JPS6249341A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent the title device from miscopying by moving a variable magnification lens block along an X-direction fixed scale to be a setting refer ence for an original in accordance with the storing reference or paper. CONSTITUTION:When the storing reference for a paper feed cassette which is detected by a cassette size detecting switch is one-side reference, a light emission display element 30a on an operation panel 30 is turned off and a light emission display element 30b is turned off. Even if copying magnification is unmagnification, reduction or unlargement when both the original setting reference and paper storing reference are one-side reference, the center of the original does not coincide with the center of paper P. Consequently, the variable magnification lens block 8 the copying magnification set by a magnification setting key 306 and the paper size detected by the cassette size detecting switch.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image forming apparatus applied to, for example, an electronic copying machine.

[Technical background of the invention and its problems]

As is well known, some electronic copying machines have a document set at the center of the document table, and others set the document on one side of the document table. Since the setting standards for these originals are fixed by the copying machine, it is fine if the user uses a copying machine with which the setting standards are familiar, but if not, it may be difficult to use because the setting standards are different from normal ones. There is,
In some cases, there is a problem in that a copying error occurs, such as an image being formed only on a portion of the paper.

[Object of the invention] This invention was made based on the above circumstances,
The purpose is to provide an image forming apparatus that allows originals to be set according to familiar standards and that can prevent copying errors.

[Summary of the invention]

According to the present invention, for example, the document setting position can be changed to a central reference or a one-sided reference depending on the storage standard of the paper stored in the selected paper feed cassette, and furthermore,
By moving the variable magnification lens block along the fixed scale in the X direction, which is the reference for setting the original, according to the paper's storage g1 standard, the image formation position on the paper is moved and the image is correctly copied onto the paper. It was designed so that

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 4 and 5 schematically show an image forming apparatus, such as a copying machine, according to the present invention. That is, 1 is a main body of the copying machine, and on the top surface of this main body 1 is a document stand (
Transparent glass) 2 is fixed. The document table 2 is provided with fixed scales 2x and 2y (the fixed scale 2y is shown in FIG. 1) on which the cellar 1 reference of the document is shown, respectively, along the width direction and the length direction of the document table. ,
A VAI cover 1 and a work table 12, which can be opened and closed, are provided near the document table 2. The original placed on the original platen 2 is exposed to an exposure lamp 4, a mirror 5.
6. The optical system consisting of
By reciprocating in the direction, exposure scanning is performed during the reciprocating movement.

In this case, mirror 6.7 moves at half the speed of mirror 5 so as to maintain the optical exposure length. The light reflected from the original by the scanning of the optical system, that is, the light reflected from the original by the light irradiation of the exposure lamp 4, is reflected by the mirror 5.6.7, passes through the variable magnification lens block 8, and then passes through the mirror. 9 and guided to the photoreceptor drum 10,
An image of the original is formed on the surface of the photosensitive drum 10.

The photosensitive drum 10 rotates in the direction of arrow C in the figure, and the surface is first charged by a charging device 11, and then an image is exposed to slit light to form an electrostatic latent image on the surface. This electrostatic latent image is formed by the adhesion of toner by the developing device 12. ! l It is designed to be visualized.

On the other hand, the paper (material to be transferred) P is taken out one by one from the selected upper paper feed cassette 13 or lower paper feed cassette 14 by the delivery roller 15 or 16, and passed through the paper guide path 17 or 18. It is guided to a pair of registration rollers 19, and guided to a transfer section by this pair of registration rollers 19. Here, the paper feed cassettes 13 and 14 are removably provided at the lower right end of the main body 1, and either one can be selected on the operation panel described later. In addition, each of the paper feed cassettes 13.14 is configured so that the cassette size and the storage standard of the paper stored in the paper feed cassettes 13.14 are detected by size detection switches 601 and 602. There is. That is, the cassette size detection switches 601 and 602 are composed of a plurality of microswitches, and as will be described later, these microswitches detect the paper size and paper storage standards by means of protrusions provided on the side of the paper feed cassette. It is designed to be operated on and off.

The paper P sent to the transfer section comes into close contact with the surface of the photoreceptor drum 10 at the transfer charger 20, so that the toner image on the photoreceptor drum 10 is transferred by the action of the charger 20. . This transferred paper P is transferred to the peeling charger 2
It is electrostatically peeled off from the photoreceptor drum 10 by the action of step 1 and transported by a conveyor belt; The image is fixed. After fixing, the paper P is transferred to a tray 25 outside the main body 1 by a pair of paper ejection rollers 24.
It is becoming more and more popular. After the photosensitive drum 10 has been transferred, the charge is removed by the charger 26, residual toner on the surface is removed by the cleaner 27, and the residual image is erased by the charge removal lamp 28, so that the drum 10 returns to its initial state. It looks like this. Note that 29 is a cooling fan for preventing the temperature inside the main body 1 from rising.

FIG. 6 shows the operation panel 30 provided on the main body 1. 30t is a copy key for commanding the start of copying, 302
is the numeric keypad for setting the number of copies, etc., and the 0 of each part of 303 is
304 is a cassette selection key for selecting the upper and lower paper feed cassettes 13 and 14; 305 is a cassette display section for displaying the selected cassette; 30s is a copy enlargement; A magnification setting key for setting the reduction magnification in a predetermined relationship, 307 a zoom key for steplessly setting the enlargement and reduction magnification, 30e a display section for displaying the set magnification, 309 a density setting section for setting the copy density, Reference numerals 30a and 30b are light-emitting display elements that display the cellar 1 standard of the original document in accordance with the storage standard of the paper stored in the selected paper feed cassette.

FIG. 7 shows an example of the drive configuration of each drive section of the copying machine configured as described above, and is composed of the following modes and modes. That is, 31 is a lens motor, which is a motor for moving the position of the lens block 8 that performs magnification change. 32 is a mirror motor, which is a motor for changing the distance (optical path length) between the mirror 5 and the mirror 6.7 for changing the magnification. 33 is a scanning motor, which connects the exposure lamp 4 and mirror 5.
, a motor for moving the mirror 6.7 for document scanning. 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, and the developing motor 35 is a developing motor of the developing device 12.
This is a motor for driving a motor, etc. 36 is a drum motor, which is a motor for driving the photosensitive drum 10. 37 is a fixing motor, which connects the paper conveyance path 22. This is a motor for driving the fixing roller pair 23 and the paper ejection roller pair 24. 38 is a paper feed motor, which is a motor for driving the delivery rollers 15 and 16. A paper feeding motor 39 is a motor for driving the registration roller pair 19.

A fan motor 40 is a motor for driving the cooling fan 29.

FIG. 8 shows a drive mechanism for reciprocating the optical system. That is, the mirror 5 and the exposure lamp 4 are supported by a first carriage 411, and the mirror 6.7 is supported by a second carriage 422, and these carriages 411 and 412 are guided by guide rails 421 and 422 in the direction of arrow a. It can be moved in parallel. That is, the four-phase pulse motor 33 drives the boot 943. An endless belt 45 is stretched between the pulley 43 and the fiddle pulley 44, and one end of a first carriage 411 that supports the mirror 5 is fixed to a midway portion of the belt 45. On the other hand, a second carriage 422 supporting the mirror 6.7
The guide portion 46 includes two grooves spaced apart in the axial direction of the rail 422.
Two pulleys 47.47 are rotatably provided, and a wire 48 is stretched between these pulleys 47.47. One end of this wire 48 is connected to the fixing part 49 at 11! ! The ends are each fixed to the fixing part 49 via a coil spring 50. Further, one end of a first carriage 411 is fixed to a midway portion of the wire 48. Therefore, as the pulse mower 933 rotates, the belt 45 rotates, the first carriage 411 moves, and the second carriage 422 also moves accordingly. At this time, since the pulleys 47, 47 serve as movable pulleys, the second carriage 422 moves in the same direction as the first screw carriage 411 at 1/2 the speed. Note that the moving directions of the first and second carriages 41r and 412 are controlled by switching the rotational direction of the pulse motor 33.

FIG. 9 shows a drive mechanism for the variable magnification lens block 8. As shown in FIG. The motor 31 is the first carriage 41! A lead screw 61 arranged along the moving direction (y direction) is rotated. Bushes 63+ and 632 provided at one end of the base 62 are screwed into the lead screw 61, and when the lead screw 61 is rotated, the substrate 62 is moved in the X direction.

A guide member 621 is provided at the other end of the substrate 62, and this guide member 621 is slidably engaged with the guide rail 64. Also,! ! A movable body 65 is provided on the plate 62 and is movable in a direction perpendicular to the substrate 62 (X direction), to which the variable power lens block 8 is attached. That is, supports 65 are provided at both ends of this moving body 65.
r, 652 is provided, this support 651.6
Reference numeral 52 denotes guide members 66r, 66 provided on the substrate 62.
Guided and held by 2. Moreover, the support body 65
! A rack 653 is provided on the longitudinal side surface of the rack 653, and a pinion 68 rotated by a pulse motor 67 provided on the base plate 62 is engaged with the rack 653. Therefore, the variable power lens block 8 is moved in the X direction by driving the motor 67. In addition, the micro stitches 691 and 692 are respectively connected to the substrate 62 and
This is to detect the initial position of the moving body 65.

Next, the relationship between the operation of the variable magnification lens block 8 and the image formed will be explained. In FIG. 10(a), the focal length of the variable power lens block 8 is f, the optical path length from the document table 2 to the variable power lens block 8 is ya, and from the variable power lens block 8 to the photosensitive drum 10. When the optical path length of is yb and the total optical path length from the document table 2 to the photosensitive drum 10 is yc, the optical formula is expressed as follows.

1/f=1/ya+1/yb Also, the magnification is expressed as (-yb/ya).Since the focal length f of the variable magnification lens block 8 is constant, in order to focus when changing the magnification, it is necessary to It can be seen that in addition to changing the optical path length yc, it is also necessary to change ya or yb.
can be changed by moving the variable power lens block 8 in the X direction. Further, the total optical path length yc can be changed by moving the second carriage 412 and changing the position of the mirror 6.7.

On the other hand, as shown in FIG. 10(b), the distances between the document table 2, the variable magnification lens block 8, and the photosensitive drum 10 are kept constant, and the variable magnification lens block 8 is moved by the motor 67 in the X direction by a distance of, for example, ff1Xl. When the photoreceptor drum 1 moves
The image on 0 is moved by a distance x 2 given by the following equation.

X2 =XI Xyt)/ya In the case of a same size copy, In this way, by moving the variable magnification lens block 8 in the X direction, the center of the copied image can be moved.

FIG. 11 shows the overall control circuit, showing the main processor group 71 and the first . Second sub-processor group 72.
It is mainly composed of 73. The main processor group 7
1 is an operation panel 30 and various switches and sensors, such as the cassette size detection switch 6C)+, 60
A high-voltage transformer 76 that detects input from an input device 75 such as 2 and drives the various chargers, and the static elimination lamp 28.
, a blade solenoid 27a1 of the cleaner 27, a heater 23a of the constant inspection roller pair 23, the exposure lamp 4,
and controlling each of the motors 31 to 40, 38, etc.,
In addition to performing the above-mentioned copying operation, the motor 67 is controlled to perform an operation of moving the original image in accordance with a document setting standard, which will be described later.

Among the motors 31 to 40.67, motor 35.37
．． A toner motor 77 that supplies toner to the 40 and the phenomenon device 12 is controlled by the main processor group 71 via a motor driver 78, and
are controlled by the first sub-processor group 72 via a pulse motor driver 79, and the motors 36, 39, 38 are controlled by the second sub-processor group 7'3 via a pulse motor driver 80. Further, the exposure lamp 4 is controlled by the main processor group 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, from the main processor group 71, the first. Second sub-processor u72.
The drive/stop +I=command for each motor is sent to 73, and the first
．． First sub-processor group 72. A status signal indicating the drive/stop state of each motor is sent from '73 to the main processor group 71. In addition, the first sub-processor group 72
Inputs position information from a position sensor 83 that detects each initial position of the motors 31 to 34.67.

FIG. 12 shows an example of the configuration of the main processor group 71. That is, 91 is a one-chip microcomputer (hereinafter simply referred to as microcomputer), which detects human input of keys on an operation panel (not shown) and controls various displays via an input/output board 92. Furthermore, the microcomputer 91 is expanded by input/output ports 93-96. The input/output port 93 is connected to a high voltage transformer 76, a motor driver 78, a lamp regulator 81, and other outputs, and the input/output boat 94 is connected to a size switch for detecting paper size and an external power source. A copying condition setting switch and other human power are connected to the capo-1-95.

Note that the input/output port 96 is an option.

FIG. 13 shows an example of the configuration of the first sub-processor group 72. That is, 101 is a microcomputer, which is connected to the main processor group 71.

102 is a programmable interval timer for controlling the phase switching interval time of the pulse motor;
By setting a set value from 1, counting is performed based on the set value, and when the count out b is reached, an end pulse is output to the interrupt line of the microcomputer 101. Said timer 1
A reference clock pulse is input to 02. Also,
The microcomputer 101 receives position information from the position sensor 83, and input/output ports 103 and 104.
is connected. The input/output boat 104 is connected to the motor 31 via the pulse motor driver 79.
~34.67 are connected.

The input/output board 103 is used, for example, to output status signals of each pulse motor to the main processor group 71.

FIG. 14 shows the configuration of the second sub-processor group 73. That is, 111 is a microcomputer, which is connected to the main processor group 71. 112 is a programmable interval timer for controlling the phase cut 1fk interval time of the pulse motor, and when a setting value is set by the microcomputer 111, it starts counting out based on the setting value, and outputs an end pulse when it counts out. This termination pulse is latched by the latch circuit 113, and its output is supplied to the interrupt line and input/output board input line of the microcomputer 111. In addition, the microcomputer 111 also has an input/output board 1.
14 is connected to the motor 36.3 through the pulse motor driver 80.
8.39 is connected.

Figure 15 shows the control circuit of the pulse motor.
The input/output boat 121 (corresponding to the input/output boats 104 and 114 in Figs. 13 and 14) has a pulse motor driver 1.
22 (corresponding to the pulse motor driver 79.80 in FIG. 11) is connected to the pulse motor driver 122,
．． 38, 39, and 67) are connected to each other.

Figure 16 shows a method for controlling the speed of a pulse motor.

Figure (a) shows the speed curve of the pulse motor, and Figure (b) shows the speed curve of the pulse motor.
) indicates the phase switching interval. As is clear from this figure, the phase switching interval is initially long, gradually shortens, eventually becomes equal, and gradually improves again until it stops. In other words, this indicates the through-up and through-down of the pulse motor, starting from the self-starting region, being used in the high-speed region, and finally falling down. In addition, tl, t2...
-tx indicates the phase switching interval time.

Next, the gist of the invention will be explained.

In this invention, it is determined whether the paper stored in the selected paper feed force cellar 1- is based on the center reference of the paper feed set or the one [1111 reference] based on the output signals of the cassette size detection switches 60+ and 602. Depending on the discrimination result, the reference for setting the original can be selected such as the center of the fixed scale 2x of the document table 2, or one side of the fixed scale 2X, and the conversion lens block 8 can be set on the photosensitive drum according to the discrimination result. By moving along, the position at which the original image is formed relative to the photosensitive drum is moved.

FIG. 17 shows the standard for storing sheets in the paper feed cassette. In FIG. 5A, paper P is stored with the center of the paper feed cassette 13a as a reference;
In the same figure (b), one side of the paper feed cassette h13b is set as a reference. These paper cassettes 1
The size and accommodation standard of the paper stored in the paper feed cassettes 3a and 13b are set by a code on the identification part 13c, which is made up of a plurality of protrusions provided on the side of the paper feed cassette. If 5A arrives, the above-mentioned cassette size detection switch 60! , 602.

In the above configuration, the operation will be explained. When the upper or lower paper feed cassette is selected by operating the cassette selection key 304 on the operation panel 30, the identification portion 13C is detected by the cassette size detection switch corresponding to the selected paper feed power cell I. . In the main processor group 71, this detected identification unit 13C
If it is determined that the paper storage standard of the selected paper feed cassette is the center standard, the light emitting display element 30a of the operation panel 30 is lit. This allows the operator to confirm that the document setting standard is the central standard! can do. In this way, when the document setting reference and the paper storage reference are the center, the center of the document G and the center of the supplied paper P coincide.

Therefore, the variable magnification lens block 8 is moved to the same magnification position M as shown in FIG. 1(a) according to the set copy magnification.
From a, it is moved only in the reduction magnification direction Mb and the enlargement magnification direction Mc (direction of arrow X in the figure), but not in the X direction.

On the other hand, when the paper feed cassette accommodation standard detected by the cassette size detection switch is one-sided standard, the light-emitting display element 30a of the operation panel 30 is turned off, and the light-emitting display element 30b is turned on.

Therefore, the operator can recognize that the document is set with one side of the fixed scale 2X as a reference. In this way, when the original setting percentage and the paper accommodation standard are both one-sided, as shown in Figure 1(b), even if the copying magnification is equal, reduced, or enlarged, the center of the IPi The centers of paper P do not match. Therefore, the variable magnification lens block 8 moves in the X direction and the be done.

That is, when the document setting standard and the paper storage standard are on one side, the shifting darkness of the variable magnification lens block 8 is determined as follows. As shown in FIG. 2, the distance from the center of the document table 2 to one end of the fixed scale 2x and the distance from the center of the document table 2 (image carrier 10) to the paper storage standard are set as Xσ, respectively. The moving distance of the variable lens block 8 according to the magnification is y, and the variable magnification lens block 8 (indicated by a solid line) when it is dark and the variable magnification lens block 8 (indicated by a dotted line) at a predetermined copying magnification. The angle formed by the line connecting the centers of the above and the optical axis of the variable power lens block 8 shown by the solid line is θ, and the distance between the variable power lens block 8, the document table 2, and the image carrier 10 shown by the dotted line is θ. a, respectively
b, then these relationships are: 2XO/(a+b)-(xg-ytanθ)7'b. The focal side lf' of the variable power lens block 8 is 1
/ a + 1 / b - 1, / f, so
From these, the following relationship is obtained: X - (2f-a) xQ /a. When the variable magnification K is -b/a, it is expressed by the following relational expression: x-1: (K, XO, f). Here, since xg and f are constants determined by the copying machine, the above equation can be transformed into x-F(K). Based on this relationship, the pulse motor 6
By driving the lens block 7 and moving the variable magnification lens block 8, both images of the document can be formed at the center of the sheet. As a method of driving this variable magnification lens block 8, the above relational expression may be solved each time, but data such as The pulse motor 67 may be driven in accordance with this data.

According to the above-mentioned embodiment, it is possible to change the standard for original documents depending on the amount of paper stored in the paper feed cassette. Therefore, the operator can arbitrarily select the document setting standard by attaching the paper feed force sensor 1 or selecting the paper feed cassette using the cassette selection switch, so that copies can be made using the familiar setting standard. This makes it possible to prevent copying errors.

Furthermore, the light-emitting display element 30a1 or 30a self-detects the storage standard of the paper stored in the paper feed cassette by a cassette size detection switch, and displays the cent standard of the document.
0b is turned on, and the variable magnification lens block 8 is moved according to the paper stored therein. Therefore, even if paper storage standards change,
Accordingly, it is possible to copy the image of the document set in the center of the paper.

In the above embodiment, the conversion lens block 8 is driven according to the accommodation standard of the paper stored in the paper feed cassette, but the invention is not limited to this. For example, as shown in FIG. Selection keys 30G, 3 for selecting set criteria
It is also possible to provide a lens block 0d and drive the variable magnification lens block 8 according to the operation state of the selection keys 30c and 30d and the detection output of the cassette size detection switches 601 and 602.

It goes without saying that various other modifications can be made without departing from the gist of the invention.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide an image forming apparatus in which originals can be set according to familiar standards and copying errors can be prevented.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of an image forming apparatus according to the present invention. FIG. FIG. 3 is a schematic configuration diagram for explaining the moving state of the image forming apparatus, and FIG. 3 is a plan view showing the configuration of the operation panel, and FIGS. Fig. 4 is an external perspective view, Fig. 5 is a side sectional view, Fig. 6 is a plan view showing the structure of the operation panel, and Fig. 7 is a perspective view showing the structure of the drive section. Fig. 8 is a perspective view that does not schematically show the drive mechanism of the optical system, Fig. 9 is a perspective view that does not show the structure of the lens block for variable magnification, and only shows the main parts, and Fig. 10 is a perspective view that does not schematically show the drive mechanism of the optical system. 11 is a block diagram showing the overall control circuit, FIG. 12 is a block diagram of the main processor group, and FIG. 13 is a block diagram of the first sub-processor group. FIG. 14 is a configuration diagram of the second sub-processor group, FIG. 15 is a schematic configuration diagram showing a pulse motor control circuit, and FIG. 16 is a diagram shown for explaining a pulse motor speed control method. FIG. 17 is a perspective view of a main part showing the standard for storing sheets stored in the paper feed cassette. 1... Main body, 2... Original table, 2X, 2y... Fixed scale, 8... Lens block for variable magnification, 10...
Photosensitive drum, 30...operation panel, 30a, 30b
. . . Light emitting display element, 60r, 602 . . . Cassette size detection switch, 71 . . . Main processor group. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 (b) Figure 2 Figure 7 Figure 9 Figure 10 Figure 14 Figure 15 (a) (b) Figure 17

Claims (2)

[Claims] (1) a scanning means that moves along a document table and optically scans a document placed on the document table according to a setting standard;
It consists of an image carrier on which an image corresponding to the original image guided by the scanning means is formed, and a transfer means for transferring the image formed on the image carrier onto a transfer material supplied from a cassette. In the image forming apparatus, a determining means for determining the size of the transferred material accommodated in the cassette and whether the accommodation standard for the transferred material is one side reference or center reference, and an image carrier movable along the image carrier. An image forming apparatus comprising: a changing means for changing the imaging position of an image relative to the image forming apparatus; and a control means for operating the changing means in accordance with a determination result of the determining means. (2) The setting reference is disposed in a direction of movement of the scanning means and in a direction orthogonal to the movement direction, and the setting reference of the document can be selected as a center reference or a one-sided reference according to the determination result of the determination means. An image forming apparatus according to claim 1, characterized in that: