Detection system

Abstract

The present invention provides a detection system 100 for detecting a presence of an object in a passageway 17, including a first object detection unit 11 that detects the presence of the object in a first detection area 13; a second object detection unit 12 that detects the presence of the object in a second detection area14, wherein the first object detection unit 11 and the second object detection unit 12 are arranged along a passage gate line 19, the passage gate line 19 orthogonal to a predetermined passageway line 18 that passes between the first object detection unit 11 and the second object detection unit 12; a first center line 15 of the first detection area 13 is at an angle with respect to the passage gate line 19; a second center line 16 of the second detection area 14 is at an angle with respect to the passage gate line 19; and the first detection area 13 and the second detection area 14 do not overlap.

Description

DETECTION SYSTEM

[0001] The present invention relates to a detection system for detecting the presence of objects in a passageway.

[0002] In conventional detection systems, it has been conceived of to detect the presence of objects in a passageway using two or more detection units in order to understand, for example, the movement of the object through the passageway. For example, the object may be a person, and the detection system may be used to monitor access to a restricted area which may only be accessed by authorized people, such as people who have paid a fee or people who work at the facility where the detection system is equipped. In these situations, the detection system must be capable of recognizing the movement of the person into or out of the restricted area through the passageway.

[0003] However, a commercially viable detection system must not only be able to detect the object entering or leaving the restricted area, but must also be effective at preventing unauthorized entry and minimizing false alarms. Unauthorized entry is a common problem when attempting to limit access to a restricted area such that only authorized objects can enter. For example, if the object is a person, the person may attempt to enter the restricted area without authorization by following closely behind an authorized person in front of them (hereafter, ‘tailgating’), by walking side-by-side with an authorized person (hereafter, ‘sidegating’), or by going over or under the detection area. The opposite problem is the occurrence of false alarms, wherein a detection system used for access control may deny entry or sound an alarm because it mistakenly believes that unauthorized passage through the passageway into the restricted area has occurred. False alarms are undesirable because they slow down flow through the passageway and increase necessary spending on security guards or the like who must check the passageway when a false alarm occurs.

[0004] For example, Patent Literature 1 describes one such security system for monitoring the movement of people through a passageway, and it attempts to prevent unauthorized entry and minimize false alarms using at least two time-of-flight sensors as detection units arranged on opposing sides of the passageway. Relative to the direction of travel thorough the passageway, one of the time-of-flight sensors is arranged in front of the other, and each lets out a beam of light perpendicular to the direction of movement though the passageway, such that the detection area of the first time-of-flight sensor is in front of the detection area of the second time-of-flight sensor. The movement of a person through the passageway can then be determined by detecting the presence of the person in each separate detection area, and the separate detection in each of the two detection areas can be analyzed to determine that an attempted entry is unauthorized.

[0005] However, this type of system for monitoring people through a passageway requires that one of the time-of-flight sensors be placed in front of the other. This necessitates the system to have an increased footprint (i.e., the floorspace taken up by the device), since the device must have sufficient length in the direction of travel through the passageway for the detection units to be placed one in front of the other. This creates the problem that the system may be unusable in narrow or crowded spaces, and because more materials must be used, increasing costs.

[0006] Patent Application Publication US 2020 / 0041688A1

[0007] The present invention aims to solve the above-mentioned problems, and its object is to provide a detection system for detecting the presence of objects in a passageway that makes it possible to reduce the footprint of the detection system while still ensuring that the system can effectively detect unauthorized passage through the passageway and prevent false alarms.

[0008] A detection system according to the present invention is one for detecting a presence of an object in a passageway, and includes a first object detection unit that detects the presence of the object in a first detection area; and a second object detection unit that detects the presence of the object in a second detection area, and is a detection system wherein the first object detection unit and the second object detection unit are arranged along a passage gate line, the passage gate line orthogonal to a predetermined passageway line that passes between the first object detection unit and the second object detection unit; a first center line of the first detection area is at an angle with respect to the passage gate line; a second center line of the second detection area is at an angle with respect to the passage gate line; and the first detection area and the second detection area do not overlap.

[0009] This configuration allows a great reduction in the footprint of the detection system while still allowing the system to detect the presence of an object in two detection areas, which allows the system to determine the movement of the object from one of the detection areas to the other.

[0010] It is preferable that the detection system further include a crossing determining unit that determines that the object has crossed the passage gate line based on the detection of the presence of the object by the first object detection unit and the detection of the presence of the object by the second object detection unit.

[0011] This configuration allows the detection system to determine that the object has crossed the passage gate line based on the movement of the object from the first object detection area to the second object detection area, or from the second object detection area to the first object detection area. Thus, the system can make various determinations about the movement of objects through the gate, such as the number of objects that have passed through the gate.

[0012] Furthermore, it is preferable that the detection system be one in which the crossing determining unit determines that the object has crossed the passage gate line if the detection of the presence of the object by the first object detection unit and the detection of the presence of the object by the second detection object occurs within a predetermined time frame.

[0013] With this configuration, the detection system is able to reduce false detections of objects crossing the passage gate line. That is, when an object such as a person passes through the gate, it usually moves from one of the detection areas to the other in a given time frame. Thus, if an object is detected in one of the detection areas and then an object is detected in the other of the detection areas outside of that time frame, there is a relatively high likelihood that they are not the same object, and thus a determination should not be made that an object has crossed the passage gate line.

[0014] It is further preferable that the detection system be one wherein the predetermined time frame is determined based on the angle of the first center line with respect to the passage gate line and the angle of the second center line with respect to the passage gate line.

[0015] Via this configuration the detection system is able to adjust the predetermined time frame by changing the angle of the first center line and the angle of the second center line. As the angle of each of the center lines is increased to be farther away from the passage gate line, the distance between them increases, so that the predetermined time frame should be longer for objects moving between them at the same speed. The angle can be adjusted, for example, to lower the possibility of a false alarm caused by a bag or a person’s arm swinging.

[0016] It is preferable that the detection system also include an unauthorized object determining unit that determines if the object crossing the passage gate line is not authorized to cross.

[0017] With this configuration, the detection system makes a determination that an unauthorized object has crossed the passage gate line, which allows the detection system to be used effectively in security or business settings. For example, it can be determined that an intruder is trying to enter a security area, or that a customer has not properly paid for access to an area, etc.

[0018] It is preferable that the detection system further include a gate door that closes if the unauthorized object determining unit determines that the object is not authorized to cross.

[0019] Configured like this, the detection system has greater usefulness for security or businesses uses, since an unauthorized object can be prevented from entering a secure area by the gate door closing and preventing the movement of the object therein.

[0020] It is preferable that the detection system also include an alarm unit that issues an alarm if the unauthorized object determining unit determines that the object is not authorized to cross.

[0021] With this configuration, the detection system is able to have greater usefulness for security or business uses, since an alarm can be issued to alert security of an unauthorized object attempts to cross the passage gate line and enter a secure area. This way, security staff can be alerted to the unauthorized entry into the secure area and intervene however necessary.

[0022] It is preferable that the detection system be one wherein the first object detection unit and the second object detection unit each comprise a light emitting unit and a light receiving unit and detect the presence of the object based on light from the light emitting unit reflecting off the object and being received by the light receiving unit.

[0023] This a specific configuration of the first object detection unit and the second object detection unit for one aspect of the present invention. A configuration including a light emitting unit and a light receiving unit allows light reflected off an object to be detected, thus determining the present of an object in the detection area.

[0024] It is preferable that the detection system be one wherein at least one of the first detection area and the second detection area extends vertically so as to have a planar vertical detection surface.

[0025] With this configuration, at least one of the first detection area and the second area extends vertically so as to have a planar vertical detection surface.　Thanks to the vertical extension of the detection area, an object crossing the passage gate line cannot escape detection by going over or under the detection area.

[0026] It is preferable that the detection system further include a direction determining unit that determines a travel detection of the object in the passageway based on an output from the first object detection unit and an output from the second object detection unit.

[0027] With this configuration, the detection system can determine the direction of travel of an object that crosses the passage gate line, so it possible to detect whether an object is entering or leaving a secure area.

[0028] Furthermore, it is preferable that the detection system be one wherein the direction determining unit determines the travel direction of the object in the passageway based on a difference of time between when the first object detection unit detects the object and when the second object detection unit detects the object.

[0029] This is a specific configuration of the direction determining unit in one aspect of the present invention. By using the time when the object was detected by the first object detection unit, and the time when the object was detected by the second object detection unit, it is possible to determine the direction of movement based on which occurred first in time.

[0030] It is preferable that the detection system be one wherein the first object detection unit and the second object detection unit form opposing sides of a gate surrounding the passageway.

[0031] This configuration allows the first object detection unit and the second object detection unit to serve as a gate through which the passageway goes. Thus, the movement of objects through the passageway can be confined so as to move between the first object detection unit and the second object detection unit.

[0032] It is preferable that the detection system be one wherein the first object detection unit and the second object detection unit each have a cylindrical shape.

[0033] This configuration allows the gate to have as small a footprint as possible thanks to the first object detection unit and the second object detection unit having a cylindrical shape, such that each takes up a relatively small amount of space compared to other shapes that would extend further lengthwise.Advantageous Effects of the Invention

[0034] According to the present invention, a detection system is provided for detecting the presence of objects in a passageway that makes it possible to reduce the footprint of the detection system while still ensuring that the system can effectively detect unauthorized passage through the passageway and prevent false alarms.

[0035] A schematic diagram of a detection system according to one embodiment of the present invention.A functional block diagram of the first object detection unit, the second object detection unit, and the information processing unit according to the same embodiment.A plan view of an object moving through the passageway according to the same embodiment.A perspective view of an object and the detection system according to the same embodiment.A perspective view of an object and the detection system according to another embodiment.A plan view of the detection system according to another embodiment.A plan view of the detection system according to another embodiment.Description of the Embodiments

[0036] A first embodiment of the present invention is described below with reference to the drawings.

[0037] A detection system 100 of the present embodiment detects the presence of an object in a passageway.

[0038] As shown in FIG 1, the detection system 100 of the present invention includes an access gate 10 of a passageway through which an object can enter or leave a restricted area as well as an information processing unit 20.

[0039] The access gate 10 includes at least a first object detection unit 11 and a second object detection unit 12 that are each in communication with the information processing unit 20. The first object detection unit 11 and the second object detection unit 12 are arranged directly across from each other on opposite sides of the passageway 17, such that a line passing through the first object detection unit 11 and the second object detection unit 12, hereafter called the passage gate line 19, is orthogonal to a predetermined passageway line 18 that is a line within the passageway 17. Here, the passageway line 18 is the center line of the passageway 17.

[0040] The first object detection unit 11 and the second object detection unit 12 each detect the presence of objects in a detection area 13,14. Specifically, the first object detection unit 11 detects the presence of objects in a first detection area 13 and the second object detection unit 12 detects the presence of objects in a second detection area 14. As shown in FIG 1, as viewed from above the center line 15 of the first detection area 13 (the ‘first center line 15’) and the center line 16 of the second detection area 14 (the ‘second center line 16’) are both arranged at an angle with respect to the passage gate line 19, each on opposite sides of the passage gate line 19. In the present embodiment, the center line 15 of the first detection area 13 and the center line 16 of the second detection area 14 are substantially parallel. Furthermore, the first detection area 13 and the second detection area 14 do not overlap, and as such a gap is formed between the first detection area 13 and the second detection area 14.

[0041] As shown in FIG 3, because the first detection area 13 and the second detection area 14 do not overlap and a gap is formed between them, an object moving through the passageway 17 will first enter one of the detection areas 13, 14 before entering the other.

[0042] As shown in FIG 4, the first object detection unit 11 and the second object detection unit 12 may have a columnar shape, and here are cylindrical columns, but the detection system is not limited to this.

[0043] In the present embodiment, the first object detection unit 11 and the second object detection unit 12 are each equipped with a light emitting unit 111, 121 and a light receiving unit 112, 122. The light emitting unit 111, 121 emits light into the corresponding detection area 13, 14. Then, if an object is present therein, light is reflected off the object and received by the light receiving unit 112, 122. Light being emitted by the light emitting unit 111, 121 and received by the light receiving unit 112, 122 is used to determine the presence of an object in the detection area 13, 14, as is explained in greater detail below.

[0044] Specifically, the light emitting unit 111, 121 may emit a pulse of light, and the light receiving unit 112, 122 may receive a return pulse.

[0045] In this embodiment, the light emitting units 111, 121 are each a laser light source that emits infrared laser light, and the light receiving units 112, 122 are each a photodetector capable of detecting infrared light in the corresponding wavelength range. However, the device is not limited to this, and other types of light sources and light detectors may be used. Furthermore, lenses and mirrors may be used to shape the light appropriately. As shown in FIG 4, the light may be emitted as one or more beams of light. FIG 4 shows two beams of light merely as an example, but only at least one is necessary.

[0046] The first object detection unit 11 and the second object detection unit 12 each output a signal to the information processing unit 20 when light is emitted from the light emitting unit 111, 121 (a ‘light emitted signal’) and another signal when light is received by the light receiving unit 112, 122 (a ‘light received signal’).

[0047] The information processing unit 20 is a so-called computer containing, for example, a CPU, memory, an input and output interface, and so on. Functionally, the CPU and other peripherals work together in accordance with a program stored in the aforementioned memory to perform the functions of an object detection signal receiving unit 21, a time of flight determining unit 22, an object presence determining unit 23, a crossing determining unit 24, a direction determining unit 25, a credential confirming unit 26, an unauthorized object determining unit 27, a barrier control unit 28, and an alarm unit 29.

[0048] The object detection signal receiving unit 21 receives the light emitted signals and the light received signals output from the first object detection unit 11 and the second object detection unit 12, and outputs said signals to the time of flight determining unit 22.

[0049] The time of flight determining unit 22 uses the time of flight principle to determine the distance to an object present within the detection area 13, 14. That is, a pulse of light is emitted by the light emitting unit 111, 121, a corresponding pulse of light is received by the light receiving unit 112, 122, and the total amount of time elapsed between these two events (the ‘time of flight’) is calculated. The time of flight represents the amount of time it takes for light to travel from the light emitting unit 111, 121 to the light receiving unit 112, 122 and, because the speed of light is constant, is a measure of the distance to the object. The time of flight determining unit 22 then outputs the calculated time of flight to the object presence determining unit 23.

[0050] The object presence determining unit 23 uses the time of flight output from the time of flight determining unit 22 to determine if an object is present in the detection area 13, 14. More specifically, in the present embodiment, the object presence determining unit determines that an object is present in the detection area 13, 14 if the time of flight is shorter than a predetermined shortest time.

[0051] The predetermined shortest time effectively defines a distance beyond which objects will not be detected, since it corresponds to a time of flight for a given distance. For example, depending on the facility or area where the detection system 100 is installed, one or both of the detection areas 13, 14 may extend to a barrier such as a wall or other fixed object. To ignore the barrier, the predetermined shortest time may set to be the time of flight from the object detection unit 11, 12 to the barrier. In this example, by determining that an object is present in the detection area 13, 14 only when the time of flight is shorter than the predetermined shortest time corresponding to the distance to the barrier, light reflected off the barrier will not cause the object presence determining unit 23 to determine than an object is present; rather, an object will be determined to be present only when it is closer to the object detection unit 11, 12 than the barrier.

[0052] The predetermined shortest area may be determined ahead of time by operating the device when no objects are present in the passageway, taking into consideration variations due to noise or error, or may be input by a user or the like. As such, the object presence determining unit 23 may be capable of receiving an external input from an input device or the like.

[0053] The object presence determining unit 23 outputs a signal (a ‘presence-of-object signal’) to the crossing determining unit 24 each time it determines that an object is present in the first detection area 13 or the second detection area 14. The presence-of-object signal indicates which of the detection areas 13, 14 the object was determined to be present in as well as the time at which the object was present.

[0054] The crossing determining unit 24 determines that an object in the passageway has crossed the passage gate line 19 based on at least two presence-of-object signals received from the object presence determining unit 23. Specifically, in the present embodiment, the crossing determining unit 24 determines that the object has crossed the passage gate line 19 if, within a predetermined timeframe, the object is determined to be present in one of the detection areas 13, 14 and is thereafter determined to be present in the other of the detection areas 13, 14.

[0055] The crossing determining unit 24 is able to reduce the number of false alarms by using the predetermined timeframe in making its determination. For example, if an object in the passageway enters the first detection area 13 as it approaches the passage gate line 19 from one side, but then turns around and leaves without crossing the passage gate line 19, a different object could then enter the second detection area 14 on the other side, and this could be mistakenly determined to be a crossing and cause a false alarm. However, this chain of events may occur over a relatively long timeframe compared to an actual crossing in a commercial use case (e.g., people walking past the passage gate line 19 to enter a restricted area), and as such false alarms can be reduced by not determining that a crossing has occurred if the detections on each side have occurred too far apart in time.

[0056] The crossing determining unit 24 outputs a signal to the direction determining unit 25 when a determined has been made that an object has crossed the passage gate line 19.

[0057] The direction determining unit 25 determines the direction of the crossing of the object past the passage gate line 19 based on whether the object was determined to first be present in the first detection area 13 or to first be present in the second detection area 14. That is, if the object was determined to be present in the first detection area 13 before being present the second detection area 14, it is determined to have moved from the first detection area 13 across the passage gate line 19 towards the second detection area 14. Conversely, if the object was determined to be present in the second detection area 14 before being present the first detection area 13, it is determined to have moved from the second detection area 14 across the passage gate line 19 towards the first detection area 13. Upon determining the direction of the crossing, the direction determining unit 25 then outputs a crossing direction signal to the unauthorized object determination unit 27.

[0058] The unauthorized determination unit 27 receives not only crossing direction signals from the direction determining unit 25, but also credential confirmation signals from the credential confirmation unit 26, which will now be explained.

[0059] The credential confirming unit 26 receives an external credential signal containing credential information, confirms that the credential information is legitimate and that it indicates authorization to enter the restricted area, and upon said confirmation outputs a credential confirmation signal to the unauthorized object determining unit 27. Credential information is information including at least an indication of whether or not the object is authorized to enter the restricted area, but may also include identifying information about the object or the like. The credential confirmation signal may be output to the credential confirming unit 26 when, for example, the object presents a credential to a credential reader (not shown), wherein the credential may itself contain the credential information or may identify the object (e.g., to compare the identity to credential information stored elsewhere). Examples of a credential include a ticket, a security token, a smart card, a biometric identifier, a QR code, and so on.

[0060] The unauthorized object determining unit 27, upon receiving a crossing direction signal from the direction determining unit 25 indicating that an object has crossed the passage gate line 19 into the restricted area, checks whether it has received a credential confirmation signal indicating that the object is authorized to enter the restricted area. If the credential confirmation signal indicating that the object is authorized to enter the restricted area has been received, the object is allowed to enter the restricted area. On the other hand, if the credential confirmation signal indicating that the object is authorized to enter the restricted area has not been received, the unauthorized object determining unit 27 determines that the object is an unauthorized object, and outputs an unauthorized object signal to the barrier control unit 28 and to the alarm unit 29.

[0061] Note that, depending on the needs of the facility to which the detection system 100 is equipped, it is also possible for the unauthorized object determining unit 27 to, in the same manner, check whether an object leaving the restricted area through access gate 10 is authorized to leave the restricted area, and output an unauthorized object signal if the object is not authorized to leave.

[0062] The barrier control unit 28, upon receiving an unauthorized object signal from the unauthorized object detection unit 27, outputs a barrier close signal to an actuator or lock or the like (not shown), to cause a barrier to block the object from progressing further into the restricted area. The barrier may then remain in a state of blocking the object from progressing further until, for example, a credential containing proper authorization is presented or the object leaves the vicinity.

[0063] The alarm unit 29, upon receiving an unauthorized object signal from the unauthorized object detection unit 27, sends an alarm signal to an external alarm. The alarm then sounds an alarm to indicate that unauthorized access to the restricted area is being attempted. The alarm may, for example, sound in an area in which staff or security guards are present so they can check the access gate 10 to determine if further action is needed.

[0064] The detection system is thus able to detect the presence of objects in the passageway while reducing the footprint of the detection system and also ensuring that the system can effectively detect unauthorized passage through the passageway and prevent false alarms. The footprint of the detection system can be reduced thanks to the fact that the first object detection unit 11 and the second object detection unit 12 need not be placed one in front of the other in the direction of travel through the passageway 17. Instead, the first object detection unit 11 and the second object detection unit 12 may be placed directly across from each other on opposite sides of the passageway 17, while nevertheless allowing there to be two different detection areas 13, 14, one on each side of the passage gate line 19, and thereby allowing the detection system to determine when an object has crossed the passage gate line 19, to determining the direction of the crossing, and to implement measures to detect unauthorized entry and minimize false alarms.

[0065] The detection system is not limited to the above-described embodiment.

[0066] In the above-described embodiment, the light emitting units 111, 121 emit the light as one or more beams of light. However, as shown in FIG 5, it is also possible for the detection system to make use of mirrors and lenses and the like to shape the light to extend vertically and form a detection surface with a sheet-like shape. In other words, the light that forms the first detection area 13 or the second detection area 14 or both may be shaped so as to extend vertical such that the area in which light is emitted has a planar vertical detection surface. By shaping the light in this way, it is possible for the detection surface of the detection area 13, 14 to extend vertically from a significant height all the way down to the floor.

[0067] As shown in FIG 6, in one embodiment the barrier may be a gate door 31 attached to a side block 32, 33 that forms side boundaries of the passageway 17. Here, the gate door 31 may be made up of two half-doors, one included on a first side block 32 and one included on a second side block 33. Furthermore, the first object detection unit 11 may be included in the first side block 32, and the second object detection unit 12 may be included in the second side block 33. The gate door 31 is preferably on the side of the restricted area to prevent unauthorized access thereto.

[0068] As shown in FIG 7, in another embodiment the side blocks 32, 33 that form the side boundaries of the passageway 17 are lengthened in the direction of travel through the passageway 17 such that the gate door 31 may be installed to the side blocks 32, 33 sufficiently far away from the passage gate line 19 for the gate door 31 to not enter the detection areas 13, 14 in both the open state and the closed state.

[0069] In one embodiment, the time of flight determining unit 22 can determine the time of flight of the object in the detection areas 13, 14 at a plurality of points in time in order to make a time of flight dataset thereof. This time of flight dataset may then be used to generate a point cloud, and the point cloud can be analyzed by the unauthorized object detection unit 27 to determine whether unauthorized access, such as tailgating or sidegating, is being attempted.

[0070] In the embodiments described above, the time of flight determining unit 22 determines the time of flight of the light to the object and back. However, in another embodiment the time of flight determining unit 22 need not be included, and the object presence determining unit 23 may determine the presence of the object merely by return light being received by the light receiving unit 121, 122.

[0071] It is needless to say that the present invention is not limited to the embodiments described above and various modifications can be made to the present invention without departing from the spirit of the present invention.

[0072] According to the present invention, a detection system is provided for detecting the presence of objects in a passageway that makes it possible to reduce the footprint of the detection system while still ensuring that the system can effectively detect unauthorized passage through the passageway and prevent false alarms.Reference Sign List

[0073] 100 detection system 11 first object detection unit 12 second object detection unit 13 first detection area 14 second detection area 15 first center line 16 second center line 24 crossing determining unit 25 direction determining unit 27 unauthorized object detection unit 29 alarm unit 31 gate door

Claims

1. A detection system for detecting a presence of an object in a passageway, comprising: a first object detection unit that detects the presence of the object in a first detection area; a second object detection unit that detects the presence of the object in a second detection area, wherein the first object detection unit and the second object detection unit are arranged along a passage gate line, the passage gate line orthogonal to a predetermined passageway line that passes between the first object detection unit and the second object detection unit; a first center line of the first detection area is at an angle with respect to the passage gate line; a second center line of the second detection area is at an angle with respect to the passage gate line; and the first detection area and the second detection area do not overlap.

2. The detection system according to claim 1, further comprising a crossing determining unit that determines that the object has crossed the passage gate line based on the detection of the presence of the object by the first object detection unit and the detection of the presence of the object by the second object detection unit.

3. The detection system according to claim 2, wherein the crossing determining unit determines that the object has crossed the passage gate line if the detection of the presence of the object by the first object detection unit and the detection of the presence of the object by the second object detection unit occurs within a predetermined time frame.

4. The detection system according to claim 3, wherein the predetermined time frame is determined based on the angle of the first center line with respect to the passage gate line and the angle of the second center line with respect to the passage gate line.

5. The detection system according to claim 2, further comprising an unauthorized object determining unit that determines if the object crossing the passage gate line is not authorized to cross.

6. The detection system according to claim 5, further comprising a gate door that closes if the unauthorized object determining unit determines that the object is not authorized to cross.

7. The detection system according to claim 5, further comprising an alarm unit that issues an alarm if the unauthorized object determining unit determines that the object is not authorized to cross.

8. The detection system according to claim 1, wherein the first object detection unit and the second object detection unit each comprise a light emitting unit and a light receiving unit and detect the presence of the object based on light from the light emitting unit reflecting off the object and being received by the light receiving unit.

9. The detection system according to claim 1, wherein at least one of the first detection area and the second detection area extends vertically so as to have a planar vertical detection surface.

10. The detection system according to claim 1, further comprising a direction determining unit that determines a travel detection of the object in the passageway based on an output from the first object detection unit and an output from the second object detection unit.

11. The detection system according to claim 10, wherein the direction determining unit determines the travel direction of the object in the passageway based on a difference of time between when the first object detection unit detects the object and when the second object detection unit detects the object.

12. The detection system according to claim 1, wherein the first object detection unit and the second object detection unit form opposing sides of a gate surrounding the passageway.

13. The detection system according to claim 12, wherein the first object detection unit and the second object detection unit each have a cylindrical shape.

Images