Abstract: An improved key pin and action pin that is resistant to corrosion, is very durable and has surfaces with a very low coefficient of friction. The pins are preferably made of aluminum or aluminum alloy with a hardened anodized oxide surface. The anodized pins may be polished to provide a surface with a very low coefficient of friction that is also very durable. As a consequence of the low friction and corrosion resistance, piano actions using the pins have less resistance providing an action with a lighter “feel” and consistency. Longevity of the components of the action and the pins is also greatly improved especially for pianos located in humid climates where traditional pins experience corrosion.

Abstract: An apparatus and method of controlling note velocity within an electronically controlled player piano in response to the analog characteristics (level, strength, amplitude, etc.) of a received audio signal encoded with a MIDI (or similar) note stream. The invention allows conventional audio playback devices to be utilized as a source for MIDI information which drives the actuation of the keys of the player piano.

Abstract: An apparatus and method of controlling note velocity and thus relative instrument volume within an electronically controlled player piano in response to the characteristics (level, strength, amplitude, etc.) of a received audio signal encoded with a MIDI (or similar) note stream. The invention allows conventional audio playback devices to be utilized as a source for information which drives the actuation of the keys of the player piano and allows the volume control of these devices to control the overall volume of an electronic musical instrument.

Abstract: A method and apparatus for limiting which player pianos can properly play notes within a media file or stream without playing additional “bad notes” encoded in the stream for disrupting the playback of that musical composition so as to prevent playback on unauthorized systems. Bad notes are encoded within a file or stream containing the proper “good notes” of the composition along with control commands to allow identifying the bad notes (e.g., by location, relative position, characteristics and so forth). Player pianos of a first manufacturer, having the proper programming, properly decode the control commands to locate the bad notes and prevent them from being played back with the good notes, therein properly rendering the musical composition. Player pianos from other manufacturers will play all the notes thus obfuscating the playback of the musical composition. Fidelity of playback on authorized system is not affected.

Abstract: An improved key pin and action pin that is resistant to corrosion, is very durable and has surfaces with a very low coefficient of friction. The pins are preferably made of aluminum or aluminum alloy with a hardened anodized oxide surface. The anodized pins may be polished to provide a surface with a very low coefficient of friction that is also very durable. As a consequence of the low friction and corrosion resistance, piano actions using the pins have less resistance providing an action with a lighter “feel” and consistency. Longevity of the components of the action and the pins is also greatly improved especially for pianos located in humid climates where traditional pins experience corrosion.

Abstract: A method of utilizing previous event feedback information from historical derived hammer velocity data, such as associated with a MIDI record function, for providing non-real-time feedback when controlling actuators. The use of non-real-time feedback within the present invention provides a number of advantages over the use of conventional real-time feedback mechanisms. Utilization of the non-real-time (historical) key actuation information reduces the amount of circuitry necessary for correcting the operation of the actuators (i.e. solenoids) during playback on the instrument. By way of example, a programmable circuit element receives velocity information on previous key strikes for adjusting the actuator velocity output signal which will be generated for future key strikes. The accuracy of key strike normalization provided by this method approaches that which is achievable using real-time feedback, because the velocity profiles for each key remain substantially constant during playback.

Abstract: A mounting bracket for supporting a key movement recording sensor assembly within a keyboard-operated musical instrument. The mounting bracket of the present invention incorporates a locking mechanism to prevent sensor assembly movement and it preferably conforms to a portion of the hammer flange assembly to reduce vertical space requirements. The locking mechanism, or alternatively the sensor board itself, provides a biasing force for engaging the sensor assembly. Applying a sufficient manual force to a release member on the locking mechanism overcomes the biasing force to unlock the sensor assembly to allow for the insertion, adjustment, or removal of the sensor assembly from the mounting bracket. A keyed retention mechanism augments the sensor assembly to simplify engagement and adjustment of the sensor assembly.

Abstract: A method of estimating solenoid heat accumulation and providing output power compensation thereof. The method is particularly well suited for compensating the drive solenoids within a player piano mechanism, or similar. A heat value is maintained for each coil whose accumulated heat is of interest. A quantity of heat is periodically removed from each heat value which corresponds to the level of thermal dissipation for the solenoid during the period. Similarly, a quantity of heat is periodically added to the heat value to account for the power being applied to the active solenoids. A gain compensation value may then be calculated from the heat value and used to temperature compensate the power being applied to the solenoids wherein force roll-off is prevented in response to solenoid use.

Abstract: A method of estimating solenoid heat accumulation and providing output power compensation thereof. The method is particularly well suited for compensating the drive solenoids within a player piano mechanism, or similar. A heat value is maintained for each coil whose accumulated heat is of interest. A quantity of heat is periodically removed from each heat value which corresponds to the level of thermal dissipation for the solenoid during the period. Similarly, a quantity of heat is periodically added to the heat value to account for the power being applied to the active solenoids. A gain compensation value may then be calculated from the heat value and used to temperature compensate the power being applied to the solenoids wherein force roll-off is prevented in response to solenoid use.

Abstract: An extruded recording sensor mounting rail for keyboard operated musical instruments, particularly electronic player pianos, which can be used to install recording sensors in a new or existing piano. First and second flanges extend longitudinally along the front and rear of the mounting rail. A shelf is provided on the first flange, with the shelf configured for receiving and supporting one edge of a circuit board in a sensor assembly. The first flange includes a groove adapted to receive a threaded fastener for securing the edge of the circuit board onto the shelf. In the preferred embodiment, the second flange includes an inward facing lip which defines a flute configured for receiving and supporting the other edge of the circuit board. In the alternate embodiment, the second flange includes a shelf and a groove adapted to receive a threaded fastener for securing the other edge of the circuit board onto the shelf.

Abstract: A method for eliminating or reducing noise created by the action mechanisms of piano keys during its return stroke after striking a string, by regulating the amount of time for the mechanism to return to rest. The method comprises the steps of sequentially initiating a pair of braking pulses by the actuator solenoid to slow the action mechanism during its return stroke. Each braking pulse is of a specified duration and magnitude such that the mechanism's return time is maximized while eliminating the possibility of double hits on the string.

Abstract: An extruded recording sensor mounting rail for keyboard operated musical instruments, particularly electronic player pianos, which can be used to install recording sensors in a new or existing piano. First and second flanges extend longitudinally along the front and rear of the mounting rail, and a shelf is provided on each flange, with the shelves configured for receiving and supporting a circuit board in a sensor assembly. Each flange includes an outward facing lip which extends longitudinally along the flange. One or more clips each include flanges which fit over the outward facing lips and retain the sensor board on the mounting rail.

Abstract: A piano pedal optical sensor apparatus and method for accurately measuring, recording and reproducing the pedal expression generated during piano performances. A plurality of optical emitter/sensors are mounted on the pedal support assembly of a piano, and a plurality of corresponding optical reflectors are mounted on the moving connecting rods associated with piano pedals on the piano. Output voltage signals from the optical emitter sensors, which vary according to pedal movement, are monitored and used to generate and record pedal position values. The recorded pedal position values are then used to recreate the original pedal expression of the piano performance by generation of pulse width modulation signals which are used to drive solenoids associated with piano pedals.

Abstract: A method and apparatus for accurately sensing key motion in a keyboard operated musical instrument, in which optical emitters and sensors are positioned adjacent to the keys. The optical emitters and sensors are arranged on a plurality of individually addressable sensor boards, and the sensor boards are divided into a plurality of individually addressable sensor banks. Each sensor board is independently and sequentially activated by a controller according to a specified timing sequence. As the controller activates a sensor board in one bank, allowing the board to warm up, another sensor board in the second bank, which has previously been activated and warmed up, is read and analyzed by the controller. Activation and reading of sensor boards alternates between sensor banks as the sensor boards are sequenced through.

Abstract: A method and apparatus for accurately sensing key motion in a keyboard operated musical instrument, in which optical emitters and sensors are positioned above the hammer catchers. The optical emitters and sensors are arranged on a plurality of individually addressable sensor boards, and the sensor boards are divided into a plurality of individually addressable sensor banks. Each sensor board is independently and sequentially activated by a controller according to a specified timing sequence. As the controller activates a sensor board in one bank, allowing the board to warm up, another sensor board in the second bank, which has previously been activated and warmed up, is read and analyzed by the controller. Activation and reading of sensor boards alternates between sensor banks as the sensor boards are sequenced through.

Abstract: A method and apparatus for actuating solenoids in an electronic player piano where a Musical Instrument Digital Interface (MIDI) velocity value is translated to a solenoid driving signal, a counter is activated by the solenoid driving signal, and a solenoid is energized from the counter according to the solenoid driving signal. A central processing unit (CPU) reads the MIDI data from a digital data storage device, and selects the corresponding solenoid driving parameters from a look-up table stored in read only memory (ROM). The solenoid driving parameters are converted into a pulse width modulation (PWM) waveform by a driving circuit containing counters. The PWM signal is sent to the gate of a field effect transistor (FET) switch connected to the solenoid and the solenoid is energized by the FET according to the PWM signal.

Abstract: An extruded recording sensor mounting rail for keyboard operated musical instruments, particularly electronic player pianos, which can be used to install recording sensors in a new or existing piano and provide for accurate alignment of the sensors with the individual keys in the instrument. A first flange extending along the rear of the mounting rail is configured for receiving one edge of a circuit board in a sensor assembly, while a second flange and shelf extending along the front of the mounting rail are configured for supporting the other edge of the circuit board and flexible recording sensors. Each flange also includes longitudinal slots for receiving fasteners for joining multiple mounting rails in an end to end configuration so that mounting rail assemblies of varying lengths can be fashioned to accommodate different keyboard sizes and key spacing configurations.

Abstract: A method and apparatus for accurately sensing key motion in a keyboard operated musical instrument, in which optical emitters and sensors are positioned above the hammer shanks. The optical emitters and sensors are arranged on a plurality of individually addressable sensor boards, and the sensor boards are divided into a plurality of individually addressable sensor banks. Each sensor board is independently and sequentially activated by a controller according to a specified timing sequence. As the controller activates a sensor board in one bank, allowing the board to warm up, another sensor board in the second bank, which has previously been activated and warmed up, is read and analyzed by the controller. Activation and reading of sensor boards alternates between sensor banks as the sensor boards are sequenced through.

Abstract: A method and apparatus for sensing the velocity of key motion in a keyboard operated musical instrument, in which sensors (10) have a polymer piezoelectric film (18) laminated to a mylar backing material (20) are mounted in proximity to the keys (12) of a keyboard operated musical instrument. When deflected by the keys (12), the sensors (10) produce analog circuit output voltages proportional to the velocity of key motion. The analog signals are then converted to digital signals and processed by a digital microprocessor (36) to represent the velocity factor component of musical information in Musical Instrument Digital Interface (MIDI) or other digital formats. The digital data is then presented directly to a reproducing musical instrument or recorded on an electronic storage media.

Abstract: A method and apparatus for re-creating expression effects contained in musical renditions recorded in MIDI format for reproduction on solenoid actuated player piano systems. Detected strike velocity information contained in the MIDI recording is decoded and correlated to strike maps stored in a controlling microprocessor, the strike maps containing data corresponding to desired expression effects. Time differentiated pulses of fixed width and amplitude are directed to the actuating solenoids in accordance with the data in the strike maps, and the actuating solenoids in turn strike the piano strings. Thereafter, pulses of uniform amplitude and frequency are directed to the actuating solenoids to sustain the strike until the end of the musical note. The strike maps dynamically control the position of the solenoid during the entire duration of the strike to compensate for non-linear characteristics of solenoid operation and piano key movement, thus providing true reproduction of the original musical performance.