WO2014167673A1

WO2014167673A1 - Screen device

Info

Publication number: WO2014167673A1
Application number: PCT/JP2013/060836
Authority: WO
Inventors: 育也菊池
Original assignee: パイオニア株式会社
Priority date: 2013-04-10
Filing date: 2013-04-10
Publication date: 2014-10-16
Also published as: JPWO2014167673A1

Abstract

This screen device is provided with a screen and drive unit that causes the oscillation of the screen around a first axis separated from the screen plane and parallel to an axis along one direction in the screen plane, and a second axis separated from the screen plane and parallel to an axis along another direction intersecting the one direction in the screen plane.

Description

Screen device

The present invention relates to a technical field using a screen.

Conventionally, a screen is used when an image is generated by a laser scanning projector or when an intermediate image is generated by a head-up display or a head-mounted display using a laser scan engine. In addition, as a technique related to such a screen, a technique has been proposed in which light projected on the screen is diffusely reflected (or diffusely transmitted) on the screen to increase the viewing angle and the observable range. Furthermore, a technique for reducing speckles (generated due to interference caused by random irregularities on the reflecting surface) generated by diffusing light on a screen has been proposed. For example, a technique for reducing speckles by driving a screen surface (translational motion or the like) has been proposed.

The technology relating to the screen as described above is disclosed in, for example, the following Patent Documents 1 to 7.

JP-A-6-208089 JP 2005-338241 A JP 2007-244103 A JP 2012-247424 A JP 2009-244590 A Japanese Patent No. 4303926 US Patent No. 8031403

In the conventional technology that translates the screen, the screen may rotate within the screen surface. If the screen rotates within the screen surface, it may cause problems such as a reduction in the speckle reduction effect. Therefore, it is desirable to suppress this. Such a problem will be described in detail in the section “2. Problems of Comparative Example”.

Examples of the problem to be solved by the present invention include the above. An object of the present invention is to provide a screen device capable of effectively reducing speckles, for example, rather than a configuration in which the screen is translated or the like.

In the invention described in claim, the screen device includes a screen and an axis along a first axis that is parallel to an axis along a direction in the plane of the screen and that is spaced from the plane of the screen. Swinging the screen about an axis along a second axis that is parallel to an axis along the other direction intersecting the one direction in the plane of the screen and spaced from the plane of the screen And a drive unit to be provided.

In the invention described in claim, the screen device includes a screen and a drive unit that swings the screen along a predetermined toroidal surface perpendicular to a normal direction of the surface of the screen. Features.

A specific example of a display system to which the screen device according to this embodiment is applied will be described. The structure of the screen apparatus based on a present Example is shown. The figure for demonstrating the drive method of the screen which concerns on a present Example is shown. The structure of the screen apparatus which concerns on the comparative example 1 is shown. The structure of the screen apparatus which concerns on the comparative example 2 is shown. The figure for supplementarily explaining Comparative Examples 1 and 2 is shown. The figure for demonstrating the speckle reduction effect is shown. The figure for demonstrating the reason which becomes difficult to rotate a screen according to a present Example in a surface is shown. The example of the various cross-sectional shapes applicable to a support part is shown. The figure for demonstrating the method to change a resonant frequency by the x direction and ay direction is shown. The structure of the support part which concerns on the modification 2 is shown. The structure of the screen apparatus which concerns on the modification 3 is shown. The structure of the screen apparatus which concerns on the modification 4 is shown. The figure for demonstrating the drive method of the screen which concerns on the 1st example of the modification 4 is shown. The figure for demonstrating the drive method of the screen which concerns on the 2nd example of the modification 4 is shown.

In one aspect of the present invention, a screen device includes a screen and an axis along a first axis that is parallel to an axis along a direction in the plane of the screen and spaced from the plane of the screen. Swinging the screen about an axis along a second axis that is parallel to an axis along the other direction intersecting the one direction in the plane of the screen and spaced from the plane of the screen And a drive unit to be operated.

In the above screen device, the screen has a diffusing surface for diffusing incident light. The drive unit is parallel to an axis along one direction in the screen surface, and around the axis along the first axis spaced from the screen surface and in another direction intersecting the one direction in the screen surface. The screen is swung about an axis along a second axis that is parallel to the axis along the axis and spaced from the screen surface. For example, the drive unit causes the screen to oscillate using the first axis and the second axis as virtual rotation axes by generating torque around the first axis and torque around the second axis on the screen. According to the above screen device, since the screen is moved and tilted, speckles can be reduced more effectively than a configuration in which the screen is translated, for example.

In one aspect of the above screen device, the screen device further includes a support portion that is arranged non-parallel to an axis along the normal direction of the surface of the screen and supports the screen. Thereby, rotation of the screen within the screen surface can be appropriately suppressed.

Preferably, in the above screen device, the support portion is projected along a surface formed by an axis along the one direction and an axis along the normal direction, and along the other direction. At least one of the projection shapes on the surface formed by the axis along the normal direction and the axis along the normal direction is arranged to be non-parallel to the axis along the normal direction.

In another aspect of the above screen device, the first resonance frequency around the first axis and the second resonance frequency around the second axis in the screen may be configured to be different.

In another aspect of the screen device, the screen device further includes a control unit that controls the driving unit based on both the first resonance frequency and the second resonance frequency. By controlling the drive unit in this way, it is possible to appropriately impart motions around the two axes (the first axis and the second axis) to the screen at the same time.

In another aspect of the above screen device, the control unit may be configured such that a rotational angular velocity around the first axis on the screen surface and a rotational angular velocity around the second axis on the screen surface are simultaneously “ The drive unit is controlled by setting a frequency ratio and an amplitude ratio between the first resonance frequency and the second resonance frequency so as not to become “0”. Thereby, the motion around the two axes (the first axis and the second axis) can be more appropriately given to the screen, and the speckle can be effectively averaged.

In another aspect of the screen device, the screen device further includes a control unit that controls the drive unit based on one of the first resonance frequency and the second resonance frequency. That is, the screen may be driven based on one of the first resonance frequency and the second resonance frequency.

In another aspect of the above screen device, the driving unit applies force in the axial direction along the one direction and applies force in the axial direction along the other direction. Thereby, the screen can be appropriately swung around the first axis and the second axis.

In another aspect of the screen device, the driving unit applies a force in an axial direction different from the axis along the one direction and the axis along the other direction. Also by this, the screen can be appropriately swung around the first axis and the second axis. Moreover, according to the said aspect, a drive part can be comprised simply and it becomes possible to implement | achieve cost reduction of a screen apparatus.

Preferably, in the above screen device, the support portion is made of an elastic body and supports the screen at four points. For example, the support portions are provided near the four corners of the screen.

Also preferably, the elastic body has a cross-sectional shape in which a length along the one direction is different from a length along the other direction. Thereby, since the bending rigidity (spring constant) in each direction in a support part differs, it becomes possible to implement | achieve appropriately two different resonance frequencies.

In another aspect of the present invention, a screen device includes a screen and a drive unit that swings the screen along a predetermined toroidal surface perpendicular to a normal direction of the surface of the screen. Also by this, since the screen is moved and tilted, speckles can be reduced more effectively than a configuration in which the screen is translated, for example.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

1. Screen Device According to this Example First, the screen device according to this example will be described.

1-1. System Configuration FIG. 1 shows a specific example of a display system to which a screen device 100 according to this embodiment is applied. FIG. 1A shows a display system 400 a that projects an image (real image) onto the screen 1 of the screen device 100 by using, for example, a laser scanning projector 200. In FIG. 1B, an intermediate image is formed on the screen 1 of the screen device 100 by an image projected from the projector 200 using a laser scan engine or the like, and light corresponding to the intermediate image is reflected by the combiner 300. Thus, the display system 400b that visually recognizes an image as a virtual image is illustrated.

As shown in FIGS. 1A and 1B, the screen device 100 mainly includes a screen 1, a drive unit 2 as an actuator that drives the screen 1, and a CPU (Central Processing Unit that controls the drive unit 2. ) And the like. The screen 1 has a reflective diffusion surface, and functions to reflect and diffuse incident light (hereinafter referred to as “beam” as appropriate). In addition, it is not limited to applying a reflection type diffusion surface to the screen 1, You may apply a transmission type diffusion surface instead of a reflection type diffusion surface. In the following description, the screen 1 having a reflective diffusion surface is taken as an example.

1-2. Configuration of Screen Device FIG. 2 is a diagram illustrating a configuration of the screen device 100 according to the present embodiment. 2, the front view of the screen device 100 is shown in the upper left, the side view of the screen device 100 observed from the direction of the arrow Ar11 in the front view is shown in the upper right, and the screen device observed from the direction of the arrow Ar12 in the front view in the lower left. A side view of 100 is shown. In addition, the definition of a front view and a side view is the same also in the figure of the screen apparatus mentioned later.

As shown in FIG. 2, the screen device 100 according to the present embodiment mainly includes a screen 1,

drive units

2 a and 2 b, a support unit 3, and a base 4. The screen 1 is configured as a substantially flat plate having a rectangular plane, and has a reflective diffusion surface that reflects and diffuses the light from the projector 200 described above. As the reflective diffusion surface, various known ones can be applied. The screen 1 is supported by four support portions 3 provided near the four corners of the rectangle, and is fixed to the base 4 via the support portions 3. The screen 1, the support portion 3, and the base 4 are fixed so as not to be separated from each other.

Each of the four support portions 3 is formed of an elastic body such as a spring, and is referred to as a normal direction of the screen surface (hereinafter, referred to as “z direction” as appropriate. An axis along the z direction is referred to as “z axis”). .) Extends from the screen 1 toward the base 4 in a non-parallel direction, that is, obliquely with respect to the z-axis. More specifically, the support unit 3 is arranged so that the projection shape on the xz plane (see the left side view in FIG. 2) is non-parallel, and the projection shape on the yz plane (see FIG. 2). (See the side view on the upper right). In the example shown in FIG. 2, both the projection shape on the xz plane and the projection shape on the yz plane for the two support portions 3 are “C” -shaped. In one example, the four support portions 3 are arranged so that the inclination degrees of the four support portions 3 with respect to the z axis are the same. In addition, it is not limited to arrange | positioning the support part 3 so that both the projection shape to xz plane and the projection shape to yz plane may become non-parallel, The projection shape to xz plane and the projection shape to yz plane You may arrange | position the support part 3 so that only either one may become non-parallel.

The screen 1 is supported by the support portion 3 as described above so as to move along a predetermined toroidal surface perpendicular to the z-axis. That is, the screen 1 has an X ′ axis substantially parallel to the x axis (hereinafter, the direction around the X ′ axis is appropriately referred to as “β direction”) and a Y ′ axis (hereinafter, the direction approximately parallel to the y axis). The direction around the Y ′ axis is referred to as “α direction” as appropriate). Further, in the screen device 100, the resonance frequency around the z axis is set to a frequency higher than the resonance frequencies around the X ′ axis and the Y ′ axis.

Here, the x-axis is an axis passing through the center of gravity G of the screen 1 and along the length direction of one side of the screen 1, and the y-axis is passing through the center of gravity G of the screen 1 and the one in the screen 1. An axis along the length direction of the side perpendicular to the side. The X ′ axis and the Y ′ axis are virtual rotation axes substantially parallel to the x axis and the y axis, respectively, and are located away from the screen 1, specifically in front of the screen surface (base 4). That is, the X ′ axis and the Y ′ axis do not exist in the xy plane. Note that the screen 1 is configured to have a uniform surface density, and the rectangular center position of the screen 1 and the position of the gravity center G coincide with each other.

The X ′ axis corresponds to an example of the “first axis” in the present invention, and the Y ′ axis corresponds to an example of the “second axis” in the present invention. Further, the resonance frequency around the X ′ axis corresponds to an example of “first resonance frequency” in the present invention, and the resonance frequency around the Y ′ axis corresponds to an example of “second resonance frequency” in the present invention.

The

drive units

2 a and 2 b constitute the drive unit 2 shown in FIG. 1 and drive the screen 1 with a force that passes through the center of gravity G. Specifically, the drive portion 2a, the force F _x of generally along direction x-axis to impart to the screen 1, the driving unit 2b, a force F _y of generally along direction y-axis to the screen 1 It gives to. More specifically, each of the

drive units

2a and 2b is fixed to the screen 1 (that is, always in contact with the screen 1), and applies a force for pushing the screen 1 and a force for pulling the screen 1. To do. Since the X ′ axis and the Y ′ axis do not exist in the xy plane as described above, the screen 1 is driven with the torque around the X ′ axis and the torque around the Y ′ axis by driving the moving

parts

2a and 2b. It becomes. Various types such as an electromagnetic type, an electrostatic type, and an electrostrictive type can be applied to the driving

units

2a and 2b. The

drive units

2a and 2b are controlled by the control unit 10 (see FIG. 1) described above.

1-3. Screen Driving Method With reference to FIG. 3, a method for driving the screen 1 in this embodiment will be described. As shown in FIG. 3A, the angle around the Y ′ axis as the virtual rotation axis, that is, the angle in the α direction is defined as “angle α”, and the angle around the X ′ axis as the virtual rotation axis, The angle in the β direction is defined as “angle β”. In the present embodiment, the control unit 10 drives the driving force (driving in the x direction) by the driving unit 2a so that the angle α and the angle β draw a Lissajous figure as shown in FIGS. Force) and the driving force (driving force in the y direction) by the driving unit 2b are controlled.

FIG. 3B shows a Lissajous figure drawn by the angle α and the angle β when the amplitude ratio is “1: 1” and the frequency ratio is “1: 1.5”. In this case, “α = sin (ωt)” and “β = sin (1.5ωt)”. FIG. 3C shows a Lissajous figure drawn by the angle α and the angle β when the amplitude ratio is “1: 1” and the frequency ratio is “0.5: 1”. In this case, “α = sin (0.5ωt)” and “β = sin (ωt)”. FIG. 3D shows an angle α and an angle β when the amplitude ratio between the angle α and the angle β is “1: 1” and the frequency ratio between the angle α and the angle β is “1: 1”. Shows the Lissajous figure drawn by. In this case, “α = sin (ωt)” and “β = sin (ωt)”.

In this embodiment, the control unit 10 simultaneously sets both the rotational angular velocity dα / dt in the α direction (around the Y ′ axis) and the rotational angular velocity dβ / dt in the β direction (around the X ′ axis) on the screen 1 to “0”. In order to avoid this, an amplitude ratio and a frequency ratio between the driving force by the driving unit 2a and the driving force by the driving unit 2b are set. For example, the amplitude ratio and the frequency ratio are set so that the Lissajous figure shown in FIGS. 3B and 3C can be obtained. In the Lissajous figure shown in FIG. 3D, the rotational angular velocities are “0” in both the α direction and the β direction at both ends, and thus the amplitude ratio and the frequency ratio that become such a Lissajous figure are not adopted.

Note that the driving force by the driving unit 2a and the driving by the driving unit 2b are used instead of or in addition to the amplitude ratio and / or the frequency ratio between the driving force by the driving unit 2a and the driving force by the driving unit 2b. The phase difference from the force may be controlled.

2. Problems of Comparative Example Next, a comparative example for comparison with the present example will be given, and problems of the comparative example will be described. Here, Comparative Examples 1 and 2 are described in which the screen 1 is translated in the in-plane direction in order to increase the emission angle of light from the screen 1 and to reduce speckle.

2-1. Comparative Example 1
FIG. 4 is a diagram illustrating a configuration of the screen device 100x1 according to the first comparative example. In the screen device 100x1 according to the comparative example 1, in order to translate the screen 1 in the x direction and the y direction, the screen 1 is supported by the support portion 3x1 as a leaf spring having an arcuate shape (the support shown in the upper right). (See enlarged view of section 3x1). The support portion 3x1 functions as a thin leaf spring in the x direction and the y direction, thereby enabling the screen 1 to move in the xy plane. On the other hand, the support 3x1 regulates the movement of the screen 1 by the width of the spring in the z direction (the direction perpendicular to the paper surface).

Such a screen device 100x1 according to Comparative Example 1 has the following problems. First, in the screen device 100x1 according to the comparative example 1, the rotational motion around the center of gravity G (θ direction) (that is, in-plane rotation of the screen 1) cannot be restricted. Further, the resonance frequency of the translational motion and the resonance frequency of the rotational motion are close to each other. Further, since driving at the resonance frequency is close to the resonance frequency of translational motion and the resonance frequency of rotational motion, it is necessary to eliminate rotational motion as much as possible. This is because uneven speed occurs in the plane of the screen 1 (details will be described with reference to FIG. 6). Furthermore, in order to realize the translational movement, the driving forces F _x and F _y need to pass through the center of gravity G, so that precise position adjustment of the driving

mechanisms

2a and 2b is necessary.

2-2. Comparative Example 2
FIG. 5 is a diagram illustrating a configuration of a screen device 100x2 according to the second comparative example. In the screen device 100x2 according to the comparative example 2, in order to translate the screen 1 in the x direction and the y direction, the screen 1 is supported using four support portions 3x2 as parallel springs.

Such a screen device 100x2 according to Comparative Example 2 has the following problems. First, in the screen device 100x2 according to the comparative example 2, the rotational motion around the center of gravity G (θ direction) (that is, in-plane rotation of the screen 1) cannot be restricted. Further, the resonance frequency of the translational motion and the resonance frequency of the rotational motion are close to each other. Further, since driving at the resonance frequency is close to the resonance frequency of translational motion and the resonance frequency of rotational motion, it is necessary to eliminate rotational motion as much as possible. This is because uneven speed occurs in the plane of the screen 1 (details will be described with reference to FIG. 6). Furthermore, in order to realize the translational movement, the driving forces F _x and F _y need to pass through the center of gravity G, so that precise position adjustment of the driving

mechanisms

2a and 2b is necessary.

2-3. Supplementation of Comparative Examples 1 and 2 With reference to FIG. FIG. 6A shows a case where the center of gravity driving of the screen 1 is realized. Specifically, the case where the driving force F passing through the center of gravity G is applied to the screen 1 is shown. In this case, no torque is generated around the center of gravity G, and the screen 1 moves in translation, so that the speed of any position in the screen 1 is equal. For example, the y-direction speed V _G at the center of gravity G is equal to the y-direction speeds V _P1 and V _P2 at two positions P1 and P2 that are separated from the center of gravity G by the distance L1 (V _G = V _P1 = V _P2 ). .

FIGS. 6B and 6C show a case where the screen 1 is driven with a non-centroid. Specifically, as shown in FIG. 6B, a case where the driving force F is applied to the screen 1 from a position shifted from the center of gravity G by “ε” is shown. In this case, as shown in FIG. 6C, the motion is the same as the synthesized expression of the gravity center driving force F and the torque T (T = F * ε) around the gravity center G. Thus, for example, a y-direction velocity _{V G} of the center of gravity G, the y-direction velocity _{V P1} at the position P1, the y-direction velocity _{V P2} at the position P2 becomes different respectively _{(V G} ≠ _V P1, _{V G} ≠ V _P2 , V _P1 ≠ V _P2 ). Therefore, even if the speed at which the speckle disappears near the center of the screen 1, a phenomenon may occur in which, for example, the speckle does not disappear at the position P <b> 1 because the speed is low. Actually, since the rotational motion also affects the motion in the x direction, the rotational motion in the plane of the screen 1 needs to be reduced as much as possible.

3. 3. Functions and effects of the present embodiment 3-1. Speckle Reduction FIG. 7 is a diagram for explaining the effect of reducing speckle (speckle noise). FIGS. 7A to 7C schematically show how an incident beam having a uniform intensity distribution is diffusely reflected by the screen 1. When the beam is diffusely reflected by the screen 1 in this way, the viewing angle and the observable range can be expanded.

FIG. 7A shows a comparative example in which the screen 1 is fixed without moving. In this case, the intensity distribution corresponding to the unevenness of the screen 1 is generated due to the interference caused by the random unevenness of the screen 1 (phase difference due to the unevenness), that is, speckles occur. FIG. 7B shows a comparative example in which the screen 1 is translated. In this case, the intensity distribution corresponding to the unevenness of the screen 1 changes. Accordingly, the speckle is reduced by averaging the intensity distribution.

FIG. 7C shows the present embodiment in which the screen 1 is moved and tilted (specifically, the screen 1 is moved along a predetermined toroidal surface perpendicular to the z axis). In this embodiment, by driving the screen 1 at a high speed (for example, a frequency higher than the refresh rate), the intensity distribution corresponding to the unevenness of the screen 1 is changed at a high speed as in the example shown in FIG. To average. Here, according to the present embodiment, since the screen 1 is moved and tilted, the intensity distribution can be averaged more effectively than the example shown in FIG. 7B. That is, according to the present embodiment, speckle can be reduced more effectively than the configuration in which the screen 1 is translated.

In this embodiment, since the screen 1 is tilted, the direction of the optical axis also changes, but this influence can also be averaged by high-speed displacement. Further, since the incident beam is close to parallel light and has a wide focal depth, spot blur can be ignored.

3-2. Here, it will be described that according to the present embodiment, rotation within the screen surface (in the xy plane) can be appropriately suppressed. In this embodiment, as shown in FIG. 2, the support portion 3 is arranged non-parallel to the z direction. However, by arranging the support portion 3 in such a manner, the screen 1 is difficult to rotate in the plane. . This will be specifically described with reference to FIG.

FIG. 8 shows the operation when the screen 1 is driven. FIG. 8A shows an operation example of the screen 1 in the comparative example. In the comparative example, unlike the present embodiment, the support portion 3 (parallel spring) disposed in parallel with the z direction is used. In the screen 1 supported by the support portion 3, the screen 1 maintains a substantially horizontal posture with the base 4 during the movement in both translational and rotational movements. That is, for example, if the points a, b, c, and d on the screen 1 are moved to the points a ′, b ′, c ′, and d ′ by rotating the screen 1, the points a ′, b ′, The distances ha ′, hb ′, hc ′, hd ′ from c ′, d ′ to the base 4 are equal (ha ′ = hb ′ = hc ′ = hd ′). Therefore, in the comparative example, both when the screen 1 is translated and when the screen 1 is rotated in the θ direction, the support part 3 as an elastic body moves with the same deformation. Therefore, in the comparative example, there is a problem that if the translational movement is facilitated, the rotational movement is also facilitated.

FIG. 8B shows an operation example of the screen 1 in this embodiment. In the present embodiment, unlike the comparative example, a support portion 3 (non-parallel spring) arranged non-parallel to the z direction is used. Here, in order to simplify the description, only the projection shape on the xz plane is shown as the support portion 3 (that is, the projection shape on the yz plane is parallel). When the screen 1 supported by the support unit 3 rotates, the screen 1 is inclined with respect to the base 4 during movement. That is, for example, when the points a, b, c, and d on the screen 1 are moved to the points a ′, b ′, c ′, and d ′ by rotating the screen 1, from the point a ′ to the base 4 The distance ha ′ and the distance hc ′ from the point c ′ to the base 4 are equal, and the distance hb ′ from the point b ′ to the base 4 is equal to the distance hd ′ from the point d ′ to the base 4. The distances ha ′ and hc ′ of the points a ′ and c ′ are different from the distances hb ′ and hd ′ of the points b ′ and d ′ (ha ′ = hc ′ ≠ hb ′ = hd ′). In order to absorb such a difference, a force for further deforming the support portion 3 as an elastic body is required. Therefore, according to the present embodiment, it is possible to obtain characteristics suitable for supporting the screen 1 such that the translational movement in the x direction and the y direction is easy and the rotational movement in the θ direction is difficult.

3-3. Summary In summary, according to the present embodiment, the speckle can be reduced more effectively by moving and tilting the screen 1. Further, according to the present embodiment, since the support portion 3 as an elastic body arranged non-parallel to the z direction can be used, the in-plane rotation of the screen 1 can be controlled with a simple configuration, so that the cost is low. Thus, the screen device 100 with high reliability can be realized.

4). Modified Example Next, a modified example of the above-described embodiment will be described. Note that the following modifications can be implemented in any combination.

4-1. Modification 1
Modification 1 relates to another example of the support part 3 according to the above-described embodiment.

FIG. 9 shows examples of various cross-sectional shapes applicable to the support portion 3 described above. Specifically, examples of the cross-sectional shape of the support portion 3 along the cutting line D1-D2 shown in FIG. 9A are shown in FIGS. 9B to 9D. FIG. 9B shows an example of the support portion 3 having a circular cross-sectional shape, and FIG. 9C shows an example of the support portion 3 having a square cross-sectional shape, and FIG. ) Shows an example of the support portion 3 having a rectangular (rectangular) cross-sectional shape.

Here, when the support part 3 having a rectangular cross section as shown in FIG. 9D is used, the resonance frequency can be changed between the x direction and the y direction. Since the x-direction dimension and the y-direction dimension are different in the rectangular cross-sectional shape, the x-direction bending rigidity (spring constant) and the y-direction bending rigidity (spring constant) of the support portion 3 are different. The resonance frequency differs in the y direction. In addition, what is necessary is just to set the rectangular dimension in the support part 3 according to two resonance frequencies to apply.

Further, a support portion 3 having a circular or square cross-sectional shape as shown in FIGS. 9B and 9C (that is, a support portion 3 having a cross-sectional shape in which the dimension in the x direction is not different from the dimension in the y direction). ) Can also be used to change the resonance frequency between the x direction and the y direction. This will be described with reference to FIG.

FIG. 10 is a diagram for explaining the spring constant f ₀ x in the x direction on the left side (a side view observed along the y direction), and a diagram for explaining the spring constant f ₀ y in the y direction on the right side. (A side view observed along the x direction) is shown. As shown in FIG. 10A, when the support portion 3 is arranged in parallel with the z direction, the spring constant f ₀ x in the x direction and the spring constant f ₀ y in the y direction are equal. On the other hand, when the support portion 3 is arranged non-parallel to the z direction, the spring constant f ₀ x in the x direction and the spring constant f ₀ y in the y direction tend to be different. For example, as shown in FIG. 10B, when the support unit 3 is arranged so that the projection shape on the xz plane is parallel to the z direction and the projection shape on the yz plane is non-parallel to the z direction. , The spring constant f ₀ y in the y direction is equal to or greater than the spring constant f ₀ x in the x direction. This is because only bending stress is generated in the support portion 3 when the support portion 3 is parallel to the z direction, but only bending stress is applied to the support portion 3 when the support portion 3 is non-parallel to the z direction. This is because a compressive elongation stress is also generated and deformation is difficult (that is, the total spring constant is increased). Further, as shown in FIG. 10C, the spread angle (parallelism) of the support portion 3 may be made different between the x direction and the y direction. By doing so, even if the support part 3 having a circular or square cross-sectional shape is used, it is possible to appropriately realize different resonance frequencies in the x direction and the y direction.

In addition, when the support part 3 as a spring having a circular or square cross-sectional shape is used, it is easy to handle, and the cost can be reduced due to the easily available shape.

4-2. Modification 2
Modification 2 relates to still another example of the support part 3 according to the above-described embodiment.

FIG. 11 is a diagram illustrating a configuration of the support portion 3a according to the second modification. As shown to Fig.11 (a), the support part 3a has the low-rigidity elastic body 3a1 and the high-rigidity member 3a2. That is, unlike the support part 3 according to the embodiment, only a part of the support part 3a is made of an elastic body. In such a support portion 3a, as shown in FIG. 11B, only the low-rigid elastic body 3a1 is deformed when the screen 1 is movable. Therefore, it becomes close to the movement connected by the link.

4-3. Modification 3
In the above-described embodiment, the support portion 3 is disposed so as to spread from the screen 1 toward the base 4. In other words, the support portion 3 is disposed at a position outside the region where the screen 1 is projected onto the base 4. It was connected (see FIG. 2). In the third modification, instead of this, the support portion is arranged so as to narrow toward the base 4 from the screen 1, in other words, the support portion is connected to a position in an area where the screen 1 is projected onto the base 4. Let

FIG. 12 is a diagram illustrating a configuration of a screen device 100b according to the third modification. As shown in FIG. 12, in the screen device 100 b according to the third modification, the support portion 3 b is disposed so as to narrow from the screen 1 toward the base 4. Specifically, the support portion 3b is connected to a position in a region R1 (see the thick line shown in the side view) where the screen 1 is projected onto the base 4. In the third modification, the X ′ axis and the Y ′ axis as virtual rotation axes are set behind the screen surface (that is, on the base 4 side) with the use of the support portion 3b as described above. The screen device 100b according to the third modified example functions similarly to the screen device 100 according to the above-described embodiment.

4-4. Modification 4
In the above-described embodiment, the two driving

units

2a and 2b are used. However, in the fourth modification, only one driving unit is used.

FIG. 13 is a diagram illustrating a configuration of a screen device 100c according to the fourth modification. As shown in FIG. 13, the screen device 100 c is different from the screen device 100 according to the embodiment in that the screen device 100 c includes only one driving unit 2 c instead of the two driving

units

2 a and 2 b. In the screen device 100c, the driving unit 2c generates a driving force F in an axial direction different from the x axis and the y axis. Also in this case, similarly to the above-described embodiment, the force F _{x in} the direction substantially along the x axis and the force F _{y in} the direction substantially along the y axis are applied to the screen 1. Therefore, as in the embodiment, when the screen 1 is driven by the torque around the X ′ axis and the torque around the Y ′ axis, the screen 1 swings around the X ′ axis and the Y ′ axis, that is, z. Move along a predetermined toroidal plane perpendicular to the axis.

Speckle can be appropriately reduced also by the screen device 100c according to Modification 4. Therefore, according to the screen device 100c according to the modified example 4, since only one driving unit 2c is used, speckle reduction can be realized at low cost.

Here, the inclination of the direction in which the driving force F is applied to the x axis is “γ”, the rotational radius of the center of gravity G around the X ′ axis is “Rx”, and the rotational radius of the center of gravity G around the Y ′ axis is Let it be “Ry”. When Rx and Ry are relatively small, the installation position of the drive unit 2c and the drive unit 2c with respect to the screen 1 are realized so that γ obtained by “γ = tan ⁻¹ (Rx ² / Ry ² )” is realized. It is better to design the inclination of By doing so, the angular velocity amplitude around the X ′ axis and the angular velocity amplitude around the Y ′ axis can be made substantially equal to facilitate control.

Next, with reference to FIG. 14 and FIG. 15, a method for driving the screen 1 in Modification 4 will be described.

FIG. 14 is a diagram for explaining a method of driving the screen 1 according to the first example of the fourth modification. FIG. 14A shows the frequency on the horizontal axis and the angular velocity amplitude of the screen 1 on the vertical axis. A graph G11 represented by a thick line shows the relationship between the frequency around the X ′ axis (β direction) and the angular velocity amplitude, and a graph G12 represented by a thin line represents the frequency around the Y ′ axis (α direction) The relationship with the angular velocity amplitude is shown. The frequency f ₁ indicates the resonance frequency of the rotational motion around the X ′ axis, and the frequency f ₂ indicates the resonance frequency of the rotational motion around the Y ′ axis.

By setting the resonance frequency f ₁ and the resonance frequency f ₂ to different frequencies, when the screen 1 is driven based on the resonance frequency f ₁ , a rotational motion about the X ′ axis is obtained, and the resonance frequency f _When the screen 1 is driven based on ₂ , a rotational motion about the Y ′ axis can be obtained. Further, when the screen 1 is driven based on the resonance frequency f ₁ and the resonance frequency f ₂ , rotational motion about the X ′ axis and the Y ′ axis can be obtained. Therefore, in the first example of the modified example 4, the signal having the frequency components of the resonance frequency f ₁ and the resonance frequency f _{2 in} order to simultaneously give the screen 1 rotational motion about the two axes (X ′ axis and Y ′ axis). Is input to the drive unit 2c.

FIGS. 14B and 14C show the angles α and X ′ around the Y ′ axis (α direction) in the screen 1 when the amplitude ratio and frequency ratio between the resonance frequency f ₁ and the resonance frequency f ₂ are controlled. An example of a Lissajous figure drawn by an angle β around the axis (β direction) is shown. FIG. 14B shows a Lissajous figure drawn by the angle α and the angle β when the amplitude ratio is “1: 1” and the frequency ratio is “1: 1.5”. c) shows a Lissajous figure drawn by the angle α and the angle β when the amplitude ratio is “1: 1” and the frequency ratio is “0.5: 1”. For example, if the amplitude ratio and the frequency ratio between the resonance frequency f ₁ and the resonance frequency f ₂ are set so that the Lissajous figure shown in FIGS. 14B and 14C is obtained, the rotation around the X ′ axis and the Y ′ axis is performed. It is possible to cause the screen 1 to perform a rotational motion that always has an angular velocity, and it is possible to appropriately average speckles.

FIG. 15 is a diagram for explaining a method for driving the screen 1 according to the second example of the fourth modification. FIG. 15A shows a diagram that is substantially the same as FIG. Elements having the same reference numerals as those in FIG. 14A have the same meanings and will not be described. In FIG. 15A, the vertical axis further indicates the phase (phase difference) between the velocity component around the X ′ axis and the velocity component around the Y ′ axis. A graph G21 represented by a thick broken line indicates a relationship between the frequency and the phase difference around the X ′ axis (β direction), and a graph G22 represented by a thin broken line represents the relationship around the Y ′ axis (α direction). The relationship between frequency and phase difference is shown.

Unlike the first example of the modification 4, the second example of the modification 4 drives the screen 1 with a single frequency. Specifically, in the second example of the modification 4, driving the screen 1 by one of the resonance frequencies f ₁ and the resonance frequency f _2. In the second example of the modification 4, the direction γ (see FIG. 13) in which the driving force F is applied to the x-axis is the angular velocity around the X ′ axis at the resonance frequency f ₁ or the resonance frequency f _2. It is set based on the ratio between the amplitude (Gx1 or Gx2) and the angular velocity amplitude (Gy1 or Gy2) around the Y ′ axis. Specifically, in the case of driving at the resonance frequency _{f 1} by applying the gamma obtained from ^{"γ = tan -1 (Gy1 / Gx1} ) ", "gamma = tan in the case of driving at the resonance frequency _{f 2} ⁻¹ (Gx2 / Gy2) ”is applied (Gx1, Gx2, Gy1, and Gy2 are expressed in linear). By so doing, the velocity component around the X ′ axis and the velocity component around the Y ′ axis can be made substantially equal.

When the screen 1 is driven at the resonance frequency f ₁ or the resonance frequency f ₂ as described above, the phase difference of each speed component at the resonance frequency f ₁ or the resonance frequency f ₂ is 90 ° (in FIG. 15A). As shown in FIG. 15B, the screen 1 moves on a substantially circular trajectory. Therefore, speckle can be appropriately averaged. Further, even if slightly deviated from the frequency the resonance frequency f ₁ or the resonance frequency f _2, for movement of the screen 1 elliptical orbit as shown in FIG. 15 (c) (FIG. 15 (c) is the phase difference is 60 ° The above effect is maintained.

Preferably, from the viewpoint of efficiency, in _(higher resonant frequency than the resonance frequency f ₁₎ near the resonance frequency f _2, the frequency slightly lower than the resonance frequency f _2, may be used as the driving frequency.

5. Application Example In one example, the present invention can be applied to a screen of a laser projector. As a result, it is possible to realize an image with high resolution and good color reproducibility without laser-specific speckles. In another example, the present invention can be applied to a head-up display or a head-mounted display that generates an intermediate image from a laser scanning light source. In yet another example, the present invention can be applied to a light source of LCD (Liquid Crystal Display) or DLP (Digital Light Processing). Thereby, a display with good color reproducibility can be realized.

DESCRIPTION OF SYMBOLS 1

Screen

2, 2a, 2b Drive part 3 Support part 4 Base 10 Control part 100 Screen apparatus 200

Projector

400a, 400b Display system

Claims

Screen,
Others that are parallel to an axis along one direction in the plane of the screen and that intersect with the one direction along the first axis spaced from the plane of the screen and intersect the one direction in the plane of the screen A drive unit that swings the screen about an axis along a second axis that is parallel to an axis along the direction of
A screen device comprising:
The screen device according to claim 1, further comprising a support portion that is arranged non-parallel to an axis along a normal direction of a surface of the screen and supports the screen.
The support portion has a projection shape on a surface formed by an axis along the one direction and an axis along the normal direction, and an axis along the other direction and along the normal direction. The screen apparatus according to claim 2, wherein at least one of the projection shapes onto the surface formed by the axis is arranged so as to be non-parallel to the axis along the normal direction.
The first resonance frequency around the first axis and the second resonance frequency around the second axis in the screen are configured to be different from each other. A screen device according to claim 1.
5. The screen device according to claim 4, further comprising a control unit that controls the drive unit based on both the first resonance frequency and the second resonance frequency.
The control unit is configured to prevent the first resonance so that the rotational angular velocity around the first axis on the screen surface and the rotational angular velocity around the second axis on the screen surface do not simultaneously become “0”. The screen device according to claim 5, wherein the drive unit is controlled by setting a frequency ratio and an amplitude ratio between a frequency and the second resonance frequency.
The screen device according to claim 4, further comprising a control unit that controls the driving unit based on one of the first resonance frequency and the second resonance frequency.
8. The drive unit according to claim 1, wherein the driving unit applies a force in an axial direction along the one direction and applies a force in an axial direction along the other direction. A screen device according to claim 1.
The said drive part gives force to the axial direction different from the axis | shaft along the said one direction, and the axis | shaft along the said other direction, The Claim 1 thru | or 7 characterized by the above-mentioned. Screen device.
The screen device according to claim 2 or 3, wherein the support portion is made of an elastic body and supports the screen at four points.
The screen device according to claim 10, wherein the elastic body has a cross-sectional shape in which a length along the one direction is different from a length along the other direction.
Screen,
A drive unit that swings the screen along a predetermined toroidal surface perpendicular to the normal direction of the surface of the screen;
A screen device comprising: