Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
     Pursuant to 35 U.S.C. §119(e), this application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/112,086, entitled Control Head with Electroluminescent Panel in Land Mobile Radio, filed Nov. 6, 2008. The disclosure of the aforementioned provisional patent application is incorporated herein by reference in its entirety for any and all purposes. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to the field of land mobile radio and more particularly, but not by way of limitation, to a control head having an electroluminescent panel. 
     BACKGROUND 
     Land Mobile Radio (LMR) systems are deployed by organizations requiring instant communication between geographically dispersed and mobile personnel. Typical users of LMR systems include police departments, fire departments, medical personnel, EMS and the military. 
     SUMMARY 
     According to an exemplary aspect of the present disclosure, a control head for land mobile radio comprises an electroluminescent panel. As described below, it comprises several aspects capable of enabling one or more of a multitude of advantages and benefits. 
     One technical aspect of the exemplary control head may be the capability to utilize halo light of the control head to implement a multi-function indicator that communicates a state of the land mobile radio. 
     Another aspect may be the capability to buffer images constructed from data received from the land mobile radio into a video stream for rendering on an electroluminescent display. 
     Another aspect may include the capability for a user to modify a configuration stored on the land mobile radio that defines one of several display modes to be utilized in generating data for use in forming images to be rendered on an electroluminescent display. 
     Other technical advantages may be readily apparent to one skilled in the art after review of the following figures and description associated herewith. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts, in which: 
         FIG. 1  is a perspective view of a control head remote from a land mobile radio. 
         FIG. 2  is a perspective view of a control head attached to or integrated with a land mobile radio. 
         FIG. 3  is a frontal view of an electroluminescent panel of a control head. 
         FIG. 4  is another frontal view of the electroluminescent panel of a control head. 
         FIG. 5  is a view of a display of a control head. 
         FIG. 6  is a list of symbols that may be used on the display to indicate various operating modes and status. 
         FIG. 7  is a functional block diagram illustrating a land mobile radio system implementing a control head. 
         FIG. 8  is a flow diagram illustrating a method of operation for controlling a multi-function indicator implemented utilizing a halo light of a control head. 
         FIG. 9  is an electronic circuit diagram for a control head. 
         FIG. 10  is a perspective view illustrating programming of a configuration of a control head utilizing a computer processor. 
         FIG. 11  is a set of views illustrating results of varying configurations of a control head to provide different display modes. 
         FIG. 12  is a screenshot illustrating a user interface component whereby a selection is made for the control head configuration whether to inhibit a zone/channel indicator. 
         FIG. 13  is a screenshot illustrating a user interface component whereby a selection is made for a control head configuration of a controller head type. 
         FIG. 14  is a screenshot illustrating a user interface component whereby a selection is made for a control head configuration of a display mode. 
         FIG. 15  is a screenshot illustrating the user interface component of  FIG. 14  whereby another selection is made for the control head configuration of a different display mode. 
         FIG. 16  is a screenshot illustrating a user interface component whereby a selection is made for a control head configuration of display options for the display mode selected in  FIG. 14 . 
         FIG. 17  is a screenshot illustrating a user interface component whereby a selection is made for a control head configuration of display options for the display mode selected in  FIG. 15 . 
     
    
    
     DETAILED DESCRIPTION 
     It should be understood at the outset that although exemplary implementations of the present disclosure are illustrated below, the present disclosure may be implemented using any number of techniques, whether currently known or in existence. The present invention should in no way be limited to the exemplary implementations, options, drawings, and techniques illustrated below, including the exemplary design and implementation illustrated and described herein. Additionally, the drawings contained herein are not necessarily drawn to scale. 
     A component for land mobile radios is a control head that offers superior readability and display options for the radio user. Referring to  FIG. 1 , the control head can be fitted to a remote mount in a land mobile radio installation. Alternatively, referring to  FIG. 2 , the control head can be fitted or integrated as a dash mount in a land mobile radio installation. 
     Turning to  FIG. 3 , the front panel of the control head can have multiple features. For example, it can have an on-off/volume switch  100  for turning the power on/off function to the radio. When the power is on, this control can be rotated to adjust the radio speaker volume. Also, an electroluminescent display  102  can show all primary operating information, such as active channel, zone, channel/zone alias, status symbols, and labels for the function buttons under the display. In the embodiment shown in  FIG. 3 , five buttons are provided under the display on the control head. Additionally, a multi-function indicator  104  can be provided in which halo light surrounding a button or switch, such as a select zone/channel switch  106 , is used to indicate radio transmit and receive status. A steady red halo, in one embodiment, may indicate that the radio is transmitting, while a steady green halo may indicate that the radio is receiving, and a steady amber halo may indicate that the radio is idle. Further, the select zone/channel switch  106  may be implemented with two actions: rotation and press. In normal nonmenu mode, pressing the control can select either the zone or the channel. Then, rotation of the control can change either the zone or channel. An indication can be provided on the display whether zone or channel is selected. Yet further, a microphone connection  108  can be provided that allows a compatible microphone to plug into this jack connector. Further still, the control head can have a number, such as eight, one-touch buttons  110 , including two on the left of the display, five under the display, and an orange button on the right of the display. These buttons in certain embodiments may be programmed with different radio functions. Finally, a 4-way navigation pad  112  may be provided for navigating through various radio functions and menus. In other embodiments the navigation pad  112  may be implemented with either more or less than a 4-way pad. Like the buttons  110 , the pad  112  can be programmed with different radio functions. 
     Turning now to  FIG. 4 , as mentioned above, the control head can have a number, such as nine, of programmable controls  114 - 130 . A number of land mobile radio functions can be assigned to these buttons using a computer processor that connects to the land mobile radio control head via the microphone connection  108 . Example radio functions that the user can configure include scan, backlight level, monitor, emergency, and transmitter power. 
     Referring now to  FIG. 5 , an advantageous feature of the control head is a highly readable electroluminescent display. In some embodiments, the display is a monochrome display with 320×80 pixels. This display can support a Classic Single Line display mode familiar to users of previous types of land mobile radio control head displays. In Classic Single Line display mode, the display can have primary fields corresponding to the fields available on earlier model(s) of control heads, but with the addition of the soft menu keys and display of labels  132  of functions assigned to those soft menu keys as described above. More familiar display contents include channel name  134 , zone number  136 , channel number  138 , and symbols  140 A- 140 C to indicate operating mode and status. A list of symbols used on the display to indicate various operating modes and status that may be implemented in certain embodiments is provided in  FIG. 6 . 
     The electroluminescent display panel provides a clear, bright and readable display, which is advantageous in public safety applications. In some embodiments, the electroluminescent display features high brightness and contrast, resists fading, provides long operating life, has a viewing angle greater than 160°, and provides 200 G shock durability. Furthermore, the electroluminescent display incorporates, in some embodiments, emissive pixel technology, which makes small text more legible. The electroluminescent display may be operated in a reflective mode to provide crisp, clear viewing of the electroluminescent display in bright light, even through polarized lenses. Additionally, the size of alphanumeric characters presented on the electroluminescent display may be adjusted. 
     Turning now to  FIG. 7 , a land mobile radio system  142  generally has a control head controller  144  that operates as a slave to a land mobile radio master controller  146 . The control head controller  144  detects user actuations of controls  148 A- 148 D and signals the master controller  146 . Controller  144  also reacts to user actuation of a push to talk microphone by signaling transmission and passing the audio data. 
     The master controller  146  transmits audio data from microphone  150  via transmitter  154 , and drives speakers  156  to output audio data received via receiver  158 . Also, the master controller  146  constructs user interface data frame contents of electroluminescent display  160  in accordance with a configuration stored in data store  152 . Additionally, the master controller  146  operates the UI in response to the user actuations at least partly in accordance with the configuration. Controller  144  constructs UI data received from master controller  146  into images that are buffered into a video stream for rendering on electroluminescent display  160 . 
     Additional components of the control head operated by master controller  146  in accordance with the configuration include indicators, such as lights or LEDs, located behind light pipes  162 A- 162 E. These light pipes provide halo light for controls  148 A- 148 D, and for display  160 . In one embodiment, each of the light pipes  162 A- 162 E has an amber LED that provides the halo light at an intensity level recorded in the configuration, and that can be adjusted by user actuation of one of the controls  148 A- 148 D, or another control. At least one of the light pipes additionally may include red and green LEDs collocated with its amber LED. A signal line  164  to that amber LED can be controlled independently of signal lines  166  to the other amber LEDs. The red and green LEDs may also have independently controllable signal lines  168  and  170 . 
     Turning now to  FIG. 8 , the controllers operate the LEDs according to a method that accomplishes indication of the LMR transmit/receive status. Beginning at power up  172 , the configuration is read at step  174  to determine an intensity level for the amber LEDs, and an active state is set for the amber LEDs at step  176  according the configuration. Next, one or all inactive amber LEDs may be activated at step  178 . Thereafter, the user can adjust intensity of the LEDs by actuation of one of the controls of the control head, resulting in modification of the configuration according to the user selections at step  180 . If the radio is determined to be idle at decision step  182 , then processing may return to step  174  and steps  174 - 182  are traversed continually, resulting in adjustment of the intensity level of the amber LEDs according to the user selections. 
     When the radio is transmitting or receiving, this state change will be detected at step  182 , resulting in deactivation at step  184  of the amber LED that is collocated with the red and green LEDs. Then, if the radio is determined to be transmitting at decision step  186 , then the red LED, in one embodiment, is activated at step  188 . Thereafter, as long as the radio is determined to still be transmitting at decision step  190 , the red LED will remain active. Once a determination is made at step  190  that the transmission has ended, then the red LED is deactivated at step  192 , and processing returns to step  174 . Thereafter, the amber LED is reactivated at step  178  and remains active as long as the radio is determined to be idle at step  182 . 
     Processing during a receive state is similar to that during the transmit state. If the radio is determined to be receiving at decision step  194 , then the green LED, in one embodiment, is activated at step  196 , and it remains activated as long as the radio is determined to be receiving at decision step  198 . Once the receipt is determined to have ended at step  198 , then green LED is deactivated at step  200 , and processing returns to step  174 . Thus, a halo light behind one of the user interface components serves as a multifunction indicator without interfering with the halo function of the other components, and while allowing the intensity of the amber halo light of the components to be adjusted of the red and green indicator lights. 
     Turning now to  FIG. 9 , the control head display  202 , in one embodiment, can be implemented as an alternating-current thin-film electroluminescent (AC-TFEL) display. In this case, the display glass panel can be covered by two sets of electrodes (80 row electrodes and 320 column electrodes) in the horizontal and vertical directions. The electrodes are separated by thin film insulating layers. The center layer can be a phosphor layer that emits light when exposed to a strong electric field. A single light emitting pixel is created at the intersection of each row and column electrode. The brightness of the pixel is determined by the voltage between the two electrodes. In other embodiments, the control head display  202  may be implemented using other known or available display technology. 
     The control head controller  204 , in one embodiment, may be Freescale MC9S08QE128 which has internal FLASH and SRAM for program and data storage, general purpose I/O ports, and a UART port for communication with the master controller in the land mobile radio. In some embodiments, the control head controller  204  is configured to operate as a slave to the master controller in the land mobile radio for most I/O. In this case, it reports key presses, switch changes, and microphone inputs to the master controller via RS485 serial data links. In one embodiment, the control head controller  204  does not act on these data. Similarly, control of LEDs and other output functions can be directed by the master controller. In one embodiment, the control head controller  204  formats the data, from the master controller, into a pixel image that is displayed on the AC-TFEL Display. 
     The low voltage power supply  206  can be one or more switching and low drop out linear regulators which provide power to the logic and analog circuits. Contained within this block is a circuit that generates a reset signal if the battery (13.6 Vdc nominal) supply from the radio, the 3.3 Vdc supply, or 1.2 Vdc supply, for example, is out of tolerance. 
     The high voltage (HV) power supply  208  may be a PWM controlled flyback transformer design which provides nominal 220 Vdc, 50 Vdc, and −150 Vdc outputs to power the AC-TFEL Display. Input power to supply may be provided in one implementation from the radio battery supply (13.6 Vdc nominal) through a FET switch controlled by the Display FPGA  210 . The output voltage levels can be adjusted by a volume adjustment potentiometer  212  to set the brightness level of the AC-TFEL Display. The power supply switching frequency (150 KHz) is controlled by Display FPGA  210 . 
     A display frame in one implementation may be composed of 80 lines of 320 bits (pixels) for a total of 25600 pixels per frame. In operation, a line of pixels ( 320 ) can be shifted into a Column HV Driver/Shift Register  216  and latched into output registers which control the outputs of the HV output drivers attached to the column electrodes on the AC_TFEL Display. A new line of pixels is shifted into the register  216  after the pixels for the line have been latched into the output registers. 
     When the column data is latched, a HV pulse from the Row HV Driver/Shift Register  214  can be applied to the AC_TFEL Display row electrode associated with that line of pixels. 
     The HV pulse on the active row electrode is either 200 Vdc or −150 Vdc. A pixel will begin to emit light when the voltage across its row and column electrode exceed approximately +/−180 Vdc. For a positive row voltage of pulse of 200 Vdc, a column voltage of 0 Vdc will light the pixel and a column voltage of 50 Vdc will in turn it off. For a negative row voltage of pulse of −150 Vdc, a column voltage of 50 Vdc will light the pixel and a column voltage of 0 Vdc will in turn it off. 
     The Row HV Driver/Shift Register  214  may be loaded at the beginning of each frame, in one embodiment, with a seed bit that enables a single row HV driver output. After a row is pulsed, the seed bit is shifted to the next row to enable its HV driver output. The polarity of the row voltage pulse alternates with each line of pixels. The Positive Row Voltage Charge/Discharge FET  218  and Negative Row Voltage Charge/Discharge FET  220  circuits generate the HV pulses applied to the row electrode through the HV output drivers in the Row HV Driver/Shift Register  214  and discharge the electrode after the pulse has been applied. 
     The Display FPGA  210  controls the operation of the circuitry associated with the AC_TFEL Display  202  to display images on the display that are generated by the control head controller  204 . Functionally the Display FPGA  210  contains a display data buffer, a frame timing generator, and display control logic to control operation of the Negative Row Voltage Charge/Discharge FET  220 , Positive Row Voltage Charge/Discharge FET  218 , Row HV Driver/Shift Register  214 , and Column HV Driver/Shift Register  216 . 
     The display buffer can be a 3200 byte dual port RAM that is accessed by the control head controller  204  to load pixel data for screen images and by the internal frame generator logic to read the pixel data. The control head controller can load data into the display buffer though an eight bit parallel data port. Two internal eight bit registers form the byte address of display buffer to which the control head controller writes data. The control head controller  204  can load an address into these registers though the eight bit parallel data port. The combined address register can be auto-incremented each time the control head controller  204  writes to the display buffer. 
     The frame timing generator can generate internal frame start, line start, pixel data, and pixel clock signals that are used by the display control logic to control the circuitry surrounding the AC_TFEL Display  202 . The frame refresh rate can be controlled by a register that is set by the control head controller  204  via the eight bit parallel data port. 
     The display control logic can use the framing, clock, and pixel data from the frame timing generator to generate the actual signals used by the AC_TFEL Display electronics. This signal generation can include timing for HV row charge/discharge pulses, shifting and latch column and row data, and alternating polarity of row charge/discharge pulses. Additionally, the display control logic can provide for an orderly start up/shut down of the AC_TFEL Display  202  after reset or if the High Voltage Power Supply  208  is in an under voltage condition. 
     Turning now to  FIG. 10 , the display mode of the land mobile radio  222  can be programmed by the end user, in one implementation, employing a computer processor  224  to define a display configuration of the land mobile radio  222 . To this end, the computer processor  224  can communicate with the land mobile radio  222  by a cable that connects to the microphone port on the control head. The computer processor  224  runs a program that allows the user to define the configuration stored in a processor memory of the radio through a set of menus. By defining this configuration, a number of different display modes can be realized. 
     Turning to  FIG. 11 , there are a variety of display modes that can be available in some embodiments. For example, a classic mode  226  can be available that provides a display mode like that provided by previous land mobile radios not having electroluminescent displays. There can also be an enhanced single line mode  228  with zone/channel display similar to that of the classic mode, but with soft key function labels and additional or different symbols for indicating operational modes and statuses of the radio. 
     Another display mode  230  can be an enhanced single line mode in which display of zone and channel is inhibited, permitting display of additional text. An additional display mode  232  can be an enhanced dual line display mode allowing display of even more text with zone and channel display inhibited. 
     Yet another display mode  234  can be a dual line display mode in which zone and channel are displayed. Finally, an enhanced menu  236  can be displayed with user configurable options that are navigable by use of a control on the control head. These modes can be selected by the user selecting options for controller head type, whether to inhibit zone/channel display, a classic versus enhanced display mode, and if in the enhanced mode, whether to exercise the option to display two lines of text, as indicated below in Table 1. 
     
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Control Head 
                 Inhibit Zone 
                 Display Mode 
               
               
                   
                 Type Normal/ 
                 Chan Indicator 
                 Standard/ 
               
               
                   
                 Lightning 
                 Checkbox 
                 Enhanced 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Classic with Zone 
                 Normal 
                 Off 
                 Standard 
               
               
                 Chan 
               
               
                 Classic without Zone 
                 Normal 
                 On 
                 Standard 
               
               
                 Chan 
               
               
                 Enhanced Single with 
                 Lightning 
                 Off 
               
               
                 Zone/Chan 
               
               
                 Enhanced Single 
                 Lightning 
                 On 
               
               
                 without Zone Chan 
               
               
                 Enhanced Dual with 
                 Lightning 
                 Off 
               
               
                 Zone/Chan 
               
               
                 Enhanced Dual 
                 Lightning 
                 On 
               
               
                 without Zone/Chan 
               
               
                   
               
             
          
         
       
     
     There are a number of menus that allow the user to configure the display mode of the control head in addition to other functions of the radio. For example, turning to  FIG. 12 , one of the menus that allows the user to make a selection for configuring the display mode can contain a checkbox  238  for exercising an option to inhibit the zone/channel indicator. Selecting this checkbox can inhibit the display of the zone/channel indicator even in the classic mode. Also, turning to  FIG. 13 , a controller type drop down menu  240  can allow the user to select controller type. Turning to  FIGS. 14 and 15 , a display mode drop down menu  242  allows the user to select a standard or enhanced display mode, which can affect options provided for configuring the radio. Some of these options relate to display options. For example, turning to  FIGS. 16 and 17 , display options  244  for the standard display mode do not permit selection to display two lines of text. In contrast, the display options  246  in the enhanced mode permit selection to display two lines of text. 
     Thus, it is apparent that there has been provided, in accordance with the present disclosure, a control head that satisfies one or more of the advantages set forth above. Although the preferred embodiment has been described in detail, it should be understood that various changes, substitutions, and alterations can be made herein without departing from the scope of the present disclosure, even if all of the advantages and benefits identified above are not present. For example, the various embodiments and examples shown in the drawings and descriptions provided herein illustrate that the present disclosure may be implemented and embodied in numerous different ways that still fall within the scope of the present disclosure, whether expressly shown herein or not. For example, the various elements or components may be combined or integrated in another system or certain features may not be implemented. Also, the techniques, systems, sub-systems, and methods described and illustrated in the preferred embodiment as discrete or separate may be combined or integrated with other systems, designs, techniques, or methods without departing from the scope of the present disclosure. For example, the control head can be used with a wide variety of types of LMR systems and networks, including those not specifically discussed herein. Other examples of changes, substitutions, and alterations are readily ascertainable by one skilled in the art and could be made without departing from the spirit and scope of the present disclosure.

Technology Category: 2