JPS5962887A - Sealed hologram disc - Google Patents

Abstract

PURPOSE:To give a very stout structure and setting the thickness of a cover glass relatively thin because of the cover glass supported at the inside and outside circumferential parts by fixing a hologram disc and the cover glass along respective inside and outside circumferential parts with an adhesive. CONSTITUTION:A positive photoresist is coated onto the surface of the disc 1 having about a 100mm. outside diameter, about 3mm. thickness, and an about 30mm. center hole 1a diameter, and photographing is performed by a two-luminous flux interference method using an He-Cd laser, and developed to form a hologram diffraction grating 2. Meanwhile, a reflection preventing film is provided on both surfaces of the cover glass 3 having about the 100mm. outside diameter, about the 2mm. thickness, and a 30mm. transmission hole 3a. Adhesives 4a and 4b containing a pearl 5 which functions as spacer are formed with about 3mm. width on the concentric circles in the outside and the inside circumferential parts of the cover glass 3. After defoaming and prehardening, the disc 1 and the cover glass 3 are incorporated to surround the hologram diffraction grating 2, are pressurized with prescribed pressure to form them into one body.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to holography technology, and more particularly to a sealed hologram disk that allows a hologram to be maintained in a sealed state.

Conventionally, hologram diffraction gratings have been used as optical scanning Hft in laser printers and the like.

It is desirable that the hologram used in such an optical scanning device has a structure that is not affected by changes in environmental conditions and is not physically deformed. For example, it is possible to form a hologram diffraction grating using a 1-naphthoquinonediazide derivative-phenol/novolak resin-based positive photoresist (or dichromate gelatin, etc.), but such a hologram diffraction grating is moisture resistant. Sex is not very good. For example, 40℃, 90%RH
If the resist film is left under these conditions, cracks may occur on the resist film surface within 2 to 3 days, and the diffraction efficiency may be significantly reduced. Furthermore, such holographic gratings are susceptible to accidental blows and scratches.

It is easily susceptible to physical damage due to contact, etc., and has a lead hardness of B or less, and the diffraction efficiency decreases to the extent that fingerprints are attached to it.

In this way, optical scanning devices etc. that use holograms are not influenced by surrounding environmental conditions.
In addition, it is desired that the hologram be physically strong.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a hologram that is not affected by environmental conditions, particularly humidity, and is capable of preventing physical damage. purpose. Furthermore, the present invention aims to provide a hologram that is suitable for use in an optical scanning device such as a laser printer and can be used for a long period of time.

Still another object of the present invention is to provide a sealed hologram disk that can maintain a hologram formed on the hologram disk in a sealed state.

The sealed hologram disk of the present invention includes a hologram disk having a circular hole in the center and a circular hologram formed on one surface, and a cover glass formed in substantially the same shape as the hologram disk. an adhesive interposed along the inner and outer peripheries of the hologram disk and the cover glass to fix them together; and a spacer to maintain the hologram disk and the cover glass at a predetermined distance. The hologram is in a sealed state. As described above, in the sealed hologram disk of the present invention, since the hologram disk and the cover glass are fixed with adhesive along the inner and outer peripheral portions of each, an extremely robust structure can be achieved. have. Further, since the cover glass is supported at the inner peripheral portion and the rear peripheral portion, it is possible to set the thickness of the cover glass to be relatively thin.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 to 6 show the manufacturing process of a first embodiment of the sealed hologram disk of the present invention. First, as shown in FIGS. 1 and 2, a glass disk 1 having a transmission hole 1a in the center is prepared. The outer diameter of the glass disk 1 is approximately 100 mm, the diameter of the center hole 1a is approximately 30 mm, and the thickness of the disk 1 is approximately 3n+.
It is m.

A positive photoresist (e.g.
A phenol-novolac positive resist containing a naphthoquinone diazide compound as a photosensitizer; manufactured by Shipley Co., Ltd. AZ-1350) was heated to about 1.2
A hologram diffraction grating with a spatial frequency of 2.235 lines/mm was photographed by three-beam interferometry using a He-Cd laser, and then a developer (AZ developer manufactured by Shipley Co., Ltd. /2 dilution) to form a hologram diffraction grating 2. In this way, a transmission type hologram diffraction grating was obtained, whose maximum diffraction efficiency was 1-18
-Ne laser reproduction light was measured under the condition of 45 degrees of incidence and found to be 75%.

Next, a cover glass 3 having a transmission hole 3a in the center is prepared. The outer diameter of the cover glass 3 is approximately 10Qmm,
The diameter of the transmission hole 3a is 3Qmm, and the thickness is about 2Qmm.
It is mm. )-1e- on both sides of this cover glass 3.
An antireflection film is provided so that the reflectance is 0.2% when Ne laser reproduction light (wavelength G, 328 people) is incident at 45 degrees. Next, adhesives 4a and 4b containing true spherical particles 5 functioning as spacers are formed concentrically on the outer and inner peripheral parts of the cover glass 3, each having a width of 3 mm. In this case it is advisable to use the known screen printing method. Moreover, as the true spherical particle 5, the diameter is 14p.
m divinylbenzene-based true spherical plastic particles (manufactured by Sekisui Fine Chemicals) can be used, and the adhesives 4a and 4b can be epoxy adhesives (for example, L I X0NBOND manufactured by Chisso Corporation). is desirable. Next, after degassing and pre-curing, the disk 1 and the cover glass 3 are combined so that the hologram diffraction grating 2 is surrounded, as shown in FIGS. Integrate by applying pressure.

In the above-described embodiment of the present invention, the glass disk 1 having a transparent hole in the center and the cover glass 3 are integrally formed with adhesive along the inner and outer peripheries with spacers interposed therebetween. Therefore, the structure is robust and the hologram 2 can be reliably maintained in a sealed state.

Table 1 shows the change in diffraction efficiency over time when the sealed hologram disk obtained as described above was placed in an environment of a temperature of 40 DEG C. and a humidity of 90% R)-1.

7 to 10 show another embodiment of the invention. In this embodiment, unlike the first embodiment described above, a ring-shaped spacer 7 having a constant thickness is used instead of a true spherical particle to hold the disk 1 and the cover glass 3 in a predetermined position. This is to maintain the Fe1t interval state. 7 and 8 show a cover glass 3 in a second embodiment of the present invention, the shape and dimensions of which are the same as those shown in the first embodiment. Adhesives 4a and 4b are provided along the inner and outer peripheries of the cover crow 3.

In this case, it is preferable to use an epoxy adhesive as the adhesive, and approximately 3n+ by screen printing.
It is desirable to form an adhesive layer by curing the inner periphery and the outer periphery with a width of m.

Note that when forming the adhesive layers 4a and 4b by screen printing, it is necessary to take into account the viscosity of the adhesive used. Furthermore, when using an adhesive other than epoxy, it is necessary to use one with characteristics that will not corrode the hologram 2. As shown in FIG. 7, a notch 6 is formed in a part of the adhesive layer 4a provided along the outer periphery. The cutout portion 6 is a gas vent hole through which internal gas is extracted when the cover glass 3 is attached to the disk 1. Therefore, when the cover glass 3 is combined with the disk 1 and bonded together by applying pressure, it is possible to prevent defects from occurring in the bonded portion due to expansion of the enclosed air.

9 and 10 show a second embodiment of the sealed hologram disk of the present invention. In this case, in order to maintain the hologram disk 1 and the cover crow 3 at a constant distance, A ring-shaped spacer 7 is used. As such a spacer 7, it is possible to use, for example, a polyester film cut into a ring shape. Further, the width of the spacer 7 can be, for example, 2IIIm and the thickness can be 23p-, but normally the thickness of the spacer can be 2 to 100 μm, and the width can be 1 It is possible to set it between 5 mm and 5 mm. Incidentally, the thickness of the spacer 7 must be set to a thickness that does not damage the hologram 2.

As shown in FIG. 9, after the cover glass 3 is pressed and adhered to the disk 1, the notch 6 is filled with a sealing adhesive 6a to seal the hologram 2. In this embodiment, the adhesive layer 4a is provided with a base 4 nore on the outer peripheral part.
Although a ring-shaped object is used, it is also possible to additionally provide a similar spacer 7 adjacent to the adhesive layer 4b formed on the inner periphery. By providing spacers on the inner and outer peripheries in this way, it is possible to make the hologram disk assembly even more robust. This hologram disk has the above configuration.

Table 1 shows the change over time in the diffraction efficiency when placed in an environment of a temperature of 40° C. and a humidity of 90% RH. In addition, in Table 1, Comparative Example 1 is the case where Nocovar crow is not provided, and Comparative Example 2 is the case where no anti-reflection film is provided on the cover glass. It shows.

Table 1 FIG. 11 shows the influence on the diffraction efficiency when an antireflection film is provided on the cover glass.

That is, in FIG. 11, the solid line indicates the diffraction efficiency when the cover is in front of the glass lath 3, and the dashed and dotted lines indicate the diffraction efficiency after the cover glass 3. The efficiency is shown by the dotted chain line for the case where no antireflection film was provided, and the dotted line for the case where the antireflection film was provided on both sides of the cover glass 3. As is clear from FIG. 11, when the antireflection film is not provided on the cover glass 3, the diffraction efficiency may vary in a ripple-like manner depending on the hologram position.

Note that this ripple may or may not appear depending on the parallelism between the cover glass 3 and the hologram surface.

Furthermore, as is clear from FIG. 11, the diffraction efficiency also decreases by 5 to 15% on average due to the influence of reflection. Therefore,
It is desirable to form a foul prevention film on the cover glass 3, and although it is effective even if it is provided on only one side, it is more desirable to provide it on both sides.

As described in detail above, according to the present invention, it is possible to maintain the hologram in a sealed state, and therefore it is possible to prevent the hologram from being influenced by the external environment such as humidity. Furthermore, since the cover glass and the disk are integrally bonded at both ends of the inner and outer peripheral portions of the disk, the vibrational strength is significantly improved. In addition, since the disk and cover glass are integrally formed with adhesive at the inner and outer peripheral portions, there is greater freedom in providing spacers to maintain a constant distance between the disk and cover glass. is high. For example, by mixing true spherical particles into an adhesive and performing double-screen printing, it is possible to form the adhesive into a glass layer, which improves productivity. Furthermore,
By forming an antireflection film on the cover glass, it is possible to improve the optical properties of the sealed hologram disk.

Above, I gave a false explanation about the specific structure that has not been invented yet.
The present invention should not be limited to these specific examples,
Of course, various modifications can be made without departing from the technical scope of the invention. Furthermore, the Hf1V of the present invention is applicable not only to optical devices such as laser printers but also to a wide range of technical fields such as barcode readers and holographic displays.

[Brief explanation of the drawing]

Fig. 1 is a plan view of the glass disk 1 on which the hologram 2 is formed, Fig. 2 is a sectional view taken along the line A plan view showing the cover glass 3 on which the kudzu adhesive layers 4a and 4b containing true spherical fine particles are formed, FIG. 4 is the IV shown in FIG. 3.
FIG. 5, a cross-sectional view taken along the line -IV, shows an embodiment of the sealed hologram disk of the present invention, which is constructed by integrating the disk 1 shown in FIGS. 1 to 4 with the cover glass 3. The plan view shown in Fig. 6 is VI-VI shown in Fig. 5.
7 is a sectional view taken along the FM, FIG. 7 is a plan view showing the cover glass 3 in the second embodiment of the present invention, and FIG. 8 is a sectional view taken along the line ■-■ shown in FIG. 9 is a plan view showing the second embodiment of the present invention, FIG. 10 is a sectional view taken along x-xm shown in FIG. 9, and FIG. 11 is a cross-sectional view of the cover glass 3. It is a graph diagram showing the influence of silkworms when an anti-reflection film is provided. (Explanation of symbols) 1: Glass disk 1a: Center hole 2 of glass disk 1: Hologram diffraction grating 3: Cover glass 3B 2 Center holes 4a, 4b of cover glass 3: Adhesive layer 5: True spherical particle 6: Notch Part (gas vent hole) 7: Spacer ring

Claims (1)

[Scope of Claims] 1. A hologram disk having a circular hole in the center and a circular hologram formed on one surface, and a cover glass formed in substantially the same shape as the hologram disk;
an adhesive that is cured and interposed between the inner and outer peripheral portions of the hologram disk and the cover glass to fix them together; and a spacer that maintains the hologram disk and the cover glass at a predetermined distance. have,
A sealed hologram disk characterized in that the hologram is in a sealed state. 2. The sealed hologram disk according to item 1 above, wherein the spacer is a true spherical particle, and a plurality of the true spherical particles are mixed in the adhesive. 3. The sealed hologram disk according to item 2 above, wherein the true spherical particles are true spherical particles made of glass or plastic. 4. The sealed hologram disk according to item 2 above, wherein the spacer is a ring having predetermined inner and outer diameters and a constant thickness. 5. The sealed hologram disk according to item 4 above, wherein the ring is a polyester film. 6. The sealed hologram disk according to item 1 above, characterized in that an antireflection film is formed on at least one side of the cover glass.