Apparatus for counting the number of passing persons by stature
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a method for counting the number of passing persons by stature and more particularly to a method for counting the number of persons by stature who are passing through a gateway or a passage in a building such as a department store or an exhibition building. 
     2. Description of the Prior Art 
     Heretofore, there has been known a method for counting the number of passing persons wherein a projector and a receptor are disposed at an upper portion of a gateway or a passage. According to this method, when a person has arrived at a crossing portion of a light beam emitted from the projector and an extension of a light incoming path in the receptor, there is formed a light loop between the projector and the receptor. This light loop is then taken out as a signal and, thereafter, a counting operation is performed (as disclosed in Japanese Patent Laid-Open Nos. 65075/79 and 16278/80). 
     According to the above conventional method, it is possible to discriminate whether the stature of the passing person is large or small, that is, whether the passing person is an adult or a child, or whether baggage is passing through the gateway or passage, on the basis of the height of the loop formed. However, one set of the projector and the receptor merely permits the discrimination of the height, and it is impossible to discriminate plural heights, or count the number of passing persons by stature. 
     For the discrimination of plural heights in the conventional method it is necessary to provide several projectors according to the number of heights to be discriminated, resulting in that the mounting space becomes larger and a signal control means becomes complicated and expensive inevitably. Furthermore, for every change in position of the projector and the receptor it is required to manually adjust the respective positions. Since this adjustment is performed in high positions, not only the working efficiency is poor but also it is dangerous. 
     SUMMARY OF THE INVENTION 
     It is the object of the present invention to eliminate the above-mentioned drawbacks of the prior art and provide a simple means capable of efficiently counting the number of passing persons by stature. 
     The counting method of the present invention, according to a first embodiment thereof, is characterized in that a projector for radiating light toward the head of a passing person, a light receiving lens for receiving light reflected from the person&#39;s head, and a light position detector are arranged as a set at an upper portion of a gateway or a passage. The light receiving lens converges reflected light to different light-receiving positions of the light position detector according to the height of the reflective positions. The light position detector outputs electric signals which differ according to the reflected light received at the light-received positions and a counting operation is performed discriminatively at every output of the signal. 
     In a second embodiment, the counting method of the present invention is characterized in that the output signals from the light position detector are each discriminated by a discrimination device consisting of a comparator and a setting unit capable of setting a threshold value. In a third embodiment, the counting method of the present invention is characterized in that plural sets consisting of the projector, light receiving lens and light position detector are arranged side by side in the width direction of the gateway or the passage. 
     Further, according to a fourth embodiment, the counting method of the present invention is characterized in that two sets consisting of the projector, light receiving lens and light position detector are arranged in spaced relation to each other along the passing direction of the gateway or the passage, and whether each person is entering or leaving is discriminated on the basis of a light reception sequence of the light position detectors in both sets. 
     According to the first embodiment of the present invention, light emitted from the projector is reflected by the head or a shoulder portion of a passing person and the reflected light is received by the light position detector through the light receiving lens (the resolving power for the stature corresponds to the head length). In this case, the reflected light is focused at a specific position of the light position detector corresponding to the height of the reflective position, that is, the stature of the passing person, and an electric signal is outputted. Therefore, statures of passing persons are classified by discriminating such output signals and the number of passing persons by stature is determined by counting such output signals. 
     According to the second embodiment of the present invention, each output signal from the light position detector is compared with an input value (threshold value) preset in the setting unit and thereby discriminated. The input value can be set and changed at a remote place. 
     According to the third embodiment of the present invention, even when plural persons pass side by side simultaneously, the passing persons are counted discriminately for for each set, thereby counting the number of passing persons by stature. Further, according to the fourth embodiment of the present invention, when the light position detector in a rear row (as seen from the exterior of the gateway or the passage) first receives light and thereafter the light position detector in a front row receives light, this passing person is judged to be a visitor, while when the front and rear light position detectors receive light in this order, it is judged that the passing person is leaving the gateway or the passage, and counting is made. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram showing fundamental operations of the counting method according to a first embodiment of the present invention; 
     FIG. 2 is an arrangement diagram, according to a fourth embodiment the present invention, of two sets of detecting portions for counting the number of entering and leaving persons; 
     FIG. 3 is a block diagram of the discriminator device connected to the detecting portions shown in FIG. 2, according to a second embodiment of the present invention; and 
     FIG. 4 is a plan view showing a mode of arrangement of plural sets of detecting portions, according to a third embodiment of the present invention. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Embodiments of the present invention will be described in detail hereinunder with reference to the drawings. 
     In FIG. 1, which is a block diagram showing the fundamental operations of the present invention, a projector 1, a light receiving lens 2, and a position detector 3 are provided as members of one set constituting a detecting portion A 1 . 
     The detecting portion A 1  is disposed in an upper position of a gateway or passage B, for example on the ceiling wall, by hanging, direct fixing, or embedding. 
     The projector 1 comprises a light emitting element capable of emitting an infrared ray or visible or invisible light from an upper to lower portion vertically or at a suitable angle so that the light is directed to the head of a person C passing through the gateway or passage B. 
     The light receiving lens 2 converges light which has been reflected by the head of the passing person C after emission from the projector 1, and is disposed near the light position detector 3. 
     The light position detector 3 comprises a light position detecting element 3a, such as a PSD element or a phototransistor, and an arithmetic unit 3b. In this embodiment, a PSD element is used as the light position detecting element 3a and is disposed on an optical axis of the light receiving lens 2 at a predetermined spacing from the lens. 
     The light position detecting element 3a outputs signals which differ according to light-radiated positions, namely, signals proportional to light-received positions. Those signals are subjected to arithmetic processing, including addition, subtraction and division, in the arithmetic unit 3b, which in turn outputs continuous electric signals corresponding to light-received positions. 
     The present invention intends to discriminate statures by utilizing the aforementioned characteristic of the light position detecting element 3a and the fact that the height of light reflected position differs depending on the stature of the passing person C. 
     More specifically, as shown in FIG. 1, when there is no passing person, light emitted from projector 1 is reflected as reflected light a 1  from the floor surface and the reflected light a 1  is received at position a 1  &#39; of the light position detecting element 3a through the light receiving lens 2. On the other hand, when there is a passing person C on the radiated light ray, reflected light a 2  from the head or a shoulder portion of the passing person is received at position a 2  &#39; of the light position detecting element 3a through the light receiving lens 2. In the case of a passing person C of a higher stature, reflected light a 3  is received in position a 3  &#39; of the detecting element 3a. 
     In order to count the number of persons by stature, the light position detector 3 outputs electric signals proportional to the reflected light-received at light-received positions a 1  &#39;, a 2  &#39;, a 3  &#39;, . . . of the detecting element 3a that are counted discriminatively. 
     In the illustrated embodiment, as a discriminating and counting device there is provided comparators 4 1 , 4 2 , 4 n , setting units 5 1 , 5 2 , . . . 5 n  and counters 6 1 , 6 2 , . . . 6n. Each such comparator, setting unit and counter are combined as a 4 1 , 5 1  and 6 1 , . . . 4 n , 5 n  and 6 n , and such sets are provided by a number corresponding to statures (e.g. 150 cm, 160 cm, 170 cm, 180cm) to be discriminated. 
     Threshold values corresponding to statures are set beforehand in the setting units 5 1 , 5 2 , . . . 5 n  by means of an input/output device 7. The threshold values and the foregoing output signals provided from the light position detector 3 are compared in the comparators 4 1 , 4 2 , . . . 4 n , and any one of the counters 6 1 , 6 2 , . . . 6 n  in the set including coincidence of the two is counted up, whereby the number of persons by stature is counted. 
     The comparators 4 1 , 4 2 , . . . 4 n , setting units 5 1 , 5 2 , . . . 5 n  counters 6 1 , 6 2 , . . . 6 n  and input/output device 7 are connected through an external bus to a central processing unit (CPU) which constitutes a microcomputer, and their operations are controlled thereby. If necessary, there may be additionally used a date and time inputting device, a printing device, a display device or a device for communication to POS. 
     It is assumed that the value set in each of the setting units 5 1 , 5 2 , . . . 5 n  can be varied by the input/output device 7. 
     FIG. 2 shows an example in which two sets of detecting portions A 1  and A 2 , each consisting of the projector 1, light receiving lens 2 and light position detector 3 are arranged in spaced relation to each other along the passing direction. of the gateway or passage B. 
     The operations of the detecting portions A 1  and A 2  are the same as in the previous case of using a single detecting portion in FIG. 1, but sequence discriminators 10 and 10&#39; are interposed between the comparators 4 1 , 4 2 , . . . 4 n , 4 1  &#39;, 4 2  &#39;, . . . 4 n  and the counters 6 1 , 6 2 , . . . 6 n  6 1  &#39;, 6 2  &#39;, . . . 6 n  &#39; as a discriminating and counting device, and both discriminators 10 and 10&#39; are connected together to detect a detecting operation, sequence of both detecting portions A 1  and A 2  (see FIG. 3). 
     The discriminators 10 and 10&#39; receive both count signals from the comparators 4 1 , 4 2 , . . . 4 n  on the detecting portion A 1  side and count signals from the comparators 4 1  &#39;, 4 2  &#39;, . . . 4 n  &#39; on the detecting portion A 2  side. The discriminator 10 first receives a count signals on the detecting portion A 1  side and, upon subsequent receipt of a count signal on the detecting portion A 2  side, it determines whether the passing person C is incoming, and causes any one of the counters 6 1 , 6 2 , . . . 6 n  to count up. 
     On the other hand, the discriminator 10&#39; first receives a count signal on the detecting portion A 2   side, and upon subsequent receipt of a count signal on the detecting portion A 1  side, it determines whether the passing person is leaving, and causes any one of the counters 6 1  &#39;, 6 2  &#39;, . . . 6 n  &#39; to count up. 
     Thus, the detecting portions A 1  and A 2  operate to count incoming and leaving persons, respectively. 
     FIG. 4 shows an example in which plural detecting portions A 1  and A 2  are arranged side by side along the width direction of the gateway or passage B. The spacing between adjacent detecting portions A 1 , A 1 , or A 2 , A 2  is set on the basis of a passing width of one passing person. 
     Since the detecting portions A 1  and A 2  are arranged side by side like above, even when plural persons are incoming or leaving simultaneously in parallel, the number of incoming or leaving persons can be counted for each stature by the detecting portions A 1  and A 2 . 
     According to the present invention, the number of passing persons can be counted at desired plural stages of stature by a set projector, light receiving lens and light position detector. Furthermore, since the input value each setting unit for setting a threshold value for each stature is made variable, the stature range to be counted can be changed without angular adjustment for the projector, etc. Thus, the counting method of the present invention is superior in operability and can enhance safety. 
     Moreover, by arranging plural sets of projectors, light receiving lenses and light position detectors in the transverse direction of the gateway or passage, it is made possible to ensure accurate counting and enhance reliability even in the case of simultaneous and parallel passing of plural persons. 
     Further, by arranging two sets of the projectors, light receiving lenses and light position detectors in the passing direction spacedly from each other, it is possible to judge a moving direction of each passing person (i.e., whether the passing person is incoming or leaving), and thereby count the number of passing persons in plural stages of stature.