JP2023024226A - display system - Google Patents

Abstract

To provide a display system that can realize a wide vision range as well as increasing the luminance and securing the transparency of a display screen.SOLUTION: The display system according to an embodiment includes: a picture output module for outputting a picture light for forming a picture to display to an observer; a light diffusion screen for forming a picture by diffusing the picture light output from the picture output module; and a transparent display screen for reflecting the picture formed by the light diffusion screen and displaying the picture to the observer.SELECTED DRAWING: Figure 1

Description

The present invention relates to display systems.

Techniques disclosed in Patent Document 1 and Patent Document 2 are known as prior art in this technical field. Patent Literature 1 discloses a technique for displaying a real image on the front window by adding light-diffusing particles or a liquid crystal layer to the front window. Patent Document 2 discloses a technique for projecting a reflected image of a liquid crystal display directly onto a front window.

WO2020/080355 Japanese Unexamined Patent Application Publication No. 2020-44961

When diffusing particles are added to the front screen as described in Patent Literature 1, if too many diffusing particles are added, the screen becomes cloudy due to the influence of outside light, impairing the field of view. On the other hand, if the amount of particles added is within the range where transparency can be maintained, a sufficient amount of reflected light cannot be obtained, and the visibility of the displayed image cannot be obtained. When the reflected image of the liquid crystal display is directly projected onto the front window as in Patent Document 2, visibility cannot be ensured with the brightness of the liquid crystal display.

An object of the present disclosure is to provide a display system capable of improving the brightness while ensuring the transparency of the display screen and realizing a wide viewing range.

A display system according to one embodiment includes an image output module that outputs image light for forming an image to be displayed to an observer, and the image light output from the image output module is diffused to form the image. and a display screen having transparency and reflecting the image formed by the light diffusion screen to display the image to the viewer.

Advantageous Effects of Invention According to the present disclosure, it is possible to provide a display system capable of improving brightness while ensuring transparency of a display screen and realizing a wide viewing range.

FIG. 1 is a schematic diagram showing the configuration of a display system according to one embodiment. FIG. 2 is a schematic diagram for explaining the configuration of an example of the video output module. FIG. 3 is a functional block diagram of an example of a control device. FIG. 4 is a drawing for explaining an example of angular anisotropy of reflectance in a light diffusion screen. FIG. 5 is a schematic diagram showing the configuration of a display system according to Modification 1. As shown in FIG. FIG. 6 is a schematic diagram showing the configuration of a display system according to Modification 2. As shown in FIG. FIG. 7 is a schematic diagram showing the configuration of a display system according to Modification 3. As shown in FIG. FIG. 8 is a schematic diagram showing the configuration of a display system according to Modification 4. As shown in FIG. FIG. 9 is a schematic diagram showing the configuration of a display system according to modification 5. As shown in FIG. FIG. 10 is a schematic diagram showing the configuration of a display system according to modification 6. As shown in FIG. FIG. 11 is a schematic diagram showing the configuration of a display system according to Modification 7. As shown in FIG. FIG. 12 is a schematic diagram showing the configuration of a display system according to modification 8. As shown in FIG. FIG. 13 is a drawing for explaining the configuration of an example of an external light cutting member included in the display system shown in FIG. FIG. 14 is a schematic diagram showing the configuration of a display system according to Modification 9. As shown in FIG. FIG. 15 is a schematic diagram of the light diffusion screen shown in FIG. 14 viewed from the front side. FIG. 16 is a drawing for explaining the F.theta. lens system shown in FIG. FIG. 17 is a schematic diagram showing the configuration of a display system according to Modification 10. As shown in FIG. 18 is a perspective view of the light diffusion screen shown in FIG. 17. FIG. FIG. 19 is a drawing for explaining the Fθ lens system and the light diffusion screen shown in FIG. 17. FIG.

[Description of Embodiments of the Present Disclosure]
First, the contents of the embodiments of the present disclosure will be listed and described.

A display system according to one embodiment includes an image output module that outputs image light for forming an image to be displayed to an observer, and the image light output from the image output module is diffused to form the image. and a display screen having transparency and reflecting the image formed by the light diffusion screen to display the image to the viewer.

In the above configuration, an image is formed on the light diffusion screen. An image is displayed to an observer by reflecting the image on a display screen. Therefore, the observer visually recognizes the reflected image of the image (real image) formed on the light diffusion screen. In this case, the brightness and viewing range of the image can be adjusted with a light diffusing screen. Therefore, while ensuring the transparency of the display screen, it is possible to improve the brightness and realize a wide viewing range.

A display system according to one embodiment is arranged between the light diffusion screen and the display screen, and cuts off at least part of external light propagating between the light diffusion screen and the display screen. A member may further be provided. In this case, it is possible to suppress deterioration in image contrast caused by external light.

An example of the external light cutting member may be a louver film.

The light diffusion screen may have angular anisotropy in reflectance or transmittance. In this case, it is easy to improve the luminance.

A screen gain of the light diffusing screen may be 0.5 or more in a desired viewing range. In this case, it is possible to improve the brightness in the desired viewing range.

The display system according to one embodiment may further include a first enlarging optical system arranged between the light diffusion screen and the display screen for enlarging the image displayed on the light diffusion screen. With this configuration, when the size of the image on the light diffusion screen projected on the display screen is fixed, the light diffusion screen can be made smaller than when the first magnifying optical system is not used. Therefore, the above configuration contributes to miniaturization of the display system.

The display system according to one embodiment further includes a reflecting section disposed between the image output module and the light diffusion screen for reflecting the image light output from the image output module toward the light diffusion screen. You may prepare. In this case, the optical path of the image light output from the image output module can be bent by the reflector. Therefore, it is possible to bring the video output module and the light diffusion screen close to each other while ensuring the optical path length. Therefore, the above configuration contributes to miniaturization of the display system.

A display system according to one embodiment is arranged between the image output module and the light diffusion screen, and propagates the image light to the light diffusion screen so that the image displayed on the light diffusion screen is enlarged. You may further provide the 2nd expansion optical system for doing. With this configuration, when the size of the image formed on the light diffusion screen is fixed, the light diffusion screen and the image output module can be arranged closer than when the second enlarging optical system is not used. Therefore, the above configuration contributes to miniaturization of the display system.

The image light is linearly polarized light, and the display screen has a transparent screen body and a polarizing element provided in the screen body for selectively reflecting the linearly polarized light. good too. With this configuration, an image formed on the light diffusion screen can be reflected by the polarizing element. Therefore, higher luminance can be achieved. Since the polarizing element transmits light other than linearly polarized light, the viewer can see the background through the display screen.

The display screen may include a transparent screen body and a dielectric multilayer film provided on the screen body and selectively reflecting light in a wavelength band included in the image light. In this configuration, an image formed on the light diffusion screen can be reflected by the dielectric multilayer film. Therefore, higher luminance can be achieved. Since the dielectric multilayer film transmits light in a wavelength band other than the wavelength band included in the image light, the observer can visually recognize the background through the display screen.

The image light may be laser light including laser light of at least one color of red, green and blue. Since laser light has high directivity, it is possible to efficiently control the luminous flux reaching the observer even with a small luminous flux amount. Therefore, it is easy to improve the luminance.

The image output module may scan and output the laser light to form the image. In this case, the video output module is a focus-free module. Therefore, since the light diffusion screen and the video output module can be arranged close to each other, the above configuration contributes to miniaturization of the display system.

The display system according to one embodiment may further include an Fθ lens system arranged between the video output module and the light diffusion screen. As a result, it is possible to reduce the spread of the incident area (or beam spot) of the image light incident on the light diffusing screen even in areas where the angle of view is wide, such as the edges of the image. As a result, deterioration of image quality caused by the expansion of the incident area can be suppressed.

A first surface of the light diffusion screen on which the image light from the image output module is incident may be a convex curved surface facing away from the first surface. In this case, it is easier for the image light to enter the first surface perpendicularly, compared to the case where the first surface is a flat surface. Therefore, the spread of the incident area (or beam spot) of the image light incident on the first surface can be reduced. As a result, deterioration of image quality caused by the expansion of the incident area can be suppressed.

A display screen according to one embodiment is disposed between the image output module and the light diffusion screen, and propagates the image light to the light diffusion screen so that the image displayed on the light diffusion screen is enlarged. and an Fθ lens disposed between the magnifying optical system and the light diffusion screen, wherein the image light is laser light of at least one color of red, green, and blue. wherein the image output module scans and outputs the laser light so as to form the image, and a first surface of the light diffusion screen on which the image light from the image output module is incident may be a convex curved surface facing away from the first surface.

In the above configuration, the video output module outputs laser light, which is video light, while scanning. Such a video output module is a focus-free module. Therefore, the light diffusion screen and the video output module can be arranged close to each other. Since the display screen is provided with the second magnifying optical system, when the size of the image formed on the light diffusing screen is fixed, the light diffusing screen and the image output module are more convenient than when the second magnifying optical system is not used. Can be placed close together. The first surface of the light diffusion screen, on which image light is incident, is the aforementioned curved surface. In this case, by bringing the light diffusion screen closer to the image output module, even if the angle of view in the vicinity of the edge of the image increases, the first surface is flat, compared to the case where the Fθ lens system is not used, etc. , the expansion of the incident area (or beam spot diameter) of the laser light, which is image light, can be reduced. Therefore, deterioration of image quality caused by the expansion of the incidence area can be suppressed. Therefore, with the above configuration, it is possible to reduce the size of the display system while suppressing deterioration in image quality. Since the Fθ lens system is provided and the first surface of the light diffusion screen is the curved surface, the condensing conditions of the Fθ lens system for suppressing the expansion of the incident area of the laser beam are limited only to the Fθ lens system. It is more relaxed than when the spread suppression is realized. Therefore, for example, it is possible to make the size of the Fθ lens system smaller than the image formed on the light diffusion screen. In this respect as well, it is possible to reduce the size of the display system.

[Details of the embodiment of the present disclosure]
Specific examples of embodiments of the present disclosure will be described below with reference to the drawings. The present invention is not limited to these examples, but is indicated by the scope of the claims, and is intended to include all modifications within the meaning and scope of equivalents to the scope of the claims. In the description of the drawings, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

FIG. 1 is a schematic diagram schematically showing the configuration of a display system according to one embodiment. As shown in FIG. 1 , the display system 1 comprises a video output module M, a light diffusion screen 2 and a display screen 3 . The display system 1 displays the video output from the video output module M on the light diffusion screen 2 as a real image (video) 4a. An observer E visually recognizes a reflected image (image) 4b of the real image 4a on the display screen 3 . In FIG. 1, the real image 4a and the reflected image 4b are schematically shown by dashed lines. The real image 4a and the reflected image 4b are similarly schematically shown in other figures unless otherwise specified.

The image output module M outputs an image shown to an observer E. FIG. In this embodiment, the image output module M is a drawing module that outputs drawing laser light (image light) L for forming an image. The image output module M is a laser scanning module that outputs the drawing laser beam L while scanning so as to draw the image. The video output module M has an optical output section 10 and a scanning section 20, as shown in FIG.

The light output unit 10 outputs drawing laser light L. FIG. The drawing laser light L is laser light including laser light of at least one color of red, green, and blue. An example of the oscillation wavelength (or center wavelength) of red laser light is 620 nm or more and 650 nm or less. An example of the oscillation wavelength (or center wavelength) of green laser light is 510 nm or more and 540 nm or less. An example of the oscillation wavelength (or center wavelength) of blue laser light is 435 nm or more and 465 nm or less. Hereinafter, unless otherwise specified, the drawing laser light L is laser light including red laser light, green laser light, and blue laser light.

The optical output section 10 has a light source section 11 and a combining section 13 . The light source unit 11 has at least one light source (for example, a laser diode chip described later) for outputting drawing laser light L including laser light of at least one color of red, green, and blue from the light output unit 10. In this embodiment, the drawing laser light L is laser light including red laser light, green laser light, and blue laser light. Therefore, the light source section 11 has a first light source 12a, a second light source 12b and a third light source 12c.

The first light source 12a is a semiconductor laser element that outputs a first laser beam L1. The first laser light L1 is any one of red laser light, green laser light, and blue laser light. The second light source 12b is a semiconductor laser element that outputs a second laser beam L2. The second laser beam L2 is any one of the red laser beam, the green laser beam and the blue laser beam other than the laser beam of the color corresponding to the first laser beam L1. The third light source 12c is a semiconductor laser element that outputs a third laser beam L3. The third laser beam L3 is laser beam other than the laser beam of the color corresponding to the first laser beam L1 and the second laser beam L2 among the red laser beam, the green laser beam and the blue laser beam.

Examples of the first light source 12a, the second light source 12b and the third light source 12c are laser diodes (LD). The first light source 12a, the second light source 12b and the third light source 12c may be laser diode chips (LD chips). The first light source 12a, the second light source 12b, and the third light source 12c may be CAN-type semiconductor laser elements.

In the following description, unless otherwise specified, the first laser beam L1, the second laser beam L2 and the third laser beam L3 are the laser beams shown below.
First laser beam L1: Red laser beam Second laser beam L2: Green laser beam Third laser beam L3: Blue laser beam

The multiplexing unit 13 is configured to be able to multiplex the first laser beam L1, the second laser beam L2, and the third laser beam L3. An example of the multiplexing unit 13 will be described based on the multiplexing unit 13 shown in FIG. The combining section 13 has a lens 14a, a lens 14b, a lens 14c, a filter 15a, a filter 15b and a filter 15c.

The lens 14a is a collimating lens that collimates the first laser beam L1. The lens 14b is a collimating lens that collimates the second laser beam L2. The lens 14c is a collimating lens that collimates the third laser beam L3.

Filter 15a, filter 15b and filter 15c are, for example, wavelength selective filters.

The filter 15a reflects the first laser beam L1 collimated by the lens 14a toward the filter 15b. The filter 15b transmits the first laser beam L1 and reflects the second laser beam L2 collimated by the lens 14b toward the filter 15c. Thereby, the first laser beam L1 and the second laser beam L2 are combined. The filter 15c transmits the first laser beam L1 and the second laser beam L2 (that is, the combined light of the first laser beam L1 and the second laser beam L2) and filters the third laser beam L3 collimated by the lens 14c. The light is reflected to the side opposite to 15b (scanning unit 20 side in FIG. 2). As a result, the drawing laser beam L, which is combined light obtained by combining the first laser beam L1, the second laser beam L2, and the third laser beam L3, is obtained. Since the first laser beam L1, the second laser beam L2, and the third laser beam L3 combined using the filters 15a, 15b, and 15c are collimated beams, the drawing laser beam L is also collimated beam.

A case where all of the first laser beam L1, the second laser beam L2, and the third laser beam L3 are output has been described as an example. However, if any one of the first laser beam L1, the second laser beam L2, and the third laser beam L3 is not output, the drawing laser beam L is light obtained by combining the output laser beams. .

The scanning unit 20 reflects the drawing laser light L and two-dimensionally scans the drawing laser light L so as to draw an image (the real image 4a and its reflected image 4b) shown to the observer E. FIG. FIG. 2 schematically shows the scanning unit 20 . The scanning unit 20 has a reflecting mirror (reflecting unit) 21 that reflects the drawing laser beam L, and a driving mechanism 22 that drives the reflecting mirror 21 two-dimensionally. An example of the scanning unit 20 is a MEMS chip using MEMS (Micro Electro Mechanical Systems) technology. In this case, reflector 21 is a MEMS mirror.

The light output unit 10 and the scanning unit 20 may be provided on an electronic cooling module (hereinafter also referred to as TEC (Thermo-Electric Cooler)). Examples of TECs are thermoelectric coolers, or Peltier modules (Peltier elements).

In the optical path of the drawing laser beam L, an aperture through which the drawing laser beam L passes may be provided between the multiplexing unit 13 and the scanning unit 20 . This makes it possible to further reduce the diameter of the drawing laser beam L and cut unnecessary light that does not contribute to drawing.

The light output unit 10 and scanning unit 20 may be accommodated in a package (accommodating unit) 30 . In this case, the package 30 is formed with a window portion 31 through which the drawing laser beam L passes. Window portion 31 can be formed, for example, by attaching window member 32 to opening 30 a formed in the wall surface of package 30 . In one embodiment, the package 30 may be hermetically sealed.

The display system 1 may have a control device 40 that controls the video output module M, as shown in FIG. The control device 40 controls the light output section 10 and the scanning section 20 . The control device 40 drives the light source unit 11 and the scanning unit 20 so that the drawing laser light L draws an image shown to the observer E according to an image input signal input to the control device 40 from the outside. The control device 40 is, for example, an FPGA (field-programmable gate array).

The video input signal is a signal containing information of a video to be displayed (position information of each pixel, color information of each pixel, etc.). The video input signal is produced by a video production device that produces the video to be displayed. The image creation device is, for example, a computer in which image creation software and the like are installed.

FIG. 3 is a functional block diagram of an example of the control device 40. As shown in FIG. The control device 40 has a signal input section 41 , a signal analysis section 42 , a scanning control section 43 , a light source control section 44 and a storage section 45 .

The signal input section 41 receives a video input signal. The signal input unit 41 includes ports to which signal lines and the like are connected.

The signal analysis section 42 analyzes the video input signal input to the signal input section 41 . The signal analysis unit 42 inputs to the light source control unit 44 position information and color information of a plurality of pixels forming an image to be displayed among the image information included in the image input signal.

The scanning control unit 43 controls the scanning unit 20 to draw an image with the drawing laser light L based on the specified frequency. The scanning control unit 43 detects the driving state of the scanning unit 20 and inputs timing information corresponding to the position information of the plurality of pixels to the light source control unit 44 .

The light source control unit 44 drives the light source unit 11 based on the position information, color information, and timing information of the plurality of pixels. Specifically, the light source control unit 44 controls the first light source 12a, the first light source 12a, the Each of the second light source 12b and the third light source 12c is driven.

The storage unit 45 stores a program for causing the computer to function as the control device 40 of the video output module M, information necessary for controlling the video output module M, and the like.

Controller 40 may be, for example, a device dedicated to the display system. Alternatively, a personal computer or the like can be used as the control device 40 by executing a program that implements the functions of the control device 40 . The controller 40 may be part of the video output module M.

Returning to FIG. 1, the light diffusion screen 2 will be described. The light diffusion screen 2 is a screen having light diffusion properties. The light diffusing screen 2 forms a real image (video) 4a by diffusing the drawing laser light L that enters. The light diffusion screen 2 may have light diffusion properties by dispersing light diffusion particles. For example, a light diffusing screen may be a screen having a substrate and light diffusing particles dispersed in the substrate. The light diffusing screen 2 may have light diffusibility due to a fine structure (uneven structure, microlens structure, etc.) provided on the front surface, the back surface, or inside. For example, the light diffusing screen 2 may be a screen having a substrate and the above microstructures provided on the substrate. The base material may be a member formed of a single material (single-layer structure member) or a member in which layers of different materials are laminated (multilayer structure member). The substrate may be a transparent member.

When the surface of the light diffusion screen 2 on which the drawing laser light L is incident is referred to as a front surface 2a, and the surface opposite to the front surface 2a is referred to as a rear surface 2b, the light diffusion screen 2 in this embodiment has a real image on the front surface 2a side. 4a is the screen formed (front type screen). Such a form corresponds to a form in which the light diffusion screen 2 reflects the drawing laser beam L. FIG. The light diffusion screen 2 may have an angular anisotropy of reflectance (or diffusion). In one embodiment, the light diffusion screen 2 has an angular anisotropy of reflectance that can improve the brightness of the image (the real image 4a and its reflected image 4b) shown to the observer E. FIG. The light diffusing screen 2 can have the angular anisotropy in at least one of two orthogonal directions in the real image 4a. The two orthogonal directions are, for example, the long side direction and the short side direction when the formation area of the real image 4a is a rectangle, and the directions of the two orthogonal sides when the formation area is a square. be.

FIG. 4 is a drawing showing an example of the angular anisotropy of the reflectance of the light diffusion screen 2. As shown in FIG. The horizontal axis of FIG. 4 is the angle at the center position of the light diffusion screen 2 with respect to the vertical direction when the light diffusion screen 2 is viewed from the front (front surface 2a side). Equivalent to. The vertical axis in FIG. 4 indicates the screen gain. In one embodiment, the angular anisotropy of the reflectance of the light diffusing screen 2 is represented by the angular anisotropy of the screen gain, as shown in FIG. For example, the light diffusion screen 2 has a mountain-shaped screen gain with a peak gain PG. The light diffusion screen 2 may be a screen having a screen gain of 0.5 or more in the desired viewing range (-α° or more +α° or less). Peak gain PG is, for example, 1.0 or more. The desired viewing range may be, for example, depending on the application of the display system 1, and examples thereof include −70° to 70°, −45° to 45°, and the like. The screen gain characteristic shown in FIG. 4 is an example for one of the above-mentioned two orthogonal directions in the real image 4a, but the other can also have the same screen characteristic. If the real image 4a has the screen gain characteristics (or the angular anisotropy of the reflectance) in both of the two orthogonal directions, the characteristics may be different.

Returning to FIG. 1, the display screen 3 will be described. The display screen 3 is a member for showing the image output from the image output module M to the observer E, having transparency. The display screen 3 is arranged with respect to the light diffusion screen 2 so that the real image 4a on the light diffusion screen 2 is reflected. In such an arrangement, the real image 4 a shown on the light diffusing screen 2 is Fresnel reflected by the display screen 3 . Therefore, the reflected image (video) 4b of the real image 4a is displayed to the observer E. FIG.

The display screen 3 may be an optical member having transparency. The transparency of the display screen 3 is such that the observer E can view the rear side of the display screen 3 (the side opposite to the observer E when viewed from the display screen 3). For example, the above-mentioned "transparency" can be evaluated by the transmittance (light transmittance) in the visible light wavelength band (380 nm or more and 780 nm or less). The display screen 3 is, for example, a screen having a transmittance of 70% or more in the wavelength band of visible light. The transmittance of the display screen 3 may be 80% or more, or 90% or more. Examples of materials for the display screen 3 are glass and resin. A window or the like can also be used as the display screen 3 .

In the display system 1 described above, the drawing laser light L (scanned drawing laser light L) output from the image output module M is incident on the light diffusion screen 2 to form a real image 4a on the light diffusion screen 2. be done. In other words, the image (scanned drawing laser light L) output from the image output module M is projected onto the light diffusion screen 2 . The drawing laser light L that has entered the light diffusion screen 2 and has been diffusely reflected by the light diffusion screen 2 further enters the display screen 3 . The drawing laser beam L incident on the display screen 3 is Fresnel-reflected on the display screen 3 to form a reflected image 4b. In other words, the real image 4 a is reflected on the display screen 3 . Therefore, an observer E looking at the display screen 3 can visually recognize the reflected image 4b.

In the display system 1, since the display screen 3 is transparent, the observer E can see the reflected image 4b (the image output from the image output module M) displayed on the display screen 3 while viewing the display screen 3. The back side (background) of is also visible. That is, in the display system 1, the reflected image 4b can be superimposed on the background and displayed to the observer E, and for example, augmented reality can be realized.

A real image 4 a formed on the light diffusion screen 2 is reflected by the display screen 3 . Therefore, the observer E visually recognizes the reflected image 4b corresponding to the real image 4a. In this case, the display screen 3 is not required to have light diffusing properties as compared to the case where the image output from the image output module M is directly projected onto the display screen 3 . For example, the display screen 3 may not have light diffusing properties. Therefore, the visibility of the background for the observer E is improved.

Since the real image 4a formed on the light diffusion screen 2 is reflected by the display screen 3, in the configuration of the display system 1, the brightness and field of view of the image (specifically, the reflected image 4b) displayed to the observer E are The range is adjustable by the light diffusing screen 2 . Therefore, high brightness and a wide viewing range can be secured. Therefore, for example, a plurality of viewers E can view the video simultaneously. As a result, the observers E can communicate with each other based on the displayed image.

In the form in which the light diffusion screen 2 has angular anisotropy of reflectance, it is easy to improve the brightness of the image (real image 4a). In particular, when the light diffusion screen 2 has the screen gain described with reference to FIG. 4, high brightness can be achieved in the desired viewing range.

As described in this embodiment, the drawing laser beam L is used to form the real image 4a. Since laser light has high directivity, it is possible to efficiently control the luminous flux reaching the field of view of the observer E even with a small luminous flux amount. In other words, by using laser light with high directivity, the light output from the image output module M (drawing laser light L in this embodiment) can be effectively utilized. Therefore, the brightness of the image displayed to the observer E (specifically, the reflected image 4b) can be increased. Since the light output from the video output module M can be effectively used, it is possible to reduce the power consumption of the display system 1 (more specifically, the video output module M).

Furthermore, when the real image 4a is formed by scanning the drawing laser beam L, the image output module M is a module realizing focus-free. In this case, the video output module M and the light diffusion screen 2 can be arranged close to each other. Therefore, the size of the image forming unit (image device) including the image output module M and the light diffusion screen 2 can be reduced, and as a result, the size of the display system 1 can be reduced. Furthermore, the fact that the video output module M is a focus-free module contributes to the simplification of the configurations of the video forming unit and the display system 1 .

In the display system 1, the brightness of the light output from the video output module M, the light diffusibility of the light diffusion screen 2, and the like can easily improve the brightness. Therefore, for example, the brightness of the image (reflected image 4b) visually recognized by the observer E can be increased compared to the case where the image is displayed on a liquid crystal display. Furthermore, the light diffusion screen 2 forms a real image 4a by diffusing the incident light. Therefore, since liquid crystal elements and the like are not required, the durability of the display system 1 can be improved.

When the first light source 12a, the second light source 12b, and the third light source 12c are LD chips, the size of the image output module M can be reduced. As a result, it is easy to realize miniaturization of the video output module M and the display system 1 including the same.

When the first light source 12a, the second light source 12b, the third light source 12c, and the combining section 13 are mounted on a substrate, the first light source 12a, the second light source 12b, the third light source 12c, and the combining section 13 may, for example, , a support base (for example, a submount), or the like.

If the scanning unit 20 is a MEMS chip and is accommodated in the package (accommodating unit) 30 together with the light output unit 10, the size of the image output module M can be reduced. For example, if the scanning unit 20 is a MEMS chip, the scanning unit 20 can also be mounted on the substrate on which the light output unit 10 is mounted. Thereby, the package 30 can be miniaturized. When mounting the first light source 12a, the second light source 12b, the third light source 12c, the combining unit 13 and the MEMS chip (scanning unit 20) on the same substrate, for example, they are appropriately mounted on a support base (for example, a submount) or the like. may be mounted on the substrate via

(Modification 1)
FIG. 5 is a schematic diagram of a display system according to Modification 1. As shown in FIG. A display system 1A shown in FIG. 5 is different from the display system 1 in that an enlarging optical system (first enlarging optical system) 5 is provided between the light diffusion screen 2 and the display screen 3 . The configuration of the display system 1A is the same as that of the display system 1, except that it further includes the magnifying optical system 5. FIG. Therefore, the display system 1A has effects similar to those of the display system 1. FIG.

The magnifying optical system 5 is an optical system that magnifies the real image 4 a and projects it onto the display screen 3 . Specifically, the enlarging optical system 5 propagates the drawing laser light L diffusely reflected by the light diffusing screen 2 to the display screen 3 so that the reflected image 4b becomes larger than when the enlarging optical system 5 does not exist. It is a system. Examples of the magnifying optical system 5 are a magnifying lens, a Fresnel lens, a diffractive lens, and the like. A magnifying lens may be realized by a combination of multiple lenses. A real image 4 a magnified by the magnifying optical system 5 is reflected on the display screen 3 . Therefore, for example, when obtaining a reflected image 4b of the same size, the size of the light diffusion screen 2 can be reduced by providing the enlarging optical system 5. FIG. As a result, the size of the display system 1A can be reduced.

(Modification 2)
FIG. 6 is a schematic diagram of a display system according to Modification 2. As shown in FIG. A display system 1B shown in FIG. 6 is different from the display system 1 in that a reflective section 6 is provided between the image output module M and the light diffusion screen 2. The display system 1B shown in FIG. The configuration of the display system 1B is the same as that of the display system 1, except that the display system 1B further includes a reflector 6. FIG. Therefore, the display system 1B has effects similar to those of the display system 1A.

The reflector 6 is arranged on the optical path of the drawing laser light L output from the image output module M. As shown in FIG. The reflector 6 reflects the drawing laser beam L toward the light diffusion screen 2 . An example of the reflector 6 is a reflector. The reflecting section 6 may be a flat mirror or a curved mirror that magnifies the image output from the image output module M and projects it onto the light diffusion screen 2 . For example, the reflecting surface of the reflecting section 6 may have a convex curved surface facing the light diffusion screen 2 side.

The reflector 6 can bend the optical path of the drawing laser light L from the image output module M to the light diffusion screen 2 . As a result, as shown in FIG. 6, the image output module M is arranged close to the light diffusion screen 2 while securing an optical path length for obtaining a certain size (desired size) of the real image 4a. It is possible. As a result, the size of the image forming unit (image device) having the image output module M and the light diffusion screen 2 can be reduced, and further the size of the display system 1A can be reduced.

If the reflecting section 6 has an image enlarging function, the optical path length for obtaining an image of a certain size can be shortened. Therefore, it is possible to further reduce the size of the image forming unit and the display system 1A.

(Modification 3)
FIG. 7 is a schematic diagram of a display system according to Modification 3. As shown in FIG. A display system 1</b>C shown in FIG. 7 differs from the display system 1 in that an enlarging optical system (second enlarging optical system) 7 is provided between the image output module M and the light diffusion screen 2 . The configuration of the display system 1C is the same as that of the display system 1, except that it further includes the magnifying optical system 7. FIG. Therefore, the display system 1</b>C has effects similar to those of the display system 1 .

The enlarging optical system 7 is an optical system for enlarging the image output from the image output module M and projecting it onto the light diffusion screen 2 . Specifically, the magnifying optical system 7 diffuses the light (drawing laser light L in this modification) output from the image output module M so that the real image 4a is magnified more than when the magnifying optical system 7 does not exist. It is an optical system that propagates to the screen 2 . An example of the magnifying optical system 7 is a magnifying lens. The enlarging optical system 7 may be composed of a plurality of lenses so as to correct chromatic aberration. An enlarged image output from the image output module M is projected onto the light diffusion screen 2 by the enlarging optical system 7 . For example, when obtaining a real image 4a of the same size, it is possible to shorten the distance between the image output module M and the light diffusion screen 2 by providing the magnifying optical system 7. FIG. As a result, the size of the image forming unit (image device) having the image output module M and the light diffusion screen 2 can be reduced, and further the size of the display system 1C can be reduced.

(Modification 4)
FIG. 8 is a schematic diagram of a display system according to Modification 4. As shown in FIG. A display system 1D shown in FIG. 8 differs from the display system 1 in that it has a light diffusion screen 2A instead of the light diffusion screen 2. FIG. The configuration of the display system 1D is the same as that of the display system 1 except that it has the light diffusion screen 2A. Therefore, the display system 1</b>D has the same effects as the display system 1 .

The light diffusion screen 2A differs from the light diffusion screen 2 in that the front surface 2a is curved. The front surface 2a may be a curved surface designed to have at least one of the function of improving the brightness of the real image 4a (reflected image 4b) and widening the viewing range. Even when the angle of view of the drawing laser beam L is large (for example, when the drawing laser beam L is scanned in the vicinity of the edge of the real image 4a), the front surface 2a has an incident area (see FIG. 15) of the drawing laser beam L on the front surface 2a. (corresponding to the beam spot BS shown) can be a curved surface capable of suppressing the spread. In other words, the front surface 2a is a curved surface such that the size of the incident area of the drawing laser light L when the angle of view is large is the same as the incident area when the drawing laser light L is incident near the center of the real image 4a. is. An example of the light diffusion screen 2A having the front surface 2a as a curved surface capable of suppressing the expansion of the incident area of the drawing laser light L is the light diffusion screen 2A1 shown in FIG. For example, the front surface 2a is a curved surface formed so that the drawing laser light L is incident on the front surface 2a more perpendicularly than when the front surface 2a is flat, regardless of the angle of view. In one embodiment, the front surface 2a is formed such that the writing laser beam L is incident on the front surface 2a perpendicularly. For example, as shown in FIG. 8, the front surface 2a may be a convex curved surface toward the rear surface (second surface) 2b opposite to the front surface 2a. The front surface 2a may be curved. The incident area is an area where the drawing laser light L and the front surface 2a intersect when the drawing laser light L (laser beam) being scanned is incident on the front surface 2a.

The front surface 2a may be a curved surface having different curvatures in two orthogonal directions in the real image 4a. The two orthogonal directions are, for example, the long side direction and the short side direction when the formation area of the real image 4a is a rectangle, and the directions of the two orthogonal sides when the formation area is a square. be. The two orthogonal directions may be the horizontal direction and the vertical direction. The front surface 2a may be a free curved surface. Like the light diffusion screen 2A shown in FIG. 8, the rear surface 2b may also have the same curved surface as the front surface 2a.

By forming the front surface 2a into a curved surface in this way, it is possible to control the luminance of the real image 4a (reflected image 4b). In the form in which the front surface 2a is a convex curved surface toward the back surface 2b side, it is possible to reduce the expansion of the incident area of the drawing laser beam L even when the angle of view is large. Therefore, it is possible to suppress the deterioration of the image quality due to the expansion of the incident area. For example, when the image output module M is arranged close to the light diffusion screen 2A in order to reduce the size of the image forming unit (image device) having the image output module M and the light diffusion screen 2, the vicinity of the edge of the real image 4a angle of view becomes relatively large. Even in such a case, deterioration of image quality can be suppressed by using the light diffusion screen 2A having a curved front surface 2a. As a result, in the display system 1D, it is possible to present a clear image to the observer E while reducing the size of the image forming unit (image device).

(Modification 5)
FIG. 9 is a schematic diagram of a display system according to modification 5. As shown in FIG. The display system 1E shown in FIG. 9 is different from the display system 1 in that the drawing laser light L is linearly polarized laser light and that a display screen 50A is provided instead of the display screen 3. FIG. The configuration of the display system 1E is the same as that of the display system 1 except for the differences described above. Therefore, the display system 1E has effects similar to those of the display system 1. FIG.

The video output module M outputs drawing laser light L that is linearly polarized light. When the first light source 12a, the second light source 12b, and the third light source 12c of the image output module M are LD chips, the LD chips output linearly polarized light (for example, S-polarized light). Therefore, by using LD chips for the first light source 12a, the second light source 12b, and the third light source 12c, the linearly polarized drawing laser light L can be easily output. In the form in which the first light source 12a, the second light source 12b and the third light source 12c are LD chips, the output end surface of the LD chip is the main surface of the substrate (the first light source 12a, the second light source 12b and the third light source 12c are mounted). When the first light source 12a, the second light source 12b, and the third light source 12c are mounted so as to be perpendicular to the surface of the light source 12a, the drawing laser light L output from the light output unit 10 is an S-polarized (or TE mode) laser beam. Light. The image output module M may form the linearly polarized drawing laser light L using a linear polarizer. In this case, the first light source 12a, the second light source 12b and the third light source 12c are not limited to LD chips.

The display screen 50</b>A has a screen body 51 and a polarizing element 52 provided on the front surface 51 a of the screen body 51 . The front surface 51a is the surface of the screen main body 51 facing the viewer E (or the surface facing the light diffusion screen 2). The screen main body 51 may be the same member as the display screen 3 shown in FIG. In this case, the display screen 50A corresponds to the screen in which the display screen 3 is provided with the polarizing element 52 .

The polarizing element 52 is a reflective polarizing element that selectively reflects linearly polarized light. The configuration of the polarizing element 52 is not limited as long as it has such characteristics. One example of polarizing element 52 is a wire grid polarizer. The polarizing element 52 is arranged on the screen main body 51 so as to be able to reflect the drawing laser light L, which is linearly polarized light.

The display screen 50A forms a real image 4a, and the drawing laser light L incident on the display screen 50A (the drawing laser light L diffusely reflected by the light diffusion screen 2) is reflected by the polarizing element 52. FIG. Therefore, the amount of reflection is greater than in the case of Fresnel reflection, and as a result, the brightness of the reflected image 4b is improved. Since the polarizing element 52 transmits light other than linearly polarized light, the observer E can also visually recognize the background. That is, the display system 1E can form the reflected image 4b with higher brightness while ensuring the visibility of the background.

(Modification 6)
FIG. 10 is a schematic diagram of a display system according to Modification 6. As shown in FIG. A display system 1F shown in FIG. 10 differs from the display system 1 in that a display screen 50B is provided instead of the display screen 3. In FIG. The configuration of the display system 1</b>F is the same as that of the display system 1 except for the differences described above. Therefore, the display system 1F has effects similar to those of the display system 1. FIG.

The display screen 50</b>B has a screen body 51 and a dielectric multilayer film 53 provided on the front surface 51 a of the screen body 51 . The screen body 51 may be the same member as the display screen 3 shown in FIG. 1, similarly to the screen body 51 described in Modification 5. In this case, the display screen 50B corresponds to the display screen 3 provided with the dielectric multilayer film 53 .

In this modification, the dielectric multilayer film 53 is a flat film. The dielectric multilayer film 53 includes a film with a high refractive index (for example, a film with a refractive index of 2.0 or more and 2.6 or less) and a film with a low refractive index (for example, a film with a refractive index of 1.3 or more and 1.6 or less). film) are alternately laminated. The thickness of the dielectric multilayer film 53 is, for example, 20 nm or more and 900 nm or less. The dielectric multilayer film 53 is a film having a reflection characteristic of selectively reflecting light in the wavelength band included in the drawing laser beam L. FIG. The reflectance of light in the wavelength band reflected by the dielectric multilayer film 53 is, for example, 40% or more and 90% or less, and the transmittance in the visible light wavelength band other than the above wavelength band is 50% or more and 98% or less. be. The drawing laser light L includes three primary colors (red, green and blue). Therefore, in this modification, the dielectric multilayer film 53 selectively reflects red laser light, green laser light, and blue laser light. The wavelength band of red laser light is, for example, a wavelength of 615 nm or more and a wavelength of 660 nm or less. The wavelength band of green laser light is, for example, a wavelength of 495 nm or more and a wavelength of 545 nm or less. The wavelength band of blue laser light is, for example, a wavelength of 430 nm or more and a wavelength of 480 nm or less.

The reflection characteristics of the dielectric multilayer film 53 can be realized by adjusting the thicknesses, materials, etc. of each of the multiple layers that constitute the dielectric multilayer film 53 . An example of the thickness of the layer having a high refractive index in the dielectric multilayer film 53 is 10 nm or more and 100 nm or less, and an example of the thickness of the layer having a low refractive index in the dielectric multilayer film 53 is 10 nm or more and 100 nm or less. be. Examples of materials for the layers having a high refractive index in the dielectric multilayer film 53 include TiO ₂ (titanium dioxide), Nb ₂ O ₂ (niobium pentoxide), Ta ₂ O ₅ (tantalum pentoxide), and the like. Examples of materials for the layers having a low refractive index in the dielectric multilayer film 53 include SiO ₂ (silicon dioxide), MgF ₂ (magnesium fluoride), Al ₂ O ₃ (aluminum oxide), and the like.

The dielectric multilayer film 53 selectively reflects light in the wavelength band included in the drawing laser light L as described above. Therefore, the drawing laser light L (the drawing laser light L diffusely reflected by the light diffusion screen 2 ) forming the real image 4 a and incident on the display screen 50 A is reflected by the dielectric multilayer film 53 . In this case, since the amount of reflection is greater than in the case of Fresnel reflection, the brightness of the reflected image 4b is improved.

Since the dielectric multilayer film 53 transmits light in a wavelength band other than the wavelength band included in the drawing laser light L, the observer E can also visually recognize the background. That is, in the display system 1F, it is possible to form the reflected image 4b with higher brightness while ensuring the visibility (transparency) of the background.

The spectral linewidth of laser light is narrow. Therefore, in the dielectric multilayer film 53, it is possible to increase the reflectance with respect to the drawing laser beam L while minimizing the decrease in the transmittance. As a result, in the mode in which the drawing laser beam L is used as the image light, it is easier to form the high-brightness reflected image 4b while ensuring the visibility (transparency) of the background.

(Modification 7)
11 is a schematic diagram of a display system according to Modification 7. FIG. A display system 1G shown in FIG. 11 differs from the display system 1E shown in FIG. 9 in that a light diffusion screen 2B is provided instead of the light diffusion screen 2. The configuration of the display system 1G other than the above differences is the same as that of the display system 1E. Therefore, the display system 1G has effects similar to those of the display system 1E.

The light diffusion screen 2B is a transmissive screen. In other words, the light diffusion screen 2B is a rear type (or rear projection type) screen. In the light diffusion screen 2B, a real image 4a is formed on the rear surface 2b opposite to the front surface 2a on which the drawing laser beam L is incident. That is, the light diffusion screen 2B has a light diffusing property in which the drawing laser light L is mainly diffused from the front surface 2a toward the back surface 2b. In the display system 1G, the real image 4a formed on the back surface 2b side of the light diffusion screen 2B is reflected by the polarization element 52 of the display screen 50A to form the reflected image 4b.

Since the light diffusion screen 2B is of transmissive type, the arrangement of the video output modules M can be changed.

The light diffusion screen 2B may have an angular anisotropy of transmittance. The angular anisotropy of transmittance may be the same as the angular anisotropy of reflectance. Angular anisotropy of transmittance can be evaluated by screen gain as in the light diffusion screen 2 . An example of the screen gain of the light diffusion screen 2</b>B with angular anisotropy of transmittance is the same as that described for the light diffusion screen 2 . The effects of the light diffusion screen 2B having angular anisotropy of transmittance are the same as those of the light diffusion screen 2 having angular anisotropy of reflectance.

(Modification 8)
FIG. 12 is a schematic diagram of a display system according to modification 8. As shown in FIG. A display system 1H shown in FIG. 12 is different from the display system 1 shown in FIG. 1 in that an external light cutting member 60 is provided between the light diffusion screen 2 and the display screen 3. The configuration of the display system 1H is the same as that of the display system 1 except for the differences described above. Therefore, the display system 1H has effects similar to those of the display system 1. FIG.

The external light cut member 60 is a member (for example, an external light cut filter) for suppressing a decrease in contrast of the reflected image 4b caused by the external light OL. The external light OL is light from outside the system of the display system 1, and is light other than the drawing laser light L, for example.

In one embodiment, as shown in FIG. 12, the external light cut member 60 is the external light OL that enters the display screen 3 from the back side of the display screen 3 and is directed from the display screen 3 to the light diffusion screen 2. A part of the external light OL, a part of the external light directed toward the display screen 3 after being reflected by the light diffusion screen 2, and the like can be cut. The external light cut member 60 is configured to allow the drawing laser beam L to pass therethrough.

For example, the external light cut member 60 may be arranged on a light-transmissive support member, or if the light diffusion screen 2 is arranged inside a housing, it is formed in the housing. It may be arranged in the housing so as to cover the window which is a window and is for propagating the drawing laser beam L (or the real image) to the display screen 3 .

An example of the external light cutting member 60 is a louver film 60A (or louver sheet) schematically shown in FIG. The louver film 60A has louver layers 61 . The louver layer 61 is a layer having a louver structure. Specifically, the louver layer 61 is a layer in which a plurality of light transmitting members 61a and a plurality of light shielding members 61b are alternately arranged along one direction. The light transmission member 61a is an optical member that transmits light (at least light including the wavelength band of the drawing laser light L). The light transmission member 61a is, for example, transparent silicone rubber.

The light shielding member 61b is an optical member for cutting light (at least light including the wavelength band of the drawing laser light L). The light shielding member 61b is a member for cutting light by absorbing or reflecting light. The light shielding member 61b is, for example, black silicone rubber. In one embodiment, the light shielding member 61b is inclined with respect to the thickness direction of the louver layer 61 (the direction perpendicular to the arrangement direction of the light transmitting members 61a and the light shielding members 61b) as shown in FIG. . In the louver film 60A, the arrangement pitch of the plurality of light shielding members 61b (or the interval between adjacent light shielding members 61b), the angle of inclination of the light shielding members 61b with respect to the thickness direction of the louver layer 61, the thickness of the louver layer 61, etc. is adjusted to cut off the external light OL as described above.

The external light cut member 60 may have transparent films 62 and 63 provided on both sides of the louver layer 61 as shown in FIG. Examples of the transparent films 62 and 63 are transparent resin films such as polycarbonate films. The transparent films 62 and 63 can function as protective films for the louver layer 61, for example. The transparent film 63 can also function as a support layer for the louver layer 61 .

Since the external light cut member 60 passes the drawing laser beam L, for example, the external light OL on the same optical path as the drawing laser beam L passes through the external light cut member 60 . However, the external light OL having an optical path different from that of the drawing laser light L is cut by the external light cutting member 60 . Therefore, for example, the contrast of the reflected image 4b is improved compared to the case where the external light cut member 60 is not arranged. As a result, the observer E can easily see the reflected image 4b more clearly.

The external light cutting member 60 is not limited to the illustrated louver film 60A. The external light cut member 60 may be a linear polarization element. The linear polarization element is not limited as long as it has linear polarization characteristics. Examples of linear polarizing elements include linear polarizing films, wire grid polarizers, and the like. The external light cut member 60 is arranged so as to pass the drawing laser light L, which is linearly polarized light. As a result, of the external light OL, a polarized component different from the linearly polarized component of the drawing laser beam L is cut by the external light cut member 60, which is a linearly polarized film. As a result, the contrast of the reflected image 4b is improved. An example of the external light cut rate of the linear polarizer (external light cut member 60) is 55% or more.

The external light cut member 60 may be, for example, a dielectric multilayer film that selectively passes light of each color wavelength band contained in the drawing laser beam L and cuts other light. A dielectric multilayer film can be formed, for example, on a transparent support (eg, transparent film). In one embodiment, the support may also be part of the external light cutting member 60 . In the form in which the drawing laser light L can include red laser light, green laser light, and blue laser light, the dielectric multilayer film (external light cutting member 60) emits red laser light, green laser light, and blue laser light. It is sufficient that it has an optical characteristic of selectively passing the laser light of the other wavelength band and cutting the light of other wavelength bands. Examples of the wavelength bands of red laser light, green laser light, and blue laser light selectively passed through the dielectric multilayer film are the same as the wavelength bands described in relation to the dielectric multilayer film 53 in Modification 6. can be the same. Since the dielectric multilayer film, which is the external light cut member 60, can pass the drawing laser beam L, the reflected image 4b can be visually recognized by the observer E. Since the light outside the wavelength band of each color is cut by the dielectric multilayer film, the influence of the external light OL on the reflected image 4b can be reduced. Although the dielectric multilayer film has been described as an example here, the external light cut member 60 may be a wavelength cut film (or wavelength cut filter) having substantially the same optical characteristics as the dielectric multilayer film.

(Modification 9)
14 is a schematic diagram of a display system according to Modification 9. FIG. A display system 1I shown in FIG. 14 is different from the display system 1 shown in FIG. The configuration of the display system 1I is the same as that of the display system 1 except for the differences described above. Therefore, the display system 1I has effects similar to those of the display system 1. FIG.

The Fθ lens system 8 will be described with reference to FIGS. 15 and 16. FIG. FIG. 15 is a schematic diagram of the light diffusion screen 2 viewed from the front surface 2a side. FIG. 16 is a drawing for explaining the Fθ lens system 8. FIG. For convenience of explanation, the X direction and the Y direction are set as shown in FIG. The X direction is the direction from the end face 2c to the end face 2d of the light diffusion screen 2 (or from the end face 2d to the end face 2c). 2 d of end faces are the surfaces on the opposite side to the end face 2c. The Y direction is the direction from the end face 2e to the end face 2f of the light diffusion screen 2 (or from the end face 2f to the end face 2e). The end surface 2f is a surface opposite to the end surface 2e. In FIG. 15, the real image 4a is schematically shown by broken lines. In Modified Example 9, the light diffusion screen 2 and the real image 4a are oblong, and the length in the X direction is longer than the length in the Y direction. In FIG. 15, beam spots BS, which will be described later, are indicated by hatching. FIG. 16 schematically shows the image output module M, the Fθ lens system 8 and the light diffusion screen 2 viewed from the side of the white arrow A shown in FIG. 14 . In FIG. 16, for convenience of explanation, the light diffusion screen 2 is not tilted, that is, the light diffusion screen 2 is tilted so that the end surface 2e of the light diffusion screen 2 is perpendicular to the direction of the white arrow A in FIG. is placed.

The F.theta. The drawing laser beam L is condensed. The predetermined direction is at least the direction in which the length of the real image 4a is longer, out of the X direction and the Y direction. Specifically, in the ninth modification, the predetermined direction is the X direction. The beam spot BS corresponds to the incident area in Modification 4. A diameter d of the beam spot BS is called a beam spot diameter d. The Fθ lens system 8 may be a single lens, or may be composed of a combination of multiple lenses.

By using the F.theta. It can be reduced compared with the case where it is not used. As a result, it is possible to suppress deterioration in image quality due to the expansion of the beam spot diameter d, and to present a clear image to the observer E. FIG.

In Modified Example 9, since the real image 4a is assumed to be horizontally long, the effect of the beam spot diameter d in the vertical direction (Y direction) is small. Therefore, in the ninth modification, the beam spot diameter d should be substantially the same at least within the scanning range in the X direction. However, the Fθ lens system 8 may converge the drawing laser beam L so that the beam spot diameter d is substantially the same within the scanning range in both the X direction and the Y direction. In this case, the influence of the expansion of the beam spot diameter d can be reduced even in a form in which the real image 4a has the same length in the X direction and the Y direction, or a form in which the length in the Y direction is longer than the X direction.

(Modification 10)
FIG. 17 is a schematic diagram of a display system according to a tenth modification. A display system 1J shown in FIG. and the image output module M in that an enlarging optical system 7 is provided between the display system 1 shown in FIG. The configuration of the display system 1J is the same as that of the display system 1 except for the differences described above. Therefore, the display system 1J has effects similar to those of the display system 1. FIG. Modification 10 will also be described using the same X and Y directions as in Modification 9. FIG. In Modification 10, as in Modification 9, the light diffusion screen 2A1 and the real image 4a are horizontally long, that is, the length in the X direction is longer than the length in the Y direction.

The display system 1J will be described with a focus on the above differences with reference to FIGS. 18 and 19. FIG. FIG. 18 is a perspective view of the light diffusion screen 2A1. FIG. 19 is a drawing for explaining the Fθ lens system 8 and the light diffusion screen 2A1. FIG. 19 schematically shows a case where the image output module M, the enlarging optical system 7, the F.theta. In FIG. 19, for convenience of explanation, the light diffusion screen 2A1 is not tilted, that is, the light diffusion screen 2A1 is tilted such that the end face 2e of the light diffusion screen 2A1 is perpendicular to the direction of the white arrow B in FIG. is placed.

Since the magnifying optical system 7 is the same as the magnifying optical system 7 described in Modification 3, the description thereof is omitted.

As shown in FIGS. 18 and 19, the light diffusion screen 2A1 mainly differs from the light diffusion screen 2 shown in FIG. 1 in that the front surface 2a is curved. In Modified Example 10, the front surface 2a is a curved surface convex toward the rear surface 2b when viewed from the end surface 2e side. In Modification 10, the back surface 2b is also the same curved surface as the front surface 2a. The front surface 2a is curved such that the beam spot diameter d is substantially the same within the scanning range of the drawing laser beam L in a predetermined direction. is curved so that it is incident on the As in the case of Modification 9, the predetermined direction in Modification 10 is at least the direction in which the length of the real image 4a is longer, out of the X direction and the Y direction. Specifically, the predetermined direction is the X direction. .

The F.theta. lens system 8 is the same as the F.theta. lens system 8 described in the ninth modification. Specifically, the Fθ lens system 8 converges the drawing laser light L so that the beam spot diameter d is substantially the same within the scanning range of the drawing laser light L in the predetermined direction.

In Modified Example 10, the light diffusion screen 2A1 has the curved front surface 2a, and the display system 1J has the Fθ lens system 8, so that the beam spot diameter d is increased in the predetermined direction by combining them. The light diffusion screen 2A1 and the Fθ lens system 8 are designed to have substantially the same size within the scanning range.

Since the F.theta. Therefore, even when the angle of view is wide, the spread of the beam spot diameter d (see FIG. 15) of the drawing laser light L is reduced, and as a result, deterioration of image quality is reduced. When the image output module M is arranged close to the light diffusion screen 2A1, the angle of view near the edge of the real image 4a becomes relatively large. Even in such a case, deterioration of image quality can be suppressed by providing the Fθ lens system 8 and using the light diffusion screen 2A1. As a result, in the display system 1J, it is possible to present a clear image to the observer E while reducing the size of the image forming unit (image device).

The display system 1J includes the Fθ lens system 8, and the light diffusion screen 2A1 has the front surface 2a described above. As a result, the conditions required for the F.theta. For example, when the front surface 2a of the light diffusion screen 2A1 is a flat surface and the drawing laser beam L is caused to enter the front surface 2a more perpendicularly due to the action of the Fθ lens system 8, the size of the Fθ lens system 8 is It is preferably the same size as the formation area of the real image 4a. On the other hand, by using the light diffusion screen 2A1 having the front surface 2a together with the F.theta. lens system 8, the size of the F.theta. lens system 8 (eg, the diameter of the F.theta. lens system 8) can be reduced. In this respect as well, it is possible to present a clear image to the observer E while miniaturizing the image forming unit (image device).

Since the display system 1J includes the magnifying optical system 7, as described in Modification 3, the size of the image forming unit (image device) can be reduced, and the size of the display system 1J can also be reduced.

Since it is assumed that the real image 4a is horizontally long also in the tenth modification, the influence of the change in the size of the beam spot diameter d in the vertical direction (Y direction) is small. Therefore, in the case of Modification 10, it is sufficient that the beam spot diameter d is substantially the same at least within the scanning range in the X direction. However, the front surface 2a and the Fθ lens system 8 may be designed such that the beam spot diameter d is substantially similar within the scanning range in both the X and Y directions. In this case, even if the real image 4a has the same length in the X direction and the Y direction, or the length in the Y direction is longer than the X direction, the influence of the spread of the beam spot diameter d can be reduced.

As described above, in the display system 1J, it is possible to reduce the size of the video forming unit (video device). Furthermore, the display system 1J can suppress degradation of image quality while having a configuration that contributes to miniaturization of the display system 1J.

Although the embodiments of the display device and the display system according to the present disclosure have been described above, the display device and the display system according to the present disclosure are not limited to the illustrated embodiments, and various modifications are possible.

When displaying the real image 4a (reflected image 4b) in, for example, one color, the drawing laser light is red, green, or blue laser light. In this embodiment, the light output unit 10 has at least a light source that outputs red, green, or blue laser light and a scanning unit 20 . When the light output unit 10 has two or more light sources that output red, green, or blue laser light, the light output unit 10 has a multiplexing unit. Red or green has better visibility than blue, for example, so when the real image 4a (reflected image 4b) is displayed using red or green, the observer E can easily visually recognize the reflected image 4b. In a mode in which the real image 4a (reflected image 4b) is displayed in one color, for example, and in a mode in which the display screen has a dielectric multilayer film as described in Modification 6, the dielectric multilayer film is sensitive to the drawing laser beam. It may be designed to selectively reflect the wavelength band of the corresponding color laser light (red, green or blue laser light). As a result, as in the case of modification 6, it is possible to improve the visibility of the reflected image (video) 4b while ensuring the visibility of the background.

When displaying the real image 4a (reflected image 4b) in, for example, two colors, the drawing laser light is, for example, a laser light obtained by synthesizing a red laser light and a green laser light. Specifically, the light output unit 10 includes at least one light source that outputs red laser light, at least one light source that outputs green laser light, and a multiplexing unit that multiplexes the red laser light and the green laser light. and a scanning unit 20 . As described above, red or green has better luminosity than, for example, blue. ) 4b is easily visible. In a form in which the real image 4a (reflected image 4b) is displayed in two colors, for example, and in which the display screen has a dielectric multilayer film as described in Modification 6, the dielectric multilayer film is sensitive to the drawing laser beam. It may be designed to selectively reflect the wavelength bands of the included two-color laser beams (two-color laser beams out of red, green, and blue laser beams). Accordingly, as in the case of Modification 6, the visibility of the reflected image (image) 4b for the observer E can be improved while ensuring the visibility of the background.

The number of light sources (laser light sources) included in the light output unit 10 is not limited to three. It may be one or two. Additionally, more than four light sources may be used.

The image light may be light other than laser light. For example, an LED may be employed as the light source provided in the video output module. In this case, the video output module may reflect the light from the LED with a DMD (Digital Mirror Device) and output video light to which image information is added. If the image light is light other than laser light, directivity may be imparted by a lens or the like. In this case, since the image light has directivity, it is easy to achieve high luminance, as in the case of laser light.

Although the case where the image light is drawing laser light that is linearly polarized light has been described, the image light may be light other than linearly polarized light (for example, non-polarized light).

The magnifying optical system 7 described in Modification 7 may be incorporated in the video output module M. In other words, the magnifying optical system 7 may be part of the video output module M. For example, as shown in FIG. 2, when the image output module M has a package 30 having a window 31, the window member 32 of the window 31 may be replaced with an enlarging optical system 7 (e.g., a magnifying lens). may be used.

The various embodiments and modifications described above may be appropriately combined without departing from the scope of the present disclosure. For example, the display system 1J shown in Modification 10 may further include the external light cutting member 60 described in Modification 8, or the display screen described in Modification 5 instead of the display screen 3 in the display system 1J. 50A or the display screen 50B described in modification 6 may be used.

1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J... Display system 2, 2A, 2A 1, 2B... Light diffusion screen 2a... Front surface 2b... Rear surface 2c... End face 2d... End face 2e... End face 2f end face 3 display screen 4a real image 4b reflected image 5 magnifying optical system (first magnifying optical system)
6... Reflector 7... Enlargement optical system (second enlargement optical system)
8 F.theta. lens system 10 light output unit 11 light source unit 13 combining unit 12a first light source 12b second light source 12c third light source 14a lens 14b lens 14c lens 15a filter 15b filter 15c Filter 20 Scanning section 21 Reflector 22 Drive mechanism 30 Package 31 Window 30a Opening 32 Window member 40 Control device 41 Signal input section 42 Signal analysis section 43 Scanning control section 44 Light source Control unit 45 Storage unit 50A, 50B Display screen 51 Screen body 51a Front surface 52 Polarizing element 53 Dielectric multilayer film 60 Outside light cutting member 60A Louver film 61 Louver layer 61a Light transmitting member 61b Light shielding member 62 Transparent film 63 Transparent film BS Beam spot A White arrow B White arrow d Beam spot diameter E Observer M Image output module L Drawing laser beam L1 First laser beam L2 Second laser beam L3 Third laser beam OL External light PG Peak gain

Claims (15)

an image output module that outputs image light for forming an image to be displayed to an observer;
a light diffusion screen that diffuses the image light output from the image output module to form the image;
a display screen that has transparency and reflects the image formed by the light diffusion screen to display the image to the viewer;
comprising
display system. Further comprising an external light cutting member disposed between the light diffusion screen and the display screen for cutting at least part of external light propagating between the light diffusion screen and the display screen;
The display system of Claim 1. The external light cutting member is a louver film,
3. A display system according to claim 2. The light diffusion screen has angular anisotropy in reflectance or transmittance,
4. A display system according to any one of claims 1-3. The screen gain of the light diffusion screen is 0.5 or more in the desired viewing range.
5. A display system according to any one of claims 1-4. Further comprising a first magnifying optical system disposed between the light diffusion screen and the display screen to magnify the image displayed on the light diffusion screen,
6. A display system according to any one of claims 1-5. further comprising a reflection unit disposed between the image output module and the light diffusion screen for reflecting the image light output from the image output module toward the light diffusion screen;
7. A display system according to any one of claims 1-6. a second enlarging optical system disposed between the image output module and the light diffusion screen for propagating the image light to the light diffusion screen so that the image displayed on the light diffusion screen is enlarged; further prepare,
A display system according to any one of claims 1 to 7. the image light is linearly polarized light,
The display screen is
a transparent screen body;
a polarizing element provided on the screen body for selectively reflecting the linearly polarized light;
having
9. A display system according to any one of claims 1-8. The display screen is
a transparent screen body;
a dielectric multilayer film that is provided on the screen body and selectively reflects light in a wavelength band included in the image light;
having
9. A display system according to any one of claims 1-8. wherein the image light is laser light containing at least one color of red, green, and blue laser light;
11. A display system according to any one of claims 1-10. The video output module scans and outputs the laser light so as to form the video.
12. The display system of Claim 11. further comprising an F-theta lens system disposed between the video output module and the light diffusion screen;
13. A display system according to claim 12. A first surface of the light diffusion screen on which the image light from the image output module is incident is a convex curved surface facing away from the first surface.
14. A display system according to claim 12 or 13. a second enlarging optical system disposed between the image output module and the light diffusion screen for propagating the image light to the light diffusion screen so that the image displayed on the light diffusion screen is enlarged; ,
an Fθ lens system arranged between the second magnifying optical system and the light diffusion screen;
further comprising
the image light is laser light containing at least one color of red, green, and blue laser light;
The image output module scans and outputs the laser light so as to form the image;
A first surface of the light diffusion screen on which the image light from the image output module is incident is a convex curved surface facing away from the first surface.
A display system according to any one of claims 1 to 7.

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