Image forming device

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile by an electrophotographic method. Specifically, a substantially vertical path type image in which a sheet material is supplied and conveyed substantially vertically to form a target image on the sheet material. Regarding the forming device.

【0002】

[Conventional technology]

In recent years, image forming devices having multiple functions such as copiers, printers, and facsimiles have become widespread. Until now, such an image forming apparatus has been built based on a copier, and when used as a printer, a reversing mechanism has been mounted on a peripheral device or the like in order to output in page order. However, due to the recent rapid spread of personal computers, printer-based construction is becoming the mainstream. This employs a substantially vertical path method, that is, a method in which a paper feeding unit is arranged downward and a paper ejection unit is arranged upward with the image forming means portion in the middle, and the paper is ejected with the image surface facing downward. Compared to conventional copiers, the transport path is extremely short, and most of the transport path can be opened simply by opening the side of the device. Very good jam removal.

【0003】

[Problems to be Solved by the Invention]

However, there is a problem that it is difficult to attach post-processing equipment such as a sorter, a stapler, and a finisher. To explain this concretely, the upper part of the image forming apparatus becomes the discharge port of the sheet material, so if the aftertreatment equipment is installed directly there, the height of the entire apparatus becomes higher, and the scanner as a platen is used accordingly. The operation unit becomes high and the operability deteriorates. In addition, the height of the device is naturally limited in relation to operability, and it is practically impossible to arrange many trays. Further, since the image forming apparatus receives the weight of the post-processing equipment, it is required to improve the mechanical strength of the image forming apparatus, and the cost increase due to this is unavoidable. As described above, there is a problem that the advantage of the substantially vertical path method cannot be fully utilized when the aftertreatment device is used.

【0004】

Therefore, an object of the present invention is to provide an image forming apparatus capable of using an aftertreatment device while fully utilizing the advantages of the substantially vertical path method.

【0005】

[Means for solving problems]

The present invention is based on the idea that the post-processing device is installed at a position where problems such as height and weight do not occur with respect to the image forming device, and the post-processing device and the paper ejection portion of the image forming device are communicated with each other. .. Specifically, in the invention according to claim 1, a paper feeding section is provided below the image forming means section and a paper ejection section is provided above, and the sheet material is supplied and conveyed substantially vertically to the sheet. In a substantially vertical path type image forming apparatus that forms a target image on a material surface, a sheet material conveying unit that connects an aftertreatment device mounted on the image forming apparatus and a paper ejection portion on the upper surface of the image forming apparatus. Is provided along the upper surface of the apparatus, and the sheet material transport unit has a stack portion for loading an image-formed sheet material discharged from the paper ejection unit, and the sheet material discharged from the paper ejection unit. The stack transport means for transporting to the stack portion, the post-treatment transport means for transporting the sheet material to the post-processing equipment, and the sheet material entering the post-treatment transport means and the stack transport means. It is configured to include a branching means for switching and a control means for controlling the branching means.

【0006】

In the invention according to claim 2, in the configuration according to claim 1, when the sheet material is allowed to enter the post-treatment transport means, the branching means is turned on and the sheet material is allowed to enter the stack transport means. In some cases, the control is performed to turn off the branching means. In the invention according to claim 3, in the configuration according to claim 1, the sheet full detection means for detecting whether or not the sheet material loaded on the stack portion is full is provided, and when it is determined that the sheet material is full, it is determined that the sheet material is full. The sheet material is allowed to enter the post-treatment transport means. In the invention according to claim 4, in the configuration according to claim 1, 2 or 3, the trigger signal for operating the branching means is from a sheet material detection sensor provided at the most downstream of the transport path of the image forming apparatus. It is a signal.

【0007】

[Example]

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 6. As schematically shown in FIG. 1, an image forming means unit 6 is provided in the apparatus main body 4 of the image forming apparatus 2, and a paper feeding unit 8 is provided below the image forming means unit 6 in the middle. , A paper ejection section 12 is provided above. A scanner 18 for reading a document is installed above the apparatus main body 4 via scanner bases 14 and 16, and a post-processing device such as a sorter, a stapler, a finisher, etc. having a stack portion 20a is installed on the side surface of the apparatus main body 4. 20 is installed. A sheet material transfer unit 22 having a unique transfer path and transfer function is provided on the upper surface of the apparatus main body 4 along the upper surface.

【0008】

The paper feed unit 8 is provided with a plurality of paper feed cassettes 24 and 26, and each of them accommodates, for example, sheet materials 28 and 30 of different sizes. Due to the vertical serial arrangement configuration with the image forming means 6 inside, the sheet path extends substantially vertically, that is, from the feeding section 8 to the paper ejection section 12 through the image forming means 6. P is formed.

【0009】

The image forming means unit 6 is mainly provided with a photoconductor 32 as an image carrier driven to rotate counterclockwise, and an optical writing device 34 for forming an electrostatic latent image on the photoconductor 32. .. More specifically, around the photoconductor 32, a charger 36 that uniformly charges the photoconductor 32, an eraser (not shown) that erases the electric charge in the non-image area, and an electrostatic latent image are visualized. The developing device 38 and the visible image formed by the developing device 38 are transferred to the sheet material, and the transfer device 40 that conveys the sheet material and the toner remaining on the photoconductor 32 after the transfer are removed to remove the photoconductor. A cleaning unit 42 for cleaning 32 and a static eliminator (not shown) for erasing the electric charge remaining on the photoconductor 32 after transfer are provided. Further, a fixing device 44 for melting and fixing the toner image transferred by the transfer device 40 is provided between the transfer device 40 and the paper ejection unit 12. The optical writing device 34 is a unit that converts image data from the scanner 18 into an optical signal to perform optical writing corresponding to the original image and optical writing according to image information from a personal computer, and is a laser beam from a laser light source. Is scanned through the polygon mirror, and the scanning light is guided to the photoconductor 32 by the fθ lens via the reflecting mirror to form an electrostatic latent image.

【0010】

The sheet material 28 or 30 is fed by the paper feed roller 46 and separated one by one by the separation rollers 48, and is conveyed in a substantially vertical sheet path by the transfer roller 50. A resist roller pair 52 that sends out the sheet material 28 or 30 between the transfer device 40 and the photoconductor 32 at a predetermined timing is arranged in front of the transfer device 40, and a sheet is placed in front of the resist roller pair 52. A material detection sensor 54 is provided.

【0011】

The paper ejection unit 12 is provided with a paper ejection roller 56, and in front of the paper ejection roller 56, a paper ejection sensor 58 as a sheet material detection sensor located at the most downstream of a substantially vertical sheet path is provided. ing. The scanner 18 has a contact glass 60 on which the document is placed, a white pressure plate 61 that holds the document, an illumination lamp 62 that irradiates the document placed on the contact glass 60 with light, and a folded light reflected from the surface of the document. It is composed of a reflecting scanning mirror 63, optical path folding mirror pairs 64a and 64b moving at half the speed of the scanning mirror 63, an imaging lens 66, and a CCD 67.

【0012】

The main process equipment of the image forming means unit 6, the paper feeding unit 8, and the paper ejection unit 12 are built in the apparatus main body 4, and most of the substantially vertical sheet paths are opened by opening the side plate 4a of the apparatus main body 4. It is supposed to be done. This facilitates jam processing.

【0013】

The sheet material transfer unit 22 has a stack unit 68 for loading the image-formed sheet material discharged from the paper discharge unit 12, and a stack transport unit for transporting the sheet material from the paper discharge unit 12 to the stack unit 68. Means 70, post-processing transport means 72 for transporting the sheet material to the post-processing equipment 20, branching means 74 for switching the course of the sheet material coming out of the paper ejection unit 12, and control means 76 for controlling the branching means 74 ( It is composed of Fig. 2). The stack portion 68 is provided with a sheet full detection sensor 78 as a sheet full detection means for detecting that the sheet material is full. The stack transport means 70 includes a sheet path 75 that connects between the paper ejection section 12 and the stack section 68, and a paper ejection roller that is located downstream of the sheet path 75 and discharges the sheet material to the stack section 68. 77 is provided. The post-processing transfer means 72 is located downstream of the sheet path 79, the transfer rollers 80 and 81, and the sheet path 79 that communicate between the paper ejection unit 12 and the post-processing device 20, and reaches the post-processing device 20. It is composed of a paper ejection roller 82 for ejecting sheet material and a sheet material detection sensor 83 located between the transport rollers 80 and 81. The stack portion 20a of the post-processing device 20 is also provided with a sheet full detection sensor 83 as a sheet full detection means. The branching means 74 is composed of a branching claw 74a and a solenoid 74b (FIG. 2) that drives the branching claw 74a.

【0014】

As shown in FIG. 2, detection signals are input to the control means 76 as a microcomputer from the paper discharge sensor 58, the sheet full detection sensor 78, the sheet full detection sensor 83, etc., and the control means 76 is based on these information. The solenoid 74b of the branching means 74 is controlled to be turned on / off. When processing by the post-processing device 20, it is set via the operation panel 84.

【0015】

Next, the image forming operation and the operation of the sheet material conveying unit 22 will be described. Optical writing is performed by the optical writing device 34 according to the information of the surface of the photoconductor 32 whose surface is uniformly charged by the charger 36, the image of the document read by the scanner 18, or the image from the personal computer, and is static. An electro-latent image is formed. After the charge on the non-image portion is erased by the eraser, the electrostatic latent image on the photoconductor 32 is attached with the toner charged by the developing device 38 to form a visible image. On the other hand, the sheet material 28 is fed by the paper feed roller 46 from, for example, the paper cassette 24 of the paper feed unit 8, and is separated one by one by the separation roller 48 and sent into the sheet path. The resist roller pair 52 sends the sheet material 28 to the transfer device 40 at a timing when the visible image on the photoconductor 32 and the sheet material 28 coincide with each other at the nip portion between the photoconductor 32 and the transfer belt. The sheet material 28 to which the toner image is transferred is sent to the fixing device 44, where the toner image is heat-fixed to the sheet material 28. The image-formed sheet material is discharged from the paper ejection unit 12, but when a mode that does not require processing by the post-processing device 20 is selected, the solenoid 74b is controlled by the control means 76 as shown in FIG. Is turned on, and the branch claw 74a rotates downward. As a result, only the sheet path 75 of the stack transport means 70 is opened, and the sheet material 28 or 30 is transported by the stack transport means 70 and loaded on the stack portion 68. This is the so-called normal paper ejection operation. When a mode for processing by the post-processing device 20, for example, a staple mode, is selected, as shown in FIG. 4, the solenoid 74b remains off and only the seat path 79 of the post-processing transfer means 72 is opened. .. The sheet material 28 or 30 discharged from the paper ejection unit 12 is conveyed by the post-processing transport means 72 and sent to the post-processing device 20. Although not shown, the sheet material 28 or 30 is loaded on the stack portion 20a after the completion of a predetermined job such as staples in the aftertreatment device 20.

【0016】

Normally, paper can be discharged to the stack portion 20a of the post-processing equipment 20, but in order to shorten the so-called first copy time, normal paper discharge is normally performed by stacking the sheet material transport unit 22 unless post-processing is required. Made to Part 68. The reason why the post-processing transfer means 72 is made to correspond to the off position of the solenoid 74b is that the post-processing device 20 has a larger number of stacks, so it is assumed that the continuous paper passing time may be longer. This is to reduce the size and cost of the solenoid 74b by lowering the duty of the 74b. Although not shown, the post-processing device 20 has a staple function inside.

【0017】

Next, the relationship between the stack function and the seat full detection sensor 78 will be described. When a mode that does not require processing in the post-processing device 20 is selected and a job that exceeds the number of stacks in the stack portion 68 of the sheet material transport unit 22 is executed, the sheet is as shown in FIG. Based on the detection signal from the full detection sensor 78, the control means 76 turns off the solenoid 74b and switches the transport path to the post-processing transport means 72. Therefore, the image formation can be continuously performed at one time for the total number of stacks of the sheet material transport unit 22 and the number of stacks of the post-processing device 20. Based on the information of the sheet full detection sensor 83, the above switching can be prevented when the stack portion 20a of the post-processing device 20 is full. FIG. 6 is a flowchart of the above operation. As can be seen from this, the solenoid 74b is on-controlled based on the detection signal of the paper ejection sensor 58 located at the most downstream of the sheet path of the apparatus main body 4. The seat full detection sensor 78 has a configuration in which, for example, an arm provided so as to be swingable is moved by a discharge operation of the seat material, and a return position thereof is detected to determine fullness. Since this is a well-known technique disclosed in, for example, Japanese Patent Application Laid-Open No. 4-280774, details are omitted.

【0018】

As described above, the post-processing device 20 is mounted so that the height is not bulky with respect to the device main body 4 and the weight is not added to the device main body 4, and the post-processing device 20 and the device main body 4 are discharged. By connecting the paper unit 12 with the sheet material transport unit 22 provided along the upper surface of the apparatus main body 4, the post-processing device 20 can be used without diminishing the advantages of the substantially vertical path method. I can do it.

【0019】

[Effect of the invention]

According to the invention of claim 1, a sheet material conveying unit is provided along the upper surface of the apparatus to communicate the paper ejection unit and the post-processing device 20, and the sheet material conveying unit normally ejects paper and post-processes. Since the transfer to the device is switched according to the mode of the image forming apparatus, the post-processing device can be used without diminishing the advantages of the substantially vertical path method. When post-processing is not required, the paper is discharged to the stack portion of the sheet material transport unit, so that the first copy time can be shortened. According to the inventions of claims 2 and 4, the transport path to the aftertreatment device is opened by the off operation of the branching means. Therefore, in addition to the effect of claim 1, the drive source of the branching means is downsized. , Cost reduction can be achieved.

【0020】

According to the invention of claim 3, the sheet full detection means is provided, and when the stack capacity of the sheet material transport unit is exceeded, the stack is automatically switched to the post-processing device and stacked. In addition to the above effect, the number of images exceeding the stack capacity of the sheet material transport unit can be continuously formed without stopping the apparatus.

[Simple explanation of drawings]

[Figure 1]

It is a schematic side view of the image forming apparatus which shows one Example of this invention.

[Figure 2]

It is a control block diagram.

[Fig. 3]

It is a side view of the main part which shows the state of carrying to the stack part of a sheet material transfer unit.

[Fig. 4]

It is a side view of the main part which shows the state of carrying to a post-processing equipment.

[Fig. 5]

It is a side view of the main part which shows the state which is stuck in the post-processing equipment when the stack part of a sheet material transfer unit is full.

[Fig. 6]

It is a flowchart which shows the operation of a sheet material transfer unit.

[Explanation of symbols]

6 Image forming means section 8 Paper feed section 12 Paper output section 20 Post-processing equipment 22 Sheet material transfer unit 28,30 Sheet material 58 Paper discharge sensor as a sheet material detection sensor 68 Stack part 70 Stack transport means 72 Post-processing transport means 74 Branching means 76 Control means 78 Seat full detection sensor as a seat full detection means