JPH0840570A - Paper feeding device - Google Patents

Abstract

PURPOSE:To provide a paper feeding device provided with a sheet size detecting mechanism simple in structure and easily applicable to even a compact small- space device. CONSTITUTION:A sheet cassete 31 is provided with a regulating member 46 for regulating the sheet side edge, movably in a direction H, and arms 51, 52 are fitted to the lower part. A sheet placing plane part 42 is provided with guide grooves 56, 57 for respectively guiding the arms 51, 52, and the arms 51, 52 are formed in such a way as to protrude/recede to the outside of the cassette from an opening 55, provided at a wall part 43, while being guided by the guide grooves 56, 57 according to the movement of the regulating member 46. Two detecting members are disposed outside of the cassette so as to detect the tip parts of the arms 51, 52 protruding from the opening 55. The protruding state of the arms 51, 52 differs according to the moving position of the regulating member 46 corresponding to the sheet size, and this is detected by the detecting members to enable the detection of the sheet size.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to an image forming apparatus such as a printer or a copying machine, and has a paper size detecting mechanism for detecting the size of the paper stored in a paper cassette detachable from the main body of the apparatus. The present invention relates to a provided paper feeding device.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a printer or a copying machine in which a large number of standard sheets are stacked and housed in a sheet cassette, an image is correctly formed on sheets of different sizes such as B5 and A4. Therefore, the size of the sheets loaded in the sheet cassette is automatically detected to adjust the sheet feeding timing and the like.

Normally, the paper cassette is provided with a regulating member for regulating the rear end face and side end face of the stacked sheets.
There are roughly two types of paper cassettes provided with such a regulation member. One is that the regulation member is provided with its position fixed according to the paper size, and is used as a dedicated cassette corresponding to each paper size. The other is that the regulation member is provided so that the position can be freely moved in the horizontal direction according to all sizes of paper, so that one paper cassette can handle a plurality of paper sizes. It is a thing. In any case, since the position of the regulating member differs depending on the sheet size, many ordinary sheet size detecting mechanisms detect the sheet size by detecting the moving position of the regulating member. . An example of such a conventional paper size detection mechanism is shown in FIGS.

A paper cassette 1 shown in FIG. 13 has a paper loading flat surface portion 2 for stacking and holding a large number of paper sheets P and a wall surface portion 3 standing upright around the paper loading flat surface portion 2. A regulating member 4 for regulating the rear end face and the side end face of P, respectively.
5 is provided movably in the horizontal direction (arrow direction) along the guide grooves 6 and 7, respectively. The restriction members 4 and 5 are
The stacked sheets P are appropriately moved to a position according to the sheet size and used. In addition, in FIG.
An example in the case of restricting the position to one side inside is shown. In order to detect the sheet size in the sheet cassette 1 as described above, a sheet size detecting mechanism as shown in FIG. 14 is provided. That is, the detected member 8 is attached to the lower part of the one regulating member 4 in the paper cassette 1, and the above-mentioned subject that moves according to the position of the regulating member 4 according to the paper size is arranged below the paper cassette 1 in the apparatus main body. The detection members 9 (9a, 9b, 9c) are arranged at positions facing the position of the detection member 8, respectively. The detected member 8 and the detected member 9 may be, for example, a light reflecting plate and a reflective photocoupler, or may be a magnetic body and a magnetic sensor. The respective detection members 9a, 9b, 9c correspond to the positions of the detected member 8 when the paper size is, for example, B5 plate, A4 plate, and B4 plate, respectively. With such a detection mechanism, the paper size in the paper cassette 1 can be detected based on which of the three detection members 9a, 9b, 9c detected the detected member 8.

In FIG. 14, a paper feed roll 10 for feeding the paper P from the topmost paper in the direction of arrow A,
An urging member 10a for placing the front end portion of the paper P and urging the vertically movable bottom plate 1a in the direction of arrow B to press the front end surface of the paper P against the paper feed roll 10 is also shown.

FIG. 15 shows another conventional paper cassette 1
1 is a view of the sheet 1 viewed from the back side, and a regulation member 12 similar to the regulation member 4 shown in FIG. The size of the sheet is detected based on the moving position of the regulating member 12. That is, first, the paper cassette 1
An arm 15 having a substantially V shape is provided rotatably around a fulcrum 15a on the bottom surface portion 14 of No. 1, and the arm 15 is restricted by a groove 16 provided obliquely to the guide groove 13. A pin 17 provided at the lower end of the member 12 is slidably fitted therein, and the free end of the arm 15 moves in the direction of arrow D as the regulating member 12 moves in the direction of arrow C. Further, a string member 21 is stretched around the back side of the paper cassette 11 via pulleys 18, 19, 20, etc., and a part of the string member 21 passes through the front end of the paper cassette 11, and a projection member 22 is provided at that part. Connected and also pulley 1
The free end of the arm 15 is connected to the portion located between 8 and 19, and the string member 21 is moved in accordance with the movement of the free end of the arm 15 in the direction of arrow D as the regulating member 12 moves in the direction of arrow C. The projecting member 22 moves in the direction of the arrow E through the interposition. That is, the projection member 22 can take a position in the arrow E direction corresponding to the movement position of the regulation member 12 in the arrow C direction according to the sheet size. And, in front of the paper cassette 11 in the main body of the apparatus,
The detection member 23 is appropriately located at a position where the protruding member 22 that moves according to the position of the regulation member 12 according to the sheet size is engaged.
(23a, 23b, 23c) are arranged, and the combinations of the detection members to be pressed are set to be different depending on each sheet size. Such a detection member 2
For example, a dip switch, a micro switch or the like is used as 3. According to such a detection mechanism, it is possible to detect the paper size in the paper cassette 11 based on which of the three detection members 23a, 23b and 23c and which of the three detection members is pushed by the protrusion member 22. .

[0007]

In the paper size detecting mechanism as shown in FIG. 14, a space for arranging the detecting member 8 is required below the paper cassette 1 in the apparatus main body. Therefore, such a detection mechanism can be operated, for example, on the image forming apparatus as shown in FIG. 10 (that is, on the front surface of the apparatus, and the overall size of the apparatus can be reduced.
Even if the present invention is applied to a device having a feature that it is possible to feed paper in two stages by further adding a paper feeding unit to the lower part of the device, the detection member 8 can be arranged below the paper cassette. It is impossible because there is no extra space. On the contrary, it can be said that the device having the detection mechanism as shown in FIG. 14 cannot realize the above-described characteristics of the device shown in FIG.

Therefore, in consideration of such a point, FIG.
As shown in FIG. 5, it can be said that it is desirable to arrange the detection member by utilizing the space existing in the front (or the rear or the side) of the paper cassette. However, in such a case as shown in FIG. 15, the detection member is interlocked with the movement of the regulation member. The mechanism for doing so becomes very complicated and large-scaled, which not only complicates the work of assembling the paper cassette, but also leads to an increase in the size and cost of the paper cassette.

In view of the above problems, it is an object of the present invention to provide a paper feeding device provided with a paper size detecting mechanism having a simple structure which can be easily applied to a small-sized device having a small space. .

[0010]

In order to achieve the above object, the present invention provides a sheet stacking plane portion for stacking and holding a large number of sheets, and a sheet stacking flat sheet provided movably in the horizontal direction on the sheet stacking plane portion. A paper cassette that includes a regulation member that regulates the end face, a wall portion that is erected around the periphery, and is detachably attached to the apparatus body, and a detection mechanism that detects a paper size to be stacked in the attached paper cassette. In the paper apparatus, the paper cassette includes an opening provided in the wall surface portion, and first and second actuating members provided in the regulation member and capable of projecting and retracting from the opening to the outside of the cassette in accordance with a movement state thereof. ,
And a first guide member provided on the sheet stacking flat surface portion for guiding the movement of the first and second actuating members, respectively, and the detection mechanism responds to a moving state of the regulating member. It is characterized in that the protruding state of the first and second actuating members from the opening is detected, and thereby the size of the paper to be stacked in the mounted paper cassette is detected.

[0011]

When the regulating member moves according to the size of the paper loaded in the paper cassette, the first,
The second operating member projects or retracts outside the cassette from the opening of the wall surface of the paper cassette while being guided by the first and second guide members, respectively. That is, the protruding states of the two operating members from the opening differ depending on the size of the sheets stacked in the sheet cassette. Therefore, by detecting the protruding state of these two operating members by the detection mechanism, the sheet size corresponding to the protruding state is detected as the sheet size to be stacked in the sheet cassette.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 9 is a perspective view showing an entire sheet cassette in a sheet feeding device according to an embodiment of the present invention, FIG. 1 is a perspective view showing an essential part of the sheet cassette, FIG. 2 is a plan view of the sheet cassette, and FIG. FIG. 3 is a plan view of the paper cassette shown in FIG. 2 with a paper stacking flat portion removed. This embodiment considers a case where it is applied to the image forming apparatus shown in FIG. 10 (here, a printer is shown as an example).

In the apparatus of FIG. 10, a paper cassette 31 is stacked and accommodated, and a paper cassette 31 is detachably attached to the apparatus main body M in the paper feeding direction (direction of arrow F), and a paper feed roll 32 for sequentially feeding the stacked paper sheets. , A pair of slip rolls 3 that inherits the paper fed by the paper feed roll 32 and conveys it further downstream
In addition to the sheet feeding device of the present embodiment having 3 or the like, a pair of standby rolls 34 for temporarily holding the sheet fed by this sheet feeding device and re-conveying it at a predetermined timing, and image information on the re-conveyed sheet. Image forming unit 3 for forming a toner image based on
5 (photosensitive drum 35a, charging device 35b, optical writing head 35c, developing device 35d, transfer device 35e, cleaner 3
5f), a fixing device 3 for fixing the toner image on a sheet
6. Paper discharge roll pair 3 that discharges the fixed paper to the outside of the device
7. A paper discharge tray 38 for storing the discharged paper is provided. This image forming apparatus can be operated from the front side (left side in the drawing) of the sheet cassette 31 as described above.
Is also removable from the front of the device, and the overall size of the device has been reduced by making the paper transport path into an S-shape and minimizing wasted space. It has a feature that it is possible to feed paper in two stages by further adding a unit. The sheet feeding device of this embodiment is applied to such an image forming apparatus.

As shown in FIG. 9, the paper cassette 31 has a paper loading flat surface portion 42 for stacking and holding a large number of paper sheets and a wall surface portion 43 standing upright around the paper loading flat surface portion 42. A bottom plate 44 that can move up and down with the front end of the paper placed
When the paper cassette 31 is attached to the apparatus main body M, the bottom plate 44 is pushed up by a biasing member 45 such as a spring as shown in FIG. 10, and the upper surface of the front end of the paper is pressed against the peripheral surface of the paper feed roll 32. It is supposed to be done. In addition, FIG.
As shown in FIG. 3, a regulation member 45 for regulating the rear end surface of the stacked sheets is provided on the sheet stacking plane portion 42 so as to be movable in the front-back direction (direction of arrow G) in the horizontal plane with a predetermined frictional resistance, and A regulating member 4 for regulating the left and right end surfaces of the paper
Reference numerals 6 and 47 are provided so as to be movable in the horizontal direction (direction of arrow H) in the horizontal plane with similar frictional resistance. The side end surface regulating members 46 and 47 are configured to move symmetrically with each other so as to regulate the sheet at the central position of the sheet cassette 31, and as such a configuration, for example, a rack and A known interlocking mechanism using a pinion mechanism or a belt or the like can be adopted. Each regulation member 45, 46,
The sheet 47 is used while being moved to a position corresponding to the sheet size of the stacked sheets.

Further, in order to detect the sheet size in the sheet cassette 31, a sheet size detecting mechanism as shown in FIGS. 1 to 3 is provided at a position surrounded by a chain line K in FIG. That is, first, the regulating member 46 at the sheet side edge is
In the lower part of the first and second arms 5 as an operating member.
1, 52 are attached to be rotatable about fulcrums 53, 54. Further, as shown in FIGS. 1 and 9, an opening 55 is provided in the side wall of the wall surface portion 43, and as shown in FIGS.
First and second guide grooves 56, 57 are provided as guide members for guiding the 1, 52. The arms 51 and 52 are configured to be capable of projecting and retracting from the opening 55 to the outside of the cassette while being guided by the guide grooves 56 and 57 in accordance with the movement of the restricting member 46 in the direction of the arrow H. Furthermore, inside the apparatus main body M, first and second detection members 58 and 59, each of which includes a microswitch, are arranged as a part of the detection mechanism at a position facing the opening 55 of the mounted paper cassette 31. Each of them can detect the tip of each arm 51, 52 when protruding. These configurations will be described more specifically below.

As shown in FIG. 3, the two arms 51 and 52 have different shapes. The first arm 51 has a simple elongated shape, while the second arm 52 has different directions. First and second protrusions 52 extending in different lengths
It has a substantially V shape formed by combining a and 52b. The first arm 51 has a long hole 5 formed in its longitudinal direction.
The fulcrum portion 53 is fitted in the la 1a so as to be slidable in the longitudinal direction of the elongated hole 51a thereof, and is constantly urged toward the center of the cassette by the tension spring 60, and by the spring 60 of the first arm 41. Movement in the biasing direction is restricted by the stopper 63. Further, the first arm 51 has another position at a position separated from the fulcrum portion 53 by a predetermined distance.
One fulcrum portion 61 is provided, and these two fulcrum portions 53,
When 61 is inserted into the first guide groove 56,
The arm 51 is guided and moved along the first guide groove 56. Note that the regulation member 46 is used for the B4 size sheet described later.
Is moved, the first arm 51 is also moved against the spring 60, but the urging force of the spring 60 does not have such an urging force as to pull back the regulating member 46. Further, the second arm 52 is provided with the fulcrum portion 54 at the connecting portion of the first and second protrusions 52a and 52b, and is provided with another fulcrum spaced from the fulcrum portion 54 toward the first protrusion 52a by a predetermined distance. Another fulcrum portion 62 is provided at the position, and the two fulcrum portions 54 and 62 are fitted into the second guide groove 57, whereby the second arm 52 is guided and moved along the second guide groove 57. To be done.
In these configurations, the main part of the paper cassette 31 is
4 is a cross-sectional view taken along the arms 51, 52 of FIG.
And in more detail in FIG.

The two guide grooves 56 and 57 have the same shape as shown in FIG. 2, and both guide the arms 51 and 52 along the moving direction of the regulating member 46 (direction of arrow H). A linear first guide portion 56a,
57a and the arms 51, 52 provided continuously with the first guide portions 56a, 57a as they approach the wall surface portion 43.
Is constituted by second guide portions 56b and 57b for guiding while curving in a direction deviating from the arrow H direction.

The fulcrum portions 53, 54, 61, and
The configuration of 62 is as shown in detail in FIGS.
The shaft 5a, 54a, 61a, 62a is rotatable about the roller 5
3b, 54b, 61b, 62b are fitted and retaining rings 53c, 54c, 61c, 62c are fitted at the tip of the shaft. These fulcrums 53, 54, 6
The arms 51 and 52 can be easily removed by disassembling the arms 1 and 62.

The operation of the paper size detecting mechanism of the present embodiment having the above construction will be described below with reference to FIGS. Here, in FIGS. 6, 7, and 8, the sheet sizes of the sheets to be stacked in the sheet cassette 31 are B5 and A4, respectively.
The states of the arms 51 and 52 in the case of the plate and the B4 plate are shown. It should be noted that FIGS. 1 and 9 described above show states in which the sheet sizes are A4 and B4, respectively.

First, when the paper size is B5 size, as shown in FIG. 6, the restricting member 46 takes a moving position (first moving position) corresponding thereto, and at this moving position,
The first arm 51 is at a position (first position) in which it is fully pulled to a position where it comes into contact with the stopper 63 by the urging force of the tension spring 60, and the fulcrums 53 and 61 are both the first
It is in the first guide portion 56a of the guide groove 56 of. As described above, when the first arm 51 is at the first position, the tip of the first arm 51 projects from the opening 55 to the outside of the cassette, and the first detection member 58 is turned on. On the other hand, in the second arm 52, the fulcrum portions 54 and 62 are both inside the first guide portion 57a of the second guide groove 57, and the tip of the first protruding portion 52a projects from the opening 55 to the outside of the cassette. Without the second detection member 59
It is in a position (first position) retracted from the position where the switch is turned on.
That is, when the paper size is the B5 size, the first detection member 58 is turned on and the second detection member 59 is turned off.

When the paper size is A4 size, as shown in FIG.
As shown in FIG.
To the fulcrum 53 connected to the regulating member 46.
Slides in the long hole 51a of the first arm 51, the first arm 51 is the same as in the case of the B5 plate.
The position is set, and the first detection member 58 is turned on. On the other hand, in the second arm 52, the fulcrums 54 and 62 are the same as in the case of the B5 plate.
7a, but to the position (second position) where the tip of the first protrusion 52a protrudes from the opening 55 to the outside of the cassette and the second detection member 59 is turned on as much as the restricting member 46 approaches the opening 55. Moving. That is, when the paper size is A4 size, both the first and second detection members 58 and 59 are turned on.

When the paper size is the B4 size, FIG.
As shown in FIG. 7, the regulation member 46 accordingly takes a moving position (third moving position) further approaching the wall surface portion 43, and at this moving position, the first arm 51 pulls the tension spring 60.
Since the fulcrum portion 61 moves into the second guide portion 56b of the first guide groove 56 because it moves against the urging force of the first guide groove 56, the entire first arm 51 inclines and the tip thereof is opened. The position (2nd position) retracted from inside to the cassette. In this second position, the tip of the first arm 51 is the first
The first detection member 58 is turned off because it is a position retracted from the position where the first detection member 58 abuts. On the other hand, when the fulcrum portion 62 enters the second guide portion 57b of the second guide groove 57 and the second arm 52 tilts as a whole, the first protrusion 52a retracts into the cassette from the opening 55. At the same time, this time, the second protrusion 52b projects from the opening 55 to the outside of the cassette to turn on the second detection member 59 (third position).
Position). That is, when the paper size is B4 size, the first detection member 58 is turned off and the second detection member 59 is turned on.

As described above, since the ON and OFF states of the first and second detection members 58 and 59 differ depending on the paper size, the paper size corresponding to the combination is set as the paper size to be stacked in the paper cassette 31. Can be detected.

Therefore, according to this embodiment, the regulating member 46 is
Two arms 5 that move according to the moving state of
The sheet size can be detected only by providing a very simple structure such as 1, 52, and the detecting member 5 is provided in a small space on the side of the sheet cassette 31 in the apparatus main body M.
Since 8 and 59 can be arranged, it can be easily applied to a small-sized and small-space device as shown in FIG. 10 without impairing its advantages. Moreover, as described above, the members added to the paper cassette 31 have a simple structure, and since these members are accommodated in the small space indicated by the one-dot chain line K in FIG. 10, the assembly of the paper cassette 31 is completed. Not only is the work extremely easy, but it is also possible to minimize the size increase and cost increase of the paper cassette.

In addition to the paper sizes such as B5 plate, A4 plate, and B4 plate, which are generally used,
There are paper sizes such as letter size and legal size, but in order to accommodate such sizes, the shapes of the first and second arms 51 and 52 may be slightly changed. Moreover, each arm 51, 52 can be removed by simply removing the fulcrum portions 53, 54, 61, 62 supporting it.
Since it can be easily replaced with an arm compatible with other sizes,
It can easily handle combinations of paper sizes.

By the way, in the above embodiment, it is premised that the paper cassette 31 is properly attached to the image forming apparatus when the paper size is detected. Further, the protrusion lengths of the arms 51 and 52 from the cassette have been described as being substantially the same. This means that the paper cassette is usually handled by the user to replace or replenish the paper, but it is temporarily placed in a state where it is completely removed from the main body of the device, or it is installed properly after the paper is loaded. This is because it is difficult to take a state other than the two states, that is, the state where the

However, the cassette is not placed in the middle of its attachment and detachment. For example, FIG. 12 shows that in the above embodiment, the arm 52 in the projecting state faces the position of the first detection member 58 in the middle of the attachment / detachment direction of the paper cassette 31 (note that the position is the same).
This figure shows the case where the sheets to be stacked are the A4 size as described in FIG. 7, but the same applies when the sheets to be stacked are the B4 size as described in FIG. 8). It may be placed in the middle of attachment and detachment. And the arms 51, 5
If the protruding lengths of the two cassettes are substantially the same, these protruding portions pass along the imaginary passage line 70. Therefore, regarding the arm 52, there is a moment when the arm 52 is also engaged with the first detection member 58. As a result, in the state of FIG. 12, the first detection member 58 is turned on and the second detection member 59 is turned off. Therefore, in the detection state, the case where the sheets to be stacked shown in FIG. There is also a problem in that they become the same and are erroneously detected.

Therefore, it is desirable to assume such a case and prevent erroneous detection. FIG. 11 shows another embodiment in consideration of such erroneous detection. As shown in FIG. 7A, in this embodiment, the protruding length of the arm 51 'to the outside of the cassette is set to be one minute longer than that of the arm 52 and corresponds to the passing virtual line 71 of the arm 51'. Let

[0029]

[Outside 1]

The first detecting member 58 'is arranged at a position which is not operated by the passage of the arm 52. Therefore, even if the arm 52 faces the first detection member 58 'during the attachment / detachment of the paper cassette 31, as shown in FIG. 9A (example of A4 size sheets to be stacked), the first detection is performed. Member 5
Since 8'is not turned on, the above-mentioned erroneous detection does not occur. When the cassette is properly mounted, the size of the sheet is reliably detected by the first detection member 58 'and the second detection member 59, as shown in FIG. Therefore, it is not necessary to separately provide a means for detecting whether or not the cassette is mounted.

In the above embodiment, the arms 51 (51 ') and 52 are provided as the operating members and the guide grooves 56 and 57 are provided as the guiding members. However, in the present invention, the operating members and the guide members have the same structure. The present invention is not limited to the arm and the guide groove, and the shape may be such that the paper size can be projected and retracted outside the cassette according to the movement state of the regulation member, and the paper size can be determined by detecting the projection state. For example, various other modified examples can be adopted. For example, the guide member may be a rib-shaped member instead of the groove.

As the detecting member for detecting the protruding state of the actuating member, in addition to the contact type sensor such as the micro switch shown in the above embodiment, a non-contact type using a photo coupler, a magnetic sensor or the like. It is also possible to adopt the sensor of.

Further, in the image forming apparatus shown in FIG.
It is difficult to arrange the detection member because there is no extra space in front of or behind the paper cassette, but if the device has such extra space in front of or behind the paper cassette, use that space. It goes without saying that the detection member may be arranged by using the above. At that time, instead of using the movement of the regulating member that regulates the side end surface of the sheet as in the above-described embodiment, the movement of the regulating member that regulates the rear end surface of the sheet may be used.

[0034]

According to the present invention, it is possible to detect the paper size by only providing an operating member having a simple structure that moves according to the moving state of the regulating member and other simple members, and the apparatus main body can be detected. Since the detection member can be arranged in a small space existing on the side (or front or rear) of the paper cassette in the above, it can be easily applied to a device configured for the purpose of small size and small space without losing its advantage. Is.

[Brief description of drawings]

FIG. 1 is a perspective view showing a main part of a paper cassette 31 according to an embodiment of the present invention.

FIG. 2 is a plan view of a paper cassette 31. FIG.

3 is a plan view of the paper cassette 31 shown in FIG. 2 with a paper stacking flat portion 42 removed.

FIG. 4 is a cross-sectional view of a main part of the paper cassette 31 taken along a first arm 51.

5 is a cross-sectional view of a main part of the paper cassette 31 taken along a second arm 52. FIG.

FIG. 6 is a diagram showing a state of arms 51 and 52 when a sheet size of sheets to be stacked in a sheet cassette 31 is a B5 size.

FIG. 7 is a diagram showing a state of arms 51 and 52 when a sheet size of sheets to be stacked in the sheet cassette 31 is A4 size.

FIG. 8 is a diagram showing a state of the arms 51 and 52 when the paper size of the paper to be stacked in the paper cassette 31 is the B4 size.

9 is a perspective view showing an entire sheet cassette 31. FIG.

FIG. 10 is an overall view of an image forming apparatus to which the sheet feeding device of the above embodiment is applied.

FIG. 11 shows an arm 51 'and a first detection member 58' in another embodiment, (a) shows the paper cassette 31 when the paper size to be stacked in the paper cassette 31 is A4 size.
6B is a diagram illustrating a state in which the sheet cassette 31 is being mounted, and FIG.

FIG. 12 is a diagram illustrating the positional relationship between the arm 52 and the first detection member 58 during the mounting of the paper cassette 31.

FIG. 13 is a plan view of a conventional paper cassette 1.

FIG. 14 is a diagram showing an example of a conventional paper size detection mechanism applied to a conventional paper cassette 1.

FIG. 15 is a view showing another example of a conventional paper size detection mechanism applied to the conventional paper cassette 11.

[Explanation of symbols]

 31 Paper Cassette 42 Paper Loading Flat Surface 43 Wall Surface 45, 46, 47 Restricting Member 51, 51 'First Arm 51a Long Hole 52 Second Arm 52a First Projection 52b Second Projection 53, 54 Support Point Part 55 Opening 56 First guide groove 56a First guide part 56b Second guide part 57 Second guide groove 57a First guide part 57b Second guide part 58, 58 'First detecting member 59th 2 Detection member 60 Extension spring 61, 62 Support point 63 Stopper

Claims (4)

[Claims] 1. A sheet stacking flat surface portion for stacking and holding a large number of sheets, a regulating member movably in the horizontal direction on the sheet stacking flat surface portion for regulating an end surface of stacked sheets, and a wall surface provided upright around the sheet. A sheet cassette that is detachably attached to the main body of the apparatus and a detection mechanism that detects the size of the sheet to be loaded in the attached sheet cassette, the sheet cassette being provided on the wall surface section. With an opening
First and second actuating members provided on the restricting member and projecting and retracting from the opening to the outside of the cassette according to the moving state of the restricting member, and the sheet stacking device for guiding the movement of the first and second actuating members, respectively. A first guide member and a second guide member provided on a flat surface portion, and the detection mechanism detects a protruding state of the first and second actuating members from the opening according to a moving state of the regulating member. And a sheet size to be stacked in the mounted sheet cassette is detected thereby. 2. The paper feeding device according to claim 1, wherein the paper cassette is attached and detached in the direction in which the paper is to be fed. 3. The paper feeding device according to claim 1, wherein the wall surface portion extends along the attachment / detachment direction of the paper cassette. 4. The regulating member takes first, second, and third movement positions according to the size of sheets to be stacked in the sheet cassette, and the detection mechanism is one of the first and second actuating members. First and second detection members for respectively detecting the protruding state are provided, and the paper size is detected based on a combination of detection results by the first and second detection members. The guide member is provided with a first guide portion that guides the first and second actuating members along the movement direction of the regulating member, and is provided continuously to the first guide portion and approaches the wall surface portion. And a second guide portion that guides the first and second actuating members in a direction deviating from the movement direction of the restricting member. The first actuating member includes the first and second restricting members.
Of the first guide member when in the moving position of
Of the first guide member, the first position being detected by the first detection member, and the second guide portion of the first guide member when the regulating member is in the third movement position. The second operating member is guided and takes a second position which is a position retracted from the detection position of the first detecting member, and the second actuating member includes first and second protrusions extending in different directions. When the restriction member is in the first movement position, the first and second protrusions are guided by the first guide portion of the second guide member and the first and second protrusions are detected by the second detection member. The first position, which is a position retracted from the position, is taken, and the first protrusion is guided by the first guide portion of the second guide member when the restricting member is in the second moving position. Detected by the second detection member 2nd position, the first protrusion is guided by the second guide portion of the second guide member when the regulating member is in the third movement position, and the first protrusion is the second detection member. The third protrusion which is retracted from the detection position by and the second protrusion is detected by the second detection member.
The sheet feeding device according to any one of claims 1 to 3, which takes a position.