Music – Instruments – Electrical musical tone generation
Reexamination Certificate
2003-01-29
2004-11-23
Donels, Jeffrey W (Department: 2837)
Music
Instruments
Electrical musical tone generation
Reexamination Certificate
active
06822155
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a key top switch for an electronic musical instrument such as an electronic piano, which is disposed in an operation panel of the electronic musical instrument as a versatile switch.
2. Description of the Prior Art
FIG. 1
illustrates an example of a conventional key top switch for an electronic piano equipped with a speaker (not shown). The key top switch
51
is disposed in an operation panel
52
, for example, as a tone selection switch. The key top switch
51
comprises a switch board
53
made of a printed wiring board; and a large number of key tops
54
supported on the switch board
53
. Each of the key tops
54
, implemented by a molding made of synthetic resin, has a support
55
attached on the switch board
53
; and a body
57
supported by the support
55
through a hinge
56
. The support
55
has a top surface adhered to the back surface of the operation panel
52
with a double-sided adhesive tape
58
. A pair of contacts
59
are formed on the surface of the switch board
53
and the lower surface of the body
57
, respectively, such that they oppose each other.
As a player presses the body
57
of a key top
54
constructed as described above, the pair of contacts
59
are brought into contact to turn ON the key top
54
. Responsively, the switch board
53
outputs an ON signal to a controller (not shown) to control the tone of the electronic piano. The top surface of the support
55
of the key top
54
adhered to the back surface of the operation panel
52
with the double-sided adhesive tape
58
prevents bouncing caused by relative vibrations between the operation panel
52
and key top
54
produced by acoustic vibrations generated from the speaker to limit noise.
FIG. 2
illustrates another example of a conventional key top switch for an electronic piano. The key top switch
60
is disposed in an operation panel
61
, for example, as a tone selection switch, as is the case with the key top switch
51
. The operation panel
61
, made of an extrudate, comprises a large number of key top holes
62
extending therethrough in the vertical direction; and ribs
63
, each of which protrudes at a predetermined position on the back side of the operation panel
61
and extending in the horizontal direction. The key top switch
60
comprises a switch board
64
in a similar structure to the switch board
53
; and a large number of key tops
65
supported on the switch board
64
and slightly protruding from the key top holes
62
of the operation panel
61
associated therewith. Each of the key tops
65
, which is a molding made of synthetic resin or the like, comprises a support
66
fitted on the rib
63
and attached to the switch board
64
; and a body
67
supported by the support
66
. The key top
65
is attached to the operation panel
61
with the support
66
fitted on the rib
63
of the operation panel
61
, to position the key top
65
relative to the operation panel
61
at a predetermined position in the longitudinal direction. The key top
65
is positioned in the horizontal direction by adhering the top surface of the support
66
to the back surface of the operation panel
61
with a double-sided adhesive tape
58
, while determining a position at which the key top
65
is attached through a visual check or the like, such that the center of the body
67
is aligned with the center of the key top hole
62
.
Though not shown, the key top
65
is provided with a pair of positioning collapse sections protruding in the longitudinal direction at predetermined positions of the rib
63
in the horizontal direction for positioning of the key top
65
in the horizontal direction. The support
66
of the key top
65
is inserted between the positioning collapse sections to carry out the positioning. The positioning collapse sections are formed by pressing the rib
63
using a dedicated pressing die previously provided therefor.
However, in the conventional key top switch
51
illustrated in
FIG. 1
, the support
55
of the key top
54
must be adhered to the operation panel
52
using the double-sided adhesive tape
58
for preventing the key top
54
from bouncing. Since such a complicated operation must be performed for each of a large number of key tops
54
, the key top switch
51
suffers from an increased manufacturing cost.
The conventional key top switch
60
illustrated in
FIG. 2
, in turn, implies the following problems. When the key top
65
is positioned relative to the operation panel
61
in the horizontal direction using the double-sided adhesive tape
58
, each of a large number of key tops
65
must be adhered while determining a position at which the key top
65
is attached. This adhering operation is very complicated, causing an increase in the manufacturing cost of the key top switch
60
. Also, since the human's vision is relied on to determine the position at which the key top
65
is attached, the position cannot be accurately determined in some cases. Even if the position is accurately determined, it is difficult to precisely adhere the key top
65
at that position, thereby failing to provide a high accuracy for the attachment and a uniform quality.
On the other hand, when the key top
65
is positioned in the horizontal direction using the positioning collapse sections formed on the rib
63
of the operation panel
61
, it is technically difficult to form the positioning collapse sections with a high accuracy through pressing. In addition, the aforementioned pressing die is required for forming the positioning collapse sections. However, the fabrication of such an expensive pressing die only for purposes of positioning causes a large costly burden and a resulting increase in the manufacturing cost of the key top switch.
SUMMARY OF THE INVENTION
The present invention has been made to solve the problems as mentioned above, and it is an object of the invention to provide a key top switch for an electronic musical instrument which is capable of preventing noise due to bouncing between an operation panel and a key top, and permitting accurate and easy positioning of the key top at a predetermined position in the longitudinal direction and horizontal direction of the operation panel, and can be manufactured at a low cost.
To achieve the above object, according to a first aspect of the present invention, there is provided a key top switch for an electronic musical instrument disposed in an operation panel thereof, which is characterized by comprising a switch board attached on a back side of the operation panel; and a key top sandwiched between the operation panel and the switch board, and including a contact member in contact with the switch board, and a resilient arm for urging the contact member toward the switch board.
In this key top switch for an electronic musical instrument, the key top is sandwiched between the operation panel and the back side of the switch board, and the contact member of the key top is in contact with the switch board, and urged by the resilient arm of the key top toward the switch board. Since the key top is pressed against the switch board through the urged contact member at all times, the key top is prevented from vibrating with respect to the operation panel due to acoustic vibrations generated from a speaker. Consequently, it is possible to prevent bouncing between the key top and operation panel and noise caused thereby. Thus, unlike the conventional key top switch, the attachment of the key top to the operation panel can be simplified by omitting the adhesion of the key top with a double-sided adhesive tape for preventing noise, thereby reducing the manufacturing cost of the key top switch.
According to a second aspect of the present invention, there is provided a key top switch for an electronic musical instrument disposed in an operation panel thereof. The operation panel has a rib protruding on a back side thereof and tapered toward its leading end. The key top switch is characterized by comprising a switch
Crowell & Moring LLP
Donels Jeffrey W
Kabushiki Kaisha Kawai Gakki Seisakusho
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