Patent Description:
Embodiments of this application relate to the technical field of flexible printed circuits, and in particular, to a flexible printed circuit assembly and an electronic device including the flexible printed circuit assembly.

In a device including a structural member required to be folded, slid, extended/retracted, and the like, a flexible printed circuit (Flexible Printed Circuit, FPC) which can be easily bent is usually used to achieve electrical connection between a movable structural member and a stationary structural member such as a printed circuit board (Printed Circuit Board, PCB). During the movement of the structural member, a distance relative the stationary structural member changes. Therefore, a redundant length of the FPC appears. A redundant free section of the FPC is inconsistent in shape and is likely to be folded by squeeze. For example, as shown in <FIG>, in a mobile phone <NUM>, a camera assembly <NUM> extends/retracts to drive an end of an FPC <NUM> to move. The FPC <NUM> is in a straight state when the camera assembly <NUM> extends, and has a redundant length when the camera assembly <NUM> retracts. The redundant length of the FPC <NUM> is in a freely-moving state. Therefore, folding shown in <FIG> is likely to occur. In another example, as shown in <FIG>, in a foldable-display structure <NUM>, a side display <NUM> rotates relative to a stationary member <NUM>, one end of an FPC <NUM> is fixed at the stationary member <NUM>, and an other end of the FPC moves with the side display <NUM>. During switching of the side display <NUM> from a folded state to an unfolded state, a shape of a redundant length of the FPC <NUM> is out of control. As a result, the redundant length is likely to be squeezed into a half-folded state by a structural member (the stationary member or the side display). During folding of the PFC, there is almost no transition of a rounded corner or the rounded corner is very small, and stress concentration occurs at a folding position. As a result, copper in the FPC is prone to a fracture failure.

<CIT> relates to a portable electronic apparatus comprising first and second portions, which are arranged such that the two portions are relatively movable between a first configuration and a second configuration, and are electrically connected by a flexible electrical connector, wherein the route of the connector between the two portions is defined by an obstacle, such that in the first configuration, the connector is constrained to follow a first route, and in the second configuration, the connector is constrained to follow a second, different, route.

<CIT> relates to a foldable electronic device comprising a first casing; a second casing; a two-axis hinge having first and second pivot shafts to pivotally connect the first and second casings; and a wiring cable to electrically connect the first and second casings through the two-axis hinge, wherein the wiring cable is wound around the first pivot shaft of the two-axis hinge in a first direction, and around the second pivot shaft of the two-axis hinge in a second direction opposite to the first direction. <CIT> relates to a stretchable flexible substrate comprising a film base, wherein at least a portion of the film base comprises a rolled part including a first curved part having a curved shape in which the film base is folded back with one main surface of the film base facing inward, a second curved part having a curved shape in which the film base is folded back with another main surface of the film base facing inward, and a base layered part located outside the first curved part and the second curved part, the base layered part having a shape in which the film base is rolled in such a way that a portion of the film base that is contiguous with the first curved part and another portion of the film base that is contiguous with the second curved part are layered on one another, and the rolled part has a tensile spring against a direction to unroll the base layered part.

In view of the above, this application provides a flexible printed circuit assembly with a controllable redundant length.

In view of the above, this application provides a flexible printed circuit assembly. The flexible printed circuit assembly includes a flexible printed circuit and a control structure. The control structure is configured to drive a redundant length generated by movement of the flexible printed circuit to bend to form an arc. The control structure includes a transmission member and two reels. The two reels are arranged on the transmission member at an interva and are symmetrically arranged with respect to a rotary shaft of the transmission member.

The flexible printed circuit passes between the two reels. The transmission member is configured to drive the two reels to rotate and to provide guidance for bending of the flexible printed circuit, so that the flexible printed circuit is wound on entire peripheral sides of the two reels.

In the above design, a redundant length generated by the flexible printed circuit is converted from a free shape to an arcuate shape formed by bending when driven by the control structure, so that a stress is evenly distributed on the arc of the flexible printed circuit, thereby avoiding stress concentration on the flexible printed circuit, and increasing the life of the flexible printed circuit.

The two reels have a same diameter and are rotatable symmetrically with respect to a rotary shaft of the transmission member.

In the above design, the two reels are arranged symmetrically with respect to the rotary shaft of the transmission member, so that the movement of the flexible printed circuit is stable.

In a possible design, a length L of each of the reels along an axial direction is greater than a width W of the flexible printed circuit, and a difference between the length Land the width W ranges from <NUM> to <NUM>.

In the above design, the length L of the reel along the axial direction is greater than the width W of the flexible printed circuit, so that the flexible printed circuit can be stably wound on the reel without falling off during the rotation of the reel.

This application provides another flexible printed circuit assembly not encompassed by the claims. The flexible printed circuit assembly includes a flexible printed circuit and a control structure. The control structure includes a transmission member, a guide shaft, and a connecting member. The guide shaft is located on a side of the flexible printed circuit. The connecting member has one end arranged on the transmission member and an other end connected to the guide shaft. The transmission member is configured to drive the connecting member to drive the guide shaft to move, and the guide shaft is configured to drive the flexible printed circuit to bend.

In the above design, the transmission member rotates and drives the connecting member to drive the guide shaft to move, so that the guide shaft drives the flexible printed circuit to bend and form a circular arc shape. In this way, a stress is evenly distributed on the arc of the flexible printed circuit, thereby avoiding stress concentration on the flexible printed circuit, and increasing the life of the flexible printed circuit.

In a possible design, a plurality of guide shafts and a plurality of connecting members are arranged, where one end of each connecting member is arranged on the transmission member, and an other end of each connecting member is connected to one of the guide shafts; along an extending direction of the flexible printed circuit, each two adjacent guide shafts are respectively located on two opposite sides of the flexible printed circuit; and the transmission member is configured to drive the plurality of connecting members to drive the corresponding guide shafts to move, and the plurality of guide shafts are configured to drive the flexible printed circuit to bend to form a plurality of arcs, so that the flexible printed circuit is in a wave form.

In the above design, the transmission member drives the plurality of connecting members to drive the plurality of guide shafts to move, and the plurality of guide shafts drive the flexible printed circuit to bend to form a plurality of arcs, and bending directions of adjacent two arcs are different, thereby forming a wave form.

In a possible design, the plurality of guide shafts have a same diameter, and the arcs formed by the bending of the flexible printed circuit are semicircles.

In the above design, the diameters of the plurality of guide shafts are the same, but are not limited thereto. Since the diameters of the plurality of guide shafts are the same, and the guide shafts provide guidance for the bending of the flexible printed circuit, radii of the arcs formed by the bending of the flexible printed circuit are the same, and bending variations of the flexible printed circuit are the same.

According to a second aspect, this application provides an electronic device. The electronic device includes a stationary member, at least one movable member movable relative to the stationary member, and a flexible printed circuit assembly according to the first aspect. Two connecting portions are arranged on the flexible printed circuit, at least one of the connecting portions is arranged on the movable member, and the control structure is arranged between the two connecting portions.

In the above design, the flexible printed circuit assembly with a controllable redundant length is applied to the electronic device, so that the electrical connection of the movable member of the electronic device is stable, thereby improving functional stability of the electronic device.

In a possible design, the movable member is a camera assembly, where the camera assembly is configured to extend and retract relative to the stationary member, and one of the connecting portions of the flexible printed circuit is arranged on the camera assembly.

In the above design, the flexible printed circuit assembly with a controllable redundant length is applied to the electronic device, so that the electrical connection of the camera assembly of the electronic device is stable, thereby improving functional stability of the electronic device.

In a possible design, two movable members: a first middle frame and a second middle frame are arranged, where the first middle frame and the second middle frame are rotatably arranged on the stationary member to be folded or unfolded, and two of the connecting portions of the flexible printed circuit are respectively arranged on the first middle frame and the second middle frame.

In the above design, the flexible printed circuit assembly with a controllable redundant length is applied to the electronic device, so that the electrical connection of the first middle frame and the second middle frame of the electronic device is stable, thereby improving functional stability of the electronic device.

In a possible design, the transmission member is drive-connected to the movable member, so that the transmission member rotates and moves.

In the above design, energy of an external driving force is acquired by the movable member, and the movable member moves to drive the transmission member to move, so that the control structure can control the redundant length of the flexible printed circuit.

The embodiments described along <FIG> are not according to the invention and present for illustrative purposes only.

Mobile phone <NUM>; Foldable-display structure <NUM>; Side display <NUM>; Electronic device 400a, 400b, 400c, 400d, 400e; Stationary member <NUM>, 401a, <NUM>; First middle frame <NUM>; Second middle frame <NUM>; Circuit board <NUM>, <NUM>; First hinge <NUM>; Gear portion <NUM>; Second hinge <NUM>; Camera assembly <NUM>, <NUM>; Flexible printed circuit assembly <NUM>, 100a, 100b, <NUM>, 200a, 200b, <NUM>; FPC <NUM>, <NUM>, <NUM>; First connecting portion <NUM>; Second connecting portion <NUM>; Winding portion <NUM>; First extension <NUM>; Second extension <NUM>; Control structure <NUM>, 20a, 20b, 20c, <NUM>, 210a, 210b, 210c, <NUM>, 31c, 31d; Transmission member <NUM>, 21a, 21b, 21c, <NUM>, 211a, 211b, 211c, <NUM>, 311a, 311b; Reel <NUM>, 23a, 23b, 23c; Connecting member <NUM>, 213a, 213b, 213c, 313a, 313b; Guide shaft <NUM>, 215a, 215b, 215c, <NUM>, 315a, 315b, 315c, 315d.

The accompanying drawings and embodiments are combined below to further describe the technical means and effects adopted by this application to achieve the intended application purpose. Apparently, the described embodiments are only some rather than all of the embodiments of this application.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by a person of ordinary skill in the art to which this application belongs. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only, and are not intended to limit this application.

Some implementations of this application provide a flexible printed circuit assembly.

The flexible printed circuit assembly includes a flexible printed circuit and a control structure. The control structure is configured to drive a redundant length generated by movement of the flexible printed circuit to bend to form an arc. The control structure includes a transmission member and two reels. The two reels are arranged on the transmission member at an interval. The flexible printed circuit passes between the two reels along an extending direction. The transmission member is configured to drive the two reels to rotate, so that the flexible printed circuit is wound on peripheral sides of the two reels. Alternatively, the control structure includes a transmission member, a guide shaft, and a connecting member. The guide shaft is located on a side of the flexible printed circuit. The connecting member has one end arranged on the transmission member and an other end connected to the guide shaft. The transmission member is configured to drive the connecting member to drive the guide shaft to move, and the guide shaft is configured to drive the flexible printed circuit to bend.

In the above flexible printed circuit assembly, the transmission member of the control structure drives the reels or the guide shaft, and provides guidance for bending of the flexible printed circuit, so that a redundant length of the flexible printed circuit is bent to form an arcuate or circular arc shape. Since the redundant length of the flexible printed circuit is controlled by the control structure, uncertainty of the redundant length is avoided. A stress is evenly distributed on the arc of the flexible printed circuit, thereby avoiding stress concentration, and increasing the life of the flexible printed circuit. Some embodiments of this application are described in detail below with reference to the accompanying drawings. The embodiments described below and features in the embodiments may be combined with each other without conflict.

Referring to <FIG>, an embodiment of this application provides a flexible printed circuit assembly <NUM> with a controllable redundant length. The flexible printed circuit assembly <NUM> is applicable to an electronic device. The electronic device includes a stationary member and a movable member movable relative to the stationary member. The movable member can extend/retract, slide, rotate, fold, or the like relative to the stationary member. The electronic device includes but is not limited to a mobile terminal (such as a mobile phone, a tablet computer, or a notebook computer), a wearable device (such as a watch, glasses, or the like), a display device (such as a television or a display), a camera, or a game console.

The flexible printed circuit assembly <NUM> includes a flexible printed circuit (Flexible Printed Circuit, FPC) <NUM> and a control structure <NUM>. A plurality of connecting portions are arranged on the FPC <NUM>. The plurality of connecting portions include a first connecting portion <NUM> and a second connecting portion <NUM>, but this application is not limited thereto. The first connecting portion <NUM> is connected to the movable member, and the second connecting portion <NUM> is connected to the stationary member, but this application is not limited thereto. The first connecting portion <NUM> moves with the movable member. Therefore, a distance from the second connecting portion <NUM> increases (shown in <FIG>) or decreases (shown in <FIG>). When the distance between the first connecting portion <NUM> and the second connecting portion <NUM> gradually decreases, the FPC <NUM> has a redundant length. The control structure <NUM> is arranged between the first connecting portion <NUM> and the second connecting portion <NUM>. The control structure <NUM> drives the FPC <NUM> to bend, so that the FPC <NUM> forms a transitional shape of an arcuate shape. Since the redundant length of the FPC <NUM> is controlled by the control structure <NUM>, uncertainty of the redundant length is avoided.

The redundant length of the FPC <NUM> is converted from a free shape to an arcuate shape formed by bending when driven by the control structure <NUM>, so that a stress is evenly distributed on the arc of the FPC <NUM>, thereby avoiding stress concentration on the FPC <NUM>, and increasing the life of the FPC <NUM>.

Still referring to <FIG>, the control structure <NUM> includes a transmission member <NUM> and two reels <NUM>. The two reels <NUM> are arranged on the transmission member <NUM> at an interval. The FPC <NUM> passes between the two reels <NUM> along an extending direction, as shown in <FIG>. The transmission member <NUM> is configured to drive the two reels <NUM> to rotate, so that the FPC <NUM> is wound on entire peripheral sides of the two reels <NUM>, as shown in <FIG>.

Specifically, referring to <FIG>, the FPC <NUM> further includes a winding portion <NUM> between the first connecting portion <NUM> and the second connecting portion <NUM> and a first extension <NUM> and a second extension <NUM> located on two sides of the winding portion <NUM>. The winding portion <NUM> passes between the two reels <NUM> and is wound on the two reels <NUM> in a substantially S shape. When the first connecting portion <NUM> moves toward the second connecting portion <NUM> with the movable member, the first extension <NUM> and the second extension <NUM> each generate a redundant length. The transmission member <NUM> rotates and drives the two reels <NUM> to rotate. The first extension <NUM> and the second extension <NUM> of the FPC <NUM> rotate with the reels <NUM> and are wound around entire peripheral sides of the first connecting portion <NUM> and the second connecting portion <NUM>. In a possible implementation, when a position of the second connecting portion <NUM> or the first connecting portion <NUM> relative to the stationary member remains unchanged, the transmission member <NUM> rotates while moving relative to the stationary member, so that the first extension <NUM> and the second extension <NUM> do not generate redundant lengths and are stressed evenly when released and wound simultaneously. For example, when the position of the second connecting portion <NUM> relative to the stationary portion remains unchanged, the transmission member <NUM> moves away from the second connecting portion <NUM> while rotating, to release the first extension <NUM> and the second extension <NUM>, so that the second extension <NUM> does not generate a redundant length. The transmission member <NUM> rotates and moves toward the second connecting portion <NUM>, to avoid an excessive pulling force on the second extension <NUM> during simultaneous wounding of the first extension <NUM> and the second extension <NUM>, so that winding forces on the first extension <NUM> and the second extension <NUM> are even.

In a possible implementation, the first extension <NUM> and the second extension <NUM> have a same length, but this application is not limited thereto. The control structure <NUM> is substantially located at middle symmetrical positions between the first connecting portion <NUM> and the second connecting portion <NUM>, so that the forces on the first extension <NUM> and the second extension <NUM> are more even. It may be understood that, in other embodiments, the first extension <NUM> and the second extension <NUM> may have different lengths, provided that a part of the first extension <NUM> or the second extension <NUM> is wound on the two reels <NUM>.

A diameter D of each of the reels <NUM> satisfies: <NUM>≤D≤<NUM>, but this application is not limited thereto. The diameter D of the reel <NUM> is set according to a requirement for a bending radius of the FPC <NUM> and a space in the electronic device.

In order to ensure that the FPC <NUM> is stably wound on the reel <NUM> without falling off, an axial length L of the reel <NUM> is greater than a width W of the FPC <NUM>. When the reel <NUM> rotates, the FPC <NUM> is unlikely to be separated from the reel <NUM>. A difference between the length L and the width W ranges from <NUM> to <NUM>. For example, the difference between the length L and the width W is <NUM>.

It may be understood that, in other embodiments, the electronic device may include two movable members, and the first connecting portion <NUM> and the second connecting portion <NUM> of the FPC <NUM> are respectively connected to the two movable members. The first connecting portion <NUM> and the second connecting portion <NUM> can move with the two movable members. The control structure <NUM> is arranged between the first connecting portion <NUM> and the second connecting portion <NUM>, and a position of the transmission member <NUM> relative to the stationary member may remain unchanged. The transmission member <NUM> only rotates to cause the first extension <NUM> and the second extension <NUM> to be simultaneously wound or released.

It may be understood that, in other embodiments, the plurality of connecting portions of the FPC <NUM> may further include a third connecting portion (not shown). Along the extending direction of the FPC <NUM>, the first connecting portion <NUM>, the second connecting portion <NUM>, and the third connecting portion are arranged in sequence. The second connecting portion <NUM> is fixedly arranged in the electronic device, and a position of the second connecting portion relative to the stationary member remains unchanged. The first connecting portion <NUM> and the third connecting portion are connected to the movable member for movement. Two control structures <NUM> are arranged between the first connecting portion <NUM> and the second connecting portion <NUM> and between the second connecting portion <NUM> and a third connecting portion respectively.

In order to wind and release the FPC <NUM> evenly, the diameters of the two reels <NUM> are the same, and distances between the two reels <NUM> and the rotary shaft of the transmission member <NUM> are equal, so that the two reels <NUM> can rotate symmetrically with respect to the rotary shaft of the transmission member <NUM>. Rotation speeds of the first extension <NUM> and the second extension <NUM> during winding and releasing are uniform, so that the movement stability of the FPC <NUM> is improved. It may be understood that, in other embodiments, the diameters of the two reels <NUM> may be different, and the distances between the two reels <NUM> and the rotary shaft of the transmission member <NUM> may be not equal, so that the FPC <NUM> is wound around the entire peripheral sides of the two reels <NUM> in a substantially cam shape.

The reels <NUM> of the control structure <NUM> provide guidance for bending of the redundant length of the FPC <NUM>, so as to present a transitional shape of an arc. In order to prevent the FPC <NUM> from being damaged due to an excessive winding force of the reels <NUM> on the FPC <NUM>, the FPC <NUM> is configured with a sufficient length, and the first extension <NUM> and the second extension <NUM> wound around the peripheral sides of the two reels <NUM> are in no contact or partially in contact.

The transmission member <NUM> may be drive-connected to a movable structure in the electronic device by the transmission structure, so that the transmission member <NUM> can realize rotation or movement. The transmission structure may be a structure that realizes transmission by gear transmission, a sliding block linkage, or the like. Alternatively, the transmission member <NUM> may be connected to a driving structure arranged in the electronic device, and the transmission member <NUM> is driven by the driving structure to move. The rotation speed of the transmission member <NUM> and the diameters of the reels <NUM> may be set according to a variation of the distance between the first connecting portion <NUM> and the second connecting portion <NUM> and a speed of the movable member.

Referring to <FIG> and <FIG>, an electronic device 400a is a mobile terminal device, such as a foldable-display mobile phone or a foldable-display electronic reader. Two movable members: a first middle frame <NUM> and a second middle frame <NUM> are arranged. The first middle frame <NUM> and the second middle frame <NUM> are rotatably arranged on the stationary member <NUM>. Specifically, the first middle frame <NUM> is in a rotation-preventing connection to a first hinge <NUM> to prevent rotation, and the first hinge <NUM> is connected to the first middle frame <NUM> without relative rotation. The first hinge <NUM> is rotatably arranged on the stationary member <NUM>. The second middle frame <NUM> is in a rotation-preventing connection to the second hinge <NUM>, and the second hinge <NUM> is connected to the second middle frame <NUM> without relative rotation. The second hinge <NUM> is rotatably arranged on the stationary member <NUM>. The FPC <NUM> passes by the entire peripheral sides of the first hinge <NUM> and the second hinge <NUM> along the extending direction, the first connecting portion <NUM> is arranged on a circuit board <NUM> of the first middle frame <NUM>, and the second connecting portion <NUM> is arranged on a circuit board <NUM> of the second middle frame <NUM>, and the FPC <NUM> realizes electrical connection between the first middle frame <NUM> and the second middle frame <NUM>. The first middle frame <NUM> and the second middle frame <NUM> can be rotated relative to the stationary member <NUM> to form a plane, as shown in <FIG>. The first middle frame <NUM> and the second middle frame <NUM> can be rotated relative to the stationary member <NUM> to be folded together, as shown in <FIG>. The flexible printed circuit assembly 100a includes two control structures, that is, a control structure 20a and a control structure 20b. Two reels 23a of the control structure 20a are wound by the FPC <NUM> and are located between the first connecting portion <NUM> and the first hinge <NUM>. Two reels 23b of the control structure 20b are wound by the FPC <NUM> and are located between the second connecting portion <NUM> and the second hinge <NUM>.

When the first middle frame <NUM> and the second middle frame <NUM> are converted from the folded state to the unfolded state by an external driving force, the FPC <NUM> has redundant lengths on two sides of the stationary member <NUM>. A transmission member 21a rotates and moves to drive the two reels 23a to rotate, and a transmission member 21b rotates and moves to drive the two reels 23b to rotate, so that parts of the FPC <NUM> located on the two sides of the stationary member <NUM> are wound around the two reels 23a and the two reels 23b respectively. The FPC <NUM> is connected between the first middle frame <NUM> and the second middle frame <NUM> in the transitional shape of the arc, and the control structure 20a and the control structure 20b can control the redundant length of the FPC <NUM>, thereby avoiding a folded shape.

When the first middle frame <NUM> and the second middle frame <NUM> are converted from the unfolded state to the folded state by the external driving force, the transmission member 21a rotates and moves to drive the two reels 23a to rotate, and the transmission member 21b rotates and moves to drive the two reels 23b to rotate, so as to release the FPC <NUM> wound around the reels 23a and the reels 23b.

The external driving force causes the first hinge <NUM> to rotate with the first middle frame <NUM> and the second hinge <NUM> to rotate with the second middle frame <NUM>. The transmission member 21a may be drive-connected to the first hinge <NUM> (the movable structure in the electronic device) to realize rotation and movement, and the transmission member 21b may be drive-connected to the second hinge <NUM> (the movable structure in the electronic device) to realize rotation and movement. For example, referring to <FIG>, a gear portion <NUM> is arranged on the first hinge <NUM>, the transmission member <NUM> is a gear structure, and the transmission member <NUM> is engaged with and drive-connected to the gear portion <NUM>. When the external driving force drives the first middle frame <NUM> to rotate, the transmission member 21a rotates about an axis thereof and rotates about a rotary shaft of the first hinge <NUM> to achieve movement.

It may be understood that, in other embodiments, the transmission member <NUM> may be caused to rotate and move in other driving manners. For example, an independent driving structure such as a motor assembly is arranged in the electronic device 400a, and the motor assembly directly drives the transmission member <NUM> to move.

It may be understood that, in other embodiments, in order to reduce a size of the electronic device and simplify a structure of the electronic device, the first middle frame <NUM> and the second middle frame <NUM> may be rotatably arranged on the stationary member <NUM> by one hinge (not shown). For example, the hinge includes a shaft and two leaves arranged on the shaft, and the first middle frame <NUM> and the second middle frame <NUM> are respectively connected to the two leaves.

Referring to <FIG> and <FIG>, the electronic device 400b is a mobile terminal device such as a mobile phone including a movable member that can perform a telescopic movement. A stationary member 401a is a circuit board on a middle frame or a housing structure of the electronic device 400b. A movable member is a camera assembly <NUM>. The camera assembly <NUM> is slidably arranged on the stationary member 401a. The camera assembly <NUM> can extend out of or retract into the housing of the electronic device 400b. The first connecting portion <NUM> of the FPC <NUM> is arranged on the camera assembly <NUM>, and the second connecting portion <NUM> is arranged on the stationary member 401a. Two reels 23c of a control structure 20c are wound by the FPC <NUM> and are located between the first connecting portion <NUM> and the second connecting portion <NUM>.

When the camera assembly <NUM> is converted from an extended state to a retracted state, the distance between the first connecting portion <NUM> and the second connecting portion <NUM> of the FPC <NUM> is shortened, and the transmission member 21c rotates and moves to drive the first extension <NUM> and the second extension <NUM> of the FPC <NUM> to be wound around peripheral sides of the two reels 23c, so that the FPC <NUM> is connected between the camera assembly <NUM> and the stationary member 401a in the transitional shape of the arc, and the control structure 20c can control the redundant length of the FPC <NUM>, thereby avoiding a folded shape.

The electronic device 400b further includes a driving structure (not shown). The transmission member 21c may be connected to the driving structure, and the driving structure drives the camera assembly <NUM> to move and drive the transmission member 21c to rotate and move.

Referring to <FIG>, an embodiment of this application provides a flexible printed circuit assembly <NUM> with a controllable redundant length. The flexible printed circuit assembly <NUM> is applicable to an electronic device. The electronic device includes a stationary member and a movable member movable relative to the stationary member. The flexible printed circuit assembly <NUM> includes an FPC <NUM> and a control structure <NUM>. A plurality of connecting portions are arranged on the FPC <NUM>. The plurality of connecting portions include a first connecting portion <NUM> and a second connecting portion <NUM>, but this application is not limited thereto. The first connecting portion <NUM> is connected to the movable member, and the second connecting portion <NUM> is connected to the stationary member, but this application is not limited thereto. For example, the electronic device may further include another movable member, and the second connecting portion <NUM> may be connected to the another movable member, so that the first connecting portion <NUM> and the second connecting portion <NUM> of the FPC <NUM> both can move. The first connecting portion <NUM> moves with the movable member. Therefore, a distance from the second connecting portion <NUM> increases (a position shown by dashed lines in <FIG>) or decreases (a position shown by solid lines in <FIG>). When the distance between the first connecting portion <NUM> and the second connecting portion <NUM> gradually decreases, the FPC <NUM> has a redundant length. The control structure <NUM> is arranged between the first connecting portion <NUM> and the second connecting portion <NUM>. The control structure <NUM> drives the FPC <NUM> to bend, so that the FPC <NUM> forms a transitional shape of a circular arc. The redundant length of the FPC <NUM> is limited by the control structure <NUM>, so that a radius R of the arc formed by the bending of the FPC <NUM> satisfies requirements. For example, the radius R is greater than <NUM>.

The redundant length of the FPC <NUM> is converted from a free shape to the arc shape formed by bending when driven by the control structure <NUM>, so that a stress is evenly distributed on the arc of the FPC <NUM>, thereby avoiding stress concentration on the FPC <NUM>, and increasing the life of the FPC <NUM>.

The control structure <NUM> includes a transmission member <NUM>, a guide shaft <NUM>, and a connecting member <NUM>. One transmission member <NUM>, one guide shaft <NUM>, and one connecting member <NUM> are arranged, but this application is not limited thereto. The transmission member <NUM> may be drive-connected to a movable structure in the electronic device, so that the transmission member <NUM> can realize rotation or movement. One end of the connecting member <NUM> is arranged on the transmission member <NUM>, and an other end of the connecting member is arranged on the guide shaft <NUM>. The guide shaft <NUM> is located on a side of the FPC <NUM>. The transmission member <NUM> rotates and drives the connecting member <NUM> to drive the guide shaft <NUM> to move. The guide shaft <NUM> moves to come into contact with a side of the FPC <NUM>, and continues moving to drive the FPC <NUM> to bend to form an arc shape. The FPC <NUM> moves along the guide shaft <NUM> by a tension of the FPC, and the arcs formed by the FPC <NUM> on two sides of the guide shaft <NUM> are substantially the same.

The guide shaft <NUM> is rotatably arranged on the connecting member <NUM>, so that the guide shaft <NUM> can roll along the FPC <NUM>. In this way, a friction between the guide shaft <NUM> and the FPC <NUM> is reduced. It may be understood that, in other embodiments, the guide shaft <NUM> and the connecting member <NUM> may be connected together without relative rotation.

Diameters of the plurality of guide shafts <NUM> are the same, but this application is not limited thereto. Since the diameters of the plurality of guide shafts <NUM> are the same, and the guide shafts <NUM> provide guidance for the bending of the FPC <NUM>, radii of the arcs formed by the bending of the FPC <NUM> are the same, and bending variations of the FPC <NUM> are the same.

It may be understood that, in other embodiments, the diameters of the guide shafts <NUM> may be different, and the FPC <NUM> bends to form a plurality of arcs with different radii. It may be understood that, in other embodiments, a plurality of guide shafts <NUM> and a plurality of connecting members <NUM> may be arranged. For example, in till another embodiment, referring to <FIG>, a control structure <NUM> of a flexible printed circuit assembly <NUM> is substantially the same as the control structure <NUM>, except that the control structure <NUM> includes two connecting members, that is, a connecting member 313a and a connecting member 313b, and two guide shafts, that is, a guide shaft 315a and a guide shaft 315b. One end of the connecting member 313a is arranged on the transmission member <NUM>, and an other end of the connecting member is arranged on the guide shaft 315a. One end of the connecting member 313b is arranged on the transmission member <NUM>, and an other end of the connecting member is arranged on the guide shaft 315b. Along the extending direction of the FPC <NUM>, the guide shaft 315a and the guide shaft 315b are located on two opposite sides of the FPC <NUM> respectively. The first connecting portion <NUM> and the second connecting portion <NUM> of the FPC <NUM> move relative to each other. Therefore, a distance between the two portions increases (a position shown by dashed lines in <FIG>) or decreases (a position shown by solid lines in <FIG>). When the distance between the first connecting portion <NUM> and the second connecting portion <NUM> of the FPC <NUM> decreases and a redundant length is generated, the transmission member <NUM> drives the connecting member 313a and the connecting member 313b to respectively drive the corresponding guide shaft 315a and the guide shaft 315b to move. The guide shaft 315a and the guide shaft 315b respectively move from the two sides of the FPC <NUM> to come into contact with the FPC <NUM>, and continue moving to cause the FPC <NUM> to move to form two arcs. The two arcs form a wave form.

It may be understood that, in other embodiments, three, four, or other numbers of guide shafts <NUM> and connecting members <NUM> may be arranged. The numbers of the guide shafts <NUM> and the connecting members <NUM> may be set according to the redundant length generated by the FPC <NUM>, as long as each two adjacent guide shafts <NUM> are respectively located on the two opposite sides of the FPC <NUM> along the extending direction of the FPC <NUM>. The transmission member <NUM> drives the plurality of connecting members <NUM> to drive the plurality of guide shafts <NUM> to move, and the plurality of guide shafts <NUM> drive the FPC <NUM> to bend to form a plurality of arcs, and bending directions of adjacent two arcs are different, so that the FPC <NUM> forms a wave form.

It may be understood that, in other embodiments, a plurality of transmission members <NUM> may be arranged. Each transmission member <NUM> is connected to one connecting member <NUM>, to drive one corresponding guide shaft <NUM> to come into contact with the FPC <NUM>, so as to cause the FPC <NUM> to bend to form an arc.

Referring to <FIG> and <FIG>, an electronic device 400c is substantially the same as the electronic device 400a in the first embodiment, except that a control structure of the electronic device 400c is different from the control structures 20a and 20b of the electronic device 400a. The control structure of the electronic device 400c is the control structure <NUM> shown in <FIG>.

The flexible printed circuit assembly 200a in the electronic device 400c includes two control structures, that is, a control structure 210a and a control structure 210b. The control structure 210a is located between the first hinge <NUM> and the circuit board <NUM> of the first middle frame <NUM>. The control structure 210b is located between the second hinge <NUM> and the circuit board <NUM> of the second middle frame <NUM>.

When the first middle frame <NUM> and the second middle frame <NUM> are converted from the folded state to the unfolded state by an external driving force, the FPC <NUM> has redundant lengths on two sides of the stationary member <NUM>. A transmission member 211a of the control structure 210a rotates and moves, so that a connecting member <NUM> a drives a guide shaft 215a to come into contact with the FPC <NUM>, thereby causing the FPC <NUM> between the first hinge <NUM> and the circuit board <NUM> to bend to form an arc. A transmission member 211b of the control structure 210b rotates and moves, so that a connecting member 213b drives a guide shaft 215b to come into contact with the FPC <NUM>, thereby causing the FPC <NUM> between the second hinge <NUM> and the circuit board <NUM> to bend to form an arc. The FPC <NUM> is connected between the first middle frame <NUM> and the second middle frame <NUM> in the transitional shape of the arc, and the control structure 210a and the control structure 210b can control the redundant length of the FPC <NUM>, thereby avoiding a folded shape.

When the first middle frame <NUM> and the second middle frame <NUM> are driven by an external driving force to be converted from the unfolded state to the folded state, parts of the FPC <NUM> between the first hinge <NUM> and the circuit board <NUM> and between the second hinge <NUM> and the circuit board <NUM> substantially each exhibit a plane. The transmission member 211a and the transmission member 211b respectively drive the guide shaft 215a and the guide shaft 215b to move to be tangent to the substantially planar portions on the FPC <NUM>, but this application is not limited thereto. For example, in another embodiment, the guide shaft 215a and the guide shaft 215b may not be in contact with the FPC <NUM>.

It may be understood that, in other embodiments, when the electronic device 400c is in a folded state, the parts of the FPC <NUM> between the first hinge <NUM> and the circuit board <NUM> and between the second hinge <NUM> and the circuit board <NUM> each may be a curved surface. The guide shaft 215a and the guide shaft 215b respectively intersect with the curved surfaces, and a bending radius of the curved surface is greater than a radius of the arc of the FPC <NUM> when the electronic device 400c is in the unfolded state. Referring to <FIG>, when the electronic device 400c is in the unfolded state, the arc generated by the FPC <NUM> is a semicircle, and distances l between the guide shaft 215a and the guide shaft 215b and an axis of symmetry O1 of the stationary member 401a satisfies: l=4R. A length N of the wave form formed between the first hinge <NUM> and the circuit board <NUM> by the FPC <NUM> satisfies: N=<NUM>. R is the radius of the arc formed by the bending of the FPC <NUM>, and R><NUM>. It may be understood that, in other embodiments, the arc generated by the FPC <NUM> may be an inferior arc, and correspondingly, the distances l may be less than 4R.

The transmission member 211a is drive-connected to the first hinge <NUM> (the movable structure) to realize rotation and movement, and the transmission member 211b is drive-connected to the second hinge <NUM> (the movable structure) to realize rotation and movement. For example, as shown in <FIG>, a gear portion <NUM> is arranged on the first hinge <NUM>, the transmission member 211a is a gear structure, and the transmission member 211a is engaged with and drive-connected to the gear portion <NUM>. One end of the connecting member <NUM> is connected to the transmission member <NUM> without relative rotation, and an other end of the connecting member is rotatably connected to the guide shaft 215a. When the external driving force drives the first middle frame <NUM> to rotate, the transmission member 211a rotates about an axis of the transmission member and rotates about the rotary shaft of the first hinge <NUM> to achieve movement, so that the guide shaft 215a comes into contact with the FPC <NUM> to cause the FPC <NUM> to bend.

The electronic device 400c acquires energy of the external driving force by using the movable members (the first middle frame <NUM>, the first hinge <NUM>, the second middle frame <NUM>, and the second hinge <NUM>), and the movement of the movable members drives the transmission member 211a and the transmission member 211b to move, so that the control structure 210a and the control structure 210b can control the redundant length of the FPC <NUM>.

Referring to <FIG> and <FIG>, an electronic device 400d is substantially the same as the electronic device 400a in the first embodiment, except that a control structure of the electronic device 400d is different from the control structures 20a and 20b of the electronic device 400a. A control structure of the electronic device 400d is the same as the control structure <NUM> shown in <FIG>.

The flexible printed circuit assembly <NUM> in the electronic device 400d includes two control structures, that is, a control structure 31c and a control structure 31d. The control structure 31c is located between the first hinge <NUM> and the circuit board <NUM> of the first middle frame <NUM>. The control structure 31d is located between the second hinge <NUM> and the circuit board <NUM> of the second middle frame <NUM>.

When the first middle frame <NUM> and the second middle frame <NUM> are converted from the folded state to the unfolded state by an external driving force, the FPC <NUM> has redundant lengths on two sides of the stationary member <NUM>. Two guide shafts 315c of the control structure 31c are in contact with the two sides of the FPC <NUM>, and cause the FPC <NUM> between the first hinge <NUM> and the circuit board <NUM> to bend to form two arcs. Two guide shafts 315d of the control structure 31d are in contact with the two sides of the FPC <NUM>, and cause the FPC <NUM> between the second hinge <NUM> and the circuit board <NUM> to bend to form two arcs. The FPC <NUM> is connected between the first middle frame <NUM> and the second middle frame <NUM> in the transitional shape of the arc, and the control structure 31c and the control structure 31d can control the redundant length of the FPC <NUM>, thereby avoiding a folded shape.

Referring to <FIG>, an electronic device 400e is substantially the same as the electronic device 400b in the second embodiment, except that a control structure 210c of the electronic device 400e is different from the control structure 20c of the electronic device 400b. The control structure 210c of the electronic device 400e is the same as the control structure <NUM> shown in <FIG>. The control structure 210c is located between the first connecting portion <NUM> and the second connecting portion <NUM> of the FPC <NUM>.

When the camera assembly <NUM> is converted from the extended state to the retracted state, the distance between the first connecting portion <NUM> and the second connecting portion <NUM> of the FPC <NUM> is shortened. The transmission member 211c rotates and moves, to drive the connecting member 213c to drive the guide shaft 215c to move to come into contact with the FPC <NUM>, and continues moving to cause the FPC <NUM> bend to form an arc. The FPC <NUM> is connected between the camera assembly <NUM> and the stationary member 401a in the transitional shape of the arc, and the control structure 210c can control the redundant length of the FPC <NUM>, thereby avoiding a half-folded shape.

Claim 1:
A flexible printed circuit assembly (<NUM>), characterized by comprising a flexible printed circuit (<NUM>) and a control structure (<NUM>), wherein the control structure (<NUM>) comprises:
a transmission member (<NUM>); and
two reels (<NUM>), arranged on the transmission member (<NUM>) at an interval, and being symmetrically arranged with respect to a rotary shaft of the transmission member (<NUM>) wherein the flexible printed circuit (<NUM>) passes between the two reels (<NUM>); and
the transmission member (<NUM>) is configured to rotate and to drive the two reels (<NUM>) to rotate, and to provide guidance for bending of the flexible printed circuit, so that the flexible printed circuit (<NUM>) is wound on entire peripheral sides of the two reels (<NUM>) and so that a redundant length of the flexible printed circuit (<NUM>) is bent to form an arcuate shape or a circular arc shape, wherein the two reels (<NUM>) have a same diameter and are rotatable symmetrically with respect to the rotary shaft of the transmission member (<NUM>).