JPH0237369A - Double-side copying machine - Google Patents

Abstract

PURPOSE:To achieve double-side copying capable of selecting either the top and bottom of front or back of paper in a short time when paper is fed once by selecting the scanning direction of a two-way scanning means and the appearing position of an optical switching means through the use of a transfer belt. CONSTITUTION:The copying machine is provided with an optical means 6 provided in a direction intersecting with the optical path between an original 10 and a photosensitive body 1 and opposite to the projecting direction, the optical switching means allowing the optical means 6 to appear from the optical path, the scanning means 9 scanning the original 10 in two directions, and a selecting and copying means which selects the scanning direction of the scanning means 9 and copies the original. Accordingly, two kinds of images; namely, an inverted front image, and an electing front image being projected on a photosensitive body 1 by switching an optical means 6, and an image of inverted mirror image projected without depending on the optical means, and a scanning direction of both the directions are selected in accordance with the either case of the top and bottom direction and the scanning direction of the image is coincident or crosses with each other. Thus, top and bottom of the copied images on the front and back of paper can be collated.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a double-sided copying machine that uses a photoreceptor and a transfer belt to perform double-sided copying in one pass of paper. This invention relates to a double-sided copying machine that aligns the top and bottom of both sides of a copy.

[Prior Art] Conventionally, double-sided copying, in which images recorded on a plurality of pages of original documents are copied onto both sides of copy paper, has been widely practiced for the purpose of saving paper.

Conventional double-sided copying machines are equipped with an intermediate tray, in which the paper that has been copied on one side is stored, and when the copying on one side is completed, the paper is reversed and re-supplied from there, and the paper is copied on the other side to make double-sided copies. (e.g. JP-A No. 62-6271)
A method that uses an intermediate transfer body such as a transfer belt to form front and back images on the intermediate transfer body and a photoconductor, and then passes paper between the intermediate transfer body and the photoconductor to make double-sided copies (for example, Japanese Patent Publication No. 54
-28740) is publicly known.

[Problem to be solved by the invention]

However, in the former conventional double-sided copying machine, 2
This method requires multiple passes of paper, requires a large amount of processing time for double-sided copying, and complicates the paper conveyance path, which may cause malfunctions such as paper jams.

Additionally, a problem common to both types of duplex copying machines is that when copying onto both sides of a sheet of paper with the top and bottom directions of the original image and the scanning direction in the same direction, the top and bottom of the copied image may be reversed on the front and back sides. there were. Figure 9 shows the paper after duplexing when a conventional double-sided copying machine is used to make a double-sided copy with the top and bottom of the image R aligned in the scanning direction shown by the arrow. The top and bottom are reversed from the image on the back shown in . This reversal of the top and bottom of the front and back images is vertical paper,
This occurs regardless of whether it is a horizontal paper or not.

Therefore, in conventional double-sided copying machines, in order to solve this problem, if the top and bottom direction of the original is the same as the scanning direction,
When copying the back side, it is necessary to invert the document by 180 degrees, which poses a problem in that the copying time increases.

The present invention has been developed in view of the above circumstances, and by using a transfer belt and selecting the scanning direction of the bidirectional scanning means and the protruding/retracting position of the optical switching means, it is possible to achieve the following in a short time with one paper passing. To provide a double-sided copying machine that enables double-sided copying by freely selecting the top and bottom sides.

[Means to solve the problem]

A double-sided copying machine according to the present invention includes an image of a document formed on a photoconductor, and an image of the document formed on a transfer means adjacent to the photoconductor that transfers the image on the photoconductor. In a double-sided copying machine that copies onto paper passed between the photoreceptor and the transfer means, a double-sided copying machine is provided in a direction intersecting the optical path between the original and the photoreceptor, and projects a normal image onto the photoreceptor; an optical means provided so that the projection directions thereof are opposite to each other; an optical switching means in which the optical means is movable in and out of the optical path; a scanning means for bidirectionally scanning the document; The present invention is characterized by comprising a selective copying means for selecting a scanning direction and copying.

[Effect]

In the present invention, two types of images, an inverted normal image and an erect normal image, which are projected on the photoreceptor by switching the optical means, and an inverted mirror image, which is projected without passing through the optical means, and a bidirectional scanning direction. By selecting , depending on whether the top-bottom direction of the image and the scanning direction match or intersect with each other, the top-bottom of the front and back images of the copied images can be aligned.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on drawings showing embodiments thereof.

FIG. 1 is a schematic side sectional view showing the configuration of a double-sided copying machine according to the present invention (hereinafter referred to as the present invention machine).

In the figure, l is a photoreceptor whose surface is coated or coated with a photoconductive material, and rotates in the direction of the arrow in the figure. Around the photoconductor 1, there is a developing device 2 that applies toner to the electrostatic latent image formed on the surface of the photoconductor 1, and a developer 2 that attaches toner to the electrostatic latent image formed on the surface of the photoconductor 1, and a developer 2 that attaches toner to the electrostatic latent image formed on the surface of the photoconductor 1.
A cleaner 3 for removing toner remaining on the surface, an eraser 4 for erasing charges on the surface of the photoreceptor 1, and a charger 5 for charging the surface of the photoreceptor 1 to a predetermined charge are provided. A horizontally movable glass document table 9 is provided obliquely above the photoreceptor 1, and a document 21 to be copied is placed on the top surface of the glass document table 9. An exposure lamp 8 that illuminates the original 21 is provided below the original table 9, and a first mirror 20a that emits reflected light from the original 21 in a 90° direction is provided below the exposure lamp 8. There is. In the light emission direction of the first mirror 20a, a prism device 6, which is an optical switching means for switching the image formed on the photoreceptor 1, is provided with its longitudinal direction perpendicular to the light emission direction. A lens 7 for forming an image on the photoreceptor 1 is provided in the output direction of the prism device 6, and a second mirror 20b for emitting a light beam to the photoreceptor 1 is provided in the output direction.

A transfer belt 10 is provided below the photoreceptor 1 and is a transfer member that transfers toner, which is a developer attached to the photoreceptor 1 . The transfer bell) 10 is composed of a dielectric layer and a conductive layer.
A 10th layer 101 and a 2nd layer are made of a polymer resin having layers, and are located near the first transfer charger 11, which will be described later.
20th line 102 located near the transfer charger 15
Appropriate tension is applied to the loop, forming a closed loop. Also, due to the rotation of the rollers 101 and 102, the photoreceptor 1
It is possible to rotate in the opposite direction to the photoreceptor 1 in synchronization with the photoreceptor 1.

The lower surface of the transfer belt 10 has a scraper shape for removing toner remaining after being transferred to paper, and a belt cleaner 13 that rotates between a pressure position shown by a solid line and a retracted position shown by a broken line presses one end of the belt cleaner 13. ing. On the opposite side of the belt cleaner 13 sandwiching the transfer belt 10, there is a backup roller 12 which receives the pressing force of the belt cleaner 13.
is provided. Further, a toner receiver 14 is provided below the belt cleaner 13 to collect removed toner. Further, a first transfer charger 11 is provided on the downstream side of the belt cleaner 13 in the lower movement direction of the transfer belt 10, for charging the transfer belt to a predetermined potential.

On the other hand, at a position opposite to the 10th roller 101 of transfer belt number 0, there is a first timing roller, which is made up of two rollers and determines the timing for feeding paper supplied from a paper feed tray 191, which will be described later, to the photoreceptor 1. 194, consisting of two rollers rotating in the same direction, a sabaki roller 193 for feeding the paper one by one, a pickup roller 192 for feeding the paper from the paper feed tray 191, and a paper feed tray 191 for storing the paper. are provided in this order.

The aforementioned paper feed tray 191 and pickup roller 192
, a cutting roller 193, and a timing roller 194 constitute a paper feeding device 19.

Further, above the 20th roller 102, there is a second transfer charger 15 for transferring the image on the transfer belt 10 to the back surface of the paper.
is provided. Furthermore, an upper fixing roller 16 and a lower fixing roller 17 each having a heater lamp 18° 18 inside are provided in the paper ejection direction of the transfer bell O, and fix the toner of the paper onto which the original image has been transferred onto the paper. .

FIG. 2 is a perspective view showing the configuration of a prism device which is the gist of the present invention. In the figure, 6a is a drive frame,
The drive frame 6a has a rectangular parallelepiped shape, and a prism drive motor 63 with a pulley directly connected to its upper surface is provided to horizontally drive the pulley, and a driven pulley 64 is provided at an appropriate distance from the acid motor 63 in the longitudinal direction. It is rotatably provided in a horizontal plane.

Two guide rails 62.6 are provided on the side surface of the drive frame 6a at an appropriate distance apart for guiding a prism mount 61, which will be described later.
One end of 2 is attached. Guide rail 62.62
has a rectangular bar shape, is perpendicular to the light incident direction, and has a longitudinal length slightly longer than twice the moving direction length of the prism mount 61, and the other end is attached to the driven frame 6b. The driven frame 6b has a rectangular parallelepiped shape, and has two driven pulleys 6.
4 and 64 are prism drive motors 6 of the drive frame 6a.
3 and the driven boob IJ64 so as to be rotatable in a horizontal plane.

Further, between the guide rails 62, 62, there is a prism mount 6 having rectangular grooves on both sides that engage with the guide rails 62, 62.
1 is slidably provided with the longitudinal direction of the guide rails 62 and 62 as the moving direction. The prism mount 61 has a flat plate shape, and has a groove in the center of the upper part for locking the prisms 68 and 69. Further, a flat plate-like projection 66 is formed at the side end of the prism mount 61 in the light incident direction, and the position is detected by this. Further, wires 65 for moving the prism mount 61 are attached to both sides of the prism mount 61 in the moving direction of the light image incident direction, and the wire 65 is connected to a driven pulley 64.
, 64.64 and the outer circumference of the pulley of the prism drive motor 63, and the prism frame 61 is connected to the guide rail 62.
62 in the longitudinal direction.

Prism 6 locked in a groove in the center of prism mount 61
8.69, it is preferable to use the image reversing prism used in the imaging device disclosed in Japanese Patent Publication No. 61-273531, for example. The prisms 68 and 69 have a substantially rectangular parallelepiped structure in which a V-groove is formed on the entire surface.
The prism 6 is attached with its groove facing toward the driven frame 6b, and the prism 6 is attached with its groove facing upward. Further, the side of the driving frame 6a will be called the front side of the invention machine, and the side of the driven frame 6b will be called the back side of the invention machine.

Further, near the guide rail 62 in the incident direction of the optical image, there are three position detection sensors 67a and 67b using proximity switches for detecting the position of the protrusion 66 of the prism mount 61.

67c is provided, and the protrusion 66 is a position detection sensor 67a,
When approaching the position facing prism mount 67b and 67c, position detection sensors 67a, 67b, and 67c detect protrusion 66 and detect the position of prism mount 61.

The position detection sensors 67a, 67b, and 67c are installed at a position where the prisms 68 and 69 are evacuated from the incident light, a position where the prism 68 faces the lens 7, and a position where the prism 69 faces the lens 7, respectively.

Further, a control device (not shown) for controlling the present invention is provided inside the copying machine.

Next, the operation of the apparatus of the present invention constructed as above will be explained.

The machine of the present invention is capable of scanning a document during both bidirectional relative movement between the document table 9 and the optical system, and the case where the document table 9 moves in the right direction in FIG. 1 is defined as pressure motion. Further, moving to the left is considered to be forward motion.

Next, an explanation will be given of the operation of performing double-sided copying with the top and bottom of the image aligned in the longitudinal direction of the paper by horizontally passing or vertically passing the paper.

In the following explanation, an inverted normal image refers to an image obtained by rotating the original by 180 degrees, an erect normal image refers to an image that is the same as the original, and an inverted mirror image refers to an image obtained by rotating the original reflected in a mirror by 180 degrees. .

FIG. 3 is a perspective view showing the operation of first image formation when duplex copying is performed by horizontal paper feeding, and FIG. 4 is a side view showing the state of reflection of the optical path within the prism 68.

The first image of the original 21a has an image "R" at the bottom left, and the upper and lower directions of the image "R" are perpendicular to the scanning direction of the pressure movement shown by arrows, as shown in FIG. The document is placed on the document table 9 with the side and the bottom facing you.

When copying both sides of a document using horizontal paper feeding, when a duplex copy key (not shown) is pressed, the control device detects that duplex copying is being performed, and also detects that horizontal paper feeding is being performed using the selected paper feed tray 191. do.

Note that this detection may be performed by providing a changeover switch to detect horizontally passing paper or vertically passing paper. When double-sided copying and horizontal paper feeding are detected, the prism device 6 is moved by the prism drive motor 63 to the position where the position detection sensor 67b detects the protrusion 66, in other words, the prism 68 is opposed to the lens 7, and the optical path is aligned. It is switched from the retracted position to the intersecting position.

Next, a print button L7 (not shown) is pressed, and when the print button is pressed, a drive unit (not shown) presses the document table 9 while exposing the document 21a with the exposure lamp 8 to form a first image. Move from left to right in Figure 1. The light image is reflected by the first mirror 20a, reflected three times by the prism 68 in a vertical plane as shown in FIG. The first layer is placed on the surface of the photoreceptor 1 which is charged to 500
An inverted normal image of the image, that is, as shown in FIG. A latent image is formed, toner is attached to the latent image by the developing device 2, and the latent image is developed into a toner image. Then, the toner image on the photoreceptor 1 is transferred to the transfer belt 10 charged to about -1.2 kV by the first transfer charger 11, and a toner image of an inverted mirror image of the first image, that is, an image as shown in FIG. This is an image in which the arcuate portion and the shaded portion of “R” are oriented in the opposite direction of the rotation direction of the transfer belt 10. When the transfer to the transfer belt 10 is completed, the belt cleaner 13 is retracted, and the first toner image rotates once. At this time, the transfer charger 11 may be turned on or off. When the first toner image passes through the belt cleaner 13, the belt cleaner 13 returns to the pressure position and cleans the transfer belt 10.

Further, the prism device 6 moves to the retracted position when the pressing movement of the document table 9 is completed.

Next, the operations of forming the second image and duplex copying will be explained. FIG. 5 is a perspective view showing the formation of the second image and the double-sided copying operation, and the document 21b of the second image has an image "R" which is slightly smaller than the image of the first image. It is placed on a document table 9. When the print button is pressed in the same way as for the first image, the document table 9 moves as shown by the arrow, and the light image passes through the lens 7 and onto the photoreceptor 1 without passing through the prism 68. An inverted mirror image of two images, that is, as shown in FIG. 5, the arcuate part and the diagonal line part of image "R" are taken as the direction of rotation of the photoreceptor, and the latent image of the image is made with the top on the front side and the ground on the back side. The toner image is formed and developed by the developing device 2.

Then, the leading edges of the toner image on the transfer belt 10 of the first image and the toner image of the second image on the photoreceptor 1 are brought into alignment at a first transfer position where the photoreceptor 1 and the transfer belt 10 are closest to each other. synchronization is maintained as much as possible. At the same time, the paper 195 in the paper feed tray 191 (see FIG. 1) is transferred to the pickup roller 192. The paper is supplied to the timing roller 194 via the Sabaki roller 193, and the paper is supplied to the first transfer position by the timing roller 194 so that the leading edge of the first and second toner images and the leading edge of the paper 195 coincide with each other. Two images are transferred to the surface, ie, the top surface, of paper 195. Next, the second transfer charger 1
5 is applied with a voltage of opposite polarity to that of the first toner image, and the first image is transferred to the back surface, ie, the bottom surface, of the paper 195. Finally the top.

Lower fixing roller 16. ], 7, both sides are fixed at the same time and double-sided copying is completed.

Next, a case will be described in which the vertical direction of the image and the scanning direction are set to be the same direction by vertically passing paper.

FIG. 6 is a perspective view showing the operation of forming the first image when duplex copying is performed by vertically passing paper, and FIG. 7 is a plan view showing the state of reflection of the optical path within the prism 69.

The original 21a of the first image is the same as that used for horizontal feeding,
The longitudinal direction of the image "R" is in the same direction as the scanning direction, and the top is on the right side and the bottom is on the left side as shown in FIG.・It is listed on. In the case of longitudinal paper, as in the case of horizontal paper, when the control device detects from the paper feed tray 191 and the duplex copy key that double-sided copying of longitudinal paper is being performed, the prism device 6 is activated by the prism drive motor 63. The position is switched to a position where the positioning sensor 63c detects the protrusion 66, in other words, a position where the prism 69 faces the lens 7 and intersects the optical path.

Next, a print button (not shown) is pressed, and when it is detected, the document table 9 is moved to form a first image. At this time, the light image is transmitted in the same direction from the prism 69 through the lens 7 as shown in FIG. 7, and an erect image of the first image, that is, an image "R" as shown in FIG. A latent image of the image is formed, with the arcuate part and the hatched part facing toward the back, and the ground in the direction of rotation of the photoreceptor 1, and is transferred to the development and transfer heald 10 in the same way as in the case of horizontal paper feeding. A royal mirror image of one image, that is, a toner image in which the arcuate portion and the hatched portion of the image "R" face toward the back as shown in FIG. 6 is transferred. After that, it will be the same as in the case of Yokomichi paper.

Next, the operations of forming the second image and duplex copying will be explained. FIG. 8 is a perspective view showing the formation of the second image and the operation of double-sided copying.The same image "R" as in the case of the horizontal paper is used for the second image document 21b, and the document platen is used in the same manner as the first image. Manuscript 21 on 9
Place b. The subsequent operations are the same as those for forming the second image on Yokomichi paper and duplex copying, and an inverted mirror image, that is, an arcuate portion and a diagonal line portion of the image “R” as shown in FIG. 8, is formed on the surface of the photoreceptor 1. A latent image of the image is formed with the image facing toward the front side and with the ground in the rotational direction of the photoreceptor 1, and is copied on both sides at the same timing as in the case of horizontal paper feeding, and the images are fixed on both sides of the paper 195.

As described above, by switching the prism device, the image projected onto the photoreceptor is an inverted normal image, an inverted mirror image, or an erect normal image, and by this and the selection of the scanning direction, the vertical direction and the scanning direction of the image are in the same direction. Even when copying both sides of an original, the paper does not turn upside down.

When copying is performed on only one side, copying is performed using the same procedure as for forming the second image.

Note that in this embodiment, in the case of vertically running paper and horizontally running paper, the top and bottom of the images copied on the front and back sides of the paper are aligned, but the present invention is not limited to this. You may choose the prism and scanning direction to reverse the direction.

Further, when paper is passed sideways, the prism may be selected in the scanning direction so that the front and back sides are reversed.

Furthermore, in this embodiment, two sets of prisms were used as the optical means, but the present invention is not limited to this, and the optical means may be capable of separately projecting an erect normal image and an inverted normal image onto the photoreceptor. For example, the prism may be mounted so as to be rotatable by 90 degrees around the optical axis.

In addition, in this embodiment, vertically passing paper and horizontally passing paper are detected,
Although the prism device and the scanning direction are switched based on this, the present invention is not limited to this. An input switch is provided to determine whether or not the vertical direction of the image and the scanning direction are the same, and thereby the prism device and the scanning direction are switched. The scanning direction may also be switched.

Furthermore, in this embodiment, the present invention is applied to a copying machine with a moving document table, but the present invention is not limited to this, and can also be applied to a copying machine with a moving optical system. Needless to say, the present invention can also be applied to a copying machine equipped with such a device.

〔Effect of the invention〕

As detailed above, according to the present invention, when images formed on the transfer belt and the surface of the photoreceptor are copied onto both sides of a sheet of paper,
By selecting the scanning direction and the prism used,
The top and bottom of the image can be freely selected, and even if the top and bottom direction of the image and the scanning direction are the same, the top and bottom of the images copied on both sides can be aligned, and the copying speed can be increased. play.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing the configuration of a double-sided copying machine according to the present invention, FIG. 2 is an enlarged perspective view of the prism device, and FIG. 3 is a perspective view showing the operation of first image formation in the case of cross-feeding. Figure 4 is a side view of the prism, Figure 5 is a perspective view showing the second image formation and double-sided copying operations in the horizontal direction, and Figure 6 is the first image formation in the lengthwise direction. A perspective view showing the operation, FIG. 7 is a plan view of the prism, FIG. 8 is a perspective view showing the operation of second image formation and double-sided copying in the case of horizontal paper feeding, and FIG. 9 is a copying machine using a conventional double-sided copying machine. FIG. 1... Photoreceptor 6... Prism device 68.69.
...Prism 9...Manuscript table 10...Transfer belt 21...During the manuscript Applicant Minolta Camera Co., Ltd. Agent Patent attorney Noboru Kono Figure b! lI diagram

Claims (1)

[Scope of Claims] 1. The image of the original formed on the photoreceptor and the image of the original formed on a transfer means that is adjacent to the photoreceptor and transfers the image on the photoreceptor, In a double-sided copying machine that copies onto a sheet of paper passed between a photoreceptor and a transfer means, a double-sided copying machine is provided in a direction intersecting the optical path between the original and the photoreceptor, and projects a normal image onto the photoreceptor, and an optical means provided so that the projection directions are opposite to each other; an optical switching means in which the optical means is movable in and out of the optical path; a scanning means for bidirectionally scanning the document; and scanning by the scanning means. 1. A double-sided copying machine comprising a selective copying means for selectively copying in a direction.