JPS6033252B2 - Adhesion method of polarizing film in liquid crystal cell - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for adhering a polarizing film in a liquid crystal cell.

In the early days when liquid crystals began to be used as displays for digital watches, polarizing film was placed on top of the liquid crystal cell body.

However, the polarizing film is warped, and interference fringes occur when it comes into contact with the cell body.As a countermeasure, a spacer was supported between the cell body and the polarizing film, but this became a major obstacle in making the cell body thinner and lighter. However, the number of man-hours required for adhering polarizing films has been reduced due to rationalization such as making multiple cells, whereas the process of adhering polarizing films has been changed to a method of directly adhering polarizing films using automatic adhesion machines such as labeling machines. I couldn't use it due to problems with soaking it in hot water or misalignment after adhesion, so I peeled off the protective layer of the polarizing film with tweezers.
Because the adhesive process was done manually by positioning the cell body and polarizing film using a simple jig and pasting them on one side at a time, nearly half of the completed cell processing time was spent on the adhesive process. The present invention is aimed at reducing the cost of completed cells by solving problems such as scratches on the polarizing film and misalignment of the adhesive, and by simultaneously attaching the upper and lower polarizing films to streamline the adhesive work.
The configuration of the present invention will be explained below with reference to the drawings.

FIG. 1 is a structural diagram of a liquid crystal cell, in which figure a shows the state before upper and lower polarizing films and the cell body are bonded together, and figure b shows the completed cell in which the polarizing film is bonded to the liquid crystal cell body.

In the liquid crystal cell body 1, an upper glass 2 and a lower glass 3 are joined together by a sealing member of about 10 mm, and a liquid crystal substance is injected into the gap between them.

The upper polarizing film 4 includes an upper protective film 6 a lower protective film 7 and a glue layer 5
Similarly, the lower polarizing film 8 has a laminated structure consisting of an upper protective film 10, a lower protective film 11, and a glue layer 9. Both polarizing films 4 and 8 have cross sections with the glue layer as the inner surface. It is pre-shaped into an arc shape.

Both polarizing films 4 and 8 are integrated with the liquid crystal cell body 1 by an adhesion process to be described later, thereby completing the liquid crystal cell 12 shown in Figure b. FIG. 2 shows a working process diagram of the polarizing film bonding apparatus according to the present invention.

The work is film supply process (A for upper polarizing film, A for lower polarizing film, A'), protective film peeling process (B for upper polarizing film, B for lower polarizing film), polarizing film curling process (C for upper polarizing film, C for lower polarizing film). ') and adhesion step D.

Figures 3a and 3b are perspective views and cross-sectional views showing the holding state of the polarizing film in the film supplying steps A and A', and the polarizing film is arranged in a curved shape within the frame of the carrier 20 and is held by its own elasticity. ing.

The direction in which the carrier 201' is housed is the same for the upper polarizing film 4 and the lower polarizing film 8. The protective film peeling process B is a first peeling process B in which the upper protective film 6 is peeled off;
It is constituted by a peeling process B3. In each of the above-mentioned protective film peeling steps B and B3, a method is adopted in which the protective film is peeled off using an adhesive tape that is normally used for purposes such as insulation, wrapping, and bundling. The operation of the protective film stripping device will be explained with reference to FIG.

FIGS. 4a to 4f are diagrams of the protective film peeling process in the protective film peeling device, and the configuration will be explained with reference to FIG.
33 is a carrier push-up piece, 34 is a polarizing film presser that prevents the polarizing film from lifting when the protective film is peeled off, and a roller receiver 3 that also serves as an adhesive tape pushing operation.
A protective film peeling roller 36 is attached to 5, and an adhesive tape protrusion lever 37 is placed above it.

The protective film peeling adhesive tape 38 comes out from the mounting flange 39 and is wound around the winding flange 401. The operation of the protective film peeling apparatus having the above structure will be explained step by step.
The carrier 20 flowing on the conveyor belt 30 detects the stereotactic layer by the detector emitter 32 and the detector receiver 33 in the state shown in figure a, generates a unit activation signal, and stops with a claw protruding from the side of the rail. Next, as shown in figure b, the carrier push-up piece 33 rises and lifts up the carrier 20, and the adhesive tape 38 is adhered to the upper protective film 6 of the polarizing film 4 via the peeling roller 36. Next, as shown in figure c. As shown, the roller receiver 35 rises and the protruding lever 37 is expanded, and the upper protective film 6 of the polarizing film 4 is peeled off from both ends and attached to the adhesive tape 38 side. Next, as shown in Figure d, the carrier push-up piece 33 descends and the roller receiver 35 returns to its original position. Next, as shown in figure e, the roller receiver 35 is lowered and at the same time the tape winding flange 40
The upper protective film 6 is rotated by a certain amount and the peeled upper protective film 6 is rolled up. Then, as shown in Fig. f, the two carriers are transported to the next step by the transport belt 30. This operation is shown in B and B in Figure 2.
After being carried out in the first peeling process of B2 and 2', the lower protective films 7 and 11 are peeled off in the second peeling process of B3 and B3'. In the curling step shown in FIG. 2c, the polarizing films 4 and 8 are curled as shown in FIG. 1a by blowing hot air at about 80°C for several seconds while holding both polarizing films 4 and 8 in a carrier. Furthermore, in the bonding process D, the liquid crystal cell body 1 automatically supplied to the index table 50', which will be described later, undergoes a cleaning process using a dryer, and in the temporary bonding process D, the upper and lower polarizing films 4 and 8 are temporarily bonded to the liquid crystal cell body 1 at the same time. be done.

Fig. 5 is a configuration diagram of the temporary adhesion device, in which Fig. a shows a state in which the liquid crystal cell body 1 and both polarizing films 4 and 8 are aligned, and Fig. b
The figure shows a state in which the temporary bonding device is in operation and temporary bonding is performed, and figure C is a plan view of the polarizing film pushing jig plates 4 and 42.

There is an upper polarizing film pushing pick-up plate 41 and an upper polarizing film pushing piece 43 that are fixed to the spindle of the machine body. A polarizing film guide pin 45 is press-fitted so that the polarizing film guide pin 45 follows the localization calendar.

The lower polarizing film side is similarly formed by a lower polarizing film pushing jig plate 42, a lower polarizing film pushing piece 44, and a lower polarizing film guide pin 46. As for the movement, first, carriers 20 are set above and below the liquid crystal cell body 1 supplied from the index table 5, the upper and lower polarizing film pushing guide plates 41 and 42 move, and the upper and lower polarizing film guide pins 45 and 46 move the liquid crystal cell body 1. Next, the upper and lower polarizing film pushing pieces 43 and 44 push out the polarizing films 4 and 8 from the carrier 20 and temporarily adhere them to the upper and lower surfaces of the liquid crystal cell body 1 as shown in FIG. 5b.

The pushing force at this time is preferably several tens of minutes, and if it is stronger than this, bubbles tend to form between the liquid crystal cell body 1 after adhesion and both polarizing films 4 and 8, and on the other hand, if it is weaker, positional displacement occurs. The orientation of the upper and lower polarizing films 4 and 8 with respect to the liquid crystal cell body 1 in the temporary adhesion step D is such that the adhesive layer is oriented toward the liquid crystal cell body 1 side by the reversing step shown in FIG. 2E. The main bonding step D2 is a step of fixing the temporarily bonded upper and lower polarizing films, and will be explained with reference to FIG. FIG. 6 is a configuration diagram of the bonding apparatus, and FIG. 6A is a front view, B is a side view, and C is a perspective view showing a state in which the upper and lower polarizing films 4 and 8 are temporarily bonded to the liquid crystal cell body 1. The upper roll 61 and the lower roll 62 rotate at the same speed in the direction of arrow R, and the gap between them is set to be about 50 to 100 narrower than that of the completed cell 12.

When the temporarily bonded liquid crystal cell 12 shown in FIG. 6c is fed into the gap between the upper roll 61 and the lower roll 62 as shown in FIGS. 6a and 6b in the direction of arrow L, the curled upper polarizing film 4 and The lower polarizing film 8 is gradually bonded to the glass surface of the liquid crystal cell body 1 while spreading to both sides as if pushing out air. The main adhesion is performed without generating any air bubbles.

Is Roll Yogi 30? If it is larger than this, air bubbles are likely to occur between the polarizing film and the glass surface after main adhesion, no matter how much force is attached to the polarizing film. As described above, according to the present invention, since the film coated with an adhesive or the like is held and conveyed in the carrier by its own elasticity, it becomes extremely easy to feed the film to the carrier, and it also prevents the peeling of the protective film in the subsequent process. It is easier to adhere to the surface, and by curling the film, it is possible to adhere the two without creating air bubbles on the adhesive surface, and the polarizing film adhesive work shown in this example is faster than conventional methods. This reduces the number of man-hours by more than half, which greatly contributes to reducing the cost of completed liquid crystal cells.

[Brief explanation of the drawing]

Figures 1a and b are configuration diagrams of the liquid crystal cell, Figure 2 is a working process diagram of the polarizing film bonding device according to the present invention, and Figures 3a and b are
4 is a perspective view and a cross-sectional view showing the state in which the polarizing film is held in a carrier, FIGS. 6 is a block diagram of the temporary bonding device, and FIGS. 6a, b, and c are block diagrams of the main bonding device. DESCRIPTION OF SYMBOLS 1...Liquid crystal cell body, 4...Upper polarizing film, 8...Lower polarizing film, 5, 9...Glue layer. Figure 4 Figure 1 Figure 2 Figure 3 Figure 5 Figure 6

Claims (1)

[Claims] 1. In a method of bonding an upper polarizing film and a lower polarizing film to the upper and lower surfaces of a liquid crystal cell, the upper polarizing film and the lower polarizing film are each attached to the inside of a frame-shaped carrier. The process includes a holding step, a step of removing the protective films of both the polarizing films, and a step of simultaneously adhering both the polarizing films from which the protective films have been removed to the upper and lower surfaces of the liquid crystal. A liquid crystal cell characterized in that the polarizing films are made slightly smaller than the dimension of one side of each polarizing film so that each of the polarizing films is held and conveyed by a carrier by its own elasticity. Adhesion method for polarizing film. 2. A method for adhering polarizing films in a liquid crystal cell, wherein both polarizing films according to claim 1 are previously formed to have an arcuate cross section.