JPH04112150A - Paper feeding device - Google Patents

Abstract

PURPOSE:To prevent the erroneous display which accelerates a user to supply paper sheets in spite of the existence of paper sheets by installing a judgement processing intercepting means for intercepting the judgement processing in a paper existence judging means during the time when revolution operation signals are outputted. CONSTITUTION:During the turning operation of a paper tray 3, even if the signal level supplied from a paper existence sensor 35 changes to the paperless state judgement level by the vibration caused by the mechanical operation, a paper existence judging means 44 does not output the result of the paperless state judgement. Accordingly, the generation of the trouble that the erroneous display for a user to accelerate to supply paper sheets in spite of the existence of paper sheets is prevented.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a paper feeding device applied to, for example, a copying machine or a printer. The present invention relates to a paper feeding device equipped with a tray rotation unit that automatically changes the orientation of the tray.

[Conventional technology]

The direction in which copy paper is fed in a copying machine is usually set to match the longitudinal direction of the largest size document placed on a document table. For example, in a copying machine whose maximum document size is A3, for documents of size A4 or smaller, the paper tray that accommodates the copy paper is moved to the horizontal feed position where the longitudinal direction is perpendicular to the feed direction, and By selecting either the vertical feeding position where the longitudinal direction is parallel to the direction and loading it into the copying machine, the original on the document tray can be placed horizontally or vertically. It is possible to make copies. Note that, for example, when copying a size A3 document by reducing it to size A4, it is necessary to set the size A4 paper tray to the vertical feeding position and load the paper tray 4.

In this way, A4 paper that can be used for both cross-feeding and fir-feeding.
Conventionally, there are two types of paper trays for B5, A5, etc., one for vertical feeding and one for horizontal feeding, and the paper trays are replaced as necessary. however,
Since a large number of paper trays are required and the replacement work is troublesome, for example, as described in Japanese Patent Laid-Open No. 56-59245, it is possible to rotate the paper tray over a 90 degree angle range. The orientation of the paper tray can be switched between the horizontal feed position and the vertical feed position within the paper feeder, and a sensor is provided to detect the size and orientation of the document on the document tray, and the detection signals from these sensors are Copying machines have also been put into practical use that have a function to automatically change the orientation of the paper tray from copying modes such as normal size and variable magnification.

By the way, the paper feed device in the above-mentioned copying machine has
A paper presence/absence sensor is further provided to detect the presence or absence of paper in the paper tray. In the device described in the above-mentioned publication, a non-contact optical sensor consisting of a light emitting element and a light receiving element is provided above and below the paper tray, and is located on the optical path from the light emitting element on the bottom of the paper tray. A through hole is drilled in. As a result, when the paper tray runs out of paper, the state changes from a light-blocking state to a transmitting state, and the amount of light received by the light receiving sensor changes to determine the presence or absence of paper, and the result of this judgment is sent to the copying operation panel, for example. This is displayed to prompt the user to replenish paper.

Note that if the topmost sheet of paper stacked in the storage tray is kept at a nearly constant height,
Instead of the transmissive optical sensor described above, it is also possible to adopt a configuration in which a reflective photo ink printer is disposed above the paper tray to detect the presence or absence of paper. That is, the paper tray as described above is usually further provided with a paper mounting plate, and claws for preventing double feeding are provided at the left and right corners of the feeding example. Further, a push-up member is provided that elastically pushes up the feeding side of the paper mounting plate, and thereby, the paper placed on the paper mounting plate is The side corners are held in contact with the claws.

Therefore, even when the topmost paper is fed one by one, the topmost position is maintained almost constant at the height position where it contacts the claw due to the upward elastic force of the push-up member. be done. Therefore, even in the above-mentioned reflective photointerrupter, which has unique distance characteristics depending on the spacing and orientation of the emitting and light-receiving elements that are pancaged in one direction, the detection area is set at the height of the uppermost sheet of paper. By arranging them together, it is possible to determine the presence or absence of paper.

By using such a reflective photo ink converter in which the light emitting and light receiving elements are integrated, it is possible to reduce the number of parts and assembling steps for routing electrical wiring.

[Problem to be solved by the invention]

However, when detecting the presence or absence of paper using the reflective photo ink printer as described above, during the rotation of the paper tray as described above, even though there is paper remaining in the paper tray, First, there is a problem in that it is easy to misjudge that there is no paper. In other words, although the elastic force of the push-up member, for example, acts to hold the paper at a substantially constant height, during the above-mentioned rotational movement, the height of the paper changes as a result of this rotational movement. Due to the vibration, the height position of the top paper changes, and as a result, the top paper moves out of the detection area of the reflective photo ink printer, and the amount of reflected light falls below the paper out detection level. It becomes. Based on such a detection signal, conventionally,
For example, an erroneous display prompting the user to replenish paper may cause the user to perform unnecessary operations such as pulling out the paper tray from the paper feeder in an attempt to replenish the paper, resulting in feelings of distrust and discomfort. It is something that gives rise to

[Means to solve the problem]

In order to solve the above problems, the paper feeding device of the present invention has the following features:
As shown in the figure, a rotation mechanism 21 for rotating the paper tray 3 in which paper is stored and reversibly changing the position to either a vertical feed position or a horizontal feed position, and A rotational operation signal output means 42 is provided for outputting a corresponding rotational operation signal during the rotational operation, and also emits light toward the paper tray 3 and
a paper presence/absence sensor 35 that outputs a signal according to the amount of reflected light that varies depending on the presence or absence of paper in the paper presence/absence sensor 3;
5, the paper presence/absence determining means 44 determines the presence or absence of paper in the paper tray 3 based on a signal from the paper tray 3. The present invention is characterized in that it is further provided with discrimination processing interrupting means 51 for interrupting the discrimination processing.

[For production]

According to the above configuration, during the rotation operation of the paper tray 3,
Even if the signal level from the paper presence/absence sensor 35 changes to the paper-out determination level due to vibrations caused by mechanical operations during this time, the paper-absence determination means 44 does not output the paper-out determination result. As a result, it is possible to prevent false messages from being displayed, such as prompting the user to replenish paper, even though paper is present, thereby reducing the sense of distrust and discomfort that previously caused users to feel confused. It can be prevented.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 2 to 7.

As shown in FIG. 2, the paper feed bag W2 provided below the copying machine main body 1 rotates the paper tray 3 stored therein by 90 degrees within a horizontal plane, so that the paper feeding direction can be changed to vertical feeding. The tray rotation unit 4 has a function that can be changed to horizontal feeding.

Note that when double-sided copying or composite copying is performed, a sheet of paper on which one side has been copied is temporarily stored between the paper feeding device 2 and the copying machine main body 1, and the paper is turned upside down, or the front and back sides are left as they are. A re-copying tray unit 5 is provided for re-feeding paper to the copying machine main body 1.

As shown in FIG. 3, the tray rotation unit 4 includes a tray storage box 1 whose opposing side edges are supported by the paper feeder main body 11 via slide mechanisms 12.
3 is provided. The tray storage box 13 has a box-like shape with an open top, and the removable paper tray 3, which has a box-like shape with an open top corresponding to the size of paper to be stored, is installed inside the box. There is. Further, the tray storage box 13 is arranged outward from the position inside the paper feeder main body 11 (
It can be slid horizontally along the slide mechanism 12 (downward in the figure), and replenishing the paper tray 3 with paper is performed while it is in this outwardly drawn position.

A lead screw 14 is provided inside the tray storage box 13 and extends in parallel along a vertical plane on the paper feeding direction side (right side in the figure). The rear end (upper end in the figure) of the lead screw 14 protruding from the tray storage box 13 is configured to engage with a coupling clutch 16 of a driving force transmission mechanism 15 attached to the paper feeder main body 11. It has become. As a result, the rotation of the motor 17, which is further provided within the paper feeder main body Il, is decelerated by the driving force transmission mechanism section 15 and transmitted to the lead screw 14.

A movable piece 18 is screwed onto this lead screw 14, and the paper tray 3 is held in a state in which the tip of a connecting lever 19 connected to one corner thereof is engaged with the movable piece 18. It is installed in the tray storage box 13. on the other hand,
The tray storage box 13 is further provided with an elongated plate-shaped swinging arm 20 whose one end is pivoted on the bottom surface of the tray storage box 13. It is installed with the back side of the bottom center part engaged. Then, by rotating the lead screw 14 and moving the moving piece 18 from the lower end position shown in the figure to the upper end position, for example, the paper tray 3 is moved from the vertical feeding position shown by the solid line in the figure to the 90° position. It is possible to reversibly change the traverse feed position to a position indicated by a two-dot chain line having a different direction. Therefore, in this embodiment, the lead screw 14
- The moving piece 18, the connecting lever 19, and the swing arm 2o constitute a rotation mechanism 21 for changing the paper tray 3 between the vertical feeding position and the horizontal feeding position.

Note that a light shielding plate 22 is provided on the moving piece 18, and an optical vertical feed position sensor 23 and a horizontal feed position sensor 24 each consisting of a light emitting element and a light receiving element are attached to the paper feeder main body 11. It is being The vertical feed position sensor 23 is provided at a position where the optical path is blocked by the light shielding plate 22 when the paper tray 3 is located at the vertical feed position, and therefore the signal in this light shielded state is used as the vertical feed position signal as described above. It is output from the vertical feed position sensor 23.

Similarly, the horizontal feed position sensor 24 is connected to the paper tray 3.
The light shielding plate 22 is provided at a position where the light shielding plate 22 is in a light-shielding state when the sensor is located at the traverse-feeding position, and therefore, a signal at this time is outputted from the traverse-feeding position sensor 24 as a traverse-feeding position signal.

On the other hand, within the paper tray 3, a paper mounting plate 25, which has substantially the same shape as the paper stored therein, is further provided so as to be movable up and down. The paper tray 3 is also provided with locking claws 27 for preventing electrical transmission at the upper end positions of each corner located on the feeding port 26 side of the paper feeding device main body 11 in the vertical feeding position and the horizontal feeding position. ..., and three conical coil-shaped push-up springs 28a-c are provided between the paper placement plate 25 and the bottom surface of the paper tray 3. The first push-up spring 28a is provided at a position close to the vertical wall surface of the feeding port 26 when located at the vertical feed position, while the second push-up spring 28b is provided at a position close to the vertical wall surface of the feeding port 26 when located at the horizontal feed position. It is provided at a position close to the vertical wall surface of the 26 outlets. Note that the third push-up spring 28c is provided at a position apart from the first and second push-up springs 28a and 28b, respectively, in order to balance the tilted state of the paper placement plate 25, which will be described later. Furthermore, edge pulling mechanisms 29a and 29b are provided on each vertical wall surface located on the opposite side of the feeding port 26 in the vertical feeding position and the horizontal feeding position, respectively. These edge pulling down mechanisms 29a and 29b selectively function on the side opposite to the feeding port 26 by a pulling down operation guide groove (not shown) formed in the bottom of the tray storage box 13. It is supposed to be done.

As a result, when the paper tray 3 is located at the vertical feeding position as shown in FIG. 1 push-up spring 28a pushes up the left and right corners of the uppermost sheet 30 so that they come into contact with the locking claw 27 for preventing double feeding from below, while the side opposite to the feeding port 26 is pressed up against the edge It is held in an inclined state 1 m1 (hereinafter referred to as a paper feeding inclined state) which is pulled down to the bottom side of the paper tray 3 by the pulling down mechanism 29a. When the paper tray 3 is rotated from the vertical feeding position to the horizontal feeding position, the operation of the edge pulling mechanism 29a is gradually released, and the other edge pulling mechanism 29b When the edge is pulled down and the inclination direction is changed to the lateral feed position as shown in FIG. 5, the feed port 2
The paper feed is held in an inclined state with the 6th side pushed upward.

On the other hand, the paper tray 3 in the paper feeding inclined state as described above
As shown in FIGS. 4 and 5, in order to feed the sheets 30 stored in the copying machine one sheet at a time from the topmost sheet according to a sheet feeding command from the copying machine main body 1 side, as shown in FIGS. On the feeding port 26 side, a drawing roller 31 having a semicircular cross section and a pair of paper feeding rollers 32 are further arranged. When the above-mentioned drawing roller 31 has its flat part located on the lower side,
It is located slightly above and spaced apart from the top sheet 30. Then, it rotates once in response to the above-mentioned paper feeding command, and at this time, the arc surface section follows the rotation locus shown by the two-dot chain line in the figure.
The paper 30 rotates while being pushed down slightly against the upward push-up blade by the push-up spring 28a or 28b. As a result, a predetermined contact pressure is generated between the paper 30 and the uppermost paper 30 as the pull-in roller 31 rotates.
is sent out from the paper tray 3 to the feeding port 26, and further, the leading edge side of the paper 30 is fed between the paper feed rollers 32, 32 which are rotating at the same time, so that these paper feed rollers 32, 32 Then, it is further fed into the feeding path 33 shown in FIG. 2 and sent to the copying machine main body 1 side.

As shown in FIGS. 4 and 5, the paper feeding device 2 has a
A paper presence/absence sensor 35 is further provided. This paper presence/absence sensor 35 is made of a reflective photo ink printer, and is located at the top of the paper 3 in the above-mentioned paper feeding inclined state.
Light is irradiated toward a predetermined location of 0, and a voltage level corresponding to the amount of reflected light at that location is compared with a preset reference voltage. The paper mounting plate 25 has through holes 25a and 2 at respective positions corresponding to the irradiation direction from the paper presence/absence sensor 35 at the vertical feeding position and the horizontal feeding position.
5b is perforated, and therefore, the above-mentioned reference voltage is the same as that of the paper 30 on the paper mounting plate 25 for a state in which reflection from the paper 30 occurs when the paper 30 is present on the paper mounting plate 25. Therefore, the through hole 25a
- The level is set to determine a state where almost no amount of reflected light occurs as a result of the irradiated light traveling straight through 25b. More specifically, the above-mentioned reflective photo ink actuator has a unique distance characteristic depending on the spacing and orientation of the light-emitting and light-receiving elements that are packaged in one direction. Since the amount of received light changes depending on the distance from the reflective surface of In addition, even during switching between the vertical feed position and the horizontal feed position, the detection area is the position on the feeding port 26 side where the height change is small. If the corner is within a predetermined range, - paper presence/absence sensors 35 detect the paper 3.
The presence or absence of 0 can be detected.

When the detection signal level exceeds the reference voltage level from the paper presence/absence sensor 35, an "H" level signal (hereinafter referred to as an ON signal) corresponding to "paper present" is output.
If the voltage is below the reference voltage level, an "L" level signal (hereinafter referred to as an OFF signal) corresponding to "no paper" is output.

As shown in FIG. 6, the copying machine configured as described above is further provided with a copying control device 41 comprising, for example, a microcomputer, in the copying machine main body 1 in order to control the operation of the copying machine. This copying control device W41 is provided with a copying operation control section 42, and this copying operation control section 42 allows
The copying machine main body 1, the re-copying tray unit 5, and A series of copying operations of the sheet feeding device 2 are controlled, and the following description will focus on controlling the operations of the sheet feeding device W2.

When the copy operation start switch is turned ON on the operation panel, first, paper of a size corresponding to the set copy mode (hereinafter referred to as setting mode) is ready to be fed to the paper feeder 2. It is determined whether or not, and further,
It is determined whether the paper feeding direction corresponds to the setting mode based on the signals from the vertical feeding position sensor 23 and the horizontal feeding position sensor 24. If the feeding direction is different from the setting mode, the paper tray 3 described above is rotated, for example, by 90 degrees from the vertical feeding position to the horizontal feeding position. This rotational operation is performed by outputting an operating signal to the motor 17, and the vertical feed position sensor 2
The motor 17 is stopped when a feed position signal is output from the sensor corresponding to the new feed direction among the transverse feed position sensor 24 and the transverse feed position sensor 24.

Next, the paper 30 is fed to the copying machine main body 1 side (by rotating the pull-in roller 31 and paper feed rollers 32, 32, the uppermost paper 30 in the paper tray 3 passes through the feeding path 33). It is fed to the copying machine main body 1.
The operation signal to the paper feed rollers 32, 32 is sent to the feed path 33.
It is stopped based on a signal from a paper trailing edge position detection switch 43 attached to a portion of the paper feeding device 2 connected to the feeding port 26 at . That is, after the trailing edge of the paper 30 fed into the feeding path 33 from the paper feeder 2 side passes through the mounting portion of the paper trailing edge position detection switch 43, the paper trailing edge position detection switch 43 detects the Paper feed roller 32・
32 is stopped to complete the paper feeding operation.

On the other hand, in the copying control device 41, a paper presence/absence monitoring section (paper presence/absence determining means) 44 is further provided which monitors the presence or absence of paper 30 in the paper tray 3 in parallel with the above-described control. The detection signal from the paper presence/absence sensor 35 is input to this paper presence/absence monitoring section 44 . A tray presence/absence detection switch 45 that outputs an ON signal when the paper tray 3 is installed in the tray storage box 13 is further connected to the paper presence/absence monitoring section 44 . , rotation operation signal Sr of paper tray 3
and a signal Sf indicating that paper is being fed are input. When no feed position signal is input from either the vertical feed position sensor 23 or the horizontal feed position sensor 24, the copying operation control unit 42 determines that the paper tray 3 is rotating and outputs the rotation operation signal Sr. Therefore, in this embodiment, the copying operation control section 42 also functions as a rotational operation signal output means for outputting a corresponding rotational operation signal during the rotational operation of the paper tray 3. ing. The copying operation control unit 42 also sends a signal Sf during paper feeding, which is equivalent to a paper feeding signal output to the drawing roller 31 and the paper feeding rollers 32, 32 in order to perform the paper feeding operation described above. is input to the paper presence/absence monitoring unit 44 as follows.

Based on each input signal as described above, the paper presence/absence monitoring section 4
In step 4, the presence or absence of paper 30 in paper tray 3 is determined according to the procedure shown in FIG. That is, the above paper tray 3
The presence or absence of the paper 30 in the paper is determined based on the output signal from the paper presence/absence sensor 35. Before determining the output state of the paper presence/absence sensor 35, first, in Sl.
The paper tray 3 is set in the tray storage box 13 according to the signal from the tray presence/absence detection switch 45, and in S2, the paper tray 3 is rotating depending on whether the rotation operation signal Sr is in the output state or not. that it is not,
Further, in S3, after sequentially determining whether the paper is not being fed based on whether the signal Sf during paper feeding is in an output state,
In S4, the output signal from the paper presence/absence sensor 35 is read, and when this signal is the ON signal, the paper out flag is reset to O (S5). On the other hand, when the output signal from the paper presence/absence sensor 35 is the OFF signal, the out-of-paper flag is set to 1 (S6), and then the process returns to step S1 described above.
The processes from 1 to S6 are repeated.

On the other hand, it is determined in Sl that the paper tray 3 is not set in the tray storage box 13, that the paper tray 3 is rotating in S2, and that paper is being fed in S3. If so, the process returns to 31 without going through the processes of 34 to S6, and therefore, during this time, the paper out flag is held in the previously set or reset state.

When the paper out flag changes to a state where 1 is set, the copying operation control section 42 interrupts the copying operation and turns on the paper out indicator lamp on the operation panel. After that, the user puts the paper 30 into the paper tray 3.
is replenished and the out-of-paper flag changes to the reset state of 0 through processing in the paper presence/absence monitoring unit 44, the copying operation control unit 42 turns off the out-of-paper indicator lamp, and the out-of-paper flag is set on the operation panel. Resumes the copy operation in the copy mode.

As described above, in the above embodiment, the output of the determination result of the presence or absence of paper 30 based on the signal from the paper presence/absence sensor 35 is not performed during the rotation operation of the paper tray 3 or during the paper feeding operation. It looks like this. In other words, mechanical vibrations are likely to occur in the paper tray 3 during the above-described rotational operation. The paper presence/absence sensor 35 is connected to the push-up spring 28a.
The detection area is set in accordance with the height position of the uppermost sheet 30 which is pushed up into an inclined state by the elastic force of the sheet 28b and held approximately at a predetermined height position. When vibration occurs, the height position of the uppermost sheet 30 may change, causing the sheet to deviate from the detection area of the sheet presence/absence sensor 35. For this reason, paper 3
Conventionally, even though 0 exists, an erroneous determination result indicating that there is no paper is output. However, in the embodiment described above, during the rotation operation of the paper tray 3, the determination of the presence or absence of paper based on the output signal of the paper presence/absence sensor 35 as described above is interrupted, and the previous determination result is retained. This prevents malfunctions such as turning on the paper out indicator lamp based on the above-mentioned erroneous determination results. As a result, even though the paper 30 is present, the user is not forced to perform unnecessary operations such as pulling out the tray storage box 13 from the paper feeder main body 11 in order to replenish paper. It is possible to prevent the discomfort and mistrust that would otherwise have occurred.

Furthermore, conventionally, malfunctions such as those described above have also occurred during paper feeding. That is, as described above, in the paper feeding operation, the drawing roller 31 rotates and its arcuate surface feeds the uppermost paper 30.
At this time, the paper 30 is slightly pushed down by the arcuate surface of the pull-in roller 31, so that the height position of the paper 30 from the detection area of the paper presence/absence sensor 35 is As a result, an erroneous determination result indicating that there is no paper was output. However, in the above embodiment, even during such paper feeding operation, the determination result based on the output signal from the paper presence/absence sensor 35 is interrupted, so malfunctions based on erroneous determination results are prevented. be done.

Note that the above embodiments do not limit the present invention, and various changes can be made within the scope of the present invention. For example, in the above description, an example has been described in which the discrimination processing interrupting means 51 is configured in step S2 of FIG. The above-mentioned discrimination processing interrupting means can also be constituted by a circuit that outputs the logical sum of a signal corresponding to the rotation operation of the paper tray 3 when the paper tray 3 is not in use, and the output signal of the paper presence/absence sensor 35. Further, the present invention can be applied not only to the paper feeding device in a copying machine as in the embodiment described above, but also to a paper feeding device supplied to other image forming apparatuses such as printers.

〔Effect of the invention〕

As described above, the paper feeding device of the present invention suspends the determination process by the paper presence/absence determining means based on the signal from the paper presence/absence sensor while the rotation operation signal corresponding to the rotation operation of the paper tray is output. This configuration further includes a discrimination processing interrupting means for interrupting the discrimination process.

This prevents an erroneous display, such as prompting the user to replenish paper even though paper is present, to be displayed while the paper tray is rotating. This has the effect of preventing feelings of distrust and discomfort.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram of a paper feeding device according to the present invention. 2 to 7 show an embodiment of the present invention. FIG. 2 is a front view schematically showing the overall structure of the copying machine, and FIG. 3 is a schematic plan view showing the internal structure of the paper feeding device. FIG. 4 is a schematic front view showing the tray storage box when the paper tray is positioned at the vertical feeding position. FIG. 5 is a schematic front view showing the tray storage box when the paper tray is positioned at the horizontal feed position. FIG. 6 is a control block diagram for controlling the operation of the paper feeding device in the copying control device. FIG. 7 is a control flowchart showing a procedure for determining the presence or absence of paper in the copying control device. 2 is a paper feeding device, 3 is a paper tray, 21 is a rotation mechanism, 30
35 is a paper presence/absence sensor, 42 is a copying operation control section (rotation operation signal output means), 44 is a paper presence/absence monitoring section (paper presence/absence determination means), and 51 is a discrimination processing interrupting means. Patent applicant Sharp Co., Ltd.

Claims (1)

[Claims] 1. A rotation mechanism for reversibly changing a paper tray in which paper is stored to either a vertical feed position or a horizontal feed position; and rotation of the paper tray. A rotational operation signal output means is provided for outputting a corresponding rotational operation signal during operation, and also emits light toward the paper tray and responds to an amount of reflected light that varies depending on the presence or absence of paper in the paper tray. In a paper feeding device that includes a paper presence/absence sensor that outputs a signal and a paper presence/absence determination unit that determines the presence or absence of paper in a paper tray based on the signal from the paper presence/absence sensor, the rotational operation signal described above is output. A paper feeding device further comprising a discrimination processing interrupting means for interrupting the discrimination processing by the paper presence/absence discriminating means during the paper presence/absence discriminating means.