JPH0954214A - Hologram laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve appearance by specifying the difference between the cloud value of the part laminated with a hologram and the cloud value of the part not laminated with this hologram. SOLUTION: The hologram 14 is encapsulated in sandwich glass formed by laminating two sheets of glass plates 11 and 11' via an intermediate film 12 consisting of PVB, etc. The hologram 14 is laminated between the glass plate 11 and the intermediate film 12 by disposing a barrier layer 13 on the intermediate film side. This barrier layer 13 consists of, for example, PVA, etc. The influence of the plasticizer contained in the intermediate film usually consisting of PVB is prevented. The hologram 14 is encapsulated in part of the entire surface of the sandwich glass. At this time, the difference between the cloud value of the part 21 disposed with the hologram 14 of the sandwich glass and the cloud value of the part 23 not disposed with the hologram is specified to <=1.0, by which the part 21 encapsulated with the hologram 14 is made less conspicuous than the other parts and the sandwich glass having the good appearance is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hologram laminate in which holograms are arranged on a transparent substrate, and more particularly, a hologram is provided on a windshield of a vehicle such as a vehicle, an aircraft or a ship to project information required by a driver. The present invention relates to a hologram laminate that is suitable for use in a holographic display device.

[0002]

2. Description of the Related Art As a means for displaying information to a driver of a vehicle such as an automobile, a head-up display (hereinafter referred to as HUD
And other display devices have been proposed. HUD is
The optical information projected from the information projection means such as a liquid crystal display device is projected on a combiner composed of a hologram or a half mirror incorporated in the windshield of an automobile, etc. Is designed to be read.

A hologram may have a lens function and the like as well as a function of diffracting optical information. Therefore, in particular, a hologram using a hologram as a combiner not only diffracts optical information in the direction of the driver's visual field, but also can form information at an arbitrary position without using an optical system such as a lens. Also, since the hologram has a narrow half-width of the diffraction spectrum,
It has a feature that a high-luminance display image can be obtained without impairing the foreground luminance, and is effective as a combiner of a display device.

FIG. 10 is a conceptual diagram showing an example of an automobile HUD. Light 3 emitted from the light source 6 and passing through the transmissive liquid crystal display element 5 via the lens system 4 and containing information to be displayed.
Is irradiated onto the hologram 2 provided on the windshield 7 of the vehicle body, diffracted, and visually recognized by the driver at the observation position 1.

Further, if the hologram has a magnification, the display images of the speed display 8 and the warning display 9 can be formed at a distance.
Furthermore, if necessary, a wavelength selection filter or a hologram for aberration correction can be used.

Since the hologram has a wavelength selection function,
The image of the desired color can be displayed. Usually, the color is often single, but multi-color display by holograms that have been subjected to multiple exposure can be performed, and the amount and quality of display information can be improved. For example,
By making the speed display 8 green and the warning display 9 red, the information can be more accurately transmitted to the driver.

Generally, a hologram uses coherent light typified by a laser to cause the object light, which is the reflected light of the object to be recorded, and the reference light (the laser light itself) to interfere with each other, and the interference fringes formed on some material. It was recorded. In the case of a hologram used as a combiner of a display device such as a HUD, the laser light itself is used as the object light without using the object.
By adjusting the positions (distance and angle) of the divergence points of the object light and the reference light, a combiner having desired characteristics (magnification, etc.) can be manufactured.

The hologram material generally used is made of an organic substance, and the interference fringe intensity distribution of laser light is recorded on the hologram photosensitive material by a photopolymerization reaction or a photocrosslinking reaction.
Although there are various recording modes, the interference fringes are recorded due to differences in the refractive index, the density, and the transmittance between the strong light portion and the weak light portion. Since such a structure is sized at the wavelength level of light, the light incident on the hologram is
In addition to being diffracted by the original function of the hologram, it may be randomly scattered. In particular, when there is fluctuation in material or there is a speckle pattern due to fluctuations in laser light or the exposure optical system, the light incident on the hologram is strongly scattered. Therefore, the hologram looks slightly clouded.

When the hologram is opaque in the display device using the hologram as described above, halation occurs or a halo that causes a vague glow around the display image occurs,
There is a problem that the display image is blurred and the visibility of the display is deteriorated. It is effective to reduce the amount of light incident on the hologram in order to avoid the halo or the like, but naturally the brightness of the display image also becomes dark, so that the visibility of the display also deteriorates.

On the other hand, since the hologram is generally made of an organic material as described above, many holograms have an absorption band in the ultraviolet region. The absorption band extends slightly to the visible light region (particularly in the blue region), so that the hologram looks slightly yellowish. Yellowness Y is a method to quantify the yellowness of materials.
There is a measurement of I. YI is defined by K7103 of Japanese Industrial Standards (hereinafter referred to as JIS), and is calculated from the transmission or reflection spectrum of the material (this JIS-
K7103 is also specified in ASTM E313. ). The larger the YI, the stronger the yellow color.

The driver of the vehicle drives while watching the outside world through the yellowish hologram, and also reads the information displayed there. Therefore, if the YI of the hologram material is high, the color tone of the foreground changes.

As described above, when the yellowish or cloudy hologram is provided on the windshield, the hologram portion is more noticeable than the portion without the hologram, and it can be seen both inside and outside the vehicle. There is a problem in that the appearance is poor and the design of the vehicle equipped with the hologram is impaired. This was a very important issue for passenger cars and the like, where the appearance is important.

The visible light transmittance of the windshield for automobiles (hereinafter referred to as T _v ) is 7 according to JIS-R3211.
It is regulated to be 0% or more. Generally, the windshield of an automobile is a laminated glass using colored glass.
_v is about 80 to 85%. On the other hand, not only the hologram but also the combiner has a function of reflecting light, so that T _v is lowered. In particular, when using a hologram on the combiner, in order to obtain a multicolor display of the display device, or to approximate to white reflection color of external light by the hologram, in the case of using the hologram exposing a plurality of wavelengths, the T _v The decrease is remarkable.

When such a holographic combiner is provided on the windshield, the effect of light absorption by the hologram material itself is added, and T _v is further reduced. In particular, a hologram material having a high YI absorbs a large amount of light, so that there is a problem that the JIS standard cannot be satisfied.

FIG. 11 shows a transmission spectrum of a hologram laminated body in which a conventional high YI hologram is enclosed in an automobile windshield to form a safety laminated glass. Reference numeral 10a is a transmission spectrum of a portion of the laminated glass in which the hologram is enclosed, and 20 is a transmission spectrum of the hologram material itself.

This laminated glass was constituted by using a bronze glass plate as an outer plate, a colorless transparent glass plate as an inner plate, and polyvinyl butyral (PVB) as an intermediate film. The hologram was enclosed between the inner plate and PVB via a barrier layer (polyvinyl alcohol: PVA) used to prevent the influence of the plasticizer contained in PVB.

This hologram was subjected to three-color exposure in order to bring the color tone of its reflected color close to white.
It has three diffraction peaks corresponding to around 540 and 640 nm. As indicated by 20 in FIG. 11, the transmittance of the hologram material itself is remarkably reduced in the short wavelength region. The YI of this material itself is calculated from the transmission spectrum 20 and YI =
It is 19.3, and its appearance has a yellowish color close to brown. Also, since this high YI lowers T _v , the total T _v is finally 70 when enclosed in laminated glass.
% In order to above, blue hologram, green, the diffraction efficiency of light corresponding to red had to respectively 30,40,30% (T _v of the laminated glass after encapsulation at this time is 70 It was 0.2%.).

In the above example, it was assumed that green was displayed as the display color when the HUD was constructed by using the hologram as a combiner. In this case, when the information light of 540 nm is irradiated toward the combiner, the diffraction efficiency of the hologram is suppressed to 40%, so that the brightness of the display image is small and the visibility of the display image is deteriorated. As described above, in order to satisfy the JIS standard regarding T _v , the brightness of the display image must be sacrificed.

[0019]

The present invention has been made to solve the above-mentioned drawbacks of the prior art, and provides a hologram laminate in which a hologram is laminated on a part of the entire surface of a transparent substrate. When the difference between the haze value (unit:%) of the hologram laminated body portion where the hologram is laminated and the haze value (unit:%) of the hologram laminated body portion where the hologram is not laminated is 1.0 or less. There is provided a hologram laminate characterized by being present.

The present invention also provides a hologram laminate in which holograms are laminated on a part of the entire surface of a transparent substrate, and the degree of yellowness of the hologram laminated portion in the hologram laminate and the hologram laminate The difference from the yellowness of the area where the hologram is not laminated is 10
Provided is a hologram laminated body characterized by the following.

Further provided is a hologram laminate in which a hologram is laminated on a part of the entire surface of a transparent substrate, wherein the hologram has a yellowness of 10 or less.

Furthermore, the present invention is a hologram laminate in which holograms are laminated on a part of the entire surface of a transparent substrate, and the degree of whiteness of the portion of the hologram laminate where the holograms are laminated and the hologram laminate. The difference from the whiteness of the part of the body where the holograms are not stacked is
Provided is a hologram laminated body characterized by being equal to or less than a prescribed value set in advance.

There are several means for quantifying the degree of white turbidity or whiteness of a material, and examples include quantification based on haze value (turbidity, haze) and whiteness. Among them, the most common method is quantification by haze value. The method for measuring the haze value is defined in JIS-R3212 and K7105, and is calculated by measuring the integrated intensity of scattered light having a scattering angle of 8 ° or more. The haze value H (unit:%) is calculated by the formulas (a), (b), (c).
Calculated by

[0024]

[Number 1] H (%) = 100 · T d / T t ··· (a) T d ( diffuse transmittance,%) = 100 · (T 1 T 4 -T 2 T 3) / T 1 2 · ·· (b) _{T t} (total light _{transmittance,%) = 100 · T 2} / T 1 ··· (c)

Here, T ₁ is the amount of incident light when there is no object to be measured, T ₂ is the total amount of light transmitted through when there is an object to be measured, T ₃
Is the amount of scattered light of the device when there is no object to be measured, and T ₄ is the amount of diffuse transmitted light when there is an object to be measured. The haze value indicates that the larger the value is, the more cloudy or white the material is, and is usually used to quantify the degree of scattering of transmitted light.

The recognition that the material is cloudy or white is
It largely depends on the sensory evaluation of the human being to observe. Although there are individual differences in the sensory evaluation, when the statistics of the sensory evaluation are taken, a correlation between the haze value and the sensory evaluation of appearance shown in Table 1 is found. It can be seen that when the haze value is more than 1.0, the material becomes strongly clouded and very worrisome.

[0027]

[Table 1]

The laminated glass for automobiles is JIS-R32.
Based on the abrasion resistance test specified in No. 12, JIS-R3211 is specified so that the haze value can be suppressed to 2% or less. Therefore, if the laminated glass has a haze value of 2% or less as a result of the abrasion resistance test, no unsightly appearance occurs in the observation of the entire surface of the laminated glass.

On the other hand, when the hologram is enclosed in the laminated glass as described above, the hologram enclosing portion is more likely to become cloudy than the other portions. Such a problem is solved by the hologram laminate of the present invention. That is, since the difference between the haze value of the portion where the hologram is arranged in this hologram laminate and the haze value of the portion where it is not arranged or the transparent substrate is 1.0 or less, white turbidity of the hologram laminate is not a concern. Can be level.

As described above, as a means for quantifying the white turbidity or whiteness of a material, a method of measuring a haze value is generally used. However, since the haze value is measured by measuring the integrated intensity of scattered light having a scattering angle of 8 ° or more, the scattered light is below the detection limit for a material such as a hologram having high transparency and a small scattering angle. Therefore, it may not be possible to measure a sufficient haze value. Therefore, the whiteness can be used as another means for quantifying the white turbidity and whiteness of a material. This whiteness is obtained by evaluating the spectrum of reflected scattered light or transmitted scattered light. Therefore, it is preferable as one means for quantifying the white turbidity and whiteness of the material because it has a correlation with the apparent degree of white turbidity.

The whiteness is the degree of representing the "whiteness" of an object, and the perfect diffuse reflection surface (ideal white) is taken as the whiteness of 100. It is defined in JIS-L1015, etc., calculated from the reflection spectrum, and the greater the whiteness, the stronger the degree of white turbidity (this JIS-L is.
1015 is also defined in ASTM E313. ).

The whiteness is represented by the following WI, W
b and W are illustrated. The whiteness WI defined by JIS-L1015 is represented by formula (d). In the formula (d), B and G are XY defined in JIS-Z8701.
It is a value calculated by B = 100Z / 118.225 and G = Y using Z. The whiteness Wb represents the whiteness by the blue reflectance and is represented by the formula (e) using XYZ defined in JIS-Z8701. Whiteness W
Is the whiteness W defined by JIS-L1015 and is represented by the formula (f). Standard light C defined in JIS-Z8701 is used as the light source used in the calculation of the expressions (d) to (f).

[0033]

[Number 2] WI = 4B-3G ··· (d ) Wb = B = 100Z / 118.225 ··· (e) W = 100- [(100-L) 2 + a 2 + b 2] 1/2 · .. (f)

These whitenesses are calculated from the reflection or transmission spectrum of the object to be measured. When the DUT is a hologram, a peak due to diffraction of the hologram may exist in the reflection or transmission spectrum. In this case, accurate whiteness of the material itself cannot be obtained. Therefore, accurate whiteness can be obtained by calculating the whiteness based on the spectrum corresponding to the reflection or transmission spectrum of the hologram material itself, which is obtained by excluding the diffraction peak and interpolating the baseline of the spectrum. To be

Here, the sensory evaluation rank regarding the degree of whiteness and appearance of the hologram material is defined. As shown in Table 2, this rank is, for example, a level at which turbidity is not noticed at rank 6 and a level at which turbidity is very noticeable at rank 1. And when the rank of cloudiness is 2 or less, the cloudiness of the material is strong and very worrisome, but when it is 3 or more, especially 4 or more, the level of cloudiness is almost unnoticeable. It should be noted that this ranking is also based on a qualitative evaluation based on statistics of human sensory evaluation of cloudiness and used as an index of cloudiness.

[0036]

[Table 2]

FIGS. 2A to 2C show the whitenesses WI, Wb of holograms produced by changing the composition and process conditions.
The correlation between W and the degree of cloudiness ranked above is shown.
To obtain this correlation, a sample was used in which a hologram material was laminated on a glass substrate and the entire surface was irradiated with incoherent light (UV lamp in this case). In this sample, the relationship between the whiteness and the rank of cloudiness can be expressed by comparing the portion having the hologram material and the glass substrate based on the rank of cloudiness. In this case, by taking the difference between the whiteness of the portion having the hologram material and the whiteness of the glass substrate on the horizontal axis, the correlation between the whiteness and the rank of cloudiness can be remarkably expressed. Since the hologram is exposed with incoherent light, there is no diffraction peak due to the hologram, and the degree of whiteness of the material itself can be known.

As can be seen from the figure, the whiteness and the white turbidity are correlated in any case, and the whiteness increases as the white turbidity increases (the white turbidity rank decreases). The prescribed value of whiteness can be determined in advance from the correlation between the white turbidity rank and whiteness. The specified value is appropriately determined according to the application of the hologram laminate. In order to make the white turbidity less noticeable, or not so much at all, it is preferable to set the specified values to 3 for the whiteness WI, 1.5 for Wb, and 5 for W.

In the hologram laminate according to the present invention, the whiteness of the portion where the hologram is arranged,
The difference from the whiteness of the non-disposed portion or the transparent substrate is set to the above specified value or less. Therefore, the rank of white turbidity becomes 3 or more, and the level of white turbidity can be reduced to a level where it does not matter, and a hologram laminate having an appearance superior to that of the related art can be obtained.

The whiteness is represented by the above WI,
There are various means other than Wb and W. However, all of them are calculated from the spectrum of the measured object. Therefore, even if the expression of whiteness is different, it can be easily converted into WI, Wb, and W based on the above calculation formula. Then, even if they are expressed differently, it is possible to know whether or not the whiteness is equal to or less than the specified value by reheating the whiteness shown in the present invention.

There are several means to quantify the degree of yellowness of a material. For example, the yellowness YI defined in JIS-K7103 mentioned above can be mentioned. Yellowness YI is J
It is represented by the formula (g) using XYZ defined in IS-Z8701. As the light source used for the calculation of the formula (g), the standard light C defined in JIS-Z8701 is used.

[0042]

## EQU00003 ## YI = 100. (1.28X-1.06Z) / Y ... (g)

Table 3 shows the results of the sensory evaluation on the degree of yellowishness, as with the degree of white turbidity. There is a correlation between YI which is quantitative data and the sensory evaluation result which is statistics of qualitative data. And, when YI is 10 or more, the yellowishness of the material is strong and very worrisome, but when it is less than 10 and particularly less than 5, the yellowishness is at a level where it is hardly noticeable.

[0044]

[Table 3]

Next, FIG. 3 shows an example of the relationship between YI and T _v of the hologram material itself. It can be seen that T _v decreases as YI increases. As described above, since the hologram has a function of reflecting light and lowers T _v , the conventional HUD using a hologram with a high YI as a combiner.
Then, a hologram with high diffraction efficiency could not be used.
Therefore, by using the present invention, it is possible to use a hologram having a higher efficiency as compared with the conventional one while ensuring a T _v value that satisfies the standard as a laminated glass for automobiles, and a HU having a high display brightness.
D can be realized.

As described above, the hologram laminate of the present invention has the haze value, whiteness, and yellowness of the portion where the hologram is arranged in the hologram laminate and the haze value, whiteness, and yellowness YI of other portions. Is set to be small, it is possible to obtain a hologram laminate having a good appearance. In particular, by reducing the YI of the hologram itself,
HUD with high visibility and less decrease in visible light transmittance T _v
Is obtained.

[0047]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view (a) and a schematic front view (b) of an essential part showing an example of the basic configuration of a hologram laminate according to the present invention. The hologram 14 is
Two glass plates 11 and 11 'are enclosed in laminated glass with an intermediate film 12 made of PVB or the like interposed therebetween. In this example, the hologram 14 is laminated between the glass plate 11 and the intermediate film 12 with the barrier layer 13 disposed on the intermediate film side. The barrier layer 13 is made of, for example, PVA or the like, and prevents the plasticizer contained in the interlayer film normally made of PVB from affecting the hologram. Further, in this example, the hologram is enclosed in a part of the entire surface of the laminated glass.

[Example of Hologram] Next, four holograms in the present invention will be illustrated.

(Hologram A) As shown in FIG. 1, the hologram A has a laser exposed portion 14a and an unexposed portion 14b.
And are exposed so that and are formed. The unexposed portion 14b is formed on the periphery of the hologram 14 itself at a portion of about 1 cm. The exposure is performed by three-color exposure in order to bring the appearance (color tone of reflection color) of the hologram close to white. Specifically, Ar having a wavelength of 476 nm
A laser, a dye laser using a rhodamine 110 dye having a wavelength of 547 nm and a Kr laser having a wavelength of 647 nm are coaxially overlapped and directed toward the hologram photosensitive material from both sides of the hologram photosensitive material at incident angles of 45 ° and 60 °, respectively. It was irradiated and exposed to light to produce a volume phase reflection hologram.

The hologram A thus produced has the characteristics shown in Table 4 in which the spectrum of the direct transmitted light of the hologram when light is incident on the hologram at an incident angle of 45 ° (peak center wavelength: λ, peak Full width at half maximum: Δλ, transmittance at central wavelength of peak: τ).

From the above transmittance τ, the (reflection) diffraction efficiency η of hologram A can be known. The diffraction efficiency represents how much the light incident on the hologram is diffracted. Therefore,
The diffraction efficiency η was determined from the ratio of the above transmittance τ to the baseline of the transmission spectrum. The reason for "about" is that the actual diffraction efficiency is slightly smaller than the value obtained from the measurement of the transmission spectrum (due to the absorption and scattering of light by the hologram).

[0052]

[Table 4]

An acrylic photopolymer was used as the photosensitive material of the hologram A. The size of this photosensitive material was 150 mm in width × 150 mm in length × 10 μm in thickness.

(Hologram B) Hologram B is the one in which the entire surface of the photosensitive material is exposed without the unexposed portion shown in FIG. The exposure was carried out using Rhodamine 11 with a wavelength of 555 nm.
A volume laser reflection hologram was produced by irradiating a hologram photosensitive material with a dye laser using 0 dye at incident angles of 45 ° and 60 ° to perform exposure.

The hologram B produced in this manner has the characteristics shown in Table 5 in which the spectrum of the directly transmitted light of the hologram when the light is incident on the hologram at an incident angle of 45 ° (the center wavelength of the peak: λ, Full width at half maximum: Δλ, transmittance at central wavelength of peak: τ). The (reflection) diffraction efficiency η of the hologram B can be known from the transmittance τ.

[0056]

[Table 5]

As the photosensitive material for hologram B, an acrylic photopolymer was used. The size of this photosensitive material was 150 mm in width × 150 mm in length × 20 μm in thickness.

(Hologram C) The hologram C is produced so that the hologram photosensitive material is not exposed to laser and a diffraction grating is not formed. That is, the hologram was produced without using coherent light in the usual hologram production process. In the preparation, the entire surface of the hologram photosensitive material was irradiated with ultraviolet rays from one surface side of the hologram photosensitive material perpendicularly to the surface, and only UV curing and heat treatment were performed. Hologram C
An acrylic photopolymer was used as the photosensitive material. The size of this photosensitive material is 150 mm wide x 150 m long
m × thickness 20 μm.

With this hologram C, since there is no diffraction peak, the haze value, whiteness, and
Yellowness can be easily measured.

(Hologram D) As shown in FIG. 1, the hologram D has a laser-exposed portion 14a and an unexposed portion 14b.
And are exposed so that and are formed. The unexposed portion 14b is formed on the periphery of the hologram 14 itself at a portion of about 1 cm. The exposure is two-color exposure for multi-color display of red, green and mixed colors (yellow, orange). Specifically, the wavelength is 647.1.
beam of two wavelengths of a Kr laser of 1 nm and a dye laser using a rhodamine 6G dye having a wavelength of 576 nm are coaxially overlapped, and the incident angle is 51.3 from both sides of the hologram photosensitive material.
The exposure was carried out at 3 ° and 30.6 ° to produce a volume phase reflection hologram.

This hologram D has diffraction peaks at 612 nm and 545 nm in the spectrum of light that is incident at an incident angle of 60 ° and is diffracted at a reflection diffraction angle of 38 °.
These wavelengths correspond to the wavelengths of the red and green light emitted by the hot cathode tube. Thus, when a liquid crystal display element is used in the display device, the hot cathode tube is used as a backlight of the liquid crystal display element to enable multicolor display by the hologram D.

The hologram D thus produced has the characteristics shown in Table 6 in which the spectrum of the transmitted light of the hologram when light is incident on the hologram at an incident angle of 60 ° (center wavelength of peak: λ, half of peak). Value range: Δλ, transmittance at the center wavelength of the peak: τ). The (reflection) diffraction efficiency η of the hologram D can be known from the transmittance τ.

[0063]

[Table 6]

An acrylic photopolymer was used as the photosensitive material for the hologram D. The size of this photosensitive material was 150 mm in width × 100 mm in length × 20 μm in thickness.

(Hologram E) As shown in FIG. 1, the hologram E includes a laser-exposed portion 14a and an unexposed portion 14b.
And are exposed so that and are formed. The unexposed portion 14b is formed on the periphery of the hologram 14 itself at a portion of about 1 cm. The exposure was performed in the same manner as in the production of hologram D. Specifically, two wavelength light beams of a Kr laser having a wavelength of 647.1 nm and a dye laser using a rhodamine 6G dye having a wavelength of 576 nm are coaxially overlapped, and the incident angles of 51.3 ° and 3
Exposure was performed at 0.6 ° to produce a volume phase reflection hologram.

This hologram E has diffraction peaks at 612 nm and 545 nm in the spectrum of light that is incident at an incident angle of 60 ° and is diffracted at a reflection diffraction angle of 38 °.
These wavelengths correspond to the wavelengths of the red and green light emitted by the hot cathode tube. Thus, when a liquid crystal display element is used in the display device, a hot cathode tube is used as a backlight of the liquid crystal display element, thereby enabling multicolor display by the hologram E.

The hologram E thus produced has the characteristics shown in Table 7 in which the spectrum of the transmitted light of the hologram when light is incident on the hologram at an incident angle of 60 ° (center wavelength of peak: λ, half of peak). Value range: Δλ, transmittance at the center wavelength of the peak: τ). The (reflection) diffraction efficiency η of the hologram D can be known from the transmittance τ.

[0068]

[Table 7]

An acrylic photopolymer was used as the photosensitive material for the hologram E. The size of this photosensitive material was 150 mm in width × 100 mm in length × 20 μm in thickness.

[Example of Hologram Laminate] Next, an example in which a hologram laminate is constructed by using the holograms A to E will be shown.

Example 1 In the laminated glass shown in FIG. 1, the glass plate 11 is a colorless transparent glass plate, and the glass plate 1
A bronze glass plate was used for 1 ', and a hologram A was used for hologram 14. As described above, the thickness of hologram A is 1
0 μm. By reducing the thickness of the hologram in this way, the yellowness, whiteness, and
The haze value could be reduced.

On the other hand, when the thickness of the hologram is reduced, its diffraction efficiency is lowered. Therefore, in this example, a hologram photosensitive material having a large refractive index modulation amount is used. This is because the diffraction efficiency of the volume phase hologram is
This is because it is determined by the refractive index modulation amount and the material thickness. And by using a material with a large amount of refractive index modulation,
The yellowness, whiteness, and haze of the hologram material itself could be reduced without reducing the diffraction efficiency of the hologram. The refractive index modulation amount of the photosensitive material specifically used for hologram A was 0.05.

The refractive index modulation amount is one measure showing the characteristics of the photosensitive material when the interference fringe intensity distribution of the laser light recorded on the hologram photosensitive material is recorded by the difference in the refractive index. Since the interference fringe intensity distribution has a spatially sinusoidal distribution, the refractive index distribution recorded is also ideally a sinusoidal distribution. The refractive index modulation amount corresponds to half the difference between the maximum and minimum values of the refractive index in this sinusoidal refractive index distribution. That is, it is the amplitude of the refractive index that changes in a sinusoidal manner.

In this example, a hologram photosensitive material containing a base polymer having a low refractive index and a photopolymerizable monomer having a high refractive index as main components was used. The monomer is polymerized mainly in a place where the intensity of laser light interference fringes is high. Further, the monomer in the place where the intensity of the laser light interference fringes is small diffuses and moves to the place where the intensity is large, so that the refractive index distribution is formed.
Therefore, the refractive index modulation amount depends on the difference in the refractive index between the monomer and the base polymer. In this example, the combination of the monomer having a large difference and the base polymer was optimized to obtain a hologram having a larger refractive index modulation amount than the conventional one.

Next, the values of yellowness, whiteness, and haze of the hologram A and the laminated glass using the hologram A will be described. An unexposed portion 14b exists on the periphery of hologram A about 1 cm. Therefore, it is possible to easily measure the values of yellowness, whiteness, and haze of the portion of the laminated glass in which the hologram is enclosed, without being affected by the diffraction characteristics of the hologram.

(A) Haze value From the portion 21 in FIG. 1, the haze value of the portion where the hologram is arranged in the hologram laminated body of the laminated glass structure having the configuration shown in FIG. 1 is measured. From the portion 23 in FIG. 1, the haze value of the portion where the hologram is not arranged in the hologram laminate or the haze value of the transparent substrate (in this case, the laminated glass itself) is measured.

The haze value is calculated by the ratio of the scattering transmittance to the total transmittance of light (the above-mentioned formula (a)). The measurement of the amount of light in formulas (b) and (c) was performed with a direct reading haze computer (HGM-3DP manufactured by Suga Test Instruments Co., Ltd.). Light from a halogen lamp is evenly applied to the surface of the DUT, and the light that has passed through the DUT excluding the light that enters the device at an angle of 8 ° or less from the axis perpendicular to the DUT surface is integrated. It was diffusely reflected on the inner surface of the sphere and detected by a spectral sensor through a luminosity filter. The spectroscopic sensor has a light receiving sensitivity in the wavelength range of 450 to 700 nm.

As a result, the haze value of the non-encapsulated portion 23 of the laminated glass was 0.10. The haze value of the hologram enclosing portion 21 (unexposed portion) in the laminated glass was 0.55. The difference between the two is 0.45 (= 0.55-0.10), which is a specified value of 1.0 or less. Moreover, since it was 0.5 or less, the appearance of the laminated glass was very excellent.

In this way, the difference between the haze value of the part where the hologram of the laminated glass is arranged and the haze value of the part where it is not arranged is set to 1.0 or less, so that the part where the hologram is enclosed is the other part. A laminated glass with a good appearance was obtained, which was less noticeable than the laminated glass.

(B) Whiteness FIG. 4 shows the reflection spectrum of each part of the laminated glass in this example. Reference numeral 30 denotes a reflection spectrum of an unenclosed portion of the hologram (23 portion of FIG. 1), 31 denotes a reflection spectrum of an unexposed portion of the hologram (21 portion of FIG. 1), and 32 denotes an exposed portion of the hologram (of FIG. 1). 22 part).

The reflection spectrum was measured with an integrating sphere type spectrophotometer (CM-2002, manufactured by Minolta Co., Ltd.). That is, the light of the flash xenon lamp is diffused and reflected on the inner surface of the integrating sphere and is uniformly irradiated on the surface of the DUT, and the reflected light of the object forms an angle of 8 ° from the axis perpendicular to the DUT surface. Detect with a spectroscopic sensor. The spectroscopic sensor is composed of an interference filter array and a silicon photodiode array, and measures a reflection spectrum at intervals of 10 nm in a wavelength range of 400 to 700 nm.

The measurement of the reflection spectrum is not limited to the above-mentioned device, but may be, for example, a spectrocolorimeter (SE- manufactured by Nippon Denshoku Industries Co., Ltd.).
2000) and the like. This is not an integrating sphere type, but a 0 ° -45 ° optical system (JIS
-Z8722)). That is,
The light of the halogen lamp is applied vertically to the surface of the object to be measured, and the light reflected by the surface of the object to be measured at an angle of 45 ° is detected by the spectroscopic sensor. The spectroscopic sensor consists of a rotating disk type interference filter array and a photodiode,
The reflection spectrum is measured at 10 nm intervals in the wavelength range of 380 to 780 nm.

Since this measuring apparatus is a 0 ° -45 ° optical system, the whiteness is more accurate than that of the integrating sphere type measuring apparatus except for the hologram which diffracts incident light having an incident angle of 0 ° to 45 °. can get. This is because no diffraction peak appears in the reflection spectrum even if the reflection spectrum of the exposed portion of the hologram is measured. Further, it is possible to measure with an ordinary spectroscope instead of the spectrocolorimeter.

In this example, the whiteness was calculated from the above calculation formula based on the above reflection spectrum. WI, W below
b and W have different calculation methods.

(1) Whiteness WI WI was calculated based on the equation (d). The WI of the non-encapsulated portion 23 of the laminated glass, that is, the laminated glass itself was 0.36. The WI of the hologram enclosing portion 21 (unexposed portion) in the laminated glass was 1.56. The difference is 1.2 (=
The value was 1.56 to 0.36) and the specified value was 3 or less, and the appearance of the laminated glass was excellent.

(2) Whiteness Wb Wb was calculated based on the equation (e). The Wb of the non-encapsulated portion 23 of the laminated glass was 1.55. The Wb of the hologram enclosing portion 21 (unexposed portion) in the laminated glass was 1.88. The difference was 0.33 (= 1.88-1.55), which was a specified value of 1.5 or less, and the appearance of the laminated glass was excellent.

(3) Whiteness W W was calculated based on the equation (f). W of the non-encapsulated portion 23 of the laminated glass is 13.
53. The W of the enclosed portion 21 (unexposed portion) of the hologram in the laminated glass was 14.05. The difference was 0.52 (= 14.05-13.53), which was a specified value of 5 or less, and the appearance of the laminated glass was excellent.

(C) Yellowness index FIG. 5 shows a transmission spectrum of each portion of the laminated glass in this example. The transmission spectrum is obtained by measuring the directly transmitted light of the light incident from the position perpendicular to the hologram surface, that is, the light transmitted perpendicularly to the hologram surface. 20
Is a transmission spectrum of a portion of the hologram which is not enclosed (23 in FIG. 1), 10b is an unexposed portion of the hologram (21 of FIG. 1), and 10a is an exposed portion of the hologram (22 of FIG. 1). (Part) is a transmission spectrum.

From this transmission spectrum, YI was calculated based on the formula (g). The YI of the non-encapsulated portion 23 of the hologram in the laminated glass was 5.1.
In addition, the hologram enclosing portion 21 in the laminated glass
The YI of (unexposed portion) was 11.5. The difference was 6.4 (= 11.5-5.1), which was a specified value of 10 or less, and the appearance of the laminated glass was excellent.

Although the above measurement was performed using the transmission spectrum, it can be similarly calculated using the reflection spectrum.

(Embodiment 2) As Embodiment 2, a case will be described in which a diffraction peak exists on the entire surface of the hologram and there is no laser unexposed portion such as 14b in FIG.

In this example, a laminated glass having the same structure as in Example 1 in which a hologram was enclosed in laminated glass was used as the hologram laminate. However, the hologram used is hologram B. In this case, the laminated glass in this example has the same structure as the laminated glass shown in FIG.
Bronze glass plate, hologram 14 hologram B
Is used, and corresponds to the one without the portion 14b shown in the figure.

For the hologram B, as the component substance of the light-sensitive material, a substance having low light absorption in the blue region and high compatibility was selected. Furthermore, the molecular weight and degree of polymerization of these components were optimized, and the values of yellowness, whiteness, and haze of the hologram itself could be reduced.

Next, the values of yellowness, whiteness and haze of the hologram B and the laminated glass using the hologram B will be described. Since the hologram B has no unexposed portion like the hologram A, the values of yellowness, whiteness, and haze value cannot be simply obtained as in the first embodiment. In such a case, various corrections are required.

(A) Haze Value In Example 1, since the hologram had an unexposed portion,
It suffices to measure the amount of transmitted light in the unexposed area. In this example, since there is no unexposed portion in the hologram, it is necessary to obtain the diffraction efficiency from the measurement of the spectrum and make the correction. The spectral diffraction spectrum for the wavelength λ of the hologram is T
(Λ) and the spectral spectrum of the standard light source A is S
(Λ) and the color matching function is {y bar} (λ), the diffraction efficiency η of the hologram is calculated from the equation (h).

[0096]

(Equation 4)

Where S (λ) and {y bar} (λ)
May use a value defined by JIS-Z8701. Using the above η, the haze value of the hologram is calculated by the formula (i),
Calculated by (j).

[0098]

[Equation 5] Haze value H (%) = 100 · T _d ′ / T _t ... (i) T _d ′ (%) = 100 · (T ₁ T ₄ −T ₂ T ₃ −ηT ₁ T ₂ ). / T ₁ ² ... (j)

The haze value of the hologram enclosing portion (exposed portion: corresponding to 22 in FIG. 1) on the laminated glass before correction is H = 2.5 (T _d = 1.95, T _t = 7).
6.8, T ₁ = 100, T ₂ = 76.8, T ₃ = 0.
2, T ₄ = 2.1). However, although hologram B is a reflection type hologram, diffraction of about 2.0% was caused by a transmission type unnecessary diffraction grating. This measuring method is the same as the method shown in Example 1.

Therefore, in order to correct the apparent increase (η = 0.02) due to this diffraction, calculation was performed by the formula (h). As a result, the haze value was 0.53 (T _d '= 0.41, T
_t = 76.8).

On the other hand, the haze value of the laminated glass itself used in this example (the portion where no hologram is arranged: corresponding to 23 in FIG. 1) was 0.10. The difference between the two is 0.43
(0.53-0.10 = 0.43), and the specified value is 1.
0 or less. Thus, the haze value of the exposed portion of the hologram can be calculated by obtaining and correcting the diffraction efficiency of the hologram, and a laminate having a haze value difference of 1.0 or less was obtained.

(B) Whiteness The whiteness is also calculated as W, because there is a diffraction peak due to the hologram when calculated from the reflection spectrum for the exposed portion.
I = -1.74, which is a negative value, and accurate whiteness cannot be obtained. Therefore, the whiteness was calculated based on the reflection spectrum obtained by excluding the two diffraction peaks and interpolating the baseline of the spectrum. The reflection spectrum is obtained by the same method as shown in Example 1.

(1) Whiteness WI When the WI was calculated based on the equation (d) by the above method, WI = 1.85. On the other hand, the laminated glass itself used in this example (the portion where the hologram is not arranged: FIG. 1)
Corresponding to 23) was 0.14. The difference between the two was 1.71 (= 1.85-0.146), which was a specified value of 3 or less. Thus, the whiteness of the exposed portion of the hologram can be calculated by excluding the diffraction peak of the hologram, and a laminate having a difference in whiteness WI of 3 or less was obtained.

(2) Whiteness Wb When Wb is calculated based on the equation (e) by the above method, Wb = 0.75. On the other hand, the laminated glass itself used in this example (the portion where the hologram is not arranged: FIG. 1)
Corresponding to 23) was 0.11. The difference between the two is 0.64 (= 0.75-0.11), which is the specified value 3.
It was below. Thus, the whiteness of the exposed portion of the hologram can be calculated by excluding the diffraction peak of the hologram, and a laminate having a difference in whiteness WI of 1.5 or less was obtained.

(3) Whiteness W When W was calculated based on the equation (f) by the above method, W = 6.17. On the other hand, the whiteness of the laminated glass itself used in this example (portion where hologram is not arranged: corresponding to 23 in FIG. 1) was 3.09. The difference between the two was 3.08 (= 6.17-3.09), which was less than or equal to the specified value 5. Thus, the whiteness of the exposed portion of the hologram can be calculated by excluding the diffraction peak of the hologram, and a laminate having a difference in whiteness WI of 5 or less was obtained.

(C) Yellowness The yellowness is also calculated from the transmission spectrum of the exposed part,
Accurate Y because there is a diffraction peak due to the hologram
The value of I cannot be calculated. Therefore, as in the case of the whiteness measurement, the yellowness degree is determined based on the JIS-K7103 standard based on the transmission spectrum due to the influence of the hologram material itself obtained by excluding the diffraction peak and interpolating the spectrum baseline. Was calculated. The transmission spectrum is obtained by the same method as shown in Example 1.

From this transmission spectrum, YI was calculated based on the formula (g). The YI of the non-encapsulated portion 23 of the hologram in the laminated glass was 5.3.
In addition, the hologram enclosing portion 22 in the laminated glass
The YI of (exposed portion) was 14.4. The difference is 9.
1 (= 14.4-5.3), which was a specified value of 10 or less, and the appearance of the laminated glass was excellent.

(Embodiment 3) As Embodiment 3, there is no diffraction peak on the entire hologram surface, that is, 14a in FIG.
A case will be described in which there is no such laser exposure part.

In this example, a laminated glass having the same structure as in Example 1 in which a hologram was enclosed in laminated glass was used as the hologram laminate. However, the hologram used is hologram C. In this case, the laminated glass in this example is the laminated glass having the structure shown in FIG.
The glass plate 11 is a colorless transparent glass plate, the glass plate 11 'is a bronze glass plate, and the hologram C is a hologram C, which corresponds to the one without the portion 14a shown in the figure.

As with hologram B, hologram C was selected as a component material of the photosensitive material thereof, which has low light absorption in the blue region and high compatibility. Furthermore, the molecular weight and degree of polymerization of these components were optimized, and the values of yellowness, whiteness, and haze of the hologram itself could be reduced.

Next, the values of yellowness, whiteness, and haze of the hologram C and the laminated glass using the hologram C will be described. Since the hologram C has no diffraction grating, the values of yellowness, whiteness, and haze can be easily measured.

(A) Haze Value The haze value was measured in the same manner as in Example 1. In this case, since the hologram has no diffraction grating, it is not necessary to select and measure the unexposed portion of the hologram as in the first embodiment. In this way, the haze value is calculated from the ratio of the scattered transmittance to the total light transmittance by the above formula.

The haze value of the part where the hologram was not enclosed in the laminated glass was 0.15. Further, the haze value of the enclosed portion (unexposed portion) of the hologram in the laminated glass was 0.45. The difference between the two is 0.30 (=
0.45-0.15 = 0.30), which is a specified value of 1.0 or less. Moreover, since it was 0.5 or less, the appearance of the laminated glass was very excellent.

Thus, by setting the difference between the haze value of the portion of the laminated glass where the hologram is arranged and the haze value of the portion where it is not arranged to be 1.0 or less, the portion in which the hologram is enclosed is the other portion. A laminated glass with a good appearance was obtained, which was less noticeable than the laminated glass.

(B) Whiteness The whiteness value was measured in the same manner as in Example 1. In this case, since the hologram has no diffraction grating, it is not necessary to select and measure the unexposed portion of the hologram as in the first embodiment.

(1) Whiteness WI WI was calculated based on the equation (d). The WI of the non-encapsulated hologram in the laminated glass, that is, the laminated glass itself was 0.14. The WI of the hologram enclosing portion in the laminated glass is 1.69.
Met. The difference is 1.55 (= 1.69-0.14)
The specified value was 3 or less, and the appearance of the laminated glass was excellent.

(2) Whiteness Wb Wb was calculated based on the equation (e). Wb of the portion of the laminated glass where the hologram is not enclosed is 0.1.
It was one. The Wb of the enclosed portion of the hologram in the laminated glass was 0.68. The difference is 0.57
(= 0.68-0.11), the specified value is 1.5 or less,
The appearance of the laminated glass was excellent.

(3) Whiteness W W was calculated based on the equation (f). The W of the unencapsulated hologram in the laminated glass was 3.09. The W of the enclosed portion of the hologram in the laminated glass was 5.83. The difference is 2.74 (=
It was 5.83-3.09) and the specified value was 5 or less, and the appearance of the laminated glass was excellent.

(C) Yellowness The transmission spectrum was measured by the same method as in Example 1, and the value of yellowness was obtained by the same method as in Example 1. In this case, since the hologram has no diffraction grating,
It is not necessary to select and measure the unexposed portion of the hologram as in the above.

YI was calculated from the transmission spectrum based on the formula (g). The YI of the unencapsulated portion of the laminated glass was 5.3. Also, the YI of the enclosed portion of the hologram in the laminated glass is 1
4.0. The difference is 8.7 (= 14.0-5.
In 3), the specified value was 10 or less, and the appearance of the laminated glass was excellent.

(Embodiment 4) As Embodiment 4, the configuration of the hologram laminate in Embodiment 1 shown in FIG. 1, the glass plate 11 'is a green glass plate, and the hologram 14 is an unexposed portion 14b at the peripheral portion. An example is the same except that the hologram D having is used.

For the hologram D, similarly to the holograms B and C, as the component substance of the photosensitive material, a substance having a small light absorption in the blue region and a high compatibility was selected. Furthermore, the molecular weight and degree of polymerization of these components were optimized, and the values of yellowness, whiteness, and haze of the hologram itself could be reduced.

Next, the values of yellowness, whiteness, and haze of the hologram D and the laminated glass using the hologram D will be described. In this case, since the hologram D has an unexposed portion like the hologram A, the values of yellowness, whiteness, and haze can be easily measured by the same method as in Example 1.

(A) Haze Value The haze value of the portion of the laminated glass where the hologram was not enclosed was 0.13. Further, the haze value of the enclosed portion (unexposed portion) of the hologram in the laminated glass is 0.4.
It was 3. The difference between the two is 0.30 (= 0.43-0.
In 13), the specified value is 1.0 or less. Moreover, since it was 0.5 or less, the appearance of the laminated glass was very excellent.

Thus, the difference between the haze value of the part where the hologram of the laminated glass is arranged and the haze value of the part where it is not arranged is set to 1.0 or less, so that the part where the hologram is enclosed is the other part. A laminated glass with a good appearance was obtained, which was less noticeable than the laminated glass.

(B) Whiteness FIG. 6 shows the reflection spectrum of each part of the laminated glass in this example. This spectrum was measured using a spectrophotometer (SE-2000, manufactured by Nippon Denshoku Industries Co., Ltd.).

(1) Whiteness WI WI was calculated based on the equation (d). The WI of the non-encapsulated portion of the laminated glass, that is, the laminated glass itself was 0.21. The WI of the enclosed portion of the hologram in the laminated glass is 1.23.
Met. The difference is 1.02 (= 1.23-0.21)
The specified value was 3 or less, and the appearance of the laminated glass was excellent.

(2) Whiteness Wb Wb was calculated based on the equation (e). Wb of the portion of the laminated glass where the hologram is not enclosed is 0.1.
It was 3. Further, Wb of the enclosed portion of the hologram in the laminated glass was 0.48. The difference is 0.35
(= 0.48-0.13), the specified value is 1.5 or less,
The appearance of the laminated glass was excellent.

(3) Whiteness W W was calculated based on the equation (f). The W of the unencapsulated portion of the laminated glass was 3.20. The W of the hologram enclosing portion in the laminated glass was 4.78. The difference is 1.58 (=
4.78-3.20), and the specified value was 5 or less, and the appearance of the laminated glass was excellent.

(C) Yellowness The transmission spectrum was measured by the same method as in Example 1, and the value of yellowness was obtained by the same method as in Example 1. FIG. 7 shows a transmission spectrum of each part of the laminated glass in this example.

YI was calculated from the transmission spectrum based on the formula (g). The YI of the non-encapsulated portion of the hologram in the laminated glass was -0.3. Also,
The YI of the enclosed portion of the hologram in the laminated glass was 5.3. The difference is 5.6 (= 5.3-(-0.
In 3)), the specified value was 10 or less, and the appearance of the laminated glass was excellent.

(Example 5) As Example 5, the structure of the hologram laminate in Example 1 shown in FIG. 1 and the green glass plates on the glass plates 11 and 11 'were used.
4 shows the same example except that the hologram E having the unexposed portion 14b at the peripheral portion is used.

For the hologram E, as well as the holograms B, C and D, as the component substance of the photosensitive material, one having a small light absorption in the blue region and a high compatibility was selected. further,
By optimizing the molecular weight and degree of polymerization of these components, the yellowness, whiteness, and haze of the hologram itself could be reduced.

Next, the values of yellowness, whiteness, and haze of the hologram E and the laminated glass using the hologram E will be described. In this case, since the hologram E has an unexposed portion like the hologram A, the values of yellowness, whiteness, and haze can be easily measured by the same method as in Example 1.

(A) Haze Value The haze value of the portion of the laminated glass where the hologram was not enclosed was 0.40. Further, the haze value of the enclosed portion (unexposed portion) of the hologram in the laminated glass is 0.4.
It was 7. The difference between the two is 0.07 (= 0.47-0.
40), the specified value is 1.0 or less. Moreover, since it was 0.5 or less, the appearance of the laminated glass was very excellent.

Thus, by setting the difference between the haze value of the portion of the laminated glass where the hologram is arranged and the haze value of the portion where it is not arranged to be 1.0 or less, the portion in which the hologram is enclosed becomes the other portion. A laminated glass with a good appearance was obtained, which was less noticeable than the laminated glass.

(B) Whiteness FIG. 8 shows the reflection spectrum of each part of the laminated glass in this example. This spectrum was measured using a spectrophotometer (SE-2000, manufactured by Nippon Denshoku Industries Co., Ltd.).

(1) Whiteness WI WI was calculated based on the equation (d). The WI of the non-encapsulated portion of the laminated glass, that is, the laminated glass itself was 0.23. The WI of the enclosed portion of the hologram in the laminated glass is 1.04.
Met. The difference is 0.81 (= 1.04-0.23)
The specified value was 3 or less, and the appearance of the laminated glass was excellent.

(2) Whiteness Wb Wb was calculated based on the equation (e). Wb of the portion of the laminated glass where the hologram is not enclosed is 0.1.
It was 4. In addition, Wb of the enclosed portion of the hologram in the laminated glass was 0.43. The difference is 0.29
(= 0.43-0.14), which is less than or equal to the specified value of 1.5,
The appearance of the laminated glass was excellent.

(3) Whiteness W W was calculated based on the equation (f). The W of the unencapsulated portion of the laminated glass was 3.29. The W of the enclosed portion of the hologram in the laminated glass was 4.68. The difference is 1.39 (=
4.68-3.29), and the specified value was 5 or less, and the appearance of the laminated glass was excellent.

(C) Yellowness The transmission spectrum was measured by the same method as in Example 1 and the value of yellowness was obtained by the same method as in Example 1. FIG. 9 shows a transmission spectrum of each part of the laminated glass in this example.

From the transmission spectrum, JIS-K7103
YI was calculated based on the above-mentioned formula (g) defined in the above.
The YI of the unencapsulated portion of the laminated glass was -1.9. The YI of the enclosed portion of the hologram in the laminated glass was 3.6. The difference is 5.5 (= 3.6-(-1.9)) and the specified value is 10
Below, the appearance of the laminated glass was excellent.

Example 6 The YI of the material itself of the hologram D in Example 4 was calculated from the transmission spectrum before enclosing the hologram in laminated glass, and the result was YI =
5.3. Its appearance was slightly yellowish, but was barely noticeable.

This hologram was enclosed in laminated glass and the visible light transmittance T _v was measured. The part of the laminated glass in which the hologram is not enclosed has a _Tv of 85.
5. The T _v of the portion of the laminated glass in which the hologram was enclosed was 85.4%. The diffraction efficiency of the hologram D at this time is 75%, and the total T _v is finally 70 in a state of being enclosed in a laminated glass using a colored glass plate while ensuring the diffraction efficiency with which the display image can be visually recognized well. %
That's it.

[Embodiment] As a method of obtaining a hologram having a low haze value, as in the above holograms A to E, the hologram itself is made thin, or in order to reduce scattering centers which contribute to white turbidity, a crystal is used. It is possible to use a material that is hard to be converted or a material that has high solubility. It is also effective to remove minute dust contained in the material.

In addition, minute inhomogeneity of the hologram material may cause light scattering and increase white turbidity. Such inhomogeneity can be improved by increasing the compatibility of the component substances in the multi-component hologram material. Further, such inhomogeneity is related to the degree of polymerization of the photopolymer and its variation, and depends on various conditions such as a laser exposure process and subsequent light irradiation, heat treatment, development treatment, and drying treatment. Therefore, by optimizing the process conditions, white turbidity can be improved and a hologram with a low haze value can be obtained.

As a method of obtaining a hologram with low whiteness, the hologram itself may be thinned, or a material that is difficult to crystallize may be used in order to reduce scattering centers that contribute to white turbidity, as in the above holograms A to D. It is possible to use a material having high solubility. It is also effective to remove minute dust contained in the material.

In addition, minute inhomogeneity of the hologram material may cause light scattering and increase white turbidity. Such inhomogeneity can be improved by increasing the compatibility of the component substances in the multi-component hologram material. Further, such inhomogeneity is related to the degree of polymerization of the photopolymer and its variation, and depends on various conditions such as a laser exposure process and subsequent light irradiation, heat treatment, development treatment, and drying treatment. Therefore, by optimizing the process conditions, white turbidity can be improved and a hologram with low whiteness can be obtained.

As a method of obtaining a hologram having a low degree of yellowness, it is possible not to use a sensitizing dye having an absorption in the blue region and to reduce the amount thereof as in the above holograms A to D. When a sensitizing dye having absorption in the blue region is used, bleaching (decolorization / bleaching) by heat or UV light or a bleaching treatment with a solvent that selectively dissolves the dye may be performed. In addition, the light absorption in the blue region of the hologram material itself instead of the dye may be reduced.

Further, the by-products generated in the hologram manufacturing process may be colored. Therefore, it is preferable to select a material component such that this by-product has no absorption in the blue region.

On the other hand, incorporating a component substance having absorption in the red region into the light-sensitive material is also an effective means for reducing the yellowness. In this case, there is a concern that the transmittance in the visible region will decrease. Therefore, it is preferable to adjust the amount of the above-mentioned component substances to be contained so that _Tv is 70% or more.

Further, a fluorescent whitening agent may be added. Since the fluorescent whitening agent emits light in the blue region, it can supplement the light in the blue region absorbed by the hologram. In this case, there is a concern that the haze value and whiteness may increase,
It is required to appropriately adjust the amount to be added.

In Example 5, a green glass plate is used as the glass plate forming the laminated glass. Therefore, the yellowness of the laminated glass itself has a negative value. If the degree of yellow is negative, the color is bluish. Therefore, if the yellowness of the laminated glass itself is too small (negative value and absolute value is large), T _v
May be less than 70%.

When a hologram having a low yellowness is used by the above means, the yellowness of the hologram itself may have a negative value in some cases. Then, in the hologram laminate of the present invention, the difference between the yellowness value of the portion in which the hologram is enclosed and the yellowness value of the portion in which the hologram is not enclosed may be a negative value. obtain. In this case, even a difference of the 10 or less, T _v of hologram laminate sometimes becomes less than 70%. Therefore, T _v of hologram laminate in the present invention, it is preferably 70% or more.

An example of using the hologram laminate thus obtained in a HUD for automobiles is shown below. As shown in FIG. 10, the hologram laminate of the present invention was used as the windshield 7. Below the windshield 7, a light emitting display means including a light source 6, a lens system 4, and a transmissive liquid crystal display element 5 is provided. The light including the information emitted from the light emitting display means is irradiated toward the hologram and reflected and diffracted toward the observation position 1 of the observer. Thus, the observer visually recognizes the display image (8, 9) at a distance.

The windshield is constructed by arranging a bronze-colored glass plate on the outside of the automobile and a colorless transparent glass plate on the inside, and enclosing a hologram between them.
The hologram is arranged on a part of the entire surface of the windshield. As this hologram, the above hologram A is used.
Was used. The hologram A has three diffraction peaks corresponding to 470, 540, and 640 nm in the diffraction spectrum of light that is incident at an incident angle of 45 ° and is diffracted at a reflection diffraction angle of 60 °.

As the light emitting display means, one capable of emitting light of three primary colors of blue, green and red was used. In this way, the display image of the information to be displayed can be a multi-color display using the three primary colors of blue, green, and red as the display color.

The hologram laminated body provided in this HUD is composed of a windshield made of laminated glass and a hologram enclosed therein. The difference between the haze value of the portion where the laminated glass hologram is arranged and the haze value of the portion where it is not arranged is 1.0% or less, and the whiteness of the portion where the hologram of the laminated glass is arranged is not arranged. Since the difference from the whiteness of the part is less than the specified value and the difference between the yellowness of the part where the hologram of laminated glass is arranged and the yellowness of the part where it is not arranged is 10 or less, the hologram is enclosed. The parts that were marked were less conspicuous than the other parts, and the appearance was good. In addition, since halation and halo do not occur in the display image, it is possible to obtain good visibility and high brightness.

In the above HUD example, the hologram is enclosed in the windshield, but it may be provided on the surface of the windshield (the outside surface of the vehicle or the inside surface of the vehicle). Considering the protection of the hologram, it is preferable to use it by enclosing it in the windshield which is a laminated glass as in this example.

The light emitting display means in the present invention has a function of emitting light to display, and a hot cathode tube, cold cathode tube, fluorescent display tube, It emits light emitted from a light source including a halogen lamp, a metal halide lamp, a light emitting diode, a semiconductor laser, and the like, and may have these functions together.

When the hologram of the present invention is used for color display, the liquid crystal display element may be a color liquid crystal display element including a color filter and a transmission type twisted nematic type liquid crystal element, a super twisted nematic type liquid crystal display element, or the like. It can be preferably used, and light emitted from one light source can be irradiated as light of a desired color.

In this way, lights of a plurality of colors can be emitted from the same light emitting display means. When the lights of a plurality of colors are simultaneously displayed, the display images are displayed in an overlapping manner. On the contrary, in order to prevent the display images from overlapping, a combination of a color filter and a light source or a color liquid crystal display element may be controlled as necessary to prevent simultaneous irradiation of light of a plurality of colors.

Alternatively, instead of using the light-receiving display element, the light source itself may be patterned and arranged to generate specific information as light. In the case where the light source is used together with the light receiving display element, an appropriate light collimating means such as a lens system or a curved reflecting mirror, and a suitable light guiding means such as a light guide plate are provided between the light receiving display element and the light source. You may arrange. Further, if necessary, an optical polarization means or KNO is provided in the optical path until the light is projected on the hologram.
A non-linear optical element such as ₃ may be arranged.

The information to be displayed is appropriately selected according to its display application, and includes vehicle speedometer, tachometer, shift lever display, various warning lamps, navigation information, air conditioner, audio equipment, etc. Device information and the like can be exemplified. Information from outside the vehicle such as road information and parking lot availability information can also be displayed.

Further, the hologram laminate according to the present invention can be used not only for the above-mentioned automobile applications but also for aircrafts and ships. For aircraft and ships, various information related to vehicle operation and duties, such as position and orientation information such as latitude, longitude, altitude, direction of travel, weather information, radar obstacle information, fish finder information, etc. can be considered. . The observer is mainly a driver of a vehicle such as a vehicle, but may include passengers and other passengers, and all of them.

A hologram is usually several tens of mm to several hundreds.
The area is about square mm and the thickness is about several μm to several tens of μm. Such a hologram is desirable in that a volume / phase hologram such as a Lippmann type can obtain high diffraction efficiency, but a hologram such as an emboss type or a rainbow type can be widely used.
As the hologram photosensitive material, various photosensitive materials such as polyvinyl carbazole, acrylic-based photopolymers, dichromated gelatin, photoresists, and silver salts can be used.

In the above HUD example, a hologram having three wavelength peaks exposed by three colors is shown, but the hologram used for the HUD is a hologram corresponding to one or two colors such as hologram B or hologram D. Alternatively, it may be a hologram corresponding to more colors.

Further, the combination of the incidence of the hologram, the diffraction angle, the diffraction wavelength, the full width at half maximum of the diffraction peak, the diffraction efficiency, etc. is appropriately determined according to the information to be displayed and various uses of the display device. Although the reflection hologram has been described above as an example, a transmission hologram may be used depending on the application.

Whiteness and yellowness can be derived from the spectrum of vertical transmission or reflection. That is, even in the case of a hologram having no unexposed portion as described above, by excluding and interpolating the peak portion due to the diffraction of the hologram, the measurement value due to the diffraction of the hologram can be optimized. Therefore, no inconvenience occurs even if the hologram is a transmission type or a reflection type. On the other hand, the haze value cannot be adequately optimized by simply excluding the peak.

With respect to the reflection type hologram, Example 2 shows an example of measuring the haze value when the hologram has no unexposed portion. Therefore, as for the transmission hologram, an example of measuring the haze value of the hologram having no unexposed portion is shown below.

As the transmission hologram, a hologram having a diffraction efficiency of 35% was used when the light having a wavelength of 675 nm was made incident at 45 ° and measured at a position at an emission angle of 15 °. This hologram has a diffraction spectrum with a half-value width of 23.
It was of 0 nm. The haze value of the enclosed portion (exposed portion) of the hologram before correction is H = 36.6 (T _d = 3
3.6, T _t = 91.9, T ₁ = 100, T ₂ = 91.
9, T ₃ = 0.2, T ₄ = 33.7). The diffraction efficiency was 36.0% when the spectroscopic spectrum of this measured object was measured and calculated by the formula (h).

Therefore, the apparent increase due to diffraction (η =
0.36) is calculated by the equation (j), the haze value is 0.47 (T _d '= 0.43, T _t = 91.
9), which is 0.37 (0.47-0.10 = 0.37), which is less than the specified value 1.0. In this way, by obtaining the diffraction efficiency of the hologram and performing correction, the haze value of the exposed portion of the hologram can be calculated, and a laminate having a haze value difference of 1.0 or less can be obtained.

The use of the hologram laminate of the present invention is not limited to the above-mentioned example used in the HUD for automobiles. For example, a high mount stop that arranges a hologram on the rear glass and diffracts braking information toward an observer such as a driver of a rear vehicle by using a hologram to emit light from a light emitting display unit that emits light in synchronization with the braking operation of the driver. The hologram laminate according to the present invention can also be used for a lamp.

In addition, when the hologram is used for the meter display section in the dashboard, or when the hologram is used for the HUD combiner separately provided on the dashboard, the hologram laminate of the present invention is used. Can be used. Also, for partitioning of buildings, etc., and for holographic display devices that add decorative effects to window glass in stores,
INDUSTRIAL APPLICABILITY The present invention can be applied to a wide range of display devices using holograms. Further, these hologram laminated bodies can be made to have excellent appearance without the hologram portion being conspicuous.

As the hologram laminate, besides the above laminated glass, a hologram is laminated on one glass plate, or a synthetic resin film is laminated on the surface of one glass plate or laminated glass. The hologram may be attached or enclosed. As the transparent substrate on which the hologram is arranged, in addition to the above glass plate, a transparent synthetic resin plate called organic glass, a synthetic resin film, and the like can be exemplified.

As a method for producing the hologram laminated body, when the hologram laminated body is a laminated glass, an ordinary method for producing a laminated glass can be sufficiently used. That is, a hologram-encapsulated laminated glass can be obtained by preliminarily press-bonding an intermediate film and a hologram between two glass plates, followed by heating and press-bonding in an autoclave. In this case, one of the two glass plates may be used as a supporting substrate for producing the hologram. It is also possible to separately prepare a hologram by supporting the hologram photosensitive material on a supporting substrate, and then remove the hologram from the supporting substrate and interpose it between the two glass plates.

The hologram of the present invention is laminated on a part of the entire surface of the transparent substrate. The occupation ratio of the entire surface of the transparent substrate is appropriately determined according to the application of the hologram laminate. For example, when the hologram laminate is used for the HUD in which the combiner is provided on the windproof glass, the hologram preferably occupies a small area of the entire surface of the transparent substrate. Further, when used in a HUD provided separately on the dashboard, the hologram preferably occupies a large area of the entire surface of the transparent substrate.

The place where the holograms are laminated is also appropriately determined according to the application. Further, the hologram may be laminated at one place on the transparent substrate or may be laminated at a plurality of places. This is also appropriately determined according to the application. In this case, it is not necessary that all of the plurality of places where the holograms are stacked be less noticeable than the portion where the holograms are not stacked. That is, it is sufficient that at least one of the portions where the holograms are laminated in the hologram laminate satisfy the configuration of the present invention, depending on the application. However, since it is normally desired that the entire area of the hologram laminate has a good appearance, it is preferable that the configuration defined in the present invention is satisfied at all the locations where the holograms are laminated.

[0179]

As described above, according to the present invention, as the hologram laminate, the values of yellowness, whiteness, and haze of the portion where the hologram is arranged in the hologram laminate and the portions where the hologram is not arranged are shown. By reducing the difference from the values of yellowness, whiteness, and haze value, the portion in which the hologram is enclosed is less conspicuous than other portions, and the appearance can be improved. Further, by setting the yellowness of the hologram itself to be small, the visible light transmittance at that time can sufficiently satisfy the regulation.

[Brief description of drawings]

FIG. 1 is a schematic sectional view (a) and a schematic front view (b) of a main part showing an example of a hologram laminate according to the present invention.

FIG. 2 is a graph showing the correlation between whiteness and the degree of white turbidity.

FIG. 3 is a graph showing a correlation between yellowness and visible light transmittance.

FIG. 4 is a graph showing an example of a reflection spectrum of the hologram laminate according to the present invention.

FIG. 5 is a graph showing an example of a transmission spectrum of a hologram laminate according to the present invention.

FIG. 6 is a graph showing an example of a reflection spectrum of the hologram laminate according to the present invention.

FIG. 7 is a graph showing an example of a transmission spectrum of a hologram laminate according to the present invention,

FIG. 8 is a graph showing an example of a reflection spectrum of the hologram laminate according to the present invention.

FIG. 9 is a graph showing an example of a transmission spectrum of the hologram laminate according to the present invention.

FIG. 10 is a conceptual diagram showing an example of a vehicle HUD.

FIG. 11 is a graph showing an example of a transmission spectrum of a hologram-encapsulated laminated glass.

[Explanation of symbols]

 11, 11 ': Glass plate 12: Intermediate film 14: Hologram

Claims (12)

[Claims] 1. A hologram laminate in which holograms are laminated on a part of the entire surface of a transparent substrate, the haze value (unit:%) of the portion of the hologram laminate where the holograms are laminated, and the hologram laminate. The difference from the haze value (unit:%) of the part where the hologram is not laminated on the body is
A hologram laminate, which is 1.0 or less. 2. A hologram laminate in which holograms are laminated on a part of the entire surface of a transparent substrate, and the degree of yellowness of a portion where the holograms are laminated in the hologram laminate and the hologram in the hologram laminate are laminated. A hologram laminate, wherein the difference from the yellowness of the non-coated portion is 10 or less. 3. A hologram laminated body in which holograms are laminated on a part of the entire surface of a transparent substrate, wherein the hologram has a yellowness of 10 or less. 4. A hologram laminate in which a hologram is laminated on a part of the entire surface of a transparent substrate has a whiteness of JIS.
-Whiteness WI = 4B-3G defined by L1015, and B and G using standard light C JIS-Z870
Using XYZ obtained by the method specified in 1, B = 100
Z / 118.225, a value calculated by G = Y, and a whiteness of a portion of the hologram laminated body where the hologram is laminated and a whiteness of a portion of the hologram laminated body where the hologram is not laminated. Difference of 3
The hologram laminated body characterized by the following. 5. A hologram laminate in which a hologram is laminated on a part of the entire surface of a transparent substrate, and white is obtained by using XYZ obtained by a method defined in JIS-Z8701 using light C having a standard whiteness. Degree Wb = 100Z / 118.2
25, the difference between the whiteness of the portion of the hologram laminated body where the hologram is laminated and the whiteness of the portion of the hologram laminated body where the hologram is not laminated is 1.5 or less. And a hologram laminate. 6. A hologram laminate in which a hologram is laminated on a part of the entire surface of a transparent substrate, wherein the whiteness is the whiteness W determined by a method specified in JIS-L1015 using standard light C, W = 100- [(100-L) ² +
a ² + b ² ] ^1/2, the whiteness of a portion of the hologram laminate where the hologram is laminated and the whiteness of a portion of the hologram laminate where the hologram is not laminated. A hologram laminate, wherein the difference is 5 or less. 7. The difference between the haze value (unit:%) of the portion where the hologram is laminated in the hologram laminate and the haze value (unit:%) of the portion where the hologram is not laminated in the hologram laminate are , 1.0 or less, The hologram laminate according to claim 4, 5 or 6, wherein. 8. The difference between the yellowness of the portion where the hologram is laminated in the hologram laminate and the yellowness of the portion where the hologram is not laminated in the hologram laminate is 10 or less. Claims 1, 4,
5, 6, or 7 hologram laminate. 9. The hologram laminate according to claim 1, wherein the hologram has a yellowness of 10 or less. 10. The haze value is a haze value defined by JIS-R3212, and is a value measured using a standard light A, according to claim 1, 7, 8 or 9. Hologram stack. 11. The yellowness index YI defined by JIS-K7103, which is a value calculated from a transmission or reflection spectrum of an object to be measured. Or a hologram laminate of 9. 12. The hologram laminate according to claim 1, wherein the visible light transmittance T _v in each portion of the hologram laminate is 70% or more.