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Researchers Submit Patent Application, "Method and Device for Identifying Half Point of Pedal on Keyboard Musical Instrument", for Approval

July 24, 2014



By a News Reporter-Staff News Editor at Computer Weekly News -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors FUJIWARA, Yuji (Hamamatsu-shi, JP); OBA, Yasuhiko (Hamamatsu-shi, JP), filed on December 24, 2013, was made available online on July 10, 2014.

The patent's assignee is Yamaha Corporation.

News editors obtained the following quote from the background information supplied by the inventors: "The present invention relates to a method and device for identifying a half point of a pedal on a keyboard musical instrument, and a non-transitory, computer-readable storage medium storing therein a program for identifying such a half point. The present invention also relates to a method and device for reproducing a half point performance of a pedal on a keyboard musical instrument, and a non-transitory, computer-readable storage medium storing therein a program for reproducing such a half point performance.

"Heretofore, keyboard musical instruments have been known which can generate sounds by striking strings (string sets) via hammers as in an acoustic piano and which include depressable pedals. Among such pedals is one which is designed to make variable non-key-depressed-state corresponding positions (i.e., rest positions) that are initial relative positions of hammers relative to string sets in a non-key-depressed state. Such a pedal is commonly called 'shift pedal' in the grand piano or 'soft pedal' in the upright pedal.

"In the case of the grand piano, a key frame moves horizontally in a left-right direction relative to string sets, so that non-key-depressed-state corresponding positions (rest positions) of hammers too horizontally move in the left-right direction. In the grand piano, the number of component wire members (i.e., string elements) constituting the string set of each note differs depending on the pitch range which the string set belongs to that is, whereas the number is only one in a lowest pitch range, two wire members are placed in substantially parallel relation to each other in a low pitch range, and three wire members are placed in parallel in medium and higher pitch ranges. If positions at which the string sets are to be struck by the hammers (i.e., hammers' string-striking positions) are shifted in response to depression of the shift pedal, the number of wire members to be struck by each of the hammers changes in the pitch ranges other than the lowest pitch range. Also, in all of the pitch ranges, portions of the hammers actually contacting or abutting against the string sets are shifted in position horizontally.

"Further, in the high pitch range, for example, whereas the number of wire members to be struck is 'three' when the shift pedal is in a non-depressed state, the number of wire members to be struck is 'two' when the shift pedal is in a completely depressed state. Further, in the low pitch range, whereas the number of wire members to be struck is 'two' when the shift pedal is in the non-depressed state, the number of wire members to be struck is 'one' when the shift pedal is in the completely depressed state. Such arrangements permit variations in sound color and volume.

"Also known in the art is a performance expression effected by a human player depressing keys while depressing the shift pedal to a halfway point of a so-called pedal stroke from the non-depressed state or position to a completely-depressed state or position.

"Further, a portion of a hammer felt which frequently strikes a string set tends to have a greater dent and greater hardness than the other portions. Thus, if the hammer strikes the string set with a horizontal positional shift relative to the string set, it would strike the string set by its portion differing in dent size and hardness from the frequently-striking portion, thereby resulting in variations in sound color and volume. Therefore, when a key is depressed with the shift pedal depressed to a halfway point, the portion of the hammer striking the string set varies to thereby achieve variations of tone characteristics. Further, in that case, a state where a single wire member located at an end of the string set is struck incompletely can also be realized. In this way, desired subtle variations in sound color and volume can be expressed by a depressing state of the shift pedal.

"In the depressing stroke, from the non-depressed position to the completely-depressed position, of the shift pedal, there is a region or point where tone characteristics produced by string striking change. Such a region or point will hereinafter be referred to as a 'half region' or 'half point' of the shift pedal.

"Furthermore, among the conventionally-known keyboard musical instruments is one which can execute an automatic performance, including loud pedal (damper pedal) operations, by supplying a driving electric current to a solenoid coil to thereby drive the loud pedal. In an automatic performance, it is desirable that appropriate pedal operation control corresponding to a half pedal region of the loud pedal be performed in order to enhance reproducibility of the performance. With the shift pedal too, reproducibility of a performance in an automatic performance can be enhanced if appropriate reproduction of the half region or half point can be realized.

"However, static and dynamic characteristics of the pedals are characteristics unique to each keyboard musical instrument and differ from one keyboard musical instrument to another depending also on mounted states and conditions of the pedals. Thus, it is difficult to accurately identify a half point in the half region.

"Methods for identifying a half point of the loud pedal on the basis of load information of the pedal are disclosed in Japanese Patent Nos. 2606616 and 4524798. However, unlike with the loud pedal to which a damper lifting load starts to be applied even in the middle of a pedal depression operation, it is difficult to identify a half point of the shift pedal on the basis of a load on the shift pedal. Therefore, in a case where tone characteristics of the grand piano are to be controlled, it was impossible to control tone characteristics by use of a half point of the shift pedal. For this reason, it has been desirable to establish a method for accurately identifying a half point of the shift pedal.

"Generally, in the case of the upright piano, on the other hand, a distance, to the string set, of the hammer in the non-key-depressed-state corresponding position (rest position) changes in response to depression of the soft pedal. Thus, even when the key is depressed at a same velocity, changing the depressing state of the soft pedal can vary a string striking velocity and hence sound volume. With the uptight-type piano too, it is conceivable to employ a construction where there exists a point at which tone characteristics change. In such a case too, it is desirable to establish a method for accurately identifying a half point of the soft pedal."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "In view of the foregoing prior art problems, it is an object of the present invention to provide an improved technique for appropriately identifying a half point of a pedal, such as a shift pedal or soft pedal, on a keyboard musical instrument. It is another object of the present invention to provide an improved method and device for appropriately reproducing a half point performance of the pedal by use of the identified half point.

"In order to accomplish the above-mentioned object, the present invention provides an improved method for identifying a half point of a pedal on a keyboard musical instrument, the keyboard musical instrument including: a key; a hammer constructed to make a pivotal motion in response to an operation of the key; and a string set comprised of at least one wire member and constructed to be struck by the hammer and the pedal constructed to make a stroke motion in response to a depressing operation performed thereon, the pedal being constructed to change a rest position of the hammer relative to the string set in accordance with a stroke position thereof, the method comprising: a step of striking the string set by the hammer in association with individual ones of different rest positions of the hammer, each of the different rest positions of the hammer corresponding to each of a plurality of stroke positions within one stroke of the pedal; a detection step of, in response to the hammer striking the string set, detecting data indicative of at least one of behavior of the hammer and reaction of the string set, the detection step detecting the data in association with the individual ones of the plurality of stroke positions; and an identification step of identifying a half point of the pedal on the basis of the data detected by the detection step in association with the plurality of stroke positions.

"The present invention constructed in the aforementioned manner can appropriately identify a half point of the pedal, such as a shift pedal or soft pedal, constructed to relatively displace the rest position of the hammer. The half point identified in this manner can be advantageously used in various scenes. For example, information of the identified half point is preferably stored in a memory, so that, when an automatic performance of the keyboard musical instrument is to be executed, the pedal can be automatically operated in accordance with the stored information of the identified half point so that an automatic performance involving half pedal operations can be executed with ease.

"Preferably, the identification step identifies a half region, indicative of a transient variation characteristic, on the basis of a distribution curve of the data detected in association with the plurality of stroke positions and identifies the half point in the identified half region.

"Preferably, the detection step detects a string striking velocity of the hammer and a string releasing velocity of the hammer after striking of the string set and calculates, as a coefficient of rebound indicative of the reaction of the string set, a ratio of the string striking velocity to the string releasing velocity.

"Preferably, the string set comprises at least two wire members and is constructed so as not to abut against an outermost wire member of the at least two wire members of the string set in response to depression of the key in a completely-depressed state of the pedal, and the detection step detects vibrations of the outermost wire member as data indicative of the reaction of the string set.

"In order to accomplish the above-mentioned object, the present invention also provides an improved apparatus for identifying a half point of a pedal on a keyboard musical instrument, the keyboard musical instrument including: a key; a hammer constructed to make a pivotal motion in response to an operation of the key; and a string set comprised of at least one wire member and constructed to be struck by the hammer; and the pedal configured to make a stroke motion in response to a depressing operation performed thereon, the pedal being constructed to change a rest position of the hammer relative to the string set in accordance with a stroke position thereof, the apparatus comprising: a sensor adapted to detect a plurality of stroke positions within one stroke of the pedal; a detector adapted to, in response to the hammer striking the string set, detect data indicative of at least one of behavior of the hammer and reaction of the string set; and a processor. The processor is adapted to: for each of the plurality of stroke positions within one stroke of the pedal and in response to the hammer striking the string set from the rest position corresponding to the stroke position, detect the at least one of behavior of the hammer and reaction of the string set; and identify a half point of the pedal on the basis of the data detected in association with the plurality of stroke positions.

"Also provided by the present invention is an improved method for reproducing a half point performance of a pedal on a keyboard musical instrument, the keyboard musical instrument a key; a hammer constructed to make a pivotal motion in response to an operation of the key; and a string set comprised of at least one wire member and constructed to be struck by the hammer; and the pedal configured to make a stroke motion in response to a depressing operation performed thereon, the pedal being constructed to change a rest position of the hammer relative to the string set in accordance with a stroke position thereof, the method comprising: a step of providing a memory storing therein data identifying a half point of the pedal; a step of striking the string set by the hammer in accordance with automatic performance data including at least data for driving the key; and a driving step of automatically driving the pedal in accordance with data included in the automatic performance data and instructing behavior of the pedal, the driving step positioning the pedal at a position of the half point stored in the memory when the data instructing the behavior of the pedal is indicative of an intermediate value of a depression depth of the pedal.

"The present invention may be constructed and implemented not only as the method invention discussed above but also as an apparatus or device invention. Also, the present invention may be arranged and implemented as a software program for execution by a processor, such as a computer or DSP, as well as a non-transitory computer-readable storage medium storing such a software program. In this case, the program may be provided to a user in the storage medium and then installed into a computer of the user, or delivered from a server apparatus to a computer of a client via a communication network and then installed into the client's computer. Further, the processor used in the present invention may comprise a dedicated processor with dedicated logic built in hardware, not to mention a computer or other general-purpose processor capable of running a desired software program.

"The following will describe embodiments of the present invention, but it should be appreciated that the present invention is not limited to the described embodiments and various modifications of the invention are possible without departing from the basic principles. The scope of the present invention is therefore to be determined solely by the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

"Certain preferred embodiments of the present invention will hereinafter be described in detail, by way of example only, with reference to the accompanying drawings, in which:

"FIG. 1 is a partly sectional view showing an example construction of a keyboard musical instrument, particularly in relation to a given key, to which are applied a method and device for identifying a half point of a pedal in accordance with an embodiment of the present invention;

"FIG. 2 is a block diagram showing an example construction of a control mechanism of the keyboard musical instrument;

"FIG. 3 is a schematic plan view showing relationship between a hammer head and a string set in a high pitch range of the keyboard musical instrument;

"FIG. 4 is a diagram showing an example of a curve indicative of relationship between non-key-depressed-state corresponding positions and coefficients of rebound;

"FIG. 5 is a block diagram showing example operational flows of servo drive for a curve calculation process;

"FIG. 6 is a flow chart showing an example operational sequence of half point determination processing; and

"FIGS. 7A and 7B are conceptual diagrams showing distribution information indicative of half regions determined by the half point determination processing for individual sound pitches (keys or notes) and pitch ranges."

For additional information on this patent application, see: FUJIWARA, Yuji; OBA, Yasuhiko. Method and Device for Identifying Half Point of Pedal on Keyboard Musical Instrument. Filed December 24, 2013 and posted July 10, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=7478&p=150&f=G&l=50&d=PG01&S1=20140703.PD.&OS=PD/20140703&RS=PD/20140703

Keywords for this news article include: Software, Yamaha Corporation.

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Source: Computer Weekly News


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