Keyboard device capable of ensuring positioning and fixing of keyboard body relative to case

Information

  • Patent Grant
  • 6179500
  • Patent Number
    6,179,500
  • Date Filed
    Wednesday, September 29, 1999
    25 years ago
  • Date Issued
    Tuesday, January 30, 2001
    23 years ago
Abstract
A keyboard device is disclosed which has a structure capable of ensuring positioning and fixing of a keyboard body relative to a case. The keyboard device has a keyboard body and a case. The case comprises an upper case which covers the upper surface side of the keyboard body and a lower case which covers the lower surface side of the keyboard body. A tongue piece and a cutout portion for engagement with the upper and lower cases are provided centrally of two longitudinally extending inner side and this side of the keyboard body. Positioning and fixing of the keyboard body relative to the case are effected by those two engaging portions. Also at two positions of the inner side of the keyboard body are provided fixing portions for fixing the keyboard body to the case, namely, the upper and lower cases.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to a keyboard device and particularly to a keyboard body positioning and fixing structure in a keyboard device having a keyboard body and a case which accommodates the keyboard body therein.




2. Description of the Related Art




A conventional keyboard generally has a keyboard body with a large number of key tops attached thereto and a case which accommodates and holds the keyboard body therein. The case is of a combined structure comprising an upper case which covers the upper surface side of the keyboard body and a lower case which covers the lower surface side of the keyboard body, the upper case having window portions through which a large number of key tops are exposed. The reason for adopting this structure is that this structure facilitates the keyboard assembling work. The keyboard body has several kinds of key groups different in function, including ordinary types of input keys, ten keys, and function keys. The key groups are partitioned and somewhat spaced from one another by beam portions each disposed between adjacent window portions formed in the upper case.




Recently, in the field of information processors such as personal computers, there has been an increasing demand for the reduction of size, thickness and weight from the standpoint of space saving and portability improvement. With such a demand as background, also in the field of keyboard as an input device of an information processor, a demand has been being raised to the effect that the keyboard itself should be reduced in size, thickness and weight. In this connection, for reducing the size of conventional keyboards having the above structure, there has been proposed a keyboard in which the number of beam portions for partitioning key groups is decreased, the spacing between adjacent key groups is made smaller, and the width of an outer frame portion is reduced. According to this keyboard, the reduction in size of the keyboard can be implemented in comparison with the other conventional keyboards of the foregoing structure because the key group-to-key group spacing is narrowed and the external frame is reduced in width. Further, the reduction in weight of the keyboard can be attained by using a light-weight resin as the material of the case.




However, although the reduction in size and weight of the keyboard can be attained by making some improvement with respect to the structure and material, other inconveniences have occurred.




For example, at the time of installing the keyboard body into the case, it is necessary to effect positioning of the keyboard body accurately with respect to the case. But, since there is no beam portion crossing above the keyboard body, the positioning of the keyboard body relative to the case is inevitably performed along an edge portion of the keyboard body. In this type of a conventional keyboard, such a positioning is conducted at an end portion of an edge extending in the longitudinal direction of the keyboard body. In such a positioning method, it has been difficult to attain a satisfactory positioning accuracy particularly at the opposite-side end portion. Usually, therefore, a slight clearance is formed between window edges in the upper case and the key tops located on the outermost periphery so as to prevent mutual contact. However, there has been the problem that the clearance is not uniform throughout the whole of the keyboard. Such a problem may be avoided by providing positioning portions at both ends, but in this case an extra space is required for such positioning portions.




The keyboard body is fixed to the lower case with screws or the like from the back side of the lower case so as not to be visible in the normal state of use. No matter how simplified the structure of the case may be for the reduction in size and weight of the keyboard, the case and the keyboard body must not become easily disengaged from each other at their fixed portions when a slight shock is exerted on the keyboard. It is necessary that the keyboard body be held and fixed positively at a predetermined position in the case.




SUMMARY OF THE INVENTION




The present invention has been accomplished for solving the above-mentioned problems and it is an object of the invention to provide a keyboard device having a structure which permits a keyboard body to be positioned and fixed reliably relative to a case.




For achieving the above-mentioned object, the keyboard device of the present invention has a generally rectangular keyboard body with a plurality of key tops attached to the upper surface thereof and a case which accommodates the keyboard body therein, the case comprising an upper case which covers the upper surface side of the keyboard body and a lower case which covers the lower surface side of the keyboard body, the upper case having window portions through which the key tops are exposed, in which keyboard device a first body-side engaging portion is provided centrally of a longitudinally extending side of the keyboard body, a first upper case-side engaging portion for engagement with the first body-side engaging portion is provided centrally in the longitudinal direction of the upper case, and a first lower case-side engaging portion for engagement with the engaged portion of the first body-side engaging portion and the first upper case-side engaging portion is provided centrally in the longitudinal direction of the lower case.




In the conventional keyboard device the positioning of the keyboard body is performed at a longitudinal end of the keyboard body and therefore there occurs a large positional deviation at the opposite-side end portion, whereas in the keyboard device of the present invention the positioning is effected at an engaging portion positioned centrally in the longitudinal direction of the keyboard body, that is, the distance from the positioning portion up to an end portion of the keyboard body is short, so that sufficiently high positioning accuracy is obtained even at the end portion and the clearance between the window edges of the upper case and the key tops positioned at the outermost periphery can be made uniform throughout the whole of the keyboard. Further, since all of the three members, namely keyboard body, upper case and lower case, are engaged with one another centrally in the longitudinal direction of the keyboard body, the positioning accuracy among the three members is improved to a greater extent.




According to one example of a more concrete mode, the first body-side engaging portion, the first upper case-side engaging portion and the first lower case-side engaging portion are formed by projections projecting from the keyboard body, upper case and lower case, respectively, the projection as the first body-side engaging portion being held grippingly between the projections as the first upper and lower case-side engaging portions.




According to this construction, when the above first engaging portions are regarded as both positioning means and fixing means, the keyboard body is fixed firmly between the upper and lower cases because the projection as the first body-side engaging portion is held grippingly between the projections as the upper and lower case-side engaging portions




In the above keyboard device of the present invention, preferably, a second body-side engaging portion is provided centrally of the side opposite to the side where the first body-side engaging portion of the keyboard body is provided, and a second case-side engaging portion for engagement with the second body-side engaging portion is provided centrally in the longitudinal direction of at least one of the upper and lower cases. In this case, engaging portions for engagement with the case are respectively provided centrally of the two opposed sides extending in the longitudinal direction of the keyboard body, and thus the positioning of the keyboard body relative to the case is effected by those two engaging portions.




Thus, by positioning the keyboard body and the case relative to each other at the two opposed sides, the keyboard body is prevented from being displaced in a rotational direction thereof and it is possible to improve the positioning accuracy.




Further, in the above keyboard device of the present invention it is preferable that on the side where the first body-side engaging portion of the keyboard body is provided, third body-side engaging portions be provided at two positions spaced from each other with the first body-side engaging portion therebetween and that third upper case-side engaging portions and third lower case-side engaging portions each for engagement with the third body-side engaging portions be provided in the upper and lower cases, respectively.




In this case, not only are engaging portions for engagement with the case provided at two spaced positions on one longitudinal side of the keyboard body, but also an engaging portion (the second engaging portion) for engagement with the case is provided centrally of the side of the keyboard body opposed to the side where the above engaging portions are provided, and thus the keyboard body is fixed at these three engaging portions relative to the case.




According to this construction, the keyboard body, the upper case and the lower case are fixed respectively at the apexes of a triangle constituted by two third engaging portions and one second engaging portion, so even if external forces are exerted on the keyboard in various directions, those three components are held in a firmly fixed state. Thus, it is possible to provide a keyboard device which is strong against a mechanical shock.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a perspective view showing an entire construction of a keyboard device according to an embodiment of the present invention;





FIG. 2

is a perspective view showing an exploded state of an upper case, a keyboard body and a lower case of the keyboard device;





FIG. 3

is a diagram showing a state of engagement using a tongue piece of the keyboard body in the keyboard device, in which

FIG. 3A

is a perspective view showing an exploded state and

FIG. 3B

is a perspective view showing an assembled state;





FIG. 4

is a diagram showing a state of engagement using a third cutout portion of the keyboard body in the keyboard device, in which

FIG. 4A

is a perspective view showing an exploded state and

FIG. 4B

is a perspective view showing an assembled state;





FIG. 5

is an exploded perspective view of components, showing a state of engagement using an annular fixing portion of the keyboard body in the keyboard device;





FIG. 6

is a diagram showing a structure for fixing the upper and lower cases to each other in the keyboard device, in which

FIG. 6A

is a perspective view showing an exploded state and

FIG. 6B

is a perspective view showing an assembled state; and




FIG.


7


A and

FIG. 7B

are a sectional view thereof.











DESCRIPTION OF A PREFERRED EMBODIMENT




An embodiment of the present invention will be described hereunder with reference to

FIGS. 1

to


7


.





FIG. 1

is a diagram showing an entire construction of a keyboard device


1


embodying the present invention. The keyboard device


1


is a transparent keyboard of small size and small thickness in which a case


2


and key tops


3


are formed of a transparent resin. A cable


4


for connection to, say, a computer body (not shown) is drawn out from a rear side of the keyboard device


1


(the inner side and this side as seen from the user side may sometimes be referred to as rear side and front side, respectively), and connectors


5


conforming to the USB standard for common connection to various external devices are attached to side faces on the rear side of the keyboard device


1


.




The keyboard device of this embodiment, as shown in FIG.


2


, is substantially composed of a generally rectangular keyboard body


6


with a large number of key tops


3


attached thereto, a case


2


which accommodates the keyboard body


6


therein, and a control unit


7


which controls the transmission and reception of various signals to and from a computer body for example. The keyboard body


6


, as shown in

FIG. 5

, comprises a housing


8


which supports a large number of key tops


3


, three sheets which constitute a membrane switch


9


and which are two circuit sheets


10


,


11


and one spacer sheet


12


, and a metallic plate


13


which holds and supports the three sheets


10


,


11


and


12


between it and the housing


8


.




The case


2


comprises an upper case


14


which covers the upper surface side of the keyboard body


6


and a lower case


17


which covers the lower surface side of the keyboard body


6


, the upper case


14


having window portions


15


and


16


through which plural key tops


3


are exposed. The window portion


15


of the upper case


14


is for the exposure of ordinary input keys and function keys, while the window portion


16


is for the exposure of ten keys, with a slight clearance being formed between the edges of both window portions


5


and


6


and the key tops


3


located at the outermost periphery. For making this clearance uniform throughout the whole circumference of the window portions


15


and


16


and for preventing wobbling of the keyboard body


6


within the case


2


, the keyboard body


6


and the case


2


are established their positions and fixed at the following three places.




As shown in

FIG. 2

, nearly centrally of the inner side of the metallic plate


13


as a constituent of the keyboard body


6


, out of the two longitudinally extending sides of the keyboard body, there is provided a tongue piece


18


(a first body-side engaging portion, a projection) which projects horizontally to the inner side, while on the upper case


14


side is provided two downwardly projecting projections


19


(a first upper case-side engaging portion, a projection) of a position corresponding to the tongue piece


18


of the keyboard


6


. On the lower case


17


side is provided an upwardly projecting tongue piece


20


(a first lower case-side engaging portion, a projection) at a position corresponding to the tongue piece


18


of the keyboard body


6


.





FIGS. 3A and 3B

are enlarged diagrams of the portion in question. As shown in

FIG. 3A

, a first cutout portion


21


(a first body-side engaging portion) is formed centrally in the width direction of the tongue piece


18


of the keyboard body


6


. The width of the first cutout portion


21


is equal to the width of the tongue piece


20


of the lower case


17


On both sides of the tongue piece


18


of the keyboard body


18


are formed second cutout portions


22


(first body-side engaging portions) by cutting out the metallic plate


13


inwards. The width of each cutout portion


22


is equal to the width of each projection


19


of the upper case


14


and the spacing between the second cutout portions


22


is equal to the spacing between the projections


19


of the upper case


14


. The numerals


23


and


24


in

FIG. 3A

denote a printed circuit board and a shielding plate, respectively, in the control unit


7


disposed between the lower case


17


and the keyboard body


6


.




The shapes of various components located in this portion are as described above. In an assembled state of the keyboard device


1


, as shown in

FIG. 3B

, the first cutout portion


21


of the tongue piece


18


in the keyboard body


6


and the tongue piece


20


of the lower case


17


are engaged with each other and the two second cutout portions


22


in the keyboard body


6


and the two projections


19


of the upper case


14


are respectively engaged with each other. Thus, the tongue piece


18


of the keyboard body


6


is held grippingly between the tongue piece


20


of the lower case


17


and the two projections


19


of the upper case


14


.




As shown in

FIG. 2

, a third cutout portion


25


(a second body-side engaging portion) is formed nearly centrally of this side of the housing


8


as a constituent of the keyboard body


6


, out of the two longitudinally extending sides of the keyboard body, while in the lower case


17


is formed a projection


26


(a second case-side engaging portion) at a position corresponding to the third cutout portion


25


of the keyboard body


6


, the projection


26


being H-shaped in plan and projecting upward. The width of the third cutout portion


25


is equal to the width of the projection


26


of the lower case


17


.

FIGS. 4A and 4B

are enlarged diagrams of this portion. In an assembled state of the keyboard device


1


, as shown in

FIG. 4B

, the third cutout portion


25


of the keyboard body


6


and the inner U-shaped portion of the projection


26


of the lower case


17


are engaged with each other.




Thus, in the keyboard device


1


of this embodiment, there is made positioning at two central portions of the two longitudinally extending sides of the keyboard body


6


.




As shown in

FIG. 2

, on the inner side extending in the longitudinal direction of the metallic plate


13


of the keyboard body


6


are formed two annular fixing portions


27


(third body-side engaging portions) at two right and left positions with the central tongue piece


18


therebetween so as to project horizontally toward the inner side, the annular fixing portions


27


each having a central hole. At positions of the lower case


17


corresponding to the fixing portions


27


of the keyboard body


6


are provided screw bosses


28


(third lower case-side engaging portions) for fixing the keyboard body


6


and the upper case


14


. Further, at positions of the upper case


14


corresponding to the fixing portions


27


of the keyboard body


6


are provided cylindrical screw bosses


29


(third upper case-side engaging portions) (only one is shown in

FIG. 2

for the convenience of illustration), the screw bosses


29


being each internally formed with a tapped hole (not shown). The inside diameter of the hole formed in each fixing portion


27


of the keyboard body


6


is larger than the outside diameter of each screw boss


29


of the upper case


14


so that the screw boss


29


can be inserted into the hole of the fixing portion


27


.




In the keyboard device


1


of this embodiment, the portion in question is used not only for fixing the case


2


and the keyboard body


6


to each other but also for fixing the USB connectors


5


. As shown in

FIG. 5

, therefore, each screw boss


29


of the upper case


14


can also be inserted into a hole formed in a connecting portion


30


of each USB connector


5


. In an assembled state of the keyboard device


1


, the screw bosses


29


of the upper case


14


are inserted successively from above into the holes of the fixing portions


27


in the keyboard body


6


and the holes of the connecting portions


30


of the USB connectors


5


, and when the screw bosses


29


of the upper case


14


and the screw bosses


28


of the lower case


17


come into abutment so as to be aligned with each other, screws


31


are threadedly engaged with the lower case


17


from below, whereby the upper case


14


, keyboard body


6


and lower case


17


are fixed together.




Thus, in the keyboard device


1


of this embodiment, the upper case


14


, keyboard body


6


and lower case


17


are fixed at two positions on the inner side of the keyboard body, the lower case


17


and the keyboard body


6


are fixed together by one engaging portion (the portion of engagement of the third cutout portion


25


with the projection


26


of the lower case


17


) provided centrally of this side of the keyboard body


6


, and the case


2


and the keyboard body


6


are fixed together at three positions corresponding to the apexes of a triangle formed by those engaging portions.




The case


2


comprising the upper case


14


and the lower case


17


is fixed with screws at the fixing portions


27


of the keyboard body


6


and is also fixed at the front side of the case


2


. As shown in

FIG. 2

, upwardly projecting hook portions


32


are formed at plural positions (six positions in this embodiment) of the front edge of the lower case


17


, while on the front edge side of the upper case


14


are formed downwardly projecting hook receiving portions


33


(only one is shown in

FIG. 2

for the convenience of illustration) at positions corresponding to the positions of the hook portions


32


.





FIGS. 6A and 6B

are enlarged diagrams showing each hook portion


32


of the lower case


17


and each hook receiving portion


33


of the upper case


14


. As shown in

FIG. 6A

, a pawl


34


for engagement with the hook receiving portion


33


is formed at an upper position of the hook portion


32


, while in the hook receiving portion


33


is formed a rectangular hole


35


for insertion therein of the pawl


34


of the hook portion


32


. In an assembled state of the keyboard device


1


, as shown in

FIG. 6B

, the pawl


34


of the hook portion


32


is inserted into the hole


35


of the hook receiving portion


33


, and by engagement of the pawl


34


of the hook portion


32


with a horizontal bar


36


of the hook receiving portion


33


, the upper case


14


and the lower case


17


are fixed together firmly.

FIGS. 7A and 7B

are sectional views showing positional relations between the pawl


34


of the hook portion


32


and the horizontal bar


36


of the hook receiving portion


33


before and after fixing the upper and lower cases


14


,


17


by fitting.




In the conventional keyboard device the positioning of the keyboard body is performed at a longitudinal end portion, while in the keyboard device


1


of this embodiment the positioning of the keyboard body


6


is conducted by the tongue piece


18


and the third cutout portion


25


both positioned centrally in the longitudinal direction of the keyboard body


6


. In the conventional keyboard device, therefore, positional deviation at the end portion opposite to the positioning side becomes large, while in the keyboard device


1


of this embodiment sufficiently high positioning accuracy can be attained even at an end portion because the distance from the positioning portion up to an end portion of the keyboard


6


becomes short. In addition, by positioning the keyboard body relative to the case


2


at two longitudinal opposed sides, it is also possible to prevent displacement of the keyboard body


6


in its rotational direction, whereby the positioning accuracy can be improved. As a result, the clearance between the edges of the window portions


15


and


16


of the upper case


14


and the key tops


3


located at the outermost periphery can be rendered uniform throughout the whole of the keyboard.




Particularly, the three components, namely keyboard body


6


, upper case


14


and lower case


17


, are all engaged together at the position of the tongue piece


18


of the keyboard body


6


, so there accrues an advantage that the positioning accuracy among those three components is further improved. Further, since the tongue piece


18


of the keyboard body


6


is held grippingly between the tongue piece


20


of the lower case


17


and the two projections


19


of the upper case


14


, the keyboard body


6


can be fixed firmly between the upper case


14


and the lower case


17


.




The above two engaging portions serve not only as positioning means but also as fixing means for fixing the keyboard body


6


relative to the upper and lower cases


14


,


17


. In the keyboard device


1


of this embodiment, the annular fixing portions


27


are provided at two inner side positions of the keyboard body


6


and the screw bosses


29


of the upper case


14


are inserted into the holes of the fixing portions


27


and are brought into threaded engagement with the screw bosses


28


of the lower case


17


, to thereby fix the keyboard body


6


and the upper and lower cases


14


,


17


relative to each other. According to this construction, since the keyboard body


6


and the upper and lower cases


14


,


17


are firmly fixed together at their outer peripheral portions, even if external forces are applied in various directions to the keyboard, those three components will be held in the firmly fixed state and thus it is possible to obtain a keyboard device which is strong against mechanical shocks.




The technical scope of the present invention is not limited to the above embodiment, but various modifications and changes may be made within the scope not departing from the gist of the present invention. For example, as to the various engaging portions used for positioning and fixing the keyboard body relative to the upper and lower cases in the above embodiment, their shapes, positions and numbers are not limited to those referred to in the above embodiment. A change of design may be made as necessary.




According to the keyboard device of the present invention, as set forth hereinabove, the positioning of the keyboard body is effected at longitudinally central engaging portions of the keyboard body and the distance from the positioning portion up to an end portion of the keyboard body becomes short, so that sufficiently high positioning accuracy can be attained even at the end portion and the clearance between the window edges of the upper case and the outermost peripheral key tops can be made uniform throughout the whole of the keyboard. In addition, since all the three components, namely keyboard body, upper case and lower case, are engaged together centrally in the longitudinal direction of the keyboard body, the positioning accuracy among the three components is further improved. Moreover, by positioning the keyboard body relative to the case at two opposed sides of the keyboard body, displacement of the keyboard body in its rotational direction is prevented and hence it is possible to improve the positioning accuracy. Further, since the keyboard body is fixed firmly between the upper and lower cases by virtue of the first to third engaging portions, even if external forces are applied in various directions to the keyboard, the firmly fixed state of those three components is maintained and it is possible to obtain a keyboard device which is strong against mechanical shocks despite of small size and small thickness.



Claims
  • 1. A keyboard device comprising:a generally rectangular keyboard body comprising an upper surface side, a lower surface, a longitudinally extending side and a plurality of key tops attached to the upper surface thereof; a case accommodating said keyboard body therein, said case comprising an upper case covering the upper surface side of said keyboard body and a lower case covering the lower surface side of said keyboard body, said upper case having window portions through which said plural key tops are exposed; a first body-side engaging portion provided centrally of the longitudinally extending side of said keyboard body, said first body-side engaging portion comprising a projection from the keyboard body; a first upper case-side engaging portion to engage said first body-side engaging portion, said first upper case-side engaging portion disposed centrally in a longitudinal direction of said upper case and comprising a projection from the upper case; a first lower case-side engaging portion to engage an engaged portion of said first body-side engaging portion, said first upper case-side engaging portion provided centrally in a longitudinal direction of said lower case and comprising a projection from the lower case, wherein the projection from the keyboard body is held grippingly between the projection from the upper case and the projection from the lower case.
  • 2. The keyboard device according to claim 1, further comprising:a second body-side engaging portion provided centrally of a side opposed to the longitudinally extending side of said keyboard body; and a second case-side engaging portion to engage said second body-side engaging portion provided centrally in the longitudinal direction of at least one of said upper case and said lower case.
  • 3. The keyboard device according to claim 1, further comprising third body-side engaging portions provided at two spaced positions with said first body-side engaging portion of said keyboard body therebetween, said upper case and said lower case being respectively provided with a third upper case-side engaging portion and a third lower case-side engaging portion each to engage said third body-side engaging portion.
  • 4. The keyboard device according to claim 2, further comprising third body-side engaging portions provided at two spaced positions with said first body-side engaging portion of said keyboard body therebetween, said upper case and said lower case being respectively provided with a third upper case-side engaging portion and a third lower case-side engaging portion each to engage said third body-side engaging portion.
  • 5. The keyboard device according to claim 2, the second body-side engaging portion being a second projection from keyboard body and the second case-side engaging portion being a second projection from one of said upper case and said lower case.
  • 6. The keyboard device according to claim 3, the second and third body-side engaging portions being projections from keyboard body and the second and third case-side engaging portions being projection from said upper case and said lower case.
  • 7. The keyboard device according to claim 4, the second and third body-side engaging portions being projections from keyboard body and the second and third case-side engaging portions being projection from said upper case and said lower case.
Priority Claims (1)
Number Date Country Kind
10-294557 Sep 1998 JP
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Number Name Date Kind
4549825 Fish Oct 1985
5253142 Weng Oct 1993
5421659 Liang Jun 1995
5535091 Lee Jul 1996
5694123 Selker et al. Dec 1997
5810491 Muller et al. Sep 1998
5938352 Chen Sep 1998