Abstract:
A surveillance camera for wild game animals includes a camera having automatic flash, focus, aperture and shutter speed and film advance functions. The camera is mounted within a housing adapted for outdoor installation and protection from adverse weather conditions. An electronic control circuit mounted within the housing is operably connected to the camera and includes a programmable microprocessor providing an interval set function for timing between taking photographs. The camera is activated by a passive infrared sensor detecting body heat of the animal or group of animals to be photographed. Day/night enable and aiming light functions are provided. The electronic control circuit is designed for extremely low voltage requirements.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to surveillance cameras and particularly to self-operating cameras which are battery operated and used for taking still photographs of game animals and other wildlife.  
         BACKGROUND OF THE INVENTION  
         [0002]    Surveillance cameras for photographing game animals and other wildlife have become popular as the technology of such cameras has improved. These advanced cameras utilize a relatively inexpensive fully automatic camera which provides automatic focus, flash, aperture and shutter speed and film advance functions. Such cameras are mounted along trails, salt licks, feeders and in other areas known to be frequented by game animals and other wildlife. By using these cameras, wildlife agencies may identify species within the area of study and determine the density and health of the population. Wildlife agencies are not the only purchasers of game cameras and they are also popular with sportsmen hunters who use game cameras to identify trophy animals within the study area. Especially popular with deer hunters, a hunter may use several game cameras to determine the location and routines of large bucks. The surveillance camera is mounted along a trail or watering hole and is left for several days or several weeks until the person returns and unloads the film for processing.  
           [0003]    These cameras are designed to take a photograph upon sensing an animal within a preselected target area. Sensors for some cameras include photoelectric eyes which sense an interruption in a lightbeam between emitters and reflectors. Other types of sensors used are infrared sensors which sense the body heat of an animal. The sensitivity of an infrared receiver may be selected so as to trigger the game camera shutter release only upon receiving an IR intensity above a given threshold, such as a level associated with a large game animal such as a trophy deer instead of the local skunk passing through. Moreover, the game camera is left out in the field during daylight and nighttime conditions and necessitates day/night enable capabilities.  
           [0004]    The environment of use of a game camera is hostile. Winter temperatures during operation may be as low as 0° F., particularly for the period shortly before dawn when many animals are most active. Summer temperatures within the game camera housing may approach 150° F. when in direct sunlight in southern climes. Temperature variations between these extremes requires stable operation over a wide range of temperatures for control electronics within the game camera. Preferably, the game camera must be capable of continuous operation for multi-day and multi-week periods from readily available battery power sources. For example, the inventor has determined that a 6 volt dc battery is an ideal, inexpensive and readily available power source, but to last for several weeks of continuous operation, the powered device must consume no more than small amounts of power such as 20 to 50 microamperes. The electronics of the game camera must be reasonably tolerant of power supply sag as the battery approaches its discharge limits. These requirements tend to require electronic devices with a very stable operation with low power requirements. The inventor has determined that a game camera is preferably controlled by a microprocessor unit specially designed for extremely low power consumption.  
         SUMMARY OF THE INVENTION  
         [0005]    A surveillance camera particularly for game and wildlife comprises a camera having automatic flash, focus, aperture and shutter speed and film advance functions. The camera is mounted within a housing adapted for outdoor installation and protection from adverse weather conditions including intense sun, cold and precipitation. An electronic camera control circuit is mounted within the housing and connected to the camera. The control circuit is designed for extremely low power consumption and includes a programmable microprocessor allowing users to control some of the functions of the camera.  
         OBJECTS OF THE INVENTION  
         [0006]    The objects of the present invention are:  
           [0007]    to provide a game camera having photograph taking intervals settable by a camera user;  
           [0008]    to provide such a game camera which is resistant to climatic extremes;  
           [0009]    to provide such a game camera using an electronic control circuit with extremely low power consumption requirements; and  
           [0010]    to provide such a game camera which is economic to produce, reliable and long-lasting in operation and particularly well adapted to the intended purpose. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is a plan view of a game camera embodying the present invention.  
         [0012]    [0012]FIG. 2 is a frontal elevational view of the game camera shown in FIG. 1.  
         [0013]    [0013]FIG. 3 is a side elevational view of the game camera shown in FIG. 1.  
         [0014]    [0014]FIG. 4 is a bottom view of the game camera.  
         [0015]    [0015]FIG. 5 is a plan view of the game camera with housing lid removed to show internal components.  
         [0016]    [0016]FIG. 6 is an enlarged view of the control panel of the game camera.  
         [0017]    [0017]FIG. 7 is a block diagram showing the functions of the electronic circuit of the game camera.  
         [0018]    [0018]FIG. 8 is an electrical schematic of the electronic circuit.  
         [0019]    [0019]FIG. 9 is a flow diagram of an initialize software algorithm in the processor of the electronic circuit.  
         [0020]    [0020]FIG. 10 is a flow diagram of a take picture software algorithm within the processor of the game camera circuit.  
         [0021]    [0021]FIG. 11 is a flow diagram of a wait for target software algorithm within the processor.  
         [0022]    [0022]FIG. 12 is a flow diagram of a timing software algorithm within the processor of the electronic circuit. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0023]    The reference number  1 , FIGS.  1 - 4 , generally indicates a game camera embodying the present invention. The game camera  1  consists of a housing  2  containing elements as hereinafter disclosed and a mounting bracket  3  attached to the back of the housing  2 . The game camera  1  is constructed for placement along a game trail or other place where game animals or other wildlife are likely to pass. The housing  2  is designed and constructed to be impervious to the adverse summer and winter weather conditions normally encountered in continental U.S. conditions. The mounting bracket  3  consists of an angled metal strap with oppositely extending wings  4  for attachment to a support structure, as by bolting to a tree. The metal wings  4  can be bent to accommodate connection to a smaller diameter tree, post or the like. The mounting bracket  3  is attached to the rear of the housing  2  by bolts  5  with spacers. The housing  2  is preferably of an impact resistant plastic and has a main body  7  with a removable lid  8 . The main body  7  has an inner well  9 , FIG. 5, to receive the inner components and an electronics well  10  located at the bottom of body  7 . The removable lid  8  fits snugly against the body  7  by snaps  11  at opposite sides of the housing  2 . A visor  12  extends outwardly from the lid  8  and protects the front of the main body  7  from the elements.  
         [0024]    The front side  14  of the main body  7  includes a lens hole  15  and a flash hole  17 , behind which a camera  20 , FIG. 5, is positioned. The camera  20  includes a camera lens  21  and a camera flash aperture aligned with the lens hole  15  and the flash hole  17 . The camera  20  is preferably a 35-millimeter camera controlled by a CPU and is fully automatic, providing an auto-focus system, an electronic shutter with multiple exposure capability and slow shutter, a built-in flash, a viewfinder, an automatic film advance and rewinding mechanism. The camera uses two 1.5 volt AA batteries and provides a date imprint on the film. A suitable camera is a Charman AF 9000D remote auto-focus camera.  
         [0025]    The game camera  1  includes an electronics package  24 , FIG. 5, which cooperates with the camera  1  to enable the user to take pictures during daylight only, nighttime only, or day or night. The camera can also be set to have a delay between each picture taken. The camera provides a minimum delay of fifteen seconds and a maximum of thirty minutes. The delay is adjustable and designed to help conserve film usage in the camera. For example, if the camera was set up on a feeder, the user would probably want a three to five minute delay. In a low activity area, such as a scrape line or trail, a fifteen second delay is useful. For extended filming, the thirty minute delay is useful to take one picture per activity. However, the camera could monitor a particular area for several weeks using the thirty minute delay feature. The front side  14  of the main body  7  includes an aperture  26  for an aim light, an aperture  27  for a day light detector and an aperture  28  for an infrared detector.  
         [0026]    Referring to FIG. 5, the camera  20  is positioned within a camera well  29  and adjacent a battery  31 . The battery is preferably a six volt 1.3 AH battery in size 613 with its terminals connected to leads into the electronic package  24  via alligator clips  33  and  34 . The electronics are covered by a face plate  36  including a manufacturer&#39;s name  37  with inbound leads  39  from the battery  31 . A camera flash lead  41  extends out from the face plate  36  to connect to a flash input on the body of the camera  20 . Referring to FIG. 6, several controls are apparent. Photo interval is set by a potentiometer  43  and ranges between 15 seconds and 30 minutes. A switch array  45  provides options of settings for operation of the camera during daylight only, night-time only, or day and night. Switch One  46  sets the daytime mode for “On or Off.” Switch Two  47  sets the night-time mode “On or Off.” Switch Three  48  in the up position provides a preset ten minute delay between taking photographs. In the down position, Switch Three permits the user to set the delay time using the photo interval dial potentiometer  43 . The potentiometer dial  43  is graduated from fifteen seconds to a thirty minute delay between photos. Switch Four  49  turns off or on an aiming light, which is emitted through housing aperture  26 . The aiming light is simply a beam of light directed through the aperture  26  so that the picture-taking direction of the game camera  1  can be adjusted to photograph the area selected by the user.  
         [0027]    The photo interval delay set by using the photo interval potentiometer  43  is adjustable between a minimum delay of fifteen seconds and a maximum of thirty minutes. The delay is designed to help conserve film usage in the camera  20 .  
         [0028]    The general layout of the electronics package  24  is shown in connection with FIG. 7. This controller package is of a small physical size in order to minimize undesirable parasitic electrical effects with the low noise passive infrared (PIR) differential signal processing. As shown in FIG. 7, a passive infrared sensor  51  signals a PIR signal processor  52  which in turn lights a presence indicator LED  53 . The PIR signal processor  52  provides a presence impulse to the main system processor  67 , which is in turn acted upon by the option settings  57  located in the switch array  45  and including switches one, two, three and four identified by numerals  46  through  49 . The ambient light sensor, otherwise known as the daylight detector  58 , operates as a light meter having an eye located behind the aperture  27  and provides an input signal to the system processor  67 . The processor  67  then provides appropriate inputs to the automatic camera circuitry within the camera  20 . Also shown in FIG. 7 is the DC battery  31  which provides an unregulated power lead  60  and a regulated power lead  61  through a power regulator/modulator  62 .  
         [0029]    An electrical circuit diagram is shown in FIG. 8. This circuit is designed around the system processor  67  which preferably is an 8-bit, 8-pin CMOS micro controller selected from the PIC 12C50X family of microprocessors. This micro controller can be configured to meet all requirements of the game camera  1  and is of a single package design requiring no external support components. This provides significant improvements in circuit board layout, packaging and is of a reasonable cost. The selected micro controller has significant benefits over a design using either discrete components or general purpose (CISC) microprocessors. The selected micro controller  67  includes six pins dedicated to providing a variety of programmable inputs and output of various types. It uses a unique Schmitt trigger input which is dynamically programmable as an input or an output in operation of the electrical circuit shown in FIG. 8. The passive infrared (PIR) sensor  51  detects the presence of an infrared-emitting body and provides an input to the PIR processor  52 . A pin  65  of the PIR sensor  51  provides a differential-mode signal from the PIR sensor  51  to the PIR processor  52 . Resistors R 1  and R 2  program the PIR processor  52  for sensitivity and responsiveness. Triggering conditions are completely related to internal algorithms of the PIR processor  52 , but generally depend on relationships between the strength and timing of the signal at  66  of the PIR sensor  51 . objects of a sufficient size are acted upon. Once the processor  52  has decided that the differential input from the passive infrared sensor  51  is indicating a target, signals are from the processor  56  to an aiming light LED  53  which then emits if the aiming light switch  49  is switched on. This function is useful for testing and setup wherein a user may position the game camera  1 , turn appropriate switches to the on position and then walk in front of the camera. Upon sensing the infrared emissions of the person, the sensor  51  activates, signals the aiming light  53  to emit a beam of light demonstrating line of view and initiate triggering of the camera  20 . From the PIR processor  52 , a signal also goes to a camera timing control processor  67 . Processor  67  cooperates with PIR processor  52  to trigger the camera  20  with camera inputs passing through transistor Q 2  at  68 .  
         [0030]    The passive infrared sensor  51  is composed of two sensors, one of which receives infrared from the target and the other of which is blind to infrared. The processor  56  determines a difference between the blind sensor and the active sensor so any background noise comprises common mode to both signals and is ignored. Other inputs to the processor  67  are through a switch block  45  including the daytime on/off (morning enable) switch  46 , the night on/off (evening enable) switch  47 , and the delay switch, which selects either a ten minute delay or routes control from the switch to the potentiometer  43 , which is variable between fifteen seconds and a thirty minute delay. If the potentiometer delay is enabled at  48 , the potentiometer R 15  at  70  is enabled. If the delay at  48  is grounded, the system processor  67  determines that the input is in fixed delay mode. If the input is not grounded, then the processor uses a timing circuit composed of resistor R 14 , resistor R 15  and capacitor C 12 , the resistors R 14  and R 15  identified as numeral  70  and the capacitor C 12  at  71 . The processor  67  discharges the capacitor C 12  at  71  and then waits for the capacitor to recharge. The length of time it takes capacitor C 12  at  71  to charge provides an indication to the processor  67  of the relative value resistor R 15  (the potentiometer) is set to and hence, what relative time delay to use.  
         [0031]    The inputs from the morning and evening enable switches  46  and  47  input to the processor  67  at GP 5  and GP 4 , respectively. Behind the aperture  27  is the daylight sensor  73 , FIG. 8, which provides light level signals to pin  4  of the processor  67  which are indicative of daylight conditions. Resistors R 11 , R 12  and R 13  (if used) connected to the morning, evening and delay switch lines, respectively joining switches  46  and  47  to the processor  67 , are pull-ups for the switches and pull the signal to logic-high if the switches  46  and  47  are open, or allow the signal to fall to logic-low if the switches  46  and  47  are closed. A triggering signal is sent via pin  6  from the processor  67  through resistor R 16  at  75  and then through transistor Q 2  at  68 . Diodes D 2  and D 3  at  76  provide circuit isolation for the camera  20 .  
         [0032]    [0032]FIG. 9 is a software logic flow diagram of the main control logic which is programmed into the system processor  67 . The program runs from “initialize” down to a run loop and does not terminate until the battery is removed or becomes discharged. The software acts upon a signal input from the sensor  51  or any other signal change conditions from any of the input pins. The software determines whether the input signal is a wake-up, a time-out, a changed condition, a pin change or any of the other inputs for the microprocessors having changed state. Upon a change of state, the system processor  67  activates. If there is no input from any of the processor pins, the system processor  67  falls into a nearly no current sleep mode and then wakes up only when a time-out occurs or if a long enough time passes with no inputs. The software causes the system processor  67  to wake up just long enough to confirm that there are no changed conditions. Otherwise, the software keeps the system processor  67  not running, which occurs approximately ninety-eight percent of its lifetime. After initialization and the software parsing for current conditions, the software causes the system processor  67  to wait in target mode, in which it will await a target signal. If there is a target signal and all of the conditions, such as daylight or not daylight and delay are adequate, the system processor  67  triggers the camera  20  and then goes into a wait period again. The waiting is for a fixed delay time or a time delay based upon the potentiometer setting. Then, the software reinitiates and waits for another target. Thus, FIG.  9  is a loop program which will loop as long as there is sufficient battery current, generally down to 4.75 volts. Operation may be unreliable when battery voltage drops into or below this region.  
         [0033]    [0033]FIG. 10 is another software flow chart documenting the software logic upon taking a picture. After enabling the camera trigger, there is a six second delay to enable the flash to charge again before it can fire. After the delay (by which time the picture will have been taken), the camera trigger is again disabled and the program execution returns to the main loop on FIG. 9.  
         [0034]    [0034]FIG. 11 is a software logic flow diagram for a wait for target mode. If no target presence is detected, the PIR processor  52  remains in a sleep mode where it is simply waiting for a time-out or a change and consuming substantially no battery power. If a target presence is detected, then the software checks whether it is daylight or night and whether day only or night only is enabled. If it is daylight and night only is enabled, then the processor goes back to a sleep mode and vice versa. If the logic returns from wait for target, the flow will go immediately to take pics, FIG. 10. In FIG. 11, arrival at “return” means to take a picture. “Sleep” means that the program will cause the system processor  67  to wait for something to happen, again in the ultra-low power sleep mode.  
         [0035]    [0035]FIG. 12A shows an upper logic loop at  80  which constitutes a procedure for determining a wait period based upon the settings of the delay switch  48  and the timer potentiometer  43 . In an alternative embodiment of the invention, the manufacturer may provide the circuit board with resistor R 13  only or resistors R 14 , R 15  and capacitor C 12  at  70  and  71 , FIG. 8, and the software can determine how the circuit board is equipped. An input to the system processor  67  enables the software to determine whether or not there is a fixed delay time by determining whether the switch  48  is on and the circuit is grounded or if the resistor R 13  is present and there is no capacitor C 12  there, so there is no charge-up time. The software attempts to signal the timing line from pin  5  and if it finds the timing line is pulled high or pulled low, it provides either a three minute or ten minute fixed delay. If the software attempts to pull the signal low and it fails to immediately come back high, then the software logic loop  80  runs while timing how long it takes for the signal to come back high, indicating a recharged capacitor. If the capacitor C 12  takes too long to recharge, indicating a fault in the charging circuit, the software sets a thirty minute delay and defaults to thirty minutes. If the capacitor C 12  returns high, the program checks to determine if the capacitor charged too fast, indicating another fault and the software sets a three minute delay. If the capacitor C 12  did not charge too fast, then the software determines where in the range of possible delays the delay signal most likely is and develops an index that represents from immediate to very long, which tells it roughly the setting of the potentiometer C 12  at  71 . The software uses the delay index computed by any of the methods or any of the fail-safes present in the program, the fixed configuration or the potentiometer reading. The delay index is used to compute counters based upon the speed of the system microprocessor  67  and then the software times while the counters time out and permit the time between pictures to run, loop  83 , FIG. 12B. There is an escape from the bottom loop  83  so that if the day/night switches are changed, it indicates that the program is actually in a test mode so the program causes the system processor  67  to sleep one minute and return to let matters stabilize and then take another photograph. The whole purpose of the software shown in FIG. 12 is to determine how long to wait and then cause the wait.  
         [0036]    The software described in FIGS. 9 through 12, in combination with only one pin of input to the microprocessor  67 , computes a relative time based upon a plurality of different configurations without having to change anything in the software. This software enables very low power consumption of the system processor  67  during a waiting state, down to 12 ua (micro-amperes).  
         [0037]    The invention afore described provides a very low power consumption for long battery life with a small size for the electronic circuit. This permits a small size overall of the game camera. With the selected microprocessor, the control algorithms may be modified as necessary without substantial change to the support circuitry.  
         [0038]    While certain forms of the present invention have been described and illustrated herein, it is not to be limited thereto except insofar as such limitations are included in the following claims.