JPH07149449A - Sheet feeding device and recording device - Google Patents

Abstract

(57) [Summary] [Purpose] A large number of sheet sizes can be detected with a small number of detection sensors. A structure having a length detection sensor 70 arranged in the length direction of the sheet S and a width detection sensor 80 arranged in the width direction of the sheet S are provided, and the length detection sensor 70 and the width detection sensor are provided. Letter size and legal size are identified by identifying four types of sheet sizes A4, A5, B4, and B5 based on the combination of detection / non-detection information from 80, and keeping the width detection sensor 80 constantly detected by the shielding member 90. It is possible to distinguish between the two types of sheet sizes. This makes it possible to identify two other sheet sizes by using the detection sensors 70 and 80 that have identified four sheet sizes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device for feeding sheets such as recording paper to recording devices such as facsimiles, copiers and printers.

[0002]

2. Description of the Related Art In a recording apparatus using a sheet cut into a standard size (cut sheet), a plurality of accommodating means for accommodating the sheet are arranged in the recording apparatus main body or connected to the outside in response to a user's request. Many things have been used in recent years. As the accommodating means, there are a type of supporting sheets on a tray and a type of accommodating sheets in a sheet feeding cassette or a sheet feeding deck.

In such a recording apparatus having a plurality of sheet accommodating means, it is necessary to identify which size of sheet is accommodated in each sheet accommodating means. This is to select a sheet suitable for the size of the print data for printing and perform optimum printing.

Conventionally, there is the following size detecting means for identifying the size of the sheet accommodated in the sheet accommodating means to the recording apparatus main body.

In a dedicated paper feed cassette or the like in which the size of the sheets to be accommodated is fixed, an identification means such as a protrusion is provided on the paper feed cassette body side so that the recording device body side can identify the sheet. Further, in a so-called universal cassette capable of accommodating a plurality of types of sheets of different sizes, for example, a sensor for detecting the moving position of a side regulation plate that regulates the position of the sheet in the width direction and a rear edge regulation plate that regulates the rear end of the sheet For example, there is a device in which the size is determined by detecting the size.

[0006]

For example, in a facsimile machine or the like, which is used domestically (hereinafter referred to as domestic specifications), four types of sheets A4, A5, B4, B5 are usually used. It is necessary to detect the type of sheet size. In addition, when used in foreign countries, such as North America (hereinafter referred to as North American specifications), letters (LT
Since two types of sheets of R size and legal (LGL) size are used, it is necessary to detect these two types of sheet sizes.

Therefore, in a recording apparatus in which sheets of these six sizes are used, a universal cassette is used because it is inconvenient for a dedicated type paper feed cassette.
However, in the case of detecting six types of sheet sizes in the universal cassette, it is possible to detect using a large number of detection sensors, but there is a problem that the cost will increase significantly by that amount. Also, in particular, A4
Since there is not much difference in the outer dimensions between the size sheet and the letter size sheet, the mounting positions of the detection sensors are close to each other, which is a large limitation in the configuration.

Further, if the detection sensors are properly attached according to the specifications, it will not be necessary to use many detection sensors, but it will not be possible to standardize the products.
There is a problem that the manufacturing cost will increase significantly.

The present invention has been made in view of the above problems, and an object thereof is to make it possible to detect a large number of sheet sizes with a small number of detection sensors.

[0010]

SUMMARY OF THE INVENTION The present invention provides a sheet feeding device including sheet storing means for storing sheets and size detecting means for detecting the size of the sheets stored in the sheet storing means. A plurality of detection sensors arranged to detect the sheets accommodated in the sheet accommodating means, and identification means for identifying the sizes of the plurality of sheets based on the information of the detection / non-detection of the sheets by the respective detection sensors,
In order to identify a sheet of another size that cannot be identified by the identifying means, a control member that selects the plurality of detection sensors corresponding to other sizes to keep the detection state or non-detection state at all times, and the control member And a discriminating means for discriminating the size of the sheet on the basis of the information on the detection state or the non-detection state of the detection sensor.

[0011]

According to the above construction, the sizes of a plurality of sheets are identified based on the information of the detection / non-detection of the sheet by the detection sensor, and the same detection sensor is used to continuously detect the detection sensor or not detect the detection sensor. Since the sizes of other sheets are identified based on the above information, a large number of sheet sizes can be detected without increasing the number of detection sensors.

[0012]

Embodiments of the present invention will now be described with reference to the drawings. 1 is a vertical sectional view of a facsimile apparatus embodying the present invention, FIG. 2 is a perspective view of the facsimile apparatus shown in FIG. 1, and FIG. 3 is a state in which a paper feed cassette is removed in the apparatus shown in FIG. FIG.

A portion above the line C (horizontal plane) in FIG. 1 shows the recording apparatus main body 3, and a portion below the line C shows an optional paper feeding unit 30 which will be described in detail later.

The recording apparatus main body 3 is detachably provided with a paper feed cassette 2 for accommodating a sheet S which is a recording paper. The paper feed cassette 2 is a box-shaped cassette trough portion 2a.
An intermediate plate 2b provided in the cassette trough portion 2a for stacking and supporting the sheets S, a spring 2c for pushing up the intermediate plate 2b, and a sheet S by regulating the leading end side corner portion of the sheet S. Separation claw 2d for separating each side, and side regulation plate 2 for regulating the side end portion and the rear end portion of the sheet S, respectively.
f and a rear end regulating plate 2e.

The paper feed cassette 2 is a so-called universal cassette capable of accommodating sheets S of a plurality of sizes by moving the side regulation plate 2f and the rear edge regulation plate 2e according to the size of the sheet S. In this embodiment, in the domestic specifications, A5 width (length 148 mm), B5 width (length 182)
mm), A4 length (length 297 mm), B4 length (length 36)
4 mm), and can accommodate two types of sheets S of letter (LTR) size and legal (LGL) size in North American specifications. The length in the parentheses indicates the length of the sheet S in the conveyance direction.

As shown in FIG. 4, a mounting portion E for the paper feed cassette 2 is provided in the lower portion of the recording apparatus main body 3, the cassette mounting portion E has an open bottom, and the left and right leg portions 3 are provided.
Guide rails 28 for guiding the mounting of the paper feed cassette 2 are provided on both inner side surfaces of a and 3b. Then, the guide rail 28 is engaged with a guide (not shown) provided on the side surface of the sheet feeding cassette 2 and the sheet feeding cassette 2 is pushed in, so that the sheet feeding cassette 2 can be attached to the recording apparatus main body 3.

As shown in FIG. 1, a cassette presence / absence detecting sensor 25 for detecting whether or not the sheet feeding cassette 2 to be mounted in the recording apparatus main body 3 is correctly mounted at the sheet feeding position in the cassette mounting portion E. Is provided.

In the main body 3 of the recording apparatus, a cassette mounting portion E
Sheets S stored in the paper feed cassette 2 attached to the
Is provided with a half-moon shaped sheet feeding roller 4a for slidingly feeding the uppermost sheet of the sheet feeding roller 4a.
The sheets S sent out in 1 are separated one by one by the separating claw 2d provided in the sheet feeding cassette 2.

The sheet S separated and sent out from the sheet feeding cassette 2 by the separating claw 2d is nipped and conveyed by the conveying roller 5 and the roller 6 which is brought into pressure contact with the conveying roller 5, and further U-turned by the reversing guide 7. The sheet is fed to the recording unit A in the reverse direction in the direction opposite to the feeding direction from the sheet feeding cassette 2.

A front guide 8 is provided on the upstream side of the recording portion A, and the front guide 8 is composed of a plurality of ribs. Further, an upper guide 9 is provided facing the upper portion of the front guide 8. Then, the front guide 8 and the upper guide 9 constitute a conveyance path for guiding the sheet S that is reversed and sent.

The recording section A in this embodiment records by the ink jet recording method. The recording head is
The inkjet cartridge 10 is a disposable type cartridge in which an ink tank is integrated. The inkjet cartridge 10 is a carriage 11
It is mounted so that it can run, and recording is performed by reciprocating. A platen 12 that supports the sheet S is provided on the opposite side of the inkjet cartridge 10.

Conveying means for conveying the sheet S are provided on the upstream side and the downstream side of the platen 12 respectively, and on the upstream side, the feed roller 13 and the pressing roller 14 which is in pressure contact with the feed roller 13. And a sheet discharging roller 15 is provided on the downstream side.
Conveying means including a spur 16 that contacts the paper discharge roller 15 is provided. The spur 16 is made of a material that is not transferred even if it comes into contact with the printing surface of the sheet S printed by the inkjet cartridge 10.

The ink jet system of this embodiment is
This is a system in which recording is performed by energizing the electrothermal converter according to a signal and ejecting ink toward the sheet from the ejection port of the recording head due to growth of bubbles caused by heating beyond film boiling by the electrothermal converter. However, the recording method of the recording unit A of the apparatus to which the present invention is applied is not limited to the inkjet method, and may be any other recording method such as an electrophotographic method and a thermal transfer method.

A rear guide 17 composed of a plurality of ribs is provided at the rear of the downstream conveying means, and the recording section A is provided.
A conveyance path for guiding the lower surface of the sheet S printed by is constructed. After this, a pair of discharge rollers 19 is provided at the downstream end of the guide 17.
Is arranged, and the sheet S conveyed on the rear guide 17 is discharged.

On the downstream side of the pair of discharge rollers 19, a main body paper discharge section 20 which is integrally extended from the main body frame 18 is arranged, and the main body paper discharge section 20 is provided with a plurality of ribs 20a. Further, a cassette lid 21 which also serves as a cassette paper ejection portion is arranged on the downstream side of the main body paper ejection portion 20, and the cassette lid 21 is provided with a plurality of ribs 21a. Then, the sheet Sa discharged by the discharge roller pair 19 slides on the ribs 20a and 21a, and each rib 2
0a and 21a are stacked one after another in a state of being suspended.

As shown in FIGS. 5 and 6, the cassette lid 21 is formed so as to cover only the rear side of the cassette trough portion 2a, and the ribs 21a are formed along the conveying direction of the sheet S. There is. A rib 22 is formed along the periphery on the back side of the cassette lid 21, and the rib 22 is attached by being fitted to the cassette trough portion 2a.

Further, the cassette lid 21 is the cassette trough 2
Since it is attachable to and detachable from a, if the C portion side in FIG. 5 comes off, the leading edge of the discharged sheet S is caught and a defective discharge occurs. Therefore, the cassette lid 21
By providing a plurality of protrusions 23 that enter the bottom of the frame of the recording apparatus main body 3 on the cassette lid 2
It prevents the deviation of 1. Furthermore, the ribs 21a on the upper surface of the cassette lid 21 are formed so that the height of the ribs 21a is 1 mm lower than that of the ribs 20a of the main body discharge part 20 in the attached state. The upper portion of the rib 21a is smoothly conveyed and sequentially stacked. In addition, as shown in FIG. 7, the protrusion provided on the cassette lid 21 has a rib shape 23 over the entire width direction.
It may be a.

Further, as shown in FIG. 8, the cassette lid 21
The shape of the surface on which the sheets S are stacked may have an arcuate cross-section in which the left and right ends are raised and the central portion is recessed toward the downstream side in the sheet S transport direction. The sheet Sa is warped to increase the strain in the longitudinal direction of the sheet S, and in the long sheet S or the like, the portion separated from the upper surface of the lid does not hang down.
It will not slip off.

As the outer shape of the cassette lid 21, as shown in FIG. 9, the left and right portions 21b and 21c may be extended from the cassette trough 2a to the front of the recording apparatus main body 3. When the cassette lid 21 has such a shape as to have a clearance in the central portion, the recorded sheet S can be easily pulled out by holding the central portion of the sheet S, which improves usability.

The cover 23 covering the recording head provided in the recording apparatus main body 3 is releasably provided, and in the released state, the ink jet cartridge 1
The space required for 0 replacement is opened, and the space above the front guide 8 and the rear guide 17 is also released to facilitate jam processing.

As shown in FIGS. 1 and 2, a reading section B for reading image information of a document is provided on the upper portion of the recording apparatus main body 3, and when the document is set from the front side, the document is separated. The sheet is separated and conveyed one by one by the conveying unit Ba, the image information is read by the reading sensor Bc, and the image is ejected onto the rear ejection tray Bd. In addition, O
Is an operation unit provided on the upper surface of the reading unit B,
Operation buttons and display panel are provided.

As shown in FIG. 1, the optional sheet feeding unit 30 is removably arranged on the lower side of the recording apparatus main body 3 to increase the feeding capacity of the sheets S or feed sheets S of different sizes. It is to make it possible. As shown in FIG. 2, the optional sheet feeding unit 30 of the present embodiment is smaller than the outer shape of the recording apparatus main body 3, and by making the optional sheet feeding unit 30 small in this way, a neat design is obtained. The entire device also looks compact. This optional paper feed unit 3
The paper feed cassette 12 attached to 0 is the same as the paper feed cassette 2 attached to the recording apparatus main body 3, and therefore detailed description thereof will be omitted.

The sheets S stored in the sheet feeding cassette 12 are sent out by the optional sheet feeding roller 4b, separated one by one by the separating claw 2d, and then nipped and conveyed by the optional sheet feeding roller 33 and the roller 34. Paper guide 3
It is sent from the outlet 35 to the inlet 36 of the recording apparatus main body 3 through 2. After that, the sheet is conveyed by the conveying roller 5 on the side of the recording apparatus main body 3 and is recorded and ejected in the same manner as the sheet S sent out from the paper feed cassette 2 on the side of the recording apparatus main body 3.

The option frame forming the frame of the option paper feed unit 30 supports the option paper feed roller 4b and the paper feed guide 32. Further, as shown in FIGS. 1 and 3, a plate-like member is stretched between the left and right legs above the front of the option sheet feeding unit 30.
The plate-shaped member is a mounting guide 30 that guides mounting of the sheet feeding cassette 2 mounted in the recording apparatus body 3 when the optional sheet feeding unit 30 is connected to the recording apparatus body 3.
a.

As shown in FIG. 4, when the recording apparatus main body 3 is used alone, when the paper feed cassette 2 is mounted, the upper surface of the desk or the like on which the recording apparatus main body 3 is placed serves as a guide, The mounting can be easily performed by pushing the paper feed cassette 2 along the upper surface.

However, the optional paper feeding unit 3
When 0 is connected, the cassette mounting portion E of the recording apparatus main body 3 comes to the upper side, so if there is no standard for mounting, the operability of mounting the paper feed cassette 2 will deteriorate, but as in this embodiment. Since the mounting guide 30a provided in the optional sheet feeding unit 30 serves as a guide for mounting the sheet feeding cassette 2, the operability at the time of mounting can be significantly improved. In addition,
The shape of the guide or guide rail 28 so that the guide (not shown) of the paper feed cassette 2 and the guide rail 28 of the cassette mounting portion E are engaged only by pushing the paper feed cassette 2 along the mounting guide 30a. By appropriately setting, it is possible to further improve the operability when the paper feed cassette 2 is attached to the recording apparatus main body 3.

Next, the size detecting means for detecting the size of the sheets S stored in the sheet feeding cassettes 2 and 12 will be described with reference to FIGS.

First, the role of size detection will be explained. When the facsimile apparatus receives the recording data, the recording data is stored in the memory 140 (shown in FIG. 14) in the recording apparatus main body 3.
Then, it is determined how large the size of one page of the stored recording data is, for example, whether it is in the size of A4 or the size of which is not B4.

For example, an A4 size sheet S is stored in the upper sheet feeding cassette 2 and a B4 sheet is stored in the lower sheet feeding cassette 12.
In the case of containing two different size sheets S containing size sheets S, it is necessary to select from which paper feed cassette the paper should be fed. Therefore, the control means 100 of the recording apparatus main body 3 must recognize which size of the sheet S is accommodated in each paper feed cassette. Further, when the control means 100 receives print data that does not fit in any size, it must judge how much the image can be printed by reducing or enlarging the image. In this way, the size detection of the sheets accommodated in each of the sheet feeding cassettes 2 and 12 is performed in order to supply the sheet S having the optimum size according to the received print data. Next, the configuration of the size detecting means will be described.
First, in the case of domestic specifications, it is configured as follows to detect the sizes of the four types of sheets S of A4, A5, B4, and B5.

As shown in FIG. 12, notches 70a, 70b are provided in the cassette trough portion 2a and the intermediate plate 2b of the paper feed cassette, respectively.
80a is formed. The notch 70a of the cassette trough portion 2a is not closed when the A5 and B5 size sheets S are stored, and is arranged at a position where the cutout 70a is closed when the A4 and B4 size sheets S are stored. Further, the notch 80a of the intermediate plate 2b is arranged so as not to be closed when the A4 and A5 size sheets S are stored, and to be closed when the B4 and B5 size sheets S are stored.

As shown in FIG. 10, the notch 7 is provided on the recording apparatus main body 3 side when the paper feed cassette 2 is mounted.
The sheet S length detection sensor 70 and the sheet S width detection sensor 80 are arranged in association with 0a and the cutout 80a, respectively. Each of the detection sensors 70 and 80 is a reflection type photo sensor, and the cutout 70a in the sheet S,
When 80a is blocked, an H level signal is output, and when it is not blocked, an L level signal is output.

For example, when the sheet S of A4 size is stored in the paper feed cassette 2, the cutout 70a is closed and the cutout 80a is released, so that the length detection sensor 70 is at the H level. The width detection sensor 80 outputs L. Then, as shown in Table 1, the detection sensor 70,
The sheet size can be identified by the combination of the signals output from 80. The arithmetic circuit 110 identifies the sheet size based on the combination of Table 1.

[0043]

[Table 1]

Next, in the case of North American specifications, since letter (LTR) size and legal (LGL) size sheets S are mainly used in North America, these two sizes can be detected. As shown in FIG. 13, since the letter size sheet S and the legal size sheet S have the same width and a length difference of 77 mm, the length detection sensor 70 cannot identify them. Therefore, in the case of North American specifications, the detection sensors 70, 8 as in domestic specifications are used.
The combination of outputs from 0 cannot identify the sheet size.

Therefore, in the case of North American specifications, the seat is identified as follows. For example, when the legal size sheet S is used, the width detection sensor 80 is always in the H level state by attaching and blocking the shielding member 90 to the notch 70a, and when the state is detected, the determination circuit 120 is detected. Recognize that the sheet S accommodating is a legal size. Further, when the shield member 90 is removed, the width detection sensor 80 is always in the L level state, and when this state is detected, the discrimination circuit 120.
Recognize that the sheet S accommodating is a letter size. The sensor output at this time is as shown in Table 2. In addition,
On the contrary, when the letter size sheet S is used, the shielding member 90 may be attached for identification.
Further, the length detection sensor 70 may be eliminated.

In this way, the size detection for the domestic specifications and the size detection for the North American specifications are performed, and switching of these specifications is performed by the switching means 130 (provided in the operation section O of the recording apparatus main body 3). (Illustrated in FIG. 14).

[0047]

[Table 2]

The shielding member 90 may be attached to and detached from the intermediate plate 2b by fitting it to the intermediate plate 2b with a claw or the like.
It may be slidably provided and moved appropriately to the shielding position.

As described above, the sheet S size can be detected by providing the shielding member 90 in the North American specification by using the size detecting sensor in the domestic specification. In this way, a common configuration can be used in each country.

Micro switches may be used as the size detection sensors 70 and 80 instead of the photo sensors. In this case, two micro switches are turned on according to the movement of the side regulation plate 2f and the rear regulation plate 2e that regulate the end portion of the sheet S provided in the paper feed cassette 2.
-It may be arranged so as to be turned off. For example, in FIG. 12, when the side regulating plate 2f is in the position for regulating the B5 size sheet S, the first micro switch is turned on.
When the FF is performed, the first microswitch is turned on when the sheet S of A5 size is regulated, and the rear end regulation plate 2e is at the position of regulating the sheet S B4 size, Turn off the 2 micro switch
The second micro switch is turned on when the A-size sheet S is in the position to be regulated. By doing so, the photo sensors 70, 80
As with the size detection by the combination of the detection signals of A, A4, A
Four types of sheet S size detection of 5, B4, and B5 can be performed.

Further, in the case of North American specifications, a regulation member is provided in the sheet feeding cassette so that the first micro switch is always turned on, thereby recognizing that the accommodated sheets S are legal size. To do so.

The size detecting means described above can be applied to both the paper feed cassette 2 mounted in the recording apparatus main body 3 and the paper feed cassette 12 mounted in the optional paper feed unit 30.

The recording operation of the facsimile apparatus having the above configuration will be briefly described.

The control means 100 includes a size detection sensor 7
A size signal indicating the size of the sheet S accommodated in each of the sheet feeding cassettes 2 and 12 identified by the calculating unit 110 based on the signals from 0 and 80 is input, and when the recording start signal is received, the recording is started. It is determined which of the upper and lower sheet feeding cassettes 2 and 12 the sheet S of the optimum size is stored in and the sheet feeding is started. When the sheet S stored in the upper paper feed cassette 2 is selected, the recording apparatus main body 3
The sheet feeding roller 4a on the side rotates to feed the sheet S in the sheet feeding cassette 2. The fed sheet S is U-turned by the conveyance roller 5 and the reversing guide 7 and is fed to the recording unit A.

In the recording unit A, the sheet S is recorded by the ink jet cartridge 10 while being conveyed by the feed roller 13 and the paper discharge roller 15. And
The sheet S on which an image has been formed is discharged onto the rib 20 a of the main body discharge unit 20 and the cassette lid 21 by the discharge roller pair 19.

Further, the sheets S stored in the paper feed cassette 12 mounted in the optional paper feed unit 30
The same applies when recording on the optional paper feed roller 4
The sheet S delivered by b is conveyed by the optional feeding roller 33 and the roller 34, passes through the outlet 35, and is inserted into the recording apparatus body 3 from the inlet 36 of the recording apparatus body 3. The inserted sheet S is sent to the recording unit A by the transport roller 5, and the subsequent recording operation is the same as the above-mentioned content.

Here, the paper feed cassette 2 is attached to the recording apparatus main body 3.
15 is not attached, the sheet S is fed from the sheet feeding cassette of the optional sheet feeding unit 30 and is recorded and ejected, so that there is no cassette lid 21 that constitutes the sheet ejection unit, and therefore, the configuration shown in FIG. The recorded sheet Sa
Will fall. Therefore, when the recording device main body 3 does not have the paper feed cassette 2, the cassette presence / absence detection sensor 25 detects the absence of the paper feed cassette 2 and sends the signal to the control means 100, and the control means 100 performs the paper feed operation. Prohibit
Therefore, the delivery of the sheet S from the option sheet feeding unit 30 is prohibited. The print data received at this time is accumulated in the memory 140, and when the paper feed cassette 2 is installed in the recording apparatus main body 3, the recording operation is started and the print data accumulated in the memory 140 is recorded on the sheet S. To do so.

As described above, the presence or absence of the paper feed cassette 2 in the recording apparatus main body 3 is detected, and the recording operation is not performed when the paper feed cassette 2 is not present, so that the reliability of paper ejection is improved. be able to.

Instead of the sensor 25 for detecting the presence / absence of the sheet feeding cassette 2, a sheet presence / absence sensor for detecting the presence / absence of the sheet S accommodated in the sheet feeding cassette 2 may be used.
This will be explained below.

The sheet presence / absence sensor is generally used and detects the presence / absence of the sheet S based on the displacement of the lever by abutting the lever on the uppermost surface of the accommodated sheet S. Any type of device may be used, such as a device that detects the presence or absence of the sheet S by detecting the reflection of light emitted toward the sheet S. When the sheet presence / absence sensor determines that there is no sheet S accommodated in the paper feed cassette 2 in the recording apparatus main body 3, the control unit 100 performs recording in the same manner as the control by the cassette presence / absence detection sensor 25. Prohibit operation.

Here, when the sheet presence sensor detects the absence of a sheet, the sheet feeding cassette 2 is set to the cassette mounting portion E.
It is considered that the sheet S is not attached to the cassette attaching section E and the sheet cassette 2 is not attached to the cassette attaching section E.

In the former case, since the paper feed cassette 2 is attached, there may be no problem with paper ejection.
Since it is possible to change the size of the sheet S by performing the operation of replenishing the sheet S, it may be possible to perform recording on the optimal size sheet S by starting recording after replenishing the sheet S. This is preferable in selecting the size of the sheet S for recording.

In the latter case, the control is the same as the control by the cassette presence / absence detection sensor 25 described above. Therefore, optimum control can be performed also by the sheet presence sensor.

Next, another embodiment will be described. In this embodiment, only the frame configurations of the recording apparatus main body 3 and the option paper feeding unit 30 are different, and the other configurations are the same as the above-described embodiments.

As shown in FIGS. 16 and 17, bottom plates 37 and 38 are provided on the recording apparatus main body 3 and the option paper feed unit 30, respectively.
The paper feed cassettes 2 and 12 are thus supported. The bottom plates 37, 38 are common parts for cost reduction.

If the outer shape of the option sheet feeding unit 30 is formed smaller than the outer shape of the recording apparatus main body 3, the bottom plate 37 of the recording apparatus main body 3 is formed in conformity with the optional sheet feeding unit 30, so that the recording apparatus is formed. Providing a common bottom plate for the main body 3 shortens the inlet side of the paper feed cassette 2. Therefore, a plate-shaped mounting guide 30a is provided on the upper front side of the optional sheet feeding unit 30 to compensate for the shortage of the bottom plate on the recording apparatus main body 3 side, so that the sheet feeding cassette 2 can be easily attached to the recording apparatus main body 3. It can be greatly improved.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to these embodiments. For example, in the above-described embodiment, the facsimile apparatus is described as an example of the recording apparatus including the sheet feeding apparatus to which the present invention is applied, but the present invention is applied to the sheet feeding apparatus provided in the copying machine, the printer, the typewriter, and the like. May be.

[0068]

As described above in detail, according to the present invention, the sizes of a plurality of sheets are identified based on the information of the detection / non-detection of the sheet by the detection sensor, and the same detection sensor continuously detects the state or the non-detection state. Since the sizes of other sheets are discriminated based on the information on the detection state, it is possible to detect a plurality of sheet sizes without increasing the number of detection sensors, and it is possible to reduce the cost.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a facsimile apparatus and an optional sheet feeding unit embodying the present invention.

FIG. 2 is a perspective view of the device shown in FIG.

FIG. 3 is a perspective view showing a state in which a paper feed cassette is removed in FIG.

4 is a perspective view of a recording apparatus main body of the apparatus shown in FIG.

FIG. 5 is a vertical cross-sectional view of the recording apparatus main body showing an engaged state of a cassette lid that also serves as a paper discharge unit.

FIG. 6 is a perspective view of the paper feed cassette shown in FIG.

FIG. 7 is a perspective view showing another embodiment of the cassette lid.

FIG. 8 is a perspective view showing another embodiment of the cassette lid.

FIG. 9 is a perspective view showing another embodiment of the cassette lid.

FIG. 10 is a vertical cross-sectional view of the recording apparatus main body showing an arrangement state of each size detection sensor.

FIG. 11 is a perspective view showing a cassette trough portion of a paper feed cassette.

FIG. 12 is a plan view showing a state where domestic sheets are stored in a paper feed cassette.

FIG. 13 is a plan view showing a state in which North American sheets are stored in the paper feed cassette.

FIG. 14 is a control block diagram.

FIG. 15 is a diagram showing a state in which a sheet is ejected when a paper feed cassette is not attached to the main body of the recording apparatus.

FIG. 16 is a perspective view of a facsimile apparatus according to another embodiment.

FIG. 17 is a vertical sectional view of the device shown in FIG.

[Explanation of symbols]

 2 paper feed cassette (sheet accommodating means) 70 length detection sensor 80 width detection sensor 90 shielding member (control member) 100 control means 110 arithmetic circuit (arithmetic means) 120 discriminating circuit (discriminating means) 130 switching means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsushi Saito 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Noriyuki Aoki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Akio Okubo 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Shigeyuki Sugiyama 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (8)

[Claims] 1. A sheet feeding device comprising a sheet containing means for containing a sheet and a size detecting means for detecting the size of the sheet contained in the sheet containing means, wherein the sheet containing means is contained in the sheet containing means. A plurality of detection sensors arranged to detect the sheet, an identification unit that identifies the sizes of the plurality of sheets based on the information of the detection / non-detection of the sheet by each detection sensor, and another size of the sheet that cannot be identified by the identification unit. In order to identify the sheet, a control member that selects the plurality of detection sensors corresponding to other sizes to keep them in a constant detection state or a non-detection state, and a constant detection state or non-detection state of the detection sensor by the control member A sheet feeding device, comprising: a determination unit that determines the size of a sheet based on state information. 2. The plurality of detection sensors include a length detection sensor arranged in the length direction of the sheet and a width detection sensor arranged in the width direction of the sheet, and the identification means is Detection from the length detection sensor and width detection sensor
The sheet feeding device according to claim 1, wherein four types of sheet sizes can be identified by a combination of undetected information. 3. The discriminating means is capable of discriminating two kinds of sheet sizes by keeping either one of the length detecting sensor and the width detecting sensor in a constantly detecting state or a non-detecting state by the control member. Item 2. The sheet feeding device according to item 2. 4. The sheet feeding apparatus according to claim 3, further comprising a switching unit that switches between a discriminating operation by the discriminating unit and a discriminating operation by the discriminating unit. 5. The detection sensor is a photo sensor,
The sheet feeding device according to claim 1, wherein the control member is a detachable shield member that is provided so as to shield the photo sensor. 6. The sheet feeding apparatus according to claim 1, wherein the detection sensor is a micro switch, and the control member is a detachable restricting member that turns on the micro switch. 7. A recording comprising a sheet containing means for containing a sheet to be supplied to an image forming means of an image forming apparatus main body, and a size detecting means for detecting a size of a sheet contained in the sheet containing means. In the apparatus, a plurality of detection sensors arranged to detect the sheets accommodated in the sheet accommodating means, and an identification means for discriminating the sizes of the plurality of sheets based on the information of the detection / non-detection of the sheets by each detection sensor, A control member for selecting a plurality of detection sensors corresponding to another size so as to always detect a state or a non-detection state in order to identify a sheet of another size that cannot be identified by the identifying means; And a discriminating means for discriminating the size of the sheet on the basis of the information of the detection state or the non-detection state of the detection sensor. Apparatus. 8. The recording apparatus according to claim 7, wherein a switching unit that switches between the discriminating operation by the discriminating unit and the discriminating operation by the discriminating unit is provided in the operation unit of the image forming apparatus main body.