JPH0797197B2 - Variable magnification copying machine magnification conversion mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a magnification conversion mechanism of a variable magnification copying machine capable of performing magnification conversion by changing the position of a lens without using a drive source such as a motor. Regarding

(B) Conventional Technology In a conventional variable-magnification copying machine, magnification conversion is performed by changing the lens position using a motor.

(C) Problems to be Solved by the Invention However, in such a copying machine, it is necessary to use sensors and the like for detecting the amount of movement of other lenses that use a motor. There is a drawback that the cost of the entire copying machine becomes high because the size of the whole becomes large and the price thereof is high because of the use.

The object of the present invention is to move the lens position to the correct position without using a motor, etc., and with a simple structure, it is easy even if the paper size type (AB system or inch system) changes. It is to provide a magnification conversion mechanism for a variable-duplication copying machine that can handle the above.

(D) Means for Solving Problems The present invention relates to a magnification conversion lever provided on an operation panel, a magnification switching arm that interlocks with the operation of the magnification conversion lever, and a sliding shaft that is slidably fitted. A lens holder that is engaged with a part of the magnification switching arm and slides on the sliding shaft as the arm moves, a lens held by the lens holder, and the lens. A lens movement restricting pin provided on a holding table, and a lens position restricting plate provided in parallel with the sliding shaft and having a concave portion into which the lens movement restricting pin fits when the lens holding table is at a predetermined position. The concave portions of the lens position regulating plate are formed on both sides of the regulating plate, and the concave portion is formed at a position corresponding to AB type paper on one side and the inch type paper on the other side. At the position corresponding to A concave portion is formed, and the lens position regulating plate can be selectively attached such that the concave portion on either side of the regulating plate is opposed to the lens movement regulating pin.

(E) Action In the magnification conversion mechanism according to the present invention, by operating the magnification conversion lever, the lens holder that holds the lens moves along the sliding axis in association with the operation amount. Therefore, the operator can set the lens to a predetermined position by simply operating the magnification conversion lever without using a motor or the like.

Further, since the lens position regulating plate is provided with a concave portion to which the lens movement regulating pin provided on the lens holding plate is fitted, when the lens movement regulating pin is fitted to the concave portion of the lens position regulating plate, the operator is You can feel a click on the magnification conversion lever. Therefore, the position of the recess formed on the lens position regulating plate should be adjusted to the paper size (for example, A4
By setting the position corresponding to the plate and B5 plate), the operator can set the lens to the correct position by stopping the magnification conversion lever at a position where there is a click.

Further, the concave portions of the lens position regulating plate are formed on both sides of the regulating plate, and the concave portion is formed on one side at a position corresponding to AB type paper and on the other side corresponding to inch type paper. Since the concave portion is formed at the position, it is possible to correspond to either AB series or inch series paper by changing the mounting direction of the lens position regulating plate without changing other elements.

(F) Embodiment FIG. 1 shows an electrophotographic copying machine which is an embodiment of the present invention. The present embodiment will be described below in the following order.

Appearance (see FIG. 1) Overall configuration (see FIG. 2) Operation panel (see FIG. 3) Lens unit (see FIGS. 4 to 5) Blank lamp unit (see FIG. 6) Optical device cleaning structure ( 7 to 9) Exhaust structure (see FIG. 10 and FIG. 11) Lens position warning display control (see FIG. 12) Description of embodiment External view FIG. 1 is an electronic photograph showing an embodiment of the present invention. It is an external view of a copying machine. A document cover 2 is supported on the top 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 bottom of the copying machine main body 1. The paper feed cassette 3 can be selected according to the size of paper to be stored. A paper discharge tray 4 is attached to the left side of the copying machine body 1. The paper fed from the paper feed cassette 3 passes through the copying process unit in the copying machine main body 1, and is guided to the paper discharge tray 4 via a paper discharge unit not shown. An operation panel 5 is provided on the front upper portion of the copying machine main body 1, and is provided with a print switch and a magnification setting lever as described later.

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

A photoconductor drum 10 that rotates in the direction of the arrow in the figure is disposed in the approximate center of the copying machine body 1. Around the photosensitive drum 10, a main charger 11 and a blank lamp unit are provided.
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 in this order. Point P in the figure of the photoconductor drum 10 represents an exposure point, and light from the optical system enters.

The optical system is composed of a lens unit 20 and a light source unit 21. The lens unit 20 is movable along the optical axis 1 and is also movable in a direction perpendicular to the optical axis 1 (direction perpendicular to the paper surface) and two reflecting mirrors 40, 4
It has 1 and. The lens unit 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. An air circulation hole (suction hole) is formed in a part of the lens unit base.

The light source unit 21 includes a light source 21a and a reflector 21b. The copying machine of this embodiment is of a movable type. Therefore, the light source unit 21 and the lens unit
The numeral 20 is fixed in the main body 1 of the copying machine.

The photoconductor drum 10, the main charger 11 and the cleaner unit 16 are integrated as a unit and are detachably attached to the copying machine main body 1. Similarly developing unit
13 is also detachable from the copying machine main body 1, and each unit can be replaced as needed.

Two sets of conveying rollers 6 are provided on the lower right side of the photosensitive drum 10.
0, 61 and a transport path 62 are provided, and a crescent-shaped sheet feed roller 63 is disposed further below. When the paper feed roller 63 makes one rotation, the uppermost paper stored in the paper feed cassette 3 is fed, and is fed to the copy process section by the feed rollers 61, 60 and the feed path 62. Photoconductor drum 10
A fixing roller 64 is provided on the left side of the. The sheet on which the image is transferred in the copying process is fixed by the fixing roller 64 and is discharged to the discharge tray 4. In this embodiment, the fixing roller 64 also serves as a paper discharge roller. 18 is an exhaust fan.

With the above configuration, when the document is set and the print switch is operated, the document table is reciprocated and the light source unit 21 scans the document surface. The reflected light from the original passes through the lens unit 20 and is guided to the exposure point P of the photosensitive drum 10,
A latent image is formed here. Next, the latent image formed on the photosensitive drum is visualized by the developing unit 13, and the image is transferred by the transfer charger 14 onto the sheet conveyed from the sheet feeding cassette 3. The paper then passes through the fixing roller 64, where it is fixed and discharged to the paper discharge tray 4. The cleaner unit 16 removes the residual toner from the photoconductor drum 10, and the charge removal lamp 17 removes the charge to prepare for the next copying cycle.

Operation Panel FIG. 3 is a block diagram of the operation panel. Reference numeral 70 is a print switch (print key), 71 is a clear key for clearing the number data, 72 and 73 are copy number setting keys for multi-copying, and 74 is a ready lamp indicating a copy ready state. 75
Is an indicator, 76 is an alarm display lamp, 77 is an exposure mode setting switch, and 78 is a magnification conversion lever.

The alarm display lamp 76 displays a paper jam, a toner shortage, etc., and the exposure mode setting switch 77 is a switch for setting the standard mode, the dark mode, or the light mode of the automatic exposure. Also, the magnification conversion lever 78 sets the magnification to 4
It is a switch set in stages.

Lens Unit This section describes the features of the present invention.

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 described later. Flexible light-shielding sheets 31 are provided on both sides of the lens 30 between the lens unit body 32. The flexible light shielding sheet 31 is for shielding light (stray light) other than passing through the lens. The ends of the flexible light shielding sheet 31 are in contact with the inner wall of the lens unit main body 32, respectively. The flexible light-shielding sheet 31 is arranged in the lens unit main body 32 so as to meander in an inverted S shape as a whole. A first slit 33 is provided between the lens 30 and the first reflecting mirror 40, and a second reflecting mirror of the lens unit base 34.
A second slit 36 is provided in a portion facing 41.

Light reflected from the original is first reflected by the first reflecting mirror 40, passes through the first slit 33, and enters the lens 30. Lens 30
The light emitted from the second reflection mirror 41 is reflected downward, passes through the second slit 36 provided in the lens unit base 34, and reaches the exposure point P of the photosensitive 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 the magnification conversion lever 78 shown in FIG.

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

The moving lever 100 and the magnification converting lever 78 are connected via a link mechanism (not shown), that is, by connecting the both ends of the link so that the respective levers move in the same direction. This moving lever 100 can move in the directions of arrows A and B in the figure. Move lever 10
Reference numeral 0 is fixed to a slide lever 101 provided along the side plate of the lens unit main body 32. The slide lever 101 is supported by a slide lever support member 102 so as to be slidable in the directions of arrows A and B. One end of a substantially V-shaped magnification switching arm 104 is rotatably supported on the upper end of the slide lever 101 by a pin 103.
The magnification switching arm 104 has a pin 105 at a substantially central portion thereof.
It is rotatably supported by. Magnification switching arm 104
An elongated hole 106 is formed at the other end of the. A pin 107 is fitted in this long hole 106. The pin 107 is provided on a lens holder 108 that holds the lens 30 so as to project to the front side perpendicular to the paper surface. The lens holder 108 is slidable on a slide shaft 109, and both ends of the slide 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. On the left side of the support plate 110, a slightly curved elongated groove guide groove 111 is formed. A roller-shaped guided member 112 is fitted in the guide groove 111. The guided member 112 is attached to one end of the arm 113. An inverted L-shaped first lens movable member 114 is rotatably connected to the other end of the arm 113 by a pin 115, and further, an inverted L-shaped first lens movable member 114 is symmetrical to the first lens movable member 114. The second lens movable member 116 is the first lens movable member 1
It is connected to 14 by pin 117. The first lens movable member 114 and the second lens movable member 116 have elongated holes 118 and 119 respectively formed at the tip end portions thereof, and the elongated holes 118 and 119 project from the lens 30 to the front side perpendicular to the paper surface. Pins 120 and 121 are fitted in each.

The lens 30 is composed of a compound lens body and a case,
Each of the pins 120 and 121 is movable in the arrow direction (AB direction) in the figure. The pins 120 and 121 are fixed to a predetermined lens body of the compound lens body in the case. This pin 12
By moving 0 and 121, the lens body to which the pin is fixed also moves, and the focal length of the entire lens 30 changes. That is, the magnification can be changed. The lens having such a structure is widely used in a variable-magnification copying machine and has a well-known structure.

A lens movement regulating pin 122 is provided at a position on the opposite side of the lens holding base 108 from the lens 30 via a leaf spring 126. A lens position regulating plate 123 is attached on the right side of the sliding shaft 109 in parallel with the sliding shaft 109. Four recesses 127 are provided on the left side of the lens position regulating plate 123, and detection switches 124 are provided in the recesses, respectively. 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 drawing. As will be described later, the recessed portion provided on the right side is used when handling inch-type paper.

When the lens movement restricting pin 122 is fitted in the recess 127 and the detection switch 124 is pushed down, it is possible to detect that the lens holding base 108 is at a predetermined position by an ON signal of the switch. The four concave portions 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 portion of the lens position regulating plate 123 corresponds to a magnification of × 1.24, and the upper portion thereof is × 1.
Corresponds to (actual size). Furthermore, the upper one corresponds to a magnification of × 0.8, and the uppermost concave portion corresponds to a magnification of × 0.7. The lens holder 108 slides on the sliding shaft 109 so that the lens holder 10
The position of the lens 30 is determined by which recess the lens movement restricting pin 122 fixed to 8 is fitted.

In FIG. 5B, the lens holder 108 moves above the sliding shaft 109, and the lens movement restricting pin 122 causes the lens position restricting plate 123 to move.
It shows the state when fitted in the uppermost recess of the. Fifth
When the lens holder 108 moves from the state shown in FIG. 5A to the state shown in FIG. 5B, the lens 30 naturally moves to the upper left. That is, the lens 30 is parallel to the sliding axis 109,
That is, the body moves about the optical axis 1 while tilting. In this way, the lens 30 tilts and moves according to the magnification,
This is because the original placed on the original table is placed on the basis of one side. In other words, if you place the original on one side,
This is because, for example, the B5 size document and the A4 size document are displaced from each other by the senler line of the document, that is, the optical axis l.

The detection switch 124 arranged in each of the recesses 127 is for detecting that the lens movement restricting pin 122 is located in a predetermined recess, and as will be described later, if this switch is not turned on, the operation panel An error is displayed on the display 75 of. By the action of the detection switch 124, it is possible to confirm whether or not the lens 30 is in the correct position corresponding to the magnification set by the magnification conversion lever 78.

Action of lens unit moving mechanism From the state shown in FIG.
Suppose you moved in the direction. Magnification conversion lever on the operation panel
78 is located at a magnification of 1.24 in the state shown in FIG. 5 (A). Moving the moving lever 100 in the direction of arrow A means that the operator operates the magnification converting lever 78 to the left from the position of 1.24. When the moving lever 100 moves in the A direction, the slide lever 101 moves in the A direction. At this time, the magnification switching arm 104 rotates clockwise around the pin 105. As a result, the lens holding base 108 moves the sliding shaft 109.
Along with, the lens 30 also moves in the direction of arrow D. At this time, the guided member 112 is guided along the guide groove 111, and the arm 113 is slightly rotated in the clockwise direction as a whole. By this operation, the first lens movable member 114 slightly rotates clockwise about the pin 115, and the rotation operation is transmitted to the second lens movable member 116 via the pin 117, so that the second lens movable member 114 is moved. Member 116
Also rotates slightly about the pin 125 counterclockwise. As a result, the pins 120 and 121 slightly move in the B direction and the A direction, respectively, and the lens 3 in which the pins 120 and 121 are provided.
The lens body within 0 moves in the lens 30 in the directions of arrows B and A, respectively. The individual lenses are moved within the lens 30 by the magnification conversion for adjusting the focal length.

With the above operation, the lens 30 moves to a predetermined position.
The operator can feel a click when the magnification conversion lever 78 is operated to the display position of × 0.7. This is because the lens movement restricting pin 122 is pressed by the plate spring 126 toward the lens position restricting plate 123. Of course, when operating the magnification conversion lever 78 to the left, ×
A click feeling can be felt even at the display position of 1 and the display position of × 0.8. 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 quick feeling. At this time, since the lens movement restricting pin 122 is fitted in the concave portion corresponding to the set magnification, the detection switch 124 arranged in the concave portion is turned on. If this switch is not turned on, the lens 30 is not set to the correct position, so the control unit displays an error message on the display 75 and warns the operator that the magnification conversion lever 78 is not in the correct position. To do.

Structure of Lens Position Limiting Plate In the lens unit moving mechanism described above, the lens position limiting plate 123 used in this embodiment is provided with concave portions on the left and right sides into which the lens movement regulating pins 122 are fitted. The concave portion 127 shown on the left side of the figure corresponds to AB type documents such as A4 size and B5 size. Further, the concave portion 128 provided on the right side corresponds to an inch type original. When assembling a copying machine, if the model needs to handle AB type paper,
The lens position restricting plate 123 is attached so that the recess of AB system corresponds to the lens movement restricting pin 122. Further, when it is necessary to make a copying machine that handles inch type paper, this lens position regulating plate 123 is attached so that the inch type concave portion 128 corresponds to the lens movement regulating pin 122. AB handled
It is only the mounting method of the lens position regulating plate 123 that determines whether the system is the inch system or the inch system, and it is not necessary to change other elements. Therefore, there is an advantage that the assembly work system is extremely improved. The switch 124 is the lens position regulating plate 1.
Although it can be attached to the back side of 23, it is needless to say that each switch needs to be attached to the corresponding concave portion of the inch system when making it compatible with the inch system.

Further, in the lens unit moving mechanism of this embodiment, the lens 30 is interlocked with the operation of the magnification conversion lever 78 operated by an operator without using a driving device such as a motor. Moreover, the position of the lens 30 is the lens position regulating plate 123.
By the action of the lens movement restricting pin 122, the correct position is always set. Therefore, there is an advantage that the cost is drastically reduced because the motor, the sensor for controlling the moving position thereof, the control unit, and the like are unnecessary, and the motor and the like are not necessary, and the entire size can be reduced.

Blank Lamp Unit FIG. 6 shows the structure of the blank lamp unit.

As shown in FIG. 2, the blank lamp unit 12 includes a main charger (charging device) 11 that uniformly charges the surface of the photoconductor drum 10 and a developing unit (developing device) 13 in the photoconductor drum axial direction. It is provided along with. The blank lamp unit 12 includes a total of five blank lamps 80a to 80e, each of which is controlled to blink independently. Each blank lamp removes unwanted charges on the surface of the photoreceptor drum. The blank lamps 80a to 80d on the left side of the drawing remove unnecessary electric charges depending on the size of the image formed on the surface of the photosensitive drum. Further, the single blank lamp 80e on the right side removes unnecessary electric charges in 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 (sheet edge portion). The position indicated by V indicates the end of the separation belt 81. The separation belt 81 is located at the interval t of PV. The separation belt 81 is for separating the paper after transfer from the photoconductor drum. As shown in the figure, the separation belt 81 is provided so as to face one end portion below the photosensitive drum 10. The paper 82 has its end placed on the separation belt 81 at the transfer portion. That is, the separation belt 81 is interposed between the paper and the photoconductor drum at one end of the paper 82. As a result, the paper 82 after transfer is separated from the separation belt 81.
Is forcibly separated from the surface of the photosensitive drum 10 by
It will come off reliably.

Separation belts having such a structure are already known.

Blank lamp on the right side of the blank lamp unit 12
80e is the image reference position P from the end position V of the separation belt 81.
The electric charge in the right side region over is removed. by this,
Toner does not adhere to the portion of the photosensitive drum 10 that contacts the separation belt 81. That is, the separation belt 81
Toner does not adhere to the
It is possible to prevent the edge portion of the paper sheet 82 from being soiled by the toner soiling.

Each of the blank lamps 80a to 80e removes an electric charge in a predetermined area on the photoconductor 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 forms a room for individually partitioning the blank lamps 80a to 8ge, and an opening 84 for passing the light of the lamp is provided in a portion facing the photoconductor drum 10. The opening 84 of each room is sized to regulate the range of light emitted from each lamp. As shown in the figure, for example, in a room accommodating the blank lamp 80d, the size of the opening 84 should be the irradiation light shown by the hatching in the figure, that is, from the position a1 of the photosensitive drum a5
The size is set so that the irradiation is performed over the position. 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 beyond the position a2 to the position a6, and the opening 84 of the room that houses the blank lamp 80b is , A3 to a position in the vicinity of the left end portion of the photoconductor drum 10 is set to irradiate the area. The opening 84 of the room accommodating the leftmost blank lamp 80a is sized to irradiate the area from the position a5 to the position near the left end of the photosensitive drum 10.

The positions of a1 to a6 indicate the positions of the left end portions of the images formed corresponding to the document size and the set magnification, respectively. Therefore, for example, when the position of the left end of the image to be formed is a1, the blank lamps 80a to 80d are all turned on,
All the charges in the region from the position a1 to the left end of the photoconductor drum 10 are removed. When the position of the left end of the image to be formed is a3, the blank lamps 80a and 80b are turned on and the blank lamps 80c and 80d are turned off. The position of a5 indicates the image position of the left end portion when the image to be formed is A4 size.

The opening portion 84 of the lamp box 83 that houses the blank lamp 80e is set to a size that removes the electric charge in the photoconductor region facing the separation belt 81. That is, the left end portion of the light emitted from the blank lamp 80e coincides with the left end position V of the separation belt 81 as shown in the figure, and the region from the position V to the right end of the photosensitive drum is irradiated. The size of the opening 84 is set so as to be set.

Blank lamps 80a-80e and lamp box 8 above
3 is attached to a blank lamp support plate 85.
The 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 portion of the blank lamp support plate 85, and a unit alignment engaging projection 87 protruding rightward is provided at a position slightly left of the connector 86. ing. The frame 88 is provided with a main body side connector 89 connected to the connector 86,
Further, an engagement hole 90 with which the unit alignment engagement projection 87 is engaged is provided. Blank lamp unit 12
The one end of is aligned by engaging the unit alignment engagement projection 87 with the engagement hole 90. When this engagement is performed, the connector 86 is simultaneously connected to the main body side connector 89, and power is supplied from the main body side to each blank lamp.

FIG. 6 (B) shows an external view of the vicinity of the unit alignment engaging projection 87 and the engaging hole 90 with which the projection is engaged.

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

By the way, if a little toner adheres to the separation belt 81, the adhered toner becomes dirty 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 portion of the irradiation light of 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 portion of the blank lamp unit 12 is aligned and then the right end portion of the blank lamp unit is fixed, the length between the left end portion and the position V is long. In addition, an error is likely to occur in the position of the opening 84 that irradiates the light of the blank lamp 80e. However, in the present embodiment, since the reference position when mounting the blank lamp unit 12 is the right end portion thereof, an error is unlikely to occur, and the position of the opening portion 84 for irradiating the light of the blank lamp 80e is properly aligned. There is an advantage.

That is, in the blank lamp unit of the present embodiment, the unit alignment engaging projection 87 is provided at the end portion facing the position of the separation belt 81, and this projection 87 is provided in the engaging hole of the frame 88.
The opening 8 for irradiating the light of the blank lamp 80e is provided by performing the alignment by engaging with 90 and then fixing the other end of this unit 12 by screwing.
There is an advantage that the position of 4 is correctly aligned without any error.

In the above embodiment, the engaging protrusion 87 is provided on the blank lamp unit side and the engaging hole 90 is provided on the frame side for performing the alignment, but the reverse is also possible.

Optical Device Cleaning Structure FIGS. 7 to 9 are views for explaining the optical device cleaning structure.

In the electrophotographic copying machine of this embodiment, the portion of the upper plate of the main body of the electrophotographic copying machine that faces the light source unit is removable, and the lens unit body portion that faces this portion is also removable.

FIG. 7 is a view showing the structure of the upper plate of the copying machine main body of this embodiment. The upper plate 150 of the main body of the copying machine is divided into three parts, covers 150a, 150b and 150c, each of which is removable.
Mounting is done with screws and can be easily removed by removing the screws. It should be noted that the upper plate 150 of the copying machine main body is removed by opening the original cover 2 and removing the original placing table together.

Of the removable covers 150a to 150c forming the upper plate 150 of the copying machine main body, the centrally located 150b is located directly above the light source unit 21, and the upper left side of the lens unit 20 is opposed. As will be described later, this lens unit
The left upper part and the right upper part of 20 are provided with covers that can be freely opened and closed.

Due to the above structure, the original cover 2 is opened, the original placing table is removed, and the central cover 150b of the upper plate 150 of the copying machine main body is removed. Therefore, the reflector 21b and the light source 21a can be easily cleaned from above. Also,
It is also possible to remove this light source unit 21.

FIG. 8 is a lens unit structure diagram.

As described above, the lens unit 20 is provided with the lens 30 and the two reflecting mirrors 40 and 41, and these are mounted on the lens unit main body 32.
It is stored inside. The lens unit 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 34 that is located at the bottom of the side plate.

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

9A and 9B are views for explaining the opening / closing mechanism of the lens unit cover 43. FIG. 9A is a front view of a main part and FIG. 9B is a plan view of the main part.

The hooking portion 44 formed on the side plate of the lens unit main body 32 so as to project upward has hooking protrusions 44a and 44b at its front end and rear end. In addition, the same figure (B)
As shown in, the lens unit cover 43 is provided with projections 43a and 43b that project toward the front in the axial direction of the photosensitive drum. The hooking protrusion 44a is locked to the left end portion a1 of the protrusion 43a of the lens unit cover 43. Further, the hooking projection 44b is locked to the right end portion a2 of the projection 43b on the right side of the lens unit cover 43. The lens unit cover 43 is divided into a left side and a right side at a point Q in the drawing, and respective end portions of the left side lens unit cover and the right side lens unit cover overlap at the point Q. Notches 35a and 35b are formed on both sides of the hook portion 44 of the side plate 35.
The length l of the notches 35a, 35b is sufficiently longer than the length of each of the hooking protrusions 44a, 44b of the hooking portion 44,
Further, the depth h is set to such a size that the lower ends of the hooking protrusions 44a and 44b do not come into contact with each other.

Next, the opening and closing work of the lens unit cover will be described.

In a normal state, the hooking protrusions 44a and 44b of the side plate 35 are located at the respective end portions a of the protrusions 43a and 43b of the lens unit cover 43.
It is locked to 1, a2. Therefore, the lens unit cover 43 cannot be moved in the directions of arrows B and C. However, when the portion of the left side lens unit cover 43 facing the cutout portion 35a of the side plate 35 is pressed in the direction of arrow A as shown in FIG. 4A, the portion facing the cutout portion 35a is indicated by a two-dot chain line. Bend as shown in. If the pressing force in the direction of arrow A is increased to the extent that the locking state of the hooking protrusion 44a is released, the protrusion 4 by the hooking protrusion 44a
The locked state of 3a is released, and the lens unit cover 43 on the left side is released.
Can move in the direction of arrow B. That is, the lens unit cover 43 can be moved in the arrow B direction by moving in the arrow B direction while pressing in the A direction. As a result, the lens unit cover 43 on the left side of the lens unit body 32 can 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 on the upper left side of the lens unit 20. Also this light source unit
The cover 150b on the upper plate of the main body of the copying machine located at the upper part of 21 is removable. Therefore, by removing the 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 to the lens unit 20 from above. That is, the light source unit 21 can be cleaned by removing the cover 150b, and the lens unit cover 43 on the left side of the lens unit 20 can be opened to clean the inside of the lens unit 20 by removing the light source unit 21 as well. For cleaning the inside of the lens unit cover, it is sufficient to remove this left side cover, but in this embodiment, as shown in FIG. 7, the right side cover 150c of the upper plate of the copying machine body can also be removed. There is. Therefore, it is possible to remove the cover 150c and open the lens unit cover 43 on the right side of the lens unit 20 in the direction of arrow C (see FIG. 9) to further sufficiently clean the lens unit cover (particularly on the right side). Become.

As described above, in the present embodiment, the light source unit 21 can be easily cleaned by making the portion of the upper plate of the copying machine body facing the light source unit detachable. The lens unit cover on the left side of the lens unit 20 can be opened and closed by removing it. That is, the inside of the lens unit 20 can be easily cleaned (including cleaning of the lens). Further, in this embodiment, the upper plate of the copying machine main body above the right side portion 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 150c and opening the lens unit cover 43 on the right side, the inside of the lens unit 20 (particularly the right side) can be cleaned more easily.

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

FIG. 10 shows how the air containing ozone and the developer generated around the photosensitive drum 10 and the 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 that constitutes the bottom plate of the lens unit 20, and an exhaust hole 42a is formed in the portion of the side plate 35 located below the first reflection mirror 40. Has been done. FIG. 11 is a view of the mirror unit base 34 as viewed from below. Reference numeral 36 denotes an exposure point P of the photosensitive drum 10 that reflects the light reflected from the second reflection mirror 41.
It is a slit for irradiating to.

As described above, the suction holes 34a are provided at a plurality of positions of the lens unit base 43, and the exhaust holes 42a are provided at the portion of the side plate 35 located below the first reflection mirror 40. Ozone generated, especially ozone generated from the main charger 11, air containing developer scattered around the photosensitive drum, and heat generated from the fixing roller 64 enter the lens unit 20 through the suction holes 34a. It is carried to the exhaust hole 42a along the lens unit base 34, and is further exhausted to the outside of the lens unit 20 from the exhaust hole 42a. The exhausted air is further exhaust fan 18
Is discharged to the outside of the copying machine main body 1.

With such an exhaust structure, the lens unit 20
The inside of the lens 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, so that it does not move upward in the unit. It is discharged to the outside of the unit through the exhaust hole 42a along the lens unit base 34. Therefore, it is possible to prevent the reflection mirrors 40 and 41 and the lens 30 from being contaminated by the air that has entered the lens unit 20.

Lens position warning display control (see FIG. 12) In the electrophotographic copying machine of this embodiment,
Magnification conversion lever 78 for position control of 30 without using a motor, etc.
This is done by a mechanism that is linked to the operation of. Also, in order to stop the lens 30 at the correct position when the magnification conversion lever 78 is operated, as shown in FIG.
123 is provided, and a concave portion 127 corresponding to each magnification is provided on a side portion of the lens position regulating plate 123. A lens movement restricting pin 122 provided on the lens holding base 108 that holds the lens 30.
The correct stop position of the lens 30 is ensured when is correctly fitted into the recess 127. However, if the stop position of the magnification conversion lever 78 is incorrect, the lens movement restricting pin 122 may not be accurately fitted into the recess 127 of the lens position restricting plate 123. In that case, since the position of the lens 30 is incorrect, accurate image formation cannot be performed.

Therefore, in the electrophotographic copying machine of the embodiment, as described above, the detection switch 124 is arranged in each concave portion 127 of the lens position regulating plate 123, and the lens movement regulating pin 122 makes the concave portion
The switch 124 in that position is turned on when it is correctly fitted to the 7. FIG. 12 is a flow chart 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 for the control unit,
The output signals of various switches and sensors are all input to this microcomputer.

In FIG. 12, if all 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 the copying operation is being performed at that time. If copying is not in progress, proceed to step n4 and display
An error display (E display) is displayed on 75 (see FIG. 3). If a copying operation is in progress, the operation proceeds from n1 to n2, and the operation instruction flag F for the next copy is reset here. Further, at n3, wait for the copy paper to be ejected and proceed to n4 to display an error.
When an error message is displayed in n4, the operator can know that the magnification conversion lever 78 is not set to the correct position at that time.

By the above operation, it is possible to easily recognize whether or not the lens 30 is set at the correct position, give the operator a sense of security, and prevent miscopy or the like.

(G) Effects of the Invention As described above in detail in the “Lens Unit” section of the “(e) Action” and the “(f) Example”, according to the present invention, the concave portion of the lens position regulating plate is used. When the lens movement restriction pin is fitted to the operator, the operator can feel a click on the operation of the magnification conversion lever, so if the position of the recess is set to a position corresponding to the paper size, it is not necessary to use a sensor or the like. Can also set the lens in the correct position. In addition, the concave portions of the lens position regulating plate are formed on both sides thereof, and the concave portion is formed on one side at a position corresponding to AB type paper, and the concave portion is formed on the other side at a position corresponding to inch type paper. Therefore, by simply changing the mounting direction of the lens position regulating plate, it is possible to correspond to either AB series or inch series paper without changing other elements. Therefore, there is an effect that the assembly work system is extremely improved.

[Brief description of drawings]

FIG. 1 shows an external view of an electrophotographic copying machine which is an embodiment of the present invention. FIG. 2 shows a block diagram of the electrophotographic copying machine. FIG. 3 shows a block diagram of the operation panel of the electrophotographic copying machine. FIG. 4 is an external perspective view of the lens unit of the electrophotographic copying machine. 5 (A) and 5 (B) are a plan view of the lens unit moving mechanism and a view showing the operating state. 6 (A) and 6 (B) are a structural view and a perspective view of a main part 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 are a front view and a plan view of a main part 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 as seen from below. FIG. 12 is a flowchart showing the operation of the control unit when the lens position is incorrect. 30 …… Lens, 78 …… Magnification conversion lever, 104 …… Magnification switching arm, 108 …… Lens holder, 109 …… Sliding axis, 122 …… Lens movement restriction pin, 123 …… Lens position restriction plate, 127,128 …… A recess.

Continuation of the front page (56) Reference JP 60-59337 (JP, A) JP 61-138244 (JP, A) JP 60-207125 (JP, A) JP 58-214140 (JP , A) JP 58-85458 (JP, A) JP 59-29237 (JP, A)

Claims (1)

[Claims] 1. A magnification conversion lever provided on an operation panel, a magnification switching arm interlocked with the operation of the magnification conversion lever, and a sliding shaft slidably fitted to a part of the magnification switching arm. And a lens holding base that slides on the sliding shaft as the arm moves, a lens held by the lens holding base, and a lens movement restricting pin provided on the lens holding base. A lens position regulating plate provided in parallel with the sliding axis and having a concave portion into which the lens movement regulating pin fits when the lens holding base is at a predetermined position, The recesses are formed on both sides of the regulation plate, the recesses are formed on the two sides at positions corresponding to AB type paper, and the other sides are formed at positions corresponding to inch type paper. And the lens position ruler Magnifying mechanism for a variable magnification copying machine plate, characterized in that selectively either the recess of one side of the regulating plate is counter to the lens movement regulation pin is mountable.