JPH0469931B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application 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) Prior Art In a variable magnification copying machine that enlarges or reduces the size of an image on a document and copies it, the position of the lens is moved between the document and the photosensitive drum to adjust the size of the image in the scanning direction of the optical system. Stretch or shrink the size in the vertical 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 system disclosed in Japanese Patent Application Laid-Open No. 165633/1983, a plurality of planetary gears each having a different number of teeth are provided to mesh with the input shaft gear, and the output is achieved by switching the planetary gear that meshes with the output shaft gear. The rotation speed of the shaft gear is changed. In addition, when switching the planetary gear that meshes 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 that is linked to a manually operated control lever. It is controlled by changing the contact position between the provided control pawl and the pawl provided on the spring clutch.
With the above configuration, the configuration of the transmission gear is simplified, and the scanning speed can 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 each time the scanning speed is changed, and the control provided on the claw and arm of the spring clutch rotates. The problem was that it made a lot of 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 a large main motor.

An object of this invention is to switch the rotational speed of the output shaft by selectively connecting a gear that meshes with the input shaft gear and a gear that meshes with the output shaft gear, thereby reducing the size of the device and manually switching the scanning speed. It is an object of the present invention to provide a scanning speed changing mechanism for a variable magnification copying machine, which can realize the above, prevent the generation of scanning speed switching noise, and reduce the cost by reducing the torque of the motor.

(d) Means for Solving the Problems The scanning speed changing mechanism for a variable magnification copying machine of 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. located coaxially with
Select one of the predetermined number of rotation transmission members and rotation transmission members that transmit the respective rotations of the predetermined number of output shaft transmission gears and input shaft transmission gears to the opposing output shaft transmission gears, each having a different number of teeth. The present invention is characterized by comprising a gear ratio selection member that makes the gear ratio effective.

(e) Effect In the scanning speed change mechanism of the variable magnification copying machine of the present invention, the 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 transmission gears to rotate. An output shaft gear is fixed to the output shaft, and a predetermined number of output shaft gears are meshed 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 input 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 activated by a transmission ratio selection member. be done. 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 gear 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 Figure 6) (See Figures 7 to 9) Exhaust structure (See Figures 10 and 11) Lens position warning display (See Figure 12) Operation speed change mechanism (See Figures 13 to 16) Description of the embodiment External appearance FIG. 1 is an external view of an electrophotographic copying machine which is an embodiment of the present invention. A document cover 2 is supported at the upper part of the copying machine main body 1 at its rear end so as to be openable and closable. Further, a paper feed cassette 3 is attached to the copying machine main body 1 at the bottom. The 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 fed from the paper feed cassette 3 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.

Overall Configuration FIG. 2 is a diagram showing the overall configuration of the copying machine.

A photosensitive drum 10 that rotates in the direction of the arrow in the figure is arranged approximately in the center of the copying machine main body 1. As shown in FIG.
A main charger 11, a blank lamp unit 12, a developing unit 13, a transfer charger 14, a pair of peeling rollers 15, a cleaner unit 16, and a charge eliminating lamp 17 are provided around the photosensitive drum 10 in this order. A point P in the diagram of the photosensitive drum 10 represents an exposure point, and light from the optical system is incident thereon.

The optical system is composed of a lens unit 20 and a light source unit 21. Lens unit 20
includes a lens 30 that is movable along the optical axis l and also movable in a direction perpendicular to the optical axis l (direction perpendicular to the plane of the paper), two reflective mirrors 40,
41. The lens unit main body is composed of a side plate, a lens unit cover that covers the upper part of the 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, air circulation holes (suction holes) are formed in a part of the lens unit base.

The light source unit 21 is composed of a light source 21a and a reflector 21b. Note that the copying machine of this embodiment has a movable document table. For this reason, the light source unit 21 and lens unit 20 are fixed within the copying machine main body 1.

The photosensitive drum 10 and the main charger 1
1 and a cleaner unit 16 are integrated as a unit and are detachably attached to the main body 1 of the copying machine. Similarly, the developing unit 13 is also removable from the copying machine main body 1, and each unit can be replaced as necessary.

Two sets of conveyance rollers 60 and 61 and a conveyance path 62 are provided below the right side of the photoreceptor drum 10, and a half-moon-shaped paper feed roller 63 is further below the conveyance rollers 60 and 61.
is installed. When the paper feed roller 63 rotates once, the top sheet of paper stored in the paper feed cassette 3 is fed, and the paper is transferred to the transport rollers 61, 60.
The paper is then sent to the copying process section via 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 a 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 set 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 photosensitive 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 the fixing roller 64
The image is fixed there, and then the paper is 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 configuration diagram of the operation panel. 70 is a print switch (print key), 71 is a clear key to clear the set number data, 72, 73
is the copy number setting key during multi-copying, 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 indicates paper jams, toner shortages, etc., and the exposure mode setting switch 7
7 is automatic exposure, standard mode, dark mode,
This is a switch to set it to one of the light modes. Further, 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. Flexible light-shielding sheets 31 are provided on both sides of the lens 30 and between them 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). The ends of the flexible light-shielding sheet 31 are in contact with the inner wall of the lens unit body 32, respectively. The flexible 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 first passes through 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 the second
The second slit 3 provided in the lens unit base 34 is reflected downward by the reflecting mirror 41.
6 and reaches the exposure point P of the photoreceptor drum 10.

Structure of Lens Unit Moving Mechanism The lens unit moving mechanism 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. 5A is a diagram showing the 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 being connected to both ends of the link so that the respective levers can move in the same direction. 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 main body 32. This slide lever 101 is attached to the slide lever support member 102 by arrows A and B.
It is supported so that it can slide freely in the direction. One end of a substantially square-shaped magnification switching arm 104 is rotatably supported at the upper end of the slide lever 101 by a pin 103. The magnification switching arm 104 has a pin 10 at its approximate center.
5 is rotatably supported. 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 provided on a lens holder 108 that holds the lens 30 so as to protrude toward the front side perpendicular to the plane of the paper. Lens holding stand 1
08 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. Support plate 11
On the left side of 0 is a slightly curved elongated guide groove 11.
1 is formed. 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 L-shaped first lens movable member 114 is attached to the pin 1 at the other end of the arm 113.
The first lens movable member 114 is rotatably connected to the first lens movable member 114 by a reverse L.
The letter-shaped second movable lens member 116
The lens movable member 114 is connected to the lens movable member 114 by a pin 117. Elongated holes 118 and 119 are formed at the tips of the first lens movable member 114 and the second lens movable member 116, respectively, and the lens 3 is inserted into these elongated holes 118 and 119.
Pin 12 drilled on the front side perpendicular to the paper surface in 0
0 and 121 are inserted respectively.

The lens 30 is composed of a compound lens body and a case, and the pins 120 and 121 are movable in the arrow direction (AB direction) in the figure. Pins 120 and 121 are each fixed to a predetermined lens body of a compound lens body within the case. When the pins 120 and 121 move, the lens body to which the pins are fixed also moves, and the focal length of the entire lens 30 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 30 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.
are provided, and a detection switch 124 is further provided in each of the recesses. 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.

The lens movement regulating pin 122 is in this recess 1.
27 and press down the detection switch 124, it is possible to detect that the lens holder 108 is at a predetermined position based on the ON signal of the switch. The four recesses 127 specify 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 part of the lens position regulating plate 123 corresponds to a magnification of ×1.24, and the one above corresponds to ×1 (same magnification).
corresponds to Furthermore, the top corresponds to a magnification of ×0.8, and the uppermost recess corresponds to a magnification of ×0.7. The position of the lens 30 is determined by which recess the lens movement regulating pin 122 fixed to the lens holder 108 is fitted into when the lens holder 108 slides on the sliding shaft 109.

In FIG. 5B, the lens holder 108 is attached to the sliding shaft 10.
9 upward and remove the lens movement regulating pin 12.
2 shows the state when the lens position regulating plate 123 is fitted into the uppermost concave portion. When the lens holder 108 moves from the state shown in FIG. 5A to the state shown in FIG. 5B, 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. In this way, lens 30
The reason why the image is tilted and moved according to the magnification is because the document placed on the document table is placed with one side referenced. In other words, if the original is placed on one side, the center line of the original, and thus the optical axis l, will be shifted between, for example, a B5-sized original and an A4-sized original.

The detection switch 124 disposed in each recess 127 is for detecting that the lens movement regulating pin 122 is positioned in a predetermined recess.As will be described later, if this switch is not turned on, the operation panel An error message is displayed on the display 75. By the action of the detection switch 124, it can be confirmed whether the lens 30 is at the correct position corresponding to the magnification set by the magnification conversion lever 78.

Function of the lens unit moving mechanism From the state shown in FIG. 5A, the moving lever 100
Suppose that it moves in the direction of arrow A. The magnification conversion lever 78 on the operation panel is at the position of magnification x 1.24 in the state shown in FIG. 5A. Moving lever 10
To move 0 in the direction of arrow A, the operator operates the magnification conversion lever 78 to the left from the x1.24 position. The moving lever 100 is A
When the slide lever 101 moves in the direction of arrow A, the slide lever 101 moves in the direction of arrow A. Magnification switching arm 104
At this time, it rotates clockwise around pin 105. As a result, the lens holder 108 moves in the direction of arrow D along the sliding shaft 109, and the lens 30 also moves in the direction of arrow D accordingly. At this time, the guided member 112 is guided along the guide groove 111, and the arm 113 as a whole rotates slightly clockwise. This action causes the first
The second lens movable member 114 rotates slightly clockwise around a pin 115, and this rotational movement is transmitted to the second lens movable member 116 via a pin 117.
This second lens movable member 11
6 also rotates slightly counterclockwise around the pin 125. As a result, the pins 120 and 121 move slightly in the B direction and the A direction, respectively, and the lens body within the lens 30 on which these pins 120 and 121 are provided moves within 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.

The above action moves the lens 30 to a predetermined position. The operator can feel a click when the magnification conversion lever 78 is operated to the x0.7 display position. This is because the lens movement regulating pin 122 is pressed in the direction of the lens position regulating plate 123 by the leaf spring 126. Of course, when operating the magnification conversion lever 78 to the left, a clicking sensation can be felt between the ×1 display position and the ×0.8 display position. The operator can hold the lens 30 at 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, the lens movement regulating pin 12
2 fits into the recess corresponding to the set magnification, so 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.

Structure of lens position regulating plate In the above lens unit moving mechanism, the lens position regulating plate 123 used in this example
Recesses into which the lens movement regulating pins 123 fit are provided on the left and right sides, respectively. The recessed portion 127 shown on the left side of the figure corresponds to AB type originals such as A4 size and B5 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 type paper, the lens position regulating plate 123 is installed so that the AB series recess corresponds to the lens movement regulating pin 122. In addition, if it is necessary to use a copying machine that handles inch paper, the lens position regulating plate 123 should be adjusted so that the inch series concave portion 128 is connected to the lens movement regulating pin 12.
Install it so that it corresponds to 2. Handling manuscripts
Whether to use the AB system or the inch system can be determined only by the method of attaching the 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. 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 magnification conversion lever 7 is operated by an operator.
The lens 30 is linked to the operation of 8. Moreover, the position of the lens 30 is determined by the lens position regulating plate 123.
By the action of the lens movement restriction 122, the lens is always set at the correct position. 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 FIG. 6 shows a structural diagram of the blank lamp unit.

As shown in FIG. 2, the blank lamp unit 12 is arranged between a main charger (charging device) 11 that uniformly charges the surface of the photosensitive drum 10 and a developing unit (developing device) 13. It is provided along the axial direction. This blank lamp unit 12 has a total of five blank lamps 80, each of which is independently controlled to blink.
It is equipped with a to 80e. Each blanking lamp removes unwanted charge on the photoreceptor drum surface.
The blank lamps 80a to 80d on the left side of the figure are
To remove unnecessary charges depending on the size of an image to be formed on the surface of a photoreceptor drum. Also,
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 V indicates the end of the separation belt 81. A separation belt 81 is located at the interval t of P-V. The separation belt 81 is for separating the paper after transfer from the photoreceptor drum. As shown in the figure, this separation belt 81 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 is interposed between the paper and the photosensitive drum at one end of the paper 82 . As a result, the paper 82 after the transfer is forced onto the photoreceptor drum 1 by the separation belt 81.
It is separated from the surface of 0 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 charge in the area on the right side from the end position V of the separation belt 81 beyond the image reference position P. 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 due to toner stains on the separation belt 81.

Each of the blank lamps 80a to 80e removes charge from a predetermined area on the photosensitive drum, and the blank lamp unit 12 is provided with a lamp box 83 having a predetermined shape in order to restrict the charge removal area.

The lamp box 83 forms a room that separates each of the blank lamps 80a to 80e, and is further provided with an opening 84 in a portion facing the photosensitive drum 10 through which light from the lamps passes. The opening 84 of each room is set to a size to regulate the range of light irradiated by each lamp. As shown in the figure, for example, in a room housing a blank lamp 80d, the size of the opening 84 is such that the irradiation light is shown by hatching in the figure, that is, the irradiation light is emitted from the position a1 to the position a5 of the photoreceptor drum 10. The size is set to Similarly, the size of the opening 84 of the room that houses the blank lamp 80c is set to a size that irradiates the area from the a2 position to the area beyond the a6 position, and the blank lamp 80b
The opening 84 of the room that houses the photoreceptor is set to a size that illuminates an area from the position a3 to a position near the left end of the photoreceptor drum 10. The opening 84 of the room that accommodates the blank lamp 80a at the leftmost end is located at the photosensitive drum 1 from the position a5.
The size is set to irradiate an area up to a position near the left end of 0.

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, if the left end of the image to be formed is at position a1, all blank lamps 80a to 80d are turned on, and all charges in the area from position a1 to the left end of photoreceptor drum 10 are removed. will be done. Further, when the left end position of the image to be formed is at a3, the blank lamp 80
a and 80b are turned on, and the blank lamp 80
c, 80d are turned off. Note that the position a5 indicates the image position at the left end when the image to be formed is A4 size.

The opening 84 of the lamp box 83 that accommodates the blank lamp 80e 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 irradiated from the blank lamp 80e is irradiated so that it coincides with the left end position V of the separation belt 81 as shown in the figure, and the area from the position V to the right end of the photoreceptor drum is irradiated. The size of the opening 84 is set so that

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 has a main body side connector 8 connected to the connector 86.
9, and an engagement hole 90 into which the unit positioning engagement protrusion 87 engages. 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 engagement is performed, the connector 86 is connected to the main body connector 89 at the same time.
power is supplied to each blank lamp from the main unit.

Figure 6B shows the engaging protrusion 8 for unit positioning.
7 and an external view of the vicinity of an engagement hole 90 in which the protrusion is engaged.

After one end of the blank lamp support plate 85 is engaged as described above, the other end of the blank lamp support plate 85 is tightened and fixed with the screw 91.

By the way, if even a small amount of toner adheres to the separation belt 81, the adhered toner becomes dirt and appears 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 photosensitive drum 10. In this case, if the left end of the blank lamp unit 12 is used as a reference for alignment and then the right end of the blank lamp unit is fixed, the length between the left end and position V 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.
Positioning is performed by engaging the protrusion 87 with the engagement hole 90 of the frame 88, and then the other end of the unit 12 is fixed with a screw.
There is an advantage that the position of the aperture 84 that irradiates the light 0e is correctly aligned without error.

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.

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 top plate of the electrophotographic copying machine main body facing the light source unit is made freely removable, and the lens unit main 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 is divided into three parts, covers 150a, 150b, and 150c, each of which 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, the document cover 2 is opened and each document placement table is removed.

Among the removable covers 150a to 150c constituting the upper plate 150 of the copying machine main body, the center 150b is located directly above the light source unit 21, and the upper left side of the lens unit 20 is opposite to it. As will be described later, a cover that can be opened and closed is provided on the upper left side and the upper right side of the lens unit 20.

Because of the above configuration, open the document cover 2 and remove the entire document placement table, and then remove the cover 15 located in the center of the upper plate 150 of the copying machine main body.
When 0b is removed, the light source unit 2 is located directly below it.
1, 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 reflecting mirrors 40 and 41, which are housed within the lens unit body 32. The lens unit main body 32 includes a side plate 35, a lens unit cover 43 that covers the upper part 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 projecting upward is formed on the side plate 42, and the lens unit cover 43 is always hooked onto this hook portion 44 as will be described later.

FIG. 9 is a diagram explaining the opening/closing mechanism of the lens unit cover 43, and FIG. 9A 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 main body 32 so as to protrude upward is
Hooking protrusions 44a at the front and rear ends thereof,
44b. Further, as shown in FIG. B, the lens unit cover 43 is provided with protrusions 43a and 43b that protrude toward the front in the axial direction of the photoreceptor drum. The hooking protrusion 44a is located at the left end a of the protrusion 43a of the lens unit cover 43.
It is locked at 1. 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 overlap at this point Q. Said side plate 35
Notches 35a, 3 are provided on both sides of the hook portion 44.
5b is formed. This notch 35a, 3
The length l of 5b is sufficiently longer than the length of each of the hooking protrusions 44a and 44b of the hooking part 44, and the depth h is the lower end of the hooking protrusions 44a and 44b. The size is set so that they do not touch each other.

Next, the opening and closing operations of this lens unit cover will be explained.

In a normal state, the hooking protrusions 44a and 44b of the side plate 35 are attached to the respective ends a1 and a of the protrusions 43a and 43b of the lens unit cover 43.
It is locked to 2. Therefore, the lens unit cover 43 cannot be moved in the directions of arrows B and C. However, when the part of the left lens unit cover 43 facing the notch 35a of the side plate 35 is pressed in the direction of arrow A as shown in FIG. It bends like this.
When the pressing force in the direction of arrow A is increased to the extent that the hooking protrusion 44a is released, the hooking protrusion 44a releases the protrusion 43a, and the left lens unit cover 43 is opened. 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 cover 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. Further, the cover 150b of the top plate of the copying machine body located above the light source unit 21 is removable. Therefore, by removing this cover 150b and further removing the light source unit 21, a force in the direction of arrow A shown in FIG. 9 can be applied from above to the lens unit 20. That is, by removing the cover 150b, the light source unit 21 can be cleaned, and by also removing this light source unit 21, the lens unit cover 43 on the left side of the lens unit 20 can be opened.
It becomes possible to clean within 0. To clean the inside of the lens unit cover, it is sufficient to simply remove this left cover, but in this example, the seventh
As shown in the figure, the cover 150c on the right side of the top plate of the copying machine body can also be removed.
Therefore, by removing this cover 150c and opening the lens unit cover 43 on the right side of the lens unit 20 in the direction of arrow C (see FIG. 9), it is possible to more thoroughly clean the lens unit cover (especially the right side). Become.

As described above, in this embodiment, by making the portion 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 the lens unit 21, the lens unit cover on the left side of the lens unit 20 can be opened and closed.
That is, cleaning inside the lens unit 20 (including cleaning the lens) can be easily performed. Also,
In this embodiment, it is possible to remove the top plate of the copying machine body located above the right side portion of the lens unit 20, and the right lens unit cover 43 can be opened and closed, so that the cover 150c of this top plate can be removed. By removing the lens unit cover 43 and opening the right lens unit cover 43, the inside of the lens unit 20 (especially the right side) can be cleaned more easily.

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

FIG. 10 shows how air containing ozone and developer generated around the photosensitive drum 10 and heat generated from the fixing roller 64 are exhausted.

A plurality of suction holes (air circulation holes) 34a are formed in the lens unit base 34 constituting the bottom plate of the lens unit 20, and an exhaust hole 42a is formed in a portion of the side plate 35 located below the first reflecting mirror 40. has been done. FIG. 11 is a view of the mirror unit base 34 viewed from below.
Note that 36 is a slit for irradiating the light reflected from the second reflecting mirror 41 onto the exposure point P of the photoreceptor drum 10.

As described above, the suction holes 34a are provided at multiple locations on the lens unit base 43, and the side plate 35
Since the exhaust hole 42a is provided in a portion located below the first reflecting mirror 40, ozone generated around the photoreceptor drum 10, especially ozone generated from the main charger 11, and ozone scattered around the photoreceptor drum are removed. The air containing the developing agent and the heat generated from the fixing roller 64 are absorbed into the suction hole 34.
The air enters the lens unit 20 from the point a, is carried along the lens unit base 34 to the exhaust hole 42a, and is further exhausted to the outside of the lens unit 20 through the exhaust hole 42a. The exhausted air is further exhausted to the outside of the copying machine main body 1 by an exhaust fan 18.

With such an exhaust structure, the inside of the lens unit 20 can be effectively used as an exhaust path, and the exhaust hole for the air sucked into the lens unit 20 is located below the first reflecting mirror 40. Therefore, all lenses can be attached to the base 3 without moving upwards within the unit.
4 and is discharged to the outside of the unit from the exhaust hole 42a. Therefore, it is possible to prevent the reflecting mirrors 40, 41 and the lens 30 from becoming dirty due to air entering the lens unit 20.

Lens position warning display control (see FIG. 12) In the electrophotographic copying machine of this embodiment, as described above, the position control of the lens 30 is controlled by a mechanism linked to the operation of the magnification conversion lever 78 without using a position control motor or the like. I'm going. In addition, a lens position regulating plate 123 is provided as shown in FIG. 5A so that the lens 30 stops at the correct position when the magnification conversion lever 78 is operated.
A recessed portion 127 corresponding to each magnification is provided on the side of the lens. Lens holding stand 10 that holds the lens 30
Lens movement regulating pin 122 provided at 8
When the lens 30 is properly fitted into this recess 127, an accurate stopping position of the lens 30 is guaranteed. However, if the stop position of the magnification conversion lever 78 is incorrect,
There may be cases where the lens movement regulating pin 122 does not fit into the recess 127 of the lens position regulating plate 123 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 lens position regulating plate 12 is
A detection switch 124 is arranged in each recess 127 of 3, and the lens movement regulating pin 122
When the switch 7 is properly fitted, a switch 124 at that position is turned on. FIG. 12 is a flowchart showing the operation when the detection switch 124 is not turned on when the magnification conversion lever 78 is operated. 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, proceed to step n4 and display an error (E display) on the display 75 (see Figure 3).
I do. If a copying operation is in progress, the process proceeds from n1 to n2, and here the next copying operation instruction flag F is reset. Furthermore, wait for the copy paper to be ejected at n3, then proceed to n4 and display an error message.
When an error message is displayed at n4, the operator can know that the magnification conversion lever 78 is not set at the correct position at that point.

Through the above-described operations, it is possible to easily recognize whether the lens 30 is set at the correct position, giving the operator a sense of security and preventing copy errors and the like.

Scanning speed change mechanism In this column, features of the present invention will be explained.

FIG. 13 is a diagram showing a lens unit moving mechanism including a part of the scanning speed changing mechanism. 13th
The figure shows the lens moving mechanism shown in FIG. 5A with omitted parts added.

A rack gear 201 is formed in a part of the slide lever 101. This rack gear 20
1 and the pinion gear 202 is meshed with the pinion gear 202. A pinion 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, the rack gear 201 provided on the slide lever 101 also moves in the same way. This movement causes pinion gear 202 to rotate, and rotating shafts 203 and 204 to rotate.

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

The input shaft 210 is pivotally supported by the rear frame 226 via a bearing 231 . A transmission gear 229 is fixed to the end of the input shaft 210 protruding from the rear frame 226. This transmission gear 22
9 meshes with a transmission gear (not shown), receives driving force from a motor (also not shown), and rotates together with the input shaft 210. A connecting gear 2 is connected to the input shaft 210.
13 and one of the electromagnetic clutches 214 is fixed. The electromagnetic clutch 214 on the other hand connects the input shaft gear 2 rotatably to the input shaft 210.
15 is fixed. 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 meshes with four input shaft speed change gears 219a to 219d, which are pivotally supported by shafts 222a to 222d. However, in FIG. 14, the shaft 222b
-d and input shaft transmission gears 219b-d are omitted. Further, output shaft speed change gears 220a to 220d (output shaft speed change gears 220b to 220d are omitted in the figure) are supported by the shafts 222a to 222d. Rotation transmission members 221a to 221d are provided on opposing sides of the input shaft transmission gears 219a to 219d and the output shaft transmission gears 220a to 220d (rotation transmission members 221b to 221d are omitted in the figure).
is fixed. Rotation transmission members 221a-d
The output shaft transmission gears 219a to 219d are kept away from the output shaft transmission gears 220a to 220d by a spring provided inside.

The output shaft gears 220a to 220d are connected to the output shaft 212.
It meshes with an output shaft gear 218 fixed to. Further, the output shaft gear 218 meshes with the gear 224.

Connecting gear 213 fixed to input shaft 210
is meshed with a connecting gear 216 that is rotatably supported by a reversing output shaft 211 that is rotatably supported by the rear frame 226 via a bearing 234 . Reversing output shaft 211
is provided with an electromagnetic clutch 217, which is fixed on the one hand to the coupling gear 216 and on the other hand to the reversing output shaft 211. 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 21
It is rotating with 0. Therefore, when the electromagnetic clutch 217 is driven, the reversing output shaft 211 rotates together with the coupling gear 216. The reflective output shaft 211 has a gear 225 fixed at the end exposed from the front frame 227.
5 rotates together with the reversing output shaft 211. A gear 224 that meshes with the output shaft gear 218 and a gear 225 that is fixed to the reversing output shaft 211 are both meshed with a drive gear (not shown), and are moved to the document table (not shown) by the rotation of this drive gear.

Internal frame 228 and input shaft speed change gear 219
A control plate 241, which is a gear ratio selection means of the present invention, is provided between a to d. This control plate 241 has a shaft 222a as shown in FIG.
-b are engaged in elongated holes 243 and 244. Input shaft transmission gears 219 a - d supported by shafts 222 a - d all have the same number of teeth, and shafts 222 a - d are located concentrically with respect to output shaft gear 215 . For this reason, the control board 2
41 is the center position of the input shaft gear 215, that is,
It is rotatable about the center position of the input shaft 210 as a fulcrum.

A rack gear 245 is formed on a part of the control plate 241. This rack gear 245 is formed in a part of an arc centered on the rotation axis of the control plate 241. The rack gear 245 is a selection member rotating gear 204 fixed to the rotating shaft 203.
It's meshing with each other. 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.

Convex portions 242a to 242d are formed on the control plate 241. The convex portions 242a to 242d are formed at positions where they can come into contact with the input shaft transmission gears 219a to 219d, respectively. Control plate 241 is rotated in the direction of arrow O or P by rotating selection member rotary gear 204.
When rotated in the direction of arrow Q or R, the convex portion 242
Any one of a to d is the input shaft transmission gear 219a to
contact d. Which of the protrusions 242a to 242d contacts the input shaft transmission gears 219a to 219d is determined by the rotation angle of the control plate.

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

As shown in FIG. 16A, when the convex portion 242a of the control plate 241 is not in contact with the input shaft speed change gear 219a, the elastic force of the rotation transmission member 221a causes the input shaft speed change gear 219a and the output shaft speed change gear 220a to are separated. 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. 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, the output shaft transmission gear 22
The numbers of teeth 0a to 0d are different from each other. That is, each of the output shaft speed change gears 220a to 220d is ×0.7×1 (same size), ×1.24, and ×
Each corresponds to the scanning speed at a magnification of 0.8. On the other hand, the rotation angle of the selection member rotating gear 204 in the direction of arrow O or P corresponds to the amount of movement of the moving lever 100 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 a different rotation angle for each selected copying magnification. The formation positions of the convex portions 242a to 242d on the control board 241 are determined in consideration of the above, and when the magnification of ×0.7 is selected, the convex portion 242a contacts the input shaft speed change gear 219a, and the magnification of ×1 When the magnification (same magnification) is selected, the convex portion 242b is connected to the input shaft speed change gear 21.
9b, and when the magnification of x1.24 is selected, the convex portion 242c contacts the input shaft speed change gear 219c, and when the magnification of x0.8 is selected, the convex portion 242d contacts the input shaft speed change gear 219d.

With the above configuration, the movement of the moving lever 100 when selecting the copy magnification is transmitted to the control plate 241 by the rack gear 201, pinion 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 gears 219a-d. As a result, the input shaft speed change gears 219a to 219d are connected to any of the output shaft speed change gears 220a to 220d corresponding to the scanning speed of the selected copying magnification.

When the electromagnetic clutch 214 is driven in this state during the copying process, the rotation of the input shaft 210 is caused by the rotation of the input shaft gear 215 and the input shaft gear 219.
The signal is transmitted to the output shaft speed change gears 220a to 220d via a to d, and the document table 2 moves at a scanning speed corresponding to the selected copy magnification. When the document table 2 is returned after the copying process is completed, the electromagnetic clutch 214 is stopped and the electromagnetic clutch 217 is activated. Thereby, 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 the document table 2 does not affect the copying process, it moves at a fixed speed regardless of the selected copy magnification.

As described above, according to this embodiment, when copying magnification is selected, manual scanning is performed to switch the lens position and to switch the scanning speed, and the switching operation of the scanning speed is performed by manual operation. Therefore, no driving device is required for switching the scanning speed, and cost and space savings can be achieved.

(g) Effects of the Invention According to the present invention, the rotation of the input shaft is transmitted to the output shaft through the connection between the input shaft speed change gear and the output shaft speed change gear by the rotation transmission member. A predetermined number of input shaft speed change gears and output shaft speed change gears are provided,
The output shaft transmission gears are formed to have different numbers of teeth. Therefore, by selecting the rotation transmission member to be enabled using the gear ratio selection member, the number of teeth of the output shaft transmission gear connected to the input shaft transmission gear can be selected, and the rotational speed of the output shaft can be changed. can be easily done. At this time, the operating force necessary for the switching operation is only the force that operates the gear ratio selection member, and 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 required when switching the scanning speed is extremely small and no special driving force is required, making it possible to achieve manual operation and reduce costs.
Furthermore, it is possible to similarly reduce the operation noise generated due to the large mass not moving during the scanning speed switching operation.

[Brief explanation of the drawing]

FIG. 1 shows an external view of an electrophotographic copying machine which is an embodiment of the present invention. FIG. 2 shows a configuration diagram of the electrophotographic copying machine. 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.
5A and 5B are plan views of the lens unit moving mechanism and diagrams showing the operating state. 6A and 6B 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. 9A and 9B 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 change mechanism of the variable magnification copying machine;
The figure is a side sectional view showing the main parts of the scanning speed change mechanism.
FIG. 15 is a front view showing a part of the scanning speed changing mechanism, and FIGS. 16A and 16B 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, 219
a to d...Input shaft speed change gear, 220a to d...Output shaft speed change gear, 221a to d...Rotation transmission member,
241...control board.

Claims (1)

[Scope of Claims] 1. A scanning speed changing mechanism for a variable magnification copying machine that changes the original scanning speed of an optical system according to a selected copying magnification, comprising: an input shaft gear fixed to an input shaft; a predetermined number of input shaft gears meshing with the output shaft gear, an output shaft gear fixed to the output shaft; and a predetermined number of input shaft gears meshing with the output shaft gear and coaxially with the input shaft gear,
Select one of the predetermined number of rotation transmission members and rotation transmission members that transmit the respective rotations of the predetermined number of output shaft speed change gears and input shaft speed change gears to the opposing output shaft speed change gears, each having a different number of teeth. A scanning speed change mechanism for a variable magnification copying machine, comprising: a speed change ratio selection member that makes the speed change ratio effective.