Patent Publication Number: US-2022217307-A1

Title: Door peephole viewer camera with wireless connectivity

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of Provisional Patent Application Ser. Nr. 63/125,402, filed on Dec. 15, 2020, which is entirely incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to the field of wireless camera systems for home monitoring. More particularly, the present disclosure relates to assemblies, sensors, methods of attachment, and operational processes of door mounted camera systems intended to be used in conjunction with a door&#39;s peephole viewer. 
     BACKGROUND 
     Many home entry doors include a peephole viewer mounted in the door, as described in U.S. patent US4269474A to Yasushi Kamimura (1979). In the past decade, video doorbells became affordable and popular as an alternative to peephole viewers. 
     Video doorbells allow a homeowner or renter to monitor the area around the front entrance to the home. Such video doorbells are convenient for homeowners, but are not conducive to installation in most rental apartment units. Many home owners&#39; associations (HOA) and landlords will not allow residents to install cameras outside of their homes. Such devices provides wireless remote monitoring, alerting the user when a person is present on the other side of the door. 
     Peephole door viewer camera devices are available from a number of companies. One example is the Ring Peephole Cam (https://ring.com/products/door-peephole-security-camera). Such devices require the user to remove or alter the current peephole viewer using tools, and to install a bulky module over the peephole on both sides of the door. Most of these devices include a camera module with a button, which is mounted on the outside-facing side of the door over the peephole, or next to the door. This makes it obvious to any passer-by that they are potentially being recorded. These devices usually use a low power PIR (passive infrared) sensor to turn the camera on only when activity is detected, in order to maximize battery life. PIR and other proximity sensors cannot operate through opaque materials or glass. Thus, these camera devices must have an enclosure with a camera and PIR sensor which is mounted over the peephole viewer on the outside-facing side of the door. 
     Although other door peephole viewer camera designs exist, some embodiments in the specification herein have the following advantages: 
     (a) The door peephole viewer camera does not require replacing the current peephole viewer. 
     (b) It is simpler to install, requiring no tools. 
     (c) It is easy to remove. 
     (d) The outside-facing side of the door remains unchanged. 
     (e) Any passer-by is not alerted to being video-monitored. 
     (f) External motion sensors can be added to extend battery life. 
     (g) It is portable, for temporary use such as on a hotel room door. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings. To facilitate this description, like reference numerals designate like structural elements. Embodiments are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings. 
         FIG. 1 —Embodiment A—isometric view of peephole viewer camera apparatus installed on the door 
         FIG. 2 —Embodiment A—isometric view of removable camera apparatus assembly, door bracket assembly installed on the door 
         FIG. 3A —Embodiment A—front view of peephole viewer camera apparatus 
         FIG. 3B —Embodiment A—side cross-section view of peephole viewer camera apparatus installed on the door 
         FIG. 3C —Embodiment A—side cross-section view of camera module 
         FIG. 4  Embodiment A—exploded isometric view of peephole viewer camera apparatus 
         FIG. 4A —Embodiment A—diagram of system components 
         FIG. 4B —Embodiment A—operational flow chart 
         FIG. 4C —Embodiment A—operational flow chart with cloud processing 
         FIG. 4D —Embodiment A—operational flow chart for cloud server 
         FIG. 4E —Embodiment A1—exploded isometric view of door bracket assembly with support ring 
         FIG. 4F —Embodiment A1—front view of door bracket assembly with support ring 
         FIG. 4G —Embodiment A1—exploded isometric view of door bracket assembly with support ring with cutout 
         FIG. 5 —Embodiment B—side cross-section view of peephole viewer camera apparatus installed on the door 
         FIG. 6 —Embodiment B—exploded isometric view of peephole viewer camera apparatus 
         FIG. 7 —Embodiment C—isometric view of peephole viewer camera apparatus as it can be attached to a steel door 
         FIG. 8 —Embodiment C—exploded isometric view of peephole viewer camera apparatus 
         FIG. 9 —Embodiment C—side cross-section view of peephole viewer camera apparatus installed on the door 
         FIG. 10 —Embodiment D—isometric view of peephole viewer camera apparatus with hinge, installed on the door 
         FIG. 11 —Embodiment D—front view of peephole viewer camera apparatus with hinge 
         FIG. 12 —Embodiment D—exploded isometric view of peephole viewer camera apparatus with hinge 
         FIG. 14 —Embodiment D—isometric view of peephole viewer camera apparatus with hinge, opened to show hinge operation 
         FIG. 15 —Embodiment E—isometric view of peephole viewer camera apparatus with pivot hinge, installed on the door 
         FIG. 16 —Embodiment E—isometric view of peephole viewer camera apparatus with pivot hinge, installed on the door, opened to show hinge operation 
         FIG. 17 —Embodiment E—exploded isometric view of peephole viewer camera apparatus with pivot hinge 
         FIG. 18 —Embodiment F—exploded isometric view of peephole viewer camera apparatus with internal flip mirror and actuator 
         FIG. 19 —Embodiment F—isometric internal view of mirror actuator apparatus only 
         FIG. 20 —Embodiment F—isometric internal view of mirror actuator apparatus only, mirror flipped up by actuator 
         FIG. 21 —Embodiment F—side cross-section view of peephole viewer camera apparatus with internal flip mirror and actuator 
         FIG. 22 —Embodiment F—side cross-section view of peephole viewer camera apparatus with internal flip mirror and actuator, mirror flipped up by actuator 
         FIG. 23 —Embodiment G—isometric view of peephole viewer camera apparatus with internal flip mirror and external lever means of actuation 
         FIG. 24 —Embodiment G—isometric view of peephole viewer camera apparatus with internal flip mirror and external lever actuated 
         FIG. 25 —Embodiment G—isometric internal view of mirror actuator apparatus only 
         FIG. 26 —Embodiment G—isometric internal view of mirror actuator apparatus only, mirror flipped up by lever 
         FIG. 27 —Embodiment H—isometric view of peephole viewer camera apparatus with external lever, installed on the door 
         FIG. 28 —Embodiment H—exploded isometric view of peephole viewer camera apparatus with external lever 
         FIG. 29 —Embodiment H—isometric internal view of mirror actuator apparatus only 
         FIG. 30 —Embodiment H—isometric internal view of mirror actuator apparatus only, mirror flipped up by lever 
         FIG. 31 —Embodiment J—side cross-section view of peephole viewer apparatus with integrated sensors 
         FIG. 32 —Embodiment J—side cross-section isolated view of sensor with FFC (flat flexible cable) only 
         FIG. 33 —Embodiment J—side cross-section exploded view of peephole viewer apparatus with integrated sensors 
         FIG. 34 —Embodiment J—isometric exploded view of peephole viewer apparatus with integrated sensors 
         FIG. 35 —Embodiment J—isometric isolated view of sensor with FFC (flat flexible cable) only 
         FIG. 36 —Embodiment J—front view of peephole viewer apparatus with integrated sensors 
         FIG. 37 —Embodiment J—opaque front view of peephole viewer apparatus with integrated sensors 
         FIG. 38 —Embodiment K—exploded view of welcome mat with integrated proximity sensors 
         FIG. 39 —Embodiment K—top view of welcome mat with integrated proximity sensors 
         FIG. 40 —Embodiment K—side view of welcome mat with integrated proximity sensors 
         FIG. 41 —Embodiment L—isometric view of wireless passive infrared proximity sensor module 
         FIG. 42 —Embodiment L—exploded isometric view of wireless passive infrared proximity sensor module 
         FIG. 43 —Embodiment L—top view of wireless passive infrared proximity sensor module 
         FIG. 44 —Embodiment L—side cross-section view of wireless passive infrared proximity sensor module 
         FIG. 45 —Embodiment M—isometric view of wireless proximity sensor module 
         FIG. 46 —Embodiment M—exploded isometric view of wireless proximity sensor module 
         FIG. 47 —Embodiment N—isometric view of wireless proximity sensor module with varied sensor angles 
         FIG. 48 —Embodiment N—exploded isometric view of wireless proximity sensor module with varied sensor angles 
         FIG. 49 —Embodiment N—top view of wireless proximity sensor module with varied sensor angles 
         FIG. 50 —Embodiment N—side cross-section view of wireless proximity sensor module with varied sensor angles 
         FIG. 51 —Embodiment P—isometric view of the door hanger sensor apparatus 
         FIG. 52 —Embodiment Q—isometric view of the door hanger sensor apparatus with key-holder magnet 
     
    
    
     DETAILED DESCRIPTION—FIGS.  1 ,  2 ,  3 A,  3 B,  3 C,  4 —EMBODIMENT A 
       FIG. 1  shows an overview of embodiment A in isometric view. Peephole viewer camera apparatus  108  is mounted on door  100 . Display  102  is on the front face of camera apparatus front housing  106 . Front proximity sensor  104  is also on the front face of housing  106 . 
       FIG. 2  shows an exploded isometric view of removable camera apparatus assembly  218  and door bracket assembly  214  installed on the door  100 . The main structure of door bracket assembly  214  is door bracket  210 , which is attached to door  100  by means of removable adhesive tape. The door bracket  210  has a door bracket viewing aperture  404 , which is centered on door peephole viewer  212 . A door bracket alignment magnet  204  is placed in each corner of the bracket  210 . On the surface of bracket  210  is door bracket alignment feature  208 . Alignment feature  208  may be a notch or ridge in a known configuration.  FIG. 2  depicts the alignment feature  208  as three notches positioned radially in a symmetric pattern surrounding aperture  404 . 
       FIG. 2  also shows removable camera apparatus assembly  218 . It includes camera apparatus front housing  106 , which is rigidly attached to housing lid  216 . A housing alignment magnet  202  is placed in each corner of the lid  216  such that each matches the placement of magnet  204  on bracket  210 . On the surface of lid  216  is housing alignment feature  206 . Alignment feature  206  may be a notch or ridge in a known configuration.  FIG. 2  depicts the alignment feature  206  as three notches or ridges positioned radially in a symmetric pattern such that the alignment feature  206  mates with alignment feature  208  when assembly  218  is pressed against assembly  214 . Similarly, magnets  202  and magnets  204  will align and come into contact, pulling together assembly  218  and assembly  214  against door  100 . Display  102  and front proximity sensor  104  are shown on the front face of housing  106 . 
     Note that alignment features  206  and  208  are described as notches or ridges. However, these alignment features can represent any type of protrusion, cavity, or other type of feature, as long as feature  206  and  208  are able to mate. For instance, if feature  206  is a protrusion, then feature  208  must be a cavity, and vice versa. 
       FIG. 3A  shows a front view of peephole viewer camera apparatus  108 . It shows placement of magnets  202 , alignment features  206 , and battery  302 . 
       FIG. 3B  shows a cross-section view from  FIG. 3A . Door bracket  210  is attached to door  100  by means of removable adhesive tape. Magnets  202  and magnets  204  align and pull bracket  210  and lid  216  tightly face to face. Housing  106  is rigidly attached to lid  216 . Peephole viewer  212  with peephole viewer primary lens  314  are mounted on door  100 . Camera attachment bracket  312  is rigidly attached to housing  106 . Camera module  310  is attached to bracket  312  such that its optical axis is 90 degrees offset from optical axis of peephole viewer  212 . Mirror  306  is rigidly attached to mirror bracket  304 , which is rigidly attached to housing  106 . Mirror  306  is mounted such that its optical axis is 45 degrees offset offset from the optical axis of peephole viewer  212 . Main processing board  308  and battery  302  are also attached to housing  106 . Display  102  and front proximity sensor  104  are shown on the front face of housing  106 . 
       FIG. 3C  shows a side cross-section view of camera module  310 . One or more lenses  316  are mounted in camera lens housing  318  such that they are optically aligned with image sensor  320 . Housing  318  is rigidly attached to camera attachment bracket  312 . 
       FIG. 4  is an exploded isometric view of peephole viewer camera apparatus  108 . Door peephole viewer  212  defines an optical axis which is aligned with door bracket viewing aperture  404 , housing lid viewing aperture  402 , and mirror  306 . Mirror  306  is mounted to mirror bracket  304  such that its optical axis is 45 degrees offset from the optical axis of peephole viewer  212 . Camera module  310  is attached to bracket  312  such that its optical axis is 90 degrees offset from optical axis of peephole viewer  212 . 
     Display  102  is an optional feature. Front proximity sensor  104  is also an optional feature. 
     Magnet  204  and magnet  202  are each preferably a strong magnet such as one made of neodymium. However, magnet  204  may be replaced by a simple piece of ferromagnetic metal such as steel. It should be noted that fewer or greater number of magnets  202  and magnet  204  can be used, and need not be located in the corners of bracket  210 . Similarly, alignment features  206  and  208  may be arranged in any pattern, and there may be more or fewer features than depicted in the figure. 
     Door bracket  210  may made from a rigid material such as ABS plastic. Alternatively, door bracket  210  may be a thin, flexible material such as a thermoplastic. 
     Batteries  302  provide power to the apparatus  108 . Although not shown in the figures, a connector may be added to the peephole viewer camera apparatus  108  for charging the batteries  302  and providing power to the apparatus  108 , which may bypass usage of the batteries  302  when plugged in to a power source. It should be noted that the peephole viewer camera apparatus  108  may be plugged in via power cable while mounted on the door. The power cable may be routed to the door hinge, and along the wall to a power supply, preferably plugged into a wall outlet. Such a power supply could be a simple USB charger or similar. In this case, the peephole viewer camera apparatus  108  may operate without as limited constraints on power usage. 
     Operation— FIGS. 1, 2, 3A, 3B, 3C, 4, 4A, 4B, 4C —Embodiment A 
     As shown in  FIG. 3B  and  FIG. 4 , Door peephole viewer  212  defines an optical axis which is aligned with door bracket viewing aperture  404 , housing lid viewing aperture  402 , and mirror bracket  304 . Mirror  306  is mounted to mirror bracket  304  such that its optical axis is 45 degrees offset offset from the optical axis of peephole viewer  212 . Camera module  310  is attached to bracket  312  such that its optical axis is 90 degrees offset from optical axis of peephole viewer  212 . Mirror  306  redirects the optical path such that it aligns with camera module  310 . The view seen through the peephole will pass through lenses  316  and resolve the image on image sensor  320 . Peephole viewer  212  offers a wide angle view. One or more lenses  316  within camera module  310  are arranged such that they alter the field of view seen through the peephole viewer such that it covers image sensor  320 . 
     Removable camera apparatus assembly  218  blocks the person&#39;s view through the door peephole viewer  212 . In some cases, a person on the inner side of the door may want to look through the door peephole viewer  212  to verify that it is safe to open the door.  FIG. 2  illustrates how assembly  218  may be separated from the door bracket assembly  214 . Assemblies  218  and  214  are held firmly together by magnets  202  and  204 . In addition, alignment features  206  and  208  aid in keeping the assemblies  218  and  214  aligned and prevents them from sliding or rotating with respect to each other. This maintains that the optical axis of peephole viewer  212  will project correctly onto mirror  306 , and finally onto image sensor  320  as shown in  FIG. 4 . 
     Once assemblies  214  and  218  are separated, the user may look unobstructed through peephole viewer  212 . When done looking, the user places removable camera apparatus assembly  218  against assembly  214  again. It will snap into place from the magnetic force of magnets  202  and  204 . The alignment features  206  and  208  ensure that the two assemblies  214  and  218  are aligned. Once in place, the optical path through peephole  212  will pass directly onto image sensor  320 . 
       FIG. 4A  shows an overview diagram of the system&#39;s data flow. The camera apparatus comprises CPU and video processor  414 , camera module  310 , internal activity sensors  426 , and communications module  416 . The CPU and video processor  414  control and read image data from camera module  310 . Camera module  310  is shown as part of the camera apparatus in  FIG. 3B  and  FIG. 4 . The CPU and video processor  414  also transmit and receive data via communications module  416 . Transmission and reception of data pass through communications network  418 , and reaches an endpoint at cloud server  420 . Cloud server  420  may be a physical server on the internet, a local computer acting as a server on a local area network, or a virtual cloud platform such as Amazon AWS, Microsoft Azure, or Google Cloud Platform. 
     CPU  414  may also communicate with internal activity sensors  426 . These sensors  426  may be mounted within camera apparatus  108 . Sensors  426  may include inertial sensors such as gyroscope, accelerometer, magnetometer, or barometric sensor. The sensors  426  may also include a microphone or other type of vibration sensor. These sensors&#39; output can be processed by CPU  414  to determine if some activity has occurred. For instance, the accelerometer, gyro, or magnetometer sensor may determine whether the door has rotated. The barometric sensor can report a change in barometric pressure which occurs when the door is opened. The accelerometer, vibration, or microphone sensor may be used to report if a door knock has been detected. The microphone sensor may also be used to determine whether human voices are detected outside of the door. 
     In this embodiment, the Communications module  416  transmits and receives data to the communication network  418  via 802.11 TCP/IP communication via WiFi. However, it should be noted that the method of communication can be any type of network protocol, wired or wireless. This includes WiFi, Bluetooth, Zibgee, Ethernet, RS485 and others. 
     The CPU and video processor  414  also may communicate with external sensor  424  via a sensor communication network  422 . This sensor communication network  422  may be wired or wireless, and use one or more communication protocols such as WiFi, Bluetooth, Zigbee, Ant or other wireless protocols. Similarly, sensor communication network  422  may use a wired connection over Ethernet, RS485, I2C, SPI, UART, or other wired communication protocol. More than one external sensor may communicate with the CPU and video processor  414 . A variety of types of external sensors may be used, including passive infrared proximity sensors, time-of-flight proximity sensors, microphones, LIDAR, other imaging sensors, accelerometers, gyroscopes, magnetometers, barometric pressure sensors, microphones, or other types of sensors. Later embodiments describe implementations of certain external sensors. 
     One internal activity sensor  426  shown in  FIG. 2  is front proximity sensor  104 . In this embodiment, sensor  104  is a time-of-flight proximity sensor which can measure the approximate distance of an object in its field of view. A nominal field of view for this sensor is  30  degrees. Any object detected at near the height of the proximity sensor  104  is likely a person approaching the door. Thus, CPU  414  can monitor proximity sensor  104 . The CPU and video processor  414  is also connected to display  102 . When the CPU determines that a person is detected by proximity sensor  104 , it can turn on display  102  and show the current video stream from camera module  310 . The CPU and video processor  414  may also perform face detection and face recognition on the images from camera module  310 . In this case, it may show an overlay with face recognition metadata on display  102 . Such metadata could include a name or secondary photo of the detected person. 
     Door bracket  210  is designed to be simple to install on the door  100 . The back side of door bracket  210  may be covered in an adhesive tape. The adhesive tape can have a protective coating. When the coating is peeled off of the tape, the bracket  210  can be positioned over the peephole viewer  212  such that aperture  404  is centered on peephole viewer  212 , and pressed against to the door  100 . Once pressed against the door, it will be held firmly in place by the adhesive. One example adhesive tape is the  3 M command strip. If the user wants to remove the bracket from the door, the user can peel back bracket  210  from the door. The removable adhesive tape will leave no residue on the door. If made of a flexible material, door bracket  210  can be made of a flexible, thin material to make it easier to peel back during removal. Using a thin, flexible material for bracket  210  also makes manufacturing more economical. 
       FIG. 4B  is a flowchart showing the operating process for the peephole viewer camera apparatus  108  described in this embodiment. It begins at step  426 , in which the device enters idle state. The device enacts a low power mode to conserve battery life. CPU  414 , camera module  310 , and communications module  416  all enter low power state. 
     In the next step  428 , the CPU  414  queries any internal sensors  426  and external sensors  424  for activity. Such activity could be determined by an external proximity sensor indicating that an object is nearby. Similarly, an internal accelerometer, gyro, or magnetometer internal sensor may determine whether a door motion activity has occurred. An internal barometric sensor may report a change in barometric pressure which occurs when the door is opened. An internal accelerometer, vibration, or microphone sensor may be used to report activity if a door knock has been detected. The microphone sensor, if present, may be used to determine whether human voices are detected outside of the door. Any of these or other internal sensors  426  and external sensors  424  may be used to determine whether activity is detected. Note that any specific individual sensors  424  or  426  may be excluded from use in determining step transition in this flowchart. 
     In the next step  430 , if activity is detected then transition to step  440 . If internal sensors  426  and external sensors  424  report no activity detected, then transition to step  432  in which the system enters ultra low power mode and sleeps for N seconds. 
     The duration of sleep is configurable, but a nominal value of N is two seconds. In state  432  any external sensor  424  or internal sensor  426 , if present, may alert the CPU  414  by interrupt request to wake it up. For example, if an external sensor such as a proximity sensor is used on the outer side of the door, it may wake up the CPU  414  early by an interrupt request. In this case, the duration N can be a much higher value, such as twenty seconds, to conserve battery life further. 
     When the CPU  414  wakes up from sleep in step  432 , it transitions to step  434 . Here it enables camera module  310  and acquires an image. Then it transitions to step  436  in which it processes the image. CPU and video processor  414  may include artificial intelligence acceleration hardware to allow for fast AI inference execution, such as facial detection and facial recognition. In this case, the CPU stores the results in memory, which may include whether a face is detected, and if so, the metadata attached to the detected face. This metadata may include the person&#39;s id, name and a secondary image of the person. Then, transition to the next step  438 . 
     In step  438 , the CPU  414  determines if activity was detected. If a person was detected or an external sensor detected activity, then transition to step  440 . However, if no activity was detected then transition back to step  426  and enter idle state. 
     In step  440 , log the detected activity to memory and nonvolatile storage. The logged data should include metadata of any detected person via face recognition, as well as a current timestamp. The logged data should also include any type of activity detected by the internal sensors  426  and external sensors  424 . Then notify the user. This can include enabling display  102  and showing the current video stream from camera module  310 . If face recognition metadata is available, an overlay with face recognition metadata may be shown on display  102 . Such metadata could include a name or secondary photo of the detected person. This step may also send a push notification to show an alert on the user&#39;s phone or other connected device such as a smart screen device. Examples of such a device are Amazon Echo Show and Facebook Portal. This step  440  may also send a message to a server on the Internet as well. After step  440  is complete, transition to step  442 . 
     In step  442 , the CPU and video processor  414  begins recording the video stream from camera module  310 . The CPU  414  may write the video stream to local nonvolatile storage. In addition, it may begin streaming the video stream to cloud server  420  via communications network  418 . As described previously, this may be an internet server, or a local server on the local area network. Next, transition to step  444 . 
     In step  444 , process the current image frame from the camera module  320 , running face detection on the image frame. Transition to step  446 . Here, determine if activity is detected. If a person is detected or external sensors report activity detected, then transition back to step  444 . However, if no activity is detected then transition to step  448 . 
     In step  448 , test if the duration of the current video recording is less than M seconds. A nominal value for M is ten seconds. If the duration is less than M seconds, then transition back to step  444  and process another frame. However, if the video duration is greater than or equal to M seconds, then transition to step  450 . 
     In step  450 , stop recording and stop streaming the video. If recording to local nonvolatile storage, then close the file. Transition to step  426  and enter idle, low power state. 
       FIG. 4C  is a flowchart showing an alternative operating process for the peephole viewer camera apparatus  108  described in this embodiment. In this operating process, the CPU  414  may not have any AI inference acceleration hardware, and thus face detection and face recognition are completed on the cloud server  420 . 
     The process begins at step  426 . Steps  426 ,  428 ,  430 ,  432 , and  434  are the same as in  FIG. 4B . After step  434 , transition to step  452 , where the acquired image is packaged into a message format and transmitted to cloud server  420  via communications network  418 . Transition to step  454 , in which the CPU  414  waits for communications module  416  to receive a message in reply from cloud server  420 . Once a message is received, or if no message is received, transition to step  456 . 
     In step  456 , the CPU  414  parses the received message. The message will indicate whether activity was detected in the image. In no activity was detected, or if no message was received, transition back to step  426  and enter idle mode. However, if the received message indicates that activity was detected, transition to step  458 . In step  458 , the CPU  414  may log the detected activity to memory and nonvolatile storage and notifies the user. Similar secondary actions as step  440  from  FIG. 4B  can be performed. Then transition to step  460 . 
     In step  460 , the CPU and video processor  414  begins recording the video stream from camera module  310 . The CPU  414  may write the video stream to local nonvolatile storage. In addition, it begins streaming the video stream to cloud server  420  via communications network  418 . Next, transition to step  462 . 
     In step  462 , the video streaming to cloud server  420  continues. Simultaneously, the CPU  414  waits to receive a message from cloud server  420  via communications network  418 . In step  464 , a message is received from cloud server  420 . If the message includes command to continue streaming video, then transition back to step  462  and await another message. However, if the received message does not indicate to continue streaming, transition to step  466 . 
     In step  466 , stop recording and stop streaming the video. If recording to local nonvolatile storage, then close the file. Transition to step  426  and enter idle, low power state. 
       FIG. 4D  is a flowchart showing how the cloud server operates and communicates with the peephole viewer camera apparatus  108  whose process is described in  FIG. 4C . The process begins at step  468 , in which the cloud server  420  waits for a message from the peephole viewer camera apparatus&#39; communication module  416 . Transition to step  470 , where a message was received and the cloud server  420  processes the image. Processing the image may use facial detection and facial recognition algorithms. In this case, the cloud server  420  stores the results in memory, which may include whether a face is detected, and if so, the metadata attached to the detected face. This metadata may include the person&#39;s id, name and a secondary image of the person. Then, transition to the next step  472 . 
     In step  472 , the cloud server  420  determines if activity was detected. If a person or other activity was detected, then transition to step  476 . However, if no activity was detected then transition back to step  474 , send a reply message to peephole viewer camera apparatus&#39; communication module  416  indicating that there is no activity detected. Then transition back to step  468  and wait for another message. 
     In step  476 , log the detected activity to memory and nonvolatile storage. The logged data should include metadata of any detected person via face recognition, as well as a current timestamp. Then notify the user. This step may send a push notification to show an alert on the user&#39;s phone or other connected device such as a smart screen device. Examples of such a device are Amazon Echo Show and Facebook Portal. This step  476  may also send a message to a server on the Internet as well. After step  476  is complete, transition to step  478 . 
     In step  478 , cloud server  420  waits to receive streaming video from peephole viewer camera apparatus&#39; communication module  416 . Once video streaming has begun, transition to step  480 . 
     In step  480 , the video streaming from communication module  416  continues. Cloud server  420  may write the video stream to local nonvolatile storage. Simultaneously, the cloud server  420  processes the current image frame. Processing the image frame may use facial detection and facial recognition algorithms. In this case, the cloud server  420  stores the results in memory, which may include whether a face is detected, and if so, the metadata attached to the detected face. This metadata may include the person&#39;s id, name and a secondary image of the person. Then, transition to the next step  482 . 
     In step  482 , the cloud server  420  determines if activity was detected in the processed image frame. If a person or other activity was detected, then transition to step  484 . However, if no activity was detected then transition to step  486 . In step  486 , test if the video duration is less than M seconds. A nominal value for M is ten seconds. If the duration is less than M seconds, then transition back to step  480  and process another frame. However, if the video duration is greater than or equal to M seconds, then transition to step  488 . 
     In step  484 , cloud server  420  logs any activity detected, and transitions back to step  480 . 
     In step  488 , if recording the streaming video to local nonvolatile storage, then close the file. Send a message to peephole viewer camera apparatus&#39; communication module  416  indicating to stop streaming video. Then transition back to step  468  and wait for another message. 
     Detailed Description— FIGS. 4E, 4F, 4G —Embodiment A1 
     Embodiment A1 is a variation on embodiment A.  FIG. 4E  shows an exploded isometric view of door bracket  210  and housing lid  216  with added door bracket support ring  406 . Support ring  406  has an inner diameter which matches the outer diameter of door peephole viewer front ring  410 . Support ring  406  has an outer diameter which matches both the diameter of door bracket viewing aperture  404  and also matches the diameter of housing lid viewing aperture  402 . 
       FIG. 4F  shows a front view of door bracket  210  with added door bracket support ring  406 . Support ring  406  has an inner diameter which matches the outer diameter of door peephole viewer front ring  410 . Support ring  406  has an outer diameter which matches the diameter of door bracket viewing aperture  404 . When mounted on the door, the door peephole viewer front ring  410  provides support for the door bracket  210  against gravity, to aid in preventing the bracket  210  from sliding along the surface of the door. 
     Support ring  406 , if long enough, may extend through both aperture  404  and aperture  402 , thus providing support for both the door bracket  210  and removable camera apparatus assembly  218 . Alternatively, the ring  406  may be designed to extend only as far as bracket  210 . 
       FIG. 4G  shows an alternative design for support ring  406 . It is replaced by support ring  408 , which has a notch cut such that it forms a “C” shape. It serves the same purpose as ring  406 . However, ring  408  has a gap which allows certain types of peephole viewers with privacy covers to allow placement of the ring  408  which would not be possible with ring  406 . 
     It should be noted that the support ring  406  and  408  may have an adhesive backing to aid in preventing any sliding motion after installation. 
     Operation— FIGS. 4E, 4F, 4G —Embodiment A1 
     Embodiment A1 adds a support ring  406 . During installation, the user takes support ring  406  and places it onto the door such that it fits snugly around peephole viewer front ring  410 . Then the user places the door bracket  210  onto the door with removable adhesive tape, such that door bracket viewing aperture  404  fits snugly against the outer circumference of ring  406 . When mounted on the door, the door peephole viewer front ring  410  provides support for the door bracket  210  against gravity, to aid in preventing the bracket  210  from sliding along the surface of the door. 
     Ring  406  can be replaced with ring  408 , which has a cutout to make a “C” shape, but offers the same functionality. This allows installation on doors which have a pivoting privacy cover attached to the peephole viewer front ring  410 . 
     Note that ring  406  and ring  408  of this embodiment may be added as a feature in other embodiments described herein. 
     Detailed Description— FIGS. 5, 6 —Embodiment B 
     Embodiment B is very similar to embodiment A. However, in this embodiment the peephole viewer camera apparatus has camera module  310  mounted such that it is aligned with the primary optical axis of the door peephole viewer  212 .  FIG. 5 . depicts a side cross-section view of peephole viewer camera apparatus installed on the door in this embodiment. 
     Door bracket  210  is attached to door  100  by means of removable adhesive tape. In the same way as in embodiment A, magnets  202  and  204  and optional alignment features  206  and  208  align and pull bracket  210  and lid  216  tightly face to face. Housing  106  is rigidly attached to lid  216 . Peephole viewer  212  with peephole viewer primary lens  314  are mounted on door  100 . Camera module  310  is attached to housing  106  such that its optical axis is aligned with the optical axis of peephole viewer  212 . Main processing board  308  and battery  302  are also attached to housing  106 . Display  102  and front proximity sensor  104  are shown on the front face of housing  106 . 
     Display  102  and front proximity sensor  104  are optional features. 
       FIG. 6  shows an exploded isometric view of peephole viewer camera apparatus in this embodiment. Camera module  310  is aligned with the primary optical axis of door peephole viewer  212 . Door peephole viewer  212  defines an optical axis which is aligned with door bracket viewing aperture  404 , housing lid viewing aperture  402 , and camera module  310 . 
     Note that the mounting of the camera module  310  as described in this embodiment may be applied to later embodiments as well. 
     Operation— FIGS. 5, 6 —Embodiment B 
     The operation of this embodiment is very similar to embodiment A. The primary difference is that camera module  310  is aligned with the optical axis of door peephole viewer  212 , rather than offset by 90 degrees. Therefore the mirror and mirror bracket are not needed. The view seen through the peephole viewer  212  passes through lenses  316  and resolves the image on image sensor  320 . 
     Detailed Description— FIGS. 7, 8, 9 —Embodiment C 
       FIG. 7  shows an overview of embodiment C. In this embodiment, removable camera apparatus assembly  218  is mounted on steel door  702 . No door mounting bracket is necessary, as magnets  202  firmly attaches assembly  218  to the steel door  702 . Display  102  and front proximity sensor  104  are on the front face of camera apparatus front housing  106 , but both are optional features. 
       FIG. 8  shows an exploded view of removable camera apparatus assembly  218  in this embodiment. It includes camera apparatus front housing  106 , which is rigidly attached to housing lid  216 . Housing lid  216  has a housing lid viewing aperture  402 , which is centered on door peephole viewer  212 . A housing alignment magnet  202  is placed in each corner of the lid  216 . Display  102  and front proximity sensor  104  are shown on the front face of housing  106 . 
       FIG. 9  is a side cross-section view of removable camera apparatus assembly  218  installed on the steel door  702 . Housing  106  is rigidly attached to housing lid  216 , which has embedded magnets  202 . The magnets hold the assembly  218  firmly against the steel door  702  such that the assembly  218  is centered on door peephole viewer  212 . 
     Operation— FIGS. 7, 8, 9 —Embodiment C 
     The operation of this embodiment is very similar to embodiment A. One difference is that this embodiment lacks a door bracket. The housing lid  216  has magnets  202  which come directly in contact with the door. Removable camera apparatus assembly  218  be easily removed from the steel door  702  by pulling it away from the door to disengage the magnets  202 . 
     For added support, the support ring  406  from embodiment A1 may be added. In addition, removable adhesive tape may be added to the back of housing lid  216  to provide more stability when mounted on the door. 
     The user may quickly and easily remove the entire apparatus  108  from the steel door  702  with very little effort. 
     Detailed Description— FIGS. 10, 11, 12, 14 —Embodiment D 
       FIG. 10  shows an isometric view of embodiment D. Peephole viewer camera apparatus  108  is mounted on door  100 . Display  102  and front proximity sensor  104  are on the front face of camera apparatus front housing  106 . In this embodiment, a housing hinge  1002  is present. 
       FIG. 11  shows a front view of the camera apparatus  108  with housing hinge  1002 . 
       FIG. 12  shows an exploded view of the camera apparatus  108  in this embodiment. The front housing  106  is rigidly attached to hinged housing lid  1208 , which has a housing lid viewing aperture  402 . Lid  1208  is attached to hinged door bracket  1202  by housing hinge  1002 . Door bracket  1202  includes door bracket viewing aperture  404 . Lid  1208  has a fixed housing lid closure magnets  1206 , while bracket  1202  has a fixed door bracket closure magnets  1204 . Lid  1208  and bracket  1202  are pressed face to face, attached by hinge  1002 . In this way, magnets  1206  and  1204  come into contact with each other. Similarly, aperture  402  and aperture  404  are co-linear with the optical axis of door peephole viewer  212  when lid  1208  and bracket  1202  are pressed face to face. Camera module  310  is also shown here, which is as described in other embodiments. 
     It should be noted that either magnet  1206  or magnet  1204  could be replaced by a ferromagnetic feature, but not both. 
     Operation— FIGS. 10, 11, 12, 14 —Embodiment D 
       FIG. 14  shows an isometric view of the camera apparatus  108  in this embodiment, opened to show hinge operation. Hinged door bracket  1202  is affixed to the door by removable adhesive tape such that aperture  404  is centered on the optical axis of peephole viewer  212 . Bracket  1202  is attached to lid  1208  by hinge  1002 . As housing  106  is rigidly attached to lid  1208 , the housing  106  therefore can be rotated to the side, as it pivots around the hinge  1002 . Opening it as shown in  FIG. 14  allows the person to look through the peephole viewer  212  unimpeded. 
     Once done looking through the peephole viewer  212 , the person can rotate the front housing  106  toward bracket  1202  until the bracket  1202  and lid  1208  surfaces are flush with each other. Magnets  1206  and  1204  will engage to ensure that the housing  106  stays in place relative to bracket  1202 . This ensures that the optical path from the peephole viewer  212  will pass through apertures  404  and  402  such the camera module  310  again has a clear view through the peephole viewer  212 . 
     Detailed Description— FIGS. 15, 16, 17 —Embodiment E 
     Embodiment E is similar to embodiment D, but uses a different type of hinge.  FIG. 15  shows an isometric view of the camera apparatus  108  in this embodiment, installed on the door  100 . Display  102  and front proximity sensor  104  are on the front face of camera apparatus front housing  106 . In this embodiment, a housing pivot-hinge  1502  is present. 
       FIG. 17  shows an exploded view of the camera apparatus  108  in this embodiment. The front housing  106  is rigidly attached to pivot-hinged housing lid  1502 , which has a housing lid viewing aperture  402 . Lid  1702  is attached to pivot-hinged door bracket  1604  by hinge  1502 . Door bracket  1604  includes door bracket viewing aperture  404 . Lid  1502  has affixed housing lid closure magnets  1206 , while bracket  1604  has affixed door bracket closure magnets  1204 . Lid  1702  and bracket  1604  are pressed face to face, attached by pivot-hinge  1502 . In this way, magnets  1206  and  1204  come into contact with each other. Similarly, aperture  402  and aperture  404  are co-linear with the optical axis of door peephole viewer  212  when lid  1702  and bracket  1604  are pressed face to face. Camera module  310  is also shown here, which is as described in other embodiments. 
     Operation— FIGS. 15, 16, 17 —Embodiment E 
       FIG. 16  shows an isometric view of the camera apparatus  108  in this embodiment, opened to show hinge operation. 
     Pivot-hinged door bracket  1604  is affixed to the door by removable adhesive tape such that aperture  404  is centered on the optical axis of peephole viewer  212 . Bracket  1604  is attached to lid  1702  by pivot-hinge  1502 . As housing  106  is rigidly attached to lid  1702 , the housing  106  therefore can be rotated to the side, as it pivots around the pivot-hinge  1502 . Opening it as shown in  FIG. 16  allows the person to look through the peephole viewer  212  unimpeded. 
     Once done looking through the peephole viewer  212 , the person can rotate the front housing  106  toward peephole viewer  212  until the bracket  1604  and lid  1702  surfaces are flush with each other. Magnets  1206  and  1204  will engage to ensure that the housing  106  stays in place relative to bracket  1604 . This ensures that the optical path from the peephole viewer  212  will pass through apertures  404  and  402  such the camera module  310  again has a clear view through the peephole viewer  212 . 
     Detailed Description— FIGS. 18, 19, 20, 21, 22 —Embodiment F 
     Embodiment F is similar to embodiment A, however, instead of a rigidly mounted mirror, embodiment F employs an actuator which can flip the mirror up by ninety degrees. 
       FIG. 18  shows an exploded isometric view of the peephole viewer camera apparatus  108  in this embodiment. Front housing  106  is rigidly attached to housing lid  216 . Front housing  106  has a front housing viewer aperture  1802 , which is along the optical path of peephole viewer  212  and housing lid aperture  402 . Mirror actuator apparatus  1804  is attached to front housing  106  by mirror hinge pin  1808 . Main processing board  308 , batteries  302 , mirror assembly actuator  1812 , camera attachment bracket  312 , and display mainboard bracket  1810  are all rigidly attached to the front housing  106 . Display  102  is attached to the mirror actuator apparatus  1804  such that it is covers aperture  1802 . A display FFC (flat flexible cable)  1806  connects display  102  to display mainboard bracket  1810 , providing power and data. Front housing  106  also has a front proximity sensor  104  on its face. 
       FIG. 19  shows an isometric view of the mirror actuator apparatus  1804 . Mirror bracket  304 , plunger receiving feature  1904 , and display  102  are all rigidly attached together. Mirror hinge pin  1808  passes through mirror bracket  304 , allowing the bracket  304  to rotate freely around the long axis of pin  1808 . Pin  1808  also passes through hinge pin brackets  1906 . Brackets  1906  are rigidly attached to front housing  106  (not shown here). Mirror assembly actuator  1812  has an actuator plunger  1902 , which it drives up and down when electrical current is applied. Actuator  1812  is rigidly attached to housing  106 . 
       FIG. 20  shows an isometric view of the mirror actuator apparatus  1804 , with the mirror flipped up by ninety degrees. Mirror bracket  304 , plunger receiving feature  1904 , and display  102  are all rigidly attached together. Mirror hinge pin  1808  passes through mirror bracket  304 , allowing the bracket  304  to rotate freely around the long axis of pin  1808 . Pin  1808  also passes through hinge pin brackets  1906 . Brackets  1906  are rigidly attached to front housing  106  (not shown here). Mirror assembly actuator  1812  is also rigidly attached to housing  106 . In this figure, the actuator  1812  is engaged, and actuator plunger  1902  is fully extended. Camera module  310  is attached to camera attachment bracket  312 , which in turn is rigidly attached to main processing board  308 . Peephole viewer  212  is shown as well. 
       FIG. 21  shows a side cross-section view of the peephole viewer camera apparatus  108  in this embodiment, as it is mounted on the door  100 . Housing lid  216  is rigidly attached to front housing  106 . Lid  216  is attached to the door  100  by removable adhesive tape. Camera module  310  is attached to camera attachment bracket  312 . Bracket  312  and main processing board  308  are rigidly attached to front housing  106 . Mirror  306  is attached to mirror bracket  304  such that the mirror  306  is oriented at a forty-five degree angle relative to the optical axis of peephole viewer  212 . Mirror  306  is also oriented at a forty-five degree angle relative to the optical axis of camera module  310 . Mirror bracket  304  has plunger receiving feature  1904 , which rests on top of actuator plunger  1902 . The plunger  1902  is an integral part of mirror actuator  1812 . Also shown is display FFC  1806 , which is connected to display mainboard bracket  1810   
       FIG. 22  shows a side cross-section view of the peephole viewer camera apparatus  108  in this embodiment, with the mirror flipped up by ninety degrees. Housing lid  216  is rigidly attached to front housing  106 . Lid  216  is attached to the door  100  by removable adhesive tape. Camera module  310  is attached to camera attachment bracket  312 . Bracket  312  and main processing board  308  are rigidly attached to front housing  106 . Mirror  306  is attached to mirror bracket  304 . Mirror bracket  304  has plunger receiving feature  1904 , which rests on top of actuator plunger  1902 . Here, the plunger  1902  is full extended, and mirror actuator  1812  is engaged. Also shown is display FFC  1806 , which is connected to display mainboard bracket  1810 . 
     Operation— FIGS. 18, 19, 20, 21, 22 —Embodiment F 
     The peephole viewer camera apparatus  108  in this embodiment includes a mirror actuator apparatus  1804 , which allows the mirror  306  to be flipped up by ninety degrees. In doing so, a person can look directly through front housing viewer aperture  1802  and have a clear view of peephole viewer  212 . When the mirror  306  is flipped back down, the mirror  306  is oriented at a forty-five degree angle relative to the optical axis of peephole viewer  212 . Mirror  306  is also oriented at a forty-five degree angle relative to the optical axis of camera module  310 . Thus, the view through peephole viewer  212  is reflected such that its optical axis aligns with the camera module  310 . 
     The mechanical motion of flipping up the mirror  306  is enabled by use of the mirror actuator  1812 . The actuator  1812  can be a linear actuator or any other type of actuator apparatus which can convert electrical energy to linear motion. Plunger receiving feature  1904  rests on the actuator plunger  1902 . When the actuator  1812  is engaged, it drives the plunger  1902  upwards, pushing up the plunger receiving feature  1904 , which is rigidly attached to mirror bracket  304  and mirror  306 . Mirror bracket  304  is constrained to rotate around mirror hinge pin  1808 . Thus, when the plunger  1902  moves upwards, it rotates the mirror bracket and mirror up by ninety degrees. 
     When the actuator is disengaged, the plunger  1902  will return to its original position. Thus, the mirror bracket and mirror will rotate back down to their original position aided by gravity. Alternatively, a spring could be added to push the mirror back to its original rotation. 
     The front housing  106  has proximity sensor  104 , which can sense when a person is within a threshold distance. This proximity sensor can be configured to engage the actuator  1812  when a person comes close enough to the peephole viewer camera apparatus  108 . Thus, when a person approaches the apparatus  108  to look through the peephole viewer, the mirror bracket  304 , mirror  306 , and display  102  will flip up and allow the person a clear view through the peephole viewer  212 . When the person moves away, the mirror bracket  304 , mirror  306 , and display  102  will flip back down to cover the front housing viewer aperture  1802 . In this configuration, the display  102  will be visible on the front housing  106 . 
     The display  102  can be turned on based on any type of logic provided from the mainboard. It may also be turned on or off by a threshold distance as reported by the proximity sensor  104 . Alternatively, the display  102  can be eliminated, replaced by an opaque material such as plastic or metal. 
     It should be noted that although the actuator  1812  is described as a linear actuator, it could be replaced by a rotational actuator or any other type of actuator apparatus which can convert electrical energy to rotational motion. 
     Detailed Description— FIGS. 23, 24, 25, 26 —Embodiment G 
     Embodiment G is similar to embodiment F, but includes an external lever instead of a motorized actuator to flip the mirror. 
       FIG. 23  shows an isometric view of the peephole viewer camera apparatus  108  in this embodiment. Mirror actuator apparatus  1804  is attached to front housing  106  by mirror hinge pin  1808 . Hinge pin  1808  is extended to the side face of housing  106 , where it attaches to mirror actuator lever  2302 . 
       FIG. 24  shows an isometric view of the peephole viewer camera apparatus  108  in this embodiment, with the mirror flipped up. Mirror actuator apparatus  1804  is attached to front housing  106  by mirror hinge pin  1808 . Hinge pin  1808  is extended to the side face of housing  106 , where it attaches to mirror actuator lever  2302 . With the mirror flipped up, a person can look through front housing viewer aperture  1802 , and have an unobstructed view through peephole viewer  212 . 
       FIG. 25  shows an isometric internal view of the mirror actuator apparatus  1804 . Hinge pin  1808  attaches to mirror actuator lever  2302 . 
       FIG. 26  shows an isometric internal view of the mirror actuator apparatus  1804 , which is flipped up by lever  2302 . Hinge pin  1808  attaches to mirror actuator lever  2302 . 
     Operation— FIGS. 23, 24, 25, 26 —Embodiment G 
     The operation of this embodiment is very similar to embodiment F. However, the person who wishes to look through the peephole viewer  212  must rotate the lever  2302  up by ninety degrees. Once rotated up by ninety degrees, the person can look through front housing viewer aperture  1802  and have an unobstructed view through peephole viewer  212 . This is illustrated in  FIG. 26 . When the person releases the lever  2302 , gravity will pull the mirror actuator apparatus  1804  down, as shown in  FIG. 25 . Alternatively, a spring may be added to apply downward force on apparatus  1804 . Thus, the mirror is situated such that it reflects the view from peephole viewer  212  onto camera module  310 , as described in the previous embodiment F. 
     Although not shown, a feature may be added to housing  106  in order to stop the mirror actuator apparatus  1804  from rotating too far in either direction. 
     Detailed Description— FIGS. 27, 28, 29, 30 —Embodiment H 
     Embodiment H is similar to embodiment G, but uses a different type of lever actuator to flip up the mirror. 
       FIG. 27  shows an isometric view of the peephole viewer camera apparatus  108  in this embodiment, mounted on the door  100 . Apparatus  108  includes a front housing  106 , front proximity sensor  104 , fixed front housing viewer aperture  2704 , and mirror actuator lever  2302 . 
       FIG. 28  shows an exploded isometric view of the peephole viewer camera apparatus  108  in this embodiment. Housing  106  is rigidly attached to lid  216 . Door peephole viewer  212  defines an optical axis which is aligned with housing lid viewing aperture  402 , mirror  306 , and aperture  2704 . Below mirror  306  is camera module  310 , which is attached to bracket  312  such that its the camera module  310  optical axis is 90 degrees offset from optical axis of peephole viewer  212 . Mirror bracket  304  is rigidly attached to front housing  106 . Hinge pin  1808  is rigidly attached to mirror  306  and mirror actuator lever  2302  such that the angle between mirror  306  and lever  2302  is forty-five degrees. Hinge pin  1808  passes through bracket  304  such that it can rotate freely relative to the bracket  304 . 
       FIG. 29 . shows an internal isometric view of the apparatus  108  in this embodiment. Hinge pin  1808  is rigidly attached to mirror  306  and mirror actuator lever  2302  such that the angle between mirror  306  and lever  2302  is forty-five degrees. Hinge pin  1808  passes through bracket  304  such that it can rotate freely relative to the bracket  304 . Below mirror  306  is camera module  310 , which is attached to bracket  312 . 
       FIG. 30 . shows an internal isometric view of the apparatus  108  in this embodiment, with the mirror  306  and lever  2302  flipped up by forty-five degrees. Hinge pin  1808  is rigidly attached to mirror  306  and mirror actuator lever  2302  such that the angle between mirror  306  and lever  2302  is forty-five degrees. Hinge pin  1808  passes through bracket  304  such that it can rotate freely relative to the bracket  304 . Below mirror  306  is camera module  310 , which is attached to bracket  312 . 
     Operation— FIGS. 27, 28, 29, 30 —Embodiment H 
     The operation of this embodiment is very similar to embodiment H, but differs in how the lever  2302  actuates the rotation of the mirror  306 . The person who wishes to look through the peephole viewer  212  must rotate the lever  2302  up by forty-five degrees. As the mirror  306 , hinge pin  1808 , and lever  2302  are all rigidly connected, the act of rotating the lever  2302  up will create the same rotation in the mirror  306 . With the mirror  306  rotated up by forty-five degrees, the person can look through the fixed front housing viewer aperture  2704  and have an unobstructed view through peephole viewer  212 . This is illustrated in  FIG. 30 . When the person releases the lever  2302 , gravity will pull the mirror  306  and lever  2302  back down, as shown in  FIG. 29 . Alternatively, a spring may be added to apply downward force on lever  2302 . Thus, the mirror is situated such that it reflects the view from peephole viewer  212  onto camera module  310 , as described in the previous embodiment H. 
     Although not shown, a feature may be added to housing  106  in order to stop the lever  2302  and mirror  306  from rotating too far in either direction. 
     Detailed Description— FIGS. 31, 32, 33, 34, 35, 36, 37 —Embodiment J 
     This embodiment describes a peephole viewer apparatus with integrated sensors. This apparatus is similar to the wide-angle optical door viewer apparatus described in U.S. Pat. No. 4,269,474. However, the embodiment described herein adds an integrated proximity sensor. 
       FIG. 31  shows a side cross-section view of peephole viewer apparatus with integrated sensors  3102 . Peephole front housing tube  3108  is threaded such that it can be screwed into rear housing tube  3110 , which is also threaded. Front housing tube  3108  includes one or more peephole lens elements  3104 . Primary lens  314  is aligned with the optical axis of lenses  3104 . This optical axis is also aligned with housing tube  3108  and  3110 . Peephole front flange ring  3106  is threaded, and fits over primary lens  314 . Front flange ring  3106  has one or more flange ring sensor recesses  3118 . Sensor  3112  is placed inside of sensor recess  3118 . Sensor  3112  is connected to sensor FFC  3114  (flat flexible cable), which is terminated by FFC connector  3116 . 
     In this embodiment, the sensor  3112  is a time-of-flight (ToF) sensor, which can report proximity of an object. It requires only two small apertures to emit and collect infrared light. An example sensor is about three millimeters in length, and two millimeters wide. The required sensor apertures may be as small as one millimeter in diameter. 
     Note that the sensor may be of any variety including but not limited to time-of-flight, passive infrared, image or camera-based, microphone, LIDAR, ultrasonic, or other type of proximity sensor. 
       FIG. 32  shows a side cross-section view of the sensor  3112 , sensor FFC  3114 , and FFC connector  3116 . 
       FIG. 33  shows a side cross-section exploded view of the peephole viewer apparatus  3102 . This view shows the same labeled components as  FIG. 31 . It also shows flange ring threads  3120 , and flange receiving threads  3122 . These threads allow the front flange ring  3106  to be screwed onto the front housing tube  3108 . 
       FIG. 34  shows an isometric exploded view of the peephole viewer apparatus with integrated sensors  3102 . This view shows the same labeled components as  FIG. 31 . and  FIG. 33 . It shows a clearer view of the recess  3118 , which has flange ring sensor apertures  3402  to allow the sensor to see or hear through the flange ring  3106 . 
       FIG. 35  shows an isometric view of the sensor  3112 , sensor FFC  3114 , and FFC connector  3116 . 
       FIG. 36  shows a front view of the peephole viewer apparatus  3102 . Front flange ring  3106  has one or more flange ring sensor recesses  3118 . Sensor  3112  is placed inside of sensor recess  3118 , which has flange ring sensor apertures  3402  to allow the sensor to see or hear through the flange ring  3106 . 
       FIG. 37  shows a front view of the peephole viewer apparatus  3102 . This is the same view as  FIG. 36 , but it is an opaque view to show front surface details. Front flange ring  3106  holds primary lens  314  in place. Flange ring sensor apertures  3402  allow sound or light to pass through flange ring  3106  to reach the sensor  3112  inside. 
     Note that although the figures show four sensor recesses  3118 , there may be more or fewer in a practical implementation, depending on need. The sensor recesses  3118  may be placed anywhere around the flange ring  3106 . Also note that only one sensor  3112  is shown in the figures. More sensors may be added to make use of any sensor recesses  3118  available. 
     Operation— FIGS. 31, 32, 33, 34, 35, 36, 37 —Embodiment J 
     The peephole viewer apparatus with integrated sensors  3102  is meant to be installed on a door, such that the person on the indoor side of the door may look through the peephole viewer and see what is on the other side of the door. The peephole viewer&#39;s lenses are arranged such that the viewer provides a wide-angle field of view through the door. 
     The peephole viewer apparatus  3102  described in this embodiment includes one or more integrated sensors  3112  which are placed within the flange ring  3106 . When installed on the door, this flange ring  3106  is on the outside surface of the door. Thus any sensors  3112  in the flange ring  3106  can see or hear through flange ring sensor apertures  3402  to the space on the outdoors side of the door. Each sensor  3112  has a sensor FFC  3114 , which passes data and power through the housing tubes  3108  and  3110 . This allows the sensor to connect to a host microcontroller or CPU on the indoors side of the door. Such a microcontroller or CPU may then access the sensor  3112  data. If the sensor  3112  is a proximity sensor, the CPU or microcontroller may process the proximity data and determine whether there is activity on the other side of the door. 
     Such a CPU or microcontroller is described in a previous embodiment A. In  FIG. 4A , CPU  414  connects via sensor communication network  422  to an external sensor  424 . Any integrated sensor  3112  in the current embodiment may be used as external sensor  424  in  FIG. 4A  of embodiment A. 
     Detailed Description— FIGS. 41, 42, 43, 44 —Embodiment L 
       FIG. 41  shows an isometric view of wireless passive infrared sensor module  4102 . Sensor module front housing  4104  has a lens  4106  on its surface, and rear housing  4108 . Lens  4106  may be a Fresnel variety of lens, which is able to pass through light in the infrared range as required by a passive infrared sensor. 
       FIG. 42  shows an exploded isometric view of wireless passive infrared sensor module  4102 . Sensor circuit board  4110  has a passive infrared sensor  4112 , antenna  4114 , battery  4116 , and processor with rf transceiver  4118 . The circuit board  4110  is held between front housing  4104  and rear housing  4108 . Housing  4104  and  4108  are rigidly attached together, for example, by mechanical means or ultrasonic welding. Front housing  4104  has lens  4106  positioned over passive infrared sensor  4112 . An example Fresnel lens which is  2 cm by  3 cm in width and height is placed  8  millimeters above sensor  4112  for the best performance in infrared light collection. 
       FIG. 43  shows a top view of sensor module  4102 .  FIG. 44  shows a side cross-section view of sensor module  4102 . 
     Operation— FIGS. 41, 42, 43, 44 —Embodiment L 
     Wireless passive infrared sensor module  4102  may be used to remotely detect proximity of a person or animal. Overall, the module  4102  may be very small. In one design, the nominal size of module  4102  is  4 cm wide,  3 cm long, and  8 mm thick. This makes the module  4102  very inconspicuous, and easy to place anywhere in the area outside of the door for remote proximity detection. The bottom side of the module  4102  may be backed with adhesive tape to mount on the door frame, the door, or a wall. 
     The lens  4106  focuses infrared light from a very wide field of view onto passive infrared sensor  4112 . The processor with rf transceiver  4118  on the circuit board  4110  processes the sensor  4112  output and determines whether a person is present. When a person is determined to be present, the processor  4118  transmits a message using antenna  4114  indicating that activity is detected. 
     Battery  4116  provides power to the circuit board and all components. This type of system requires very little power, and can generally run for up to ten years on a single CR 2032  lithium coin cell battery (see https://www.ti.com/tool/TIDA- 01398 ) 
     The processor with rf transceiver  4118  may use any low power radio frequency protocol to transmit the “activity present” message. Some examples are Bluetooth, Zigbee, ANT, or other proprietary radio frequency communication protocols. Alternatively, a different type of transceiver could be used, replacing radio frequency transmission. Other types of transceivers could be used including infrared, sound, or other types of light-based communication. Alternatively, a wired method of communication could be used such as RS485, UART, Ethernet, I2C, or SPI. 
     Sensor module  4102  may thereby act as external sensor  424  in  FIG. 4A  of embodiment A. In  FIG. 4A , CPU  414  connects via sensor communication network  422  to an external sensor  424 . 
     Detailed Description— FIGS. 38, 39, 40 —Embodiment K 
       FIG. 38  shows an exploded isometric view of welcome mat with integrated sensors  3802 . Mat  3804  is a typical rectangular piece of material, such as one might place in front of one&#39;s entry door to a home. Around the border edge of mat  3804  are a number of sensor module recesses  3808 . Within each recess  3808  is a sensor module  3806 . This sensor module  3806  may be, for instance, a wireless passive infrared sensor module as described in embodiment L. As shown in  FIG. 42 , the wireless passive infrared sensor module  4102  has a lens  4106 , which in this case is a Fresnel lens. In general, Fresnel lenses designed for passive infrared usage are either translucent white material, or black, with a smooth or matte texture. The border around the mat  3804  may be composed of a similar material to match the appearance of the Fresnel lens. This makes it blend in with the appearance of mat  3804  such that a person looking at the mat will not notice it. 
       FIG. 39  shows a top view of welcome mat  3802 . A sensor module  3806  is found in each corner of the mat  3804 .  FIG. 40  shows a side view of the welcome mat  3802 . 
     In this embodiment, the sensor modules  3806  preferably use passive infrared such as the wireless passive infrared sensor module  4102  in embodiment L. Alternatively, other types of sensors could be used. 
     Note that four sensor modules  3808  are shown, but there may be more or as few as one sensor module  3808 . The modules  3808  are shown in the corners of mat  3804 , but they may be located anywhere on the mat. 
     An alternative in this welcome mat embodiment is using the same concept in the form of a welcome sign. Instead of placing it on the floor, it may be hung on the door. In this case, the sensor modules  3808  may be placed anywhere on the surface of the sign. One or more sensor modules  3808  may be placed under the background of the sign, or under the text. This is optimal if a large, thick black font is used. In this case, a black Fresnel lens may be used inside of one or more of the letters in the welcome message on the sign. The black material used for the letters can be chosen to match the Fresnel lens such that the lens is not noticeable. 
     Any number of ornamental designs may be used for this type of sign, and the same for the welcome mat. 
     Operation— FIGS. 38, 39, 40 —Embodiment K 
     The user places the welcome mat  3802  outside of the entry door, such as on a porch or main doorway to an apartment, condo, or house. Once in place, the sensor modules  3808  may monitor the area in front of the doorway or porch. 
     Preferably, sensor modules  3808  are implemented as the wireless passive infrared sensor module  4102  in embodiment L. In this case, each sensor module  3808  may thereby act as external sensor  424  in  FIG. 4A  of embodiment A. In  FIG. 4A , CPU  414  connects via sensor communication network  422  to an external sensor  424 . 
     As few as one sensor module  3808  may be used in mat  3802 . The welcome mat is intended to be stepped upon, and people may wipe their dirty shoes on it upon entering the home. Adding more sensors may be beneficial, in case one or more of the sensor module  3808  on the mat  3802  becomes occluded by dirt or grime from shoes as they tread upon the mat  3802 . 
     Note that although the sensor module  4102  is described as similar to embodiment L, any type of proximity sensor module could be used. Another example of a proximity sensor is in embodiment M and embodiment N. 
     Detailed Description— FIGS. 45, 46 —Embodiment M 
       FIG. 45  an isometric view of wireless proximity sensor module  4502 . Sensor module front housing  4104  has a plurality of proximity sensor housing apertures  4504  on its surface. 
       FIG. 46  is an exploded isometric view of wireless proximity sensor module  4502 . Sensor module front housing  4104  is shown with a plurality of proximity sensor housing apertures  4504  on its surface. Sensor circuit board  4110  has a one or more proximity sensors  4506 , antenna  4114 , battery  4116 , and processor with rf transceiver  4118 . The circuit board  4110  is held between front housing  4104  and rear housing  4108 . Housing  4104  and  4108  are rigidly attached together, for example, by mechanical means or ultrasonic welding. 
     Note that the sensors  4506  may be of any variety including but not limited to time-of-flight, passive infrared, image or camera-based, microphone, LIDAR, ultrasonic, or other type of proximity sensor. 
     Operation— FIGS. 45, 46 —Embodiment M 
     This embodiment is similar to embodiment L, but instead of using passive infrared sensors it uses active proximity sensors. In this embodiment, the wireless proximity sensor module  4502  uses one or more proximity sensors  4506 . These proximity sensors are preferably time-of-flight sensors, which can report proximity of an object. In this case, each sensor  4506  requires only two small apertures  4504  to emit and collect infrared light. An example sensor is about three millimeters in length, and two millimeters wide. The required sensor apertures may be as small as one millimeter in diameter. 
     In general, a time-of-flight sensor has a field of view of about thirty degrees. Thus, multiple sensors may be added with overlapping fields of view to cover a larger, virtual field of view. 
     Wireless proximity sensor module  4502  may be used to remotely detect proximity of a person. The processor with rf transceiver  4118  on the circuit board  4110  processes the proximity sensors  4506  outputs and determines whether a person is present. When a person is determined to be present, the processor  4118  transmits a message using antenna  4114  indicating that activity is detected. 
     Battery  4116  provides power to the circuit board and all components. An external port may be added to recharge the battery  4116 . 
     The processor with rf transceiver  4118  may use any low power radio frequency protocol to transmit the “activity present” message. Some examples are Bluetooth, Zigbee, ANT, or other proprietary radio frequency communication protocols. Alternatively, a different type of transceiver could be used, replacing radio frequency transmission. Other types of transceivers could be used including infrared, sound, or other types of light-based communication. Alternatively, a wired method of communication could be used such as RS485, UART, Ethernet, I2C, or SPI. 
     In this embodiment, the “activity present” message may include extra information such as estimated proximity distance. 
     Wireless proximity sensor module  4502  may thereby act as external sensor  424  in  FIG. 4A  of embodiment A. In  FIG. 4A , CPU  414  connects via sensor communication network  422  to an external sensor  424 . In this type of a setup, the user would mount the sensor somewhere on the outside area of the doorway. For instance, the user could use adhesive tape to attach the module  4502  to the door frame, wall, or outside surface of the door. 
     Sensors  4506  are preferably time-of-flight sensors, which are extremely small. Therefore, the sensor module  4502  can be made very thin and low profile. It is possible to make the module less than a few millimeters in thickness. In addition, the top surface of the module  4502  may be customized with any type of material or finish. Thus, it can be customized to match the surface on which it is mounted. This makes the module  4502  difficult to notice by an observer. 
     In one design, the nominal size of module  4502  is  4 cm wide,  3 cm long, and  3 mm thick. This makes the module  4102  very inconspicuous, and easy to place anywhere in the area outside of the door for remote proximity detection. Module  4502  may be backed with adhesive tape for easy mounting on the door, door frame, wall, or any surface in the area outside of the door. 
     Detailed Description— FIGS. 47, 48, 49, 50 —Embodiment N 
     Embodiment N is a variation of the embodiment M. In this embodiment, a plurality of proximity sensors are mounted at varying angles to allow a wide virtual field of view. 
       FIG. 47  shows an isometric view of wireless proximity sensor module A  4702 . Sensor module front housing  4104  has a plurality of proximity sensor housing apertures  4504  on its surface. Rear housing  4108  is attached to front housing  4104 . 
       FIG. 48  shows an exploded isometric view of wireless proximity sensor module A  4702 . Sensor module front housing  4104  is shown with a plurality of proximity sensor housing apertures  4504  on its surface. Sensor circuit board  4110  has a one or more proximity sensors  4506  mounted on sensor flexible printed circuit  4704 , antenna  4114 , battery  4116 , and processor with rf transceiver  4118 . The circuit board  4110  is held between front housing  4104  and rear housing  4108 . Housing  4104  and  4108  are rigidly attached together, for example, by mechanical means or ultrasonic welding. In this embodiment, sensors  4506  are mounted on a flexible printed circuit  4704 , which is connected to circuit board  4110 . This allows the sensors  4506  to be mounted at varying angles by bending the flexible printed circuit  4704  where needed. 
     Note that the sensors  4506  may be of any variety including but not limited to time-of-flight, passive infrared, image or camera-based, microphone, LIDAR, ultrasonic, or other type of proximity sensor. 
       FIG. 49  shows a top view of wireless proximity sensor module A  4702 .  FIG. 50  shows a side cross-section view of wireless proximity sensor module A  4702 . 
     Operation— FIGS. 47, 48, 49, 50 —Embodiment N 
     The operation of this embodiment is virtually the same as the previous embodiment M. The primary difference is that the sensors  4506  are mounted on a flexible printed circuit  4704  at varying angles, to increase the overall virtual field of view. Otherwise, please refer to the operation description for embodiment M. 
     In one design, the nominal size of module  4702  is  4 cm wide,  3 cm long, and  3 mm thick. This makes the module  4702  very inconspicuous, and easy to place anywhere in the area outside of the door for remote proximity detection. Module  4702  may be backed with adhesive tape for easy mounting on the door, door frame, wall, or any surface in the area outside of the door. 
     Detailed Description— FIG. 51 —Embodiment P 
     This embodiment is door hanger which has an embedded proximity sensor. 
       FIG. 51  shows an isometric view of the door hanger sensor apparatus  5102 . Door hanger  5108  is an elongated “S” shaped hanger designed to hang on a door. Door hanger top hook  5110  hooks over the top of the door, and it is thin enough to fit between the top of the door and the door frame. Hanger outside hook  5112  is allows the user to hang a sign, wreath, or other festive decoration on the outer side of the door. The length between the top hook  5110  and outside hook  5112  can be varied depending depending on the desired height of outside hook  5112  above the floor. 
     Embedded inside of hanger  5108  is proximity sensor  4506 , which is facing the outside surface of the hanger  5108 . In this embodiment sensor  4506  is a passive infrared sensor. Flush with the outside facing surface of hanger  5108  is a lens  4106 . Lens  4106  is mounted such that it focuses a wide field of view of infrared light onto sensor  4506 . The surface material of hanger  5108  can match the color and surface finish of the lens  4106 , such that a person looking at the hanger apparatus  5102  cannot notice the lens  4106 . 
     Sensor  4506  is mounted on sensor circuit board  4110 . A sensor power and data cable  5104  connects to circuit board  4110  and travels along the hanger  5108  upwards, past the top hook  5110 . It there connects to processor circuit board  5106 , which is mounted inside a cavity on the hanger  5108 . When the hanger apparatus  5102  is hung on the door, this cavity with circuit board  5106  will be on the inside facing side of the door. 
     Circuit board  5106  has a processor with rf transceiver  4118 , antenna  4114 , and battery  4116 . Cable  5104  connects the processor  4118  to proximity sensor  4506 . Cable  5104  also provides power to the sensor  4506 . 
     In this embodiment, the sensor  4506  preferably use passive infrared in a similar fashion as the wireless passive infrared sensor module  4102  in embodiment L. Alternatively, sensor  4506  could use a time-of-flight sensor as described in embodiment M. If a time-of-flight sensor is used, then lens  4106  would be eliminated, and replaced with sensor apertures  4504  as shown in  FIG. 46 . 
     Note that while only one sensor  4506  is shown, there may be more added if desired. They may be placed anywhere on the outer surface of hanger  5108 . 
     Also note that while sensor  4506  is described as a passive infrared sensor or time-of-flight sensor, a variety of types of external sensors may be used. Such types of sensors include but are not limited to microphones, LIDAR, ultrasonic, FLIR, or imaging sensors. 
     Operation— FIG. 51 —Embodiment P 
     Door hangers are common, and allow the user to hang a sign, ornament, or festive decoration on the outside surface of the door, without permanent modification of the door. The door hanger sensor apparatus  5102  works in the same way, but adds a proximity sensor to detect when there is activity outside of the door. 
     The apparatus  5102  works in the same way as the wireless passive infrared sensor module described in embodiment L. However, the sensor circuit board  4110  is separated from the processor circuit board  5106 , connected by sensor power and data cable  5104 . This cable  5104  may be a standard multi-conductor cable, a flat flexible cable (FFC), or a flat printed circuit (FPC). 
     The bulkier components are the circuit board  5106  with battery  4116 , and these are mounted on the indoors side of the door. This allows the hanger  5108  section with the sensor  4506  to be very thin. 
     Functionally, the operation of the sensor  4506  is very close to embodiment L. Refer to embodiment L operation description for more details. 
     The processor with rf transceiver  4118  may use any low power radio frequency protocol to transmit the “activity present” message. Some examples are Bluetooth, Zigbee, ANT, or other proprietary radio frequency communication protocols. Alternatively, a different type of transceiver could be used, replacing radio frequency transmission. Other types of transceivers could be used including infrared, sound, or other types of light-based communication. 
     The door hanger sensor apparatus  5102  may thereby act as external sensor  424  in  FIG. 4A  of embodiment A. In  FIG. 4A , CPU  414  connects via sensor communication network  422  to an external sensor  424 . In the current embodiment the communication method is described as a low power radio frequency method. 
     Alternatively, a wired connection could be used to connect processor circuit board  5106  from the current embodiment to CPU  414  from embodiment A, as shown in  FIG. 4A . This would involve adding a cable from the circuit board  5106  and connecting it to the peephole viewer camera apparatus  108  in embodiment A. Doing so would make it possible to eliminate battery  4116 , as the apparatus  5102  could consume power from apparatus  108  via the added cable. 
     Detailed Description— FIG. 52 —Embodiment Q 
       FIG. 52  shows an isometric view of the peephole viewer camera apparatus  108  of this embodiment. The apparatus  108  is very similar to embodiment A, but includes a key-holder magnet  5202  on the front facing surface of camera apparatus front housing  106 . 
     Magnet  5202  may be embedded under the surface of housing  106 , such that it is not visible and the housing  106  has a uniform surface finish of any color. The surface of housing  106  may offer a visual indication that the area underneath has a magnet. 
     Alternatively, the magnet may be placed on the surface of housing  106  such that it offers a visual cue to the user that it is a magnetized area. 
     Note that although the magnet  5202  is shown in the lower right corner of housing  106 , it may be located anywhere on housing  106 . Likewise, its size and shape may be varied from its depiction in the drawing. 
     Operation— FIG. 52 —Embodiment Q 
     Key-holder magnet  5202  is a convenience feature of apparatus  108 . When installed on the door  100  over the peephole viewer, the apparatus  108  is easy to reach, at about shoulder height on most doors. The person may place his keys on key-holder magnet  5202 , and they will stick to the surface of apparatus  108 . 
     For people who are physically disabled or in a wheelchair, the door to their home likely has a peephole door viewer installed at a lower accessible height. Therefore, the apparatus  108  will still be within easy reach and the key-holder magnet  5202  feature is still accessible. 
     Conclusions, Ramifications and Scope 
     The above description of illustrated implementations, including what is described in the Abstract, is not intended to be exhaustive or to limit the scope of the disclosure to the precise forms disclosed. While specific implementations of, and examples for, the embodiments disclosed herein are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the disclosure, as those skilled in the relevant art will recognize.