JP2002347949A - Image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation device capable of precisely discriminating a sheet size even if a sheet regulating plate is not closely fitted to the sheet. SOLUTION: The regulating member 3 is provided in a sheet stacking means 1 stackable multiple sizes of sheets in such a state as orthogonally moving in the sheet conveying direction and regulates the movement of the sheets stacked on the sheet stack means 1 in the width direction orthogonally to the sheet conveying direction. The sheet stack means 1 is provided with moving members 5a and 5b moving interlocked with the width-directional movement of the regulating member 3 in the rear surface and the moving member 5a is provided with a discrimination part 7 having a pattern for discriminating the size of the sheet. This device is so constituted that, even if the pattern of the discrimination part 7 is moved in a position capable of regulating the sheet movement without making the regulating member 3 abut on the sheet, the sheet size can be discriminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus, and more particularly to an arrangement for identifying the size of a sheet stacked on a sheet stacking means.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus such as a copying machine, a printer, a facsimile, etc., which conveys a sheet stacked on a sheet stacking means capable of stacking sheets of a plurality of sizes to an image forming section to form an image. In the above, as a sheet stacking means, for example, a large-capacity elevator-type tray disposed inside the apparatus main body, a cassette detachably mounted on the apparatus main body, and fixedly or foldably mounted on the apparatus main body, and stacked and stored. Some have a multi-tray or the like in which a part of the sheet is exposed from the apparatus main body.

Incidentally, in an image forming apparatus in which sheets are stacked on such various sheet stacking means, it is necessary to identify the size of the stacked sheets.
Here, for example, in the case of a cassette, there is a case in which the size of sheets that can be stacked is predetermined, and when such a cassette is used, when the cassette is mounted on the apparatus main body, the type of the cassette is identified. By doing so, the size of the sheet can be identified.

In the case of a cassette (multi-cassette) in which sheets of an arbitrary size can be stacked and stored, a user manually switches a detected portion installed in the cassette according to the size of the loaded sheets. Or
When the user adjusts the position of the regulating plate that regulates the end portion of the sheet to the end portion of the sheet, the portion to be detected installed in the cassette is switched in conjunction with it.

After the detected portion is switched in accordance with the sheet size as described above, when the cassette is mounted in the main body, the detected portion switched in accordance with the sheet size is placed in the main body. The installed detection unit can detect and identify the sheet size.

In the case of a multi-tray, if it is detachably attached to the apparatus main body, a method of identifying the sheet size by a method similar to that of the above-mentioned cassette can be adopted.

On the other hand, in the case of a device fixed to the apparatus main body, unlike a detachable cassette, it is difficult for a user to switch the detected portion, so that the detected portion is often not mounted. Further, even when the non-detection unit is switched by some method, if the switching operation is not a series of the sheet stacking operation, the switching operation may be forgotten.

For this reason, for example, a variable resistor is provided on a regulating plate for regulating the width of the sheet, the displacement of the regulating plate when regulating the sheet is output as a voltage, and the voltage is obtained by A / D conversion. The position of the regulating plate is calculated from the obtained data, and an automatic identification function such as identifying the sheet size by comparing the determined regulating plate position with the regulating plate position corresponding to the previously input sheet size is provided. There is something.

However, in such an apparatus, since the sheet size is determined based on the width of the actually stacked sheets, the sheet size can be accurately identified, but the cost of the apparatus increases. Since the apparatus becomes large, it cannot be mounted on a small and inexpensive printer. Further, when it is not necessary to know the size of the sheet exactly, there are cases where the specification becomes excessive and wasted.

Therefore, in order to solve these problems, for example, as shown in FIG. 10, a sheet regulating plate 3 of a multi-tray 1B foldably attached to the apparatus main body 100B as shown in FIG. On the rack 5 thus provided, a detected portion 7 having a pattern corresponding to a plurality of sheet sizes is provided in advance, and a detector 8 is provided at a position facing the detected portion 7, and sheet detection is performed by the detector 8. There is a type in which a pattern that changes with the movement of the plate 3 (rack 5) is detected so that the sheet size can be identified.

Here, the sheet size detection pattern includes, for example, one side edge of a predetermined sheet among the sheets having the size shown in FIG. Position TP (the sheet minimum width including the larger size tolerance and the smaller size including the smaller size tolerance) when the centers of the two sizes are matched. It is configured to switch at the middle of the difference between the maximum sheet widths.

[0012]

However, in such a conventional image forming apparatus, after the sheets are stacked on the sheet stacking plate 2 of the multi-tray 1B, the user is shown in FIGS. 12 (a) and 12 (b). 13 (a) of FIG.
And (b), the sheet regulating plate 3 may be slightly opened with respect to the sheet S to adjust the sheet S slightly. In contrast,
Adjusting the sheet regulating plate 3 slightly narrowly with respect to the sheet hardly occurs, for example, because the sheet S bends as shown in FIGS. 14A and 14B.

Therefore, when the gap between the sheet of a predetermined size and the sheet one size larger than the sheet in the width direction is narrow, the user may open the sheet regulating plate 3 with respect to the stacked sheets. If they match,
In some cases, the sheet was identified as a size one size higher than the actually stacked sheets.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an image forming apparatus capable of correctly identifying a sheet size even when a sheet regulating plate is not exactly fitted to a sheet. It is the purpose.

[0015]

According to the present invention, there is provided an image forming apparatus for conveying a sheet loaded on a sheet loading means capable of loading sheets of a plurality of sizes to an image forming section to form an image. A regulating member that is provided so as to be movable in a direction orthogonal to the sheet conveying direction, and that restricts the movement of the sheets stacked on the sheet stacking unit in the width direction orthogonal to the sheet conveying direction; A moving member provided on the back surface of the sheet stacking surface and moving in conjunction with the movement of the regulating member in the width direction; and an identification unit provided on the moving member and having a pattern for identifying the size of the sheet. The pattern of the identification portion can be identified by the size of the sheet even when the sheet is moved to a position where the movement of the sheet can be regulated without contacting the regulating member with the sheet. It is characterized in that configured so that.

Further, according to the present invention, when the pattern is arranged such that the center of the sheet and the sheet one size larger than the sheet coincides with one side edge of the sheet stacked on the sheet stacking means. The sheet is configured to be switched at a position farther than a half position of a difference between the widths of the two sizes of sheets in the width direction.

Further, according to the present invention, the pattern is made such that one side edge of a sheet stacked on the sheet stacking means coincides with the other side edge of the sheet and a sheet one size larger than the sheet. In this case, the sheet is switched at a position farther than a half of the difference between the widths of the two sizes of the sheet in the width direction.

Further, the present invention is characterized in that the moving member is a rack provided integrally with the regulating member.

Further, the present invention is characterized in that a rack is provided integrally with the regulating member, and the moving member is a pinion that meshes with the rack and rotates in conjunction with the movement of the regulating member. Is what you do.

Further, in the present invention, the regulating member is provided integrally with a rack meshing with a pinion, and the moving member meshes with a tooth surface provided on a surface of the rack opposite to a surface meshing with the pinion. And a rotating body that rotates.

Further, the present invention is characterized in that a detecting means for detecting the pattern is provided, and the pattern is formed in a convex, concave or perforated manner on the moving member according to the structure of the detecting means. is there.

Further, the present invention is characterized in that the pattern is detected by a non-contact type detecting means.

Further, as in the present invention, a regulating member is provided on the sheet stacking means on which sheets of a plurality of sizes can be stacked so as to be movable in a direction perpendicular to the sheet conveying direction, and the regulating member is stacked on the sheet stacking means. The movement of the sheet in the width direction orthogonal to the sheet conveying direction is restricted. A moving member is provided on the back surface of the sheet stacking means, the moving member moving in conjunction with the movement of the regulating member in the width direction, and an identification portion having a pattern for identifying the size of the sheet is provided on the moving member. The pattern of the section is configured so that the size of the sheet can be identified even when the sheet is moved to a position where the movement of the sheet can be regulated without contacting the regulating member with the sheet.

[0024]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a perspective view of an image forming apparatus according to a first embodiment of the present invention.
Denotes an image forming apparatus, and 100 denotes an image forming apparatus main body (hereinafter, referred to as an apparatus main body). Reference numeral 1 denotes this device main body 100
This is a paper feed tray unit fixed to.

The sheets S stacked on the paper feed tray unit 1 are conveyed by a conveying means (not shown) to an image forming section 50 for forming an image by, for example, an ink jet method through a path shown in FIG. When passing through the image forming section 50, an image is formed. After the image is formed as described above, the sheet S passes through a fixing unit (not shown), and thereafter, the apparatus main body 1 shown in FIG.
The sheet is discharged to a sheet discharge section 51 provided on the upper surface of the sheet No. 00.

The sheet feeding unit 1 serving as the sheet stacking means has a sheet stacking section 2 for stacking sheets as shown in FIG. 3, and a direction perpendicular to the direction in which the sheets are conveyed to the sheet stacking section 2. A sheet regulating plate 3 (3a, 3b), which is a pair of regulating members that are provided so as to be movable in a direction (hereinafter, referred to as a width direction) and that regulate the movement of the sheets stacked on the sheet stacking unit 2 in the width direction. It is arranged on a surface opposite to the sheet stacking surface of the sheet stacking unit 2, and is attached to the pair of sheet regulating plates 3 via a connecting member (not shown) that moves along a slide hole 4 provided in the sheet stacking unit 2. A pair of racks 5 (5a, 5b) and a pinion 6 located between the pair of racks 5 for interlocking the respective racks 5a, 5b.

Further, in the present embodiment, the paper feed tray unit 1 is provided on one 5a of a pair of racks 5 constituting a moving member and has a pattern for identifying the position of the pair of racks 5. Detected part 7 which is a part
And a detector 8 which is a detecting means for detecting information of the detected portion 7 in contact with the detected portion 7.

In this embodiment, the detected portion 7 has one or a plurality of convex portions arranged in the moving direction of the pair of sheet regulating plates 3 (rack 5) as shown in FIG. And three pattern rows H1, H2, H3
By combining these three pattern rows H1, H2, and H3, the 7 of the pair of sheet regulating plates 3 (rack 5) is
(= 2 ³ -1) positions can be detected.

Here, the seven positions of the pair of sheet regulating plates 3 are positions corresponding to the sheet size. By detecting the positions of the pair of sheet regulating plates 3, the seven positions are stacked on the sheet feed tray unit 1. It is possible to identify which size sheet is currently stacked among the seven types of possible size sheets.

On the other hand, as shown in FIG. 5, the detector 8 has three switches 9a, 9b and 9c, the number of which is the same as the number of pattern rows H1, H2 and H3. When the pair of sheet regulating plates 3 (rack 5) moves, the respective switches 9a, 9b, 9c are turned on or off.

The switches 9a, 9b, 9c
Is input to a control unit (not shown), and the control unit recognizes the sheet size based on on / off signals from the switches 9a, 9b, and 9c.

Next, the sheet size identifying operation of the image forming apparatus 100A thus configured will be described.

Before starting the image forming operation, the sheets are stacked on the sheet stacking section 2 and one of the pair of sheet regulating plates 3 is moved so as to match the width of the stacked sheets. The other of the pair of sheet regulating plates 3 is also moved by the racks 5 provided on the regulating plates 3 to a position where the other ends of the pair of sheet regulating plates 3 are aligned with the ends of the sheets. Be loaded.

When the pair of racks 5 moves as described above, one of the racks 5a
Pattern rows H1, H2, H3 of the detected part 7 provided in
The switches 9a, 9b, 9c of the detector 8 are turned on / off in response to the control signal, and the control unit identifies the sheet size based on the on / off signals from the switches 9a, 9b, 9c.

The pattern of the detected portion 7 shown in FIG. 4 can be classified as shown in FIG. 6, for example. Here, in the figure, the circles indicate the pattern rows H1, H2, H3.
Indicates that the switches 9a, 9b, 9c of the detector 8 are turned on. In this example, only the size of the sheet in the width direction is roughly understood, and if necessary, the sheet may be classified more finely.

The detector 8 shown in FIG.
This shows a state in which the top switch 9a corresponding to the pattern row H3 among the three switches 9a, 9b, 9c is turned on. Then, when the uppermost switch 9a is turned on, it indicates the state of G according to the classification of FIG. That is, a business card (a business card width sheet) is loaded on the sheet loading unit 2.

As described above, the sheet size can be identified only by moving the pair of sheet regulating plates 3 in the sheet width direction. Compared with the case where the size is identified by collating with the position of the sheet regulating plate 3, there is no need for expensive parts, and the sheet size can be identified with a simple configuration. Thereby, the inexpensive image forming apparatus 10
OA can be provided.

In addition, the sheet size can be identified only by adding the switches 9a, 9b and 9c, compared with the conventional configuration having no sheet size identification function, so that there is no great restriction on the configuration and the configuration is free. Parts can be arranged, and the apparatus main body 100 does not become large.

Further, in the case where the sheet size identification function is not provided, for example, in a fixing device for fixing a toner image transferred onto a sheet after an image is formed, the entire heating section is heated. By making it possible to identify the sheet size as in the embodiment, the heat-generating portion is adjusted to the sheet size so that a portion through which the sheet does not pass (a non-sheet passing portion) and a portion through which the sheet passes (a sheet passing portion). Can be used separately. As a result, the heat generating portion of the fixing device can be efficiently heated, and power can be saved without using unnecessary power.

In the present embodiment, the seven patterns of the detected portion 8 are divided from one side end of the sheet stacked on the sheet stacking section 2 into a sheet having a size one size larger than this sheet. Are switched at positions farther than half the difference between the lengths of the two size sheets in the width direction when the centers of the two sheets are matched.

Then, the pattern is changed to a pattern switching portion (a portion indicated by reference numeral TP in FIG. 4).
Is set to be the larger size side, even if the user adjusts the sheet regulating plate 3 slightly more slightly than the loaded sheet, in other words, even if the sheet regulating plate 3 is not exactly fitted to the sheet, It is possible not to discriminate as the next larger size, and the sheet size can be more accurately discriminated.

Next, a second embodiment of the present invention will be described.

FIG. 7 is a perspective view showing the back surface of the paper feed tray unit of the image forming apparatus according to the present embodiment. In the figure, the same reference numerals as those in FIG. 3 indicate the same or corresponding parts.

In FIG. 5, reference numeral 6A denotes a pinion located between the pair of racks 5 for interlocking the pair of racks 5, and the lower surface of the pinion 6A identifies the position of the pair of sheet regulating plates 3. To be detected 7A having a pattern for the detection. Further, a detector 8A is arranged so as to be in contact with the detected portion 7A and detects information of the detected portion 7A.

Here, the detected portion 7A rotates and moves in accordance with the movement of the pair of sheet regulating plates 3 (rack 5), and in this embodiment, is concentrically formed on the lower surface of the pinion 6A constituting the moving means. The three pattern rows H1, H2, and H3 formed in the above-described manner. By combining the three pattern rows H1, H2, and H3, 7 (= 2 ³ −1) The position can be detected.

Then, before starting the image forming operation, the sheets are stacked on the sheet stacking section 2 and one sheet regulating plate 3 is moved so as to match the end of the sheet so as to match the width of the stacked sheets. The other sheet regulating plate 3 also automatically moves to a position where it meets the end of the sheet, and the sheet is stacked so as to be located at the center of the sheet stacking section 2 in the width direction.

Here, the pair of sheet regulating plates 3
Move, the pinion 6A rotates with the movement of the sheet regulating plate 3, and the switches 9a, 9a, 9b, 9c, of the detector 8 correspond to the pattern rows H1, H2, H3 of the detected parts 7A provided on the pinion 6A. The switches 9b and 9c are turned on and off, and the control unit determines the sheet size based on the on / off signals from the switches 9a, 9b and 9c.

In this embodiment, too, the seven patterns of the detected portion 8 are set such that, from one side end of the sheet stacked on the sheet stacking portion 2, this sheet and one sheet larger than this sheet are provided. When the center of the sheet is matched,
The sheet is configured to be switched at a position farther than a half position of the difference between the widths of the two size sheets in the width direction.

Thus, even if the user does not fit the sheet regulating plate 3 exactly on the stacked sheets, it is possible to prevent the user from erroneously identifying the sheet as the next larger size, and more accurately identify the sheet size. Become like

Next, a third embodiment of the present invention will be described.

FIG. 8 is a perspective view showing the back surface of the paper feed tray unit according to the present embodiment. 7, the same reference numerals as those in FIG. 7 indicate the same or corresponding parts.

Referring to FIG. 5, reference numeral 5c denotes one rack constituting a pair of racks 5, and a tooth surface 5c1 is provided on a surface of the one rack 5c opposite to a surface meshing with the pinion 8. Reference numeral 10 denotes a disk which is a rotating body which rotates while meshing with the tooth surface 5c1 provided on the opposite surface of the rack 5c and which constitutes a moving means in the present embodiment. Are provided with three pattern rows H1, H2, H3. By combining the three pattern rows H1, H2, and H3, seven (= 2 ³ -1) positions of the pair of sheet regulating plates 3 can be detected.

Then, before the image forming operation is started, the sheets are stacked on the sheet stacking section 2 and one sheet regulating plate 3 is moved so as to match the end of the sheet so as to match the width of the stacked sheets. The other sheet regulating plate 3 also automatically moves to a position where it meets the end of the sheet, and the sheet is stacked so as to be located at the center of the sheet stacking section 2 in the width direction.

Here, the pair of sheet regulating plates 3
Is moved, the pair of racks 5 is moved with the movement of the sheet regulating plate 3, and one of the racks 5 is moved with this movement.
c, the pattern rows H1, H2, H
The switches 9a, 9b, and 9c of the detector 8 are turned on and off in response to 3, and the control unit determines the sheet size based on the on / off signals from the switches 9a, 9b, and 9c.

In this embodiment, too, the seven patterns of the detected portion 8 are set such that, from one side end of the sheet stacked on the sheet stacking section 2, the sheet and the sheet one size larger than the sheet. When the center of the sheet is matched,
The sheet is configured to be switched at a position farther than a half position of the difference between the widths of the two size sheets in the width direction.

Thus, even when the user does not fit the sheet regulating plate 3 exactly on the stacked sheets, it is possible to prevent the user from erroneously discriminating the sheet as the next larger size, and more accurately identify the sheet size. Become like

By the way, a description has been given of a so-called center reference in which the stacked sheets are positioned at the center in the width direction. However, the present invention is not limited to this, and one of the sheet regulating plates is fixed and the other is fixed. Also in a movable so-called one-side reference sheet feeding unit, from one side end of a sheet stacked on the sheet stacking unit 2, the other side end of this sheet and a sheet one size larger than this sheet are matched. The same effect can be obtained by a configuration in which the switching is performed at a position that is more than half the difference between the widths of the two sizes of sheets in the width direction.

When there are many types of sheets to be stored, for example, if four pattern rows are provided, 15 (= 2 ⁴ -1) positions of the pair of sheet regulating plates 3 can be detected. become. The patterns H1, H2, H3 are:
Instead of protruding, it may be recessed according to the type of the detector 8. Further, when a non-contact type, for example, a reflection type detector is used, the detected portion 7 may be painted or formed of a reflection member accordingly.

Further, as shown in FIG. 9, a pattern row of the detected portion 7 is formed in the disk 10 which is a moving member, and the pattern row is read by a transmissive detector 81 to identify the sheet size. You may make it.

[0061]

As described above, according to the present invention, an identification portion having a pattern for identifying the size of a sheet is provided on a moving member that moves in conjunction with the movement of the regulating member,
By providing the pattern of the identification portion so that the sheet size can be identified even when the sheet is moved to a position where the movement of the sheet can be regulated without abutting the regulating member on the sheet, the sheet regulating plate is not fitted exactly to the sheet. Even in such a case, the sheet size can be correctly identified.

[Brief description of the drawings]

FIG. 1 is a perspective view of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a sheet conveyance path of the image forming apparatus.

FIG. 3 is a perspective view showing a back surface of a paper feed tray unit of the image forming apparatus.

FIG. 4 is a rear view of the paper feed tray unit.

FIG. 5 is a perspective view of a detector provided in the paper feed tray unit.

FIG. 6 is a diagram showing a sheet size classification pattern by the detector.

FIG. 7 is a perspective view showing a back surface of a sheet feed tray unit of the image forming apparatus according to the second embodiment of the present invention.

FIG. 8 is a perspective view showing a back surface of a sheet feed tray unit of an image forming apparatus according to a third embodiment of the present invention.

FIG. 9 is a perspective view illustrating a back surface of a sheet feed tray unit of an image forming apparatus according to a fourth embodiment of the present invention.

FIG. 10 is a perspective view of a conventional image forming apparatus.

FIG. 11 is a rear view of a paper feed tray unit of the image forming apparatus.

FIGS. 12A and 12B are a front view and a top view, respectively, showing a state in which a sheet regulating plate is exactly fitted to a sheet stacked on a sheet feed tray unit of the image forming apparatus.

13A is a front view and FIG. 13B is a top view illustrating a state in which a sheet regulating plate is slightly opened and aligned with sheets stacked on a sheet tray unit of the image forming apparatus.

FIGS. 14A and 14B are a front view and a top view, respectively, showing a state in which a sheet regulating plate is slightly closed to a sheet stacked on a sheet tray unit of the image forming apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 paper feed tray unit 2 sheet stacking section 3 (3a, 3b) sheet regulating plate 5a, 5b, 5c rack 5c1 tooth surface 6, 6A pinion 7, 7A detected section 8, 8A, 81 detector 9a, 9b, 9c switch 10 disk 50 image forming unit 100 apparatus main body 100A image forming apparatus S sheet

Continued on front page F term (reference) 2H072 AA12 AA23 AB04 HB10 3F343 FA02 FB02 FB03 FB04 FC29 FC30 GA02 HA12 HA33 HD07 HD14 HE04 HE20 HE22 KB03 KB20

Claims (8)

[Claims] An image forming apparatus configured to convey a sheet stacked on a sheet stacking unit capable of stacking sheets of a plurality of sizes to an image forming unit to form an image, wherein the sheet stacking unit includes a sheet orthogonal to a sheet conveying direction. A regulating member that is provided movably in a direction in which the sheet is stacked on the sheet stacking unit, and that restricts movement of a sheet stacked on the sheet stacking unit in a width direction orthogonal to the sheet conveying direction. ,
A moving member that moves in conjunction with the movement of the regulating member in the width direction; and an identification unit provided on the moving member and having a pattern for identifying the size of the sheet. An image forming apparatus configured to identify a size of the sheet even when the sheet moves to a position where the movement of the sheet can be regulated without contacting the regulating member with the sheet. 2. The method according to claim 1, wherein the pattern is formed such that the center of the sheet stacked on the sheet stacking unit and the center of the sheet one size larger than the sheet are aligned with one side edge of the sheet stacked on the sheet stacking unit. 2. The image forming apparatus according to claim 1, wherein the switching is performed at a position apart from a position which is more than half of a difference between the lengths of the sheets in the width direction. 3. The method according to claim 1, wherein the pattern is set such that, from one side end of a sheet stacked on the sheet stacking unit, the other side end of the sheet and a sheet one size larger than the sheet are matched. The image forming apparatus according to claim 1, wherein the switching is performed at a position separated from a position that is more than half a difference between the widths of the two size sheets in the width direction. 4. The image forming apparatus according to claim 1, wherein the moving member is a rack provided integrally with the regulating member. 5. The regulating member is provided with a rack integrally therewith, and the moving member is a pinion that meshes with the rack and rotates in conjunction with the movement of the regulating member. The image forming apparatus according to any one of claims 1 to 3. 6. The regulating member is provided integrally with a rack meshing with a pinion, and the moving member is rotated by meshing with a tooth surface provided on a surface of the rack opposite to a surface meshing with the pinion. The image forming apparatus according to claim 1, wherein the image forming apparatus is a rotating body. 7. A method according to claim 1, further comprising: detecting means for detecting the pattern, wherein the pattern is provided on the moving member in a convex, concave or perforated form according to the configuration of the detecting means. The image forming apparatus according to claim 1. 8. The apparatus according to claim 1, wherein said pattern is detected by a non-contact type detecting means.
The image forming apparatus according to claim 1.