JP5337653B2 - Paper supply apparatus and image forming apparatus equipped with the same - Google Patents

Description

  The present invention relates to a paper supply device used in an image forming apparatus represented by a copying machine, a printer, a facsimile, and the like, and an image forming apparatus equipped with the same.

In this type of paper supply device, the remaining amount of paper is detected. Specifically, an actuator having a shielding portion is rotatably supported in the image forming apparatus main body, and the tip of the actuator is configured to be able to contact the uppermost sheet of the sheet cassette (for example, , See Patent Document 1).
Then, according to the position where the shielding unit shields the two optical sensors, a total of three states, that is, the remaining amount of paper, the remaining amount, and the remaining amount can be detected.

JP-A-5-97278

However, the above-described conventional technology has a problem that the stroke of the actuator becomes long and it is difficult to apply to a small capacity paper feed cassette.
This is because the shading unit of the technology detects a large amount of remaining paper in a state where the shading unit does not face each sensor at all, and further, the remaining amount of paper or no remaining amount in a state where the light of each sensor is blocked. This is because the stroke of the actuator needs to be longer than the sensor interval in order to detect these three states.

In addition, although not specifically described in the art, in order to detect a state without a paper feed cassette, the actuator must move further. As a result, the stroke of the actuator is about 3 times the sensor interval. Double the length.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a paper supply device that solves the above-described problems and that requires a short stroke of an actuator, and an image forming apparatus equipped with the paper supply device.

  A first invention for achieving the above object is configured to be detachable from the main body of the image forming apparatus, and is capable of storing a sheet of paper stacked in the thickness direction and rotated to the main body of the apparatus. The light-shielding plate includes a light-shielding plate and includes an actuator capable of contacting the uppermost layer of the paper and a plurality of detection means arranged on the movement path of the light-shielding plate. And has a hole with a diameter smaller than the interval between the detection means, and by arranging the hole between the detection means, the remaining amount of paper in the paper feed cassette is detected. Yes.

  According to the first invention, the sheet feeding cassette can store sheets of sheets stacked in the thickness direction. On the other hand, the actuator is rotatably supported by the apparatus main body and includes a light shielding plate having a hole having a diameter smaller than the interval between the plurality of detection means. This interval is, for example, the interval from the upper sensor to the lower sensor in the case of two detection means, and the sensor located at the uppermost position in the case of three or more detection stages. Is the distance from the sensor to the lowest position.

  Then, the remaining amount of paper in the paper cassette is detected according to the position of the hole of the light shielding plate and the detecting means. The state where the hole is located between the detecting means is used for detecting the remaining amount of paper. ing. Therefore, the stroke of the actuator is shorter than the conventional configuration in which only the state where the light shielding plate blocks the light of each detection means or the state where the light shielding plate does not face each detection means is used for detecting the remaining amount of paper. It can be easily applied to paper cassettes with a small total storage capacity.

  According to a second aspect of the present invention, in the configuration of the first aspect, each of the detection means is composed of a total of two, and is arranged along the vertical direction of the apparatus main body. Is detected to indicate that the remaining amount of paper in the paper cassette is large, and by disposing this hole between each detection means, the amount of paper remaining in the paper cassette is small. Is detected.

  Further, by arranging this hole so as to face the upper detection stage, it is detected that there is no remaining amount of paper in the paper feed cassette, and this hole is arranged further above the upper detection stage. Thus, it is detected that there is no paper feed cassette.

  According to the second invention, in addition to the operation of the first invention, a total of four states are detected: a remaining amount of paper, a small amount of remaining amount, no remaining amount, and no sheet cassette. This is a case where “large amount”, “small amount”, “no paper” and “no paper cassette” are detected despite the use of two detection means. Even so, the stroke of the actuator may be twice as long as the interval of the detection means.

A third invention is an image forming apparatus equipped with the paper supply device of the first or second invention.
According to the third aspect of the invention, in addition to the effects of the first and second aspects of the invention, the actuator body can be further reduced by shortening the stroke of the actuator.

  According to the present invention, since the state in which the hole of the light shielding plate is positioned between the respective detection means is used for detecting the remaining amount of the sheet, the sheet supply device that shortens the stroke of the actuator and the image forming apparatus equipped with the sheet supply device Is to provide.

1 is a configuration diagram of a printer according to an embodiment. FIG. 2 is an explanatory diagram of a transmissive sensor or the like installed in the printer main body of FIG. 1. It is explanatory drawing of the actuator supported by the apparatus main body of FIG. FIG. 4 is a state explanatory diagram of the transmissive sensor of FIG. 2 and the light shielding plate of FIG. 3.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of a printer according to this embodiment. The printer 1 includes a box-shaped apparatus main body 2 (a part of the apparatus main body 2 is shown in FIG. 2), and a paper supply device is disposed below the apparatus main body 2.

The paper supply apparatus of this embodiment has a paper feed cassette 3 that can be attached and detached by being pulled out and pushed in from the apparatus main body 2.
Sheets before image formation are stored in the cassette 3 in a stacked state in the thickness direction, and the sheets are separated one by one and delivered to the inside of the apparatus main body 2.

Inside the apparatus main body 2, the registration roller 5, the image forming unit 8, and the transfer unit 12 are arranged in this order when viewed in the sheet conveyance direction.
The image forming unit 8 includes a photosensitive drum, and the surface of the charged drum is irradiated by the exposure unit 6 to form an electrostatic latent image.

When toner is electrostatically attached to the surface of the drum, a toner image corresponding to the electrostatic latent image by the exposure unit 6 is developed on the surface.
The transfer unit 12 includes a transfer roller, and the drum and the transfer roller form a transfer nip for transferring the toner image onto the paper, and when the paper passes between the drum and the transfer roller, the toner image Is transferred to the paper.

Further, the fixing unit 14 and the discharge roller 16 are arranged in this order on the downstream side of the transfer unit 12 when viewed in the sheet conveyance direction, and the sheet sent from the fixing unit 14 is discharged to a discharge tray.
By the way, the paper supply apparatus of this embodiment includes two transmissive sensors (detecting means) 30 and 40 made of a photo interrupter or the like.

Specifically, as shown in FIG. 2, transmissive sensors 30 and 40 are arranged along the vertical direction of the apparatus main body 2 at an appropriate position above the paper feed cassette 3 inside the apparatus main body 2. ing.
More specifically, the transmissive sensor 30 includes a light emitting unit 32 and a light receiving unit 34, and the light from the light emitting unit 32 can be detected by the light receiving unit 34.

The transmissive sensor 40 is arranged above the transmissive sensor 30, and the sensor 40 also has a light emitting unit 42 and a light receiving unit 44, and light from the light emitting unit 42 can be detected by the light receiving unit 44. Configured.
Then, the controller 20 provided at an appropriate position of the apparatus main body 2 determines a total of four states, which will be described later, using signals from these two transmission sensors 30 and 40.

On the other hand, a shaft portion 26 is projected in the vicinity of the transmission sensors 30 and 40 inside the apparatus main body 2. The shaft portion 26 of this embodiment extends along the irradiation direction of the light from the light emitting portions 32 and 42 described above, and supports the actuator 50 so as to be rotatable.
As shown in FIG. 3, the actuator 50 includes a rotation support portion 52, a contact portion 54, and an arc-shaped light shielding plate 56, and the rotation support portion 52 is free to play on the peripheral wall of the shaft portion 26 described above. Fitted.

The contact portion 54 is disposed on the right side of the rotation support portion 52 as viewed in FIG. 3, and the end portion thereof can contact the uppermost sheet, and after the sheet feeding cassette 3 is pulled out from the apparatus main body 2. Is configured to be able to contact the bottom surface of the apparatus main body 2.
Further, the light shielding plate 56 is disposed on the left side of the rotation support portion 52 as seen in the figure, and has a curved main body 58 and a hole 60 drilled through the curved main body 58.

The hole 60 of the present embodiment is formed with a smaller diameter than the vertical interval between the transmission sensors 30 and 40.
When the rotation support portion 52 is loosely fitted to the shaft portion 26, the actuator 50 can be rotated about the rotation support portion 52, and the transmission sensors 30 and 40 are on the movement locus of the light shielding plate 56. Be placed.

  Next, when the contact portion 54 is brought into contact with the uppermost sheet, the actuator 50 rotates clockwise as viewed in FIG. 3 according to the remaining amount of the sheet, so that the controller 20 removes the sheet in the sheet feeding cassette 3. The remaining amount and each state without the cassette 3 can be respectively determined.

  More specifically, when the paper feed cassette 3 to which the sheet is added is pushed into the apparatus main body 2, the rotation support part 52 rotates and the contact part 54 comes into contact with the uppermost sheet. The posture of the actuator 50 corresponds to the posture shown in FIG. 3, and the hole 60 of the light shielding plate 56 faces the transmissive sensor 30 (FIG. 4A).

That is, since the hole 60 of the light shielding plate 56 in this case faces the light emitting unit 32, in the transmissive sensor 40, the curved main body 58 blocks light from the light emitting unit 42 to the light receiving unit 44, and the controller 20 It is determined as “0”.
In contrast, in the transmissive sensor 30, the curved main body 58 does not block the light from the light emitting unit 32 to the light receiving unit 34, and the light from the light emitting unit 32 is detected by the light receiving unit 34 through the hole 60. 20 is determined as “1”.

Therefore, the controller 20 obtains logic (0, 1) and determines that the remaining amount of paper in the paper feed cassette 3 is large.
Next, when the sheets are separated one by one from the cassette 3 and sent toward the registration roller 5, the actuator 50 rotates clockwise from the posture of FIG. 3, and the hole 60 and the transmissive sensor 30 are transmissive. It faces between the sensors 40 (FIG. 4B).

  In other words, the hole 60 of the light shielding plate 56 in this case does not face the light emitting portions 32 and 42. That is, in the transmissive sensors 30 and 40, the curved main body 58 blocks all the light from the light emitting units 32 and 42 to the light receiving units 34 and 44, so the controller 20 determines “0”.

As a result, since the logic (0, 0) is obtained in the controller 20, it is determined that the remaining amount of paper in the paper feed cassette 3 is small.
Thereafter, when all the sheets are sent from the cassette 3 toward the registration roller 5, the actuator 50 further rotates clockwise, and the hole 60 faces the transmission sensor 40 (FIG. 4C).

  That is, since the hole 60 of the light shielding plate 56 in this case faces the light emitting portion 42, in the transmissive sensor 40, the curved main body 58 does not block light from the light emitting portion 42 to the light receiving portion 44, and the light emitting portion The light from 42 is detected by the light receiving unit 44 through the hole 60, and the controller 20 determines “1”.

On the other hand, in the transmissive sensor 30, the curved body 58 blocks light from the light emitting unit 32 to the light receiving unit 34, so the controller 20 determines “0”.
Therefore, the controller 20 obtains logic (1, 0), and determines that there is no remaining amount of paper in the paper feed cassette 3. In this case, the controller 20 turns on a lamp that informs the user that there is no paper on the operation panel of the printer 1.

Subsequently, for example, when the paper cassette 3 is pulled out from the apparatus main body 2 to replenish paper, the actuator 50 further rotates clockwise, and the hole 60 is positioned above the transmission sensor 40 ( FIG. 4 (d)).
In other words, the hole 60 of the light shielding plate 56 in this case does not face the light emitting portions 32 and 42.

  In addition, in the transmissive sensors 30 and 40, the bending main body 58 does not block any light from the light emitting units 32 and 42 to the light receiving units 34 and 44, and the light from the light emitting unit 32 does not pass through the hole 60. 34, and the light from the light emitting unit 42 is also detected by the light receiving unit 44 as it is.

Therefore, the controller 20 obtains logic (1, 1), and determines that there is no paper feed cassette 3. In this case, the controller 20 turns on a lamp for notifying that the cassette is not present on the operation panel of the printer 1.
Returning to FIG. 1 again, when the printer 1 equipped with the above-described paper supply device performs printing, the paper reaches the registration roller 5 from the cassette 3.

The registration roller 5 feeds the sheet toward the transfer unit 12 while correcting the oblique feeding of the sheet and measuring the image transfer timing with the toner image formed by the image forming unit 8.
On the other hand, the input port 22 in this figure is configured to be able to receive image data to be printed from the outside. This image data is data in which various images such as characters, codes, figures, symbols, diagrams, and patterns are converted into data. Based on this data, the controller 20 controls light irradiation and the like.

As a result, an electrostatic latent image is formed on the surface of the drum through charging and exposure, and a toner image corresponding to the electrostatic latent image is transferred to the sheet.
Thereafter, the sheet is fed toward the fixing unit 14 while carrying an unfixed toner image, and is heated and pressurized by the heat roller of the fixing unit 14 to fix the toner image. Next, the sheet sent from the fixing unit 14 is discharged to a discharge tray by a discharge roller 16.

  As described above, according to the present embodiment, the sheet feeding cassette 3 can store sheets of sheets stacked in the thickness direction. On the other hand, the actuator 50 is rotatably supported by the apparatus main body 2 and includes a light shielding plate 56 having a hole 60 having a diameter smaller than the interval between the two transmission sensors 30 and 40.

  The remaining amount of paper in the paper feed cassette 3 is detected according to the position of the hole 30 of the light shielding plate 56 and the sensors 30, 40. The state where the hole 60 is located between the sensors 30, 40 is detected. Used to detect the remaining amount of paper. Therefore, the stroke of the actuator 50 is shorter than the conventional configuration in which only the state where the light shielding plate blocks the light of each sensor or the state where the light shielding plate does not face each sensor is used for detecting the remaining amount of paper. It can be easily applied to a paper feed cassette that has a small total storage capacity.

  In addition, it is possible to detect a total of four states including a remaining amount of paper, a small amount of remaining amount, no remaining amount, and a state where there is no paper cassette, which improves convenience, and two transmissive sensors. In spite of the use of 30, 40, the stroke of the actuator 50 is the interval between the sensors 30, 40 even when “large”, “small”, “no paper” and “no paper cassette” are detected. Twice as long.

Further, the shortening of the stroke of the actuator 50 contributes to the miniaturization of the apparatus main body 2.
The present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the claims.

  For example, in the above-described embodiment, the transmissive sensor 30 or 40 is composed of two transmissive sensors. However, the transmissive sensor may be composed of three transmissive sensors. While the interval is set to be larger than the interval, the interval may be set to be smaller than the interval from the uppermost sensor to the lowermost sensor.

The detection means of the present invention is not limited to the transmission type sensor of the embodiment, and may be a reflection type sensor.
Furthermore, although the above embodiment shows an example in which the image forming apparatus is embodied in a printer, the image forming apparatus of the present invention can naturally be applied to a copying machine, a facsimile, and the like.

  In any of these cases, as described above, the actuator stroke can be shortened.

1 Printer (image forming device)
2 Image forming apparatus body 3 Paper feed cassette 30, 40 Transmission type sensor (detection means)
32, 42 Light emitting part 34, 44 Light receiving part 50 Actuator 52 Rotation support part 54 Contact part 56 Light shielding plate 58 Curved body 60 Hole

Claims (2)

A paper feed cassette configured to be detachable from the image forming apparatus main body, and capable of storing sheets of sheets stacked in the thickness direction;
An actuator that is rotatably supported by the apparatus main body, includes a light-shielding plate, and can contact an uppermost layer of the paper;
A plurality of detection means arranged on the movement locus of the light shielding plate,
The light-shielding plate is drilled through the light-shielding plate and has a hole having a smaller diameter than the interval between the detection means, and the hole is disposed between the detection means ,
Each of the detection means is composed of a total of two, and is arranged along the vertical direction of the apparatus body,
By arranging the hole facing the lower detection stage, it is detected that the remaining amount of paper in the paper feed cassette is large,
By arranging the holes between the detection means, it is detected that the remaining amount of paper in the paper cassette is small,
By arranging the hole facing the upper detection stage, it is detected that there is no remaining amount of paper in the paper feed cassette,
By detecting the absence of the paper feed cassette by disposing the hole further above the upper detection stage ,
Each stroke of the displacement of the actuator is detected during the process from when the remaining amount of paper in the paper cassette changes from a large amount to no, and from when there is no remaining amount to when there is no paper cassette. A paper supply apparatus characterized in that the length is set to twice the interval of the means . An image forming apparatus comprising the paper supply device according to claim 1.

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