spaced, gradually becomes longer again, and then stops. In other words, this indicates the through-up and through-down of the pulse motor, and it is used at first from the self-starting region to the startup region, then to the high-speed chain region, and then finally comes down.

tl...tX indicates the time of the phase switching interval.

Next, the operation in such a configuration will be explained. For example, right now, after the power is turned on, the main processor group 7 controls whether the paper P is transferred to the paper transport path 51 in response to a signal from the switch sensor 75.
Check that there is no residue on top. If there is no residue, the main processor group 7 is switched to the detection switch 301.
The paper size of the upper paper feed cassette 13 is determined based on a detection signal from
Output to. Then, the microcomputer 101 switches to pulse mode 1'.
By driving the motor 33 using the l';y lever 79, the first and second caliper horns 411 and 412 are moved.

As a result, the mirror 5 moves from point A to point 5B as shown in FIG.
moved to the point. And the microcomputer 101 is the motor 33
For a predetermined period of time after the initial position detection signal is output from the position sensor 83, that is, the horizontal line 621 of the scale 62.
The scale 62 is moved to the point where (scale position fitL) becomes the length of the A4 size paper P in the conveying force direction, and then moved from point 8 to point C. At this time, the main processor group 71 performs blind light control on the auxiliary display section 63 to provide an auxiliary display of the copy range. For this,
As shown in FIG. 7, the copy range for A4 size paper P is indicated on the document table 2. As shown in FIG. In addition, microcontroller 10
11d, the lens and mirror are driven by using the pulse motor driver 79 to drive the lens motor 31, the mirror motor 32, and the mirror motor 34.

The shutter is moved to the initial position and then to the same magnification position to complete initialization. Also, when the power is turned on,
The main processor group 7 turns on the shift fan motor 40 by driving the motor driver 78, and turns on the shift heater 23a by controlling the heater control s82.

Then, when the temperature of the heater 23a reaches a temperature that allows fixing, the main processor group 4 displays a multifunction function.

In this situation, two A4-sized paper sheets are
Copying to fAP of 4 sizes.

do. First, as shown in FIG. 7, the first manuscript 54 is placed at a position corresponding to the size according to the instructions on the scale 61, 62 and the auxiliary display section, and then the second manuscript 55 is placed on the first manuscript 54. The document 54 is placed along the edge of the document 54. Next, the division key 14 is turned on, the duplex key 145 is turned on, the number of copies is set using the numeric keypad 132, and the copy key 13 is turned on. Then, the main processor group 7 determines that two A4 size originals are to be divided and double-sided copies are to be made, and outputs the result of this determination to the microcomputer 101. According to this, the microcomputer 101 drives the motor 33 and the first. The second carriage 411, 412 is made to travel. At this time, the lighting of the connection rung 4 of the main processor group 7 is controlled. As a result, the light from the exposure lens 4 is irradiated onto the first original 54 . The reflected light from the first original 54 reaches the mirror 9 via the variable magnification lens block 8 which is set to 10x magnification by mirrors 5 and 6, and is reflected by the mirror 9 and exposed to light. body drum lO.

As a result, an electrostatic latent image of the first document 54 is formed on the photoreceptor drum 10, and this electrostatic latent image is formed on the photoreceptor drum 10.
As the image rotates, it is sent to the developing device 12 and developed. At this time, the paper P from the paper feed cassette 13 is taken out and passed through the registration rollers 19 to the photosensitive drum 10 and the transfer charger 2.
0. Here, the image @ on the photosensitive drum 10 is transferred onto the surface of the sheet P by the action of the transfer charger 200, and after this transfer, it is peeled off by the action of the peeling charger 2. Then, the sheet P on which Fjh(M has been transferred) is sent to the fixing roller pair 23 by the running of the conveyor belt 22,
Here, the hoe is stored in a fixed reservoir and is discharged by a pair of discharge rollers 24,24. This ejected paper P is guided to the paper introduction path 151 side by the gate 150 and is folded into the paper feed roller 1.
After the sheet is once sent in the direction of the arrow d by the rotation of the rollers 52 and 152, the feed rollers 152 and 152 are reversely rotated to send it back in the direction of the arrow e, where it is held and conveyed by the conveyor belts 153 and 153. Then, the paper P discharged from the conveyor belts 153, 153 is fed into a reversing path 154, reversed, and then centered toward the registration rollers 19.

Next, the microcomputer 101 drives the motor 3 to set the variable magnification lens block 8 to the 1.02x position, and moves the motor 33 to set the zoom lens block 8 to the 1.02x position. The second carriages 411, 412 are moved back a little and then run again. At this time, exposure rung 4
The second original 55 is irradiated with the light. This second principle
The reflected light from the height 55 passes through the mirrors 5, 6.7, and the variable magnification lens block 8, which is set to 102 times, and reaches the mirror 9, where it is reflected by the photoreceptor drum l.
Guided by O. As a result, an electrostatic residue of the second original 55 is formed on the photoreceptor drum 10, and this water is poured into the developing unit 12 by the rotation of the photoreceptor drum YO and is developed. The phenomenon with respect to this second original 55 is that when the above-mentioned inverted paper P sent to the registration rollers 19 is introduced between the photosensitive drum 10 and the transfer charger 20 via the registration rollers 19. For transcription on the back side @
It is transferred by the action of the electric appliance 200. And this picture (3
) After the image has been fixed on the transferred paper P by a pair of fixing rollers 23.23, it is discharged by a pair of discharge rollers 24.24.

When the document scanning is completed, the mirror 5 is moved to point A (home I position) shown in FIG. 1 and stopped.

Thereafter, double-sided copying for the number of copies is performed continuously.

At the same time, it is assumed that an A3 size original is to be copied. First, turn on the lower cassette selection key 137. Then, the main processor group 7 determines the paper size of the lower paper feed cassette 14 based on the detection signal from the detection switch 301, and initializes the optical system 3 according to this determination result.
A signal indicating the corner and the length of the paper P is output to the microcomputer 101. Then, the microcomputer 101 drives the motor 33 using the Nogles motor driver 79, and the first . 7. Move the second type carriages 411, 412. As a result, the similar mirror 5 is moved from point A to point B as shown in FIG. Then, the microcomputer 101 detects the initial position of the motor 33 (for a predetermined period of time after 3-Q is output from the position sensor 83), the scale is scaled until the length of the 9th scale 62 is equal to the length of the A3 size paper P in the transport direction. 6
Move 2. As a result, the mirror 5 is moved from point B to DA as shown in FIG. At this time, the display of the auxiliary display section 63 is controlled by the main processor group 7) to provide an auxiliary display of the copy range. As a result, as shown in FIG. 16, the copy range for the A3 size paper P is completely specified on the document table 2. In response to this instruction, an A3 size document ff: is placed on the document table 2.

Next, the release keys 143 and 147 are turned on, the number of copies is set using the ten keys 7 and 72, and the copy key 13 is turned on. Then, the main processor group 7 judges that it is a copy of an A3 size document, and as a result of this judgment, the microcomputer 1
Output to 01. Based on this, the microcomputer 101 controls the motor 3.
By driving the first. Second carriage 41
Run 1.412. At this time, the main processor group 71 controls the exposure rung 4 to turn on.

As a result, the light of the exposure rung 4 is irradiated onto the original. The reflected light from this original passes through the mirrors 5, 6.7, and further reaches the mirror 9 via the variable magnification lens block 8.
and is guided to the photoreceptor drum 10. As a result, an electrostatic latent image of the document is formed on the photoreceptor drum 10.
As the photoreceptor drum 10 rotates, this electrostatic latent image is sent to a developing device 12 and developed. At this time, the paper feed cassette 14
The paper P is taken out and sent between the photosensitive drum IO and the transfer charger 20 via the registration row 219.

Here, the image on the photoreceptor drum 1θ is transferred to the transfer charger 20.
The image is transferred onto the surface of the paper P by the action of , and is peeled off by the action of the peeling charger 21 during this transfer. Then, the sheet P on which the image has been transferred is conveyed by the conveyor belt 220 to the pair of fixing rollers 23, where it is delivered to the iIi! The -C paper ejection roller pair 24, . 24.

When scanning of the original is completed, the mirror 5 is moved to point A (home position) shown in FIG. 1 and stopped.

Thereafter, copies are made continuously for the number of copies.

In addition, when copying at a variable magnification ratio of X using a variable magnification switch (not shown), the scale 62's scale &! 621 (scale position) as "L=t/x J" and moving the scale 62, the copying range corresponding to the magnification ratio is indicated on the document table 2.

As described above, since the scale 62 is set at a position equal to the length of the copy paper in the feeding direction, the copy range can be confirmed on the document table 2, and copy errors can be reduced.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to provide an image forming apparatus that can form both edges.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a cross-sectional view showing the overall configuration, FIG. 2 is a diagram for explaining the open/closed state, and FIG. 3 is a diagram showing the configuration of the operation/main channel. A plan view showing,
Fig. 4 is a diagram showing the relationship between the document table of the drive unit and the moving mechanism of the optical system, Fig. 8 is a diagram showing the configuration of the auxiliary display unit, Fig. V is a configuration diagram of the overall control circuit, and Fig. The 1v diagram is mainp. Ya, group V, ) composition, ah □ chant. Wow, the configuration diagram of the processor group, Figure 1v is the configuration diagram of the second processor group,
Figure 1ψ is a schematic configuration diagram showing the control circuit of the pulse motor, and Figure 1v is a plan view of the pulse motor. DESCRIPTION OF SYMBOLS 1...Main body, 11...Upper unit, 12...Lower unit, 2...Document stand, 3...Optical system, 5, 6
゜7.9... Mirror, 8... Lens block for variable magnification, 10... Photosensitive drum, 13... Upper paper feed cassette, 14... Lower paper feed cassette, P... Paper (Driven hoe-shaped g body), s o,, s o,... Cassette size detection switch, 31... Lens motor, 32...
...Mirror motor, 33...Scanning motor, 411
...First gear rigid (moving mechanism), 472...Second
Kiya's manuscript, 55...second # draft, 56...book, 6
7', "J62...Scale, 62!・τ・Kei Green, 63...Auxiliary display section, 71...Main processor group, 9th. 101...Microcomputer, 131...Copy key, 135
. . . Upper cassette selection key, 137 . . . Lower cassette selection key, 141 . . . Division key, 143 .
0...r-t, 151...introduction path, 152,152...
...Feed roller pair, 153...Transport belt, 154
・Reverse path. 78th figure 8 mouth==ko~21 figure 9

Claims (1)

[Scope of Claims] (1) In an image forming apparatus with a fixed document table, the r
An optical system for optically scanning fJAm, a moving mechanism for moving this optical system, a display means provided in this moving mechanism and provided at the bottom of the document table, and a measuring device for detecting the size of the object to be imaged. and a control means for controlling the moving mechanism so as to move the display means to a position corresponding to the length of the image forming object in the feeding direction according to the detection result by the detection means. An image forming apparatus is characterized in that it is configured to display a range that can be produced by an art dealer on a document table. (2) When the moving mechanism places the display means in a position where the display means is applied to the length of the plate 1 formation body in the forwarding direction, the length of the image forming body in the forwarding direction and the deceleration ii!!I image forming apparatus according to claim 1, characterized in that the image forming apparatus is set at a position in which the distance is added. (3) A patent claim characterized in that the display means is a scale. The image forming apparatus according to item 1. (4) The display means is fixed to a scale and a moving mechanism, and a display section that is provided outside the maximum image formation range at the bottom of the document table and that emits a spot light. An image forming apparatus according to claim 1, characterized in that the image forming apparatus is comprised of: