Patent Publication Number: US-2004041793-A1

Title: Handheld multimeter with computer functions

Description:
[0001] The present application claims priority to U.S. Provisional Application of Glenn Redding et al., Application No. 60/407,236, filed Sep. 3, 2002, the entirety of which is hereby incorporated into the present application by reference. 
    
    
     
       FIELD OF THE INVENTION  
       [0002] The present invention relates to handheld multimeters.  
       BACKGROUND AND SUMMARY OF THE INVENTION  
       [0003] Handheld computers, such as personal organizers and personal digital assistants (PDAs), have grown in popularity partly due to their small size, easy portability, and their versatile operating systems that provide multiple functions such as a scheduler, an address book, a notepad, and connection to the Internet, for example. However, known handheld computers lack the structure and programming to perform the functions of multimeter. Specifically, known handheld computers are unable to measure and display the values of several different electrical parameters such as current, voltage, and resistance.  
       [0004] Typical handheld multimeters cannot offer the user access to the same applications as a handheld computer due to their limited computing power.  
       [0005] It is one object of the present invention to overcome the deficiencies noted above. In accordance with the principles of the present invention, this objective is achieved by providing a handheld multimeter including an outer shell configured to be received in a user&#39;s hand, a computer processor housed within the outer shell for processing data, and a pressure-sensitive display screen facing outwardly from a front side of the outer shell. The pressure-sensitive display screen is electrically coupled to the computer processor to enable the processor to display simulated input elements on the screen and enable the user to input data commands into the computer processor by contacting the pressure-sensitive display screen. A data port is coupled to the computer processor. A conductive probe assembly is structured to generate electrical data. The probe assembly is electrically coupled to the data port to enable communication of the electrical data between the probe assembly and the computer processor. The computer processor is configured to (a) process the electrical data received from the probe assembly and display an output value on the display screen that includes at least one of an electrical voltage value, an electrical resistance value, and an electrical current value, and (b) perform the functions of at least one of a scheduler, an address book, and a notepad.  
       [0006] Further, typical multimeters use a graphical display in conjunction with soft keys to operate the multimeter. To reduce the size of the multimeter and improve portability of the multimeter, it would be advantageous to provide a multimeter with a touchscreen display, such as those utilized in handheld computers (e.g., PDAs).  
       [0007] Another object of the present invention is to provide a multimeter with a touchscreen display. In accordance with the principles of the present invention, this objective is achieved by providing a handheld multimeter including an outer shell configured to be received in a user&#39;s hand, a computer processor housed within the outer shell for processing data, and a pressure-sensitive display screen facing outwardly from a front side of the outer shell. The pressure-sensitive display screen is electrically coupled to the computer processor to enable the processor to display simulated input elements on the screen and enable the user to input data commands into the computer processor by contacting the pressure-sensitive display screen. A data port is coupled to the computer processor. A conductive probe assembly is structured to generate electrical data. The probe assembly is electrically coupled to the data port to enable communication of the electrical data between the probe assembly and the computer processor. The computer processor is configured to process the electrical data received from the probe assembly and display an output value on the display screen that includes at least one of an electrical voltage value, an electrical resistance value, and an electrical current value.  
       [0008] These and other objects, features, and advantages of this invention will become apparent from the following detailed description when taken into conjunction with the accompanying drawings, which are part of this disclosure and which illustrate, by way of example, the principles of this invention. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0009] The accompanying drawings facilitate an understanding of the various embodiments of this invention. In such drawings:  
     [0010]FIG. 1 is top view of an embodiment of a handheld multimeter constructed in accordance with the principles of the present invention;  
     [0011]FIG. 2 is a schematic view of the handheld multimeter of FIG. 1;  
     [0012]FIG. 3 is a perspective view of another embodiment of a handheld multimeter; and  
     [0013]FIG. 4 is a top view of another embodiment of a handheld multimeter.  
    
    
     DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS  
     [0014] Referring no more particularly to FIG. 1, there is shown therein a handheld multimeter  10 , which embodies the principles of the present invention. The handheld multimeter  10  is constructed and arranged to perform several computer functions including performing the function of a multimeter, as will be further discussed. Thus, the handheld multimeter  10  is structured to measure and display the values of several different electrical parameters such as current, voltage, and resistance, for example.  
     [0015] The handheld multimeter  10  includes an outer shell  12 , which is preferably made from a hard plastic-based material, such as PVC. As illustrated, the edges  14  of the outer shell  12  are preferably over molded with a higher friction material, such as a high coefficient of friction plastic or a rubber based material, to enhance the grip of the handheld multimeter  10  and provide some impact protection. In the illustrated embodiment, the outer shell  12  has a general rectangular configuration. However, the outer shell may have any configuration, such as being ergonomically designed to comfortably fit any user&#39;s hand.  
     [0016] As shown in FIG. 2, a computer processor  16  is housed within the outer shell  12  for protection. The computer processor  16  is adapted to receive data signals from its onboard input/output system  18  and a probe assembly  60  (see FIG. 1) coupled to its data port  20  and to process those data signals. The term processor is used to denote the general processing system for operating the handheld multimeter  10 . This processing system may be provided by a single processor responsible for all functions of the multimeter  10  or a series of interconnected processors each dedicated to different functions of the multimeter  10 .  
     [0017] The onboard input/output system  18  includes a display screen  22  that is electrically coupled to the computer processor  16  to enable the computer processor  16  to display information on the display screen  22 . The display screen  22  is disposed on the front side of the outer shell  12  so as to face outwardly therefrom through an opening  24  in the outer shell  12 .  
     [0018] In the illustrated embodiment, the display screen  22  is an LCD screen of the pressure sensitive type (i.e., touchscreen display) that enables the user to input data commands into the computer processor  16  by contacting the display  22  with a contacting member, such as a stylist or finger, to activate a series of pressure sensitive elements embedded within the display  22 , as will be further discussed.  
     [0019] The input/output system  18  may also include a plurality of soft keys to supplement the touchscreen display  22 . In the illustrated embodiment, the input/output system  18  may include an up-arrow button  34 , a down-arrow button  36 , and an activation button  38 . These buttons may be used to enable the user to input data commands by maneuvering the arrow buttons  34 ,  36  to maneuver a cursor on the display  22  and activating the activation button  38  to invoke a simulated input element when the cursor is positioned on the input element.  
     [0020] The data port  20  is electrically coupled to the processor  16 . The data port  20  is adapted to be electrically coupled to a probe assembly  60  to enable the communication of data between the computer processor  16  and the probe assembly  60 . In the illustrated embodiment, the data port  20  includes two input jacks  26 ,  28  that are structured to be electrically coupled with input ends  62   a ,  62   b  of the probe assembly  60 . Typically, the probe assembly  60  includes two measuring lines  64   a ,  64   b  with each measuring line  64   a ,  64   b  including an input end  62   a ,  62   b  and a measuring probe  66   a ,  66   b , respectively. As shown in FIG. 1, the input jacks  26 ,  28  are positioned on an upper edge of the outer shell  12  so the probe assembly  60  does not inhibit visibility of the display  22  when coupled thereto. The probe assembly  60  may be wrapped around the periphery of the outer shell  12  when the handheld multimeter  10  is not in use.  
     [0021] It is contemplated that additional data ports may be provided to enable the processor  16  to be electrically coupled to a keyboard, a personal computer docking cradle, or the Internet, for example. When coupled to a docking cradle, the operating system of the handheld multimeter  10  can be updated, software programs can be added or upgraded, and the user can synchronize data on the handheld multimeter  10  with data on a personal computer, for example.  
     [0022] A memory  30  is electrically coupled to the processor  16  for storing executable programs and data which is to be retrieved at later times. The memory  30  may have any suitable structure, such as ROM and/or volatile/nonvolatile RAM. The memory  30  may be replaced and/or augmented. Further, the memory  30  may be a separate programmed memory module that is coupled to the processor  16 .  
     [0023] A multimeter software program is provided for loading into the memory  30  of the handheld multimeter  10  so that the handheld multimeter  10  can perform multimeter functions. The multimeter software program comprises a series of computer executable instructions that are executable by the computer processor  16  to interpret the data signals generated by the probe assembly  60  and convert those signals into instructions which are recognizable and executable by the computer processor  16  and its operating system. For example, the multimeter software program interprets data signals transmitted by the probe assembly  60  and converts them into instructions which the operating system recognizes and causes the processor  16  to execute.  
     [0024] Typical PDA software programs are also loaded into the memory  30  of the handheld multimeter  10  so that the handheld multimeter  10  can perform typical PDA functions such as a scheduler, an address book, and a notepad.  
     [0025] A power source  32  is coupled to the processor  16  to supply power for operating the processor  16 . The power source  32  may be battery power, DC power, or any other suitable power source.  
     [0026] A power button  40  is mounted on a lower portion of the outer shell  12  adjacent the softkey input system. The power button  40  is coupled to the power source  32  to turn the handheld multimeter  10  on and off. An LED  42  is provided to generate a light when the power button  40  is in the on position. The power source  32  may be in the form of an auto-power off power source wherein the power source  32  automatically powers off when not in use after a predetermined period of time, i.e., 30 minutes.  
     [0027] A speaker/buzzer  41  is coupled to the processor  16  to provide audio confirmation when performing a continuity check with the multimeter function and/or to provide an alarm to notify the user of an appointment with the calendar function, for example. The speaker/buzzer  41  may also act as a voice recorder to record notes.  
     [0028] The multimeter  10  may include a backlight to illuminate the display  22  for clearer readings in poorly lighted areas. The display  22  may include a backlight key for operating the backlight feature.  
     [0029] Operation of the handheld multimeter  10  will now be described in greater detail. The multimeter software program within the memory  30  includes the series of computer executable instructions that are executable by the computer processor  16  to display simulated input elements on the display  22 . As shown in FIG. 1, the input elements include a plurality of keys corresponding to conventional symbols associated with multimeters such as a range key  44  and a hold key  46  for maintaining an element on the display  22 . The display  22  displays a digital output value  48  with the unit of measurement (e.g., 500 VAC) measured by the probe assembly  60  coupled to the handheld multimeter  10 . The graphical user interface display  22  also includes a graphical display  50  that corresponds to operating ranges of the multimeter function of the handheld multimeter  10 . Specifically, the graphical display  50  includes an indicator  52  that indicates the electrical parameter that the user is measuring. The indicator  52  is adjustable such that the multimeter can read and measure AC voltage, DC voltage, resistance, and various magnitudes of current, for example. The indicator  52  is also adjustable such that the handheld multimeter  10  can perform a continuity check. The user must select which operating range is appropriate for the measurement the user wants to make.  
     [0030] The display  22  includes a information key  54  dedicated to an information function. This key may invoke the processor  16  to display a help guide for operating the multimeter function of the handheld multimeter  10 , a products guide, or a teaching guide for non-skilled users whom are diagnosing home repairs, automotive repairs, industrial repairs, etc. on a variety of fix-it-yourself items.  
     [0031] The display  22  also includes a HOME key  56  that can direct the user to a simulated menu that includes input elements for typical PDA functions such as a scheduler, an address book, and a notepad.  
     [0032] The display  22  may include a number of keys dedicated to predetermined macro functions that invoke predetermined commands that are often utilized by the user when operating the handheld multimeter  10 .  
     [0033] In operation, the input system  18  (i.e., touchscreen display  22  or softkeys  34 ,  36 ,  38 ) is configured to determine when a user invokes a simulated input element displayed on the display screen  22 . For example, the user may contact the appropriate location on the display screen with a stylist or finger so as to activate an input element and the processor as directed by the computer executable instructions determines that element has been invoked by sensing actuation of the pressure sensitive elements at the associated location on the screen. The processor then executes a command or data input corresponding to the invoked simulated input element.  
     [0034] When utilizing the multimeter function of the handheld multimeter  10 , the user adjusts the indicator  52  to the desired operating range with the input system  18 . Then, the user uses the probe assembly  60  coupled to the data port  20  to perform the desired measurement with the output value being displayed on the display  22 .  
     [0035] In some typical PDA functions, such as notepad, the user may contact the display  22  in a handwriting-type manner to activate the pressure sensitive elements within the display  22 . A series of computer executable instructions coverts the handwriting type movements into data for processing and/or storage.  
     [0036] The handheld multimeter  10  may include a cover pivotally connected to the outer shell  12  for selective movement about a rotational axis between a protecting position and an operating position. In the protecting position, the cover is positioned in overlying relationship with respect the front side of the handheld multimeter  10  to protect the display  22 . The handheld multimeter  10  may include a cover that is slidably mountable to the outer shell  12 .  
     [0037] Another embodiment of the handheld multimeter, indicated as  210  is shown in FIG. 3. In this embodiment, the handheld multimeter  210  includes a built-in probe assembly  260  at a top edge thereof. The remaining components of the handheld multimeter  210  are similar to the components of the handheld multimeter  10  and thus will not be further detailed herein. The built-in probe assembly  260  includes a first probe  262  and a second probe  264  that are electrically coupled to the processor  16  to enable the communication of data between the processor  16  and the first and second probes  262 ,  264 . The outer shell  12  is suitably structured to accommodate the first and second probes  262 ,  264 . In operation, the user positions the first and second probes  262 ,  264  adjacent to or in contact with the component to be measured. The display  22  displays the output value in accordance with the selected measurement.  
     [0038] Alternatively, the first and second probes  262 ,  264  may be movably mounted within the outer shell  12  to enable the user to extend the first and second probes  262 ,  264  outwardly from the housing  12  to perform a measurement and to retract the first and second probes  262 ,  264  back into the outer shell  12  after measurements have been completed.  
     [0039] Another embodiment of the handheld multimeter, indicated as  310  is shown in FIG. 4. The components of the handheld multimeter  310  are substantially similar to the components of the handheld multimeter  10  and thus will not be further detailed herein. In contrast to the multimeter  10 , the multimeter  310  does not include an up-arrow button, a down-arrow button, an activation button, or a speaker/buzzer. Further, the multimeter  310  illustrates another embodiment of the configuration of the elements displayed on the display screen  22 . For example, the display  22  of the multimeter  310  includes a backlight key  47  for operating the backlight feature and a record key  49  (i.e., REC) for recording minimum and maximum readings, for example.  
     [0040] The handheld multimeter  10 ,  210 ,  310  is advantageous in that it offers greatly reduced size for improved portability versus traditional multimeters. Moreover, the handheld multimeter  10 ,  210 ,  310  offers increased computing power for multiple applications choices versus traditional multimeters. However, the handheld multimeter  10 ,  210 ,  310  may be configured such it is operable to perform a multimeter function only without any typical PDA functions.  
     [0041] It can thus be appreciated that the objectives of the present invention have been fully and effectively accomplished. The foregoing specific embodiments been provided to illustrate the structural and functional principles of the present invention and is not intended to be limiting. To the contrary, the present invention is intended to encompass all modifications, alterations, and substitutions within the spirit and scope of the appended claims.