Abstract:
A thermal imaging system having a remote user interface comprises a portable thermal imager (such as a handheld thermal imager) having a communication interface for transfer of data. The imager further has an on-board memory in which image data is stored as well as an imager display to show a processed thermal image based on the image data stored in memory. A remote computer is operative to communicate with the thermal imager via the communication interface. The computer runs software operative to transfer the image data to the computer and show the processed thermal image on a computer display thereof on a real-time basis.

Description:
PRIORITY CLAIM 
     This application claims the benefit of provisional application Ser. No. 60/904,282, filed Mar. 1, 2007, which is relied upon and incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to thermal imagers. More particularly, the invention relates to a system and method for providing control of a thermal imager at a remote user interface. 
     Thermal imaging cameras are used in a wide variety of applications, such as predictive maintenance in industrial facilities. Such cameras, often simply referred to as “thermal imagers,” include some type of infrared engine that converts infrared energy into electrical signals. For example, many thermal imagers include a detector array located in the focal plane of the camera optics. Infrared energy impinging the focal plane array (FPA) is read out for further processing on a pixel-by-pixel basis. 
     The “raw” data produced by the infrared engine is then converted through digital signal processing techniques to the visible image that can be displayed. In this regard, objects in the image are often depicted in colors corresponding to their relative temperature. Text and other graphics can also be overlaid on the thermal image, or provided in different zones of the display. Some thermal imagers are also capable of determining and displaying a temperature measurement for the object at the “cross hairs” of the thermal image. The processed images thus produced may be stored in local memory before subsequent download to a personal computer, such as using a serial data link. 
     SUMMARY OF THE INVENTION 
     According to one aspect, the present invention provides a thermal imaging system having a remote user interface. The system comprises a portable thermal imager (such as a handheld thermal imager) having a communication interface for transfer of data. The imager further has an on-board memory in which image data is stored as well as an imager display to show a processed thermal image based on the image data stored in memory. 
     A remote computer is operative to communicate with the thermal imager via the communication interface. The computer runs software operative to transfer the image data to the computer and show the processed thermal image on a computer display thereof on a real-time basis. 
     In some exemplary embodiments, the software running on the remote computer is operative to generate at least one graphical representation on the computer display representing an actuator on the thermal imager. For example, the software may be operative to generate a plurality of graphical representations indicative of respective buttons on the thermal imager. In such embodiments, the software also preferably operates to determine when a computer user has selected the graphical representation and responsively communicate a corresponding command back to the thermal imager. 
     Often, portions of a target object being viewed with the thermal imager are shown in the processed thermal image in colors corresponding to relative temperatures thereof. The processed thermal image may further include textual information. Moreover, the processed thermal image may include multiple zones in which various information is shown. 
     In many embodiments, the communication interface of the thermal imager is operative to communicate with the remote computer via a wired connection. For example, the communication interface may be a universal serial bus interface. Often, it will be desirable for the system to show the processed thermal image simultaneously on the imager display and the computer display. 
     According to another aspect, the present invention provides a method for use with a portable thermal imager. One step of the method involves utilizing the thermal imager to detect infrared energy emitted by a target object. Electrical signals indicative of the target object are processed using a processor on-board the thermal imager to produce a processed thermal image. The method also involves transferring image data for the processed thermal image to a remote computer on a real-time basis. Next, the processed thermal image is displayed on a computer display of the remote computer. 
     A still further aspect of the present invention provides a thermal imaging system having a remote user interface. The system comprises a portable thermal imager having a communication interface for transfer of data. The imager has an on-board memory in which image data is stored and an imager display to show a processed thermal image based on the image data stored in the memory. 
     A remote computer is operative to communicate with the thermal imager via the communication interface. The computer runs software operative to transfer dummy image data to the memory of the thermal imager. As a result, the processed thermal image shown on the imager display will be based on the dummy image data rather than current image data. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof, to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying drawings, in which: 
         FIG. 1  shows a personal computer being used in accordance with the present invention as a remote user interface for a thermal imager; 
         FIG. 2  is an enlarged view showing the USB connector port of the thermal imager shown in  FIG. 1 ; 
         FIG. 3  is a front perspective view of the thermal imager of  FIG. 1 ; 
         FIG. 4  is a rear perspective view of the thermal imager of  FIG. 1 ; 
         FIG. 5  is a diagrammatic representation showing functional components of a thermal imager that may be used in the implementation of the present invention; 
         FIG. 6  shows an exemplary thermal imager display along with a corresponding display on a computer monitor in accordance with the present invention; and 
         FIG. 7  is a diagrammatic representation showing use of the present invention in a classroom setting. 
     
    
    
     Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention. 
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary constructions. 
     Referring now to  FIG. 1 , a thermal imager  10  is in electrical communication with a conventional personal computer  12 . As will be described more fully below, personal computer  12  functions as a user interface for thermal imager  10 , allowing remote replication of the imager&#39;s controls. In addition, images and other information stored on the computer may be fed to thermal imager  10  for user training or other purposes. 
     As one skilled in the art will appreciate, the term “computer” as used herein is not limited to a traditional desktop or laptop personal computer. Instead, “computer” is included to cover other devices, such as various personal digital assistants (PDAs), that may be capable of performing the described functionality. In this embodiment, however, computer  12  is a traditional desktop personal computer having a main housing  14  containing processing electronics, disk drives and the like. A suitable computer display  16 , in this case an LCD flat screen display, is also provided. The user interacts with computer  12  using keyboard  18  and mouse  20  in the conventional manner. 
     The invention contemplates various techniques for providing a data link between imager  10  and computer  12 , such as various wireless communication protocols. In the illustrated embodiment, however, electrical communication between imager  10  and computer  12  is accomplished using a typical serial cable  22 . Cable  22  includes universal serial bus (USB) connectors at each end, one of which plugs into a corresponding port on the front of housing  14  (as indicated at  24 ). 
     As can be most clearly seen in  FIG. 2 , the other connector  26  is configured as a mini-USB connector. Connector  26  is inserted into a corresponding port  28  located on the side of imager  10 . In this embodiment, a receptacle  30  is located adjacent to mini-USB port  28  for connecting a battery charger when necessary to recharge the imager&#39;s internal batteries. 
     Referring now to  FIGS. 3 and 4 , certain details about the construction of imager  10  can be more easily explained. As shown, imager  10  includes a housing  32  in which the components of a thermal image camera are located. A lens  34  ( FIG. 3 ) carried by a focus ring  36  is located near the front of housing  32 . As one skilled in the art will appreciate, the target energy enters the device through this lens. 
     Housing  32  includes a handle  38  by which the operator holds and aims the device. A trigger  40 , located on handle  38 , permits the user to store selected images in the device&#39;s internal memory. In the illustrated embodiment, laser diode  42  ( FIG. 2 ) projects a dot of light forward of the imager to facilitate aiming. 
     As shown in  FIG. 4 , a display  44  is preferably located at the rear of imager  10 . In this case, the display is a color display of the LCD type. A plurality of function buttons  46 ,  48  and  50  are also located on the rear portion of housing  32 . In this embodiment, buttons  46 ,  48  and  50  are used as “soft keys” to navigate the menu structure of the imager, access functions and select values for adjustable parameters. Button  48  is also used to turn the imager “on” and “off” (when pressed for a selected period of time, e.g., 2 seconds). 
     Referring again to  FIG. 1 , the software on computer  12  may be used to download information to and upload information from thermal imager  10 . For example, processed images that have been previously obtained through the use of imager  10  in the field can be read out of its internal memory into computer  12 . Once the data is located in computer  12 , it can be permanently stored, or used in the creation of maintenance reports and the like. 
     In addition, however, the software allows the current image being seen by thermal imager  10  to be transferred to computer  12  on a real-time basis. As a result, an operator sitting at computer  12  can see the same image on the computer&#39;s display. Moreover, “dummy” images can be transferred in real-time from computer  12  to imager  10 . These will appear as “real” processed images to an operator of imager  10 . Among other benefits, these techniques are particularly helpful in training new operators in the use of imager  10 . 
     Certain internal components of imager  10  useful in the present invention can be most easily described with reference to  FIG. 5 . As shown, imager  10  includes an infrared engine  52  that converts infrared radiation into electrical signals. Typically, engine  52  will include a focal plane array (FPA), as well as some electronic circuitry for preprocessing of the data. The “raw” data output by the infrared engine is fed to a FPGA (“field programmable gate array”)  54 . The “raw” data is stored in certain memory locations (indicated by the designation “R”) within volatile memory  56 . 
     As one skilled in the art will appreciate, the “raw” data stored in memory  56  is not in a form suitable for being shown on display  44 . Accordingly, the processed image is produced from the raw image data by digital signal processor (“DSP”)  58 . Toward this end, raw data is pulled by FPGA  54  from memory locations R and transferred to DSP  58 . After processing in DSP  58 , the processed image data is then returned to memory  56  via FPGA  54 . This processing includes the generation of a visible image using a color scale indicative of each object&#39;s relative temperature. Various graphics and textual overlays are also produced. The processed image data is stored in locations within memory  56  (indicated by the designation “P”) other than those in which the raw data is located. FPGA  54  then functions as a buffer to pull the processed image data out of memory  56  and provide it to display  44 . 
     Imager  10  also includes a flash read only memory (“ROM”)  60 . ROM  60  stores firmware run by DSP  58  during the processing of the raw image data. When DSP  58  powers up, it reads its program from ROM  60  and operates accordingly. In addition, ROM  60  maintains images stored by the operator during use of imager  10  for subsequent download. 
     A USB interface  62  is provided to facilitate serial communication with an external computer. As indicated at  64 , interface  62  is in electrical communication with the imager&#39;s USB port. Interface  62  is also in electrical communication with FPGA  54 . This allows access to the memory locations R and P where the raw image data and processed image data are respectively stored. As a result, the processed image data (and the raw image data, if desired) can be read out of the imager  10  on a real-time basis. The image can then be shown on the display of a personal computer, or even projected on the wall in a large conference room for training purposes. In addition, software running on the computer can allow the user to simulate presses of a button on image  10 . Again, this is useful for training purposes. 
     Alternatively, dummy image data (either processed or “raw”) can be fed from the computer into the memory of imager  10 . Processed image data fed into imager  10  in this manner will overwrite the image that would otherwise be shown on display  44 . This can be used to simulate various “real world” conditions in a classroom. 
     Feeding known “raw” data into imager  10  in this manner can be used to check the calibration of the instrument. In other words, known raw data should produce a known image for display. If the processed image thus produced is other than expected, this indicates a calibration problem with the imager. 
     As shown, USB interface  62  also controls a “switch”  66 . Normally, switch  66  is positioned to allow electrical communication between infrared engine  52  and DSP  58  (via line  68 ). As a result, DSP  58  can send configuration data to engine  52 . Upon receipt of a suitable command, however, switch  66  is “thrown” to allow communication between USB interface  62  and infrared engine  52 . This allows infrared engine  52  to be controlled from the PC, which is also useful for testing and calibration purposes. One skilled in the art will appreciate that “switch”  66  represents a function of the device, and may not be realized by a physical switch. 
     As noted above, DSP  58  normally reads its program from ROM  60  and operates accordingly. The illustrated configuration, however, allows direct communication between USB interface  62  and DSP  58 , as indicated at line  70 . As a result, a different program can be supplied into DSP  58  from the computer, such as for testing purposes. 
     Referring now to  FIG. 6 , an exemplary processed image is being shown on display  44 . As can be seen, the processed image may be divided into a number of zones which show different information. For example, the header zone  72  displays information such as imager status, battery charge state, power source and connection status. It can also be seen that header zone  72  in this case displays the USB symbol, thus indicating that imager  10  is connected via its USB port to a personal computer. The image zone  74  displays live, frozen and stored thermal images. The information zone  76  displays imager settings, status comments and selection options. This zone also indicates the temperature measurement (in this case, 25.4° C.) at the “crosshairs” of the image zone  74 . A temperature gradient scale may also be provided in this zone. 
     As can be seen, the entire display of thermal imager  10  is also depicted on computer display  16 . In addition, the software running on the computer has generated “buttons”  78 ,  80  and  82  corresponding to buttons  46 ,  48  and  50  on imager  10  itself. These graphically generated buttons can be selected using mouse  20 . For example, the user of the computer could simply move the computer cursor  84  over the desired “button” and select (such as by a left click). 
       FIG. 7  illustrates use of the present invention in a classroom or conference room setting. In this case, the computer is connected to a projector  86  which projects the processed thermal image onto a screen  88 , as indicated at  90 . As shown, screen  90  is located on a wall  92  of the room. An instructor  94  discusses various aspects of the processed thermal image and operation of imager  10  with pupils in attendance. Typically, these pupils would be individuals undergoing training in the use of thermal imager  10 . As shown, instructor  94  may utilize a pointer, such as laser pointer  96 , to indicate particular items of interest in the thermal image. 
     It can thus be seen that the present invention provides a novel system and method for transferring information to and from a thermal imager on a real time basis. While preferred embodiments of the invention have been shown and described, modifications and variations may be made thereto by those of ordinary skill in the art without departing from the spirit and scope of the present invention. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to be limitative of the invention as further described in the appended claims.