JP2746166B2 - Transparent object detection sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent body detecting sensor, and more particularly to a transparent body detecting sensor for detecting, for example, a vinyl envelope as a transparent body supplied to an automatic mail sorting machine.

[0002]

2. Description of the Related Art Since a transparent body cannot be detected by light, a detection sensor using ultrasonic waves has been considered. Conventionally, an ultrasonic transmission type sensor used as a transparent body detection sensor of this type includes a sound emitting unit 1 having an ultrasonic oscillation unit 2 for outputting an ultrasonic wave 7 as shown in FIG. Thus, the sound receiving unit 3 includes an ultrasonic transmission detection unit 4 that detects the presence or absence of the transparent body 6, and an amplifier 5 that amplifies a detection signal output from the sound receiving unit 3. This type of ultrasonic transmission type sensor is disclosed in, for example,
It is disclosed in, for example, Japanese Patent Publication No.

[0003]

However, the ultrasonic transmission type sensor configured as described above is not limited to the transparent body 6, and when an object is detected, the ultrasonic transmission sensor is disposed between the sound projecting unit 1 and the sound receiving unit 3. Since there is a spread of sound peculiar to sound waves, an error occurs in a detection signal depending on whether an object passes through any position between the sound projecting unit 1 and the sound receiving unit 3, and accurate signal detection cannot be obtained. For this reason, when recognizing the full length of an object, there was a problem that it was difficult to recognize the exact length.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a transparent body detecting sensor which enables accurate detection of a transparent body without a detection error. It is in.

[0005]

In order to achieve the above object, a sensor for detecting a transparent object according to the present invention comprises an ultrasonic oscillator for outputting ultrasonic waves to the transparent object and an ultrasonic wave reflected from the transparent object. A sound projecting unit having an ultrasonic direct reflection detecting unit for detecting sound waves, and an ultrasonic transmission detecting device disposed opposite to the ultrasonic oscillating unit of the sound projecting unit and detecting the presence or absence of a transparent body by detecting or not detecting ultrasonic waves. a sound receiving unit having a part, projecting clef ultrasound directly reflected output from the detecting portion of the ultrasonic direct reflection detection signal and the sound receiving portion of the transparent body which is output from the ultrasonic transmission detection unit
An ultrasonic transmission detection signal based on the presence or absence is input, and a comparison operation is performed with predetermined data to perform detection from the ultrasonic transmission detection signal.
Calculating means for outputting a transparent body detection signal regarding the presence or absence of a transparent body from which an output error has been removed .

[0006]

According to the sensor for detecting a transparent body in the present invention, the transparent body is detected by the ultrasonic transmission detection section on the sound receiving section side when the transparent body blocks the ultrasonic wave output from the ultrasonic oscillation section. ,
The ultrasonic waves reflected by the transparent body are detected by the ultrasonic direct reflection detection unit of the sound emitting unit, and the position between the sound emitting unit and the sound receiving unit where the transparent body is located is recognized. When an ultrasonic wave is used to detect a transparent body, a detection error occurs due to the spread of sound between the sound projecting unit and the sound receiving unit. For this reason, the calculation means inputs in advance the position of the transparent body and the degree of error when the transparent body passes, the ultrasonic direct reflection detection signal from the sound projecting unit, and the ultrasonic wave from the sound receiving unit. An arithmetic operation is performed on the transmission detection signal and an accurate transparent object detection signal is output.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of an embodiment of a transparent object detection sensor according to the present invention. In FIG. 1, the sound emitting unit 11 includes an ultrasonic oscillator 1 that outputs ultrasonic waves toward a transparent body 16 such as a vinyl envelope.
2 and an ultrasonic direct reflection detection unit 13 for detecting the ultrasonic waves reflected by the transparent body 16. In addition, the sound receiving unit 14 of the sound projecting unit 11 facing the ultrasonic oscillation unit 12 includes:
An ultrasonic transmission detection unit 15 that performs detection and non-detection of ultrasonic waves based on the presence or absence of the transparent body 16 is provided.

Further, between the sound projecting section 11 and the sound receiving section 14, an ultrasonic direct reflection detection signal output from the ultrasonic direct reflection detection section 13 and a transparent output signal output from the ultrasonic transmission detection section 15 are provided. enter an ultrasonic transmission detection signal based on the presence or absence of the body, about the precise presence of the transparent body after correcting the detected errors
Calculating section 18 is connected to output the transparent body detection signal that to the outside.

In such a configuration, when the transparent body 16 passes between the sound projecting section 11 and the sound receiving section 14 which are arranged to face each other, the transparent body 16 is moved by the ultrasonic wave 17 output from the ultrasonic oscillation section 12. , The ultrasonic transmission detection unit 1 of the sound receiving unit 14
At 5, the transparent body 16 is detected. Further, the ultrasonic wave 17 ′ reflected by the transparent body 16 is detected by the ultrasonic direct reflection detecting unit 13 of the sound projecting unit 11, whereby the transparent position is determined between the sound projecting unit 11 and the sound receiving unit 14. The presence of the body 16 is recognized.

When the ultrasonic wave 17 is used to detect the transparent body 16, a detection error occurs due to the spread of sound between the sound projecting unit 11 and the sound receiving unit 14. Therefore, the arithmetic unit 18 has built-in data in advance which position the transparent body 16 passes through and how much error there is, and the arithmetic unit 18 outputs the data which is output from the sound receiving unit 14. The sound wave transmission detection signal and the ultrasonic direct reflection detection signal output from the sound projecting unit 11 are input, and an accurate transparent object detection signal is output from which an error has been removed by performing arithmetic processing.

FIG. 2 is a block diagram for explaining the operation process of the operation unit 18 described above. In FIG. 2, first,
The ultrasonic transmission detection signal S output from the sound receiving unit 14 of FIG.
1 is input to the transparent object detection signal calculation unit 20 and also input to the first counter 21 and the second counter 22, respectively. On the other hand, the ultrasonic direct reflection detection signal S2 output from the sound projecting unit 11 of FIG. 1 is input to the first counter 21 and the second counter 22, respectively.

Here, the first counter 21 counts up based on the ultrasonic direct reflection detection signal S2, and stops counting based on the ultrasonic transmission detection signal S1. Also, the second
Counter 22 counts up based on the ultrasonic transmission detection signal S1 and stops counting based on the ultrasonic direct reflection detection signal S2. Therefore, the first counter 21 and the second
Of the first counter 21 and the second counter 22 depends on whether the ultrasonic transmission detection signal S1 is detected quickly or the ultrasonic direct reflection detection signal S2 is detected quickly. Counts up, and at this time, the other counter stops.

Output data output from these two types of first counter 21 and second counter 22 are input to a data selection circuit 23, an effective count value is selected, and an object insertion position detection calculation unit 24 Is entered. Also,
Fixed distance data D corresponding to the distance between the sound projecting unit 11 and the sound receiving unit 14 is also input to the object insertion position detection calculating unit 24 at the same time.

The object insertion position detection / calculation section 24 performs a calculation process based on these two data, outputs the object insertion position data to the error data table 25, and specifies a certain address. The error data table 25 outputs the error data corresponding to the address to the transparent object detection signal calculation unit 20. The error data table 25 is, for example, R
It is formed by OM or the like, and receives error data. In the transparent body detection signal calculation section 20, based on the ultrasonic transmission detection signal S1 which has already been input to the error data
To remove the error and output an accurate transparent object detection signal S3.

According to such a configuration, even if the transparent body 16 passes through any position between the sound projecting section 11 and the sound receiving section 14, the position of the transparent body 16 is not affected by the spread of the sound wave. Can be accurately detected.

[0016]

As described above, according to the present invention,
Simultaneous detection of the transparent body and position detection using ultrasonic waves can provide accurate detection signals without errors, making it possible to detect transparent bodies without being affected by the spread of ultrasonic waves. Has an extremely excellent effect.

Further, if the sensor for detecting a transparent object according to the present invention is applied to an object position detecting means, an extremely excellent effect that an accurate position detection of an object can be performed can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of a transparent object detection sensor according to the present invention.

FIG. 2 is a block diagram illustrating a configuration of the amplifier in FIG. 1;

FIG. 3 is a diagram showing a configuration of a conventional transparent object detection sensor.

[Explanation of symbols]

11: sound projection unit, 12: ultrasonic oscillation unit, 13: ultrasonic direct reflection detection unit, 14: sound reception unit, 15: ultrasonic transmission detection unit,
16: Transparent object, 17: Ultrasonic wave, 17 ': Reflected ultrasonic wave, 18: Operation unit, 20: Transparent object detection signal operation unit, 21
.. A first counter, 22 a second counter, 23 a data selection circuit, 24 an object insertion position detection calculation unit, and 25 an error data table.

Claims (2)

(57) [Claims] 1. A and projecting clef with ultrasound direct reflection detection unit for detecting the ultrasonic wave reflected by the oscillator and the transparent body for outputting an ultrasonic wave to the transparent body, the oscillation of the projection clef A sound receiving unit disposed opposite to the unit and having an ultrasonic transmission detection unit for detecting the presence or absence of the transparent body by detecting or not detecting the ultrasonic wave; and an ultrasonic direct reflection detection unit of the sound projecting unit. An ultrasonic direct reflection detection signal and an ultrasonic transmission detection signal based on the presence or absence of the transparent body output from the ultrasonic transmission detection unit of the sound receiving unit are input, and a predetermined data and a comparison operation process are performed.
The detection error is removed from the ultrasonic transmission detection signal
And a calculating means for outputting a transparent body detection signal regarding the presence or absence of the transparent body. 2. The method according to claim 1, wherein the calculating means is configured to count up by the ultrasonic direct reflection detection signal before counting up.
A first counter that stops counting by the ultrasonic transmission detection signal, and a counter that counts up by the ultrasonic transmission detection signal and
A second counter to stop the counting by waves direct reflection detection signal, selects the valid count data from the count data input from said first counter and said second counter
A data selection circuit for outputting Te, the a valid count data, enter a fixed distance data between the projection clef and the sound receiving unit, the transparent body is of the projection clef and the sound receiving portion An object insertion position detection calculation unit that calculates whether the data has been inserted into any of the positions, and outputs corresponding address data; an error data table that inputs the address data and outputs error data; the type and an ultrasonic transmission detection signal,
Based on the error data from the ultrasonic transmission detection signal
A transparent body detection signal calculation unit that removes the detection error and outputs the transparent body detection signal.