United States Patent [«j
`Tanaka
`
`[54] WATER-PROOF CASE FOR DIGITAL
`ELECTRONIC TIMEPIECES
`Inventor: Eiichiro Tanaka, Tokorozawa, Japan
`[75]
`[73] Assignee: Citizen Watch Co., Ltd., Tokyo,
`Japan
`[21] Appl. No.: 92,932
`[22] Filed:
`Nov. 9, 1979
`Foreign Application Priority Data
`[30]
`Nov. 22, 1978 [JP] Japan .................................. 53-144784
`Int. Cl.3............... G04C 19/00; G04C 23/02;
`[51]
`G04B 37/00
`U.S. Q................................... 368/82; 368/88;
`368/300
`Field of Search.......... 58/23 R, 50 R, 88 R,
`58/127 R; 368/82-84, 88, 239-242, 276, 281,
`286, 289, 291-292, 297-300, 309
`References Cited
`U.S. PATENT DOCUMENTS
`3,355,875 12/1967 Jeanmonod et al................... 58/50 R
`
`[56]
`
`[52]
`
`[58]
`
`[ii] 4,281,406
`[45] Jul. 28, 1981
`
`6/1972 Berget...................................... 58/50 R
`3,672,155
`5/1973 Aoki............................. 368/291
`3,729,924
`10/1975 Yamazaki ............................... 58/50 R
`3,910,029
`10/1975 Keida....................................... 368/281
`3,910,031
`3/1976 Mason...................................... 58/50 R
`3,945,195
`9/1976 Burke et al............................... 58/23 R
`3,978,653
`5/1977 Yoshida et al........................... 58/50 R
`4,020,627
`5/1978 Yonekawa et al....................... 58/50 R
`4,086,954
`Primary Examiner—Vit W. Miska
`Attorney, Agent, or Firm—Sherman & Shalloway
`ABSTRACT
`[57]
`The invention relates to a thin water-proof timepiece
`case designed for digital electronic timepieces which
`employ panel-type display device such as liquid crystal
`display device. A glass cover, a panel cover which
`conceals the periphery of the display panel, and a cou­
`pling member for anchoring the screw on the back
`surface of the panel cover, are formed as a unitary struc­
`ture. The glass cover and the case are water-tightly
`coupled together by the coupling member and a screw
`member which penetrates through the case.
`
`9 Claims, 8 Drawing Figures
`
`Page 1 of 7
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`Tianma Exhibit 1009
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`U.S. Patent Jul. 28, 1981 ' Sheet 1 of 2
`U.S. Patent
`sul. 28, 1981 °
`Sheet 1 of 2
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`4,281,406
`4,281,406
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`U.S. Patent Jui. 28, i98i
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`Sheet 2 of 2
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`4,281,406
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`Page 3 of 7
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`1
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`4,281
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`WATER-PROOF CASE FOR DIGITAL
`ELECTRONIC TIMEPIECES
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`10
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`15
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`25
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`BACKGROUND OF THE INVENTION 5
`This invention relates to a water-proof case for digital
`electronic timepieces.
`Timepiece cases have so far been composed of a case
`body, a back cover, a glass cover and a bezel ring. Such
`general timepiece cases have been designed mainly for
`analog timepieces which display the time by means of
`indicating hands. In the analog timepieces, the whole
`areas covered with the glass cover serve as a display
`portion, and the glass cover must be secured at the edge
`portion thereof using a bezel.
`The conventional timepiece cases employing bezel do
`not necessarily adapt well to the timepieces which digi­
`tally display the time using a panel-type display device
`such as liquid crystal display device.
`On the periphery of the panel-type display device are
`located a member for electrical connection and a mem­
`ber for fastening the panel, which do not directly partic­
`ipate in the function of display. To conceal such mem­
`bers, therefore, a panel cover must be employed. Conse­
`quently, with digital timepieces using such a display
`device, the entire area covered by the glass cover does
`not serve as a display portion, visibility is restricted by
`the panel cover and only the central area serves as a
`display portion.
`Further, a panel-type display device, especially the
`liquid crystal display device, consists of many plate-like
`members. Hence, the light is reflected at the interfaces
`of the plate-like members, making it difficult to recog­
`nize the display.
`Thus, since the analog timepieces are different in
`nature from digital timepieces, it is urged to provide a
`thin water-proof case adapted to the digital timepieces.
`This invention is attained based upon the above-men­
`tioned background.
`SUMMARY OF THE INVENTION
`Accordingly, the object of this invention is to pro­
`vide a thin water-proof case of a simple construction
`which is adapted to digital timepieces.
`Another object of this invention is to provide a wa­
`ter-proof case for digital timepieces which permits the
`display panel to be easily replaced.
`A further object of this invention is to provide a
`digital timepiece having a legible display portion with
`less interfacial reflection.
`The invention relates to a timepiece case of a con­
`struction which is altogether different from that of the
`conventional timepiece case, and provides a thin water­
`proof case adapted to digital timepieces employing
`panel-type display device. According to the invention, a
`glass cover and a panel cover for concealing the periph­
`ery of the display panel, and a coupling member for
`anchoring the screw on the back surface of the panel
`cover are constructed as a unitary structure, wherein
`the glass cover and the case are coupled together in a
`water-tight manner by means of the coupling member
`and the screw which penetrates through the case.
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a front view illustrating a timepiece case
`according to an embodiment of this invention;
`
`,406
`2
`FIG. 2 is a cross-sectional view along the line 2—2 of
`FIG. 1; and
`FIGS. 3 to 8 are cross-sectional views illustrating
`important portions of the timepiece case of the inven­
`tion according to various other modified embodiments.
`DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`Embodiments of the invention are illustrated below in
`conjunction with the accompanying drawings. FIG. 1 is
`a front view illustrating a timepiece case according to
`this invention, in which the areas covered with a glass
`cover are limited by a panel cover 2, so that only the
`central portions serve as a display portion 22.
`FIG. 2 is a cross-sectional view illustrating the con­
`struction of the invention. First, the whole construction
`is mentioned below. A cover plate 1 is made of a trans­
`parent glass or a plastic material with a panel cover 2
`being disposed on the back surface thereof. The panel
`cover 2 will consist of a metal layer or a resin layer and
`will be directly formed on the back surface of the cover
`plate by metal vaporization or coating. Alternatively,
`the panel cover 2 will be constructed as a separate unit
`and will then be attached to the back surface of the
`cover plate 1. A coupling member 3 is located on the
`back side of the panel cover 2. The coupling member 3
`is made of a metal such as stainless steel or of a plastic
`material, and has screw holes in foot portions thereof.
`The number of the holes is preferably four, but may be
`suitably decreased or increased. The cover plate 1, the
`panel cover 2 and the coupling member 3 are then con­
`structed as a unitary structure by way of adhesion,
`insertion by compression crimping or caulking. A digi­
`tal display panel 5 is affixed to the central portion at the
`back surface of the cover plate 1, the adhering surface
`extending up to the back side of the panel cover 2.
`Needless to say, an adhesive layer 6 used to adhere the
`digital display panel 5 to the cover plate 1 should be
`transparent and should have a reflective index which is
`equal to or nearly equal to that of the cover plate 1 and
`the digital display panel 5, in order to prevent the reflec­
`tion of light on the surface. The digital display panel 5
`mentioned here refers to a liquid crystal display. How­
`ever, other types of displays having nearly the same
`panel shape may be used, such as electrochromic dis­
`play. An electrically conductive elastomeric connector
`7 serves as a connector for supplying electric power to
`the digital display panel 5. The connector 7 is usually
`secured to the side of a movement 11 and is separated on
`a plane for drawing the electrodes of the digital display
`panel 5. The connector 7 maintains the electrically con­
`ductive state owing to the contacting pressure.
`The case 4 usually consists of a case body 41 and a
`back cover 42. According to this invention, however,
`since the cover plate 1 is removeably attached, the
`movement 11 and other components can be mounted
`from that side occupied by the cover plate 1. There is no
`need for separately forming the case body and the back
`cover. In other words, the case can be formed of a
`one-piece construction. This enables the construction to
`be simplified and provides an increased mechanical
`strength even when the thickness of the case 4 is re­
`duced. Details of the construction of the case 4 are
`mentioned below. In the front surface of the case 4 is
`formed a fitting groove which fits to the outer shape of
`the coupling member 3, and a packing 8 is placed on a
`shoulder portion of the fitting groove. A plurality of
`holes for penetrating screws 10 are formed in the bot-
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`15
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`4,281,406
`tom of the case 4. The head portion of the screws 10 is
`recessed into the hole so as not to protrude beyond the
`lower surface of the case 4. A packing 9 is placed on the
`fitting surface of the head portion of the screws 10 and
`is compressed by the back surface of the head of the 5
`screws 10 to attain sealing. The coupling member 3 is
`secured to the case 4 being pulled by the screws 10
`which penetrate through the case 4, whereby the seal­
`ing is attained by the packings 8 and 9 which are com­
`pressed. The movement 11 is secured onto the bottom 10
`surface of the case 4 being pressed by springs 21. In
`addition to the above-mentioned fastening method, the
`movement may be directly secured to the case 4 by
`screws, by means of a fastening ring or by way of con­
`tacting frictional force.
`FIG. 3 is a cross-sectional view illustrating major
`portions of the invention, in which the cover plate 1, the
`panel cover 2 and the coupling member 3 are formed as
`a unitary structure as mentioned earlier. A digital dis­
`play panel adhered to the back surfaces of the cover 20
`plate 1 and of the panel cover 2 is a FETN (field effect
`twisted nematic)-type liquid crystal display panel which
`is composed of an upper polarizer plate 12, an upper
`substrate glass 13, a liquid crystal layer 17, a lower
`substrate glass 14, a lower polarizer plate 15 and a re- 25
`fleeting plate 16. Using present technology, the total
`thickness of the FETN-type liquid crystal display panel
`can be reduced to 0.6 mm or less. Therefore, adhering
`the liquid crystal display panel to the cover plate 1 is
`advantageous from the standpoint of reinforcing the 30
`strength. With the above-mentioned construction, the
`distance in height between the surface of the panel
`cover 2 and the surface of the dial is about 0.3 mm,
`which can virtually be seen as flush by the naked eye,
`enabling a particular display to be presented. The above 35
`feature is possible because of the construction which
`permits the cover plate 1 to be detachably attached.
`With the conventional construction in which the cover
`plate and the case are formed as a unitary structure, the
`liquid crystal display panel cannot be adhered to the 40
`cover plate because such a construction does not permit
`repair or replacement to be effected.
`FIG. 4 illustrates the construction of FIG. 3 but from
`which the digital display panel is removed; the digital
`display panel is secured onto the movement 11 which is 45
`shown in FIG. 2. In the embodiment of FIG. 4, the
`cover plate 1, the panel cover 2 and the coupling mem­
`ber 3 are formed as a unitary structure like the previous­
`ly-mentioned embodiment. However in this embodi­
`ment these three members can be replaced as a unitary 50
`structure to easily modify the appearance. This is ad­
`vantageous from the standpoint of mass production.
`Although the coupling member 3 shown in FIG. 4 has
`screw holes, threaded feet penetrating through the bot­
`tom of the case may be attached to the coupling mem- 55
`ber 3 being fastened with nuts from the lower surface of
`the case.
`The invention is mentioned below with reference to
`FIGS. 5 and 6, which illustrate the methods of coupling
`the cover plate 1 and the coupling member 3 together. 60
`FIG. 5 illustrates the case in which the cover plate 1 and
`the coupling member 3 are coupled together using an
`adhesive 18 which is composed of a resin such as epoxy
`resin or those of the hot-melting type. The panel cover
`2 which is formed by metal vaporization on the back 65
`surface of the cover plate 1 leaves no problem with
`respect to the adhesive strength. In this case, the cou­
`pling member 3 may also be adhered by solder. On the
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`4
`other hand, when the panel cover 2 of a resin layer is
`formed by printing on the back surface of the cover
`plate 1, it is necessary to use an ink which adheres to the
`cover plate 1. When the panel cover 2 is formed as a
`single unit, an adhesive of the type of epoxy resin or of
`the type which undergoes the hardening with the irradi­
`ation of ultraviolet rays should be used. FIG. 6 shows
`the case in which the panel cover and the coupling
`member are formed as a unitary structure 19. In this
`case, the surface of adhesion serves as a portion of inter­
`face between the cover plate 1 and the panel cover,
`enabling the working efficiency and the reliability of
`adhesion to be enhanced.
`FIG. 7 shows the position of the packing 8 used for
`attaining the sealing between the case 4 and the cou­
`pling member 3. In this case, the deforming force of the
`packing 8 is exerted in the radial direction of the case 4,
`which does not work to push the cover plate 1 open.
`From the viewpoint of design, therefore, the construc­
`tion of FIG. 7 may be more desirable than that of FIG.
`2. Further, it is also allowable to form a groove (not
`shown) for accepting the packing 8 on the side of the
`coupling member 3. FIG. 8 shows an arrangement in
`which a stop ring 20 is fitted to the screw 10 so that it
`will not be removed and lost. From the standpoint of
`machinability of the groove, the packing 9 has a shape
`different from that of the embodiment of FIG. 2.
`While the contents of the invention are as mentioned
`above, the greatest feature of the invention resides in
`that the cover plate which can be easily attached and
`detached by a screw driver. Owing to this feature, the
`timepiece case of this invention can be of a fashionable
`nature. In effect, the digital display panel, the panel
`cover and the cover plate can be treated as a unitary
`structure making it possible to change the color tone
`and to select the display functions or, in other words,
`making it possible to replace the panel with the one
`which displays the hour and minute in large characters,
`or to replace the panel with the one which displays the
`hour, minute, second, date and day. It will further be
`easily recognized that the above-mentioned unitary
`structure can be replaced even by unskilled people
`without permitting fingerprints to be left on the display
`surface. Further, since the aforementioned three mem­
`bers are replaced as a unitary structure, there develops
`no design unbalance between the display panel and the
`panel cover.
`The advent of this invention having the above-men­
`tioned various features is based upon such a background
`that the digital wrist watches necessarily require a panel
`cover at the back of the cover plate due to their struc­
`ture. Namely, this invention stems from the fact that the
`appearance is not at all affected even if the back surface
`of the panel cover is used as a coupling element. The
`above construction could not be realized with the con­
`ventional analog timepieces. It is therefore proper to
`say that the case construction for digital wrist watches
`of this invention is the one which utilizes those charac­
`teristics inherent in digital watches.
`What is claimed is:
`1. A water-proof case for use in digital display time­
`pieces comprising:
`(a) a cover plate;
`(b) a panel cover coupled with the back surface of the
`cover plate;
`(c) a display panel arranged on the back side of the
`panel cover and the periphery of said display panel
`being concealed by said panel cover;
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`4.281.406
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`4. A water-proof case for digital timepieces as set
`(d) a coupling member attached to the back surface of
`forth in claim 1, wherein said panel cover is made of a
`said panel cover as a unitary structure and having
`thin metallic plate and is adhered onto the back surface
`at least one hole therein, the hole being adapted to
`of said panel cover.
`grip a fastener;
`5. A water-proof case for digital timepieces as set
`(e) a case body and a back cover being of a one-piece 5
`forth in claim 1, wherein a portion defining a display
`construction formed as a unitary structure;
`portion of said panel cover is a peripheral edge which is
`(f) an aperture in said back cover corresponding to
`tilted toward the inner side, and said panel cover is
`each of said holes in the coupling member, each
`adhered onto the back surface of said panel cover.
`aperture being coaxially positioned with each hole;
`6. A water-proof case for digital timepieces as set
`(g) each aperture being provided with a fastener, the 10
`forth in claim 1, wherein an upper portion of said cou­
`fastener penetrating the back cover through one of
`pling member serves as a panel cover.
`said apertures and being gripped by the corre­
`7. A water-proof case for digital timepieces as set
`sponding hole in the coupling member.
`forth in claim 1, further comprising a packing accom­
`2. A water-proof case for digital timepieces as set
`modated in a groove which is formed in the inner side of
`forth in claim 1, wherein said panel display device is a 15
`said case.
`liquid crystal display device of the FETN type (field
`8. A water-proof case for use in digital timepieces
`effect twisted nematic type), and is adhered onto the
`wherein said fasteners are screws.
`lower surface of said glass cover.
`9. A water-proof case for digital timepieces as set
`3. A water-proof case for digital timepieces as set
`forth in claim 8, further comprising a stop ring fitted to
`forth in claim 1, wherein said panel cover consists of an 20
`said coupling screws.
`opaque film which is printed or vaporized onto the back
`*****
`surface of said glass cover.
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`UNITED STATES PATENT AND TRADEMARK OFFICE
`CERTIFICATE OF CORRECTION
`PATENT NO. : 4,281,406
`July 28, 1981
`DATED
`INVENTOR(S) ·. Tanaka, Eiichiro
`It is certified that error appears in the above—identified patent and that said Letters Patent
`is hereby corrected as shown below:
`
`Claim 8 should read as follows:
`
`8. A water-proof case for use in digital timepieces
`as set forth in claim 1 wherein said fasteners are
`Signed and Sealed this
`Twenty-second Day of September / 981
`
`|SEAL|
`
`Attest:
`
`Attesting Officer
`
`Commissioner of Patents and Trademarks
`
`GERALD J MOSSINGHOFF
`
`Page 7 of 7
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