JP2008134729A - Entering/leaving managing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an entering/leaving managing apparatus capable of surely detecting unauthorized entrance or leaving of a room. <P>SOLUTION: The entering/leaving managing apparatus comprises an operating means 3a installed in a shared space, an ID authenticating means 3 for performing ID authentication regarding a person who enters into a restricted area and a person who leaves from the restricted area using operating means 3b installed in the restricted area; a locking means 1 for performing lock or release of a door provided at a doorway of the restricted area; a lock control means 2 for making the lock means 1 locked or released, in response to ID authentication or an operation from the restricted area side; and an image monitoring means 4 comprising imaging means 40 for imaging an imaging area near the doorway installed at a door opening side and an opposite side from among the common space in the limited area or outside of the restricted area; a number of passing persons counting means 41 for counting the number of persons who passes through the doorway during a released time period in time series from an image of the imaging means 40; and a signal processing means 42 for outputting a detection signal, when mismatch is detected between entering a room and leaving the room, from the number of passing persons counted by the number of passing persons counting means 41. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an entrance / exit management device for managing entrance / exit.

  2. Description of the Related Art Conventionally, an entry / exit management device that restricts unauthorized entry / exit and tightens entry / exit management has been provided (see, for example, Patent Document 1).

  In this entrance / exit management device, ID authentication means for performing ID authentication of a person entering the restricted area outside the restricted area that restricts entry / exit (that is, the common space), and imaging means for imaging the vicinity of the entrance / exit in the shared space; And locking means for locking or unlocking the door of the restricted area based on the authentication result of the ID authentication means, and entering and leaving the room from the direction of movement of the person extracted from the image of the imaging means. And a passing number counting means for counting the number of people passing through the doorway simultaneously and in time series, the number of passing people at the doorway counted by the passing number counting means and the number of authentications authenticated by the ID authentication means When inconsistency occurs, it is judged as an unauthorized passage and an alarm is output.

In addition, in this entrance / exit management device, when a person who wants to enter a restricted area with the door locked is engaged in an authentication operation by the ID authentication means, a plurality of people stay near the entrance / exit from the image of the imaging means There has also been proposed a method for preventing unauthorized entry (joining entry room) that brings in a person without authentication authority by not unlocking when it is detected.
JP 2006-243972 A

  In the entrance / exit management device described above, since the imaging means is installed on the shared space side, in an environment where the door provided at the entrance / exit of the restricted area opens to the shared space side, the authentication is successful and the door is unlocked. If the door is opened to the common space after the door has been opened, the opened door enters the imaging area of the imaging means, and a blind spot is generated by this door, so the number of people who pass through the doorway or the number of people who stay in the imaging area Could not be detected accurately, and unauthorized entry / exit could not be detected reliably.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an entry / exit management device that can reliably detect unauthorized entry / exit.

  In order to achieve the above object, the invention of claim 1 includes an ID authentication means for performing ID authentication at least for a person entering the restricted area, and a lock for locking or unlocking a door provided at the entrance / exit of the restricted area. Means, lock control means for locking or unlocking the locking means according to the operation from the ID authentication or restricted area side, and the restricted area or the shared space outside the restricted area on the side opposite to the side where the door opens A first image pickup means for picking up an image pickup area near the doorway, a passage number counting means for counting the number of people passing through the doorway during the unlocking period from the image of the first image pickup means, and the passage It comprises an output means for comparing the number of passing people counted by the number counting means and the number of authentications authenticated by the ID authentication means and outputting a detection signal when there is a mismatch.

  According to a second aspect of the present invention, in the first aspect of the invention, the number of staying person counting means for counting the number of people staying in the imaging area from the image of the first imaging means, and the installation position of the first imaging means are on the restricted area side If the installation position is input as a shared space by the installation position switching means and the installation position switching means for inputting whether the number of stays counted by the visitor number counting means at the time of locking exceeds a predetermined allowable number And an entrance / exit restriction means for stopping the unlocking process by the lock control means, and the passing person counting means determines the detection direction of entering and leaving the restricted area based on the installation position input by the installation position switching means. It is characterized by switching.

  The invention of claim 3 is the invention of claim 1, wherein the first imaging means is installed on the restricted area side, the second imaging means installed in the common space and images the imaging area near the entrance and exit, A staying-counter counting unit that counts the number of people staying in the imaging area from the image of the second imaging unit, and if the staying-counter counted by the staying-counter counting unit during locking exceeds a predetermined allowable number, An entry / exit restricting means for stopping the lock process is provided, and the output means compares the number of passing persons counted by the passing person counting means with the number of authentications authenticated by the ID authenticating means at the time of unlocking and there is a mismatch. A detection signal is output.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, at least one of the first and second imaging means irradiates the imaging area with modulated light and measures the reflection time thereof, thereby measuring the inside of the imaging area. It is characterized by comprising an active distance image sensor that generates a distance image using a distance value to a target object as a pixel value.

  According to a fifth aspect of the present invention, in the third aspect of the invention, the first and second imaging means irradiate the imaging area with modulated light and measure the reflection time thereof, thereby measuring the distance to the object in the imaging area. It comprises an active distance image sensor that generates a distance image with the value as a pixel value, and the second imaging means stops irradiation of modulated light when unlocked.

  According to the first aspect of the invention, since the first imaging means is installed on the side opposite to the side where the door opens, the first door is opened by the door regardless of the direction of the restricted area side or the common space side. There is no blind spot in the imaging area of the imaging means, and it is possible to reliably detect a person passing through the imaging area. Therefore, by comparing the number of people passing and the number of authentications authenticated by the ID authentication means, unauthorized entry and exit can be prevented. There is an effect that it can be surely prevented.

  According to the invention of claim 2, by inputting the installation position of the first imaging means using the installation position switching means, the passing direction of the person passing through the doorway can be switched according to the installation position. The first imaging means can be installed and used on either the restricted area side or the shared space side.

  According to invention of Claim 3, a visitor number counting means counts the number of persons staying in the desired detection area of the imaging area of a 2nd imaging means from the image of the 2nd imaging means installed in the shared space. Since the unlocking process is stopped when the number of visitors exceeds the allowable number of people, the person who does not have authentication authority enters the room together with the person entering the room (join room entry), or the person who does not have authentication authority does not have the right to enter the room It is possible to reliably prevent a person from entering (passing into each other).

  According to the invention of claim 4, since the distance image sensor is used for at least one of the first and second imaging means, the human body is accurately extracted from the background image as compared with the case where the grayscale image is used. This is advantageous in that false detection can be reduced.

  According to the invention of claim 5, since the distance image sensor is used as the imaging means, the human body can be accurately extracted from the background image as compared with the case where the grayscale image is used, and the effect of reducing false detection can be obtained. is there. In addition, since the second imaging means installed in the common space stops the irradiation of the modulated light at the time of unlocking, the first imaging means for detecting at the time of unlocking from the light source of the second imaging means, There is also an effect that it is possible to prevent malfunction due to the modulated light irradiated through the doorway where the door is opened.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
Embodiment 1 of this invention is demonstrated based on FIGS. 1-3. FIG. 1 is a schematic block diagram of an entrance / exit management device of the present embodiment, and FIGS. 2A and 2B are layout diagrams schematically showing an example of the arrangement of each part.

  The entrance / exit management device is used for managing entrance / exit into the room R, which is a restricted area, and includes a lock means 1 composed of an electric lock that locks / unlocks the door D provided at the entrance / exit E of the room R; Lock control means 2 for controlling the unlocking / locking of the lock means 1, ID authentication means 3 for determining whether or not the person who intends to enter the room is permitted in advance, and image monitoring means 4 And as a main component. Here, in the present embodiment, the door D provided at the entrance / exit E opens to the shared space A side, and the imaging means 40 of the image monitoring means 4 captures the vicinity of the entrance / exit E of the room R, which is a restricted area. It has become.

  The ID authentication means 3 has appropriate operation means 3a and 3b that can specify an individual such as an IC card, face authentication, fingerprint authentication, etc., and an operation means in which a room occupant performs an authentication operation in a predetermined area near the entrance E in the shared space A. 3a is installed, and an operating means 3b in which a person leaving the room performs an authentication operation in a predetermined area near the entrance E in the room R is installed.

  The image monitoring means 4 is installed on the ceiling X of the room R, and is imaged by a first imaging means (hereinafter abbreviated as imaging means) 40 that images the inside of the room R in the vicinity of the entrance E and the imaging means 40. The moving / still person in the imaging area W is extracted from the captured image, the number of objects (persons) appearing near the entrance E and moving inside the room R (number of people entering the room), and the direction from the inside of the room R to the entrance E The number of passing persons counting means 41 for counting the number of objects (persons) who have moved to and disappeared near the entrance / exit E (the number of people leaving the room), and the number of authentications and the number of passing persons of the ID authentication means 3 input via the lock control means 2 Signal processing means 42 (output means) for determining the presence or absence of unauthorized entry / exit based on the count value is provided.

  The passing person counting means 41 uses, for example, a distance image picked up by the image pickup means 40, stores a background image in which no person exists in advance, and cuts out the foreground portion obtained from the difference between the stored background image and the current time image. Thus, the object (person H) within the imaging range is extracted, and such an object extraction process is performed at regular time intervals to calculate the position of the extracted object on the image. The passing person counting means 41 performs tracking of the moving extracted object by associating the calculated position of the extracted object at the current time with the calculated position at the previous time. Those who appear in the vicinity of E and whose tracking disappears on the room R side are called entrance persons, and those who move from the inside of the room R to the entrance / exit E side and the tracking disappears in the vicinity of the entrance / exit E are regarded as exiting persons. Each person is counted.

  Next, operation | movement of this entrance / exit management apparatus is demonstrated according to the flowchart of FIG. Note that the flowchart of FIG. 3 is expressed in a block diagram so that the operations of the above-described means 1 to 4 can be easily understood.

  First, the authentication process by the lock control means 2 will be described. When an authentication operation is performed using the operation means 3a, 3b such as a card reader installed in the common space A or the room R, the ID authentication means 3 outputs a room entry authentication request or a room authentication request to the lock control means 2. (S1). When the entrance authentication request or the exit authentication request is input from the ID authentication means 3, the lock control means 2 determines whether or not the person who intends to enter the room has the authority to enter the room, or the person who intends to leave the room has already authenticated. It is determined whether or not the person has already entered the room (S2). If the authentication request is valid, the valid number of authentications (number of room authentications or number of room exits) is output to the image monitoring means 4 each time. (S3) An unlocking process for unlocking the lock means 1 is performed.

  If the lock control means 2 determines that the authentication request is valid as a result of the determination in S2, the lock control means 2 outputs a lock / unlock signal for unlocking the lock means 1 (S4). The lock means 1 is unlocked according to the lock / unlock signal from the lock control means 2 (S5), and the door open / closed state detection signal and the lock / unlock input from a sensor (not shown) for detecting the opening / closing of the door D. A signal indicating the state is output to the lock control means 2 (S6). When a predetermined time (for example, 10 seconds) elapses after unlocking and the door D is closed, the locking means 1 locks (S5), and locks the door open / closed state detection signal and the signal indicating the unlocked state. It outputs to the means 2 (S6). In addition, the timing which locks after unlocking the locking means 1 is good also as the time of detecting that the door D is closed after unlocking. When the lock control means 2 receives the door open / closed state detection signal and the lock / unlock state detection signal from the lock means 1, the lock control means 2 outputs these signals to the image monitoring means 4 (S7).

  In the image monitoring means 4, the passing person counting means 41 acquires images from the imaging means 40 at a predetermined sampling interval (S8), extracts a human body using a method such as background difference (S9), and then extracts the extracted human body. Are tracked (S10), and this series of processing is repeatedly executed. The human body extraction process and tracking process may be performed using a general-purpose image processing method.

  In the image monitoring means 4, when the number of entrance authentications or the number of exit authentications is inputted from the lock control means 2, the entrance authentication number or the exit authentication number is counted up using the built-in entrance authentication number counter or the exit authentication number counter. Perform (S11). The count values of the entrance authentication number counter and the exit authentication number counter are initialized (cleared to zero) by the following procedure. That is, the image monitoring means 4 acquires signals indicating the unlocked state and the door D open / closed state from the lock control means 2 (S12), and for example, the lock state is locked from the unlocked state based on these signals. When the state changes, zero clear is performed (S13). In this case, each counter counts the number of authentications between the unlocked state before unlocking and the subsequent unlocking. The image monitoring means 4 clears the authentication count value to zero when the number of passing people detected at the time of unlocking reaches the number of authentications or when the lock state changes from the unlocked state to the locked state, whichever comes first. In this case, the number of authentications until the number of passing persons reaches the number of authentications after being unlocked from the locked state before unlocking is counted in the counter. The reason for performing the zero clear in such a procedure is to compare the number of passing people measured in the unlocked state with the number of valid authentications for which the authentication processing has been performed.

  Further, when the lock state is acquired from the lock control unit 2 (S12), the image monitoring unit 4 determines whether or not the unlocking is being performed (S14). If unlocking is being performed, the person obtained by the tracking process of S10 is obtained. Based on the detection result of the time series movement of H, the passage direction (entrance direction or exit direction) of the person is detected, and the number of people passing the room or the number of persons passing the room is counted up by the built-in entrance passage counter or the exit passage counter. (S15). The image monitoring means 4 initializes (zero clears) the count value of the entrance / exit counter in the following procedure.

  In the signal processing means 42 of the image monitoring means 4, the entrance authentication count value NI1 of the built-in entrance authentication number counter, the exit authentication count value NO1 of the exit authentication number counter, the entrance passer count value NI2 of the entrance pass counter, and the exit pass counter The number of people passing through and the number of people passing through the number NO2 are detected by the following method to detect the mismatch between the number of people passing through and the number of authentications, that is, unauthorized entry / exit (S16). Here, when only the entrance is monitored and the exit can be performed freely, the signal processing means 42 authenticates the passing person and the passing person count value NI2 when the entrance passing person count value NI2 exceeds the entrance authentication count value NI1 (NI1 <NI2). It is determined that a number mismatch has occurred, an alarm signal is output (S17), and an alarm is output from an alarm output means (not shown) such as an electronic buzzer built in the lock control means 2 (S18). When it is desired to monitor both entrance and exit, the signal processing means 42 determines whether the entrance pass count value NI2 exceeds the entrance authentication count value NI1 (NI1 <NI2) or the exit pass count value NO2 is the exit authentication count. When the value exceeds NO1 (NO1 <NO2), it is determined that there is a mismatch between the number of people passing and the number of authentications on the entrance or exit side, and an alarm signal is output (S17). An alarm is output from the output means (S18).

  Further, the image monitoring means 4 initializes the count value of the built-in / passing person count counter or the exit passing person counter at the following timing (S19). In other words, the image monitoring means 4 initializes the count values of the passing person counter (the entering person passing person count value and the leaving person passing person count value) at the timing when the locked state changes from the unlocked state to the locked state. It is possible to count the number of people who have passed through the lock and before it is locked again. In the image monitoring means 4, either the time when the measured value of each passing person counter (number of persons entering or leaving the room) reaches the number of authentications, or the time when the lock state changes from the unlocked state to the locked state. The count value of the passing number counter may be initialized earlier, and the number of persons who have passed from the locked state until unlocked after being unlocked can be counted.

  The image monitoring means 4 detects a mismatch between the number of people passing through and the number of authentications and outputs a warning signal (for example, when the entrance authentication count value is 1 and the number of people passing through the room count is 2). If unlocking is in progress, the count value of the number of people passing through the room counted by the entrance counter is rewritten to 1 (the entry authentication count value at this time). Thus, if the image monitoring means 4 rewrites the number of people passing through the room entry count value to the current entry authentication count value, the person who wants to enter the room during unlocking uses the ID authentication means 3 to perform authentication processing. Then, the entrance authentication count value becomes 2, and then, when this person enters the room, the entry passing person count value becomes 2, so that the entrance authentication count value and the entrance passing person count value become the same value, Since there is no mismatch with the number of authentications, no alarm signal is output. If the number of people passing through the room is not corrected after the alarm signal is generated, if the person who wants to enter the room during the unlocking period after the alarm is output enters the authentication process, the entrance authentication count is 2, Although the value is 3 and there is a mismatch between the number of authentications and the number of people passing through even after passing after authentication, an alarm signal is output. Can be prevented by rewriting to the current entry authentication count value.

  The entrance / exit management device of the present embodiment has the above-described configuration and is opposite to the side where the door D provided at the entrance / exit E opens in the room R which is a restricted area or the shared space A outside the room R. Since the image pickup means 40 is installed on the side (for example, the room R in this embodiment), even when the door D is opened, no blind spot is generated by the door D in the image pickup area W of the image pickup means 40. Therefore, the image monitoring means 4 can accurately detect the number of people passing through the doorway E (number of people entering the room, the number of people leaving the room) based on the image taken by the image pickup means 40, so that unauthorized entry / exit can be ensured. Can be detected. In this embodiment, since the door D opens to the shared space A side, the image monitoring means 4 is installed on the room R side (monitoring area side). However, when the door D opens to the room R side, the image monitoring means 4 is opened. As long as it is installed on the shared space A side, a blind spot cannot be formed by the door D in the imaging area of the imaging means 40 as described above, so that it is possible to reliably detect unauthorized entry and exit by accurately detecting the number of people passing by. Can do.

  By the way, as shown in FIG. 11, the image pickup means 40 used in the image monitoring means 4 of the present embodiment includes a light source 11, an optical system 12, a light detection element 13, a sensor control means 14, and an image generation means 15. And.

  The light source 11 includes, for example, an infrared LED array arranged in one plane, an infrared semiconductor laser, a diverging lens, or the like in order to ensure light intensity. As shown in FIG. The intensity K1 of the infrared light is modulated so as to periodically change at a constant period in accordance with the modulation signal from, and the detection area (imaging area W) is irradiated with the intensity-modulated infrared light. The intensity waveform of the intensity-modulated infrared light is not limited to a sine wave but may be a triangular wave or a sawtooth wave.

  The optical system 12 is a light receiving optical system, which is configured by, for example, a lens and an infrared transmission filter, and condenses infrared light from the detection area on the light receiving surface (each photosensitive unit 131) of the light detecting element 13. The optical system 12 is disposed, for example, so that its optical axis is orthogonal to the light receiving surface of the light detection element 13.

  The light detection element 13 is formed in a semiconductor device, and includes a plurality of photosensitive units 131, a plurality of sensitivity control units 132, a plurality of charge integration units 133, and a charge extraction unit 134. Each photosensitive unit 131, each sensitivity control unit 132, and each charge integration unit 133 constitute a two-dimensional photosensitive array as a light receiving surface arranged facing the detection area via the optical system 12.

  As shown in FIGS. 13A and 13B, each photosensitive unit 131 is formed as a photosensitive element of a 100 × 100 two-dimensional photosensitive array, for example, by a semiconductor layer 13a to which impurities are added in a semiconductor substrate. The photosensitivity controlled by the corresponding sensitivity control unit 132 generates an amount of charge corresponding to the amount of infrared light from the detection area. For example, the semiconductor layer 13a is n-type, and the generated charge is electrons.

When the optical axis of the optical system 12 is orthogonal to the light receiving surface, the vertical axis (longitudinal direction) and the horizontal direction (lateral direction) of the light receiving surface and the optical axis are set to three axes of the orthogonal coordinate system. If the origin is set at the center of the optical system 12, each photosensitive unit 131 generates an amount of charge corresponding to the amount of light from the direction represented by the azimuth angle and the elevation angle. When there is one or more physical objects in the detection area, the infrared light emitted from the light source 11 is reflected by the physical object and received by the photosensitive unit 131. Therefore, the photosensitive unit 131 is as shown in FIG. In addition, intensity-modulated infrared light delayed by a phase ψ corresponding to the round-trip distance to the physical object is received, and an amount of charge corresponding to the intensity K2 is generated. The intensity-modulated infrared light is
K2 · sin (ωt−ψ) + B (Expression 1)
Where ω is an angular frequency and B is an external light component.

  The sensitivity control unit 132 is formed by a plurality of control electrodes 13b stacked on the surface of the semiconductor layer 13a via an insulating film (oxide film) 13e. According to the sensitivity control signal of the sensor control unit 14, the sensitivity control unit 132 has a corresponding sensitivity control unit 132. Control sensitivity. In FIGS. 13A and 13B, the width dimension of the control electrode 13b in the left-right direction is set to about 1 μm. The control electrode 13b and the insulating film 13e are formed of a material that is transparent to the infrared light of the light source 11. As shown in FIGS. 13A and 13B, the sensitivity control unit 132 includes a plurality of (for example, five) control electrodes for the corresponding photosensitive unit 131. For example, when the generated charge is an electron, a voltage (+ V, 0V) is applied to each control electrode 13b as a sensitivity control signal.

  The charge integration unit 133 includes a potential well (depletion layer) 13c that changes in response to a sensitivity control signal applied to each corresponding control electrode 13b, and captures and accumulates electrons (e) in the vicinity of the potential well 13c. To do. Electrons that are not accumulated in the charge accumulation unit 133 disappear due to recombination with holes. Therefore, the photosensitive sensitivity of the photodetecting element 13 can be controlled by changing the size of the region of the potential well 13c according to the sensitivity control signal. For example, the sensitivity in the state of FIG. 13A is higher than that in the state of FIG.

  For example, as shown in FIG. 14, the charge extraction unit 134 has a structure similar to a frame transfer (FT) type CCD image sensor. In the imaging region L1 constituted by a plurality of photosensitive units 131 and the light-shielded accumulation region L2 adjacent to the region L1, the semiconductor layer 13a integrally continuous in each vertical direction (longitudinal direction) has a charge in the vertical direction. Used as a transfer path. The vertical direction corresponds to the left-right direction in FIGS.

  The charge extraction unit 134 includes an accumulation region L2, each transfer path, and a CCD horizontal transfer unit 13d that receives charges from one end of each transfer path and transfers the charges in the horizontal direction. The charge transfer from the imaging region L1 to the storage region L2 is executed once in the vertical blanking period. That is, after charge is accumulated in the potential well 13c, a voltage pattern different from the voltage pattern of the sensitivity control signal is applied to each control electrode 13b as a vertical transfer signal, and the charge accumulated in the potential well 13c is transferred in the vertical direction. Is done. As for the transfer from the horizontal transfer unit 13d to the image generating means 15, a horizontal transfer signal is supplied to the horizontal transfer unit 13d, and the charge for one horizontal line is transferred in one horizontal period. In an alternative example, the horizontal transfer unit transfers charges in the direction normal to the planes of FIGS.

  The sensor control means 14 is an operation timing control circuit, and controls the operation timing of the light source 11, each sensitivity control unit 132, and the charge extraction unit 134. That is, since the propagation time of the light at the round-trip distance is a very short time of nanosecond level, the sensor control unit 14 supplies a modulation signal having a predetermined modulation frequency (for example, 20 MHz) to the light source 11, Controls the change timing of the intensity of the intensity-modulated infrared light. The sensor control means 14 applies a voltage (+ V, 0V) as a sensitivity control signal to each control electrode 13b, and switches the sensitivity of the light detection element 13 to high sensitivity or low sensitivity.

  Further, the sensor control unit 14 supplies a vertical transfer signal to each control electrode 13b during the vertical blanking period, and supplies a horizontal transfer signal to the horizontal transfer unit 13d during one horizontal period.

  The image generation unit 15 is configured by, for example, a CPU and a storage device that stores a program and the like, and generates a distance image and an intensity image based on a signal from the light detection element 13.

Hereinafter, the operation principle of the sensor control unit 14 and the image generation unit 15 will be described. Since the phase (phase difference) ψ in FIG. 12 corresponds to the round-trip distance between the light receiving surface of the light detection element 13 and the physical object in the detection area, the distance to the physical object is calculated by calculating the phase ψ. be able to. The phase ψ can be calculated from the time integral value (for example, the integral values Q0, Q1, Q2, and Q3 of the period Tw) of the curve represented by the above (formula 1). The time integration values (light reception amounts) Q0, Q1, Q2, and Q3 start from phases 0 degree, 90 degrees, 180 degrees, and 270 degrees, respectively. The instantaneous values q0, q1, q2, and q3 of Q0, Q1, Q2, and Q3 are respectively q0 = K2 · sin (−ψ) + B
= -K2 · sin (ψ) + B
q1 = K2 · sin (π / 2−ψ) + B
= K2 · cos (ψ) + B
q2 = K2 · sin (π−ψ) + B
= K2 · sin (ψ) + B
q3 = K2 · sin (3π / 2−ψ) + B
= −K2 · cos (ψ) + B
Given by. Therefore, the phase ψ is given by the following (Equation 2), and the phase ψ can be obtained by (Equation 2) even in the case of a time integral value.

ψ = tan ⁻¹ {(q2-q0) / (q1-q3)} (Formula 2)
Since the amount of charge generated in the photosensitive unit 131 is small during one period of the intensity-modulated infrared light, the sensor control unit 14 controls the sensitivity of the photodetecting element 13 so that a plurality of periods of the intensity-modulated infrared light are emitted. The charges generated by the photosensitive unit 131 in the meantime are accumulated in the charge accumulation unit 133. Since the phase ψ and the reflectivity of the physical object hardly change during a period of a plurality of periods of the intensity-modulated infrared light, for example, when the charge corresponding to the time integration value Q0 is integrated in the charge integration unit 133, it corresponds to Q0. During the period, the sensitivity of the light detection element 13 is increased, and during the other periods, the sensitivity of the light detection element 13 is decreased.

  If the photosensitive unit 131 generates a charge proportional to the amount of received light, when the charge accumulation unit 133 accumulates the charge of Q0, a charge proportional to αQ0 + β (Q1 + Q2 + Q3) + βQx is accumulated. Here, α is the sensitivity in the period corresponding to Q0 to Q3, β is the sensitivity in the other period, and Qx is the received light amount other than the period in which Q0, Q1, Q2, and Q3 are obtained. Similarly, when the charge accumulation unit 133 accumulates the charge of Q2, a charge proportional to αQ2 + β (Q0 + Q1 + Q3) + βQx is accumulated. Q2-Q0 = (α-β) (Q2-Q0) and Q1-Q3 = (α-β) (Q1-Q3), (Q2-Q0) / (Q1-Q3) are not required from (Equation 2) Since the theoretical value is the same regardless of the presence or absence of charge, the phase ψ to be obtained is the same value even if unnecessary charge is mixed.

  After a plurality of periods of intensity-modulated infrared light, the sensor control means 14 supplies a vertical transfer signal to each control electrode 13b in the vertical blanking period in order to take out the charges accumulated in the charge integration unit 133, A horizontal transfer signal is supplied to the horizontal transfer unit 13d in one horizontal period.

  Since Q0 to Q3 reflect the brightness of the physical object, the added value or average value of Q0 to Q3 corresponds to the intensity (density) value in the infrared intensity image (grayscale image). Therefore, the image generation means 15 can generate a distance image and an intensity image from Q0 to Q3. Moreover, the distance value and the intensity value at the same position can be obtained by generating the distance image and the intensity image from Q0 to Q3. The image generation means 15 calculates a distance value from Q0 to Q3 according to (Equation 2), and generates a distance image from each distance value. At this time, three-dimensional information of the detection area may be calculated from each distance value, and a distance image may be generated from the three-dimensional information. Since the intensity image includes the average value of Q0 to Q3 as the intensity value, the influence of the light from the light source 11 can be removed.

  In the present embodiment, an active distance image sensor that generates a distance image using a distance value to a target object in the detection area as a pixel value is used as the image pickup unit 40. Even if it has the same color, it is possible to accurately extract the human body that is the object as compared with the case of using a grayscale image, and the passing number of people detection processing and the number of staying people detection processing described later are accurately performed. It can be carried out.

(Embodiment 2)
A second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a schematic block diagram of the entrance / exit management device of the present embodiment, and FIGS. 5A and 5B are layout diagrams schematically showing an example of the arrangement of each part.

  The entrance / exit management device is used to manage entry / exit into a room R (restricted area), which is a restricted area, and is a lock comprising an electric lock that locks / unlocks the door D provided at the entrance / exit E of the room R. Means 1, lock control means 2 for controlling the unlocking / locking of the lock means 1, ID authentication means 3 for judging whether or not the person who wants to enter the room has the right to enter the room, and image monitoring Means 4 is provided as a main component. Here, in this embodiment, the door D provided at the entrance / exit E is opened to the room R side which is a restricted area, and the imaging means 40 of the image monitoring means 4 is an imaging set near the entrance / exit E of the common space A. The area W is imaged. Since the configuration other than the image monitoring unit 4 is the same as that of the first embodiment, common components are denoted by the same reference numerals, and description thereof is omitted.

  The image monitoring means 4 is installed on the ceiling X of the shared space A, and is a first imaging means (hereinafter abbreviated as imaging means) 40 that images the imaging area W in the shared space A in the vicinity of the entrance E. By extracting moving / still persons in the imaging area W from the image captured by the imaging means 40 and tracking the extracted objects, the passing person counting means 41 for counting the number of people entering and leaving the room, and the imaging means 40 The number of people staying in the desired detection area of the imaging area W is extracted from the captured image and the number of people staying in the desired detection area is counted. Presence / absence of unauthorized entry / exit based on the number of authentications of the ID authentication means 3 and the count value of the number of passing persons input via the lock control means 2 And determine When the installation position is input to the shared space A side by the installation position switching means 44, the unlocking process by the lock control means 2 is stopped when the number of staying persons counted by the staying person counting means 43 exceeds a predetermined allowable number of persons. And signal processing means 42 for restricting entrance / exit.

  The installation position switching means 44 is composed of a changeover switch such as a slide switch, for example. When the image monitoring means 4 is constructed, the installer switches the switching position of the changeover switch according to the installation position of the image monitoring means 4 and inputs the installation position. It is supposed to be.

  The passing person counting means 41 uses, for example, a distance image picked up by the image pickup means 40, stores a background image in which no person exists in advance, and cuts out the foreground portion obtained from the difference between the stored background image and the current time image. Thus, the object (person H) within the imaging range is extracted, and such an object extraction process is performed at regular time intervals to calculate the position of the extracted object on the image. The passing person counting means 41 switches the direction of detection of entering and leaving the room R based on the installation position input by the installation position switching means 44. Then, the passing person counting means 41 performs tracking of the moving extracted object by associating the calculated position of the extracted object at the current time with the calculated position at the previous time. Alternatively, when the exit position is determined and the installation position is input as the common space A by the installation position switching means 44, the person who moves to the entrance / exit E side and whose tracking disappears in the vicinity of the entrance / exit E is entered. A person who appears in the vicinity and whose tracking disappears on the shared space A side is regarded as a person leaving the room, and the number of persons entering and leaving the room is counted. When the installation position is input as the room R by the installation position switching means 44, the passing person counting means 41 detects from the inside of the room R, those who appear in the vicinity of the entrance E and whose tracking disappears on the room R side. A person who moves to the entrance / exit E side and whose tracking disappears in the vicinity of the entrance / exit E is regarded as a person leaving the room, and the number of persons entering and leaving the room is counted.

  The visitor number counting means 43 uses, for example, a distance image captured by the imaging means 40, stores a background image in which no person exists in advance, and cuts out the foreground portion obtained from the difference between the stored background image and the current time image. Thus, the object (person H) within the imaging range is extracted, and the number of people staying in the imaging area W is counted by performing the labeling process of the extracted object, and the counting result is signal processing means 42. Output to.

  Next, the operation of the entrance / exit management device will be described with reference to the flowchart of FIG. Note that the flowchart of FIG. 6 is also expressed in a block diagram so that the operations of the respective means 1 to 4 described above can be easily understood. Further, the same processes as those in the flowchart of FIG. 3 are denoted by the same reference numerals and the description thereof is omitted, and only the characteristic part of the present embodiment will be described below.

  First, the unlock determination process by the lock control means 2 will be described. If the lock control means 2 determines that the authentication request is valid as a result of the determination in S2, it is determined whether or not to unlock the lock means 1 based on the number of visitors input from the image monitoring means 4. (S20). For example, in an operation in which only one person is permitted to authenticate and pass at the time of authentication, the lock control means 2 does not unlock the lock means 1 when the number of staying persons is two or more, and only when the number of staying persons is one. A locking / unlocking signal for unlocking the locking means 1 is output (S4). On the other hand, in the operation of unlocking if the authentication is valid regardless of the number of visitors, the lock control means 2 unlocks the lock means 1 if the authentication request is determined to be valid in the determination of S2. A signal is output (S4).

  Next, the number of staying people detection process by the image monitoring means 4 will be described. In the image monitoring means 4, the passing person counting means 41 acquires images from the imaging means 40 at a predetermined sampling interval (S8), and extracts a target object (human body) using a method such as background difference (S9). The number of staying persons is counted by performing a labeling process (labeling process) on the extracted human body (S21), and the extracted human body is tracked (S10). This series of processes is repeatedly executed. The human body extraction process, the visitor counting process and the tracking process may be performed using a general-purpose image processing method.

  A process of counting the number of passing people by the image monitoring unit 4 will be described. Since the image pickup means 40 of the image monitoring means 4 is installed on the side opposite to the side where the door D opens, in this embodiment, an installation position switching means 44 for inputting the installation position of the image pickup means 40 is provided. Then, when the installer inputs the installation position of the imaging means 40 using the installation position switching means 44 during the construction of the entrance / exit management device (S22), the image monitoring means 4 uses the video imaged by the imaging means 40, Based on the installation position information of the installation position switching means 44, the direction of the human body to pass (the entrance direction or the exit direction) is determined, and the number of people who have entered the room and the number of people who have left the room are counted.

  That is, when the lock state is acquired from the lock control means 2 (S12), the image monitoring means 4 determines whether or not unlocking is in progress (S14). If unlocking is in progress, the person obtained by the tracking process in S10 is obtained. A person's passage direction is detected based on the detection result of the time series operation of H. The detection method of the passage direction is switched according to the installation position of the imaging means 40. For example, when the installation position of the imaging unit 40 is input as the common space A using the installation position switching unit 44, the passing person counting unit 41 moves in the direction of the entrance / exit E and enters the person who enters the object that disappears in the vicinity of the entrance / exit E The built-in exit counter is counted up, and the object that appears near the entrance E and moves toward the shared space A is judged as a person leaving the room, and the built-in exit counter is counted up. Yes. On the other hand, when the installation position of the imaging means 40 is input as room R using the installation position switching means 44, the passing person counting means 41 is a person who enters an object that appears near the entrance E and moves inside the room R. The built-in exit counter is counted up, and an object that moves in the direction of the entrance E and disappears in the vicinity of the entrance E is judged as a person leaving the room, and the built-in exit counter is counted up. Yes.

  As described above, in the present embodiment, the installation position switching means 44 for inputting the installation position of the image monitoring means 4 is provided, and the passing number counting means 41 enters or exits according to the setting of the installation position switching means 44. Since the detection direction is switched, the same image monitoring means 4 can be installed and used in either the room R (monitoring area) or the common space A by switching the detection direction according to the opening / closing direction of the door D in the installation environment. can do.

  In the image monitoring means 4, when the number of staying persons detected by the staying person counting means 43 exceeds a predetermined allowable number of persons, the signal processing means 42 serving as an entrance / exit restriction means stops the unlocking process by the lock control means 2. Therefore, it is possible to prevent a person who has no authority to enter the room from entering or leaving the room illegally together with the person who has completed ID authentication.

  Here, when it is determined whether unlocking is possible according to the number of people staying at the time of authentication, after the lock control means 2 unlocks the locking means 1 according to ID authentication of the first authenticator, The authentication process by the ID authenticating means 3 may be stopped, and by stopping the second and subsequent authentications, it is possible to prevent a subsequent person from entering or leaving the room following the first person. At this time, only the authentication process by the operation means 3a on the entrance side is stopped, and the authentication process by the operation means 3b on the exit side is continued, so that the entrance can be performed while preventing the second and subsequent persons from entering the room. Then, both the authentication process by the entrance side operation means 3a and the authentication process by the exit side operation means 3b may be stopped to prevent the successor from any direction.

  The period during which the ID authentication is stopped is a period from when the locking means 1 is unlocked according to the ID authentication of the first authenticator until the locking means 1 is locked. Only one person can pass through the lock. Also, the lock control means 2 does not output the number of authentications to the image monitoring means 4 even if the authentication is successful, instead of stopping the ID authentication after unlocking the lock means 1 in response to the first person's ID authentication. Even in this case, it is possible to prevent the successor from passing.

  If the lock means 1 is unlocked if the authentication is valid regardless of the number of people staying at the time of authentication, the lock control means 2 switches whether or not the ID authentication is possible according to the following procedure. May be. That is, if the lock control means 2 stops the ID authentication after the first person's authentication and the image monitoring means 4 detects the passage of the person, or if the ID authentication is restarted at the time of the next lock, A plurality of persons can be prevented from passing in a short time, and can be smoothly passed while preventing non-detection or false detection due to proximity passing or close-contact passing. Further, the lock control means 2 may stop the ID authentication after the first person's authentication, and may restart the ID authentication after a certain time or when it is locked next time, and the same effect is obtained. . Further, when it is not necessary to prevent a plurality of persons from passing in a short time, the lock control means 2 may perform ID authentication continuously without stopping ID authentication.

(Embodiment 3)
A third embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a schematic block diagram of the entrance / exit management device of this embodiment, and FIGS. 8A and 8B are layout diagrams schematically showing an example of the arrangement of each part.

  The entrance / exit management device is used to manage entry / exit into a room R (restricted area), which is a restricted area, and is a lock comprising an electric lock that locks / unlocks the door D provided at the entrance / exit E of the room R. Means 1, lock control means 2 for controlling the unlocking / locking of the lock means 1, ID authentication means 3 for determining whether the person who wants to enter the room has authority to enter the room, and image monitoring means 4a and 4b are provided as main components. Here, in this embodiment, the door D provided at the entrance / exit E opens to the shared space A side, and one image monitoring means 4a is installed on the side opposite to the side where the door D opens (room R side). The imaging area W1 set in the vicinity of the entrance / exit E in the room R is imaged, and the other image monitoring means 4b is installed on the side where the door D opens (the shared space A side), and near the entrance / exit E in the shared space A The imaging area W2 set to is imaged. Since the configuration other than the image monitoring units 4a and 4b is the same as that of the first embodiment, the same components are denoted by the same reference numerals and the description thereof is omitted.

  Since the image monitoring units 4a and 4b have the same configuration as the image monitoring unit 4 (see FIG. 4) described in the second embodiment, common components are denoted by the same reference numerals, and the description thereof is omitted. Is omitted. The image monitoring unit 4 a is installed on the ceiling X <b> 1 of the room R, and the installation position is set to the room R using the installation position switching unit 44. The image monitoring unit 4 b is installed on the ceiling X <b> 2 of the shared space A, and the installation position is set in the shared space A using the installation position switching unit 44.

  Next, the operation of the entrance / exit management device will be described with reference to the flowchart of FIG. The flow diagram of FIG. 9 is also expressed in a block diagram so that the operation of each of the means 1 to 4 can be easily understood. Further, since the operation of each part is the same as that of the second embodiment, the same processes as those in the flowchart of FIG. 6 are denoted by the same reference numerals and description thereof is omitted, and only the characteristic part of this embodiment will be described below. To do. Since the operations of the image monitoring units 4a and 4b are substantially the same as those described in the second embodiment, illustration and description of common operations are omitted, and different operations will be described below.

  In the image monitoring means 4a and 4b, the signal processing means 42 switches the operation according to the installation position input using the installation position switching means 44. In the image monitoring means 4a installed in the room R, the lock control means 2 is switched. When the number of room authentications or the number of room authentications is input, the room authentication number counter or the room authentication number counter is incremented (S11). When the lock state is input from the lock control means 2, the image monitoring means 4a acquires the lock state (S12), the authentication number initialization determination process (S13), and the unlocking determination process (S13). S14) is performed. Further, when the image monitoring means 4a determines in S16 that there is a mismatch between the number of authentications and the number of passing people, it outputs an alarm signal (S17) and outputs an alarm from the alarm output means built in the lock control means 2. (S18). In addition, in the image monitoring means 4a installed in the room R, the process of counting the number of people passing is performed only at the time of unlocking, and the number of staying persons is not detected. In addition, the image monitoring means 4a may perform the counting process of the number of visitors, but the counting result is not output to the lock control means 2.

  On the other hand, since the operation of the image monitoring unit 4b installed in the common space A is substantially the same as the operation of the image monitoring unit 4 described in the second embodiment, illustration and description of common operations are omitted. The image monitoring unit 4b has acquired the lock state from the lock control unit 2 (S12), performs detection processing for the number of staying people during locking, and outputs the detection result of the number of staying people to the lock control unit 2 (S21). If the lock control means 2 determines that the authentication request is valid as a result of the determination in S2, whether or not to unlock the lock means 1 based on the number of staying persons input from the image monitoring means 4 is determined. Is determined (S20). For example, in an operation in which only one person is permitted to authenticate and pass at the time of authentication, the lock control means 2 does not unlock the lock means 1 when the number of staying persons is two or more, and only when the number of staying persons is one. A locking / unlocking signal for unlocking the locking means 1 is output (S4). On the other hand, in the operation of unlocking if the authentication is valid regardless of the number of visitors, the lock control means 2 unlocks the lock means 1 if the authentication request is determined to be valid in the determination of S2. A signal is output (S4).

  At the time of unlocking, the image monitoring means 4b does not perform the process of detecting the number of visitors. In addition, the image monitoring means 4b installed in the common space A does not perform the process of counting the number of people passing through (number of people who have entered the room, the number of people who have left the room), and also performs the process of determining inconsistency between the number of people passing and the number of authentications. Not.

  As described above, in the present embodiment, the number of staying persons is counted from the image of the image monitoring means 4b installed in the common space A, and when the number of staying persons exceeds a predetermined allowable number of persons, entrance / exit is restricted and a room that is a monitoring area The number of passing people is counted from the image of the image monitoring means 4a installed in R, and an illegal entry / exit is detected from the mismatch between the number of passing people and the number of authentications. In addition, in the image monitoring means 4b installed on the shared space A side where the door D opens, the passing person count process is not performed, and the staying person count is performed in a locked state, that is, the door D is closed. Therefore, even if a blind spot is formed by opening the door D, the counting process is not affected. Further, since the door D is closed at the time of locking, the intensity-modulated light from the light source 11 is shielded by the door D even if both the light sources 11 of the imaging means 40 of the image monitoring means 4a and 4b are lit. In the means 4a and 4b, the intensity-modulated light from the other image monitoring means 4b and 4a is not affected.

  On the other hand, if the door D is opened at the time of unlocking, there is a risk that malfunction will occur due to the intensity-modulated light emitted from the other light source 11, but at the time of unlocking, the image monitoring means 4b installed in the common space A is the number of visitors Neither the detection of the number of persons nor the number of passing people is performed. It is possible to prevent the intensity-modulated light from the other image monitoring means 4b from affecting the image monitoring means 4a that performs detection at the time of unlocking. Therefore, the intensity-modulated lights emitted from the image monitoring means 4a and 4b do not interfere with each other, and there is an advantage that erroneous detection can be prevented. When the door D is formed of a material that transmits the intensity-modulated light from the light source 11, if the intensity-modulated light is irradiated from the light source 11 of each image monitoring apparatus 4a, 4b during locking, the image monitoring apparatus 4a, The imaging means 40 of 4b may be affected by the intensity-modulated light emitted from the light source 11 of the other image monitoring device 4b, 4a, but the modulation frequency and demodulation are applied to the imaging means 40 of the image monitoring means 4a, 4b. If a plurality of frequencies are prepared and the image monitoring means 4a and 4b used adjacently use different modulation frequencies and demodulation frequencies, interference of modulated light can be prevented. In this embodiment, the image monitoring means 4a and 4b both use the image pickup means 40 for picking up the distance image, but only one of the image monitoring means 4a and 4b picks up the distance image. May be used, and the other may be an image pickup means for picking up a gray image.

  By the way, you may use the entrance / exit management apparatus of this embodiment in an installation environment as shown to Fig.10 (a) (b). That is, in the usage environment of FIG. 10, the door D1 is installed at the entrance E1 of the room R, which is a restricted area, and the interlock room L is provided outside the room R, and the entrance between the interlock room L and the common space A is provided. A door D2 is installed at E2. Then, the image monitoring means 4b is installed on the ceiling X2 of the interlock room L, and the entire inside of the interlock room L is photographed by the imaging means 40, and the operation means 3a of the ID authentication means 3 is set in the interlock room L. In the vicinity of the door D1, the operation means 3b is installed in the vicinity of the door D2 in the room R. The lock control means 2 is input with information indicating the locking / unlocking state of the lock means (not shown) provided in the door D2 that partitions the interlock room L and the common space A. The door D1 and the door The locking / unlocking of the locking means 1 of the door D1 and the locking means of the door D2 is controlled so that D2 is not unlocked at the same time.

  When the above-mentioned entrance / exit management device is used in such a use environment, the lock control means 2 uses the detection result of the number of staying persons by the image monitoring means 4b installed in the interlock room L to lock the lock means 1. The degree of security can be enhanced by unlocking only when the number of staying persons is one when entering the room and unlocking only when the number of staying persons is zero when leaving the room.

  By the way, in the entrance / exit management device of each embodiment described above, the person leaving the room R, which is the restricted area, also performs ID authentication, but the operation means 3b installed in the room R is eliminated and the inside of the door D ( The person who leaves the room may open the door D by operating the unlocking knob provided on the room R side by hand and unlocking the locking means 1 by the lock control means 2. In this case, the lock control means 2 locks the lock means 1 once the door D is opened and then closed, thereby preventing the lock means 1 from being held in the unlocked state. .

  It should be noted that a wide variety of different embodiments can be configured without departing from the spirit and scope of the present invention, and the present invention is not limited to a specific embodiment.

It is a schematic block diagram of the entrance / exit management apparatus of Embodiment 1. FIG. (A) (b) is explanatory drawing which showed typically the example of arrangement | positioning same as the above. It is a flowchart explaining operation | movement same as the above. It is a schematic block diagram of the entrance / exit management apparatus of Embodiment 2. (A) (b) is explanatory drawing which showed typically the example of arrangement | positioning same as the above. It is a flowchart explaining operation | movement same as the above. It is a schematic block diagram of the entrance / exit management apparatus of Embodiment 3. (A) (b) is explanatory drawing which showed typically the example of arrangement | positioning same as the above. It is a flowchart explaining operation | movement same as the above. (A) (b) is explanatory drawing which showed typically the other example of arrangement | positioning same as the above. It is a block diagram of the distance image sensor used for the same as the above. It is operation | movement explanatory drawing of the distance image sensor of FIG. (A) and (b) are the figures which show the area | region corresponding to one photosensitive part in the distance image sensor of FIG. It is explanatory drawing of the electric charge extraction unit in the distance image sensor of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lock means 2 Lock control means 3 ID authentication means 3a, 3b Operation means 4 Image monitoring means 40 Imaging means (1st imaging means)
41 Passing number counting means 42 Signal processing means (output means)

Claims (5)

  ID authentication means for performing ID authentication for at least a person entering the restricted area, locking means for locking or unlocking the door provided at the entrance / exit of the restricted area, and operation from the ID authentication or restricted area side A locking control means for locking or unlocking the locking means, and an imaging area in the vicinity of the doorway that is installed on the opposite side of the restricted area or the shared space outside the restricted area on the side where the door opens. A first imaging means, a passing number counting means for counting the number of passing persons passing through the doorway during the unlocking period from an image of the first imaging means, and a passing number counted by the passing number counting means And a number of authentications authenticated by the ID authentication means, and an output / output means for outputting a detection signal when there is a mismatch.   Number-of-staying-counting means for counting the number of people staying in the imaging area from the image of the first imaging means, and installation position switching means for inputting whether the installation position of the first imaging means is on the restricted area side or the shared space side When the installation position is input as a common space by the installation position switching means, and the number of staying persons counted by the staying person counting means at the time of locking exceeds a predetermined allowable number of persons, the entrance / exit to stop the unlocking process by the lock control means 2. The entrance according to claim 1, further comprising: a restricting unit, wherein the passing number counting unit switches a detection direction of entering and leaving the restricted area based on the installation position input by the installation position switching unit. Exit management device.   The first imaging means is installed on the restricted area side, the second imaging means is installed in the shared space and images the imaging area near the entrance, and the imaging area from the image of the second imaging means A staying number counting means for counting the number of staying persons, and an entry / exit restriction means for stopping the unlocking process by the lock control means when the staying number counted by the staying number counting means at the time of locking exceeds a predetermined allowable number of persons The output means compares the number of passing people counted by the passing number counting means with the number of authentications authenticated by the ID authentication means at the time of unlocking, and outputs a detection signal when there is a mismatch. The entrance / exit management device according to claim 1.   A distance in which at least one of the first and second imaging means irradiates the imaging region with modulated light and measures a reflection time thereof to set a distance value to an object in the imaging region as a pixel value. The entrance / exit management device according to claim 3, comprising an active distance image sensor that generates an image.   The first and second imaging means irradiate modulated light to the imaging region and measure a reflection time thereof to generate a distance image having a distance value to a target in the imaging region as a pixel value. 4. The entrance / exit management device according to claim 3, comprising a distance image sensor, wherein the second imaging means stops irradiation of the modulated light when unlocked.

Images