WO2006129911A1

WO2006129911A1 - Hinge apparatus

Info

Publication number: WO2006129911A1
Application number: PCT/KR2006/001146
Authority: WO
Inventors: Sang Wook Park; Yong Keun Choi
Original assignee: P.K. Tech System Co., Ltd.
Priority date: 2005-05-28
Filing date: 2006-03-29
Publication date: 2006-12-07
Also published as: CN101185046A; KR20060122998A; KR100703876B1

Abstract

The present invention relates to a hinge apparatus. The main object of the invention is to provide a hinge apparatus having a stopper function for preventing further opening at the state where the display unit of a notebook computer is opened at a certain angle with respect to the base unit. In the hinge apparatus for achieving the object of the invention, among a plurality of hinge structures forming the hinge apparatus, a stopper 55 is formed in the fixed cam 50 and a stopper guide cam face 65 is formed in the rotatable cam 60 so as to correspond to the stopper 50.

Description

HINGE APPARATUS

Description

Technical Field

The present invention relates to a hinge apparatus .

More particularly, the invention relates to a hinge

apparatus, in which a display unit is prevented from being

opened with respect to a base unit by means of a cam

operation at a completely folded state while excluding a

separate latch device, a click phenomenon of opening and

closing occurs at a certain angle, and a stopper function is

provided for preventing further opening at the state where

the display unit is opened at a certain angle with respect

to the base unit.

Background Art

Recently, along with the rapid advancement of

information and communications technologies, a computer has

become almost one of necessaries in people's every day life.

That is, such computers are necessarily used in the

offices, schools and homes. Dissimilar to a desk top

personal computer that is installed in a limited space as

above, a notebook computer can be conveniently carried around and used at any time anywhere and thus has been

rapidly popularized.

For the purpose of convenient portability, the

notebook computer includes a base unit and a display unit.

The base unit includes a main board, a CPU, various chipsets,

a memory device such as a hard disk, a data input device

such as a keyboard and touch pad, a battery for power supply,

and a LAN card for on-line functions. The display unit

includes a liquid crystal display device where various

images are displayed through the manipulations and

operations of the base unit. One end of the display unit is

hinged to the base unit so as to be opened and closed with

respect to each other.

In the above notebook computers, the hinge apparatus

of the base unit and the display unit may be formed in

various configurations. Mostly, the display unit is

pivotally rotated with respect to the base unit by means of

a certain external force, but not freely pivoted or turned.

Thus, a user can maintain the open state stably at a

selected opening angle.

The conventional hinge apparatus is constructed to

prevent a free movement of the display unit with respect to the base unit, but in case where the base unit and display

unit are folded and carried, the center of gravity of the

base unit or the display unit is directed downward, and the

base unit or the display unit can be opened by means of

free-falling because its weight overcomes the force of

inhibiting free-movement thereof.

Thus, in order to prevent the base unit and the

display unit from being opened against each other at the

folded state, generally a latch device is provided as a

locking means.

That is, a latch device is provided for holding the

base unit and the display unit with the display unit folded

with respect to the base unit.

In the case of a notebook computer having the above

latch device, however, inconveniently the locked state of

the latch device must be released every time to open the

display unit at a certain angle with respect to the base

unit. In addition, such a latch device leads to an increase

in the cost of the notebook computers .

In order to solve the above problems, Korean Patent

Application No. 2004-44837, which has been filed by the

present applicant, discloses a hinge apparatus for a notebook computer. In the disclosed hinge apparatus, the

display unit is prevented from being opened with respect to

the base unit by means of a cam operation at a completely

folded state while excluding a separate latch device for

preventing them from being opened at the folded state. And a

click phenomenon of opening and closing occurs at a certain

angle .

In the hinge apparatus for a notebook computer

disclosed in the Korean Patent Application No. 2004-44837,

the base unit and the display unit are prevented from being

opened with respect to each other due to the cam operation

without necessity of a separate latch device, at the state

where the display unit is completely folded on the base unit.

In addition, click phenomenon of opening and closing occurs

at a certain angle. However, if a certain amount of force

is exerted on the display unit at the state where the

display unit is opened at about 170° against the base unit,

it is likely to fall or lean all the way back.

That is, at the state where the display unit is opened

at an angle of around 170 degrees with respect to the base

unit, the center of the first cam of a rotatable cam is

latched at the step of a protruded slant face of a fixed cam, thereby providing a stopper function to some degree.

However, this is a stopper function only by means of a

certain torque. Thus, if a user exerts a force beyond a

certain limit, the display unit is made to fall all the way

back, thereby failing to satisfy consumers .

Disclosure of Invention

Technical Problem

Accordingly, the present invention has been made in

order to solve the above problems occurring in the prior art,

and it is an object of the invention to provide a hinge

apparatus, in which a display unit is prevented from being

opened with respect to a base unit by means of a cam

operation at a completely folded state while excluding a

separate latch device, a click phenomenon of opening and

closing occurs at a certain angle, and a stopper function is

provided for preventing them from being further opened with

respect to each other at the state where the display unit is

opened at a certain angle with respect to the base unit.

Technical Solution

In order to accomplish the above objects, according to one aspect of the invention, there is provided a hinge

apparatus having a hinge structure, the hinge structure

including a shaft having a bracket formed to be fixed to one

side of a frame of a display unit, a system bracket fixed to

one side of a base unit so as to allow the shaft to be

rotated and adapted to hold the display unit in place when

the display unit rotates, and a fixed cam, a rotatable cam,

a plurality of leaf springs and a guide washer that are

sequentially coupled to the shaft, wherein the fixed cam

includes a circular through-hole formed in the center

thereof not to be rotated along wih the rotation of the

shaft, a first cam groove and a second cam groove formed so

as to face each other with respect to the through-hole, a

first cam face and the second cam face formed between the

first cam groove and the second cam groove so as to face

each other, and a stopper provided at one side of the first

cam face in such a fashion as to be protruded beyond the

first cam face by a certain height; and wherein the

rotatable cam includes an angular groove formed at the

center thereof so as to be rotated along with the rotation

of the shaft, a first cam face and a second cam face formed

so as to face each other with respect to the angular groove to correspond to the first cam groove and the second cam

groove respectively of the fixed cam, a first cam groove and

a second cam groove formed between the first cam face and

the second cam face so as to correspond to the first cam

face and the second cam face of the fixed cam, and a stopper

guide cam face formed over a certain length of circumference

inwards of the first cam face, the second cam face, the

first cam groove and the second cam groove so as to

correspond to the stopper.

In this case, the first cam groove and the second cam

groove are connected with the first cam face and the second

cam face with slant faces formed in-between, respectively,

the slant faces being inclined upwardly at certain angle .

In addition, the stopper of the fixed cam has a width

corresponding to a distance extending from an outer

circumference of the through-hole of the fixed cam to a

position spaced apart inwards of the outer circumference of

the fixed cam.

On the other hand, the stopper guide cam face of the

rotatable cam has a width corresponding to the width of the

stopper .

In addition, the stopper guide cam face is extended to a part of the second cam face and the second cam groove of

the rotatable cam from the first cam groove of the rotatable

cam.

In addition, the stopper guide cam face of the

rotatable cam includes a first stopper guide slant face, a

first stopper guide cam groove extended from the first

stopper guide slant face, a first stopper guide cam face

extended between the first stopper guide cam groove and a

second stopper guide slant face, and a second stopper guide

cam groove extended between the first stopper guide cam face

and a third stopper guide slant face and having a side wall

to which the stopper of the fixed cam is latched.

In addition, the third stopper guide slant face and

the second stopper guide cam groove are flush with the first

stopper guide cam face.

In addition, when the display unit is completely

folded onto the base unit to form an angle of zero, the

slant faces of the rotatable cam are offset from and engaged

with the slant faces of the fixed cam.

In addition, when the display unit is pivotally

rotated with respect to the base unit to form an angle of around 150°, the stopper of the fixed cam abuts against the

end portion of the second stopper guide cam groove of the

rotatable cam such that no further rotating occurs.

On the other hand, when the display unit is closably

rotated with respect to the base unit to form an angle of

around 5°, a click phenomenon occurs at a time point when

the slant faces of the rotatable cam abuts against the slant

faces of the fixed cam.

Advantageous Effects

According to the hinge apparatus of the present

invention, the display unit and the base unit are prevented

from being opened with respect to each other by means of a

cam engagement even when they are completely folded onto

each other. Thus, a separate latch device is not needed,

thereby providing a simpler design of notebook computer and

also reducing the manufacturing cost thereof.

In addition, when the display unit is opened and

closed with respect to the base unit, a click phenomenon

occurs at a certain angle, thereby improving the sense of

use.

In particular, when the display unit is opened to a certain angle (around 150°) with respect to the base unit,

further opening is prevented by means of a stopper function.

Thus, the display unit is prevented from falling all the way

back from the base unit, thereby providing an improved

performance .

Description of Drawings

Further objects and advantages of the invention can be

more fully understood from the following detailed

description taken in conjunction with the accompanying

drawings in which:

FIG. 1 is a perspective view of a notebook computer

where a hinge apparatus of the invention is installed;

FIG. 2 is an enlarged view showing the connection of

important elements in FIG. 1;

FIG. 3 is an elevation showing a fixed cam and a

rotatable cam applied to the hinge apparatus of the

invention;

FIG. 4 is a perspective view of FIG. 3;

FIG. 5 is a perspective view of FIG. 4 seen from a

different direction;

FIG. 6 shows a horizontal outline of the curvature of the fixed cam of FIG. 3;

FIG. 7 shows a horizontal outline of the curvature of

the rotatable cam of FIG. 3;

FIG. 8 shows a horizontal outline of the curvature of

the stopper guide cam in the rotatable cam of FIG. 3;

FIG. 9 shows the positions of the fixed cam and the

rotatable cam where the display unit is completely folded

with respect to the base unit;

FIG. 10 shows the positions of the fixed cam and the

rotatable cam where the display unit is opened with respect

to the base unit to make a click; and

FIG. 11 shows the positions of the fixed cam and the

rotatable cam where the display unit is completely opened to

the limit.

Mode for Invention

The preferred embodiments of the invention will be

hereafter described in detail with reference to the

accompanying drawings .

FIG. 1 is a perspective view of a notebook computer

where a hinge apparatus of the invention is installed. FIG.

2 is an enlarged view showing the connection of important elements in FIG . 1 .

As illustrated in the figures, a hinge apparatus for

notebook computers includes a shaft 20 having a bracket 12

integrally formed at its lateral end, a system bracket 30

pivotably coupled to the shaft 20 and a spacer washer 24 in-

between, and a hinge structure sequentially coupled to one

side of the shaft 20. The bracket 12 is fixedly coupled to

the frame of a display unit. The system bracket 30 is

fixedly coupled to one side of the frame of a base unit 2.

The shaft 20 is provided integrally with a latching

plate 22 formed at the intermediate periphery thereof.

Although not shown in detail, the shaft 20 is formed of a

cylindrical section for a certain length from one face of

the latching plate 22, an angular section for a certain

length from the cylindrical section, and a threaded section

for a certain length from the angular section. The angular

section has two planes facing each other in its sides.

On the other hand, the system bracket 30, coupled to

the shaft 20, is composed of a first bracket 32 having a

through-hole formed for being inserted into the cylindrical

section of the shaft 20, a second bracket 34 formed

perpendicularly from one end of the first bracket 32, and a pern nut 40 extended from one side of the second bracket 34

and fixedly coupled with the frame of the base unit 20.

As illustrated in FIGS. 2 to 5, the hinge structure is

composed of a fixed cam 50 inserted into the cylindrical

section of the shaft 20 and then fixed with the first

bracket 32 of the system bracket 30, a rotatable cam 60

inserted into the angular section of the shaft 30 to

rota'tionally engage with the cam face of the fixed cam 50

and interlocked with the shaft 20, a plurality of leaf

springs 70 and guide washers 80 inserted into the angular

section of the shaft 20, and a nut 90 fixedly connected with

the threaded section of the shaft 20.

One end of the fixed cam 50 is fixedly connected with

the first bracket 32 of the system bracket 30.

Therefore, the through-hole formed in the first

bracket 32 of the system bracket 30 is inserted from the end

portion of the shaft 2 such that one face of the first

bracket 32 is closely contacted with one face of the

latching plate 22 of the shaft 20. Then, the fixed cam 50,

the rotatable cam 60, and the plurality of leaf springs 70,

and the guide washer 80 are sequentially inserted and

thereafter the nut 90 is inserted to be engaged with the threaded section of the shaft 20.

At this time, the protruded portion at one end of the

fixed cam 50 is fitted into a fixing groove formed in the

first bracket 32 of the system shaft 30. Finally connected

nut 90 is controlled in its torque to a pre-determined value,

and then riveting is carried out to finish the final

assembling.

On the other hand, the through-hole formed in the

first bracket 32 of the system bracket 30 is inserted from

the end portion of the shaft 2 such that one face of the

first bracket 32 is closely contacted with one face of the

latching plate 22 of the shaft 20. Then, the fixed cam 50,

the rotatable cam 60, the plurality of leaf springs 70, and

the guide washer 80 are sequentially inserted and thereafter,

without a nut, a riveting process may be carried out to

finish the final assembling.

In this way, at the assembled state, the pem nut 40,

formed at one face of the second bracket 34 of the system

bracket 30, is fixedly coupled to the frame of the base unit

2, and the bracket 12 is fixedly connected to the lateral

portion of the frame of the display unit 2.

The operation of the hinge apparatus combined in a notebook computer will be explained below.

When the display unit 4 is pivotally rotated with

respect to the base unit 2 with the base unit 2

horizontally rested on the floor, the bracket 12, where the

frame of the display unit 4 is fixedly installed, is

pivotally rotated and thus the shaft fixed to the bracket 12

is cooperatively rotated together.

At this time, since the pern nut 40 is fixedly coupled

to the frame of the base unit 2, the system bracket 30

remains in place and the fixed cam 50, one end of which is

fixed with the first bracket 32 of the system bracket 30, is

interlocked with the shaft 20 and remains fixed without

rotating.

That is, among the first bracket 32 of the system

bracket 30, the fixed cam 50, the rotatable cam 60, the

plurality of leaf springs 70, the guide washer 80 and the

nut 90 that are sequentially connected to the shaft 20, the

system shaft 30 and the fixed cam 50 remain at fixed state,

and the remaining rotatable cam 60, the plurality of leaf

springs 70, the guide washer 80 and the nut 90 only are

interlocked with the shaft 20 to rotate.

As described above, it is because the through-hole formed in the first bracket 32 of the system bracket 30 and

the through-hoe 51 of the fixed cam 50 are formed in a

circular shape and inserted into the cylindrical section of

the shaft 20 and thus do not move but slide even if the

shaft 20 rotates.

On the contrary, the through-hole of the rotatable cam

60, the plurality of leaf springs 70 and the guide washer 80

are formed in angular shape corresponding to the angular

section of the shaft 20 and thus rotate as the shaft 20

rotates. And since the nut 90 is connected with the threaded

section of the shaft 20, it rotates along with the shaft 20.

On the other hand, FIG. 3 is an elevation showing a

fixed cam and a rotatable cam applied to the hinge apparatus

of the invention. FIG. 4 is a perspective view of FIG. 3.

FIG. 5 is a perspective view of FIG. 4 seen from a different

direction.

In addition, FIG. 6 shows a horizontal outline of the

curvature of the fixed cam of FIG. 3. FIG. 7 shows a

horizontal outline of the curvature of the rotatable cam of

FIG. 3. FIG. 8 shows a horizontal outline of the curvature

of the stopper guide cam in the rotatable cam of FIG. 3.

As shown in the figures, a first cam groove 52a and a second cam groove 52b are formed in the cam face of the

fixed cam 50 so as to be extended by a certain angle, facing

each other with the through-hole 51 in-between. Formed

between the first cam groove 52a and the second cam groove

52b are a first cam face 53a and a second cam face 53b, with

upwardly inclined first, second, third, and fourth slant

faces 54a, 54b, 54c and 54d in-between.

That is, the first cam groove 52a is extended from one

side of the first cam face 53a with the first slant face 54a

in-between. The second cam face 53b is extended from one

side of the first cam groove 52a with the second slant face

54b in-between. The second cam groove 52b is extended from

one side of the second cam face 53b with the third slant

face 54c in-between. Again, the first cam face 53a is

extended in circumferential direction from one side of the

second cam groove 52b with the fourth slant face 54d in-

between .

The first cam groove 53a and the second cam groove 52b,

and the first cam face 53a and the second cam face 53b are

flush with each other, respectively, and the planes

extending from the outer circumference of the through-hole

51 to their outer circumferences form the same planes, respectively.

In addition, from the first slant face 54a forming a

boundary between the first cam face 53a and the first cam

groove 52a to a certain portion of the first cam face 53a

(approximately to the center of the first cam face) , a

stopper 55 is formed so as to be protruded upwardly from the

first cam face 53a.

The stopper 55 has a width from the circumference of

the through-hole 51 of the fixed cam 50 to the intermediate

point between the circumference of the through-hole and the

circumference of the fixed cam.

The height and width of the stopper 55 correspond to

those of a stopper guide cam face of the rotatable cam,

which will be explained below.

On the other hand, formed in the cam face of the

rotatable cam 60 are a first cam face 62a and a second cam

face 62b, which correspond to the first cam groove 52a and

the second cam groove 52b of the fixed cam 50. In addition,

a first cam groove 63a and a second cam groove 63b are

formed correspondingly to the first cam face 53a and the

second cam face 53b of the fixed cam 50.

That is, the first cam face 62a, the second cam face 62b, the first cam groove 63a and the second cam groove 63b

of the rotatable cam 60 correspond the first cam groove 52a,

the second cam groove 52b, the first cam face 53a and the

second cam face 53b of the fixed cam 50, respectively.

Similar to the fixed cam 50, in the rotatable cam 60,

the first cam face 62a is extended from one side of the

first cam groove 63a with a first slant face 64a in-between.

The second cam groove 63b is extended from one side of the

first cam face 62a with a second slant face 64b in-between.

The second cam face 62b is extended from one side of the

second cam groove 63b with a third slant face 64c in-between.

Again, the first cam groove 63a is extended in

circumferential direction from one side of the second cam

face 62b with a fourth slant face 64d in-between.

Therefore, the first slant face 64a, the second slant

face 64b, the third slant face 64c and the fourth slant face

64d of the rotatable cam 60 correspond to the first slant

face 54a, the second slant face 54b, the third slant face

54c and the fourth slant face 54d of the fixed cam 50,

respectively.

On the other hand, in the rotatable cam 60, the second

cam groove 63b has a width extending on the same plane from the circumference thereof to the circumference of the

angular groove 61.

However, from the first slant face 64a to a part of

the first cam groove 63a, the second cam face 62b and the

second cam groove 63b, a width corresponding to a certain

distance extending from the outer circumference of the

rotatable cam 60 towards the angular groove 61 is provided.

This width corresponds to the width subtracting the width of

the stopper 55 from the width of the first cam face 53a of

the fixed cam 50.

Therefore, inwardly a part of the first cam groove 63a,

the second cam face 62b and the second cam groove 63b from

the first slant face 64a, a stopper guide cam face 65 is

formed so as to be depressed with a depth corresponding to

the height of the stopper 55.

As aforementioned, the stopper guide cam face 65 has a

width from the inner circumference of the first slant face

64a, the first cam groove 63a, the part of the second cam

face 62b and the second cam groove 63b to the outer

circumference of the angular groove 61. The angle of

circumference is approximately 220°.

In the stopper guide cam face 65, a first slant face 66a of the stopper guide is formed on the radially same line

from the central axis of the first slant face 64a. A first

cam groove 65a of the stopper guide is extended in

circumferential direction from the first slant face 66a of

the stopper guide. A first cam face 65b of the stopper

guide is extended from one side of the first cam groove 65a

of the stopper guide with the second slant face 66b of the

stopper guide in-between. A second cam groove 65c of the

stopper guide is extended from one side of the first cam

face 65a of the stopper guide with the third slant face 66c

of the stopper guide in-between.

In the stopper guide cam face 65, the first cam groove

65a of the stopper guide is positioned on the radially same

line from the central axis of the first cam groove 63a of

the rotatable cam 60. The second slant face 66b of the

stopper guide corresponds to the fourth slant face 64d of

the rotatable cam 60. The first cam face 65b of the stopper

guide corresponds to the second cam face 62b of the

rotatable cam 60. The third slant face 66c of the stopper

guide corresponds to the third slant face 64c of the

rotatable cam 60. The second cam groove 65c of the stopper

guide corresponds to the part of the second cam groove 63b of the rotatable cam 60.

In addition, the first slant face 66a of the stopper

guide corresponds to the first slant face 64a of the

rotatable cam 60.

Here, in the stopper guide cam face 65, the third

slant face 66c of the stopper guide and the second cam

groove 65c of the stopper guide may be formed in the same

plane as the first cam face 65b of the stopper guide.

The fixed cam 50 and the rotatable cam 60 having the

above-construction are operated such that the display unit

of a notebook computer performs an angular movement as

follows .

For reference, the cam face of the fixed cam and the

cam face of the rotatable cam are made to be engaged with

each other. That is, the right side of the rotatable cam is

supposed to be engaged with the left side of the fixed cam.

However, for the sake of convenient explanation, the left

side of the rotatable cam is illustrated as being engaged to

the left side of the fixed cam in the drawings.

As previously mentioned, first, when the cam face of

the fixed cam 50 abuts against the cam groove of the

rotatable cam 60, the cam faces and the cam grooves corresponding to each other are made to be engaged with each

other.

That is, the first cam groove 52a of the fixed cam 50

is corresponding to and engaged with the first cam face 62a

of the rotatable cam 60. The second cam groove 52b of the

fixed cam 50 is corresponding to and engaged with the second

can face 62b of the rotatable cam 60. The first cam face

53a of the fixed cam 50 is corresponding to and engaged with

the first cam groove 63a of the rotatable cam 60. The

second cam face 53b of the fixed cam 50 is corresponding to

and engaged with the second cam groove 63b of the rotatable

cam 60.

Of course, in this case, the first, second, third,

fourth slant faces 54a, 54b, 54c and 54d of the fixed cam 50

correspond to and with the first, second, third, fourth

slant faces 64a, 64b, 64c and 64d of the rotatable cam 60,

respectively.

In this way, with the fixed cam 50 and the rotatable

cam 60 engaged with each other, the stopper 55 of the fixed

cam 50 is made to be placed near the first stopper guide cam

groove 65a and the first stopper guide slant face 66a in the

stopper guide cam face 65. However, as described above, at the state where the

cam grooves 52a and 52b and the cam faces 53a and 53b of the

fixed cam 50 are fitted and engaged with the cam faces 62a

and 62b and the cam grooves 63a and 63b of the rotatable cam

60, respectively, a slight clearance may occur.

That is, it is assumed that a completely engaged state

of the cam grooves 52a and 52b and the cam faces 53a and 53b

of the fixed cam 50 with the cam faces 62a and 62b and the

cam grooves 63a and 63b of the rotatable cam 60 is where the

base unit 2 and the display unit 4 of a notebook computer

are completely folded against each other to thereby form a

zero (0) degree of opening angle. In this case, if the

notebook computer is carried upside down, a clearance may

occur at the engaged state of the cam grooves 52a and 52b

and the cam faces 53a and 53b of the fixed cam 50 with the

cam faces 62a and 62b and the cam grooves 63a and 63b of the

rotatable cam 60. Thus, a slight mobility is caused from

the completely folded state of the base unit 2 and the

display unit 4.

Thus, in order for the above clearance not to be

caused, as illustrated in FIG. 9, when the base unit 2 and

the display unit 4 are completely folded to each other, i.e., the opening angle of the base unit 2 and the display unit 4

is zero (0) degree, the slant faces 64a, 64b, 64c and 64d of

the rotatable cam 60 and the slant faces 54a, 54b, 54c and

54d of the fixed cam 50 are made to be engaged offset

against each other. Thus, a continual torque caused by an

inter-friction is caused to prevent the display unit 4 from

having a mobility with respect to the base unit 2 unless an

external force larger than the torque is exerted.

That is, as aforementioned, the state, in which the

cam grooves 52a and 52b of the fixed cam 50 and the cam

faces 62a and 62b of the rotatable cam 60, the cam faces 53a

and 53b of the fixed cam 50 and the cam grooves 63a and 63b

of the rotatable cam 60, and the slant faces 54a, 54b, 54c

and 54d of the fixed cam 50 and the slant faces 64a, 64b,

64c and 64d of the rotatable cam 60 are aligned and engaged

with each other, respectively, is adjusted such that the

display unit 4 has an angle of around - 11° with respect to

the base unit 2.

However, practically, the display unit 4 cannot be

folded with a minus angle with respect to the base unit 2.

In the case where the display unit 4 is completely folded

into the base unit 2 to have an opening angle of zero (9) degree, as illustrated in FIG. 9, the slant faces 64a, 64b,

64c and 64d of the rotatable cam 60 and the slant faces 54a,

54b, 54c and 54d of the fixed cam 50 are made to be engaged

offset against each other. Thus, a continual torque caused

by an inter-friction is caused to prevent the display unit 4

from having a mobility with respect to the base unit 2

unless an external force larger than the torque is exerted.

In this way, at the state where the display unit 4 is

completely folded with respect to the base unit 2, if the

display unit 4 is pulled up by means of a force larger than

the above torque to be turned upwardly by a certain angle,

the bracket 12 is cooperatively pivoted as the display unit

4 rotates. Thus, the shaft 20 rotates in turn and thus the

rotatable cam 50 rotates. Of course, in this case, since

the fixed cam 50 is fixedly connected with the first bracket

32 of the system shaft 30, which is fixedly coupled to the

frame of the base unit 2, the fixed state is maintained.

Thus, the rotatable cam 60 rotates with respect to the

fixed cam 50. The rotating of the cam faces 62a and 62b of

the rotatable cam 60 along the cam faces 53a and 53b of the

fixed cam 50 is the state of angular turning of the display

unit 4 with respect to the base unit 2. As described above, since the cam faces 62a and 62b of the rotatable cam 60

rotates while pressing the cam faces 53a and 53b of the

fixed cam 50, the plurality of leaf spring 70 remains

compressed. At this time, due to an established torque, the

display unit 4 is not freely rotated with respect to the

base unit 2, but remains fixed at a selected point.

According to the angular turning of the display unit 4,

when the cam faces 62a and 62b of the rotatable cam 60

rotates while pressing the cam faces 52a and 52b of the

fixed cam 50, the stopper 55 of the fixed cam 50 maintains

its fixed position. At this time, the stopper guide cam

face 65 of the rotatable cam 60 allows the stopper 55 not to

be latched.

That is, the depth of the stopper guide cam face 65 of

the rotatable cam 60 is made as high as height of the

stopper 55. Thus, when the rotatable cam 60 rotates with

respect to the fixed cam 50, latching does not occur.

On the other hand, as described above, the stopper

guide cam face 65 is formed over part of the second cam

groove 63b from the fourth slant face 64a, not over the

entire circumference, i.e., over 360°, of the rotatable cam

60. Thus, if one side wall of the stopper 55 abuts against the side wall of the second stopper guide cam groove 65c in

the stopper guide cam face 65, in other words, closely

contacts with the cut-out side wall of the second cam groove

63b, no further rotation can occurs. (Refer to FIG. 11)

In this way, while the rotatable cam 60 rotates, the

position, where the stopper 55 of the fixed cam 50 butts

into the second stopper guide cam groove 65c (the end

portion of the stopper guide cam face 65), i.e., the cut-out

side wall of the second cam groove 63b, is a state where the

display unit 4 is opened with around 150° with respect to

the base unit 2.

In addition, if the display unit 4 turns with respect

to the base unit 2 in the opposite direction, the display

unit 4 is closed at around 5° with respect to the base unit

2 with a click phenomenon.

That is, upon the completion of the contact between

the cam faces 62a and 62b of the rotatable cam 60 and the

cam faces 53a and 53b of the fixed cam 50, when the slant

faces 64a, 64b, 64c and 64d of the rotatable cam 60 starts

to run on the slant faces 54a, 54b, 54c and 54d of the fixed

cam 50, the plurality of leaf springs 70 is recovered to

cause a closing click. Of course, if the display unit 4 is completely folded

onto the base unit 2 to form zero (0) degree, the slant

faces 64a, 64b, 64c and 64d of the rotatable cam 60 is

latched with the slant faces 54a, 54b, 54c and 54d of the

fixed cam 50 by means of a frictional force. At this time,

the generated torque maintains the latched state, i.e., a

locked state, unless an external force of above a certain

magnitude is exerted.

The fixed cam 50 and the rotatable cam 60 may

experience a significant abrasion by frequent friction

events. Thus, it is preferable that the cams are formed of

stainless steel through a known MIM technology to thereby

improve the abrasion resistance thereof. The MIM technology

is a combination of a plastic injection molding and a

sintering process, which is suitable for mass production of

a sophisticated item such as computer and electronics parts.

Industrial Applicability

As apparent from the above description, according to

the hinge apparatus of the present invention, the display

unit and the base unit are prevented from being opened from

each other by means of a cam engagement even when they are completely folded onto each other. Thus, a separate latch

device is not needed, thereby providing a simpler design of

notebook computer and also reducing the manufacturing cost

thereof.

In addition, when the display unit is opened and

closed with respect to the base unit, a click phenomenon

occurs at a certain angle, thereby improving the sense of

use.

In particular, when the display unit is opened to a

certain angle (around 150°) with respect to the base unit,

further opening is prevented by means of a stopper function.

Thus, the display unit is prevented from falling all the way

back from the base unit, thereby providing an improved

performance .

While the present invention has been described with

reference to the particular illustrative embodiments, it is

not to be restricted by the embodiments but only by the

appended claims. It is to be appreciated that those skilled

in the art can change or modify the embodiments without

departing from the scope and spirit of the present invention.

Claims

1. A hinge apparatus having a hinge structure, the

hinge structure including a shaft having a bracket formed to

be fixed to one side of a frame of a display unit, a system

bracket fixed to one side of a base unit so as to allow the

shaft to be rotated and adapted to hold the display unit in

place when the display unit rotates, and a fixed cam, a

rotatable cam, a plurality of leaf springs and a guide

washer that are sequentially coupled to the shaft,

wherein the fixed cam includes a circular through-hole

formed in the center thereof not to be rotated along wih the

rotation of the shaft, a first cam groove and a second cam

groove formed so as to face each other with respect to the

through-hole, a first cam face and the second cam face

formed between the first cam groove and the second cam

groove so as to face each other, and a stopper provided at

one side of the first cam face in such a fashion as to be

protruded beyond the first cam face by a certain height; and

wherein the rotatable cam includes an angular groove

formed at the center thereof so as to be rotated along with

the rotation of the shaft, a first cam face and a second cam face formed so as to face each other with respect to the

angular groove to correspond to the first cam groove and the

second cam groove respectively of the fixed cam, a first cam

groove and a second cam groove formed between the first cam

face and the second cam face so as to correspond to the

first cam face and the second cam face of the fixed cam, and

a stopper guide cam face formed over a certain length of

circumference inwards of the first cam face, the second cam

face, the first cam groove and the second cam groove so as

to correspond to the stopper.

2. The hinge apparatus according to claim 1, wherein

the first cam groove and the second cam groove are connected

with the first cam face and the second cam face with slant

faces formed in-between, respectively, the slant faces being

inclined upwardly at a certain angle.

3. The hinge apparatus according to claim 1, wherein

the stopper of the fixed cam has a width corresponding to a

distance extending from an outer circumference of the

through-hole of the fixed cam to a position spaced apart

inwards of the outer circumference of the fixed cam.

4. The hinge apparatus according to claim 3, wherein

the stopper guide cam face of the rotatable cam has a width

corresponding to the width of the stopper.

5. The hinge apparatus according to claim 1, wherein

the stopper guide cam face is extended to a part of the

second cam face and the second cam groove of the rotatable

cam from the first cam groove of the rotatable cam.

6. The hinge apparatus according to claim 5, wherein

the stopper guide cam face of the rotatable cam includes a

first stopper guide slant face, a first stopper guide cam

groove extended from the first stopper guide slant face, a

first stopper guide cam face extended between the first

stopper guide cam groove and a second stopper guide slant

face, and a second stopper guide cam groove extended between

the first stopper guide cam face and a third stopper guide

slant face and having a side wall to which the stopper of

the fixed cam is latched.

7. The hinge apparatus according to claim 6, wherein the third stopper guide slant face and the second stopper

guide cam groove are flush with the first stopper guide cam

face.

8. The hinge apparatus according to claim 1, wherein,

when the display unit is completely folded with respect to

the base unit to form an angle of zero, the slant faces of

the rotatable cam are offset from and engaged with the slant

faces of the fixed cam.

9. The hinge apparatus according to claim 8, wherein,

when the display unit is pivotally rotated with respect to

the base unit to form an angle of around 150°, the stopper

of the fixed cam abuts against the end portion of the second

stopper guide cam groove of the rotatable cam such that no

further rotating occurs.

10. The hinge apparatus according to claim 8, wherein,

when the display unit is closably rotated with respect to

the base unit to form an angle of around 5°, a click

phenomenon occurs at a time point when the slant faces of

the rotatable cam abuts against the slant faces of the fixed cam.