Hinge assembly and foldable electronic device including the same
A foldable electronic device includes: a display, a first housing, a second housing, and a hinge assembly, wherein the hinge assembly includes: a hinge cover connected to the first housing and the second housing, a first hinge connected to the hinge cover to support the first area, and a second hinge connected to the hinge cover to support the second area, wherein each of the first hinge and the second hinge includes: a shaft with a folding axis, a first cam configured to perform a linear motion along the folding axis, a second cam configured to contact the first cam, and a third cam configured to contact the first cam, wherein the first cam is configured to contact only one of the second cam and the third cam.
1 . A foldable electronic device, comprising:
a display comprising a first area, a second area, and a flexible area between the first area and the second area;
a first housing located around the first area of the display;
a second housing located around the second area of the display; and
a hinge assembly connected between the first housing and the second housing adjacent to at least a portion of the flexible area of the display and configured to operate between a folded position at which the first area and the second area face each other and an unfolded position at which the first area and the second area do not face each other,
wherein the hinge assembly comprises:
a hinge cover connected to the first housing and the second housing;
an elastic body;
a first hinge connected to the hinge cover to support the first area of the display; and
a second hinge connected to the hinge cover to support the second area of the display,
wherein each of the first hinge and the second hinge comprises:
a shaft with a folding axis;
a first cam configured to perform a linear motion along the folding axis;
a second cam configured to contact the first cam; and
a third cam configured to contact the first cam, and
wherein the first cam is configured to contact only one of the second cam and the third cam at a time, and
wherein the elastic body exerts a force on the first cam in a direction parallel to the folding axis.
2 . The foldable electronic device of claim 1 , wherein the first cam is configured to
maintain contact with the second cam while the hinge assembly changes from the unfolded position to the folded position, and
when the hinge assembly enters the folded position, release the contact with the second cam and contact the third cam.
3 . The foldable electronic device of claim 1 , wherein:
the first cam comprises a first cam body and a first cam surface formed on the first cam body,
the second cam comprises a second cam body and a second cam surface configured to contact the first cam surface, and
the second cam surface is configured to apply a maintain open torque to the first cam surface to maintain the hinge assembly at the unfolded position when the hinge assembly starts to change from the unfolded position to the folded position.
4 . The foldable electronic device of claim 1 , wherein:
the second cam comprises a second cam body and a second cam surface formed on the second cam body,
the second cam surface comprises:
a first variable portion;
a second variable portion; and
an intermediate variable portion between the first variable portion and the second variable portion, and
the first cam is configured to stop at a predetermined position of the intermediate variable portion while the hinge assembly changes from the unfolded position to the folded position.
5 . The foldable electronic device of claim 1 , wherein:
the second cam comprises a second cam body and a protruding portion formed on the second cam body,
each of the first hinge and the second hinge further comprises:
a support ring comprising a ring body configured to rotate about the shaft, and
a support protrusion formed on the ring body and configured to support the second cam, and
the support protrusion is configured to support the protruding portion while the hinge assembly changes from the unfolded position to the folded position.
6 . The foldable electronic device of claim 5 , wherein the support protrusion is configured not to support the protruding portion when the hinge assembly enters the folded position.
7 . The foldable electronic device of claim 1 , wherein:
each of the first hinge and the second hinge further comprises:
a fixing body comprising a fixing plate configured to fix the shaft to the hinge cover and a stopper connected to the fixing plate;
a rotating body connected to the shaft to support the display; and
a support ring comprising:
a ring body configured to rotate about the shaft, and
a stopping protrusion formed on the ring body and configured to meet the stopper, and
the ring body is configured to rotate in a direction opposite to a rotation direction of the rotating body when the stopping protrusion meets the stopper.
8 . The foldable electronic device of claim 1 , wherein the first cam is configured to:
maintain contact with the third cam while the hinge assembly changes from the folded position to the unfolded position, and
release the contact with the third cam and contact the second cam when the hinge assembly enters the unfolded position.
9 . The foldable electronic device of claim 1 , wherein:
the first cam comprises a first cam body and a first cam surface formed on the first cam body, and
the third cam comprises a third cam body and a third cam surface formed on the third cam body,
the third cam surface comprises:
a third variable portion;
a fourth variable portion; and
a fifth variable portion between the third variable portion and the fourth variable portion, and
the first cam surface is configured to move, contacting the fifth variable portion, along the fifth variable portion from the third variable portion toward the fourth variable portion while the hinge assembly changes from the folded position to the unfolded position.
10 . The foldable electronic device of claim 1 , wherein:
the second cam comprises a second cam body and a protruding portion formed on the second cam body,
each of the first hinge and the second hinge further comprises:
a support ring comprising a ring body configured to rotate about the shaft, and
a support protrusion formed on the ring body and configured to support the second cam, and
the support protrusion is configured not to support the protruding portion while the hinge assembly is at the folded position or changes from the folded position to the unfolded position.
11 . The foldable electronic device of claim 1 , wherein:
each of the first hinge and the second hinge further comprises a support ring configured to support the second cam, and
the support ring is configured to guide the second cam so that the second cam meets the first cam when the hinge assembly enters the unfolded position.
12 . A hinge assembly, comprising:
a hinge,
wherein the hinge comprises:
a shaft with a folding axis;
a first cam configured to perform a linear motion along the folding axis;
an elastic body configured to exert a force upon the first cam in a direction parallel to the folding axis;
a second cam configured to contact the first cam; and
a third cam positioned inside the second cam and configured to contact the first cam,
wherein the first cam is configured to contact only one of the second cam and the third cam at a time, and
wherein a radial distance between the second cam and the shaft is greater than a radial distance between the third cam and the shaft.
13 . The hinge assembly of claim 12 , wherein:
the second cam comprises a second cam body and a second cam surface formed on the second cam body, and
the second cam surface comprises:
a first variable portion;
a second variable portion; and
an intermediate variable portion between the first variable portion and the second variable portion.
14 . The hinge assembly of claim 12 , wherein:
the third cam comprises a third cam body and a third cam surface formed on the third cam body, and
the third cam surface comprises:
a third variable portion;
a fourth variable portion; and
a fifth variable portion between the third variable portion and the fourth variable portion.
15 . The hinge assembly of claim 12 , wherein the hinge further comprises a support ring comprising a ring body and a support protrusion formed on the ring body and configured to support the second cam.
16 . The hinge assembly of claim 15 , wherein the support protrusion has an inclined surface configured to guide a protruding portion so that the second cam performs a translational motion along the folding axis.
17 . The hinge assembly of claim 12 , further comprising a hinge cover connected to the hinge,
wherein the hinge further comprises:
a fixing body comprising a fixing plate configured to fix the shaft to the hinge cover and a stopper connected to the fixing plate; and
a support ring comprising a ring body and a stopping protrusion formed on the ring body and configured to meet the stopper.
18 . The hinge assembly of claim 12 , wherein:
the second cam and the third cam are disposed to surround the shaft.
19 . The hinge assembly of claim 12 , further comprising a hinge cover connected to the hinge,
wherein the hinge further comprises a fixing body configured to fix the shaft to the hinge cover.
20 . The hinge assembly of claim 12 , wherein the hinge further comprises a rotating body rotatably connected to the shaft.