JP3854628B2 - Multi-optical axis photoelectric sensor and projector / receiver included therein - Google Patents

Description

  The present invention relates to a multi-optical axis photoelectric sensor and a projector / receiver included therein.

  Conventionally, in order to detect the presence or absence of an object in a wide detection area, a multi-optical axis photoelectric sensor unit having a projector and a light receiver as one unit is used. A typical example of the use of a multi-optical axis photoelectric sensor unit is as follows. When a part of the body such as the fingertip of an operator enters the work area, this is detected by a multi-optical axis photoelectric sensor, and the operation of the machine is immediately stopped and / or alarmed to protect the operator and workers. Used to emit.

  If the work area boundary is large compared to the light curtain that can be made with many optical axes in a single unit multi-axis photoelectric sensor, multiple units can be created to create the light curtain with the required spread. Are connected to each other.

  Patent Document 1 of Anderson et al. Teaches that a plurality of units are connected by a flexible cable. Specifically, a flexible cable that connects adjacent projectors and adjacent receivers is provided. Connection is made at the end of each projector and each light receiver.

  According to the connection method using the flexible cable, the angle between adjacent units can be freely set. For example, a corner of a work area having a rectangular outline or a curved portion having an arcuate outline. It is suitable for making a light curtain along.

  However, in Patent Document 1, since a flexible cable is connected to the ends of each projector and each light receiver using an external connector, adjacent ones arranged on the same plane for interference between adjacent connectors. Therefore, a separation distance is generated between the projectors that are adjacent to each other and between adjacent optical receivers. Is effectively difficult to maintain between adjacent projectors and receivers. For this reason, when the pitch of the light projecting elements is increased between the adjacent projectors and the pitch of the light receiving elements is increased between the adjacent light receivers, an undetectable region is generated in the light curtain.

  In order to solve such a problem, Patent Document 2 prepares a molded coupler that receives an end portion of an adjacent projector and an end portion of an adjacent photoreceiver, and uses this molded coupler to make an adjacent projector and an adjacent light receiving device. Teaching to connect devices. This molded coupler is plastic molded so as to have a predetermined bending angle.

According to the proposed molded coupler, the distance between adjacent projectors arranged on the same plane and the distance between adjacent receivers can be made small and constant, so the pitch between a plurality of posting elements built in the projector In addition, there is an advantage that the pitch between the plurality of light receiving elements built in the light receiver, that is, the interval between the optical axes constituting the light curtain can be maintained between the adjacent projectors and between the light receivers.
USP No. 5,198,661 WO00 / 54077 International Publication

  However, when the molded coupler disclosed in Patent Document 2 is used, the angles provided between the adjacent projectors and the adjacent light receivers are defined by the angles provided by the molded coupler. Thus, there is a problem that the degree of freedom of the setting angle between adjacent projectors and between adjacent optical receivers is an advantage, which is an advantage of adopting the flexible cable.

  An object of the present invention is to make it easy to freely set the bending angle between adjacent projectors and between adjacent light receivers when a plurality of multi-optical axis photoelectric sensors are connected to each other to form a wide light curtain. An axial photoelectric sensor and a projector / receiver are provided.

  Another object of the present invention is to prevent the external connector from protruding or protruding when the adjacent projectors and adjacent receivers are connected using a flexible cable as in Patent Document 1. It is an object of the present invention to provide a multi-optical axis photoelectric sensor and a light emitter / receiver that can perform the above-mentioned.

  Another object of the present invention is that when a plurality of multi-optical axis photoelectric sensors are connected to each other to form a wide light curtain, the distance between adjacent projectors and between adjacent light receivers can be reduced. It is an object of the present invention to provide a multi-optical axis photoelectric sensor and a light projecting / receiving device that can easily keep a separation distance between optical axes constituting an optical curtain substantially constant between adjacent multi-optical axis photoelectric sensors.

According to the present invention, such a technical problem is
A multi-optical axis photoelectric sensor having an elongated bar-shaped outer shape, in which optical elements are arranged in a row at regular intervals from one end portion to the other end portion,
The outer shape of the multi-optical axis photoelectric sensor includes a case body having an elongated U-shaped cross-section with both ends open, an elongated shape that closes one end and opens the other end and accommodates a plurality of optical elements, and opens the case. Formed with a terminal member connected to the case body in a state in which the opened end is butted against the open end of the case body,
The terminal member is cut out from the same cross-sectional shape as the case main body, a horizontal plane parallel to the optical axis without interfering with the optical axis accommodated in the terminal member, a light projecting surface or a light receiving surface A stepped notch shape that forms a vertical wall that is offset from the rear side and extends in the longitudinal direction of the terminal member,
The vertical wall is formed with an insertion port through which an external connector having a possibility cable can be accessed in the optical axis direction from the light emitting surface or the light receiving surface side of the terminal member toward the back side. A connector pin is placed facing the mouth,
When the external connector is accessed to the insertion port along the horizontal plane and connected to the connector pin through the insertion port, the terminal member including the external connector has substantially the same cross-sectional shape as the case body. This is achieved by providing a multi-optical axis photoelectric sensor.

  That is, according to the present invention, adjacent multi-optical axis photoelectric sensors are connected to each other via a flexible cable, and therefore the bending angle between these multi-optical axis photoelectric sensors can be freely set. Further, since the external connector occupying a relatively large volume is accommodated in the stepped notch portion of the terminal member, the possibility that the connector protrudes outward and causes interference between the connectors can be reduced. With a multi-optical axis photoelectric sensor, it becomes easy to make a light curtain having optical axes with substantially equal intervals.

  FIG. 1 shows an overall outline of a light receiver 1 included in a multi-optical axis photoelectric sensor unit. The illustrated light receiver 1 is merely an example, and an eight optical axis type including eight light receiving elements in which the interval between adjacent light receiving elements is set to a pitch of 20 mm is illustrated, but is not limited thereto. is not. The light receiver 1 has a maximum of 64 light receiving elements arranged at a pitch of 20 mm up to 64 optical axis types, for example, with 4 light receiving elements as a unit, 12 optical axes, 16 optical axes, 20 optical axes,.・ Various types are available. Although the projector of the multi-optical axis photoelectric sensor unit is not shown, it should be understood that it has substantially the same appearance as the light receiver 1.

  As described above, the light receiver 1 has a pitch between adjacent light receiving elements set to 20 mm, and the distance between the light receiving element located at the end of the light receiver 1 and the end face of the light receiver 1 is Half of 20 mm, or 10 mm or less. By making the distance between the light receiving element located at the end of the light receiver 1 and the end face of the light receiver 1 smaller than 10 mm, the distance between the optical axes between the adjacent light receivers 1 and 1 is 20 mm or less. Easy to keep in.

  The light receiver 1 has an elongated case body 2 made of Al made of an extruded product. The case main body 2 has an elongated cross-sectional substantially U-shaped shape with both ends and one side open, and its occupied cross-sectional area is small and slim compared to conventional ones. On one side surface or the light receiving surface 3 of the case body 2, an elongated window 4 extending in the longitudinal direction is formed.

  A terminal member 5 formed by using a mold made of a metal such as Zn or plastic, for example, is attached to both ends of the case main body 2, and the light receiver 1 is connected to the pair of terminal members 5 and the case main body 2. Are formed. As will be described later, four light receiving elements included in the eight optical axis type light receiver 1 are disposed on the case body 2 and two are disposed on each terminal member 5.

  The terminal member 5 has two light receiving element through holes 8 spaced apart in the longitudinal direction on the light receiving surface 3. As can be understood from FIG. 1, the terminal member 5 has a stepped shape in which a part thereof is cut out from substantially the same cross-sectional shape as the case main body 2. More specifically, the terminal member 5 has an inner portion 9 located adjacent to the case body 2 and an outer portion 10 extending outward from the inner portion 9 in the axial direction. The inner part 5 has substantially the same outer shape as the case body 2 and ends with a vertical wall 11. The end portion 10 extends outward in the axial direction from the vertical wall 11 of the inner portion 9 and ends at the end of the terminal member 5.

  The outer portion 10 is also provided with one plane that is parallel to the optical axis without interfering with the optical axis, that is, a horizontal plane 12, and the horizontal plane 12 and the vertical wall 11 are used for connection with other units. A notch portion 14 for arranging the external connector 13 (FIG. 2) to be used is formed. In other words, the light receiver 1 has a notch 14 for receiving the external connector 13 by notching a part of both ends of the bar having substantially the same cross-sectional shape from one end to the other end. When the external connector 13 is mounted with the formed shape, the external connector 13 is integrated to form a part of the bar shape. The length in the longitudinal direction of the notch 14 is the sum of at least the pitch between adjacent light receiving elements, that is, 20 mm, and the distance between the light receiving element located at the end of the light receiver 1 and the end face of the light receiver 1. It is slightly larger than the distance.

  In the outer portion 10, an insertion port 15 that can receive the external connector 13 is disposed offset to the inner portion 9 side and to the rear side. That is, the insertion port 15 is formed at a position adjacent to the vertical wall 11 and adjacent to the surface opposite to the light receiving surface 3. The insertion port 15 substantially has a ceiling wall 15a that forms an upper surface substantially common to the upper surface of the inner portion 5 and a longitudinally intermediate portion of the plane 12 that hangs down from the end of the ceiling wall 15a. It is formed with the end wall 15b which merges, and is open | released toward the light-receiving surface 3 side. The deep portion of the insertion port 15 is located adjacent to the surface opposite to the light receiving surface 3 where the light receiving element through hole 8 is located. The deep portion of the insertion port 15 includes an optical axis and Main connector pins 16 extending in parallel are arranged (FIG. 5), and the main connector pins 16 extend to the light receiving surface 3 side. By moving the external connector 13 backward from the light receiving surface 3 side, the external connector 13 and the main connector pin 16 are electrically connected.

  In the following description, for ease of explanation, for convenience, the surface on which the notch portion 14 is formed is referred to as “upper surface or top surface”, and the surface on which the light receiving element through hole 8 is formed is referred to as “front surface”. Alternatively, the surface opposite to the front surface is referred to as “rear surface”, and the surface opposite to the upper surface is referred to as “lower surface or bottom surface”.

  The outer contour of the terminal member 5 will be described again using terms such as the upper surface and the rear surface. The upper surface of the terminal member 5 has an outer portion 10 and an insertion port 15 adjacent to the inner portion 9 on the rear surface. The external connector 13 is arranged in a notch portion 14 that is formed along the area and occupies the other area. The external connector 13 can access the insertion port 15 by moving from the front side toward the rear side in the optical axis direction. In other words, the insertion port 15 of the terminal member 5 is disposed rearward from the longitudinal axis of the light receiver 1 and is disposed offset from the end edge of the terminal member 5 inward in the axial direction.

  As can be seen from FIG. 2, the external connector 13 has a substantially rectangular outer shape that is elongated along the longitudinal direction of the horizontal plane 12. When connected to the light receiver 1, the external connector 13 is integrated with the terminal member 5 to form a cross-sectional shape common to the case body 2. The length in the longitudinal direction of the external connector 13 is slightly larger than the pitch between adjacent light receiving elements, that is, 20 mm. Therefore, the external connector 13 extends from the vertical wall 11 to the vicinity of the end surface of the terminal member 5. The external connector 13 also has a flexible cable 20 extending rearward from the rear surface and the outer end, and the flexible cable 20 is disposed along the end wall 15b.

  Thus, since the external connector 13 is accommodated in the notch part 14 and becomes a part of the outer shape of the bar-shaped light receiver 1, the end faces of the adjacent light receivers 1 are in contact with or close to each other. A plurality of light receivers 1 can be arranged. In this connection, the end face of the terminal member 5 and the end face of the external connector 13 are not particularly limited, but are tapered so that other light receivers (not shown) can be arranged adjacent to each other. It is good to have the surface 5a or 13a. According to this, even if it arrange | positions in the state which the adjacent light receiver 1 bent, the pitch between optical axes can be maintained moderately.

  Furthermore, since the adjacent light receivers 1 are connected to each other by the flexible cable 20, the bending angle between the adjacent light receivers 1 and 1 is arbitrary. In addition, since the flexible cable 20 extends backward from the notch portion 14, in other words, the flexible cable 20 does not extend outward in the longitudinal direction from the end of the light receiver 1, The flexible cable 20 does not get in the way when the adjacent optical receivers 1 are arranged close to each other.

  FIG. 3 shows the internal structure of the light receiver 1. Inside the light receiver 1, a light receiving element holder 22 is disposed along the front surface or the light receiving surface 3 of the light receiver 1. The light receiving element holder 22 includes an elongated rectangular plate 23 extending from end to end of the light receiver 1. The plate 23 is formed with eight light receiving circular openings 24 along the longitudinal direction. Needless to say, the pitch between adjacent openings 24 is 20 mm. A lens plate 25 (FIG. 4) is detachably attached to the front surface of the holder plate 23.

  The light receiving element holder 22 also includes eight cylindrical bodies 26 formed integrally with the plate 23, and each cylindrical body 26 is located facing the opening 24 and extends rearward. That is, the cylindrical body 26 extends from the opening 24 along the optical axis, and the light receiving element 27 is positioned at the rear end of the cylindrical body 26. The two cylindrical bodies 26 positioned at the respective end portions of the light receiving element holder 22 are covered with the terminal member 5. On the other hand, the four cylindrical bodies 26 located in the intermediate part of the light receiving element holder 22 are covered with the case body 2.

  The light receiver 1 includes therein a first printed circuit board 30 disposed along the lower surface of the light receiver 1 and a second printed circuit board 31 disposed along the rear surface of the light receiver 1. . That is, the first substrate 30 extends rearward from the lower edge of the plate 23 of the light receiving element holder and is arranged in parallel with the optical axis. The pair of legs of each light receiving element 27 is provided on the first substrate 30. Are connected (FIG. 3). On the other hand, the second substrate 31 extends upward from the rear edge of the first substrate 30, that is, in a direction orthogonal to the optical axis, and is positioned facing the light receiving surface 3.

  The first substrate 30 has an elongated rectangular shape extending from end to end of the light receiver 1 along the lower surface of the light receiver 1. On the other hand, the second substrate 31 has a substantially rectangular shape extending from end to end along the rear surface of the light receiver 1 and partially cut away. That is, the second substrate 31 has a shape in which the upper corner portion is cut out into a rectangular shape at both end portions of an elongated rectangle. The cutout portion 32 of the second substrate 31 is formed corresponding to the cutout portion 14 of the terminal member 5 described above. That is, the longitudinal length of the cutout portion 32 of the second substrate 31 is substantially equal to the distance between the end wall 15 b that forms the insertion port 15 of the terminal member 5 and the edge of the terminal member 5.

  As can be seen from the above description, both the first substrate 30 and the second substrate 31 have shapes that allow the internal space of the light receiver 1 to be used without waste. In particular, since the main connector pin 16 is disposed at the end of the second substrate 31 and the external connector 13 is inserted into the main connector pin 16 from the front side, the second substrate 31 is connected to the light receiver 1. It can arrange | position over substantially the whole area | region of the length direction. Therefore, the circuit design of the first and second substrates 30 and 31 can be performed using the limited internal space of the light receiver 1 to the maximum.

  The eight light receiving elements 27 of the light receiver 1 are connected to a first substrate 30 that extends parallel to the optical axis along the lower surface of the light receiver 1. The first substrate 30 typically includes the following elements.

(1) Light receiving element 27;
(2) a first-stage light receiving amplifier or amplification circuit associated with each light receiving element 27;
(3) Second-stage light receiving amplifier that amplifies outputs from the eight light receiving elements 27, that is, an amplifier circuit. (4) An optical axis switching circuit for sequentially activating the light receiving elements 27.

  On the other hand, the following elements are typically incorporated in the second substrate 31, and the second substrate 31 and the first substrate 30 described above are connected by a connector not shown.

(1) Power supply circuit;
(2) Two communication circuits;
(3) Overall control circuit of the light receiver 1;
(4) Output circuit;
(5) Two main connector pins 16 to which the external connector 13 can be connected.

  The first-stage light-receiving amplifiers associated with the respective light-receiving elements 27 are sequentially operated according to instructions from the optical axis switching circuit, and the output is amplified by the second-stage amplifier. The processes so far are performed on the first circuit board 30. The output of the second-stage amplifier is input to the overall control circuit of the second circuit board 31, and is signal-processed by this overall control circuit, and after the presence or absence of light shielding is determined by the output circuit (detection circuit), the main connector pin 16 to the outside. The output circuit occupies a relatively large occupied area because it includes a function of repeating the determination two to three times within a predetermined period in order to ensure the determination of the presence or absence of light shielding.

  As will be understood by those skilled in the art, a circuit directly related to the light receiving element 27 is incorporated in the first circuit board 30 on which the plurality of light receiving elements 27 are mounted. The circuit board 31 incorporates an overall control of the light receiver 1, an output circuit occupying a relatively large occupied area, and a circuit related to communication with the outside. Thus, since the rational board | substrate structure classified functionally is employ | adopted, the connector for electrically connecting the 1st, 2nd board | substrates 30 and 31 can be minimized. In other words, if all the circuits described above are incorporated in one substrate, the single substrate must be large, and accordingly, the outer shape of the light receiver 1 must be large. I don't get it.

  Furthermore, if an overall control circuit is provided on the first substrate 30 and a light receiving amplifier is provided on the second substrate 31, a line for transmitting and receiving signals between the first substrate 30 and the second substrate 31 is provided. The number increases, and the number of connectors between the first and second substrates 30 and 31 increases. Needless to say, as the number of internal connectors increases, the area that can be used on the first substrate 30 and the second substrate 31 decreases.

  Further, as described above, the photoreceiver 1 is prepared with various optical axis numbers up to 64 optical axis types having 64 light receiving elements in units of 4 optical axes. In order to realize this, as shown in FIG. 6, an extension substrate 35 and additional connector pins 36 are prepared.

  The extension board 35 has internal connectors 37 (only one connector is shown in FIG. 6 and the other internal connector is not shown) at both ends, and the first board is provided via the internal connector 37. 30 and other extension substrates 35 can be connected.

  The extension substrate 35 includes substantially the same elements as those of the first substrate 30 except for the second-stage amplifier as described below.

(1) a first-stage light receiving amplifier associated with each light receiving element 27;
(2) An optical axis switching circuit for sequentially activating the light receiving element 27.

  The additional connector pins 36 have a harness 39 including a connector 38, and are connected to the pins 16 of the second substrate 31 via the connector 38. The additional connector pins 36 may be prepared in various types with different lengths of the harness 39, for example, for 12 optical axes, 16 optical axes,... 64 optical axes.

  As described above, when the additional connector pins 36 and the extension substrate 35 are used, the terminal member described above is prepared by preparing the case body 2 of different types such as for the 12 optical axes and for the 16 optical axes. 5 can be used to manufacture light receivers having various numbers of light receiving elements.

  In addition, the processing inside the light receiver 1 is performed in such a manner that the first-stage light receiving amplifiers associated with the respective light receiving elements 27 of the first substrate 30 are sequentially in accordance with instructions from the optical axis switching circuit of the first substrate 30. When the operation of the light receiving element 27 on the first substrate 30 is completed, the first-stage light receiving amplifier associated with each light receiving element (not shown) on the extension substrate 35 is connected to the optical axis of the extension substrate 35. The operation is sequentially performed according to an instruction from a switching circuit (not shown), and the output is amplified by the second-stage amplifier of the first substrate 30. The processing so far is performed with the first substrate 30 and the extension substrate 35 arranged on the same plane. Then, the output of the second stage amplifier is input to the overall control circuit of the second substrate 31, and is signal-processed by this overall control circuit, and is output to the outside through the output circuit and the main connector pin 16 or the additional connector pin 36. Is output.

  With reference to FIG. 7 and FIG. 8, the preferable aspect regarding positioning of the light receiving element 27 is demonstrated. The light receiving element holder 22 includes at least a pair of parallel columns 40 that are fixed to the rear end of the cylindrical body 26 and extend vertically. The substantial distance between the pair of support columns 40 is the same as the width of the light receiving element 27, and the light receiving element 27 is snapped onto the pair of support columns 40, whereby the light receiving element 27 is cylindrical. 26, that is, the light receiving element holder 22 can be easily positioned.

  The structure of the end of the light receiver 1, that is, the structure for housing the external connector 13 in the notch 14, the access direction of the external connector 13, or the internal structure of the light receiver 1 has been described above with the light receiver 1 as a main component. However, this can be similarly applied to a projector that is paired with the light receiver 1.

  In the case of a projector, the following elements may be included in the first substrate 30 described above.

(1) Projecting element;
(2) Projection circuit associated with each projection element;
(3) Optical axis switching circuit.
The second substrate 31 may include the following elements.
(1) Power supply circuit;
(2) Communication circuit;
(3) Overall control circuit.

  FIG. 9 is an explanatory diagram of the most basic configuration for creating a light curtain with a single unit comprising the projector 45 and the light receiver 1 according to the present invention. In the drawings such as FIG. 9, the end structure (notch portion 14) and the external connector 13 of the light projector 45 and the light receiver 1 and the external connector 13 are omitted in order to avoid complication of the diagram. The illustrated projector 45 and light receiver 1 are of the 12 optical axis type.

  Both the projector 45 and the light receiver 1 are provided with an optical axis adjustment display unit 50 in which a plurality of light emitting diode (LED) segments are juxtaposed vertically, and the LED segment is, for example, a two-color light emitting diode that emits red or green. The Further, the projector 45 and the light receiver 1 emit green light at the normal time, and on the other hand, when an unscheduled optical axis other than the normal time is blocked or received, or when the system itself fails. An output indicator lamp that is an LED that emits red light, that is, an on / off indicator lamp 52 is provided.

  The display format of the optical axis adjustment display unit 50 composed of a plurality of light emitting diode segments is not particularly limited. For example, when all the optical axes 54 of the projectors 45 constituting the unit are incident on the light receiver 1. All LED segments are colored green. When some of the optical axes 54 are shielded, a number of segments corresponding to the proportion of the shielded optical axes 54, in other words, the proportion of the incident optical axes emits red light from below, and the shielded optical axes The number of segments corresponding to 54 is turned off from above. That is, a bar-type display in which a red bar extends upward as the light incident rate increases or according to the degree of optical axis adjustment is performed.

  Referring to FIG. 10, the projector 45 includes N (12) light projecting circuits 102 that drive the light projecting elements 101 including N (12) light emitting diodes, and the light projecting circuits 102. A light projecting element switching circuit (optical axis switching circuit) 103 that scans in a time-sharing manner and a light projecting element control circuit 104 that controls the projector 45 as a whole are provided. A control signal is output to the indicator lamp 52.

  Further, the light projecting element control circuit 104 receives the clock signal from the clock generating circuit 105, and generates a light projecting timing for sequentially causing the N light projecting elements 101 to emit light. That is, for example, with reference to FIG. 9, the N light projecting elements 101 sequentially emit light at a predetermined timing from the lowermost light projecting element 101 toward the light projecting element 101 located at the uppermost end. To do.

  The projector 45 further controls communication between the first projector communication control circuit 106 that controls transmission and reception of bidirectional signals with the light receiver 1 and an additional projector (not shown in FIG. 9) connected in series. And a timing receiver circuit 108 that receives a timing signal between the second projector communication control circuit 107 and a light receiver (not shown in FIG. 9) connected in parallel.

  On the other hand, the light receiver 1 includes N (12) light receiving circuits 202 that drive N (12) light receiving elements 27, a light receiving element switching circuit 203 that scans these light receiving circuits 202 in a time-sharing manner, and The amplifier circuit 204 and a light receiving element control circuit 205 that controls the entire light receiver 1 are provided, and a control signal is output from the light receiving element control circuit 205 to the optical axis adjustment display unit 50 and the output indicator lamp 52.

  In addition, the light receiving element control circuit 205 receives a signal from the clock generation circuit 206 and sequentially allows the N light receiving elements 27 to receive light, and makes the light receiving elements other than the selected light receiving elements 27 incapable of receiving light. That is, for example, with reference to FIG. 9, the N light receiving elements 27 can receive light sequentially from the lowermost light receiving element 27 toward the uppermost light receiving element 27 at a predetermined timing. Is generated.

  The light receiver 1 further communicates between a first light receiver communication control circuit 207 that controls transmission and reception of bidirectional signals with the projector 45 and an additional light receiver (not shown in FIG. 9) connected in series. And a timing transmitter circuit 209 for transmitting a timing signal to another unit of projectors connected in parallel (not shown in FIG. 9). The light shielding signal generated by the light reception control circuit 205 is output via an output circuit 210, for example, an external device such as a control unit of a press apparatus surrounded by a light curtain formed by the light receiver 1 and the projector 45, or an alarm lamp. (Not shown) and immediately stops the operation of the press device.

  FIG. 11 shows an example in which a plurality of units are connected to each other by using a multi-optical axis photoelectric sensor unit including the projector 45 and the light receiver 1. Referring to the unit located in the lower left of FIG. 11, the number of units is not particularly limited with respect to the lower left unit, but two units are added in series to form a first series unit group. Is formed. In addition, a lower right unit is added in parallel to the lower left unit in FIG. 11, and the number of units is not limited to this lower right unit, but one unit is added in series. Yes.

  In the system illustrated in FIG. 11, “L” is assigned to the first series group unit located on the left side, and “R” is assigned to the second series group unit located on the right side added in parallel. The units belonging to each group are identified by numbering in order from the bottom to the top.

The lowermost unit L1 of the first series group operates as a master unit with respect to the extension units L2 and L3 of the first series group. On the other hand, the lowest unit R1 of the additional second series group operates as a master unit with respect to the additional unit R2 of the second serial group.
First, the wiring of the first series group will be described. The light projector 45 and the light receiver 1 of the parent unit L1 of the first group are connected by an inter-unit communication line CL1 including the flexible cable 20.

The first unit parent unit L1 and the second unit L2, which is the first child unit illustrated on the first group, are a series extension communication in which the light projectors 45 and the light receivers 1 are each composed of the flexible cable 20. They are connected by a line CL2.
The second unit L2 and the third unit L3 which is the second child unit illustrated on the second unit L2 are connected to each other by the serial extension communication line CL2 including the flexible cable 20 between the light projectors 45 and the light receivers 1. It is connected.
Next, a description will be given of the additional second series group on the right side of FIG. 11. The projector 45 and the light receiver 1 of the first unit (the parent unit of the second series group) R1 are the same as the parent unit L1 of the first group. Further, they are connected by an inter-unit communication line CL1 made of a flexible cable 20.

  The second unit R1 and the second unit R2 which is the child unit illustrated on the second group R1 are connected to each other by the serial extension communication line CL2 including the flexible cable 20 between the light projectors 45 and the light receivers 1. Has been.

  Finally, the connection between the first series group and the second series group added in parallel to the first series group will be described. The parent units L1 and R1 of each series group are connected as follows. Has been. That is, the light receiver 1 of the first group parent unit L1 and the light projector 45 of the second group parent unit R1 are connected by the parallel connection communication line CL3 including the flexible cable 20.

  The connection relationship of these multiple units can be best understood from FIG. That is, in the first series group, the parent unit L1 and the second unit L2 are configured such that the second projector communication control circuit 107 of the parent unit L1 and the first projector communication control circuit 106 of the second unit L2 communicate with each other for series expansion. The second optical receiver communication control circuit 208 of the parent unit L1 and the first optical receiver communication control circuit 207 of the second unit L2 are connected by a serial extension communication line CL2.

  Similarly, the second unit L2 and the third unit L3 are configured such that the second projector communication control circuit 107 of the second unit L2 and the first projector communication control circuit 106 of the third unit L3 are connected by the serial extension communication line CL2. In addition, the second light receiver communication control circuit 208 of the second unit L2 and the first light receiver communication control circuit 207 of the third unit L3 are connected by the serial extension communication line CL2.

  The same applies to the second series group. The parent unit R1 and the extension unit R2 are configured such that the second projector communication control circuit 107 of the parent unit R1 and the first projector communication control circuit 106 of the second unit R2 are connected for series extension. The second optical receiver communication control circuit 208 of the first unit R1 and the first optical receiver communication control circuit 207 of the second unit R2 are connected by a serial extension communication line CL2.

  The first series unit group and the additional second series unit group are connected as follows. That is, the timing transmission circuit 209 of the light receiver 1 of the first unit parent unit L1 and the timing transmission circuit 108 of the light projector 45 of the second group parent unit R1 are connected by the parallel extension communication line CL3.

  A plurality of units connected to each other as described above output signals to external devices via output lines 211 connected to the output circuit 210 of the parent unit L1 and the extension parent unit R1 for each group (see FIG. 12).

  In the first group parent unit L1, first, the light projecting element control circuit 104 generates a synchronization timing, and this synchronization timing is transmitted to the light receiving element control circuit 205 through the light receiving unit communication control circuit 207 via the inter-unit communication line CL1. The light projector 45 of the first unit parent unit L1 and the N light projector circuits 102 and the light receiver circuit 202 of the light receiver 1 are operated in order. The light receiving element control circuit 205 displays the light receiving state and the output (light shielding) state by the optical axis adjustment display unit 50 and the output indicator lamp 52 of the light receiver 1, and this display data is input to the light projecting element control circuit 104. The projector 45 also displays the same display as the corresponding light receiver 1.

  Regarding the light projection / reception in the plurality of units, the light emission / light reception timing signals are first supplied from the first group parent unit L1 to the first series group units to the child units L2, L3. That is, the light projection completion signals in all the light projecting elements 101 of the first series unit group are transmitted from the first communication control circuit 106 of the light projector 45 of the parent unit L1 to the first communication control circuit 207 of the light receiver 1 of the parent unit L1. Is input to the light receiving element control circuit 205. On the other hand, a light reception completion signal in all the light receiving elements 27 of the first series unit group is input to the light receiving element control circuit 205. As a result, in the light receiving element control circuit 205 of the parent unit L1, the light projection completion signal from the first communication control circuit 106 of the projector 45 and the light reception completion signals in all the light receiving elements 27 in the light receiver 1 are normal. When the light emitting / receiving operation is confirmed, a timing signal generation command signal is transmitted to the timing transmission circuit 209. The timing transmission circuit 209 receives this command signal and transmits a timing signal to the timing reception circuit of the projector 45 of the expansion parent unit R1 of the second series unit group via the parallel expansion communication line CL3. Thus, when the light projection of the units in the first series group is completed, the light projection of the units belonging to the second series group is started.

  That is, in accordance with an instruction from the first group parent unit L1, first, the light projecting / receiving of the parallel extension parent unit R1 is started, and the N light projecting circuits 102 and the light receiving circuit 202 of the parent unit R1 operate in order. When all the light reception of the parent unit R1 is completed, the parent unit R1 is transferred to the first communication control circuit 106 of the projector 45 and the first communication control circuit 207 of the light receiver 1 of the child unit R2 of the second series unit group. Each transmits a timing signal. When the timing signal is received by the first communication control circuit 106 of the projector 45 of the child unit R2 and the first communication control circuit 207 of the light receiver 1, the N light emitting circuits 102 and the light receiving circuit 202 of the child unit R2 are sequentially turned on. Operate. When all the light transmission / reception of the second series unit group is completed in this way, the light transmission / reception of the first series unit group is started again.

  Here, again, as a method for starting the light transmission / reception of the first series unit group, the light receiving element control circuit 205 of the parallel extension parent unit R1 recognizes the completion of all the light transmission / reception in the second series unit group. Based on this, the timing signal may be returned to the parent unit L1 of the first series unit group via the first light receiver communication control circuit 207 and the first communication control circuit 106 of the parent unit R1, or the first After a timer is set in the series unit group and a timing signal is transmitted from the first series unit group to the second series unit group, after the time necessary for all the light projecting and receiving operations of the second series unit group has elapsed, the first The light transmission / reception of the series unit group may be started. In this way, in a system in which a plurality of series unit groups are connected in parallel, after the light emitting / receiving operation of the upstream series unit group is completed, the operation of the downstream series unit group is started. As a result, it is possible to prevent the projection of one unit from affecting other units.

  An optical axis adjustment display unit 50 and an output indicator lamp 52 included in all the units are provided, and the display is controlled by the control means of each unit, that is, the light receiving element control circuit 205. The display data related to these displays is supplied to the parent units L1 and R1 for each group via the serial extension communication line CL2. That is, the parent units L1 and R1 of each group not only communicate to unify the display between the projector 45 and the light receiver 1 included in the parent units L1 and R1, but also with the child units added in series. So that the display of the optical axis adjustment display unit 50 and the output indicator lamp 52 can be substantially controlled via the serial extension communication line CL2 between each unit within a predetermined communication cycle. Allocate time and exchange data with other units in order.

  For example, the display data in the light receiver 1 of the upper left unit in FIG. 11, that is, the third unit L3 of the first series group, in sequence is the light receiver 1 of the second unit L2, the light receiver 1 of the parent unit L1, and the parent unit L1. The light is transmitted to the projector 45, the projector 45 of the second unit L2, and the projector 45 of the third unit L3. Thereby, the display of the projector 45 and the light receiver 1 of the third unit L3 is unified. That is, with respect to the optical axis adjustment display unit 50 of the third unit L3, when light shielding occurs in the third unit L3, this light shielding state is provided in both the projector 45 and the light receiver 1 of the third unit L3. Displayed by the optical axis adjustment display unit 50.

  In addition, regarding the output indicator lamp 52 of the third unit L3 of the first group, the data related to the output display is uniformly displayed on all the units of the first series group. That is, when light shielding occurs in the third unit L3, not only the third unit L3 but also the output indicator lamps 52 provided in all the projectors 45 and the light receivers 1 of the parent unit L1 and the second unit L2 are red. Flashes to indicate the off output status.

  Regarding the control of the output indicator lamp 52 in a unified manner for each group divided into a first series group and a second series group, for example, when the unit stops operating in an error state and / or It may be turned on during ranking teaching or when this teaching is completed, and another display means for displaying these is provided in at least one of all the light receivers 1 and the projectors 45. Also good.

  In the optical axis adjustment display unit 50 that displays each unit independently, when a unit fails, this may be displayed using the optical axis adjustment display unit 50 of the failed unit. Good. Further, when only one optical axis is shielded, the one optical axis shielding may be displayed on the optical axis adjustment display unit 50 of the shielded unit. Further, for example, when dust is attached to the lens attached to the light projecting element 101 or the light receiving element 27 and the light quantity is insufficient, only the optical axis adjustment display unit 50 of the unit having the insufficient light quantity is used. You may make it display.

It is the perspective view which looked at the light receiver of the multi-optical axis photoelectric sensor of an Example from diagonally forward. It is the figure which looked at the light receiver of FIG. 1 from diagonally upward. It is a figure for demonstrating arrangement | positioning of the components arrange | positioned inside the light receiver of FIG. It is a figure mainly explaining the structure of an element holder. It is the cross-sectional view cut | disconnected along the VV line | wire of FIG. It is a figure which shows the state which connected the board | substrate for extension to the 1st board | substrate containing the circuit directly related to the light receiving element. It is a figure for demonstrating the means for positioning a light receiving element to an element holder. FIG. 8 is a perspective view of the light receiver viewed from above in relation to FIG. 7. It is a figure for demonstrating the connection method in the case of making the light curtain which consists of a single unit of the multi-optical axis photoelectric sensor to which this invention is applied. FIG. 10 is an internal block diagram of a projector and a light receiver shown in FIG. 9. It is a figure for demonstrating the connection method in the case of making the several wide independent light curtain using the multi-optical axis photoelectric sensor to which this invention is applied. FIG. 12 is a block diagram corresponding to FIG. 11.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light receiver 2 Case main body 3 Light-receiving surface 5 Terminal member 13 External connector 14 Notch 15 Insertion port 15a Ceiling wall of insertion port 15b End wall of insertion port 20 Flexible cable extending from external connector 36 Addition Connector pin 45 Floodlight

Claims (9)

A multi-optical axis photoelectric sensor having an elongated bar-shaped outer shape, in which optical elements are arranged in a row at regular intervals from one end portion to the other end portion,
The outer shape of the multi-optical axis photoelectric sensor includes a case body having an elongated U-shaped cross-section with both ends open, an elongated shape that closes one end and opens the other end and accommodates a plurality of optical elements, and opens the case. Formed with a terminal member connected to the case body in a state in which the opened end is butted against the open end of the case body,
The terminal member is cut out from the same cross-sectional shape as the case main body, a horizontal plane parallel to the optical axis without interfering with the optical axis accommodated in the terminal member, a light projecting surface or a light receiving surface A stepped notch shape that forms a vertical wall that is offset from the rear side and extends in the longitudinal direction of the terminal member,
The vertical wall is formed with an insertion port through which an external connector having a flexible cable can be accessed in the optical axis direction from the light projecting surface or light receiving surface side of the terminal member toward the back surface side. A connector pin is placed facing the slot,
When the external connector is accessed to the insertion port along the horizontal plane and connected to the connector pin through the insertion port, the terminal member including the external connector has substantially the same cross-sectional shape as the case body. A multi-optical axis photoelectric sensor. When the external connector is connected to the connector pin through the insertion port of the terminal member, the external connector has a substantially rectangular parallelepiped shape extending to a longitudinal end portion of the terminal member, and the flexible cable is the external cable Extending from the longitudinal outer end of the connector toward the back side of the terminal member,
The horizontal surface that receives the external connector of the terminal member is extended to the back surface of the terminal member, and the flexible cable of the external connector can extend to the back surface side of the terminal member by the extended horizontal surface. 2. The multi-optical axis photoelectric sensor according to 1.   The multi-optical axis photoelectric sensor according to claim 2, wherein the terminal member is provided with an optical element having two optical axes.   The longitudinal length of the horizontal plane that receives the external connector of the terminal member is larger than the pitch between adjacent optical elements, and the external connector has a longitudinal length that occupies substantially the entire longitudinal length of the horizontal plane. The multi-optical axis photoelectric sensor according to claim 3, which is provided.   5. The multi-light according to claim 1, wherein the multi-optical axis photoelectric sensor includes a printed circuit board including a power circuit, and the printed circuit board and the connector pin are connected via a harness. Axis photoelectric sensor. Elongated bar-shaped outer shape having a light-projecting surface facing a light-receiving surface of a multi-optical axis elongated bar-shaped light receiver, and light projecting elements at regular intervals from one end to the other end Projectors arranged in a row,
The outer shape of the projector includes a case body having an elongated U-shaped cross-section with both ends open, an elongated shape that closes one end and opens the other end and accommodates a plurality of light projecting elements, and has an open end. It is formed with a terminal member connected to the case body in a state of being butted against the open end of the case body,
The terminal member is cut out from the same cross-sectional shape as the case main body, a horizontal plane parallel to the optical axis without interfering with the light projecting element accommodated in the terminal member, and the rear surface from the light projecting surface. A stepped notch shape that forms a vertical wall that is offset to the side and extends in the longitudinal direction of the terminal member;
The vertical wall is formed with an insertion port through which an external connector having a flexible cable can be accessed in the optical axis direction from the light projecting surface side to the back surface side of the terminal member. The connector pins are arranged,
When the external connector is accessed to the insertion port along the horizontal plane and connected to the connector pin through the insertion port, the terminal member including the external connector has substantially the same cross-sectional shape as the case body. A projector characterized by   The two light projecting elements are accommodated in the terminal member, and a pitch between a light projecting element located at the outermost end and a longitudinal end of the terminal member is equal to or less than half of a pitch between the light projecting elements. 6. The projector according to 6. Equipped with an elongated bar-shaped outer shape with a light-receiving surface facing the light-projecting surface of a multi-optical axis elongated bar-shaped projector, and a row of light-receiving elements at regular intervals from one end to the other A receiver arranged in
The outer shape of the light receiver includes an elongated case body having an approximately U-shaped cross-section with both ends open, an elongated shape that closes one end and opens the other end and accommodates a plurality of light receiving elements. It is formed with a terminal member connected to the case body in a state of being butted against the open end of the case body,
The terminal member is cut out from the same cross-sectional shape as the case main body, without interfering with the light receiving element accommodated in the terminal member, and parallel to the optical axis, and from the light receiving surface to the rear side. A stepped notch shape that forms a vertical wall that is offset and extends in the longitudinal direction of the terminal member;
The vertical wall is formed with an insertion port that allows an external connector having a flexible cable to be accessed in the optical axis direction from the light receiving surface side to the back surface side of the terminal member, and faces the insertion port. The connector pins are arranged in
When the external connector is accessed to the insertion port along the horizontal plane and connected to the connector pin through the insertion port, the terminal member including the external connector has substantially the same cross-sectional shape as the case body. An optical receiver characterized by   The two light receiving elements are accommodated in the terminal member, and the pitch between the light receiving element located at the outermost end and the longitudinal end of the terminal member is equal to or less than half of the pitch between the light receiving elements. Floodlight.

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