JPS6258291A - Light controlling film and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention Field of the Invention The present invention relates to a light control film suitable as a display surface of an optical display device, and more specifically, to a light control film for adjusting transmitted light so that it becomes parallel light. and a designated mark (letters, designs, etc.) on it.
Regarding the light control film displayed.

BACKGROUND OF THE INVENTION In recent years, this type of light control film has been used, for example, as a display surface for a switch knob of a switch mounted on an automobile instrument panel. In a switch knob that uses this light control film as a display surface, a light source is placed behind the light control film as a display surface, and when the car is driving at night, this light source is turned on and the light control film is placed behind the light control film. It is now more illuminated. The transmitted light that passes through the light control film from behind to the front is collimated into parallel light. In this way, the light control film serving as the display surface of the switch knob emits the regulated light, which makes the light easy to see and allows the driver to visually recognize the position of the switch knob.

In addition, there are several types of switches on automobile instrument panels, but to distinguish them from each other, a symbol mark is usually displayed on the display surface of each switch knob, that is, on the light control film. .

FIG. 6 shows a light control film l which is attached as a display surface to the front surface of such a switch knob and has a mark 2. In FIG. 6, the mark is illustrated as a triangular mark for simplicity.

Conventionally, there are two types of structures of such marked light control films.

FIG. 7(I) shows one such structure. In the figure, reference numeral 4 denotes a transparent base film, and a light-shielding partition wall (light regulating layer) 5 is integrally adhered to one side of the base film 4. A print film 6 is adhered to the surface of the light-shielding partition wall 5 opposite to the base film 4. Marks 2 are formed by applying paint 3 having a predetermined color to the upper surface of this print film 6. The paint 3 is applied to the entire print film 6 within the outline of the mark 2. The light-shielding partition wall 5 has various patterns, such as a honeycomb pattern as shown in FIG. 5, a striped pattern, or a lattice pattern.

When using a light control film having the structure shown in FIG. 7(1), a light source (not shown) is placed on the base film 4 side of the film.

The light emitted from the light source passes through the base film 4 and the light-shielding partition wall 5 and is transmitted forward. Oblique light incident obliquely on the light control film 1 hits the light-shielding partition wall 5 and is absorbed therein. Therefore, the light that passes through the light control film 1 is extracted as almost parallel light. However, as shown in the figure, the edge 3a of the paint 3 of the mark 2 applied on the print film 6 may exist on the light-shielding partition wall 5, or
As shown in the figure, it may exist on the self.

As shown in the figure, if there is one edge 3a of the paint 3 on the self, the transmitted light will pass through this edge 3a.
When the light hits the edge 3a, diffuse reflection occurs at the edge 3a. Therefore, paint 3 for forming mark 2 in this way
When applied over the entire upper surface of the print film 6 fixed to the light-shielding partition wall 5, a problem arises in that the original function of the light control film I, that is, the light regulation property is impaired.

The light control film having the above structure is usually manufactured as follows. That is, first, the base film 4
A photocurable resin is applied on top, and then a mask with a predetermined pattern of light-transmitting parts (the remaining parts are light-absorbing parts) is placed on top of it, and light is irradiated to form a photocurable resin corresponding to the pattern. The resin part is cured, the uncured part is washed and removed, and the cured part is dyed to the inside with a light-absorbing dye to form the light-shielding partition wall 5. Then, the print film 6 is formed. It is adhered onto the light-shielding partition wall 5, and furthermore, marks 2 are printed on this print film 6 using paint 3.

FIG. 7 (II) shows another conventional structure.

This light control film 1 is constructed by photolithography using a photocurable resin, as in the case of FIG. 7 (■), but in this example, the lower surface of the base film 4 is Mark 2 is drawn with paint 3 on the light source side.

In this case, although the light scattering phenomenon seen in FIG. 7(I) is unlikely to occur, there is a problem that the mark 2 is very difficult to see during the daytime when the light source is not turned on. This is because this mark 2 is provided on the back side of the light control film 1, so when viewing this mark 2, the partition light-shielding wall 5 will be in the way, and the mark 2 will be very dark and unclear. It becomes something.

Technical Problems of the Present Invention Accordingly, the technical problem to be solved by the present invention is to clearly display display marks in this type of mark-equipped light control film without impairing the light regulating properties inherent to the film. There is a particular thing.

SUMMARY OF THE INVENTION In order to solve the above technical problems, the present inventors provide a first invention relating to the light control film itself, and a second invention relating to a method for manufacturing the light control film.

(First invention) The light control film according to the first invention provides a predetermined pattern formed by a first light-absorbing paint of a predetermined color on either the inside of the outline of the predetermined mark on one side of the transparent mask film or the background part outside the outline. A second light-absorbing paint having a color different from that of the first light-absorbing paint is applied to either the inside of the outline of the predetermined mark on the one side of the transparent mask film or the background area outside the outline of the predetermined mark on the other side of the transparent mask film. The transparent mask film has one-sided printing, and a light regulation layer is integrally provided on the printed surface of the transparent mask film. The light regulating layer has light-shielding partition walls corresponding to at least the pattern-coated portions of the first light-absorbing paint, and the portion between the light-shielding partition walls is configured as a light-transmitting portion.

When the light control film having the above structure is used as a display surface, the light source is placed on the light-shielding partition wall side of the film, while the transparent mask film is used as the front surface.

In the daytime, the color of the paint representing the inside of the outline of the mark is different from the color of the paint in the background, so the mark can be clearly seen.

Since this mark is printed on the back of the transparent mask film (not on the back of the light-shielding partition wall), this mark will not be obstructed by the light-shielding partition wall, and therefore this mark will be clearly visible. It can be visually recognized as a mark.

On the other hand, when the light source is turned on at night, the mark itself or the background portion of the light control film selectively emits light. In other words, the mark can be clearly identified against the background by the light that passes through the light-transmitting part between the light-shielding partition walls that make up the mark, or by the light that passes through the light-transmissive part between the light-shielding partition walls that make up the background part. be able to. and,
This light-shielding partition wall matches the pattern of the first light-absorbing paint, and there is no misalignment between the mark and the light-shielding partition wall as in the conventional example shown in FIG. 7(I). There is no light scattering phenomenon at the edges of the paint. In other words, in this light control film, the light regulating properties of the film are not impaired at all. Therefore, in this light control film, the mark can be clearly seen as a light emitting part or as a dark part surrounded by a light emitting background.

(Second invention) The second invention relates to a method for easily manufacturing the light control film according to the first invention by photolithographically processing a photocurable resin. This manufacturing method consists of the following five steps. That is, a predetermined pattern is printed with a first light-absorbing paint of a predetermined color on either the inside of the outline of the predetermined mark on one side of the transparent mask film or the background area outside the outline, while on the one side of the transparent mask film. A first step of printing one side of either the inside of the outline of the predetermined mark or the background part outside the outline with a second light-absorbing paint having a color different from the first light-absorbing paint; and a transparent mask film. A second step of applying a photocurable resin onto the printing surface, and applying light from the opposite side of the transparent mask film to the printing surface to apply the photocurable resin to areas other than the light-absorbing paint application pattern. a fourth step of cleaning and removing uncured portions of the photocurable resin corresponding to the coating pattern portions of the first light-absorbing paint; The method is characterized in that it includes a fifth step of forming a light-shielding partition wall in the space.

In this manufacturing method, the transparent mask film consists of: 1)
It is used as a base film for photocurable resins, 2) as a mark printing material, 3) as a mask material in photolithography, and 4) as a light control film. Therefore, according to this method, a special base film is not required. Furthermore, since the light control film manufactured by this manufacturing method incorporates the mask film itself, this mask film serves as a skeletal structure of the light control film and makes the film itself durable. Furthermore, by using this mask film, it is possible to print in the desired color,
The degree of freedom in the design of the mark or the design of the background section increases.

An embodiment of the present invention will be described in detail below with reference to FIGS. 1 to 5.

Different light control films 1 1.1 1' are shown in FIGS. 1 (I) and (II), respectively. Figure 1 (■
) is an example in which the light control film shown in FIG. The light control film 11 is shown as a non-light-emitting portion and is illuminated by a light source S.

On the other hand, the embodiment shown in FIG. 1(n) uses the light control unit 11' shown in FIG. The background part 18 outside the outline of 12 is configured as a light emitting part, and this light control film 11' is used as a light source S.
This shows the state of illumination.

First, according to Figure 3 (I), Figure 1 (■) and Figure 2 (
The structure of the light control film in Example 1) will be explained in detail.

In FIG. 3(I), 19 is a transparent mask film, and a predetermined mark 12 is printed on one side of this mask film 19 (the bottom side in this drawing). That is, a first light-absorbing paint 132-12- of a predetermined color, for example green, is printed within the outline 24 of this mark 12 in a predetermined pattern, for example a honeycomb-shaped pattern P as shown in FIG. ing. In other words, when looking microscopically at the formed marks, the paint is not applied all over the surface, but forms a honeycomb pattern. On the other hand, a second light-absorbing paint 13 is applied to the background area 18 outside the outline of the mark 12 on one side of the transparent mask film 19.
' is printed on one side. This second light-absorbing paint has a different color from the first light-absorbing paint, for example black.

A light regulation layer 25 is integrally fixed to the lower surface of the transparent mask film 19 on which the mark 12 is printed.

The light regulation layer 25 is composed of a light-shielding partition wall 15 and a transparent column portion 20 filling the space between the light-shielding partition walls 15. The light-shielding partition wall 15 is composed of, for example, a honeycomb-shaped pattern P shown in FIG. ing.

If the light control film with the above configuration is used as a display surface, the mark 12 will be displayed during bright daytime hours.
The mark 12 is made of the first light-absorbing paint 13, that is, green, while the background part 18 is made of the second light-absorbing paint 13', that is, black.
8 can be clearly identified. Since this mark 12 is printed on the back surface (above lower surface) of the transparent mask film 19, all of the paint 13 on this mark can be seen without any obstruction. Mark 12 becomes very clear.

On the other hand, at night, if the light control film is illuminated from behind by the light source S, the oblique light L1 will be absorbed by the light-shielding partition wall 15, and only the parallel light Lt will pass through the transparent column 20 and the transparent mask film 19 to the front. reach. In other words, the light from the light source is adjusted by the light control film 11 and becomes easily visible light. In this case, the background portion 18 includes a second light-absorbing paint 13' and a second light-absorbing paint 15 provided corresponding to this paint 13'.
Since the light is completely absorbed by the light, this background part 18 does not emit any light and becomes a dark part. On the other hand, the triangular mark as a whole stands out clearly from the light passing through the transparent columns 20 between the light shielding partition walls 15 of the predetermined pattern P within the outline of the mark 12, and the driver can clearly see it.

In this case, as mentioned above, the light regulating properties of this light control film are maintained as they are, and the mark 1 is maintained.
The situation in which the first light-absorbing paint 13 constituting the first light-absorbing paint 13 scattering transmitted light does not occur at all.

The above embodiment shown in FIG. 3(I) merely shows a light control film that can be easily manufactured by one manufacturing method described later in FIG. 4, and this light control film is shown in FIG. , (III) are also possible.

FIG. 3(n) shows a modification of the light-shielding partition wall, and in this modified example, the light-shielding partition wall 15' is constituted by a foil-like light-shielding partition wall 15' formed on the side surface of the transparent column 20. ing. Therefore, although there is a space between the foils 15', the pair of light-shielding partition walls 15' and the paint 13 are integrated into one body, and the space is equivalent to the light-shielding partition wall 15 in the embodiment described above. It makes up the structure. Therefore, the light-shielding partition wall 1 in this modified example
5' has the same function as the light-shielding partition wall 15 in the first embodiment.

FIG. 3 (II[) shows the transparent column 20 in the above embodiment.
and a light-shielding partition wall 15 behind the second light-absorbing paint 13'.
A modified example is shown in which . In the first embodiment, a transparent column 20 remains for manufacturing reasons, but this transparent column 20 is a part that transmits light from a light source and may not be necessary. In addition, the background part 18
Since the second light-absorbing paint 13' itself that constitutes the second light-absorbing paint 13' blocks transmission of light, the light-shielding partition wall 15 behind the second light-absorbing paint 13' can also be omitted.

The above embodiments and modifications are examples in which the mark 12 is used as a light emitting part, but on the other hand, as shown in FIG. 1(n) and FIG. 2(II), the background part 18 is When used as a light-emitting part, the printing of the first light-absorbing paint in a predetermined pattern and the one-sided printing of the second light-absorbing paint are simply reversed from those in the first embodiment, and are different from those in the first embodiment. The structure of the light regulating layer in the mark part remains the same as the background part 18 in this case.
The structure of the light regulating layer of the background part 18 in the above embodiment can be applied as is to the structure of the light regulating layer of the mark part in this case.

FIG. 4 illustrates a method for manufacturing the light control film 11 shown in FIG. 3(I).

This embodiment of the manufacturing method is an example in which the mark portion is used as a light emitting portion.

First step (printing step)...FIG. 4A First, a predetermined pattern P1, e.g. The honeycomb pattern shown in FIG. 5 is printed. On the other hand, the predetermined mark 1 on the same side of the transparent mask film I9
The background portion 18 outside the outline of No. 2 is printed with the second light-absorbing paint 13'. The second light-absorbing paint 13' is, for example, black, and has a different color from the first light-absorbing paint 13.

Second step (photocurable resin coating step)...FIG. 4B Next, a photocurable resin is coated on the printing surface of the transparent mask film 19. In this case, it is preferable to apply an appropriate adhesive to the printing surface of the transparent mask film 19.

Third step (light irradiation step)...FIG. 4B Next, light is irradiated from the opposite printing surface side of the transparent mask film 19, that is, from the mask film 19 side, to apply the light-absorbing paint 13, 13' to the patterned area. Photocurable resin 22 corresponding to the other parts
Lightly cure the part.

Fourth step (cleaning step)...FIG. 4C Next, the uncured portions of the photocurable resin corresponding to the pattern-applied portions of the light-absorbing paint 13 and 13' are removed by cleaning to form the space 23. do.

Step 5 (Light-shielding partition wall type step...Fourth drawing) Then, in the space 23 formed between the cured parts of the photocurable resin corresponding to the application pattern of the light-absorbing paint 13 and 13',
A light-shielding partition wall 15 is formed by filling a light-shielding agent containing a light-absorbing dye.

Through the above steps 1 to 5, the light control film shown in FIG. 3(1) can be easily obtained.

In addition, when forming the light-shielding partition wall 15' shown in FIG. 3 (It), it can be constructed by applying a thin layer of light-absorbing paint to the side surface of the transparent column 20 formed in the fourth step. can.

In the example of the above manufacturing method, an example is shown in which a light control film is manufactured in which the mark part of the light control film is used as the light emitting part, but on the contrary, when the background part 18 is used as the light emitting part Since the areas to which the first light-absorbing paint 13 and the second light-absorbing paint 13' are applied are simply reversed between the mark part and the background part, a detailed explanation will be omitted.

[Brief explanation of the drawing]

Figures 1 to 5 show examples of the present invention, and Figure 1 (I) is an explanatory diagram showing an example using a light control film in which the mark part is the light emitting part, Figure 1-19 = (II) Figure 2 (1) is an explanatory diagram showing an example of a light control film in which the background part is the light emitting part, and Figure 2 (1) is the same as Figure 1 (
FIG. 2 (II) is a plan view of the light control film used in FIG. 1 (I[), and FIG. 3 (II) is a plan view of the light control film used in FIG.
1) is an enlarged cross-sectional view of the main part of the light control film in Fig. 1 (I) and Fig. 2 (I), and Fig. 3 (n)
, (II[) are shown in FIG. 3(I). An enlarged sectional view of the main part showing a modification of the embodiment, and FIG. 4 is an explanation showing the process of manufacturing the light control film shown in FIG. 1 (I), FIG. 2 (■), and FIG. 3 (I). Figure, 5th
The figures are diagrams showing the pattern of the first light-absorbing paint of the light control film used in Figures 1 to 4, Figure 6 is a plan view generally showing the light control film with marks, and Figures 7 (I), ( n) is an enlarged sectional view of a main part of a light control film with marks according to a conventional example. 11.11'...Light control film, 1
2... Mark, 13... First light-absorbing paint, 13'
...Second light-absorbing paint, 15.15'...Light-shielding partition wall, 17...Cell, 18...Background part, 19...Mask film, 20...Transparent column, 22... ...Photosetting resin, 23...Space, 24...Contour inside, 25
...Light regulating layer, S...Light source, P...Pattern, N, L
...Light, L...Diagonal light, L. ...Parallel light. , Patent Applicant: Tokai Rika Denki Seisakusho Co., Ltd., Representative, Patent Attorney: Aohaku Ao, and 2 others

Claims (1)

[Claims] 1. First light absorption of a predetermined color is applied to either the inside of the outline (24) of the predetermined mark (12) on one side of the transparent mask film (19) or the background part (18) outside the outline. While having a predetermined pattern (P) printed with a transparent mask film (13), either the inside (24) of the outline (24) or the background part (18) outside the outline of the predetermined mark (12) on one side of the transparent mask film (19) On the other hand, the first light-absorbing paint (
It has one-sided printing with a second light-absorbing paint (13') different in color from 13), and a transparent mask film (13').
A light regulating layer (25) is integrally provided on the printed surface of 19), and the light regulating layer (25) has a light blocking layer (25) corresponding to at least the pattern coated portion of the first light absorbing paint (13). A light control film characterized in that it has a partition wall (15), and a portion between the light-shielding partition walls (15) is configured as a light transmitting portion. 2. A first light-absorbing paint (13) of a predetermined color is applied to either the inside of the outline (24) or the background part (18) outside the outline of the predetermined mark (12) on one side of the transparent mask film (19). While printing a predetermined pattern (P),
The first light-absorbing paint (1
A first step of printing on one surface with a second light-absorbing paint (13') having a different color from 3), and a second step of applying a photocurable resin on the printed surface of the transparent mask film (19). A third step of photocuring the photocurable resin portions corresponding to the areas other than the coating pattern portions of the light-absorbing paint (13, 13') by irradiating light from the opposite-to-print side of the transparent mask film (19). a fourth step of cleaning and removing uncured portions of the photocurable resin corresponding to the coating pattern portions of the first light-absorbing paint (13); and a space (23) between the cured portions of the photocurable resin. ) a fifth step of forming a light-shielding partition wall (15).