JP4159466B2 - Projection configuration - Google Patents

Description

  The present invention is a projection arrangement having a projection device and a projection surface, and in order to form an image on the projection surface, illuminates the projection surface with a light flux for each pixel of the image to be formed by the projection device. Further, the present invention relates to a projector having a light diffusing device for diffusing light passing through the projection surface.

The same kind of projection arrangement known from German Patent No. 19540108C2 is arranged in the instrument panel of an automobile and has a mapping optical system behind the projection surface, the focus on the object side being the projection device and the light beam. Located between the diffuser. By doing so, the image on the projection surface is reflected and magnified by the windshield and can be perceived as a virtual image by the observer.

  However, enlarging and projecting a virtual image on the windshield in this way requires a mapping optical system and requires a large space in the instrument panel. But such a space can hardly be secured by a car. This is because the electrical wiring for the instruments and operating elements and the ducts for the ventilation fan are densely packed in the instrument panel. Any attempt to place the mapping optics in the area below the instrument panel would require a significant change in the design of the car. Furthermore, a very large opening in the instrument panel is required to advance unimpeded by light, which is unacceptable for design reasons.

Furthermore, a holographic projection surface for an automobile is known from German Patent Application No. 19730563 A1. The image information is emitted toward the viewer within an adjustable angle range that is preset when the hologram is formed, and the holographic projection surface absorbs ambient light and only the light required for image display is obtained. It is to be deflected towards the observer. However, the disadvantage of such a projection surface is that the nature of this type of projection surface is almost uncontrollable depending on the wavelength of the incident light bundle and the incident direction of the effective light beam bundle. Furthermore, the quality of the image display and the state of the projection surface itself are very strongly dependent on the viewing direction.

  An object of the present invention is to improve the projection arrangement of the kind described at the beginning and realize a high quality image display.

  In order to solve this problem, in the projection arrangement of the type described at the beginning, the projection surface includes a mirror, and a light diffusing device is provided in front of the mirror when viewed in the direction of the light bundle incident on the projection surface. And the mirror reflects each ray bundle coming from the projection device, passing through the light diffusing device and impinging on the mirror, so that at least one outgoing ray bundle passing through the light diffusing device is formed with the principal ray. And the principal rays of the outgoing light bundle starting from the location of the projection plane that is adjacent in the first direction (or a location on the projection plane) converge in a virtual observation field in one plane, and The diffusion of each outgoing light bundle caused by the light diffusing device is such that the outgoing light bundle is diffused each time and the illumination field or more is not illuminated in the plane. Reflecting with a mirror and diffusing the outgoing light bundle with a light diffusing device advantageously allows almost all of the light energy to reach the field of view, thus significantly increasing the brightness of the image. When the projection arrangement according to the present invention is incorporated into a vehicle such as an automobile, a contrast ratio of up to 1: 500 can be achieved.

Furthermore, the structure of the projection arrangement is relatively simple based on the projection plane, so that the projection arrangement can be realized particularly inexpensively.
Due to the directivity of the projection plane and the high brightness of the image based thereon, the power consumption of the projection arrangement is also very low, for example less than 50 watts.

  In an advantageous configuration of the projection arrangement according to the invention, the projection surface is curved. This curvature may be different in various directions, and in particular the curvature can be selected such that the projection surface is, for example, wavy. However, since directivity is always given regardless of the curvature present on the projection surface, it is advantageous that the geometric shape of the projection surface can be selected regardless of its optical properties. Taking advantage of this, for example, when the projection arrangement according to the present invention is used in an automobile, the projection surface is provided on the instrument panel in conformity with the (curved) shape of the instrument panel, or is integrated with the instrument panel. Can be By doing so, the demand for high design is met, especially in automobile manufacturing.

  In a preferred configuration of the projection arrangement according to the invention, the light diffusing device includes a scattering layer, which may in particular be formed as a foil. This scattering layer allows the outgoing beam to be diffused as desired in a very simple manner. Such a scattering layer can be provided with a small gap with the mirror or directly on the mirror, whereby an optimum image quality is achieved. The scattering layer can preferably have the same curvature as the projection surface and can therefore be made very compact.

  Further, in the projection arrangement according to the present invention, the intensity distribution of the outgoing light bundle is defined by the light diffusing device, and the principal ray intensity is maximum in each ray bundle, and the angle with respect to the principal ray for the remaining rays. As it increases, it can decrease. With such an intensity distribution, good image quality is achieved.

  In particular, the light diffusing device may further include a light shielding plate that blocks incident light coming from a direction different from the direction of the light flux coming from the projection device and the direction of the outgoing light. Such a light-shielding plate ensures that the incident light bundle hits the mirror without being disturbed, and that the outgoing light bundle is perceived by the observer, while unwanted ambient light is blocked and therefore does not degrade the image display quality. Is done. Furthermore, when this projection arrangement is used in an automobile, the light shielding plate ensures that the projection surface outside the automobile is not perceived as a bright light emitting surface. Furthermore, the shading plate can be colored in the same color as the instrument panel, so that the projection plane can be visually integrated with the instrument panel.

  In particular, such a light shielding plate can be positioned in front of the scattering layer in the direction of the light beam incident on the projection surface. In such an arrangement, the action of the light shielding plate is very effective. The light shielding plate further includes a plurality of thin plates that are separated from each other and extend in parallel, and shields light that strikes these thin plates. The light-shielding plate can further include a plurality of second thin plates that are spaced apart from each other and extend in parallel. These thin plates shield light that strikes the thin plates and are disposed in a transverse direction with respect to the first thin plate. ing. Such a light-shielding plate having a thin plate is described in, for example, US Pat. No. 6,269,911 B1, and is commercially available as a foil. Therefore, the projection arrangement according to the present invention can be easily realized.

  Furthermore, the projection arrangement according to the invention may include a reflective layer in which the mirror is curved and continuous. This can be achieved, for example, by a mirror-finished surface of the support, which is formed as a continuously extending free-form surface. In this case, the curvature of the free-form surface is selected so that the chief rays converge on the corresponding pixels in the specular reflection of the incident beam.

Alternatively, in the projection arrangement according to the invention, the mirror can also be formed as a polygon mirror having a plurality of smooth mirror surfaces. In this case, a part of the scattering layer can be directly provided as a coating on each mirror surface. In such a polygonal mirror, it is possible to define the inclination of the mirror surface regardless of the desired curvature of the projection surface.

  In particular, the mirror surfaces can be arranged such that the surface normals of at least two mirror surfaces are not parallel to each other. Preferably, an arrangement is selected such that the reflection causes chief ray convergence. As a result, the directivity of the projection plane can be adjusted regardless of the desired curvature of the projection plane, and the projection plane can be easily adapted to predetermined basic conditions.

  In a particularly preferred configuration example of the projection arrangement according to the invention, the area of each mirror surface is smaller than the size of the pixels of the image to be formed on the projection surface. In this case, if the number of mirror elements is twice the number of pixels, the image quality is significantly improved. In this configuration example, a plurality of non-parallel outgoing beam bundles can be formed from one incident beam bundle by reflecting the incident beam bundle on a plurality of mirror surfaces.

In an advantageous configuration of the projection arrangement according to the invention, the mirror is a reflecting mirror. In this case, it is possible to effectively prevent contamination and image display deterioration due to the contamination.
Furthermore, in the projection arrangement according to the invention, the mirror can include a transparent plate, at least one side of the plate is structured such that the direction of the light bundle passing through the plate changes. By doing so, the mirror can be realized particularly simply. The plate also causes the chief rays to converge based on the direction change caused by the plate.

  Preferably, the side of the plate opposite the light diffusing device is structured and mirrored so that the mirror can be realized in a compact form with only one element. This also makes it possible to reduce the production costs of the mirror and thus the projection arrangement according to the invention.

  In the projection arrangement according to the invention, the principal rays of the outgoing light bundle starting from the location of the projection plane adjacent in the second direction converge in the observation field based on the reflection in the mirror, and in the second direction. Is different from the first direction. In particular, both directions can surround a 90 ° angle. In particular, all the principal rays of the outgoing light bundle can be converged in the observation field. This configuration example is advantageous in that the brightness of the image can be increased.

  In particular, in the projection arrangement according to the present invention, the projection device can form a light beam whose intensity is adjusted, and can be deflected by the projection surface to form an image. This deflection of the light bundle can be in the form of a scan pattern (deflection is linear over the entire image range, the light bundle is scanned darkly in dark pixels) or in vector form (deflection is mainly performed only along bright pixels). Done). Thereby, it is possible to easily form a real image on the projection surface.

  Conveniently, the beam bundle is approximately collinear and the emittance can be less than 0.2 mm mrad (eg, 0.1 mm mrad). Such a light bundle can be formed particularly simply and efficiently by a laser and can be monochromatic or multicolored for color images.

Along with the use of such a descriptive projection apparatus, it is also possible to provide a mapping projection apparatus. In the mapping type projection apparatus, a desired image can be formed by, for example, a vibrating mirror matrix or an LCD module, and can be projected on a projection surface by a projection optical system.

  The projection arrangement according to the invention is advantageous when used in the case where an image is emitted with a specific radiation characteristic from a surface having a predetermined surface shape. This is because the projection plane of the projection arrangement configuration according to the present invention can be formed according to a predetermined surface shape.

It is particularly advantageous when the projection arrangement according to the invention is used in a motor vehicle, the projection plane being preferably formed on the instrument panel or as a component part thereof.
The projection arrangement according to the present invention can be configured so that a real image on the projection plane can be directly grasped by the observer. In this case, display of a real image with a very high quality is achieved.

Alternatively, the projection arrangement according to the invention can have a (preferably substantially smooth) reflection surface arranged in front of the projection surface, and the outgoing light flux is reflected on this reflection surface, so that the projection surface The image formed above can be grasped as a virtual image. Therefore, the projection plane can advantageously be arranged so that it is not directly visible to the observer, thereby increasing the possibility of the arrangement of the projection plane.

  When the projection arrangement according to the invention is used in a motor vehicle, the reflecting surface can be realized particularly simply by means of a windshield (or preferably a smooth glass plate arranged in front of the windshield in the motor vehicle). Since the image can be formed in a desired size on the projection surface, it is advantageous that no mapping optical system is required between the projection surface and the reflection surface.

  Particularly advantageous in this case is that this virtual image can be grasped by the observer in a scene image in front of the windshield (i.e. outside the car), so that the observer or driver sees the eye slightly when observing the virtual image. Only need to be adapted.

  If the windshield is curved, the dimensions of the image may change slightly. In this case, the geometry correction of the image known by tilt projection can be performed. This is described, for example, in DE19737374C2.

  In the projection arrangement according to the invention, the outgoing beam bundle is preferably diffused isotropically, so that the light diffusing device can be constructed particularly simply. When the projection arrangement according to the invention is used in a motor vehicle, the divergence angle of the outgoing beam can be 2 to 10 °, particularly in a space situation typical in a motor vehicle, especially when the divergence angle is 5 °. It turns out to be advantageous. For example, when the observation field has various widths and heights, it is possible to cause the diffusion of the outgoing light beam to be anisotropic.

  Furthermore, the reflective layer of the mirror where the specular reflection takes place can be structured such that the function of the light diffusing device is also triggered at the time of reflection. Such a mirror can be produced, for example, by mirroring the structured surface after the desired surface structure has been imitated on the surface of the plate.

Embodiments of the present invention will be described below in detail with reference to the drawings.
FIG. 1 shows a side view of an embodiment of a projection arrangement according to the invention. This projection arrangement is incorporated in an automobile and includes a projection device 1 and a projection plane 2. The projection device 1 is disposed in the vicinity of the windshield 3 in the ceiling area in the automobile, and the projection surface 2 is provided on the instrument panel 4. In this case, the shape of the projection surface 2 is usually adapted to the shape of the instrument panel 4 having different curvatures in various directions. Of course, it is also possible for the projection plane 2 to be configured as an integral part of the instrument panel 4 at the same time, which can typically have a size of 35 cm wide and 10 cm high.

The projection device 1 forms a light bundle 5 having an intensity adjusted substantially parallel. The beam bundle 5 is deflected by the projection plane 2 as shown schematically in FIG. 1 to produce a real image thereon. The projection surface 2 emits the light coming from the projection device 1 as an outgoing light bundle 6 toward the driver 8 only in a predetermined space region 7. As a result, when the driver sits in the driver's seat of the automobile, a real image can be grasped on the projection plane 2.

  Based on this predetermined radiation property of the projection plane 2, the image on the projection plane 2 can only be seen within an observation field located in one plane at any distance from the projection plane. In FIG. 1, the observation visual field 9 is directly written in the range of the driver's eyes 10.

  The size of the observation field 9 is defined by the radiation characteristic of the projection plane 2 and this radiation characteristic is adjusted by the measures detailed below so that drivers 8 of different physiques can see the image of the projection plane. It is like that. In addition, the normal range of motion of the head (and thus also the range of motion of the eye) is taken into account, where the rectangular observation field 9 has an extension of about 30 × 30 cm at a position about 800 mm away from the projection plane 2.

  In order to form the desired radiation characteristics of the projection surface 2, the projection surface 2 has a polygon mirror 11 as seen in the exploded view of the portion of the projection surface 2 shown in FIG. A light diffusing device 12 composed of 13 and a blind type light shielding plate 14 is mounted.

  The polygonal mirror 11 on the projection surface 2 serves to locally and individually reflect the incident light beam 5 of the projection device 1, and a scattering layer 13 is provided to diffuse the reflected light beam 6 as desired. The blind shading plate 14 can be used to limit the light diffusion caused by the scattering layer 13, if necessary. Further, the blind light shielding plate 14 prevents undesirable ambient light from hitting the polygonal mirror 11 to deteriorate the image display, and prevents the real image from being viewed by a third party. The polygon mirror 11, the scattering layer 13, and the blind light shielding plate 14 are optimized with respect to their optical roles.

  For example, the polygon mirror 11 includes a PMMA plate 15 (PMMA: polymethyl methacrylate), and the surface directed to the scattering layer 13 is structured and mirror-finished. The structuring is performed such that a large number of microprisms 16 are formed and each prism surface is used as a smooth mirror surface 17. By appropriately forming the microprisms 16, it is possible to adjust the inclination of the mirror surfaces 17 completely independently of each other and within wide limits irrespective of the geometric (visual) shape of the projection surface 2. This adjustment is performed in a known shape or a predetermined shape of the projection surface 2 so that the light beam reflected by the mirror surface 17 is reflected only by the spatial region 7 as described in detail below.

  The scattering layer 13 is formed as a foil. The foil rests directly on the polygonal mirror 11, and the divergence angle of the light beam passing through the scattering layer 13 (half the open angle of the light beam) is shown as schematically shown by the scattering lobe 18 in FIG. Enlarge. Here, the diffusion caused by the scattering layer 13 is selected such that the divergence angle of the outgoing beam 6 is in the range of 2 to 10 °. For the scattering layer 13, for example, a holographic diffuser manufactured by POC Physical Optics Corporation Torrance (Trans, Canada) can be used. This has the advantage that the transmission is almost independent of the wavelength used here.

A blind-type light shielding plate 14 is provided on the scattering layer 13. It is formed as a foil and has a large number of thin plates 19 which are spaced apart and extend in parallel, and the thin plates 19 absorb the light impinging on the thin plates. The angle range of incident light and outgoing light can be limited in the transverse direction with respect to the thin plate 19 by the distance between the thin plates 19, the inclination in the foil, and the height. In this case, the blind light shielding plate 14 is configured such that the incident light bundle 5 and the outgoing light bundle 6 can pass through the blind light shielding plate without being obstructed. In particular, the blind-type light shielding plate 14 disadvantageously prevents external light (for example, sunlight or indoor lighting) that strikes the projection surface 2 from being perceived on the projection surface 2 by the driver 8. Further, the blind light-shielding plate 14 can be colored with the same color as the instrument panel 4 to adapt the appearance of the projection surface 2 to the instrument panel. Furthermore, the blind light shielding plate 14 prevents the projection surface 2 from appearing as a light emitting surface outside the automobile. Such a blind foil 14 having the desired properties (e.g. sheet slope) can be purchased from 3M Company, for example.

As can best be seen in the side view of FIG. 3, the projection device 1 uses a collinear (or nearly collinear) beam bundle, each of which is intensity-adjusted, in one of the primary colors, ie red, green and It includes three laser light sources 20, 21, 22 that emit blue and a light collecting device 23. The light collecting device 23 superimposes the three light bundles of the laser light sources 20, 21, and 22 on one common red, green, and blue light bundle. The beam bundle is then scanned across the projection plane 2 in a row direction (parallel to the windshield 3) and in a column direction perpendicular thereto by a deflector 24 operating in a biaxial manner in the projection apparatus 1. The deflection angle in the column direction is ψ, and the deflection angle in the row direction is φ as shown in FIG. 4 as viewed from the line of sight of the driver 8. Furthermore, the ray paths for the various pixels P1, P2, P3, P4, P5 and P6 on the projection plane 2 are shown (P1-P3 in the column direction and P4-P6 in the row direction are adjacent). The size of the image is determined by the sizes of the angles ψ and φ and the distance between the deflecting device 24 and the projection plane 2. In the example shown in the figure, this interval is about 700 mm, ψ = 4 °, and φ = 28 °, and the image size is about 10 × 35 cm. When the angles ψ and φ are set as fixed values by the deflecting device 24 and the desired image size cannot be obtained on the projection plane 2 (for example, when the projection interval is determined by the assembling conditions), deflection A known conversion optical system can be placed in the beam path behind the device to adapt the deflection angle and image size as desired.

  As can be seen in FIG. 3, the nearly collinear beam bundle 5 has an emittance of less than 0.2 mm mrad (eg 0.1 mm mrad) and is directed to the projection plane 2 to form the pixels P1 to P6. It is emitted from the surface 2 as a divergent beam bundle 6 each having a principal ray 25 (the principal ray 25 is generated on the basis of specular reflection without ray diffusion, that is, according to the law of reflection (incident angle and emission angle are equal). Light). In this case, all the principal rays 25 converge on the eye point 26 in the observation visual field 9 or on a spatial region including the eye point 26. This is accomplished by tilting the mirror surface 17 corresponding to each of the pixels P1 to P6 and deflecting the chief ray 25 toward the eye point 26 when the incident ray bundle 5 is specularly reflected.

  Therefore, the inclination of the mirror surface 17 is adjusted according to the local position in the projection surface 2, the distance from the eye point 26, and the incident angle of the light beam 5 impinging on the projection surface 2 according to the law of reflection. In order to clearly show this reflection, in FIG. 3, an optical perpendicular line 27 is written for the pixel P2, and in FIG. 4, an optical perpendicular line 27 'is written for the pixel P5.

  Further, as shown in FIG. 3 and FIG. 4, when the macroscopic surface normal 28 for the pixel P2 and the macroscopic surface normal 28 'for P5 are assigned to the projection plane 2, the optical normal is applied in both the row direction and the column direction. 27, 27 'and the surface normals 28, 28' have different inclinations. In FIG. 3 and FIG. 4, the angles γ and δ surrounded by these lines are entered. From this, it is clear that the (visual) surface shape of the projection surface 2 can be selected irrespective of the desired direction of the reflected light bundle 6. Therefore, the desired optical properties of the projection surface 2 can be formed almost independently of the shape (or curvature) of the projection surface 2.

  Further, the light beam reflected on the mirror surface 17 is diffused by the scattering layer 13, and the divergence angle Θ of the output light beam 6 in the column direction and the divergence angle τ in the row direction take predetermined values. These values arise from the distance between the viewing field 9 and the projection plane 2 and are selected so that the divergent beam 6 illuminates the viewing field 9 respectively.

In the example described here, the distance between the driver 8 and therefore the observation field 9 and the projection plane 2 is about 800 mm, and the observation field has a spread of 20 × 20 cm.
Are preferably adjusted to 5 ° respectively. Thereby, the diffusion by the scattering layer 13 is isotropic, and the divergence angles Θ and τ are equal.

Of course, the divergence angles Θ and τ can have different values. In this case, the spread of the observation field is also different in the row direction and the column direction.
Further, also in FIGS. 3 and 4, a scattering lobe 18 for the illustrated outgoing ray bundle 6 is shown. It can be seen from these scattering lobes 18 that the brightness of the image is highest at the center of the observation field 9 and decreases toward the periphery. In this case, the decrease is relatively small at the beginning from the center, and decreases very strongly in the peripheral region. By doing so, the brightness of the image can be distributed relatively uniformly over the entire observation field.

  Due to the directional radiation characteristics of the projection plane 2, it is also achieved that almost all the light energy used for the projection is mapped in the observation field 9 and thus in the range of movement of the eye 10. By doing so, sufficient brightness of the projected image can be caused, and the image can be seen well by the driver 8 even in the daytime.

  FIG. 5 is an enlarged cross-sectional view of a portion of the projection plane 2. As can be seen in FIG. 5, the projection plane 2 produces from each incident beam bundle 5 an outgoing beam bundle 6 having a principal ray 25. The direction of the principal ray 25 is also determined based on the specular reflection in the mirror-finished microprism surface 17. The divergence angles Θ and τ of the outgoing light beam 6 are adjusted by the scattering layer 13. In the example shown in FIG. 5, the brand-type light shielding plate 14 also contributes to the restriction of the divergence angle. This is because the blind light-shielding plate 14 absorbs scattered light that causes the divergence angle to increase. Therefore, the blind type light-shielding plate 4 can further reduce the divergence angle of the outgoing light bundle 6 formed by the scattering layer 13 in a planned manner.

  FIG. 6 shows another possibility of realizing the polygon mirror 11 in an exploded view. The polygon mirror 11 includes a first PMMA plate 29 and a second PMMA plate 30. On the surface of the first plate 29, grooves 31 extending in parallel with each other are formed. These grooves 31 have a V-shaped cross section (as shown in the enlarged partial view). This surface is mirror-finished, and the smooth mirror surface 17 has an incident angle of 40 °. The second PMMA plate 30 has a flat side 30 ′ directed to the first plate 29 and a second side 32 opposite thereto. The second side 32 includes a number of V-shaped cross-sectional grooves 33 extending parallel to each other. In this case, one side of the V-shaped cross section is substantially perpendicular to the flat side 30 ', and the other side of the V-shaped cross section acting as the optical working surface 34 is more flat than the first side together with the flat side 30'. Surround a small angle. Further, the inclination angle of the working surface 34 of the groove 33 increases from the center M of the second plate 30 toward both outer sides in a direction orthogonal to the groove direction. The second PMMA plate 30 having the same function as the cylindrical lens is placed on the first PMMA plate 29 so that the groove 33 intersects the groove 31 at a right angle. By doing so, the deflection of the outgoing beam 6 is formed on the one hand by refraction on the second plate 30 and on the other hand by reflection on the first plate 29.

  With the polygon mirror shown in FIG. 6, the convergence of the principal ray 25 is caused only for the outgoing beam bundle 6 starting from the location of the projection surface adjacent in the groove direction of the groove 31, and is orthogonal to the groove direction. The principal rays of the beam bundle 6 starting from the adjacent locations can travel in parallel or spread out. In this case, the diffusion of the outgoing beam bundle in this direction is chosen so that the outgoing beam bundles still overlap in the range of the eye 10.

  In another possible configuration of the polygonal mirror 11 shown in FIG. 7, a groove structure having a groove 36 having a V-shaped cross section is formed below the PMMA plate 35, and this groove structure is mirror-finished. Since a groove structure corresponding to the PMMA plate 30 is provided on the upper side of the plate 35, the polygon mirror 11 is formed as a back mirror.

  Another embodiment of a projection arrangement according to the present invention is shown in FIG. The difference from the embodiment shown in FIG. 1 is that the projection device 1 is not located in the ceiling area of the automobile, but is incorporated inside or behind the instrument panel 4.

  The light beam emitted from the projection device 1 travels substantially parallel to the windshield 3, hits a reflector 37 disposed in the vicinity of the windshield 3 in the ceiling area inside the automobile, is reflected here, and is again reflected on the windshield 3. And almost parallel to the projection surface 2. The position of the reflecting mirror 37 can be adjusted or fixed to match the position of the image to the driver's desire. The driver is preferably used only to bend the beam path. Then, the projection apparatus 1 can be arranged in the instrument panel 4, and the space required for the projection arrangement configuration in the automobile room accessible to the driver is only the (small) reflector 37.

  The space for incorporating the reflecting mirror 37 can be hidden by the rearview mirror 38, for example. As shown in FIG. 8, when the light shielding plate 39 is further provided on the windshield 3, the reflecting mirror 37 cannot be seen from the outside of the automobile. It is possible to hide the reflecting mirror 37 in the same manner for the projection apparatus 1 in the embodiment shown in FIG.

  FIG. 9 shows another embodiment of the projection arrangement according to the invention. Unlike the above-described embodiment, the projection surface 2, particularly the blind light shielding plate 14, is formed so that the projection surface 2 is not directly visible to the driver 8. The driver 8 sees an image in which the real image (intermediate image) generated on the projection surface 2 is reflected by the inner side 40 of the windshield 3. Therefore, for the driver 8, a real image (virtual) image 41 generated on the projection plane 2 appears in an actual scene image in front of the windshield 3. The other elements of the projection arrangement shown in FIG. 9 substantially correspond to the elements of the embodiment shown in FIG.

  In particular, when the projection apparatus 1 having a laser light source is used, a sufficiently bright image impression can be obtained due to the reflectivity existing at the glass / air interface. In order to suppress ghosting that may be caused by reflection at the outer interface of the windshield 3, known measures can be implemented, for example, enhancing broadband reflection at the inner surface 40 of the windshield 3.

In the embodiment shown in FIG. 9, since the light shielding plate 42 can be provided on the inner side 40 of the windshield 3 in the range of the instrument panel 4, the projection plane 2 is not visible from the outside.
The projection arrangement shown in FIG. 10 is slightly different from the embodiment shown in FIG. 9, and the projection apparatus 1 is not in the ceiling area of the automobile, but inside the instrument panel 4 (similar to the projection arrangement shown in FIG. 8). Is arranged. Further, a reflecting mirror 37 is disposed between the rearview mirror 38 and the light shielding plate 39 in the automobile ceiling area. The light beam 5 emitted from the projection device 1 travels substantially parallel to the windshield 3 and strikes the reflecting mirror 37. The reflecting mirror 37 reflects the light beam 5 to the projection plane 2. The light beam 6 starting from the projection surface 2 is reflected by the inner side 40 of the windshield 3, and the virtual image 41 can be seen in the actual scene image in front of the windshield 3 outside the automobile again for the driver 8.

  Of course, in addition to the embodiments described above, the projection device 1 is arranged in another area of the ceiling surface or in the side frame of the windshield 3, for example in the area of the A pillar, and projected obliquely on the projection surface 2, or in some cases It is possible to provide a necessary reflecting mirror.

The side view of embodiment of the projection arrangement configuration by this invention. FIG. 2 is an exploded view of an enlarged portion of the projection surface shown in FIG. 1. The side view which added the light path for description in embodiment shown in FIG. The figure which looked at the embodiment shown in Drawing 3 from the driver. The expanded sectional view of the part of the projection surface shown in FIG. It is a figure which shows embodiment of the mirror of a projection surface. The figure which shows another embodiment of the mirror of a projection surface. FIG. 6 is a side view of another embodiment of a projection arrangement according to the present invention. FIG. 6 is a side view of another embodiment of a projection arrangement according to the present invention. FIG. 6 is a side view of still another embodiment of the projection arrangement according to the present invention.

Claims (19)

A projection device (1) and a projection surface (2), and each pixel (P1-P6) of the image to be formed by the projection device (1) to form an image on the projection surface (2 ) . Projection arrangement configuration comprising a light diffusing device (12) for illuminating the projection surface (2) with a light beam bundle (5), and for the projection surface (2) to diffuse light passing through the projection surface (2) In
The projection surface (2) includes the mirror (11), and a light diffusing device (12) is provided in front of the mirror (11) when viewed in the direction of the light beam (5) incident on the projection surface (2). The mirror (11) comes from the projection device (1), passes through the light diffusing device (12), reflects each light beam (5) impinging on the mirror (11), and reflects the light diffusing device (12). At least one outgoing beam bundle (6) is formed by the chief ray (25), and the outgoing beam bundle (6) starting from the location of the projection plane (2) adjacent in the first direction ) Converges in a virtual viewing field (9) in one plane, and the diffusion of each outgoing beam bundle (6) caused by the light diffusing device (12) The bundle diffuses each time, and only the range of the observation field (9) is illuminated within a predetermined plane,
The mirror (11) is formed as a polyhedral mirror having a plurality of smooth mirror surfaces (17), each mirror surface (17) defining an optical normal (27, 27 '), and each optical normal (27, 27'). ) Are perpendicular to the corresponding mirror surface (17), and the incident angle of the light beam line (5) incident on each mirror surface (17) and the emission angle of the principal ray (25) from each pixel are represented by When measured with the optical perpendicular (27, 27 ') as a reference, the incident angle and the outgoing angle are equal,
The macroscopic surface shape of the projection plane (2) has a curved portion including a plurality of pixels (P1-P6), and each pixel (P1-P6) has a macroscopic normal (28, 28 ′). ) And viewed with the naked eye, each macroscopic normal (28, 28 ') is perpendicular to the corresponding pixel (P1-P6),
Furthermore, the specular surface normal (28, 28 ') and the optical perpendicular (27, 27') can be set to have different inclinations depending on each mirror surface (11) , and the surface shape of the projection surface (2) Is a projection arrangement configuration characterized in that it can be selected irrespective of the desired direction of the reflected beam (6).   Projection arrangement according to claim 1, characterized in that the projection surface (2) is curved.   Projection arrangement according to claim 1 or 2, characterized in that the light diffusing device (12) includes a scattering layer (11).   Projection arrangement according to claim 3, characterized in that the scattering layer (13) is attached to the mirror (11).   The light diffusing device (12) includes a light shielding plate (14), and the light shielding plate (14) is different from the direction of the light beam (5) coming from the projection device (1) and the direction of the outgoing light (6). The incident light coming from the direction is blocked, and the light shielding plate (14) is preferably arranged so as to be positioned in front of the scattering layer (13) when viewed in the direction of the light beam (5) incident on the projection surface (2). The projection arrangement configuration according to claim 1, wherein the projection arrangement configuration is provided.   The projection arrangement according to claim 5, wherein the light shielding plate (14) further includes a plurality of thin plates (19) which are spaced apart from each other and extend in parallel to shield light hitting the thin plates (19). Constitution.   The light shielding plate further includes a plurality of second thin plates that are spaced apart from each other and extend in parallel. These thin plates shield light that strikes the thin plates and are transverse to the first thin plate (19). The projection arrangement configuration according to claim 6, wherein the projection arrangement configuration is arranged as follows.   The projection arrangement according to claim 1, wherein the mirror includes a reflective layer that is curved and continuous. The projection arrangement according to any one of claims 1 to 8, wherein the mirror surface (17) is arranged in a direction in which surface normals of at least two mirror surfaces (17) are not parallel to each other. The mirror surface (17) is arranged in such a direction that the convergence of the chief ray is achieved by reflection. The projection arrangement configuration according to claim 1, wherein the projection arrangement configuration is provided. 11. Projection arrangement according to any one of the preceding claims, characterized in that the area of each mirror surface (17) is smaller than the size of the pixels of the image to be formed on the projection surface (2). The mirror (11) includes a transparent plate (30, 35), and at least one side of the plate is structured so that the direction of the light bundle passing through the plate (30, 35) changes. The projection arrangement configuration according to any one of claims 1 to 11, wherein: 13. Projection arrangement according to claim 12, characterized in that a chief ray convergence is achieved on the basis of the direction change caused by the plates (30, 35). 14. Projection arrangement according to claim 12 or 13, characterized in that the opposite side of the plate (35) from the light diffusing device is structured and mirror-finished. The principal ray (25) of the outgoing beam bundle (6) starting from the location of the projection plane (2) adjacent in the second direction converges on the observation field (9) based on the reflection at the mirror (11). The projection arrangement according to any one of claims 1 to 14, wherein the second direction is different from the first direction. 16. Projection arrangement according to any one of the preceding claims, characterized in that all principal rays (25) of the outgoing beam (6) converge in the viewing field (9). 17. Projection arrangement according to any one of the preceding claims, wherein the projection device (1) forms a beam of light with an adjusted intensity and deflects it with the projection surface (2) to form an image. . On the reflection surface (3) provided in front of the projection surface (2), the outgoing light beam (6) is reflected by this reflection surface (3), and the image formed on the projection surface (2) thereby becomes a virtual image. The projection arrangement according to any one of claims 1 to 17, wherein the arrangement is arranged so as to be grasped. The projection arrangement according to any one of claims 1 to 18, wherein the mirror and the light diffusing device are integrally formed.

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