Communications: electrical – Audible indication – Electronic
Reexamination Certificate
1999-06-25
2002-11-05
Tong, Nina (Department: 2632)
Communications: electrical
Audible indication
Electronic
C340S384100, C340S384300, C340S425500
Reexamination Certificate
active
06476711
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sounding-body driving circuit outputting to a sounding body a drive signal for generating an artificial striking sound similar to a striking sound of a mechanical relay, and to an operating-sound generating apparatus using the circuit.
2. Description of the Related Art
A direction indicating apparatus of a vehicle generally has a mechanical relay for flashing a turn signal indicator, which is flashed by the mechanical relay in accordance with operation of a turn signal lever. Further, a driver of the vehicle can recognize that the turn signal indicator is in a state of flashing by means of both a visual warning of the flashing display of the indicator and an audio warning of the striking sound of the mechanical relay.
The mechanical relay is generally disposed near the driver's seat so that the driver can hear the string sound. In the case where the mechanical relay is miniaturized, or disposed in the engine room for circuit construction reasons, it becomes hard for the driver to hear the striking sound of the mechanical relay. Furthermore, when the flashing operation of the turn signal indicator is performed using a semiconductor switch and the like, the mechanical relay itself is unnecessary, so that the striking sound of the mechanical relay is not generated.
On the other hand, as disclosed in Japanese Unexamined Utility Model Publications JP-U 59-102448(1984) and JP-U 4-136948(1992), in the case of adopting such a construction that a sounding body such as a piezoelectric buzzer or a speaker is used and driven to generate a sound synchronized with the flashing operation of the turn signal indicator, the flashing operation state of the turn signal indicator can be indicated auditorially to the driver without the striking sound of the mechanical relay.
However, since the striking sound of the mechanical relay has been used for a long time as a flashing operation sound of the turn signal indicator, drivers are accustomed to such a tone. Accordingly, in the case where a sound different from a striking sound is generated as a flashing operation sound from the sounding body, as disclosed in the publications, the drivers have an undesireable unusual feeling because the flashing operation sound is fairly different in tone from the accustomed striking sound of the mechanical relay.
In the case of reproducing the striking sound of the mechanical relay faithfully, as shown in
FIG. 9
, it is necessary to generate a driving signal having an irregular waveform
4
showing a complicated envelop
2
. There is consequently a problem such that the driving circuit is complicated and expensive.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a sounding-body driving circuit and operation sound generating apparatus which allows generation of a flashing operation sound of a turn signal indicator with a simple and low-cost construction without presenting an unusual feeling to a vehicle driver.
Even if the striking sound of a mechanical relay is not reproduced faithfully, when an artificial striking sound similar to the striking sound is obtained as the flashing operation sound of the turn signal indicator, the driver has no unusual feeling toward the artificial striking sound. Thus, the object of the invention is achieved by adopting a driving circuit for generating the artificial string sound and putting some constructional thought into designing the driving circuit.
According to the invention, there is provided a sounding-body driving circuit outputting to a sounding body a driving signal for generating an artificial string sound similar to a striking sound of a mechanical relay. The sounding-body driving circuit generates a plurality of signals having different frequencies, synthesizes the plurality of signals in sequence of time, and repeatedly outputs the generated synthetic signal at intervals of a predetermined time.
No restriction is placed on the plurality of signals with respect to frequency, waveform, amplitude etc. as long as they are different in frequency. For example, with respect to waveform, any wave such as a rectangular wave, sine wave, triangular wave or the like may be used. With respect to amplitude, a constant value may be set or different values may be set at random or according to differences in frequency between the signals.
There is no particular restriction on the specific method of synthesizing the plurality of signals in sequence of time (e.g., order of synthesis of the signals, wave number of each signal, or method of combining the signals).
The synthetic signal denotes a signal obtained by connecting in sequence of time at least two kinds of signals of different frequencies. A synthetic signal may be generated by forming two or more kinds of signals of frequencies by a single oscillation circuit and connecting the signals in sequence of time.
As shown in the construction mentioned above, the sounding-body driving circuit according to the invention outputs the driving signal for generating an artificial striking signal to the sounding body. Since the plurality of signals having different frequencies are generated and synthesized in sequence of time and the synthetic signal thus generated is repeatedly outputted at intervals of a predetermined time, the following effects can be obtained.
Various tones can be obtained by synthesizing a plurality of signals having different frequencies, such various tones cannot be obtained by signals of a single frequency. The synthesis is performed in sequence of time so that the plurality of signals are properly arranged to generate a synthetic signal and the synthetic signal is outputted to the sounding body, thereby realizing an artificial string sound similar to the striking sound of the mechanical relay. Moreover, since the synthetic signal is repeatedly outputted at intervals of a predetermined time, by adjusting the predetermined time to a proper value, not only the tone of the artificial striking sound but also the generation interval can be made similar to those of the flashing operation sound of the turn signal indicator, that is, the striking sound of the mechanical relay.
According to the invention, a plurality of signals having different frequencies are generated and synthesized in sequence of time (that is, simply connected based time), thereby realizing an artificial striking sound similar to the striking sound of the mechanical relay with a simple and low-cost construction. By repeatedly outputting the synthetic signal at intervals of a predetermined time, the flashing operation sound of a turn signal indicator which does not sound unusual to the driver can be obtained.
Although there is no specific restriction on the duration of the synthetic signal of the invention, since the duration of the striking sound of the mechanical relay is about 12 ms, it is preferable to set the duration to 12 ms or less, more preferably 6 ms or less. It is generally said in connection with the sense of hearing of humans that a duration of 1 ms or more is necessary to identify the tone of the sound, a duration of 10 ms or more to have sequential feeling, and a duration of 100 ms or more to perceive the order of time. When the duration of the synthetic signal is set to be longer than required, the sound becomes similar to an electronic sound rather than similar to the striking sound of the mechanical relay. It is preferable to set the duration of the synthetic signal rather short to such an extent that the sequential feeling of the sound is not perceived.
As long as the sounding-body driving circuit is constructed to generate a plurality of signals having different frequencies, to synthesize the plurality of signals in sequence of time, and to repeatedly output the generated synthetic signal at intervals of a predetermined time, the signal process may be performed in a software or hardware manner. A specific construction of the latter manner is, for example, a construction comprising a signal generating circuit for generating
Fujinami Naohiro
Kitamura Hajime
Omori Katsuyoshi
Star Micronics Co.,Ltd.
Tong Nina
Wenderoth , Lind & Ponack, L.L.P.
LandOfFree
Sounding-body driving circuit and operating sound generating... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sounding-body driving circuit and operating sound generating..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sounding-body driving circuit and operating sound generating... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2971264