Sensor for an automatic door or gate, and an automatic door or gate having such a sensor

Abstract

The present invention relates to a sensor (10, 40) for an automatic door or gate, in which a rotating mirror (12, 42) has at least three different light-emitting mirror surfaces, the rotation axis is perpendicular to a reference plane, and has at least one light pulse generating unit (18a, 18b, 68a, 68b) generating infrared pulses with a specific beam width, the light-emitting optical paths (20a, 20b) are embodied such that the light-emitting pulses can be reflected by the mirror surfaces (14a-14e, 46a-46c), the light-emitting optical paths (20a, 20b) define the incident pulse direction of the light-emitting pulses, the reflected pulses can be echoed back by objects in the scanning field, the echoed pulses are reflected by the light-receiving mirror surfaces (16a-16e), and it is possible to distinguish which light-emitting optical path (20a, 20b) the light-emitting pulses of the echoed pulses were originally sent to.

Description

[Technical field]

[0001] The invention relates to a sensor for an automatic door or gate for detecting an object near the door opening according to the preamble of claim 1. [Background technology]

[0002] A laser scanner is known from WO 2015 / 014556 A1, in which a rotating mirror is used to generate a scanning field of less than 180°. A similar solution is disclosed in DE 10 2015 013 710 A1.

[0003] US 7,349,074 B2 discloses a multi-faceted laser scanner having an inclined surface with a scan angle of about 90°. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication WO2015 / 014556 [Patent Document 2] DE 10 2015 013 710 A1 [Patent Document 3] U.S. Patent No. 7,349,074 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention relates to a sensor for use in an automatic door or gate. The sensor operates on the basis of a pulse-echo evaluation of a light pulse, preferably determining the distance of an object relative to the sensor by evaluating the time of flight of the emitted and echoed light pulse. Depending on the detected position of an object or person near the door opening, the sensor acts on the door controller providing a signal to the door controller so that the door controller can determine whether a particular operation of the door is required. Such an operation of the door controller to monitor the security of the gate is usually to stop or reverse a closing or opening operation.

[0006] Typically, automatic doors or gates, especially sliding doors, are monitored to protect the main closing end, since this is considered the most dangerous when the door is closing.

[0007] However, for example, if a sliding door opens against a wall, a person may become trapped between the door body and the wall, and a critical situation may occur even during the door opening operation.

[0008] Such a situation cannot be adequately monitored by prior art door sensors which monitor the primary closed end.

[0009] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to improve the scanning area parallel to the door plane by maintaining high accuracy of sensors monitoring automatic doors. [Means for solving the problem]

[0010] The sensor of the present invention comprises at least one rotating mirror having at least three different reflective-emitting mirror surfaces arranged around its axis of rotation, the rotating mirror being driven by a motor, the axis of rotation being perpendicular to a reference plane.

[0011] The sensor further comprises a light pulse generating unit including a light emitter. The light pulse generating unit generates light pulses that are reflected by the mirror surface. The light pulses are sent towards the rotating mirror via two different light emission paths. Each of the different light emission paths is composed of at least one optical component. In particular, the light emitter, the lens and the mirror are understood as optical components.

[0012] The two emitted light paths define an incident pulse direction, which is the direction of the pulse incident on the mirror.

[0013] The projections of both incident pulse directions onto the reference plane, further referred to as incident beam projections, intersect at an intersection point with an intersection angle less than 160°, preferably between 30° and 160°. The intersection plane is defined as being perpendicular to the bisector of the projections of the incident pulses and passing through the intersection point where the bisector lies on the reference plane.

[0014] To allow for a scan field of 180° or more, the intersection angle is less than 160°. The incident beam projection has a width perpendicular to its incident pulse direction, and the intersection point is preferably at the centerline of the incident beam projection.

[0015] The axis of rotation of the rotating mirror intersects the bisector and the axis of rotation of the mirror is positioned such that the resulting scan field has a scan angle greater than 150°.

[0016] Each emission light path has an optical component following the incident beam closest to the rotating mirror, hereafter referred to as the "closest optical component."

[0017] To obtain a large scan angle, the rotating mirror is positioned so that its axis of rotation is between the intersection plane and the closest optic.

[0018] The distance between the closest optic and the intersection plane is determined from the outermost edge of the beam at the closest optic.

[0019] Pulses are sent from the sensor by reflecting incident pulses off the facets of the emitting mirror. These reflected pulses establish a scan field, which is echoed back by objects within the scan field. The reflected pulses define a scan field of a scan angle that spans between the outermost reflected beam projections, which are projections of the reflected pulses on a reference surface.

[0020] Preferably, the incident pulses can have a direction that is essentially parallel to the reference plane. "Essentially parallel" in this context means parallel with a maximum deviation of 45°, more preferably parallel with a maximum deviation of 30°, and even more preferably parallel with a maximum deviation of 15°.

[0021] The mirrors and their rotation axes are set accordingly so that the reflected beam projections from each of both incident optical paths have an innermost reflected pulse that is at least parallel to the bisector or even crosses the bisector away from the intersection plane, i.e., on the side of the scanning field, such that the scanning field is a nearly continuous field from one outermost reflected beam to the other.

[0022] The sensor further comprises a rotating mirror having an equal amount of light receiving mirror surface area along which light pulses echoed back from the object are deflected.

[0023] The sensor further comprises a receiving means for receiving light pulses echoed back by objects in the scanning field, whereby the echoed pulses are deflected by the receiving mirror surface and are subsequently received in such a way that it is possible to distinguish on which emission light path the emission pulse of the echoed pulse was originally sent. The sensor comprises a receiving lens arranged between the rotating mirror and the receiving means. The receiving lens has an optically effective width, which is preferably the diameter of the lens perpendicular to its optical axis.

[0024] Preferably, the two receiving optical paths are separate optical paths, and more preferably the receiving means comprises two separate receivers, each dedicated to a receiving optical path.

[0025] The sensor preferably comprises an evaluation unit which determines the distance of the object by evaluating the time of flight between emission and reception of the light pulse.

[0026] The evaluation unit defines a monitoring area and determines whether the measured distance is within the monitoring area. The evaluation unit can output a control signal to communicate whether the object is within the monitoring area.

[0027] The setup according to the invention provides a sensor capable of scanning an area with a scanning angle of at least 160°, providing at least three curtains, which may be in the same plane or in planes inclined with respect to each other.

[0028] The present invention allows the sensor to be embodied as a fairly compact device providing high scanning speeds and / or high resolution over a large scanning range.

[0029] According to a further embodiment of the invention, each of the light-emitting mirror surfaces can have a different inclination with respect to the axis of rotation. The same is true for the light-receiving mirror surfaces. The different inclinations allow the sensor to scan planes with different inclinations with respect to each other. Thus, the sensor can scan not only one plane, but a large width of three-dimensional space. For example, a so-called "0° plane" is parallel to the axis of rotation, a further mirror surface is inclined +2° with respect to the axis of rotation, and another further mirror surface is inclined, for example, -2° with respect to the axis of rotation. According to this example, the angles +2° and -2° are inclined in opposite inclination directions with respect to the "0° plane". In each case, the absolute angle between the reflecting surface and the axis of rotation is 2°.

[0030] Thus, tilted surfaces, except for the 0° surface, have a tilt axis around which the surface tilts. Preferably, the tilt axis is at the same height as the surface, and more preferably at the center of the height of the surface. In this case, the circumferential radius of the mirror can be determined by the height of the tilt axis.

[0031] According to a further advantageous embodiment of the invention, the sensor meets the conditions described below.

[0032] A pulse emitted at a first angular position of the mirror defines a start angle of the mirror rotation for the outermost pulse, and the first mirror surface defines a first mirror line at that angular position. The first mirror surface intersects with a pulse emitted at a second angular position of the mirror to define an end angle of the innermost pulse, and the mirror defines a second mirror surface at this angular position.

[0033] A pulse corridor is defined around the emission beam projection with the width of the receiving lens.

[0034] The pulse corridor on the reference plane is bounded by an inner boundary and an outer boundary, the inner boundary being on the opposite side of the scan field relative to the centerline of the emission beam projection.

[0035] The second mirror line intersects with the first mirror line in the pulse corridor.

[0036] Further, a first rotation center line is defined that intersects the intersection point of the outer boundary line and the first mirror line, and an angle A between the first mirror line and the first rotation center line is defined. (ML1-RCL1) A (ML1-RCL1) =(N-2)*90 / N, where the center of rotation intersects the bisector and N is the number of faces.

[0037] Further, a second rotation center line is defined that intersects the intersection point of the inner boundary line and the second mirror line, and an angle A between the second mirror line and the first rotation center line is defined. (ML2-RCL2) A (ML2-RCL2) =(N - 2) * 90 / N, and the center of rotation intersects the bisector.

[0038] The centerline of rotation is selected such that it defines a triangle with the mirror line, the mirror line including an acute angle.

[0039] The mirror lines preferably intersect within the pulse corridor.

[0040] The inner radius of the mirror is at least the distance from the centre of rotation to the mirror line. Since the centre of rotation is preferably located on the bisector of the two mirror lines, the distance to both mirror lines is preferably the same.

[0041] The axis of rotation is located substantially at the intersection of the rotation centerlines.

[0042] A sensor configuration satisfying these conditions would provide a large scanning field in the smallest possible device size.

[0043] According to a further advantageous embodiment of the invention, the number N of mirror faces is 3, 4 or 5. This number N of emitting faces allows a scanning range of about 180° or more while maintaining a reasonable device size.

[0044] According to a further embodiment of the invention, the door sensor described above comprises a housing, the housing having a curved window transparent to both the light emitting pulses and the light receiving pulses. The curved window extends from a start angular position to an end angular position, and the axis of rotation of the rotating mirror is located between a line connecting the start and end positions (of the curved window) and the curved window at an angular position centered on the start and end angular positions of the curved window. The window does not necessarily have to be continuously transparent, but may include non-transparent portions in between.

[0045] This setup allows the scanning range to be greater than about 180° while keeping the device size of the sensor fairly small.

[0046] According to a further embodiment of the invention, the sensor is embodied with an optical feedback component capable of directing a beam from an emission optical path to a reception optical path at a particular angular rotation position of the mirror, i.e. the feedback position.

[0047] This allows the emitted beam to be transmitted from the light emitting portion of the sensor to the light receiving portion, which are optically shielded from each other to avoid the influence of stray light from the light emitting portion to the light receiving portion.

[0048] The rotating mirror may advantageously be configured with at least one mirror surface having a width such that the emitted light beam is reflected by the mirror surface at the feedback location to strike the optical feedback component.

[0049] The sensor may comprise an optical feedback determination unit for determining a characteristic of the emitted light pulses that are not echoed back by objects within the scan field.

[0050] The optical feedback component can be positioned between the rotating mirror and the curved window, where the optical feedback component is positioned at an angle to the emitted light beam that is greater than the angle of the innermost beam.

[0051] Alternatively, especially by having three mirror surfaces, the optical feedback component can be located at an intermediate position in the incident light path, in which case the optical feedback component does not introduce a shadowing effect into the scanning field.

[0052] According to a further refinement of the invention, the first light emitting beam paths and the corresponding light receiving beam paths are arranged one above the other when viewed orthogonal to the reference plane.

[0053] If the light emitting and light receiving optical paths are arranged one above the other, the mirror also has light emitting and light receiving mirror surfaces which are parallel to each other. Preferably, there is a light shield between the light emitting and light receiving mirror surfaces.

[0054] Advantageously, such a rotating mirror is embodied as an integrated element driven by a single motor, which has the advantage that no special synchronization is required between the light emitting and receiving parts.

[0055] According to a further advantageous aspect of the invention, the width of at least one facet is greater than the width of the other facet, and the angular optical feedback position of the rotating mirror is set to an angular position where the luminescence pulse strikes the enlarged portion of the facet and is then reflected towards the optical feedback component, which may comprise a mirror and / or an optical fiber and / or a prism.

[0056] A further aspect of the present invention relates to an automatic door or gate.

[0057] An automatic door or gate comprises at least one leaf that at least partially covers a door opening. The at least one leaf is driven by a motor that is controlled by a door controller, and a control signal is provided to the door controller to act on the motor, for example to stop or reverse a current motion.

[0058] Typically, a door controller has input ports (plural) which are independent inputs for each function, e.g. "resume," "stop," "reverse," etc., and controls are triggered by closing or opening input switches connected to the ports.

[0059] Preferably, the input switch is part of a sensor that triggers a dedicated switch upon a particular detected condition.

[0060] Alternatively, this signal can be transmitted to the door controller via a bus system, preferably a CAN-Bus.

[0061] The automatic door or gate according to the invention comprises a sensor having two light pulse echo units and a rotating mirror, and an evaluation unit for determining a position in response to detection of an object in a combined scanning field provided by the two light pulse echo units, each light pulse echo unit comprising a light emitting unit and a light receiving unit. The two light pulse echo units provide a light path via the rotating mirror, and the combined scanning field provided by both light pulse echo units has a scanning angle of 160° or more, preferably providing an area monitored by both light pulse echo units.

[0062] The common scanning field is therefore a combination of the two scanning regions provided by the two optical pulse echo units.

[0063] By using a common rotating mirror, there is a mechanically defined relationship between the two scanning fields, which allows very accurate measurement of the object position within the scanning field, which is especially important for small objects such as fingers.

[0064] By evaluating the overlapping area of ​​the two scan areas, the masking effect can be reduced and the coverage is also improved since there are no angular derivations in different laser scanner setups.

[0065] The sensor may preferably be embodied as described in detail above.

[0066] Sensors protecting automatic doors or gates are mounted either on the door frame, on the door or gate leaf, or adjacent to the door or gate, respectively.

[0067] Such sensors transmit the detected status to a door controller, which has information about the current operating mode of the motor and may also have information about the current position of the door leaf, and can control the door or gate according to the detected status information.

[0068] According to a further embodiment of the automatic door, the door can be of the swing door type, either single or double leaf. The door body of the swing door can have a sensor according to the invention, which is mounted on the door leaf and monitors the main and secondary closing edges simultaneously.

[0069] In this case, two danger zones can be monitored by simply connecting one sensor device.

[0070] According to a further embodiment of the automatic gate, the gate can be of the swing gate type. It can be of the single or double leaf type. In contrast to a swing door, the upper edge of the leaf can be at a lower height. By providing a sensor with a detection range of more than 180°, it is possible to position the sensor device below the upper edge of the leaf and still monitor the entire hinge up to the top. This is, for example, in the middle of a transversely extending leaf.

[0071] According to a further embodiment of the invention, the automatic sliding door can be of single or double leaf type. Preferably, the sensor is mounted on the door frame, monitoring the opening end on one side of the sensor and the secondary closing end on the other side.

[0072] The double-leaf type automatic sliding door has two sliding door leaves that are automatically driven, and the scanner is mounted on the sliding door leaves to provide at least one curtain that extends generally parallel to the door leaves or perpendicularly at a very acute angle to the door leaves. Each door leaf has a main closing edge and a secondary closing edge, and the scanning field covers the position of the main closing edge when the door is fully closed and the position of the secondary closing edge when the door is fully open.

[0073] The sensor preferably provides at least three successive zones in the width direction, and the scanner has a first minor closing edge zone, a major zone, and a second minor closing edge zone. A detection event in the first minor closing edge zone provides a first signal to the door controller for triggering a first action, a detection event in the major zone provides a signal for triggering a second action different from the first action, and a detection event in the third zone provides a signal for triggering a third action different from the second action. The third action can be different from the first action or the same as the first action.

[0074] Preferably, the first motion is a stop motion and the second motion is a reverse motion.

[0075] Preferably, the door sensor is embodied as described above.

[0076] Further advantages, features and potential applications of the present invention can be gleaned from the following description taken in conjunction with the embodiments illustrated in the drawings.

[0077] Throughout this specification, claims and drawings, these terms and associated reference numbers are used as noted from the enclosed list of reference numbers. [Brief description of the drawings]

[0078] [Figure 1a] FIG. 2 is a perspective view of the essential optical components of one embodiment of the sensor. [Figure 1b] FIG. 2 is a plan view of the components of FIG. 1 including the housing. [Figure 2a] FIG. 2 is another plan view of FIG. [Figure 2b] FIG. 1b is an incident beam projection of the emitted light beam onto the reference plane of the sensor of FIG. [Figure 2c] FIG. 1 is an incident light beam projection diagram showing the first mirror line for generating the outermost beam. [Figure 2d]FIG. 11 is an incident light beam projection showing the second mirror line for the innermost beam. [Figure 2e] FIG. 13 is a diagram showing a combination of a first mirror line and a second mirror line that defines the position of a rotation axis. [Figure 3a] FIG. 13 is a perspective view of a further embodiment of the present invention. [Figure 3b] FIG. 3b shows a top view of the embodiment according to FIG. 3a. [Figure 4a] FIG. 3b shows a top view of the embodiment according to FIG. 3a. [Figure 4b] FIG. 3b is an incident beam projection of one emitted light beam on the reference plane of the sensor of FIG. 3a. [Figure 4c] FIG. 1 is an incident light beam projection diagram showing the first mirror line for generating the outermost beam. [Figure 4d] FIG. 11 is an incident light beam projection showing the second mirror line for the innermost beam. [Figure 4e] It is the combination of the first mirror line and the second mirror line that defines the position of the rotation axis. [Diagram 5] 1 shows an automatic door including a sensor according to the present invention; [Figure 6] FIG. 1 is a schematic diagram of a sensor according to the present invention for use in an automatic door or gate; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0079] 1a is a perspective view of the essential optical components of a sensor 10. The sensor 10 comprises a rotating mirror 12 which rotates about a rotation axis A. The rotating mirror has five light-emitting mirror surfaces 14a, 14b, 14c, 14d, 14e which have different inclinations with respect to the rotation axis A. Similarly, the rotating mirror 12 has five light-receiving mirror surfaces 16a, 16b, 16c, 16d, 16e which are in the same position and have the same inclination as the light-emitting mirror surfaces.

[0080] Furthermore, the sensor 10 has two separate optical components embodied as pulse generating units 18a, 18b that emit laser pulses along an emission optical path to be reflected by the emission mirror surfaces 14a-14e.

[0081] The emission light paths 20a, 20b are embodied to provide the incident beam direction that the pulses have before being reflected by the mirror 12. The emission light beam 22a can be sent along the first light path 20a, and another beam can be sent along the second light path 20b. In FIG. 1, the emission light beam 22a sent along the first light path 20a shows the direction it would have if it had not been reflected by a mirror. The beam 22b sent along the second light path is shown reflected by the emission mirror surface 14a. The reflected beam forms a scanning field due to the rotation of the rotating mirror 12, and the pulses are echoed back by objects present in the scanning field. The echoed back pulses are received as the received light beam 24b. The received light beam is received by the dedicated receivers 27a, 27b that receive the light paths. The axis of rotation A is perpendicular to the reference plane R. Each receiving beam 24a, 24b passes through a receiving lens 29a, 29b, which is shown diagrammatically, before reaching the receiver 27a, 27b. Each receiving beam 24a, 24b is focused to impinge on a corresponding receiver 27a, 27b, each receiving lens 29a, 29b having an optically effective diameter for the curved part of the lens, which is taken as the width W of the lens to define the size of the receivable beam. FIG. 1b is a plan view of FIG. 1a, further showing the housing. From this figure it can be seen that the axis of rotation A is between the intersection plane P and the nearest optical components 18a, 18b, which in this case are embodied as light emitters. This setup allows a large field angle FA of the scanning field extending between the two outermost beams OBa, OBb. The field angle FA in this case is about 180°. FIG. 1b further shows diagrammatically that the sensor 10 comprises a first non-transparent housing 32 and a transparent window 28, which is embodied in a curved manner. The window 28 extends from a first angular position to a second angular position, where the non-transparent wall is between the optical component and the axis of rotation of the mirror.

[0082] It can be further derived from Fig. 1a that the 0° surface 14a, parallel to the rotation axis, is wider than the other surfaces, so that a reflection at a particular angular rotation position hits the optical feedback component 26a or the optical feedback component 26b at the other angular rotation position, respectively. The optical feedback components 26a, 26b each have two mirrors and provide a periscope that deflects the beam from the light emitting part of the sensor to the light receiving part.

[0083] Figure 2a is another plan view of the sensor 10 of Figure 1a. From Figure 1b it can be seen that the incident beams are in this figure the same as the incident beam projections in Figures 2b-2e. These incident beam projections, i.e. the centre lines CL-22a and CL-22b, will intersect at a point of intersection of an intersection plane perpendicular to the reference plane with a bisector BS of the intersection angle IA in the reference plane. The intersection angle IA in this example is 130°.

[0084] As can be seen in FIG. 2a, the mirror has a pentagonal shape and rotates about an axis of rotation A.

[0085] According to the invention, there is a distance D to the light emitting side between the intersection plane P and the rotation axis A. This setup allows to project a nearly continuous scanning field over a large angular range providing multiple scanning curtains.

[0086] FIG. 2b shows the incident beam projections 22a, 22b, and the following description of determining the center of rotation will only describe the incident beam projection 22a with the bisector BS as its axis of symmetry.

[0087] Figure 2b shows, in comparison with 29a, 29b in Figure 1a, a beam projection 22a with a centerline CL22a around which there exists a pulse corridor defined by the size of the receiving lens, i.e. the width W perpendicular to the beam direction in the reference plane, which exemplarily has about 1.5 times the width of the beam projection 22a. The corridor is defined by an inner boundary IBL and an outer boundary OBL. A part of the scanning field generated by the first incident beam 22a is established between the outermost beam OB in the first angular rotation position of the rotating mirror 12 and the innermost beam IB in the second angular rotation position.

[0088] FIG. 2c shows a first mirror line ML1 at a first angular rotation position of the rotating mirror to generate the outermost beam OB. At the intersection of the first mirror line and the outer boundary line, a first rotation center line is defined that crosses the intersection of the outer boundary line and the first mirror line. The angle between the first mirror line and the first rotation center line is A (ML1-RCL1) =(N-2)*90 / N, where the rotation center line crosses the bisector. N is the number of mirror faces, which is 5 in this example. The angle between the rotation center line RCL1 and the first mirror line ML1 is 54°.

[0089] FIG. 2d shows the second mirror line ML2 at a second angular rotation position of the rotating mirror to generate the innermost beam IB. A second rotation center line RCL2 is defined that crosses the intersection of the inner boundary line IBL and the second mirror line ML2, and the angle between the second mirror line ML2 and the first rotation center line RCL2 is A. (ML2-RCL2) =(N-2)*90 / N. The angle between the rotation center line RCL2 and the first mirror line ML2 is 54°.

[0090] Figure 2e shows a combination of Figures 2c and 2d, in which the first rotation centerline RCL1 and the second rotation centerline RCL2 intersect at a bisector to define the position of the rotation axis. Furthermore, the rotation centerlines RCL1 and RCL2 intersect the bisector of the mirror lines ML1 and ML2.

[0091] The inside radius of the face of the rotating mirror is at least the distance from the center of rotation to the mirror line.

[0092] The rotational centers RCL1, RCL2 are selected such that each rotational center RCL1, RCL2 defines a triangle with the mirror lines ML1, ML2, which include an acute angle. The mirror lines ML1, ML2 cross the inside of the corridor between the outer boundary OBL and the inner boundary IBL.

[0093] Figure 3a shows a further embodiment of a sensor 40 according to the invention, with a similar setup as the sensor described in figure 1a. The sensor 40 comprises a rotating mirror 42 with three faces 46a, 46b, 46c with the same inclination relative to the rotation axis A of the rotating mirror 42. In this case, the sensor 40 can monitor a scanning range with a field angle FA of about 270°.

[0094] There are at least two optical components in each optical path, namely the emission optical path has pulse generating units 68a, 68b and mirrors 72a, 72b. Each emission optical path has an optical component in the form of mirrors 72a, 72b that deflects the emitted beam to generate the input optical path, in this case such that the crossing angle IA between the two input optical paths is 45°. In this arrangement, mirrors 72a, 72b are the closest optical components along the optical path to the rotating mirror.

[0095] The echoed pulses are directed along a receiver optical path that includes mirrors 66a, 66b and optical receivers 62a, 62b. Mirrors 72a and 66a can be fabricated as a single reflective component, as can mirrors 72b and 66b. There is preferably an optical shield attached between mirrors 66a, 72a or to the single reflective component that separates the two mirrors.

[0096] The projections of the incident beams intersect at a plane of intersection P. The axis of rotation is parallel to this plane of intersection and is located away from it.

[0097] As can be seen in FIG. 3b, the centre of rotation is between the intersection plane and mirrors 72a, 72b.

[0098] The sensor 40 includes optical feedback components 74a, 74b that direct the emitted beams to the optical receivers 62a, 62b.

[0099] As shown in Figure 3b, the optical components are disposed within a non-transparent housing 56, and the rotating mirror 42 is disposed within a transparent housing 58 that is at least partially transparent to allow passage of the beam. The transparent housing 58 is a curved window that extends from a first angular position 60a to a second angular position 60b. The non-transparent portion of the housing is indicated by a dashed rectangle.

[0100] The non-transparent housing 56 and the transparent housing 58 have an opening extending from a first angular position 60a to 60b, which opening is smaller than the maximum extension in the same direction of the transparent housing 58. Both housings 56, 58 may be part of a single housing of the device.

[0101] FIG. 4a shows an incident beam at a crossing angle of 45° with a bisection angle BA1 of 22.5°.

[0102] The outermost beams OBa, OBb are at +45° and −45° to the bisector, so the scan field has a subtense of 270°.

[0103] 4b to 4e show exemplary conditions for setting the center of rotation for the incident beam projection.

[0104] Figure 4b shows the beam projection 52a with its centre line CL52a around which a pulse corridor is defined that is 1.5 times the width of the beam projection 52a. The corridor is defined by an inner boundary line IBL and an outer boundary line OBL. The scanning field of the first incident beam 52a is established between the outermost beam OB in the first angular rotation position of the rotating mirror 42 and the innermost beam IB in the second angular rotation position. The angle BA1 between the projection of the incident beam and the bisector of the incident beam is by definition half the intersection angle IA.

[0105] The intersection point is defined as the intersection of the bisector BS and the center line CL52a of the input beam projection. The setup is symmetric about the bisector.

[0106] FIG. 4c shows the first mirror line ML1 at a first angular rotation position of the rotating mirror that generates the outermost beam. At the intersection of the first mirror line ML1 and the outer boundary line OBL, a first rotation center line RCL1 is defined that crosses the intersection of the outer boundary line OBL and the first mirror line ML1. The angle between the first mirror line ML1 and the first rotation center line RCL1 is A (ML1-RCL1) =(N-2)*90 / N, and the rotation center line RCL1 crosses the bisector. N is the number of mirror faces, which is 3 in this example. The angle between the rotation center line RCL1 and the first mirror line ML1 is 30°.

[0107] FIG. 4d shows the second mirror line ML2 at a second angular rotation position of the rotating mirror where the innermost beam IB is generated. A second rotation center line RCL2 is defined that crosses the intersection of the inner boundary line IBL and the second mirror line ML2, and the angle between the second mirror line ML2 and the first rotation center line RCL2 is A. (ML2-RCL2) = (N - 2) * 90 / N. The angle between the rotation center line RCL2 and the first mirror line ML2 is 30°. The triangle of the first mirror line ML1, the second mirror line ML2, and the rotation center lines RCL1 and RCL2 has an acute angle between the first mirror line ML1 and the second mirror line ML2.

[0108] Figure 4e shows the center of rotation A where the first mirror line intersects with the bisector of the first and second rotation center lines RCL1 and RCL2, which lies on the bisector BS of the incident beam.

[0109] The minimum value of the inner radius of mirror 42 is equal to or greater than the distance from the rotation center A of mirror 42 to mirror lines ML1 and ML2.

[0110] Such a setup makes it possible to provide a compact device with a fairly large scanning field.

[0111] Figure 5 shows an automatic sliding door assembly 80 according to the invention. The automatic sliding door assembly 80 consists of a sensor 82 and two sliding door panels 84, 86. The first door panel has a main closing edge 88a and a secondary closing edge 88b, and the second door panel 86 has a main closing edge 90a and a secondary closing edge 90b. The sensor 82 has a field angle of 180° and is embodied, for example, as shown in figure 1a. The sensor 82 provides different information depending on the detection zone in which an object is detected. The zones in this case are A, B and C. The zones A and C are intended to prevent the collision of an object with the secondary closing edges 88b, 90b of the door panels 84, 86. In particular, pinching between the door panel and the wall must be prevented during opening.

[0112] Zone B is monitored to prevent objects from being crushed between the main closing edges 88a,90a of the two door leaves 84,86.

[0113] Thus, the door controller of the automatic door can be made to stop or reverse the movement of the door leaf depending on the direction of door movement and the zone in which the object is detected.

[0114] FIG. 6 is a schematic diagram of a sensor 92 according to the invention, which is integrated into an automatic door or gate (not shown). The automatic door or gate consists of at least one door leaf driven by a motor 100. The sensor 92 comprises two light pulse echo units 102, 104. The emitting and receiving light beams of both light pulse echo units 102, 104 are deflected by a rotating mirror 106 having four faces to provide four curtains, said four faces being preferably inclined with respect to each other to provide four intersecting planes in the sensor. Both light pulse echo units 102, 104 are connected to an evaluation unit 94. As the light beams of the first light pulse echo unit 102 and the second light pulse echo unit 104 are deflected by the same rotating mirror, a very precise detection can be achieved in the scanning field. As both light pulse echo units 102, 104 are connected to the same evaluation unit 94, the evaluation of the scanning field can be made on the basis of the information collected by both light pulse echo units 102, 104. An advantage is obtained since the two optical pulse echo units can generate a scanning field with an overlapping area that is scanned from two directions. This situation and the common evaluation unit 94 make it possible to reduce shadowing effects in this area.

[0115] An evaluation unit 94 evaluates the position of the object within the scanning field and then triggers an output port 96 to act on a control unit 98, which acts on a motor 100 that drives the door leaf.

[0116] The evaluation unit 94 is able to trigger different signals depending on the detection of an object within a predefined zone of the scanning field.

[0117] This general basic setup as described with respect to FIG. 6 may comprise the optical setup described in FIG. 1a or FIG. 3a.

[0118] In accordance with the present invention, a very large scan area can be monitored very accurately with a single sensor 92 that is part of an automatic door or gate. [Explanation of symbols]

[0119] 10 sensors, 12 rotating mirrors, 14a~14e Mirror surface, 16a~16e Mirror surface, 18a pulse generating unit, 18a Optical components, 20a, 20b light emission path, 22a luminous beam, 24b receiving beam, 27a, 27b receiver, 26a Optical feedback components, 28 windows, 29a, 29b light receiving lens, 32 Non-transparent housing, 40 sensors, 42 rotating mirror, 46a~46c Mirror surface, 52a, 52b beam projection, 56 Non-transparent housing, 58 Transparent housing, 60a, 60b 1st angular position, 62a, 62b receiver, 66a~66c Mirror, 68a pulse generating unit, 68b pulse generating unit, 72a, 72b mirror, 74a, 74b feedback components, 80 Automatic Sliding Door Assembly, 82 sensors, 84 Door panel, 86 Door panel, 88a Main closure edge, 88b secondary closing edge, 90a Main closure edge, 90b secondary closing edge, 92 sensors, 94 evaluation units, 96 output ports, 98 control unit, 100 motor, 102 Optical pulse echo unit, 104 Optical Pulse Echo Unit, 106 rotating mirror, A rotation axis, BA1 bisector angle, BS bisector, CL22a center line, CL22b center line, CL52a center line, CL52b center line, FA field angle, IA intersection angle, IB innermost beam, IBL inner border, ML1 Mirror Line No. 1, ML2 2nd mirror line, OBa, OBb outermost beam (outermost beam), OBL outer border, P intersection plane, RCL1 First rotation center line, RCL2 Second rotation center line, R Reference plane.

Claims

1. A sensor (10, 40) for an automatic door or gate, said sensor (10, 40) operating on the basis of pulse-echo evaluation, a rotating mirror (12, 42) having at least three different light-emitting mirror surfaces, the axis of rotation being perpendicular to a reference plane; at least one optical pulse generating unit (18a, 18b, 68a, 68b) for generating infrared pulses having a specific beam width, said pulses being sent along two different emission optical paths (20a, 20b), each optical path (20a, 20b) having at least one optical component (18a, 18b, 68a, 68b, 72a, 72b); the emission light paths (20a, 20b) are embodied so that the emission pulses can be reflected by mirror surfaces (14a-14e, 46a-46c), and the emission light paths (20a, 20b) define an incident pulse direction of the emission pulses; the reflected pulses establish a scanning field, each of said reflected pulse directions defining a reflected beam projection by projection onto said reference plane (R); the emission light paths (20a, 20b) are arranged so that the angle (IA) between the projections of the incident beams, i.e. the projection of the incident pulse direction onto the reference plane, is between 30° and 160°; Furthermore, the axis of rotation (A) lies on the bisector (BS) of the projection of these beams between the plane of intersection (P) and the optical component that is closest to the rotating mirror along the optical path; The rotating mirrors (12, 42) and the rotation axes (A) of the mirrors are set so that each of the reflected beam projections (22a, 22b) from both incident optical paths has an innermost reflected pulse (IB) that is at least parallel to the bisector (BS) or even crosses the bisector (BS) on the side of the scanning field, the scanning field is bounded by two outermost reflected pulses (OBa, OBb), and the scanning field between the two outermost reflected pulses (OBa, OBb) has an angular range of greater than 150°; The rotating mirrors (12, 42) have light-receiving mirror surfaces (16a to 16e) of the same amount as the light-emitting mirror surfaces (14a to 14e, 46a to 46c), The reflected pulse can be echoed back by an object within the scanning field, and the echoed pulse is reflected by the receiving mirror surface (16a-16e) and then received by a receiver (26a, 26b, 62a, 62b), which can distinguish which emission optical path (20a, 20b) the emission pulse of the echoed pulse was originally sent to.

2. A sensor (10) for an automatic door as described in claim 1, characterized in that the light-emitting mirror surface (14a to 14e) rotating around the rotation axis (A) has at least two surfaces (14a to 14e) having different inclinations relative to the reference surface.

3. 3. The sensor (10) for an automatic door according to claim 2, wherein the surfaces (14a to 14e) except for the 0° surface have pivot axes, the surfaces are inclined around the pivot axes, and the pivot axes are at the same height as the surfaces.

4. 2. The sensor according to claim 1, wherein the sensor (40, 60) comprises a housing having a curved window (28, 58) transparent for the light emission pulses, the curved window extending from a start angular position (30a, 60a) to an end angular position (30b, 60b), the rotation axis (A) being between a connecting line between the start angular position (30a, 60a) and the end angular position (30b, 60b), and the curved window (28, 58) being at an angular position midway between the start angular position (30a, 60a) and the end angular position (30b, 60b).

5. 5. The sensor of claim 4, wherein the shape of the curve is essentially a circular arc.

6. 5. The sensor according to claim 4, wherein the sensor (40, 60) is embodied such that a first light-emitting path (20a, 20b) and the light-receiving path overlap each other, and the sensor comprises an optical feedback component capable of directing a beam from the light-emitting path to the light-receiving path at a specific angular position of the mirror.

7. The optical feedback component is located between the rotating mirror (12, 42) and the curved window.

7. The sensor according to claim 6, wherein the sensor comprises:

8. The width of at least one surface (14a) is much greater than the other surfaces (14b-14e). and allowing the reflection of the light emitting pulses reaching the optical feedback components (26a, 26b).

5. The sensor of claim 4, wherein the sensor is adapted to:

9. 5. The sensor according to claim 4, characterized in that the receiving mirror surface (16a-16e) and the emitting mirror surface (14a-14e) have the same axis of rotation (A), one above the other.

10. A sensor as described in claim 6, characterized in that the light-receiving mirror surface (16a to 16e) and the light-emitting mirror surface (14a to 14e) have the same rotation axis (A) and one is above the other.

11. 10. The sensor according to claim 9, characterized in that the mirror (12, 42) is a one-piece mirror drum.

12. An automatic door (80) having at least one automatically operated door leaf (84, 86) for covering a door opening (83), the automatic door comprising: a sensor (82) for determining the presence of an object in the vicinity of the door opening (83); and a control unit (98) for controlling the movement of the at least one door leaf (84, 86) according to the detection state of the sensor (82, 92), the sensor (82, 92) having two light pulse echo units and a single rotating mirror (106) having at least three reflective and emitting surfaces, the two light pulse echo units each having a light pulse receiving unit (27a, 27b) and a light pulse generating unit (18a, 18b), 1. An automatic door (80), wherein the pulse echo units are arranged symmetrically with respect to a mid-plane, the rotation axis (A) of the rotating mirror (12) being in said mid-plane, the optical pulse echo units and the mirror being arranged such that the outermost light emitting beams (OBa, OBb) of the two light emitting and receiving units define an angle (FA) between the two outermost light emitting beams (OBa, OBb) of greater than 160°, and the innermost beams (IBa, IBb) are arranged so as to be at least parallel or overlapping, and the sensor (82) further comprises an evaluation unit for determining the position of an object within a scanning field taking into account the TOF measurements of both optical pulse echo units.

13. An automatic door comprising a sensor (82) in the form of a sensor according to any one of claims 1 to 10, said automatic door being in the form of an automatic sliding door (80).

14. The automatic door according to claim 12, wherein the automatic door is in the form of an automatic sliding door and comprises two automatically operated sliding door panels (84, 86), the sensor (82) provides at least three curtains attached to the top of the sliding door panels (84, 86), at least one curtain extending in a substantially vertical direction generally parallel to the door panels (84, 86) or at an acute angle to the door panels (84, 86), the door panels (84, 86) each having a main closing edge (88a, 90a) and a secondary closing edge (88b, 90b), and the scanning field extends from the secondary closing edge (88b) of the first door panel (84) to the secondary closing edge (90b) of the second door panel (86).

15. 15. The automatic door of claim 14, wherein the sensor provides at least three zones (A, B, C) extending in the width direction, the sensor (82) having a first secondary closing edge zone (A), a main zone (B), and a second secondary closing edge zone (C), wherein detection in the first secondary closing edge zone (A) provides a first signal to the door controller that triggers a first action, detection in the main zone (B) provides a signal that triggers a second action different from the first action, and detection in the second secondary closing edge zone (C) provides a signal that triggers a third action different from the second action.

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