Multi-axis hinge device and electronic device using the multi-axis hinge device

Abstract

To provide a multi-axis hinge device capable of stably keeping closing states of a first housing and a second housing.SOLUTION: A space portion capable of housing a folded part of a flexible display sheet folded in closing a first housing and a second housing, is formed between a base plate 7, and a front-side plate 9 and a rear-side plate 10. A synchronous rotation mechanism for synchronously rotating the front-side plate and the rear-side plate in accompany with opening / closing of the first housing and second housing, and an energization mechanism for energizing the front-side plate and the rear-side plate in a closing direction and capable of keeping a closing state and an opening state of the front-side plate and the rear-side plate, are disposed.SELECTED DRAWING: Figure 7

Description

Technical Field

[0004] ,

[0003]

[0001] The present invention relates to a multi-axis hinge device suitable for use in various electronic devices such as mobile phones, electronic notebooks, PDAs, netbooks, and even notebook computers, which is formed by attaching a flexible display sheet made of, for example, organic EL across both surfaces of a first housing and a second housing.

Background Art

[0002] In recent years, electronic devices such as mobile phones have been developed and are becoming popular, which are formed by attaching a single flexible display sheet made of organic EL across both surfaces of a first housing and a second housing. As a hinge device for connecting the first housing and the second housing of such an electronic device so as to be openable and closable with each other, a multi-axis hinge device using a plurality of hinge pins is known from the following Patent Document 1. This multi-axis hinge device is configured such that the bending portion maintains a constant radius of curvature in the internal space of the multi-axis hinge device so that the flexible display sheet does not bend or malfunction when the first housing and the second housing are opened and closed.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In some multi-axis hinge devices, if the repulsive force of the flexible display sheet, which has a teardrop-shaped cross-section, is large, the bent flexible display sheet can push apart the first and second housings in their closed state, making it impossible to maintain the closed state with the multi-axis hinge device while supporting the weight of the electronic device. Also, if the mounting accuracy of the flexible display sheet to the first and second housings is low, wrinkles or sagging may occur in the flexible display sheet when the first and second housings are in their open state. The present invention aims to provide a multi-axis hinge device that can smoothly achieve and stably maintain the closed state of the first and second housings. It also aims to provide a multi-axis hinge that is less prone to wrinkles and sagging in the flexible display sheet when the first and second housings are open. [Means for solving the problem]

[0005] To solve the above problems, the present invention provides a multi-axis hinge device that is provided below the flexible display sheet of an electronic device having a flexible display sheet attached across both surfaces of a first housing and a second housing, and connects the first housing and the second housing so that they can be opened and closed, comprising: a base plate provided in the left-right direction on each of the rear ends of the first housing and the second housing facing each other; a front side plate and a rear side plate rotatably attached to the front and rear sides of the base plate via a first hinge pin and a second hinge pin, respectively; a first mounting plate and a second mounting plate rotatably attached to the base plate via a first pivot pin portion and a second pivot pin portion, and further slidably attached to the free ends of the front side plate and the rear side plate via a third hinge pin and a fourth hinge pin, respectively, and attaching the respective rear ends of the first housing and the second housing to the respective free ends, wherein the base plate and the... A multi-axis hinge device is provided such that a space is formed between the front side plate and the rear side plate that can accommodate the folded portion of the flexible display sheet that is folded when the first housing and the second housing are closed, and the device comprises a synchronous rotation mechanism that synchronously rotates the front side plate and the rear side plate in conjunction with the opening and closing of the first housing and the second housing, and a biasing mechanism that biases the front side plate and the rear side plate in the closing direction and can maintain the closed and open states of the front side plate and the rear side plate, wherein the biasing mechanism comprises a compression coil spring that is compressed in the front-rear direction along the base plate, a pair of slide cams provided at both ends of the compression coil spring, and a pair of cam follower parts provided on the front side plate and the rear side plate that slide the slide cams in conjunction with rotation via the first hinge pin and the second hinge pin to compress the compression coil spring in the front-rear direction.

[0006] Next, the invention described in claim 2 has a tension adjustment mechanism that adjusts the tension of the flexible display sheet by moving at least one of the first mounting plate and the second mounting plate, which is maintained in an open state by the biasing mechanism, in the front-rear direction according to the tension of the flexible display sheet, the tension adjustment mechanism is characterized by having a slider that contacts at least one of the third hinge pin and the fourth hinge pin and slides in the front-rear direction, and a compression coil spring provided between at least one of the first mounting plate and the second mounting plate and the slider.

[0007] Next, the invention described in claim 3 is characterized in that the synchronous rotation mechanism comprises a first lever gear, which is rotatably mounted on the base plate via a third pivot pin and driven by rotation via the first hinge pin of the front side plate, and a second lever gear, which is rotatably mounted on the base plate via a fourth pivot pin and driven by rotation via the second hinge pin of the rear side plate, meshing together.

[0008] Next, the invention described in claim 4 is characterized in that the synchronous rotation mechanism has a suction mechanism that sucks the front side plate and the rear side plate into a closed state and an open state to stop rotation, the suction mechanism has a fixed cam plate that is rotatably connected to the third support pin portion and the fourth support pin portion, a pair of rotating cam plates that are fixed to the third support pin portion and the fourth support pin portion by overlapping the uneven surface with the fixed cam plate, and a compression spring member that compresses the overlap between the fixed cam plate and the rotating cam plates.

[0009] Next, the invention described in claim 5 is a multi-axis hinge device provided below the flexible display sheet of an electronic device having a flexible display sheet attached across both surfaces of a first housing and a second housing, and connecting the first housing and the second housing so that they can be opened and closed, comprising: a base plate provided in the left-right direction on each of the rear ends of the first housing and the second housing facing each other; a front side plate and a rear side plate rotatably attached to the front and rear sides of the base plate via a first hinge pin and a second hinge pin, respectively; and a first mounting plate and a second mounting plate rotatably attached to the base plate via a first pivot pin portion and a second pivot pin portion, and further slidably attached to the free ends of the front side plate and the rear side plate via a third hinge pin and a fourth hinge pin, respectively, for attaching the respective rear ends of the first housing and the second housing to each of their free ends. A multi-axis hinge device having the following features: a base plate, a front side plate, and a rear side plate, wherein a space is formed between the base plate, the front side plate, and the rear side plate that can accommodate the folded portion of the flexible display sheet that is folded when the first housing and the second housing are closed; a synchronous rotation mechanism that synchronously rotates the front side plate and the rear side plate in conjunction with the opening and closing of the first housing and the second housing; and a tension adjustment mechanism that adjusts the tension of the flexible display sheet by moving at least one of the first mounting plate and the second mounting plate toward the open state in the front-rear direction according to the tension of the flexible display sheet, wherein the tension adjustment mechanism comprises a slider that contacts at least one of the third hinge pin and the fourth hinge pin and slides in the front-rear direction, and a compression coil spring provided between at least one of the first mounting plate and the second mounting plate and the slider.

[0010] To solve the above problems, the electronic device of the present invention is characterized by using a multi-axis hinge device as described in any one of claims 1 to 5. [Effects of the Invention]

[0011] With the configuration described in claim 1, even if the repulsive force of the flexible display sheet, whose cross-section is bent into a teardrop shape, is large when the first and second housings are closed, the first and second housings can be maintained in a stable closed state while supporting the weight of the electronic device.

[0012] With the configuration described in claim 2, even if the mounting accuracy of the flexible display sheet is low, wrinkles and sagging are less likely to occur in the flexible display sheet when the first housing and the second housing are opened.

[0013] As configured in claim 3, the synchronous rotation mechanism allows the first mounting plate and the second mounting plate to rotate synchronously and open and close symmetrically, thereby improving the operability of the multi-axis hinge device. Furthermore, the synchronous rotation mechanism can be realized with a simple and relatively easy configuration using a small number of parts, making the multi-axis hinge device thinner.

[0014] As configured in claim 4, the suction mechanism sucks the first mounting plate and the second mounting plate into the closed position and open position, respectively, near the open position, and stops them there. This stabilizes the open and closed states of the multi-axis hinge device 6 and improves the operability of the opening and closing process of the multi-axis hinge device 6.

[0015] With the configuration described in claim 5, even if the mounting accuracy of the flexible display sheet is low, wrinkles and sagging are less likely to occur in the flexible display sheet when the first housing and the second housing are opened.

[0016] With the configuration described in claim 6, even if the repulsive force of the flexible display sheet, which has a teardrop-shaped cross-section, is large when the electronic device is in a closed state, the electronic device can be supported by its own weight and maintained in a stable closed state. [Brief explanation of the drawing]

[0017] [Figure 1]An electronic device having a flexible display sheet using the multi-axis hinge device according to the present invention is shown, which is a perspective view of a state where the first housing and the second housing are opened 180 degrees. [Figure 2] In the electronic device shown in FIG. 1, it is a perspective view of a closed state where the first housing and the second housing are closed to 0 degrees. [Figure 3] In the electronic device shown in FIG. 1, it is a cross-sectional view of a closed state where the first housing and the second housing are closed to 0 degrees. [Figure 4] In the electronic device shown in FIG. 1, it is a perspective view of a state where the flexible display sheet and the protective sheet are removed to expose the multi-axis hinge device. [Figure 5] It is an enlarged perspective view of the multi-axis hinge device shown in FIG. 4 taken out and enlarged. [Figure 6] It is an enlarged perspective view of the multi-axis hinge device shown in FIG. 4 as seen from above in a closed state where the first mounting plate and the second mounting plate are closed to 0 degrees. [Figure 7] It is an exploded perspective view of the multi-axis hinge device shown in FIG. 4. [Figure 8] It is an exploded perspective view of the synchronous rotation mechanism of the multi-axis hinge device shown in FIG. 7. [Figure 9] It is an exploded perspective view of the first mounting plate including the tension adjustment mechanism of the multi-axis hinge device shown in FIG. 7. [Figure 10] It is an exploded perspective view of the front side plate including the biasing mechanism of the multi-axis hinge device shown in FIG. 7. [Figure 11] It is an exploded perspective view of the base plate including the biasing mechanism of the multi-axis hinge device shown in FIG. 7. [Figure 12] It is an explanatory view of the structure of the base plate of the multi-axis hinge device shown in FIG. 7, where (a) is a perspective view and (b) is a plan view. [Figure 13] It is an explanatory view of the structure of the front side plate of the multi-axis hinge device shown in FIG. 7, where (a) is a perspective view and (b) is a perspective view seen from another angle. [Figure 14] It is an explanatory view of the structure of the first mounting plate of the multi-axis hinge device shown in FIG. 7, where (a) is a perspective view and (b) is a perspective view seen from another angle. [Figure 15] Figure 7 is an explanatory diagram of the first guide portion and the second guide portion formed on the first mounting plate and the second mounting plate of the multi-axis hinge device shown, where (a) is a cross-section of the synchronous rotation mechanism and (b) is a cross-section of the biasing mechanism. [Figure 16] Figure 7 is an explanatory diagram of the operation of the synchronous rotation mechanism and tension adjustment mechanism of the multi-axis hinge device, where (a) is the closed state with the hinge closed to 0 degrees, (b) is the open state with the hinge open to 90 degrees, and (c) is the fully open state with the hinge open to 180 degrees. [Figure 17] Figure 7 is an explanatory diagram of the operation of the biasing mechanism of the multi-axis hinge device, where (a) is the closed state with the hinge closed to 0 degrees, (b) is the open state with the hinge open to 90 degrees, and (c) is the fully open state with the hinge open to 180 degrees. [Figure 18] Figure 7 is an explanatory diagram showing that the multi-axis hinge device, when opened 180 degrees, has a first mounting plate and a second mounting plate that are movable outward and inward in the front-rear direction, where (a) is the state when moved outward in the front-rear direction, and (b) is the state when moved inward in the front-rear direction. [Figure 19] Figure 7 is an explanatory diagram illustrating how the movement of the first and second mounting plates is restricted in the closed state (0 degrees) and the open state (90 degrees) of the multi-axis hinge device shown, where (a) is the closed state (0 degrees), (b) is the open state (90 degrees), and (c) is the open state (180 degrees). [Figure 20] Figure 8 is a conceptual schematic diagram illustrating the operation of the suction mechanism, where (a) is the closed state with the suction mechanism closed to 0 degrees, (b) is the state with an open angle close to 0 degrees, (c) is the state with an open angle close to 180 degrees, and (d) is the open state with the suction mechanism open to 180 degrees. [Modes for carrying out the invention]

[0018] Embodiments of the multi-axis hinge device according to the present invention and electronic devices using this multi-axis hinge device will be described in detail below with reference to the attached drawings. Figures 1 to 4 schematically show a mobile phone (smartphone) as an example of an electronic device using the multi-axis hinge device according to the present invention. In the following figures, the free end side from which the first housing 2 and the second housing 3 are opened is called the front end side, and the side from which the first housing 2 and the second housing 3 are connected by the multi-axis hinge device 6 is called the rear end side. Also, when viewed from the front end side of the first housing 2, the left side in the left-right direction is called the left side, and the right side is called the right side, the upper side in the up-down direction is called the upper side, and the lower side is called the lower side, the front side in the front-back direction is called the front side, and the back side is called the rear side. Therefore, the direction in which the first housing 2 and the second housing 3 are connected is called the front-back direction, and the width direction perpendicular to the front-back direction is called the left-right direction.

[0019] As shown in Figure 1, the mobile phone 1 has a flexible display sheet 5 attached across both surfaces of a first housing 2 and a second housing 3. As shown in Figures 2 and 3, the mobile phone 1 is folded in half with the flexible display sheet 5 facing inward by a multi-axis hinge device 6. As shown in Figure 4, the multi-axis hinge device 6 is provided below the flexible display sheet 5 and a pair of protective sheets 4 of the mobile phone 1, and connects the first housing 2 and the second housing 3 so that they can be opened and closed. The multi-axis hinge device 6 has a base plate 7, a front side plate 9 and a rear side plate 10, a first mounting plate 17 and a second mounting plate 18, and a space 30 can be formed between the base plate 7 and the front side plate 9 and the rear side plate 10 to accommodate the folded portion of the teardrop-shaped cross-section of the flexible display sheet 5 that is folded when the first housing 2 and the second housing 3 are closed. The protective sheets 4 may back up the entire surface of the flexible display sheet 5 as described in Japanese Patent Application Publication No. 2020-125841.

[0020] As shown in Figure 4, the multi-axis hinge device 6 is fixed to the frame 2a of the first housing 2 by fastening the free end 17f of the first mounting plate 17 to the frame 2a of the first housing 2 by fastening the screw 6a to the mounting hole 17a. The free end 18f of the second mounting plate 18 is fixed to the frame 3a of the second housing 3 by fastening the screw 6a to the mounting hole 18a. As shown in Figure 5, magnetic sheets 9c and 10c are attached to the front side plate 9 and the rear side plate 10.

[0021] The magnetic sheets 9c and 10c attract a magnetic layer (not shown) provided on the back of the flexible display sheet 5, causing the flexible display sheet 5 to expand to fill the space 30 and form a large radius when folded. As shown in Figure 10, the magnetic sheets 9c and 10c are attached to the front side plate 9 and the rear side plate 10 using double-sided adhesive tapes 9d and (10d: not shown).

[0022] Next, the components of the multi-axis hinge device 6 will be described. In the following description, the front side plate 9 and the rear side plate 10, as well as the first mounting plate 17 and the second mounting plate 18, are each formed in the same shape and symmetrical in the longitudinal direction. For this reason, the front side plate 9 and the first mounting plate 17 will be described in detail, and for the rear side plate 10 and the second mounting plate 18, the numerical parts 9 and 17 in the reference numerals will be read as 10 and 18, respectively, and redundant explanations will be omitted.

[0023] As shown in Figure 4, the base plate 7 is provided on the left-right side of each rear end of the first housing 2 and the second housing 3 that face each other. As shown in Figure 5, the base plate 7 has a first pivot pin portion 13 and a second pivot pin portion 14 at the center of the front-rear direction of the left-right ends. As shown in Figure 12, the base plate 7 has a first hinge pin 11 and a second hinge pin 12 located at a predetermined distance D outside the first pivot pin portion 13 and the second pivot pin portion 14 in the front-rear direction.

[0024] As shown in Figures 7, 11, and 12, the base plate 7 is a vertically elongated molded product made of synthetic resin, formed symmetrically with a cable insertion portion 7s located in the center of its longitudinal direction, and is constructed by attaching bearing portions 7h, 7h to both ends of the main body 7g. The base plate 7 has a connecting portion for the front side plate 9 using a first hinge pin 11 and a bearing portion 11d on the front side in the front-rear direction, and a connecting portion for the rear side plate 10 using a second hinge pin 12 and a bearing portion 12d on the rear side in the front-rear direction. The connecting portion for the front side plate 9 is formed to protrude forward, and a pin hole 11e for the first hinge pin 11 is formed therein. The connecting portion for the rear side plate 10 is formed to protrude rearward, and a pin hole 12e for the second hinge pin 12 is formed therein. The bearing portions 11d, 11d are fixed to the base plate 7 on the same axis as the first hinge pins 11, 11, and rotatably support the shaft portions 11c, 11c of the front side plate 9. The bearing portions 12d, 12d are fixed to the base plate 7 on the same axis as the second hinge pins 12, 12, and rotatably support the shaft portions 12c, 12c of the rear side plate 10.

[0025] As shown in Figures 7, 10, 13, and 15, the front side plate 9 and the rear side plate 10 are rotatably attached to the front and rear sides of the base plate 7 via a first hinge pin 11 and a second hinge pin 12, respectively. The front side plate 9 and the rear side plate 10 have a third hinge pin 15 and a fourth hinge pin 16 on the side where they can rotate freely relative to the base plate 7.

[0026] The front side plate 9 and rear side plate 10 are elongated molded products made of synthetic resin, formed symmetrically with a cable insertion portion 9s located in the center of the longitudinal direction. As shown in Figure 10, the front side plate 9 is attached to the base plate 7 by crimping the connecting portion 11f with a pin 11g. The front side plate 9 is provided with connecting portions 15a and 15b of the first mounting plate 17 using a third hinge pin 15. The rear side plate 10 is similarly provided with connecting portions 12f of the base plate 7 and connecting portions 16a and 16b of the second mounting plate 18.

[0027] The first hinge pins 11, 11 are rotatably inserted at one end into the pin holes 11a, 11a of the front side plate 9, and the other end is press-fitted into the pin holes 11e, 11e of the base plate 7. The second hinge pins 12, 12 are rotatably inserted at one end into the pin holes 12a, 12a of the rear side plate 10, and the other end is press-fitted into the pin holes 12e, 12e of the base plate 7. The shaft portions 11c, 11c are on the same axis as the first hinge pins 11, 11 inserted into the pin holes 11a, 11a, and are fixed to the front side plate 9. The shaft portions 12c, 12c are on the same axis as the second hinge pins 12, 12 inserted into the pin holes 12a, 12a, and are fixed to the rear side plate 10.

[0028] The third hinge pin 15 has a flange portion 15c and a ring groove 15d. As shown in Figure 6, the third hinge pin 15 is assembled by inserting it from the outside through the working holes 17c, 17c of the first mounting plate 17 into the connecting portions 15a, 15b and guide portion 17d of the front side plate 9, and fitting a ring member (not shown) into the ring groove 15d. Similarly, the fourth hinge pin 16 is assembled by inserting it from the outside through the working hole 18c of the second mounting plate 18 into the connecting portions 16a, 16b and the second guide portion (18d: Figure 15) of the rear side plate 10.

[0029] As shown in Figures 16 and 19, the first mounting plate 17 and the second mounting plate 18 are rotatably attached to the base plate 7 via the first pivot pin portion 13 and the second pivot pin portion 14. The first mounting plate 17 and the second mounting plate 18 are slidably attached to the free ends of the front side plate 9 and the rear side plate 10 via the third hinge pin 15 and the fourth hinge pin 16, respectively, and the rear ends of the first housing 2 and the second housing 3 are attached to the free ends of the first mounting plate 17 and the rear side plate 10, respectively. The first guide portion 17d and the second guide portion 18d guide the third hinge pin 15 and the fourth hinge pin 16 so that they can slide diagonally and rotate.

[0030] As shown in Figures 7 and 14, the first mounting plate 17 and the second mounting plate 18 are elongated molded products made of synthetic resin, formed symmetrically with cable insertion portions 17s and 18s located in the center of their longitudinal direction. The first mounting plate 17 has connecting portions (holes 13a) for the base plate 7 using first pivot pin portions 13 at the tip of the arm portions 17e at both ends in the longitudinal direction, and a connecting portion (first guide portion 17d) for the front side plate 9 using a third hinge pin 15 inside. Similarly, the second mounting plate 18 has connecting portions (holes 14a) for the base plate 7 using second pivot pin portions 14 at the tip of the arm portions 18e at both ends in the longitudinal direction, and a connecting portion (second guide portion 18d) for the rear side plate 10 using a fourth hinge pin 16 inside.

[0031] As shown in Figures 14 and 15, the guide portion 17d of the first mounting plate 17 is formed with edges facing each other between the inner bevel 17g in the left-right direction and the two outer bevels 17h, 17h, and guides the side surface of the third hinge pin 15. Similarly, the second mounting plate 18 has oblique second guide portions 18d, 18d formed thereon to guide the fourth hinge pin 16. As shown in Figure 16, the third hinge pin 15 is guided by the guide portion 17d as the front side plate 9 rotates and slides obliquely relative to the first mounting plate 17, causing the free end of the front side plate 9 to recede obliquely from the plane of the first mounting plate 17. The fourth hinge pin 16 is guided by the second guide portion 18d as the rear side plate 10 rotates and slides obliquely relative to the second mounting plate 18, causing the free end of the rear side plate 10 to recede obliquely from the plane of the second mounting plate 18. As the front side plate 9 and rear side plate 10 retract, a space 30 is formed to accommodate the folded portion of the flexible display sheet 5, as shown in Figure 3. As the first housing 2 and second housing 3 move from the open state to the closed state via the synchronous rotation mechanism 20, a symmetrical space 30 is formed inside the thickness of the first mounting plate 17 and second mounting plate 18, sandwiched between the front side plate 9 and rear side plate 10 with the base plate 7 as the bottom surface.

[0032] The base cover 8 covers the synchronous rotation mechanism 20, suction mechanism 21, and biasing mechanism 22, which are installed on the underside of the base plate 7, and has a boat-like shape with a curved cross-section. The base cover 8 is attached to the base plate 7 by fastening screws 20s, 20s through holes 8a, 8a and holes 20g, 20g of the synchronous rotation mechanism 20 to the female threads of the fixing parts 20r, 20r of the base plate 7. The synchronous rotation mechanism 20 is fixed to the base plate 7 integrally with the base cover 8 using screws 20s, 20s.

[0033] [Synchronized rotation mechanism] Next, the configuration of the synchronous rotation mechanisms 20 and 20' will be described. Figure 16 is a cross-sectional view of BB in Figure 5. As shown in Figure 16, the synchronous rotation mechanism 20 rotates the front side plate 9 and the rear side plate 10 synchronously as the first housing 2 and the second housing 3 are opened and closed. The synchronous rotation mechanism 20 is provided on the base plate 7 via the third pivot pin portion 20a and the fourth pivot pin portion 20b. The synchronous rotation mechanism 20 consists of a first lever gear 20c and a second lever gear 20d that mesh together, and when one of the front side plate 9 and the rear side plate 10 is rotated, the other rotates symmetrically via the meshing of the first lever gear 20c and the second lever gear 20d.

[0034] The first lever gear 20c is rotatably mounted on the base plate 7 via the third pivot pin portion 20a and is driven to rotate via the first hinge pin of the front side plate 9. The second lever gear 20d is rotatably mounted on the base plate 7 via the fourth pivot pin portion 20b and is driven to rotate via the second hinge pin 12 of the rear side plate 10.

[0035] As shown in Figure 8, the third and fourth pivot pin portions 20a and 20b are sandwiched between bearing members 20f, 20f and rotatably mounted on the base plate 7. The bearing members 20f, 20f, 20f, 20f are constrained in the axial direction by the stepped grooves 20e, 20e, 20e, 20e of the third and fourth pivot pin portions 20a and 20b. The flattened shaft portions 20u, 20u of the third and fourth pivot pin portions 20a and 20b are rotatably supported by the round holes 20k, 20k of the spacers 20h, 20i. The flattened shaft portions 20u, 20u constrain the rotation of the first lever gear 20c and the second lever gear 20d via the flattened holes 20j, 20j.

[0036] As shown in Figure 16, the first lever gear 20c and the second lever gear 20d are linked to the front side plate 9 and the rear side plate 10 via a pair of pins 20t, 20t. One end of the pair of pins 20t, 20t is fixed to the pin holes 11b and 12b of the front side plate 9 and the rear side plate 10 shown in Figure 10, and the other end is held in the oval holes 20p and 20q of the first lever gear 20c and the second lever gear 20d. Therefore, when the front side plate 9 is rotated relative to the base plate 7, the drive is transmitted from the pin 20t on the front side plate 9 side, through the meshing of the first lever gear 20c and the second lever gear 20d, to the pin 20t on the rear side plate 10 side, causing the rear side plate 10 to rotate symmetrically. Conversely, when the rear side plate 10 is rotated relative to the base plate 7, the drive is transmitted in the opposite direction, causing the front side plate 9 to rotate. In this way, the synchronous rotation mechanism 20 opens and closes the first mounting plate 17 and the second mounting plate 18 symmetrically. Because the synchronous rotation mechanism 20 is simply constructed with a small number of parts, the multi-axis hinge device 6 can be made thinner.

[0037] Incidentally, as shown in Figures 7 and 8, the synchronous rotation mechanism 20 and the synchronous rotation mechanism 20' are identically configured, but the multi-axis hinge device 6 is symmetrically arranged with the left-right orientation reversed. For this reason, in the synchronous rotation mechanism 20', the relationship between the first lever gear 20c and the second lever gear 20d and the front side plate 9 and the rear side plate 10 is reversed compared to the synchronous rotation mechanism 20. That is, in the synchronous rotation mechanism 20', the first lever gear 20c is linked to the rear side plate 10 via pin 20t, and the second lever gear 20d is linked to the front side plate 9 via pin 20t.

[0038] As shown in Figure 8, the synchronous rotation mechanism 20 is equipped with a suction mechanism 21. The suction mechanism 21 sucks the front side plate 9 and the rear side plate 10 into a closed state and an open state to stop their rotation. The suction mechanism 21 includes a fixed cam plate 21c that is rotatably connected to the third pivot pin portion 20a and the fourth pivot pin portion 20b, a pair of rotating cam plates 21a and 21b that are mounted on the third pivot pin portion 20a and the fourth pivot pin portion 20b respectively, with their rotation fixed by overlapping the fixed cam plate 21c and the uneven surfaces 21m and 21n, and compression spring members 21e, 21e that compress the overlap between the fixed cam plate 21c and the rotating cam plates 21a and 21b.

[0039] The flattened shaft portions 20u, 20u of the third and fourth pivot pin portions 20a and 20b are rotatably supported by the spacer 21d and the round holes 21k, 21g of the fixed cam plate 21c, respectively. The flattened shaft portions 20u, 20u of the third and fourth pivot pin portions 20a and 20b restrict the rotation of the rotating cam plates 21a, 21b via the flattened holes 21f, 21f. The compression spring member 21e is an assembly of washer springs, consisting of four umbrella-shaped washer springs stacked alternately in their orientations.

[0040] As shown in Figure 16, the third pivot pin portion 20a and the fourth pivot pin portion 20b of the multi-axis hinge device 6 rotate by approximately 30 to 40 degrees, respectively, between the closed and open states. As shown in Figure 20, the suction mechanism 21 engages with the uneven surfaces 21m and 21n of the fixed cam plate 21c and the rotating cam plates 21a and 21b as the third pivot pin portion 20a and the fourth pivot pin portion 20b rotate, causing the compression spring member 21e to expand and contract. The suction mechanism 21 sucks in and stops the first mounting plate 17 and the second mounting plate 18 to the angular position where the compression spring member 21e located at both ends of the above angular range is extended (Figures 20(a), (d)). Then, in a predetermined angular range located midway between the two ends of this angular range, the compression spring member 21e is compressed to a constant degree, causing the fixed cam plate 21c and the rotating cam plates 21a and 21b to generate only friction (Figures 20(b) and (c)), and the multi-axis hinge device 6 enters a so-called free-stop state where it can stop at any open angular position. For this reason, the suction mechanism 21 stabilizes the open and closed states of the multi-axis hinge device 6 and improves the operability of the opening and closing process of the multi-axis hinge device 6.

[0041] [Biasing mechanism] Next, the configuration of the biasing mechanism 22 will be described. Figure 17 is a cross-sectional view AA of Figure 5. As shown in Figure 17, the biasing mechanism 22 biases the front side plate 9 and the rear side plate 10 in the closing direction and can maintain the closed and open states of the front side plate 9 and the rear side plate 10. The biasing mechanism 22 includes a compression coil spring 22a that is compressed in the front-rear direction along the base plate 7, a pair of slide cams 22b provided at both ends of the compression coil spring 22a, and a pair of cam follower parts 22c provided on the front side plate 9 and the rear side plate 10 that slide the slide cams 22b in accordance with rotation via the first hinge pin 11 and the second hinge pin 12, thereby compressing the compression coil spring 22a in the front-rear direction.

[0042] As shown in Figure 11, the lower surface of the base plate 7 is provided with holding spaces 7a, 7a for the biasing mechanism 22. The slide cam 22b has a plurality of protrusions 22d, 22d, 22d, 22d that hold the compression coil springs 22a, 22a, 22a, 22a in a left-right arrangement. The base plate 7 has guide portions 22f, 22f that hold a pair of slide cams 22b, 22b slidably in the front-rear direction outside the arranged compression coil springs 22a, 22a, 22a, 22a. Therefore, the compression coil spring 22a is supported by the base plate 7 via the slide cam 22b.

[0043] As shown in Figure 17, the biasing mechanism 22 has cam follower portions 22c, 22c that protrude in a lever-like manner on the opposite side from the third hinge pin 15 and fourth hinge pin 16, with the first hinge pin 11 and second hinge pin 12 as pivot points. The cam follower portions 22c, 22c are provided on the front side plate 9 and the rear side plate 10 by fixing separate members made of a low-wear material to them, respectively. As the front side plate 9 and the rear side plate 10 rotate via the first hinge pin 11 and the second hinge pin 12, the cam follower portions 22c, 22c slide against the slide cams 22b, 22b, pressing against the slide cams 22b, 22b and moving them in the front-rear direction.

[0044] The slide cams 22b, 22b are set to a predetermined cam curve 22i or a predetermined suction characteristic curve. As shown in Figure 7(a), the slide cam 22b is set to a convex portion 22g that opens the multi-axis hinge device 6, a concave portion 22h that closes the multi-axis hinge device 6, and a cam curve 22i that connects the two (22g, 22h). The cam follower portions 22c, 22c move their sliding points along the cam curve 22i of the slide cams 22b, 22b and are driven outward with a force corresponding to the cam curve 22i. Note that the cam curves of the slide cams 22b, 22b are not limited to the curves described here.

[0045] As shown in Figure 7(b), the cam curve 22i is set such that the slide cams 22b, 22b press and move the cam follower portions 22c, 22c outward from the closed state where the first mounting plate 17 and the second mounting plate 18 are closed at 0 degrees to the open state at 90 degrees. Therefore, within this angular range, the first mounting plate 17 and the second mounting plate 18 open against the biasing force of the multiple compression coil springs 22a, and when released, the multi-axis hinge device 6 attempts to return to the closed state.

[0046] As shown in Figure 17(c), when the first mounting plate 17 and the second mounting plate 18 are brought close to the open state of 180 degrees, the biasing force of the compression coil spring 22a tends to press the shaft portions 11c and 12c outward, and the closing moment acting on the cam follower portions 22c and 22c decreases. As a result, the force required to open the first mounting plate 17 and the second mounting plate 18 also decreases, and the first mounting plate 17 and the second mounting plate 18 are biased toward the open state of 180 degrees, and the open state of 180 degrees is self-held.

[0047] Furthermore, the 0-degree and 180-degree angle restrictions between the first mounting plate 17 and the second mounting plate 18 are achieved by the engagement structure between the base plate 7 and the first and second mounting plates 17 and 18. As shown in Figure 19, the arc-shaped guide grooves 13c and 14c provided in the base plate 7 guide the guide pins 13b and 14b provided in the first and second mounting plates 17 and 18, thereby positioning the first and second mounting plates 17 and 18 linearly in the open state and parallel to each other in the closed state.

[0048] Therefore, the biasing mechanism 22 can bias the first housing 2 and the second housing 3 over a wider angular range than a general suction mechanism or the suction mechanism 21 described above, leading them to a closed state, and can provide an easy-to-operate multi-axis hinge device 6 that can stably hold the first housing 2 and the second housing 3 in both the closed and open states. Furthermore, the biasing mechanism 22 regulates the open and closed states of the first mounting plate 17 and the second mounting plate 18 by guide grooves 13c and 14c provided on the left and right end faces of the base plate 7, thereby improving both the positional accuracy of the first housing 2 and the second housing 3 in the closed and open states and the rigid strength of the multi-axis hinge device when using the biasing mechanism 22.

[0049] [Tension adjustment mechanism] Next, the configuration of the tension adjustment mechanism 24 will be described. Figure 18 is a BB cross-sectional view of a part of the side view of Figure 5 along the front-rear direction. Figure 19 is a CC cross-sectional view of Figure 5. The tension adjustment mechanism 24 adjusts the tension of the flexible display sheet 5 by moving at least one of the first mounting plate 17 and the second mounting plate 18, which are kept open by the biasing mechanism 22, in the front-rear direction according to the tension of the flexible display sheet 5. The tension adjustment mechanism 24 includes a slider 24b that contacts at least one of the third hinge pin 15 and the fourth hinge pin 16 and slides in the front-rear direction, and a compression coil spring 24a provided between at least one of the first mounting plate 17 and the second mounting plate 18 and the slider 24b.

[0050] A guide pin 13b is fixed to the arm portion 17e of the first mounting plate 17, and a guide pin 14b is fixed to the arm portion 18e of the second mounting plate 18. When the first mounting plate 17 and the second mounting plate 18 rotate symmetrically around the first pivot pin portion 13 and the second pivot pin portion 14, the guide pin 13b rotates integrally with the first mounting plate 17 and the guide pin 14b rotates integrally with the second mounting plate 18, guided by the arc-shaped guide grooves 13c and 14c.

[0051] In the closed state shown in Figure 19(a) and the 90-degree open state shown in Figure 19(b), the guide pins 13b and 14b are constrained to the full width of the guide grooves 13c and 14c, so there is no room for the first pivot pin portion 13 and the second pivot pin portion 14 to move within the oval holes 13a and 14a. However, as shown in Figure 19(c), in the open state at 180 degrees, the direction in which the guide pins 13b and 14b can move along the guide grooves 13c and 14c coincides with the longitudinal direction of the oval holes 13a and 14a. As a result, the first mounting plate 17 has room to move in the longitudinal direction of the oval hole 13a, and the second mounting plate 18 has room to move in the longitudinal direction of the oval hole 14a. The tension adjustment mechanisms 24, 24 utilize the range of movement of the first mounting plate 17 and the second mounting plate 18 to adjust the tension of the flexible display sheet 5 stretched between the first mounting plate 17 and the second mounting plate 18.

[0052] As shown in Figure 18(a), the first mounting plate 17 and the second mounting plate 18 are movable in the front-rear direction relative to the first pivot pin portion 13 and the second pivot pin portion 14. When the first mounting plate 17 and the second mounting plate 18 move outward, the distance between the first mounting plate 17 and the second mounting plate 18 is wide X. As shown in Figure 18(b), when the first mounting plate 17 and the second mounting plate 18 move inward, the distance between the first mounting plate 17 and the second mounting plate 18 is narrow Y. The tension adjustment mechanism 24 utilizes this XY range of movement to elastically support the flexible display sheet 5, which is provided straddling the first mounting plate 17 and the second mounting plate 18, in the tension direction.

[0053] The tension adjustment mechanisms 24, 24 shown in Figure 9 are attached to the recesses 17b, 17b on the lower surface of the first mounting plate 17 shown in Figure 14(b). The tension adjustment mechanisms 24, 24 are assembled by inserting screws 24f, 24f into the holes 21g of the slider guide 24d and tightening them into the female threads 24i, 24i on the lower surface of the first mounting plate 17 shown in Figure 14(b). The slider guide 24d is capable of holding the position of the slider 24b, which has a compression coil spring 24a interposed between the abutment portion 24h and the abutment portion 24e of the compression coil spring 24a. Similarly, the tension adjustment mechanisms 24, 24 are attached to the recesses 18b, 18b on the lower surface of the second mounting plate 18.

[0054] As shown in Figure 16(c), the tension adjustment mechanism 24 biases the first mounting plate 17 and the second mounting plate 18 outward when they are in the open state, with the first mounting plate 17 and the second mounting plate 18 open to 180 degrees, thereby generating tension in the flexible display sheet 5. The sliders 24b, 24b, pressed by the third hinge pin 15 and the fourth hinge pin 16, move outward, and the flexible display sheet 5, which is mounted across the first mounting plate 17 and the second mounting plate 18, is pulled outward, resulting in the sliders 24b, 24b being separated from the abutment portions 24h, 24h.

[0055] On the other hand, as shown in Figures 16(a) and (b), when the flexible display sheet (5) is folded, the third hinge pin 15 and the fourth hinge pin 16 are separated from the sliders 24b, 24b, so the sliders 24b, 24b are pressed by the compression coil spring 24a and come into contact with the abutment portion 24h.

[0056] As shown in Figure 18, the first mounting plate 17 and the second mounting plate 18, on which the flexible display sheet 5 is stretched, are movable in the front-rear direction with the expansion and contraction of the compression coil spring 24a. The compression coil spring 24a elastically pushes the first mounting plate 17 and the second mounting plate 18 outward relative to the front side plate 9 and the rear side plate 10, thereby adjusting the tension of the flexible display sheet 5 stretched between the first mounting plate 17 and the second mounting plate 18. In other words, when the flexible display sheet 5 stretched between the first mounting plate 17 and the second mounting plate 18 is long, the distance between the first mounting plate 17 and the second mounting plate 18 becomes wide X, as shown in Figure 18(a). On the other hand, when the flexible display sheet 5 stretched between the first mounting plate 17 and the second mounting plate 18 is short, the distance between the first mounting plate 17 and the second mounting plate 18 becomes narrow Y, as shown in Figure 18(b). Therefore, when the multi-axis hinge device 6 having the tension adjustment mechanism 24 opens the first mounting plate 17 and the second mounting plate 18 to open the flexible display sheet 5, sagging and wrinkles in the long flexible display sheet 5 are removed, and excessive tension is avoided on the short flexible display sheet 5.

[0057] In this description, an embodiment in which tension adjustment mechanisms 24 are provided on both the first mounting plate 17 and the second mounting plate 18 has been explained. However, the tension adjustment mechanism 24 may be provided on only one of the first mounting plate 17 or the second mounting plate 18. The number of tension adjustment mechanisms 24 provided on the first mounting plate 17 and the second mounting plate 18, and the number of compression coil springs 24a provided in each tension adjustment mechanism 24, can also be arbitrarily determined according to the required tension setting range. [Industrial applicability]

[0058] As configured as described above, the multi-axis hinge device of the present invention can smoothly achieve and stably maintain the closed state of the first and second housings. Furthermore, wrinkles and sagging are less likely to occur in the flexible display sheet when the first and second housings are open.

[0059] The present invention provides a multi-axis hinge device suitable for use in foldable electronic devices, such as mobile phones, smartphones, electronic organizers, PDAs, netbooks, video display devices, portable game consoles, and notebook computers, in which a flexible display sheet is stretched across a first housing and a second housing. The present invention is also suitable for use in foldable electronic devices using this multi-axis hinge device. The multi-axis hinge device according to the present invention is not limited to mobile phones, but can be widely used in foldable electronic devices, as described above, in which a first housing and a second housing, each having a flexible display sheet attached to its surface, are connected to each other in an openable and closable manner. [Explanation of Symbols]

[0060] 1. Mobile phone (electronic device) 2. First cabinet 3. Second cabinet 4. Protective film 5 Flexible display sheet 6. Multi-axis hinge device 7 Base Plate 7a Holding space 7g main unit 7h axis support 8 Base plate cover 9 Front side plate 10 Rear side plates 11. First hinge pin 11a Pin hole 11b pin hole 11c Shaft 11d Bearing part 11e pinhole 12. Second hinge pin 12a Pin hole 12b Pinhole 12c Shaft 12d bearing part 12e pinhole 13. First pivot pin section 13a hole 13b Guide pin 13c guide groove 14. Second pivot pin section 14a hole 14b Guide pin 14c guide groove 15. Third hinge pin 15a, 15b connection part 16. Fourth hinge pin 16a, 16b connection part 17. First mounting plate 17a Mounting hole 17b recess 17c working hole 17d 1st information section 17e Arm section 17f Free end side 17g slope 17h 18. Second mounting plate 18a Mounting hole 18b recess 18c working hole 18d 2nd information section 18e Arm section 20 Synchronous rotation mechanism 20a Third axis support pin section 20b Fourth axis support pin section 20c 1st lever gear 20d Second lever gear 20f Bearing Member 20h, 20i spacers 21 Suction mechanism 21a, 21b Rotating cam plate 21c Fixed Cam Plate 21e Compression spring member 22 Biasing mechanism 22a Compression coil spring 22b Slide Cam 22c Cam follower section 22d protrusion 22f Guide Section 24 Tension adjustment mechanism 24a Compression coil spring 24b Slider 24c spring hole 24d Slider Guide 24e Butt part 24f screw 24g hole 30 Space section

Claims

1. A multi-axis hinge device is provided below a flexible display sheet of an electronic device having a first housing and a second housing, the flexible display sheet being attached across both surfaces of the first housing and the second housing, and connecting the first housing and the second housing to each other in an openable and closable manner, a base plate provided across the left and right direction on each rear end side of the first housing and the second housing facing each other; a front side plate and a rear side plate rotatably attached to the front and rear sides of the base plate via a first hinge pin and a second hinge pin, respectively; a first mounting plate and a second mounting plate rotatably attached to the base plate via a first pivot pin portion and a second pivot pin portion, and further slidably and rotatably attached to free ends of the front side plate and the rear side plate via a third hinge pin and a fourth hinge pin, for mounting the rear ends of the first housing and the second housing to the free ends of the front side plate and the rear side plate, a space capable of accommodating a folded portion of the flexible display sheet that is folded when the first housing and the second housing are closed, between the base plate and the front side plate and the rear side plate, a synchronous rotation mechanism that synchronously rotates the front side plate and the rear side plate in response to opening and closing of the first housing and the second housing; a biasing mechanism that biases the front side plate and the rear side plate in a closing direction and that can maintain the front side plate and the rear side plate in a closed state and an open state, the biasing mechanism includes a compression coil spring that is compressed in the front-rear direction along the base plate, a pair of slide cams provided at both ends of the compression coil spring, and a pair of cam follower portions that are provided on the front side plate and the rear side plate and slide the slide cams in accordance with rotation via the first hinge pin and the second hinge pin, thereby compressing the compression coil spring in the front-rear direction. Multi-axis hinge device.

2. a tension adjustment mechanism that adjusts the tension of the flexible display sheet by moving at least one of the first attachment plate and the second attachment plate, which are maintained in an open state by the biasing mechanism, in a front-to-rear direction in accordance with the tension of the flexible display sheet; the tension adjustment mechanism includes a slider that abuts against at least one of the third hinge pin and the fourth hinge pin and slides in the front-rear direction, and a compression coil spring that is provided between the slider and at least one of the first mounting plate and the second mounting plate. The multi-axis hinge device according to claim 1 .

3. the synchronous rotation mechanism is configured by meshing a first lever gear rotatably attached to the base plate via a third pivot pin portion and driven by rotation via the first hinge pin of the front side plate, and a second lever gear rotatably attached to the base plate via a fourth pivot pin portion and driven by rotation via the second hinge pin of the rear side plate. The multi-axis hinge device according to claim 1 .

4. the synchronous rotation mechanism has a suction mechanism that sucks the front side plate and the rear side plate into a closed state and an open state to stop rotation, The suction mechanism is characterized by comprising: a fixed cam plate that rotatably connects the third pivot pin portion and the fourth pivot pin portion; a pair of rotating cam plates that overlap the fixed cam plate with their concave and convex surfaces and are fixed in rotation to the third pivot pin portion and the fourth pivot pin portion, respectively; and a compression spring member that compresses the overlap between the fixed cam plate and the rotating cam plate. The multi-axis hinge device according to claim 3 .

5. A multi-axis hinge device is provided below a flexible display sheet of an electronic device having a first housing and a second housing, the flexible display sheet being attached across both surfaces of the first housing and the second housing, and connecting the first housing and the second housing to each other in an openable and closable manner, a base plate provided across the left and right direction on each rear end side of the first housing and the second housing facing each other; a front side plate and a rear side plate rotatably attached to the front and rear sides of the base plate via a first hinge pin and a second hinge pin, respectively; a first mounting plate and a second mounting plate rotatably attached to the base plate via a first pivot pin portion and a second pivot pin portion, and further slidably and rotatably attached to free ends of the front side plate and the rear side plate via a third hinge pin and a fourth hinge pin, for mounting the rear ends of the first housing and the second housing to the free ends of the front side plate and the rear side plate, a space capable of accommodating a folded portion of the flexible display sheet that is folded when the first housing and the second housing are closed, between the base plate and the front side plate and the rear side plate, a synchronous rotation mechanism that synchronously rotates the front side plate and the rear side plate in response to opening and closing of the first housing and the second housing; a tension adjustment mechanism that adjusts the tension of the flexible display sheet by moving at least one of the first attachment plate and the second attachment plate, which are moving toward an open state, in a front-to-rear direction in accordance with the tension of the flexible display sheet; the tension adjustment mechanism includes a slider that abuts against at least one of the third hinge pin and the fourth hinge pin and slides in the front-rear direction, and a compression coil spring that is provided between the slider and at least one of the first mounting plate and the second mounting plate. Multi-axis hinge device.

6. An electronic device, comprising the multi-axis hinge device according to any one of claims 1 to 5.

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