Cassettes for receiving glass substrates

Abstract

Cassettes for receiving objects. The cassettes include a frame, a sidewall and a cantilever. The sidewall is perpendicular to a horizon. The cantilever for supporting the object includes a fixed-end attached to the sidewall, thereby forming an angle with the horizon.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to cassettes, and more particularly, to cassettes for receiving glass substrates of liquid crystal displays (LCDs).

2. Discussion of the Related Art

Panels of display devices often comprise transparent substrates, which are becoming increasingly thinner and reducing the size, weight of products. Transparent substrates comprise glass, quartz, or organic transparent materials such as polycarbonate (PC), poly methyl methacrylate (PMMA). In a thin film transistor-liquid crystal displays (TFT-LCDs) manufacturing process, glass substrates of the panel or other plate-like objects are loaded and stored in a cassette, and can be moved or transported by mechanical arms.

As shown in FIG. 1A, glass substrates S₁′ are stored in a cassette C. The cassette C comprises a frame 100′ and a plurality of cantilevers 101′ and 102′. The frame 100′ is rectangular. The cantilevers 101′ and 102′ are evenly disposed on inner walls 110′ and 120′ of the frame 100′. The frame 100′ is divided into a plurality of floors 105. Each floor 105 has a height H_p, which is a floor pitch or distance between floors. Each substrate S₁′ is supported by two cantilevers 101′ and 102′ at the same level.

FIG. 1B is a front view of the conventional cassette C when a mechanical arm M is transferring a glass substrate S₁′ therein. The mechanical arm M comprises a first support portion 5′ and a second support portion 6′ with a predetermined distance W′ therebetween. When the mechanical arm M transports the substrate S₁′, the mechanical arm M moving into an assigned floor 105 of the cassette C, transfers the substrate S₁′ on the cantilever 101′ and 102′, thereby completing storage of the substrate S₁′. Conversely, when taking the substrate S₁′ out of the cassette C, the mechanical arm M moves into the cassette C directly under the substrate S₁′, and the support portions 5′ and 6′ thereof simultaneously support the substrate S₁′ and move it out of the cassette C.

The substrate S₁′ is supported by the cantilevers 101′ and 102′ on the inner walls 110′ and 120′ of the cassette C; however, due to the self-weight of the substrate S₁′, a central portion thereof is slightly deformed downward.

Furthermore, the glass substrates are categorized into various generations with different dimensions such as the 2.5-generation (370 mm by 470 mm), the 3^rd-generation (550 mm by 650 mm), the 3.5-generation (660 mm by 720 mm), the 4^th-generation (680 mm by 880 mm), the 5^th-generation (1100 mm by 1250 m). The trend is toward even larger substrate sizes, such as 6^th- or 7^th-generation substrates (about 1900 mm by 2200 mm). The thickness thereof is reduced from 0.7 mm to the current 0.4 mm. That is, the substrates are larger and thinner, and thus, the deflection ratio of the central portion of the substrates is increased.

When the mechanical arm M is loading the large and thin substrate S₁′, each end E₁ of the substrate S₁′ is naturally deflected downward by self-weight, as shown in FIG. 1C. H_c is the deflected length of the end E₁. In the conventional cassette C, during transportation, if the misalignment of the mechanical arm M is severe enough, it may cause one end E₁ of the substrate S₁′ to strike the cantilevers 101′ and 102′ of the cassette C and break inside the cassette C. Thus, yield rate is reduced, wasting materials and increasing process time.

To safely transport the substrates S₁′ from the cassette C, the distance H_p must be greater than H_c. The distance H_p of each floor 105 must be increased to avoid contact between the ends E₁, E₂ of the substrate S₁′ and the cassette C. Thus, the large substrates require a larger sized cassette. Furthermore, due to space constraints, the cassette must be appropriately sized for convenience during storage and removal of the substrates, and thus, the storage volume of the cassette C is reduced accordingly. Hence, reduction of defects in the glass substrate when transferred from one position to another is critical.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is improving cassette and to safely transport the objects not struck the cassette during transportation.

Another object of the present invention to change the cantilevers shaped of the cassette, which to reduce the total height and weight of the cassette.

Further another object of present invention to increased the floor amount, which to increase the stored amount of objects.

For the purpose of the present invention, cassettes are provided. An exemplary embodiment of a cassette for receiving an object comprises a sidewall and a cantilever. The sidewall is perpendicular to a horizon. The cantilever for supporting the object comprises a fixed-end attached to the sidewall, thereby forming an angle with the horizon, and the angle in the range of about 1° to 10°.

The cantilever further comprises a front-end, and a lower portion of the front-end comprises a notch. The thickness of the cantilever decreases along the front-end.

Additionally, the lower portion of the front-end is substantially step-shaped. The cassette further comprises a pad, and the pad is disposed on the front-end. The pad comprises an elastic polymer such as rubber, soft Polypropylene, or like.

Further provided is a cassette for receiving an object comprising a sidewall and a cantilever. The sidewall is perpendicular to a horizon. The cantilever for supporting the object comprises a fixed-end attached to the sidewall and a front-end having a thickness less than that of the fixed-end. The front-end comprises a notch. The thickness of the cantilever decreases from the fixed-end to the front-end. Moreover, the front-end is substantially step-shaped. The cassette further comprises a pad, disposed on the front-end. The pad comprises an elastic polymer such as rubber, soft Polypropylene, or like.

Some embodiments of a cassette for receiving an object comprise a first sidewall, a first cantilever, a second sidewall, and a second cantilever. The first sidewall is perpendicular to a horizon. The first cantilever is disposed on the first sidewall. The second sidewall opposes and parallel to the first sidewall. The second cantilever is disposed on the second sidewall. The first cantilever and the horizon form a first angle, and the second cantilever and the horizon form a second angle. The first angle and the second angle are substantially identical.

DESCRIPTION OF THE DRAWINGS

Cassettes for receiving glass substrates can be more fully understood by reading the subsequent detailed description in conjunction with the examples and references made to the accompanying drawings, wherein:

FIG. 1A is a schematic internal view of a conventional cassette;

FIG. 1B is a front view of the conventional cassette with a mechanical arm;

FIG. 1C is a local enlarged view of the conventional cassette;

FIG. 2A is a front view of an embodiment of a cassette;

FIG. 2B is a front view of the cassette with a mechanical arm of the FIG. 2A;

FIG. 2C is a local enlarged view of a first cantilever of the cassette of the FIG. 2A;

FIG. 3A is a front view of an embodiment of a cassette;

FIG. 3B is a front view of an embodiment of the cassette with a mechanical arm of the FIG. 3A;

FIG. 3C is a local enlarged view of a first cantilever of the cassette of the FIG. 3A;

FIG. 3D is a local enlarged view of a variation of the first cantilever of the cassette of the FIG. 3A;

FIG. 4A is a front view of an embodiment of a cassette;

FIG. 4B is a front view of an embodiment of the cassette of the FIG. 4A with a mechanical arm;

FIG. 4C is a local enlarged view of a first cantilever of the cassette of the FIG. 4A;

FIG. 4D is a local enlarged view of a variation of the first cantilever of the cassette of the FIG. 4A.

DETAILED DESCRIPTION

Cassettes for receiving glass substrates are provided. An exemplary embodiment of a cassette for receiving glass substrates is applicable to a TFT-LCD panel manufacturing process when transporting a plurality of objects such as glass substrates or other plate-shaped objects in a cassette by a mechanical arm M. The cassette is used to load and store the objects S₁. The mechanical arm M can enter the cassette and move horizontally upward or downward to transfer the object S₁.

FIG. 2A is a front view of an embodiment of a cassette C₁. The cassette C₁ comprises a frame 100, a first sidewall 110, a second sidewall 120, a first cantilever 11, and a second cantilever 12. Note that the quantity of cantilevers is not limited to two, and the cassette C₁ can comprise a plurality of cantilevers. In some embodiments, the first cantilever 11 and the second cantilever 12 are provided.

The first sidewall 110 and the second sidewall 120 are perpendicular to a horizon h. The second sidewall 120 is opposing and parallel to the first sidewall 110. The first cantilever 11 comprises a first fixed-end 11a and a first front-end 11b. The first fixed-end 11a is attached to the first sidewall 110. The second cantilever 12 comprises a second fixed-end 12a and a second front-end 12b. The second fixed-end 12a is attached to the second sidewall 120. The object S₁ is supported by the front-ends 11b and 12b of the cassette having a plurality of pads 160 disposed thereon, preventing direct contact between the object S₁ and the cantilevers 11 and 12.

The first cantilever 11 and the horizon h form a first angle θ₁. The second cantilever 12 and the horizon h form a second angle θ₂. The first angle θ₁ is substantially identical the second angle θ₂. The first and second angles θ₁, θ₂ in the range of about 1° to 10°, preferably range of about 1° to 4°, varying with the length, thickness, weight and materials of the object S₁.

FIG. 2B is a front view of the cassette C₁ with a mechanical arm M. FIG. 2C is a local enlarged view of a first cantilever 11 of the cassette C₁. The mechanical arm M comprises two support portions 5 and 6 located inside a floor 150 of the cassette C, supporting one of the objects S₁. When supported by the mechanical arm M, two ends of the object S₁ is deformed downward. The first angle θ₁ of the first cantilever 11 is substantially identical an inclined angle θ₁′ of the end section E of the object S₁. Thus, the first cantilever 11 is substantially parallel to the section E.

Since the shapes of the cantilevers and the end sections of the objects are similar and parallel, the end section E does not strike the cantilevers when the mechanical arm M loading the substrate moves up or down therebetween, preventing breakage of the substrate.

Furthermore, as shown in FIG. 2C, the first cantilever 11 is inclined upward, an additional height D₁ is provided for the floor 105 near the front-end 11b, and thus, distance between floors of the cassette can be increased. The additional height D₁ provides sufficient clearance, preventing contact between the object S₁ and the cantilevers 11 and 12 during transportation. Since the distance between the floors 105 in the cassette C₁ can be reduced, the overall size of the cassette C₁ can be reduced, providing a more compact sized cassette. Under other circumstances, when a larger storage capacity is required, since the distance between the floors can be reduced, the overall size of the cassette C₁ can remain the same but more floors can be added for storing more objects. Hence, the capacity of the cassette C₁ can be increased without increasing overall size thereof.

FIGS. 3A, 3B, and 3C are schematic views of an embodiment of the cassette C₂. The cassette C₂ comprises a frame 200, a first sidewall 210, a second sidewall 220, a first cantilever 21, and a second cantilever 22. Note that explanations of elements and connecting structures common to the previously described embodiments are omitted.

As shown in FIG. 3A-3C, the difference is that the shapes of the front-ends 21b and 22b of the first cantilever 21 and the second cantilever 22 are different. The thickness of the front-ends 21b and 22b is less than that of the fixed-ends 21a and 22a. That is, the first front-end 21b of the first cantilever 21 comprises a notch 25, and the second front-end 22b of the second cantilever 22 comprises a notch 26. The cantilevers 21 and 22 are substantially step-shaped.

Moreover, the first and the second cantilevers 21 and 22 remain horizontal, unlike the inclined cantilevers in some embodiments. Similarly, the pads 260 are disposed on the first and second cantilevers 21, 22 to prevent direct contact of the object S₂.

FIG. 3B is a front view of the cassette C₂ with a mechanical arm M. FIG. 3C is a local enlarged view of a first cantilever of the cassette C₂. As shown in FIGS. 3B and 3C, the mechanical arm M is located on a floor 250 of the cassette C₂ and loads one of the objects S₂ by the support portions 5 and 6 thereof. When the mechanical arm M is loading the object S₁, two end sections E thereof are slightly deflected downward. Since the first front-end 21b of the first cantilever 21 comprises a notch having a height D₂, which varies with inclined angle of the end sections E of the object S₂, the notch 25 provides an additional transport space for the mechanical arm M such that contact between the end section E and the first cantilever can be prevented. Thus, the floor pitch H₂ of the cassette C₂ can be reduced accordingly. The overall size of the cassette C₂ can be reduced, providing a more compact sized cassette. In some embodiments, when larger storage capacity of the cassette C₂ is required, since distance between the floors can be reduced, the overall size of the cassette C₂ can remain the same and more of the floors can be added for storing more objects. Hence, the capacity of the cassette C₂ can be increased without increasing overall size thereof.

The cassette further has a variation. As shown in FIG. 3D, from which common elements share the same symbols and description thereof is omitted. The first cantilever 21′ is provided as an example. The first cantilever 21′ and the horizon h form a third angle θ₃, and the third angle in the range of about 1° to 10°, and the third angle θ₃ preferably range of about 1° to 4°.

Since the first cantilever 21′ and the second cantilever 21′ are symmetrically arranged, the figure of the second cantilever 22′ is omitted. Although not shown, the second cantilever 22′ has substantially identical angle θ₃ as that of the first cantilever 21′. The third angle θ₃ varies with the length, thickness, weight and materials of the object S₂.

Since the cantilever is inclined at the third angle θ₃, an additional height D₃ is provided to increase transport space in the cassette. Thus, each floor pitch H₂′ can be reduced accordingly. In this variation, the floor pitch H₂′ is less than the floor pitch H₂. Since floor pitch H₂ or H₂′ can be reduced, capacity of the cassette C₂ can be increased.

FIGS. 4A, 4B, and 4C are schematic views of the cassette C₃. The cassette C₃ comprises a frame 300, a first sidewall 310, a second sidewall 320, a first cantilever 31, and a second cantilever 32.

The difference is the shape of the front-ends 31b and 32b of the first and second cantilevers 31 and 32. The thickness of the front-ends 31b and 32b of the first and second cantilevers 31 and 32 is less than that of the fixed-ends 31a and 32a. The thickness of the cantilevers 31 and 32 decreases from the fixed-ends 31a and 32a along the front-ends 31b and 32b.

As shown in FIGS. 4B and 4C, a section P₁ of the first cantilever 31 comprises a slope 33, forming a fourth angle θ₄ with the horizon h. The slope 33 of the section P₁ of the first cantilever 31 is substantially parallel to the end section E of the object S₃ with similar shapes. Likewise, the second cantilever 32 has a slope forming a fifth angle θ₅ with the horizon h. The additional distance D₄ provides extra transport space. Thus, contact between the end section E of the objects S₃ and the cantilevers 31 and 32 can be prevented when the mechanical arm M loads the object.

Note that, in some embodiments, the first and second cantilevers 31 and 32 remain horizontal. That is, the first and second cantilevers 31 and 32 are perpendicular to the first and second sidewalls 310 and 320. Moreover, elastic pads 360 can be disposed on the first and second cantilevers 31, 32, preventing direct contact between the object S₃ and the cantilevers 31, 32.

Thus, since the floor pitch H₃ of the cassette C₃ can be reduced accordingly, the overall size of the cassette C₃ can be reduced, potentially providing a more compact sized cassette. In some embodiments, when larger storage capacity of the cassette C₃ is required, since distance between the floors can be reduced, the overall size of the cassette C₃ can remain the same, and more of the floors can be added for storing more objects. Hence, the capacity of the cassette C₃ can be increased without increasing overall size thereof.

The cassette C₃ has a variation. As shown in FIG. 4D, from which common elements share the same symbols and description thereof is omitted. The first cantilever 31′ is provided as an example. The first cantilever 31′ and the horizon h form a sixth angle θ₆, the sixth angle in the range of about 1° to 10°, and the sixth angle θ₆ preferably range of about 1° to 4°. Since the first cantilever 31′ and the second cantilever 31′ are symmetrically arranged, the figure of the second cantilever 32′ is omitted. Although not shown, the second cantilever 32′ has the same sixth angle θ₆ as that of the first cantilever 31′. The sixth angle θ₆ varies with the length, thickness, weight and materials of the object S₃.

Since the cantilever 31′ is inclined at the sixth angle θ₆, an additional height D₄ is provided to increase transport space in the cassette. Thus, each floor pitch H₃′ can be reduced accordingly. In this variation, the floor pitch H₃′ is less than the floor pitch H₃ of the cassette C₃. Since floor pitch H₃ or H₃′ can be reduced, capacity of the cassette C₃ can be increased.

Cassettes for receiving glass substrates may prevent contact between the objects and the cantilevers during transport and provide a compact cassette with lighter weight and reduced height.

While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.

Claims

1. A cassette, comprising:

a frame having two sidewalls perpendicular to a horizon; and

a plurality of cantilevers, each having a front-end and a fixed-end attached to one of the two sidewalls, thereby forming an angle with the horizon.

2. The cassette of claim 1, wherein the angle is in the range of about 10 to 100.

3. The cassette of claim 1, wherein the front-end comprises a notch.

4. The cassette of claim 1, wherein the thickness of each of the cantilevers decreases along the front-end.

5. The cassette of claim 1, wherein a lower portion of the front-end is substantially step-shaped.

6. The cassette of claim 1, further comprising a pad disposed on the front-end.

7. The cassette of claim 6, wherein the pad comprises an elastic polymer.

8. A cassette, comprising:

a frame having two sidewalls perpendicular to a horizon; and

a plurality of cantilevers, each having a front-end and a fixed-end attached to one of the two sidewalls, the front-end having a thickness less than that of the fixed-end.

9. The cassette of claim 8, wherein the front-end comprises a notch.

10. The cassette of claim 8, wherein the thickness of each of the cantilevers substantially gradually decreases from the fixed-end to the front-end.

11. The cassette of claim 8, wherein the front-end is substantially step-shaped.

12. The cassette of claim 8, further comprising a pad disposed on the front-end.

13. The cassette of claim 12, wherein the pad comprises an elastic polymer.