Light source device and projection device

Abstract

To provide a light source device and a projection device capable of reducing speckle noise while realizing reduction in size.SOLUTION: A projection device 10 comprises: a lens member 172 that guides light to a display element 50 that generates image light; a blue light source device 70A and a red light source device 80 as light irradiation devices that emit the light toward the lens member 172; and a drive device 300 that vibrates the lens member 172 back and forth at a predetermined angle around a rotational axis RA passing through the lens member 172 as a rotation center so as to displace the lens member in a light emission direction, where on an incident surface of the lens member 172, an intersection point between an emission optical axis of the blue light source device 70A and the incident surface of the lens member 172 is separated from the rotational axis RA.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a light source device and a projection device. [Background technology]

[0002] Today, projection devices are used to project image data stored on personal computer screens, video screens, memory cards, etc. onto a screen. These projection devices focus light emitted from a light source using a laser diode or fixed phosphor onto a micromirror display element called a DMD (Digital Micromirror Device) or a liquid crystal panel, and display a color image on the screen.

[0003] For example, Patent Document 1 describes a projection device equipped with a light source device having the following configuration. Specifically, this projection device has a light source device including a semiconductor laser, a first optical system including a collimator lens and an imaging lens that convert an image at infinity, a second optical system including a plurality of lenses, and an optical deflection means that deflects the light emitted through the first optical system and emits it toward the second optical system. The optical deflection means is provided with a rotary oscillating mirror that rotates so as to describe a conical surface by a rotary motor. The optical deflection means reduces speckle noise of the light from the semiconductor laser. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-002176 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above-mentioned projection device has a problem that the light source device and the projection device become large in size because of the presence of a rotary motor and a rotary oscillating mirror of the light deflection means as a movable body rotated by the rotary motor.

[0006] In view of the above, an object of the present invention is to provide a light source device and a projection device that can reduce speckle noise while being miniaturized. [Means for solving the problem]

[0007] The light source device of the present invention comprises a lens member that guides light to a display element that generates image light, a light irradiation device that emits the light toward the lens member, and a drive device that vibrates the lens member back and forth at a predetermined angle so as to displace the lens member in the emission direction of the light, with a rotation axis passing through the lens member as the center of rotation, and at the incident surface of the lens member, the intersection point between the emission optical axis of the light irradiation device and the incident surface of the lens member is separated from the rotation axis.

[0008] The light source device of the present invention comprises a lens member that guides light to a display element that generates image light, a light irradiation device consisting of a plurality of light-emitting devices that emit the light toward the lens member, and a drive device that vibrates the lens member back and forth at a predetermined angle so as to displace the lens member in the emission direction, with a rotation axis passing through the lens member as the center of rotation, and at the incident surface of the lens member, the intersection point between at least some of the emission optical axes of the plurality of light-emitting devices of the light irradiation device and the incident surface of the lens member is separated from the rotation axis.

[0009] The projection device of the present invention comprises the above-mentioned light source device, a display element that generates image light, a projection optical system that projects the image light emitted from the display element onto a projection target, and a control unit that controls the light source device and the display element. Effect of the Invention

[0010] According to the present invention, it is possible to provide a light source device and a projection device that can reduce speckle noise while achieving miniaturization. [Brief description of the drawings]

[0011] [Figure 1]FIG. 2 is a diagram showing functional circuit blocks of the projection device according to the present embodiment. [Diagram 2] FIG. 2 is a schematic plan view showing the internal structure of the projection device according to the present embodiment. [Diagram 3] 2 is a schematic plan view showing a light source optical system and the incidence and exit points of light according to the embodiment; FIG. [Figure 4] FIG. 2 is a front view showing a configuration example of a drive device. [Diagram 5] 1 is a diagram showing an example of a laser spot formed on an entrance surface of a microlens array by a laser diode; [Figure 6] 1 is a diagram showing an example of a laser spot formed on an entrance surface of a microlens array by a laser diode; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a functional circuit block diagram of a projection device 10. The projection device control unit includes a CPU including an image conversion unit 23 and a control unit 38, a front-end unit including an input / output interface 22, a display encoder 24, a display drive unit 26, and a drive unit 300 described later. Image signals of various standards input from an input / output connector unit 21 are converted by the image conversion unit 23 via the input / output interface 22 and a system bus SB so as to be unified into image signals of a predetermined format suitable for display, and then output to the display encoder 24.

[0013] The display encoder 24 expands and stores the input image signal in the video RAM 25, generates a video signal from the stored contents of the video RAM 25, and outputs the video signal to the display driver 26. The display driver 26 drives a display element 50 such as a DMD, which is a spatial light modulator (SOM), at an appropriate frame rate in response to the image signal output from the display encoder 24.

[0014] The projection device 10 irradiates a light beam emitted from the light source device 60 onto the display element 50 via a light guide optical system 170 (see FIG. 2) described later, thereby forming an optical image with the light reflected from the display element 50, and projects and displays the image on a projection target such as a screen (not shown) via a projection optical system 220 (see FIG. 2) described later. A movable lens group 235 of the projection optical system 220 can perform zoom adjustment and focus adjustment by driving a lens motor 45.

[0015] The image compression / expansion unit 31 performs a recording process in which the luminance signal and the color difference signal of the image signal are compressed by processes such as ADCT and Huffman coding, and the data is written sequentially to a memory card 32, which is a removable recording medium. Furthermore, the image compression / expansion unit 31 reads out image data recorded on the memory card 32 in a playback mode, expands each piece of image data constituting a series of moving images on a frame-by-frame basis, and outputs the expanded data to the display encoder 24 via the image conversion unit 23. Thus, the image compression / expansion unit 31 can output moving images, etc., based on the image data stored in the memory card 32.

[0016] The control unit 38 is responsible for controlling the operation of each circuit in the projection device 10, and is composed of a CPU, a ROM in which operating programs such as various settings are permanently stored, a RAM used as a work memory, and the like.

[0017] The key / indicator section 37 is composed of a main key and an indicator provided on the housing. An operation signal of the key / indicator section 37 is directly sent to the control section 38. In addition, a key operation signal from the remote controller is received by the Ir receiving section 35, demodulated into a code signal by the Ir processing section 36, and output to the control section 38.

[0018] The control unit 38 is connected to an audio processing unit 47 via a system bus SB. The audio processing unit 47 includes a sound source circuit such as a PCM sound source, and converts audio data into analog data in the projection mode and the playback mode, and drives a speaker 48 to emit amplified sound.

[0019] The control unit 38 controls a light source control circuit 41. The light source control circuit 41 individually controls switching of emission from a blue light source device 70A, an excitation light irradiation device 70B, a red light source device 80, and the like (see FIG. 3), which will be described later, so that light of a predetermined wavelength band required for image generation is emitted from the light source device 60.

[0020] Furthermore, the control unit 38 causes the cooling fan drive control circuit 43 to detect temperatures using a plurality of temperature sensors provided in the light source device 60 etc., and controls the rotation speed of the cooling fan 56 based on the results of this temperature detection. The control unit 38 also controls the cooling fan drive control circuit 43 to continue rotating the cooling fan 56 using a timer or the like even after the power supply to the projection device 10 main body is turned off, or to turn off the power supply to the projection device 10 main body based on the results of temperature detection by the temperature sensors.

[0021] Next, the internal structure of the projection device 10 will be described. Fig. 2 is a schematic plan view showing the internal structure of the projection device 10. Here, the housing of the projection device 10 is formed in a substantially box shape, and includes an upper panel and a lower panel (not shown), a front panel 12, a rear panel 13, a right panel 14, and a left panel 15. The projection device 10 has a projection port 12a on the front side. In the following description, the left and right of the projection device 10 refer to the left and right directions when the projection target is viewed from the projection port 12a in the projection direction, and the front and rear refer to the front and rear directions along the traveling direction of the light beam when projected from the projection device 10 to the subject.

[0022] The projection device 10 includes a control circuit board 242 near the left panel 15. The control circuit board 242 includes a power circuit block, a light source control block, etc. The projection device 10 includes a light source device 60 disposed approximately in the center of the projection device 10. Between the light source device 60 and the right panel 14, a power connector 52, a heat sink 54, a cooling fan 56, etc. are disposed.

[0023] The light source device 60 includes a blue light source device 70A and an excitation light emitting device 70B which are light sources of blue wavelength band light, a red light source device 80 which is a light source of red wavelength band light, and a green light source device 90 which is a light source of green wavelength band light. The blue light source device 70A includes a laser diode as at least one semiconductor light emitting element capable of emitting a blue laser. The excitation light emitting device 70B includes a laser diode as at least one semiconductor light emitting element capable of emitting a blue laser or a laser with a wavelength shorter than blue. The green light source device 90 includes an excitation light emitting device 70B and a fixed phosphor (fluorescent light emitting device) 100. The red light source device 80 includes a laser diode as at least one semiconductor light emitting element capable of emitting a red laser. The light source device 60 includes a light source optical system 140 which guides the blue wavelength band light, the red wavelength band light, and the green wavelength band light.

[0024] The light source optical system 140 includes the fixed phosphor 100, a dichroic mirror 200 as an example of an optical device, a first diffusion plate 76A, and a second diffusion plate 76B. The optical device may use other optical elements having similar functions instead of the dichroic mirror 200. The light source optical system 140 focuses the light beams emitted from the blue light source device 70A, the red light source device 80, and the green light source device 90 on the incident surface of a microlens array 172 (lens member) of the light guide optical system 170 described later. Between the excitation light irradiation device 70B and the left panel 15, a projection optical system 220 for projecting the projection light from the projection port 12a, and a light guide optical system 170 for guiding the light from the light source optical system 140 to the projection optical system 220 are arranged.

[0025] The blue light source device 70A and the excitation light irradiation device 70B are disposed in the approximate center inside the housing of the projection device 10, and have the same configuration. The blue light source device 70A shown in FIG. 3 has a light source package 72A in which chips of a plurality of blue laser diodes 73A (light emitting devices) which are semiconductor light emitting elements that emit blue wavelength band light are mounted adjacent to each other in a line or matrix, and a collimator lens 71A which is disposed for each chip of the plurality of blue laser diodes 73A and collimates the light emitted from the blue laser diodes 73A. The excitation light irradiation device 70B shown in FIG. 3 has a light source package 72B in which chips of a plurality of blue laser diodes 73B (light emitting devices) which are semiconductor light emitting elements that emit blue wavelength band light or wavelength band light shorter than blue are mounted adjacent to each other in a line or matrix, and a collimator lens 71B which is disposed corresponding to each chip of the plurality of blue laser diodes 73B and collimates the light emitted from the blue laser diodes 73B. The light source package 72A and the light source package 72B are so-called MCPs (Multi Chip Packages), which allows the light source device 60 to be made compact.

[0026] The blue light source device 70A (light irradiation device) and the red light source device 80 (light irradiation device) described later are arranged in such a manner that the angles of incidence of the emitted blue wavelength band light and red wavelength band light with respect to the optical axis A1 (the optical axis of the light guide optical system 170 (microlens array 172)) are substantially the same. That is, the blue light source device 70A and the red light source device 80 are arranged opposite to each other across the optical axis A1 along the second direction D2 (described later), and are preferably configured such that the angles of incidence of the blue wavelength band light emitted by the blue light source device 70A with respect to the microlens array 172 and the angles of incidence of the red wavelength band light emitted by the red light source device 80 with respect to the microlens array 172 are the same. The blue light source device 70A and the red light source device 80 are each held by a holding member (not shown) and connected to the heat sink 54 via a heat pipe (not shown). The blue light source device 70A and the red light source device 80 are cooled by dissipating heat from the heat sink 54 via the heat pipe. In the projection device 10, the emission period of the blue wavelength band light from the blue light source device 70A and the emission period of the red wavelength band light from the red light source device 80 are controlled by the control unit 38 in a time-division manner.

[0027] The red light source device 80 has the same configuration as the blue light source device 70A and the excitation light irradiation device 70B, except that the emitted light is red wavelength band light. The red light source device 80 has a light source package 82 in which chips of multiple red laser diodes 83 (light emitting devices), which are semiconductor light emitting elements that emit red wavelength band light, are mounted closely together in a line or matrix, and a collimator lens 81 that is arranged corresponding to each chip of the multiple red laser diodes 83 and collimates the light emitted from the red laser diodes 83. The light source package 82 is a so-called MCP (Multi Chip Package), which allows the light source device 60 to be made compact.

[0028] In the red light source device 80, the emission direction (optical axis) of the emitted red wavelength band light and the optical axis A1 of the light guide optical system 170 are tilted with respect to the optical axis A1 so that they form a predetermined angle (hereinafter, for example, "θ" is shown). Similarly, in the blue light source device 70A, the emission direction (optical axis) of the emitted blue wavelength band light and the optical axis A1 are tilted with respect to the optical axis A1 so that they form a predetermined angle θ. The optical axis A1 is parallel to the normal direction at the center of the entrance surface of the microlens array 172.

[0029] The green light source device 90 has a fixed phosphor 100 and a green side lens group 94. The fixed phosphor 100 has a base material 101 and a fluorescent light emitting region 102. The base material 101 can be made of a metal material such as copper or aluminum. A flat reflecting portion that is mirror-processed by silver deposition or the like is formed on the surface of the base material 101 facing the dichroic mirror 200. The fluorescent light emitting region 102 is disposed on the reflecting portion on the surface of the base material 101. The fixed phosphor 100 is held by a holding member (not shown) and connected to the heat sink 54 via a heat pipe (not shown). The fixed phosphor 100 is cooled by dissipating heat from the heat sink 54 via the heat pipe.

[0030] The fluorescent light-emitting region 102 is made of a phosphor layer in which phosphor particles are dispersed. The phosphor particles are excited by blue wavelength band light as excitation light irradiated to the fluorescent light-emitting region 102, and emit fluorescence of green wavelength band light. A part of the excitation light irradiated to the fluorescent light-emitting region 102 excites the phosphor particles, which causes the fluorescent light-emitting region 102 to emit fluorescence. Another part of the excitation light is reflected by the reflecting portion of the mirror-processed base material 101 and excites the phosphor particles, but a part of the excitation light reflected by the reflecting portion of the base material 101 does not excite the phosphor particles and is emitted as it is from the fluorescent light-emitting region 102. When the phosphor particles are excited, fluorescence is emitted in all directions, some of which remains as it is, and the other part is reflected by the base material 101 and emitted from the fluorescent light-emitting region 102.

[0031] The green-side lens group 94 focuses the excitation light transmitted through the dichroic mirror 200 onto the fluorescence-emitting region 102 toward the fixed phosphor 100 side, and also guides the fluorescence emitted from the fluorescence-emitting region 102 toward the dichroic mirror 200 side. The green-side lens group 94 is composed of two focusing lenses of different sizes.

[0032] The dichroic mirror 200 is disposed at a position where the optical axis A2 of the excitation light from the excitation light irradiating device 70B intersects with the optical axis A1, making an angle of 45 degrees with respect to each of the optical axes A1 and A2.

[0033] The first diffusion plate 76A is disposed between the blue light source device 70A and the red light source device 80 and the dichroic mirror 200, and diffuses the light from the blue light source device 70A and the red light source device 80, and emits the light toward the dichroic mirror 200. The light emitted from the blue light source device 70A and the red light source device 80 is incident on the dichroic mirror 200 at an angle with respect to the optical axis A1 in a manner that is line-symmetrical with respect to the optical axis A1 of the microlens array 172, the concave lens 174, the condenser lens 175, etc. of the light guide optical system 170. On the other hand, the second diffusion plate 76B is disposed between the excitation light irradiation device 70B and the dichroic mirror 200, and diffuses the light from the excitation light irradiation device 70B, and emits the light toward the dichroic mirror 200. The light emitted from the excitation light irradiation device 70B is incident on the dichroic mirror 200 at an angle of about 45°.

[0034] In the following, as shown in FIG. 3, the direction along the light L2 of the excitation light irradiation device 70B from the excitation light irradiation device 70B via the dichroic mirror 200 toward the fixed phosphor 100 of the green light source device 90 is referred to as the first direction D1, the direction along the optical axis A1 from the dichroic mirror 200 toward the light-guiding optical system 170 is referred to as the second direction D2, and the direction along the optical axis A1 from the fixed phosphor 100 of the green light source device 90 toward the excitation light irradiation device 70B via the dichroic mirror 200 is referred to as the third direction D3.

[0035] Dichroic mirror 200 has a green reflecting surface 254 on the surface facing light-guiding optical system 170. Green reflecting surface 254 is formed by applying a dichroic coating or the like. This green reflecting surface 254 reflects light in the green wavelength band and transmits light in the blue wavelength band and the red wavelength band.

[0036] In the light source device 60 configured as described above, the blue wavelength band light emitted from the blue light source device 70A is diffused by the first diffuser plate 76A and then enters the dichroic mirror 200, and then enters the microlens array 172 at the above-mentioned predetermined angle θ with respect to the optical axis A1. On the other hand, the red wavelength band light emitted from the red light source device 80 is diffused by the first diffuser plate 76A and then enters the dichroic mirror 200, and then enters the microlens array 172 at the above-mentioned predetermined angle θ with respect to the optical axis A1 so as to be linearly symmetrical with the blue wavelength band light emitted from the blue light source device 70A across the optical axis A1.

[0037] The blue wavelength band light emitted from excitation light irradiation device 70B is diffused by second diffuser plate 76B, passes through dichroic mirror 200, and enters fluorescence emission region 102 of fixed phosphor 100 via green side lens group 94 of green light source device 90. The green wavelength band light emitted in fluorescence emission region 102 is incident on green reflecting surface 254 at an angle of approximately 45°, is reflected by this green reflecting surface 254 at a substantially right angle to third direction D3, and is guided in second direction D2 and is emitted toward microlens array 172 of light guide optical system 170.

[0038] The light guide optical system 170 has a microlens array 172, a concave lens 174, and a condenser lens 175. The microlens array 172, the concave lens 174, and the condenser lens 175 are arranged so that their optical axes coincide with the optical axis A1. The concave lens 174 is arranged between the microlens array 172 and the condenser lens 175. The microlens array 172 is an integrator lens that uniformizes the in-plane amount of light irradiated to the display element 50 that generates image light.

[0039] 2 has a condenser lens 195, an irradiation mirror 185, a movable lens group 235, and a fixed lens group 225. The condenser lens 195 emits image light emitted from a display element 50 arranged on the rear panel 13 side of the condenser lens 195, toward the projection optical system 220. A heat sink 190 is provided on the rear panel 13 side of the display element 50. The display element 50 is cooled by this heat sink 190.

[0040] The fixed lens group 225 is disposed on the optical axis of the condenser lens 195 on the front panel 12 side, and is built into a fixed lens barrel. The movable lens group 235 is moved manually or automatically, allowing zoom adjustment and focus adjustment.

[0041] Next, referring to FIG. 3, a mode in which light emitted from each light source device constituting the light source device 60 of the projection device 10 according to this embodiment is guided will be described. In the projection device 10 according to this embodiment, the control unit 38 controls each light source device in a time-division manner to emit blue wavelength band light, red wavelength band light, and green wavelength band light, and projects an image. First, a case in which blue wavelength band light is emitted from the blue light source device 70A will be described. The blue wavelength band light emitted from the blue light source device 70A is emitted at a predetermined angle (θ in this embodiment) with respect to the optical axis A1 (second direction D2), and passes through the green reflection surface 254 in the dichroic mirror 200. The blue wavelength band light from the blue light source device 70A that has passed through the dichroic mirror 200 is incident on the microlens array 172 of the light guide optical system 170. In this way, the blue wavelength band light emitted from the blue light source device 70A can be used as light source light.

[0042] Next, a case where red wavelength band light is emitted from the red light source device 80 will be described. The red wavelength band light emitted from the red light source device 80 is emitted at a predetermined angle (θ in this embodiment) with respect to the optical axis A1 (second direction D2), and passes through the green reflecting surface 254 of the dichroic mirror 200. The red wavelength band light transmitted through the dichroic mirror 200 is incident on the microlens array 172 of the light guiding optical system 170. In this way, the red wavelength band light emitted from the red light source device 80 can be used as light source light.

[0043] Next, a case where green wavelength band light is emitted from green light source device 90 will be described. The blue wavelength band light emitted from the excitation light irradiation device 70B passes through the green reflecting surface 254 of the dichroic mirror 200 and is emitted towards the green side lens group 94. The blue wavelength band light incident on the green side lens group 94 is collected and emitted by the green side lens group 94, and is incident on the fluorescent light-emitting region 102 of the fixed phosphor 100. When the fluorescent light-emitting region 102 is irradiated with the blue wavelength band light, which is excitation light, fluorescence in the green wavelength band (light L3 shown in FIG. 3) is emitted. The light emitted in the fluorescent light-emitting region 102 includes fluorescence containing green wavelength band light and excitation light (hereinafter referred to as "residual excitation light") that is not irradiated on the fluorescent light-emitting region 102 but is reflected by the mirror-finished surface of the base material 101 as it is, does not excite the fluorescent light-emitting region 102 of the fixed phosphor 100, and is emitted as it is.

[0044] The green wavelength band light emitted from fluorescent light-emitting region 102 enters green-side lens group 94, and is guided toward dichroic mirror 200 in third direction D3 and emitted. The green wavelength band light emitted toward dichroic mirror 200 is incident on green reflecting surface 254 at an angle of approximately 45°, is reflected by green reflecting surface 254 at a substantially right angle to light L2, and is guided in second direction D2.

[0045] The green wavelength band light reflected by the green reflecting surface 254 and guided in the second direction D2 is incident on the microlens array 172. In this manner, the green wavelength band light can be used as light source light. Note that the residual excitation light reflected by the base material 101 of the fixed phosphor 100 is emitted towards the dichroic mirror 200 via the green side lens group 94. The residual excitation light incident on the dichroic mirror 200 passes through the green reflecting surface 254 without being reflected. In this manner, the residual excitation light is removed.

[0046] Here, the blue wavelength band light emitted from the excitation light irradiating device 70B has sufficient diffusivity to achieve both the light collecting property of the excitation light irradiating the fluorescent light emitting region 102 of the green light source device 90 and the flattening of the light amount distribution by being diffused by the second diffusion plate 76B. On the other hand, the blue wavelength band light emitted from the blue light source device 70A and the red wavelength band light emitted from the red light source device 80 are used as light source light. When light emitted from a laser diode is used as light source light, speckle noise may occur in the projected light, and the diffusion plate (first diffusion plate 76A) can reduce this speckle noise but may not be able to completely remove it. In the light source device 60 of this embodiment, the driving device 300 shown in FIG. 4 causes the microlens array 172 to vibrate back and forth (reciprocating rotational motion) so as to displace the microlens array 172 in the light emission direction, thereby reducing the speckle noise. In FIG. 4, the light irradiated to the entrance surface of the microlens array 172 is guided from the front side of FIG. 4 to the back side.

[0047] As shown in FIG. 4, the driving device 300 includes a support 310 having a substantially rectangular ring shape. A frame 320 that holds the microlens array 172 is provided inside the support 310. The frame 320 is formed in a substantially rectangular shape, and two corners corresponding to one of two sets of diagonal lines are C-chamfered. At the two corners that are C-chamfered, substantially cylindrical shafts 321 and 322 whose axes coincide with the diagonal lines are provided to protrude. The support 310 is provided with a bearing 330 into which the shafts 321 and 322 are inserted. The shafts 321 and 322 are supported by the bearing 330 so as to be rotatable around a rotation axis RA, which is the axis of the shafts 321 and 322. Therefore, the microlens array 172 (frame 320) is provided so as to be rotatable around the rotation axis RA as the center of rotation.

[0048] A driving unit 360 is provided at one corner (lower corner in FIG. 4) on the other diagonal of the frame body 320. The driving unit 360 has a magnet 361 provided at the corner of the frame body 320. The magnet 361 is a permanent magnet. The driving unit 360 is provided with a coil support unit 365 so as to cover a portion of the frame body 320 corresponding to the magnet 361 from the support body 310. In FIG. 4, the coil support unit 365 is indicated by a two-dot chain line. The coil support unit 365 is provided with an electromagnetic coil (not shown). The electromagnetic coil of the coil support unit 365 generates a magnetic force that attracts or repels the magnet 361 depending on the direction of the current passed through it. The current passing through the electromagnetic coil of the coil support unit 365 is controlled by the driving circuit 110. The drive circuit 110 controls the electromagnetic coil so that the frame 321 (microlens array 172) vibrates back and forth around the rotation axis RA (specifically, when focusing on the corner of the frame 320 where the magnet 361 is provided, the corner moves alternately between the front and rear sides of the page). This reciprocating vibration occurs at a predetermined angle around the rotation axis RA. Note that a structure that uses magnetic force or elastic force to keep the frame 320 in a neutral position when no current is applied to the electromagnetic coil of the coil support part 365, and a regulating structure that regulates overrun of the reciprocating vibration can be appropriately provided.

[0049] The driving circuit 110 is controlled by the control unit 38. Based on a control signal from the control unit 38, the driving circuit 110 appropriately sets the frequency of the current passed through the coil of the coil support unit 365, and vibrates the frame body 321 (microlens array 172) back and forth at a predetermined frequency. In the example of FIG. 4, the rotation axis RA is set so as to pass through the diagonal of the microlens array 172, but the angle of the rotation axis RA with respect to the horizontal direction (vertical direction) of the microlens array 172 can be set arbitrarily by changing the mounting positions of the shaft parts 321, 322 (bearings 330). The rotation axis RA can also be set to the horizontal or vertical direction of the microlens array 172. Furthermore, it is preferable that the rotation axis RA passing through the microlens array 172 passes through the center of the microlens array 172 when viewed from the entrance surface side of the microlens array 172. With this configuration, the microlens array 172 is vibrated back and forth, and speckle noise of the light of the laser diode can be reduced.

[0050] Here, the light source package 72A of the blue light source device 70A and the light source package 82 of the red light source device 80 may have a structure in which four blue laser diodes 73A and red laser diodes 83 are arranged in a linear row as light-emitting devices (hereinafter referred to as a "single row structure"), a structure in which four blue laser diodes 73A and red laser diodes 83 are arranged in a linear row in a total of eight red laser diodes 83 are arranged in two parallel rows (hereinafter referred to as a "two row structure"), or a structure in which four blue laser diodes 73A and red laser diodes 83 are arranged in a linear row in a total of five parallel rows (hereinafter referred to as a "five row structure").

[0051] Figures 5(A) to 5(F) and Figures 6(A) to 6(D) each show a state in which light from blue light source device 70A or red light source device 80 is irradiated onto the incident surface of microlens array 172, and the ellipse within the area of ​​microlens array 172 shows a state in which light emitted from one laser diode is irradiated onto the incident surface of microlens array 172 as a laser spot SP.

[0052] 5(A) and 5(B) show a state in which light from light source packages 72A and 82 in a single row is irradiated onto microlens array 172. Four laser spots SP are arranged in the horizontal direction (i.e., one row and four columns). FIG. 5(A) shows an example of driving device 300 in which rotation axis RA is set at 45° with respect to the horizontal direction (vertical direction) of microlens array 172. FIG. 5(B) shows an example of driving device 300 in which rotation axis RA is set to the vertical direction of microlens array 172.

[0053] 5(C) and 5(D) show a state in which light from light source packages 72A and 82 with a two-column structure is irradiated onto microlens array 172. Laser spots SP are arranged in two rows and four columns. FIG. 5(C) is an example of driving device 300 in which rotation axis RA is set at 45° with respect to the horizontal direction (vertical direction) of microlens array 172. FIG. 5(D) is an example of driving device 300 in which rotation axis RA is set to the vertical direction of microlens array 172.

[0054] 5(E) and 5(F) show a state in which light from light source packages 72A and 82 with a 5-column structure is irradiated onto microlens array 172. Laser spots SP are arranged in 5 rows and 4 columns. FIG. 5(E) is an example of driving device 300 in which rotation axis RA is set at 45° with respect to the horizontal direction (vertical direction) of microlens array 172. FIG. 5(F) is an example of driving device 300 in which rotation axis RA is set to the vertical direction of microlens array 172.

[0055] In any of Figs. 5(A) to 5(F), the rotation axis RA passing through the microlens array 172 passes through the center O of the microlens array 172 when viewed from the entrance surface side of the microlens array 172 (in other words, when viewed from the light emission direction) and extends along the entrance surface of the microlens array 172. It is desirable that the rotation axis RA also passes through the center in the thickness direction of the microlens array 172. This is to achieve well-balanced reciprocating vibration. The rotation axis RA passes through the center O (the center of the figure formed when connecting the center points of the outermost laser spots SP among the laser spots SP) of the multiple light laser spots SP formed on the entrance surface of the microlens array 172 as viewed as shown in Figs. 5(A) to 5(F) (in other words, when viewed from the light emission direction (entrance side of the microlens array 172)), and is set so that the normal distance to any one of the multiple laser spots SP is maximized. Note that the optical axis of each laser spot SP is not located on the rotation axis RA.

[0056] Comparing the irradiation modes of the laser spots SP shown in Figures 5(A), 5(C), and 5(E) with the rotation axis RA at 45°, the irradiation position of each laser spot SP in the irradiation mode of the laser spot SP shown in Figure 5(A) is closer to the rotation axis as a whole than the irradiation mode of the laser spot SP shown in Figure 5(C). The irradiation position of each laser spot SP in the irradiation mode of the laser spot SP shown in Figure 5(E) is farther away from the rotation axis as a whole than the irradiation mode of the laser spot SP shown in Figure 5(C). This is due to how far the irradiation position of each laser spot SP is from the rotation axis in the direction perpendicular to the rotation axis RA.

[0057] In comparison with the irradiation mode of the multiple laser spots SP shown in FIG. 5(A), in FIG. 5(C), the ratio of the laser spots SP that are far from the rotation axis RA is high. Therefore, when the oscillation vibration is performed around the rotation axis RA tilted by 45°, the overall magnitude of oscillation of the multiple laser spots SP is larger in the irradiation mode of FIG. 5(C) than in the irradiation mode of FIG. 5(A). On the other hand, compared with the irradiation mode of the eight laser spots SP shown in FIG. 5(C), the ratio of the laser spots SP that are far from the rotation axis is high in the irradiation mode of the twenty laser spots SP shown in FIG. 5(E). Therefore, when the oscillation vibration is performed around the rotation axis tilted by 45°, the overall magnitude of oscillation of the multiple laser spots SP is larger in the irradiation mode of FIG. 5(E) than in the irradiation mode of FIG. 5(C). Therefore, it can be said that the irradiation mode of the eight laser spots SP shown in FIG. 5(C) and the irradiation mode of the twenty laser spots SP shown in FIG. 5(E) are more desirable from the viewpoint of reducing speckle noise than the irradiation mode of the four laser spots SP shown in FIG. 5(A).

[0058] The same can be said when, in the irradiation mode of multiple laser spots SP shown in Figures 5(B), 5(D), and 5(F), the rotation axis RA is set along the vertical direction of the light source device 60 (i.e., the direction perpendicular to the left-right and front-back directions in the projection device 10) and reciprocating vibration is performed.

[0059] Fig. 6(A) shows that the microlens array 172 is oscillated and vibrated around a rotation axis RA that is inclined 20° with respect to the horizontal direction by the driving device 300. Fig. 6(B) shows that the microlens array 172 is oscillated and vibrated around a rotation axis RA along the horizontal direction by the driving device 300.

[0060] FIG. 6(C) shows that the rotation axis RA is aligned with a horizontal line passing through the center O of the microlens array 172, and the four laser spots SP formed on the incident surface of the microlens array 172 are shifted in an upward direction away from the rotation axis RA, thereby oscillating the microlens array 172 around the rotation axis RA along the horizontal direction of the light source device 60 (i.e., the direction horizontal to the left-right and front-back directions in the projection device 10).

[0061] Fig. 6(D) shows that the irradiation position of one laser spot SP formed on the incident surface of the microlens array 172 is shifted upward away from the horizontal rotation axis RA, and the microlens array 172 is swung around the horizontal rotation axis RA. In the example of Fig. 6(D), the long axis direction of the elliptical laser spot SP is set to the horizontal direction.

[0062] Even when the irradiation pattern of the same eight laser spots SP is used, when the microlens array 172 is oscillated with the rotation axis RA tilted 20° relative to the horizontal direction as shown in FIG. 6(A) compared to when the microlens array 172 is oscillated around a rotation axis along the horizontal axis as shown in FIG. 6(B), the laser spots SP are more likely to be away from the rotation axis RA in the direction perpendicular to the rotation axis RA, resulting in sufficient oscillation of each laser spot SP and effective suppression of speckle noise.

[0063] Next, referring to Fig. 6(C), it can be seen that the irradiation positions of the four laser spots SP are farther upward from the rotation axis RA coinciding with the center line than when they are arranged along the horizontal center line of the microlens array 172 (see, for example, the laser spots SP shown in Fig. 5(A)). When the microlens array 172 is swung around the rotation axis RA at the irradiation positions of the laser spots SP shown in Fig. 6(C), it is more effective in suppressing speckle noise than when the laser spots SP are arranged along the horizontal center line and the microlens array 172 is swung and vibrated with the rotation axis RA coinciding with the horizontal center line.

[0064] Furthermore, referring to Fig. 6(D), it can be seen that the irradiation position of one laser spot SP is away in the upward direction from the rotation axis RA that coincides with the horizontal line. When the microlens array 172 is swung around the rotation axis RA at the irradiation position of the laser spot SP shown in Fig. 6(D), the oscillation of the laser spot SP becomes more sufficient than when the microlens array 172 is swung with the rotation axis RA that coincides with the horizontal line as the irradiation position of one laser spot SP, and it can be said that this is effective in suppressing speckle noise.

[0065] In any of Figs. 6(A) to 6(D), the rotation axis RA passing through the microlens array 172 passes through the center O of the microlens array 172 when viewed from the incident surface side of the microlens array 172, and extends along the incident surface of the microlens array 172. It is preferable that the rotation axis RA also passes through the center in the thickness direction of the microlens array 172. The rotation axis RA passes through the center O (the center of the figure formed when connecting the center points of the outermost laser spots SP among the laser spots SP) of the plurality of light beams formed on the incident surface of the microlens array 172 when viewed from the light emission direction (incident side of the microlens array 172) shown in Figs. 6(A) to 6(C), and is set so that the normal distance to any one of the plurality of laser spots SP is maximized. Note that the optical axis of each laser spot SP is not located on the rotation axis RA.

[0066] Here, a light source in which one laser diode is mounted on one IC chip is called a "single LD", and a light source in which multiple laser diodes are mounted on one IC chip is called a "multi-chip LD". In the case of a high-output single LD, the light beam is concentrated at the center of the incident surface of the microlens array 172, so shifting the rotation axis RA of the microlens array 172 from the center is effective in suppressing speckle noise. On the other hand, in the case of a multi-chip LD, it is desirable to arrange the rotation axis RA of the microlens array 172 so that it does not pass through the optical axis of each chip LD in the microlens array 172.

[0067] The projection device 10 according to the present embodiment includes a light source device 60, a display element 50 that generates image light, a projection optical system 220 that projects the image light emitted from the display element 50 onto a projection target, and a control unit 38 that controls the light source device 60 and the display element 50. The light source device 60 according to the present embodiment includes an example of a light irradiation device, and this light irradiation device is, for example, a blue light source device 70A that can pass through the dichroic mirror 200 without being reflected by the dichroic mirror 200 and directly enter the microlens array 172. In this embodiment, both a case in which the light irradiation device includes the above-mentioned single LD and a case in which the light irradiation device includes multiple LDs are assumed. That is, the blue light source device 70A as an example of a light irradiation device may be configured to include a LD as a single light-emitting device, or may be configured to include LDs as multiple light-emitting devices. Note that the light irradiation device may include, for example, a red light source device 80 instead of or in addition to the above-mentioned blue light source device 70A, and may further include an excitation light irradiation device 70B.

[0068] In this embodiment, when the light source device 60 of the projection device 10 employs a configuration in which the blue light source device 70A includes a single LD, the light source device 60 can be configured as follows. Specifically, the light source device 60 includes a microlens array (MLA) 172 as an example of an integrator lens (lens member) that guides light to the display element 50 that generates image light and uniforms the amount of in-plane light irradiated onto the display element 50, a blue light source device 70A that emits light, for example, coherent light, toward the microlens array 172, and a drive device 300 that reciprocates the microlens array 172 at a predetermined angle around a rotation axis RA that passes through the microlens array 172 as a rotation center so as to displace the microlens array 172 in the light emission direction. The light source device 60 is configured such that, on the incident surface of the microlens array 172, an intersection point between the optical axis of at least a part of the LDs in the blue light source device 70A and the incident surface of the microlens array 172 is separated from the rotation axis RA.

[0069] In this embodiment, the driving device 300 controls the amplitude, amplitude direction, and driving frequency of the reciprocating vibration under the control of the control unit 38, and as described above, vibrates the microlens array 172 reciprocally within the incident plane of the microlens array 172 at a predetermined frequency and at a predetermined angle so as to displace the microlens array 172 in the light emission direction, with the rotation axis RA passing through the microlens array 172 as the center of rotation.

[0070] Also, in this embodiment, the driving device 300 may instead be configured to vibrate the microlens array 172 back and forth at a predetermined frequency and angle around an axis passing through a diagonal corner of the microlens array 172 as the center of rotation.

[0071] The rotation axis RA passes through the center of the microlens array 172. The rotation axis RA is set so that one of the normal distances from the centers of the multiple spots formed on the surface of the microlens array 172 to the rotation axis RA is maximized when viewed from the emission direction of the blue wavelength band light emitted from the blue light source device 70A. Furthermore, it is desirable to set the rotation axis RA so that at least some of the multiple laser spots are asymmetric with respect to the rotation axis RA. By making at least some of the multiple laser spots asymmetric with respect to the rotation axis RA, speckle noise can be reduced more effectively.

[0072] In this embodiment, the driving device 300 uses magnetic force as a driving source for reciprocating vibration of the microlens array 172. However, other driving sources, such as a configuration including a motor or a piezoelectric actuator, may also be used.

[0073] As described above, the projection device 10 of this embodiment includes a light source device 60, a display element 50 that generates image light, a projection optical system 220 that projects the image light emitted from the display element 50 onto a projection target, and a control unit 38 that controls the light source device 60 and the display element 50.

[0074] In the projection device 10, when the blue light source device 70A and the red light source device 80 are configured to include a single LD, the light source device 60 can be configured as follows. Specifically, the light source device 60 includes a microlens array (MLA) 172 as an example of an integrator lens (lens member) that uniforms the amount of in-plane light irradiated to the display element 50 that generates image light, a blue light source device 70A and a red light source device 80 that emit light toward the microlens array 172, and a driving device 300 that vibrates the microlens array 172 back and forth at a predetermined angle so as to displace the microlens array 172 in the light emission direction, with a rotation axis RA passing through the microlens array 172 as the center of rotation. On the incident surface of the microlens array 172, the intersection between the emission optical axis of the blue light source device 70A and the red light source device 80 and the incident surface of the microlens array 172 is separated from the rotation axis RA.

[0075] With this configuration, unlike changing only the position of the laser spot SP formed on the entrance surface of the microlens array 172 on the entrance surface, the laser spot SP formed on the entrance surface of the microlens array 172 by the blue laser diode 73A and the red laser diode 83 of the blue light source device 70A and the red light source device 80 can be reciprocated (reciprocated rotational movement) at a predetermined angle so as to be displaced in the direction of emission of light from each color light source device, and therefore the speckle noise of the light from the blue laser diode 73A and the red laser diode 83 can be reduced. When light is incident on the microlens array 172 at an angle to its entrance surface, this configuration in which the outer laser spot SP moves more is more effective in reducing speckle noise. In addition, in general, in order to rotate the microlens array 172 in a plane horizontal to the entrance surface of the microlens array 172, it is necessary to attach a predetermined mechanism to the outside of the microlens array 172 to hold the microlens array 172, which tends to complicate the structure, but in this embodiment, for example, the diagonal corners of the microlens array 172 may be held by bearings, which simplifies the structure. According to this embodiment, it is possible to reduce speckle noise while achieving miniaturization.

[0076] In addition, in this embodiment, the blue light source device 70A and the red light source device 80 as an example of a light irradiation device may be configured to include multiple LDs instead of the above-mentioned configuration including one LD. In such a configuration, the projection device 10 includes a microlens array (MLA) 172 as an example of an integrator lens that uniformizes the amount of in-plane light irradiated to the display element 50 that generates image light, the blue light source device 70A consisting of multiple light emitting devices (multiple LDs) that emit light toward the microlens array 172, and a drive device 300 that vibrates the microlens array 172 back and forth at a predetermined angle so as to displace the microlens array 172 in the light emission direction, with a rotation axis passing through the microlens array 172 as the rotation center, and on the incident surface of the microlens array 172, an intersection point between at least some of the emission optical axes of the multiple light emitting devices (multiple LDs) of the blue light source device 70A and the red light source device 80 and the incident surface of the microlens array 172 is separated from the rotation axis RA.

[0077] With this configuration, the same effect as described above can be achieved, and even when using blue light source device 70A and red light source device 80 equipped with multiple light emitting devices (multiple LDs) that are more likely to generate speckle noise, the oscillating operation of microlens array 172 can further suppress speckle noise. When multiple laser spots SP are formed on the entrance surface of microlens array 172, speckle noise is reduced by oscillating some of the multiple laser spots SP with a large displacement, rather than oscillating all of the laser spots SP with the same displacement, with the distances from the optical axes of the laser spots SP to rotation axis RA being uniform. This is because if a certain percentage (e.g., 30%) of the light irradiated to microlens array 172 is displaced significantly, it is effective in reducing speckle noise. Therefore, according to this embodiment, even when using blue light source device 70A and red light source device 80 equipped with multiple light emitting devices (multiple LDs), speckle noise can be reduced while still achieving miniaturization.

[0078] In this embodiment, the lens member is a microlens array 172 that is an example of an integrator lens that uniformizes the in-plane amount of light irradiated onto the display element 50 that generates image light. Therefore, more uniform light source light can be obtained than with a light tunnel or a light guiding rod.

[0079] In this embodiment, the rotation axis RA passes through the center of the microlens array 172, which is an example of an integrator lens as a lens member, and extends along the incident surface of the microlens array 172. In this embodiment, the rotation axis RA may be an axis passing through a diagonal of the microlens array 172. In this embodiment, the rotation axis RA may be an axis extending through the microlens array 172 in the horizontal or vertical direction of the projection device 10. In this manner, various arrangements of the rotation axis RA can be set according to the aspect of the laser spot SP formed on the incident surface of the microlens array 172.

[0080] The above-described embodiments are presented as examples, and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims. For example, in the above-described embodiments, the dichroic mirror 200 is exemplified as an example of an optical device, but this is not limited thereto, and a dichroic prism may be adopted. Furthermore, for example, in the above-described embodiments, a configuration in which the microlens array 172 is arranged in a part of the light-guiding optical system 170 is exemplified, but a light tunnel or a light-guiding rod may be arranged instead of the microlens array 172.

[0081] In addition, in this embodiment, the emission direction of the red wavelength band light emitted from the red light source device 80 and the optical axis A1 of the light-guiding optical system 170 are tilted relative to the optical axis A1 so that they form a predetermined angle, and the emission direction of the blue wavelength band light emitted from the blue light source device 70A and the optical axis A1 of the light-guiding optical system 170 are tilted relative to the optical axis A1 so that they form a predetermined angle, but this is not limited to the above, and the optical axis of the light emitted from each color light source device may be aligned with the optical axis A1.

[0082] In addition, the blue light source device 70A and the excitation light irradiating device 70B are light sources of the same blue wavelength band light, but the wavelength of the excitation light irradiating device 70B constituting the green light source device 90 may be shorter than the blue wavelength band light and different from that of the blue light source device 70A. Furthermore, the blue light source device 70A and the excitation light irradiating device 70B are separate MCPs, but the blue light source device 70A and the excitation light irradiating device 70B may be configured as a single MCP so that each can be individually controlled to be turned on. [Explanation of symbols]

[0083] 10 Projection device 12 Front panel 12a Projection port 13 Rear panel 14 Right Panel 15 Left Panel 21 Input / Output Connector Section 22 Input / Output Interface 23 Image conversion unit 24 Display encoder 25 Video RAM 26 Display driver 31 Image compression / expansion section 32 Memory card 35 Ir receiving unit 36 ​​Ir processing unit 37 Key / indicator section 38 Control section 41 Light source control circuit 43 Cooling fan drive control circuit 45 Lens motor 47 Audio processing unit 48 Speaker 50 Display element 52 Power Connector 54 Heat Sink 56 Cooling fan 60 Light source device 70A Blue light source device 70B Excitation light irradiation device 71A, 71B Collimator Lens 72A, 72B Light Source Package 73A, 73B Blue laser diode 76A First diffuser plate 76B Second diffuser plate 80 Red light source device 81 Collimator lens 82 Light source package 83 Red laser diode 90 Green light source device 94 Green side lens group 100 Fixed phosphor 101 substrate 102 fluorescent emission region 110 Drive circuit 140 Light source optical system 170 Light guiding optical system 172 Microlens array 300 Oscillating device 310 Support 320 Frame 321 Shaft 322 Shaft 330 Bearing 360 Drive unit 361 Magnet 365 Coil support D1 1st direction D2 2nd direction D3 Third direction

Claims

1. a lens member that guides light to a display element that generates image light; a light irradiation device that emits the light toward the lens member; a drive device that reciprocally vibrates the lens member at a predetermined angle around a rotation axis passing through the lens member as a rotation center so as to displace the lens member in the emission direction of the light, A light source device, characterized in that, on the incident surface of the lens member, an intersection point between an emission optical axis of the light irradiation device and the incident surface of the lens member is separated from the rotation axis.

2. a lens member that guides light to a display element that generates image light; a light irradiation device including a plurality of light emitting devices that emit the light toward the lens member; a drive device that reciprocally vibrates the lens member at a predetermined angle around a rotation axis passing through the lens member as a rotation center so as to displace the lens member in the emission direction of the light, A light source device characterized in that, on the incident surface of the lens member, the intersection point between at least some of the multiple emission optical axes of the multiple light-emitting devices of the light irradiation device and the incident surface of the lens member is separated from the rotation axis.

3. 3. The light source device according to claim 1, wherein the lens member is an integrator lens that equalizes an in-plane amount of light irradiated onto the display element that generates image light.

4. 3. The light source device according to claim 1, wherein the rotation axis passes through a center of the lens member and extends along an incidence surface of the lens member.

5. The light source device according to claim 4 , wherein the rotation axis is an axis passing through a diagonal corner of the lens member.

6. The light source device according to claim 4 , wherein the rotation axis is an axis that extends through the lens member in a horizontal or vertical direction of the light source device.

7. the rotation axis passes through a center of the lens member and extends along an incidence surface of the lens member; 3. The light source device according to claim 2, wherein the rotation axis passes through a center of the plurality of light spots formed on the surface of the lens member when viewed from the light emission direction, and is set so as to maximize a normal distance to any one of the plurality of light spots.

8. The light source device according to claim 1 or 2, a projection optical system that projects the image light emitted from the display element onto a projection target; A control unit that controls the light source device and the display element. Projection device.

9. The control unit is 9. The light source device according to claim 8, wherein the lens member is reciprocally vibrated at a predetermined frequency and at the predetermined angle by controlling an amplitude and a drive frequency of the reciprocating vibration.

Images