Patent Publication Number: US-10765221-B2

Title: Origami armrest

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to human limb supports and, in particular, to portable limb supports. 
     BACKGROUND 
     Portable electronic devices such as smartphones and tablets are ubiquitous in the modern era. Most of these devices require both visual and tactile interaction, meaning that the user must be able to both see and touch the device in order to use it. Handheld electronic devices satisfy the tactile requirement by their nature—i.e., the devices are within reach while being held. This means that users must look toward their hands while using such a device, which has led to a variety of relatively new repetitive body motions and positions. Users must extend their arms forward and upward to be able to properly view the handheld device, and/or they must lower their gaze with their arms rested on their laps in a more relaxed position. The results of these body positions when held for prolonged periods may include arm and shoulder fatigue from arm extension, as well as hunched posture and neck fatigue from looking down toward the handheld device. Users in moving vehicles may experience motion sickness while looking down at a handheld device due in part to reduced peripheral vision of vehicle motion. 
     U.S. patent application publication 2009/0172884 by Semlitsch discloses an arm rest for positioning the arm of a medical patient in relation to an examination table, especially during a tomographic radioscopy examination or an operation. The arm rest includes a base plate that can be pushed under the patient, an inclined support plate extending from the base plate, and an elongated and inclined carrier element on the end of the supporting plate. The carrier element supports the arm of the patient above the examination table and uses the patient&#39;s weight to hold the arm rest in place. The arm rest is not portable and is configured for only one arm to be rested off to the side of the patient&#39;s body. 
     SUMMARY 
     In accordance with various embodiments, a portable armrest includes a lap portion, an arm portion, and a support portion. The support portion vertically spaces the arm portion from the lap portion when the lap portion is positioned on the lap of a seated user with the armrest in a deployed configuration. In the deployed configuration, the weight of an extended arm of the seated user is transferred to the lap when the arm is rested on the arm portion. The armrest is manually convertible between the deployed configuration and a folded configuration. 
     In some embodiments, the support portion includes an end wall and a pair of side walls. The end wall extends between an end of the lap portion and the arm portion, and the side walls extend from opposite ends of the end wall to form respective acute angles with the end wall in the deployed configuration. 
     In some embodiments, the armrest includes a segmented panel having a plurality of flat segments interconnected by hinge joints. 
     In some embodiments, flat segments of the armrest are arranged in a plurality of parallel planes and overlap each other in the folded configuration so that the portable armrest is flat when in the folded configuration. 
     In some embodiments, at least one hinge joint of the armrest is configured to provide 360 degrees of relative movement between adjacent flat segments of the armrest. 
     In some embodiments, at least one hinge joint of the armrest is non-linear so that relative movement between adjacent flat segments of the armrest about the non-linear joint is restricted to only a partial rotational degree of freedom. 
     In some embodiments, a non-linear hinge joint connects the arm portion to the support portion. 
     In some embodiments, the armrest includes a foldable connector connecting the lap portion to the support portion. The foldable connector is flat in the folded configuration and folded over on itself in the deployed configuration. 
     In some embodiments, the armrest includes a foldable connector connecting the arm portion to the support portion. The foldable connector is folded over on itself in the deployed configuration. 
     In some embodiments, the armrest includes a foldable connector connecting the support portion to the arm portion or to the lap portion via one or more hinge joints. The foldable connector includes a plurality of flat segments interconnected by additional hinge joints. 
     In some embodiments, a foldable connector of the armrest is folded in a first direction about one of the hinge joints in the deployed configuration and in an opposite second direction in the folded configuration. 
     In some embodiments, the armrest includes a reversible fastener that engages to couple the arm portion with the support portion in the deployed configuration and is disengaged in the folded configuration. 
     In some embodiments, the armrest includes an upholstery layer and a segmented layer. The segmented layer includes a plurality of rigid plates spaced apart from each other at fixed locations along the upholstery layer. Each of the rigid plates has an edge that runs parallel with an edge of an adjacent rigid plate along a gap. The upholstery layer spans the gap to at least partly define a hinge joint between the adjacent plates. 
     In some embodiments, the armrest includes a plurality of hinge joints. Each hinge joint is located along parallel edges of adjacent rigid plates of a segmented layer of the armrest. A first pair of adjacent plates is spaced apart a different amount than a second pair of adjacent plates so that widths of the respective hinge joints are different. 
     In some embodiments, the armrest includes an additional upholstery layer, and a segmented layer is disposed between upholstery layers. A hinge joint of the armrest includes a portion of both upholstery layers. 
     In some embodiments, the armrest includes a cushion layer disposed between a segmented layer an upholstery layer. 
     In some embodiments, a cushion layer of the armrest is segmented so that the cushion layer does not span a hinge joint of the armrest. 
     In some embodiments, the armrest includes an armrest accessory extending from the arm portion when the portable armrest is in the deployed configuration. 
     Various aspects, embodiments, examples, features and alternatives set forth in the preceding paragraphs, in the claims, and/or in the following description and drawings may be taken independently or in any combination thereof. For example, features disclosed in connection with one embodiment are applicable to all embodiments in the absence of incompatibility of features. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       One or more embodiments will hereinafter be described in conjunction with the appended drawings, wherein like designations denote like elements, and wherein: 
         FIG. 1  depicts a seated user with an embodiment of a portable armrest in a deployed configuration positioned on her lap; 
         FIG. 2  is a perspective view of an embodiment of the portable armrest from a forward-facing side of the armrest; 
         FIG. 3  is a perspective view of the portable armrest of  FIG. 2  from a body-facing side of the armrest; 
         FIG. 4  is a plan view of a pattern for the portable armrest in an opened-flat configuration; 
         FIGS. 5A-5E  illustrate the portable armrest of  FIG. 4  in various stages of folding from the opened-flat configuration to a folded-flat configuration; 
         FIGS. 6A-6C  illustrate the portable armrest of  FIGS. 4-5E  in various stages of folding from an intermediate configuration to the deployed configuration; 
         FIG. 7  is a plan view of another pattern for the portable armrest in an opened-flat configuration; 
         FIGS. 8A-8D  illustrate the portable armrest of  FIG. 7  in various stages of folding from the opened-flat configuration to a folded-flat configuration; 
         FIG. 9  illustrates the portable armrest of  FIGS. 7-8D  in the deployed configuration; 
         FIG. 10  is an enlarged schematic depiction of an upper foldable connector of the deployed armrest of  FIG. 9 ; 
         FIG. 11  is an enlarged schematic depiction of the upper foldable connector of the deployed armrest of  FIG. 6C ; 
         FIG. 12  is an exploded view of a segmented panel based on the pattern of  FIG. 7 , illustrating a segmented layer and a cushion layer between upholstery layers; 
         FIG. 13  is an exemplary cross-sectional view of a portion of a segmented panel; 
         FIG. 14  depicts the portable armrest in the folded configuration, including an elastic closure; 
         FIG. 15  depicts the portable armrest functioning as a sleeve for an electronic device; 
         FIG. 16  illustrates a location of the electronic device of  FIG. 15  relative to the segmented panel; 
         FIG. 17  depicts the portable armrest in a different folded configuration functioning as a handled carrier for a larger electronic device; 
         FIG. 18  illustrates a location of the electronic device of  FIG. 17  relative to the segmented panel; and 
         FIG. 19  illustrates the armrest of  FIG. 3  with an attached device holder. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The armrest described herein enables seated users to relax their extended arms and maintain an upright posture while bringing a handheld device or other item into viewing range. The armrest can also be folded into a small packaging space for portability and useful deployment in various different scenarios, such as in automobiles, passenger trains, or buses or while seated nearly anywhere. The armrest can have a one-piece unitary construction such that separate components do not have to be assembled together when deploying the armrest from its portable configuration. The one-piece construction can be in the form of a continuous and generally flat panel or sheet divided into segments by hinge joints. The joints allow the panel to be folded back on itself in a manner reminiscent of origami paper art, particularly when the segments are primarily triangular, giving the armrest a desirable aesthetic appeal and a compact and intuitive folding. 
       FIG. 1  depicts a seated user with an embodiment of a portable armrest  10  positioned on her lap. The armrest  10  includes a lap portion  12 , an arm portion  14 , and a support portion  16  extending between the lap and arm portions. The support portion  16  vertically spaces the arm portion  14  from the lap portion  12  when the lap portion is positioned on the lap of the seated user with the armrest  10  in the deployed condition, as shown in  FIG. 1 . When the user rests one or both extended arms on the arm portion  14  in this configuration, the weight of each arm is transferred to the lap. Unlike traditional armrests usually found off to the side of the seated user along the left and/or right side of a chair or other seat, the illustrated armrest  10  is configured to support the arms of the user toward the center of the body for a more direct line-of-sight to handheld objects. The armrest  10  is manually convertible between the deployed configuration and a folded configuration, as discussed further below. 
     With reference to  FIGS. 2 and 3 , the support portion  16  of the illustrated armrest  10  includes an end wall  18  and a pair of side walls  20 . The end wall  18  extends laterally along one longitudinal end  22  of the lap portion  12  and away from the end  22  of the lap portion to the arm portion  14 . Each of the side walls  20  extends from one of the opposite lateral ends  24  of the end wall  18 . When in the deployed configuration, the side walls  20  form respective acute angles α with the end wall  18  and are generally perpendicular to the lap portion  12 , with the bottom of each end wall extending over and being supported by the lap portion  12 . 
     The arm portion  14  extends laterally along an upper end  26  of the end wall  18  of the support portion  16  and away from the upper end  26  of the support portion in the same longitudinal direction as the lap portion  12  such that the arm portion  14  extends over the lap portion and is within the projected area of the lap portion. It is noted that directional terms such as lateral, longitudinal, vertical, top, bottom, upper, lower, etc. are used here in reference to the armrest  10  in its intended orientation of use. In this orientation of use, the lap portion  12  rests on the lap of the seated user, and the longitudinal end  22  of the lap portion from which the end wall  18  extends is the end of the lap portion that is nearest the torso of the seated user, as depicted in  FIG. 1 . In other words, if the seated user holds the deployed armrest upside-down or rotated to a different orientation than that depicted in  FIG. 1 , this does not change the portions of the armrest being referred to in this disclosure.  FIG. 2  thus shows a forward-facing side of the deployed armrest  10 , which faces away from the torso of the user, and  FIG. 3  shows a body-facing side of the deployed armrest that faces the torso of the user. 
     The illustrated armrest  10  additionally includes upper and lower foldable connectors  28 ,  30  that facilitate convertibility between the deployed configuration and the folded configuration. Each connector  28 ,  30  is in a flat configuration when the armrest  10  is in the folded configuration, and each connector is folded when the armrest is in the deployed condition. When in use in the deployed configuration, the connectors  28 ,  30  also restrict relative movement of the lap, arm, and support portions  12 - 16 . 
     In particular, the upper foldable connectors  28  connect the arm portion  14  to the side walls  20  of the support portion  16  and restrict relative movement between the side walls and the arm portion. Each upper foldable connector  28  extends from a lateral end of the arm portion  14  and wraps around an upper end of the respective side wall  20 , thereby restricting downward movement of the arm portion relative to the support portion  16 . A reversible fastener  32 , such as a snap, magnet, or hook-and-loop fastener, may be included to reversibly couple the arm portion  14  with the support portion  16  via the foldable connector  28  in the deployed configuration, with the fastener disengaged in the folded configuration. The fasteners  32  further restrict movement of the arm portion  14  relative to the support portion  16 , particularly in the vertical direction, which is the direction of applied load during use as an armrest. 
     The lower foldable connectors  30  connect the lap portion  12  to the side walls  20  of the support portion  16  and restrict relative movement between the side walls and the lap portion. Each lower foldable connector  30  extends from a lateral end of the lap portion  12  and from the bottom end of each side wall  20 . In the deployed configuration, each lower foldable connector  30  is folded over on itself in the manner of an origami reverse fold. In particular, each foldable connector  30  is folded in a first direction about a hinge joint  34  between the connector  30  and the side wall  20  in the deployed configuration and in an opposite second direction when the armrest is in the folded configuration, as illustrated further below. The foldable connector  30  restricts horizontal movement of the side walls  20  relative to the lap portion  12  in the deployed configuration. 
       FIG. 4  is a plan view of the portable armrest  10  of  FIGS. 2 and 3  in an opened-flat configuration, which may be referred to as a pattern for the armrest. As illustrated, the portable armrest  10  may be constructed as a segmented panel  36  having a plurality of flat segments  38  interconnected into a one-piece structure by a plurality of hinge joints  34 . The illustrated pattern includes eighteen polygonal flat segments. Each one of the lines within the outer perimeter of the illustrated pattern represents a hinge joint  34  in  FIG. 4 . In some embodiments, the segmented panel  36  has a higher rigidity at the segments  38  than at the joints  34 . For example, each individual segment  38  may be sufficiently rigid to support its own weight without bending when the flat planes are oriented horizontally, while the joints may be formed from a material with essentially zero resistance to bending. In some cases, only a portion of the segments  38  are more rigid than the joints  34 . 
     Each segment  38  has a perimeter, and one of the hinge joints  34  connects each segment to an adjacent segment along the perimeter of the adjacent segment. In the illustrated example, each segment  38  is in the shape of a triangle or a quadrilateral, and each hinge joint  34  is a linear hinge joint that provides a single rotational degree of freedom of movement between the segments that it joins. Each of the lap portion  12 , arm portion  14 , support portion  16 , and foldable connectors  28 ,  30  includes a plurality of segments  38  and at least one hinge joint  34 . Each segment  38  is labeled in  FIG. 4  with the portion of the armrest  10  to which it belongs, with the end wall  18  and sidewalls  20  of the support portion  16  labeled separately. 
     The lap portion  12  includes a pair of adjacent rectangular segments connected by a central hinge joint. The arm portion  14  includes a pair of adjacent quadrilateral segments connected by a central hinge joint. The end wall  18  of the support portion  16  includes four triangular segments, a pair of which are connected to the lap portion  12  by a hinge joint, and another pair of which are connected to the arm portion  14  by a hinge joint. The two pairs of triangular segments of the end wall  18  are connected to each other by diagonal hinge joints, and the pair of triangular segments of the end wall that are connected to the arm portion  14  are connected to each other by a hinge joint. Each side wall  20  includes only one quadrilateral segment and is connected to the end wall  18  by a respective hinge joint. Omission of a hinge joint in the side walls may offer greater arm load support without buckling. Each upper foldable connector  28  is connected to a respective segment of the arm portion  14 . Each lower foldable connector  30  is connected to one of the side walls  20  and one of the segments of the lap portion  12 . Each foldable connector  28 ,  30  includes respective pairs of triangular segments connected by hinge joints. 
     The segmented panel  36  is constructed such that some of the hinge joints  34  maintain a full rotational degree of freedom about an axis parallel with the linear joint, and some of the hinge joints have only a partial rotational degree of freedom. For example, the hinge joints connecting the side walls  20  to the end wall  18  provide 360 degrees of relative rotational movement between the end wall and the side walls. In other words, the side walls can be folded over onto the end wall in both directions—on top of the end wall or under the end wall when laid flat as in  FIG. 4 . The hinge joints  34 ′ connecting the arm portion  14  to the end wall  18 , on the other hand, have only a partial rotational degree of freedom about the joint, as do the diagonal joints connecting the triangular segments of the end wall  18 . These restrictive hinge joints  34 ′ have limited freedom of movement about the joint because they extend only partially across the pattern. Restrictive hinge joints  34 ′ can be useful in the deployed configuration at locations where joint stability is desired, such as at the joint between the arm portion  14  and the end wall  18 , which must bear some of the load of the arms of the seated user. 
       FIGS. 5A-5E  illustrate the armrest  10  during conversion to the folded configuration from the opened-flat configuration of  FIG. 4 . In these figures, one planar side of the segmented panel is unshaded, and the opposite side is shaded. The shaded and unshaded sides correspond to the depiction in  FIGS. 1-3 , where the body-facing side of the deployed armrest is shaded. Some reference numerals are omitted in  FIGS. 5A-5E  as well, for clarity in illustration, but the reference numerals used in the following description can be found in  FIG. 4 .  FIG. 5A  illustrates the segmented panel of  FIG. 4  in the opened-flat configuration with two folding axes (A) also illustrated. The side walls  20  and the lower foldable connectors  30  are folded inward about the axes (A) in the direction of the curved arrows over the lap portion  12  and the end wall  18  to reach the configuration of  FIG. 5B . The upper foldable connectors  28  are then folded inward about folding axes (B) in the direction of the curved arrows over the arm portion  14  and the side walls  20  to reach the configuration of  FIG. 5C . The end wall  18  is then folded about a folding axis (C) in the direction of the curved arrow over the lap portion  12  to reach the configuration of  FIG. 5D . Finally, one segment of the lap portion  12  is folded over the other about a folding axis (D) to reach the folded configuration of  FIG. 5E , in which the armrest is folded flat with all of the flat segments  38  arranged in a plurality of parallel planes with some of the segments overlapping each other. At least a portion of the folded-flat configuration includes eight overlapping layers of flat segments. 
     In the illustrated folded configuration, the armrest  10  is portable and occupies significantly less volumetric space than in the deployed configuration. Both the lateral width and the longitudinal length of the folded armrest are approximately one half of the respective width and length in the deployed configuration. The vertical height is decreased even more significantly from the deployed to the folded configuration and may be referred to as the thickness of the armrest in the folded configuration. For example, the thickness of the folded armrest may be only 10-20% of the height of the deployed armrest. In one non-limitimg example, the pattern of  FIG. 4  has a length and a width of about 600 mm and a thickness of about 5 mm, resulting in a deployed configuration having dimensions of about 300×370×275 mm (L×W×H) and a folded configuration having corresponding dimensions of about 150×185×40 mm. Stated differently, the folded armrest would fit into a rectangular box occupying less than 5% of the volume of a box in which the deployed armrest would require to fit into. 
     The armrest  10  may include a closure (not illustrated) that engages to prevent the armrest from unfolding when in the folded configuration. One example of a closure is an elastic strap that wraps around the folded armrest when engaged and which can be selectively unwrapped or slid off of the folded armrest when a used wished to convert the armrest to the deployed configuration. Other non-limiting examples of closures include snaps, buckles, ties, zippers, buttons, hooks-and-loops, or magnets, to name a few. Such a closure may be attached to the segmented panel as part of the one-piece construction. In another embodiment, the length and width of the armrest in the folded configuration may be sized to accommodate the outer dimensions of a notebook or tablet computer. For instance, at least one segment of the lap portion may include an additional layer of material and a closure to form a closable storage compartment for such a device. 
       FIGS. 6A-6C  illustrate the armrest  10  during conversion to the deployed configuration. From the folded configuration, the steps illustrated in  FIGS. 5C-5E  are first performed in reverse to reach the configuration of  FIG. 6A , although it is not necessary to completely unfold the armrest about the folding axis (C) to the fully flat configuration of  FIG. 6A . The end wall  18  is then partially folded about the folding axis (C) in the direction of the curved arrow of  FIG. 6A  so that the angle formed between the end wall  18  and the lap portion  12  is greater than 90 degrees to reach the configuration of  FIG. 6B . 
     From the configuration of  FIG. 6B , the armrest is unfolded along multiple folding axes (A) and (E). In particular, the segments of the lower foldable connectors  30  that are connected to the lap portion  12  (i.e., the large segments in this example) are kept flat against the lap portion while the other segments (i.e., the small segments in this example) of the foldable connectors  30  are folded about the folding axes (E) until the two segments of each foldable connector are flat against one another. This causes the side walls  20  to pivot about the folding axes (A) away from the end wall  18  such that, when the small segments of the foldable connectors  30  are brought flat against the large segments, the side walls are upright over the lap portion  12  and extending vertically away from the lap portion as in  FIG. 6C . This forms the origami-like reverse folds described above. The simultaneous closing fold about the folding axes (E) and opening fold about the folding axes (A) also brings the end wall  18  to an upright orientation. 
     After the reverse folds are completed, the segments of the arm portion  14  are folded about folding axes (F) to reach the configuration of  FIG. 6C  in which the arm portion extends from the upper end of the end wall  18  in the same direction as the lap portion  12 —i.e., away from the seated user. The degree of folding of the arm portion  14  about these axes (F) is limited by virtue of the restrictive hinge joints that lie therealong, as described above, which helps the arm portion support a load without collapsing. The small segments of the upper foldable connectors  28  fold along their respective hinge joints with the arm portion  14  in the opposite direction from the folded configuration of the armrest so that they extend upward from the lateral ends of the arm portion to the large segments of connectors  28 , which extend downward along an exterior of the side walls  20  and can be attached to the side walls via fasteners  32  to complete deployment of the armrest  10 . The segments of the arm portion  14  may be inclined with respect to the lap portion, at an angle greater than zero and less than 30 degrees, for example, with the exterior side of the arm portion  14  tilted toward the user or in the same direction as the body-facing side of the armrest. 
       FIG. 7  is a plan view of another embodiment of the portable armrest  10  in the opened-flat configuration. The illustrated armrest  10  is again constructed as a segmented panel  36  having a plurality of flat segments  38  interconnected into a one-piece structure by hinge joints  34 , each represented by lines within the outer perimeter of the pattern. Some of the hinge joints  34  are linear, and some are non-linear hinge joints  34 ′, which is a form of restrictive hinge joint. Each of the lap portion  12 , arm portion  14 , support portion  16 , and foldable connectors  28 ,  30  includes a plurality of segments  38  and at least one hinge joint  34 . Each segment  38  is labeled in  FIG. 7  with the portion of the armrest  10  to which it belongs, with the end wall  18  and sidewalls  20  of the support portion  16  labeled separately. 
     The lap portion  12  includes a pair of adjacent rectangular segments connected by a central hinge joint. One corner of each rectangular segment is rounded. The arm portion  14  includes a pair of adjacent four-sided segments connected by a central linear hinge joint. The end wall  18  of the support portion  16  includes a pair of adjacent four-sided segments connected by a central linear hinge joint. The arm portion  14  and end wall  18  are connected to each other by non-linear hinge joints  34 ′. Each side wall  20  includes only one quadrilateral segment and is connected to the end wall  18  by a respective hinge joint. Each upper foldable connector  28  includes a pair of triangular segments, one of which is connected to a segment of the arm portion  14  by a hinge joint, and another of which is connected to one of the side walls  20  by a hinge joint. The two triangular segments of each upper foldable portion are connected by a hinge joint as well. Each lower foldable connector  30  includes a pair of triangular segments connected by a hinge joint, a first of which is connected to one of the side walls  20  and a second of which is connected to a segment of the lap portion  12 . 
     The non-linear hinge joints  34 ′ have only a partial rotational degree of freedom about the joint, and the orientation of the folding axis associated with the non-linear hinge joints may change as the degree of folding changes. These restrictive hinge joints  34 ′ have a freedom of movement that is more limited than in the corresponding restrictive hinge joints described in conjunction with  FIG. 4  and can be useful in the deployed configuration where increased joint stability is desired, such as at load bearing joints. 
       FIGS. 8A-8D  illustrate the armrest  10  converted to the folded configuration from the opened-flat pattern of  FIG. 7 , with opposite sides of the segments shaded consistent with the previous figures. Some reference numerals are omitted for clarity in illustration, but the reference numerals of  FIG. 7  are used in the following description.  FIG. 8A  illustrates the segmented panel of  FIG. 7  in the opened-flat configuration with two folding axes (A). The side walls  20 , the lower foldable connectors  30 , and a portion of the upper foldable connectors  28  are folded inward about the axes (A) in the direction of the curved arrows over the lap portion  12 , the end wall  18 , and the arm portion  14  to reach the configuration of  FIG. 8B . The triangular segments of the upper foldable connectors  28  through which the folding axes (A) run may be non-rigid segments as discussed further below. The lap portion  12  is then folded about the folding axis (C) in the direction of the curved arrow over the end wall  18  to reach the configuration of  FIG. 8C . Finally, one segment of the lap portion  12  is folded over the other about the folding axis (D) to reach the folded configuration of  FIG. 8D , in which the armrest is folded flat with all of the flat segments  38  arranged in a plurality of parallel planes with some of the segments overlapping each other. At least a portion of the folded-flat configuration includes eight overlapping layers of flat segments, and the armrest  10  may include a closure to prevent the armrest from unfolding, as described in conjunction with  FIGS. 6A-6E . 
     In the illustrated folded configuration, the lateral width of the folded armrest is approximately one half of the width in the deployed configuration, and the length of the folded armrest is approximately two-thirds of the length of the deployed configuration. The vertical height is decreased more significantly, with the thickness of the folded armrest being be only 10-20% of the height of the deployed armrest. In one non-limiting example, the pattern of  FIG. 7  has a width of about 600 mm, a length of about 500 mm, and a thickness of about 5 mm, resulting in a deployed configuration having dimensions of about 250×370×275 mm (L×W×H) and a folded configuration having corresponding dimensions of about 165×185×40 mm. Stated differently, the folded armrest would fit into a rectangular box occupying less than 5% of the volume of a box in which the deployed armrest would require to fit into. 
     Conversion of the armrest  10  to the deployed configuration with the pattern of  FIG. 7  is substantially identical to that described in conjunction with  FIGS. 6A-6C , except for the final folds involving the upper foldable connectors  28 . Starting with the configuration of  FIG. 8B , the end wall  18  is folded upward about the folding axis (C) enough to allow the reverse fold to be formed in the lower foldable connectors  30 , which brings the upright sidewalls  20  over the lap portion  12 . Then the segments of the arm portion  14  are folded down about the non-linear hinge joint  34 ′, and the upper foldable connectors  28  are folded along folding axes (G), along which the two triangular segments of each upper foldable connector  28  are joined (see  FIG. 8B ). This fold is analogous to an outside reverse fold in origami. The segment of the connector  28  adjacent the arm portion  14  ends up on the outside of the other segment of the connector  28  to arrive at the deployed configuration of  FIG. 9 , in which the illustrated fasteners  32  are magnetic and embedded in the segmented panel. 
     There are therefore three overlapping segments at each lateral end of the arm portion  14  all interconnected by hinge joints, including both triangular segments of the upper foldable connector  28  and the respective sidewall  20 . A view from the forward-facing side of the deployed armrest in  FIG. 10  shows these folds in further detail.  FIG. 10  is only a schematic representation in which the individual segments of the arm portion  14 , the side wall  20 , and the two segments of the upper foldable connector  28  are illustrated with respective hinge joints  34  shown as relatively short, thick line segments. 
     Similarly,  FIG. 11  is a view from the forward-facing side of the deployed armrest of  FIG. 6C  schematically illustrating the corresponding folds associated with the upper foldable connectors  28  in further detail, where the upper end of the sidewall  20  is disposed between the two segments of the foldable connector  28 . 
       FIG. 12  is an exploded view depicting one manner of construction of the segmented panel  36  based on the pattern of  FIG. 7 , including a segmented layer  40  and a cushion layer  42  disposed between first and second upholstery layers  46 ,  48 , as well as edge trim  50  and a plurality of lines of stitching  52 . The panel  36  of  FIG. 12  is inverted from that of  FIG. 8A  to better illustrate some of the layers. The segmented layer  40  includes a plurality of rigid plates  54 , each of which fits within an individual segment  38  of the panel  36 . The cushion layer  42  also includes a plurality of separate pieces  56 , each of which is the same shape as an overlapping one of the rigid plates  54 . An exemplary cross-sectional view of the segmented panel  36  is provided in  FIG. 13 . 
     The upholstery layers  46 ,  48  provide the visible outer surfaces of the segmented panel  36  and may have the flexible properties of a fabric i.e., it is foldable without plastic deformation of the upholstery material and has a negligible flexural modulus. Each upholstery layer may include or be a fabric layer woven, knit, or spun from synthetic and/or natural fibers, for example. Synthetic microfiber fabrics are one example of suitable upholster layer materials. Nearly any material can be used as the upholstery layers  46 ,  48  to provide a desired aesthetic and feel, so long as the material has a sufficiently low resistance to bending out of plane in the form of a hinge joint. In some embodiments, the upholstery layers have a thermoplastic component suitable to be laminated together to form the hinge joints  34  between adjacent segments  38  and plates  54 , as shown in  FIG. 13 . 
     The rigid plates  54  of the segmented layer  40  are not foldable or bendable without plastically deforming the plate material and can be made from any suitable material exhibiting such properties, such as filled or unfilled polymeric materials, metals, or ceramics. The thickness of the plates also affects their rigidity, such that the plates can be made thinner from stiffer materials such as metals or polymer composites. An exemplary rigid plate  54  is a glass-filled thermoplastic material having a thickness between 2 mm and 4 mm. The rigid plates  54  are spaced apart from each other at fixed locations along and between the upholstery layers  46 ,  48 . The plate locations can be fixed by lamination, an adhesive layer, stitching, or other suitable means. Each of the rigid plates  54  has an edge  58  that runs parallel with an edge of an adjacent rigid plate along a gap  60 . The upholstery layers  46 ,  48  span the gap  60  to at least partly define the hinge joint  34  between the adjacent plates. 
     The spacing between adjacent plates  54  of the segmented layer  40  determines a width of the respective hinge joint  34 . In some embodiments, the spacing between different pairs of adjacent plates  54  varies such that widths of the respective hinge joints are different. For example, the hinge joints  34  located along the parallel edges of the plates  54  lying along folding axes (C) and (D) may have a width that is greater than the width of other hinge joints of the segmented panel  36 . Joint width may be defined in part by the number of interposed layers of segments  38  between the outermost layers when the armrest  10  is in the folded configuration. Hence, the hinge joints lying along folding axes (C) and (D) may be wider than other hinge joints in this example because the final two folds are formed along those joints. The hinge joint lying along the final folding axis, axis (D) in this example, may have the greatest width among the hinge joints. In one non-limiting example, the hinge joint  34  lying along the final folding axis (axis D in the illustrated examples) during conversion to the folded configuration has a width and a spacing between adjacent rigid plates of about 15 mm. The hinge joint  34  lying along the second to last folding axis (axis C in the examples) has a width and a spacing between adjacent rigid plates of about 10 mm, while the remaining hinge joints have a width of about 2 mm. 
     In some embodiments, not all segments  38  of the segmented panel include a rigid plate  54 . In the illustrated example, rigid plates  38  are omitted from the segmented layer  40  along one of the two segments of each foldable connector  28 ,  30 . Since the foldable connectors  28 ,  30  are folded back on themselves in the deployed configuration, this helps limit the thickness of the connectors  28 ,  30  when in the deployed configuration. Also, omission of the rigid plate can allow an individual segment of the foldable connectors to be folded in the folded configuration of the armrest, such as with the upper foldable connectors  28  discussed in conjunction with  FIG. 8A . Rigid plates may be omitted from other portions of the segmented layer, although they are preferably included in the support portion  16 , as well as in the lap portion  12  and the arm portion  14  for structural reasons. 
     The optional cushion layer  42  is a layer of foam or other suitable material located between one of the upholstery layers and the segmented layer  40 . The cushion layer  42  is provided to help isolated the rigid plates  54  from the arms and legs of the user more than the upholstery layers  36 ,  38  can on their own and to provide a comfortable arm-resting surface. As such, pieces  56  of the cushion layer  42  are preferably located in the segments  38  corresponding to the lap portion  12  and the arm portion  14  of the armrest, although cushion layer pieces  56  can be included in other segments as well. In some embodiments, all of the rigid plates  54  have a piece  56  of the cushion layer  42  in an overlapping arrangement. The cushion layer  42  preferably does not span the hinge joints  42 , as this would impart the hinge joints with excess thickness and an undesirable elastic quality. 
     The edge trim  50  may be provided along the outer perimeter of the opened-flat pattern to conceal the cut edges of the upholstery layers  36 ,  38  and/or enclose any rigid plates  54  between the upholstery layers where there is no hinge joint already doing so. The edge trim  50  may be attached via one of the lines of stitching  52 , as shown in  FIG. 13 , or by other suitable means (e.g., adhesive, heat sealing, etc.). 
     The illustrated lines of stitching  52  may be decorative, functional, or both. In the example of  FIG. 13 , the line of stitching  52  located along the illustrated hinge joint  34  is primarily decorative, giving the appearance of a sewn hinge joint which is actually formed by lamination. But the stitching  52  is also a fail-safe for the hinge joint, in the event the upholstery layer delaminates at the joint  34 . In the illustrated example, a line of stitching  52  is provided along every hinge joint  34  between every pair of adjacent segments  38 . Lines of stitching may be additionally provided away from hinge joints, such as in the form of visual aids that help the user properly convert the armrest among its various configurations. In some embodiments, dual lines of stitching are provided along each hinge joint spaced apart in an amount of the desired joint width. Such lines of stitching can, for example, surround each of the plates  54  of the segmented layer and eliminate lamination and/or the need for additional attachment layers such as adhesive. 
     In one manner of making the armrest, the first and second upholstery layers  36 ,  38  are cut to the desired pattern shape, and the segmented and cushion layers  40 ,  42  stacked together and laminated between the upholstery layers. Then, the lines of stitching  52  are sewn along the hinge joints  34 , and the edge trim is affixed along the perimeter of the pattern. A step of providing the segmented layer  40  and/or the cushion layer  42  may include die cutting each layer from sheet material. In one example, the segmented and cushion layers  40 ,  42  are die cut simultaneously from stacked layers of the desired materials into rigid plates  54  of the desired size and shape and cushion layer pieces  56  having shapes identical to the rigid plates. The reversible fasteners  32  may be added along the upholstery layer(s) prior to lamination. 
       FIGS. 14-19  illustrate various modifications of the portable armrest.  FIG. 14  illustrates the portable armrest  10  in the folded configuration, as in  FIG. 5E , as a stand-alone item with an elastic closure  62  that may remain attached to the armrest when in the deployed and the folded configurations. 
       FIG. 15  illustrates the portable armrest  10  in a secondary function as a sleeve for a tablet or small notebook computer. The segmented panel may include one or more additional segments and/or layers of material specifically configured to receive and accommodate the tablet, or the tablet can simply be slid into an open end of the folded configuration so that it is surrounded on three of the four edges and both opposite faces. For example, the tablet can be slid between one of the foldable connectors  30  and a segment of the lap portion  12  during conversion to the folded configuration as shown in  FIG. 16 , or slid into the same location after conversion to the folded configuration. 
     Similarly,  FIG. 17  illustrates the portable armrest  10  in a secondary function as a sleeve or carrying case for a laptop computer. The folded configuration illustrated in  FIG. 17  includes one less fold than that of  FIG. 15  and corresponds to the configuration of  FIG. 5D . The illustrated armrest  10  includes handles  64  attached to the segmented panel  36 , in particular along edges of the lap portion  12  and arm portion  14 . The segmented panel  36  may include one or more additional segments and/or layers of material specifically configured to receive and accommodate the computer, or the computer can be slid into an open end of the folded configuration near the handles  64  so that it is surrounded on three of the four edges and both opposite sides. For example, the laptop computer can be slid between the lap portion  12  and the lower foldable connectors  30  during conversion to the folded configuration as shown in  FIG. 18 , or slid into the same location after conversion to the folded configuration. Optionally, an additional closure may be provided to further secure the laptop computer between layers of the folded configuration. 
     In  FIG. 19 , the armrest  10  includes an armrest accessory  66  configured to hold a mobile phone, tablet, or other similarly sized device. The illustrated accessory  66  extends from an edge of the arm portion  14  and may be an integrated and permanent part of the armrest  10 , or it may be detachably fastened to the armrest via a clip or other temporary fastener. Non-limiting examples of armrest accessories, all of which provide some functionality other than resting the arms, include various holders, retainers, containers, and handles. 
     It is to be understood that the foregoing is a description of one or more preferred exemplary embodiments of the invention. The invention is not limited to the particular embodiment(s) disclosed herein, but rather is defined solely by the claims below. Furthermore, the statements contained in the foregoing description relate to particular embodiments and are not to be construed as limitations on the scope of the invention or on the definition of terms used in the claims, except where a term or phrase is expressly defined above. Various other embodiments and various changes and modifications to the disclosed embodiment(s) will become apparent to those skilled in the art. All such other embodiments, changes, and modifications are intended to come within the scope of the appended claims. 
     As used in this specification and claims, the terms “for example,” “for instance,” “such as,” and “like,” and the verbs “comprising,” “having,” “including,” and their other verb forms, when used in conjunction with a listing of one or more components or other items, are each to be construed as open-ended, meaning that the listing is not to be considered as excluding other, additional components or items. Other terms are to be construed using their broadest reasonable meaning unless they are used in a context that requires a different interpretation.