JPH0338374A - Printing method - Google Patents

Abstract

PURPOSE:To uniformize the thickness of the ink printed like an oriented film by providing a part performing printing falsely in front of the moving direction of a plate from a part for the original printing and performing printing using said plate. CONSTITUTION:A region 32 wherein an oriented film is formed to the surface of glass substrate 24 using a plate 22 corresponds to a protruding part 30. A region 33 having an oriented film printed thereon is formed to the substrate corresponding to the protruding part 31 subjected to false printing. Printing pressure is unstable in the region 34 in front of a moving direction 5 on the glass substrate 24 and the region 34 is one reduced in the thickness of the oriented film being printed ink. Regions 35 reduced in the thickness of the oriented film are formed in the vicinity of both side parts of a plate cylinder 21 in the axial line direction thereof because of unstable printing pressure and generated only within the region 33 printed by the part 31 performing false printing and the thickness of the oriented film is uniform in the part 30 for true printing.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a printing method, and more specifically, to a printing method for printing an alignment film on a substrate of a liquid crystal display element used in, for example, a liquid crystal television receiver, a watch, a personal computer, etc. The present invention relates to a printing method that can be advantageously implemented for manufacturing liquid crystal display elements.

Conventional technology For example, super twisted nematic (abbreviated as 5T)
N) In a display element using liquid crystal, it is important to make the thickness of the alignment film uniform in order to improve the display quality. In order to form an alignment film for a liquid crystal display element, a letterpress printing transfer method, which has excellent workability and is low cost, is often used. This prior art is shown in FIG. 5, and its front view as seen from the entry side (right side of FIG. 5) is shown in FIG. In Figure 6, 2a
) is wrapped around it, and the edition! A glass substrate 4 on which an alignment film of a liquid crystal display element is to be formed is mounted on 3 and moved in the direction of arrow 5. As a result, an alignment film is printed on the substrate 4. On the relief plate 2, the zero plate cylinder 1 to which the alignment film material, which is ink, is adhered by the ink roller 6,
Anti-cuff a.

7b; 8a, 8b, a hydraulic cylinder, a spring, etc. are provided to apply the resilient printing pressure.

FIG. 7(1) is a perspective view showing the relief plate 2 in a flattened state. In this relief plate 2, a convex portion 10 shown as a diagonal line is formed on a base material 9, and an alignment film material tl, which is an ink, is applied to the convex portion 10.
As shown in , a region 11 in which an alignment film is printed, indicated by diagonal lines, is formed on the substrate 4 .

Problems to be Solved by the Invention In such a prior art, when the substrate 4 is moved together with the printing plate 3 in the direction of the arrow 5, v) a collision occurs with the substrate 4 at the front end of the convex portion 10; Print pressure 7a, 7b; 8
The escape of the plate cylinder 1 and plate 3 by a and 8b is not uniform, and as a result, as shown in FIG. Near the front end, the alignment film becomes thinner in a region 12 indicated by crossed diagonal lines. In this way, unevenness occurs in the thickness of the alignment film in the portion 11 on the substrate 4 where the alignment film is formed. Therefore, the display quality of the liquid crystal display element deteriorates.

When the convex portions 10 are formed on the base material 9a of the relief plate 2a toward one side of the moving direction 5 as shown in FIG. 8 (1), as shown in FIG. 8 (2), In the portion 11a where the alignment film formed on the substrate 4a is printed, the thickness of the alignment film not only becomes thinner at the front end 12a in the direction of movement 5, but also at the side portions 13 in the direction of movement 5. However, the alignment film becomes thinner, and unevenness in film thickness occurs.

In FIG. 6, as shown in FIG. 8, the convex portion 1 of the relief plate 2a is
0a is formed on one side of the curve in the moving direction 5. At this time, the printing pressure in the axial direction of the plate p1141 (left-right direction in FIG. 6) is indicated by the arrow 7a.

As shown in 7b, it is larger on the side where the protrusion 10a is formed, and it is larger on the side where the protrusion 10a is not formed (see F)
As shown by 8a and 8b, the printing pressure is small, and therefore the thickness of the alignment film becomes uneven as described above.

An object of the present invention is to provide a printing method that makes the thickness of printed ink, such as an alignment film, uniform.

Means for Solving the Problems The present invention is directed to a printing method in which a plate and a printing material are interposed between a cylinder and a supporting member to apply elastic printing pressure. This is a printing method characterized in that a part is pseudo printed in front of the part in the direction of movement of the plate, and printing is performed using a second plate.

(For Y According to the present invention, a printing plate such as a letterpress is placed in a pseudo-printing area in front of the part for original printing, that is, the part where the alignment film of the liquid crystal display element is to be formed, in the direction of movement of the printing plate. The part where printing is performed, for example, in letterpress printing, has a convex part, and since printing is performed using such a plate, the printing pressure is The thickness of the ink on the printed material becomes thinner than the rest of the printed material, resulting in unevenness. The area is not originally used for, for example, a liquid crystal display.Therefore, in the area used for the original liquid crystal display, the thickness of the ink printed with a stable printing pressure is uniform.In this way, the thickness of the ink is uniform. A uniform thickness of the ink in the area to be used above can be achieved.

Embodiment FIG. 1 is a surface measurement diagram of an embodiment of the present invention, and No. 2121
is a front view seen from the entrance side (right side in Figure 1). With reference to these drawings, the glass substrate 24 of the liquid crystal display element
A method for forming an alignment film thereon will be described. A relief plate 22 (
212th! 22a> is wound and attached.

A substrate 24 is fixed on a platen 23, which is a horizontally disposed support member, and moves in a moving direction 25 together with the plate cylinder 21 to perform printing. To the relief plate 22, an elastic printing pressure is applied to the zero plate cylinder 21 and the plate plate 23, to which the alignment film material as ink is supplied one inch from the ink roller 26 in the direction of mutual proximity. The reaction force is 9 symbols 27
a, 27 b; 28 ri, 28 b, respectively. Such printing pressure 4! This can be achieved by urging the plate cylinder 21 or the plate plate 23 with a fluid pressure cylinder or a spring.

FIG. 3 (1) is a perspective view showing a state in which the relief plate 22 is expanded in the circumferential direction. On the base material 29 of the relief plate 22, a raised part 30, which is a part for original printing shown by diagonal lines, is formed, and a square frame is formed at a distance outwardly near the raised part 30. A convex portion 31, which is indicated by diagonal lines on the top and is printed in a pseudo manner, is formed. Such a letterpress 22 is a plate cylinder 21
The relief plate 22 is rotated and moved in the rotational direction 32 of the plate cylinder 21.

No. 317I (2) is the relief plate 22 shown in FIG. 3 (1)
FIG. 3 is a perspective view showing a state in which an alignment film is printed on the surface of a glass substrate 24 using the method. The area where the alignment film is formed is 9
The reference numeral 32 is indicated by diagonal lines, which corresponds to the convex portion 30 . Corresponding to the convex portions 31 on which pseudo printing is performed, there are areas 33 printed with an alignment film on the substrate 24, which are indicated by diagonal lines.
is formed. On this glass substrate 24, the moving direction 5
The printing pressure is unstable in the wX region 34 indicated by crossed diagonal lines in front of the region 34, and the thickness of the alignment film, which is the printed ink, is thin. Further, near both sides rt of the plate cylinder 21 in the axial direction, a region where the alignment film is thin is formed as indicated by reference numeral 35 due to unstable printing pressure. Such a region where the alignment film is thin occurs only in the region 33 printed by the portion 31 that performs pseudo printing, and the thickness of the alignment film is uniform according to the portion 30 for original printing. In this way, by forming the portion 31 for pseudo printing on the outer periphery of the portion 30 for original printing, the area t1i32 corresponding to the portion 30 is
According to an experiment conducted by the inventor of the present invention, an alignment film having a uniform thickness can be formed on the substrate 24. When the target value of the thickness of the alignment film is 500 people, in the region 32, the film thickness is is almost uniform, with a variation of ±50 people at most, and for this, the part 31 where pseudo printing is performed
In the area 33 corresponding to , it was confirmed that there was a variation in thickness between 200 and 300 people.

FIG. 4(1) is a perspective view of a relief plate 22a according to another embodiment of the present invention. In this actual j*eA, a convex portion 30a for actual printing is formed near one side of the plate cylinder 21, and a portion 31a for pseudo printing in a C-shape is formed in the remaining area. . These portions 30a, 31a are shown with diagonal lines for convenience. Such a letterpress 22a is mounted on the plate cylinder 21.
When the alignment film is printed on the substrate 24a, an alignment film with a uniform thickness is formed on the substrate 24a, as indicated by reference numeral 32a, corresponding to a portion 30a for actual printing. Area 3 corresponds to the portion 31a where pseudo printing is performed.
3a is printed and formed. In this region 33a, a region with a thick film is formed in a region 34a shown by intersecting diagonal lines in the front direction in the moving direction 5 and a region 35=t on the side thereof. Thus, according to the present invention, the alignment film is printed with a uniform thickness in the region t432a used as a liquid crystal display element. Note that FIG. 2 shows a state in which the letterpress plate 2221 shown in FIG. 4(1) has been attached to the plate cylinder 21.

Even when such a letterpress 22a is used, the reaction force of printing pressure 27a, 27b; 28a, 28
b can be kept at approximately the same value, which is effective in making the film thickness uniform.

The present invention can be practiced not only in letterpress printing but also in connection with lithographic and intaglio printing.

Furthermore, the present invention can be practiced not only in relation to a super twisted nematic liquid crystal display element, but also in relation to a double twisted nematic liquid crystal (abbreviated as DST) liquid crystal display element, and in connection with other liquid crystal display elements. It can be implemented.

Furthermore, the present invention can be widely implemented for printing not only liquid crystal display elements but also other types.

Note that the areas 33 and 33a where the printed film thickness is uneven are as follows:
) When the α-crystal display element is used, it is removed and discarded.

The portions 31.31a where pseudo printing is performed may not be coated with an alignment film or the like, which is ink.

Effects of the Invention As described above, according to the present invention, the plate has a part that performs pseudo printing at the front in the direction of movement. Even if the elastic printing pressure is unstable, in the subsequent part for the original printing, stable printing pressure is applied to the printing material and printing is performed, and for the original printing. Printing can be achieved with a uniform ink thickness.

[Brief explanation of drawings]

No. 1121 is a side view of one embodiment of the present invention, No. 2I2I is a front view of one embodiment of the present invention seen from the entrance side in FIG. 1, and FIG. 3 is a relief plate 22 and substrate of one embodiment of the present invention. 24 is a perspective view showing a relief plate 22a and a substrate 24a according to another embodiment of the present invention; FIG. 5 is a side view of a prior art;
6 is a front view of the prior art shown in 512I as seen from the entrance side, FIG. 7 is a perspective view showing the letterpress 2 and the substrate 4 of the prior art shown in 5[2I and FIG. FIG. 8 is a perspective view showing a relief plate 2a and a substrate 4a in another prior art. 21... Plate cylinder, 22.22a... Letterpress, 23...
Plate plate, 24.24a...Substrate, 25...Movement direction,
300 it...part for original printing, 31.3
1a Part that performs pseudo printing

Claims (1)

[Claims] In a printing method in which a plate and a printing target are interposed between a cylinder and a support member and elastic printing pressure is applied, the plate is moved more than the part for original printing. A printing method characterized by having a portion on which pseudo printing is performed in the forward direction, and printing is performed using this plate.