JP2005328448A - Intercom system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To deal with a suspicious person or a crime such as picking by storing image data obtained by photographing using a human-sensitive sensor at an interval of a fixed distance, and displaying the image data in response to a user operation. <P>SOLUTION: An intercom system is comprised of a master unit having a monitor and a slave unit having a human-sensitive sensor, an intercom button and a photographing device. If a human body is detected by the human-sensitive sensor that the slave unit includes, the situation around the human body is photographed at a predetermined distance interval by the photographing device, image data are generated and stored in a predetermined memory. When the human body comes closest to the slave unit, the image data stored in the predetermined memory are transmitted to the master unit. The master unit stores the image data received from the slave unit. A user operates the master unit to display and confirm stored arbitrary image data on the monitor. Therefore, the user is capable of confirming a visitor who came while the user is absent, or a suspicious person who did not press the intercom button. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a door phone system capable of photographing.

  Currently, crimes due to suspicious individuals and picking are increasing year by year. Conventionally, a TV door phone system has been known as a typical security, but it operates only when the door phone is pressed, and it is impossible to recognize suspicious behavior before that. It was. For this reason, it was defenseless against crimes such as picking that did not push the doorphone.

  In order to prevent such problems, a TV intercom system that provides a human sensor on the camera-equipped slave unit and notifies the master unit when a person exists in the vicinity of the slave unit for a predetermined time and displays an external image on the monitor TV Is described in Patent Document 1. Further, Patent Document 2 describes a television intercom system in which a human sensor is provided in a slave unit with a camera, and when a person is present in the vicinity of the slave unit for a predetermined time, a captured video is recorded and recorded sound is recorded. ing.

  However, the door phone systems of these documents operate only when a person exists for a predetermined time, and cannot recognize a suspicious behavior before the predetermined time elapses. In addition, there is a problem that a person who is too close to the camera of the slave unit cannot be distinguished well.

JP-A-11-18074 JP 11-225327 A

  Examples of the problems to be solved by the present invention include the above. It is an object of the present invention to deal with crimes such as suspicious persons and picking by storing image data taken at regular distance intervals using human sensors and enabling them to be displayed by user operation. To do.

  The invention according to claim 1 is a door phone system including a child device and a parent device, wherein the child device includes at least one of a human sensor, a door phone button, the human sensor or the door phone button. An imaging device that captures a surrounding image when reacting, a distance detection unit that detects a distance between the slave unit and the human body when the human body is detected by the human sensor, and the distance detection unit detects Based on the distance, a first photographing means for photographing the human body at a predetermined distance by the photographing device, a first storage means for storing image data photographed by the first photographing means, and the human body is the child When the door phone button reacts with the first transmission unit that transmits the image data stored in the first storage unit to the master unit when the camera is closest to the machine, the imaging device captures the human body. Second imaging means for performing, and second transmission means for transmitting image data captured by the second imaging means to the master unit, wherein the master unit transmits an image transmitted by the monitor and the first transmission unit. A second storage unit configured to store data; and a display unit configured to display the image data stored in the second storage unit and the image data transmitted from the second transmission unit on the monitor.

  In one preferred embodiment of the present invention, a door phone system including a child device and a parent device, wherein the child device includes at least one of a human sensor, a door phone button, the human sensor, or the door phone button. An imaging device that captures an image of the surroundings when the above reacts, a distance detection unit that detects a distance between the slave unit and the human body when the human body is detected by the human sensor, and the distance detection unit Based on the detected distance, the imaging device captures the human body at every predetermined distance, a first storage unit that stores the image data captured by the first imaging unit, and the human body When the door phone button reacts with the first transmission unit that transmits the image data stored by the first storage unit to the base unit when the slave unit is closest to the slave unit, A second imaging unit for imaging the body; and a second transmission unit for transmitting image data captured by the second imaging unit to the parent device. The parent device includes a monitor and the first transmission unit. And a display unit for displaying the image data stored by the second storage unit and the image data transmitted by the second transmission unit on the monitor. And

  The door phone system includes a master unit having a monitor and a slave unit having a human sensor, a door phone button, and a photographing device. Usually, the master unit is installed indoors and the slave unit is installed at the entrance. The human sensor included in the slave unit is, for example, an ultrasonic sensor that detects the movement of a person or an animal. When the human sensor detects a human body, the surrounding situation is detected by the first photographing unit. Images are taken at predetermined distance intervals to generate image data. That is, the human body detected by the human sensor is photographed a plurality of times at predetermined distance intervals to generate a plurality of image data. The image data generated at this time is stored in a predetermined memory. Then, when the human body is closest to the child device, the image data stored in the predetermined memory is transmitted to the parent device. The master unit stores the image data received from the slave unit. The user can display and confirm any stored image data on the monitor by operating the master unit.

  Even when the door phone button is pressed by a visitor, the surrounding situation is photographed by the photographing means, and image data is generated. The image data generated at this time is immediately transmitted to the master unit. By displaying the image data received when the door phone button is pressed on the monitor, the master unit can confirm the appearance of the visitor at the entrance.

  According to this, since a plurality of image data photographed by the slave unit can be displayed on the monitor of the master unit, it is possible to surely check a visitor or a suspicious person. Even if a visitor or the like hides only when the door phone button is pressed, multiple image data are stored for the same person because images are automatically captured at predetermined distance intervals. The visitor and the like can be identified from the image data. Further, even when a visitor or the like commits a crime such as picking without pressing the door phone button, the visitor or the like can be identified from the stored image data. Then, the image data stored in the memory by the parent device can be used as a criminal evidence.

  In one aspect of the door phone system, the slave unit further includes a sensor sensitivity table that defines a plurality of distances between the slave unit serving as a reference for the photographing device and the human body, and the first photographing unit includes: When the distance detected by the distance detection means matches the distance specified in the sensor sensitivity table, the human body is photographed. Here, the distance defined in the sensor sensitivity table is not limited to one value, but may be a value having a predetermined width. According to this, the human body detected by the human sensor can be photographed at a plurality of distance intervals defined in advance in the sensor sensitivity table. Therefore, the user can confirm the image data photographed at an appropriate distance interval according to the installation location of the slave unit.

  In another aspect of the door phone system, the slave unit further includes a memory area for storing image data in association with each distance defined in the sensor sensitivity table, and the memory area is A storage mark indicating whether or not image data is stored in association with each distance, and the first storage unit stores the image data captured by the first imaging unit in the corresponding memory area. In addition, the corresponding saved mark is validated, and the first photographing unit performs photographing only when the saved mark corresponding to the distance detected by the distance detecting unit is invalid, and the preserved mark is valid. Do not shoot. According to this, even if the human sensor detects the human body, the first photographing unit performs photographing only once when the distance between the slave unit and the human body is approximately the same. That is, photographing at the same distance with respect to the same human body is performed only once. For this reason, it is possible to prevent the memory of the slave unit storing the captured image data from being deteriorated by wasting the storage capacity.

  In another aspect of the door phone system, the slave unit further includes a determination unit that determines whether or not the storage mark corresponding to the shortest distance among the distances defined in the sensor sensitivity table is valid. The first transmission unit transmits all the image data stored by the first storage unit to the master unit when the determination unit determines that the storage mark is valid. According to this, a 1st transmission means transmits image data to a main | base station, when the image data image | photographed when the human body approached the subunit | mobile_unit closest based on a sensor sensitivity table was preserve | saved in a memory area. The image data transmitted at this time is all the image data stored in the memory area. In this way, by using the image data captured when the human body is closest to the slave unit as a trigger for transmission to the master unit, the image data obtained by simply capturing the passing human body is eliminated, and the user's residence is improved. Only image data obtained by photographing a target human body having a high probability can be appropriately transmitted to the master unit.

  In another aspect of the door phone system, the slave unit includes invalid means that invalidates all the storage marks when a predetermined time has elapsed. Here, the predetermined fixed time is a time when it is estimated that the human body detected by the human sensor is the same person. As described above, by using a predetermined time as a reference, a plurality of image data obtained by photographing a human body estimated to be the same person in a series of flows can be associated with each other and transmitted to the parent device.

  In still another aspect of the door phone system, the photographing device is disposed at a position for photographing within a detection range of the human sensor. As a result, an image of a place where movement or the like is detected by the human sensor can be taken and transmitted. Therefore, it is possible to take an image showing the abnormal situation more accurately, and the situation determination of the user is more accurate.

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

[Basic configuration]
FIG. 1 shows an overall configuration of a door phone system according to an embodiment of the present invention. As illustrated, the door phone system 100 includes a parent device 110a installed indoors and a child device 110b installed at the entrance. A parent device 110 a having a monitor and a child device 110 b having a camera are connected to each other by a cable 103 so as to be able to communicate with each other. Here, various cables such as a signal line, a control line, a call line, a video line, and a power line can be applied as the cable 103.

  When the door phone button of handset 110b installed at the entrance is pressed, a ringing tone is generated from the speaker of base unit 110a. In addition, when the door phone button is pressed, the camera included in slave unit 110b operates, and an image of the entrance is displayed on the monitor included in master unit 110a. Then, the user can talk by talking to the microphones of the parent device 110a and the child device 110b. As described above, in the door phone system, the resident can check the appearance of the visitor at the entrance and can respond by calling while staying in the room.

  In the present invention, a human sensor is provided in the slave unit 110b in addition to the above functions, image data photographed at a fixed distance interval is stored, and these can be displayed on the master unit 110a by a user operation.

[Function block]
FIG. 2 is a functional block diagram showing a schematic configuration of the door phone system. As illustrated, in the door phone system 100, the parent device 110a and the child device 110b can communicate with each other via the cable 103.

  In the following description, if it is not necessary to distinguish between the constituent elements of the master unit or the slave unit, the suffix is omitted. For example, the term “control unit 111a” refers to the control unit of the master unit, and the term “control unit 111” refers to the control unit of either the master unit or the slave unit.

  Base unit 110a includes control unit 111a, video signal processing circuit 112a, monitor 113a, memory unit 114a, demodulation circuit 115a, signal generation unit 116a, speaker 117a, microphone 118a, and multiplexing circuit 120a. Is provided.

  The control unit 111a performs necessary control over the entire data transmission / reception process from the parent device 110a to the child device 110b, or conversely, from the child device 110b to the parent device 110a.

  The video signal processing circuit 112a processes the video signal received from the slave unit 110b via the multiplexing circuit 120a by the control unit 111a. Here, the video signal to be processed is a signal related to a video photographed by the slave device 110b by a CCD (Charge Coupled Device) camera 121b described later.

  The monitor 113a is constituted by a liquid crystal panel, for example, and is used for displaying the video processed by the video signal processing circuit 112a. The monitor 113a may display the shooting time and the current time of the displayed video.

  The memory unit 114a stores the video processed by the video signal processing circuit 112a. When storing the video, the video capture time and the reception time from the slave unit 110b may be stored in association with each other.

  The demodulation circuit 115a demodulates the audio signal received from the slave unit 110b via the multiplexing circuit 120a by the control unit 111a.

  The signal generator 116a generates a ringing tone such as “ping-pong” based on information about the ringing tone restored from the voice signal by the demodulation circuit 115a.

  The speaker 117a generates a sound restored from the sound signal by the demodulation circuit 115a and a ringing sound generated by the signal generation unit 116a.

  The microphone 118a acquires sound when a resident in the room makes a call with a visitor at the front door.

  The multiplexing circuit 120a transmits and receives multiplexed audio signals and video signals.

  On the other hand, the slave unit 110b includes a control unit 111b, a video signal processing circuit 112b, a memory unit 114b, a demodulation circuit 115b, a signal generation unit 116b, a speaker 117b, a microphone 118b, a multiplexing circuit 120b, and a CCD. The camera 121b, the human sensor 122b, and the door phone button 123b are provided. Since the functions of the control unit 111b, the demodulation circuit 115b, the speaker 117b, the microphone 118b, and the multiplexing circuit 120b are the same as those of the parent device 110a, the description thereof is omitted for the sake of convenience.

  The signal generator 116b generates a ringing tone such as “ping-pong” when the door phone button 123b is pressed by a visitor.

  The video signal processing circuit 112b processes video captured by the CCD camera 121b. The CCD camera 121b is a camera that uses a semiconductor element that converts optical information into an electrical signal. In the present embodiment, the slave unit 110b includes the CCD camera 121b. However, the present invention is not limited to this, and various imaging devices other than the CCD camera can be applied. When the visitor presses the door phone button 123b, the CCD camera 121b photographs a visitor that exists in the vicinity of the slave unit 110b. In addition, the CCD camera 121b photographs a visitor or a suspicious person (hereinafter referred to as “visitor etc.”) existing in the vicinity of the child device 110b in cooperation with the human sensor 122b.

  Here, the human sensor 122b will be described. In the present embodiment, the human sensor 122b outputs an ultrasonic pulse at a predetermined cycle, and detects the presence of a visitor or the like and the distance from the slave unit 110b based on the presence or change of the reflected wave of the ultrasonic pulse. An ultrasonic sensor capable of performing the above is applied. The human sensor 122b stores the arrival time of the reflected wave in a table or the like in advance when there is no visitor or the like and when the visitor or the like is located at a predetermined distance from the slave unit 110b. The human sensor 122b refers to the table based on the arrival time of the reflected wave, and detects the presence of a visitor and the distance from the child device 110b such as the visitor.

  Next, a process in which the CCD camera 121b performs shooting in conjunction with the human sensor 122b will be described in detail. FIG. 3 is a diagram schematically illustrating a data configuration of the sensor sensitivity table. As shown in FIG. 3, the sensor sensitivity table defines a detection range in association with an ID that is identification information. In the present embodiment, the detection range is divided into three stages of “1.0 to 2.0 m”, “0.5 to 1.0 m”, and “0 to 0.5 m”, and “2” is used as an ID for identifying each. , “1” and “0” are assigned. The detection ranges “1.0 to 2.0 m”, “0.5 to 1.0 m”, and “0 to 0.5 m” are each visited by the CCD camera 121b based on the general height of the person. It is determined in advance as a distance at which images of the whole body, the upper body, and the face of a person can be taken. Therefore, the values of these detection ranges are merely examples, and can be appropriately changed according to the installation position of the CCD camera 121b, the shootable range, and the like.

  Based on the sensor sensitivity table, the CCD camera 121b automatically detects whether or not the resident is at home when the human sensor 122b detects a visitor or the like within 2.0 m from the slave unit 110b. Take 3 steps. Specifically, when the human sensor 122b detects and photographs within the range of “1.0 to 2.0 m” from the child device 110b, image data of almost the whole body of a visitor or the like can be acquired. Further, when the human sensor 122b detects and captures an image within the range of “0.5 to 1.0 m” from the child device 110b, image data of the upper body of a visitor or the like can be acquired. Further, when the human sensor detects and captures an image within the range of “0 to 0.5 m” from the child device 110b, it is possible to acquire image data of a face up of a visitor or the like.

  In this way, the CCD camera 121b automatically photographs in conjunction with the human sensor 122b based on the sensor sensitivity table, so that a suspicious person who does not press the door phone button 123b approaches when the resident is away. Even in such a case, it is possible to acquire image data indicating a visitor or a suspicious person.

  It should be noted that the sensor sensitivity table can be arbitrarily set by the user in the parent device 110a. At this time, the sensor sensitivity table set in the parent device 110a is transmitted to the child device 110b. That is, the sensor sensitivity tables that the parent device 110a and the child device 110b respectively have are always the same.

  The memory unit 114b stores image data captured by the CCD camera 121b in conjunction with the human sensor 122b. FIG. 4 is a diagram schematically illustrating a data configuration of a memory area included in the memory unit 114b. As shown in FIG. 4, the memory area includes an ID, image data, and a storage mark. ID is identification information common to the sensor sensitivity table. The image data is image data captured by the CCD camera 121b in conjunction with the human sensor 122b, and there are a plurality of image data corresponding to each detection range of the sensor sensitivity table. In this embodiment, “2.0 m image data” is image data captured in the detection range “1.0 to 2.0 m”, and “1. “0 m image data” and image data taken in the detection range “0 to 0.5 m” are referred to as “0.5 m image data”. The storage mark is a mark indicating whether or not predetermined image data is stored in the memory area. The storage mark is “completed” when stored, and is blank when it is not stored.

  Note that the CCD camera 121b performs imaging only once within each detection range within a predetermined time. Here, the predetermined time is a time during which it is estimated that the visitors detected by the human sensor 122b are the same person. That is, performing a plurality of shootings within the same detection range within a predetermined time period results in acquiring a plurality of image data of the same person, and wastes the storage capacity of the memory unit 114b. Become. Therefore, in order to prevent this, photographing is performed only once within each detection range within a predetermined time.

  In addition, the control unit 111b stores the captured “0.5m image data” in the memory area and stores other image data captured within a predetermined time when the save mark is “completed”. A pair is transmitted to the main unit 110a. That is, the control unit 111b extracts “2m image data” and “1m image data” having the storage mark “completed” from the memory area when the “0.5m image data” is captured, and sets the pair. To the base unit 110a. If neither “2 m image data” nor “1 m image data” is stored when “0.5 m image data” is photographed, only “0.5 m image data” is stored in the parent device 110a. Send to. As described above, the image data having the shortest distance from the slave unit 110b is used as a trigger for transmission to the master unit 110a only for image data obtained by photographing a visitor or the like that is definitely intended for the residence of the resident. This is for sending. That is, image data obtained by shooting a passing person or the like is not transmitted to the main unit 110a. Normally, a passing person passes only a place far from the slave unit 110b and does not approach the slave unit 110b. Therefore, even if "2m image data" or "1m image data" is shot, "0.5m image data" Is often not filmed. Therefore, only a visitor or the like approaching the child device 110b is photographed as “0.5 m image data”, and only the image data of such a visitor or the like is transmitted to the parent device 110a. In this way, the control unit 111b transmits a plurality of pieces of image data captured at predetermined distance intervals to the parent device 110a in a series of flows. The image data that has not been transmitted to the main unit 110a is automatically deleted when a predetermined time elapses.

  In this embodiment, an ultrasonic sensor is applied as the human sensor 122b in order to automatically detect a visitor or the like. However, the present invention is not limited to this, and is provided in the slave unit 110b. Any sensor such as an infrared sensor can be applied as long as it is possible to detect such events and visitors.

[Image processing]
Next, image processing using the CCD camera 121b and the human sensor 122b will be described. In the present embodiment, when the human sensor 122b detects a visitor or the like based on a preset sensor sensitivity table, the CCD camera 121b included in the slave unit 110b automatically performs shooting. Image data photographed within a predetermined time is stored in a memory area and transmitted to the parent device 110a in accordance with a predetermined condition (in the above example, “shooting 0.5 m image data”). The user operates the parent device 110a to display the image data received from the child device 110b on the monitor 113a. According to this, the user can confirm the visitors who visited while absent, the suspicious person who does not press the door phone button, and the like.

  FIG. 5 shows a flowchart of image processing according to the present embodiment. This flowchart shows the processing of the slave unit 110b. Note that these processes can be realized by the control unit 111b of the slave unit 110b executing a program prepared in advance.

  According to the flowchart, the control unit 111b first sets all the storage marks in the memory area to be invalid (step S1). Here, “effective” means that the storage mark is valid, and “invalid” means that the storage mark is blank. Then, it is determined whether or not the human sensor 122b has detected a visitor or the like (step S2). When the human sensor 122b has not detected a visitor or the like (step S2; N), the control unit 111b determines whether or not the time is within a predetermined time (step S3). Here, the predetermined time is a time during which it is estimated that the visitors detected by the human sensor 122b are the same person. Such a predetermined time is set in step S10 described later. If it is within a predetermined time (step S3; N), detection by the human sensor 122b is performed until a visitor or the like is detected. On the other hand, when the predetermined fixed time is exceeded (step S3; Y), the control unit 111b returns to step S1 and sets all the storage marks in the memory area to be invalid.

  When the human sensor 122b detects a visitor or the like (step S2; Y), the control unit 111b refers to the sensor sensitivity table based on the distance from the slave unit 110b to the visitor or the like, that is, the detection range, thereby identifying the ID. “N” is specified and a variable n is set (step S4). Then, the control unit 111b determines whether or not the storage mark with the ID “n” in the memory area is valid (step S5). When the storage mark with ID “n” is valid (step S5; Y), the control unit 111b returns to step S2. On the other hand, if the save mark with ID “n” is invalid (step S5; N), the image data captured by the CCD camera 121b is acquired (step S6), and the image data is saved in the memory area with ID “n”. (Step S7). Then, the control unit 111b validates the storage mark with the ID “n” (step S8).

  Next, the control unit 111b determines whether or not the storage mark with the ID “0” is valid (step S9). When the storage mark with ID “0” is invalid (step S9; N), the control unit 111b sets a time when it is estimated that the visitor detected by the human sensor 122b is the same person and starts the timer. (Step S10). By starting the timer in this way, it is possible to associate an image obtained by photographing a person who is assumed to be the same person in a series of flows. That is, the image processing by the slave unit 110b is processing performed for each person who is estimated to be the same person. Therefore, the image processing is initialized and repeated by invalidating the storage mark in the memory area in step S1 when a certain time estimated to be the same person is exceeded.

  On the other hand, if the save mark with ID “0” is valid (step S9; Y), all image data with valid save marks is read from the memory area (step S11). Then, the control unit 111b transmits the read image data to the parent device 110a (step S12). When there are a plurality of image data read from the memory area, they are paired as image data obtained by photographing the same person and transmitted to the parent device 110a. And the control part 111b returns to step S1, and repeats the process of step S1 thru | or S12.

  The image data stored in the memory area may be deleted simultaneously when all the storage marks are invalidated in the process of step S1, or may be deleted after being stored in the memory unit 114b for a predetermined time. Good.

  Further, in the process of step S5, when it is determined that the storage mark with the ID “n” is valid, it is possible to arbitrarily set whether or not to photograph the visitor detected by the human sensor 122b. However, the image data is not stored in the memory area even if the image is taken.

  The control unit 111a of the parent device 110a stores the image data acquired from the child device 110b in the memory unit 114a for each person in association with the shooting date / time and the reception date / time. Therefore, the user can freely display the image data stored in the memory unit 114a on the monitor 113a by operating the parent device 110a. For this reason, the user can check visitors who have been away, suspicious persons who do not press the doorphone buttons, and the like.

  The master unit 110a may be set to sound a ringing tone or turn on a lamp when image data is acquired from the slave unit 110b. Further, when undisplayed image data is stored, a message to that effect may be displayed on the monitor 113a.

  As described above, according to the present embodiment, since a plurality of image data captured by the slave unit 110b can be displayed on the monitor 113a of the master unit 110a, it is possible to reliably check visitors, suspicious persons, and the like. be able to. Even if a visitor or the like hides only when the door phone button is pressed, a plurality of image data is stored for the same person because the images are taken at a predetermined distance interval. The visitor etc. can be identified.

  Further, even when a visitor or the like commits a crime such as picking without pressing the door phone button, the visitor or the like can be identified from the stored image data. Then, the image data stored in the memory 114a by the master unit 110a can be used as evidence of crime.

The whole structure of the door phone system concerning the example of the present invention is typically shown. It is a block diagram which shows the component of a door phone system. It is a figure which shows typically the data structure of a sensor sensitivity table. It is a figure which shows typically the data structure of a memory area. It is a flowchart of an image process.

Explanation of symbols

100 Door phone system 103 Cable 110a Master unit 110b Slave unit 111a, 111b Control unit 112a, 112b Video signal processing circuit 113a Monitor 114a, 114b Memory unit 115a, 115b Demodulation circuit 116a, 116b Signal generation unit 117a, 117b Speaker 118a, 118b Microphone 120a 120b Multiplexing circuit 121b CCD camera 122b Human sensor 123b Door phone button

Claims (6)

A door phone system including a slave unit and a master unit,
The slave is
A human sensor,
Door phone button,
A photographing device for photographing a surrounding image when at least one of the human sensor or the door phone button reacts;
When detecting a human body by the human sensor, distance detecting means for detecting a distance between the slave unit and the human body;
First photographing means for photographing the human body at a predetermined distance by the photographing device based on the distance detected by the distance detecting means;
First storage means for storing image data captured by the first imaging means;
First transmission means for transmitting image data stored by the first storage means to the master when the human body is closest to the slave;
A second photographing means for photographing the human body with the photographing device when the door phone button reacts;
Second transmission means for transmitting image data photographed by the second photographing means to the master unit,
The base unit is
A monitor,
Second storage means for storing the image data transmitted by the first transmission means;
A door phone system comprising: image data stored by the second storage unit and display unit for displaying the image data transmitted by the second transmission unit on the monitor. The slave unit further includes a sensor sensitivity table that defines a plurality of distances between the slave unit and the human body that serve as a reference for imaging by the imaging device,
2. The door phone system according to claim 1, wherein the first photographing unit photographs the human body when the distance detected by the distance detection unit coincides with a distance defined in the sensor sensitivity table. . The slave unit further includes a memory area for storing image data in association with each distance defined in the sensor sensitivity table,
The memory area has a storage mark indicating whether image data is stored in association with each distance,
The first storage unit stores the image data captured by the first imaging unit in the corresponding memory area and validates the corresponding storage mark,
The first imaging unit performs imaging only when the storage mark corresponding to the distance detected by the distance detection unit is invalid, and does not perform imaging when the storage mark is valid. Item 3. A door phone system according to Item 2. The slave unit further includes a determination unit that determines whether or not the storage mark corresponding to the shortest distance among the distances defined in the sensor sensitivity table is valid,
The first transmission unit transmits all image data stored by the first storage unit to the parent device when the determination unit determines that the storage mark is valid. 3. The door phone system according to 3.   5. The door phone system according to claim 3, wherein the slave unit includes invalid means for invalidating all of the storage marks when a predetermined time has elapsed. The door phone system according to any one of claims 1 to 5, wherein the photographing device is arranged at a position for photographing within a detection range of the human sensor.

Images