JP2000118729A - Sheet size detection method and device for universal sheet feed tray - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make judgement on sheet sizes over a wide range, using reduced space and simple constitution. SOLUTION: The positions of restriction guides 11 and 12 movable in a size restricting direction for restricting the sizes of sheets housed in a universal sheet feed tray 2 at a plurality of positions are detected by measuring distances A and B to the restriction guides 11 and 12 or members interlocked therewith with measurement means 21 and 22 located at a constant position relative to the universal sheet feed tray 2, and judgement is made can the sizes of sheets 6 housed in the universal sheet feed tray 2 on the basis of detected distance information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for detecting a sheet size of a universal sheet tray.

[0002]

2. Description of the Related Art In general, a paper feed tray is provided with a regulating guide for regulating the length as viewed in the paper feeding direction so that the paper of a predetermined size is regulated in size and stably fed and fed. And a regulation guide for regulating a width perpendicular to the width direction.
Since the universal paper feed tray accommodates and uses a plurality of types of papers with their sizes regulated, the two regulating guides can be moved in the size regulating direction.

[0003] Regardless of whether the universal sheet tray is of a so-called cassette type that is detachably used, the difference between the case of the vertical sheet feeding T and the case of the horizontal sheet feeding Y of the sheets stored and used therein is used. Unless the difference between a plurality of types of sizes including the size is determined, it cannot be determined whether or not the size corresponds to the size of the sheet selected by the user or required for automatic control.

Conventionally, a plurality of push-button switches arranged side by side on the copying machine main body are moved by the unevenness of a lever provided below the bottom of the universal paper feed tray in conjunction with the movement of the regulation guide. There has been proposed an apparatus in which the pressing is performed in a combination corresponding to the moving position, and the control unit determines the size of the sheet stored in the universal sheet tray based on a difference in the combination of the pressed push button switches.

[0005]

In recent years, paper sizes used in image forming apparatuses such as copying machines, printers, and facsimile machines have been diversified. Some standards having different paper sizes have dimensions that are close to each other. For example, A4T (297 mm) and Letter T (279
mm), the difference is small, such as the sheet widths of 210 mm and 216 mm. For this reason, coupled with the downsizing of the apparatus, high detection accuracy is required for the paper size detecting means stored in the universal paper feed tray.

However, in the above-described conventional detection method,
If the movement of the regulation guide is small due to space restrictions, the amount of movement of the lever in conjunction therewith is small. In order to detect the difference in position due to such a slight movement in order to detect the size between small-size sheets, even if the interval between the push-button switches is set to be small, the physical width of the push-button switches is limited. Can't respond enough. For this reason, it is difficult to distinguish a small difference in paper size. Therefore, it is not possible to sufficiently cope with a wide variety of paper sizes in recent years.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and an apparatus for detecting a sheet size of a universal sheet tray which can determine a wide variety of sheet sizes in a space-saving manner.

[0008]

In order to achieve the above object, a method of detecting a sheet size of a universal sheet tray according to the present invention regulates the size of sheets stored in the universal sheet tray at a plurality of positions. The position of the restriction guide that can be moved in the size restriction direction is detected by distance measurement to the restriction guide or a member interlocked with the restriction guide by the distance measuring means at a fixed position with respect to the universal sheet tray, and the detected position is detected. It is characterized in that the size of the paper stored in the universal paper feed tray is determined from the distance measurement information.

As described above, the position of the regulating guide which can be moved in the size regulating direction is detected by measuring the distance to the regulating guide or a member interlocked with the regulating guide by the distance measuring means at a fixed position with respect to the universal sheet feeding tray. Then, due to the distance measuring performance of a well-known distance measuring means such as a triangulation method, even a small difference in the position of the regulation guide is detected with high accuracy. It is possible to judge the difference in paper size between papers, and it is possible to sufficiently cope with a wide variety of paper sizes. In addition, a simple structure and a small space are sufficient.

The direction of distance measurement by the distance measuring means may be the direction of movement of the restriction guide, or may be the direction intersecting with the direction of movement of the restriction guide. In the case of the movement direction, the movement changes the distance in the distance measurement direction between the restriction guide and the distance measurement means, so that distance measurement information for size detection can be obtained with the restriction guide itself, and the configuration is simple. become. In the case of the intersecting direction, it is necessary to use a part to be measured whose distance in the direction of distance measurement from the distance measuring means changes in accordance with the movement of the restriction guide or a member interlocked with the restriction guide. However, the degree of freedom in setting the distance measurement direction is improved.

As a paper size detecting device for a universal paper feed tray for achieving the above-described paper size detecting method, a size of a paper accommodated in the universal paper feed tray is regulated at a plurality of positions. Distance measuring means for measuring the distance from a fixed position with respect to the universal paper tray with respect to a regulating guide or a member interlocked with the regulating guide which can move in the regulating direction, It suffices to provide a control means for judging the size, and the control means can share a device for controlling the operation of the target apparatus for feeding paper.

When the control means detects the mounting of the universal paper feed tray based on the output of the distance measuring means, the control means does not use a special detecting member. Can detect the attachment / detachment of the universal paper feed tray.

If the distance measuring direction of the distance measuring means is set to the moving direction of the restricting guide, the distance measuring direction of the restricting guide can be applied to the restricting guide in this moving direction. If it is set in the direction that intersects the movement direction,
It can be applied to the distance measurement for the regulation guide in the intersecting direction. In particular, in the distance measurement in the intersecting direction, the measurement target portion having the plurality of types of step surfaces is provided so that the step surface facing the distance measurement sensor is switched in conjunction with the movement of the regulation guide. When the distance measuring means measures the distance between the step surface corresponding to the movement position of the regulation guide and the step size between the adjacent step surfaces, the size of the step is small regardless of the movement amount of the regulation guide even in a small space. Can be set relatively large. Therefore, as long as the step surface measured by the distance measuring means is switched even with a small movement of the restriction guide, the difference in the movement amount of the restriction guide accompanying the paper size is enlarged by the size of the step between the adjacent step surfaces. The distance can be measured by the distance measuring means, and the detection accuracy of the small sheet size is further improved.

There are two types of regulation guides: one for regulating the length as viewed in the paper feeding direction, and the other for regulating the width in a direction perpendicular to the paper feeding direction. The control means determines the size of the paper accommodated in the universal paper feed tray from the distance measurement information obtained by the two distance measurement means. With the combination of sizes, the paper size determination information is doubled, and even if one size is close to the other, there is a high probability that the difference between the other sizes is large, making it possible to easily and highly accurately detect a wide variety of paper sizes. it can.

[0015] Further objects and features of the present invention will become apparent from the following detailed description and drawings. Each feature of the present invention can be used alone or in combination in various combinations as far as possible.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below together with embodiments thereof with reference to FIGS. 1 to 4 to provide an understanding of the present invention.

In this embodiment, as shown in FIG. 1, a cassette type used to be attachable to and detachable from various image forming apparatus main bodies 1, such as copiers, printers, and facsimile machines, through a slot 3 in a direction indicated by an arrow 10. This is an example of a case where the present invention is applied to the universal sheet tray 2. However, the present invention is not limited to this, and is effective when applied to any case where sheets of various sizes are selectively accommodated and supplied for image formation or other purposes. The universal paper feed tray 2 is not limited to the cassette type, but can be applied to all types having a structure and an installation state in which sheets to be stored can be exchanged or replenished.

The universal paper feed tray 2 of the present embodiment
As shown schematically in the embodiments of FIGS. 1 and 2, and the embodiment of FIG. 3, the left and right sides of the image forming apparatus main body 1 are guided by guide rails 4 to be attached and detached. The slot 3 for mounting the universal sheet tray 2 of the image forming apparatus main body 1 may be specified, or a plurality of the slot 3 may be used to supply another universal sheet tray 2 or a supply dedicated to a specific size. You may make it attach selectively with a paper tray. The right and left mounting positions of the universal paper tray 2 are positioned by the guide rails 4,
The mounting position in the attaching / detaching direction is determined by the stopper 5. Therefore, the universal paper feed tray 2 is always mounted at a fixed position with respect to the image forming apparatus main body 1 and used.

The paper sheets 6 stored in the universal paper feed tray 2 mounted on the image forming apparatus main body 1 are sent out one by one, for example, in a direction indicated by an arrow 7 by a paper feeding mechanism (not shown) on the image forming apparatus main body 1 side. The sheet is fed to an image forming mechanism that forms an image.

Sheet 6 on which an image is formed by the image forming mechanism
Is discharged to a discharge tray (not shown) provided in the image forming apparatus main body 1 and can be taken out.

The universal paper feed tray 2 has a regulation guide 11 for regulating the length as viewed in the paper feeding direction and a regulation guide 12 for regulating the width at right angles to the paper feeding direction, similarly to the one dedicated to a specific size. In order to accommodate and use a plurality of types of papers with their sizes regulated, the two regulation guides 11 and 12 can be moved in the size regulation direction as indicated by thick arrows. An elongated hole 1 for guiding the movement of the regulation guides 11 and 12 is provided at the bottom 2a of the universal sheet tray 2.
3 and 14 are formed. A screw 15 is passed through the elongated hole 13 from below and screwed into the regulation guide 11, and the regulation guide 1 is
1 is attached so as to be slidable along the slot 13 on the universal paper feed tray 2. A screw 17 is passed through the slot 14 from below and screwed into the regulation guide 12, and the regulation guide 12 is attached so as to be slidable along the slot 14 on the universal paper feed tray 2.

Such a universal paper feed tray 2 is
Any length of paper 6 that can be accommodated therein can be positioned and used with the length and width regulated by the regulation guides 11 and 12. Therefore,
It is possible to cope with paper 6 of various sizes recently.
The size of the paper 6 to be used is specified as long as the size of the paper 6 to be used is wide-ranging and limited to a fixed form.

Therefore, the difference in the sizes of a plurality of types including the case of the vertical paper feed T and the case of the horizontal paper feed Y of the paper 6 stored and used in the universal paper feed tray 2 is determined on the image forming apparatus main body 1 side. Automatically detects the size of the sheet, so that the sheet can be fed according to the size selected by the user or required in the automatic control.

The paper size detecting method according to the present embodiment, as shown in the examples of FIGS. 1 and 2, and the example of FIG. The position of the regulation guide 11 that can be moved in the size regulation direction so as to be regulated by the distance measuring device 21 is measured by the distance measuring means 21 at a fixed position with respect to the universal paper feed tray 2 to the regulation guide 11 or a member A linked thereto. The size of the paper 6 stored in the universal paper feed tray 2 is determined based on the detected distance measurement information.
Further, the position of the regulation guide 12 that can move in the size regulation direction is detected by measuring the distance B to the regulation guide 12 or a member interlocked with the regulation guide 12 by the distance measuring unit 22 at a fixed position with respect to the universal sheet tray 2. Then, the size of the sheet 6 stored in the universal sheet tray 2 is determined from the detected distance measurement information.

The outputs of the distance measuring means 21 and 22 can be used to detect the mounting of the universal paper feed tray 2, and the attachment / detachment of the universal paper feed tray 2 can be detected without using a special detecting member.

As the distance measuring means 21 and 22, those used in a camera and other measuring devices can be adopted, and an optical distance measuring sensor such as a triangular distance measuring method, or various other distance measuring sensors or distance measuring devices are employed. Can be. Distance measuring means 21, 22
Is fixed to the side of the image forming apparatus main body 1 that uses the output, but the universal paper feed tray 2 is mounted in a fixed positional relationship with the image forming apparatus main body 1 as described above. Reference numerals 21 and 22 can have a fixed positional relationship with the universal paper feed tray 2. However, when the universal paper feed tray 2 is fixed to the image forming apparatus main body 1, the distance measuring means 21 and 22 are provided on the universal paper feed tray 2 side so that both are uniquely positioned. Can also.

As described above, the positions of the regulation guides 11 and 12 are measured by measuring the distances A and B between the regulation guides 11 and 12 by the distance measuring means 21 and 22 or the corresponding members of the members linked thereto. When distance detection is performed, the restriction guide 11,
Since even a slight difference in position of 12 is detected with high accuracy,
It is possible to judge the difference in the size of the paper between the types having a small size difference only from the difference in the distance measurement information for either one of the regulation guides 11 and 12, and to sufficiently cope with the wide variety of the difference in the paper size. Can be. Moreover, the structure is simple and a small space is sufficient.

When both of the difference in the distance measurement information and the difference in the other distance measurement information are used in combination, the paper size is determined based on the difference between the two combinations of the length size and the width size of the paper. Then, the paper size determination information is doubled, and even if one of the sizes is close to the other, there is a high probability that the difference between the other sizes is large, so that a wide variety of paper sizes can be easily and accurately detected.

In the embodiment of FIGS. 1 and 2 and the embodiment of FIG.
The distance detection is performed by the distance measuring means 21 and 22 provided on the same side of the image forming apparatus main body 1 for detecting the positions of both the regulation guides 11 and 12. The distance measuring means 21 is positioned so that the distance measuring direction is oriented in the direction intersecting, specifically, the direction orthogonal to the direction, and the distance measuring means 22 is positioned such that the distance measuring means 22 is oriented in the moving direction of the regulating guide 12. Have been.

The direction of distance measurement with respect to the direction of movement of the regulation guides 11 and 12 can be freely set. However, Regulatory Guide 1
In the case where the distance measurement direction coincides with the moving direction of the distance measurement target as in the relationship between the distance measurement unit 2 and the distance measurement means 22, the embodiment shown in FIGS.
As shown in the embodiment of FIG. 3, a regulation guide 1 to be measured.
When the distance 2 moves, the distance B in the distance measuring direction with respect to the distance measuring means 22 for measuring the distance changes, so that the distance measuring means 22 can measure the distance only by the facing relationship with the moving regulation guide 12.
On the other hand, if the distance measuring direction does not coincide with the moving direction of the object to be measured, such as intersecting or perpendicular to the moving direction of the distance measuring object, as in the relationship between the restricting guide 11 and the distance measuring means 21, even if the restricting guide 11 moves, the distance is measured There is no change in the distance A with the means 21 in the distance measurement direction. Therefore, the distance measurement cannot be performed from a simple opposing relationship, unless the distance measurement direction is followed so as to be directed to the movement position of the regulation guide 11. Therefore, the distance A in the distance measuring direction from the distance measuring means 21 changes in accordance with the movement of the restricting guide 11 or a member interlocked with the restricting guide 11, for example, in the embodiments of FIGS. The part to be measured 23 as in the embodiment
You need to use When such a measured portion 23 is used, the distance measuring means 21 and 22
This increases the degree of freedom in setting the distance measurement direction. Therefore, it is advantageous for layout.

A measuring piece 18 is attached to the restricting guide 12 by the screw 17 and forms a surface facing a distance measuring means 22 necessary for distance measuring. The regulation guide 11 of the embodiment shown in FIGS.
Is provided as a lever type which is attached to the bottom portion 2a of the measuring part 23 so as to be rotatable by a screw 24. The part 23 to be measured has its long hole 23a and the screw 1
5 to the regulation guide 11 and the regulation guide 11
The part to be measured 23 is rotated about the screw 24 in conjunction with the movement of. A stepped surface 25 ₁ , 25 _{2 for} a plurality of types of fixed-size paper to be stored and used in the universal paper feed tray 2 as described above is provided on a portion of the measured portion 23 facing the distance measuring means 21 in the distance measuring direction. , 25 ₃ , ... 25 _n
Is formed, and when the regulating guide 11 is moved to a position corresponding to the size of the paper to be used, the step surfaces 25 ₁ , 25 ₂ , 25 ₃ ,.
... are to be switched is intended to face in the range finding directions to 25 _n of the distance measurement means 21.

As a result, the distance measuring means 21 is
_The distance measurement is performed with respect to the step surface corresponding to the movement position of the regulation guide 11 among ₁ , 25 ₂ , 25 ₃ ,... 25 _n . Step surfaces 25 ₁ , 25 ₂ , 25 ₃ , ...
The size of the step S between 25 _n adjacent ones is
It can be set relatively large regardless of the amount of movement of the regulation guide 11 in a small space. Therefore, as long as the step surface measured by the distance measuring means 21 is switched by a small movement of the restricting guide 11, the difference in the movement amount of the restricting guide 11 according to the paper size depends on the size of the step S between the adjacent step surfaces. Can be enlarged so that the distance can be measured by the distance measuring means 21, and the accuracy of detecting the small-size sheet size is further improved.

The embodiment shown in FIG. 3 differs from the embodiment shown in FIGS. 1 and 2 in that a slide-type portion 23 to be measured is attached to the regulation guide 11 with a screw 15 so as to move integrally therewith. The structure is simpler than that of the lever type interlocking with the regulation guide 11 shown in FIGS. There is no particular change except that the change in the distance A with respect to the size of the paper has an inversely proportional relationship. Therefore, the same members as those of the embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and duplicate description will be omitted. Note that both the measured part 23 of the embodiment of FIGS. 1 and 2 and the measured part 23 of the embodiment of FIG. 3 are individual members, but in the embodiment of FIG. Since it is good, it may be a part formed integrally in some cases.

As a device for detecting the paper size of the universal paper feed tray 2, in addition to the distance measuring means 21 and 22, a control means 31 for judging the paper size from one or both of the distance measuring information as shown in FIG. And a microcomputer for controlling the operation of the image forming apparatus main body 1 can be shared. In the embodiment shown in FIG. 4, the paper size is determined based on a combination of the distance measurement information from both the distance measurement units 21 and 22.

The following table shows the length and width corresponding to the eleven types of paper sizes actually used.

[0036]

[Table 1]

An example of the combination of the differences and the combination of the actual distance measurement information A and B by the distance measurement means 21 and 22 corresponding to the difference is shown corresponding to the embodiment of FIGS.

The control means 31 stores in advance a table of the type of the paper size of such data and the corresponding distance measurement information A and B, and detects the detected distance measurement information A and B.
If the paper size is determined based on the combination of B, the size of the paper stored in the universal paper feed tray 2 can be detected at that time.

In order to detect the paper size, the control unit 31 shown in FIG.
The signals are input to the analog ports of the PU 41, respectively. CP
U41 controls the operation of each part of the image forming apparatus main body 1 and determines the size of the paper 6 based on the outputs from the distance measuring means 21 and 22. The ROM 41, the RAM 43, the display unit 44, and the like are connected to the CPU 41 via a bus such as a data bus. The ROM 42 stores a program for performing various controls of the image forming apparatus main body 1 and a program for determining the size of the sheet 6 based on the output level of the distance measuring means 21 and 22.
The distance measuring means 21 and 22 correspond to the cassette type of which the universal sheet feeding tray 2 is detachable.
A program for detecting the mounting of the universal paper feed tray 2 based on the presence or absence of output from the printer is also stored. RAM4
Reference numeral 3 denotes a memory for temporarily storing various data required for controlling the image forming apparatus main body 1. The display unit 44 displays the size of the paper 6 determined by the CPU 41 and the like, and is provided on the operation panel of the image forming apparatus main body 1.

[0040]

According to the present invention, the position of the restriction guide moved to accommodate various sizes of paper in the universal paper feed tray is slightly different from the position of the restriction guide in terms of the distance measurement performance of the distance measuring means. Is detected with high accuracy, it is possible to determine even the difference in the size of the paper between the types having a small size difference from the difference in the distance measurement information, and it is possible to sufficiently cope with a wide variety of paper sizes. Moreover, the structure is simple and a small space is sufficient.

When the universal paper feed tray is of a cassette type that can be detached, the mounting of the universal paper feed tray can be detected without a special detection member depending on whether or not there is an output from the distance measuring means.

In the distance measurement in a direction intersecting with the movement direction of the regulation guide, a small portion of the regulation guide is used by using the measured portion whose step surface facing the distance measuring means is switched in conjunction with the movement of the regulation guide. It is only necessary to switch the stepped surface measured by the distance measuring means by movement, and the step between adjacent stepped surfaces is set relatively large in a small space, and the difference in the movement amount of the regulation guide due to the paper size is reduced. Since the distance can be enlarged and measured by the distance measuring means, the detection accuracy of the small sheet size is further improved.

The size of the paper is determined from two types of distance measurement information relating to the movement of the regulation guide for regulating the length as viewed in the paper feeding direction and the movement of regulating the width in the direction perpendicular to the paper feeding direction. By making the determination, the paper size determination information is doubled by the combination of the two sizes of the paper length size and the width size, and there is a high probability that the difference between the other sizes is large even if one size is close. In addition, a wide variety of paper sizes can be easily detected with high accuracy.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating an example of a method and an apparatus for detecting a sheet size of a universal sheet tray according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the universal paper feed tray of FIG.

FIG. 3 is a plan view showing another example of the method and the apparatus for detecting the size of the paper in the universal paper feed tray according to the embodiment of the present invention.

FIG. 4 is a block diagram showing an embodiment of a control unit for detecting a sheet size common to the embodiments of FIGS. 1 and 3;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Image forming apparatus main body 2 Universal paper feed tray 3 Slot 4 Slot 4 Guide rail 5 Stopper 6 Paper 7 Feeding direction 10 Feeding direction 11 and 12 Regulatory guide 13 and 14 Slot 15 and 17 Screw 18 Measurement piece 21 and 22 Distance measuring means 23 Measured part 23a Long hole 25 ₁ , 25 ₂ ,... 25 _n Step surface 31 Control means A, B Distance S step

Claims (8)

[Claims] 1. A distance measuring device in which a position of a regulation guide which can be moved in a size regulation direction so as to regulate a size of a sheet accommodated in a universal sheet feeding tray at a plurality of positions is fixed to the universal sheet feeding tray. Means for detecting the distance to the regulation guide or a member interlocked with the regulation guide by means, and judging the size of the sheet stored in the universal sheet tray from the detected distance measurement information. Tray paper size detection method. 2. The method according to claim 1, wherein the distance measuring direction by the distance measuring means is a moving direction of the regulating guide. 3. The method according to claim 1, wherein the direction of distance measurement by the distance measuring means is a direction intersecting with the direction of movement of the regulation guide. 4. A universal guide tray and a regulating guide that can move in a size regulating direction so as to regulate the size of the paper accommodated in the universal sheet tray at a plurality of positions or a member interlocked therewith. Paper in the universal paper feed tray, comprising: a distance measuring means for measuring a distance from a fixed position; and a control means for judging a size of the paper accommodated in the universal paper feed tray from the distance measurement information thereby. Size detection device. 5. The universal paper feed tray is of a cassette type which is used detachably, and said control means comprises:
5. The sheet size detecting device for a universal sheet tray according to claim 4, wherein the detection of the mounting of the universal sheet tray is performed based on an output of the distance measuring means. 6. The sheet size detecting device for a universal sheet feeding tray according to claim 4, wherein the distance measuring means sets a distance measuring direction to a moving direction of the regulation guide. 7. The distance measuring means sets a distance measuring direction in a direction intersecting a moving direction of the regulating guide, and moves the measured portion having the plurality of types of step surfaces in conjunction with the movement of the regulating guide. Provided so that the step surface facing the distance measuring means switches,
The sheet size detecting device for a universal sheet feed tray according to any one of claims 4 to 6, wherein the distance measuring sensor measures the distance between a step surface corresponding to a movement position of the regulation guide. 8. A regulating guide includes a regulating guide that regulates the length as viewed in the paper feeding direction and a regulating guide that regulates a width in a direction perpendicular to the paper feeding direction. The universal feeding device according to any one of claims 4 to 7, wherein means is provided, and the control means determines the size of the sheet stored in the universal sheet feeding tray from the distance measurement information obtained by the two distance measuring means. Paper tray paper size detector.