Portable information device and cover device

A portable information device includes a chassis, and a cover device that covers the back surface of the chassis. The cover device has a base cover section, a stand cover section rotatable relative to the base cover section and movable between a stored position of being provided along the back surface of the chassis and a standing position of protruding from the back surface of the chassis, and a hinge device. A first bracket has a first notch-shaped portion in a root part of the side end face thereof on the side of a hinge shaft to face the side of the second bracket in the axial direction. A second bracket has a second notch-shaped portion in a root part of the side end face thereof on the side of the hinge shaft to face the side of the first bracket in the axial direction.

FIELD OF THE INVENTION

The present invention relates to a portable information device having a cover device and the cover device.

BACKGROUND OF THE INVENTION

A portable information device such as a laptop PC or a tablet PC is required to avoid damage or breakdown when being carried around. Further, it is desired that the appearance design and the sense of touch of the portable information device should be of high quality. Therefore, a cover device may be mounted on the outer surface of the chassis of the portable information device for the purpose of protection or decoration. The applicant proposes a cover device for a foldable tablet PC in Japanese Unexamined Patent Application Publication No. 2018-105961.

SUMMARY OF THE INVENTION

As described in Japanese Unexamined Patent Application Publication No. 2018-105961, the cover device is required not only to simply cover the outer surface of the chassis, but also to be rotated as necessary so as to function as a stand for the device. The cover device of this type has a base cover section relatively fixed to the outer surface of the chassis, and a stand cover section to be rotated relative to this base cover section by using a hinge device.

In the meantime, in the cover device, a soft material such as natural leather, artificial leather, or the like may be used as the outermost surface material in consideration of the appearance design and the sense of touch of the cover device. In the cover device using this type of material, when the stand cover section is rotated relative to the base cover section at more than a certain angle, for example, up to an angle close to 180 degrees, side end faces of right and left brackets of the hinge device function as scissors blades. As a result, it is found that the surface materials of the base cover section and the stand cover section can be broken down or damaged due to the cutting power of the scissors blades.

The present invention has been made in view of the above conventional technique problem, and it is an object thereof to provide a portable information device having a cover device capable of suppressing the occurrence of breakage and damage, and the cover device.

A portable information device according to the first aspect of the present invention includes: a chassis; and a cover device provided to cover the back surface of the chassis, the cover device including: a base cover section provided along the back surface of the chassis; a stand cover section provided to be rotatable relative to the base cover section so as to be movable between a stored position where the stand cover section is provided along the back surface of the chassis and a standing position where the stand cover section protrudes from the back surface of the chassis; and a hinge device having a hinge shaft, a first bracket rotatably coupled to the hinge shaft and fixed relative to the back surface of the chassis, and a second bracket provided adjacent to the first bracket in an axial direction of the hinge shaft, coupled rotatably to the hinge shaft, and fixed to the stand cover section, wherein the first bracket has a first notch-shaped portion in a root part of a side end face thereof on the side of the hinge shaft to face the side of the second bracket in the axial direction, and the second bracket has a second notch-shaped portion in a root part of a side end face thereof on the side of the hinge shaft to face the side of the first bracket in the axial direction.

The portable information device may also be such that the base cover section has a first core material, and a first surface material formed of a material softer than the first core material to form the surface of the base cover section, the stand cover section has a second core material, and a second surface material formed of a material softer than the second core material to form the surface of the stand cover section, the first core material has a first bracket placement hole in which the first bracket is placed, and a first protruding portion protruding from an inner peripheral surface of the first bracket placement hole into the first notch-shaped portion, and the second core material has a second bracket placement hole in which the second bracket is placed, and a second protruding portion protruding from an inner peripheral surface of the second bracket placement hole into the second notch-shaped portion.

The hinge device may also be so structured that at least the shaft center of the hinge shaft is located in a position lower than the surfaces of the base cover section and the stand cover section.

The portable information device may further be such that the chassis includes: a first chassis; and a second chassis coupled adjacent to the first chassis to be rotatable relative to the first chassis, the base cover section includes: a slide cover section provided to be movable relative to the back surface of the first chassis along a line-up direction of the first chassis and the second chassis; a fixed cover section relatively fixed to the back surface of the second chassis; and a folding cover section which connects between the slide cover section and the fixed cover section to be movable relative to each other, and the stand cover section is placed to be movable relative to the back surface of the second chassis and adjacent to the fixed cover section across the hinge device.

The portable information device may further include: a display provided on at least the surface of the first chassis; and a camera provided in a peripheral portion of the display on the surface of the first chassis.

A cover device according to the second aspect of the present invention is a cover device configured to cover the back surface of a chassis of a portable information device, including: a base cover section; a stand cover section provided to be rotatable relative to the base cover section; and a hinge device having a hinge shaft, a first bracket rotatably coupled to the hinge shaft and fixed relative to the base cover section, and a second bracket provided adjacent to the first bracket in an axial direction of the hinge shaft, coupled rotatably to the hinge shaft, and fixed to the stand cover section, wherein the first bracket has a first notch-shaped portion in a root part of a side end face thereof on the side of the hinge shaft to face the side of the second bracket in the axial direction, and the second bracket has a second notch-shaped portion in a root part of a side end face thereof on the side of the hinge shaft to face the side of the first bracket in the axial direction.

The cover device may also be such that the base cover section has a first core material, and a first surface material formed of a material softer than the first core material to form the surface of the base cover section, the stand cover section has a second core material, and a second surface material formed of a material softer than the second core material to form the surface of the stand cover section, the first core material has a first bracket placement hole in which the first bracket is placed, and a first protruding portion protruding from an inner peripheral surface of the first bracket placement hole into the first notch-shaped portion, and the second core material has a second bracket placement hole in which the second bracket is placed, and a second protruding portion protruding from an inner peripheral surface of the second bracket placement hole into the second notch-shaped portion.

The hinge device may also be so structured that at least the shaft center of the hinge shaft is located in a position lower than the surfaces of the base cover section and the stand cover section.

The above-described aspects of the present invention can suppress the occurrence of breakage and damage.

DETAILED DESCRIPTION OF THE INVENTION

A portable information device and a cover device according to the present invention will be described in detail below with reference to the accompanying drawings by taking a preferred embodiment.

FIG. 1is a perspective view illustrating a state where a portable information device10according to one embodiment is closed and shaped into a folded form.FIG. 2Ais a side view schematically illustrating a state where the portable information device10illustrated inFIG. 1is opened and shaped into a flat plate form.FIG. 2Bis a side view in a state where the portable information device10illustrated inFIG. 2Ais shaped into a laptop form.FIG. 2Cis a side view in a state where the portable information device10illustrated inFIG. 2Bis closed and shaped into the folded form.

As illustrated inFIG. 1 to 2C, the portable information device10includes a first chassis12A, a second chassis12B, and a cover device14. The portable information device10of the embodiment is a foldable tablet PC or laptop PC. The cover device14has a protection function to cover the outer surfaces of the chassis12A and12B in order to protect the chassis12A and12B, and a decoration function to decorate the outer surfaces in order to enhance the appearance design. The portable information device on which the cover device14is mounted may also be a common clamshell laptop PC, a single plate-shaped tablet PC, a smartphone, a portable game machine, or the like, as well as the portable information device10.

First, the structure of the portable information device10will be described. The portable information device10includes the chassis12A,12B and a display16.

The chassis12A and12B are placed adjacent to each other. Adjacent edges12Aa and12Ba of the chassis12A and12B are covered internally with a spine member18. Each of the chassis12A and12B is formed into a rectangular, plate-shaped member with side walls standing on three sides except the adjacent edge12Aa,12Ba, respectively. The chassis12A,12B is formed from a metal plate made of stainless steel, magnesium steel, aluminum steel, or the like, or formed from a fiber-reinforced plastic plate containing reinforcing fiber such as carbon fiber.

The portable information device10as illustrated inFIG. 1toFIG. 2Cwill be described below by expressing a line-up direction of the chassis12A,12B as an X direction and a direction orthogonal to the line-up direction along the adjacent edges12Aa,12Ba as a Y direction.

The adjacent edges12Aa and12Ba of the chassis12A and12B are coupled to each other through a pair of hinges19,19. The chassis12A and12B are coupled by the hinges19to be rotatable relative to each other between the flat plate form illustrated inFIG. 2Aand the folded form illustrated inFIG. 2C. The hinges19can generate a predetermined rotation torque. Therefore, the chassis12A and12B are stabilized even in the laptop form (seeFIG. 2B) in which the angle between the chassis12A and12B is about 90° to 140°. For example, the hinges19are disposed in both end portions of the adjacent edges12Aa and12Ba of the chassis12A and12B in the Y direction, and located outside of an outer peripheral edge of the display16, respectively. The portable information device10of the embodiment is so set that the rotation center between the chassis12A and12B by the hinges19matches the surface of the display16.

Inside of the respective chassis12A and12B, various electronic components and the like, such as a motherboard, various semiconductor chips like a CPU mounted on the motherboard, a communication module, a battery device, and a cooling device, are mounted. Reference numeral17inFIG. 2AtoFIG. 2Cdenotes an imaging camera to face from an opening formed in a bezel surrounding the display16on the surface of the first chassis12A.

The display16is, for example, a touch panel liquid crystal display. A band-shaped range of the display16extending in the Y direction across the adjacent edges12Aa and12Ba is a folding region. Thus, the display16is foldable together when the chassis12A and12B are folded, and opened and closed along with the opening/closing operation of the chassis12A and12B. The display16is, for example, a flexible display such as organic EL (Electro Luminescence) having a highly flexible paper structure or the like.

The overall structure of the cover device14will next be described.FIG. 3is a plan view of the portable information device10as viewed from the side of the cover device14.

As illustrated inFIG. 1toFIG. 3, the cover device14is provided to cover the back surfaces12Ab and12Bb of the chassis12A and12B. In the flat plate form (seeFIG. 2A), the cover device14covers the entire back surfaces12Ab and12Bb. In the laptop form and the folded form (seeFIG. 2BandFIG. 2C), the cover device14covers most of the back surface12Ab and the entire back surface12Bb.

The cover device14includes a base cover section20, a stand cover section22, and a hinge device24. The cover sections20and22extend in the X direction across the hinge device24. In the flat plate form, the cover sections20and22cover the entire back surfaces12Ab and12Bb as a whole, that is, cover the chassis12A and12B from an open edge12Ac of the first chassis12A to an open edge12Bc of the second chassis12B. The open edges12Ac and12Bc are edges located on the other side of the adjacent edges12Aa and12Ba in the X direction to extend in the Y direction, respectively.

The base cover section20has a slide cover section26, a folding cover section27, and a fixed cover section28in this order from the side of the first chassis12A toward the side of the second chassis12B.

The slide cover section26is a thin plate-shaped member provided to be slidable in the X direction relative to the back surface12Ab of the first chassis12A. In the flat plate form illustrated inFIG. 2AandFIG. 3, a distal edge26aof the slide cover section26matches the open edge12Ac of the first chassis12A. The distal edge26ais located on the other side of a border line B1with the folding cover section27in the X direction, which is an edge extending in the Y direction. In the laptop form and the folded form illustrated inFIG. 2BandFIG. 2C, the slide cover section26is slid to a position where the distal edge26ais retreated from the open edge12Ac to the side of the adjacent edge12Aa, respectively. The slide structure of the slide cover section26with respect to the first chassis12A is not particularly limited. For example, a slide mechanism is so constructed that a slide part fixed to the first chassis12A is coupled to a rail fixed to the slide cover section to be slidable in the X direction.

The folding cover section27is provided in a position between the chassis12A and12B across the adjacent edges12Aa and12Ba, which is a band-shaped region narrow in the X direction and extending in the Y direction. The folding cover section27is connected to the slide cover section26to be foldable on the border line B1along the Y direction on the side of the first chassis12A. Then, the folding cover section27is connected to the fixed cover section28to be foldable on a border line B2along the Y direction on the side of the second chassis12B. The folding cover section27has flexibility as a whole to connect between the first cover section26and the fixed cover section28to be rotatable relative to each other. The folding cover section27is a flexible hinge to rotate the cover device14following the rotational operation between the chassis12A and12B. The folding cover section27is a folding region having a width dimension in the X direction to be able to cover the adjacent edges12Aa and12Ba of the chassis12A and12B at least in the folded form illustrated inFIG. 2C.

The fixed cover section28is a thin plate-shaped member to cover the back surface12Bb of the second chassis12B together with part of the folding cover section27and the stand cover section22. The fixed cover section28is formed into a shape substantially line-symmetric with respect to the stand cover section22, which is a substantially trapezoidal shape in plan view in the embodiment. The fixed cover section28is fixed relative to the back surface12Bb of the second chassis12B. The fixed cover section28of the embodiment is fixed directly to the back surface12Bb. An edge28aof the fixed cover section28on the other side of the border line B2in the X direction is adjacent to the stand cover section22through the hinge device24. The edge28ais inclined in the X direction gradually toward the Y direction.

FIG. 4is a schematic perspective view in a state where the stand cover section22is set to a standing position to make the portable information device10stand up. As illustrated inFIG. 4, the stand cover section22is provided to be rotatable relative to the fixed cover section28of the base cover section20and the back surface12Bb of the second chassis12B. The stand cover section22of the embodiment is coupled to the back surface12Bb of the second chassis12B through the hinge device24.

As illustrated inFIG. 2AtoFIG. 4, the stand cover section22is formed into a shape substantially line-symmetric with respect to the fixed cover section28, which is a substantially trapezoidal shape in plan view in the embodiment. The stand cover section22is so provided that an edge22aadjacent to the edge28aof the fixed cover section28across the hinge device24is coupled to the hinge device24. A distal edge22bof the stand cover section22on the other side of the edge22amatches the open edge12Bc of the second chassis12B.

By rotational operation of the hinge device24, the stand cover section22can move from a stored position (0°) where the distal edge22babuts against the back surface12Bb in a direction away gradually from the back surface12Bb. The distal edge22bcan move up to a position (180°) at which the distal edge22babuts against a surface20aof the base cover section20and further movement is restricted. Thus, the stand cover section22can move between the stored position (seeFIG. 2AandFIG. 3) where the stand cover section22is provided along the back surface12Bb, and the standing position (for example, seeFIG. 4) where the stand cover section22protrudes from the back surface12Bb.

As illustrated inFIG. 4, the stand cover section22is set to a proper angle (standing position) with respect to the fixed cover section28to function as a stand to keep the portable information device10in the flat plate form in a standing posture. In the standing position of the stand cover section22, a bottom edge22cas a trapezoidal bottom abuts on a desk surface or the like so that the portable information device10can be kept in a predetermined standing posture fallen a little on the side of the back surfaces12Ab and12Bb.

FIG. 5is a schematic plan view of the hinge device24. The hinge device24couples the stand cover section22to be rotatable relative to the base cover section20and the second chassis12B. As illustrated inFIG. 3andFIG. 5, the hinge device24includes a hinge shaft30, first brackets31A and31B, and second brackets32A,32B. In the hinge device24of the embodiment, a pair of the brackets31A and32A and a pair of the brackets31B and32B adjacent to each other are paired to constitute one hinge, respectively. Each pair of the first brackets and the second brackets may also be one pair, or three pairs or more.

The hinge shaft30is a metal rod-shaped member that intervenes between the edge22aof the stand cover section22and the edge28aof the fixed cover section28to extend along these edges22aand28a.The hinge shaft30is inclined in the XY directions along the edges22aand28a.

The first brackets31A and31B are mounting brackets for the second chassis12B. Each of the first brackets31A and31B has a mounting plate31aand a support cylinder31b,respectively. The first brackets31A and31B may also be fixed to the base cover section20. The first bracket31A,31B has the mounting plate31ato be mounted on the second chassis12B. The mounting plate31ais coupled to the hinge shaft30through the support cylinder31b.

The mounting plate31ais a metal plate formed into a substantially rectangular shape. In the mounting plate31a,three holes31cand one notch-shaped portion31dare provided to correspond to the four corners. Each of the holes31cis a circular hole formed to penetrate through the mounting plate31ain the plate thickness direction. The hole31cis a fastening hole through which the first bracket31A,31B is fastened to the second chassis12B with a screw33(seeFIG. 6A).

The notch-shaped portion31dis provided in a root part of the support cylinder31bof the mounting plate31a.The notch-shaped portion31dof one first bracket31A is formed on a side end face31eto face the side of the second bracket32A paired in the axial direction of the hinge shaft30. The notch-shaped portion31dof the other first bracket31B is formed on a side end face31eto face the side of the second bracket32B paired in the axial direction of the hinge shaft30. The notch-shaped portion31dis so formed that the back thereof has a semicircle shape with the same diameter as the hole31c.Thus, the notch-shaped portion31dis also used as a fastening hole for the screw33like the hole31c.

In the mounting plate31a,a positioning piece31fis also formed on the other side of the side end face31eto protrude along the axial direction of the hinge shaft30. The positioning piece31fis a positioning portion of the hinge device24with respect to the base cover section20(the fixed cover section28).

The support cylinder31bis a mounting portion of the mounting plate31afor the hinge shaft30. The support cylinder31bis externally fitted to the hinge shaft30, and the mounting plate31aprotrudes from the outer circumferential surface of the support cylinder31b.

The second brackets32A and32B are mounting brackets for the stand cover section22. Each of the second brackets32A and32B has a mounting plate32afor the stand cover section22. The mounting plate32ais coupled to the hinge shaft30through a support cylinder32b.

The mounting plate32ais a metal plate formed into a substantially rectangular shape. In the mounting plate32a,four holes32care provided to correspond to the four corners. Each of the holes32cis a circular hole formed to penetrate through the mounting plate32ain the plate thickness direction. The hole32cis a cutout hole for the purpose of weight reduction of the mounting plate32a,which may be omitted.

Notch-shaped portions32dare provided in a root part of a support cylinder32bof the mounting plate32a.InFIG. 5, it is illustrated such a structure that the notch-shaped portions32dare provided in a root part of each of both side end faces of the mounting plates32a,respectively. However, a notch-shaped portion32dof one second bracket32A has only to be formed on at least one side end face32ethat faces the side of the paired first bracket31A. Similarly, a notch-shaped portion32dof the other second bracket32B has only to be formed on at least one side end face32ethat faces the side of the paired first bracket31B. The notch-shaped portion32dhas a shape formed by notching the root part of the mounting plate32ain a substantially trapezoidal shape. The notch-shaped portion32dmay also have a shape similar to the notch-shaped portion31d.Conversely, the notch-shaped portion31dmay also have a shape similar to the notch-shaped portion32d.In this case, four holes31cmay be provided in the mounting plate31a.

The mounting plate32aalso has a positioning piece32fformed on an end face on the other side of the support cylinder32bto protrude in a direction orthogonal to the axial direction of the hinge shaft30. The positioning piece32fis a positioning portion of the hinge device24with respect to the stand cover section2.

The support cylinder32bis a mounting portion of the mounting plate32awith respect to the hinge shaft30. The support cylinder32bis externally fitted to the hinge shaft30in such a manner that the mounting plate32aprotrudes from the outer circumferential surface of the support cylinder32b.

In this hinge device24, the support cylinders31bof the pair of first brackets31A and31B are supported to be rotatable relative to the hinge shaft30with a predetermined rotational torque about the axis of the hinge shaft30. Alternatively, the support cylinders32bof the pair of second brackets32A and32B are supported to be rotatable relative to the hinge shaft30with a predetermined rotational torque about the axis of the hinge shaft30. Thus, the hinge device24couples the stand cover section22, to which the second brackets32A and32B are fixed, to the second chassis12B and the base cover section20, to which the first brackets31A and31B are relatively fixed, in such a manner that the stand cover section22is relatively rotatable with the predetermined rotational torque. As a result, the stand cover section22can keep the portable information device10in the standing position with a desired angle, thus functioning as a kickstand of the portable information device10(seeFIG. 4).

Next, a specific internal structure of the cover device14will be described.FIG. 6Ais a schematic side sectional view of the portable information device10and the cover device14taken along line VI-VI inFIG. 3.FIG. 6Bis a side sectional view in a state where the stand cover section22illustrated inFIG. 6Ais set to the standing position. Note that the line VI-VI inFIG. 3means that right-side line VI on which the first bracket31A is cut in the direction orthogonal to the axial direction of the hinge shaft30is prolonged along the axial direction of the hinge shaft30to form a straight line with left-side line VI on which the second bracket32A is cut in the direction orthogonal to the axial direction of the hinge shaft30.

As illustrated inFIG. 6AandFIG. 6B, the fixed cover section28in the base cover section20has a structure in which a core material34, a graphite sheet35, an auxiliary sheet36, and a surface material37are laminated in this order from the side of the back surface12Bb of the second chassis12B.

The core material34is a hard member as the base of the fixed cover section28. The core material34extends substantially over the entire surface of the fixed cover section28, and notch holes and cutout holes are formed in various places of the core material34for weight saving or the like. The core material34is a plate-shaped member molded with a resin, such as glass fiber reinforced plastic (GFRP) formed by impregnating glass fiber with an epoxy resin or polycarbonate (PC). For example, the core material34has a plate thickness of about 1 to 2 mm. The core material34of the embodiment is fixed to the second chassis12by using a fixing member38such as double-sided tape or screws.

The graphite sheet35is fixed with double-sided tape or adhesive and laminated on the surface of the core material34. The graphite sheet35extends substantially over the entire surface of the base cover section20. For example, the graphite sheet35has a thickness of about 0.05 to 0.15 mm. The graphite sheet35is a heat diffusion sheet which absorbs and diffuses heat generated inside the portable information device10. The graphite sheet35suppresses the formation of a local hot area (hot spot) on the surface20aof the base cover section20. The graphite sheet35may also be omitted.

The auxiliary sheet36is fixed with double-sided tape or adhesive and laminated on the surface of the graphite sheet35. The auxiliary sheet36is provided to cover substantially the entire surface of the graphite sheet35in order to prevent an uneven shape such as a wrinkle of the graphite sheet35from being transferred to the surface material37. The auxiliary sheet36is softer than the core material34and harder than the surface material37. The auxiliary sheet36is a sheet-shaped member molded with a resin such as polycarbonate (PC). For example, the auxiliary sheet36has a thickness of about 0.1 to 0.5 mm. The auxiliary sheet36may also be omitted.

The surface material37is an external covering material to enhance the appearance design and the sense of touch of the base cover section20. The surface material37is fixed with double-sided tape or adhesive and laminated on the surface of the auxiliary sheet36. The surface material37covers the entire surface of the auxiliary sheet36to form the surface20aof the base cover section20. The surface material37is formed of artificial leather, natural leather, resin, or the like, which is a sheet-shaped member softer than the auxiliary sheet36and the core material34. For example, the surface material37has a thickness of about 0.5 to 1 mm.

Although detailed description is omitted, the slide cover section26of the base cover section20is a laminated body having the same cross-sectional structure as the fixed cover section28. The slide cover section26is so constructed that the rail of the slide mechanism mentioned above is fixed to the back surface of the core material34. Unlike the fixed cover section28and the slide cover section26, the folding cover section27does not have the core material34because of the need to have flexibility as a flexible hinge. In other words, the folding cover section27has a structure in which the graphite sheet35, the auxiliary sheet36, and the surface material37are laminated in this order from the side of the back surface12Bb of the second chassis12B. Note that it is better to laminate a sheet-shaped member like the auxiliary sheet36on the back surface of the graphite sheet35, that is, between the graphite sheet35and the chassis12A,12B.

As illustrated inFIG. 6AandFIG. 6B, the stand cover section22has a structure in which a back material40, a core material41, an auxiliary sheet42, and a surface material43are laminated in this order from the side of the back surface12Bb of the second chassis12B.

The back material40is an external covering material to enhance the appearance design and the sense of touch of a back surface22dof the stand cover section22that appears outside in the standing position. The back material40is fixed with double-sided tape or adhesive and laminated on the back surface of the core material41. The back material40is a soft sheet-shaped member formed of artificial leather, natural leather, resin, or the like. For example, the back material40has a thickness of about 0.5 to 1 mm.

Since the core material41, the auxiliary sheet42, and the surface material43can be the same as or similar to the core material34, the auxiliary sheet36, and the surface material37of the base cover section20, the detailed description thereof will be omitted.

The laminated structures of the base cover section20and the stand cover section22mentioned above can be changed as appropriate, and the number of layers and the order of laminating the layers can also be changed as appropriate. Note that reference numeral44inFIG. 6Adenotes the battery device installed inside the second chassis12B.

As illustrated inFIG. 6A, the hinge device24of the embodiment is so structured that the whole of the hinge shaft30is located in a position lower than the surfaces of the surface materials37and43of the base cover section20and the stand cover section22. Thus, since the hinge shaft30, the bracket31A, and the like do not protrude from the surface of the cover device14that forms the bottom of the second chassis12B, a high appearance quality and a high sense of touch can be obtained. Note that the amount of protrusion of the hinge shaft30from the surface of the cover device14can be suppressed as long as at least the shaft center of the hinge shaft30of the hinge device24is located in a position lower than the surfaces of the surface materials37and43of the base cover section20and the stand cover section22.

FIG. 7is an enlarged diagram schematically illustrating the structure of the brackets31A,32A and the vicinity thereof illustrated inFIG. 3.FIG. 8is a schematic sectional view taken along line VIII-VIII inFIG. 7.FIG. 7illustrates a state where the surface materials37,43, the auxiliary sheets36,42, and the graphite sheet35are removed to expose the brackets31A,32A and the core materials34,41. Though not illustrated, the structure of the brackets31B,32B on the other side and the vicinity thereof is the same as the structure illustrated inFIG. 7except that it is a structure symmetrical with respect to a plane orthogonal to the hinge shaft30.

As illustrated inFIG. 7andFIG. 8, the core material34of the fixed cover section28has a bracket placement hole34a,a positioning recess34b,and a protruding portion34c.

The bracket placement hole34ais a bay-shaped hole open to face the edge28a,and the first bracket31A (31B) is placed inside the bracket placement hole34a.The bracket placement hole34ahas an inner peripheral shape slightly larger than the outer shape of the first bracket31A (31B). The positioning recess34bis provided in a notched shape to be dented from the inner peripheral surface of the bracket placement hole34a.The positioning piece31fis fitted into the positioning recess34bto position the first bracket31A (31B) with respect to the core material34. The bracket placement hole34amay also be a recessed hole, rather than the through hole.

The protruding portion34cis a plate piece protruding from a portion of the inner peripheral surface of the bracket placement hole34ato face the notch-shaped portion31dof the first bracket31A (31B) up to a position to get into the notch-shaped portion31d.The protruding portion34cextends to a position where the tip edge thereof gets into the notch-shaped portion31dat least beyond the side end face31e.Note that, since the notch-shaped portion31dof the embodiment is also used as the fastening hole of the screw33, the protruding portion34centers only up to a shallow position of the notch-shaped portion31d.In a structure that does not consider fastening the screw33, the protruding portion34cmay also be shaped to enter up to the back of the notch-shaped portion31d.

As illustrated inFIG. 7andFIG. 8, the core material41of the stand cover section22has a bracket placement hole41a,a positioning recess41b,and a protruding portion41c.

The bracket placement hole41ais a bay-shaped hole open to face the edge22a,and the second bracket32A (32B) is placed inside the bracket placement hole41a.The bracket placement hole41ahas an inner peripheral shape slightly larger than the outer shape of the second bracket32A (32B). The positioning recess41bis provided in a notched shape to be dented from the inner peripheral surface of the bracket placement hole41a.The positioning piece32fis fitted into the positioning recess41bto position the second bracket32A (32B) with respect to the core material34. The bracket placement hole41amay also be a recessed hole, rather than the through hole.

The protruding portion41cis a plate piece protruding from a portion of the inner peripheral surface of the bracket placement hole41ato face the notch-shaped portion32dof the second bracket32A (32B) up to a position to get into the notch-shaped portion32d.The protruding portion41cextends to a position where the tip edge thereof gets into the notch-shaped portion32dat least beyond the side end face32e.

In this hinge device24of the cover device14, there is a need to place the first bracket31A (31B) and the second bracket32A (32B) in a positional relationship in which both do not interfere with each other in the axial direction of the hinge shaft30but are as close as possible to each other. In other words, there is a need to place the brackets31A (31B) and32A (32B) in positions where the side end faces31eand32eof both brackets are located approximately on the same plane in the axial direction of the hinge shaft30or slightly separated from each other across this plane. This is because when the brackets31A (31B) and32A (32B) are separated in the axial direction, twists or rattles may occur between the brackets31A (31B) and32A (32B) during rotational operation to make the rotational operation of the stand cover section22and keeping the portable information device10in the standing position unstable. This is also because when the brackets31A (31B) and32A (32B) are separated, an expected rotational torque may not be able to be generated.

On the other hand, in this hinge device24, there is also a case where the stand cover section22is rotated by more than 90 degrees with respect to the fixed cover section28, that is, a case where the stand cover section22is tilted further to the right from the position illustrated inFIG. 6B. In this case, when the second bracket32A (32B) gradually approaches the first bracket31A (31B), the side end faces31eand32eof both brackets act like scissors blades. As a result, cutting power is generated between the side end faces31eand32e,and there is a concern that the surface materials37and43located therebetween might be broken down or damaged.

In this regard, in the cover device14of the embodiment, the first bracket31A (31B) and the second bracket32A (32B) paired to each other to make up the hinge have the notch-shaped portions31dand32din the root parts of the side end faces31eand32ethat face each other, respectively. This can suppress the breakage of the surface materials37and43between the side end faces31eand32ethat approach each other like scissors blades even when the stand cover section22is rotated in the standing direction until the surface material43of the stand cover section22comes into contact with the surface material37of the fixed cover section28. This is because the notch-shaped portions31dand32dare like portions of the scissors blades where root parts close to the axis of rotation are dented, and hence can reduce the cutting power generated between the side end faces31eand32e.

By providing the notch-shaped portions31dand32din the root parts, the brackets31A (31B) and32A (32B) can suppress the surface materials37and43from being subjected to the cutting power. However, since the surface materials37and43are subjected to a pressing force by contacting each other and compressed in a manner to be pushed into the notch-shaped portions31dand32d,there is also a concern that the surface materials37and43might be damaged.

Therefore, in the cover device14, the hard core materials34and41have the protruding portions34cand41cthat get into the notch-shaped portions31dand32d,respectively, as illustrated inFIG. 7andFIG. 8. Thus, even when the surface materials37and43are compressed with each other in the positions to be overlapped with the notch-shaped portions31dand32d,respectively, the back sides of the surface materials37and43are supported by the hard protruding portions34cand41c,respectively. Therefore, the surface materials37and43are prevented from being pushed into the notch-shaped portions31dand32dand broken down when being pressed against each other. If only the notch-shaped portions31dand32dare enough to get the effect of breakage prevention of the surface materials37and43, the protruding portions34cand41cmay be omitted.

In the hinge device24of the embodiment, at least the shaft center of the hinge shaft30is located in a position lower than the base cover section20, the surface material37of the fixed cover section28, and the surface material43of the stand cover section22. In other words, the cover device14that virtually forms the bottom of the second chassis12B can prevent the hinge shaft30, the bracket31A, and the like from protruding from the surface thereof. Therefore, in the laptop form illustrated inFIG. 2B, the bottom of the second chassis12B as the main body side placed on a desk or the like is flattened to ensure high stability. Moreover, since the stand cover section22and the fixed cover section28are provided on the second chassis12B as the main body side in the laptop form, the slide cover section26is never rubbed with the desk or the like when the laptop form is changed to the folded form or the flat plate form. Further, since the camera17is provided on the display side (on the side of the first chassis12A) in the laptop form, like in the case of a common laptop PC, the camera17can be used smoothly.

Note that the present invention is not limited to the aforementioned embodiment, and changes can be made freely without departing from the scope of the present invention.

In the above, the foldable portable information device10is exemplified. However, when the portable information device is a tablet PC of a flat-plate type rather than of the folded type, the base cover section20of the cover device14may be formed by the fixed cover section28alone with the slide cover section26and the folding cover section27omitted.

In the above, since the stand cover section22is so constructed that the bottom edge22cthereof matches the bottom end face of the second chassis12B extending in the X direction, the hinge shaft30is placed in a posture to be inclined in the XY directions so that the portable information device10takes a standing posture fallen a little in the standing position illustrated inFIG. 4. However, the hinge shaft30may be installed in parallel with the X direction or the Y direction depending on the installation position of the stand cover section22.

In the above, the structure in which the cover device14is fixed integrally to the chassis12A and12B is exemplified. However, the cover device14may be a single part as a body completely separated from the portable information device10. In this case, the cover device14may be detachably attached to the chassis12A and12B, for example, by using magnets or hooks. In such a cover device14, the first brackets31A and31B have only to be fixed to the core material34of the fixed cover section28.

In the above, the portable information device10foldable in half like a book is exemplified. However, in addition to the structure in which the same shaped chassis are folded in half, various structures can be exemplified as foldable portable information devices, such as a double-door structure in which two small-sized chassis are coupled to the right and left edges of a large-sized chassis in a foldable manner, an S-shaped folding structure in which two chassis different in folding direction from each other are coupled to the right and left edges of one chassis, and a J-shaped folding structure in which a small-sized chassis is coupled to one of the right and left edges of a large-sized chassis in a foldable manner, and the number of coupled chassis may be four or more. In this case, the cover device14may have such a structure as to cover the whole or part of the back surface of each chassis, and two or more chassis may be used simultaneously.