JPH0452945B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrostatic copying machine, particularly to a transfer type copying machine that performs electrophotographic dry development, and particularly to a dual-purpose copying machine capable of making single-sided and double-sided copies.

[Prior art]

Copying using copiers has traditionally been done mostly by single-sided copying due to the complexity of operation, maintaining the order of pages, and the complexity and bulk of the equipment. Double-sided copying is desired due to the appearance and weight of the copy booklet, and many copying machines for double-sided copying have already been proposed. For example, JP-A-52-137341, JP-A-Sho
No. 54-43742, etc., and proposals such as Japanese Patent Application No. 58-85103 are referred to regarding double-sided copying.

The above-mentioned proposals relate to the function of double-sided copying, and do not give consideration to the suitability of using recorded images as a recording medium.

That is, in single-sided copying, transfer paper that is as thin as possible is preferred in view of resource saving, storage space, weight, etc., and for example, paper with a basis weight of about 65 g/m ² is used as a standard. However, in the case of double-sided copying, if the paper is thin, it is very difficult to see the image on the front side through which the image on the back side is reflected, and it also looks bad as a booklet. Furthermore, double-sided copying inevitably requires passing the paper twice, and stiff, thin paper tends to wrinkle, and if jamming occurs, it is necessary to redo the copying operation twice for the front and back sides, and the document must be taken out again. etc., the post-processing of copy failures is surprisingly complicated.

[Purpose of the invention]

The present invention provides a copying machine capable of both single-sided and double-sided copying, which allows double-sided copying to be performed without difficulty in identifying the back side image by transparency and without causing accidents such as jamming when performing double-sided copying. The purpose is to provide a double-sided copying machine.

[Structure of the Invention] The present invention provides a detection means for detecting paper thickness,
The paper feeding means for either thin paper or thick paper is actuated by the output from the control section, which is controlled based on the signal from the copy designating section in the single-sided/double-sided copying machine and the information detected about the paper thickness. It is configured to supply recording paper adapted to the copying mode of the printer, and includes a plurality of paper storage sections, a paper thickness signal generating means for generating a signal indicating the paper thickness of the paper stored in each paper storage section, and a plurality of paper thickness signal generation means for generating a signal indicating the thickness of the paper stored in each paper storage section. The paper feed selection means selects a paper storage unit to feed paper from the paper storage unit, a single-sided copy designation unit, and a double-sided copy designation unit, and the paper supply selection unit selects the paper thickness signal based on a signal from the single-sided copy designation unit. A paper storage section whose paper thickness signal from the paper thickness signal generating means indicates that thin paper is stored is selected, and the paper thickness signal from the paper thickness signal generating means is determined based on the signal from the double-sided copy designating section. This is achieved by a single-sided/double-sided copying machine characterized in that the paper storage section whose signal indicates that it stores cardboard paper is selected.

〔Example〕

An embodiment of a single-sided/double-sided copying machine according to the present invention is shown in FIGS. 1 to 4.

The mechanism and operation will be explained below based on the drawings.

FIG. 1 shows a schematic configuration of an embodiment of a single-sided/double-sided copying machine according to the present invention, in which a platen glass P on which a document M is placed is provided on the upper surface of a main body 1, and this platen glass P inside the main body 1 is provided. A scanning optical system 2 is provided below. The scanning optical system 2 includes a reciprocating document illumination lamp 2a, mirrors 2b and 2c, and a fixed lens 2d and mirror 2e. A photoreceptor drum 3 is provided in the center of the main body 1 so as to be rotatable in the direction of the arrow, and a charging electrode 4 for uniformly charging the photoreceptor 3a along the rotational direction and a developing sleeve 5a are built in around the drum. developing device 5
, a transfer electrode 6 , a separation electrode 7 , and a static elimination electrode 8
and a cleaning device 9 are arranged in this order. Paper feed cassettes 10, 10' which are paper storage units
Two types of recording paper having different thicknesses are stored in the main body 1, that is, thick paper is stored in the paper feed cassette 10, and thin paper is stored in the paper feed cassette 10'. Inside the paper feed cassettes 10 and 10', there is a bottom plate 1 that lifts the recording paper upward by a pressure roller 11.
2 is provided. Reference numerals 13 and 13' are paper feed rollers that feed the recording paper stored in the paper feed cassettes 10 and 10' to the position of registration rollers 14, which will be described later, to prevent the recording paper from being fed in an overlapping manner. The rollers 13a, 13a and the stop roller 1 are respectively rotated via belts for the purpose of
3b. Reference numeral 14 denotes a registration roller that temporarily stops the recording paper fed by the paper feed roller 13 or 13', and then feeds the paper again toward the transfer position in synchronization with the leading edge of the image on the photoreceptor 3a. In the second
As shown in the figure, photocoupler units P are connected to paper thickness signal generating means between the registration roller 14 and the paper feed rollers 13 and 13', respectively.
and P' are provided, and paper feed cassettes 10 and 10' are provided.
Recording paper 11 has been slightly removed from the station and has stopped.
It is set to detect the amount of transmitted light at 0 and 110'. Reference numeral 15 denotes a conveying device that conveys the recording paper after transfer to a fixing position, and the fixing device 16 includes a heating roller 16a and a pressure roller 16b. 17
is a paper discharge roller that discharges the recording paper after fixing to a recording paper reverse feed device 18, and this recording paper reverse feed device 18 is provided separately from the main body 1 on the paper discharge side of the paper discharge roller 17. It consists of a forward rotation roller 18a and a forward and reverse rotation roller 18b. 19 is the recording paper reverse feeding device 1
A sorter 8 is provided on the paper ejection side for aligning the pages of the recorded material, and 20 is a double-sided sorter that temporarily stores the single-sided recorded paper fed from the paper reversing device 18 provided in the stand 21. This double-sided tray 20 has the front side in the feeding direction (right side in the figure) facing slightly downward to make it easier to store the recording paper, and the front side of the device to align the recording paper against the front side of the device. It is tilted downward. The double-sided tray 20 also includes a side regulating plate (not shown) that is movable according to the width of the recording paper, and a double-sided tray auxiliary guide plate 23 (described later).
1 is provided. 22 is an auxiliary conveyance belt for guiding the recording paper from the recording paper reverse feeding device 18 to the duplex tray 20 during double-sided copying, and 23, 23', and 23'' are pressure rollers that can swing freely in the direction of the arrow by parallel four-bar links 24. Yes, these pressure rollers 23, 23',
23'', the recording paper is attached to the auxiliary conveyor belt 2.
The double-sided tray auxiliary guide plate 231 held on the second side is conveyed so as to form a parallel four-bar link structure. In addition, these pressure rollers, 23, 2
3' and 23'' move integrally with the double-sided tray auxiliary guide plate 231 and are pressed against the auxiliary conveyance belt 22 according to the size of the recording paper during double-sided copying. When the recording paper size is medium (for example, B4 size), the left and center rollers 23 and 23' move to the position indicated by the chain line, and when the recording paper size is medium (for example, B4 size), When the size is small (for example, A4, B5 size), three rollers 23, 2
3' and 23'' are all moved to the position indicated by the chain line. 25 is a re-feeding roller for feeding again the recording paper on which one-sided copying has been completed in the duplex tray 20, and this re-feeding roller The roller 25 is also designed to prevent double feeding in the same way as the paper feed rollers 13 and 13'.As can be seen from the figure, the double-sided tray 20,
Auxiliary conveyance belt 22, pressure rollers 23, 23',
23'', a link 24, and a paper refeed roller 25 are provided in a record holding unit 26 that can be raised and lowered within the pedestal 21.A recording paper 27, which is fed by the paper refeed roller 25, is transferred to a registration roller. This is an intermediate roller provided between rollers 14 and 25 for conveying to position 14.

Next, the operation of the single-sided/double-sided copying machine will be explained.

First, when copying is to be performed on only one side of the recording paper, set the copy designation section to one-sided copy mode and operate the copy button.The original M on the platen glass P is exposed and scanned by the scanning optical system 2, and the photoreceptor of the photoreceptor drum 3 is An electrostatic latent image of the document M is formed on 3a. The electrostatic latent image is made into a visible image by the developing device 5, and the visible image is transferred by the transfer electrode 6 onto a thin recording paper from the paper feed cassette 10' of the main body 1. After the transfer, the recording paper is separated from the photoreceptor 3a by the separation electrode 7, conveyed to the fixing device 16 by the conveyance device 15, fixed there, and sent to the recording paper reverse feed device 18 by the paper discharge roller 17. At this time, each of the rollers 18a and 18b of the recording paper reverse feed device 18 is rotating forward (rotation direction that guides the recording paper toward the sorter 19 side), so the recording paper is sorted into the sorter 19 with its copy side facing upward. Ru.

On the other hand, when copying on both sides of recording paper, set the copy designation section to double-sided copy mode and turn on the copy button.
0 onto a cardboard recording paper by a transfer electrode 6. After the transfer, the recording paper is separated from the photoconductor 3a by the separation electrode 7, and transported by the transport device 15 to the fixing device 16, where it is fixed and transferred to the paper ejection roller 1.
7, the recording paper is sent to the recording paper reverse feeding device 18. At this time, the roller 18b of the recording paper reverse feed device 18 rotates in the reverse direction (rotation in the opposite direction to the forward rotation), and the auxiliary conveyance belt 22 starts to drive, and the pressure rollers 23, 23', 23'' according to the recording paper size are rotated. When moving to the position indicated by the chain line, the side regulating plate moves, and the recording paper, on which one side has been copied through the series of copying processes described above, is transported toward the roller 18b by the roller 18a of the recording paper reverse feeding device 18. Since the conveyance force of the roller 18a is greater than that of the roller 18b, the recording paper is conveyed with its leading edge sliding on the roller 18b.The roller 18b is not in strong pressure contact with the recording paper, and the conveyance is The force is weak and the roller 18a
No jamming occurs due to the conveying force. After that, when the trailing edge of the recording paper leaves the roller 18a, the conveyance force towards the roller 18b side (paper ejection direction) is lost, and conversely, the conveyance force in the opposite direction by the roller 18b works, albeit weakly, and the recording paper continues until that point. The paper is fed backwards with the rear end leading, and is sandwiched between the auxiliary conveyance belt 22 and pressure rollers 23, 23', 23'' that can be moved up and down according to the size of the recording paper and driven by the auxiliary conveyance belt 22, and the copy surface is The paper sheets are guided to the double-sided tray 20 in an upwardly facing state.A set number of recording sheets are sequentially stacked in the double-sided tray 20 through a similar process.
When a predetermined number of recording sheets are stacked in the double-sided tray 20 (the number of stacked sheets is based on the set number of sheets), the drive of the auxiliary conveyance belt 22 is stopped, and the forward tilting state (not shown) of the double-sided tray 20 is released. and become parallel. At the same time, a double-sided copy signal is output and a copying operation for the back side is started. That is, the uppermost recording paper in the double-sided tray 20 is lifted upward via the middle plate 102 by the rotation of the bottom plate 101 and is pressed against the paper refeed roller 25 .
Thereafter, the paper refeed roller 25 starts rotating, and the uppermost recording paper in the double-sided tray 20 is fed by the paper refeed roller 25 toward the main body 1 side. At this time, since the forward inclination of the double-sided tray 20 is already kept parallel, the paper can be easily fed by the rollers 25. The recording paper fed by the paper re-feeding roller 25 passes through the intermediate roller 27 and is sent to the position of the registration roller 14, and the subsequent recording paper follows the same path as when copying one side previously. undergoes a series of copying processes. The recording paper on which double-sided copying has been completed is discharged by the paper ejection roller 17, the roller 18a of the recording paper reverse feed device 18, and the roller 18b which is already rotating forward, and then sent to the sorter with the copy side facing upward. If equipped, it will be sorted into sorter 19.

As described above, in the single-sided/double-sided copying machine of the present invention, regardless of whether the copy designation section is set to one-sided or double-sided copy mode, by operating the copy button, paper selection appropriate for the copy mode, that is, the appropriate thickness is selected. The control and operation of this function is performed as follows.

That is, as shown in FIG. 3, the control unit (CPU) of the copying machine receives a signal from a single-sided or double-sided copy designation unit, the so-called copy mode designation unit, and the photocoupler units P and P' shown in FIG. Information regarding the amount of light transmitted through the recording paper, that is, paper thickness information, is input, and the presence and arrangement of thick or thin recording paper are identified by the memory that stores the specific amount of transmitted light. .

When the copy button is operated from this state, as shown in Fig. 4, if the double-sided copy mode is specified and the cardboard recording paper 110 is detected, the output from the front control unit (CPU) will be transferred to the control device (Fig. 4). (not shown)
The paper feed roller 13 is brought into a driving state via
10 is carried out and fed to the registration roller 14, and double-sided copying is performed by the process described above.

On the other hand, when the single-sided copy mode is specified, if the thin recording paper 110' is detected, the paper feed roller 13' is similarly driven;
A thin recording paper 110' is taken out from the paper feed cassette 10' and fed to the registration roller 14, where only one side of the recording paper 110' is transferred.

Also, no matter which copy mode is specified, if paper selection that should be given priority to each copy mode cannot be selected, that is, if the applicable recording paper is not detected, the copying machine will stop operating and copying will not be possible. It has also become a habit not to do it.

Note that instead of detecting the paper thickness of the recording paper using the photocoupler units P and P', the paper feed cassette 10 that stores the recording paper 110 and 110', respectively, is used.
Alternatively, it is also possible to provide dedicated detection portions for each of the recording paper 10' and indirectly detect the thickness and location of the recording paper using a plurality of microswitches or the like.

〔Effect of the invention〕

The present invention automatically supplies thick recording paper for double-sided copying and thin recording paper for single-sided copying, and stops copying if the corresponding recording paper is not available. It was decided to provide a single-sided/double-sided copying machine that could perform double-sided copying, thereby making it possible to make double-sided copies without the difficulty of certification and one-sided copies that were economical and took up little storage space.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a single-sided/double-sided copying machine according to the present invention.
FIG. 2 is a diagram of the main parts thereof, FIG. 3 is a control circuit diagram of the copying machine, and FIG. 4 is a flowchart thereof. 10, 10'...paper feed cassette, 110...
(Thick paper) Recording paper, 110'... (Thin paper) Recording paper, 1
3, 13'... Paper feed roller, P, P'... Photo coupler unit, 14... Registration roller, 18
... Recording paper reverse feeding device, 19 ... Sorter, 20 ...
...Double-sided tray, 25... Re-feed roller, 27...
intermediate roller.

Claims (1)

[Scope of Claims] 1. A plurality of paper storage sections, a paper thickness signal generating means for generating a signal indicating the paper thickness of the paper stored in each paper storage section, and a paper storage section that feeds paper from the plurality of paper storage sections. comprising a paper feed selection means for selecting, a single-sided copy designation section, and a double-sided copy designation section, and the paper supply selection means is configured to output a signal indicating the paper thickness from the paper thickness signal generation means from the paper thickness signal generation means to a thin paper according to a signal from the one-sided copy designation section. A paper storage section indicating that the sheet of paper is stored therein is selected, and a signal indicating the paper thickness from the paper thickness signal generating means indicates that the sheet of paper of thick paper is stored in response to a signal from the double-sided copy designating section. A single-sided/double-sided copying machine characterized by selecting a paper storage section that indicates the following.