JPS6391647A - Scanning speed changing mechanism for variable power copying machine - Google Patents

Abstract

PURPOSE:To simplify the constitution of a speed change gear and to contrive to reduce the cost of a device by changing a scanning speed as well as a lens position when copy magnification is selected. CONSTITUTION:The movement of a moving lever 100 when copy magnification is selected is transmitted to a control plate 241 through a rack gear 201, a pinion gear 206, a rotating shaft 203, and a selecting member rotating gear 204. The control plate 241 rotates by an angle of rotation specified for each selected value of copy magnification and one of projection parts 242a-242d which corresponds to the copy magnification contacts input shaft speed change gears 219a-219d. consequently, the input shaft speed change gears 219a-219d are coupled with one of output shaft speed change gears 220a-220d corresponding to the scanning speed of the selected copy magnification. When an electromagnetic clutch 214 is driven at the time of a copying machine process, the rotation of an input shaft 210 is transmitted to output shaft speed change gears 220a-220d through an input shaft gear 215 and the input shaft speed change gears 219a-219d, so that an original plate 2 moves at the scanning speed corresponding to the selected copy magnification.

Description

DETAILED DESCRIPTION OF THE INVENTION fa) Industrial Application Field This invention relates to an improvement in a scanning speed changing mechanism used in a variable magnification copying machine and changing the document scanning speed of an optical system.

(b) Conventional technology In a variable magnification copying machine that enlarges or reduces the size of the original image and copies it, the position of the lens is moved between the original and the photoreceptor drum, thereby making the image perpendicular to the scanning direction of the optical system. Stretch or shrink the size in the direction.

On the other hand, regarding the scanning direction of the optical system, it is necessary to change the document scanning speed of the optical system depending on the selected copying magnification. For this purpose, it is necessary to change the moving speed of the document table or the optical system during the copying process. Conventionally, for example, in the method disclosed in Japanese Patent Application Laid-Open No. 60-165633, a plurality of planetary gears each having a different number of teeth meshed with the input shaft gear were provided, and the output shaft gear was changed by switching the planetary gear meshed with the output shaft gear. I am trying to change the rotation speed of. In addition, when switching the planetary gear meshing with the output shaft gear, rotational force is selectively applied to the carrier of the planetary gear via a spring clutch, and the operation of the spring clutch is controlled by an arm linked to a manually operated operating lever. It is controlled by changing the contact position between the provided control pawl and the pawl provided on the spring clutch. The above configuration simplifies the configuration of the transmission gear and allows the scanning speed to be manually selected, thereby reducing the cost of the apparatus.

(C) Problems to be Solved by the Invention However, in the conventional scanning speed change mechanism described above, the planetary gear and the spring clutch rotate every time the scanning speed is changed, and the control provided on the pawl and arm of the spring clutch rotates. It had the disadvantage that it made a loud noise when it came into contact with the nails. In addition, a large torque is required to rotate the spring clutch, the planetary gear, and the carrier of the planetary gear around the input shaft, resulting in an increase in the size of the main motor.

The purpose of this invention is to switch the rotational speed of the output shaft by selectively connecting the gear that meshes with the input shaft gear and the gear that meshes with the output shaft gear, thereby realizing miniaturization of the device and manual switching of the scanning speed. Another object of the present invention is to provide a scanning speed changing mechanism for a variable magnification copying machine that can prevent the generation of scanning speed switching noise and reduce the motor torque to reduce costs.

(d) Means for Solving the Problems A scanning speed changing mechanism for a variable magnification copying machine according to the present invention is a scanning speed changing mechanism for a variable magnification copying machine that changes the document scanning speed of an optical system according to a selected copying magnification. In the mechanism, an input shaft gear fixed to the input shaft, a predetermined number of input shaft gears meshing with the input shaft gear, an output shaft gear fixed to the output shaft, and an input shaft gear shifting gear meshing with the output shaft gear. and the predetermined number of output shaft transmission gears that are located coaxially with each other and have different numbers of teeth, and the predetermined number of rotation transmission members that transmit the respective rotations of the input shaft transmission gears to the opposing output shaft transmission gears, and the rotation and a gear ratio selection member that selectively activates one of the transmission members (81).
Function: In the scanning speed change mechanism of the variable magnification copying machine of the present invention, rotation of the input shaft to which rotational force is transmitted from the drive device is transmitted to a predetermined number of input shaft speed change gears via the input shaft gear.

This causes all of the input shaft gears to rotate. An output shaft gear is fixed to the output shaft, and a predetermined number of output shaft gears mesh with the output shaft gear. The output shaft speed change gear is located coaxially with the input shaft speed change gear, and the rotation of the input shaft speed change gear is transmitted to the output shaft speed change gear via the rotation transmission member. One rotation transmission member is provided for each pair of input shaft transmission gear and output shaft transmission gear, and one of the predetermined number of rotation transmission members is selectively enabled by a transmission ratio selection member. The predetermined number of output shaft speed change gears have different numbers of teeth, and the number of rotations transmitted to the output shaft differs depending on which rotation transmission member corresponding to which output shaft speed change gear is activated. In other words, the rotation of the output shaft is changed in speed by switching the rotation transmission member to be enabled by the speed ratio selection member.

(f) Embodiment The figure shows a variable magnification copying machine equipped with a scanning speed changing mechanism which is an embodiment of the present invention. This embodiment will be explained below in the following order.

■Appearance (see Figure 1) ■Overall configuration (see Figure 2) ■Operation panel (see Figure 3) ■Lens unit (see Figures 4 and 5) ■Blank lamp unit (see Figure 6)■ Optical device cleaning structure (see Figures 7 to 9) Exhaust structure (see Figures 10 and 11) Lens position warning display (see Figure 12) Operating speed change mechanism (see Figures 13 to 13) See Figure 16. External appearance Figure 1 is an external view of an electrophotographic copying machine that is an embodiment of the present invention.A document cover 2 is attached to the upper part of the copying machine body 1 and can be opened and closed at the rear end. is supported by

Further, a paper feed cassette 3 is attached to the copying machine main body 1 at the bottom. This paper feed cassette 3 can be selected depending on the paper size to be stored. A paper discharge tray 4 is attached to the left side of the copying machine main body 1. Paper cassette 3
The paper fed from the main body 1 of the copying machine passes through a copying process section in the main body 1 of the copying machine, and is guided to the paper discharge tray 4 via a paper discharge section (not shown). An operation panel 5 is provided at the upper front of the copying machine main body 1, and includes a print switch and a magnification setting lever, as will be described later.

(2) Overall Structure FIG. 2 is a diagram showing the overall structure of the above-mentioned copying machine. A photosensitive drum 10 that rotates in the direction of the arrow in the figure is disposed approximately at the center of the main body 1 of the copying machine. A main charger 11 and a blank lamp unit 1 are arranged around the photoreceptor drum 10.
2, a developing unit 13, a transfer charger 14, a pair of peeling rollers 15, a cleaner unit 16, and a static elimination lamp 17 are provided in this order. Point P in the photoreceptor drum 1° represents an exposure point, and light from the optical system is incident thereon.

The optical system is lens unit 20 and light! It is composed of unit 21. The lens unit 2o includes a lens 30 that is movable along the optical axis l and also movable in a direction perpendicular to the optical axis e (direction perpendicular to the plane of the paper), and two reflective mirrors 40 and 41. We are prepared. The lens unit body also consists of a side plate, a lens unit cover that covers the top of this side plate,
and a lens unit base located at the bottom of the side plate. As will be described later, the lens unit cover has a sliding structure and can be opened and closed.

Additionally, a portion of the lens unit base is provided with air circulation holes (suction holes).

The light source unit 21 includes a light 121a and a reflector 2.
1b. Note that the copying machine of this embodiment has a movable document table. Therefore, the light source unit 21 and the lens unit 1-20 are fixed within the copying machine main body 1.

The photosensitive drum 10, main charger 11, and cleaner unit 16 are integrated as a unit, and are detachably attached to the copying machine main body 1. Similarly, the developing unit 13 is also removable from the copying machine main body 1, and two sets of conveying rollers 60 are provided at the lower right side of the photosensitive drum 10, each of which can be replaced as needed. , 61 and a conveyance path 62 are provided,
Furthermore, a half-moon-shaped paper feed roller 63 is arranged below it. When the paper feed roller 63 rotates once, the top sheet of paper stored in the paper feed cassette 3 is fed and sent to the copying process section by the transport rollers 61, 60 and the transport path 62. A fixing roller 64 is provided on the left side of the photosensitive drum 10. The paper onto which the image has been transferred in the copying process is fixed by the fixing roller 64 and then discharged to the paper discharge tray 4. In this embodiment, the fixing roller 64 also serves as a paper ejection roller. 18 is an exhaust fan.

With the above configuration, when a document is placed and the print switch is operated, the document table moves back and forth and the surface of the document is scanned by the light source unit 21. The reflected light from the original passes through the lens unit 20 and is guided to the exposure point P on the photoreceptor drum 10, where a latent image is formed. Next, the developing unit 13
The latent image formed on the photosensitive drum is visualized by the transfer charger 14, and the image is transferred onto the paper conveyed from the paper feed cassette 3. The paper then passes through a fixing roller 64, where it is fixed and ejected to the paper ejection tray 4. Further, residual toner is removed from the photoreceptor drum 10 by a cleaner unit 16, and electricity is further removed by a charge removal lamp 17, thereby preparing for the next copying cycle.

■Operation Panel FIG. 3 is a diagram showing the configuration of the operation panel. 70 is a print switch (print key), 71 is a clear key for clearing the set number data, 72 and 73 are keys for setting the number of copies during multi-copying, and 74 is a ready lamp indicating a copy ready state. 75 is a display, 76 is an alarm display lamp, 7
7 is an exposure mode setting switch, and 78 is a magnification conversion lever.

The alarm display lamp 76 is a switch that is set to either paper jam or toner. Also, the magnification conversion lever 78
is a switch that sets the magnification in four stages.

■Lens unit FIG. 4 is an external perspective view of the lens unit.

In this lens unit, the lens 30 can be moved to a predetermined position by a lens unit moving mechanism, which will be described later. A visible light-shielding sheet 31 is provided on both sides of the lens 300 between it and the lens unit body 32. This flexible light-shielding sheet 31 is for shielding light other than that passing through the lens (stray light). Flexible light shielding sheet 31
The end portions of the lenses are in contact with the inner wall of the lens unit main body 32, respectively. The visibility light-shielding sheet 31 is arranged so as to meander in an inverted S-shape as a whole within the lens unit main body 32. A first slit 33 is provided between the lens 30 and the first reflecting mirror 40, and a second slit 36 is provided in a portion of the lens unit base 34 facing the second reflecting mirror 41.

The reflected light from the original is first reflected by the first reflection mirror 40,
The light passes through the first slit 33 and enters the lens 30. The light emitted from the lens 30 is reflected downward by the second reflecting mirror 41, passes through the second slit 36 provided in the lens unit base 34, and reaches the exposure point P of the photoreceptor drum 10.

The lens unit moving mechanism of the lens unit J is provided on the lens unit base 34 shown in FIG. This mechanism controls the position of the lens 30 in conjunction with the operation of a magnification conversion lever 78 shown in FIG.

FIG. 5(A) is a diagram showing a lens unit moving mechanism.

The moving lever 100 and the magnification conversion lever 78 are connected via a link mechanism (not shown), that is, by #≠4. This moving lever 100 can move in the directions of arrows A and B in the figure. The moving lever 100 is fixed to a slide lever 101 provided along the side plate of the lens unit body 32. This slide lever 101 is attached to the slide lever support member 102 by arrow A.
and is supported so as to be slidable in the B direction. At the upper end of the slide lever 101, one end of a substantially curved magnification switching arm 104 is rotatably supported by a pin 103. The magnification switching arm 104 is rotatably supported by a pin 105 at approximately the center thereof. A long hole 106 is formed at the other end of the magnification switching arm 104.

A pin 107 is fitted into this elongated hole 106.

The pin 107 is a lens holder 108 that holds the lens 30.
It is provided so that it protrudes toward the front perpendicular to the plane of the paper. The lens holder 108 is slidable on a sliding shaft 109, and both ends of the sliding shaft 109 are fixed to a support plate 110. The support plate 110 is fixed on the lens unit base 34 at a slight angle. A slightly curved elongated guide groove 111 is formed on the left side of the support plate 110 . A roller-shaped guided member 112 is fitted into this guide groove 111 . This guided member 112 is attached to one end of an arm 113. An inverted first lens movable member 114 is rotatably connected to the other end of the arm 113 by a pin 115, and furthermore, this first lens movable member 11
A second lens movable member 11 having an inverted letter shape is located at a position symmetrical to 4.
6 is connected to the first lens movable member 114 by a pin 117. These first lens movable members 1
14 and the second lens movable member 116 are formed with elongated holes 118 and 119, respectively.
Pins 120 and 121 that protrude from the lens 30 perpendicularly to the plane of the paper toward the front are fitted into the lenses 18 and 119, respectively.

The lens 30 is composed of a compound lens body and a case, and the pins 120 and 121 are movable in the direction of the arrow in the figure (in the AB force direction). It is fixed to the lens body.By moving these pins 120 and 121,
The lens body to which the pin is fixed also moves, and lens 3
oThe overall focal length changes. In other words, the magnification can be changed. Lenses with such a configuration are widely used in variable magnification copying machines and have a well-known structure, so a description thereof will be omitted.

A lens movement regulating pin 122 is provided at a position on the opposite side of the lens 3o of the lens holder 108 via a plate spring 126. Further, a lens position regulating plate 123 is attached to the right side of the sliding shaft 109 in parallel with it. There are four recesses 127 on the left side of this lens position regulating plate 123.
A detection switch 12 is provided in each recess.
4 are arranged. As will be described later, the lens position regulating plate 123 is also provided with four recesses on its right side as shown in the figure. As will be described later, the recess provided on the right side is used when handling inch paper.

When the lens movement regulating pin 122 is fitted into the recess 127 and the detection switch 124 is pressed, it is possible to detect that the lens holder 108 is at a predetermined position based on the ON signal of the switch. 4 recesses 127
specifies the position of the lens 30 corresponding to the magnification set by the magnification conversion lever 78. In the example shown in the figure, the lowermost concave portion of the lens position regulating plate 123 corresponds to a magnification of Xi, 24, and the portion above corresponds to ×1 (same magnification). Furthermore, the top corresponds to a magnification of ×0.8, and the uppermost recess corresponds to a magnification of ×0.7.
It corresponds to the magnification of The lens holding base 108 is the sliding shaft 1
The position of the lens 30 is determined by which recess the lens movement regulating pin 122, which is fixed to the lens holder 108 by sliding the lens 30, fits into.

FIG. 5(B) shows the state when the lens holding base 108 has moved upward on the sliding shaft 109 and the lens movement regulating pin 122 has fitted into the recess at the top of the lens position regulating plate 123. There is. When the lens holder 108 moves from the state shown in FIG. 5(8) to the state shown in FIG. 5(B), the lens 30 naturally also moves to the upper left. That is, the lens 30 moves parallel to the sliding axis 109, that is, at an angle with respect to the optical axis l. The reason why the lens 30 tilts and moves in accordance with the magnification is because the document placed on the document table is placed on one side. In other words, if a document is placed on one side, the center line of the document, and therefore the optical axis l, will be shifted between, for example, an 85-size document and an A4-size document.

Detection switch 124 arranged in each recess 127
is for detecting that the lens movement regulating pin 122 is located in a predetermined concave portion, and as will be described later, if this switch is not turned on, the display 75 on the operation panel
I am trying to display an error message. By the action of this detection switch 124, the lens 30 is moved to the magnification conversion lever 7.
You can check whether it is in the correct position corresponding to the magnification set in step 8.

Assume that the moving lever 100 is moved in the direction of arrow A from the state shown in FIG. 5 (A). It is operated on the operation panel. When the moving lever 100 moves in the A direction, the slide lever 101 moves in the arrow A direction. At this time, the magnification switching arm 104 rotates clockwise about the pin 105. As a result, the lens holder 108 is moved to the sliding shaft 10.
9 in the direction of the arrow, and the lens 30 moves accordingly.
also moves in the direction of the arrow. Also, at this time, the guided member 112 is guided along the guide groove 111, and the arm 113
rotates slightly clockwise as a whole. This operation causes the first lens movable member 114 to rotate slightly clockwise around the pin 115, and this rotational motion is transmitted to the second lens movable member 116 via the pin 117, so that the second lens movable member 114 rotates slightly clockwise around the pin 115. The member 116 also rotates slightly counterclockwise about the pin 125. As a result, pin 120°12
1 moves a little in the B direction and the A direction, respectively, and the lens bodies in the lens 30 on which these pins 120 and 121 are provided move in the lens 30 in the arrow B and A directions, respectively. Note that the purpose of moving each lens within the lens 30 by magnification conversion is to adjust the focal length.

Due to the above-described effects, the lens 30 can be felt in a predetermined position. This is because the lens movement regulating pin 122 can produce a click feeling even when the lens position is changed by the temporary spring 126. The operator can bring the lens 30 to the correct position by stopping the magnification conversion lever 78 at the desired magnification display position, that is, by stopping the operation at the desired magnification display position with a click feeling. At this time, since the lens movement regulating pin 122 is fitted into a recess corresponding to the set magnification, the detection switch 124 disposed in the recess is turned on. If this switch is not on, the lens 30 is not set at the correct position, and the control unit displays an error message on the display 75 to warn the operator that the magnification conversion lever 78 is not set at the correct position. do.

In the lens unit moving mechanism described above, the lens position regulating plate 123 used in this embodiment is provided with recesses on the left and right sides into which the lens movement regulating pins 122 fit. ing. The recessed portion 127 shown on the left side of the figure corresponds to AB type originals such as A4 size and 85 size. Further, the recessed portion 128 provided on the right side corresponds to inch-sized originals. When assembling a copying machine, if the model needs to handle AB series paper, the lens position regulating plate 123 is attached so that the AB series recess corresponds to the lens movement regulating pin 122. If the copying machine needs to handle inch paper, the lens position regulating plate 123 is attached so that the inch series recess 128 corresponds to the lens movement regulating pin 122. The only thing that can be used to determine whether the document to be handled is AB system or inch system is the mounting method of this lens position regulating plate 123, and there is no need to change other factors. Therefore, there is an advantage that the assembly work system is extremely improved. Note that the switches 124 are attached to the back side of the lens position regulating plate 123, but it goes without saying that in order to correspond to the inch system, each switch needs to be attached to a recess corresponding to the inch system.

Furthermore, the lens unit moving mechanism of this embodiment does not use a driving device such as a motor, that is, the lens 30 is linked to the operation of the magnification conversion lever 78 operated by the operator. Moreover, the position of the lens 30 is always set at the correct position by the action of the lens position regulating plate 123 and the lens movement IJ3 regulating pin 122. Therefore, there is an advantage that the cost can be significantly reduced by eliminating the need for a motor, a sensor for controlling its movement position, a control unit, etc., and the overall size can be reduced since a motor etc. are not required.

■Blank lamp unit Figure 6 shows a structural diagram of the blank lamp unit.

The blank lamp unit 12, as shown in FIG.
A main charger (charging device) 11 that uniformly charges the surface of the photosensitive drum 10 and a developing unit (developing device) 1
3 along the axial direction of the photoreceptor drum. This blank lamp unit 12 includes a total of five blank lamps 80a to 80, each of which is independently controlled to blink.
It is equipped with e. Each blanking lamp removes unwanted charge on the photoreceptor drum surface. Blank lamps 80a to 80d on the left side of the figure remove unnecessary charges depending on the size of the image to be formed on the surface of the photoreceptor drum. Further, one blank lamp 80e on the right side removes unnecessary charges from the reference position portion of the image. In the figure, the position indicated by P on the photosensitive drum 10 indicates the image reference position (paper edge). The position indicated by ■ indicates the end of the separation belt 81. A separation belt 81 is located at the interval t between p and v. The separation belt 81 is for separating the paper after transfer from the photoreceptor drum. As shown in the figure, this separation belt 8
1 is provided facing one lower end of the photoreceptor drum 10 . The end of the paper 82 is placed on the separation belt 81 in the transfer section. That is, the separation belt 81 separates the paper 8
2, it is interposed between the paper and the photosensitive drum. As a result, the paper 82 after transfer is transferred to the separating belt 8.
1, the photoreceptor drum 10 is forcibly separated from the surface of the photoreceptor drum 10, and is surely peeled off.

Separation belts of this type are already known.

The blank lamp 80e on the right side of the blank lamp unit 12 removes the electric charges in the area on the right side beyond the image reference position P from the end position (2) of the separation belt 81. This prevents toner from adhering to the portion of the photoreceptor drum 10 that is in contact with the separation belt 81. That is, toner does not adhere to the separation belt 81, and therefore, it is possible to prevent the edges of the paper 82 from being stained by toner stains on the separation belt 81.

Each of the blank lamps 80a to 80e removes charge from a predetermined area on the photoreceptor drum, and the blank lamp unit 12 includes a lamp box 83 having a predetermined shape in order to regulate the charge removal area.

The lamp box 83 has blank lamps 80a to 80.
A room is formed to separate the cells 0e into individual sections, and an opening 84 is provided in the portion facing the photoreceptor drum 10 for passing the light from the lamp. The opening 84 in each room is sized to regulate the range of light irradiated by each lamp. As shown, for example, a blank lamp 80d
In the room where the photoreceptor drum 10 is stored, the size of the opening 84 is set so that the irradiation light is shown by hatching in the figure, that is, the area from the position al to the position a5 of the photoreceptor drum 10 is irradiated. Similarly, blank lamp 80c
The size of the opening 84 of the room that houses the blank lamp 80b is set to a size that irradiates the area from position a2 to beyond position a6, and the opening 84 of the room that houses the blank lamp 80b is set to a size that illuminates the area from position a2 to beyond position a6. The size is set to irradiate an area up to a position near the left end of the body drum 10.

The opening 84 of the room that houses the blank lamp 80a at the leftmost end is set to a size that illuminates an area from the position a5 to a position near the left end of the photoreceptor drum 10.

Positions a1 to a6 each indicate the position of the left end of an image formed corresponding to the document size and set magnification. Therefore, for example, the position of the left end of the image to be formed is 3.
1, all the blank lamps 80a to 80d are turned on, and all charges in the area from the position al to the left end of the photoreceptor drum 10 are removed.

Further, when the left end position of the image to be formed is at a3, the blank lamps 80a and 80b are turned on, and the blank lamps 80c and 80d are turned off.

Note that the position a5 indicates the left end image position when the image to be formed is A4 size.

Lamp box 8 that houses the blank lamp 80c
The opening 84 of No. 3 is set to a size that removes the electric charge from the area of the photoreceptor that the separation belt 81 faces. That is, the left end of the light emitted from the blank lamp 80e is
As shown in the figure, the size of the opening 84 is set so that it coincides with the left end portion 1v of the separation belt 81, and so that the area from the position V to the right end of the photosensitive drum is irradiated.

The blank lamps 80a to 80e and lamp box 83 described above are attached to a blank lamp support plate 85. This blank lamp support plate 85 is attached to the frame so as to be parallel to the axis of the photosensitive drum 10. A connector 86 for supplying power to each blank lamp is attached to the right end of the blank lamp support plate 85, and an engaging protrusion 87 for unit positioning that protrudes to the right is provided at a position slightly to the left of the connector 86. ing.

The frame 88 is provided with a main body side connector 89 connected to the connector 86, and further provided with an engagement hole 90 into which the unit positioning retaining protrusion 87 is engaged. One end of the blank lamp unit 12 is aligned by engaging the unit alignment engagement protrusion 87 with the engagement hole 90. When this connection is performed, the connector 86 is connected to the main body connector 8 at the same time.
9, and power is supplied to each blank lamp from the main body side.

FIG. 6(B) shows an external view of the vicinity of the unit positioning engagement protrusion 87 and the retaining hole 90 with which the protrusion is engaged.

After engaging one end of the blank lamp support plate 85 as described above, the blank lamp support plate 8
Tighten and secure the other end of 5.

By the way, if even a small amount of toner adheres to the separation belt 81, the adhered toner will appear as dirt on the paper, so the position of the opening of the lamp box 83 that regulates the irradiation range of the blank lamp 80e is Must be positioned with high precision. That is, the blank lamp unit 12 must be aligned so that the left end of the irradiated light from the blank lamp 80e passing through the opening 84 coincides with the position V of the photoreceptor drum 10. In this case, if the left end of the blank lamp unit 12 is used as a reference for positioning and then the right end of the blank lamp unit is fixed, the length between the left end and position ■ will be long. Furthermore, errors are likely to occur in the position of the opening 84 that irradiates the light from the blank lamp 80e. However, in this embodiment, since the reference position when attaching the blank lamp unit 12 is the right end thereof, errors are less likely to occur, and the position of the opening 84 that irradiates the light of the blank lamp 80e is accurately aligned. It has the advantage of

That is, in the blank lamp unit of this embodiment, an engaging protrusion 87 for unit positioning is provided at the end opposite to the position of the separation belt 81, and this protrusion 87 is connected to the frame 88.
Since positioning is performed by engaging the engagement hole 90 of the unit 12, and then the other end of the unit 12 is fixed with a screw, the position of the opening 84 that irradiates the light of the blank lamp 80e is This has the advantage of being correctly aligned without any errors.

In the above embodiment, the engaging protrusion 87 was provided on the blank lamp unit side and the engaging hole 90 was provided on the frame side for positioning, but the reverse may be used.

(2) Optical device cleaning structure FIGS. 7 to 9 are diagrams for explaining the optical device cleaning structure.

In the electrophotographic copying machine of this embodiment, the portion of the upper plate of the electrophotographic copying machine body facing the light source unit is made freely removable, and the lens unit body portion opposite to this portion is also made freely removable.

FIG. 7 is a diagram showing the structure of the upper plate of the copying machine main body of this embodiment. The copying machine main body top plate 150 has covers 150a and 150b.
, 150c, each part is removable. It is attached using screws and can be easily removed by removing the screws. Note that in order to remove the copying machine main body top plate 150,
This is performed with the document cover 2 open and each document placement table removed.

Among the removable covers 150a to 150C constituting the upper plate 150 of the copying machine main body, the cover 150 located in the center
b is located directly above the light source unit 21, and faces the upper left side of the lens unit 20. As mentioned later,
A cover that can be opened and closed is provided at the upper left side and the upper right side of the lens unit 20.

Due to the above configuration, the document cover 2 is opened and the entire document placement table is removed.
When the cover 150b located at the center is removed, the light source unit 21 is placed directly below it, so the reflector 21b and the light source 21a can be easily cleaned from above. It is also possible to remove this light source unit 21.

FIG. 8 is a structural diagram of the lens unit.

As described above, the lens unit 20 includes a lens 30 and two reflective mirrors 40 and 41, which are housed within the lens unit body 32. Lens unit body 32
consists of a side plate 35, a lens unit cover 43 covering the top of the side plate, and a lens unit base 3 located at the bottom of the side plate.
It consists of 4.

A hook portion 44 is formed on the side plate 42 and projects upward, and the lens unit cover 43 is always hooked onto this hook portion 44 as will be described later.

FIG. 9 is a diagram for explaining the opening/closing mechanism of the lens unit cover 43, and FIG. 9(A) is a front view of the main part.

Figure (B) is a plan view of the main part.

A hook portion 44 formed on the side plate of the lens unit body 32 so as to protrude upward includes hook projections 44a and 44b at its front and rear ends. Also,
As shown in FIG. 4B, the lens unit cover 43 has protrusions 43a and 43b that protrude toward the front in the axial direction of the photoreceptor drum.
It is equipped with The hooking protrusion 44a is engaged with the left end a1 of the protrusion 43a of the lens unit cover 43. Further, the hooking protrusion 44b is engaged with the right end a2 of the right protrusion 43b of the lens unit cover 43. The lens unit cover 43 is divided into a left side and a right side at point Q in the figure, and the respective ends of the left lens unit cover and the right lens unit cover meet this Q point.
They overlap at points. The hook of the side plate 35 is the part 44.
Cutout portions 35a and 35b are formed on both sides. The length β of the notches 35a and 35b is sufficiently longer than the respective lengths of the protrusions 44a and 44b, and the depth h is such that the protrusions 44a and 44b are sufficiently long.
The size is set to such an extent that the lower ends of 44a and 44b do not touch each other.

Next, the opening/closing operation of this lens unit cover will be explained.

Under normal conditions, the side plate 35 is hooked onto the protrusions 44a and 4.
4b are protrusions 43a and 43b of the lens unit cover 43
are locked to the respective ends al and a2. Therefore, the lens unit cover 43 cannot be moved in the directions of arrows B and C. However, as shown in FIG. 5A, when the part of the left lens unit cover 43 facing the notch 35a of the side plate 3s is pressed in the direction of arrow A, the part facing the notch 35a is pressed at two points. Bend as shown by the chain line. When the pressing force in the six directions of the arrows is increased to the extent that the hooking protrusion 44a is unlatched, the hooking protrusion 44a disengages the protrusion 43a, and the left lens unit cover 43 is It becomes possible to move in the direction of arrow B. That is, by moving in the direction of arrow B while pressing in the direction of A, the lens unit cover 43 can be moved in the direction of arrow B.

This allows the lens unit cover 43 on the left side of the lens unit main body 32 to be opened.

Similarly, the right lens unit force bar 43 can also be opened in the direction of arrow C.

As shown in FIG. 7, a light source unit 21 is arranged at the upper left side of the lens unit 20. Also, a cover 15 of the upper plate of the copying machine body located above the light source unit 21
0b is removable. Therefore, this cover 150
By removing b and further removing the light source unit 21, a force in the direction of arrow A shown in FIG. 9 can be applied to the lens unit 20 from above. That is, by removing the cover 150b, the light source unit 21
By also removing the light source unit 21, the lens unit cover 43 on the left side of the lens unit 20 can be opened and the inside of the lens unit 20 can be cleaned. It is sufficient to clean the inside of the lens unit cover by simply removing the left cover, but in this embodiment, as shown in FIG. 7, the right cover 150c of the top plate of the copying machine body can also be removed. There is. Therefore, remove this cover 1500 and move the lens unit cover 43 on the right side of the lens unit 20 to the arrow C.
(See FIG. 9), and the cleaning unit force bar can be cleaned more thoroughly (especially on the right side).

As described above, in this embodiment, by making the part of the upper plate of the copier main body that faces the light source unit removable, the light source unit 21 can be easily cleaned, and the light source unit 21 can be easily cleaned. By removing it, the lens unit cover on the left side of the lens unit 20 can also be opened and closed. That is, cleaning inside the lens unit 20 (including cleaning of the lens) can be easily performed. Furthermore, in this embodiment, the upper plate of the copying machine body located above the right side of the lens unit 20 can be removed, and the lens unit cover 43 on the right side can be opened and closed. By removing the lens unit 1500 and opening the right lens unit cover 43, the inside of the lens unit 20 (especially the right side) can be easily cleaned.

■Exhaust structure In the electrophotographic copying machine of this embodiment, air containing ozone and developer generated around the photoreceptor drum, and heat are exhausted to the outside from the exhaust fan through the lens unit. .

FIG. 10 shows how the air containing ozone and developer generated around the photosensitive drum 10 and the heat generated from the fixing roller 64 are exhausted from the lens unit base 34 that constitutes the bottom plate of the lens unit 20. A plurality of suction holes (air circulation holes) 34a are formed in the side plate 35.
An exhaust hole 4 is provided in a portion located below the first reflecting mirror 40.
2a is formed. FIG. 11 is a view of the mirror unit base 34 viewed from below. Note that 36 directs the light reflected from the second reflecting mirror 41 to an exposure point P of the photosensitive drum 10.
As described above, the suction holes 34a are provided at multiple locations on the lens unit base 43, and the exhaust holes 42a are provided in the portion of the side plate 35 located below the first reflecting mirror 40. , photosensitive drum 10
ozone generated around the main charger 11, air containing developer scattered around the photoreceptor drum, and heat generated from the fixing roller 64 are absorbed into the lens unit 20 through the suction hole 34a. The lens unit 20
Exhaust outside. The exhausted air is further discharged to the outside of the copying machine main body 1 by the exhaust fan 18. Because of this exhaust structure, the lens unit 2
The inside of the lens unit 20 can be effectively used as an exhaust path, and since the exhaust hole for the air sucked into the lens unit 20 is located below the first reflecting mirror 40, the air does not move upward into the unit. All lens unit base 3
4 and is discharged to the outside of the unit from the exhaust hole 42a. Therefore, it is possible to prevent the reflective mirrors 40, 41 and the lens 30 from becoming dirty due to air entering the lens unit 20.

■ Lens position warning display control (see Figure 12) In the electrophotographic copying machine of this embodiment, as described above, the position of the lens 30 is controlled by a mechanism that is linked to the operation of the magnification conversion lever 78 without using a motor or the like. Is going. In addition, in order to stop the lens 30 at the correct position when the magnification conversion lever 78 is operated, the lens position regulating plate 1 is attached as shown in FIG. 5(A).
23, and a recess 127 corresponding to each magnification is provided on the side of the lens position regulating plate 123. When the lens movement regulating pin 122 provided on the lens holder 108 that holds the lens 30 is correctly fitted into the recess 127, the correct stopping position of the lens 30 is guaranteed. However, if the stop position of the magnification conversion lever 78 is not correct, the lens movement regulating pin 122 will move into the recess 127 of the lens position regulating plate 123.
There may be cases where it does not fit accurately. In that case, accurate image formation cannot be performed because the position of the lens 30 is incorrect.

Therefore, in the electrophotographic copying machine of this embodiment, the detection switch 124 is arranged in each recess 127 of the lens position regulating plate 123, as described above, and the lens movement regulating bin 123 is provided with a detection switch 124.
When the switch 124 is properly fitted into the recess 127, the switch 124 at that position is turned on. FIG. 12 shows the detection switch 12 when the magnification conversion lever 78 is operated.
4 is a flowchart showing the operation when the switch 4 is not turned on. The electrophotographic copying machine of this embodiment uses a microcomputer as a control section, and all output signals from various switches and sensors are input to this microcomputer.

In FIG. 12, if all of the detection switches 124 are in the OFF state when the magnification conversion lever 78 is operated, it is first determined in step n1 whether or not a copying operation is in progress at that time. If copying is not in progress, step n4
Then, an error display (E display) is displayed on the display 75 (see FIG. 3). Also, if copying is in progress, proceed from n1 to n2,
Here, the next copy operation instruction flag F is reset.

Further, at n3, the process waits until the copy paper is ejected, and then advances to n4, where an error is displayed. If an error message is displayed at n4, the operator can know at that point that the magnification conversion lever 78 is not set at the correct position.

By the above-described operation, it is possible to easily recognize whether the lens 30 is set at the correct position, giving peace of mind to the operator and preventing copy mistakes and the like.

(1) Scanning speed changing mechanism: 0 for p 2 (1) 11 W Figure 13 is a diagram showing a lens unit moving mechanism including a part of the scanning speed changing mechanism. FIG. 13 shows the lens moving mechanism shown in FIG. 5(A) with omitted parts added.

A rank gear 201 is formed in a part of the slide lever 101. A pinyon gear 202 meshes with this rack gear 201. The hinge gear 202 is fixed to one end of a rotating shaft 203, and a selection member rotating gear 204 is fixed to the other end of the rotating shaft 203.

When the moving lever 100 moves in the direction of arrow A or B,
Rank gear 201 provided on slide lever 101 also moves in the same manner. With this move, Binyongya 202
rotates, and the rotating shafts 203 and 204 rotate.

FIG. 14 is a side sectional view showing the main parts of the scanning speed changing mechanism.

The input shaft 210 is connected to the rear frame 226 via a bearing 231.
is pivoted. A transmission gear 229 is fixed to the end of the input shaft 210 protruding from the rear frame 226.

This transmission gear 229 meshes with a transmission gear (not shown), receives driving force from the same motor (not shown), and rotates together with the input shaft 210. Both coupling arms 213 and one of the electromagnetic clutches 214 are fixed to the input shaft 210. On the other hand, the electromagnetic clutch 214 fixes an input shaft gear 215 that is rotatable to the input shaft 210.

When the electromagnetic clutch 214 is driven, the input shaft gear 215 is fixed to the input shaft 210 via the electromagnetic clutch 214 and rotates together with the input shaft 210. Input shaft gear 215
Four input shaft speed change gears 219a to 219d supported by shafts 222a to 222d are meshed with each other. However, the 14th
In the figure, shafts 222b-d and input shaft transmission gear 219
b to d are omitted. Furthermore, output shaft speed change gears 220a to 220d (output shaft speed change gears 220b to a are omitted in the figure) are pivotally supported on the shafts 222a to d.

Input shaft speed change gears 219a-d and output shaft speed change gears 220a
Rotation transmitting members 221a-
d (rotation transmission members 221b-d are omitted in the figure) are fixed. Rotation transmission members 221a-d
The input shaft speed change gear 21 is connected by a spring provided inside.
9a to 9d are spaced apart from the output shaft transmission gears 220a to 220d, respectively.

Output shaft gears 220a-d mesh with output shaft gear 218 fixed to output shaft 212.

Further, the output shaft gear 218 meshes with the gear 224, and the connecting gear 213 fixed to the input shaft 210 meshes with the rear frame 224.
6 through a bearing 234, and meshes with a connecting gear 216 that is rotatably supported by a reversing output shaft 211 that is rotatably supported by a bearing 234. An electromagnetic clutch 217 is provided on the reversing output shaft 211, and the electromagnetic clutch 217 is fixed to the coupling gear 216 on one side and to the reversing output shaft 211 on the other side. When the electromagnetic clutch 217 is driven, the connecting gear 216 is fixed to the reversing output shaft 211. Since the connecting gear 216 meshes with the connecting gear 213, the input shaft 2
It is rotating with 10.

Therefore, when the electromagnetic clutch 217 is driven, the reversing output shaft 211 rotates together with the connecting gear 216. The reversing output shaft 211 has a gear 225 fixed at the end exposed from the front frame 227, and this gear 225 rotates together with the reversing output shaft 211. A gear 224 meshing with the output shaft gear 218 and a gear 2 fixed to the reversing output shaft 211
25 are both engaged with a drive gear (not shown), and are moved to the document table (not shown) by the rotation of this drive gear.

A control plate 241, which is the speed ratio selection means of the present invention, is provided between the internal frame 228 and the input shaft speed change gears 219a to 219d. The control plate 241 engages with the shafts 222a-b at elongated holes 243 and 244, as shown in FIG. Input shaft transmission gears 219a--d journaled on shafts 222a-d all have the same number of teeth, and shafts 222a-d are located concentrically with respect to output shaft gear 215. For this reason, the control board 241 is connected to the input shaft gear 2.
15, that is, the center position of the input shaft 210, as a fulcrum.

A rack gear 245 is formed in a part of the control board 241. This rack gear 245 is formed in a part of a circular arc centered on the rotation axis of the control plate 241. The rack gear 245 meshes with a selection member rotation gear 204 fixed to the rotation shaft 203. Therefore, moving lever 1
When the selection member rotary gear 204 rotates in the direction of arrow O or P shown in FIG. 15 by moving in the direction of arrow A or B shown in FIG. 13, the control plate 241 moves in the direction of arrow Q or R shown in the same figure. Rotate.

The control plate 241 is formed with protrusions 242a-d.

The convex portions 242a to 242d are formed at positions where they can come into contact with each of the input shaft transmission gears 219a to 219d. When the control plate 241 rotates in the arrow Q or R direction due to the rotation of the selection member rotating gear 204 in the arrow 0 or P direction, the convex portion 242
Any one of the input shaft transmission gears 219 a to d contacts the input shaft transmission gears 219 a to 219 a to d.

Each of the convex portions 242a to 242d is the input shaft speed change gear 219ax.
d is determined by the rotation angle of the control plate.

FIGS. 16(A) and 16(B) are diagrams showing the operation of the scanning speed changing mechanism.

As shown in FIG. 16(A), the convex portion 2 of the control Fi 241
42a is not in contact with the input shaft speed change gear 219a, the input shaft speed change gear 219a and the output shaft speed change gear 220a are separated by the elastic force of the rotation transmission member 221a. Therefore, the rotation of the output shaft speed change gear 219a is not transmitted to the output shaft speed change gear 220a.

When the control plate 241 rotates and the convex portion 242a contacts the input shaft speed change gear 219a as shown in FIG. 16(B), the rotation transmission member 221a is pressed in the direction of arrow S, and the input shaft speed change gear 219a The transmission gear 220a is connected to the transmission gear 220a. As a result, the rotation of the input shaft speed change gear 219a is transmitted to the output shaft speed change gear 220a. The above operation is the same for the other convex portions 242b to 242d.

As shown in FIG. 15, output shaft transmission gears 220a-d
The number of teeth is different from each other. That is, each of the output shaft transmission gears 220a to 220d is ×0.7, ×
They correspond to scanning speeds at magnifications of 1 (same magnification), Xl, 24, and ×0.8, respectively. On the other hand, the rotation angle of the selection member rotary gear 204 in the direction of arrow O or P is determined by the movement lever 10.
0 in the direction of arrow A or B. The amount of movement of the moving lever 100 is specified for each selected copying magnification, and the rotation angle of the selection member rotating gear 204 is also specified for each selected copying magnification. Therefore, the control plate 241 rotates at different rotation angles for each selected copying magnification. The formation positions of the convex portions 242 a - d on the control board 241 are determined in consideration of the above, and when the magnification of ×0.7 is selected, the convex portions 242 a are aligned with the input shaft transmission gear 219 .
a, and when the magnification of ×1 (equal magnification) is selected, the convex portion 242b contacts the input shaft speed change gear 219b, and the magnification of ×1
．． When a magnification of 24 is selected, the convex portion 242c contacts the input shaft speed change gear 219c, and when a magnification of x0.8 is selected, the convex portion 242d contacts the input shaft speed change gear 219d.

With the above configuration, the movable lever 10 when selecting the copy magnification
The movement of 0 is transmitted to the control plate 241 by the rank gear 201, pinyon gear 206, rotating shaft 203, and selection member rotating gear 204. The control plate 241 rotates at a specified rotation angle for each selected copying magnification, and one of the convex portions 242a-d corresponding to the copying magnification comes into contact with the input shaft speed change gear 219axd. As a result, the output shaft speed change gear 22Qa corresponding to the scanning speed of the selected copying magnification
-d, the input shaft speed change gears 219a to 219d are connected to one of them.

When the electromagnetic clutch 214 is driven in this state during the copying machine process, the rotation of the input shaft 210 is transmitted to the output shaft transmission gears 220a-d via the input shaft gear 215 and the input shaft transmission gears 219a-d, and the selected The document table 2 moves at a scanning speed corresponding to the copy magnification set. When returning the document table 2 after the copying process is completed, use the electromagnetic clutch 2.
14 is stopped, and the electromagnetic clutch 217 is driven. Accordingly, the rotation of the output shaft 210 causes the reversing output shaft 211 to reverse through the coupling gears 213 and 216. This reversing operation of the reversing output shaft 211 is transmitted to the driving gear via the gear 225, and the document table 2 moves in the opposite direction to the scanning direction. Since the return operation of document table 2 does not affect the copying process, regardless of the selected copy magnification,
Move at a fixed speed.

As described above, according to this embodiment, the lens position is switched and the scanning speed is switched by manual scanning when copying magnification is selected, and the scanning speed switching operation is performed by manual operation. Therefore, a drive device is not required for switching the scanning speed, and cost and space savings can be realized.

(g1 Effects of the Invention According to this invention, the rotation of the input shaft is transmitted to the output shaft through the connection of the input shaft speed change gear and the output shaft speed change gear by the rotation transmission member.The input shaft speed change gear and the output shaft speed change gear are The output shaft transmission gears are provided at predetermined intervals, and the output shaft transmission gears are formed to have different numbers of teeth.Therefore, by selecting the rotation transmission member to be enabled by the transmission ratio selection member, the output shaft transmission gear is connected to the input shaft transmission gear. The number of teeth of the gear can be selected, and the rotational speed of the output shaft can be easily switched.At this time, the operating force required for the switching operation is only the force that operates the gear ratio selection member, The load acting on the operating force of the gear ratio selection member is the force that operates one rotation transmission member.Therefore, the operating force when switching the scanning speed is extremely small, and no special driving force is required, making manual operation possible. and cost reduction.

Furthermore, it is possible to similarly reduce the operation noise generated due to the large size 5t not operating during the scanning speed switching operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an external view of an electrophotographic copying machine according to an embodiment of the present invention. FIG. 2 shows the structure of the electrophotographic copying machine described above. FIG. 3 shows a configuration diagram of the operation panel of the electrophotographic copying machine. FIG. 4 shows an external perspective view of the lens unit of the electrophotographic copying machine. FIGS. 5(A) and 5(B) are plan views of the lens unit moving mechanism and diagrams showing the operating state. FIGS. 6(A) and 6(B) show a structural diagram and a perspective view of the main parts of the blank lamp unit. FIG. 7 shows a configuration diagram of the upper plate of the main body of the electrophotographic copying machine. FIG. 8 shows a front structural view of the lens unit. FIGS. 9(A) and 9(B) show a front view and a plan view of the main parts of the lens unit for explaining the lens unit cover opening/closing mechanism. FIG. 10 is a diagram for explaining the exhaust structure of the electrophotographic copying machine. FIG. 11 shows a perspective view of the mirror unit base viewed from below. FIG. 12 is a flowchart showing the operation of the control section when the lens position is incorrect. Fig. 13 is a diagram showing a magnification conversion mechanism including a part of the scanning speed changing mechanism of the same variable magnification copying machine, Fig. 14 is a side cross-sectional view showing the main parts of the scanning speed changing mechanism, and Fig. 15 is the same scanning speed changing mechanism. A front view showing a part of the transmission mechanism, and FIGS. 16(A) and 16(B) are diagrams showing the operation of the scanning speed changing mechanism. 210-input shaft, 212-output shaft, 215-input shaft gear, 218-output shaft gear, 219a-
d-input shaft speed change gear, 220a-d-output shaft speed change gear, 221 a-d-rotation transmission member, 241-control board.

Claims (1)

[Claims] (1) In the scanning speed changing mechanism of a variable magnification copying machine that changes the document scanning speed of the optical system according to the selected copying magnification, an input shaft gear fixed to the input shaft and a predetermined number of gears meshing with this input shaft gear are used. an input shaft speed change gear, an output shaft gear fixed to the output shaft, and the predetermined number of output shaft speed change gears that mesh with the output shaft gear and are located coaxially with the input shaft speed change gear, and each have a different number of teeth; The predetermined number of rotation transmission members transmitting the rotation of each of the input shaft transmission gears to the opposing output shaft transmission gear, and a transmission ratio selection member that selectively enables one of the rotation transmission members. Scanning speed change mechanism for variable magnification copying machine.