JP3666652B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus capable of forming an image on a sheet or roll of standard size (for example, A4 or A3).
[0002]
[Prior art]
In an image forming apparatus, it is widely known that roll paper may be used in addition to a standard size sheet. The use of the roll paper has an advantage that an image can be formed on a so-called long paper that is longer in the transport direction than the standard size.
[0003]
In general, an image forming apparatus that can use roll paper is provided with a dedicated roll paper feed unit that supplies roll paper, in addition to the standard size paper feed cassette. For this reason, this type of image forming apparatus is a so-called special one such as a large image forming apparatus such as a copying machine for drawings handling A2 size to A0 size, or a small FAX dedicated to roll paper. ing. This is because the sheet-shaped standard paper and the roll-shaped paper have different paper feed mechanisms, and a dedicated drive connection mechanism from the image forming apparatus main body to the roll paper cassette is required.
[0004]
On the other hand, there is also a demand to use roll paper to form images in long sizes other than conventional standard sizes such as banners and banners. Conventionally, these are only used for large copying machines for drawing copying. The request could not be realized.
[0005]
[Problems to be solved by the invention]
Therefore, it has been desired to develop a roll paper cassette mechanism that can be applied to a roll paper cassette and a sheet cassette that can be exchangeably mounted in the same cassette mounting portion, and in particular, to a widespread type compact image forming apparatus. .
[0006]
The present invention has been made in view of the above-described problems, and an object of the present invention is to exchangeably mount a sheet cassette loaded with a standard size sheet paper and a roll paper cassette loaded with roll paper. An image forming apparatus is provided.
[0007]
[Means for Solving the Problems]
In order to achieve the above-described object, the invention of claim 1 is an image forming apparatus in which a roll paper cassette loaded with roll-shaped long paper and a sheet cassette loaded with sheet-shaped fixed paper are interchangeably mounted. The image forming apparatus includes a paper feed roller provided in the apparatus main body for feeding the roll-shaped paper or sheet-shaped fixed paper loaded in the cassette into the image forming apparatus main body, and the roll paper cassette provided in the roll paper cassette. Rutotomoni comprising a conveying roller pair for feeding the rolled paper toward the paper feed roller that is, the drive coupling means consisting of a main body side drive source and the cassette-side drive transmission part for transmitting the drive to the transport roller pair,
Each of the roll paper cassette and the sheet cassette is provided with cassette identification means, and when the roll paper cassette is selected based on the identification information of the cassette identification detection means provided in the image forming apparatus main body, it is transported rather than the standard size. An image forming apparatus that performs image formation in a long mode in which a paper size ratio is long with respect to a direction .
[0010]
According to the present invention, when the roll paper cassette is loaded and this roll paper cassette is selected, the long mode is automatically selected. Normally, the image forming apparatus performs conveyance control such as jam detection according to the paper size to be used, but in the long mode, the paper size to be used has a longer ratio in the length direction than the standard size. Requires special transport control. As in the present invention, when the roll paper cassette is selected, the mode is automatically switched to the long mode, so that the image forming apparatus can be handled easily.
[0011]
According to a second aspect of the present invention, the roll paper cassette is an image forming apparatus provided with a cutting mechanism for cutting the roll paper loaded in the cassette into a predetermined length.
[0012]
According to the present invention, since the roll paper cutting mechanism is provided in the roll paper cassette, it is possible to use the same mechanism as before as the transport mechanism of the image forming apparatus without any significant modification. .
[0013]
According to a third aspect of the present invention, when the roll paper cassette is mounted on the image forming apparatus, the drive is transmitted to the pair of transport rollers for a predetermined time prior to the operation of the paper feed roller, and then the paper feed roller. An image forming apparatus that operates a paper roller.
[0014]
According to the present invention, as the paper feeding operation when the roll paper cassette is mounted, the transport roller is driven prior to the paper feed roller, and a slack portion of the roll paper can be formed between the paper feed roller and the transport roller. . As a result, it is possible to operate a cutting mechanism that cuts the roll paper into a predetermined length using the slack portion. Therefore, the roll paper can be cut without temporarily stopping the paper feed roller.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. 1 and 2 are external perspective views of an image forming apparatus according to an embodiment of the present invention, FIG. 3 is a longitudinal sectional view showing a main part of the image forming apparatus according to the present embodiment, and FIG. FIG. 5 is a front view of a roll paper cassette that is detachably mounted, and FIG. 5 is a top view thereof.
[0016]
The image forming apparatus shown in this embodiment is a digital copying machine. In FIGS. 1 and 2, reference numeral 1 denotes an image forming apparatus main body having a contact glass 2 on which a copy document is placed. . Reference numeral 3 denotes an automatic document feeder (ADF), the rear end of which is pivotally attached to the image forming apparatus main body 1 via hinge mechanisms 4 and 4 and separated from the contact glass 2 as shown in FIG. It can be stationary in the state. The automatic document conveying device 3 includes a conveying unit 90, 91 is a document placing table on which a copied document is placed, and 92 is a guide for regulating the copied document in a direction orthogonal to the conveying direction. An ADF contact glass 93 is provided on the side of the contact glass 2. A slit 94 is provided at a position corresponding to the ADF contact glass 93 on the bottom surface of the automatic document feeder 3. The document is read by an exposure optical system (not shown) when the document passes through the slit 94. It has become. A document mat 95 is provided on the side of the slit 94 at a position corresponding to the contact glass 2. Reference numeral 5 denotes an operation panel for inputting copy information and the like.
[0017]
Reference numeral 6 denotes a front cover, the lower end side of which is rotatably attached to the image forming apparatus main body 1 via hinge mechanisms 7 and 7 and is held in a state of projecting substantially horizontally toward the front when opened to the front side. It is like that. Reference numeral 8 denotes a toner cartridge, and 9 denotes a toner recovery tank.
[0018]
Below the front cover 6, two upper and lower sheet feeding cassettes 10 and 11 are provided. 10 is an upper paper feed cassette and 11 is a lower paper feed cassette. These upper and lower sheet feeding cassettes 10 and 11 can be mounted to the mounting port 32.33 of the image forming apparatus main body 1 and can be pulled out in the front direction in FIG. Details of the configuration of the sheet cassettes 10 and 11 will be described later with reference to FIGS.
[0019]
Returning to FIG. 1, reference numeral 14 denotes a manual paper feed unit having a manual tray 15. The manual feed tray 15 has a base end rotatably attached to the image forming apparatus main body 1 via a support shaft (not shown), and protrudes substantially horizontally toward the side as shown in the figure. A state in which the image forming apparatus main body 1 stands up almost vertically and is in close contact with the side surface of the image forming apparatus main body (stored state) can be taken.
[0020]
In addition, a copy storage unit 13 is provided above the front cover 6 for storing a copy discharged from the discharge unit 12.
[0021]
Next, with reference to FIG. 3, the conveyance of the sheet sent out from the sheet feeding cassette will be described.
FIG. 3 shows an embodiment in which a sheet cassette is mounted on the upper paper feed cassette 10 and a roll paper cassette is mounted on the lower paper feed cassette 11.
[0022]
The sheet feeding cassette 10 is provided with a lift plate 80, and the sheet-like sheet bundle loaded on the lift plate 80 is lifted upward about the fulcrum 81 by, for example, spring means when the cassette is mounted. The uppermost sheet of the sheet bundle comes into contact with the sheet feeding roller 18 provided in the image forming apparatus main body.
When the paper feed roller 18 starts rotating in response to a command from the control unit of the image forming apparatus main body, only the uppermost sheet is fed into the image forming apparatus main body by a known nail separation mechanism.
[0023]
Thus, the sheet fed from the sheet cassette 10 enters the conveyance path of the image forming apparatus main body. In the vicinity of the entrance of the transport path, registration rollers 36 and 37 are disposed so as to sandwich the transport path of the paper, and the roller 36 is driven to rotate by a driving mechanism (not shown). The roller 37 is driven by the driving of the roller 36. It is designed to turn around. A registration switch 38 for detecting the timing of the sheet whose leading edge is regulated by the registration roller pair is provided on the upstream side of the registration roller pair 36 and 37, and paper feeding is performed according to a signal given from the registration switch 38. Control is made to stop the rotation of the roller.
[0024]
An image forming unit 39 is provided above the registration rollers 36 and 37. The image forming unit 39 includes a photosensitive drum 40 on which a toner image is formed, and a cleaning unit 41, a charger 42, a developing unit 43, a transfer roller 44, and the like disposed around the photosensitive drum 40 along the rotation direction. doing. Then, the registration roller pair is re-driven in accordance with the image formation timing, and is sent to a transfer portion formed between the transfer roller 44 and the photosensitive drum 40 to transfer the toner image.
[0025]
A fixing unit 45 is provided above the image forming unit 39 (on the downstream side of the conveyance path from the transfer unit). The fixing unit 45 has a pair of rollers each composed of a pressure roller 46 and a heat roller 47 arranged to face each other so as to sandwich the sheet conveyance path. The sheet is sandwiched between these to pressurize and heat. The toner image transferred onto the paper is melted and fixed on the paper.
[0026]
Above the fixing unit 45, the discharge unit 12 is provided. The discharge unit 12 has a pair of discharge rollers 48 and 49 arranged to face each other so as to sandwich the sheet conveyance path, and the copy storage unit is configured such that the sheet passing through the fixing unit 45 is sandwiched between the discharge rollers 48 and 49. 13 is discharged.
[0027]
Note that vertical conveyance paths 91, 92, and 93 are provided on the left side of each of the cassettes 10 and 11 at the bottom of the image forming apparatus main body, and when cassettes are provided on the blocks below the respective cassettes, The sheet is guided from the lower cassette to the sheet conveyance path of the main body of the image forming apparatus.
Specifically, the vertical conveyance path 91 is for feeding the sheet fed from the lower sheet feeding cassette 11 to the registration roller pairs 36 and 37, and the vertical conveyance paths 92 and 93 are further cassettes on the lower side of the lower sheet feeding cassette 11. Is attached to the pair of registration rollers 36 and 37 via the vertical conveyance path 91. A pair of conveyance rollers 95 is provided between the vertical conveyance paths 92 and 93.
[0028]
Next, a roll paper cassette, which is a feature of the present invention and is mounted on the image forming apparatus main body as a lower paper feed cassette in this embodiment, will be described with reference to FIG. 4 (a schematic front view) and FIG. 5 (a schematic top view). explain.
[0029]
A roll paper cassette denoted as 100 as a whole is provided with a pair of support members 102 and 103 for rotatably supporting the roll paper 110 inside the cassette housing 101. Concave portions 104 and 105 are formed on the upper surfaces of the support members 102 and 103 so that the rotating shaft 106 of the roll paper 110 can be supported.
The rotation shaft 106 of the roll paper 110 is a known shaft such as a shaft inserted into the core paper of the roll paper or a shaft formed on the flange member 107 attached to the core paper of the roll paper 110. .
[0030]
Further, a lift plate 114 is provided on the bottom surface of the cassette housing 101 so as to be rotatable about a fulcrum 112 as a rotation center. Then, a spring (not shown) provided between the bottom surface of the cassette housing 101 and the lift plate 114 raises the lift plate 114 to an arrow 116 in the figure when the cassette 100 is mounted (clockwise in the figure). Turn to).
[0031]
On the other hand, two transport rollers 130 and 131 are rotatably mounted on the cassette housing 101, and a known cutter unit 134 is provided between the two transport rollers 130 and 131. This cutter means 134 is moved forward or backward in the paper width direction (arrow direction in the figure) along the carriage 172 using, for example, a disk-shaped cutter blade 170 disclosed in Japanese Patent Publication No. 7-49192 as a drive source. By doing so, the paper is cut. The cutter blade 170 of the cutter means 134 is retracted to the outside of the roll paper when not operating, and is cut by moving forward or backward in the width direction of the roll paper based on a cutting command. .
[0032]
One side (upper side in FIG. 5) of the rotation shafts 136 and 137 of the transport rollers 130 and 131 protrudes from the side wall of the cassette housing 101, and gears 138 and 139 are attached to the front ends thereof. Between these two gears 138 and 139, it is rotatably attached to the side wall of another gear 140 cassette housing 101, and a gear train by these three gears is constituted. A pin 144 for driving and coupling with a coupler 143 provided on the drive source side of the image forming apparatus main body is provided at the tip of the rotation shaft 142 of the central gear 140.
The coupler 143, the pin 144, and the gears 140, 138, and 139 constitute drive transmission means.
[0033]
On the other hand, the lift plate 114 is provided with openings 150 and 151 in a positional relationship corresponding to the two transport rollers 130 and 131 described above, and the driven roller 152 is in a positional relationship in which a part of the openings 150 and 151 protrudes. , 153 are rotatably attached to the lower surface of the lift plate 114. The conveying roller 130 and the driven roller 152 form a roller pair, and the conveying roller 131 and the driven roller 153 form a roller pair.
[0034]
In the roll paper cassette 100 described above, the roll paper 110 is pulled out and set through the lower side of the transport rollers 130 and 131 so that the leading edge of the paper is positioned at the end of the lift plate 114. When the roll paper cassette 100 with the roll paper 110 set in this way is attached to the lower cassette 16 of the image forming apparatus, the lift plate engaging mechanisms 178 and 179 are released, and the lift plate 114 in the direction indicated by the arrow 116 is raised to move the paper. The leading end is sandwiched between the lift plate 114 and the sheet paper provided on the main body of the image forming apparatus and the sheet feeding roller 19.
In FIG. 5, reference numeral 160 denotes an electrical connection provided on the side wall of the cassette housing, which identifies a cassette such as a roll cassette or a sheet cassette and supplies power to the cutter unit 134.
[0035]
If the roll paper cassette 100 is selected as the lower cassette of the image forming apparatus now, it is determined by this electrical connection portion that it is a roll paper cassette, and the drive transmission to the transport rollers 130 and 131 is made based on the start signal of the copying operation. Then, power supply to the cutter unit 134 is executed. Further, when the image forming apparatus determines whether or not the roll paper cassette is mounted, control may be performed so that the default value itself of the paper selection mode of the copying machine is set to the roll paper cassette selection state.
On the other hand, a normal sheet cassette also has an electrical connection portion similar to the electrical connection portion 160 of the roll paper cassette described above, and this sheet cassette executes a mounting determination including paper size determination information. When the image forming apparatus determines that the sheet cassette is mounted, the above-described drive source on the main body side does not operate.
[0036]
In the present embodiment described above, when a roll paper cassette is selected from the operation panel 5, a transition is made to a long paper mode suitable for image forming processing for a long paper. Specifically, the contents of the long paper mode are as follows. (1) Jam (paper double feed) detection using the registration switch 38 is not performed or the detection time is lengthened. (2) The image memory is not divided. , Consists of two elements. These will be described in detail below.
[0037]
First, (1) will be described. The registration switch 38 is turned on when the leading edge of the sheet conveyance direction reaches the registration switch 38, and the registration switch 38 is turned off when the trailing edge of the sheet conveyance direction passes the registration switch 38. The time from ON to OFF is determined by the paper size, and when this time exceeds a predetermined time, the control circuit determines that double feeding has occurred and stops the operation. This process is possible when the standard paper is continuously conveyed, because a gap is generated between the papers. However, since the long paper is continuous, the registration switch 38 remains ON unless cut. Thus, if it is determined with the same length of time as in the case of the standard paper, a malfunction occurs. Therefore, in the long paper mode, such processing is not performed or the detection time is lengthened to prevent malfunction.
[0038]
Next, (2) will be described. When image formation is performed on a standard sheet, the CPU of the control circuit temporarily expands the data read from the scanner in the bitmap memory. In this bitmap memory, the original data is expanded and secured for each page. However, in the long paper mode, the CPU eliminates the area separation for each page and makes the entire memory as one area. I try to secure it.
[0039]
Next, a case where copying is actually performed will be described. First, when the roll paper of the lower sheet cassette 11 is selected from the operation panel 5 and the print button is pressed, a copy document is sent in the length direction and is exposed by an exposure optical system disposed below the ADF contact glass 93. The original image is read. Further, the transport rollers 23 and 24 rotate to draw the leading end of the long sheet 17 into the image forming apparatus main body 1.
[0040]
The leading edge of the roll paper 17 rises in the transport path, passes through the registration switch 38 and abuts between the registration rollers 36 and 37 and stops. In the image forming unit 39, the surface of the photosensitive drum 40 is charged by the charger 42, the photosensitive drum 40 rotates, and the reflected light of the image of the copy original read by the exposure optical system is reflected on the photosensitive drum 40. The electrostatic latent image of this image is formed on the surface of the photosensitive drum 40. Then, the developing unit 43 develops the electrostatic latent image by attaching toner to the surface of the photosensitive drum 40.
[0041]
When the roll paper 17 stops and a predetermined time elapses, the registration rollers 36 and 37 rotate and the roll paper 17 rises again. Then, the toner image on the surface of the photosensitive drum 40 is transferred onto the roll paper 17 when passing between the photosensitive drum 40 and the transfer roller 44. Then, the roll paper 17 reaches the fixing unit 45 and is pressurized and heated between the rollers 46 and 47, whereby the toner image is melted and fixed on the roll paper 17. Then, the roll paper 17 on which the image is formed reaches the discharge unit 12 and is discharged to the copy storage unit 13 by the discharge rollers 48 and 49.
[0042]
The roll paper 17 is cut in the width direction by the cutter 50 when it is conveyed by a predetermined length. At this time, since the cutter 50 is provided in the roll paper cassette 11, a mechanism for rewinding the roll paper 17 is not necessary. When a new copy document is set on the document table 91 and the print button is pressed, the above operation is repeated and the next copy is performed.
[0043]
As described above, since the roll paper cassette and the sheet cassette can be mounted interchangeably, the image forming apparatus itself can be designed in a compact manner.
[0044]
The present invention is not limited to the above-described embodiment, and various modifications can be made to the above-described embodiment without departing from the gist of the present invention.
[0045]
For example, in the above-described embodiment, if the number of cassettes is only one, and the sheet cassette and the roll paper cassette are exchangeable in this one stage, a more compact image forming apparatus can be obtained.
[0046]
Of course, the present invention can also be applied to an image forming apparatus in which three or more stages of paper feed cassettes can be mounted.
[0047]
Depending on the image forming apparatus employed, a roll paper cutting cutter may be provided in the main body of the image forming apparatus.
[0048]
In the above embodiment, an example of a copying machine has been described. However, the present invention can also be applied to an image forming apparatus such as a printer or a facsimile.
[0049]
[Brief description of the drawings]
FIG. 1 is an external perspective view of an image forming apparatus according to an embodiment of the present invention.
FIG. 2 is an external perspective view of an image forming apparatus according to an embodiment of the present invention.
3 is a longitudinal sectional view of a main part of the image forming apparatus shown in FIGS.
FIG. 4 is a schematic front view of a roll paper cassette applied to the present invention. FIG. 5 is a schematic top view of a roll paper cassette applied to the present invention.
DESCRIPTION OF SYMBOLS 1 Image forming apparatus main body 10 Upper paper feed cassette 11 Lower paper feed cassette 16 Sheet paper 110 Roll paper 130 Carrying roller 131 Carrying roller 134 Cutter 143 Coupler (main body side drive source)
144 pin (cassette side drive connecting part)

Claims (3)

In an image forming apparatus in which a roll paper cassette loaded with roll-shaped long paper and a sheet cassette loaded with sheet-shaped regular paper are mounted interchangeably,
The image forming apparatus includes a paper feed roller provided in an apparatus main body that feeds roll-shaped paper or sheet-shaped fixed paper loaded in a cassette into the image forming apparatus main body,
A pair of conveyance rollers that are provided in the roll paper cassette and feed the roll-shaped paper loaded in the roll paper cassette toward the paper feed roller;
Rutotomoni a drive coupling means consisting of a main body side drive source and the cassette-side drive transmission part for transmitting the drive to the transport roller pair,
Each of the roll paper cassette and the sheet cassette is provided with cassette identification means, and when the roll paper cassette is selected based on the identification information of the cassette identification detection means provided in the image forming apparatus main body, it is transported rather than the standard size. An image forming apparatus that performs image formation in a long mode in which a paper size ratio is long with respect to a direction .   2. The image forming apparatus according to claim 1, wherein the roll paper cassette is provided with a cutting mechanism for cutting the roll paper loaded in the cassette into a predetermined length. When the roll paper cassette is mounted on the image forming apparatus, the image forming apparatus includes control means for operating the paper feed roller after transmitting the drive to the pair of transport rollers for a predetermined time prior to the operation of the paper feed roller. the image forming apparatus according to claim 2, wherein a has.

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