JPH0618350U - Paper feed detector - Google Patents

Abstract

(57) [Summary] [Purpose] To reliably detect the entry of paper into the paper feed guide. [Structure] A support shaft 13 is rotatably supported below a paper feed guide 3 via a holder 11, and a boss portion 14 is attached to the support shaft 13.
The sensing piece 15 is integrally formed via the. Further, the operating piece 16 is integrally formed at the tip of the sensing piece 15. The sensing piece 15 is biased and held in its original position by a spring 20 having a weak elastic force required for returning.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a paper feed detection device used in office equipment such as a copying machine and a facsimile.

[0002]

[Prior art]

 In general, the paper feed detection device is designed to detect the entry of paper moving in the paper feed path by a sensing piece fitted and fixed on a spindle. Further, conventionally, an operating piece is integrally fixed on the support shaft by being displaced by a predetermined angle from the above-mentioned sensing piece. When the sensing piece is pushed by the paper, the actuating piece operates a sensor such as a photo interrupter via a support shaft. Further, the sensing piece and the operating piece fitted and fixed on the support shaft are elastically urged to the side facing the sheet by a spring.

[0003]

[Problems to be solved by the device]

 However, in the above-mentioned conventional paper feed detecting device, the sensing piece and the operating piece are formed separately, and both pieces are elastically biased toward the side facing the paper by a spring at all times. For this reason, in addition to the biasing force of the spring, the paper is loaded with the weight of both the sensing piece and the operating piece. Therefore, when the stiffness of the paper is weak, the paper may pass through the paper feed guide without sufficiently rotating the sensing piece and the operating piece, which causes a problem of uncertain detection operation of the paper. In order to improve the accuracy of this detection operation, the maximum elastic force of the spring should be set below a certain value so that it can be operated reliably even on paper with a weak waist, and both the sensing piece and the operating piece should be set. In order to overcome the weight load and return to the original position, it is necessary to set the minimum elastic force above a certain value. There was a problem that it was very difficult to set the elastic force of this result spring.

The object of the present invention is to solve the above problems existing in the prior art, to reliably detect the entry of the paper in the paper guide, and to set the return force of the return member of the sensing piece. It is an object of the present invention to provide a paper feed detection device that can easily perform the above.

[0005]

[Means for Solving the Problems]

 According to the present invention, in order to achieve the above-mentioned object, a sensing piece that is pushed by a sheet advancing operation is provided so as to be swingable by a support shaft in correspondence with a sheet feeding path, and the sheet feeding path is sandwiched between the sensing pieces. On the opposite side of the shaft, a sensor that turns on and off by swinging the sensing piece is provided.

[0006]

[Action]

 In this invention, since the sensing piece also serves as the actuating piece that operates the sensor, when the weight load on the paper is reduced and the paper enters the paper path, the sensing piece is reliably rotated to operate the sensor. The operation is performed reliably.

Further, in the present invention, when a spring is used as the return member of the sensing piece, when setting the returning force, it is only necessary to consider the minimum value required to return the sensing piece to the original position. It becomes easy to set the return force of the return member.

[0008]

【Example】

 An embodiment in which the present invention is embodied in a facsimile will be described in detail below with reference to FIGS.

As shown in FIG. 4, at the front end of the body case 1 of the facsimile, a paper feed port 2 for feeding the original paper P1 is provided. Behind the paper feed port 2, a flat paper feed guide 3 formed by vertically arranging two plates for guiding the original paper P1 is arranged obliquely upward and between the paper feed guides 3 A paper feed path 9 is formed.

A roller 4 is arranged downstream of the paper feed guide 3 in the paper feed direction. The roller 4 is rotated by a motor (not shown), and an image sensor 5 for reading the image information of the original sheet P1 is arranged corresponding to the roller 4.

A platen roller 6 is arranged above the image sensor 5 so as to be rotatable by a motor (not shown). The platen roller 6 supports the unwinding portion of the roll-shaped printing paper P2 housed in the main body case 1. Further, a thermal head 7 for printing image information on the printing paper P2 is provided corresponding to the platen roller 6. Further, the original paper P1 and the printing paper P2 can be taken out from a discharge port 8 provided at the front upper part of the main body case 1.

Next, a paper feed detection device provided corresponding to the paper feed guide 3 will be described. As shown in FIGS. 1 to 3, a holder 11 is installed below the paper feed guide 3, and a spindle 13 is supported between bearings 12 between the left and right sides of the holder 11. Has been done. A plurality of (three in this embodiment) sensing pieces 15 are fixed to the support shaft 13 at equal intervals by a boss portion 14 formed at the base end thereof. Further, each sensing piece 15 enters the paper feed path 9 from a direction substantially orthogonal to the paper feed path 9 and is tilted by the original paper P1.

Further, as shown in FIG. 3, one of the sensing pieces 15 has a sensing piece 15 having a distal end formed to extend, and the sensing piece 15 operates an actuating piece 16 for actuating a sensor 17 described later. Is also used. The sensing piece 15 is interposed between a light projecting portion 18 and a light receiving portion 19 of a sensor 17 composed of a photo interrupter arranged in the upper direction of the support shaft 13 with the paper feeding path 9 interposed therebetween. The support shaft 13 and the sensing piece 15 are biased in the counterclockwise direction (original position) in FIG. 1 about the support shaft 13 by a spring 20 as a return member provided at one place. Further, the sensing piece 15 blocks the paper entry path in the paper feed guide 3 and the light emitting / receiving sections 18 and 19.

Further, in the original position shown in FIG. 1, the sensing piece 15 is locked by the stopper 21 formed on the bottom plate of the paper feed guide 3, and the sensing piece 15 rotates to the maximum when detecting the sheet P1 shown in FIG. It is locked by a stopper 22 that regulates the position.

When the original paper P1 is fed from the paper feed port 2 into the paper feed guide 3, the leading edge of the paper P1 comes into contact with the plurality of sensing pieces 15, and the pressing force of the paper P1 causes the sensing pieces to be sensed. 1, 15 is rotated clockwise against the urging force of the spring 20. Then, as shown in FIG. 2, the sensing piece 15 is separated from between the light emitting / receiving portions 18 and 19 of the sensor 17, and the detection light enters from the light emitting portion 18 into the light receiving portion 19, whereby the sheet P1 advances. ON is detected. Therefore, a motor (not shown) is activated, the platen roller 4 is rotated, and the image sensor 5 is operated, so that the image information of the original paper P1 is read by the image sensor 5 while passing between them. The image information read by the image sensor 5 is sent to the facsimile of the other party as a transmission signal from a control circuit (not shown).

The image information transmitted from the facsimile of the other party is printed on the printing paper P2 by the operation of the thermal head 7, and the paper P2 is taken out from the discharge port 8.

In the embodiment of the present invention, the sensor 17 and the corresponding actuating piece 16 are formed so as to extend from the tip of the one sensing piece 15 so as to serve as both. By comparison, the passage of the document sheet P1 can be reliably detected. That is, since there is no separate actuating piece, the weight load on the original paper P1 is small, and even if the original paper P1 is weak, the paper is not moved at the incomplete rotation position of the sensing piece 15. Only the sensing piece 15 is reliably rotated so that the detection operation is accurate.

In addition, since the weight load of the sensing piece 15 is small in this embodiment, the minimum elastic force required to return the sensing piece 15 from the detection position shown in FIG. 2 to the original position shown in FIG. 1 is small. good. Therefore, when the elastic force of the spring 20 is set, it is not necessary to take into account the rotation angle of the sensing piece 15 necessary for the document sheet P1 having a weak stiffness to pass, and the elastic force of the spring 20 can be easily set. Become.

Next, another embodiment of the present invention will be described with reference to FIG. In this embodiment, the support shaft 13 is provided above the paper feed path 9 and the sensor 17 is provided below the paper feed path 9, and the spring 20 is omitted. Then, the sensing piece 15 itself is provided with a function as a returning member, that is, the sensing piece 15 can return to the original position shown by the solid line in the figure from the detection position shown by the two-dot chain line in FIG. 5 by its own weight. I have to. Therefore, the number of parts is smaller than that of the above-mentioned embodiment, but other functions and effects are the same as those of the above-mentioned embodiment. However, the force of the return member is set by setting the weight of the sensing piece 15.

The present invention is not limited to the above embodiment, but can be embodied as follows. Although the sensing piece 15 is provided at a plurality of locations in the above-described embodiment, it may be provided at one location, or in the embodiment shown in FIG. 5, a spring (not shown) for speeding up the returning operation may be provided, and this detection device may be used as a sheet. It can be installed in front of the stacker and used for counting paper.

[0021]

[Effect of device]

 As described in detail above, the present invention has an effect that it is possible to reliably detect the entry of the sheet in the sheet guide and to easily set the restoring force of the restoring member.

[Brief description of drawings]

FIG. 1 is a sectional view of essential parts showing an embodiment in which the invention is embodied as a paper feed detection device for a facsimile.

FIG. 2 is a cross-sectional view of an essential part showing a state in which the entry of a document sheet is detected.

FIG. 3 is a partially cutaway perspective view of a paper feed detection device.

FIG. 4 is a schematic sectional view showing an entire facsimile.

FIG. 5 is a sectional view of an essential part showing another embodiment of the present invention.

[Explanation of symbols]

3 paper feed guides, 9 paper feed paths, 11 holders, 13
Support shaft, 14 boss, 15 sensing piece, 16 actuating piece,
17 sensor, 20 spring as return member, P
1 Original paper.

Claims (1)

[Scope of utility model registration request] 1. A sensing piece, which is pushed by a sheet advancing operation, is provided so as to be swingable by a spindle corresponding to a sheet feeding path, and is sensed on the opposite side of the spindle with the sheet feeding path sandwiched therebetween. Paper feed detector equipped with a sensor that turns on and off when one piece swings.