Patent Document

FIELD OF THE INVENTION 
     The present invention relates to laser beam detecting apparatus, in particular modular discrete laser beam detecting apparatus having an extendable planar configuration and selectively permitting radiant energy to pass therethrough. 
     BACKGROUND OF THE INVENTION 
     Laser beam detection is often provided by evidence of destruction of surfaces surrounding the particular laser apparatus, and furthermore, the measurements (e.g. location, burn size, etc are manually taken. Moreover such surface markings are typically permanent and cumulatively act to diminish the purpose of the surface whatever that may be, e.g. barriers, process components, curtains, etc. Additionally, such manual responses may be inaccurate, unrepeatable and sufficiently slow to minimize any value in certain applications, e.g. safety. 
     SUMMARY OF THE INVENTION 
     The present invention provides a substantially planar panel having a plurality of radiant energy sensors disposed about the periphery of the panel, which sensors detect a portion of radiant energy incident on to the planar panel reflected or refracted to the planar panel periphery. From the radiant energy detected by a plurality of peripherally disposed sensors, information such as intensity, etc. may be rapidly determined in a non-destructive environment. In one embodiment, the source of radiant energy is controlled, e.g. turned off, in response to panel or screen received radiant energy deemed excessive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       These and further embodiments of the present invention may be better understood by reading the following Detailed Description together with the Drawing figures, wherein: 
         FIG. 1  is a perspective view of one embodiment of the present invention; 
         FIG. 1A  is a perspective view of a portion of the embodiment of  FIG. 1 ; 
         FIG. 2  is a perspective view of a second embodiment of the present invention; 
         FIG. 3  is perspective view of a third embodiment of the present invention; 
         FIG. 4  is block diagram of one embodiment of the present invention; 
         FIG. 5  is a flow chart of one process according to an exemplary embodiment of the present invention; and 
         FIG. 6  is a flow chart of a second process according to an exemplary embodiment of a further feature of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     As shown in  FIG. 1 , the typical embodiment  50  of the laser detecting screen according to the present invention includes a material  52  of a defined thickness and being at least partially radiant energy transmissive from front surface  54  of the material  52 . Incident radiant energy  60 , such as from a laser, strikes the front surface  54  and at least a portion of the incident energy travels internally to peripheral edges of the material  52 , and from the peripheral edge, travels to proximal radiant energy sensor boards  70 . In the particular embodiment of  FIG. 1 , the screen material  52  is rectangular, substantially planar, and includes four peripheral edges  56 A,  56 B,  56 C, and  56 D, where peripheral edges  56 B and  56 D have at least one radiant energy detector positioned to receive radiant energy from the proximal portion of the corresponding peripheral edge. 
     A closer view of a typical sensor board  70  is shown in  FIG. 1A , wherein a light sensor  72 , e.g. a AMS/TAOS TLS2571, described in technical product specifications and applications material included by reference, is mounted with a radiant energy (visible and IR light) sensor disposed facing an edge  56  of the radiant energy absorbing to receive the radiant energy emitted from the proximal edge  56 . In one embodiment, a filter  74  is interposed between a sensor  72  and the edge  56  to allow a selected band, e.g. infrared light, to be received and detected by the sensor  72 . Alternately, the material  52  may include radiation filtering elements or substances such as an infrared filter  74 . The typical sensor board  70  may include further components (e.g. forming a circuit board) facilitating connection to and communication with corresponding modules, e.g. a controller  102  discussed below or other sensor boards according to the present invention. 
     An alternate embodiment  80  of  FIG. 2  mounts sensor boards  70  having sensors facing into a material  82  surface, e.g. a front surface  83  or a rear surface  84  having an optional recess  86  therein. Also optionally included is a radiation coupler  88  to facilitate efficient transfer of radiant energy from the internal regions of the material  82  to the sensor on the sensor board  70 . Other embodiments omit the recess  86 , receiving radiant energy by direct contact with (or via a transmissive or filtering medium) of the sensor  72  with a front or rear (or other) surface. In further alternative embodiments, the radiation coupler comprises a radiation filter material such as an infrared light filter allowing the sensor on the sensor board  70  to reject radiation outside the desired (e.g. infrared) spectrum. 
     A further alternative embodiment  90  of  FIG. 3  shows a curved (non-planar) material  92  wherein sensor boards  70  (or bare sensors) may be deployed to receive radiant energy at a peripheral edge  94  or as shown, coupled from a curved front or rear  96  surface (optionally via a radiation coupler) as shown and discussed above. Further alternative embodiments also envision a material having multiple layers, e.g.  93 A,  93 B, one or more of which may provide selected filtering of the received incident radiation on its way to the detector board  70 . 
     In one embodiment  100  of a further portion of the present invention shown in  FIG. 4 , one or more of the detector boards  70  or the individual sensors  72  communicate with a controller  102  by appropriate interconnections, such as data bus structures or as shown in  FIG. 4 , I2C serial data format from the individual radiation (e.g. TSL2571) sensors  72 A,  72 B, . . .  72 N data lines  104 A,  104 B, . . .  104 N and clock lines  106 A,  106 B, . . .  106 N to individual controller input ports (pins), and in this instance, commonly connected interrupt lines  108 A,  108 B, . . .  108 N, from each sensor connected to the controller  102 , such as a CUBLOC™ CB280 controller manufactured by Comfile Technologies, Inc., the specifications, instructions and application material being incorporated by reference herewith. In the particular embodiment  100 , the interrupt lines include diodes  110  to permit a wired logical OR connection of the interrupt from any sensor to the controller  102 . Also included are light emitting diodes to visually signal the occurrence and origin of an interrupt signal. 
     One particular embodiment of the system incorporating the controller  102  and the TSL2571 sensors  72  provides that the controller loads a specific threshold signal into each sensor  72 A,  72 B, . . .  72 N, such that the corresponding sensors do not invoke an interrupt until a received radiant energy level equals or exceeds the corresponding threshold signal level, at which time the interrupt is pulled low causing the controller  102  to respond, and in one embodiment, interrupt the source of the radiation via the interlock  122 . 
     Typically the controllers (e.g.  102 ) are operable according to programmed instruction as described according to an exemplary embodiment below with regard to the flow charts of  FIGS. 5-6  discussed below. Furthermore, the controller responds to user commands and reports to the user via a control and display panel  120  interfaced with the controller as appropriate for the display and control panel  120 , controller  102  to implement the various embodiments according to the present invention. Typically, the embodiment of  FIG. 4  provides a control signal to a controller  122  source of radiant energy that the radiation was detected by use of the panels, sensors and controllers according to the present invention, to disable (or otherwise control) the output of the source of radiant energy. Moreover, the system according to the embodiment  100  of  FIG. 4  includes a communication port  124  to communicate with other similar controllers  126 , corresponding to other laser detecting screens to provide combined or integrated laser detection operations, e.g. disable the radiant energy source  122  in response to a report of stray energy received by another screen and sensor via controller  126  communicating with the controller  102 . Other inter-controller communications can include the sharing of initialization information discussed below with regard to the embodiment of  FIG. 6 , discussed further below. 
     A general initialization flow chart  150  for an exemplary embodiment according to the present invention is shown in  FIG. 5 , including a further feature according to the present invention to monitor acceptable received radiation levels and from determined or learn acceptable received radiation levels, establish a threshold at which point the systems becomes operational, e.g. to inhibit the source of radiant energy, as shown by an exemplary flow chart  150  of  FIG. 5 . 
     Typically the routine  150  of  FIG. 5  is run initially or whenever the user changes the radiant energy (e.g. laser) environment. For instance, during normal operations of a laser, there may be scattered laser light that hits one (or more if used) detection screens, and as such is considered normal and not an event to trigger or trip an alarm or disable the energy source (laser). To configure (initialize) the system to ignore this threshold level of [laser] light, the laser must be fired while the system according to one embodiment of the present invention learns a toleration level and establishes the corresponding ‘trip’ point threshold for received radiation deemed excessive or unsafe. Once started  152 , the user is notified (e.g. by display and control panel  120 ) to ensure that the laser is not firing,  154 , and to store (in the individual sensors) a signal corresponding to the non-firing ambient light level signal,  156 , and thereafter notifying the user  158  to begin the process, e.g. laser welding. Once it is established that the laser is firing,  160 , a new ‘firing’ ambient received energy level is stored (in each sensor) and a trial percentage threshold level is calculated,  164 , and sent to each sensor  72 ,  166 . Typically in one embodiment, the percentage by which the FIRING AMBIENT signal is increased to arrive at a TRIAL THRESHOLD is a variable that is entered when the system is initially installed or configured. The higher the percentage, the faster the FINAL THRESHOLD will be achieved but at the expense of possibly overshooting the optimal threshold where the system TRIPS (i.e. the system will not be sensitive enough). The lower the percentage the longer it will take to arrive at the FINAL THRESHOLD but the FINAL THRESHOLD might be too close to the ambient (i.e. the system would be too sensitive and prone to false ‘trips’. If at the trial threshold level a sensor threshold is achieved (i.e. device ‘tripped’),  168 , then the sensor is reset,  170 , and if the number of laser firing attempts is not exceeded,  172 , the trial threshold percentage is increased or adjusted  174  and if the sensor is again triggered,  168 , but not exceeding the number of attempts allowable,  172 , the trial threshold is again adjusted  174  and the laser firing is again attempted. However, should the number of attempts exceed the number of attempts allowable, then the user is informed that the radiation (laser light) level is too high,  178 , and user is notified to stop the process (e.g. welding)  180 , and the process ends or returns,  184 . If during this process a trial level is selected such that a sensor  72  is not tripped and does not issue an interrupt,  168 , the display and control panel  120  shows the system to be armed,  176 , the radiant energy (laser) operation is stopped,  180 , the upper ‘trip’ threshold saved to each sensor(s)  169 , and the process ends or returns,  184 . 
     The above exemplary process and apparatus may be incorporated into a process  220  according to  FIG. 6 , wherein after initiation  222 , if a reset button is pressed  224 , and a ‘threshold learn’ button is pressed  226 , the ‘Trip’ threshold is set  230  (via  FIG. 5 ). If the system is armed  232  after completing the flowchart of  FIG. 5 , and an interrupt is received from a device  72 , a corresponding display provided  236 , showing the system has tripped due to an interrupt received from a sensor  72 , corresponding to a received radiant (laser) energy (at or above one or more sensor thresholds) detected, and typically provides a visual or audible alarm, e.g. at the display and control panel  120  or elsewhere and remains in that state until the reset button is pressed,  224  and the process begins again. 
     Additional embodiments provide a screen that is front-to-back at least partially transmissive to radiant energy, and such energy being the same or different wavelength or other characteristic than the energy internally reflected to the energy received by the sensors. Sensors continuously polled by a controller, parallel sensor/controller communications, and detected radiant energy threshold stored and determination of sensor-received radiation meeting or exceeding the threshold at the controller are also within the scope of the present invention. Further alternate embodiments may include a radiation diffusing surface between at or prior to the sensors, and sensors (with or without filters) responsive to visible light provided from or in response to incident radiation. Further modifications and substitutions according to the present invention made by one of ordinary skill in the art are within the scope of the invention that is not to be limited except by the claims, which follow.

Technology Category: g