Exhibition equipment

Abstract

In a tensioning device for extending a planar body, this invention provides a technology that reduces the likelihood of distortion, vibration, and other issues occurring in the extended planar body. [Solution] The tensioning device comprises a housing, a planar body that is pulled out from the housing when in use and retracted into the housing for storage when not in use, a pantograph mechanism positioned on the back side of the planar body and supporting the upper edge of the planar body, the pantograph mechanism which folds when the planar body is stored and pulls out the planar body from the housing and tensions the planar body vertically by performing an upright movement from the folded position, a reinforcing member that extends along the width direction of the planar body and tensions the planar body in the width direction, and a lift-up suppression mechanism that suppresses the lift-up of the planar body relative to the pantograph mechanism when the pantograph mechanism is in an upright position.

Description

Technical Field

[0001] The present invention relates to a device for expanding a planar body.

Background Art

[0002] Flexible displays using film OLEDs (organic light-emitting diodes) and the like are known. A film OLED is formed, for example, by forming a light-emitting element such as an organic EL (Electro Luminescence) on a flexible film substrate. Since the flexible display has flexibility, for example, when not in use, it is wound up and stored in a housing (storage case), and when in use (during viewing), it is pulled out from the housing and expanded flat.

[0003] Also, a pantograph mechanism for stretching a screen in a stored state wound up in a roll shape when in use is known (see, for example, Patent Document 1). According to the technique described in Patent Document 1, a planar body such as a screen can be expanded vertically by the pantograph mechanism.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, although the pantograph mechanism described in Patent Document 1 can hold the planar body in a state of being expanded vertically, it cannot suppress the upward floating of the planar body in a direction away from the pantograph mechanism. Therefore, due to external forces such as wind and vibration, there was a risk that the planar body would sway or be distorted.

[0006] The technology disclosed herein aims to provide a technology for a stretching device that stretches a planar body, which makes it less likely for the stretched planar body to experience distortion, vibration, etc. [Means for solving the problem]

[0007] One aspect of the technology relating to this disclosure is an extension device comprising: a housing; a planar body that is pulled out from the housing when in use and retracted into the housing for storage when not in use; a pantograph mechanism disposed on the back side of the planar body and supporting the upper edge of the planar body, the pantograph mechanism which folds when the planar body is stored and extends the planar body from the housing and extends the planar body vertically by performing an upright movement from the folded position; a reinforcing member that extends along the width direction of the planar body and extends the planar body in the width direction; and a lift-up suppression mechanism that suppresses the lift-up of the planar body relative to the pantograph mechanism when the pantograph mechanism is in an upright position. [Effects of the Invention]

[0008] According to the disclosed technology, the pantograph mechanism can be raised from its folded position to extend the planar body from the housing and stretched vertically. Furthermore, the rigidity of the planar body is increased by the stretching of the reinforcing material in the width direction, and in the upright position of the pantograph mechanism, the lift-up suppression mechanism can suppress the lifting of the planar body relative to the pantograph mechanism. This provides a technology that makes it less likely for distortion and shaking to occur in the stretched planar body in a stretching device. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a perspective view of the tensioning device according to this embodiment, viewed from the rear. [Figure 2] Figure 2 is a rear view of the tensioning device according to the embodiment. [Figure 3] Figure 3 is a side view of the tensioning device according to an embodiment. [Figure 4]Figure 4 is a perspective view of the tensioning device according to this embodiment, viewed from the rear. [Figure 5] Figure 5 is a rear view of the tensioning device according to the embodiment. [Figure 6] Figure 6 is a side view of the tensioning device according to the embodiment. [Figure 7] Figure 7 is a front view of the flexible display in its extended state. [Figure 8] Figure 8 is a perspective view of the flexible display in its extended state. [Figure 9] Figure 9 is a diagram illustrating the positional relationship of each pivot pin. [Figure 10] Figure 10 is a perspective view of the tensioning device according to this embodiment, viewed from the rear. [Figure 11] Figure 11 illustrates a modified example of the lift-up suppression mechanism. [Modes for carrying out the invention]

[0010] Embodiments of this disclosure will be described below with reference to the drawings. Note that the configurations and combinations thereof in the embodiments are examples only, and additions, omissions, substitutions, and other modifications can be made as appropriate without departing from the spirit of this disclosure.

[0011] [Embodiment] Figure 1 is a perspective view of the tensioning device 100 according to the embodiment, viewed from the rear. Figure 2 is a rear view of the tensioning device 100 according to the embodiment. Figure 3 is a side view of the tensioning device 100 according to the embodiment. The tensioning device 100 is a device for pulling out a planar body from the housing (storage case) 200 and extending it when using the planar body. In this embodiment, the tensioning device 100 also functions as a storage device that retracts (winds up) the planar body into the housing 200 and stores it when the planar body is not in use.

[0012] The planar body extended by the extension device 100 is, for example, a flexible sheet body. The type, use, etc. of the planar body are not particularly limited, but here, a flexible display having flexibility (softness) using a film OLED (organic light-emitting diode) or the like will be described as an example. The film OLED is formed by, for example, forming a light-emitting element such as an organic EL (Electro Luminescence) on a flexible film substrate. In this case, the extension device 100 can be configured as a display device, a DA (Display Audio) product, or the like. Below, the mode of configuring the extension device 100 as an in-vehicle display device mounted on a vehicle will be exemplarily described. When not in use, the extension device 100 that does not use the flexible display 300 as the planar body is stored in the housing 200. Then, when in use (during viewing), the extension device 100 pulls out the flexible display 300 from the housing 200 to the outside and extends it flat. FIGS. 1 to 3 show the "extended state" in which the flexible display 300 is pulled out from the housing 200 and extended flat.

[0013] FIGS. 4 to 6 are views showing the "stored state" in which the flexible display 300 is stored in the housing 200. FIG. 4 is a perspective view of the extension device 100 viewed from the back side. FIG. 5 is a rear view of the extension device 100, and FIG. 6 is a side view of the extension device 100 according to the embodiment. In FIGS. 1 to 6, for convenience of explanation, the housing 200 is shown in a perspective view to show its internal structure.

[0014] FIG. 7 is a front view of the flexible display 300 in the extended state viewed from the front (viewing surface) side. FIG. 8 is a partial perspective view of the flexible display 300 in the extended state viewed from the back side. The flexible display 300 will be described with reference to FIGS. 1 to 3 as well.

[0015] The flexible display 300 has a rectangular plane in the extended state. When looking at the flexible display 300 from the front (viewing surface) side, the horizontal direction is defined as the "width direction" (x - direction), and the vertical direction is defined as the "up - and - down direction" (y - direction). Also, the "thickness direction" (z - direction) of the flexible display 300 is orthogonal to the width direction (x - direction) and the up - and - down direction (y - direction). Also, reference numeral 310 is the upper edge of the flexible display 300, and reference numeral 320 is the lower edge of the flexible display 300. The upper edge 310 and the lower edge 320 of the flexible display 300 are parallel to each other. Hereinafter, in the width direction (x - direction) in the rear view, the +x direction is described as the right side and the -x direction is described as the left side. Also, in the up - and - down direction (y - direction), the +y direction is described as the upper side and the -y direction is described as the lower side.

[0016] Reference numeral 330 is a support plate attached to the upper edge 310 of the flexible display 300. The support plate 330 is a plate - shaped member extending along the width direction (x - direction) of the flexible display 300. The longitudinal dimension of the support plate 330 is, for example, equal to the width dimension of the flexible display 300. The support plate 330 is attached to the back surface of the flexible display 300. For example, the support plate 330 is adhered to the back surface of the flexible display 300. The support plate 330 is formed as a narrow - width plate having a width dimension smaller than its longitudinal dimension.

[0017] Reference numeral 340 is a cover provided on the upper part of the support plate 330. The cover 340 is a cover body for closing the opening 250 provided in the housing 200 when the flexible display 300 is in the stored state. The opening 250 and the cover 340 have, for example, a horizontally - long rectangular shape in the top - view. However, the shape of the opening 250 in the housing 200 is not particularly limited. Also, the cover 340 may be appropriately changed according to the shape of the opening 250.

[0018] In this embodiment, when the flexible display 300 is pulled out from the housing 200 from its stored state, it is pulled out from the opening 250 of the housing 200 with its upper edge 310 side leading. On the other hand, when the flexible display 300 is stored, the opening 250 of the housing 200 is closed by the cover 340 attached to the upper edge 310 side of the flexible display 300.

[0019] When the flexible display 300 is switched from a retracted state to an extended state, a pantograph mechanism 400 (see, for example, Figures 1 and 2) located on the rear side of the flexible display 300 pulls it out of the housing 200 and extends it vertically. The pantograph mechanism 400 supports the upper edge 310 side of the flexible display 300, and is folded when the flexible display 300 is retracted, and rises from the folded state when the flexible display 300 is pulled out of the housing 200. Details of the pantograph mechanism 400 will be described later.

[0020] A lower edge plate 360 ​​is attached to the lower edge 320 of the flexible display 300. The lower edge plate 360 ​​is a plate-shaped member that extends along the width direction (x direction) of the flexible display 300. The lower edge plate 360 ​​is attached to the back of the flexible display 300. For example, the lower edge plate 360 ​​is attached to the back of the flexible display 300. The longitudinal dimension of the lower edge plate 360 ​​is equal to, for example, the width dimension of the flexible display 300. The lower edge plate 360 ​​is formed as a narrow plate, with a width dimension smaller than its longitudinal dimension.

[0021] Multiple (many) reinforcing plates 350 are attached to the back of the flexible display 300. The reinforcing plates 350 are plate-shaped members that extend along the width direction (x direction) of the flexible display 300. The reinforcing plates 350 are attached to the back of the flexible display 300. It is attached. For example, the reinforcing plate 350 is attached to the back of the flexible display 300. Of the reinforcing plate 350, the direction extending along the width direction (x direction) of the extended flexible display 300 is called the "longitudinal direction," and the direction along the vertical direction (y direction) is called the "width direction." The longitudinal dimension of the reinforcing plate 350 is equal to, for example, the width dimension of the flexible display 300. The reinforcing plate 350 is formed as a narrow plate, with a width dimension smaller than its longitudinal dimension.

[0022] The reinforcing plate 350 stretches the flexible display 300 along its width direction (x direction). This increases the rigidity of the flexible display 300 in the width direction (x direction). The reinforcing plate 350 is an example of a reinforcing material according to this disclosure. The support plate 330 positioned on the upper edge 310 and the lower edge plate 360 ​​positioned on the lower edge 320 of the flexible display 300 also stretch the flexible display 300 along its width direction (x direction) in the same way as the reinforcing plate 350, thereby increasing the rigidity of the flexible display 300 in the width direction (x direction). Therefore, the support plate 330 and the lower edge plate 360 ​​according to this embodiment also function as reinforcing materials according to this disclosure.

[0023] As shown in Figures 1 to 3, multiple reinforcing plates 350 are arranged in multiple layers in the vertical direction (y direction) of the flexible display 300. Specifically, in the area sandwiched between the support plate 330 and the lower edge plate 360 ​​of the flexible display 300, numerous reinforcing plates 350 are arranged vertically in multiple layers, with their longitudinal direction aligned with the width direction (x direction) of the flexible display 300.

[0024] Gaps are formed between the reinforcing plates 350, which are arranged in multiple stages above and below the flexible display 300. Gaps are also formed between the lower edge plate 360 ​​and the reinforcing plate 350 located directly above it. These gaps extend along the width direction (x direction) of the flexible display 300. Therefore, when storing the flexible display 300 in the housing 200, it is possible to roll up the flexible display 300.

[0025] In the examples shown in Figures 1 to 3, the uppermost reinforcing plate 350 in the vertical direction (y-direction) of the flexible display 300 is wider (larger in the y-direction) than the other reinforcing plates 350. Guide grooves 370 are also provided at both ends in the longitudinal direction of each reinforcing plate 350 and lower edge plate 360 ​​(see Figure 3, etc.). The guide grooves 370 provided at the left and right ends of each reinforcing plate 350 and lower edge plate 360 ​​can accommodate the guide rails 240A and 240B of the housing 200, which will be described later. The guide grooves 370 open at the end faces of each reinforcing plate 350 and lower edge plate 360 ​​and are slidable along the guide rails 240A and 240B.

[0026] Next, the housing 200 will be described. The housing 200 is a storage case for the flexible display 300 when it is not in use (for example, when it is not being viewed). Inside the housing 200, there is a storage space S1 for the flexible display 300 (planar body). Also inside the housing 200 Various devices and components are provided for extending the flexible display 300 from the housing 200 to the outside, or for bringing it in from the outside.

[0027] Specifically, the flexible display 300 is provided with a pantograph mechanism 400 for extending it from the housing 200 and retracting it into the housing 200, an operating mechanism 500 for operating the pantograph mechanism 400, and a retraction assist mechanism 800 for assisting in retracting it into the housing 200, all located inside the housing 200. The pantograph mechanism 400 is operated by the operating mechanism 500, and can be positioned in an upright position (state) as shown in Figures 1 to 3, and in a position as shown in Figures 4 to 6. The display can be switched between the folded position (state) shown. The pantograph mechanism 400 is, for example, stored inside the housing 200 when in the folded position. When the display is raised from the folded position, at least a portion of it extends outside the housing 200, extending the supported flexible display 300 upward. The pantograph mechanism 400 is located on the rear side of the flexible display 300.

[0028] In one embodiment, the housing 200 is configured as a storage case with a housing space S1 having a roughly fan-shaped cross-section formed inside. However, the shape of the housing 200 is not particularly limited. In the following, when describing the directions of the housing 200, the directions corresponding to the width direction (x direction), up and down direction (y direction), and thickness direction (z direction) of the flexible display 300 in its extended state will be described as the "width direction," "up and down direction," and "front and back direction" of the housing 200, as shown in Figures 1 to 3. The side corresponding to the front (viewing surface) side of the flexible display 300 in its extended state will be referred to as the "front" of the housing 200, and the side corresponding to the back side of the flexible display 300 will be referred to as the "back" of the housing 200.

[0029] An opening 250 is provided on the top surface 210 of the housing 200. The opening 250 is an opening for inserting and removing the flexible display 300 from the housing 200. The opening 250 is sized so as not to interfere with the pantograph mechanism 400 that supports the flexible display 300. For example, the opening 250 is located on the top surface 210, closer to the front surface 220 of the housing 200.

[0030] A pair of left and right guide rails 240A and 240B are provided on the inner walls of the left side 230A and right side 230B of the housing 200. The guide rails 240A and 240B are guide members that serve as the trajectory for the flexible display 300 when it is pulled out of or retracted into the housing 200. In this embodiment, the guide rails 240A and 240B are configured as flat plate-shaped rail members with a curved shape, but their shape is not particularly limited. In the longitudinal direction of the guide rails 240A and 240B, reference numeral 241 indicates the base end and reference numeral 242 indicates the tip end (see Figure 3, etc.).

[0031] Furthermore, as shown in Figures 3 and 6, the front surface 220 of the housing 200 includes a flat surface 220A connected to the top surface 210, and a curved surface 220B extending from the lower end of the flat surface 220A and connected to the rear surface 260. In addition, a portion of the guide rails 240A and 240B on the tip end 242 side has a flat plate shape. Of the guide rails 240A and 240B, the portion with the flat plate shape on the tip end 242 side is positioned opposite the flat surface 220A of the front surface 220 of the housing 200. As shown in Figure 6, when the flexible display 300 is housed in the housing 200, the wide reinforcing plate 350 located at the top of the flexible display 300 is housed so as to face the flat surface 220A of the housing 200.

[0032] Inside the housing 200, there is a holding section 600 for holding the operating mechanism 500 and the like. The operating mechanism 500 includes a motor 510, which is a drive source for operating the pantograph mechanism 400, and transmission gears for transmitting the driving force of the motor 510 to the pantograph mechanism 400.

[0033] Next, the pantograph mechanism 400 will be described. The pantograph mechanism 400 supports the upper edge 310 of the flexible display 300 and is located on the rear side of the flexible display 300. The pantograph mechanism 400 includes a left pantograph 410A that supports the left side of the upper edge 310 of the flexible display 300, and a right pantograph 410B that supports the right side of the upper edge 310. The 10A and the right pantograph 410B are configured to operate synchronously by the operating mechanism 500, enabling raising and folding operations. The pantograph mechanism 400, comprising the left pantograph 410A and the right pantograph 410B, can provide balanced support for the upper edge 310 of the flexible display 300. This allows for stable extension and retraction of the flexible display 300 when the pantograph mechanism 400 is operating. Furthermore, the left pantograph 410A and the right pantograph 410B are positioned symmetrically across the center of the flexible display 300 in the width direction (x direction). This allows for balanced support of the upper edge 310 of the flexible display 300 by the left pantograph 410A and the right pantograph 410B. Therefore, stable extension and retraction of the flexible display 300 can be achieved when the pantograph mechanism 400 is operating.

[0034] The left pantograph 410A and the right pantograph 410B each have a first arm 420A and a second arm 420B, which are arranged side by side in the upright position shown in Figures 1-3, etc. The upper edge 310 of the flexible display 300 is supported near its end by the first arm 420A, and further inward by the second arm 420B. That is, in each pantograph 410A, 410B, the first arm 420A is positioned on the outside in the width direction (x direction), and the second arm 420B is positioned next to the first arm 420A.

[0035] The first arm 420A has a lower first arm portion 430 and an upper first arm portion 440 that are connected vertically. The lower first arm portion 430 and the upper first arm portion 440 are members having, for example, an elongated arm shape. The lower first arm portion 430 is pivotally connected (pivoted and connected) to the holding portion 600 in the housing 200 via a lower first pivot pin PL1 at its lower end. The upper first arm portion 440 is pivotally connected to the upper edge portion 310 (support plate 330) of the flexible display 300 via an upper first pivot pin PU1 at its upper end. The upper end of the lower first arm portion 430 and the lower end of the upper first arm portion 440 are pivotally connected to each other via an intermediate first pivot pin PM1.

[0036] Furthermore, the second arm 420B has a lower second arm portion 450 and an upper second arm portion 460 that are connected vertically. The lower second arm portion 450 and the upper second arm portion 460 are, for example, members having an elongated arm shape. The lower second arm portion 450 is pivotally connected at its lower end to the holding portion 600 in the housing 200 via a lower second pivot pin PL2. The upper second arm portion 460 is pivotally connected at its upper end to the upper edge portion 310 (support plate 330) of the flexible display 300 via an upper second pivot pin PU2. The upper end of the lower second arm portion 450 and the lower end of the upper second arm portion 460 are pivotally connected to each other via an intermediate second pivot pin PM2.

[0037] The pivots of each of the aforementioned pivot pins (PL1, PL2, PU1, PU2, PM1, PM2) extend along the front-to-back direction of the housing 200, that is, along the thickness direction (z direction) of the flexible display 300 when it is extended.

[0038] The lower first pivot pin PL1 and the lower second pivot pin PL2 are fixed to the holding portion 600 of the housing 200. The upper first pivot pin PU1 and the upper second pivot pin PU2 are fixed to the support plate 330 attached to the upper edge 310 of the flexible display 300.

[0039] Furthermore, the intermediate first pivot pin PM1 and the intermediate second pivot pin PM2 are connected to the first arm 420A and The first arm 420A and the second arm 420B are held by a link member 700 that connects them. As shown in Figures 1 and 2, the link member 700 is configured as a plate-shaped member extending in one direction. In the example shown in Figures 1 and 2, the intermediate first pivot pin PM1 is located on the central side in the longitudinal direction of the link member 700, and the intermediate second pivot pin PM2 is located on one end side. In addition, a first engaging portion 910 is provided on the other end side of the link member 700. The function of the first engaging portion 910 on the link member 700 will be described later. The first arm 420A and the second arm 420B configured as described above are connected to each other via the intermediate first pivot pin PM1 and the intermediate second pivot pin PM2 of the link member 700. The region of the link member 700 sandwiched between the intermediate first pivot pin PM1 and the intermediate second pivot pin PM2 is called the link section 710. The link member 700 is provided to take an orientation that extends along the width direction of the housing 200, that is, along the width direction (x direction) of the flexible display 300 when it is extended, when the pantograph mechanism 400 is in an upright position (for example, an orientation that extends horizontally).

[0040] Next, the operating mechanism 500 that operates the pantograph mechanism 400 will be described. As described above, the operating mechanism 500 is composed of a motor 510, a transmission gear, etc. The motor 510 and the transmission gear in the operating mechanism 500 are installed, for example, in the holding part 600 of the housing 200. For example, the motor 510 is positioned near the center in the lateral direction (x direction) of the housing 200. The rotational output of the motor 510 is transmitted to the pantograph mechanism 400 via the transmission gear.

[0041] As described above, the pantograph mechanism 400 includes a left pantograph 410A and a right pantograph 410B. Therefore, the transmission gear in this embodiment has a first transmission gear 530A that transmits the rotational output of the motor 510 to the left pantograph 410A side, and a second transmission gear 530B that transmits the synchronous rotational output to the right pantograph 410B side. The first transmission gear 530A and the second transmission gear 530B each include a worm gear 540, an intermediate gear 550, a fan-shaped sector gear 560 attached to the lower second arm portion 450 of the second arm 420B, and the like.

[0042] The worm gear 540 has a worm wheel that meshes with a worm mounted on the output shaft of the motor 510. The intermediate gear 550 transmits the rotational motion of the worm gear 540, which is rotationally driven by the motor 510, to the sector gear 560. The number of intermediate gears 550 is not particularly limited. The sector gear 560 is integrally mounted to the lower end of the lower second arm portion 450 and transmits the rotational motion of the intermediate gear 550 to the lower second arm portion 450.

[0043] As described above, the transmission gears 530A and 530B of each system transmit the output of the motor 510 to the lower second arm section 450 of the second arm 420B. This enables the raising or lowering of the left pantograph 410A and the right pantograph 410B. In this embodiment, the output of the common (single) motor 510 is distributed by the transmission gear 530A of the first system and the transmission gear 530B of the second system, causing the left pantograph 410A and the right pantograph 410B to operate synchronously.

[0044] Figure 9 is a diagram illustrating the positional relationship of each pivot pin (PL1, PL2, PU1, PU2, PM1, PM2) as described above. In this embodiment, the left pantograph 410A and the right pantograph 410B have the same structure and are arranged symmetrically with respect to the vertical axis (axis extending along the y direction) that passes through the center in the width direction (x direction) of the housing 200.

[0045] Figure 9, upper section (A) shows the positional relationship of each pivot pin (PL1, PL2, PU1, PU2, PM1, PM2) when the left pantograph 410A is in the folded position. Figure 9, lower section (B) shows the positional relationship of each pivot pin ( The positional relationships of PL1, PL2, PU1, PU2, PM1, and PM2 are shown. In Figures 9(A) and (B), the positions of each pivot pin corresponding to the left pantograph 410A are shown on the left side of the figure, and the positions of each pivot pin corresponding to the right pantograph 410B are shown on the right side of the figure.

[0046] First, the positions of the lower first pivot pin PL1 and the lower second pivot pin PL2, which pivotally connect the lower ends of the lower first arm portion 430 and the lower second arm portion 450 to the holding portion 600 of the housing 200, will be described. In the xy plane, the positions of the lower first pivot pin PL1 and the lower second pivot pin PL2 in the vertical direction (y direction) are equal to each other, but their positions in the horizontal direction (x direction) are different (hereinafter referred to as "Condition 1").

[0047] Next, the positions of the upper first pivot pin PU1 and the upper second pivot pin PU2, which pivotally connect the upper ends of the upper first arm portion 440 and the upper second arm portion 460 to the upper edge portion 310 of the flexible display 300, will be described. In the xy plane, the positions of the upper first pivot pin PU1 and the upper second pivot pin PU2 in the vertical direction (y direction) are equal to each other, but their positions in the horizontal direction (x direction) are different (hereinafter referred to as "Condition 2").

[0048] Next, we will describe the positions of the intermediate first pivot pin PM1, which pivotally connects the upper end of the lower first arm portion 430 and the lower end of the upper first arm portion 440, and the intermediate second pivot pin PM2, which pivotally connects the upper end of the lower second arm portion 450 and the lower end of the upper second pivot pin PU2. In the xy plane, the positions of the intermediate first pivot pin PM1 and the intermediate second pivot pin PM2 in the vertical direction (y direction) are equal to each other, but their positions in the horizontal direction (x direction) are different (hereinafter referred to as "Condition 3").

[0049] Here, the distance between the lower first pivot pin PL1 and the lower second pivot pin PL2 in the lateral direction (x direction) is defined as the first distance L1. The distance between the upper first pivot pin PU1 and the upper second pivot pin PU2 in the lateral direction (x direction) is defined as the second distance L2. The distance between the intermediate first pivot pin PM1 and the intermediate second pivot pin PM2 in the lateral direction (x direction) is defined as the third distance L3. In this embodiment, the first distance L1, the second distance L2, and the third distance L3 are specified to be the same dimension (hereinafter referred to as "Condition 4").

[0050] In this embodiment, when conditions 1, 3, and 4 are met, the lower first pivot pin PL1, the lower second pivot pin PL2, the intermediate first pivot pin PM1, and the intermediate second pivot pin PM2 form the vertices of a parallelogram. In other words, the shape with the lower first pivot pin PL1, the lower second pivot pin PL2, the intermediate second pivot pin PM2, and the intermediate first pivot pin PM1 as its vertices (hereinafter referred to as "first shape SP1") forms a parallelogram.

[0051] The first shape SP1 is formed by a lower edge BE1 connecting the lower first pivot pin PL1 and the lower second pivot pin PL2, an upper edge UE1 connecting the intermediate first pivot pin PM1 and the intermediate second pivot pin PM2, an outer hypotenuse DE1 connecting the lower first pivot pin PL1 and the intermediate first pivot pin PM1, and an inner hypotenuse DE2 connecting the lower second pivot pin PL2 and the intermediate second pivot pin PM2. In the first shape SP1, both the lower edge BE1 and the upper edge UE1 are parallel in the width direction (x direction). Also, in the first shape SP1, the outer hypotenuse DE1 and the inner hypotenuse DE2 are parallel to each other and inclined with respect to the lower edge BE1 and the upper edge UE1. In the left pantograph 410A and the right pantograph 410B, the lower first arm portion 430 corresponds to the outer hypotenuse DE1 of the first shape SP1, and the lower second arm portion 450 corresponds to the inner hypotenuse DE2 of the first shape SP1.

[0052] Furthermore, when conditions 2, 3, and 4 above are met, the upper first pivot pin PU1, the upper second pivot pin PU2, the intermediate second pivot pin PM2, and the intermediate first pivot pin PM1 form the vertices of the parallelogram. In other words, the upper first pivot pin PU1, the upper second pivot pin PU2 The shape with intermediate second pivot pin PM2 and intermediate first pivot pin PM1 as its vertices (hereinafter referred to as "second shape SP2") forms a parallelogram.

[0053] The second shape SP2 is formed by the lower edge BE2 connecting the intermediate first pivot pin PM1 and the intermediate second pivot pin PM2, the upper edge UE2 connecting the upper first pivot pin PU1 and the upper second pivot pin PU2, the outer hypotenuse DE3 connecting the upper first pivot pin PU1 and the intermediate first pivot pin PM1, and the inner hypotenuse DE4 connecting the upper second pivot pin PU2 and the intermediate second pivot pin PM2. In the second shape SP2, both the lower edge BE2 and the upper edge UE2 are parallel in the width direction (x direction). Also, the outer hypotenuse DE3 and the inner hypotenuse DE4 in the second shape SP2 are parallel to each other and inclined with respect to the lower edge BE2 and the upper edge UE2. In the left pantograph 410A and the right pantograph 410B, the upper first arm portion 440 corresponds to the outer hypotenuse DE3 of the second shape SP2, and the upper second arm portion 460 corresponds to the inner hypotenuse DE4 of the second shape SP2.

[0054] Furthermore, the upper edge UE1 in the first shape SP1 and the lower edge BE2 in the second shape SP2 are formed as common edges that are composed of the link section 710 of the link member 700.

[0055] When the pantograph mechanism 400 is raised from the folded position shown in Figures 4 to 6, the driving force of the motor 510 is transmitted synchronously by the operating mechanism 500 to the left pantograph 410A and the right pantograph 410B, respectively. As a result, the lower second arm portion 450 of the second arm 420B of the left pantograph 410A and the right pantograph 410B are raised with the lower second pivot pin PL2 as the pivot axis. In the example in Figure 5, the lower second arm portion 450 of the left pantograph 410A is swung in the direction of arrow A1 (counterclockwise in Figure 5), and the lower second arm portion 450 of the right pantograph 410B is swung in the direction of arrow A2 (clockwise in Figure 5).

[0056] Here, the lower first arm section 430 and the lower second arm section 450 are connected to the housing 200 at their respective lower ends via the lower first pivot pin PL1 and the lower second pivot pin PL2. The upper ends of the lower first arm section 430 and the lower second arm section 450 are connected via a link member 700 (link section 710). Therefore, when the driving force from the operating mechanism 500 acts on the lower second arm section 450, the lower first arm section 430 also moves in accordance with the lower second arm section 450 and rises upright. Referring to Figure 9, the outer hypotenuse DE1 and the inner hypotenuse DE2 gradually rise upright relative to the lower edge BE1 of the first shape SP1. At that time, the outer hypotenuse DE1 and the inner hypotenuse DE2 rise upright relative to the lower edge BE1 while maintaining a parallel relationship with each other.

[0057] Furthermore, since the lower first pivot pin PL1 and the lower second pivot pin PL2 are fixed to the housing 200, these pins become immovable points. As a result, when the outer hypotenuse DE1 and inner hypotenuse DE2 of the first shape SP1 stand upright relative to the bottom edge BE1, the top edge UE1 is displaced upward (+y direction) while maintaining its parallel relationship with the bottom edge BE1, accompanied by a horizontal displacement toward the end in the width direction (x direction). In other words, the link member 700 corresponding to the top edge UE1 of the first shape SP1 is displaced upward (+y direction) and toward the end in the width direction (x direction) while maintaining a posture parallel to the width direction (x direction) as the left pantograph 410A and the right pantograph 410B stand upright.

[0058] Furthermore, the upper edge UE1 of the first shape SP1 shares a common edge with the lower edge BE2 of the second shape SP2. Therefore, as described above, when the lower first arm portion 430 and the lower second arm portion 450 perform an upright movement, the lower edge BE2 of the second shape SP2 also displaces upward (+y direction) while being displaced towards the end in the width direction (x direction). As a result, the outer hypotenuse DE3 and the inner hypotenuse DE4 are relative to the lower edge BE2 of the second shape SP2. It stands upright relative to the lower edge BE2 while maintaining a parallel relationship. Consequently, the upper edge UE2 of the second shape SP2 is displaced upward (+y direction) while maintaining a parallel relationship with the lower edge BE2, accompanied by a horizontal displacement toward the end in the width direction (x direction).

[0059] As a result, the left pantograph 410A and the right pantograph 410B of the pantograph mechanism 400 are synchronously switched from the folded position shown in Figures 4 to 6, through the intermediate position shown in Figure 10, to the upright position shown in Figures 1 to 3. When the pantograph mechanism 400 is switched from the folded position to the upright position, the flexible display 300, whose upper edge 310 is supported by the pantograph mechanism 400, is pulled out from the housing 200 and extended in the vertical direction (y direction). With the pantograph mechanism 400 configured as described above (left pantograph 410A, right pantograph 410B), during the upright operation, the flexible display 300 can be pulled out from the housing 200 and extended upward in a stable position while the upper edge 310 (support plate 330) and link member 700 of the flexible display 300 are held in a position parallel to the width direction of the flexible display 300 (for example, a horizontal position).

[0060] Furthermore, even when the pantograph mechanism 400 is folded from the upright position shown in Figures 1 to 3 to the folded position shown in Figures 4 to 6, the flexible display 300 can be retracted into the housing 200 and stored in a stable position while the upper edge 310 (support plate 330) and link member 700 of the flexible display 300 are held in a position parallel to the width direction of the flexible display 300 (for example, a horizontal position).

[0061] Furthermore, in this embodiment, the left pantograph 410A and the right pantograph 410B of the pantograph mechanism 400 are configured such that one of the lower first arm portion 430 of the first arm 420A and the lower second arm portion 450 of the second arm 420B is configured as a drive arm, and the other as a driven arm. In the above example, the driving force of the motor 510 is transmitted to the lower second arm portion 450 by a transmission gear, thereby configuring the lower second arm portion 450 as a drive arm, and the lower first arm portion 430 is configured as a driven arm that moves with the lower second arm portion 450 (drive arm). In this way, by configuring one of the lower first arm portion 430 and the lower second arm portion 450 as a drive arm and the other as a driven arm, the raising and lowering operations of the pantograph mechanism 400 can be performed stably. Of course, the lower first arm section 430 may be configured as a driving arm and the lower second arm section 450 as a driven arm. Alternatively, both the lower first arm section 430 and the lower second arm section 450 may be configured as driving arms.

[0062] Next, the retraction assist mechanism 800 will be described. The retraction assist mechanism 800 is a mechanism for assisting the retraction operation of the flexible display 300 when storing the flexible display 300 in the housing 200. The retraction assist mechanism 800 consists of a main frame 810, elastic springs 820A, 820B, etc., which are housed inside the housing 200. The main frame 810 is a gate-shaped frame body as a whole and includes a lower edge plate 360 ​​provided on the lower edge portion 320 of the flexible display 300, and connecting arms 830A, 830B connected to both ends of the lower edge plate 360 ​​in the longitudinal direction.

[0063] As shown in Figure 2, the lower edge plate 360 ​​is positioned along the width direction (x direction) of the housing 200. One end of each elastic spring 820A and 820B is fixed to a suitable location within the housing 200, for example, to the inner wall of the side. For example, one end of elastic spring 820A is fixed to the inner wall of the left side 230A, and one end of elastic spring 820B is fixed to the inner wall of the right side 230B.

[0064] Furthermore, the other ends of the elastic springs 820A and 820B are attached, for example, to the tip 8301 of the connecting arms 830A and 830B (see Figures 3 and 6, etc.). Note that the connecting arm 83 830A and 830B are plate-shaped members extending in one direction, with their base ends opposite to the tip 8301 connected to the lower edge plate 360. The connecting arms 830A and 830B are provided with a pivot shaft 8302 in the portion between the tip 8301 and the base end. For example, the pivot shaft 8302 of connecting arm 830A is fixed to the inner wall of the left side 230A of the housing 200, and the pivot shaft 8302 of connecting arm 830B is fixed to the inner wall of the right side 230B of the housing 200. The pivot shafts 8302 of connecting arms 830A and 830B extend along the width direction (x direction) of the housing 200. Within the housing 200, the connecting arms 830A and 830B are pivotally supported so as to be rotatable around the pivot shaft 8302. Furthermore, in the longitudinal direction of the connecting arms 830A and 830B, the pivot shaft 8302 is positioned closer to the tip portion 8301.

[0065] As shown in Figures 3 and 6, the lower edge plate 360 ​​has guide grooves 370 at both longitudinal ends, similar to the reinforcing plate 350, that can accommodate the guide rails 240A and 240B. By accommodating (for example, loosely fitting) the guide rails 240A and 240B in the guide grooves 370 of each reinforcing plate 350 and lower edge plate 360 ​​of the flexible display 300, it is possible to guide the flexible display 300 along the guide rails 240A and 240B during the retraction operation into the housing 200 or the pull-out operation from the housing 200.

[0066] When the flexible display 300 is housed in the housing 200, as shown in Figure 6, the guide groove 370 of the lower edge plate 360 ​​is located on the base end 241 side of the guide rails 240A and 240B. In this state, for example, the elastic springs 820A and 820B are not stretched beyond their original shape, and no restoring force is generated in the elastic springs 820A and 820B. On the other hand, when the operating mechanism 500 is activated from this state and the pantograph mechanism 400 starts to rise from the folded position, the flexible display 300 is pulled out to the outside from the opening 250 of the housing 200, with its upper edge 310 side leading. At that time, the guide grooves 370 provided on both sides of the flexible display 300 slide along the guide rails 240A and 240B, allowing the flexible display 300 to be guided and pulled out to the outside stably and smoothly.

[0067] When the pantograph mechanism 400 begins to raise from its folded position, the connecting arms 830A and 830B connected to the lower edge plate 360 ​​of the flexible display 300 rotate in the direction of arrow B shown in Figure 6, around the pivot axis 8302. Consequently, the elastic springs 820A and 820B extend beyond their original shape, generating a restoring force in them. This restoring force acts to displace the lower edge plate 360 ​​of the flexible display 300 along the guide rails 240A and 240B from the tip end 242 towards the base end 241. In other words, the restoring force of the elastic springs 820A and 820B generated when the pantograph mechanism 400 raises biases the lower edge plate 360 ​​in the direction that the flexible display 300 is pulled into the housing 200. Furthermore, when the pantograph mechanism 400 is raised, it rises against the restoring force of the elastic springs 820A and 820B. As a result, as shown in Figures 1 to 3, the flexible display 300 is extended vertically by the pantograph mechanism 400.

[0068] In this embodiment, the tensioning device 100 includes a lift-up suppression mechanism 900 that suppresses the lifting of the flexible display 300 relative to the pantograph mechanism 400 when the pantograph mechanism 400 is in an upright position. The lift-up suppression mechanism 900 will be described below with reference to Figure 8. The lift-up suppression mechanism 900 includes a first engaging portion 910 provided on the pantograph mechanism 400 and a second engaging portion 920 provided on the reinforcing plate 350 of the flexible display 300, and is configured such that the first engaging portion 910 and the second engaging portion 920 engage when the pantograph mechanism 400 is in an upright position. When the flexible display 300 is extended, the lifting of the reinforcing plate 350 relative to the pantograph mechanism 400 is suppressed. Here, "lifting" refers to the movement of the flexible display 300 away from the pantograph mechanism 400 located on its rear side.

[0069] In this embodiment, the tensioning device 100 tensions the flexible display 300 vertically (y-direction) using a pantograph mechanism 400, tensions the flexible display 300 horizontally (x-direction) using reinforcing materials (reinforcing plate 350, support plate 330, and lower edge plate 360) provided on the flexible display 300, and suppresses the lifting of the flexible display 300 relative to the pantograph mechanism 400 using a lifting suppression mechanism 900. This allows the flexible display 300 to maintain a flat state when in use (for example, when viewing). In other words, it is possible to effectively suppress distortion of the image (video) and other issues that make viewing difficult when using the flexible display 300 (for example, when viewing).

[0070] Furthermore, since the tensioning device 100 is equipped with a lift-up suppression mechanism 900, it can suppress the flexible display 300 from lifting up relative to the pantograph mechanism 400. As a result, even when external forces such as vibrations or wind act on the flexible display 300, shaking, distortion, etc., of the flexible display 300 can be effectively suppressed. Therefore, it is possible to prevent the flexible display 300 from becoming difficult to view. In particular, when the tensioning device 100 is used as an in-vehicle unit, the environment is prone to shaking of the flexible display 300 due to vehicle vibrations, wind taken into the vehicle, etc. Therefore, the advantage of the tensioning device 100 being equipped with a lift-up suppression mechanism 900 becomes even more pronounced.

[0071] Furthermore, in this embodiment, the lift-up suppression mechanism 900 has a second engaging portion 920 on the reinforcing plate 350 of the flexible display 300, and locks the reinforcing plate 350 to the pantograph mechanism 400 when the flexible display 300 is extended. By locking the rigid reinforcing plate 350 fixed to the flexible display 300, rather than the flexible display 300 itself, the lift-up of the flexible display 300 relative to the pantograph mechanism 400 can be suppressed more effectively.

[0072] Furthermore, the lift-up suppression mechanism 900 according to this embodiment suppresses the lift-up of both ends of the reinforcing plate 350 in the longitudinal direction (x direction). Specifically, second engaging portions 920 are provided at both ends of the reinforcing plate 350 in the longitudinal direction (x direction), and the pair of left and right second engaging portions 920 can be engaged with the first engaging portions 910 provided on the link members 700 of the left pantograph 410A and the right pantograph 410B, respectively. This structure is particularly useful when the flexible display 300 is configured as a touch panel. When the flexible display 300 is a touch panel, the flexible display 300 is operated by touch by the user (viewer). According to the above structure, when a user's (viewer's) finger touches one end (for example, the left end) of the flexible display 300 in the width direction (x direction) from the front, the other end (for example, the right end) can be effectively prevented from lifting away from the pantograph mechanism 400. This improves the touch operability of the flexible display 300.

[0073] Furthermore, in the example shown in Figure 2, a second engagement portion 920 is provided on a reinforcing plate 350 located near the center of the flexible display 300 in the vertical direction (y direction). By suppressing the lifting of the flexible display 300 near the center in the vertical direction (y direction), the number of engagement points with the pantograph mechanism 400 is not unnecessarily increased. The overall rigidity of the flexible display 300 can be improved. Of course, the above embodiment is just one example. The second engagement portion 920 may be formed on multiple reinforcing plates 350 in the flexible display 300.

[0074] Furthermore, in this embodiment, a first engagement portion 910 is provided on the link member 700 of the pantograph mechanism 400 (left pantograph 410A, right pantograph 410B). As explained with reference to Figure 8, the link member 700, while maintaining a posture parallel to the width direction (x direction), is displaced toward the end side and upward (+y direction) in the width direction (x direction) as the pantograph mechanism 400 (left pantograph 410A, right pantograph 410B) rises.

[0075] In other words, the link member 700 of the left pantograph 410A is displaced toward the left end (-x direction) and upward (+y direction) while maintaining a position parallel to the width direction (x direction) as the left pantograph 410A is raised. On the other hand, the link member 700 of the right pantograph 410B is displaced toward the right end (+x direction) and upward (+y direction) while maintaining a position parallel to the width direction (x direction) as the right pantograph 410B is raised.

[0076] In this embodiment, when the pantograph mechanism 400 (left pantograph 410A, right pantograph 410B) is folded, the first engaging portion 910 of the link member 700 and the second engaging portion 920 of the flexible display 300 (reinforcement plate 350) do not engage. Then, as the pantograph mechanism 400 rises, the first engaging portion 910 and the second engaging portion 920 gradually approach each other. When the pantograph mechanism 400 moves to the upright position, the height (y-direction position) and lateral position (x-direction position) of the first engaging portion 910 and the second engaging portion 920 coincide, resulting in the engagement of the first engaging portion 910 and the second engaging portion 920. According to this, as the pantograph mechanism 400 performs its uprighting operation, the first engaging portion 910 of the link member 700 is gradually brought closer to the second engaging portion 920 of the flexible display 300 (reinforcement plate 350), and the first engaging portion 910 and the second engaging portion 920 are engaged at the right time when the pantograph mechanism 400 reaches the upright position.

[0077] When storing the flexible display 300 in the housing 200, the operating mechanism 500 activates the pantograph mechanism 400, switching the pantograph mechanism 400 from an upright position to a folded position. When the pantograph mechanism 400 (left pantograph 410A, right pantograph 410B) begins its folding operation, it transitions from the upright position shown in Figures 1 to 3, through the intermediate position shown in Figure 10, to the folded position shown in Figures 4 to 6. As a result, the flexible display 300, which is supported by the pantograph mechanism 400, is retracted into the housing 200 and stored.

[0078] When the retraction operation of the flexible display 300 (folding operation of the pantograph mechanism 400) begins, the support plate 330 and link member 700 are displaced toward the center and downward (-y direction) in the width direction (x direction), while maintaining a position parallel to the width direction (x direction), contrary to the extension operation (standing operation). As a result, the engagement between the first engagement portion 910 of the link member 700 provided on the pantograph mechanism 400 (left pantograph 410A, right pantograph 410B) side and the second engagement portion 920 provided on the flexible display 300 (reinforcement plate 350) side is released.

[0079] Furthermore, when the folding operation of the pantograph mechanism 400 is initiated, the elastic springs 820A and 820B in the retraction assist mechanism 800 are extended beyond their original shape. Therefore, the elastic springs 820A and 820B can bias the lower edge plate 360 ​​in the direction of retracting the flexible display 300 into the housing 200. As a result, the flexible display can be retracted into the housing 200. When retracting the flexible display 300, it is possible to avoid wrinkles forming on the flexible display 300 or the guide grooves 370 of the flexible display 300 getting caught on the guide rails 240A and 240B. Therefore, the retraction operation of the flexible display 300 can be performed stably and smoothly.

[0080] Furthermore, in the example shown in Figure 8, the first engaging portion 910 and the second engaging portion 920 in the lift-up suppression mechanism 900 are formed by locking claws that can engage with each other, but the configuration is not particularly limited.

[0081] Figure 11 illustrates modified versions of the lift-up suppression mechanism 900. In the modified version shown in (A), the first engaging portion 910A formed on the link member 700 has a rod-shaped portion 911. The second engaging portion 920A formed on the reinforcing plate 350 has a fitting hole 921 into which the rod portion 911 of the first engaging portion 910A can be inserted and fitted. In the modified version shown in (B), the second engaging portion 920B formed on the reinforcing plate 350 has a rod-shaped portion 922. The first engaging portion 910B formed on the link member 700 has a fitting hole 912 into which the rod portion 922 of the second engaging portion 920B can be inserted and fitted. In the modified version shown in (C), the first engaging portion 910C formed on the link member 700 has a suction portion 913, and the suction portion 913 can be attracted to the second engaging portion 920C formed on the reinforcing plate 350 by magnetic force.

[0082] While embodiments and modifications relating to this disclosure have been described above, each of the embodiments disclosed herein can be combined. Furthermore, the planar body deployed by the deployment device 100 is not limited to the flexible display 300. Examples of planar bodies deployed by the deployment device 100 include projector screens, display screens, shutters for partitioning spaces, and the like. [Explanation of Symbols]

[0083] 100: Expansion device 200: Cabinet 300: Flexible Display 310: Upper edge 330: Support plate 340: Cover 350: Reinforcement plate 360: Lower edge board 400: Pantograph mechanism 410A: Left pantograph 410B: Right-side pantograph 500: Operating mechanism 700: Link member 800: Retraction assist mechanism 900: Lift suppression mechanism 910: First engaging part 920: Second engaging part

Claims

1. The casing and A planar body that is pulled out from the housing when in use and retracted into the housing for storage when not in use, A pantograph mechanism positioned on the back side of the planar body and supporting the upper edge of the planar body, wherein the pantograph mechanism folds when the planar body is stored and extends the planar body from the housing and extends the planar body vertically by performing an upright movement from the folded position, A reinforcing member that extends along the width direction of the planar body and extends the planar body in the width direction, When the pantograph mechanism is in an upright position, a lift-up suppression mechanism is provided to suppress the lifting of the planar body relative to the pantograph mechanism, A tensioning device equipped with the following features.

2. The reinforcing material is attached to the back surface of the planar body. The lift-up suppression mechanism suppresses the lift-up of the reinforcing material relative to the pantograph mechanism. The tensioning device according to claim 1.

3. The lift-up suppression mechanism suppresses lift-up of both ends of the reinforcing material in the longitudinal direction. The tensioning device according to claim 2.

4. The lift-up suppression mechanism includes a first engaging portion provided on the pantograph mechanism and a second engaging portion provided on the reinforcing member, wherein the first engaging portion and the second engaging portion engage when the pantograph mechanism is in an upright position. The tensioning device according to claim 2.

5. When the pantograph mechanism transitions from a folded position to an upright position, the first engaging portion and the second engaging portion engage by matching their heights. The tensioning device according to claim 4.

6. Multiple reinforcing members are arranged in multiple stages in the vertical direction of the planar body. The second engagement portion is provided on the reinforcing member, which is positioned near the center in the vertical direction of the planar body. The tensioning device according to claim 4.

7. The pantograph mechanism includes a left pantograph that supports the left side of the upper edge and a right pantograph that supports the right side of the upper edge. The aforementioned operating mechanism causes the left pantograph and the right pantograph to operate synchronously. The tensioning device according to any one of claims 1 to 6.

8. The left pantograph and the right pantograph are, respectively, A first arm having a lower first arm portion whose lower end is pivotally connected to the housing via a lower first pivot pin, and an upper first arm portion whose upper end is pivotally connected to the upper edge via an upper first pivot pin and whose lower end is pivotally supported on the upper end side of the lower first arm portion via an intermediate first pivot pin, The lower second arm portion is pivotally connected to the housing at its lower end via a lower second pivot pin, and the upper end portion is pivotally connected to the upper edge portion via an upper second pivot pin, with the lower end portion connected to an intermediate second pivot pin. A second arm having an upper second arm portion pivotally connected to the upper end of the lower second arm portion via a second arm, A link member that holds the intermediate first pivot pin and the intermediate second pivot pin and extends along the width direction, Equipped with, The first distance at which the lower first pivot pin and the lower second pivot pin are separated in the lateral direction, The second distance at which the upper first pivot pin and the upper second pivot pin are separated in the lateral direction, The third distance at which the intermediate first pivot pin and the intermediate second pivot pin are spaced apart in the lateral direction, By defining the same dimensions, the lower first pivot pin, the lower second pivot pin, the intermediate first pivot pin, and the intermediate second pivot pin form the vertices of a parallelogram, and the upper first pivot pin, the upper second pivot pin, the intermediate first pivot pin, and the intermediate second pivot pin form the vertices of a parallelogram. The tensioning device according to claim 7.

9. In the process of switching the pantograph mechanism from a folded position to an upright position, the link member moves along the width direction while maintaining an extended position along the width direction. When the pantograph mechanism transitions from a folded position to an upright position, the first engaging portion and the second engaging portion engage. The tensioning device according to claim 8, relating to claim 4.

10. One of the lower first arm and the lower second arm is configured as a driving arm, and the other is configured as a driven arm. The tensioning device according to claim 8.

11. The left pantograph and the right pantograph are positioned symmetrically on either side of the central position in the width direction of the planar body. The tensioning device according to claim 7.

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