JP2012017110A - Glass substrate storage tray and tray assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass substrate storage tray capable of detecting whether a crack or a chip exists in a glass substrate stored in the tray.SOLUTION: The glass substrate storage tray on which the glass substrate 20 is placed includes a light emitting part 21 provided at one end of the tray for emitting light, and a light receiving part 22 provided at one end opposite thereto for receiving light from the light emitting part. In the glass substrate storage tray, the light emitting part is an optical fiber light source or an organic electroluminescent element, and the light receiving part is an optical fiber sensor.

Description

  The present invention relates to a tray structure for storing or transporting or transporting a glass substrate.

  A display panel of a liquid crystal display device is usually manufactured by enclosing a liquid crystal between a pair of glass substrates arranged to face each other. In order to manufacture such a display panel, the glass substrate is transported to a display panel manufacturing factory. When transporting a glass substrate to a factory, a glass substrate storage tray (hereinafter simply referred to as a tray) for storing the glass substrate is usually used. When various processes are applied to the glass substrate to form a display panel, if the conveyor or the transfer arm cannot be used, the glass substrate is accommodated in the storage tray and moved.

  Recently, a rectangular glass substrate having a thickness of 0.7 mm or less and a side of 2 m or more is used as the glass substrate. An example of a tray structure used for mounting and transporting and transporting such a large and thin glass substrate is disclosed in Patent Document 1, for example.

  The structure of the tray 10 in the above document is generally as shown in FIGS. 1 and 2. FIG. 1 is a top view, and FIG. 2 is a cross-sectional view in the vicinity of the frame portion 12 in FIG. FIG. The tray 10 is integrally formed of a foamed polyethylene resin or the like in a thin rectangular parallelepiped shape, and has a rectangular bottom surface 11 on which the glass substrate 20 to be transported is placed in a horizontal state, and side edges that extend around the entire circumference of the bottom surface 11. It has the frame part 12 provided so that it might protrude upwards.

  The bottom 11 has a rectangular shape that is slightly larger than the glass substrate 20 to be accommodated, and has a thickness of, for example, about 15 mm. The glass substrate 20 is placed on the upper surface of the bottom. In the vicinity of each corner portion of the bottom portion 10, square-shaped openings 11 a are respectively formed, and openings 11 a are also formed at respective intermediate positions between the corner portions along the side edges of the bottom portion 10. In addition, an opening is provided in the center of the bottom 11. Accordingly, nine openings 11a are provided in a matrix of 3 rows and 3 columns at the bottom. These openings are provided to insert a piston for floating the glass substrate placed on the bottom 10 from the tray.

  For example, the frame portion 12 is provided on the side edge portion of the lower portion 11 with a width of about 30 mm over the entire circumference and protruding from the upper surface of the bottom portion 11 over about 5 mm (the bottom portion is recessed). The glass substrate placed on 11 is surrounded over the entire circumference with an appropriate interval maintained.

  An upper portion of the frame portion 12 is provided with a joint portion 13 that protrudes in a flange shape in a horizontal state with a width of about 30 mm, for example, over the entire circumference. The mating part 13 is a part where the chucking claw part mates when the tray 10 is moved to a predetermined position. The upper surface of the mating part 13 is provided so as to be horizontal outside and above the upper surface of the frame part 12. Therefore, the upper surface of the mating part 13 and the upper surface of the frame part 12 form a step. The step has a function as the positioning portion 14.

As shown in FIG. 3, it is possible to stack a plurality of trays in the vertical direction, and it is efficient and preferable to transport the trays in such a stacked state. The tray stacked on the upper side is in a state in which the bottom lower protruding portion is combined with the positioning portion 14 which is a step between the upper surface of the mating portion of the lower tray and the upper surface of the frame portion 12, and the tray stacked vertically There is no possibility of displacement in the horizontal direction without any displacement. Therefore, it is usually stacked in about 60 stages for transport.

  By the way, the glass substrate is easy to bend, and when it is transported by storing it in a tray, or when transferring between processes, the end of the glass substrate is not cracked or chipped by touching the gripping jig or surrounding objects. May occur. Whether or not such cracks have occurred has to be observed visually by removing the tray assembly stacked in multiple stages in 60 stages one by one from the top stage. That is, in order to perform the inspection, there is a problem that a predetermined space and manpower are required, and it is difficult to perform the inspection when necessary at a given position.

JP 2004-59116 A

  Accordingly, an object of the present invention is to provide a tray capable of detecting whether or not a glass substrate contained in a glass substrate storage tray is cracked or chipped by a method other than visual observation.

  The invention according to claim 1 for achieving the above object is a glass substrate storage tray of a type in which a glass substrate is placed on the bottom surface of a recess, and a light emitting unit that emits light to one of the recess side walls of the tray The glass substrate storage tray is characterized in that a light receiving portion for receiving light is provided on the side wall of the other recess.

  The invention according to claim 2 is the glass substrate storage tray according to claim 1, wherein the light emitting part is an optical fiber light source and the light receiving part is an optical fiber sensor.

  The invention according to claim 3 is the glass substrate storage tray according to claim 1, wherein the light emitting part is an organic electroluminescence element and the light receiving part is an optical fiber sensor.

  The invention according to claim 4 is characterized in that a groove is provided in the side wall of the concave portion of the tray, and the light emitting part and the light receiving part have a loading / unloading ability. The glass substrate storage tray described in 1. is used.

  The invention according to claim 5 is a glass substrate storage tray assembly in which a number of the trays according to any one of claims 1 to 4 are stacked.

According to the present invention, the tray is provided with means for allowing light to enter the inside of the glass substrate from one end of the glass substrate and detecting the light emitted from the opposite end by the optical sensor. It is possible to electrically detect the presence or absence of defects such as cracks on the substrate.
As a result, it is possible to detect which tray's glass substrate has a problem without destroying the stacked tray assembly.
In addition, since labor, place, and time required for inspection can be greatly saved, productivity can be improved when applied to manufacture of a color filter substrate.
Furthermore, since the tray has a structure in which the light emitting part and the light receiving part can be attached and detached, it is not necessary to install the light emitting part and the light receiving part in all trays, and the cost can be reduced accordingly.

It is a figure of the top view of the glass substrate storage tray for a display to which this invention is applied. It is a figure of the sectional view in the AA line of FIG. It is sectional drawing of the principal part of the state which accumulated the tray up and down. It is a figure of the cross sectional view of a tray provided with the light emission part and light receiving part which become this invention. The figure explaining the mode of the light which advances the inside of a glass substrate. (A) When there are no cracks, (b) When there are cracks.

  In the present invention, the glass substrate 20 placed on the bottom 11 of the glass substrate storage tray 10 shown in FIG. 2 is horizontally aligned with the end surface of the glass substrate 20 at the side wall 15 of the recess as shown in FIG. The light emitting part 21 is installed along the side wall 15 at the place, and the light receiving part 22 is installed on the side wall 15 'facing the part.

  The light emitting unit 21 and the light receiving unit 22 may be fixed to the tray 10 or may be of a type in which a linear receiving port is formed near the side wall of the tray and a cassette type light emitting unit or the like is attached or detached. In the figure, the light emitting unit and the like are installed on a pair of sides facing each other, but the light emitting unit and the light receiving unit facing each other on four sides of the outer peripheral side wall surrounding the glass substrate can be installed.

  The light emitted from the light emitters or light emitting portions 21 arranged in a straight line and incident on the end of the glass substrate 20 travels through the glass substrate and is emitted from the opposite end, but the emitted light is arranged in a straight line. The light receiving pattern is recognized by the light receiving sensor, and the presence of chipping of the glass substrate is detected from the light intensity pattern. This is because if there is a crack, light is scattered at the site and the amount of light reaching the light receiving sensor fluctuates and the light intensity pattern also changes.

  First, since it is uneconomical that the glass substrate 20 is thin and the tray 10 is thick and large, it is desirable that the light emitting portion 21 has a configuration in which small or thin light emitting elements are arranged in an array. In a point light source, a light emitting diode (LED) and in a linear light source, an organic EL element is desirable.

  Since the LED is generally accommodated in a cylindrical case having a diameter of several millimeters, an opening that can accommodate the case is provided in the inner wall 15 of the tray, and the LED is inserted and fixed therein, or a thin optical fiber. Either of the light emitting tips may be arranged in a straight line and fixed to the side wall 15 of the tray. An LED is mounted on the incident side of the optical fiber cable. If it is this aspect, since a fiber can be made thinner than the case of LED, it will have installed many LED, and the alignment precision with the glass substrate 20 edge part will also improve. Light can be introduced into the glass substrate more efficiently.

  The organic EL element used as the light source can be made thinner and thinner, and thus is more advantageous than the LED in terms of space. The organic EL element has a structure in which an organic hole transport layer and a phosphor are stacked and sandwiched between opposing electrodes. It is manufactured by either vacuum film formation using a low molecular weight organic material on a substrate or printing by dissolving a polymer material in a solvent. Since the light emitting region can be regulated by the width and length of the electrodes and the outer shape can be determined by the cutting position of the substrate, the element shape suitable for the installation position in the tray 10 can be obtained. The LED array does not have such a degree of freedom, but has an advantage of withstanding long-term use such as a light emission life.

Since defects such as cracks and chippings in the glass substrate 20 occur in the peripheral portion of the substrate, the light emitting portion can be provided only at the corner portion of the side wall of the tray bottom 11 and is efficient. If there are only two sides facing each other, if there is a crack at the center of the side of the substrate, the defect cannot be detected unless the light emitting unit is installed there.

  There are two types of optical fibers that guide the light emitted from the LED: plastic type and glass type. In the former, the core is formed of an acrylic resin having a high refractive index, and the periphery thereof is covered with polyethylene which is a cladding material having a low refractive index. The latter is a stainless steel tube coated with a core glass fiber. The light introduced into the core propagates through the core while being totally reflected by the cladding. When the light emitter is installed at the bottom, a normal electric wire may be used instead of the optical fiber.

  As for the light receiving unit 22, photodiodes (PD) may be arranged in a straight line on the bottom of the tray facing the light emitting unit. In this case as well, the photodiodes themselves may be arranged, or a system in which a condensing microlens is attached to the tip of the optical fiber is bundled in a straight line and the other end of the optical fiber is connected to the photodiode. .

  Arranging a plurality of LEDs and PDs on the bottom of the tray is not always preferable because the number of electronic components increases in proportion to the number of trays. Therefore, it is also possible to make a detachable cassette in which LEDs are arranged in a straight line (details of the structure are not shown), and to form a receiving portion into which the cassette is inserted on the tray side, thereby making the cassette detachable. The same configuration can be applied to the light receiving unit. Such processing is not so difficult because optical fibers and wiring wires are flexible.

  An example of the structure of the cassette receiving portion on the tray side is shown in FIG. A groove 23 that can accommodate the cassette 26 is formed in the tray side wall 15. The side wall 15 is provided with a slit 24 that connects the groove 23 and the bottom so that light travels from the cassette toward the bottom 11 on which the glass substrate is placed. Do the same on the PD side. The cassette 25 may be mounted from the upper surface of the tray, or may be a form in which a guide or the like is formed and inserted from the side surface.

  FIGS. 5A and 5B schematically show how the light emitted from the horizontally long light source thus formed travels in the glass substrate. (A) is a case of a normal glass substrate having no chip, and (b) is a case of having a chip at a corner. In (a), if the light source is a periodically arranged LED, a light intensity pattern corresponding to the arrangement is observed on the light receiving side, and in the case of (b), a broken light intensity pattern caused by a chipped portion is observed. Is done.

DESCRIPTION OF SYMBOLS 10 ... Glass substrate storage tray 11 ... Bottom part 11a ... Opening part 12 ... Frame part 13 ... Engaging part 14 ... Positioning part 15, 15 '... Bottom side wall 20 ... Glass substrate 21... Light emitter 22... Light receiver 23... (Cassette accommodation) Groove 24.

Claims (5)

  A glass substrate storage tray of a type in which a glass substrate is placed on the bottom surface of a concave portion, wherein a light emitting portion for emitting light is provided on one side wall of the concave portion of the tray, and a light receiving portion for receiving light on the corresponding other side wall of the concave portion A glass substrate storage tray characterized by comprising:   The glass substrate storage tray according to claim 1, wherein the light emitting unit is an optical fiber light source and the light receiving unit is an optical fiber sensor.   The glass substrate storage tray according to claim 1, wherein the light emitting unit is an organic electroluminescence element and the light receiving unit is an optical fiber sensor.   The glass substrate storage tray according to any one of claims 1 to 3, wherein a groove portion is provided on a side wall of the concave portion of the tray, and the light emitting portion and the light receiving portion have a loading / unloading capability.   A glass substrate storage tray assembly in which a number of the trays according to any one of claims 1 to 4 are stacked.

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