JP2007271537A - Reflection sensor for automatic door - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce cost as much as possible relative to a reflection sensor for an automatic door for forming a monitoring domain by irradiating spot light matrically onto the floor surface near the automatic door. <P>SOLUTION: On the light emitting part 10 side, light emitting elements LD are classified by either line in the row direction or in the column direction, for example, by each column line, into groups as each light emitting element group X, and each light emitting element LD included in the light emitting element group X is connected so as to emit light simultaneously, and each light emitting element group X is driven by a light emission driving part 11. On the light receiving part 20A side, light receiving elements PD are classified by the other line in the row direction and in the column direction, for example, by each row line, into groups as each light receiving element group Y, and an output (an added output from each light receiving element) from each light receiving element group Y is given to a control part 23 through a selection circuit 21. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a reflective sensor for automatic doors, and more particularly to a reflective sensor for automatic doors that forms a monitoring area by irradiating a floor surface near an automatic door in a matrix.

  The reflective sensor for automatic doors has a light emitting part and a light receiving part arranged as a pair in the upper space of the automatic door as a basic structure, and irradiates light from the light emitting part to the floor surface near the automatic door. The reflected light is received by the light receiving unit, and an open / close signal is output to the automatic door in accordance with the fluctuation of the received light level.

  In order to improve the safety and detection accuracy of the reflective sensor for automatic doors, for example, as described in Patent Document 1, pixel-like information by spot light is obtained from the monitoring area, and an object enters the automatic door. The direction is judged and malfunctions due to various noises are prevented.

  A conventional example will be described with reference to FIGS. First, FIG. 5 shows, for example, eight spot lights SP11 to SP18 for one row irradiated along the railway of the automatic door 1. FIG. 4A shows such spot lights. As described above, the light emitting unit 10 includes eight light emitting elements LD11 to LD18. Moreover, as shown in FIG.4 (b), the light-receiving part 20 is similarly provided with eight light receiving element PD11-PD18. In addition, regarding the reference symbols, when it is not necessary to distinguish between the light emitting element and the light receiving element, the light emitting element is simply referred to as the light emitting element LD, and the light receiving element is simply referred to as the light receiving element PD.

  The light emitting elements LD11 to LD18 and the light receiving elements PD11 to PD18 are both arranged in a line, and light from the light emitting elements LD11 to LD18 is irradiated as spot light SP11 to SP18 for one line on the floor surface through, for example, the monocular lens 3a. The reflected light is received by the light receiving elements PD11 to PD18 through the monocular lens 3b.

  In this case, the light emitting elements LD11 to LD18 do not emit simultaneously, but first the light emitting element LD11 emits light and is received by the light receiving element PD11. Next, the light emitting element LD12 emits light and is received by the light receiving element PD12. As described above, the active spots generated on the floor surface can be scanned by sequentially causing the light emitting elements LD to emit light. As the light emitting element LD is individually selected to emit light, the corresponding element on the light receiving element PD side is also individually selected.

  In the actual monitoring area, a plurality of the above-mentioned spot light columns are generated on the floor near the automatic door. 7, the spot light SP11 to SP18 of FIG. 5 is set as the first column, the second column including the spot beams SP21 to SP28, the third column including the spot beams SP31 to SP38, and the spot beams SP41 to SP48 on the front side thereof. The area configuration of the active spot when the fourth column including the same is generated is shown.

  When generating such a matrix-shaped active spot area, as shown in FIG. 6A, the light-emitting unit 10 includes four light-emitting elements LD in four rows, that is, 32 light-emitting elements LD, that is, 4 rows × 8. They will be arranged in a matrix of rows. Similarly, as shown in FIG. 6B, 32 light receiving elements PD are arranged in 4 rows in the light receiving unit 20 as 8 in one row.

  Also in this case, the light emitting element LD and the light receiving element PD are individually selected and scanned one spot at a time. FIG. 8A shows an example of a driving circuit on the light emitting unit 10 side, and FIG. 8B shows an example of a light receiving circuit on the light receiving unit 20 side.

  According to this, a matrix drive system including column driver elements 11a to 11d connected to each column and row driver elements 12a to 12h connected to each row is adopted for the light emission drive unit on the light emitting unit 10 side. For example, as shown in FIG. 8A, when the light emitting elements LD41 in the fourth column and the first row emit light, the column driver elements 11d and the row driver elements 12a are turned on.

  On the light receiving unit 20 side, all the light receiving elements PD are connected to a multiplexer-like selection circuit 21, and a light reception signal of one light receiving element PD selected by the selection circuit 21 is given to a control circuit (not shown) via an amplifier 22, for example. It is done.

  As described above, for example, if the light emitting element LD41 in the fourth column and the first row emits light on the light emitting unit 10 side, the light receiving element LD41 corresponding to the fourth column and the first row is received by the selection circuit 21. Element PD41 is selected. The control unit monitors fluctuations in the light receiving level of the light receiving element PD, and outputs an opening / closing signal to the automatic door 1 in accordance with the fluctuations.

Japanese Patent Laid-Open No. 11-311060

  According to the conventional reflective sensor described above, pixel-like information in spot light units can be obtained from the monitoring area, so that the approach direction of the object to the automatic door can be determined, and malfunction due to various noises can be prevented. There are still problems to be solved.

  First, regarding the light emitting unit 10, since it is a matrix drive system, the number of devices is smaller than when a driver element is assigned to each light emitting element, but driver elements are added as the number of rows and / or columns increases. There is a need to. Along with this, the peripheral circuit becomes complicated and the cost increases.

  Next, with regard to the light receiving unit 20, basically a selection circuit (analog switch) for individually selecting the light receiving elements PD is required, but since the number of inputs is limited, the floor surface is limited. As the detection resolution by the spot light irradiated on the pixel increases, the selection circuit must be increased. Further, similarly to the light emitting unit 10, the peripheral circuit becomes complicated and the cost increases accordingly.

  Accordingly, an object of the present invention is to reduce the cost as much as possible in a reflective sensor for an automatic door that forms a monitoring area by irradiating a floor surface near the automatic door with a spot light in a matrix.

  In order to solve the above-described problems, the present invention provides a light emitting unit having a plurality of light emitting elements arranged in a matrix and a matrix corresponding to the plurality of light emitting elements. A light receiving unit arranged in an upper space of the automatic door together with the light emitting unit, a light emitting driving unit for driving the light emitting elements, and a light receiving signal output from the light receiving unit. A control unit that outputs an open / close signal to the automatic door according to a level, and the light emission driving unit causes the light emitting elements to emit light in a predetermined order from the light emitting unit toward the floor near the automatic door. In the automatic door reflection type sensor that irradiates spot light and receives the reflected light by the light receiving unit, on the light emitting unit side, the plurality of light emitting elements emit light for each line in the row direction or the column direction. Element group and The light emitting elements included in the light emitting element group are connected so as to emit light simultaneously, and the light emission driving unit drives the light emitting element groups according to a predetermined order. The plurality of light receiving elements are grouped as a light receiving element group for each other line in the row direction or the column direction, and an output from the light receiving element group is provided to the control unit via a selection circuit. Yes.

  According to a preferred aspect of the present invention, as described in claim 2, the output from each of the light receiving element groups is inputted to the control unit in a loop through the selection circuit, The light emission drive unit switches the light emitting element group to be driven.

  Further, according to the present invention, as set forth in claim 3, the light emission driving unit alternatively drives each of the light emitting element groups via a switching circuit by one driver element, and claims. As described in Item 4, the light emission driving unit includes an aspect in which a driver element is provided for each light emitting element group.

  In the present invention, as described in claim 5, the light receiving elements included in the light receiving element group are connected so that their outputs are added.

  According to the present invention, on the light emitting unit side, the light emitting elements are grouped as a light emitting element group for each column line, for example, a row direction or a column direction, and each light emission included in the light emitting element group is divided. The elements are connected so as to emit light at the same time, and each light emitting element group is driven by the light emission driving unit. On the light receiving unit side, the light receiving element is arranged in the row direction or the column direction, for example, for each row line. Since the light receiving element group is divided into groups, the output from the light receiving element group (added output of each light receiving element) is given to the control unit via the selection circuit, so that no row driver element is required in the light emitting part. Therefore, the part cost can be reduced and the peripheral circuit can be simplified. Further, since each light receiving element is not individually selected on the light receiving side, but can be selected in units of each light receiving element group, the selection circuit can be an inexpensive device.

  Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 3, but the present invention is not limited to this.

  FIG. 1 (a) shows a configuration example of a light emitting unit 10A included in a reflective sensor for an automatic door according to the present invention, and FIG. 1 (b) shows a configuration example of a light receiving unit 20A that is a counterpart of the light emitting unit 10A. Schematic plan view). A plurality of elements are arranged in a matrix in both the light emitting unit 10A and the light receiving unit 20A. In FIG. 1, the X-axis direction (horizontal direction) is the column direction, and the Y-axis direction (vertical direction) is the row direction. .

  Also in this embodiment, as in the conventional example described with reference to FIG. 6, the light emitting unit 10A includes 32 light emitting elements LD arranged in a matrix of 4 columns × 8 rows, and the light receiving unit 20A also corresponds to this. 32 light-receiving elements PD having a matrix arrangement of 4 columns × 8 rows are provided. As a result, as shown in FIG. 2, an active array having a matrix arrangement of 4 columns × 8 rows on the floor near the automatic door 1 is provided. Create a spot area.

  According to the present invention, the plurality of light emitting elements LD of the light emitting unit 10A are grouped as a light emitting element group for each line in either the row direction or the column direction, and on the other hand, the plurality of light receiving elements PD of the light receiving unit 20A. Are grouped as a light receiving element group for each other line in either the row direction or the column direction.

  In this example, the 32 light emitting elements LD of the light emitting unit 10A are grouped as 8 light emitting element groups X1 to X4 in the first to fourth rows. In addition, when it is not necessary to distinguish each light emitting element group on description, it is only called the light emitting element group X.

  That is, the first light emitting element group X1 in the first column includes light emitting elements LD11 to LD18, the second light emitting element group X2 in the second column includes light emitting elements LD21 to LD28, and the third column. The third light emitting element group X3 includes light emitting elements LD31 to LD38, the fourth light emitting element group X4 in the fourth column includes light emitting elements LD41 to LD48, and the light emitting elements LD in each light emitting element group X. Are electrically connected to emit light simultaneously.

  In relation to this, the light emission driving unit 11 of the light emitting unit 10A drives the light emitting element groups X1 to X4 in units of groups. In this example, the column driver elements 11a to 11d are connected to each of the light emitting element groups X1 to X4, and the light emitting element groups X1 to X4 are cyclically driven in the order of, for example, X1, X2, X3, X4, X1,. Is done.

  According to this embodiment, the row driver elements 12a to 12h shown in FIG. 8 which have been conventionally required are not required, and the part cost can be reduced correspondingly. However, unlike this embodiment, the number of rows is more than the number of columns. When the number of the light emitting elements is small, it is preferable to group the plurality of light emitting elements LD along the row line in order to further reduce the component cost. In addition, it is also possible to alternatively drive the light emitting element groups X1 to X4 according to a predetermined order through a switching circuit (not shown) by using one column driver element.

  In the light receiving unit 20A, 32 light receiving elements PD are grouped into four light receiving element groups Y1 to Y84 in the first to eighth rows. In addition, when it is not necessary to distinguish each light receiving element group for description, it is simply referred to as a light receiving element group Y.

  That is, the first light receiving element group Y1 in the first row includes the light receiving elements PD11, PD21, PD31, and PD41, and the second light receiving element group Y2 in the second row includes the light receiving elements PD12, PD22, PD32, and PD42. The third light receiving element group Y3 in the third row includes light receiving elements PD13, PD23, PD33, and PD43, and the fourth light receiving element group Y4 in the fourth row includes the light receiving elements PD14, PD24, and PD34. , PD44.

  The fifth light receiving element group Y5 in the fifth row includes light receiving elements PD15, PD25, PD35, and PD45, and the sixth light receiving element group Y6 in the sixth row includes the light receiving elements PD16, PD26, PD36, and PD46. The seventh light receiving element group Y3 in the seventh row includes light receiving elements PD17, PD27, PD37, and PD47, and the eighth light receiving element group Y8 in the eighth row includes the light receiving elements PD18, PD28, and PD38. , PD48 is included.

  The four light receiving elements PD included in each light receiving element group Y are connected so that their outputs are added, and each of the light receiving element groups Y1 to Y8 is connected to the selection circuit 21. The output (addition output) of one light receiving element group Y selected by the selection circuit 21 is given to the control unit 23 via the amplifier 22, for example. The control unit 23 monitors the output level (light reception level) of the light receiving element group Y, and outputs an open / close signal to the automatic door 1 according to the level fluctuation.

  For example, a multiplexer composed of an analog switch may be used for the selection circuit 21, and its switching order and switching timing are controlled by the control unit 23. The switching order and switching timing of the light emission driving unit 11 are also controlled by the control unit 23. Conventionally, 32 inputs are required for the selection circuit 21, but according to this embodiment, 8 inputs are sufficient, and an inexpensive device can be used for the selection circuit 21.

  An example of the operation of the present invention will be described. First, the light emitting elements LD11 to LD18 of the first light emitting element group X1 in the first column are caused to emit light simultaneously by the column driver element 11a, and the light receiving element group Y1 is selected by the selection circuit 21. To Y8 are selected in the order of, for example, Y1, Y2, Y3, Y4, Y5, Y6, Y7, and Y8. As a result, only the spot light in the first column among the spot lights SP in FIG. 2 becomes valid (active state) in the order of SP11 → SP12 → SP13 → SP14 → SP15 → SP16 → SP17 → SP18.

  When the scanning of the first column is completed, the light emitting elements LD21 to LD28 of the second light emitting element group X2 of the second column are caused to emit light simultaneously by the column driver element 11b, and the light receiving element group Y1 is selected by the selection circuit 21. To Y8 are selected in the order of, for example, Y1, Y2, Y3, Y4, Y5, Y6, Y7, and Y8. As a result, only the spot light in the second column among the spot lights SP in FIG. 2 becomes effective in the order of SP21 → SP22 → SP23 → SP24 → SP25 → SP26 → SP27 → SP28. By repeating this, the active spot can be scanned.

  Although the present invention has been described based on the illustrated example, the light emitting element group of the light emitting unit 10A is grouped along the row line, and the light receiving element group of the light receiving unit 20A is grouped along the column line. Good. In addition, the switching order of the light emitting element group X and the switching order of the light receiving element group Y may be random, and further, as shown in FIG. The light receiving element group Y on the light receiving unit 20A side may be oblique to the upper right, and such an aspect may also be included in the present invention.

FIG. 2A is a schematic plan view showing a configuration example on the light emitting unit side, and FIG. 2B is a schematic plan view showing a configuration example on the light receiving unit side, provided in the reflective sensor for automatic doors according to the present invention. The schematic diagram which shows the multi-row active spot produced | generated on a floor surface by the said reflection type sensor for automatic doors. The schematic diagram which shows the modification of this invention. The schematic diagram which shows the basic structural example by which the conventional reflection type sensor for automatic doors is equipped, (a) The basic structural example by the side of a light-emitting part, (b). The schematic diagram which shows the active spot of 1 row produced | generated on a floor surface by the light emission part and light-receiving part of FIG. The schematic diagram which shows the actual structural example by the side of the light-receiving part which (a) the light-emitting part side has with the conventional reflective type sensor for automatic doors. The schematic diagram which shows the multi-row active spot produced | generated on a floor surface by the light emission part of FIG. 6, and a light-receiving part. FIG. 7A is a schematic diagram illustrating a configuration example of a light emission driving unit on the light emitting unit side in FIG. 6, and FIG. 7B is a schematic diagram illustrating a circuit configuration example on the light receiving unit side in FIG. 6.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic door 10A Light emission part 11 Light emission drive part 11a-11d Column drive element 20A Light receiving part 21 Selection circuit 23 Control part LD Light emitting element PD Light receiving element X Light emitting element group Y Light receiving element group

Claims (5)

A light-emitting unit having a plurality of light-emitting elements arranged in a matrix and a plurality of light-receiving elements arranged in a matrix corresponding to the plurality of light-emitting elements are arranged in the upper space of the automatic door together with the light-emitting units. A light-emitting drive unit that drives each of the light-emitting elements, and a control unit that outputs an open / close signal to the automatic door according to the level of the light-receiving signal output from the light-receiving unit. Reflective sensor for automatic doors that causes the light emitting elements to emit light in a predetermined order and irradiates spot light from the light emitting part toward the floor near the automatic door and receives the reflected light by the light receiving part. In
On the light emitting section side, the plurality of light emitting elements are grouped as a light emitting element group for each line in the row direction or the column direction, and the light emitting elements included in the light emitting element group are connected so as to emit light simultaneously. And
The light emission driving unit drives the light emitting element groups according to a predetermined order,
On the light receiving unit side, the plurality of light receiving elements are grouped as a light receiving element group for each other line in the row direction or the column direction, and an output from the light receiving element group is sent to the control unit via a selection circuit. Reflective sensor for automatic doors characterized by being given.   The output from each of the light receiving element groups is cycled through the selection circuit and input to the control unit, and the light emission driving unit switches the light emitting element group to be driven. The reflective sensor for automatic doors according to 1.   3. The reflective sensor for an automatic door according to claim 1, wherein the light emission driving unit selectively drives each light emitting element group through a switching circuit by one driver element.   3. The reflective sensor for an automatic door according to claim 1, wherein the light emission driving unit includes a driver element for each light emitting element group.   5. The reflective sensor for an automatic door according to claim 1, wherein the light receiving elements included in the light receiving element group are connected so that their outputs are added.

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