JP2014202819A - Screen system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further improve energy saving effects by reducing a loss of image light projected from a projector in an optical path to reaching eyes of a person, in a screen system configured to irradiate a limited narrow area with the image light from the projector.SOLUTION: The screen system includes: a reflector 22 forming a part of a substantial spheroid 20; and a projector 38 in which an optical system iris is located at a first focus vicinity 26 of the substantial spheroid 20 and which is disposed facing the reflector 22. Consequently, image light from the projector 38 can be viewed at a second focus vicinity 28 of the substantial spheroid 20 in a direction toward the reflector 22.

Description

  The present invention relates to a screen system capable of limiting the range in which a display image can be visually recognized to a limited narrow region such as an observer's eyes (both eyes) and the periphery thereof.

Various display devices generally allow one display image to be viewed by many observers positioned at different angles with respect to the display screen. That is, the basic design philosophy is to provide a relatively wide viewing angle, high resolution, and good contrast.
Therefore, it is common to use a diffusing means for expanding the visual field, for example, a diffusing film that diffuses in all directions from all points on the image display surface as the screen of the display device. This is to realize a wide viewing angle.

  Japanese Unexamined Patent Publication No. 2007-183498 (Patent Document 1) introduces such a diffusion film and a projection system, and FIG. 6 shows an example of such a diffusion film. In FIGS. 4A to 4C, light incident on one lens (incident side lens) at the same angle is condensed at a position corresponding to the angle, and the light condensed at each position is This shows the principle of diffusion in a certain angle range by another lens (outgoing side lens) arranged near the focal point of the lens. (D) is sectional drawing of the diffusion film which integrated the said two lenses.

By making full use of such a diffusion film, the light constituting the image condensed at the position corresponding to the incident angle can be diffused in a certain range by the exit side lens by the action of the entrance side lens. , All the observers located in the diffusion angle range can visually recognize the image.
Therefore, a display device using such a diffusion film can be viewed over a wide angle range by appropriately setting the diffusion angle, thereby realizing a wide viewing angle.

By the way, not all display devices are required to have a wide viewing angle. In other words, there are many cases where a narrow viewing angle is acceptable.
For example, a television display provided for each passenger seat such as a passenger plane, or a display such as a small personal television, a personal computer, a mobile phone, a personal digital assistant, an automobile head-up display (HUD), or the like.

These displays are basically only viewed by one person and can be viewed only by that person. In extreme terms, it can be said that video light can be sent to a narrow area where both eyes of the human being exist.
However, even such a display with a narrow viewing angle usually has a viewing angle that is considerably wider than the minimum required viewing angle. Conventionally, technology development for widening the viewing angle has been actively conducted. However, there has been no technical development to narrow the viewing angle so as not to unnecessarily widen the viewing angle.

This is because the display device development engineer did not realize that widening the viewing angle more than necessary resulted in unnecessary power consumption and contrary to the spirit of energy saving.
If the display device originally has a wider viewing angle than the required viewing angle, the image light is unnecessarily output over a wide range. For example, if it is sufficient that an image can be output to both eyes of a single human being, but it has a characteristic of outputting an image to an area where several to several tens of humans can view simultaneously, the several to tens of Video output to an area where one person minus one can see is completely wasted. Naturally, this creates a waste of light and the like that is created to display an image, resulting in a waste of energy.

Many engineers are unaware of the existence of such waste, but the inventor of the present application conducted planned power outages due to the Fukushima nuclear accident caused by the Great East Japan Earthquake, legalization of power saving to large companies, small companies, general From the demand for power saving to homes, etc., we noticed unnecessary power consumption due to the viewing angle of the display device being wider than necessary, and came to recognize the need to eliminate such waste.
Furthermore, they have come to realize that if this waste can be eliminated effectively, there is a possibility of major changes in society.

This is because telecommuting can be significantly promoted. When working from home, for example, when an office worker can do the office work he / she wants to do at home, he / she can do it at home, and if there is a need for business, go straight to the sales location and return home when the business is done. Adoption was popular for a while, but its adoption has not progressed much.
However, according to the knowledge of the inventor of the present application, if the viewing angle of the display device can be kept to the minimum necessary, even if an employee projects an image on a large screen such as 70 inches at home, the power required for that is extremely high. It can be made smaller.

Specifically, a screen that is 70 inches larger than the power required for display on a liquid crystal display, such as a 17-inch liquid crystal display, of a normal size of a personal computer (so-called “personal computer”) that is used at work. The power consumption of the projection system as a display can be reduced.
And you can use some video conferences and videophones that are used in some places with a realistic face on the screen that looks the same as a person's face. More often no longer needed.

Therefore, most employees do not go to work every day, for example, work only on a predetermined date or on a date determined by circumstances, and work at home on other days, and go around as needed Therefore, it is possible to effectively eliminate the waste of commuting time such as 3 hours for a round trip or 4 hours or more every day.
If this spreads nationwide, energy used for commuting, for example, wasteful energy loss due to commuting by cars, reduction of the number of commuter trains or passenger cars of one train, will be noticeable nationwide. Can save energy.

This allows not only that a white-collar office worker can work at home, but also allows university students, high school students, vocational school students, and junior high school students to study at home. Of course, elementary school students can study at home, but elementary school students need to learn group behavior, so attending school is also important, and it may be necessary to place restrictions on increasing home study.
However, as home work and learning styles spread throughout the country in this way, energy conservation has progressed significantly, weakening or even eliminating the dependence on energy that is currently a problem, This makes it possible to reduce consumption and further reduce global warming due to the serious carbon dioxide.

In addition, a significant reduction in time loss due to office workers' commuting can have a significant impact on lifestyle patterns, enhance home services, and reduce home collapse due to so-called worker holics.
Therefore, the present inventor thinks to eliminate the waste of the energy, repeats the experiment, and as a result, the diffusion direction of the light emitted from the diffusion film used for the display is limited to a narrow angle range for image display. It came to the recognition that it is effective in eliminating the waste of the spent energy.

  That is, diffusion films used for displays such as conventional screens have the property that light emitted from all points on the display surface is diffused in all directions, and the diffusion direction is limited to a narrow angle range. There was no engineer who recognized the need to do so. As described above, it is preferable that the display be viewed as high as possible by as many people as possible existing in a wide range on the display surface side, and, of course, This is because it has been recognized that what is used as the diffusion film is preferably one in which light emitted at all points on the display surface is diffused in all directions.

However, if such a diffusion film is used, of the light emitted from the diffusion film, it is emitted at an angle toward the eyes of the observer [the pupil (diameter 2 to 8 mm)] that is utilized for image viewing. Only the emitted light and most of the emitted light is wasted. Only the light emitted in a very narrow range of angles has contributed effectively to the visual recognition of the image, and most of the energy for image display is expended in the emission of useless light.
However, if the diffusion range of light emitted from all points on the display surface of the diffusion film can be limited to a narrow angle range, the viewer's eyes are placed within the angle range to visually recognize the image display. As a result, light is irradiated only in a narrow area of the observer's eyes and only the vicinity thereof, and wasteful energy consumed for wasteful light irradiation can be extremely reduced.

Accordingly, it has been recognized that it is effective to limit the diffusion direction of light emitted from the diffusion film used for the screen to a narrow angle range in order to eliminate waste of energy consumed for image display. .
Based on such recognition, the inventors of the present application have repeated thoughts and experiments, and as a result have come up with an invention. The invention has been filed by the applicant (National Tohoku University) (patent application). 2011-159423), and the contents of the application were published in Japanese Patent Application No. 2013-25052 (Cited Document 2).

  The invention will be described with reference to FIG. 7. The screen system comprises a basic imaging system having three surfaces: an object plane, an imaging plane, and a lens plane. The object surface is positioned on the output surface of a homogenizer (reference numeral 4 in FIG. 7) that realizes at least angularly uniform light intensity, and the distance between the object surface and the lens surface (reference numeral in FIG. 7). A lens (reference numeral 8 in FIG. 7) having a focal length (reference numeral in FIG. 7) substantially equal to a) is disposed.

A lens (reference numeral 10 in FIG. 7) having a focal length f2 is disposed on the lens surface of the basic imaging system, and in the vicinity thereof (for example, a position close enough to come into contact), a transmissive light modulation means with little light diffusibility. (Reference numeral 12 in FIG. 7) is arranged.
Then, the imaging surface is positioned at a position spaced from the lens surface by a distance satisfying the following equation (reference symbol b in FIG. 7).
Equation: (1 / a) + (1 / b) = 1 / f2 (focal length of lens 10 in FIG. 7)

According to such an invention, since the transmissive light modulation means having a low diffusibility is used, the viewing angle can be narrowed. Specifically, the viewing angle can be reduced to one-hundredth, one-thousandth, and even one-hundredth-thousandth and hundredth-thousandth of a solid angle, contributing to significant energy savings. can do.
Further, since the transmissive light modulation means does not have light diffusibility, there is also an effect that it is possible to pass outside light without diffusing.

JP 2007-183498 A JP 2013-025052 A

According to the invention introduced in the above Japanese Unexamined Patent Application Publication No. 2013-025052, it is possible to irradiate image light from a projector to, for example, an extremely narrow area of the observer's eyes (both eyes) and only the vicinity thereof. , Can greatly enhance the energy saving effect.
However, in order to further enhance the energy saving effect, the inventor of the present application has made further studies and has come to make the present invention.

  Accordingly, an object of the present invention is to reduce the loss in the optical path until the image light projected from the projector reaches the human eye in a screen system in which the image light from the projector is irradiated to a limited narrow area. The purpose is to reduce the amount and to increase the energy saving effect.

  The screen system according to claim 1 includes a reflector that is substantially a part of a spheroid and a projector that projects image light. The projector includes an optical system iris whose first spheroid is the first spheroid. It is located near the focal point of 1 so that the image light from the projector is imaged on the reflector, and the image light can be visually recognized by facing the reflector near the second focal point of the spheroid. It is characterized by that.

In addition, in this specification, a reflector has only a little reflectivity, and what is recognized as a transparent body in general society, for example, a glass or a transparent resin. The reason is as follows.
For example, since an ordinary glass plate transmits almost 96% of incident light, it is generally recognized as a transparent body. However, even such an ordinary glass plate reflects about 4% of incident light.

In the present invention, even if the reflectivity is as low as about 4%, the image light from the projector arranged almost in the vicinity of one focal point of the spheroid is visible to the human eye near the other focal point. This is because it can be reflected with such a strength that it can be visually recognized.
Therefore, the reflector in the present invention is usually recognized as a transparent body, but is included if it has a slight reflectivity.

A screen system according to a second aspect is the screen system according to the first aspect, wherein a short focus oblique projection projector is used as the projector.
A screen system according to a third aspect is the screen system according to the first or second aspect, wherein the first focal point where the substantially spheroid projector is located is the second focal point where the observer's eyes (both eyes) are located. It is characterized by being located higher than.

A screen system according to a fourth aspect of the present invention is disposed between a reflector that substantially forms a part of a spheroid, a projector that emits image light, and a position near the first focal point of the reflector and the spheroid. Reflection means, and the projector is positioned so that its optical system iris is plane-symmetric with the vicinity of the first focal point of the spheroid about the plane including the reflection surface of the reflection means. It is disposed in the vicinity and facing the reflecting means, and the image light from the projector is viewed in the direction facing the reflector near the second focal point of the spheroid. To do.
The reflector different from the reflector of claim 4 includes not only a flat plate but also a concave spherical surface having a focal point, for example.

  A screen system according to a fifth aspect of the present invention is the screen system according to the first, second, third, or fourth aspect, further comprising diffusion means for adjusting diffusion characteristics in an optical path from the projector to the observer through the reflector. To do.

According to the screen system of claim 1, the optical system iris is located in the vicinity of the first focal point of the reflector that is substantially a part of the spheroid, and the projector arranged toward the reflector is arranged and projected. Since the image light is focused on the reflector, the image light from the projector can be reflected and condensed by the reflector near the second focal point of the reflector.
Therefore, when the observer faces the recording reflector and the eyes (both eyes) are positioned in the vicinity of the second focus, the image light from the projector can be visually recognized, and the image light is sent only in a narrow range. Because it can, you can strengthen the energy saving effect.

Then, it is not necessary to interpose a light transmitting means such as a lens in the optical path along which the image light that is projected from the projector and reflected by the recording reflector and travels to the vicinity of the second focal point (the eye located in the second focal point). Light loss does not occur as in the case where a light transmitting means such as a lens is interposed in the path.
Accordingly, the energy saving effect can be obtained not only by sending the image light limited to a narrow range but also by not interposing a light transmitting means such as a lens in the light path, and the energy saving effect can be extremely enhanced.

According to the screen system of claim 2, since the short focus oblique projection projector is provided as the projector in the screen system of claim 1, the present invention can be applied to a head-up display type screen system.
According to the screen system of claim 3, in the screen system of claim 1 or 2, the first focal point where the substantially spheroid projector is located is the second where the observer's eyes (both eyes) are located. Therefore, the present invention can be applied to a head-up display type screen system.

According to the screen system of claim 4, the reflecting means is provided between the reflector and the vicinity of the first focal point, and the image light projected by the projector is reflected by the reflecting means to irradiate the reflector. A screen system that is substantially optically equivalent to the screen system of Item 1 can be obtained, and substantially the same effect as the screen system of Claim 1 can be obtained.
Therefore, since the position of the projector is not limited to the vicinity of the first focal point of the spheroid, it is possible to increase options for the position of the projector.

According to the screen system of the fifth aspect, in the screen system of the first, second, third, or fourth aspect, since the diffusion characteristic adjusting diffusion means is provided, the range in which the image light can be visually recognized by the diffusion characteristic adjusting diffusion means is narrow. It can be adjusted so that it is not too much.
That is, the present invention is basically intended to obtain an energy saving effect by irradiating image light in a very narrow range, but in some cases, the range in which an image can be viewed may be too narrow. In this case, it is preferable that the image can be visually recognized even if the position of the face is slightly moved by diffusing the light by the diffusion characteristic adjusting diffusion means having an appropriate diffusion characteristic. Therefore, a diffusion means for adjusting the diffusion characteristics is provided.

1 is a longitudinal sectional view showing a first embodiment of a screen system of the present invention. It is a longitudinal cross-sectional view which shows the 2nd Example of this invention screen system. It is a longitudinal cross-sectional view which shows the 3rd Example of this invention screen system. It is a longitudinal cross-sectional view which shows the 4th Example of this invention screen system. It is a longitudinal cross-sectional view which shows the 5th Example of this invention screen system. An example of the diffusion film introduced by patent document 1 which is the technique which conventionally used the diffusion means (for example, diffusion film) for realization of a wide viewing angle is shown. In FIGS. 4A to 4C, light incident on one lens (incident side lens) at the same angle is condensed at a position corresponding to the angle, and the light condensed at each position is This shows the principle of diffusion in a certain angle range by another lens (outgoing side lens) arranged at the focal position of the lens. (D) is sectional drawing of the diffusion film which integrated the said two lenses. It is a perspective view of the screen system which shows the prior art example introduced by Japanese Patent Application No. 2013-25052 gazette (cited reference 2).

  In the screen system of the present invention, basically, a projector is arranged near one focal point of a reflector that is substantially a part of a spheroid, and the reflector is directed near the other focal point. Thus, the image light from the projector is visually recognized or optically equivalent to it.

In addition, as a reflector, for example, a member that utilizes the surface reflectivity of a member made of metal, or a member that has reflectivity by forming a reflective film on the surface of metal or resin is used. Can do.
Furthermore, there may be an embodiment in which a material having slight light reflectivity, such as glass and transparent resin, is recognized as having light transmissivity in terms of social wisdom.
Specifically, such an embodiment uses a windshield of an automobile, train, steamer, airplane, or the like as a reflector, and can be visually recognized through the windshield, overlaid on a landscape, for example, a projector for a navigation system. The image light from can be visually recognized.

(First embodiment)
FIG. 1 is a longitudinal sectional view showing a screen system 100a according to a first embodiment of the present invention.
In the drawing, 20 is a substantially spheroid, 22 is a reflector that is part of the spheroid 20, 26 is a vicinity of the first focal point of the spheroid 20, and 28 is a second part of the spheroid 20. Near the focal point.

Reference numeral 38 denotes a projector, which is arranged so that its iris is located in the vicinity of the first focal point 26 and faces the reflector 22. The vicinity of the second focal point 28 is a position where the observer's eyes (both eyes) 40 visually recognize the image light from the projector 38.
The projector 38 includes an LED projector main body 30, an imaging lens 32 that receives image light from the projector main body 30 and forms an image on the diffusion film laminate 34, and a projection imaging lens system 36.

  The diffusion film laminate 34 has a substantially uniform diffusibility in terms of angle. The reason why the diffusion film laminate 34 has a laminated structure (two-layer structure) is to obtain longitudinal diffusion and lateral diffusion. The longitudinal diffusion and the lateral diffusion of the diffusion film laminate 34 are desirably set so that all light is taken into the incident side lens of the projection imaging lens system 36.

The projection imaging lens system 36 is for enlarging and projecting image light from the projector main body 30, and the iris (pupil of the projection imaging lens system) is positioned in the vicinity of the first focal point 26 as described above. In this case, the image light is arranged on the reflector 22.
According to this embodiment 100a, the image light projected from the projector body 30 is imaged by the imaging lens 32, diffused by the diffusion film laminate 34 without angle dependency, and magnified by the projection imaging lens system 36. And projected onto the reflector 22. Then, the light is reflected and collected by the reflector 22 toward the second focal point vicinity 28.

Therefore, if a person, that is, an observer places the eyes (both eyes) 40 in the vicinity of the second focal point 28 and views the reflector 22, the image light can be visually recognized.
According to the present embodiment 100a, by providing the diffusion film laminate 34 having a low diffusibility as the diffusing means, all light can be taken into the projection imaging lens system 36.
The image light projected from the projector 38 is simply reflected inward by the reflector 22 without passing through a light-transmitting optical element such as a lens, and is visually recognized by the observer's eyes 40. Therefore, the light output can be made extremely small.

(Second embodiment)
FIG. 2 is a longitudinal sectional view showing a screen system 100b according to a second embodiment of the present invention. In FIG. 2, the illustration of the internal structure of the projector 38 is omitted. Similarly, in each of the drawings (FIGS. 3 to 5) showing the following embodiments (third to fifth embodiments), the internal structure of the projector is not shown.
Reference numeral 20 denotes a spheroid, and 22 denotes a reflector that is a part of the spheroid 20. A projector 38 is arranged in the direction near the first focal point 26 so as to face the reflector 22.
More specifically, the iris of the projection imaging lens system of the projector 38 is positioned in the vicinity of the first focal point 26. However, this does not appear in FIG. 2, so see FIG. 1 for details.

The projector 38 does not necessarily have the same structure and principle as those shown in FIG. 1, and may be any other projector as long as it functions as a projector. However, it is essential that the iris of the projection imaging lens system is positioned in the vicinity of the first focal point 26.
This embodiment 100b is different in that the projector 38 is obliquely above the reflector 22 and the human eye 40 is positioned below the projector 38, but the basic principle is completely different from that of the first embodiment 100a. It is the same and there is no difference in the effect to play.

(Third embodiment)
FIG. 3 is a longitudinal sectional view showing a screen system 100c according to a third embodiment of the present invention.
In this embodiment, a short-focus projector 38 is provided on a dashboard of an automobile or the like, and a part of the windshield or a part of the instrument panel is used as the reflector 22. The windshield or instrument panel is mounted so as to form a part of the spheroid 20 at least in the part constituting the reflector 22.

  This embodiment is suitable for a screen system such as car navigation. Originally, a person inside a vehicle such as a driver, a pilot, or an airplane sees the front through the windshield, but the part 22 is also used as a reflecting means for reflecting image light from the projector 38. The basic principle is exactly the same as in the first embodiment 100a and the second embodiment 100b.

  In FIG. 3, parts and elements that are the same as those in FIGS. 1 and 2 are given the same reference numerals, and redundant descriptions are omitted. S1 is the area of the iris surface on the projector 38 side, S2 is the area of the iris surface on the eye side, A is the distance between the projector 38 and the reflector 22, and B is the distance between the eyes (both eyes) 40 and the reflector 22. .

The following equations hold between A, B, S1, and S2.
S2 = S1 · B / A

(Fourth embodiment)
FIG. 4 is a longitudinal sectional view showing a screen system 100d according to a fourth embodiment of the present invention.
In the present embodiment 100d, a plate-like reflecting means 44 is provided between the reflector 22 which is substantially part of the spheroid 20 and the first focal point vicinity 26, and image light projected from the oblique projection projector 38a therefrom. Is reflected by the reflecting means 44 and applied to the reflector 22, and is reflected by the reflector 22 so as to be visually recognized by a human eye (both eyes) 40 located near the second focal point 28. It is.

The reflecting means 44 tilts the mirror surface 46, which is the reflecting surface, obliquely at an angle of approximately 45 degrees with respect to the line connecting the reflector 22 and the first focal point vicinity 26, and the iris surface of the projector 38a with the plane including the mirror surface 46 as the center ( 4 and the first focal point vicinity 26 are arranged so as to be plane-symmetric.
In this embodiment 100d, the reflecting means 44 is provided, and the projector 38a (its iris surface) is located at a position that is plane-symmetric with the first focal point vicinity 26 about the plane including the mirror surface 46. Although different from the first embodiment 100a, the second embodiment 100b, and the third embodiment 100c, there is no difference in the basic principle and the effect to be achieved.
Then, with the appearance of the present embodiment 100d, options for the arrangement position of the projector 38 increase.

(Fifth embodiment)
FIG. 5 is a longitudinal sectional view showing a screen system 100e according to a fifth embodiment of the present invention.
In this embodiment 100e, for example, a film-like diffusion characteristic adjusting diffusion means 48 is formed on the inner surface of the reflector 22 which is substantially part of the spheroid 20 to receive image light from the projector 38 and display an image. The range of the visually recognizable area can be expanded as an enlarged area 49 indicated by hatching in FIG.
The diffusion direction of the diffusion characteristic adjusting diffusion means 48 is the vertical direction and the horizontal direction.

The reason why the diffusion characteristic adjusting diffusion means 48 is provided in this manner is to avoid the narrowness of the area where the image can be visually recognized.
In the present invention, basically, a diffusion means having high diffusion performance is provided in order to widen the diffusion range so that the range of the region where the image can be viewed is widened. Although it is not provided, if it is too narrow to be visible only by one human eye, for example, it is necessary to make it visible to two or several people, this embodiment 100e is effective. It is.
It should be noted that the technical idea of providing the diffusion characteristic adjusting diffusion means to widen the visible region as in this embodiment can be applied to embodiments other than this embodiment.
As described above, the present invention may have various embodiments, and various modifications may exist.

  The present invention can limit the range in which a display image can be visually recognized to, for example, a limited narrow region such as an observer's eyes (both eyes) and the periphery thereof, and thus can obtain an energy saving effect. The screen system has industrial applicability.

1a to 1f ... screen system,
20 ... almost spheroid, 22 ... reflector,
26 ... near the first focal point, 28 ... near the second focal point,
38 ... projector, 38a ... oblique projection projector,
40 ... eyes (both eyes), 42 ... observer side iris surface, 44 ... reflection means,
46 ... mirror surface, 48 ... diffusion means for adjusting diffusion characteristics.

Claims (5)

A reflector that is part of a spheroid,
A projector that projects image light;
Have
The projector has its own optical system iris positioned in the vicinity of the first focal point of the spheroid, and forms image light from the projector on the reflector.
A screen system characterized in that the image light can be viewed by facing the reflector near the second focal point of the substantially spheroid. The screen system according to claim 1, wherein a short focus oblique projection projector is used as the projector. The first focal point where the projector of the substantially spheroid is located is located higher than the second focal point where the eyes (both eyes) of the observer are located. Screen system. A reflector that is part of a spheroid,
A projector that emits image light;
Reflecting means disposed between the reflector and the first focal position of the substantially spheroid;
Have
The projector is positioned in the vicinity of a position where its own optical system iris is plane-symmetric with the first focal point of the spheroid centered on a plane including the reflecting surface of the reflecting means, and faces the reflecting means. Placed in
A screen system characterized in that image light from the projector is visually recognized in a direction facing the reflector near the second focal position of the substantially spheroid. The screen system according to claim 1, further comprising a diffusing characteristic adjusting diffusing unit in a light path from the projector to the observer through the reflector.

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