JP4639691B2 - Optical scanning device and image display device - Google Patents

Description

  The present invention relates to an optical scanning device and an image display device, and more particularly to an optical scanning device for displaying an image by scanning a laser beam modulated in accordance with an image signal, and an image display device using the optical scanning device. Regarding technology.

  In recent years, laser projectors that display images using laser light have been proposed. Laser light is characterized by high monochromaticity and directivity. Further, by using a laser light generator as the light source unit, the optical system of the projector can be reduced in size. For this reason, the laser projector has an advantage that it can obtain a projection image that is small and light and has good color reproducibility, as compared with a projector using a conventional metal halide lamp.

  In the case of displaying a large image, it is necessary to increase the scanning angle for scanning with laser light. As the scanning angle increases, it becomes difficult to drive the scanning unit at high speed. For this reason, when the image becomes large, it becomes difficult to obtain a sufficient scanning speed of the laser beam, so that it becomes difficult to display a high-quality image. Further, as the image becomes larger, the change in the incident angle of the laser beam increases depending on the incident position of the laser beam incident on a predetermined surface such as a screen. When the change in the incident angle of the laser beam becomes large, the spot shape changes depending on the incident position of the laser beam. If the spot shape changes, the image is distorted, and the image cannot be displayed accurately. As a technique for shaping the spot shape, for example, there is one proposed in Patent Document 1.

Japanese Patent Laid-Open No. 5-27195

  The technique proposed in Patent Document 1 shapes the spot shape of laser light from a light source by beam shaping means. The beam shaping means shapes the spot shape of the laser light traveling in a certain direction from the light source. For this reason, even if the configuration disclosed in Patent Document 1 is used, it is difficult to shape the spot shape with respect to the laser light whose traveling direction is changed by the scanning unit. Further, even with the technique proposed in Patent Document 1, it is necessary to increase the scanning angle of the laser beam when displaying a large image.

  Thus, with the conventional technology, it is difficult to reduce changes in the spot shape on the screen and reduce the scanning angle of the laser beam. This is a problem in realizing a large and high-quality image display. The present invention has been made in view of the above-described problems, and displays a large and high-quality image by reducing a change in spot shape on a screen or the like and reducing a scanning angle of a laser beam. An object of the present invention is to provide an optical scanning device and an image display device using the optical scanning device.

  In order to solve the above-described problems and achieve the object, according to the present invention, a light source unit that supplies laser light, a scanning unit that scans laser light from the light source unit at a predetermined scanning angle, and a scanning unit And an optical element including an exit surface that emits light incident from the entrance surface, and the entrance surface and the exit surface emit light in an angle range larger than a predetermined scanning angle. It is possible to provide an optical scanning device characterized in that it is provided at an inclination angle that guides the light beam.

  The incident surface and the exit surface of the optical element are provided at an inclination angle that guides light to an angle range larger than a predetermined scanning angle. Light from the scanning unit is guided to an angle range larger than the scanning angle by the scanning unit by passing through the optical element. For this reason, even when the scanning angle by the scanning unit is small, light can be guided to a wide angle range. In particular, even when displaying a large image, the scanning angle by the scanning unit can be reduced, so that a high-quality image can be displayed at a sufficient scanning speed. Further, by providing the entrance surface and the exit surface at a predetermined inclination angle, the spot shape of the laser light is deformed so as to reduce the diameter in a predetermined direction. By modifying the spot shape so as to correspond to the incident angle of the laser beam incident on a predetermined surface such as a screen, the spot shape on the predetermined surface can be made substantially the same regardless of the incident angle of the laser beam. By obtaining a spot having a substantially constant shape at any position on the predetermined plane, an accurate image with little distortion can be displayed. By reducing the change in the spot shape on the screen or the like and reducing the scanning angle of the laser beam, it is possible to obtain an optical scanning device for displaying a large and high-quality image.

  According to a preferred aspect of the present invention, it is desirable that the optical element has a polyhedral shape. By making the optical element into a polyhedral shape, it is possible to easily form an entrance surface and an exit surface having a predetermined inclination angle.

  According to a preferred aspect of the present invention, it is desirable that at least one of the entrance surface and the exit surface has a curved surface. The curved surface includes a rotationally symmetric spherical surface, an aspherical surface, a paraboloid, and an asymmetrical free curved surface. In order to obtain a spot having a substantially constant shape at any position on the predetermined surface, it is desirable to deform the spot shape accurately corresponding to the incident angle of the laser light incident on the predetermined surface. When at least one of the entrance surface and the exit surface is a curved surface, the degree of deformation of the spot shape can be adjusted by the shape of the curved surface. Since the deformation degree of the spot shape can be adjusted, the spot shape can be deformed accurately corresponding to the incident angle of the laser beam. As a result, the degree of deformation of the spot shape can be accurately adjusted according to the position on the predetermined surface where the laser beam is incident, and spots having substantially the same shape on the predetermined surface can be obtained.

  Moreover, as a preferable aspect of the present invention, it is desirable that the curved surface has a curvature in each of two directions substantially orthogonal to each other. The curvature of the curved surface is not limited to a case where the curvature is substantially constant like a spherical surface or a cylindrical cylindrical surface, but includes a non-constant shape such as an aspherical surface, a paraboloid or a free curved surface. Thereby, it is possible to accurately adjust the degree of deformation of the spot shape in two substantially orthogonal directions on the predetermined plane.

  As a preferred aspect of the present invention, it is desirable that the incident surface and the exit surface have curved surfaces, and the direction in which the entrance surface has a curvature and the direction in which the exit surface has a curvature are substantially orthogonal to each other. Thereby, it is possible to accurately adjust the degree of deformation of the spot shape in two substantially orthogonal directions on the predetermined plane.

  Furthermore, according to the present invention, it is possible to provide an image display device that has the above-described optical scanning device and displays an image on a predetermined surface by light from the optical scanning device. By having the above optical scanning device, it is possible to reduce a change in spot shape on a predetermined surface such as a screen and to reduce the scanning angle of the laser beam. Thereby, an image display apparatus capable of displaying a large and high-quality image can be obtained.

  Moreover, as a preferable aspect of the present invention, it is preferable that the screen includes a screen that transmits light from the optical scanning device, and the predetermined surface is a surface of the screen that emits light from the optical scanning device. An image display device including a transmissive screen is configured by housing a light source unit and a scanning unit in a housing. If the scanning angle of the laser beam by the scanning unit can be reduced, a large image can be easily displayed even if the distance between the scanning unit and the screen is reduced. Thus, an image display device capable of displaying a large image with a thin casing can be obtained.

  As a preferred aspect of the present invention, the optical scanning device is configured such that light incident from the optical scanning device at a substantially central position of the predetermined surface is incident at a predetermined angle other than 0 degrees with respect to the normal of the predetermined surface. It is desirable to be placed in position. In the case of an image display device having a transmissive screen, if the laser beam is obliquely incident on the screen, a long optical path between the scanning unit and the screen can be obtained even if a thin housing is used. It becomes. If the optical path between the scanning unit and the screen can be long, a large image can be displayed at a small scanning angle. Further, when an image is displayed using a reflective screen, a large image can be displayed at a small scanning angle, and the image display device can be prevented from obstructing viewing when viewed by an observer.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of an image display apparatus 100 according to Embodiment 1 of the present invention. The image display device 100 is a so-called rear projector that supplies a laser beam L to one surface of the screen 110 and observes an image by observing light emitted from the other surface S1 of the screen 110. The image display device 100 includes an optical scanning device 120, and displays an image on the surface S1 of the screen 110, which is a predetermined surface, by the light from the optical scanning device 120.

  The optical scanning device 120 includes a light source unit 101, a galvano mirror 103 that is a scanning unit, and a triangular prism 105 that is an optical element. The light source unit 101 supplies laser light L. The laser light L includes red laser light, green laser light, and blue laser light. The laser light L modulates and supplies each color light according to an image signal. As the light source unit 101, a semiconductor laser provided with a modulation unit for modulating the laser light L or a solid-state laser can be used. As the modulation according to the image signal, either amplitude modulation or pulse width modulation may be used. Note that a shaping optical system that shapes the laser light L into, for example, a beam shape having a diameter of 0.5 mm may be provided on the emission side of the light source unit 101.

  The laser light L incident on the galvanometer mirror 103 is reflected in the direction of the triangular prism 105. The galvanometer mirror 103 scans the laser light L in a two-dimensional direction by rotating around two predetermined axes orthogonal to each other. The galvanometer mirror 103 can be created by, for example, MEMS (Micro Electro Mechanical Systems) technology. The galvanometer mirror 103 scans the laser beam L from the light source unit 101 in the vertical direction of FIG. 1 at a predetermined scanning angle θ1. The galvanometer mirror 103 scans light in the forward and backward directions of FIG. 1 in the same manner as scanning light in the vertical direction of FIG. 1 at a scanning angle θ1. The laser beam L reflected by the galvanometer mirror 103 enters the triangular prism 105.

  The triangular prism 105 is a transparent member having a quadrangular pyramid shape. The triangular prism 105 includes an incident surface on which light from the galvanometer mirror 103 is incident and an output surface from which light incident from the incident surface is emitted. The light transmitted through the triangular prism 105 is guided to an angle range θ2 larger than the scanning angle θ1 by the galvanometer mirror 103. The light transmitted through the triangular prism 105 is incident on the screen 110 at an angle.

  The optical scanning device 120 is disposed at a position where light incident from the optical scanning device 120 to a substantially central position of the screen 110 is incident with a normal N of the predetermined surface S1 and a predetermined angle θ0. The angle θ0 is an angle other than 0 (zero) degrees. When the laser beam L is obliquely incident on the screen 110, a long optical path between the galvanometer mirror 103 and the screen 110 can be obtained even if the thin casing 107 is used. If the optical path between the galvanometer mirror 103 and the screen 110 can be long, a large image can be displayed at a small scanning angle.

  The screen 110 is provided on a predetermined surface of the housing 107. The screen 110 is a transmissive screen that transmits light from the optical scanning device 120. The light from the optical scanning device 120 is incident from the surface of the screen 110 on the inner side of the housing 107 and then exits from the predetermined surface S1 on the viewer side. The observer views the image by observing the light emitted from the predetermined surface S1 of the screen 110. The scanning unit is not limited to the single galvanometer mirror 103, and a plurality of galvanometer mirrors may be used. When a plurality of galvanometer mirrors are used, for example, a configuration in which three galvanometer mirrors are used for each color light can be employed.

  FIG. 2 shows a perspective configuration of the triangular prism 105. The triangular prism 105 has a quadrangular pyramid shape including a rectangular bottom surface and four triangular side surfaces. The triangular prism 105 is arranged with the incident surface 201 that is one of the four side surfaces facing the incident side. The exit surface 202 is the side surface of the triangular prism 105 that faces the entrance surface 201.

  FIG. 3 shows a side configuration when the triangular prism 105 is projected onto the YZ plane. When the optical path of light passing through the approximate center of the scanning angle θ1 (see FIG. 1) of the galvano mirror 103 and entering the central position of the screen 110 is the optical axis X, the incident surface 201 is substantially perpendicular to the optical axis X. It is provided so as to be substantially parallel to the reference plane S2. The emission surface 202 is provided so as to form an angle α with respect to the reference surface S2. Thus, the entrance surface 201 and the exit surface 202 are provided so as to form a predetermined inclination angle with respect to the reference surface S2.

  The optical element is not limited to the one having a quadrangular pyramid shape like the triangular prism 105 as long as the incident surface and the emission surface can be provided at a predetermined inclination angle. For example, the optical element can have a polyhedral shape such as a polygonal pyramid shape other than the quadrangular pyramid shape, or a trapezoidal shape obtained by cutting the polygonal pyramid shape. By using a polyhedral prism as an optical element, an entrance surface and an exit surface having a predetermined inclination angle can be easily formed by machining or the like.

  Next, changes in the scanning angle of the laser beam L and changes in the spot shape due to the provision of the triangular prism 105 as an optical element will be described. FIG. 4 illustrates the scanning angle of the laser beam L and the spot shape when using a conventional optical scanning device without an optical element as a comparison with the present embodiment. Here, it is assumed that the galvanometer mirror 103 is on the normal line of the screen 110 surface S <b> 1 for the explanation of the scanning angle and spot shape of the laser beam. Further, the illustration of the galvanometer mirror 103 is omitted. Assuming that the galvanometer mirror 103 scans the laser beam L at the scanning angle θ3, the laser beam L is incident on the screen 110 without changing the angle range θ3.

  For this reason, when displaying a large image on the screen 110, if the distance between the galvano mirror 103 and the screen 110 is constant, it is necessary to increase the scanning angle of the galvano mirror 103. As the scanning angle of the galvanometer mirror 103 is increased, it becomes difficult to drive the galvanometer mirror 103 at high speed. For this reason, when the screen 110 becomes large, it becomes difficult to obtain a sufficient scanning speed of the laser light L, and it becomes difficult to display a high-quality image.

  It is assumed that the spot shape of the laser light L from the galvanometer mirror 103 is a substantially circular shape. The laser beam L incident from the galvanometer mirror 103 to a substantially central position of the screen 110 enters the screen 110 substantially perpendicularly. When the laser beam L is incident on the screen 110 substantially perpendicularly, the spot SP4 of the laser beam L reflected on the predetermined surface S1 of the screen 110 has a substantially circular shape. On the other hand, at a position where the incident position of the laser beam L is away from the substantially central position of the screen 110, the laser beam L is incident on the screen 110 from an oblique direction. When the laser beam L is incident obliquely upward from below on the screen 110, the spot SP5 of the laser beam L reflected on the predetermined surface S1 of the screen 110 has an elliptical shape obtained by extending a circle in the vertical direction. When the laser beam L is incident obliquely downward from above on the screen 110, the spot SP6 of the laser beam L reflected on the predetermined surface S1 of the screen 110 has an elliptical shape obtained by extending a circle in the vertical direction.

  The spot SP6 will be described as an example. As shown in FIG. 5, the laser light L traveling with the vertical width d4 enters the predetermined surface S1 of the screen 110 obliquely downward from above. The laser light L is incident on the predetermined surface S1 with a width d5 larger than the width d4. For this reason, the spot SP6 has an elliptical shape obtained by extending a circle in the vertical direction. The degree of change in the spot shape increases as the incident angle of the laser beam L with respect to the normal line of the screen 110 increases. When the spot shape changes depending on the incident position of the screen 110 in this way, an accurate image is not displayed on the screen 110. In particular, as the scanning angle of the galvanometer mirror 103 is increased by using the large screen 110, the spot shape changes significantly.

  FIG. 6 illustrates the scanning angle of the laser beam L and the spot shape when the optical scanning device 120 of this embodiment is used. As described with reference to FIG. 3, the triangular prism 105 has an incident surface 201 and an output surface 202 provided at a predetermined inclination angle. The laser light L from the galvanometer mirror 103 is subjected to a refracting action according to the inclination angle of the incident surface 201 of the triangular prism 105, the inclination angle of the emission surface 202, and the refractive index of the members constituting the triangular prism 105.

  The laser light L transmitted through the triangular prism 105 is guided to an angle range θ2 larger than the scanning angle θ1 by the galvano mirror 103 by being refracted by the triangular prism 105. As described above, the incident surface 201 and the emission surface 202 are provided at an inclination angle that guides the laser light L to an angle range θ2 larger than the predetermined scanning angle θ1. For this reason, when the triangular prism 105 is used, the laser light L can be guided to a wide angle range even when the scanning angle by the galvano mirror 103 is small. In particular, even when displaying a large image, the scanning angle by the galvanometer mirror 103 can be reduced, so that a high-quality image can be displayed at a sufficient scanning speed.

  The laser light L that has passed through the triangular prism 105 undergoes a refraction action at the triangular prism 105, thereby changing the spot shape. When the laser beam L is incident obliquely downward from above on the screen 110, a vertically long spot is projected on the screen 110 according to the conventional configuration, whereas in the configuration of this embodiment, a substantially circular spot is displayed. SP3 is projected. As shown in FIG. 7, the laser light L traveling with the vertical width d1 is converted to a width d2 smaller than the width d1 by the refracting action on the incident surface 201 and the exit surface 202 of the triangular prism 105.

  When the laser beam L having the width d2 is incident on the predetermined surface S1 obliquely from above, the laser beam L is incident on the predetermined surface S1 with a width d3 larger than the width d2. The spot of the laser light L is contracted in the vertical direction by passing through the triangular prism 105 and then stretched in the vertical direction on the predetermined surface S1, thereby having a width d3 substantially the same as the initial width d1 reflected by the galvanometer mirror 103. It is possible to obtain the spot SP3. In this manner, as shown in FIG. 6, it is possible to obtain substantially the same circular spots SP1, SP2, and SP3 regardless of the incident position of the screen 110. By obtaining a spot having a substantially constant shape at any position on the predetermined plane S1, the image display apparatus 100 can display an accurate image with little distortion.

6 and 7, the scanning range of the laser beam L in the Y direction and the change in the spot shape have been described. However, the same effect can be obtained in the X direction. By using the triangular prism 105, the optical scanning device 120 can guide the laser light L to an angle range larger than the scanning angle of the galvano mirror 103 in the X direction as in the case of the Y direction. As in the Y direction, the spot shape on the screen 110 can be made substantially uniform in the X direction. Thereby, it is possible to display a large and high quality image by reducing the change in the spot shape on the screen 110 and reducing the scanning angle of the laser light L.

  FIG. 8 shows a perspective configuration of the optical element 805 in the optical scanning device according to the second embodiment of the present invention. The optical scanning apparatus according to the present exemplary embodiment having the optical element 805 can be applied to the image display apparatus 100 according to the first exemplary embodiment. The description overlapping with that of the optical scanning device 120 of the first embodiment is omitted. The optical element 805 is characterized in that the emission surface 802 is an aspherical surface. The optical element 805 has a shape obtained by cutting a solid body having an elliptical shape along the major and minor axes of the ellipse. The incident surface 801 is a substantially rectangular plane. The exit surface 802 has a curved surface that is substantially the same as a part of the ellipse. The exit surface 802 has a curvature in the Y direction and no curvature in the X direction.

  The incident surface 801 of the optical element 805 is provided so as to be substantially parallel to a reference surface substantially perpendicular to the optical axis X, similarly to the incident surface 201 of the triangular prism 105 of the first embodiment. The laser beam L is subjected to the same refraction action as the incident surface 201 of the triangular prism 105 of the first embodiment. On the other hand, the exit surface 802 is different from the exit surface 202 of the triangular prism 105 of the first embodiment in that the exit surface 802 has a curvature in the Y direction. The laser light L is refracted according to the inclination angle of the tangent plane of the emission surface 802 at the incident position of the emission surface 802.

  When the emission surface 802 is a curved surface, the inclination angle of the tangent plane of the emission surface 802 can be changed according to the incident position of the emission surface 802. For this reason, by appropriately setting the shape of the emission surface 802, it is possible to deform the spot shape accurately corresponding to the incident angle of the laser light L incident on the predetermined surface S1. Accordingly, it is possible to accurately adjust the degree of deformation of the spot shape according to the position on the predetermined surface S1 on which the laser light L is incident, and to obtain a spot having substantially the same shape on the predetermined surface S1. Play. In addition, although the optical element 805 of a present Example was set as the structure which the output surface 802 has a curvature about a Y direction, it is not restricted to this. For example, if the exit surface 802 is configured to have a curvature in the X direction, the spot shape can be deformed accurately corresponding to the incident angle of the laser light L in the X direction.

  FIG. 9 shows a perspective configuration of an optical element 905 according to a modification of the second embodiment. The optical element 905 includes a planar incident surface 901 and an exit surface 902 having a curvature in the X direction and the Y direction. The exit surface 902 is a curved surface having a curvature with respect to the X direction and the X direction, which are two directions substantially orthogonal to each other. The degree to which the spot shape is deformed can be accurately adjusted in the X direction and the Y direction on the predetermined surface S1.

  Note that the optical element is not limited to a configuration in which only the exit surfaces 802 and 902 are curved, and only the entrance surface may be a curved surface, and the entrance surface and the exit surface may be curved. The curved surfaces constituting the entrance surface and the exit surface are not limited to the shape having an elliptic curve, but may be a rotationally symmetric spherical surface, an aspherical surface, a paraboloid, or an asymmetrical free curved surface. Here, while a spherical surface, an aspherical surface, and a paraboloid are shapes that can be defined by a simple calculation formula, a free-form surface is a shape that cannot be defined by a simple calculation formula. In addition, the curved surface is not limited to a shape having a substantially constant curvature such as a spherical surface or a cylindrical cylindrical surface, but has a shape whose curvature varies depending on the position, such as an aspherical surface, a parabolic surface, or a free-form surface. May be.

  FIG. 10 shows a perspective configuration of an optical element 1005 according to another modification of the second embodiment. The optical element 1005 has an incident surface 1001 having a curvature in the Y direction and an exit surface 1002 having a curvature in the X direction. The entrance surface 1001 and the exit surface 1002 have curved surfaces, and the Y direction in which the entrance surface 1001 has a curvature and the Y direction in which the exit surface 1002 has a curvature are substantially orthogonal to each other. Also in this case, similarly to the optical element 905 shown in FIG. 9, the degree of deformation of the spot shape can be accurately adjusted in the X direction and Y direction on the predetermined surface S1.

  FIG. 11 shows a configuration for displaying an image by the image display device 1100 according to the third embodiment of the present invention. A duplicate description with the image display device 100 of the first embodiment is omitted. The image display apparatus 1100 according to the present embodiment is a so-called front projection type projector that supplies a laser beam L onto a screen 1101 and views an image on the same side as the image display apparatus 1100. The image display device 1100 includes the same optical scanning device 120 as the image display device 100 of the first embodiment, and displays an image on the surface S3 of the screen 1101 that is a predetermined surface by the light from the optical scanning device 120.

  FIG. 12 shows a state in which an image display device 1100 displays an image as viewed from the side. The image display device 1100 is disposed at a position where light incident from the image display device 1100 at a substantially central position of the screen 1101 is incident with a normal N of the predetermined surface S3 and a predetermined angle θ4. The angle θ4 is an angle other than 0 (zero) degree. When the laser beam L is obliquely incident on the screen 1101, the optical path between the image display device 1100 and the screen 1101 is lengthened even when the image display device 1100 is disposed at a position close to the screen 1101. It becomes possible to take. If the optical path between the image display device 1100 and the screen 1101 can be long, a large image can be displayed at a small scanning angle. In addition, it is possible to prevent the image display device 1100 from being an obstacle to viewing as viewed from the observer.

  The screen 1101 is a reflective screen that reflects light from the image display device 1100 on a predetermined surface S3 on the screen 1101. The observer views the image by observing the light reflected by the predetermined surface S3 of the screen 1101. By including the optical scanning device 120, the image display device 1100 reduces the change in the spot shape on the predetermined surface S3 and reduces the scanning angle of the laser light L in the same manner as the image display device 100 of the first embodiment. be able to. Thereby, like the image display apparatus 100 of the said Example 1, a large-sized and high quality image can be displayed.

  In addition, although the image display apparatus of each said Example is set as the structure which injects the laser beam L in the diagonal direction from the lower position with respect to the normal line N of a screen, it is not restricted to this. For example, even when the laser beam L is incident obliquely downward from the upper position with respect to the normal line N, the same effects as in the above embodiments can be obtained. In each embodiment, an image is displayed using a single laser beam L for each color, but an image may be displayed by a multi-beam scanning method using a plurality of laser beams for each color. By adopting a configuration in which an image is displayed by a multi-beam scanning method, a brighter image can be obtained. Furthermore, in each Example, although it is set as the structure which uses the laser beam L, if it is the structure which uses beam-shaped light, it will not be restricted to this. For example, a light emitting diode element (LED) may be used as the light source of the image display device.

  As described above, the optical scanning device according to the present invention is useful when displaying a presentation or a moving image.

1 is a schematic configuration diagram of an image display apparatus according to Embodiment 1 of the present invention. The perspective block diagram of a triangular prism. The side view of a triangular prism. Explanatory drawing of the scanning angle and spot shape of the laser beam by the conventional optical scanning device. Explanatory drawing of the spot shape by the conventional optical scanning device. FIG. 3 is an explanatory diagram of a scanning angle and a spot shape of a laser beam by the optical scanning device of Embodiment 1. FIG. 3 is an explanatory diagram of a spot shape by the optical scanning device according to the first embodiment. FIG. 6 is a perspective configuration diagram of an optical element according to Example 2 of the present invention. FIG. 10 is a perspective configuration diagram of an optical element according to a modification of Example 2. FIG. 10 is a perspective configuration diagram of an optical element according to another modification of Example 2. FIG. 10 is a configuration diagram for displaying an image by an image display device according to a third embodiment of the present invention. The figure which shows the state which looked at the structure which displays an image with an image display apparatus from the side.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 Image display apparatus, 101 Light source part, 103 Galvano mirror, 105 Triangular prism, 107 Housing | casing, 110 Screen, 120 Optical scanning apparatus, L laser beam, N normal, S1 Predetermined surface, 201 Incident surface, 202 Outgoing surface, S2 Reference surface, SP1 to SP6 spot, 801 entrance surface, 802 exit surface, 805 optical element, 901 entrance surface, 902 exit surface, 905 optical element, 1001 entrance surface, 1002 exit surface, 1005 optical element, 1100 image display device, 1101 Screen, S3 predetermined surface

Claims (2)

A light source unit for supplying laser light;
A scanning unit that scans the laser light from the light source unit at a predetermined scanning angle;
A triangular prism comprising: an incident surface on which light from the scanning unit is incident; an output surface that emits light incident from the incident surface; and a connection unit that contacts the incident surface and the output surface. ,
The incident surface and the exit surface is provided with the optical scanning device that is provided at a tilt angle which guides the light to a predetermined scan angle larger than the angle range,
An image is displayed on a predetermined surface by the light from the optical scanning device,
The optical scanning device is disposed at a position such that light incident from the optical scanning device at a substantially central position of the predetermined surface is incident at a predetermined angle other than 0 degrees with respect to the normal of the predetermined surface,
The triangular prism is disposed farther from the predetermined surface in the normal direction of the predetermined surface than the side of the emission surface provided opposite to the connection portion.
An image display device characterized by that. A screen that transmits light from the optical scanning device;
The image display device according to claim 1 , wherein the predetermined surface is a surface of the screen that emits light from the optical scanning device.

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