Patent Publication Number: US-6911909-B2

Title: Light sensing hidden object location system

Description:
This application is a continuation of U.S. patent application Ser. No. 09/894,141, now U.S. Pat. No. 6,590,497, entitled “LIGHT SENSING HIDDEN OBJECT LOCATION SYSTEM”, by Ravi Chandar, filed Jun. 29, 2001. U.S. patent application Ser. No. 09/894,141 is hereby fully incorporated herein by reference. 

   FIELD OF THE INVENTION 
   This invention relates generally to a locating system for locating lost or hidden objects such as a television remote control device, and more particularly, a system for finding lost or hidden objects when lighting is reduced. 
   BACKGROUND FOR THE INVENTION 
   Remote control devices are well known for the operation of electronic devices such as audio and/or video equipment, e.g. television (TV) sets, video recorders (VCR), cable boxes, and compact disc (CD) players. Because remote control devices are conveniently portable, they allow users to operate electronic devices from remote locations. Often a user would misplace a remote control and not remember where he left it. Usually these devices are lost between cushions of a sofa, under magazines, or blankets, or articles of clothing, depending on where the remote control device is being used. In other words, these remote control devices are often lost in dark areas where they are not in plain view, and therefore difficult to find. 
   Problems associated with finding these devices have been addressed in the prior art. The most common types of locating devices have detectors that have to be activated in order to be found. Typically, a user who has misplaced his remote control would activate some sort of transmitter usually located on the parent appliance (TV set or CD player etc). A receiver located in the remote control receives the transmitted signal. The reception of this signal triggers some sort of alarm on the remote control device, thereby enabling the user to find it. 
   A possible disadvantage associated with such a remote control locating device is that the locating function cannot operate in an automatic mode. In order to locate the misplaced remote, the user must first trigger the locating system. Another disadvantage is that these systems require extra components, such as the transmitter attached to the parent device, which can be costly. 
   Another known type of remote control locator device is the “clapper”. When the user has discovered that the device is missing, he activates an alarm in the remote control device by clapping his hands. This enables him to locate the remote control. Some of these remote control devices may also be voice responsive. Similar to the other devices, a disadvantage associated with these devices is that they cannot be operated in an automatic mode. In order to locate the misplaced remote, the user must trigger the locating system. Input such as clapping is required by the person looking for the remote. 
   SUMMARY OF THE INVENTION 
   In one respect, the invention is a method for locating a hidden object This method involves several steps. One step is the sensing an ambient light level in the near proximity of the object. Another step is the determination of whether the light level is below a predetermined level. Another step in this method is the activation of an alarm connected to the object, in response to the determination step. 
   In another respect, the invention is a device to aid in locating an object. In this respect, the device comprises an ambient light sensor that is connectable to the object. The device also comprises an alarm that is electrically connected to the ambient light sensor. The alarm is activated when the ambient light detector senses light at a level that is below a predetermined level. 
   In this respect, the device may be divided into parts including, a first part and a second part. In this respect, the first part may consist of a first power source, a transistor, and the ambient light sensor. In this respect, the second part may consist of a second power source and the alarm. The system may also include an electro-magnetic relay that electrically connects the first part to the second part. The electromagnetic relay may be connected to actuate the alarm when the ambient light photosensor senses light at a level below the predetermined level. 
   In another respect, the invention is a system to aid in locating an object. In this respect, the system comprises an object and an ambient light sensor that is connected to the object. The system also includes an alarm that is electrically connected to the ambient light sensor. The alarm according to this invention is activated when the ambient light detector senses light at a level that is below a predetermined level. 
   In this respect, the system to aid in locating an object may be divided into parts including, a first part and a second part. In this respect, the first part may consist of a first power source, a transistor, and the ambient light sensor. In this respect, the second part may consist of a second power source and the alarm. The system may also include an electro-magnetic relay that electrically connects the first part to the second part. The electro-magnetic relay may be connected to actuate the alarm when the ambient light photosensor senses light at a level below a predetermined level. 
   In comparison to known prior art, certain embodiments of the invention are capable of achieving certain advantages. One advantage is the economy of parts associated with this device. The locating system is wholly independent of the parent device, and therefore does not require any additional elements in the parent device, such as transmitters etc. Another advantage is the use of a photosensor, which senses ambient conditions and reacts automatically to being placed in concealed locations. These and other advantages will be apparent to those skilled in the art upon reading the following detailed description of preferred embodiments, with reference to the below listed drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a wireless object according to a first embodiment. 
       FIG. 2  shows the circuitry of a wireless object locating system. 
       FIG. 3A  shows the Part A components of the circuitry of FIG.  2 . 
       FIG. 3B  shows the Part B components of the circuitry of FIG.  2 . 
       FIG. 4  shows the components of the electro-magnetic relay of FIG.  2 . 
       FIG. 5  is a flowchart of a method according to an embodiment of the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  shows a wireless object  100  according to a first embodiment. This wireless object  100  may be a remote control device for operating a parent electronic appliance The parent appliance may be a TV or a CD player or the like. As illustrated in  FIG. 1 , the wireless object has a control panel  110  that includes control buttons for operating the object related functions.  FIG. 1  also illustrates an alarm  120  that is located on the wireless object  100 . This alarm  120  may be a beeper, and upon actuation, may produce an audio signal to notify the user of its location. Also illustrated in  FIG. 1  is an ON/OFF switch  130 . This switch  130  is used to disconnect the alarm  120 , when the locating service is not desired.  FIG. 1  also illustrates an ambient light photosensor  220 . The photosensor  220  is preferably located on an upper face of the wireless object, i.e., the face of the device that has the control panel  110 , the alarm  120 , and the ON/OFF switch  130 . However, the photosensor  220  may be fitted on any other surface of the object without deviating from the scope and spirit of the present invention. 
     FIG. 2  shows the circuitry of a wireless object locating system  200 . The system  200  has a first power source  210 , a resistor  215 , a photosensor  220 , and an electro-magnetic relay  230 . This system may also include a transistor  240 .  FIG. 2  shows a second power source  250 .  FIG. 2  also shows the alarm  120  and the ON/OFF switch  130 , which were already illustrated in FIG.  1 . The system  200  can be divided into two parts, Part A and Part B, as illustrated in  FIGS. 3A and 3B . 
     FIG. 3A  shows the Part A components of the circuitry of the wireless object locating system  200 . Part A includes the power source  210  that may be a conventional battery. The power source  210  is connected to the photosensor  220 , which may be a photocell, such as a cadmium sulphide photo resistor. The photosensor  220  detects ambient light. The photocell operates in such a way that its resistance changes according to the amount of light that shines on it. The resistance of the photocell is inversely proportional to the light detected. As a result, current passing through the photocell  220  from the battery  210  changes in direct proportion to the amount of light shining on the photosensor  220 . 
     FIG. 3A  also shows the electromagnetic relay  230 . The electro-magnetic relay  230  is the element that electrically couples Parts A and B of the system  200 . With respect to Part A, the electro-magnetic relay  230  is electrically coupled to the photosensor  220 . The current flowing from the photosensor  220  activates the electro-magnetic relay  230 . Part A may also include a transistor  240  in conjunction with the photosensor  220 . This transistor  240  may be necessary because the photocell may not be able to draw enough current to activate the electro-magnetic relay  230 . The transistor  240  is used to amplify the current. 
     FIG. 3B  shows the Part B components of the circuitry of the wireless object locating system  200 . Part B includes the alarm  120  and the ON/OFF switch  130 . The ON/OFF switch  130  is also connected to the second power source  250 . According to the switch setting, the power to the alarm  120  can be turned OFF or turned ON. The default setting is preferably ON. This is achieved by having the switch  130  closed. However, the power to the alarm  120  can also be turned OFF. The alarm  120  can be turned OFF in one of two ways. First, a user using the ON/OFF switch  130  could disconnect the alarm  120  from the power source  250 . The alarm  120  could also be disengaged by the electro-magnetic relay  230 , as will be described in reference to FIG.  4 . 
     FIG. 4  shows the components of the electro-magnetic relay  230 . Also,  FIG. 4  schematically shows the connections to Parts A and B. As illustrated in  FIG. 2 , the electro-magnetic relay  230  is the element that couples Parts A and B of the locating system  200 . As illustrated in  FIG. 4 , the electro-magnetic relay  230  includes an electromagnet  310 . The relay system also includes a movable armature  320 , which is biased by a spring  330 .  FIG. 4  also shows a pair of contacts  340  and  350 . The electro-magnetic relay  230  may be used to connect and to disconnect the alarm circuit. When a sufficiently strong current is flowing through the relay  230 , the electromagnet  310  becomes energized. This current is the output current from Part A. When the electromagnet  310  becomes energized, the armature  320  is attracted towards the electromagnet  310  and the armature  320  engages the contact  340 . The effect of this is to keep the alarm circuit in an open or disengaged state. When no current flows or the current is sufficiently low, the electromagnet  310  is not energized and the biasing force of the spring  330  pulls the armature  320  away from the electromagnet  310 , bringing it into engagement with the contact  350 . This closes/engages the alarm circuit in Part B. 
   The general operation of the locating system is as follows. When the photosensor  220  detects a sufficient amount of light, the cell has almost no resistance. Therefore it conducts electricity freely. In this instance, the electromagnet  310  is energized. As a result, the armature  320  is attracted by the electromagnet  310 , brining it into engagement with the contact  340 . As explained above, this causes the alarm circuit to open. As a result, no alarm is produced. 
   When no light shines on the photosensor  220 , the resistance becomes high, thereby restricting the flow of electricity to almost zero. Because of the inadequate flow of electricity, the electro-magnet  310  is not energized, and the biasing force of the spring  330 , pulls the armature  320  away from the electromagnet  310  and into engagement with the contact  350 . In effect, this closes the alarm circuit and activates the alarm  120 . As stated above, the photosensor  220  is located on the upper surface of the object  100 . Therefore, a “no-light” condition sensed is usually indicative of a situation where the object is covered or hidden. 
     FIG. 5  is a flowchart of a method  400  according to an embodiment of the invention. This figure out lines the steps performed by the wireless object locating system  200  in locating a wireless object  100 . As illustrated in  FIG. 5 , after the process has started, the wireless object locating system  200  goes through a decision stage  410 . At this decision stage  410 , the position of the ON/OFF switch  130  is considered. If the switch  130  is in the OFF (open) position, then the entire process ends because in the OFF position, the alarm  120  is disengaged. If, however, the switch  130  is the ON (closed) position, the next stage  420  is the sensing of the ambient light. This is performed by the ambient light photosensor  220 , which is preferably positioned on the upper face of the wireless object  100 . After the ambient light has been sensed, the next stage is a decision stage  430 . At this stage, it is decided if the ambient conditions are too dark, i.e., if the ambient light is below a predetermined level. If the answer is NO, then wireless object locating system  200  re-starts the process and repeats step  410  and the relevant subsequent steps. If the decision at stage  430  is YES, i.e., the ambient lighting is too dark, i.e., if the ambient light is below a predetermined level, then the alarm  120  is activated in step  440 . This ends the process. 
   With respect to the predetermined level of light, it should be noted that a predetermined level of light might be any chosen level of light in a lighting spectrum that ranges from absolute darkness to visible light. This predetermined level can be varied to any desired level. For most users, the predetermined level would be closer to the absolute darkness portion of the spectrum. However, in the case of a visually impaired user, the predetermined level may be closer to the visible light portion of the spectrum. The light level at which the alarm is activated may be altered by adjusting the strengths of the electromagnet  310  and/or the strength of the spring  330 . 
   In the vast majority of cases, the predetermined level is not a parameter that demands exact determination. The predetermined level is simply a threshold level that distinguishes the relatively well-lit condition to which the object  100  is typically exposed when uncovered, from the relatively dark condition to which the object  100  is typically exposed when covered. Those skilled in the art can easily conduct an experiment to measure these two extreme conditions and pick any level intermediate to these extremes. 
   The wireless object locating system  200  may be integrated with the wireless object  100  as illustrated in FIG.  1 . In other words, the wireless object locating system  200  may be formed as an integral part of the wireless object  100  during the manufacture of the wireless object  100 . The wireless object locating system  200  may also be attached or retrofitted onto the wireless object  100  subsequent to the manufacture of the wireless object  100 . In the case of a remote control device, the object locating system  200  may be incorporated with the remote control device at the manufacturing stage, or the object locating system  200  may be retrofitted to a pre-existing remote control device. 
   With respect to the alarm  120 , it has already been stated that the alarm may be a noisemaker such as a beeper that upon activation may produce an audio signal. In addition to a noisemaker, the alarm  120  may be any known type that is applicable to this invention. For instance, the alarm  120  may be a flasher that may preferably emit bright light. Preferably the flasher is located on a surface different from that of the photosensor  220 . The light emitted would enable a user to locate the lost object  100 . The alarm  120  may also be a vibrator that signals a user by vibrating. The alarm  120  may also be a beacon signal (radio frequency) transmitter that may produce a “lost” signal to a user via a receiver of some type. The receiver may be in a separate device. In the case where the lost wireless object  100  is a remote control device, the receiver may be located in the parent appliance. 
   What has been described and illustrated herein are preferred embodiments of the invention along with some variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. For instance, the remote control device may be for the operation of other devices other than those mentioned specifically herein. Those skilled in the art will recognize that many variations are possible within the spirit and scope of the invention, which is intended to be defined by the following claims and their equivalents, in which all terms are meant in their broadest reasonable sense unless otherwise indicated.