Optical path changing device and projection image display device equipped therewith

Abstract

This optical path changing device has: an optical member; a first support member for supporting the optical member; a second support member for supporting the first support member to be capable of swinging about a first swing center line; a base member for supporting the second support member to be capable of swinging about a second swing center line; a first actuator disposed to one side of the first swing center line, the first actuator causing the first support member to swing; and a second actuator disposed to one side of the second swing center line, the second actuator causing the second support member to swing. Either the first swing center line is shifted toward the first actuator with respect to the center of the shape of the optical member, or the second swing center line is shifted toward the second actuator with respect to the center of the shape of the optical member.

Description

[Technical Field]

[0001] The present disclosure relates to an optical path changing device that drives an optical member to shift the projection position of image light, and a projection-type image display device including the same. [Background Art]

[0002] For example, Patent Document 1 discloses an optical path changing device mounted on a projection-type image display device that shifts an image displayed on a screen by changing the posture of an optical member through which image light transmits. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2015 / 098120 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] However, in the case of Patent Document 1, four actuators are used to change the posture of the optical member. Therefore, a high level of noise derived from the actuators is generated during the change of the posture of the optical member.

[0005] Therefore, an object of the present disclosure is to reduce the noise level generated when changing the posture of an optical member in an optical path changing device for a projection-type image display device. [Means for Solving the Problem]

[0006] In order to solve the above problem, according to one aspect of the present disclosure, an optical member; a first support member that supports the optical member; a second support member that supports the first support member so that the first support member can swing about a first swing center line extending in a direction intersecting the propagation direction of light incident on the optical member; A base member that extends in a direction intersecting the propagation direction and supports the second support member so as to be able to swing about a second pivot center line different from the first pivot center line, A first actuator is positioned on one side of the first pivot center line in the propagation direction view and pivots the first support member, The device includes a second actuator positioned on one side of the second pivot centerline in the propagation direction view, which pivots the second support member, An optical path changing device is provided, wherein, in the propagation direction view, the first oscillation center line is shifted toward the first actuator side with respect to the shape center of the optical member, or, in the propagation direction view, the second oscillation center line is shifted toward the second actuator side with respect to the shape center of the optical member.

[0007] Furthermore, according to another aspect of this disclosure, Optical components and A support member that supports the optical element, A base member that supports the support member so as to be able to swing about a pivot center line extending in a direction intersecting the propagation direction of light incident on the optical member, The system includes an actuator positioned on one side of the pivot center line in the direction of propagation, which pivots the support member, An optical path changing device is provided, wherein, in the view of the propagation direction, the oscillation center line is shifted toward the actuator side with respect to the shape center of the optical member.

[0008] Furthermore, according to different aspects of this disclosure, The optical path changing device described above, Light source and A projection-type image display device is provided, which includes an optical modulation module that converts light from the light source into image light and emits the image light toward the optical member of the optical path changing device. [Effects of the Invention]

[0009] According to the present disclosure, in an optical path changing device for a projection-type image display apparatus, the noise level generated when changing the posture of an optical member can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] [Figure 1] Schematic configuration diagram of an example projection-type image display apparatus equipped with an optical path changing device according to an embodiment of the present disclosure [Figure 2] Diagram for explaining driving of an optical member by the optical path changing device [Figure 3] Top view of the optical path changing device [Figure 4] Partial cross-sectional view of the optical path changing device in a state where image light is transmitted therethrough [Figure 5] Exploded perspective view of the optical path changing device [Figure 6] Top view of the movable unit [Figure 7] Exploded perspective view of the movable unit [Figure 8] Exploded perspective view of the first actuator [Figure 9] Exploded perspective view of the second actuator [Figure 10] Cross-sectional view of the first and second actuators [Figure 11] Diagram showing changes in the swing angle of the optical member and the first and second actuators [Figure 12] Schematic top view of an optical path changing device according to another embodiment MODE FOR CARRYING OUT THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of already well-known matters and redundant description of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding for those skilled in the art.

[0012] It should be noted that the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0013] Hereinafter, an optical path changing device and a projection-type image display device according to an embodiment of the present disclosure will be described with reference to the drawings.

[0014] FIG. 1 is a schematic configuration diagram of an example of a projection-type image display device equipped with an optical path changing device according to an embodiment of the present disclosure. The X-Y-Z orthogonal coordinate system shown in FIG. 1 is provided to facilitate understanding of the embodiments of the present disclosure, and does not limit the present disclosure. In the X-Y-Z orthogonal coordinate system, the X-axis direction indicates the width direction of an image projected by the projection-type image display device, the Y-axis direction indicates the height direction of the image, and the Z-axis direction indicates the projection direction of the projection-type image display device.

[0015] As shown in FIG. 1, the projection-type image display device 10 is a so-called projector, and includes a housing 12, a light source 14, a light modulation module 16 that converts light L from the light source 14 into image light Lm based on image data, and a projection lens 18 that projects the image light Lm onto a screen S. The light modulation module 16 is composed of, for example, a plurality of DMDs (Digital Micromirror Devices) (not shown) and a TIR prism (total internal reflection prism) (not shown). It should be noted that the present disclosure does not limit the light modulation module that converts light L into image light Lm.

[0016] The projection-type image display device 10 also includes an optical path changing device 20. The optical path changing device 20 includes an optical member 22 disposed between the light modulation module 16 and the projection lens 18.

[0017] It should be noted that the projection-type image display device 10 further includes optical members such as mirrors, prisms, and filters (not shown) between the light source 14 and the light modulation module 16, and between the light modulation module 16 and the optical member 22 of the optical path changing device 20.

[0018] In this type of projection-type image display device 10, the optical modulation module 16 converts light L from the light source 14 into image light Lm, and emits the image light Lm toward the optical element 22 of the optical path changing device 20. The image light Lm passes through the optical element 22 and the projection lens 18 and is projected onto the screen S. As a result, an image is displayed on the screen S.

[0019] Figure 2 is a diagram illustrating the driving of optical components by an optical path changing device.

[0020] As shown in Figure 2, the optical element 22 of the optical path changing device 20 is located between the optical modulation module 16 and the projection lens 18, and includes an incident surface 22a into which the image light Lm from the optical modulation module 16 is incident, and an exit surface 22b into which the image light Lm is emitted toward the projection lens 18. The incident surface 22a and the exit surface 22b are planes parallel to each other.

[0021] The optical path changing device 20 drives the optical member 22 so that it oscillates around a first oscillation center line CL1, which extends in a direction intersecting the propagation direction of the image light Lm incident on the optical member 22 (in this embodiment, the Z-axis direction) (in this embodiment, the X-axis direction). The optical path changing device 20 also drives the optical member 22 so that it oscillates around a second oscillation center line CL2, which extends in a direction intersecting the propagation direction of the image light Lm incident on the optical member 22 (in this embodiment, the Y-axis direction) and is different from the first oscillation center line CL1. This driving changes the orientation of the optical member 22. In this embodiment, the propagation direction of the image light Lm incident on the optical member 22 is the extending direction of the optical axis LA of the projection lens 18. In this propagation direction view, the first oscillation center line CL1 and the second oscillation center line CL2 are orthogonal.

[0022] When the optical path changing device 20 drives the optical member 22, the image M projected onto the screen S is shifted by a stroke range of 1 / 2 pixel in both the width direction W (X-axis direction) and the height direction H (Z-axis direction). In this embodiment, when the optical member 22 oscillates around the first oscillation center line CL1, the image M reciprocates in the height direction H. Also, when the optical member 22 oscillates around the second oscillation center line CL2, the image M reciprocates in the width direction W.

[0023] By driving the optical element 22, images M are projected onto the screen S in the following order: an image M shifted by +1 / 4 pixels in the width direction and +1 / 4 pixels in the height direction from the reference position; an image M shifted by +1 / 4 pixels in the width direction and -1 / 4 pixels in the height direction from the reference position; an image M shifted by -1 / 4 pixels in the width direction and -1 / 4 pixels in the height direction from the reference position; and an image M shifted by -1 / 4 pixels in the width direction and +1 / 4 pixels in the height direction from the reference position. The reference position is the position when the optical element 22 is not driven (i.e., in a stopped state), and is the position when the image light Lm from the optical modulation module 16 is incident on the optical element 22a at a right angle. As a result, images M are displayed on the screen S with a higher resolution than the original image data.

[0024] In order to increase the resolution of the image M on the screen S, the optical path changing device 20 needs to drive the optical member 22 at high speed. To that end, the optical path changing device 20 has the following configuration.

[0025] Figure 3 is a perspective view of the optical path changing device. Figure 4 is a top view of the optical path changing device. Furthermore, Figure 5 is an exploded perspective view of the optical path changing device.

[0026] As shown in Figures 3-5, the optical path changing device 20 includes a main unit 24 that supports the optical member 22 and a base member 26 that rotatably supports the main unit 24. In this embodiment, the optical path changing device 20 also includes a flexible printed circuit board 28 and a spacer member 30 that supports the flexible printed circuit board 28.

[0027] As shown in Figures 3 and 4, in this embodiment, the optical member 22 is a disc-shaped member made from transparent parallel flat glass. When the optical member 22 is in the reference position, the image light Lm from the optical modulation module 16 is incident on the optical member 22 at a right angle to the incident surface 22a. Also, when the optical member 22 is in the reference position, the shape centers P0 of the incident surface 22a and the exit surface 22b are located on the optical axis LA of the projection lens 18, and the incident surface 22a and the exit surface 22b are perpendicular to the optical axis LA. Furthermore, when the optical member 22 is in the reference position, the image M on the screen S is located in the reference position.

[0028] The main unit 24 is composed of multiple components and is a unit that supports the optical component 22.

[0029] Figure 6 is a top view of the main unit. Figure 7 is an exploded perspective view of the main unit.

[0030] The main unit 24 includes a subunit 32. The subunit 32 includes a first support member 34 that supports the optical element 22.

[0031] As shown in Figures 6 and 7, in this embodiment, the first support member 34 is a frame-shaped member that supports the outer edge of the optical member 22. The shape of the first support member 34 is not limited as long as it can support the optical member 22. For example, the first support member 34 may be U-shaped.

[0032] The main unit 24 also includes a second support member 36 that pivotably supports the subunit 32 about a first pivot centerline CL1.

[0033] In this embodiment, the second support member 36 is a frame-shaped member and has a through hole 36a for housing the subunit 32. The thickness of the second support member 36 (size in the Z-axis direction) is approximately equal to the thickness of the subunit 32. This reduces the thickness of the main unit 24. As a result, the optical path changing device 20 is made thinner, and the distance between the optical modulation module 16 on which the optical path changing device 20 is located and the projection lens 18 can be reduced. The shape of the second support member 36 is not limited as long as it can pivotably support the subunit 32.

[0034] In this embodiment, the second support member 36 pivotably supports the subunit 32 via two leaf spring members 38. The leaf spring members 38 are made from a deformable elastic material. For example, the leaf spring members 38 are manufactured by press-forming a thin metal sheet.

[0035] As shown in Figure 6, the two leaf spring members 38 are spaced apart in the direction of extension of the first pivot centerline CL1 (X-axis direction) when viewed from above (Z-axis direction). A subunit 32 is positioned between the two leaf spring members 38 when viewed from above. Each leaf spring member 38 includes a first fixing portion 38a fixed to the first support member 34 of the subunit 32, a second fixing portion 38b fixed to the second support member 36, and a deformable elongated connecting portion 38c that connects the first fixing portion 38a and the second fixing portion 38b. The first fixing portion 38a and the second fixing portion 38b face each other with a space between them in the direction of extension of the first pivot centerline CL1 (X-axis direction), and the connecting portion 38c that connects them extends along the first pivot centerline CL1.

[0036] As the connecting portions 38c of each leaf spring member 38 undergo elastic deformation in a twisting manner, the subunit 32 swings within the second support member 36 and also swings around the first swing centerline CL1. Furthermore, the leaf spring members 38 maintain the optical member 22 within the subunit 32 in a reference position when the optical path changing device 20 is stopped.

[0037] As shown in Figures 4 and 5, the main unit 24 is supported on the base member 26 so as to be able to swing about a second pivot centerline CL2. In this embodiment, the second support member 36 of the main unit 24 is supported on the base member 26 via two leaf spring members 40. The leaf spring members 40 are made from a deformable elastic material. For example, the leaf spring members 40 are made by press-forming a thin metal sheet.

[0038] As shown in Figure 4, the two leaf spring members 40 are spaced apart in the direction of extension of the second pivot centerline CL2 (Y-axis direction) when viewed from above (Z-axis direction). The main unit 24 is positioned between the two leaf spring members 40 when viewed from above. Each leaf spring member 40 includes a first fixing part 40a fixed to the second support member 36 of the main unit 24, a second fixing part 40b fixed to the base member 26, and a deformable elongated connecting part 40c that connects the first fixing part 40a and the second fixing part 40b. The first fixing part 40a and the second fixing part 40b face each other with a space between them in the direction of extension of the second pivot centerline CL2 (Y-axis direction), and the connecting part 40c that connects them extends along the second pivot centerline CL2.

[0039] As the connecting portions 40c of each leaf spring member 40 undergo elastic deformation in a twisting manner, the main unit 24 swings above the base member 26 and also swings about the second swing centerline CL2. Furthermore, the leaf spring members 40 maintain the optical member 22 within the main unit 24 in a reference position when the optical path changing device 20 is stopped.

[0040] As shown in Figures 3 and 4, the optical path changing device 20 includes a first actuator 42 that pivots a subunit 32 around a first pivot centerline CL1, and a second actuator 44 that pivots a main unit 24 around a second pivot centerline CL2. As shown in Figure 4, the first actuator 42 is positioned on one side of the first pivot centerline CL1 when viewed in the direction of extension of the optical axis LA (Z-axis direction). In this embodiment, the first actuator 42 is housed in a through hole 36a of the second support member 36. The second actuator 44 is positioned on one side of the second pivot centerline CL2 when viewed in the direction of extension of the optical axis LA.

[0041] Figure 8 is an exploded perspective view of the first actuator. Figure 9 is an exploded perspective view of the second actuator. And Figure 10 is a cross-sectional view of the first and second actuators.

[0042] As shown in Figure 8, the first actuator 42 is a voice coil type actuator and comprises a coil 46, a movable magnet 48, a yoke 50, and a mounting member 52.

[0043] The coil 46 is included in the fixed portion 42a of the first actuator 42 and is fixed to the base member 26 as shown in Figure 5. The coil 46 also opens in the direction of extension of the optical axis LA (Z-axis direction). Furthermore, the coil 46 receives an alternating current from, for example, a circuit (not shown) on the flexible printed circuit board 28 to generate an alternating magnetic field that drives the movable magnet 48.

[0044] The movable magnet 48 is mounted on the yoke 50 and positioned within the coil 46, as shown in Figure 10. The movable magnet 48 and the yoke 50 are included in the movable part 42b of the first actuator 42. When the coil 46 generates an alternating magnetic field, the movable part 42b reciprocates substantially in the direction of extension of the optical axis LA (Z-axis direction). However, the movable part 42b is not guided to reciprocate precisely in the direction of extension of the optical axis LA.

[0045] The mounting member 52 connects the movable part 42b of the first actuator 42 and the first support member 34 of the subunit 32, and is an elastically deformable member. For example, the mounting member 52 is a leaf spring made by press-forming a thin metal sheet.

[0046] As shown in Figure 8, the mounting member 52 includes a first fixing portion 52a provided in the center and fixed to the yoke 50, a second fixing portion 52b provided at the end and attached to the first support member 34, and a deformable connecting portion 52c that connects the first fixing portion 52a and the second fixing portion 52b. The first support member 34 includes a pair of arm portions 34a that are spaced apart in the extending direction of the first pivot centerline CL1 (X-axis direction) and project in the extending direction of the second pivot centerline CL2 (Y-axis direction). The second fixing portion 52b of the mounting member 52 is fixed to each of the arm portions 34a. As a result, the movable portion 42b of the first actuator 42 is positioned between the arm portions 34a.

[0047] With this first actuator 42, when the coil 46 generates an alternating magnetic field, the movable part 42b of the first actuator 42 reciprocates substantially in the direction of extension of the optical axis LA (Z-axis direction). This reciprocating motion of the movable part 42b causes the subunit 32 to oscillate around the first oscillation center line CL1. As a result, the optical member 22 oscillates around the first oscillation center line CL1.

[0048] As shown in Figure 9, the second actuator 44 is a voice coil type actuator and, like the first actuator 42, comprises a coil 54, a movable magnet 56, a yoke 58, and a mounting member 60.

[0049] In this embodiment, the coil 54, movable magnet 56, and yoke 58 of the second actuator 44 are substantially identical to the coil 46, movable magnet 48, and yoke 50 of the first actuator 42. The coil 54 is included in the fixed part 44a of the second actuator 44, and the movable magnet 56 and yoke 58 are included in the movable part 44b.

[0050] The mounting member 60 connects the movable part 44b of the second actuator 44 and the second support member 36 of the main unit 24, and is made of an elastic material. For example, the mounting member 60 is manufactured by press-forming a thin metal sheet.

[0051] As shown in Figure 9, the mounting member 60 includes a first fixing portion 60a provided in the center and fixed to the yoke 58, a second fixing portion 60b provided at the end and attached to the second support member 36, and a deformable connecting portion 60c that connects the first fixing portion 60a and the second fixing portion 60b. The second support member 36 includes a pair of arm portions 36b that are spaced apart in the extending direction of the second pivot centerline CL2 (Y-axis direction) and project in the extending direction of the first pivot centerline CL1 (X-axis direction). The second fixing portion 60b of the mounting member 60 is fixed to each of the arm portions 36b. As a result, the movable portion 44b of the second actuator 44 is positioned between the arm portions 36b.

[0052] With this second actuator 44, when the coil 54 generates an alternating magnetic field, the movable part 44b of the second actuator 44 reciprocates in the direction of extension of the optical axis LA (Z-axis direction). This reciprocating motion of the movable part 44b causes the main unit 24 to oscillate around the second oscillation center line CL2. As a result, the optical member 22 oscillates around the second oscillation center line CL2.

[0053] Furthermore, in this embodiment, as shown in Figure 4, the optical path changing device 20 includes a first position sensor 62 for detecting the position of the movable part 42 of the first actuator 42, and a second position sensor 64 for detecting the position of the movable part 44b of the second actuator 44.

[0054] In this embodiment, the first and second position sensors 62 and 64 are so-called Hall sensors. The first and second position sensors 62 and 64 consist of position detection magnets 62a and 64a and sensing chips (magnetic field detection units) 62b and 64b that detect the magnetic field generated from the position detection magnets 62a and 64a. The position detection magnets 62a and 64a are attached to the yokes 50 and 58 of the movable parts 42b and 44b of the first and second actuators 42 and 44. The sensing chips 62b and 64b are mounted on a flexible printed circuit board 28 and fixed to a base member 26. The first and second position sensors 62 and 64 detect the position of the movable parts 42b and 44b of the first and second actuators 42 and 44 (position in the extending direction (Z-axis direction) of the optical axis LA) based on the change in the magnetic field detected by the sensing chips 62b and 64b. Based on the detection results of the first and second position sensors 62 and 64, a processor (not shown), such as an MPU of the optical path changing device 20 mounted on the flexible printed circuit board 28, controls the alternating current supplied to the coils 46 and 54 of the first and second actuators 42 and 44.

[0055] Up to this point, we have described the configuration of the optical path changing device 20. From here on, we will describe some further features of the optical path changing device 20 according to this embodiment.

[0056] First, as shown in Figure 6, the first support member 34 of the subunit 32 and the movable part 42b of the first actuator 42 are not directly connected, but are connected via a mounting member 52. Similarly, the second support member 36 of the main unit 24 and the movable part 44b of the second actuator 44 are not directly connected, but are connected via a mounting member 60. Furthermore, since the mounting members 52 and 60 are made of elastic material, their two connecting parts 52c and 60c undergo elastic deformation. In other words, the movable part 42b of the first actuator 42 on the first support member 34 is connected via multiple elastic members (first elastic members), and the movable part 44b of the second actuator 44 on the second support member 36 is connected via multiple elastic members (second elastic members). Such connections via elastic members provide the effects described below.

[0057] Figure 11 shows the change in the oscillation angle of the optical element and the first and second actuators.

[0058] The oscillation angle θ is the oscillation angle of the optical member 22 as it oscillates around the first oscillation centerline CL1, as shown in Figure 2. The oscillation angle φ is the oscillation angle of the optical member 22 as it oscillates around the second oscillation centerline CL2. When the optical member 22 is in the reference position, both the oscillation angles θ and φ are zero degrees.

[0059] In this embodiment, the first and second actuators 42 and 44 do not oscillate. However, the oscillation angles α and β of the first and second actuators 42 and 44 can be defined as shown in the following equations 1 and 2.

[0060]

number

[0061]

number

[0062] In Equation 1, L1 is the distance between the first pivot center line CL1 and the movable part 42b of the first actuator 42. Note that distance L1 is the distance when the optical member 22 is in the reference position. d1 is the displacement amount of the movable part 42b of the first actuator 42 in the direction of extension of the optical axis LA (Z-axis direction). Note that when the optical member 22 is in the reference position, the displacement amount d1 is zero.

[0063] In Equation 2, L2 is the distance between the second pivot center line CL2 and the movable part 44b of the second actuator 44. Note that distance L2 is the distance when the optical member 22 is in the reference position. d2 is the displacement amount of the movable part 44b of the second actuator 44 in the direction of extension of the optical axis LA (Z-axis direction). Note that when the optical member 22 is in the reference position, the displacement amount d2 is zero.

[0064] As shown in Figure 11, with respect to the first oscillation centerline CL1, when the movable part 42b of the first actuator 42 oscillates at the maximum oscillation angle α (displaced by the maximum displacement amount d1), the optical member 22 oscillates at an oscillation angle θ greater than that. Similarly, with respect to the second oscillation centerline CL2, when the movable part 44b of the second actuator 44 oscillates at the maximum oscillation angle β (displaced by the maximum displacement amount d2), the optical member 22 oscillates at an oscillation angle φ greater than that.

[0065] This behavior occurs due to the elastic deformation of the connecting portions 52c and 60c of the mounting members 52 and 60. Specifically, when the displacement directions of the movable portions 42b and 44b of the first and second actuators 42 and 44 are reversed, the displacement direction of the optical member 22 is reversed with a delay due to the elastic deformation of the connecting portions 52c and 60c by inertial force. Furthermore, the elastic deformation of the connecting portions 52c and 60c causes the maximum oscillation angles θ and φ of the optical member 22 to become larger than the maximum oscillation angles α and β of the first and second actuators 42 and 44. In other words, the amplitude of the oscillation angles θ and φ of the optical member 22 becomes larger than the amplitude of the oscillation angles α and β of the first and second actuators 42 and 44.

[0066] Furthermore, the elastic deformation of the connecting portions 52c and 60c of the mounting members 52 and 60 generates a restoring force in the connecting portions 52c and 60c of the mounting members 52 and 60. Due to this restoring force, the oscillation angles θ and φ of the optical member 22 are faster than the oscillation angles α and β of the first and second actuators 42 and 44 in terms of the speed from zero to the peak and the speed from the peak to zero. As a result, even if the amplitudes are different, the frequencies of the oscillation angles θ and φ of the optical member 22 and the frequencies of the oscillation angles α and β of the first and second actuators 42 and 44 are approximately the same.

[0067] By driving the optical member 22 with the first and second actuators 42 and 44 in this manner, the optical member 22 can be driven with a large amount of oscillation with a small amount of displacement of the movable parts 42b and 44b of the first and second actuators 42 and 44. That is, when driving the optical member 22 with the amount and speed of oscillation required to increase the resolution of the image M on the screen S, the amount and speed of displacement of the movable parts 42b and 44b of the first and second actuators 42 and 44 can be reduced (compared to the case where the movable parts 42b and 44b of the first and second actuators 42 and 44 are directly connected to the first and second support members 34 and 36 without the mounting members 52 and 60). As a result, the noise level generated from the first and second actuators 42 and 44 when driving the optical member 22 can be reduced.

[0068] Furthermore, as shown in Figure 6, in this embodiment, preferably, the first support member 34 and the movable part 42b of the first actuator 42 are connected at multiple points. That is, the first support member 34 and the first actuator 42 are connected via two connecting parts 52c of the mounting member 52. Moreover, the two connecting parts 52c are spaced apart in the direction of extension of the first pivot center line CL1 (X-axis direction). As a result, the subunit 32 can pivot uniformly over the entire direction of extension of the first pivot center line CL1. In contrast, if there is only one connecting part 52c, the posture of the movable part 42b of the first actuator 42 becomes unstable and prone to tilting, and this tilt may prevent the image M on the screen S from being properly high-resolution.

[0069] Furthermore, it is preferable that the extending length of the connecting portion 52c (first elastic member) of the mounting member 52 is greater than the distance between the portion of the first support member 34 connected to the connecting portion 52c and the portion of the first actuator 42. For this reason, the connecting portion 52c extends in a meandering manner. In other words, the connecting portion 52c does not connect the first support member 34 and the first actuator 42 with the shortest possible length. In contrast, if the connecting portion 52c connects the first support member 34 and the first actuator 42 with the shortest possible distance, the connecting portion 52c cannot elastically deform with a sufficient amount of deformation. In this case, as shown in Figure 11, when the movable portion 42b of the first actuator 42 swings at the maximum swing angle α (displaces with the maximum displacement amount d1), the effect of the optical member 22 swinging at a larger swing angle θ is small. Therefore, the reduction in the noise level generated from the first actuator 42 is small. Therefore, by having the connecting portion 52c of the mounting member 52 have an extension length that is greater than the distance between the first support member 34 and the first actuator 42, the noise level generated from the first actuator 42 can be sufficiently reduced.

[0070] Similarly, as shown in Figure 6, the second support member 36 and the movable part 44b of the first actuator 44 are also connected at multiple points. That is, the second support member 36 and the second actuator 44 are connected via two connecting parts 60c of the mounting member 60. Furthermore, the two connecting parts 60c are spaced apart in the direction of extension of the second pivot centerline CL2 (Y-axis direction). As a result, the main unit 24 can pivot uniformly over the entire direction of extension of the second pivot centerline CL2.

[0071] Similarly, the extending length of the connecting portion 60c (second elastic member) of the mounting member 60 is also greater than the distance between the portion of the second support member 36 connected to the connecting portion 60c and the portion of the second actuator 44. In other words, the connecting portion 60c extends in a meandering manner. This makes it possible to sufficiently reduce the noise level generated from the second actuator 44.

[0072] In addition, as shown in Figures 4 and 6, the first and second oscillation centerlines CL1 and CL2 are offset from the shape center P0 of the optical member 22. Specifically, in the direction of extension of the optical axis LA (Z-axis direction), the first oscillation centerline CL1 is offset towards the first actuator 42, and the second oscillation centerline CL2 is offset towards the second actuator 44. As a result, the first oscillation centerline CL1 approaches the first actuator 42, and the second oscillation centerline CL2 approaches the second actuator 44. This makes it possible to reduce the required displacement of the movable parts 42b and 44b of the first and second actuators 42 and 44 compared to the case where the first and second oscillation centerlines CL1 and CL2 coincide with the shape center P0 of the optical member 22 in the direction of extension of the optical axis LA. As a result, the noise level generated from the first actuators 42 and 44 can be reduced.

[0073] Furthermore, at least one of the first and second oscillation centerlines CL1 and CL2 may coincide with the shape center P0 of the optical member 22 when viewed in the direction of extension of the optical axis LA (Z-axis direction).

[0074] Furthermore, as shown in Figures 4 and 6, it is preferable that the first oscillation centerline CL1 is closer to the center of gravity G1 of the subunit 32 than to the shape center P0 of the optical member 22. More preferably, in the direction of extension of the optical axis LA (Z-axis direction), the first oscillation centerline CL1 should coincide with the center of gravity G1 of the subunit 32. This allows the first actuator 42 to oscillate the subunit 32 around the first oscillation centerline CL1 with less force. In this embodiment, the power supplied to the coil 46 of the first actuator 42 can be kept low.

[0075] Similarly, it is preferable that the second oscillation centerline CL2 is closer to the center of gravity G2 of the main unit 24 than to the shape center P0 of the optical member 22. More preferably, in the direction of extension of the optical axis LA (Z-axis direction), the second oscillation centerline CL2 coincides with the center of gravity G2 of the main unit 24. This allows the second actuator 44 to oscillate the main unit 24 around the second oscillation centerline CL2 with less force.

[0076] Furthermore, in this embodiment, as shown in Figure 4, the position detection magnet 62a of the first position sensor 62 is located on the second oscillation centerline CL2. With this arrangement, even if the main unit 24 oscillates around the second oscillation centerline CL2, the position of the position detection magnet 62a does not substantially change. As a result, the sensing chip 62b of the first position sensor 62 can detect only the displacement of the optical axis LA of the position detection magnet 62a in the extending direction (Z-axis direction) caused by the oscillation of the subunit 32 around the first oscillation centerline CL1. Consequently, the first position sensor 62 can detect the position of the movable part 42b of the first actuator 42 with high accuracy.

[0077] According to the above embodiment, the noise level generated when changing the orientation of the optical member 22 in the optical path changing device 20 of the projection-type image display device 10 can be reduced.

[0078] Specifically, first, the orientation of the optical member 22 is changed by the minimum number of actuators (first and second actuators 42 and 44), thus reducing the noise level originating from the actuators. Furthermore, as mentioned above and as shown in Figure 4, the noise level originating from the actuators is also reduced because the first and second oscillation centerlines CL1 and CL2 are shifted from the shape center P0 of the optical member 22 towards the first and second actuators 42 and 44.

[0079] The present disclosure has been described above with reference to the embodiments described above, but the embodiments of the present disclosure are not limited to these.

[0080] For example, in the embodiment described above, as shown in Figures 8 and 9, the first and second actuators 42 and 44 are so-called voice coil type actuators. However, the embodiments of this disclosure are not limited to this. The first and second actuators may also be electromagnets.

[0081] With respect to the first and second actuators 42 and 44, in the embodiments described above, their coils 46 and 54 generate an alternating magnetic field by receiving an alternating current. However, the embodiments of this disclosure are not limited to this. The coils may intermittently generate a magnetic field by intermittently receiving a direct current.

[0082] With respect to the first and second actuators 42 and 44, in the embodiments described above, their mounting members 52 and 56 are elastically deformable leaf springs. However, embodiments of the present disclosure are not limited thereto. The mounting members may be, for example, compression coil springs. In other words, in the present disclosure, the material and shape of the mounting members are not limited as long as they are members that can be repeatedly elastically deformed.

[0083] With respect to the first and second actuators 42 and 44, in the embodiment described above, their fixed parts 42a and 44a include coils 46 and 54, and their movable parts 42b and 44b include movable magnets 48 and 56 and yokes 50 and 58. However, this embodiment is not limited thereto. The movable parts of the first and second actuators may include coils, and the fixed parts may include magnets and yokes. In this case, a flexible cable would need to be used to supply current to the moving coils.

[0084] Furthermore, in the above-described embodiment, as shown in Figure 2, the incident surface 22a and the exit surface 22b of the optical element 22 of the optical path changing device 20 are parallel planes. However, the embodiments of this disclosure are not limited to this. The optical element 22 may be, for example, a lens.

[0085] Furthermore, in the above-described embodiment, the first support member 34 and the first actuator 42 are connected via an elastically deformable mounting member 52. Also, the second support member 36 and the second actuator 44 are connected via an elastically deformable mounting member 60. However, the embodiments of this disclosure are not limited thereto. The first support member 34 and the first actuator 42 may be directly connected, or the second support member 36 and the second actuator 44 may be directly connected.

[0086] Furthermore, in the embodiment described above, as shown in Figure 2, the optical member 22 is oscillated around different first and second pivot centerlines CL1 and CL2. However, the embodiments of this disclosure are not limited thereto.

[0087] Figure 12 is a schematic top view of an optical path changing device according to another embodiment.

[0088] As shown in Figure 12, the optical path changing device 120 according to another embodiment includes a support member 134 that supports the optical member 122. The support member 134 is supported on the base member 126 so as to be able to swing about the pivot center line CL. The support member 134 is also connected to the actuator 142 via a mounting member 152 made of an elastic material. The pivot center line CL is offset towards the actuator 142 side with respect to the shape center P0 of the optical member 22 when viewed in the direction of extension of the optical axis LA (Z-axis direction).

[0089] This other embodiment of the optical path changing device 120 can also increase the resolution of the image displayed on the screen.

[0090] In other words, the embodiments of the present disclosure are, in a broad sense, optical path changing devices comprising: an optical member; a first support member for supporting the optical member; a second support member that supports the first support member so as to be pivotable about a first pivot center line extending in a direction intersecting the propagation direction of light incident on the optical member; a base member that supports the second support member so as to be pivotable about a second pivot center line extending in a direction intersecting the propagation direction and different from the first pivot center line; a first actuator positioned on one side of the first pivot center line in the propagation direction view for oscillating the first support member; and a second actuator positioned on one side of the second pivot center line in the propagation direction view for oscillating the second support member, wherein in the propagation direction view, the first pivot center line is shifted toward the first actuator with respect to the shape center of the optical member, or the second pivot center line is shifted toward the second actuator with respect to the shape center of the optical member in the propagation direction view.

[0091] Another embodiment of the present disclosure, in a broad sense, is an optical path changing device comprising: an optical member; a support member for supporting the optical member; a base member that supports the support member so as to be able to swing about a pivoting center line extending in a direction intersecting the propagation direction of light incident on the optical member; and an actuator positioned on one side of the pivoting center line in the propagation direction view for swinging the support member, wherein the pivoting center line is shifted toward the actuator side with respect to the shape center of the optical member in the propagation direction view.

[0092] Furthermore, a different embodiment of the present disclosure, in a broad sense, is a projection-type image display device having the above-described optical path changing device, a light source, and an optical modulation module that converts light from the light source into image light and emits the image light toward the optical member of the optical path changing device.

[0093] As described above, the embodiments described in this disclosure have been explained as examples of the technology. For this purpose, drawings and a detailed description are provided. Therefore, among the components described in the drawings and detailed description, there may be not only components that are essential for solving the problem, but also components that are not essential for solving the problem, in order to illustrate the technology described above. For this reason, the mere fact that these non-essential components are described in the drawings and detailed description should not be immediately assumed to be essential.

[0094] Furthermore, since the embodiments described above are for illustrative purposes of the technology described herein, various modifications, substitutions, additions, omissions, etc., can be made within the scope of the claims or equivalents thereof. [Industrial applicability]

[0095] This disclosure is applicable to devices that require changing the orientation of optical components.

Claims

1. Optical components and A first support member that supports the optical element, A second support member supports the first support member so as to be able to pivot about a first pivot center line extending in a direction intersecting the propagation direction of light incident on the optical member, A base member that extends in a direction intersecting the propagation direction and supports the second support member so as to be able to swing about a second pivot center line different from the first pivot center line, A first actuator is positioned on one side of the first pivot center line in the propagation direction view and pivots the first support member, The device includes a second actuator positioned on one side of the second pivot center line in the propagation direction view, which pivots the second support member, An optical path changing device wherein the first oscillation center line is shifted toward the first actuator side relative to the shape center of the optical member when viewed in the propagation direction, between the shape center of the optical member and the first actuator, or the second oscillation center line is shifted toward the second actuator side relative to the shape center of the optical member when viewed in the propagation direction, between the shape center of the optical member and the second actuator.

2. The optical path changing device according to claim 1, wherein, in the propagation direction view, the first oscillation center line is shifted toward the first actuator with respect to the shape center of the optical member, and the second oscillation center line is shifted toward the second actuator with respect to the shape center of the optical member.

3. A subunit comprising at least the optical member and the first support member, and comprising a member that swings about the first pivot center line, The optical path changing device according to claim 1, wherein the first pivoting center line is closer to the center of gravity of the subunit than to the center of shape of the optical member.

4. There is a main unit comprising at least the subunit and the second support member, and which is composed of a member that swings about the second pivot center line, The optical path changing device according to claim 3, wherein the second pivoting center line is closer to the center of gravity of the main unit than to the center of shape of the optical member.

5. The first actuator comprises a movable part including a movable magnet and connected to the first support member, and a fixed part including a coil that generates a magnetic field and fixed to the base member, The optical path changing device according to claim 1, wherein the second actuator comprises a movable part including a movable magnet and connected to the second support member, and a fixed part including a coil for generating a magnetic field and fixed to the base member.

6. The first actuator further includes a position detection sensor comprising a position detection magnet attached to the movable part of the first actuator and a magnetic field detection unit fixed to the base member, The optical path changing device according to claim 5, wherein the position detection magnet of the position detection sensor is arranged on the second pivot center line.

7. The first actuator includes a first movable part that moves to swing the first support member, The optical path changing device according to claim 1, wherein the second actuator comprises a second movable part that moves to swing the second support member.

8. A first connecting member that connects the first support member and the first actuator, A second connecting member that connects the second support member and the second actuator, The optical path changing device according to claim 1, further comprising:

9. Optical components and A support member that supports the optical element, A base member that supports the support member so as to be able to swing about a pivot center line extending in a direction intersecting the propagation direction of light incident on the optical member, The system includes an actuator positioned on one side of the pivot center line in the direction of propagation, which pivots the support member, An optical path changing device wherein the oscillation center line is offset toward the actuator side relative to the shape center of the optical member when viewed in the propagation direction.

10. An optical path changing device according to any one of claims 1 to 9, Light source and A projection-type image display device having an optical modulation module that converts light from the light source into image light and emits the image light toward the optical member of the optical path changing device.

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