An aspect of the present invention relates to a packaging tray.
The present application claims priority based on Japanese Patent Application No. 2017-086296 filed in the Japan Patent Office on Apr. 25, 2017, the entire contents of which are incorporated herein by reference.
Existing packaging trays for packaging display panels, such as liquid crystal panels, are used to convey the display panels. During the conveyance of display panels, breakage and damage to the display panels can be reduced by holding the display panels in the packaging trays made especially for the display panels and conveying the display panels in the packaging trays. In addition, when the packaging trays are packaged in a state of being stacked in a plurality of tiers, advantageous effects such as a reduction in the amount of packaging material usage and the downsizing of packages can be attained.
PTL 1 discloses a packaging tray including a holding portion for holding a liquid crystal panel and a protrusion that protrudes from the back surface side of the holding portion. PTL 1 describes that coming off of the liquid crystal panel is suppressed because, when the packaging trays are stacked in a plurality of tiers, the protrusion of an upper tier packaging tray press the liquid crystal panel held in a lower tier packaging tray.
PTL 2 discloses a packaging tray including a holding recess for holding a liquid crystal panel and position determining portions that are provided around the holding recess and that determine the stacking positions of other packaging trays that are placed above and below the packaging tray. PTL 2 describes as follows. The packaging tray further includes a panel pressing portion, and the panel pressing portion comes into contact with a peripheral portion of the liquid crystal panel held in the lower tier packaging tray when the packaging trays are stacked in a plurality of tiers. Thus, the liquid crystal panels are held stably, which enhances the safety of the liquid crystal panels during transportation.
However, the trays described in PTL 1 and PTL 2 are configured in such a way that, when the trays are stacked in a plurality of tiers, the liquid crystal panel held in one of the trays directly receives the load of trays placed above the one of the trays. Therefore, if the load exceeds the strength of the liquid crystal panels, defects such as fracture and chipping in the liquid crystal panels may occur.
In recent years, the mechanical strength of liquid crystal panels has tended to decrease with the thickness reduction of liquid crystal panels. Movement of the liquid crystal panels in trays due to vibration, the tilt of packages, and the like during transportation is undesirable because the movement may damage the panels. Therefore, liquid crystal panels need to be fixed to trays with appropriate force. Thus, even in a state of being stacked in a plurality of tiers, packaging trays are required to protect liquid crystal panels while fixing liquid crystal panels with appropriate force that is not likely to damage liquid crystal panels.
An aspect of the present invention has been made for solving the above problem, and an object of the aspect of the present invention is to provide a packaging tray capable of reducing the occurrence of defects in display panels when a plurality of packaging trays are stacked.
To achieve the object, a packaging tray according to an aspect of the present invention is capable of holding at least one display panel and is stackable in a plurality of tiers. The packaging tray includes at least one panel holding portion. The panel holding portion includes a holding recess that holds the display panel, a panel supporting portion that protrudes to a position above a bottom plate of the holding recess and that comes into contact with a lower surface of the display panel to support the display panel, a supporting foot protruding to a position below the bottom plate of the holding recess, a panel pressing portion provided in the supporting foot, and a tray supporting portion provided on an upper surface side of the supporting foot. In a state in which the display panel is held in the holding recess, a top tier tray having a shape of the packaging tray is stacked above the packaging tray, and a bottom tier tray having the shape of the packaging tray is stacked below the packaging tray, the supporting foot includes a first contact surface that is in contact with the tray supporting portion of the bottom tier tray, the panel pressing portion includes a second contact surface that is in contact with the display panel held in the bottom tier tray, and the tray supporting portion includes a third contact surface that is in contact with the first contact surface of the top tier tray.
In the packaging tray according to an aspect of the present invention, the panel supporting portion may be disposed at a position where the panel supporting portion comes into contact with a peripheral portion of the display panel from below, and the panel pressing portion may be disposed at a position where the panel pressing portion comes into contact with the peripheral portion of the display panel from above.
In the packaging tray according to an aspect of the present invention, the second contact surface may be provided so as to incline with respect to the first contact surface and may come into contact with an upper corner of the peripheral portion of the display panel.
In the packaging tray according to an aspect of the present invention, the panel pressing portion may further include a first step portion provided between the first contact surface and the second contact surface, and the second contact surface may come into contact with an upper surface of the peripheral portion of the display panel.
In the packaging tray according to an aspect of the present invention, the supporting foot may further include a side wall surface rising from the second contact surface toward the panel supporting portion, and a junction of the second contact surface and the side wall surface may be rounded into a curved surface.
In the packaging tray according to an aspect of the present invention, the panel pressing portion may further include a noncontact surface that is continuous from the second contact surface and that does not come into contact with the display panel and a second step portion that is provided between the second contact surface and the noncontact surface.
In the packaging tray according to an aspect of the present invention, a shape of the supporting foot as seen in a normal direction of the bottom plate may be a rectangle, and corners of the rectangle that is the shape of the supporting foot may be rounded into curved surfaces.
In the packaging tray according to an aspect of the present invention, an outer dimension of an upper side of the tray supporting portion may be relatively large, and an outer dimension of a lower side of the tray supporting portion may be relatively small.
With an aspect of the present invention, the occurrence of defects in the liquid crystal panels when a plurality of packaging trays are stacked can be reduced.
Hereinafter, a first embodiment of the present invention will be described with reference to
For easy view of each component, some components are illustrated at different scales in each following figure.
Hereinafter, the embodiments will be described on the assumption that a liquid crystal panel P is placed from above and held in a packaging tray 1, an opening side of a panel holding portion 2 for holding the liquid crystal panel P is referred to as the upper side of the packaging tray 1, and the opposite side from the opening side of the panel holding portion 2 is referred to as the lower side of the packaging tray 1.
The lateral direction of the panel holding portion 2 corresponds to the X direction, the longitudinal direction of the panel holding portion 2 corresponds to the Y direction, and the depth direction of the panel holding portion 2 corresponds to the Z direction.
As illustrated in
The packaging tray 1 is made up of, for example, a molded item produced by vacuum forming or pressure forming a thermoplastic synthetic resin sheet. That is, the packaging tray 1 is produced by heating to soften a thermoplastic synthetic resin sheet, by applying pressure (vacuum pressure or air pressure) to the softened thermoplastic synthetic resin sheet to push the thermoplastic synthetic resin sheet into a mold, and by transferring the shape of the mold surface to the thermoplastic synthetic resin sheet. Examples of thermoplastic synthetic resin sheets are foamed sheets or non-foamed sheets of polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), polyethylene (PE), and the like. The thickness of a thermoplastic synthetic resin sheet is selected appropriately, for example, within a range of 0.5 mm to 2 mm.
Here, one example of the methods for packaging a plurality of liquid crystal panels P using the packaging trays 1 will be described.
First, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, two sets of the tray stacks 3 wrapped in the inner sleeves 7 are placed into the inside of a tubular outer sleeve 8. The inner sleeve 7 and the outer sleeve 8 are made of corrugated board, for example. The corrugated board may be made of paper or plastic materials.
Next, the tray stacks 3 wrapped in the inner sleeves 7 and the outer sleeves 8 are placed in a box 9 in a plurality of tiers such as two tiers. The box 9 is a carton, for example. Top flaps of the carton are closed and sealed with an adhesive tape piece 10 to complete the packaging of the liquid crystal panels P. Although the corrugated carton is used here as the box 9 for holding the tray stacks 3, a returnable box of a synthetic resin or the like may be used.
It is not necessary that all of the above-described packaging materials, that is, the bag 5, the inner sleeve 7, the outer sleeve 8, and the box 9 be used. Packaging without some of the above-described packaging materials is possible. However, it is preferable that at least one of the bag 5 and the box 9 be used as packaging materials in order to hold the packaging trays 1 stacked in a plurality of tiers to avoid collapse of the packaging trays 1.
Hereinafter, the configuration of the packaging tray 1 will be described in detail.
The packaging trays 1 stacked in three tiers have the same configuration. The configuration will be described by focusing on mainly the packaging tray 1 in the middle tier of the three-tier packaging trays 1, for convenience of description. The packaging tray 1 in the top tier is referred to as a top tier tray 1T, and the packaging tray 1 in the bottom tier is referred to as a bottom tier tray 1B.
As illustrated in
The holding recess 12 includes a bottom plate 18 disposed at a position lower than an upper surface 13a of the panel supporting portion 13 (described below) and holds the display panel P. When the liquid crystal panel P is held in the packaging tray 1, the bottom plate 18 is not in contact with the liquid crystal panel P. The bottom plate 18 extends in the longitudinal direction of the panel holding portion 2 (Y direction) and has recesses and protrusions arranged alternately in the lateral direction of the panel holding portion 2 (X direction). Thus, the warpage of the packaging tray 1, which tends to occur when the bottom plate 18 is a flat plate, is less likely to occur.
The panel supporting portion 13 protrudes to a position above the bottom plate 18 of the holding recess 12 and supports the liquid crystal panel P in a state of being in contact with the lower surface of the liquid crystal panel P. The panel supporting portion 13 extends along four sides of the holding recess 12 so as to surround the perimeter of the holding recess 12. The panel supporting portion 13 is disposed at a position where the panel supporting portion 13 comes into contact with a peripheral portion of the liquid crystal panel P from below, when the liquid crystal panel P is held in the packaging tray 1. The edge of the upper surface 13a of the panel supporting portion 13 on the holding recess 12 side forms a curved surface 13r (rounded surface) having a predetermined radius of curvature.
The supporting foot 14 protrudes to a position below the bottom plate 18 of the holding recess 12. Thus, a space on the upper surface side of the supporting foot 14 is a recess on the side of the panel supporting portion 13. For example, when the packaging tray 1 is placed on a table, a lower surface 14b of the supporting foot 14 comes into contact with the table and supports the entire packaging tray 1. Moreover, in a state in which the packaging trays 1 are stacked in a plurality of tiers, the lower surface 14b of the supporting foot 14 is in contact with the tray supporting portion 16 (described below) of the bottom tier tray 1B. Hereinafter, the lower surface 14b of the supporting foot 14 that comes into contact with the tray supporting portion 16 will be referred to as a first contact surface 14b. That is, the supporting foot 14 includes the first contact surface 14b to be in contact with the tray supporting portion 16 of the bottom tier tray 1B.
The panel pressing portion 15 is provided at the edge of the supporting foot 14 on the holding recess 12 side of the bottom tier tray 1B. In the state in which the packaging trays 1 are stacked in a plurality of tiers, the panel pressing portion 15 is disposed at a position where the panel pressing portion 15 comes into contact with, from above, the peripheral portion of the liquid crystal panel P held in the bottom tier tray 1B. A lower surface 15b of the panel pressing portion 15 comes into contact with the liquid crystal panel P. Hereinafter, the lower surface 15b of the panel pressing portion 15 that comes into contact with the liquid crystal panel P will be referred to as a second contact surface 15b. That is, the panel pressing portion 15 includes the second contact surface 15b to be in contact with the liquid crystal panel P.
The second contact surface 15b is provided so as to incline at an angle θ of 45° to the first contact surface 14b of the supporting foot 14. The second contact surface 15b comes into contact with an upper corner of the peripheral portion of the liquid crystal panel P. The angle θ formed by the first contact surface 14b and the second contact surface 15b is not necessarily 45 degrees and may be set at any appropriate angle.
The tray supporting portion 16 is formed in a recess on an upper surface 14a side of the supporting foot 14. The tray supporting portion 16 is made up of a protrusion that protrudes from a side plate 14c of the supporting foot 14 in the longitudinal direction of the panel holding portion 2 (Y direction). The shape of the tray supporting portion 16 as seen in the longitudinal direction of the panel holding portion 2 (Y direction) is substantially semicircular. A linear part of the semicircle is at an upper position, and a curved part of the semicircle is at a lower position.
As illustrated in
In the state in which the packaging trays 1 are stacked in a plurality of tiers, an upper surface 16a of the tray supporting portion 16 is in contact with the first contact surface 14b of the top tier tray 1T. Hereinafter, the upper surface 16a of the tray supporting portion 16 that comes into contact with the first contact surface 14b will be referred to as a third contact surface 16a. That is, the tray supporting portion 16 includes the third contact surface 16a to be in contact with the first contact surface 14b of the top tier tray 1T.
As illustrated in
Regarding existing packaging trays, when the packaging trays are stacked in a plurality of tiers, a panel pressing portion of an upper tier tray is in direct contact with the upper surface of a liquid crystal panel; thus, the liquid crystal panel held in one of the trays directly receives the load of trays placed above the one of the trays. In addition, no member for supporting the panel is provided immediately below the panel pressing portion. Therefore, the existing packaging trays have a problem in that, if the load exceeds the strength of the liquid crystal panels, defects such as fracture and chipping in the liquid crystal panels may occur. Moreover, the existing packaging trays have a problem in that, if the load is small, insufficient fixing of the liquid crystal panels may result in flaws and dust generation due to the movement of the liquid crystal panels, for example, during tray transportation.
To address the problems, the packaging tray 1 according to the present embodiment includes the tray supporting portion 16 disposed on the upper surface 14a side of the supporting foot 14, and the tray supporting portion 16 receives the load of the top tier tray 1T when the packaging trays 1 are stacked in a plurality of tiers, as illustrated in
According to the configuration of the present embodiment, the second contact surface 15b of the panel pressing portion 15 comes into contact with the upper corner of the peripheral portion of the liquid crystal panel P from the direction forming an angle of 45° to the upper surface of the liquid crystal panel P. The panel pressing portion 15 restricts the movement of the liquid crystal panel P in both vertical and horizontal directions. As a result, the movement of the liquid crystal panels P during transportation is less likely to occur; thus, flaws and dust generation of the liquid crystal panels P can be suppressed.
The packaging tray 101 of the first comparative example does not include first curved surface portions at both ends of a panel pressing portion 115. In this case, of the upper surface of a liquid crystal panel P, stress is concentrated on areas Q that are in contact with the corners at both ends of the panel pressing portion 115, as illustrated in
On the other hand,
As illustrated in
The tray supporting portion 16 has a reversely tapered shape and can thus receive the load of the top tier tray 1T stably.
With the various above-described functions, the occurrence of defects in the liquid crystal panels P when a plurality of packaging trays 1 are stacked can be reduced using the packaging trays 1 according to the present embodiment.
Hereinafter, a second embodiment of the present invention will be described with reference to
The basic configuration of a packaging tray according to the second embodiment is the same as that of the first embodiment. However, the configurations of a panel pressing portion and a tray supporting portion differ from those of the first embodiment.
In
As illustrated in
As illustrated in
A supporting foot 14 includes a side wall surface 14d rising from the second contact surface 25b toward the panel supporting portion 13. The junction of the second contact surface 25b and the side wall surface 14d is rounded into a curved surface and to form a second curved surface portion 27 made up of a curved surface (rounded surface) having a predetermined radius of curvature.
The shape of a tray supporting portion 26 as seen in the longitudinal direction of the panel holding portion 22 (Y direction) is a trapezoid, and the long side of the trapezoid is at an upper position and the short side is at a lower position. That is, the shape of the tray supporting portion 26 is reversely tapered. The tray supporting portion 26 includes a third contact surface 26a to be in contact with the first contact surface 14b of the top tier tray 21T. As illustrated in
Other configurations of the second embodiment are similar to those of the first embodiment.
Also with the packaging tray 21 according to the second embodiment, the load applied by the top tier tray 21T to the liquid crystal panel P is reduced because the tray supporting portion 26 receives the load of the top tier tray 21T. In addition, because the panel supporting portion 13 is provided substantially directly below the panel pressing portion 25, the load applied by the panel pressing portion 25 to the liquid crystal panel P can be received by the panel supporting portion 13. Thus, an advantageous effect similar to that of the first embodiment, that is, an advantageous effect in which the occurrence of defects such as fracture and chipping in the liquid crystal panels P can be suppressed is attained.
The packaging tray 201 of the second comparative example differs from the packaging tray 21 according to the second embodiment in that the packaging tray 201 does not have a first step portion 23 and a second curved surface portion 27. Accordingly, a first contact surface 214b of a supporting foot 214 is a flat surface and comes into contact with a liquid crystal panel P together with a tray supporting portion 216, thus functioning as a panel pressing portion. In the configuration of the packaging tray 201 of the second comparative example, the rigidity of a side plate 214c of the supporting foot 214 tends to be higher, compared with that of the present embodiment. Therefore, relatively high pressure is applied by the first contact surface 214b to the liquid crystal panel, and stress concentrates especially on an area Q that is in contact with a corner of the supporting foot 214. As a result, fracture of the liquid crystal panel P is likely to occur near the area Q.
In contrast, in the packaging tray 21 according to the second embodiment, the panel pressing portion 25 includes the first step portion 23. Thus, the flexibility of the panel pressing portion 25 increases as the rigidity of the side wall surface 14d of the supporting foot 14 decreases, compared with the packaging tray 201 of the second comparative example without any step portions. In addition, the second curved surface portion 27 is provided at the junction of the second contact surface 25b and the side wall surface 14d.
These configurations enable the panel pressing portion 25 according to the second embodiment to press the liquid crystal panel P in a flexible manner, without causing stress concentration on a specific area of the liquid crystal panel P. Therefore, if the packaging tray 21 receives an impact, for example, during transportation, the panel pressing portion 25 can be easily deformed to relieve the impact. Accordingly, the packaging tray 21 can hold the liquid crystal panels P stably.
Other advantageous effects such as the effect produced by providing first curved surface portions 14r at both ends of the panel pressing portion 25 and the effect produced by forming the tray supporting portion 26 into a reversely tapered shape are similar to those of the first embodiment.
Hereinafter, a third embodiment of the present invention will be described with reference to
The basic configuration of a packaging tray according to the third embodiment is the same as that of the second embodiment; however, the configuration of a panel pressing portion differs from that of the second embodiment.
In
As illustrated in
As illustrated in
Other configurations are similar to those of the second embodiment.
Also with the packaging tray 31 according to the third embodiment, the load applied by a top tier tray to a liquid crystal panel P is reduced because the tray supporting portion 26 receives the load of the top tier tray. In addition, because the panel supporting portion 13 is provided substantially directly below the panel pressing portion 35, the load applied by the panel pressing portion 35 to the liquid crystal panel P can be received the panel supporting portion 13. Thus, an advantageous effect similar to that of the first and second embodiments, that is, the advantageous effect in which the occurrence of defects such as fracture and chipping in the liquid crystal panels P can be reduced is attained.
Moreover, in the case of the third embodiment, as illustrated in
Other advantageous effects such as the effect produced by providing first curved surface portions 14r at both ends of the panel pressing portion 35 and the effect produced by forming the tray supporting portion 26 into a reversely tapered shape are similar to those of the first and second embodiments.
The technical scope of the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.
For example, the shape of the tray supporting portion is reversely tapered in the above-described embodiments; however, the shape of the tray supporting portion is not necessarily reversely tapered and may or not be tapered. In addition, the number, shape, disposition, dimensions, material, and the like of each component composing the packaging tray may be modified as appropriate.
Moreover, the packaging trays for holding a plurality of small liquid crystal panels are taken as examples in the above-described embodiments; however, the present invention may be applied to a packaging tray for holding a large liquid crystal panel, for example. Furthermore, the present invention is not limited to packaging trays for liquid crystal panels and may be applied to packaging trays for other kinds of display panels such as organic electroluminescent (EL) panels.
An aspect of the present invention can be applied to packaging trays for packaging various kinds of display panels such as liquid crystal panels and organic EL panels.
Number | Date | Country | Kind |
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2017-086296 | Apr 2017 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2018/016467 | 4/23/2018 | WO | 00 |