JPH10181891A - Sheet size detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect various sheet sizes with the use of an existing sensor and no troublesome work added thereby. SOLUTION: A sheet size detector determined whether a sheet has a longer width or a shorter width with a width sensor 10. If the width sensor 10 detects that the sheet has a longer width, a size sensor 8 is set in its detection type A1 mode for the detection of the sheet size out of the four types of A4, A5, LT (letter size) and LG (legal size). If the width sensor 10 detects that the sheet has a shorter width on the other hand, the size sensor 8 is set in its detection type B1 mode, different from the detection type A1 mode, for the detection of the sheet size out of the other types including B5 and B4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a paper feeding section of a printer, a facsimile machine, a copying machine for plain paper, and the like, and is provided in a paper feeding cassette capable of storing various sizes of paper. The present invention relates to a paper size detection device that detects the size of a sheet.

[0002]

2. Description of the Related Art Conventionally, as a size sensor for detecting the size of paper stored in a paper cassette, a sensor capable of detecting four types of sizes with two bits is usually used. Since the number of possible sizes is limited, it is not possible to detect various types of paper sizes.

In order to enable detection of various types of paper sizes, a plurality of sensors are required by an operator when paper size detection is necessary, as in a paper size detection device described in Japanese Patent Application Laid-Open No. 8-36330. Is configured so that the paper size recognizing means provided with the symbol can be set at a predetermined position, thereby enabling accurate detection of various types of paper sizes.

[0004]

However, in the above-mentioned conventional technology, it is necessary to increase the detection capability of the size sensor in order to detect various types of paper sizes, and the work for detecting the paper is not easy. There were inconveniences such as complexity.

Accordingly, an object of the present invention is to provide a paper size detecting device which can detect a large number of paper sizes using a conventional size sensor without requiring complicated work for paper detection. Is to do.

[0006]

In order to achieve the above object, the present invention provides a paper size detecting device for detecting the size of paper stored in a paper cassette capable of storing paper of various sizes. A width sensor for detecting whether the width of the paper stored in the paper cassette is large or small, and detecting the size of the paper stored in the paper cassette in response to the detection of the width by the width sensor. With this configuration, even if the used size sensor has the conventional configuration and the detection capability, the size sensor uses the size sensor to determine the paper size based on two criteria. Because it can detect
The range of paper size detection by the size sensor can be expanded.

According to another aspect of the present invention, there is provided a sheet size detecting device for detecting the size of sheets stored in a sheet cassette capable of storing sheets of various sizes. , A width sensor that detects whether the width of the sheet is large or small depending on the position of the side fence, and a paper cassette that is stored in the paper cassette in response to the detection of the width by the width sensor. A size sensor for detecting the size of the sheet. With this configuration, even if the size sensor to be used has a conventional configuration and a detection capability, the size sensor is usually installed in a paper feed cassette. The paper width can be detected using the side fence, and the paper size can be detected by the size sensor based on the size of the paper width as two criteria. It is possible to widen the detection range of the paper size by capacitors.

Further, the present invention makes it possible to input paper size data that cannot be detected by the width sensor and the size sensor from outside the apparatus, thereby automatically detecting the paper size and manually setting the size. Thus, a wide variety of paper sizes can be set, and the usable range is widened.

The present invention also enables the use of paper of an unusual size by enabling paper size data to be input from outside the apparatus when the width sensor detects a small paper width. As described above, various kinds of paper sizes can be set by automatic paper size detection and manual size setting in the same manner as described above, thereby expanding the usable range.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of an image forming apparatus for explaining a first embodiment of the present invention, and 1 is a known image forming unit (not shown) for forming an image on a sheet by an electrostatic transfer method. ), 2 is a paper feed cassette for storing paper to be fed to the image forming section, 3 is an operation section including ten keys for setting various modes, 4 is an operation state of the apparatus or The display unit displays a setting mode and the like.

The paper feed cassette 2 is installed so as to be able to enter and exit from the apparatus main body 1. On one side of an outer panel 5 of the paper feed cassette 2, a size detecting plate 6 is rotatably provided. The paper size (A) provided on the detection plate 6
4, A5, etc.) are formed so that the display window 7 can be visually recognized from the outside.

A size sensor 8 is provided on the side of the apparatus main body 1 so as to face the back surface of the size detection plate 6. As shown in FIG. 2, the size sensor 8 has a pair of operating pins 8a and 8b which can be retracted, and outputs the on / off state of the operating pins 8a and 8b as an on / off signal. 2
It is possible to detect four types of paper sizes with bits. As the size sensor 8, a sensor usually used as a paper size detecting device can be adopted.

A paper cassette 2 in the apparatus main body 1 is provided.
The width sensor 10 is installed in a part of the sheet stored in the sheet cassette 2 in a portion slightly inside from the area of the maximum width. For example, as shown in FIG. 3, if it is possible to store sheets having a maximum width of A4 size in the paper feed cassette 2, the width sensor 10 is positioned at a position indicated by oblique lines in the area of A4 size. Will be installed.

FIG. 4 is an explanatory view showing an example of the configuration of the width sensor 10. The width sensor 10 includes a detection lever 11 whose one end is rotatably supported on a shaft, and an optical connection between the detection lever 11 and the other end. When the paper P having the maximum width is stored, the detection lever 11 is raised by the paper P as indicated by a two-dot chain line, and the photo sensor 12 outputs a detection ON signal. When papers other than the maximum width are stored,
Since the paper is set outside the installation area of the detection lever 11, the detection lever 11 is in a free state, the detection lever 11 is lowered as indicated by a solid line, and the photo sensor 12 outputs a detection off signal. It is configured to output.

Next, the operation relating to the paper detection of the paper size detecting device including the size sensor 8 and the width sensor 10 will be described.
This will be described with reference to the flowchart of FIG. 5 and an explanatory diagram of size detection by the size sensor of FIG.

The detection signals from the size sensor 8 and the width sensor 10 are transmitted to a CPU (not shown) of a control unit (not shown) built in the apparatus main body 1.
(Central processing unit), and the paper size is calculated. That is, when the width sensor 10 detects that the paper width is large (ON in S1-1), the size sensor 8 outputs A4, A5 by ON / OFF signals as shown in FIG. , LT (letter size), or LG (legal size) paper size (detection type A
₁₎ It becomes possible (S1-2), if any of the paper size sheet stored is in the detection range of the detection type A ₁ (size Yes in S1-2), and terminates the size detection .
Then, the image forming mode based on the detected size is set and the sheet feeding is started.

[0018] However, if the paper has been housed is not in any of the paper size of the detection range detection type A ₁ (S1-2
In the case of (No size), for example, an NG signal is displayed on the display unit 4 as undetectable (S1-3).

Further, different from the detected type A ₁ shown in the sheet width is detected as the small size by the width sensor 10 (OFF in S1-1), the size sensor 8, FIG. 7 (a), the for example B5, B4 size detection of the paper size such as (detection type B ₁₎ which allow (S1-4), if any of the paper size in the detection range of the paper stored is detected type B ₁ ( (S1-4 size available), size detection ends. Then, the image forming mode based on the detected size is set and the sheet feeding is started. However, if not one of the paper size sheet stored is in the detection range of the sensing type B ₁ (Mu size S1-4), as the same as undetectable, an NG signal to the display section 4 It is displayed (S1-3).

Next, another example of the sheet detecting operation of the sheet size detecting device including the size sensor 8 and the width sensor 10 will be described with reference to the flowchart of FIG. 6 and the explanatory diagram of the size detection by the size sensor of FIG. This will be described with reference to FIG.

Detection signals from the size sensor 8 and the width sensor 10 are sent to a CPU (not shown) of a control unit (not shown) built in the apparatus main body 1.
(Central processing unit), and the paper size is calculated. When the width sensor 10 detects that the paper width is large (ON in S2-1), the size sensor 8 responds to the ON / OFF signal as shown in FIG.
4, A5, LT (letter size) paper size detection and external input enabled mode can be set
(Detection type A ₂ ) is reached (S2-2), and if the stored paper is any paper size in the detection range of detection type A ₂ (the size of S2-2 is present), the size detection ends. .
Then, the image forming mode based on the detected size is set and the sheet feeding is started. However, if not one of the paper size sheet stored is in the detection range of the detection Type A ₂ (Mu size S2-2), the sheet from the set external input enabled mode, for example, the operation unit 3 and the like It is possible to input size data (S2-3). Then, after the input, the image forming mode based on the input size is set and the sheet feeding is started.

Further, (OFF of S2-1) it is as the detected that sheet width by the width sensor 10 is a small size, the size sensor 8, and the detection range detection type A ₂ shown in FIG. 7 (b) different, for example B5, B4 and detects the paper size, such as size, it is possible to set the external input enabled mode (detection type B ₂₎ (S2-4), paper stored is detected type B ₂ (S2-4)
), Size detection ends. Then, the image forming mode based on the detected size is set and the sheet feeding is started. However, when the stored paper is of detection type B
_When it is not any paper size in the detection range of ₂
In (S2-4 no size), an external input enabled mode is set in the same manner as described above, and it becomes possible to input paper size data from the operation unit 3 or the like (S2-3). Then, after the input, the image forming mode based on the input size is set and the sheet feeding is started.

FIG. 8 is a partially cutaway perspective view of an image forming apparatus for explaining a second embodiment of the present invention. Members corresponding to those described with reference to FIG. Reference numerals are used and detailed description is omitted.

Inside the paper cassette 2 in which the paper is stored, the paper cassette 2 is in contact with the side of the stored paper.
A pair of side fences 20 for restricting the width direction of the sheet are installed at predetermined positions in the position, which are opposed to each other and are movable in the width direction (direction of arrow H). A width sensor 21 shown in an enlarged manner in FIG. 9 is provided at one of the side fences 20 (the left side in the figure).

The width sensor 21 includes a detection arm 22 provided at an end of the side fence 20 so as to extend to the bottom of the sheet feeding cassette 2, and a photo interrupter provided in a moving area of the detection arm 22. 23 and the photointerrupter 23
Is installed at a position corresponding to a portion slightly inside from the maximum width of the sheets stored in the sheet cassette 2. For example, as shown in FIG. 10, assuming that sheets having a maximum width of A4 can be stored in the sheet feeding cassette 2, the photo interrupter 23 is installed at a position shown by oblique lines.

As shown in FIGS. 9 and 10, the width sensor 21
When the A4 size paper having the maximum width is stored in the paper cassette 2, the side fence 20 approaches the inner wall of the paper cassette 2, and the detection arm 22 of the side fence 20 blocks the detection optical path of the photo interrupter 23. And photointerrupter 23
Outputs a detection ON signal. However, when a sheet having a width other than the maximum width is stored (for example, B5 size), the side fence 20 moves inward of the sheet cassette 2 according to the width as indicated by a two-dot chain line. 22 is separated from the detection optical path of the photo-interrupter 23, and the photo-interrupter 23 outputs a detection-off signal.

The size sensor 8 used in the second embodiment has the same configuration as that of the device of the first embodiment. Next, regarding the operation relating to the paper detection of the paper size detection device according to the second embodiment including the size sensor 8 and the width sensor 21, a flowchart of FIG. 11 and an explanatory diagram of the size detection by the size sensor of FIG. It will be described with reference to FIG.

Detection signals from the size sensor 8 and the width sensor 21 are sent to a CPU of a control unit (not shown) built in the apparatus main body 1.
(Central processing unit), and the paper size is calculated. That is, when the width sensor 21 detects that the paper width is large (S3-1 ON), the size sensor 8 outputs A4, A5 by ON / OFF signals as shown in FIG. , LT (letter size), or LG (legal size) paper size (detection type A
₁₎ It becomes possible (S3-2), if any of the paper size level of included paper detection range detection type A ₁ (size Yes in S3-2), and terminates the size detection . Then, the image forming mode based on the detected size is set and the sheet feeding is started. However, when paper stored is not one of paper size detection range detection type A ₁ (Mu size S3-2), for example, so as to display the NG signal to the display section 4 as undetectable (S3-3).

When the width sensor 21 detects that the paper width is small (S3-1 OFF), an external input enabled mode is set. For example, paper size data is transmitted from the operation unit 3 or the like. Enables input (S3-4). Then, after the input, the image forming mode based on the input size is set and the sheet feeding is started.

Next, the size sensor 8 in the second embodiment
Another example of the operation related to the paper detection of the paper size detection device including the paper and the width sensor 21 will be described with reference to the flowchart in FIG. 12 and the explanatory diagram of the size detection by the size sensor in FIG. 7B.

Detection signals from the size sensor 8 and the width sensor 21 are transmitted to a CPU (not shown) of a control unit (not shown) built in the apparatus main body 1.
(Central processing unit), and the paper size is calculated. When the width sensor 21 detects that the paper width is large (S4-1 ON), the size sensor 8 outputs A4, A5, and LT according to an on / off signal as shown in FIG. 7B. It is possible to detect any of the (Letter size) paper sizes, and it is possible to set the external input enabled mode (detection type A ₂ ) (S4-2). If it is any of the paper sizes in the detection range of ₂ (the size of S4-2 is present), the size detection ends. Then, the image forming mode based on the detected size is set and the sheet feeding is started. However, when paper stored is not one of paper size detection range detection Type A ₂ (Mu size S4-2), the sheet from the set external input enabled mode, for example, the operation unit 3 and the like It is possible to input data of the size (S4-3). And
After the input, the image forming mode based on the input size is set, and the sheet feeding is started.

When the width sensor 21 detects that the paper width is small (S4-1 OFF), an external input mode is set in the same manner as described above, and the paper size is (S4-3), and after the input, the image forming mode based on the input size is set and the paper feeding is started.

[0033]

As described above, according to the paper size detecting apparatus of the present invention, even if the size sensor has the conventional configuration and the detecting ability, the paper width can be detected using the side fence or the like. , With the size of the paper width as two criteria,
Since the paper size can be detected by the size sensor, the paper size detection range of the paper size sensor can be expanded.

Further, since paper size data that is not detected by the width sensor and the size sensor can be input from outside the detecting device, the automatic size detection of the paper and the manual setting of the size enable various kinds of paper sizes. Setting can be done, and the available range expands.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram of a detection operation of the size sensor of FIG.

FIG. 3 is an explanatory diagram of an installation position of a width sensor of FIG. 1;

FIG. 4 is a schematic configuration diagram illustrating an example of a width sensor of FIG. 1;

FIG. 5 is a flowchart relating to sheet detection of the sheet size detection device according to the first embodiment of the present invention.

FIG. 6 is a flowchart illustrating another example of sheet detection by the sheet size detection device according to the first embodiment of the present invention.

FIG. 7 is an explanatory diagram of size detection by the size sensor of FIG. 1;

FIG. 8 is a perspective view of an image forming apparatus for explaining a second embodiment of the present invention.

FIG. 9 is an enlarged perspective view illustrating an example of the width sensor of FIG. 8;

FIG. 10 is an explanatory diagram of an installation position of the width sensor of FIG. 8;

FIG. 11 is a flowchart relating to sheet detection of a sheet size detection device according to a second embodiment of the present invention.

FIG. 12 is a flowchart according to another example of sheet detection of the sheet size detection device according to the second embodiment of the present invention.

[Explanation of symbols]

2 ... paper cassette, 3 ... operation unit, 4 ... display unit, 6
... size detection plate, 8 ... size sensor, 10, 21 ... width sensor, 11 ... detection lever, 12 ... photo sensor, 20 ... side fence, 22 ... detection arm, 23 ... photo interrupter.

Claims (4)

[Claims] In a paper size detection device for detecting a size of a sheet stored in a sheet cassette capable of storing sheets of various sizes, is the width of the sheet stored in the sheet cassette large? A paper size detection device, comprising: a width sensor for detecting whether the width is small; and a size sensor for detecting the size of paper stored in a paper cassette in response to detection of the width by the width sensor. . 2. A paper size detecting device for detecting the size of paper stored in a paper cassette capable of storing paper of various sizes, according to the width of paper stored in the paper cassette. A moving side fence,
A width sensor for detecting whether the width of the paper is large or small according to the position of the side fence; and a size sensor for detecting the size of the paper stored in the paper cassette in response to the detection of the width by the width sensor. A paper size detection device comprising: 3. The paper size detection device according to claim 1, wherein data of a paper size that cannot be detected by the width sensor and the size sensor can be input from outside the apparatus. apparatus. 4. The apparatus according to claim 1, wherein when the width sensor detects a small paper width, paper size data can be inputted from outside the apparatus. Paper size detection device according to the description.