JPH04213445A - Reflection type projection enlarger - Google Patents

Abstract

PURPOSE:As to a reflection type projection enlarger using a transmission type liquid crystal display unit, to surely prevent the occurrence of heat spot and to make the illuminance distribution and contrast of a displayed image uniform while making the device light in weight and thin in size and also improving the reliability. CONSTITUTION:The enlarger is constituted so that a transparent hard coating layer and a surface reflection preventing layer may be formed in order on the surface of the upper polarization plate 5 on the side of an illuminating light source 9, and in the case of installing a flexible protective plate separated from the upper polarization plate, the enlarger is constituted so that the transparent hard coating layer and the surface reflection preventing layer may be formed in order on both surfaces of the flexible protective plate. In the other way, the enlarger is constituted so that the flexible substrate provided with the thickness of >=20mum and <=1000mum may be stuck on the upper polarization plate, and then, the transparent hard coating layer and the surface reflection preventing layer may be formed in order on the surface of the flexible substrate.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflective enlargement projection apparatus for enlarging and projecting an image onto a screen.

0002

2. Description of the Related Art As a conventional reflection type magnifying projection apparatus, one equipped with a transmission type liquid crystal display unit is known. That is, it includes an overhead projector, an illumination light source, a projection optical unit consisting of a projection lens, a reflection mirror, etc., a screen, and the like.

A transmissive liquid crystal display unit is disposed on a Fresnel reflector, and when image information is input and the liquid crystal is driven, an image is displayed on the display unit. In addition, when the illumination light from the illumination light source is reflected on the Fresnel reflector through the transmissive liquid crystal display unit and projected onto the screen via the projection optical unit, an enlarged image of the image displayed on the transmissive liquid crystal display unit is displayed on the screen. It is now displayed.

When a pair of glass substrates with a thickness of approximately 1 mm are used as substrates for the liquid crystal cell of the above-mentioned transmissive liquid crystal display unit, the distance between the liquid crystal layer and the Fresnel reflector becomes wide, causing image shift in the optical system. It is known that this occurs and the projected image becomes a double image, deteriorating the display quality of the projected image. In order to eliminate this problem, the substrate of the liquid crystal cell on the Fresnel reflector side is made of flexible material such as polyester, polyethersulfone, polycarbonate, polyarylate, acrylic, etc. with a thickness of about 70 to 300 μm. A method has been proposed in which a pair of polarizing plates with a thickness of about 100 to 200 μm are adhered to both sides of a liquid crystal cell using a substrate to narrow the gap between the liquid crystal layer and the Fresnel reflector to prevent double images. ing.

On the other hand, it is known that in a reflection type enlarged projection apparatus, heat spots are generated on the projection screen due to the illumination optical system. Heat spots mainly occur when part of the illumination light is reflected on the surface of the protective plate or polarizing plate placed on the illumination light source side of the transmissive LCD unit, resulting in a bright spot or a bright spot in the center of the screen. In other words, it appears as a high-intensity spot. Heat spots cause the illuminance distribution and contrast of the display screen to deteriorate,
This significantly degrades the display quality of the projected image.

Generally, it is known that a glass substrate having a surface antireflection layer is disposed above a polarizing plate on the side of the illumination light source to prevent the generation of heat spots. Other heat spot prevention measures include forming a surface anti-reflection layer on the surface of the polarizing plate on the illumination light source side, and applying anti-glare treatment by forming fine irregularities on the surface of the upper polarizing plate as an inexpensive means. can also be considered.

[0007]

However, in such a conventional reflection type magnifying projection device, the weight and thickness of the projection device increase due to the following reasons. There have been problems such as reduced impact resistance and reliability, insufficient prevention of heat spots, and uneven illuminance distribution and contrast of displayed images.

That is, when a thick glass substrate having a surface antireflection layer is disposed on the illumination light source side of a transmissive liquid crystal display unit, the presence of the glass substrate increases the weight and the thickness of the entire projection device. become. In addition, when a front antireflection layer is formed on the surface of a polarizing plate on the side of the illumination light source, the support of the polarizing plate is usually composed of TAC, that is, a soft resin film such as triacetate, so that the front antireflection layer adheres tightly. This may lead to a decrease in reliability and impact resistance.

Furthermore, if anti-glare treatment is applied to the surface of the polarizing plate on the side of the illumination light source, the transmittance of the device will decrease, the projected image will become dark, and heat spots cannot be sufficiently removed. . Therefore, the invention as claimed in claim 1 makes it possible to reduce the weight and thickness of the device and improve reliability by sequentially forming a transparent hard coat layer and a surface antireflection layer on the surface of the second polarizing plate. , the objective is to reliably prevent the occurrence of heat spots and make the illuminance distribution and contrast of a displayed image uniform.

[0010] The invention as set forth in claim 2 provides a flexible protective plate that is spaced apart from the second polarizing plate, and a transparent hard coat layer and a surface antireflection layer are sequentially formed on both surfaces of the flexible protective plate. This improves the impact resistance and reliability of the device while reliably preventing heat spots.
The goal is to make the illuminance distribution and contrast of the displayed image uniform.

[0011] The invention according to claim 3 provides that the
By bonding a flexible substrate with a thickness of 00 μm or less to a second polarizing plate and sequentially forming a transparent hard coat layer and a surface antireflection layer on the surface of the flexible substrate, the device can be made lighter and thinner. The objective is to reliably prevent the occurrence of heat spots and make the illuminance distribution and contrast of displayed images uniform, while improving impact resistance and reliability.

0012

[Means for Solving the Problems] In order to solve the above problems, the invention according to claims 1 and 2 includes a liquid crystal layer, a first substrate made of a flexible member and closely attached to one surface of the liquid crystal layer. ,
a second substrate closely attached to the other surface of the liquid crystal layer; a first polarizing plate disposed to face the liquid crystal layer with the first substrate in between; and a first polarizing plate disposed to face the liquid crystal layer with the second substrate in between. a second polarizing plate; a drive circuit that drives the liquid crystal layer to display an image;
and a Fresnel reflector disposed on the first polarizing plate side of the transmissive liquid crystal display unit, the illumination light is reflected by the Fresnel reflector through the transmissive liquid crystal display unit to create a screen. In a reflective enlargement projection device that forms an image on a screen and projects the image displayed on a transmissive liquid crystal display unit onto a screen,
A transparent hard coat layer is formed on the surface of the second polarizing plate so as to face the second substrate with the second polarizing plate in between, and a surface antireflection layer is formed on the surface of the transparent hard coat layer. Further, a flexible protective plate is disposed opposite to the second polarizing plate and separated from the second polarizing plate, and a transparent hard coat layer is formed on both surfaces of the flexible protective plate. , a surface antireflection layer may be formed on the surface of each transparent hard coat layer.

[0013] The invention according to claim 3 includes a liquid crystal layer, a first substrate made of a flexible member and closely attached to one surface of the liquid crystal layer, and a second substrate closely attached to the other surface of the liquid crystal layer. , a first polarizing plate disposed to face the liquid crystal layer with the first substrate in between;
A transmissive liquid crystal display unit includes a second polarizing plate disposed to face the liquid crystal layer with a second substrate in between, and a drive circuit that drives the liquid crystal layer to display an image.
The transmissive liquid crystal display unit includes a Fresnel reflector disposed on the first polarizing plate side of the transmissive liquid crystal display unit, and the illumination light is reflected by the Fresnel reflector through the transmissive liquid crystal display unit to form an image on the screen. In a reflective enlargement projection device for projecting an image displayed on a screen onto a screen, the second polarizing plate may be bonded to the second polarizing plate so as to face the second substrate with the second polarizing plate interposed therebetween, and may have a thickness of 20 μm or more and 1000 μm or less. A flexible substrate is provided, a transparent hard coat layer is formed on the surface of the flexible substrate so as to face the second polarizing plate with the flexible substrate in between, and a surface antireflection layer is formed on the surface of the transparent hard coat layer. It is characterized by the fact that it has been formed.

[0014]

[Function] In the invention as set forth in claim 1, when the illumination light is incident on the transmissive liquid crystal display unit, the reflection of the illumination light is prevented by the surface antireflection layer formed on the second polarizing plate, thereby preventing the generation of heat spots. The illuminance distribution and contrast of the displayed image become uniform. Furthermore, by forming a transparent hard coat layer on the surface of the second polarizing plate and forming a surface antireflection layer on the surface, the device can be made lighter and thinner, and its reliability can be improved.

In the second aspect of the invention, when the illumination light enters the transmissive liquid crystal display unit, reflection of the illumination light is prevented by the surface antireflection layers formed on both sides of the flexible protective plate and the second polarizing plate. This prevents heat spots from occurring and makes the illuminance distribution and contrast of the displayed image uniform. In addition to providing a flexible protective plate, a transparent hard coat layer is formed on the surfaces of the second polarizing plate and the flexible protective plate, and a surface anti-reflection layer is formed on the surface of the transparent hard coat layer to improve the impact resistance of the device. performance and reliability are improved.

In the third aspect of the invention, when the illumination light is incident on the transmission type liquid crystal display unit, the reflection of the illumination light is prevented by the surface antireflection layer formed on the flexible substrate bonded to the second polarizing plate. This prevents heat spots from occurring, and makes the illuminance distribution and contrast of the displayed image uniform. In addition, the thickness of the flexible substrate should be 20 μm or more and 1000 μm.
By making the thickness less than m, the device can be made lighter and thinner, and its impact resistance and reliability can be improved.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below based on the drawings. FIGS. 1 and 2 are diagrams showing an embodiment of a reflection type magnifying projection apparatus according to the first aspect of the invention. 1 and 2, 1 is a liquid crystal layer, and a lower substrate 2 is closely attached to the lower surface of the liquid crystal layer 1 in FIGS. Further, an upper substrate 3 is closely attached to the upper surface of the liquid crystal layer 1, and the liquid crystal layer 1, the lower substrate 2, and the upper substrate 3 constitute a liquid crystal cell. The lower substrate 2 and the upper substrate 3 are made of flexible members such as polyester, polyethersulfone, polycarbonate, and polyarylate, each having a thickness of about 100 μm.

A lower polarizing plate 4 is bonded to the lower substrate 2 so as to face the liquid crystal layer 1 with the lower substrate 2 in between, and an upper polarizing plate 4 is bonded to the upper substrate 3 so as to face the liquid crystal layer 1 with the upper substrate 3 in between. 5 is glued. Further, each of the lower polarizing plate 4 and the upper polarizing plate 5 has a thickness of about 200 μm, and each of the lower and upper polarizing plates 4 and 5 has a thickness of about 200 μm, and can be attached to the corresponding substrate by using an adhesive, for example, without forming a gap between the lower substrate 2 and the upper substrate 3. It is glued so that it is in close contact with the

The liquid crystal layer 1 is driven by a driving circuit 6 to display an image, and the liquid crystal layer 1, lower substrate 2, upper substrate 3, lower polarizing plate 4, upper polarizing plate 5 and driving circuit 6 form a transmissive liquid crystal display unit. 7 is composed. Reference numeral 8 denotes a Fresnel reflector plate disposed in close contact with the lower polarizing plate 4 of the transmissive liquid crystal display unit 7. Illumination light from the illumination light source 9 passes through the transmissive liquid crystal display unit 7 and is reflected by the Fresnel reflector 8, and is imaged onto the screen 12 by a projection optical system consisting of a projection lens 10 and a reflecting mirror 11. The image displayed is enlarged and projected onto the screen 12.

As shown in FIG. 2, a transparent hard coat layer 13 is formed on the surface of the upper polarizing plate 5 so as to face the upper substrate 3 with the upper polarizing plate 5 in between. 13 is made of resin such as acrylic, urea, melamine, silicone, epoxy, phenol, etc.
Its thickness is set to 1 to 50 μm, preferably 5 to 20 μm. A surface antireflection layer 14 is formed on the surface of the transparent hard coat layer 13.
4 is formed by forming a transparent thin film by vapor deposition, sputtering, vapor phase growth, etc., and consists of a single-layer anti-reflection film or a multi-layer anti-reflection film.

When the front antireflection layer 14 is, for example, a single-layer antireflection film, the materials for the transparent hard coat layer 13 and the front antireflection layer 14 may be selected so as to satisfy the following two equations. n1d=λ/4 n1≈√n2 where n1: refractive index of the front antireflection layer d: thickness of the front antireflection layer λ: wavelength of irradiation light n2: refractive index of the transparent hard coat layer. As such a surface antireflection layer 14, Mg
There are vapor deposition materials such as F2, NaAlF6, and SiO2. On the other hand, multilayer antireflection coatings are used to provide higher performance and optimal surface antireflection coatings.

According to the above-described structure, since the surface antireflection layer 14 is formed on the illumination light source 9 side of the upper polarizing plate 5, the illumination light from the illumination light source 9 is transmitted to the transmissive liquid crystal display unit 7.
When the light is incident on the screen 12, surface reflection as shown by the broken line in FIG. 1 can be prevented, and heat spots can be prevented from being generated on the screen 12. Therefore, the illuminance distribution and contrast of the displayed image can be made uniform. Furthermore, since the transparent hard coat layer 13 is formed on the surface of the upper polarizing plate 5 and the surface antireflection layer 14 is formed thereon, the adhesion of the surface antireflection layer 14 can be improved, and the device It is possible to improve reliability while reducing weight and thickness.

FIGS. 3 and 4 are diagrams showing an embodiment of a reflective enlargement projection apparatus according to the second aspect of the invention. In addition, Figure 3
, 4, the same members as those in the embodiment shown in FIGS. 1 and 2 are given the same reference numerals, and their explanations will be omitted. In FIGS. 3 and 4, reference numeral 21 denotes a flexible protection plate 21 that faces the upper polarizing plate 5 and is spaced apart from the upper polarizing plate 5, and the flexible protection plate 21 has a thickness of 0.5 to It is made of about 2 mm of polyester, polyethersulfone, polycarbonate, polyarylate, etc. material. Flexible protection plate 1
Transparent hard coat layers 22 and 23 are formed on both surfaces of the transparent hard coat layers 22 and 23, and surface antireflection layers 24 and 25 are formed on the surfaces of each of the transparent hard coat layers 22 and 23, respectively. Each of the transparent hard coat layers 22 and 23 and the surface antireflection layers 24 and 25 is the transparent hard coat layer 13 described above.
and is formed in the same manner as the front antireflection layer 14.

According to the above structure, the front antireflection layer 14 is formed on the illumination light source 9 side of the upper polarizing plate 5, and the front antireflection layers 24 and 25 are further formed on both sides of the flexible protection plate 21. Therefore, when the illumination light from the illumination light source 9 is incident, surface reflection as shown by the broken line in FIG. 3 can be prevented, and heat spots can be prevented from being generated on the screen 12. Therefore, the illuminance distribution and contrast of the displayed image can be made uniform. Further, a flexible protection plate 21 is provided apart from the upper polarizing plate 5, and a transparent hard coat layer 22 is provided on both surfaces of the flexible protection plate 21.
23 and surface antireflection layers 24 and 25 are formed thereon, the impact resistance and reliability of the device can be further improved.

FIG. 5 is a diagram showing an embodiment of a reflective enlargement projection apparatus according to the third aspect of the invention. The transmissive liquid crystal display unit 30 shown in FIG. 5 is an example applied to the reflective enlargement projection apparatus shown in FIG. The same members as those in the embodiment are given the same reference numerals and their explanations will be omitted.

In FIG. 5, reference numeral 31 denotes a flexible substrate which is adhered to the upper polarizing plate 5 with an adhesive without a gap so as to face the upper substrate 3 with the upper polarizing plate 5 in between.
It has a thickness of not less than μm and not more than 1000 μm. The flexible substrate 31 is made of a flexible material such as polyester, polyethersulfone, polycarbonate, polyarylate, or acrylic. 32 is a transparent hard coat layer formed on the surface of the flexible substrate 31 to face the upper polarizing plate 5 with the flexible substrate 31 in between, and a surface antireflection layer is formed on the surface of the transparent hard coat layer 32. 33 is formed. Each of the transparent hard coat layer 32 and the surface antireflection layer 33 is the transparent hard coat layer 13 described above.
and has the same structure as the front antireflection layer 14.

According to the above-described configuration, the surface antireflection layer 32 is formed on the illumination light source 9 side of the flexible substrate 31 bonded to the upper polarizing plate 5, so that the illumination light from the illumination light source 9 is not incident. In this case, surface reflection on the flexible substrate 31 can be prevented, and heat spots can be prevented from being generated on the screen 12. Therefore, the illuminance distribution and contrast of the displayed image can be made uniform. Furthermore, since the flexible substrate 31 is bonded to the upper polarizing plate 5 and the surface antireflection layer 33 is formed on the transparent hard coat layer 32 formed on the flexible substrate 31, the impact resistance of the device and The device can be made lighter and thinner while improving reliability.

[0028]

According to the invention as claimed in claim 1, since the transparent hard coat layer and the surface antireflection layer are sequentially formed on the surface of the second polarizing plate, it is possible to reduce the weight and thickness of the device. While improving reliability, heat spots can be reliably prevented from occurring, and the illuminance distribution and contrast of a displayed image can be made uniform.

According to the invention as set forth in claim 2, a flexible protective plate is provided separated from the second polarizing plate, and a transparent hard coat layer and a surface antireflection layer are provided on both surfaces of the flexible protective plate. are formed in this order, it is possible to reliably prevent the occurrence of heat spots while improving the impact resistance and reliability of the device, and it is possible to make the illuminance distribution and contrast of the displayed image uniform.

According to the third aspect of the invention, a flexible substrate having a thickness of 20 μm or more and 1000 μm or less is adhered to the second polarizing plate, and a transparent hard coat layer and a surface reflective layer are formed on the surface of the flexible substrate. By forming the prevention layers in sequence, it is possible to reduce the weight and thickness of the device, improve impact resistance and reliability, and reliably prevent the occurrence of heat spots, improving the illuminance distribution and contrast of the displayed image. can be made uniform.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of a reflective enlargement projection apparatus according to the invention;

FIG. 2 is an enlarged sectional view of a main part of the transmissive liquid crystal display unit in FIG. 1;

FIG. 3 is a schematic diagram showing an embodiment of a reflection type magnifying projection apparatus according to the invention as claimed in claim 2;

FIG. 4 is an enlarged sectional view of a main part of the transmissive liquid crystal display unit in FIG. 3;

FIG. 5 is an enlarged cross-sectional view of a main part of an embodiment of a reflection type enlarged projection apparatus according to the third aspect of the invention;

[Explanation of symbols]

1 Liquid crystal layer 2 Lower substrate (first substrate) 3 Upper substrate (second substrate) 4 Lower polarizing plate (first polarizing plate) 5
Upper polarizing plate (second polarizing plate) 6 Drive circuit 7 Transmissive liquid crystal display unit 8
Fresnel reflector 12 Screen 13 Transparent hard coat layer 14 Front anti-reflection layer 21 Flexible protection plates 22, 23 Transparent hard coat layers 24, 25 Front anti-reflection layer 31 Flexible substrate 32 Transparent hard coat layer 33 Front anti-reflection layer

Claims (3)

[Claims] 1. A liquid crystal layer, a first substrate made of a flexible member and closely attached to one surface of the liquid crystal layer, and a second substrate closely attached to the other surface of the liquid crystal layer, the first substrate being sandwiched between them. A first polarizing plate arranged to face the liquid crystal layer, a second polarizing plate arranged to face the liquid crystal layer with a second substrate in between, and a drive circuit that drives the liquid crystal layer to display an image. , and a Fresnel reflector disposed on the first polarizing plate side of the transmissive liquid crystal display unit, the illumination light is reflected by the Fresnel reflector through the transmissive liquid crystal display unit. In a reflective enlarging projection device that forms an image on a screen and projects an image displayed on a transmissive liquid crystal display unit onto the screen, the surface of the second polarizing plate is arranged so as to face the second substrate with the second polarizing plate in between. 1. A reflective magnifying projection device comprising: a transparent hard coat layer formed thereon; and a surface antireflection layer formed on the surface of the transparent hard coat layer. 2. A flexible protective plate is provided opposite to the second polarizing plate and separated from the second polarizing plate, and transparent hard coat layers are formed on both surfaces of the flexible protective plate, respectively. 2. The reflective magnifying projection apparatus according to claim 1, further comprising a surface antireflection layer formed on the surface of the transparent hard coat layer. 3. The first substrate is sandwiched between a liquid crystal layer, a first substrate made of a flexible member and closely attached to one surface of the liquid crystal layer, and a second substrate closely attached to the other surface of the liquid crystal layer. A first polarizing plate arranged to face the liquid crystal layer, a second polarizing plate arranged to face the liquid crystal layer with a second substrate in between, and a drive circuit that drives the liquid crystal layer to display an image. , and a Fresnel reflector disposed on the first polarizing plate side of the transmissive liquid crystal display unit, the illumination light is reflected by the Fresnel reflector through the transmissive liquid crystal display unit. In a reflective enlarging projection device that forms an image on a screen and projects an image displayed on a transmissive liquid crystal display unit onto the screen, the second polarizing plate is bonded to the second polarizing plate so as to face the second substrate with the second polarizing plate in between. and 2
A flexible substrate having a thickness of 0 μm or more and 1000 μm or less is provided, a transparent hard coat layer is formed on the surface of the flexible substrate so as to face the second polarizing plate with the flexible substrate in between, and the transparent hard coat layer is A reflective magnifying projection device characterized in that a surface antireflection layer is formed on the surface of the layer.