JPH052930Y2 - - Google Patents

Description

[Detailed description of the invention] ...Industrial fields of application This invention applies a manuscript film to the exposed surface of the screen (ultraviolet curable resin photosensitive film surface, UV photosensitive film surface) in the manufacturing process of screen plates used for screen printing. Ultraviolet projection exposure equipment is used to irradiate ultraviolet rays through the screen, and in particular, it has a revolutionary power and light distribution compared to conventional methods, especially for the exposure surface of a huge screen with dimensions of several meters in length and width. It is characterized by being able to perform excellent ultraviolet irradiation exposure, and has also realized the production of huge screen plates, and can be used for huge screen printing several meters in length and width for printed materials such as large billboard advertisements. This made it possible.

...Prior art and its challenges Recently, large billboard advertisements measuring several meters in length and width are often seen on the walls and rooftops of buildings, along roads and railway lines, etc. These are usually formed by pasting together multiple sheets of fairly large screen printed matter.

Currently, screen plates are mainly produced by forming a UV-sensitive film on the screen, exposing the film to UV rays that pass through the original, curing the film, and removing the non-exposed areas. However, since UV photosensitive films have inferior sensitivity compared to silver-based photosensitive films, the ultraviolet rays that are magnified and projected onto the exposure surface of a large screen also have strong light energy and good light distribution. However, conventional ultraviolet magnification projection exposure equipment has the same optical configuration as that used for silver-based photoresist films, so it is necessary to There is absolutely nothing that can project irradiation with sufficiently high brightness and a uniform light distribution on the exposed surface, and increasing the area of the screen will result in underexposure, causing uneven light distribution and making it impossible to obtain accurate image lines. It was possible to manufacture only products with a maximum length of 1 m x width of 1.5 m, and even then, the printing grains were rough and the printing could not be described as beautiful.

Therefore, in order to print advertisements on large screens, the screen was divided into many parts, screen plates were made for each part, and many of the printed parts were pasted together to form the whole. Therefore, it is necessary to manufacture a large number of screen plates, and it is difficult to uniformly adjust the print finish of each plate.Also, in bonding and compositing, there are problems such as deviations in image lines and color tone in the peripheral areas of each plate. Therefore, there has been a strong demand for an excellent screen plate that can print larger and clearer lines.

...Structure of the present invention The present invention has been made to solve the above-mentioned conventional problems.

That is, the present invention transmits light most effectively in order to minimize the attenuation of the light energy (ultraviolet energy) emitted by the light source (ultraviolet light emitting lamp).
This invention has a unique optical configuration for the purpose of irradiating the exposed surface of the screen and transmitting the ultraviolet rays so that there is no unevenness in the light distribution of the exposed surface of the screen. With this, the exposure surface of the screen on which the original is enlarged and projected is exposed to light that is sufficient for short-time exposure (cure).
It is now possible to irradiate powerful ultraviolet energy, and the enlargement projection magnification can be surprisingly increased compared to conventional methods (even if increased, it retains sufficient ultraviolet energy for exposure and the light distribution does not become uneven). , is characterized by the realization of the production of screen plates with extremely clear images and huge dimensions measuring several meters in length and width.

Below, the configuration of the present invention will be explained with reference to its _embodiments . The integrator lens 4 is installed at the focal point _F2 , which is the other focal point and is also the focal point of the front Fresnel lens 3a, and parallel light rays are relayed between the front and rear Fresnel lenses 3a and 3b.
The projection lens 5 is installed at the focal point _F3 of the rear Fresnel lens 3b, and the condensing system is fixed (1,
2, 3a, 3b, 4, and 5 are installed in their respective fixed positions)
The rear Fresnel lens 3b in the condensing system is configured as follows.
An original 6 (e.g., a halftone positive film) is adjustable between the projection lens 5 and the projection lens 5, and a screen 7 (forming the exposure surface) is placed behind the projection lens 5.
An ultraviolet magnification projection exposure apparatus for the production of giant screen plates, characterized in that the position of the original and the screen can be adjusted with respect to the fixedly configured condensing system. be. (Fig. 1) (2)... Adjustment of the magnification to enlarge and project the original 6 onto the screen 7 (for example, as shown in Fig. 4, ×3 to ×15):
This is done by adjusting the distance between the original 6 and the focal point F ₂ (projection lens 5) and proportionally adjusting the distance between the focal point F ₂ and the screen 7.

(3)...An ultraviolet shutter 8 is installed between the elliptical mirror 1 and the integrator lens 4. The ultraviolet shutter 8 adopts an ultraviolet cut filter,
Even when the ultraviolet shutter 8 is closed, visible light passes through, so the original can be enlarged and projected onto the screen, and focusing can therefore be facilitated.

(4)...An ultraviolet reflecting mirror 9 is installed between the integrator lens 4 and the front Fresnel lens 3a, so that the direction of ultraviolet rays is changed by reflection from the integrator lens and sent to the front Fresnel lens 3a.

The ultraviolet reflecting mirror 9 is a so-called cold mirror that reflects ultraviolet rays and transmits infrared rays (heat rays).
(Figure 2) (5)...An ultra-high pressure mercury lamp is used as the light source 2 (ultraviolet light emitting lamp). The focal point was set to be concentrated on the focal point F ₂ (integrator lens 4). However, it is naturally possible to use only one.

In the case of a large lamp, for example, a commercially available 3.5KW ultra-high pressure mercury lamp, the electrode spacing is long, about 6.6 to 9 mm, so the total luminous flux is large but the average brightness is low. In comparison, the electrode spacing of the 1KW ultra-high-pressure mercury lamp is as short as 3 mm, and the total luminous flux is approximately in the same proportion as the two, but the average brightness is relatively high with no difference up to 1/2.

3.5KW average brightness 65000cd/cm ² Total luminous flux 175000 m 1KW average brightness 35000cd/cm ² Total luminous flux 45000 m In the case of general proofs, it is advantageous to have a large total luminous flux, but secondary and tertiary luminous flux such as projection equipment etc. When used as a light source, one with high brightness is definitely advantageous.

Therefore, as in the example, three 1KW ones are better.
Higher average brightness than a single 3KW one can be obtained,
That would be advantageous.

(6)...Also, in the above-mentioned ultra-high pressure mercury lamp, the true light source is the electrode spacing section, but this section has a length dimension (1KW is advantageous in this point as it is shorter at 3 mm). It's not a "point". Therefore, even if the light rays emitted from the light source are focused with a normal lens, they will not be accurately focused; therefore, if they are expanded, the light will disperse, the light energy will be attenuated, and the light distribution will be uneven. This will occur.

Therefore, in the present invention, an integrator lens is placed at the focal point of the light source (elliptical mirror).

When the integrator lens is used to condense and magnify the light rays from the light source, a portion (hatched area in the center) where the beams of light (nine in the illustrated example) overlap is created as shown in FIG. Naturally, the light distribution in this area is uniform and extremely good, so in the present invention, the uniform light distribution is utilized through the Fresnel lens to minimize the loss of light energy (ultraviolet energy) of the light source, and The most uniform light distribution can be obtained on the exposed surface.

...Effect (1)...The ultraviolet rays emitted from the light source 2 are relayed in parallel to the integrator lens 4 at the focal point _F2 of the elliptical mirror 1 → Fresnel lens 3a → Fresnel lens 3b → the original 6 → the projection lens 5 at the focal point F ₃ → the screen 7 is enlarged and projected onto the exposure surface, and the exposure surface is cured with ultraviolet irradiation.

(2)…Also, elliptical mirror 1 and integrator lens 4
An ultraviolet shutter 8 is installed between the two, which blocks ultraviolet rays and transmits visible rays, focuses on the visible rays, and opens the shutter 8 only during exposure to allow ultraviolet rays to pass through.

(3)...An ultraviolet reflecting mirror 9 (cold mirror) is installed between the integrator lens 4 and the front Fresnel lens 3a to reflect and change the direction of ultraviolet rays,
Infrared rays (heat rays) pass through and are radiated by the heat radiation fins 10.

(4)... Adjustment of the magnification ratio for enlarging and projecting the original 6 (e.g. halftone positive film) onto the exposure surface of the screen 7 is as follows:
Adjustment of the distance between the original 6 and the projection lens 5 (focal point F ₃ ) and the projection lens 5 proportionally corresponding thereto.
This is done by adjusting the distance between (focal point F ₃ ) and the screen 7.

For example, in FIG. 4 of the embodiment, document 6 is
As shown in the adjustment from the position 3 to the position 13, reducing the distance between the projection lenses 5 increases the magnification, and therefore the distance between the projection lenses 5 and the screen 7 is increased for adjustment.

As is clear from the embodiment drawings, the present invention can project a clear image even when the magnification is increased from the conventionally possible magnification to several times or more (even more than shown is possible). The size of the screen at ×15 is approximately 4 m in height and 7 m in width.

...Effect (1)...As mentioned above, the present invention has a fixed condensing system in which a light source, an elliptical mirror, an integrator lens, a shutter, a reflecting mirror, a Fresnel lens, etc. are arranged. , the ultraviolet energy of the light source reaches the exposed surface of the screen in the least attenuated state. Therefore, strong ultraviolet energy can provide an excellent feature of effective exposure (cure) in a short period of time.

(2)...Because only the part with the most uniform light distribution where multiple light beams are polymerized by the action of the rendegrator lens is used, the exposed surface of the screen is also irradiated with ultraviolet rays with a uniform light distribution, making it more Then,
This has the advantage that exposure (cure) is performed evenly over the entire surface.

(3)...Powerful ultraviolet energy is emitted by multiple light sources (3 examples), and the ultraviolet energy can be transmitted with less attenuation, and an extremely uniform and good light distribution can be obtained, making it a revolutionary product compared to conventional methods. It becomes possible to perform projection exposure processing on a gigantic screen with a large magnification, and thus it is possible to manufacture a screen plate with an unprecedentedly gigantic area.

Figure 5 is a graph showing the relationship between magnification, area, and ultraviolet (UV) energy intensity (expressed in μw/cm ² ) in the example device (using a 2KW ultra-high pressure mercury lamp). Even in the case of a huge screen size of 4110 x 6840 mm, there is about 50 μw / cm ² , which is about 20 times more powerful than the conventional one. ×4104
mm (approximately 2.5m x 4m), it reaches approximately 200 times the conventional size.

(4)...Since it became possible to irradiate the exposed surface of the screen with strong ultraviolet rays, the exposure time could be significantly shortened.

As a result, the exposed surface of the screen does not have time to cause a so-called dark reaction, and can be effectively cured while the UV resin sensitizer has good sensitivity.

In addition, if the exposure time is long, the original film will inevitably expand and contract due to the effects of heat, and vibrations will cause blurring, resulting in blurred and unclear projected image lines. It turned out to be something that could be avoided.

(5)...As described above, the present invention allows extremely precise resolution to be obtained on the exposed surface of the screen, and as a result, it is possible to manufacture a huge screen plate that is capable of precision printing. Printed materials with sharp images can be obtained, and therefore, large advertisements and other printed materials without (or with less) pasting can be provided. In addition, walls of buildings and other various structures,
It is also ideal for printing huge patterns as decorations on ceilings, floors, etc.

As mentioned above, the present invention can produce an unprecedentedly huge screen plate, but it can also be applied to the production of items of the same size as before, and even in that case, it is much more efficient than conventional products. It is possible to manufacture precise screen plates.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the optical configuration of the present invention, Fig. 2 is an explanatory diagram of the embodiment configuration, Fig. 3 is an explanatory diagram of the action of the integrator lens, and Fig. 4 is an illustration of the original against the projection lens in enlarged projection. FIG. 5 is a graph showing the relationship between magnification, screen area, and ultraviolet energy intensity using the device of the embodiment, and FIG. 6 is a front view of the device of the specific embodiment of the present invention. , a plan view and a side view. Code, F ₁ , F ₂ , F ₃ ... focus, 1 ... elliptical mirror,
2...Light source (ultraviolet light emitting lamp, ultra-high pressure mercury lamp),
3a...Front Fresnel lens, 3b...Rear Fresnel lens, 4...Integrator lens, 5
...projection lens, 6...original (e.g., halftone positive film), 7...screen (exposure surface), 8...shutter (ultraviolet cut filter), 9...ultraviolet reflector (infrared transmitting cold mirror), 10...
...heat dissipation fin.

Claims (1)

[Claim for Utility Model Registration] 1) A light source (ultraviolet light emitting lamp) is installed at one focal point _F1 of the elliptical mirror, and the focal point is the other focal point of the elliptical mirror and is also the focal point of the front Fresnel lens.
An integrator lens is installed at F ₂ , parallel light beams are relayed between the front and rear Fresnel lenses, and a projection lens is installed at the focal point F ₃ of the rear Fresnel lens to create a fixed condensing system. A condensing system in which a document is adjustable between the rear Fresnel lens and the projection lens, and a screen is adjustable behind the projection lens, compared to a fixed condensing system. , an ultraviolet magnification projection exposure apparatus for producing giant screen plates, which is characterized in that the positions of the original and the screen can be adjusted. 2) Adjustment of the magnification to enlarge and project the original onto the screen is performed by adjusting the distance between the original and focal point _F3 , and proportionally adjusting the distance between focal point _F3 and the screen. An ultraviolet magnification projection exposure apparatus for manufacturing a giant screen plate, as set forth in claim 1 of the utility model registration. 3) An ultraviolet magnification projection exposure apparatus for manufacturing giant screen plates, as set forth in claim 1 of the utility model registration, in which a plurality of elliptical mirrors each having a light source are installed with each focal point being concentrated at the focal _point F2. . 4) An ultraviolet magnification projection exposure apparatus for producing a giant screen plate, as set forth in claim 1 of the utility model registration, in which an ultraviolet shutter is installed between an elliptical mirror and an integrator lens. 5) An ultraviolet reflecting mirror is installed between the integrator lens and the front Fresnel lens, and the direction of the ultraviolet rays from the integrator lens is changed by reflection and sent to the front Fresnel lens, as set forth in claim 1 of the utility model registration claim. , an ultraviolet magnification projection exposure system for the production of giant screen plates.