WO1999013642A1 - The method of optical analysis of image in screens for rear projection and the screen for this method - Google Patents
The method of optical analysis of image in screens for rear projection and the screen for this method Download PDFInfo
- Publication number
- WO1999013642A1 WO1999013642A1 PCT/PL1998/000036 PL9800036W WO9913642A1 WO 1999013642 A1 WO1999013642 A1 WO 1999013642A1 PL 9800036 W PL9800036 W PL 9800036W WO 9913642 A1 WO9913642 A1 WO 9913642A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- screen
- optical
- image
- fact
- microelements
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/72—Modifying the appearance of television pictures by optical filters or diffusing screens
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/74—Projection arrangements for image reproduction, e.g. using eidophor
Definitions
- the subject of the invention is the method of optical analysis of the image in screens for rear projection, as well as the screen for this procedure.
- the focusing screens can be replaced.
- An optical focusing screen has been an optical device used in technical appliances
- An optical focusing screen used in large screens is generally made in form of a panel 3
- pixels/307 300 x 3 as image-generating elements have been used / it refers to Sony TV
- image-tube is always better while comparing optical focusing screen and colour image-tube by projecting the same pictures.
- the design assumption is to obtain high contrast of the projected image.
- the essence in the range of the method is based on the optical analysis of image, in the screens for rear projection where the light image generated by the projector is projected on
- the screen panel which structure enables to obtain the contrasted image on the forward
- microelements which are set in the screen panel best with the form of cylindrical cross
- microelement is built of a transparent core and a transparent external shell, where a refractive index of the external shell is lower than a refractive index of the optical microelement transparent core.
- optical microelement where the layer is made of the transparent material of lower refractive index equal 6.25 : 1.
- refractive index preferably of its lower value with reference to the refractive index of the optical microelement cores. It is the most convenient if the cores of optical microelements
- screen matrix are made of the same optical material as the rear panel of the screen, on
- cross section consists of two basic layers, where the rear panel contains optical
- the forward layer is a carrying element that protects
- optical microelements against mechanic defects and the fore panel contains antireflective substances. It is advantageous to combine all the optical elements by means of a transparent element which runs linearly with the reference to the space orientation and which is situated perpendicularly towards the observer.
- a profitable result of this invention is the fact, that the image projected by the rear
- Fig. 1 presents a cross-section of the subject of the invention
- fragment of the screen made of a transparent material, which has a structure according to
- Fig. 2 presents a cross-section of a single optical microelement
- Fig.3 presents the top view in section of the
- Fig. 1, Fig. 2, and Fig. 3, consists of the following elements:
- Rear surface of the screen made of plastics, located in the inner part which is made of transparent material, e.g. polymethacrylate of proper optical features;
- the light image is projected by the projector from the rear position through the optical
- optical microelement cores 2. positioned perpendicularly to both of the screen surfaces 1. and_3., optical analysis of the image takes place on the fore surface of the screen 3.; on the
Abstract
The essence of the invention in range of the method, mainly consists in the fact that: the light image generated by the projector is projected on the rear surface of the screen, optical analysis takes place on its fore surface through transparent optical microelements due to which a contrastive image without a glare effect is obtained on the fore surface of the screen. However, as far as the screen structure is concerned, the essence of the invention consists in the fact that: to make an optical analysis of the image with rear projection the screen is made in the form of the panel made of transparent material of the structure which enables to obtain a contrastive image on the fore surface without a glare effect, and that in the panel of the screen (1) there are embedded optical microelements (2).
Description
The method of optical analysis of image in screens
for rear projection and the screen for this method
The subject of the invention is the method of optical analysis of the image in screens for rear projection, as well as the screen for this procedure. The invention subject in the range
of the method is assigned to apply it in screens used for rear projection in TV-sets and
widescreen monitors, where no conventional picture tube is used. The invention subject can
be also used in rear projection techniques where the glass or plastics focusing screens have
been used so far. It also refers primarily to film cutting benches in the cinema and TV
postproduction and professional slide viewers of larger screen format. The invention subject
may also be designed whereever focusing screens are used and due to improvement of
image quality, the focusing screens can be replaced.
An optical focusing screen has been an optical device used in technical appliances,
mostly in TV sets with rear projection, where an image generated by the projector was
projected on the rear surface of the screen made in shape of turbid panel. An image which
did not cause any glare appeared on the surface of the screen.
The screens used to rear projection, e.g. in widescreen TV sets and monitors are made
in form of large sized focusing screens, many a time modified in different manners.
An optical focusing screen used in large screens is generally made in form of a panel 3
to 8 mm thick from the plastics of a special selected visible light transmittance Technical
solutions of this type are used by most of the widescreen TV and multimedia appliances
Screens for rear projections made of plastics are used by such companies as Panasonic, Philips, Pioneer, Sony, Thomson
The most modern contemporary TV projectors using rear projection have the screens
made of plastics, where designers applied optical elements which mostly use physical
properties of Fresnel lens to obtain better angular parameters of watching image on the
screen and to obtain lower light loss The image attained in this way on the screen surface
is in a sufficient contrast, brightness and sharpness
However, comparing the image tube, all images which are rear projected on the screens
and made of typical optical focusing screen or of the similar surface, do not give such a sharp and contrastive image as conventional image tube made in Delta, Qiuntrix, or Trinitron technology does To improve visual parameters in the appliances for rear
projection which have LCD-image converters, very strong light sources are used The use
of very strong light source in form of halogen lamp of a few hundred Watt of power
significantly improve brightness of the obtained image, but does not really improve the
contrast However, in case of TV sets and multimedia monitors, the acquisition of accurate
contrast on surface of a screen using optical focusing screen is very troublesome Lack of
accurate sharpness, contrast and brightness of image is a general cause of poor interest of the rear projection technology, especially in widescreen TV sets Only the latest
achievements of some companies have improved parameters of widescreen TV sets with rear projection, where three panels LCD-RGB of diagonal 1 35", resolution of 921 600
pixels/307 300 x 3 as image-generating elements have been used / it refers to Sony TV
projector model VPL-V500Q This new technology permitted for using similar parameters
as in classic TV systems with the use of kinescopes However, the application of the screens
using optical focusing screen and elements of Fresnel lens, even in so technologically advanced TV appliances, introduces quite large restrictions in creating image on the screen surface. The optical focusing screen introduces in its essence less sharp and contrast image
than the image-tube, because it is not an optically transparent system. It appears that the
image-tube is always better while comparing optical focusing screen and colour image-tube by projecting the same pictures.
The situation is similar with appliances for cinema production and viewers of larger size
of the screen. In all those equipment the screens made in form of a glass or plastic focusing screen are used.
The light loss arising due to the use of optical focusing screens are on the average
about 20 to 30 per cent. It is quite a significant problem, especially in the equipment where
the design assumption is to obtain high contrast of the projected image.
The essence in the range of the method is based on the optical analysis of image, in the screens for rear projection where the light image generated by the projector is projected on
the rear surface of the screen, whereas the optical analysis of the image takes place on its forward surface and at the same time the light is going through the transparent material of
the screen panel which structure enables to obtain the contrasted image on the forward
surface without any glare effect and the generated light goes through the transparent optical
microelements which are set in the screen panel best with the form of cylindrical cross
section, and which are located in such a manner that their longitudinal axes are
perpendicular to both surfaces of the screen and at the same time their length and number
are selected relating to the power of the light source and the required screen resolution and
contrast. Their cross sectional area is selected according to the length of the screen
diagonal.
The essence in the range of the method consists in the fact that an individual optical
microelement is built of a transparent core and a transparent external shell, where a
refractive index of the external shell is lower than a refractive index of the optical microelement transparent core.
The essence in the range of the method also consists in the fact, that the most
convenient are those optical microelements that have the external diameter in range from
0.03 mm to 1.0 mm and the ratio of microelement core thickness to the outer layer of the
optical microelement, where the layer is made of the transparent material of lower refractive index equal 6.25 : 1.
The essence of the method is also that the most convenient are optical microelements of
the same outer diameters, homogeneously settled on the surface of the screen.
The essence of the invention in the range of the screen is that the screen is made in the
form of a transparent material panel which structure enables to obtain a contrastive image
on the forward surface without the glare effect, and that the optical microelements are
embedded in the screen panel.
The essence of the invention in the range of the screen is also that the surfaces of
individual optical elements, which are parallel to both surfaces of the screen, are totally
transparent and the spaces between the cores of all optical elements, which make a
homogeneous matrix of the screen, are filled with a transparent material of properly lower
refractive index, preferably of its lower value with reference to the refractive index of the optical microelement cores. It is the most convenient if the cores of optical microelements
making a group fulfilling the whole surface of the screen, which make the homogeneous
screen matrix, are made of the same optical material as the rear panel of the screen, on
which the image is projected.
The essence of the invention in the range of screen is that the screen structure on its
cross section consists of two basic layers, where the rear panel contains optical
microelements located perpendicularly, the forward layer is a carrying element that protects
optical microelements against mechanic defects, and the fore panel contains antireflective
substances. It is advantageous to combine all the optical elements by means of a transparent element which runs linearly with the reference to the space orientation and which is situated perpendicularly towards the observer.
A profitable result of this invention is the fact, that the image projected by the rear
projection and generated on the surface of a new screen is void of all imperfections which
characterise systems of optical focusing screens. The most important advantage resulting
from applying the invention is a reasonable improvement of the image contrast. The
improvement of the image contrast obtained on the surface of the screen where the
invention essence was applied is due to the fact that new screens do not cause so significant light loss which are present in the screens with optical focusing screens. The improvement
of the optical parameters was obtained by elimination of the turbid surfaces; all surfaces are
fully transparent. This feature of the new screens makes the contrast of the image obtained on the screen surface dependable only on the parameters of the image source.
One of the most important advantages obtained due to the use of the new screen for
rear projection is the possibility to get a high degree of the image contrast comparable with
a conventional image-tube.
So far the screen systems used in TV projectors with the system for rear projection have not expressed the good sharpness of the image shapes, and there has also been a
perceivable a lower level of the image contrast. The image projected from the rear position
in medium- and widescreen TV projectors with the use of the essence of the invention may
be comparable, in respect of quality, with the image of the kinescope of the TV set.
Achieving so high quality level of the image with the use of TV projector, it can be
supposed that these appliances would have many votaries. A profitable result of the
invention essence would be a considerably lower price of this technical solution in
comparison to the newly made flat plasma screens, the so called plasmatrons, presented
among others by Sony Co..
Application of the invention essence would have a considerable effect on the growth of interest as far as widescreen technique in the equipment for cinema and TV postproduction is concerned.
An advantageous result of the invention essence would be using it in all kinds of
multimedia techniques in advertising and cinema production.
The subject of the invention is shown in Fig. 1, which presents a cross-section of the
fragment of the screen made of a transparent material, which has a structure according to
the essence of the invention; Fig. 2 presents a cross-section of a single optical microelement
made of the transparent plastics which is embedded on the screen surface of the fore panel
of the screen made of the transparent material; Fig.3 presents the top view in section of the
screen for rear projection, where the essence of the invention is applied.
The example of the screen made with the use of the invention essence and shown in
Fig. 1, Fig. 2, and Fig. 3, consists of the following elements:
1. Rear surface of the screen made of plastics, located in the inner part which is made of transparent material, e.g. polymethacrylate of proper optical features;
2. Transparent cores of optical microelements made of plastics, e.g. polymethacrylate;
3. Fore surface of the screen which is the bearing structure in a form of a panel made
of the transparent material;
4. Transparent outer shell of optical element with lower refractive index;
5. Elements in shape of strips vertically positioned on the screen, covering one vertical row of optical elements in relation to the axis of the observer, in purpose to improve
horizontal viewing of the image projected on the screen;
6. Joints of two panel surfaces made of transparent material.
The light image is projected by the projector from the rear position through the optical
system on the rear surface of the screen JL, then the image falls on the matrix of transparent
optical microelement cores 2., positioned perpendicularly to both of the screen surfaces 1.
and_3., optical analysis of the image takes place on the fore surface of the screen 3.; on the
fore screen surface 3. a contrast image with no glare is generated; improvement of horizontal viewing is attained through optical elements 5. vertically arranged with the
respect to the observer.
Claims
1. The method of image optical analysis in screens for rear projection, in which the light image, generated by the projector, is projected on the rear surface of the screen and the image optical analysis takes place on its fore surfaces, at the same time the light goes through the transparent material of the screen panel which structure makes it possible to obtain a contrastive image on the fore surface without a glare effect, significant by the fact that the generated light image goes through the transparent optical microelements embedded in the screen panel, expediently in the shape of the cylindrical cross-section, which are arranged in such a way that their longitudinal axes are perpendicular to both of the screen surfaces, at the same time the length and a number of the microelements are s selected in dependence on the intensity of the light source and the required resolution and the image contrast; the cross-sectional area of the optical microelements is selected with the respect to screen diagonal length.
2. The method of image optical analysis in screens for rear projection, ace. to Claim No.l, significant by the fact that the light flux generated by the image projector goes through the transparent core of optical microelement surrounded by the transparent outer shell, at the same time it is most advantageous when the refractive index of the outer shell is lower than the refractive index of optical microelement transparent core.
3. The method of image optical analysis in screens for rear projection, ace. to Claim No. l, significant by the fact that the most advantageous is the application of transparent optical microelements of the outer diameter in the range from 0.03 to 1.0 mm and the ratio of the microelement core thickness to the outer layer of the optical microelement made of transparent material of lower refractive index is expressed most advantageously by the ratio 6.25 : 1.
4. The method of image optical analysis in screens for rear projection, ace. to Claim No.l, significant by the fact that that the most advantageous is the application of optical microelements of the same outer diameter, which fulfil homogeneously the surface of the screen.
5. The screen for optical analysis of image for rear projection, in the form of the panel made of transparent material of the structure which enables to obtain contrastive image on the fore surface without a glare effect, significant by the fact that in the screen panel (1) optical elements (2) are embedded.
6. The screen, ace. to Claim No. 5, significant by the fact that that the surfaces of individual optical microelements (2), which are parallel to both screen surfaces, are fully transparent.
7. The screen, ace. to Claim No. 5, significant by the fact that that the space between the cores of all optical microelements (2) which make a homogeneous matrix of the screen, are filled with transparent material (4) of the proper refractive index, most advantageously of lower refractive index with the respect to the core of optical microelements (2).
8. The screen, ace. to Claim No. 5, significant by the fact that the cores of optical microelements (2) which make a homogeneous screen matrix are the most advantageous when made of the same optical material that the rear panel of the screen (1) on which the image is projected.
9. The screen, ace. to Claim No. 5, significant by the fact that the structure of the screen in cross-section advantageously consists of two basic layers, where a rear panel of the screen (1) includes optical microelements (2) situated perpendicularly, another layer, a fore panel (3), is a bearing element protecting optical microelements (2) against mechanic defects and containing antireflective substances.
10. The screen, ace. to Claim No. 5, significant by the fact that it is advantageous to join all optical microelements (2) with a transparent element (5) running linearly in relation to the assumed space orientation, most advantageously vertical with the respect to the observer.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PL32203997A PL322039A1 (en) | 1997-09-10 | 1997-09-10 | Method of optically analysing image in back-projection screens and projection screen therefor |
| PLP.322039 | 1997-09-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1999013642A1 true WO1999013642A1 (en) | 1999-03-18 |
Family
ID=20070615
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/PL1998/000036 WO1999013642A1 (en) | 1997-09-10 | 1998-08-31 | The method of optical analysis of image in screens for rear projection and the screen for this method |
Country Status (2)
| Country | Link |
|---|---|
| PL (1) | PL322039A1 (en) |
| WO (1) | WO1999013642A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6600599B2 (en) | 1998-06-09 | 2003-07-29 | Avery Dennison Corporation | Rear projection screens and light filters with conformable coatings and methods of making the same |
| EP1403696A1 (en) * | 2002-09-24 | 2004-03-31 | Seiko Epson Corporation | Rear projection screen using a light-guide faceplate and diffusing means |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2206979A (en) * | 1987-06-01 | 1989-01-18 | Scient Applied Research Sar | Display system utilising light transmitting screen and method of manufacturing same |
| US5101279A (en) * | 1989-12-14 | 1992-03-31 | Canon Kabushiki Kaisha | Liquid crystal display apparatus having lenticular elements oriented in relation to LC pixel aperture dimensions |
| EP0640850A2 (en) * | 1993-08-30 | 1995-03-01 | Toray Industries, Inc. | Microlens array sheet for a liquid crystal display, method for attaching the same and liquid crystal display equipped with the same |
| US5442482A (en) * | 1990-05-21 | 1995-08-15 | Johnson; William N. H. | Microlens screens, photopolymerisable materials and artifacts utilising the same |
| US5543870A (en) * | 1993-03-31 | 1996-08-06 | Palomar Technologies Corporation | Rear projection screen with high off-axis sunlight rejection |
| US5566007A (en) * | 1993-09-06 | 1996-10-15 | Kabushiki Kaisha Toshiba | Reflection type liquid crystal display device capable of color display |
-
1997
- 1997-09-10 PL PL32203997A patent/PL322039A1/en unknown
-
1998
- 1998-08-31 WO PCT/PL1998/000036 patent/WO1999013642A1/en active Application Filing
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2206979A (en) * | 1987-06-01 | 1989-01-18 | Scient Applied Research Sar | Display system utilising light transmitting screen and method of manufacturing same |
| US5101279A (en) * | 1989-12-14 | 1992-03-31 | Canon Kabushiki Kaisha | Liquid crystal display apparatus having lenticular elements oriented in relation to LC pixel aperture dimensions |
| US5442482A (en) * | 1990-05-21 | 1995-08-15 | Johnson; William N. H. | Microlens screens, photopolymerisable materials and artifacts utilising the same |
| US5543870A (en) * | 1993-03-31 | 1996-08-06 | Palomar Technologies Corporation | Rear projection screen with high off-axis sunlight rejection |
| EP0640850A2 (en) * | 1993-08-30 | 1995-03-01 | Toray Industries, Inc. | Microlens array sheet for a liquid crystal display, method for attaching the same and liquid crystal display equipped with the same |
| US5566007A (en) * | 1993-09-06 | 1996-10-15 | Kabushiki Kaisha Toshiba | Reflection type liquid crystal display device capable of color display |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6600599B2 (en) | 1998-06-09 | 2003-07-29 | Avery Dennison Corporation | Rear projection screens and light filters with conformable coatings and methods of making the same |
| EP1403696A1 (en) * | 2002-09-24 | 2004-03-31 | Seiko Epson Corporation | Rear projection screen using a light-guide faceplate and diffusing means |
| US7012744B2 (en) | 2002-09-24 | 2006-03-14 | Seiko Epson Corporation | Transmissive screen and rear projector |
| EP1731958A2 (en) * | 2002-09-24 | 2006-12-13 | Seiko Epson Corporation | Transmissive screen and rear projector |
| EP1731958A3 (en) * | 2002-09-24 | 2007-02-28 | Seiko Epson Corporation | Rear projection screen using a light-guide faceplate and diffusing means |
| KR100793478B1 (en) | 2002-09-24 | 2008-01-14 | 세이코 엡슨 가부시키가이샤 | Transmissive screen and rear projector |
Also Published As
| Publication number | Publication date |
|---|---|
| PL322039A1 (en) | 1998-03-02 |
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