JPS59166913A - Diffraction grating exposing device - Google Patents

Abstract

PURPOSE:To form a diffraction image whose pitch and diffraction efficiency are different by dividing into two an exposing beam passing through a shutter for controlling freely an exposure time, and condensing them to one point through a rotary mirror, etc., respectively. CONSTITUTION:An exposing laser beam passing through a shutter for varying an exposure time in accordance with a diffraction efficiency is divided into two by a beam splitter 14 of an exposure head 5, and they are condensed to one point of a small window 11 through a rotary mirror lenses 16, 18, 19, 17, 20 and 21, respectively. Subsequently, a diffraction image is formed on a film. A pitch of an interference fringe by this diffraction is varied in accordance with the sum of focusing angles theta1, theta2 varied in accordance with a rotation of the mirrors 16, 17. According to them, a desired diffraction image whose pitch and diffraction efficiency are different is formed easily and exactly.

Description

Detailed Description of the Invention The present invention relates to a device that sequentially exposes a photosensitive film by changing the pitch and light intensity of minute interference fringes caused by three-beam interference, and after exposure, the film is subjected to development processing. By doing so, a pattern based on a diffraction grating can be obtained.

Conventionally, in order to obtain patterns using diffraction gratings, masks made of photographic film or paper have been used, and in order to obtain patterns using many diffraction gratings, many masks are required. Changing the diffraction efficiency requires a huge amount of effort and time, and at present, patterns using many diffraction gratings have not been obtained.

The present invention is a device that eliminates this drawback and makes it possible to obtain a diffraction pattern in which the pitch of the diffraction grating and the diffraction efficiency are changed freely and continuously, and it is possible to obtain new images never seen before. . That is, the present invention is an apparatus comprising at least a movable document rack for placing a photosensitive film, and a movable exposure head for exposing interference fringes generated by three-beam interference on the photosensitive film. Herad.

A shutter for blocking incident light as necessary, a half mirror for dividing the light passing through the shutter into two beams, and a rotating mirror for each of the two beams divided by the half mirror. same through
A fixing block is used to fix each of the half mirror-1 rotation mirror and the lens system so that the light beams passing through the respective lens systems are guided to each of the pair of lens systems having the structure and converged at one point. The present invention relates to a diffraction grating exposure apparatus characterized in that the diffraction grating is disposed inside the diffraction grating.

The present invention will now be described with reference to the schematic diagrams of the apparatus shown in FIGS. 1 and 2. Figure 1 shows the main parts of this device, including a rotating drum (2) to which a photosensitive film (101 is pasted), a drum (5) that rotates it, and a guide to stably hold and move it. (6) Ball screw (8
), pulse motor (9), rotary encoder (
7), a laser beam oscillator (not shown), and the like. Laser beam for exposure (4
) enters the exposure head (5) K, exits from the small window circle, and reaches the photosensitive film (1o). Fig. 2 shows the inside of the exposure head (5).
18) (19) (20) (2D, Mi7- (12
1 (15) (161 (17), half mirror (14)
, shutters (ribs), and 7” to support them.
Consists of 23+ laser beams (4
) As is the case with the shutter (22+) and the mirror (12), the light beam is divided into two beams by the half mirror (14), and one beam is divided into two beams by the rotating mirror (16) and the lens Q8 (19).
) and reaches the small window (111), and the other light beam passes through the rotating mirror αη, the lens (20 +
11, and interference fringes due to the two light beams are formed at the small window ←υ. In this optical system, a rotating mirror (L61 (
In C, the lens α81 (201) is placed at the focal length f1, and these rotating mirrors (161fl
The light reflected by the force becomes light parallel to the optical axis after passing through the lens (18) and the lens 20). When this parallel light beam enters the lens α9), each lens d
9) (211).Thus, by rotating the one-rotation mirror (16) αη, the light changes its direction, but the two light beams are always at the same place, that is, all of the small windows. The pitch d of the interference fringes formed at this time is given by the following formula, λ d2, 11□, =77□□1−...Equation (1) where: , λ is the wavelength of the laser, θZ, and θ2 are the angles that the two light beams make with the normal direction of the small window circle.

In FIG. 1, θ2 is a negative value.

The exposure of the pattern onto the photosensitive film aO) by this device involves, for example, changing the angle (θ1+θ2) of the two light beams and the opening/closing time of the shutter (22) based on an electrical signal from an external scanner. In this case, the original image to be converted into a diffraction grating is first set in a scanner, and the pitch of the interference fringes is arbitrarily determined using red, green, and blue color signals obtained through a scanning head and a photoelectric conversion element. do. Next, the rotation mirror (16) α force is rotated so that the determined hit can be set on the photosensitive film aOt, and the angle (θ1+0
Change 2). Next, the opening/closing time of the shutter (221) is determined in accordance with the optical density obtained from the original image set in the scanner, and exposure is performed.Diffraction efficiency of the diffraction grating can be changed by changing the length of this exposure time.

By repeating this series of operations for each pixel, it is possible to create an image using a diffraction grating from the original image.

In the pattern of the diffraction grating created in this way,
When white light such as that from the sun is incident, colors with different brightness can be seen due to differences in the pitch and diffraction efficiency of the diffraction grating in each part of the pattern, and the overall pattern is a shining red-like pattern. You'll see.

Thanks to the invention of this device, it is possible to quickly and easily draw a picture using a diffraction grating while freely changing the pitch and diffraction efficiency of the diffraction grating without using a mask, since the present invention has the above-described configuration. It can be used in the display field and is industrially effective.

In addition, is this invention applicable to an example in which a drum-shaped document shelf is adopted? Although described above, the present invention is not limited to this, but may be an apparatus having a structure in which the document shelf is made into a flat plate, a film is placed thereon, and the head is moved back and forth and left and right. Furthermore, using the device according to the invention.

Instead of creating a diffraction grating pattern based on a signal from a scanner, it is also possible to create a diffraction grating pattern by directly outputting an original image created by a computer to a printer.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of the main parts of this apparatus, and FIG. 2 is an explanatory diagram showing the inside of the exposure head. fJ + (7)...Rotary encoder (2
+...Tram+3) (91...Pulse motor-(
4)...Laser beam (5)...Exposure head
(8)...Ball screw (10)...Photosensitive film (111...Small window f121...Mirror I...
Half mirror (15)...Mirror (+61(Iη・
...Rotating mirror (18) (19) (201(21)
1... Lens (221... Shutter (23)
...Support block patent applicant Toppan Printing Co., Ltd.

Claims (1)

[Claims] (]) A shifting device comprising at least a movable document rack for setting a photosensitive film, and a movable exposure head for shifting the exposure of interference fringes produced by three-beam interference on the photosensitive film, and The head has a shutter for blocking the light incident on it as necessary, and a nozzle for splitting the light passing through the shutter into two beams.
A half mirror is provided with a shift so that each of the two light beams split by the half mirror is guided through a rotating mirror to each of a pair of lens systems of the same configuration, so that each light beam that passes through each lens system is brought to a single point. 1. A diffraction grating exposure apparatus characterized in that each of the h-f mirror, rotating mirror and lens system is arranged within a fixed block so as to condense light at H'jl.