# US 8,541,250 B2 · Method and system for continuously manufacturing liquid crystal display device

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- Number: US 8,541,250 B2
- Document ID: US8541250B2
- Status: Granted
- Kind: B2
- Application number: 13/268,636
- Filed: 2011-10-07
- Published: 2012-04-19
- Granted: 2013-09-24
- Earliest claimed: 2010-10-13
- Assignees: Nitto Denko Corporation
- Applicants: Satoshi Hirata; Seiji Kondo; Takaichi Amano; Tadashi Yokouchi; Akira Kunikawa
- Inventors: Satoshi Hirata; Seiji Kondo; Takaichi Amano; Tadashi Yokouchi; Akira Kunikawa
- Web page: https://patentgrep.com/patent/US8541250B2

## CPC

- G02F 1/1333: Constructional arrangements; {Manufacturing methods}(G02F1/135, G02F1/136 take precedence)
- G02F 1/133528: {Polarisers}
- Y10T 156/12: Surface bonding means and/or assembly means with cutting, punching, piercing, severing or tearing
- Y10T 156/17: Surface bonding means and/or assemblymeans with work feeding or handling means
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A method for continuously manufacturing a liquid crystal display device by bonding a polarizing film to a liquid crystal panel with a pressure-sensitive adhesive interposed therebetween, includes a polarizing film supply step including drawing an optical film laminate from the continuous roll placed in a dry environment, cutting at least a polarizing film and a pressure-sensitive adhesive, while leaving a carrier film uncut and feeding the sheet piece and the pressure-sensitive adhesive piece; a liquid crystal panel supply step including feeding the liquid crystal panel in a first humid environment having a relative humidity higher than that of the dry environment; and a bonding step including bonding the sheet piece to the liquid crystal panel with the pressure-sensitive adhesive piece interposed therebetween in a second humid environment having a relative humidity higher than that of the dry environment.

## Claims

### Claim 1

A method for continuously manufacturing a liquid crystal display device by bonding a polarizing film to a liquid crystal panel with a pressure-sensitive adhesive interposed therebetween, comprising:
a polarizing film supply step comprising drawing an optical film laminate from a continuous roll placed in a dry environment, wherein the continuous roll comprises a roll of an optical film laminate comprising at least a long polarizing film having a width corresponding to a width of the liquid crystal panel and a carrier film placed on the polarizing film with a pressure-sensitive adhesive interposed therebetween, cutting at least the polarizing film and the pressure-sensitive adhesive at predetermined intervals, while leaving the carrier film uncut, so that a sheet piece of the polarizing film and a pressure-sensitive adhesive piece are obtained, and feeding the sheet piece and the pressure-sensitive adhesive piece which are placed on the carrier film;
a liquid crystal panel supply step comprising feeding the liquid crystal panel in a first humid environment having a relative humidity higher than that of the dry environment; and
a bonding step comprising bonding the sheet piece to the liquid crystal panel with the pressure-sensitive adhesive piece interposed therebetween in a second humid environment having a relative humidity higher than that of the dry environment, wherein the sheet piece is fed by the polarizing, film supply step, and the liquid crystal panel is fed by the liquid crystal panel supply step.

### Claim 2 (depends on 1)

The method according to claim 1, wherein
in a continuous liquid crystal display device manufacturing area, a polarizing film draw area is separated from a panel feed area, wherein the continuous liquid crystal display device manufacturing area is an area in which the liquid crystal display device is continuously manufactured, the polarizing film draw area is an area in which the optical film laminate is drawn from the continuous roll, and the panel feed area is an area in which the liquid crystal panel and the liquid crystal display device are fed,
the panel feed area is kept in a humid state, and
the polarizing film draw area is kept in a state drier than the panel feed area.

### Claim 3 (depends on 2)

The method according to claim 2, wherein the polarizing film draw area has a relative humidity of from 10% RH to 45% RH.

### Claim 4 (depends on 2)

The method according, to claim 2, wherein the panel feed area has a relative humidity more than 45% RH and less than 100% RH.

### Claim 5 (depends on 2)

The method according to claim 2, wherein the polarizing film draw area, the panel feed area, and a polarizing film feed area have relative humidities that satisfy
the relation (the relative humidity of the polarizing film draw area)≦(the relative humidity of the polarizing film feed area) or the relation (the relative humidity of the polarizing film feed area)≦(the relative humidity of the panel feed area), and
the relation (the relative humidity of the polarizing film draw area)<(the relative humidity of the panel feed area), wherein
the polarizing film feed area is an area in which the polarizing film is fed after it exits from the polarizing film draw area and until before it enters an inlet of the panel feed area.

### Claim 6 (depends on 5)

The method according to claim 5, wherein in the polarizing film feed area, the polarizing film or the sheet piece has a water content of less than 4.5%.

### Claim 7 (depends on 2)

A method for continuously manufacturing a liquid crystal display device, comprising providing a sheet piece of polarizing film on each of both surfaces of a liquid crystal panel with a pressure-sensitive adhesive interposed therebetween by the method according to claim 2, wherein
a first polarizing film draw area and a second polarizing film draw area are placed on one side of a continuous manufacturing area and, in planar view, opposed to a panel feed area that is placed on the other side of the continuous manufacturing area, wherein
the first polarizing film draw area is an area in which a polarizing film and a carrier film are drawn from a first continuous roll, and the second polarizing film draw area is an area in which a polarizing film and a carrier film are drawn from a second continuous roll.

### Claim 8

A method for continuously manufacturing a liquid crystal display device by bonding a polarizing film to a liquid crystal panel with a pressure-sensitive adhesive interposed therebetween, comprising:
a sheet piece supply step comprising drawing an optical film laminate from the continuous roll placed in a dry environment, wherein the continuous roll comprises a roll of an optical film laminate comprising at least sheet pieces of polarizing film having a width corresponding to a width of the liquid crystal panel and a carrier film on which the sheet pieces are placed with a pressure-sensitive adhesive interposed therebetween, and feeding the sheet pieces and the pressure-sensitive adhesive which are placed on the carrier film;
a liquid crystal panel supply step comprising feeding the liquid crystal panel in a first humid environment having a relative humidity higher than that of the dry environment; and
a bonding step comprising bonding the sheet piece to the liquid crystal panel with the pressure-sensitive adhesive interposed therebetween in a second humid environment having a relative humidity higher than that of the dry environment, wherein the sheet piece is fed by the sheet piece supply step, and the liquid crystal panel is fed by the liquid crystal panel supply step.

### Claim 9 (depends on 8)

The method according to claim 8, wherein
in a continuous liquid crystal display device manufacturing area, a sheet piece draw area is separated from a panel feed area, wherein the continuous liquid crystal display device manufacturing area is an area in which the liquid crystal display device is continuously manufactured, the sheet piece draw area is an area in which the optical film laminate is drawn from the continuous roll, and the panel feed area is an area in which the liquid crystal panel and the liquid crystal display device are fed,
the panel feed area is kept in a humid state, and
the sheet piece draw area is kept in a state drier than the panel feed area.

### Claim 10 (depends on 9)

The method according to claim 9 wherein the sheet piece draw area has a relative humidity of from 10% RH to 45% RH.

### Claim 11 (depends on 9)

The method according to claim 9, wherein the panel feed area has a relative humidity more than 45% RH and less than 100% RH.

### Claim 12 (depends on 9)

The method according to claim 9, wherein the sheet piece draw area, the panel feed area, and a sheet piece feed area have relative humidities that satisfy
the relation (the relative humidity of the sheet piece draw area)≦(the relative humidity of the sheet piece feed area) or the relation (the relative humidity of the sheet piece feed area)≦(the relative humidity of the panel feed area), and
the relation (the relative humidity of the sheet piece draw area)<(the relative humidity of the panel feed area), wherein
the sheet piece feed area is an area in which the sheet piece is fed after it exits from the sheet piece draw area and until before it enters an inlet of the panel feed area.

### Claim 13 (depends on 12)

The method according to claim 12, wherein in the sheet piece feed area, the sheet piece has a water content of less than 4.5%.

### Claim 14 (depends on 9)

A method for continuously manufacturing a liquid crystal display device, comprising providing a sheet piece of polarizing film on each of both surfaces of a liquid crystal panel with a pressure-sensitive adhesive interposed therebetween by the method according to claim 9, wherein
a first sheet piece draw area and a second sheet piece draw area are placed on one side of a continuous manufacturing area and, in planar view, opposed to a panel feed area that is placed on the other side of the continuous manufacturing area, wherein
the first sheet piece draw area is an area in which a sheet piece and a carrier film are drawn from a first continuous roll, and the second sheet piece draw area is an area in which a sheet piece and a carrier film are drawn from a second continuous roll.