TECHNICAL FIELD of the INVENTION

This invention relates generally to radio frequency communication devices, and more specifically to a radio device employing optics to control one or more operational parameters of the radio.

BACKGROUND of the INVENTION Radios typically have several control knobs, buttons, or switches that enable a radio user to change or vary one or more operational parameters of the radio. Common examples of

variable operation parameters include audio volume adjustments, squelch settings, and frequency selection. Possibly less well known, but nevertheless operationally significant, many radios enable an operator to change the radio's identification code, group affiliation, encryption key, or other such parameters essential to the proper operation of contemporary radios.

Generally, the control knobs, buttons and switches used in contemporary radios comprise electromechanical devices each of which must be electrically coupled (usually soldered) to a printed circuit (PC) board or circuit carrying substrate. Due to the mechanical contacts, such electromechanical control arrangements are unreliable and may fail after prolonged exposure to dust, humidity, or temperature. Since consumers demand every increasing levels of reliability, a superior control arrangement for a radio is needed.

SUMMARY of the INVENTION

Accordingly, it is an object of the present invention to provide a radio having optical controls.

Briefly, according to the invention, a light source transmits a light signal down an optical communication channel. In a light-reflective embodiment of the present invention, a portion of the transmitted light signal is reflected back down the optical communication channel to an optical receiver. By measuring the intensity of the reflected light, one or more operational parameters of the radio can be controlled. In a Ught-transmissive embodiment of the present invention, a portion of the transmitted light signal is allowed to pass to the end of the communication channel. By measuring the intensity of the light reaching the end of the optical communication channel, one or more operational parameters of the radio can be controlled.

BRIEF DESCRIPTION o the DRAWINGS

Figure la is an illustration of a preferred reflective embodiment of the present invention;

Figure lb is a block diagram of a radio in accordance with the preferred reflective embodiment of the present invention; Figure 2a is an illustration of a preferred transmissive embodiment of the present invention;

Figure 2b is a block diagram of a radio in accordance with the preferred transmissive embodiment of the present invention;

Figure 3a is an illustration of a preferred reflective/ transmissive embodiment of the present invention;

Figure 3b is a block diagram of a radio in accordance with the preferred reflective /transmissive embodiment of the present invention.

DESCRIPTION of the PREFERRED EMBODIMENT

To provide optical controls, the present invention contemplates a reflective embodiment, a transmissive embodiment, and a combined reflective/ transmissive embodiment. These preferred embodiments are considered separately below:

REFLECTIVE EMBODIMENT Referring to Figure la, an illustration of a portion of the radio housing 10 in accordance with the present invention is shown. As seen in Figure la, a housing 10 (or molded circuit board assembly) has molded therein an optical communication channel 12. Typically, conventional radio housings are constructed using well known injected molding processes. According to the invention, one or more optical channels 12 (which may comprise optic fibers) are molded into the housing 10 to provide one or more optical communication channels within the housing. Molding of one or more optical commiinication channels (which should be transparent to the light source of interest) into the radio's housing is preferred as

this process offers physical protection to the optic fibers. Of course, the benefit of optical controls may be achieved without molding the optical channels by careful routing the optical channels inside the housing assembly. In accordance with the invention, an optical transceiver integrated circuit (IC) 16 is coupled to the communication channel 12, and to electrical conductors 14 that will interconnect the optical transceiver IC 16 with other electronic circuits. Typically, the IC die is protected by a protective die coat 18 such as Type 6101 manufactured by Dow Corning.

Operationally, a light signal is transmitted from the IC 16 through the communication channel 12 so as to illuminate a partially reflective disc 20. According to the invention, the disc 20 is graduated to become more reflective as the disc is rotated (about its axis 22) in one direction, and less reflective as the disc is rotated in the opposite direction. The portion of light signal that is not reflected can either be absorbed, allowed to pass through the disc 20, or merely blocked and not permitted to be reflected.back. That portion of the light that is reflected back through the channel 12 is received by the optical IC 16, which converts the reflected light signal into an electronic signal that is forwarded to appropriate control circuitry capable of measuring the intensity of the returned light signal. To effect a control function, the rotatable axis 22 protrudes outside of the housing 10 so that a conventional control knob 24 may be mounted on the axis. By rotating the knob, the radio's operator will rotate the partially reflective disc 20, which varies the reflected light intensity. Control components respond to the varying light intensity by electronically controlling one or more functions of the radio.

In Figure lb a block diagram of a typical radio employing the invention is shown. An information source 100 provides an information signal (data or voice) to a transmitter 102. The transmitter is activated (i.e., controlled) (104) by a controller 106 to transmit information via the antenna switch 108 to the antenna 110. To receive a signal, the antenna 110 is coupled via

the antenna switch 108 to a receiver 112, which provides a recovered audio signal 114 to an amplifier 116. The gain of the amplifier 116 is controlled (118) by the controller 106 to vary the amplitude of the audio signal presented to the operator by the speaker 120.

According to the invention, at least a portion of the radio is optically controlled by including an optical transmitter 124 and an optical receiver 126. Preferably, the optical transmitter 124 and the optical receiver 126 respectfully comprise an MLED 71 and an MRD 701, manufactured by Motorola, Inc., or their functional equivalents. Operationally, the optical transmitter 124 transmits a light signal (modulated or unmodulated) into the optical communication channel 12, which is preferably molded into the radio housing 10. The preferred light signal resides in the infra-red Hght spectrum, although visible or ultra¬ violet light could be readily used provided an appropriate detector is employed. The light signal travels through the optical communication channel 12 until it strikes the partially reflective disc 20. Depending upon the rotation of the partially reflective disc 20, some portion of the light signal will be reflected back into the communication channel 12. That portion of reflected light is received by the optical receiver 126, which converts the received light signal into electrical signal 128 that can be measured by the controller 106. By measuring the signal 128, the controller 106 can determine the intensity of the light reflected back through the communication channel 12. Responsive to the signal 128, and thus the reflected light intensity, the controller 106 may modify data parameters (stored within the controller), control transmitter parameters (via control line 104), receiver parameters (via control line 122) or the radio's volume (via control line 118). Since no mechanical or moving electrical connections are used in the switch (control) arrangement of the present invention, reliability is greatly enhanced. Also, the present invention is not susceptible to electromagnetic interference.

TRANSMISSIVE EMBODIMENT Referring to Figure 2a, the transmissive mode of the present invention is shown. In the transmissive mode, the radio housing 10 has molded therein optical communication channels 12 and 12', between which is disposed a optical attenuator disc 20'. The optical attenuator disc operates to allow some portion of the light signal to pass from the coirimunication channel 12 to the communication channel 12' to the optical receiver IC 16a. That portion of light not transmitted from the communication channel 12 to the communication channel 12' may be either be reflected, absorbed, or merely blocked using techniques known in the art. Also, as discussed above, the benefit of optical controls may be achieved without molding the optical channels by careful routing the optical channels inside the housing assembly.

Operationally, a light signal (modulated or unmodulated) is transmitted from the IC 16a through the communication channel 12' so as to illuminate the optical attenuator disc 20'. According to the invention, the disc 20' is graduated to become more transparent (i.e., allowing light to pass) as the disc is rotated (about its axis 22') in one direction, and less transparent as the disc is rotated in the opposite direction. The portion of light signal that is not permitted to pass from the optical communication channel 12' to the optical communication channel 12 can either be absorbed or blocked by the disc 20'.

That portion of the light that passes into the optical channel 12 is received by the optical receiver IC 16a, which converts the received Hght signal into an electronic signal that is forwarded to appropriate control circuitry capable of measuring the intensity of the received Hght signal.

To effect a control function, the axis 22' is mounted so as to aUow a portion of the disc 20' to protrude outside of the housing 10 so that a conventional "thumb-wheel" type control is formed. By rotating the disc, the radio's operator varies the transmitted light intensity. Control components respond to the

varying Hght intensity by electronically controUing one or more functions of the radio.

In Figure 2b a block diagram of a typical radio employing the transmissive embodiment of the invention is shown. An information source 100 provides an information signal (data or voice) to a transmitter 102. The transmitter is activated (i.e., controUed) (104) by a controller 106 to transmit information via the antenna switch 108 to the antenna 110. To receive a signal, the antenna 110 is coupled via the antenna switch 108 to a receiver 112, which provides a recovered audio signal 114 to an ampHfier 116. The gain of the amplifier 116 is controUed (118) by the controller 106 to vary the amplitude of the audio signal presented to the operator by the speaker 120.

According to the invention, at least a portion of the radio is opticaUy controlled by including an optical transmitter 124 and an optical receiver 126. The optical transmitter 124 transmits a Hght signal (modulated or unmodulated) into the optical communication channel 12', which is preferably molded into the radio housing 10. The light signal travels through the optical communication channel 12 until it strikes the optical attenuator disc 20'. Depending upon the rotation of the attenuator disc 20', some portion of the light signal will be passed into the communication channel 12. That portion of Hght is received by the optical receiver 126, which converts the received Hght signal into electrical signal 128 that can be measured by the controller 106. By measuring the signal 128, the controller 106 can determine the intensity of the light reflected back through the communication channel 12. Responsive to the signal 128, and thus the received light intensity, the controller 106 may modify data parameters (stored within the controUer), control transmitter parameters (via control Hne 104), receiver parameters (via control line 122) or the volume (via control line 118).

REFLECTIVE /TRANSMISSIVE EMBODIMENT Referring to Figure 3a, the combined reflective/ transmissive mode of the present invention is shown. This combined mode may be useful in providing multiple control functions from a single Hght source, or may be used to effect, for example, course and fine control adjustments. In the combined mode, the radio housing 10 has molded therein optical communication channels 12, 12', and 12". Between the optical channels 12 and 12' is positioned a partially reflective disc 12, while an optical attenuator disc 20' is disposed between the optical channels 12' and 12". The partiaUy reflective disc 12 aUows some portion of the Hght signal to pass into the optical channel 12', whUe reflecting back some other portion of the Hght signal depending upon the rotatable position of the disc. The optical attenuator disc operates to receive the Hght signal aUowed to pass by the disc 20, and then permit some portion of that Hght signal to pass into the optical channel 12" so that it wiU be received by the optical receiver IC 16a. That portion of Hght not transmitted from the communication channel 12 to the communication channel 12 ^* (i.e., the reflected Hght signal) is received by the optical transceiver IC 16.

In Figure 3b a block diagram of a typical radio employing the invention is shown. An information source 100 provides an information signal (data or voice) to a transmitter 102. The transmitter is activated (i.e., controUed) (104) by a controller 106 to transmit information via the antenna switch 108 to the antenna 110. To receive a signal, the antenna 110 is coupled via the antenna switch 108 to a receiver 112, which provides a recovered audio signal 114 to an amplifier 116. The gain of the amplifier 116 is controUed (118) by the controUer 106 to vary the ampHtude of the audio signal presented to the operator by the speaker 120.

According to the invention, at least a portion of the radio is opticaUy controUed by including an optical transmitter 124 and optical receivers 126 and 126a. The optical transmitter 124 transmits a Hght signal (modulated or unmodulated) into the

optical communication channel 12, which is preferably molded into the radio housing 10. The light signal travels through the optical communication channel 12 until it strikes the partially reflective disc 20. Depending upon the rotation of the partially reflective disc 20, some portion of the light signal will be reflected back into the communication channel 12. That portion of reflected light is received by the optical receiver 126, which converts the received light signal into electrical signal 128 that can be measured by the controller 106. By measuring the signal 128, the controUer 106 can determine the intensity of the light reflected back through the communication channel 12.

That portion of the Hght signal that is not reflected back into the optical channel 12 passed into and travels through the optical communication channel 12' until it strikes the optical attenuator disc 20'. Depending upon the rotation of the attenuator disc 20', some portion of the light signal will be passed into the communication channel 12". That portion of Hght is received by the optical receiver 126a, which converts the received Hght signal into electrical signal 128a that also can be measured by the controller 106. By measuring the signals 128 and 128a, the controUer 106 can determine the intensity of the light reflected back through the communication channel 12 and the intensity of the light ultimately transmitted through the optical channel 12". Responsive to the signals 128 and 128a, the controller 106 may modify data parameters (stored within the controller), control transmitter parameters (via control line 104), receiver parameters (via control line 122) or the volume (via control line 118). Of course, numerous other combinations of each of these embodiments are possible. What is claimed is: