JPS58113055A - Paper detector - Google Patents

Abstract

PURPOSE:To prevent wrong detection of presence of paper due to an influence of external light incident from an insertion port when a paper accommodating means is removed from a paper feed part, in the captioned device detecting presence of paper in the paper accommodating means removably provided in the paper feed part. CONSTITUTION:If paper P in a paper cassette 2 mounted to a paper feed part 1a is all fed out, emitted light from a light emitting element 5a is not reflected by the paper P and not received by a light receiving element 5b to turn off a switching transistor 20. In consequence, an input line 22 holds a level H and a control unit 23 decides no presence of paper to output a control signal to a display device 24 and copying mechanism 25. While if the operator extracts the cassette 2, a swinging lever 11 is turned by a spring 12 to displace a paper feed roller 3 diagonally upward. Further a crank lever 16 is simultaneously turned, and a sensor 5 mounted to said lever 16 is tilted to prevent reception of external light incident from an insertion port 1b.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to the field of paper detection #I&value for detecting the presence or absence of paper stored in paper storage means detachably provided in a paper feed section.

TECHNICAL BACKGROUND OF THE INVENTION AND PROBLEMS THEREOF An example of a conventional sheet detection device is the one shown in FIG. This could be applied to copying machines. That is, a paper storage means such as a paper cassette 2 is removably provided through the paper feed section 1aK insertion port 1b of the copying machine main body 1, and a plurality of sheets of paper P are stored in the paper cassette 2. . The paper feeding section 1@ is provided with a feeding means, for example, a paper feeding roller 3, which sequentially feeds out the sheets one by one. This paper feed row 23 comes into contact with the surface of the top layer of paper in the paper cassette when the paper cassette 2 is installed in the paper feed section 1a, and when it is removed, an appropriate contact/separation mechanism (not shown) is used. ) from the paper surface upwards K
It's supposed to be a break from 11i. Further, a paper detecting device 4 that optically detects the presence or absence of paper P in the paper cassette 2 is provided. This is because an optical detector such as a reflective sensor 5 is provided inside the insertion slot 16 with its fluorescent image facing one sheet of paper in the paper cassette 2, and The processing means 6 determines the presence or absence of paper based on the output and sends a control signal to various copying mechanisms and display devices (not shown) to display an indication that there is no paper left, making it impossible to accept copies. ing.

Such a paper detecting device 4 reflects the light emitted from the reflective sensor 5 onto the paper in the paper cassette 2 and receives this reflected light at the reflective sensor 5 via the processing means 6. Detects the presence or absence of paper.

However, the reflective lid sensor 5 is fixedly arranged so that the light-receiving surface 5 @ always faces the paper in the paper cassette. There is a problem in that the incoming external light is received, resulting in false detection as if there is paper present.

The present invention has been made based on the above-mentioned circumstances, and prevents erroneous detection of the presence of paper due to the influence of external light entering from the insertion slot when the paper storage hand Ij & can be removed from the paper feed section. It is an object of the present invention to provide a paper detecting device that has a relatively simple configuration and can improve reliability.

Summary of the Invention The present invention detects the presence or absence of paper stored in a paper storage means removably installed in a paper feed WIK via an insertion slot.
In a paper detection device that detects with an optical detector provided in the K and inputs an output signal at this time to a processing means to determine the presence or absence of paper, the paper detection device is linked to the dispersion of the paper storage means from the paper feed section. and a retracting means for moving the light receiving surface of the optical detector toward the opposite side of the insertion port, and the light receiving surface of the optical detector is configured to avoid external light incident from the insertion port. It is.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A paper detecting device according to the present invention will be described below with reference to the drawings.

FIG. 112 is a schematic sectional view showing one embodiment of the paper detection It&11110 of the present invention, and FIG. 3 is a detailed explanatory view of the processing means. The same members as those in FIG. In a different configuration, an evacuation means for directing the light-receiving surface of the optical detector O toward the opposite side of the insertion opening in conjunction with the removal of the paper storage means from the paper feed section is provided, for example, by using the II-mechanism of the ejection means (not shown). That's what happened.

First, an example of the approach and separation mechanism of the illustrated display sending means will be explained. In 1K28, 10 is a contact/separation mechanism. This means, for example, that the middle part of the L-swing lever 110 is at the paper feed 111m.
Anti-insertion port 11KN! It is movably provided.
AV bar 11 o-1111Ka [1M1M*A retainer 1j11g that engages the tip of the dragonit 2 is formed, and the other 1
1111, the paper feed p-26 is rotatably supported via a shaft 36 for the paper feed row 2.The swing lever 11 is biased by a tension coil spring 12, and the paper cassette 2 If the paper cassette 2 is not installed, the position shown by the chain line in the illustration is the 112 position, and the paper cassette 2 is in the paper feed position 111.
When attached to @, the tip of the paper feed cassette (11) 20 engages with the engagement i1$11gK, and the IIWIk lever 11 resists the biasing force of the tension coil changer ring 12 in the direction of the second arrow IA Kll. The paper feeding roller 6 is brought into close contact with the surface of the uppermost layer of paper in the paper cassette 2.

The evacuation means 15 in this embodiment is constructed using the above-mentioned ms mechanism 10, that is, one crank lever 16.
One end of the crank lever 16 is provided to allow the paper feed 111gKJI to be moved, and the other end of the crank lever 16 is formed with a parallel elongated hole 16g that engages the paper feed roller shear 7) 3go outer periphery WAK, and the swing lever 110 swings. Accordingly, the paper feed roller shaft 6a is configured to swing the crank lever 16 while sliding within the parallel long hole 16g. The reflective center t5 is attached to the middle sK of the crank lever 16 with its light-receiving surface 51 facing the paper PK in the paper cassette 2. The output signal from the reflective sensor 5 is processed by a processing means 6.

Note that the processing means 6 is configured as shown in FIG. 883, for example. For example, the reflection g*yt5 has a built-in photodiode 5- and a phototransistor 5, and the light-emitting diode 51 has a resistor 17 connected in series for electric mim@. Resistor 18.1 for emitter glue of phototransistor 5? are connected in series, and these resistors 1
8. A switching transistor 200 is connected to the connection point 19.
The bases are connected. ◎The switching transistor 200, the resistor 19, and the light emitting diode 5 are commonly grounded.
The collector and the resistor 17 are connected to an external power supply VccK. The collector terminal of the switching transistor 200 is connected to an external voltage txv via a pull-up resistor 21.
ccK* connected and controlled via input line 22 1123
KI continues. This control 1123 determines whether the detection signal is at the rLJ level (i.e., paper present) or K (paper present) based on the detection timing, and outputs a control signal if it determines that there is no paper because the detection signal is at the rHJ level. A display device 2 that inputs this control signal and displays ``No 11''
4 is provided. In the figure, reference numeral 25 indicates various types of compound shell structures, and by inputting the control signal, it is made impossible to accept copies.Next, regarding the operation of the paper-required detection device configured as described above, l! I will clarify.

When the 7 Ototransistors 5k integrate the 7 Otodiodes, a photocurrent is output from the phototransistor 5, the switching transistor 20 is turned on, and a current flows to the ground terminal. The input line 22 connected to VCeK via the pull-up resistor 21 is at the rLJ level. Therefore, the control section 25
If the detection signal detected from the input line 22 is at the rLJ level depending on the detection timing, it is determined whether paper is present.

If all the sheets of paper P in the paper cassette are sent out and are in good condition, the light emitted from the photodiode 5g is not received by the phototransistor 5h#IC, and no photocurrent is output from the switching transistor. 20 is turned off and 11Efi does not flow at all, and the input line 22 maintains the rHJ level. Therefore, the control 11$23tj determines that there is no paper by determining that the detection signal detected from the input line 22 is at the rHJ level according to the detection timing, and displays the display device 24.
When a control signal is output to the copying mechanism 25 to indicate that there is no paper, 4hK then O makes it impossible to accept copies. After that, the ninth obereme for replenishing paper pulls out the paper cassette 2 in the direction of the second arrow X shown in the figure. and remove it.

At this time, the tip of the paper cassette 2 disengages from the engagement 1111m of the swing lever 11, and the swing lever 11 is biased by the coil spring 12 in the counterclockwise direction shown in the second figure. Moving, paper feed roller shaft 3g and 4h
K paper feed--'y3 is moved diagonally upward in the drawing by lI2.

Since the parallel elongated hole 16g of the crank lever 16 is slidably engaged with the shaft 3 for paper feeding, the crank lever 16 is connected to the shaft 3 for paper feeding.
Following the counterclockwise movement of the G, the clockwise movement causes the reflection layer sensor 50 receiver 115g attached to the intermediate portion of the crank lever 160 to be directed toward the opposite direction of the insertion slot. Note, reflective lid sen? When the paper cassette 2 is removed from the paper feed section 1LIs, the light enters from the insertion opening and does not receive any external light, which can prevent erroneous detection of the presence or absence of paper due to external light.

(The above embodiment is merely an example) It is not implied that each member may be replaced with another member having the same function.

For example, the evacuation means is Ii! in the above embodiment. The tatami mat is not limited to 10 that uses a separation mechanism, but the tatami mat can be replaced with any means that can direct the light-receiving surface of the optical detector toward the opposite side of the insertion slot in conjunction with the removal of the paper storage means. It is possible to

Also, the political detector is not limited to reflective dampness,
Transparent mnc* can be replaced! 6. At this time, receive X
The light-receiving surface of S is moved away from external light by the retracting means.

Effects of the Invention As is clear from the above explanation, the paper detecting device of the present invention prevents erroneous detection of the presence or absence of paper due to the influence of external light that enters from the insertion slot when the paper storage means is removed from the paper feed section. 〇

[Brief explanation of the drawing]

51111 is a schematic cross-sectional view showing a conventional paper detection device,
Fig. 2 is a schematic sectional view showing one embodiment of the paper detecting device of the present invention, and Fig. W43 is a detailed explanatory view of the processing means. ...Paper storage means, 5.Optical detector, 6.Processing means, 15.Evacuation means.

Claims (1)

[Claims] An optical detector provided in the paper feed section detects the presence or absence of paper stored in a good paper storage means which is removably installed in the paper feed sK through the insertion slot, and the output signal at this time is sent to the processing means. In the paper detecting device which determines the presence or absence of paper by inputting the information into A paper detecting device characterized in that a light receiving surface of an optical detector is configured to avoid external light incident from an insertion slot.