JP3723006B2 - End face detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an end face detection apparatus that detects an end face of a moving detection object, and more particularly to an end face detection apparatus that can accurately detect an end face of a detection body.
[0002]
[Prior art]
The movement of the detection body is detected by the end face detection device.
For example, as the detection body, there is a printing paper used in a printing machine. The printing paper is sequentially conveyed from the paper feed table to the paper discharge unit through the printing unit. As for the movement of the printing paper as the detection body, the end face is detected by a sensor fixed to the printing press.
By detecting the end face, the timing of the printing operation is controlled so that a stable printing operation can be performed.
[0003]
FIG. 10 is a diagram showing a first example of a printing paper end face detection device using such a sensor. FIG. 4A is a side view, and FIG.
The light from the light emitting element 40 is applied to the detection body P, and the returning light is received by the detection element 41. As shown in the drawing, the light of the light emitting element 40 is irradiated over a wide range (the shaded area in FIG. 5B). When the detection body P moves in the A direction, the end face of the detection body P can be detected at the timing when the detection element 41 receives the reflected light.
[0004]
In the case of the transmissive type, the detection element 41 is provided at a position facing the light emitting element 40 with the detection body P interposed therebetween.
According to the above configuration, even if the reflectance variation of the detection body P is large, the detection element 41 can receive the reflected light in a wide range on average and can perform stable detection.
FIG. 11 is a graph showing characteristics at the time of end face detection according to the first example. In this graph, the horizontal axis corresponds to the amount of movement of the detection body P, and the vertical axis represents the detection characteristic (light reception amount) of the detection element 41.
[0005]
Moreover, FIG. 12 is a figure which shows the end surface detection apparatus of a 2nd example. The figure (a) is a side view, and the figure (b) is a top view.
The light emitting element 50 is provided with a lens 51, and the light is converged by the lens 51 to irradiate the detection body P with a point. The end surface of the detection body P is detected at the timing when the reflected light is detected by the detection element 52. Since the detection element 52 detects the end face of the detection body P in a dot-like manner, as shown in the detection characteristic graph of FIG. Thereby, it is hard to be influenced by the variation factor, and high end face detection accuracy can be obtained.
[0006]
Further, FIG. 14 is a side view showing the end face detection device of the third example.
The light emitting element 60 and the detection element 61 are arranged to face each other with the detection body P interposed therebetween. A slit plate 62 is provided between the light emitting element 60 and the detection element 61. The slit plate 62 is formed with a slit opening 62a having a predetermined length along the end face direction of the detection body P (in the depth direction in the drawing).
Then, the detection body P moves, and the end face of the detection body P can be detected at the timing of blocking the light passing through the slit opening 62a of the slit plate 62.
[0007]
[Problems to be solved by the invention]
In the first conventional example, the emitted light is irradiated to the detection body P over a wide range. For this reason, the characteristics of the detection element 41 when the detection body P moves and the end face is detected rise gently as shown in FIG. That is, it is susceptible to the following variation factors.
[0008]
Variation factors are roughly classified into floating variation factors that change constantly and fixed variation factors that do not change after fixed installation.
The floating variation factors are: In the case of a reflection type, variation in reflectance of the detection body P; 2. 2. In the case of a transmission type, variation in transmittance of the detection body P; 3. Change with time 4. Temperature change, 5. Influence of paper dust when the detection body P is printing paper; There are variations in the angle of the detection body P, and the like.
Fixed variation factors are: 1. detection distance between the light emitting element 40 (detection element 41) and the detection body P; 2. Detection angle (X, Y direction) Circuit constants, 4. There is sensitivity adjustment.
Due to these variation factors, accurate end face detection of the detection body P cannot be performed.
[0009]
In the second conventional example, light is spot-irradiated on the detection body P by the lens 51.
However, when the variation in the reflectance of the detection body P is large, there is a problem that the end face detection accuracy is lowered or erroneously detected.
In the case where the detection body P is formed of a fiber such as printing paper or stencil paper, the reflectance changes due to unevenness of the fiber. As a result, the output of the detection element 52 becomes unstable, and even if a steep rise characteristic is obtained, the output does not increase and a predetermined detection accuracy may not be obtained.
In addition, when the reflectance is low, the output of the detection body P becomes lower than the threshold value, and erroneous detection may occur.
[0010]
In the third conventional example, since the slit 62 is provided, the amount of light received by the detection element 61 becomes low and detection becomes difficult.
Further, since the slit 62 is necessary between the light emitting element 60 and the detecting element 61, it is limited to a transmission type sensor. Furthermore, when the detection body P is the printing paper P, when paper dust is generated and enters the slit 62, the light is blocked and cannot be detected.
[0011]
The present invention has been made to solve the above-described problems, and in both the reflection type and transmission type sensors, the end face detection capable of accurately detecting the end face regardless of variations in the reflectance and transmittance of the detection body. The object is to provide a device.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, an end face detection device according to the present invention, as described in claim 1, transports a sheet-like detection body and detects the end face of the detection body during the transport.
A light emitting element for emitting light for end face detecting the light of the light emitting element on the conveying position of the detector, along the end surface direction of the detection Detai Utotomoni該検Detai surface against the focal point width A light emitting means comprising a condensing lens arranged with respect to the surface of the detection body so as to be condensed as linear light whose direction is inclined at a predetermined angle ;
And a light receiving means provided near the light emitting means for receiving the light emitted by the light emitting means.
Here, the “sheet shape” also corresponds to a portion fed out from a recording material such as thermal paper wound in a roll shape.
[0013]
Furthermore, as according to claim 2, wherein the light emitting element may be constituted by a plurality of light emitting elements along the end face of said detection body.
[0015]
According to a third aspect of the present invention, an aspheric lens for collimating light is provided on the light emitting element side of the condenser lens, and light is linearly provided along an end surface of the detection body on the emission side. It is good also as a structure provided with the cylindrical lens for condensing to.
[0017]
According to a fourth aspect of the present invention, both of the light emitting means and the light receiving means can be arranged on one surface of the detection body.
[0019]
According to the said structure, the light radiate | emitted from the light emission means is condensed in the linear form along the end surface of a detection body.
Therefore, the rising edge of the detection signal when detecting the end face of the detection body can be obtained steeply, and the end face position can be accurately detected. Further, since the linear light has a predetermined width along the end face of the detection body, the level of the detection signal can be obtained stably.
Therefore, even if the reflectance or transmittance of the detection body varies, the end face of the detection body can be detected accurately and stably.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a configuration diagram showing an end face detection device of the present invention. The figure (a) shows a side view, and the figure (b) shows a top view.
The detector P shown in the figure is made of sheet-like printing paper or stencil paper. Printing paper is used in printing machines, stencil printing machines, copiers, etc., and stencil paper is used in stencil printing machines.
These detection bodies P are transported from the paper feed table to the paper discharge table via the printing unit by a conveying means (not shown). In the drawing, the conveyance direction A is indicated by an arrow.
[0021]
A light emitting means 1 and a light receiving means 2 are provided at predetermined locations on the transport path. In the illustrated example, a reflection type sensor is shown, and the light emitting means 1 and the light receiving means 2 are fixedly arranged on one side (upper surface) of the transport path.
The light emitting means 1 emits light that forms a point-like focal point on the transport position of the detection body P as seen in a side view. Further, when viewed in a plan view, light at this focal position extends with a predetermined width L in a direction orthogonal to the transport direction. That is, this light has a wedge shape having a predetermined width L along the direction of the end face of the detection body P when viewed three-dimensionally.
[0022]
The reflected light of the light irradiated on the detection body P is detected by the light receiving means 2.
FIG. 2 is a graph showing the detection characteristics of the light receiving means 2. In the figure, the horizontal axis indicates the amount of movement of the detection body P, and the vertical axis indicates the detection output (light reception amount).
As shown in the figure, when the detection body P is conveyed and the end face of the detection body P reaches the position of the irradiated light, the light receiving means 2 detects that the output rises sharply at the position x1 where the end face is detected. Characteristics can be obtained. Thereby, the end surface position of the detection body P can be accurately detected.
[0023]
This is based on the fact that the detection state changes due to the change at this point because the light irradiated to the detection body P is point-like when viewed from the side. In addition, since this light has a predetermined width L when viewed in a plane, a predetermined amount of light can be secured, so that a stable detection signal can be obtained.
In this way, by irradiating the detection body P with light over a wide range, even if the reflectance of the detection body P varies, it can be detected by averaging, so that end face detection can be performed stably.
[0024]
FIG. 3 is a block diagram showing an example of the overall configuration of this apparatus.
As shown in the figure, the light emitting means 1 and the light receiving means 2 constitute a sensor unit 5, which is controlled by a system circuit 7.
The light emitting unit 1 includes a light emitting element 10, a condenser lens 11, and a drive circuit 12.
The light emitting element 10 includes a laser diode (LD) or a light emitting diode (LED).
The condensing lens 11 condenses the light emitted from the light emitting element 10 linearly on the detection body P as described above.
The drive circuit 12 drives the light emitting element 10 to emit light.
[0025]
The light receiving means 2 includes a light receiving element 20 and a signal processing circuit 22.
The light receiving element 20 includes a photodiode (PD) or a phototransistor (P-TR).
The signal processing circuit 22 processes the light received by the light receiving element 20. The light receiving element 20 outputs an analog detection output corresponding to the amount of received light. The signal processing circuit 22 is set with a threshold value for detecting the end face of the detection body P, compares the input detection output with the threshold value, and performs binary encoding (0/1) for output.
[0026]
The system circuit 7 includes a CPU, a ROM, a RAM, and the like. The system circuit 7 drives the light emitting unit 1 to emit light at a predetermined timing, and determines the timing for detecting the end face of the detection body P based on the detection output output from the light receiving unit 2. To do.
The determined end face detection timing is output to each part constituting the printing press and used as a signal for operation of the entire printing press.
[0027]
For example, in the case where the sensor unit 5 is provided on the paper feed tray of the printing press, it is possible to detect the paper feed timing by detecting the end face of the detection body (printing paper) P on the paper feed tray.
Based on this paper feed time, the printing machine controls operations of other units (for example, a printing unit, a transport unit, and a discharge unit) in accordance with the paper feed time.
In addition, based on the end face detection time of the detection body P, it is possible to monitor the paper feed state. For example, when the paper is not fed to the printing unit even after a predetermined time from the paper feeding time, it can be determined that a jam has occurred and the apparatus can be stopped.
[0028]
The system circuit 7 may have a function of the signal processing circuit 22. In this case, the system circuit 7 is provided with an A / D converter, and the analog detection signal output from the light receiving element 20 is converted into a digital signal and taken in.
Further, the CPU of the system circuit 7 compares the detection signal with a threshold value by a predetermined software process to determine the detection time of the end face of the detection body P.
[0029]
FIG. 4 is a plan view showing a first configuration example of the sensor unit 5.
This light emitting means 1 arranges light emitting elements 10 composed of a plurality of LDs or LEDs with a predetermined width L in a direction perpendicular to the conveying direction of the detection body P.
The condensing lens 11 condenses the light emitted from each light emitting element 10 in a linear shape.
By the way, the light receiving means 2 (not shown) is disposed below the light emitting means 1 (in the case of a transmission type, a lower position with the detection body P interposed therebetween). Further, it may be arranged in parallel with the light emitting means 1 (in the case of a reflection type, detecting reflected light).
[0030]
FIG. 5 is a perspective view showing a second configuration example of the sensor unit 5.
As illustrated, the light emitting means 1 is provided on the lower surface side of the detection body P, and the light receiving means 2 is provided on the upper surface side facing the light emission means 1 with the detection body P interposed therebetween. In the example shown in the figure, the light emitting means 1 and the light receiving means 2 are arranged so that their optical axes are perpendicular to the transport direction of the detection body P.
The lens 11 of the light emitting means 1 has different surface shapes on the light incident side and the light emitting side, respectively.
[0031]
FIG. 6 is a diagram illustrating the lens 11. (A) is a front view, (b) is a view from the incident side (rear view), (c) is a side view, and (d) is BB in FIG. (B). It is line sectional drawing.
As shown, the incident side of the lens 11 is an aspherical lens 11a. The aspherical lens 11a collimates the light emitted from the light emitting element 10.
[0032]
On the other hand, the exit side of the lens 11 is a cylindrical lens 11b. The cylindrical lens 11b has a predetermined arc shape in cross section and a predetermined length in the predetermined width L direction. It has a shape so as to constitute a part of a cylinder.
The cylindrical lens 11b condenses the light collimated in the lens 11 in a thin line shape over the predetermined width L as shown in FIG.
Incidentally, the linear light X shown in FIG. 5 positions the lens 11 in advance with respect to the transport path of the detection body P so that the detection body P coincides with the transport path.
[0033]
According to the above configuration, the light emitted from the light emitting unit 1 is collected by the lens 11 into a thin line having a predetermined width L on the conveyance path of the detection body P.
As a result, when the detection body P is transported and the end face of the detection body P reaches the linear light X , the light receiving means 2 can obtain a detection characteristic in which the output rises sharply when the end face is detected. . The end face detection characteristics at this time are obtained with the same characteristics as in FIG.
In this way, by irradiating the detection body P with light over a wide range, even if the transmittance of the detection body P varies, it can be detected by averaging, so that end face detection can be performed stably.
[0034]
Next, FIG. 7 is a perspective view showing a third configuration example of the sensor unit 5.
In the illustrated sensor unit 5, the light emitting means 1 and the light receiving means 2 are accommodated in an integrated case 30. The case 30 is provided on the lower surface of the transport path of the detection body P, and is positioned so that the linear light X coincides with the height position of the transport path.
On the upper surface of the case 30, inclined surfaces 30a and 30b having a predetermined angle are formed.
[0035]
The lens 11 is provided on one inclined surface 30a and the light receiving element 20 is provided on the other inclined surface 30b, so that the case 30 can be reduced in size and the focal length can be set small.
The lens 11 is provided so that the predetermined width L of the linear light X is parallel to the end surface of the detection body P. That is, the cylindrical lens 11 b is provided so that the length direction thereof is parallel to the end surface of the detection body P.
Even in such a configuration, the end face of the detection body P can be accurately and stably detected as shown in FIG.
[0036]
Next, FIG. 8 is a perspective view showing a fourth configuration example of the sensor unit 5.
Also in this configuration example, the sensor unit 5 is housed in a case 30 in which the light emitting means 1 and the light receiving means 2 are integrated. The case 30 is provided on the lower surface of the transport path of the detection body P.
By the way, as shown in the figure, the lens 11 is changed in the direction of 90 degrees from that of the configuration example. That is, the linear light X is inclined with respect to the transport path in accordance with the inclination angle of the inclined surface 30a. Further, the transport direction of the detection body P is also changed by 90 degrees from the configuration example.
[0037]
FIG. 9 is a diagram illustrating the conveyance direction of the sensor unit 5 and the detection body P illustrated in FIG. The figure (a) is the figure seen from the conveyance direction near side of the detection body P. FIG. In the same figure, the detection body P is conveyed to the near side. FIG. 6B is a view as seen from the side of the detection body P in the transport direction. In the figure, the detection body P moves in the direction of arrow A.
[0038]
As shown in FIG. 5A, the condensing point X is irradiated with respect to the surface of the detection body P with the width L direction inclined. On the other hand, as shown in FIG. 4B, when viewed from the front and back of the moving direction of the detection body P, the condensing point X is a dot.
Thereby, even if the distance (detection distance) from the light emission means 1 to the detection body P fluctuates, the position of the end face of the detection body P can always be detected stably.
[0039]
That is, the detection body P may move closer to or away from the sensor unit 5 as shown in FIG.
As described above, even if the transport height position of the detection body P varies, the detection deviation amount D of the end face position of the detection body P becomes a small amount as shown in the figure. Thereby, the end surface position of the detection body P can be detected with high accuracy.
And with the said structure, even if a detection distance fluctuates, the precision of an end surface position detection can be maintained. Further, it can be strengthened by variation in the detection distance as compared with the third configuration example.
When the detection body P is a thin leaf body such as printing paper or stencil paper, bending or soaring is likely to occur on the transport path, and the distance to the sensor unit 5 varies correspondingly. The said structure is suitable for detecting the end surface of such a thin leaf body.
[0040]
In each of the configuration examples described above, the lens 11 is described as a configuration in which the aspherical lens 11a and the cylindrical lens 11b are integrated.
However, these may be constituted by two separate lenses, and even in this case, the same effect as described above can be obtained.
[0041]
【The invention's effect】
According to the present invention, the light emitting means irradiates linear light having a predetermined width along the end face of the sheet-like detection body. The light receiving means has a detection characteristic that rises sharply when detecting the end face of the detection body, and can accurately detect the end face position. At the same time, since the light has a predetermined width with respect to the detection body, a stable detection level can be obtained.
Thereby, even if the reflectance and transmittance of the detection body are different, the end face position can always be detected accurately and stably.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an embodiment of an end face detection device of the present invention.
FIG. 2 is a graph showing detection characteristics of a light receiving unit.
FIG. 3 is a block diagram showing an example of the overall configuration of the apparatus.
FIG. 4 is a plan view showing a first configuration example of a sensor unit.
FIG. 5 is a perspective view showing a second configuration example of the sensor unit.
FIG. 6 shows a lens.
FIG. 7 is a perspective view showing a third configuration example of the sensor unit.
FIG. 8 is a perspective view showing a fourth configuration example of the sensor unit.
FIG. 9 is a diagram showing a relationship between the sensor unit of FIG.
FIG. 10 is a diagram showing a first example of a conventional end face detection device.
11 is a graph showing detection characteristics in the apparatus of FIG.
FIG. 12 is a diagram showing a second example of a conventional end face detection device.
13 is a graph showing detection characteristics in the apparatus of FIG.
FIG. 14 is a diagram showing an end face detection device of a third conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Light emitting means, 2 ... Light receiving means, 5 ... Sensor unit, 7 ... System circuit, 10 ... Light emitting element, 11 ... Lens, 11a ... Aspherical lens, 11b ... Cylindrical lens, 12 ... Drive circuit, 20 ... Light receiving element, 21 ... Signal processing circuit, 30 ... Case, 30a, 30b ... Inclined surface, P ... Detector.

Claims (4)

In the end face detection device that transports the sheet-like detection body and detects the end face of the detection body during the transport,
A light emitting element for emitting light for end face detecting the light of the light emitting element on the conveying position of the detector, along the end surface direction of the detection Detai Utotomoni該検Detai surface against the focal point width A light emitting means comprising a condensing lens arranged with respect to the surface of the detection body so as to be condensed as linear light whose direction is inclined at a predetermined angle ;
A light receiving means provided in the vicinity of the light emitting means for receiving the light emitted by the light emitting means;
An end face detection device comprising:   The end face detection device according to claim 1, wherein the light emitting element includes a plurality of light emitting elements along an end face of the detection body. An aspherical lens for collimating light is provided on the light emitting element side of the condensing lens, and a cylindrical lens for condensing the light in a line along the end surface of the detection body is provided on the emission side. The end face detection device according to claim 1, wherein these are integrally formed.
The end face detection device according to claim 1, which is disposed in a position.   The end face detection device according to claim 1, wherein each of the light emitting means and the light receiving means is disposed on one surface of the detection body.

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