JP2007093828A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus that can be easily changed to a type of accommodation of a small number of ejected sheets and a type of accommodation of a large number of ejected sheets at a low cost. <P>SOLUTION: Printers 1A and 1B are structured such that sheets of paper supplied from corresponding paper feed sections 2 in the respective lower positions are ejected onto corresponding paper ejection sections 5A and 5B in the respective high positions U after images are formed on the sheets of the paper by image forming sections 3 and fixing sections 4 in the respective intermediate positions M. In the printers 1A and 1B, a first top cover 11A having the paper ejection section 5A, which accommodates a small number of sheets of paper and is shallow, and a second top cover 11B having the paper ejection section 5B, which accommodates a large number of sheets of paper and is deep, are attached to the printers 1A and 1B and in the respective high positions U so as to be replaceable. By only exchanging the top covers 11A and 11B, the paper ejection section for accommodating a small number of sheets and the paper ejection section for accommodating a large number of sheets can be changed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a printer.

  2. Description of the Related Art Conventionally, in an image forming apparatus, there is an image forming apparatus in which different types of photoconductor units are attached to a basic apparatus main body so that a printing speed can be selected (see Patent Document 1).

By the way, when the paper discharge unit is provided at the upper position of the image forming apparatus, in a type having a small number of discharged sheets (for example, about 250 sheets), the paper discharge section may be shallow, and the top cover attached to the upper position of the image forming apparatus. Since the bulk of the image forming apparatus can be reduced, the overall image forming apparatus has a compact appearance with a low height. Further, in a type having a large number of discharged sheets (for example, about 500 sheets), the sheet discharge portion is deep, and the bulk of the top cover attached to the upper position of the image forming apparatus is increased. High appearance shape.
JP-A-6-110362

  However, since the image forming apparatus with a small number of discharged sheets and the image forming apparatus with a large number of discharged sheets are manufactured separately by the manufacturer, the manufacturer also considers the compatibility of both types. If the user wants to change the type of image forming apparatus with a small number of discharged sheets to a type with a large number of discharged sheets, There is a problem that the cost increases because an image forming apparatus having a large number of discharged sheets must be purchased.

  The present invention has been made to solve the above problems, and provides an image forming apparatus that can be easily and inexpensively changed to a type having a small number of discharged sheets and a type having a large number of discharged sheets. It is for the purpose.

  In order to solve the above-described problem, the present invention forms an image on a sheet supplied from a paper feed unit at a lower position by an image forming unit and a fixing unit at a middle position, and then discharges the paper to a paper discharge unit at an upper position. In the image forming apparatus, the first top cover having a shallow paper discharge unit having a small number of discharged sheets at the upper position of the image forming apparatus and a bulkier than the first top cover. It is another object of the present invention to provide an image forming apparatus characterized in that a second top cover having a deep bottom sheet discharge portion having a large number of discharged sheets is replaceably attached.

  According to a second aspect of the present invention, a low bulky first toner container with a small amount of toner and a bulky second toner container with a large amount of toner are replaceably attached to the developing unit of the image forming unit. It is preferable to make it.

  According to a third aspect of the present invention, the number of discharged sheets stored in the shallow sheet discharge section is about 250 sheets, and the number of discharged sheets stored in the deep sheet discharge section is about 500 sheets.

  According to a fourth aspect of the present invention, the image forming apparatus is preferably a printer.

  According to the present invention, as the top cover to be attached to the upper position of the image forming apparatus, the first top cover having a shallow bottom discharge portion with a small number of discharged sheets, and the deep bottom discharge with a large number of discharged sheets. When the image forming apparatus of a type with a small number of discharged sheets is prepared and a first top cover is attached to the upper position of the image forming apparatus, the number of discharged sheets can be increased. When many types of image forming apparatuses are desired, the second top cover is attached to the upper position of the image forming apparatus.

  As described above, the first top cover and the second top cover can be exchangeably attached to the upper position of the image forming apparatus. The type having a large number of discharged sheets can be easily and inexpensively changed not only by the manufacturer but also by the user.

  According to a second aspect of the present invention, when the second top cover having a deep bottom sheet discharge portion having a large number of discharged sheets is replaced, the first toner having a low bulkiness and a small amount of toner for the first top cover. Although the container may be a container, since the second top cover is bulkier than the first top cover, it can be replaced with a bulky second toner container having a large amount of toner.

  Since the maximum number of sheets that can be loaded in the sheet cassette of the sheet feeding unit is often set to about 250 sheets or about 500 sheets as described in claim 3, if the number of discharged sheets corresponding to the number is set, Thus, there is no excess or deficiency in the paper discharge storage space of the paper discharge unit.

  The printer is particularly effective because the printer often discharges the paper to the paper output unit at the upper position.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIGS. 1 to 5 illustrate a printer (an example of an image forming apparatus) 1A of a type (for example, A4 size 250 sheets) with a small number of discharged sheets (for example, A4 size 250 sheets) according to an embodiment of the present invention. FIGS. 1B is a type of printer (an example of an image forming apparatus) 1B having a large number of discharged sheets (for example, A4 size 500 sheets).

  First, a printer (an example of an image forming apparatus) 1A of a type with a small number of discharged sheets (for example, A4 size 250 sheets) shown in FIGS. 1 to 5 will be described.

  As shown in FIG. 4, the printer 1 </ b> A basically has an image formed on the sheet supplied from the sheet feeding unit 2 at the lower position D by the image forming unit 3 and the fixing unit 4 at the middle position M. The paper is discharged to the paper discharge unit 5A at the upper position U.

  As shown in FIG. 3, left and right frames 8 are arranged in the rectangular box-shaped printer body 7, and the lower ends of the left and right frames 8 are connected by a lower frame 9 having a horizontal width corresponding to the long side of A4 size. Has been.

  In the lower half between the left and right frames 8 (corresponding to the lower position D), a space for detachably storing a paper feed cassette 26 to be described later is formed, and the upper half between the left and right frames 8 (at the middle position M). The unit 12 (see FIG. 3) of the image forming unit 3 and the fixing unit 4 is attached.

  The outer periphery of the left and right frames 8 (the lower position D, the middle position M, and a part of the upper position U) is covered with an exterior cover 10, and the upper openings of the left and right frames 8 have a paper discharge section 5A. It is covered with a top cover (first top cover) 11A. The top cover 11A is detachably attached to the upper portions of the left and right frames 8.

  As shown in FIG. 4, in the image forming unit 3, the peripheral surface of the photosensitive drum 14 rotating in the direction A in the figure is uniformly charged by the charging device 13, and the laser light based on the image data is exposed to the exposure unit 15 such as LSU. Is applied to the peripheral surface of the photosensitive drum 14 to form an electrostatic latent image, and toner is supplied from the developing device 16 to the electrostatic latent image formed on the peripheral surface of the photosensitive drum 14, thereby A toner image is formed on the peripheral surface of the drum 14.

  Further, the sheet is conveyed from the sheet feeding unit 2 toward the photosensitive drum 14, and the toner image on the surface of the photosensitive drum 14 is transferred to the surface (transfer surface) of the sheet by the transfer roller (transfer device) 18. Become. The toner remaining on the photosensitive drum 14 after the transfer is removed by a cleaning device 20 provided with a cleaning roller 19, and the remaining charge on the photosensitive drum 14 thereafter is removed by a static eliminator 21.

  The paper separated from the photosensitive drum 14 by the separating device 23 is conveyed to the fixing roller pair 24 of the fixing unit 4, and the paper on which the toner image is fixed is discharged by the discharging roller pair 25 of the discharging unit 30 </ b> A. The paper is discharged to the paper portion 5A.

  The paper feed unit 2 includes a paper feed cassette 26 that is detachably attached to the printer main body 7 and can store a plurality of sheets stacked. For example, when the sheet feeding cassette 26 is set to a depth capable of storing 500 sheets of A4 size paper and is used as a sheet feeding cassette for 250 sheets of A4 size, by inserting a raised bottom member (not shown), It can be changed to a depth that can accommodate 250 sheets of A4 size paper.

  The paper feed cassette 26 is provided with a pickup roller 27 for taking out the stored paper, and a paper feed roller 28 for sending out (sheeting) the paper taken out by the pickup roller 27 one by one to the transport path. On the upstream side (right side in the drawing) of the photosensitive drum 14 in the conveyance path, a registration roller pair 29 for waiting for the sheet fed from the sheet feeding roller 28 is provided.

  The transport path includes a first transport path 31 for transporting paper from the paper feed cassette 26 toward the photosensitive drum 14, and a second transport for transporting paper from the photosensitive drum 14 toward the fixing roller pair 24. A path 32 and a third transport path 33 for transporting a sheet from the fixing roller pair 24 toward the discharge roller pair 25 of the discharge unit 30A are provided.

  The first conveyance path 31 rises substantially vertically on the right side of the figure between the lower stage position D and the middle stage position M of the printer body 7, and extends horizontally toward the left side of the figure at the middle stage position M, and the photosensitive drum 14. It is arranged to reach.

  The third conveyance path 33 rises while curving substantially perpendicularly from the fixing roller pair 24 on the left side in the figure, on the opposite side of the first conveyance path 31, that is, between the middle position M and the upper position U of the printer body 7. Are arranged as follows.

  The second conveyance path 32 is disposed substantially horizontally from the transfer roller 18 to the fixing roller pair 24 at the middle position M of the printer body 7 in order to connect the first conveyance path 31 and the third conveyance path 33. Yes.

  A manual feed tray 35 is attached to the right side of the figure of the middle position M of the printer body 7, and a paper discharge tray 36 is attached to the left side of the figure. The trays 35 and 36 are respectively laid down to the illustrated positions when in use, and are raised up to vertical positions along the right side and left side of the printer body 7 by the hinge when not in use.

  The paper conveyance during the operation of the printer 1A will be described. The paper is taken out from the paper feed cassette 26 of the paper feed unit 2 by the pickup roller 27, and the taken-out paper is fed by the paper feed roller 28 and sent one by one to the first transport path 31. The sheet sent out to the first conveyance path 31 is once put into a standby state by the registration roller pair 29.

  Then, after waiting for the toner image to be formed on the surface of the photoconductive drum 14 and releasing the standby state, the sheet is conveyed toward the photoconductive drum 14 and is disposed to face the photoconductive drum 14. The toner image on the surface of the photosensitive drum 14 is transferred to the surface (transfer surface) of the paper by the transfer roller 18.

  Next, the sheet separated from the photosensitive drum 14 by the separating device 23 is conveyed toward the fixing roller pair 24 through the second conveying path 32. Then, the paper on which the toner image is fixed by the fixing roller pair 24 is discharged to the paper discharge unit 5A by the discharge roller pair 25 through the third conveyance path 33.

  When the manual feed tray 35 and the paper discharge tray 36 are used, when paper is fed into the manual feed tray 35, the paper is conveyed from the first conveyance path 31 toward the photosensitive drum 14, and the toner on the surface of the photosensitive drum 14. The image is transferred to the surface (transfer surface) of the paper, conveyed to the fixing roller pair 24 through the second conveying path 32, and after the toner image is fixed by the fixing roller pair 24, the image is discharged to the paper discharge tray 36. It becomes like this.

  A top cover 11A of a printer (an example of an image forming apparatus) 1A that has a small number of discharged sheets (for example, 250 sheets of A4 size) has a shallow depth E1 of the sheet discharge unit 5A as shown in FIG. Therefore, the bulk T1 is lowered accordingly.

  Further, the discharge unit 30A of the third transport path 33 is attached to the top cover 11A, and since the distance from the second transport path 32 to the discharge roller pair 25 is short, the height H1 (see FIG. 4) is accordingly increased. It is low.

  Further, as shown in FIG. 2A, the toner container (first toner container) 17A of the developing device 16 can replace the toner by opening the front cover 11a of the top cover 11A. Since the volume T1 of the cover 11A is low, the volume S1 is reduced accordingly. That is, the toner accommodation amount is small.

  Next, a printer (an example of an image forming apparatus) 1B of a type with a large number of discharged sheets (for example, A4 size 500 sheets) shown in FIGS. 6 to 10 will be described.

  The printer 1B differs from the printer 1A having a small number of discharged sheets (for example, 250 sheets of A4 size) in FIGS. 1 to 5 in that a top cover having a shallow sheet discharge unit 5A having a small number of discharged sheets. Instead of 11A, the top cover 11B is replaced with a top cover (second top cover) 11B having a deep bottom discharge section 5B that is bulkier than the top cover 11A and has a large number of discharged sheets. As described above, the top cover 11A is detachably attached to the upper portions of the left and right frames 8, and the top cover 11A is removed from the upper portions of the left and right frames 8, and the top cover 11B is attached instead.

  That is, the top cover 11B of a printer (an example of an image forming apparatus) 1B having a large number of discharged sheets (for example, A4 size 500 sheets) 1B has a deep bottom where the depth E2 of the sheet discharge unit 5B is deep as shown in FIG. Therefore (E2> E1), the bulk T2 is increased accordingly (T2> T1).

  Further, the discharge unit 30B of the third transport path 33 is attached to the top cover 11B, and the distance from the second transport path 32 to the discharge roller pair 25 is long, so that the height H2 (see FIG. 9) is correspondingly increased. It is higher (H2> H1).

  Further, the toner container (second toner container) 17B of the developing device 16 can replace the toner by opening the front lid 11a of the top cover 11B as shown in FIG. Since the volume T2 of the cover 11B is high, the volume S2 can be increased accordingly (S2> S1). That is, the toner accommodation amount is large.

  In the case of the printers 1A and 1B, as the top covers 11A and 11B attached to the upper position U of the printers 1A and 1B, a top cover having a shallow discharge unit 5A having a small number of discharged sheets (for example, 250 sheets of A4 size). 11A and a top cover 11B having a deep sheet discharge unit 5B having a large number of discharged sheets (for example, A4 size 500 sheets) are prepared. When a printer 1A of a type having a small number of discharged sheets is desired, the printer 1A The top cover 11A is attached to the upper stage position U, and when the printer 1B of a type having a large number of discharged sheets is desired, the top cover 11B is attached to the upper stage U of the printer 1B.

  As described above, the top cover 11A and the top cover 11B can be interchangeably attached to the upper positions U of the printers 1A and 1B. Therefore, only by replacing the top covers 11A and 11B, the number of discharged sheets is small. As a result, the user can easily and inexpensively change to a type having a large number of discharged sheets.

  In addition, when the top cover 11B having the deep bottom discharge section 5B having a large number of discharged sheets is replaced, the first toner container 17A having a small toner storage capacity for the top cover 11A may be used. Since 11B is bulkier than the top cover 11A, it can be replaced with a bulky toner container 17B having a large toner storage capacity.

  Further, since the maximum number of sheets that can be loaded in the sheet cassette 26 of the sheet feeding unit 2 is often set to about 250 sheets or about 500 sheets at most, if the corresponding sheet storage capacity is set, the sheet discharge There is no excess or deficiency in the paper discharge accommodation space of the sections 5A and 5B.

  In the above embodiment, the printers 1A and 1B have been described. However, the printers 1A and 1B are particularly effective because they often discharge paper to the paper discharge units 5A and 5B at the upper position U. Of course, the present invention can also be applied to a multifunction peripheral or other image forming apparatus.

  In the above-described embodiment, the A4 size printers 1A and 1B are used. However, as shown in FIGS. 11 and 12, the number of discharged sheets is small (for example, A3 size is 250 sheets) type printer (an example of an image forming apparatus). It may be 1C. Although not shown, the same applies to a printer 1D of a type having a large number of discharged sheets (for example, A3 size 500 sheets).

  In this case, as shown in FIG. 12, the left and right frames 8 of the A4 size printer 1A and the left and right exterior cover portions covering the frame 8 are used as they are, and the A4 size lower frame 9 has a long side of A3 size. The A4 size unit 12 and the discharge unit 30A are changed to a unit 12 ′ and a discharge unit 30A ′ that are expanded to a horizontal width corresponding to the A3 size, respectively. Similarly, the A4 size exterior cover 10, the top cover 11A, and the like are changed to the exterior cover 10 ′ and the top cover 11A ′ that are enlarged to a width corresponding to the A3 size.

  As described above, the left and right frames 8 and the left and right outer covers of the left and right frames 8 of the A4 size printers 1A and 1B can be shared by the A3 size printers 1C and 1D, and the A4 size printers 1A and 1B. Since the lower frame 9, the unit 12, the discharge unit 30A, the exterior cover 10, the top cover 11A, etc. are only enlarged to a width corresponding to the A3 size, the A4 size printers 1A and 1B and the A3 size printers 1C and 1D The compatibility rate of parts and the standardization rate of design will increase, and it will be possible to contribute to cost reduction and the like.

FIG. 2 is a perspective view of a printer of a type with a small number of A4 size sheets according to an embodiment of the present invention, wherein (a) is a perspective view and (b) is a perspective view with a front cover of a top cover opened. 1A is a perspective view when the front cover of the top cover is opened and the toner container is replaced, and FIG. 1B is a perspective view of the toner container. It is a disassembled perspective view of the internal structure of the printer of FIG. FIG. 2 is a side sectional view of the printer of FIG. 1. FIG. 2 is a top cover of the printer of FIG. 1, (a) is a perspective view, and (b) is a rear perspective view. 1 is a perspective view of a printer of a type with a large number of A4 size sheets according to an embodiment of the present invention, wherein (a) is a perspective view and (b) is a perspective view with a front cover of a top cover opened. FIG. 6A is a perspective view when the front cover of the top cover is opened and the toner container is replaced, and FIG. 6B is a perspective view of the toner container. It is a disassembled perspective view of the internal structure of the printer of FIG. It is side surface sectional drawing of the printer of FIG. 7 is a top cover of the printer of FIG. 6, (a) is a perspective view, and (b) is a rear perspective view. FIG. FIG. 3 is a perspective view of a printer of a type with a small number of A3-size sheets that are stored. It is a disassembled perspective view of the internal structure of the printer of FIG.

Explanation of symbols

1A, 1B printer (image forming device)
2 Paper feeding unit 3 Image forming unit 4 Fixing unit 5A, 5B Paper discharging unit 7 Printer main body 11A Top cover (first top cover)
11B Top cover (second top cover)
17A, 17B Toner containers 30A, 30B Discharge unit D Lower position M Middle position U Upper position E1, E2 Depth H1, H2 Height S1, S2 Bulk T1, T2 Bulk

Claims (4)

In an image forming apparatus in which an image is formed on a sheet supplied from a paper feed unit at a lower position by an image forming unit and a fixing unit at a middle position and then discharged to a paper discharge unit at an upper position.
A first top cover having a shallow bottom discharge section with a small number of discharged sheets at the upper position of the image forming apparatus, and a deep bottom discharge that is bulkier than the first top cover and has a large number of discharged sheets. An image forming apparatus, wherein a second top cover having a paper portion is attached in a replaceable manner.   A bulky first toner container with a small amount of toner and a bulky second toner container with a large amount of toner are replaceably attached to the developing unit of the image forming unit. The image forming apparatus according to claim 1.   3. The image according to claim 1, wherein the number of discharged sheets stored in the shallow sheet discharging section is about 250 sheets, and the number of discharged sheets stored in the deep sheet discharging section is about 500 sheets. Forming equipment.   The image forming apparatus according to claim 1, wherein the image forming apparatus is a printer.

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