JPH04307569A - Filter exchanging device for copying machine - Google Patents

Abstract

PURPOSE:To repetitively and consecutively exchange and insert a blue filter, a green filter and a red filter without inserting an ND filter in an exposing optical path, to restrain the noise at the time of exchanging the filter and to make a copying speed in the case of consecutive full color copying higher. CONSTITUTION:The blue filter and the red filter 6 are opposingly arranged on a drive belt 9 which is driven and rotated by a driving motor 8. A 1st projection part 9a and a 2nd projection part 9b abut on a projecting piece 4a and on a projecting piece 6a to push out the blue filter 4 and the red filter 6 in the direction of an optical path, respectively. The green filter 5 and the ND filter 7 are opposingly arranged on a driving belt 12 which is driven and rotated by a driving motor 11. A 3rd projection part 12a and a 4th projection part 12b abut on a projecting piece 5a projecting piece 7a to push out the green filter 5 and the ND filter 7 in the direction of the optical path, respectively. Spring members 14, 15 and 16 are provided on the blue filter 4, the green filter 5 and the ND filter 7.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] In addition to three color separation filters that separate light reflected from an original into three primary colors (blue, green, and red), the present invention also uses filters that adjust the sensitivity and exposure balance of a photoreceptor, for example. ND filter (Neutral Density Fi
The present invention relates to a filter changing device for a copying machine which can perform both full-color copying and monochrome copying, and is further equipped with a filter such as a filter.

0002

[Prior Art] A full-color copying machine uses an optical scanning unit to optically scan an original placed on a transparent original placing table, and the reflected light from the original is passed through an imaging lens and an optical filter. An exposure optical system is provided which guides the exposure onto the photoreceptor using a plurality of reflecting mirrors.

Copying machines that can selectively perform monochrome copying as well as full-color copying use a blue separation filter, a green separation filter, and a red separation filter (hereinafter referred to as , referred to as blue filter, green filter and red filter, respectively)
In addition, there is an ND filter (Neutral Density Filter) that adjusts the sensitivity and exposure balance of the photoreceptor.
r) is further provided.

[0004] Blue filters, green filters, and red filters are used for full-color copying, and ND filters are used for monochrome copying.

As shown in FIG. 9, these optical filters include a blue filter 55, a green filter 56, a red filter 57, and an ND filter outside the optical path after the reflected light from the original passes through the imaging lens 51. The four filters are arranged one on top of the other in the order of 58, and are individually replaced and inserted into the optical path in order by a filter exchange device 54 comprising a drive motor 52 and a drive belt 53 rotationally driven by the drive motor 52. It has become.

[0006] When full-color copying is performed with the above-mentioned copying machine, the filter replacement operation of the filter replacement device 54 when separation exposure is performed for each color will be described below with reference to FIG. 10.

[0007] When full-color copying is performed, the optical scanning section performs optical scanning three times. First, the blue filter 55 is inserted into the optical path by the filter exchange device 54 (S1), and after that, the first optical scanning is performed by the optical scanning section, and the electrostatic charge of each blue component corresponding to the image of the original is applied to the photoreceptor. A so-called blue separation exposure is performed in which a latent image is formed (
S2).

Thereafter, the green filter 56 is exchanged and inserted into the optical path by the filter exchange device 54 (S3), followed by a second optical scan performed by the optical scanning unit, and green color separation exposure is performed (S4). ).

Furthermore, after this, the red filter 57 is exchanged and inserted into the optical path by the filter exchange device 54 (S5),
Following this, a third optical scan is performed by the optical scanning section, and red separation exposure is performed (S6). As a result, electrostatic latent images for each color component of blue, green, and red corresponding to the image of the original are formed in this order on the photoreceptor.

[0010] Furthermore, when full-color copying is performed successively for two, three, etc. in the above-mentioned copying machine, after the red separation exposure for the first sheet is completed as described above (S6), the exposure optical The system will start exposing the second sheet.

At this time, since the optical filter to be inserted into the optical path is the blue filter 55, the ND filter 58 is temporarily replaced and inserted into the optical path by the filter changing device 54 (S7), and the filter is not exposed. Immediately, the blue filter 55 is replaced and inserted into the optical path (S1). Thereafter, exposure for each color component is performed in the same manner as above.

0012

[Problems to be Solved by the Invention] The filter replacement operation by the filter replacement device 54 is started immediately after the optical scanning section completes optical scanning of the document, and the subsequent return of the optical scanning section and the further operation of the optical scanning section must be completed within a short time before starting the next optical scan.

However, in the conventional configuration described above, when full-color copying is performed continuously as described above, when the copying operation moves from the first copy to the second copy, from the second copy to the third copy, etc. First, the ND filter 58, which is not used for full-color copying, is temporarily inserted into the optical path. Therefore, when the red filter 57 is replaced with the blue filter 55, the red filter 57 is replaced with the ND filter 58 while the optical scanning section returns and starts the next optical scanning.
It is necessary to replace the ND filter 58 with the blue filter 55 twice, and the replacement speed is required to be twice as fast as when replacing the blue filter 55 with the green filter 56 and the green filter 56 with the red filter 57.

However, the replacement speed of each filter is approximately constant, and is set at a speed that allows filter replacement operations to be performed twice before the optical scanning section returns and starts the next optical scan.

[0015] Therefore, in the above conventional copying machine,
There is a problem in that the operation noise when replacing the filter is loud, and the noise emitted from the filter replacement device when the copying machine is in operation causes discomfort to the user.

[0016] Furthermore, in order to increase the copying speed during continuous full-color copying, it is necessary to further increase the filter replacement speed, which increases the operational noise during filter replacement. Furthermore, there is a limit to the filter replacement speed, and the copying speed is limited by the filter replacement speed, so it is not possible to expect much speedup.

The present invention has been made in view of the above, and an object of the present invention is to reduce the operating noise during filter replacement by replacing the filter without inserting the ND filter 58 into the optical path during continuous full-color copying. It is an object of the present invention to provide a filter replacement device for a copying machine that can contribute to reducing noise during operation of the copying machine by suppressing noise and increase copying speed.

[0018]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the filter replacement device for a copying machine of the present invention includes a first filter, for example, a blue separation filter, which separates reflected light from a document into three primary colors; A second filter, such as a red color separation filter, and a third filter, such as a green color separation filter, are provided, and the N filter adjusts the sensitivity and exposure balance of the photoreceptor.
In a filter replacement device for a copying machine which further includes a D filter or the like as a fourth filter and can individually replace and insert a predetermined filter into the exposure optical path each time the separation exposure for each color is completed, the following measures are taken.

That is, the first filter and the second filter are arranged opposite to each other on the first drive belt via the exposure optical path, and the third filter and the fourth filter are arranged on the second drive belt to face each other through the exposure optical path. The first drive belt includes a first protrusion that pushes out the first filter in the optical path direction while contacting a protrusion formed on the first filter, and a second protrusion formed on the second filter. A second protrusion is formed on the surface of the second drive belt to push out the second filter in the optical path direction while abutting against the protrusion formed on the third filter. A third protrusion that pushes out in the optical path direction, and a fourth protrusion that pushes out the fourth filter in the optical path direction while contacting a protrusion formed on the fourth filter, and the first filter and the third filter , and the fourth filter are each provided with an urging means that always applies a force in the direction of leaving the optical path. A second belt drive means for driving the belt, and a control means for controlling the operations of the first belt drive means and the second belt drive means, the control means for replacing the second filter inserted in the optical path. When replacing and inserting the first filter into the optical path, the first filter of the first drive belt is inserted during exposure.
The first belt drive means is configured to be controlled so that the protrusion moves to a position where it substantially contacts the protrusion of the first filter.

[0020]

[Operation] According to the above configuration, the first filter and the second filter
The filter is disposed opposite to the first drive belt via the exposure optical path. When the first belt driving means is actuated by the control means, the first driving belt is driven by the first belt driving means. At this time, the first protrusion of the first drive belt pushes out the first filter in the exposure optical path direction while contacting the protrusion of the first filter, and
While the second protrusion is in contact with the protrusion of the second filter, the second protrusion
The first filter or the second filter is inserted into the exposure optical path by pushing the filter out in the optical path direction.

Furthermore, the first filter is always biased by the biasing means in a direction in which it leaves the optical path. Therefore, if the first belt drive means is controlled by the control means to rotate the first drive belt in the direction opposite to the direction in which the first filter is inserted, the first filter is moved out of the optical path. It is set to leave.

[0022] Furthermore, the third filter and the fourth filter are
They are disposed opposite to each other on the second drive belt via the exposure optical path. When the second belt driving means is actuated by the control means, the second driving belt is driven by the second belt driving means. At this time, the third drive belt of the second drive belt
The protrusion pushes out the third filter in the exposure optical path direction while contacting the protrusion of the third filter, and the fourth protrusion
The third filter or ND filter is inserted into the exposure optical path by pushing out the fourth filter in the optical path direction while contacting the protruding piece of the fourth filter.

Further, the third filter and the fourth filter are always biased by the biasing means in the direction of leaving the optical path. Therefore, if the second belt drive means is controlled by the control means to rotate the second drive belt in the direction opposite to the direction in which each filter is inserted, the third filter or the fourth filter It is designed to move out of the optical path.

For example, if continuous full-color copying is performed using the first filter, second filter, and third filter, each time the separation exposure for each color is completed, the following steps will be performed: A filter replacement operation is performed.

First, the control means controls the operation of the first belt driving means, and the first filter is inserted into the exposure optical path. After this, exposure is performed.

After the exposure is completed, the control means causes the first
The operation of the belt drive means is controlled and the first filter is removed from the exposure optical path. At the same time, the control means controls the operation of the second belt driving means, and the third filter is inserted into the exposure optical path. As a result, the third filter is replaced and inserted into the optical path instead of the first filter.

After this, exposure is performed.

After the above exposure is completed, the control means causes the second
The operation of the belt driving means is controlled and the third filter is removed from the exposure optical path. At the same time, the control means controls the operation of the first belt driving means, and the second filter is inserted into the exposure optical path. As a result, the second filter is replaced and inserted into the optical path instead of the third filter.

[0029] Then, exposure is performed after this, and during this exposure, the control means controls the first
The first belt drive means is controlled to move the protrusion to a position where it substantially contacts the protrusion of the first filter.

At this time, the first drive belt is rotationally driven in the direction opposite to the direction in which the second filter is inserted, but since the second filter is not provided with biasing means, the optical path is immediately changed. It does not fall out and the second filter remains in the optical path.

After the exposure is completed, the control means controls the operation of the first belt driving means, and the first filter is inserted into the exposure optical path. At this time, since the first filter and the second filter are arranged to face each other, the second filter is pushed out of the optical path by the operation of the first filter. As a result, the first filter is replaced and inserted into the optical path instead of the second filter.

In this case, as described above, during exposure, the first protrusion of the first drive belt has been moved to a position where it substantially contacts the protrusion of the first filter, so after the exposure is completed, the first protrusion
The first filter is inserted into the exposure optical path approximately at the same time as the drive belt is driven.

[0033] Therefore, from the first filter to the third filter,
Filter replacement is performed at substantially the same replacement speed as when the third filter is replaced and inserted into the second filter.

Thereafter, in the same manner as above, each time the separation exposure for each color is completed, the first filter → third filter → second filter is changed.
The filters are successively replaced and inserted into the exposure optical path one after another in the order of filter→first filter, and so on.

As described above, when continuous full-color copying is performed using the first filter, second filter, and third filter, the fourth filter, which is not used for full-color copying, is not inserted into the optical path. . Further, each filter is replaced at substantially the same speed after the separation exposure for each color is completed.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 8.

The copying machine of this embodiment is a full-color and monochrome copying machine that can perform both full-color copying and monochrome copying, and as shown in FIG. 2, it has a transparent original table 1 on the top surface. An exposure optical system 2 is provided below the document table 1 .

The exposure optical system 2 has a light scanning section including a light source lamp 2a that irradiates light onto the original 3 placed on the original placing table 1.

In addition to the above-mentioned optical scanning section, the exposure optical system 2 also includes a plurality of reflecting lights that guide the reflected light from the original 3 onto a belt-shaped photoreceptor 24 as a photoreceptor, for example, as shown by a dashed line. It includes mirrors 2b, .

Further, the exposure optical system 2 includes a blue separation filter 4 as a first filter disposed on the optical path and that separates the reflected light from the original 3 into three primary colors (red, green, blue), and a second blue separation filter 4. In addition to the green color separation filter 5 as a filter and the red color separation filter 6 as a third filter (hereinafter referred to as a blue filter, a green filter, and a red filter, respectively), a fourth filter of the photoreceptor 24 is used as a fourth filter. ND filter (Neutr) that adjusts sensitivity and exposure balance
The filter exchange device 2d, which will be described later, is provided with a filter replacement device 2d, which includes a filter (Density Filter) 7.

Further, below the exposure optical system 2, there are four developing tanks 26 to 29, the above-mentioned belt-shaped photoreceptor 24,
Two paper feed cassettes 31 and 32 for different sizes are provided. Further, on the paper exit direction side of the photoreceptor 24, a belt-shaped intermediate transfer member 33, a conveyor belt 34, and a fixing device 3 are arranged.
5 are arranged in this order.

The photoreceptor 24 is connected to the first and second rollers 3
It is designed to be rotationally driven by 6.37. A charging charger 38 for charging the photoreceptor 24 is disposed around the outer periphery of the photoreceptor 24 in the vicinity of the first roller 36 on the side that is irradiated with the reflected light from the exposure optical system 2. A cleaning device 39 for removing toner remaining on the photoreceptor 24 is disposed below the photoreceptor 24 in the vicinity of the charger 38 .

Further, the above-mentioned developer tank 2 is installed near the center above the photoreceptor 34 without contacting the photoreceptor 34.
6 to 29 are arranged, and three color developing tanks 26 to 29 are arranged.
The developer tank 28 stores yellow, magenta, and cyan color developers, and the black developer tank 29 stores a developer containing a black pigment such as carbon black.

On the other hand, the intermediate transfer body 33 is rotationally driven by three rollers 41, 42, and 43. The second roller 37 side of the photoreceptor 24 is in pressure contact with one side of the intermediate transfer member 33.
A transfer charger 44 is disposed on the back side of the intermediate transfer body 33 at the portion where the intermediate transfer body 33 is pressed, and a transfer charger 45 and a separation charger 46 are disposed on the bottom side of the intermediate transfer body 33.

[0045] Details of the filter exchanging device 2d will be explained below.

As shown in FIG. 1, the filter exchange device 2d is provided on the optical path immediately after the reflected light from the original 3 passes through the imaging lens 2c, and includes a blue filter 4, a green filter 5, and a red filter. The filter 6 and the ND filter 7 can be individually replaced and inserted into the optical path.

The blue filter 4 and the red filter 6 are arranged opposite to each other on both sides of the exposure optical path with the imaging lens 2c as a boundary. Below these blue filters 4 and red filters 6, a drive motor 8 as a first belt drive means that can be rotated in both forward and reverse directions, and a rotating roller and a driven roller 21 of the drive motor 8 are installed. Drive belt 9 as a first drive belt rotationally driven by 8
A first drive unit 10 is provided.

A first protrusion 9a and a second protrusion 9b are formed on the surface of the drive belt 9. When the drive belt 9 is rotationally driven by the drive motor 8,
The first protrusion 9a pushes out the blue filter 4 in the optical path direction while contacting the protrusion 4a formed at the lower end of the blue filter 4 on the optical path side, and the second protrusion 9b pushes the blue filter 4 toward the optical path. The blue filter 4 or the red filter 6 is inserted into the optical path by pushing out the red filter 6 in the optical path direction while abutting against a protrusion 6a formed at the lower end on the optical path side.

Furthermore, the green filter 5 and the ND filter 7
are arranged opposite to each other on both sides of the exposure optical path with the imaging lens 2c as a boundary. Below the green filter 5 and the ND filter 7 are a drive motor 11 as a second belt drive means that can rotate in both forward and reverse directions;
A second drive unit 13 is provided, which is constituted by a drive belt 12 as a second drive belt, which is installed over the rotating roller and the driven roller 22 and is rotationally driven by the drive motor 11. The first drive section 10 and the second drive section 13
are arranged side by side with a slight interval between them.

A third protrusion 12a and a fourth protrusion 12b are formed on the surface of the drive belt 12. When the drive belt 12 is rotationally driven by the drive motor 11, the third protrusion 12a moves the green filter 5 in the optical path direction while contacting the protrusion 5a formed at the lower end of the green filter 5 on the optical path side. extrusion, and the fourth protrusion 1
The green filter 5 or the ND filter 7 is inserted into the optical path by pushing out the ND filter 7 in the optical path direction while contacting the protrusion 7a formed at the lower end of the ND filter 7 on the optical path side. ing.

Further, spring members 14 and 15 as biasing means are provided at the lower ends of the blue filter 4, the green filter 5, and the ND filter 7 on the opposite side from the optical path side, respectively.
- 16 are provided, and a force is always applied to each of these filters in the direction of leaving the optical path.

Furthermore, a convex portion 6b is formed at the upper end of the red filter 6 on the optical path side. In addition, when the ND filter 7 is inserted for replacement in place of the red filter 6 inserted in the optical path, the red filter 6 is inserted into the optical path side at the upper end of the ND filter 7 while abutting against the convex portion 6b. An extrusion portion 7c is formed for extrusion to the outside.

Further, further behind the retracted position of the blue filter 4 and the ND filter 7, there is a light transmission type blue filter detection sensor 17 equipped with, for example, a light emitting and light receiving element.
and an ND filter detection sensor 18 are provided.

The blue filter detection sensor 17 moves the blue filter 4 to the retracted position when the light from the light emitting element is blocked by the detection section 4b formed at the upper end of the blue filter 4 on the opposite side to the optical path side. It is designed to detect the presence of

Further, the ND filter detection sensor 18 detects when the light from the light emitting element is blocked by the detection section 7b formed at the upper end of the ND filter 7 on the side opposite to the optical path side. It is designed to detect that it is in the retreat position.

Furthermore, as shown in FIG. 8, the blue filter detection sensor 17 and the ND filter detection sensor 18 are
Each detection signal is output to a microcomputer (hereinafter referred to as microcomputer) 19 as a control means. That is, the microcomputer 19 detects the blue filter detection sensor 1
7 and the ND filter detection sensor 18, the positions of the blue filter 4 and the ND filter 7 are detected, and the operation of the drive motors 8 and 11 is controlled in a preset rotation direction and number of rotation steps. , to control the position of each filter.

The operation section of the copying machine further includes input keys 20 such as a copy mode switching key for selectively switching between full-color copying and monochrome copying, a 10 key for setting the number of copies, and a copying operation start key. It is provided. When the input key 20 is operated, information from the input key 20 is input to the microcomputer 19, and the microcomputer 19 controls the operation of the drive motors 8 and 11 based on this input information, and operates the filter exchange device 2d. It is designed to allow

In the above configuration, when the full color copy mode is selected by operating the copy mode switching key of the input key 20 and the 10 key, and the number of copies is set to a plurality of copies so that continuous copying is performed. The operation of the above-mentioned copying machine will be explained below.

When continuous full-color copying is performed, FIG.
As shown in FIG. 3, while the original 3 placed on the original placing table 1 is irradiated with light from the light source lamp 2a, the optical scanning unit performs optical scanning three times for each copy. Then, the reflected light from the original 3 via the reflecting mirrors 2b is sequentially decomposed into blue, green, and red color components by the blue filter 4, green filter 5, and red filter 6 of the filter exchange device 2d. Then, light for each color component for each optical scan is irradiated onto the photoreceptor 24, which is uniformly charged by the charging charger 38, and the photoreceptor 24 is exposed. That is, in the case of full color copying, a blue filter 4, a green filter 5 and a red filter 6 are used.
is used, and the ND filter 7 is not used.

The operation of the filter exchange device 2d when exposure is performed by the exposure optical system 2 will be described below with reference to FIGS. 3 to 6.

First, when the copy operation start key of the input key 20 is operated, the microcomputer 19 rotates in the direction A by a predetermined number of rotation steps, as shown in FIG.
Controls the drive motor 8. As a result, the drive belt 9 is rotationally driven in the direction A', and the blue filter 4 is pushed out by the first projection 9a of the drive belt 9 and inserted into the exposure optical path.

[0062] Thereafter, the first optical scanning is performed by the optical scanning section, and so-called blue separation exposure is performed in which electrostatic latent images for each blue component corresponding to the image of the original 3 are formed on the photoreceptor 24.

Immediately after the scanning section completes the optical scanning, the microcomputer 19 controls the drive motor 8 to rotate in the direction B by a predetermined number of rotation steps (FIG. 3).
, so as to rotate in the C direction by a predetermined number of rotation steps.
Controls the drive motor 11 (FIG. 4). As a result, the drive belt 9 is rotationally driven in the B' direction as shown in FIG. 3, and the first protrusion 9a moves to the position shown by the dashed line
The blue filter 4 is pulled back to the retracted position shown by the dashed line by the spring member 14. Further, the drive belt 12 is rotated in the C' direction as shown in FIG. 4, and the green filter 5 is pushed out by the third protrusion 12a of the drive belt 12 and inserted into the exposure optical path. As a result, the green filter 5 is replaced and inserted into the optical path instead of the blue filter 4. The above filter replacement operation is completed before the optical scanning unit returns and starts the second optical scanning.

[0064] Thereafter, a second optical scan is performed by the optical scanning unit, and electrostatic latent images for each green component corresponding to the image of the original 3 are formed on the photoreceptor 24, so-called green color separation exposure is performed. .

Immediately after the optical scanning section completes the second optical scanning, the microcomputer 19 controls the drive motor 11 to rotate in the direction D by a predetermined number of rotational steps (FIG. 4). The drive motor 8 is controlled to rotate in the B direction by a predetermined number of rotation steps (FIG. 5). As a result, the drive belt 12 is rotationally driven in the D' direction as shown in FIG. It is pulled back to the retracted position shown. Further, as shown in FIG. 5, the drive belt 8 is rotationally driven in the B' direction, and the red filter 6 is pushed out by the second protrusion 9b of the drive belt 9 and inserted into the exposure optical path.

As a result, the red filter 6 is replaced and inserted into the optical path instead of the green filter 5. The above filter replacement operation is completed before the optical scanning section returns and starts the third optical scanning.

Thereafter, the optical scanning unit performs a third optical scan, and electrostatic latent images for each red component corresponding to the image of the original 3 are formed on the photoreceptor 24, so-called red separation exposure is performed. .

Furthermore, during the red color separation exposure, the microcomputer 19 controls the drive motor 11 to rotate in the A direction by a predetermined number of rotational steps, and rotates the drive belt 9 in the A' direction, as shown in FIG. By rotationally driving the blue filter 4, the first protrusion 9a (indicated by a one-dot chain line) that has been away from the blue filter 4 is moved to a position where it substantially contacts the protrusion 4a of the blue filter 4. At this time, since no force is applied to the red filter 6 in the direction of leaving the optical path, the red filter 6 remains in the optical path.

Immediately after the optical scanning section completes the third optical scanning, the microcomputer 19 controls the drive motor 8 to rotate in the A direction by a predetermined number of rotation steps, as shown in FIG. do. As a result, the drive belt 9 is rotationally driven in the direction A', and the blue filter 4 is pushed out by the first projection 9a of the drive belt 9 and inserted into the exposure optical path. At this time, the red filter 6 is pushed out of the optical path by the action of the blue filter 4. As a result, the blue filter 4 is replaced and inserted into the optical path instead of the red filter 6. The above filter replacement operation is completed before the optical scanning unit returns and starts optical scanning in the second copying operation.

After this, blue separation exposure in the second copying operation is performed. Thereafter, the filters are replaced in the same manner as described above, and separation exposure is performed for each color of blue, green, and red, so that the photoreceptor 24 is charged with electrostatic charges for each color component corresponding to the image of the document 3. A latent image is formed in the order of blue, green, and red.

As shown in FIG. 2, each of the above-mentioned electrostatic latent images is a color having developers of yellow, magenta, and cyan, which are complementary colors of the blue filter 4, green filter 5, and red filter 6. In the portion facing the developer tanks 26 to 28, the image is developed with each developer and visualized to form a toner image. These toner images for each color component are sequentially transferred to the intermediate transfer body 33 by the transfer charger 44. In this way, toner images for each color component are sequentially superimposed,
A full color toner image is formed.

Next, the toner image on the intermediate transfer member 33 is transferred to the transfer charger when the transfer paper 47 fed from one of the paper feed cassettes 31 and 32 is brought into close contact with the lower surface of the intermediate transfer member 33. 45, the image is transferred onto the transfer paper 47. Thereafter, the transfer paper 47 is separated from the intermediate transfer body 33 by the separation charger 46, and the conveyor belt 3
4 to a fixing device 35, where the transferred image is fixed onto a transfer paper 47 and formed as a full-color copy image.

As described above, in the filter changing device 2d of the copying machine of this embodiment, when continuous full-color copying is performed, from the first sheet to the second sheet, from the second sheet to the third sheet, and so on, the next copy is When going into operation, the ND filter 7, which is not used for full-color copying, is not inserted into the optical path as in the conventional case. In addition, the replacement operation of each filter is as follows.
It starts immediately after the optical scanning unit completes optical scanning of the original 3,
Thereafter, the process is completed before the optical scanning unit returns and starts the next optical scanning, and each filter is replaced at approximately the same speed.

Therefore, when continuous full-color copying is performed at the same copying speed, the filter replacement speed can be reduced to approximately 1/2 compared to the conventional filter replacement device. Therefore, the operating noise when replacing the filter is suppressed.
This can contribute to making the copying machine quieter when operating.

Furthermore, for example, if the filter replacement speed is made as fast as before, it is possible to significantly increase the copying speed during continuous full-color copying.

The operation of the copying machine when the monochrome copy mode is selected by operating the copy mode switching key of the input key 20 will be described below.

When monochrome copying is performed, as shown in FIG. 2, while the original 3 placed on the original placing table 1 is irradiated with light from the light source lamp 2a, one copy is made by the optical scanning section. Optical scanning is performed once for each. Then, the reflected light from the original 3 passes through the ND filter 7 of the filter exchange device 2d, and is irradiated onto the photoreceptor 24, which is uniformly charged by the charger 38, and the photoreceptor 24 is exposed to light. .

That is, in the case of monochrome copying, only the ND filter 7 is used.

The operation of the filter exchange device 2d when exposure is performed by the exposure optical system 2 will be described below.

First, when the copy operation start key of the input key 20 is operated, the microcomputer 19 rotates in the direction D by a predetermined number of rotation steps, as shown in FIG.
Controls the drive motor 11. As a result, the drive belt 1
2 is rotationally driven in the D' direction, and the ND filter 7 is pushed out by the fourth protrusion 12b of the drive belt 12 and inserted into the exposure optical path.

Note that if full-color copying was performed before monochrome copying, the red filter 6 remains in the optical path, but when the ND filter 7 is inserted into the optical path as described above, , the extrusion part 7c of the ND filter 7 pushes out the red filter 6 out of the optical path while contacting the convex part 6b of the red filter 6. As a result, the ND filter 7 is replaced and inserted into the optical path instead of the red filter 6.

Thereafter, optical scanning is performed by the optical scanning unit, and the reflected light from the original 3 is transmitted through the ND filter 7 over all wavelengths in the visible range. An electrostatic latent image corresponding to the black and white density is formed.

As shown in FIG. 2, the electrostatic latent image described above is developed and visualized with a developer in a black developer tank 29 having a black developer, and then transferred to a transfer charger 44.
The image is transferred to the intermediate transfer body 33 at . Thereafter, the toner image on the intermediate transfer member 33 is transferred to the transfer paper 47 in the same manner as in the case of full-color copying, and the image is further fixed by the fixing device 35 to obtain a monochrome copy image.

When full-color copying is performed after monochrome copying, the microcomputer 19 controls the drive motor 11 to rotate in the C direction by a predetermined number of rotational steps (FIG. 7), The drive motor 8 is controlled so as to rotate in the direction A by the number of times the drive motor 8 rotates in the direction A (FIG. 3). As a result, the drive belt 12 is rotationally driven in the C' direction as shown in FIG.
It is pulled back to the retracted position shown by the dashed line. Also,
The drive belt 8 is rotationally driven in the A' direction as shown in FIG.
a and inserted into the exposure optical path. As a result, the blue filter 4 is replaced and inserted into the optical path instead of the ND filter 7.

In this embodiment, the color separation exposure is performed in the order of blue, green, and red, but the separation exposure may be performed starting from any color, and the order is not limited to this. For example, if a red filter is used as the first filter, a red filter is used as the second filter, and a green filter is used as the third filter, color separation exposure can be performed in the order of red, green, and blue.

[0086]

[Effects of the Invention] The copying machine filter replacement device of the present invention has the following features:
As described above, the first filter and the second filter are
The third filter and the fourth filter are arranged opposite to each other on the drive belt via the exposure optical path, and the third filter and the fourth filter are arranged opposite to each other on the second drive belt via the exposure optical path. A first protrusion that pushes out the first filter in the optical path direction while abutting on a protrusion formed on the first filter; and a second protrusion that pushes out the second filter in the optical path direction while abutting on a protrusion formed on the second filter. A third protrusion is formed on the surface of the second drive belt to push out the third filter in the optical path direction while contacting a protrusion formed on the third filter, and a protrusion is formed on the fourth filter. A fourth protrusion is formed that pushes out the fourth filter in the optical path direction while abutting the piece, and a force is always applied to the first filter, the third filter, and the fourth filter in the direction of leaving the optical path. A first belt drive means for driving the first drive belt, a second belt drive means for driving the second drive belt, the first belt drive means and the second belt and control means for controlling the operation with the driving means, and when the first filter is replaced and inserted into the optical path in place of the second filter inserted into the optical path, the control means controls the first filter during exposure. The first belt drive means is configured to be controlled so that the first protrusion of the drive belt moves to a position where it substantially contacts the protrusion of the first filter.

Therefore, for example, when continuous full-color copying is performed using the first filter, the second filter, and the third filter, each time the separation exposure for each color is completed, the first filter → the third filter → the third filter The filters are successively inserted and replaced individually into the exposure optical path in the order of the second filter, the first filter, and so on, and the fourth filter, which is not used for full-color copying, is not inserted into the exposure optical path. Further, each filter is replaced at substantially the same speed after the separation exposure for each color is completed.

Therefore, when performing continuous full-color copying at the same copying speed, the filter replacement speed can be approximately halved compared to conventional filter replacement devices, so the operating noise during filter replacement can be suppressed. This contributes to making the copying machine quieter during operation, and also has the effect of significantly increasing the copying speed during continuous full-color copying, for example, if the filter replacement speed is increased to the same speed as before. .

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, and is a schematic perspective view showing a filter replacement device for a copying machine.

FIG. 2 is an overall configuration diagram of the copying machine.

FIG. 3 is a schematic explanatory diagram illustrating the operation of the first drive section of the filter exchange device.

FIG. 4 is a schematic explanatory diagram illustrating the operation of the second drive section of the filter exchange device.

FIG. 5 is a schematic explanatory diagram illustrating the operation of the first drive section of the filter exchange device.

FIG. 6 is a schematic explanatory diagram illustrating the operation of the first drive section of the filter exchange device.

FIG. 7 is a schematic explanatory diagram illustrating the operation of the second drive section of the filter exchange device.

FIG. 8 is a block diagram showing the configuration of main parts of the filter exchange device.

FIG. 9 shows a conventional example, and is a schematic perspective view showing a filter replacement device for a copying machine.

FIG. 10 is an explanatory diagram illustrating the filter replacement operation of the filter replacement device when separate exposure for each color is performed when continuous full-color copying is performed in the copying machine.

[Explanation of symbols]

2d Filter replacement device 4 Blue separation filter (first filter) 5
Green separation filter (third filter) 6 Red separation filter (second filter) 7 ND filter (
4th filter) 8 Drive motor (first belt drive means) 9 Drive belt (first drive belt) 9a
First protrusion 9b Second protrusion 11 Drive motor (second belt drive means) 12
Drive belt (second drive belt) 12a Third protrusion 12b Fourth protrusion

Claims (1)

[Claims] Claim 1: In addition to a first filter, a second filter, and a third filter that separate the reflected light from the original into three primary colors,
In a filter replacement device for a copying machine further comprising a fourth filter and capable of individually replacing and inserting a predetermined filter into the exposure optical path each time separation exposure for each color is completed, the first filter and the second filter are The third filter and the fourth filter are arranged opposite to each other on the first drive belt via the exposure optical path, and the third filter and the fourth filter are arranged opposite to each other on the second drive belt via the exposure optical path, and on the surface of the first drive belt, A first protrusion that pushes out the first filter in the optical path direction while contacting a protrusion formed on the first filter, and a second protrusion that pushes out the second filter in the optical path direction while contacting a protrusion formed on the second filter. A third protrusion is formed on the surface of the second drive belt, and a third protrusion that pushes out the third filter in the optical path direction while contacting a protrusion formed on the third filter; and a third protrusion formed on the fourth filter. A fourth protrusion is formed that pushes out the fourth filter in the optical path direction while abutting the protrusion, and a force is always applied to the first filter, the third filter, and the fourth filter in the direction of leaving the optical path. A biasing means for biasing is provided, and the first belt drive means for driving the first drive belt, a second belt drive means for driving the second drive belt, and the first belt drive means and the second belt drive means are respectively provided. and control means for controlling the operation with the belt drive means, and when the first filter is replaced and inserted into the optical path in place of the second filter inserted into the optical path, the control means controls the operation of the first filter during exposure. A filter changing device for a copying machine, characterized in that the device is configured to control a first belt driving means so that the first protrusion of the first drive belt moves to a position where the first protrusion of the first drive belt substantially contacts the protrusion of the first filter. .