1. Field of the Invention

This invention relates to small sized radios which are typically housed in novelty items such as sunglasses, calendar casings, golf balls and the like.

2. Prior Art

A variety of novelty radios have been developed since the advent of small radio cir- cuitry. Typically, such novelty radios are housed in a casing which is not normally associated with the field of electronics or radio circuitry. For example, radios have been fixed in calendar casings, small desk objects such as paper weights, trophies, golf balls and other items which may be partly classified as conversational pieces.

Although larger novelty radios usually include the standard features of good reception, volume control and acceptable sound reproduction, the minaturized radios previously placed in small flashlight tubes, eyeglass rims and ^" similar novelty objects as radios have lacked the basic features normally considered necessary for a good radio. For example, a prior art device repre¬ senting this class of small-object radios is a radio device housed in a tube such as a finger— sized flashlight which could be placed in the pocket of a shirt. This device has no volume control, except by rotating the radio so that the antenna, which projects out of the casing, has an increased or decreased -sensitivity, thereby changing the level of signal received at the radio. Because of the change in signal level in

reception, the volume can be correspondingly raised or lowered at the audio output. Selection of stations on this pocket radio was accomplished by a small dial mounted on the side of the tube which could be turned to select a particular radio frequency. The audio signal is transmitted to the listener by means of an earphone coupled at one end of the radio tube. The antenna consisted of a stiff wire which extended out of the body of the radio along its general longitudinal axis. This antenna is extremely sensitive to direction and orientation of the device.

The disadvantages of this type of novel¬ ty radio included the absence of volume control. When carried in the pocket, the volume level might spontaneously change without awareness of the listener by change in his position or orientation with respect to the broadcasting signals. Conse¬ quently, the listener may suddenly be subjected to an extremely loud audio signal one moment, and then be listening to a barely audible signal the next. As indicated previously, his only method of maintaining a single listening level would be to hold the radio in a unique orientation to maintain the sensitivity of the antenna at a given level. Furthermore, to increase or reduce the volume, the user would have to rotate the casing and antenna to a specific orientation which provides the level of volume desired.

A further disadvantage of this prior art device arises from the position of the tuning control on the side of the casing. Typically, this device is positioned in the shirt pocket of

the listener, perhaps fixed in position with a pen clip. To use the radio, the listener would have to remove the device from his pocket and make adjustments on the dial positioned at the side of the casing to select his preferred station.

Another primary disadvantage of the radio device described above which was housed in a flashlight tube or the like is the cost of this item. Based on the inventor's experience, this item was retailed at $59 or more. Based on this price, this item would typically not be classified in the novelty-radio group, since such items are designed to be less expensive and more affordable to the general public. Obviously, when purchasing a $60 radio, a typical consumer would expect high quality sound, volume control and other features which could be obtained at that price in a standard radio device. Nevertheless, this latter-described radio has the primary deficien- cies experienced by the cheaper, novelty radio devices housed in eyeglass frames and similar small casings.

OBJECTS AND SUMMARY OF THE INVENTION

It is therefore an object of the present invention, to provide a pen-sized radio which is within the price range compatible with novelty devices, yet has the desired features of volume control and quality of the more expensive standard radio designs. It is a further object of the present invention to provide a novelty radio which fits within a fountain pen casing of standard size, and can be carried in the listener's pocket.

OMH

It is yet another object of this inven¬ tion to provide a pen-sized radio for use in a listener's pocket wherein the volume control and station selection can be accomplished by the use of a single hand on the radio without removing the casing from its position in the pocket of the listener.

It is a further object of this invention to provide a pen-like radio without an exposed antenna to detract from the appearance of the pen casing.

It is a still further object of this invention to provide an inexpensive pen-sized radio which can be either positioned in the user's pocket for use with a standard earphone, or can be placed on a desk or other surface for use with an external speaker.

These and other objects are realized in a pen-sized radio characterized by a tubular casing having length and width dimensions approxi¬ mating a pen body. A volume control and tuner selection assembly is attached at the top of the casing and has respective volume and tuner selec¬ tor knobs which are independently and coaxially mounted substantially along the central axis and at the top of the tubular casing to enable volume and radio frequency selection by the user with single hand contact, while the radio is still positioned in his pocket. One of the selector knobs is mounted below the other knob, with each knob being capable of independent adjustment. The upper knob has a control shaft projecting axially downward along the axis of the tubular casings

OMPI

through the lower knob, the lower knob having a sufficiently large central opening to permit free movement of this control shaft without interfering with the adjustment or position of the lower knob. The respective upper and lower knobs are coupled to volume and tuner control means which are positioned below the knobs within the tubular casing. Also positioned within the tubular casing is an antenna means for receiving radio signals and appropriate electronic circuitry mounted with¬ in the tubular casing and coupled to the antenna leads to receive radio signals therefrom and amplify and convert such signals to an audio output signal. The audio output signal is coupled to a jack receptacle positioned in the base of the tubular casing and provides means for insertion of an audio jack attached to either an earphone or an external speaker. Space is reserved within the tubular casing for a battery or other power source to provide electric power for the radio circuit. The necessary contacting leads between the volume and tuner control assembly and volume and tuner input circuitry within the electronic circuitry of the radio are also provided. The device further includes switch means coupled to the electronic circuitry and power source for selectively apply¬ ing and interrupting power supply to the electronic circuitry to enable operation of the radio.

Additional features and other objects of the invention will be apparent to those skilled in the art from the following detailed description of the invention, taken in combination with the accompanying drawings, wherein:

Figure 1 shows a cross-sectional view of the tubular casing and volume control and tuner selection assembly, with the remaining components housed within the tubular casing in plan view. Figure 2 shows a cross section taken along the line 2-2 of Figure 1.

Figure 3 presents a representative cir¬ cuit diagram for an AM radio system.

Figure 4 illustrates the pen-sized radio device positioned in a desk top object which includes an external speaker as opposed to the earphone represented in Figure 1.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings: Figure 1 shows a pen-sized radio .device housed within a tubular casing 10 made up of two sections of structure similar to a fountain pen casing. This structure includes an upper casing 11 and a lower casing 12 which are removably joined at a threaded seam 13. This construction permits separation of the upper and lower casing for changing batteries or obtaining access to other internal parts of the device. Generally, however, the lower section 12 will be locked into the threaded section 13 of the upper casing 11.

A retainer plate 14 can be positioned at the base of the upper casing 11 to protect the components positioned within the upper casing from contacting those components in the lower casing. Furthermore, this retainer plate 14 may be con¬ structed of materials which provide isolation from electric or magnetic signals generated by the

o-,:?ι

circuitry and components in the opposing upper and lower casings. Although openings 15 and 16 are shown in the retainer plate to permit passage of leads required to couple components housed within the upper casing with circuitry positioned in the lower casing, it is noted that additional isola¬ tion can be affected by conductor tabs molded within the retainer plate with contact sites on opposing sides to permit soldering or fixation of the leads required between the upper and lower casing components. To enhance the -novelty aspect of this device and improve convenience in use, a pocket clip 18 is fixed to the upper casing 11 in a manner similar to a standard pen clip. This clip serves a functional ^' purpose of keeping the radio in upright orientation to provide maximum sensitivity for reception. This functional aspect is discussed more fully in a later section of this application dealing with the antenna means. The top 19 of the upper casing is open to permit insertion of the circuitry incased therein. The bottom 20 of the lower casing is configured as a receptacle for a standard earphone jack 21. From external appearances, the tubular casing 1.0 appears to be a pen casing, except when viewed at the bottom or top. This configuration assists in developing the novelty aspect of the radio, based on the aspect of appearance.

The tubular casing 10 can be constructed of any number of materials; however, plastics are ideal, both from ^' the point of view of cost and appearance. As to structural configuration, it will be apparent to those skilled in the art that

other geometric shapes may be compatible with the containment of components and circuitry as set forth hereafter. Accordingly, the configuration of Figure 1 is merely illustrative. The open end 19 at the top of the upper casing 11 is adapted to receive a volume control and tuner selection assembly 22. This assembly includes a tuner selector knob 23 which has standard AM radio frequency references inscribed around the periphery of the face of the knob 23. The standard indexing of frequencies for AM from 520kHz to 1600kHz would be shown. If the radio circuitry and antenna design were for FM recep¬ tion, the tuner knob would be designated with the standard indexing for FM selection, ranging from 88MHz through 108MHz. The inscription of the tuning stations on the face of the knob 23 provides the benefit to the user of being able to look directly down on the top of the radio casing and make appropriate adjustments with a simple finger movement.

Disposed immediately under the tuning knob is a volume control knob 24 for enabling the user to adjust volume to a desired level. A slight space is provided between the bottom of the tuner knob 23 and the top of the volume control knob 24 to ensure independent movement of each of the respective knobs. For example, if the tuner knob was seated against the volume control knob, frictional contact between the two knobs could result in unintentional move¬ ment of the second knob upon rotation of the first.

This volume control and tuner selection assembly 22 is mounted coaxially with the central axis 26 of the tubular casing. The tuner knob 23 includes a control shaft 26 which is fixed at its base end to a conventional tuning capacitor. The specifications for such tuning capacitor are selected to give optimum sensitivity and selectivity for the type of radio frequencies being monitored. The volume control knob 24 includes a small finger or barb 28 which projects down from the bottom of the control knob 24. This finger has sufficient length and proper dimensions to fit within a small recess in the rotating portion of a variable resistor trim pot 30 which is fixed in position immediately below the volume control knob

24.

The location of this opening in the trim pot 30 is represented more clearly in Figure 2. The referenced finger 28 projects into the opening 31 in the metal leaf 32 which is the rotating element of the trim pot 30. This trim pot is of conventional structure and includes a pair of wipers 33 which track along the variable resistive carbon base 34.

The trim pot 30 includes a central opening 35 which is coaxially oriented with the tubular axis 26. This opening permits the free movement of the control shaft 26 extending down from the tuner knob 23. An insulative shield 36 is disposed around the control knob 26 to electrically segregate the respective volume and tuner sections of the volume control and tuner

ΓRE

OMM

selection assembly 22. This shield may merely be a piece of cellophane tape, or any other thin insulator which can be wrapped around the tuner control shaft. The respective volume control trim pot

30 and tuning capacitor 27 are rigidly fixed in their coaxial, stacked configuration within a cylindrical sleeve 37 which is glued or otherwise permanently fixed in place within the top of the tubular casing as shown at 38.

As an alternative to gluing the sleeve 38 within the tubular casing, the sleeve thickness can be adjusted to form a frictional fit against the interior wall of the tubular casing. The components fixed within this sleeve

38 can be glued in place at contact points such as item 39 as shown in Figure 2. Openings can be provided to enable contact leads from the trim pot or volume control means and the tuning capacitor (tuner control means) for coupling to the antenna and other circuitry within the ^" radio structure. These leads are generally designated as item 40. It will be apparent to those skilled in the art from the schematic drawings of Figure 3, in combination with the illustrations In Figures 1 and 2 that these leads perform different functions in terms of completing the connecting circuitry between the volume control and tuner selection assembly, antenna and other circuitry within the radio.

The development of a volume control and tuner selection assembly as depicted in Figure 1 provides the unique combination of inexpensive

components which can be assembled in an unique relationship to enable both volume and tuner selection at the top of the pen or tubular casing. This location is very significant for this novelty device, in view of the typical upright, pocket orientation of the radio as worn by the user. With this structure, an individual can have direct view of radio frequency or station selection and make such adjustment by the movement of a single finger along the tuner knob 23. Furthermore, similar control of volume is provided with single hand contact at the top of the radio with volume control knob 24. The combination of volume control and tuner selection at a single finger's touch, positioned at the top of the tube for convenience in view and accessability presents a novel feature unknown to the prior art. The level of volume control can easily be viewed by use of a reference mark immediately below the volume control knob 24 at the side of the tubular casing. This mark would typically indicate the low volume point, with clockwise rotation designed for increasing the volume.

Below the volume control and tuner selection assembly in Figure 1, is an open space down the chamber of both the upper and lower tube casing. This cavity area can be utilized to house the remaining components of the radio, including antenna, battery and remaining circuitry. Figure 1 indicates placement of antenna means 41 In the open cavity of the upper tube casing 11. Although a number of antenna means may be suitable for use within the tubular casing illustrated, the figures

show an elongated ferrite bar with primary windings along the longitudinal axis, as opposed to the more conventional winding pattern which is provided along the shorter width of the ferrite bar. The use of a ferrite bar antenna 41 with the subject radio avoids the need of an exterior wire antenna and correspondingly eliminates the attendant disadvantages which Include reduced sensitivity and the problem of placement of the antenna when used in a pocket.

Although it is well known in the art that a ferrite bar antenna has a much higher Q rating over an air antenna, the conventional ferrite bar antenna utilizes a primary winding in the shorter direction or width orientation of the bar. In the present invention, the orientation of winding has been reversed such that a majority of the wire winding around the ferrite bar traverses the longitudinal direction. By utilizing this orientation of winding, the normal vertical posi¬ tion of the subject invention provides maximum reception and sensitivity to incoming radio signals. Accordingly, this type of ferrite bar a.ntenna provides unique advantage for the subject novelty device whose use is designed for _. vertical orientation, both by virtue of the position of the volume control and tuner selection assembly, as well as the pen clip 18 which permits the user to wear the radio in his pocket in the same manner as with a pen or similar device. As shown in the drawing, connector leads 42 are provided from the tuning capacitor 27 and are tapped into the windings of the ferrite bar antenna 41 in conven¬ tional manner.

-fU E

OMPI ^** -

The next element shown in Figure 1 is the power source or battery 43 which is struc¬ turally well adapted for housing within the lower casing 12. A sectioning tab 44 can be used to segregate the battery compartment from the remaining cavity of the lower casing 12. Obvious¬ ly, the type of battery utilized will depend upon the nature of circuitry selected for the radio. Based on the circuitry illustrated in Figure 3, a 1.5 volt "N" battery cell would be used.

The primary circuitry 45 of the radio is positioned in the remaining cavity section of the lower casing 12. This comprises the remaining electronic circuitry required to receive the radio signal from the tuning capacitor 27 for amplifica¬ tion and conversion of the signal to an audio output signal. Such circuitry is well within the state of ^' the art and needs no detailed explana¬ tion. A schematic diagram showing typical circuitry which may be used with the subject invention is provided as Figure 3. As indicated earlier, leads 40 provide coupling of the volume and tuner control means to the electronic cir¬ cuitry 45. The basic circuitry and functional operation is provided hereafter with reference to the schematic of Figure 3.

The final element of the subject inven¬ tion is positioned at the bottom of the tubular casing and consists of the speaker means 46 and associated connecting jack 21 for coupling the speaker means to the audio output of the radio device. Although the subject invention is ideally suited for use with a standard earphone 46, Figure

4 illustrates the use of this invention as part of a novelty desk radio in which the pen casing 10 is inserted into a receptacle 47 which is configured in size to approximately conform to the outer geometrical shape of the tubular casing 10. The casing and enclosed radio mount on a similar audio jack 48 which conforms in size and specifications to the earphone jack 21 previously referenced. A small external speaker 49 is mounted within the desk-top object 50 to provide for general broad¬ cast of the audio signal. Connecting leads 51 are provided from the jack 48 to close the circuit with the speaker 49. The desk top object 50 may be a clear glass cube as shown in Figure 4, or may be a conventional pen receptacle or other struc¬ ture of decorative nature.

Switch means are provided and coupled to the electronic circuitry and power source for selectively applying and interrupting power supply to the electronic circuitry to permit operation of the radio. In Figure 1, the switch means - are actuated by the insertion of the earphone jack 21 into the receptacle 52 at the bottom of the tubular structure. The dual operation of the audio jack receptacle 52 for (1) transmission of the audio signal to the earphone 46 and (2) on/off switching of the electronic circuitry, is accomplished by using contacts A and B shown as part of the receptacle 52 as open circuit, switching contacts which are closed by insertion of the head 53 of the earphone jack 21. The position of this con¬ ducting head 53 between contacts A and B closes

O PI

the power circuit as shown in Figure 3 and turns on the radio. It will be apparent to those skilled in the art that other forms of switching means can be utilized in connection with this invention; however, the subject switching method is well adapted for the type of structure use, as well as providing a novel feature in connection with operation of the radio.

A representative circuit diagram for an AM radio is provided in Figure 3. The discussion of this circuit diagram is intended to be basic in nature, in view of the fact that the functional aspects of this circuitry are well within the state of the art. - Referring now to the drawing, the primary of LI, parallel wired to capacitor Cl, represent the resonant circuit or variable tuning circuit for the AM radio band. The value of Cl is generally a maximum of 365pf. A jumper line is provided between the bottom of the primary and bottom of the secondary of LI. The two -lines between the windings shown in LI represents the ferrite bar previously discussed. Capacitor C2 is coupled from the jumper line to ground represents an AC direct connection to ground. Because of the substantial value of C2 ( .003MfD) the bottom of the referenced two coils of LI are at AC ground. Diodes Dl and D2 are placed in series, ^' the combination being in parallel with the capacitor C2, and operate to establish the proper bias value at the base of Tl. The secondary coil of LI and the capacitor C3 represent a positive feed back loop which oscillates at 50,000 cycles per

second. This results in a continuous off/on switching sequence of Tl at the rate of 50,000 cycles per second.

By virtue of the circuitry, transistor Tl effectively operates at two different frequencies at virtually the same time. One frequency is the super-regenerative audio feedback frequency which is approximately 50,000 cycles per second, and the other Is the frequency of the particular radio band that has been tuned in by the primary of the tuning capacitor Cl. This radio signal is recircuited and amplified through C3 before it is passed on for further amplifica¬ tion. The actual signal coming out of the collector of Tl has three elements. In addition to transmitting the 50,000 cycle frequency in RF frequency previously referenced, detection of the RF signal is likewise accomplished. This results from the on/off switching operation of Tl and chopping effect of running the transistor to clipping during each cycle of the on/off switching sequence, the RF detection function is provided by this action. Accordingly, Tl operates as an oscillator, an RF detector and also provides substantial RF gain. Resistor Rl operates in connection with the diodes Dl and D2 to maintain proper biasing of Tl. A suggested value for Rl is 27k. Item L2 is an audio pass inductor which operates to filter out the previously referenced RF frequencies and allow only the audio frequency from the collector of Tl to pass on to the next stage of amplification.

Resistor R2 provides the collector voltage and has a value of 330 ohms. Capacitor C4 operates as a DC blocking capacitor for R2. C4 further operates to assist in filtering RF signal from the power feed line. The positive voltage of 1.5 volts passes through R2 upon closing the circuit at A-B. This circuit is closed upon insertion of the earphone jack 21 previously referenced and shown in Figure 1. This voltage is fed directly through L2 to the collector of Tl. The emitter of Tl goes direct to ground to provide maximum gain.

As mentioned earlier, capacitor C4 is a blocking capacitor to prevent DC current flow. It also operates to allow the AC voltage to pass to transistor T2 which is a DARLINGTON transistor used for further amplification of the RF signals.

Resistor R3 at 180k biases T2 to its normal operating mode. Capacitor C5 is for tone control and permits roll-off of higher audio frequencies to contour the sound, it also serves to. filter any remaining RF from the audio circuit.

Resistor R4 is the variable volume con¬ trol in series with the emitter of T2. This is a lk resistor and operates to raise or lower the gain of T2.

The earphone is shown off the collector of T2 and is standard in the industry.

It will be apparent to those skilled in the art that other circuitry can be substituted to accomplish the objectives required for the subject invention. This discussion is merely illustrative

OMPI

of the functional features provided in one embodi¬ ment actually constructed by the inventor.

In view of the many variations which can be implemented within the inventive scope of this disclosure, it is to be understood that the drawings and description are by way of example and are not intended. to limit the scope of the claimed subject matter in the following claims.

OMPI