Light source device and projection device

Abstract

To provide a light source device capable of reducing size, and a projection device having the light source device.SOLUTION: A light source device 60 comprises: an excitation light irradiation device 70 emitting blue wavelength band light; a switching diffraction grating 202 disposed such that the blue wavelength band light emitted from the excitation light irradiation device 70 is made incident at an angle inclined with respect to an incidence plane, for changing, in a time division manner, either a light path making the incident blue wavelength band light transmit in a first direction or a light path making the same transmit in a second direction; a fluorescent wheel device 100 disposed such that the blue wavelength band light in the second direction having transmitted the switching diffraction grating 202 is made incident, which has a red light emitting region emitting fluorescent light including red wavelength band light by irradiation of the blue wavelength band light; and a dichroic mirror surface 204 disposed between the switching diffraction grating 202 and the fluorescent wheel device 100, which reflects the red wavelength band light emitted in the red light emitting region and through which the blue wavelength band light having transmitted the switching diffraction grating 202 is transmitted.SELECTED DRAWING: Figure 7

Description

Technical Field

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

Background Art

[0002] Today, projection devices that project image data stored on the screens of personal computers, video screens, memory cards, etc. onto a screen are in use. This projection device condenses the light emitted from a light source onto a micromirror display element called a DMD (Digital Micro-Mirror Device) or a liquid crystal panel, and displays a color image on the screen. Among this type of projection device, those provided with an optical path changing unit such as a switching diffraction grating that changes the incident light in a time-sharing manner in an optical path that transmits the light in mutually different directions are known.

[0003] For example, Patent Document 1 discloses a light source device including an excitation light irradiation device that irradiates light in a blue wavelength band, a fluorescent light emission device that excites light in a green wavelength band, a red light source device that irradiates light in a red wavelength band, an optical path switching means that switches the light emitted from the excitation light irradiation device in two directions in a time-sharing manner, two dichroic mirrors, and a reflection mirror. In this light source device, the blue wavelength band light emitted from the excitation light irradiation device enters the optical path switching means and is switched by the optical path switching means into first light irradiated in a first direction and second light irradiated in a second direction.

[0004] The blue wavelength band light irradiated in the first direction by the optical path switching means is reflected by one of the dichroic mirrors and emitted from the light source device. Further, the blue wavelength band light irradiated in the second direction by the optical path switching means passes through the other dichroic mirror and enters the fluorescent light emission device. The green wavelength band light excited by the fluorescent light emission device by the blue wavelength band light is reflected by the other dichroic mirror and further reflected by the reflection mirror and emitted from the light source device. Also, the red wavelength band light irradiated from the red light source device passes through the other dichroic mirror and is reflected by the reflection mirror and emitted from the light source device.

Prior Art Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2012-141581 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, in the light source device described in Patent Document 1, the optical paths for red wavelength band light and green wavelength band light are separate from the optical path for blue wavelength band light. Therefore, it is necessary to separately arrange lens members, mirror members, etc., to guide the red wavelength band light and green wavelength band light, making it difficult to miniaturize the device.

[0007] In view of the above points, the present invention aims to provide a light source device that can be miniaturized and a projection device equipped with this light source device. [Means for solving the problem]

[0008] The present invention provides a light source that emits light in a first wavelength band; an optical path changing unit that is provided so that the light in the first wavelength band emitted from the light source is incident at an angle inclined with respect to the incident surface, and which changes either an optical path that transmits the incident light in a first direction or an optical path that transmits the incident light in a second direction in a time-division manner; a fluorescence emission device that is provided so so that the light in the first wavelength band in the second direction that has passed through the optical path changing unit is incident, and which has a first emission region that emits fluorescence including light in a second wavelength band when irradiated with the light in the first wavelength band; and a mirror unit provided between the optical path changing unit and the fluorescence emission device that reflects the light in the second wavelength band emitted in the first emission region and transmits the light in the first wavelength band that has passed through the optical path changing unit. The fluorescent light-emitting device is a fluorescent wheel device, and the mirror portion is a dichroic mirror surface provided on the side of the optical path changing portion that is on the fluorescent wheel device side. ru.

[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 object, and a control unit that controls the light source device and the display element. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a light source device that can be miniaturized and a projection device equipped with this light source device. [Brief explanation of the drawing]

[0011] [Figure 1] This figure shows the functional circuit block of the projection device according to the embodiment. [Figure 2] This is a schematic plan view showing the internal structure of the projection device according to the embodiment. [Figure 3] This is a schematic plan view of the fluorescent wheel of the fluorescent wheel apparatus according to the embodiment. [Figure 4] This is a schematic plan view of the color wheel of the color wheel device according to the embodiment. [Figure 5] In this embodiment, the diagram is schematic and shows how the optical path of blue wavelength band light irradiated onto the switching diffraction grating is transformed by the switching diffraction grating, where (a) shows the case when the switching diffraction grating is ON, and (b) shows the case when the switching diffraction grating is OFF. [Figure 6] This is an explanatory diagram illustrating the time-division control of a projection device according to an embodiment. [Figure 7] This is a schematic plan view illustrating how the blue wavelength band irradiated onto the switching diffraction grating is bent by the switching diffraction grating and transmitted through the color wheel device in this embodiment. [Figure 8] This schematic plan view illustrates how, in an embodiment, the blue wavelength band irradiated onto a switching diffraction grating is transmitted through the switching diffraction grating to irradiate a fluorescence wheel, and the fluorescence emitted by the fluorescence wheel device is reflected by a dichroic mirror surface and transmitted through the color wheel device. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a functional circuit block diagram of the projection device 10. The projection device control unit consists of 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 and a display drive unit 26, etc. Image signals of various standards input from the input / output connector unit 21 are converted by the image conversion unit 23 via the input / output interface 22 and system bus SB to unify them into image signals of a predetermined format suitable for display, and then output to the display encoder 24.

[0013] Furthermore, the display encoder 24 stores the input image signal in the video RAM 25, generates a video signal from the contents of the video RAM 25, and outputs it to the display drive unit 26.

[0014] The display drive unit 26 drives the display element 50, such as a spatial optical modulation element (SOM) or DMD, at an appropriate frame rate in response to the image signal output from the display encoder 24. The projection device 10 irradiates the display element 50 with a beam of light emitted from the light source device 60 via the light guide optical system 170, forming an optical image with the reflected light from the display element 50, and projects the image onto a projection surface such as a screen (not shown) via the projection optical system 220 (see Figure 2). The movable lens group 235 of this projection optical system 220 can be driven by the lens motor 45 for zoom and focus adjustment.

[0015] In addition, the image compression / expansion unit 31 performs a recording process of compressing the luminance signal and color difference signals of the image signal through processes such as ADCT and Huffman coding, and sequentially writing the compressed data to the memory card 32, which is a removable recording medium. Further, in the playback mode, the image compression / expansion unit 31 reads the image data recorded on the memory card 32, expands the individual image data constituting a series of moving images in units of one frame, and outputs the expanded data to the display encoder 24 via the image conversion unit 23. Therefore, the image compression / expansion unit 31 can output a moving image or the like based on the image data stored in the memory card 32.

[0016] The control unit 38 controls the operations of each circuit within the projection device 10, and is composed of a ROM that fixedly stores operation programs such as a CPU and various settings, and a RAM used as a work memory.

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

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

[0019] The control unit 38 controls the light source control circuit 41. The light source control circuit 41 individually controls the operations of the excitation light irradiation device 70, the fluorescent wheel device 100, and the color wheel device 150 (see FIG. 2) in the light source device 60 so that light in a predetermined wavelength band required during image generation is emitted from the light source device 60. Further, the light source control circuit 41 individually controls the switching between the on state and the off state of the switching diffraction grating 200 described later.

[0020] Furthermore, the control unit 38 causes the cooling fan drive control circuit 43 to detect temperature using multiple temperature sensors installed on the light source device 60, etc., and controls the rotation speed of the cooling fan 261 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 261 even after the power to the projection device 10 is turned off using a timer or the like, or to turn off the power to the projection device 10 depending on the results of the temperature detection by the temperature sensors.

[0021] Next, the internal structure of the projection device 10 will be described. Figure 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 roughly 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 also has a projection opening 12a on the front side. In the following description, left and right in the projection device 10 refers to the left and right directions with respect to the projection direction from the projection opening 12a, and front and back refers to the front and back directions with respect to the direction of the object to be projected and the direction of propagation of the light beam.

[0022] The projection device 10 includes a control circuit board 242 near the left panel 15. This control circuit board 242 includes a power supply circuit block, a light source control block, and the like. The projection device 10 also includes a light source device 60 located approximately in the center of the projection device 10. Between the light source device 60 and the right panel 14 are a power connector 57, a heat sink 130, a cooling fan 261, and the like.

[0023] The light source device 60 includes an excitation light irradiation device (light source) 70, which is a light source for blue wavelength band light (first wavelength band light) and also an excitation light source, and a red-green light source device 80, which is a light source for red wavelength band light (second wavelength band light) and green wavelength band light (third wavelength band light). The red-green light source device 80 is composed of the excitation light irradiation device 70 and a fluorescence wheel device 100. The light source device 60 is equipped with a light source optical system 140 that guides blue wavelength band light, red wavelength band light, and green wavelength band light.

[0024] The light source optical system 140 includes a fluorescence wheel device (fluorescence emission device) 100, a color wheel device (filter device) 150, a composite member 200, and a first focusing lens 142. The light source optical system 140 focuses the light beams emitted from the excitation light irradiation device 70 and the red-green light source device 80 onto the incident surface of the microlens array 90, which will be described later. The light source device 60 also has a light guide optical system 170 that guides the light from the light source optical system 140 (light transmitted through the color wheel device 150) to the projection optical system 220, which will be described later.

[0025] The excitation light irradiation device 70 is located approximately in the center of the housing of the projection device 10. The excitation light irradiation device 70 has a plurality of blue laser diodes (light emission parts) 71 and a plurality of collimator lenses (lens parts) 72. Each blue laser diode 71 and each collimator lens 72 is held by a holding member (not shown). The excitation light irradiation device 70 is connected to a heat sink 130 via a heat pipe and is cooled.

[0026] The blue laser diodes 71 constituting the light source group are semiconductor light-emitting elements that emit blue wavelength band light, which is the excitation light, and multiple units are arranged vertically (up and down) (in plan views such as Figure 2, only one blue laser diode 71 located at the top is shown). Collimator lenses 72 are positioned on the optical axis of each blue laser diode 71 and each converts the light emitted from the blue laser diode 71 into parallel light to increase its directivity. Each collimator lens 72 is positioned offset from the optical axis of the corresponding blue laser diode 71 so that it is incident at a predetermined angle on the switching diffraction grating 202 of the composite member 200, which will be described later. The blue wavelength band light emitted from each blue laser diode 71 becomes a light beam limited to a predetermined range by the collimator lens 72.

[0027] The fluorescent wheel device 100 includes a disc-shaped or annular fluorescent wheel 101, a motor 110 that rotates the fluorescent wheel 101, and a drive control device (not shown) that controls the motor 110. The drive control device is controlled by the light source control circuit 41 described above. The fluorescent wheel device 100 is positioned such that the surface side of the fluorescent wheel 101 into which blue wavelength band light is incident (the side opposite to the side where the motor 110 is located) faces the composite member 200, which will be described later.

[0028] The fluorescent wheel 101 shown in Figure 3 is made of a metal material such as copper or aluminum, and its surface is mirror-finished by silver deposition or the like. The fluorescent wheel 101 has a red light-emitting region (first light-emitting region) 104 and a green light-emitting region (second light-emitting region) 106. The red light-emitting region 104 and the green light-emitting region 106 are arranged side by side in the circumferential direction of the fluorescent wheel 101, and in the example shown in Figure 3, they are each arranged within an angular range of approximately 120 degrees. Note that the proportions occupied by each region of the red light-emitting region 104 and the green light-emitting region 106 are not limited to an angular range of approximately 120 degrees and may be changed as appropriate.

[0029] The red emission region 104 has a mirror-finished surface on which a red phosphor layer is provided. The red emission region 104 receives blue wavelength band light emitted from the excitation light irradiation device 70 as excitation light and emits fluorescence including red wavelength band light. The green emission region 106 receives blue wavelength band light emitted from the excitation light irradiation device 70 as excitation light and emits fluorescence including green wavelength band light.

[0030] The color wheel device 150 includes a disc-shaped or annular color wheel 151, a motor 160 that drives the color wheel 151, and a drive control device (not shown) that controls the motor 160. The drive control device is controlled by the light source control circuit 41 described above. The color wheel device 150 is positioned so that the surface side of the color wheel 151 (the side opposite to the side where the motor 160 is located) faces the composite member 200.

[0031] The color wheel 151 shown in Figure 4 is made of a transparent material such as glass or resin that has transparency, and has a blue transparent region (transmissive region, transparent diffusion region) 152, a red transparent region (first filter region) 154, and a green transparent region (second filter region) 156. The blue transparent region 152, the red transparent region 154, and the green transparent region 156 are arranged side by side in the circumferential direction of the color wheel 151, and in the example shown in Figure 4, they are each arranged within an angular range of approximately 120 degrees. Note that the proportions occupied by each region of the blue transparent region 152, the red transparent region 154, and the green transparent region 156 are not limited to an angular range of approximately 120 degrees and may be changed as appropriate.

[0032] The blue-transmitting region 152 transmits and diffuses blue wavelength band light. The red-transmitting region 154 transmits red wavelength band light and reflects light in other wavelength bands. The green-transmitting region 156 transmits green wavelength band light and reflects light in other wavelength bands. The wavelength band of light transmitted through the red-transmitting region 154 is, for example, 590 to 650 nm. The wavelength band of light transmitted through the green-transmitting region 156 is, for example, 465 to 590 nm. In this embodiment, the blue-transmitting region 152 transmits not only blue wavelength band light but also other wavelength bands of visible light. However, for example, the blue-transmitting region 152 may be a region that transmits blue wavelength band light and reflects light in other wavelength bands, and the wavelength band of light transmitted through the blue-transmitting region 152 may be 440 to 465 nm.

[0033] The composite member 200 is a horizontally elongated, roughly rectangular plate-shaped member, installed between the excitation light irradiation device 70 and the fluorescence wheel device 100. As shown in Figure 5, of the two plate surfaces of the composite member 200, the surface facing the excitation light irradiation device 70 is the excitation light incident surface 200a, into which blue wavelength band light emitted from the excitation light irradiation device 70 is incident, and the opposite surface (the surface facing the fluorescence wheel device 100) is the excitation light emission surface 200b, into which blue wavelength band light that has passed through the composite member 200 is emitted. The composite member 200 transmits blue wavelength band light emitted from the excitation light irradiation device 70.

[0034] As shown in Figure 5, in this embodiment, the excitation light emission surface 200b side of the composite member 200 is treated with a dichroic mirror finish and is designated as a dichroic mirror surface (mirror portion) 204. The dichroic mirror surface 204 transmits blue wavelength band light and red wavelength band light and green wavelength band light. On the other hand, the portion of the composite member 200 excluding the dichroic mirror surface 204 is designated as a switching diffraction grating (optical path changing portion) 202 such as DigiLens®. That is, the switching diffraction grating 202 includes the excitation light incident surface 200a of the composite member 200. Thus, in this embodiment, the switching diffraction grating 202 and the dichroic mirror surface 204 are provided on the same composite member 200.

[0035] The switching diffraction grating 202 is configured to receive a voltage and can switch between an ON state (voltage applied) and an OFF state (voltage not applied). Inside the switching diffraction grating 202, liquid crystal (not shown) is sealed in a predetermined orientation direction when the OFF state is reached. When the switching diffraction grating 202 switches to the ON state by applying a voltage, the orientation direction of the liquid crystal inside is switched. By controlling the orientation direction of the liquid crystal in this way, the optical path of blue wavelength band light passing through the switching diffraction grating 202 can be controlled. In the switching diffraction grating 202, the change between the ON and OFF states is controlled by the control unit 38 in a time-division multiplexer manner.

[0036] In this embodiment, when the switching diffraction grating 202 is in the off state, blue wavelength band light incident on the composite member 200 is bent in a first direction D1 toward the color wheel device 150 by the switching diffraction grating 202, passes through the switching diffraction grating 202 and the dichroic mirror surface 204, and is guided in the first direction D1 (see Figure 5(a)). On the other hand, when the switching diffraction grating 202 is in the on state, blue wavelength band light incident on the composite member 200 passes through the switching diffraction grating 202 and the dichroic mirror surface 204 without bending, and is guided in a second direction D2 toward the fluorescent wheel device 100 (see Figure 5(b)).

[0037] The first focusing lens 142 is positioned between the composite member 200 and the fluorescent wheel device 100. The first focusing lens 142 focuses the blue wavelength band light transmitted through the composite member 200 in the second direction D2 and guides it toward the fluorescent wheel device 100. The first focusing lens 142 also focuses the red wavelength band light and the green wavelength band light emitted in the red emission region 104 and green emission region 106 of the fluorescent wheel device 100 and guides them toward the composite member 200.

[0038] Next, the arrangement of each component constituting the light source device 60 will be described. The composite member 200 is arranged such that the blue wavelength band light emitted from the excitation light irradiation device 70 is incident on it at an angle that is inclined with respect to the excitation light incident surface 200a. Furthermore, as described above, the composite member 200 is arranged such that the blue wavelength band light transmitted through the composite member 200 in the first direction D1 is guided toward the color wheel device 150, and the blue wavelength band light transmitted through the composite member 200 in the second direction D2 is guided toward the fluorescent wheel device 100.

[0039] The fluorescent wheel device 100 is configured such that blue wavelength band light transmitted through the composite member 200 in the second direction D2 is incident on it. The fluorescent wheel device 100 is also configured such that red wavelength band light and green wavelength band light emitted by the fluorescent wheel 101 are incident on the dichroic mirror surface 204 of the composite member 200. The color wheel device 150 is configured such that blue wavelength band light transmitted through the composite member 200 after bending in the first direction D1, and red wavelength band light and green wavelength band light reflected by the dichroic mirror surface 204 of the composite member 200 are incident on it. In other words, the switching diffraction grating 202 is configured and the liquid crystal is oriented such that the first direction D1 is approximately equal to the direction in which red wavelength band light and green wavelength band light are reflected by the dichroic mirror surface 204.

[0040] Returning to Figure 2, the light guide optical system 170 includes a microlens array 90, a concave lens 174, a second condensing lens 175, an illumination mirror 185, and a condenser lens 195. The concave lens 174 is positioned between the microlens array 90 and the second condensing lens 175. The condenser lens 195 is also part of the projection optical system 220, as it directs image light emitted from the display element 50, which is located on the back panel 13 side of the condenser lens 195, toward the projection optical system 220.

[0041] The projection optical system 220 includes a condenser lens 195, a movable lens group 235, and a fixed lens group 225. The fixed lens group 225, which is positioned on the optical axis on the front panel 12 side of the condenser lens 195, is built into a fixed lens barrel and can be moved manually or automatically to enable zoom and focus adjustments. The projection device 10 according to this embodiment has the above configuration.

[0042] Next, based on Figure 6, the control mode of the fluorescent wheel device 100, the color wheel device 150, and the switching diffraction grating 202 in the control unit 38 when light in a predetermined wavelength band required for image generation is emitted from the light source device 60 will be explained. As shown in Figure 6, one frame consists of two subframes, and the control unit 38 uses the light source control circuit 41 to time-division control the fluorescent wheel device 100, the color wheel device 150, and the switching diffraction grating 202 in each subframe to display each color.

[0043] The control unit 38 controls the blue wavelength band light emission period so that the blue transmission region 152 of the color wheel device 150 is positioned and the switching diffraction grating 202 is in the off state. The control unit 38 controls the red wavelength band light emission period so that the red emission region 104 of the fluorescence wheel device 100 is positioned at the location where the red wavelength band light is incident, the red transmission region 154 of the color wheel device 150 is positioned, and the switching diffraction grating 202 is in the on state.

[0044] Furthermore, the control unit 38 controls the green wavelength band light emission period so that the green light emission region 106 of the fluorescent wheel device 100 is positioned at the location where the green wavelength band light is incident, the green transmission region 156 of the color wheel device 150 is positioned, and the switching diffraction grating 202 is turned on. With this control configuration, light of each wavelength band is incident on the display element 50 via the light guide optical system 170, and the display element 50 displays light of each color in a time-division manner according to the data, thereby projecting a color image onto the screen.

[0045] Next, we will explain the emission and incidence of light in each component constituting the light source device 60. First, we will explain the case where blue wavelength band light, which is the excitation light, is emitted based on Figure 7. Here, the position on the fluorescence wheel 101 where the blue wavelength band light (light L1 shown by a solid line in Figures 7 and 8) is incident is defined as the first irradiation spot SP1 (see Figure 3), and the position on the color wheel 151 where the blue wavelength band light, red wavelength band light, and green wavelength band light are incident is defined as the second irradiation spot SP2 (see Figure 4). In Figure 7, the switching diffraction grating 202 is in the off state, and the blue transmission region 152 of the color wheel 151 is located at the second irradiation spot SP2.

[0046] The blue wavelength band light (excitation light) emitted from each blue laser diode 71 of the excitation light irradiation device 70 is incident on the composite member 200 at an angle that is tilted with respect to the excitation light incident surface 200a. When the switching diffraction grating 202 is in the off state, the blue wavelength band light incident on the composite member 200 is bent in the first direction D1 (see Figure 5(a)) as it passes through the switching diffraction grating 202 and the dichroic mirror surface 204, is guided in the first direction D1, and is incident on the color wheel 151.

[0047] When the blue-transmitting region 152 is located at the second irradiation spot SP2, the blue wavelength band light incident on the color wheel 151 is diffused through the blue-transmitting region 152 and transmitted towards the microlens array 90. In this way, the excitation light, which is blue wavelength band light, can be used as a light source.

[0048] Next, we will explain the case where red wavelength band light and green wavelength band light are emitted, based on Figure 8. In Figure 8, the switching diffraction grating 202 is in the ON state, with the red emission region 104 located at the first irradiation spot SP1 and the red transmission region 154 located at the second irradiation spot SP2. Alternatively, in Figure 8, the switching diffraction grating 202 is in the ON state, with the green emission region 106 located at the first irradiation spot SP1 and the green transmission region 156 located at the second irradiation spot SP2.

[0049] The blue wavelength band light (excitation light) emitted from each blue laser diode 71 of the excitation light irradiation device 70 is incident on the composite member 200 at an angle that is inclined with respect to the excitation light incident surface 200a. When the switching diffraction grating 202 is in the ON state, the blue wavelength band light incident on the composite member 200 passes through the switching diffraction grating 202 and the dichroic mirror surface 204 without bending, is guided in a second direction D2 toward the fluorescence wheel device 100 (see Figure 5(b)), and is incident on the fluorescence wheel 101. When the red emission region 104 is located at the first irradiation spot SP1, the blue wavelength band light incident on the fluorescence wheel 101 irradiates the red phosphor layer, and when the green emission region 106 is located at the first irradiation spot SP1, the blue wavelength band light incident on the fluorescence wheel 101 irradiates the green phosphor layer.

[0050] When the red emission region 104 is irradiated with blue wavelength band light, which is the excitation light, fluorescence containing red wavelength band light (light L2 shown by the dashed line in Figure 8) is emitted. Similarly, when the green emission region 106 is irradiated with blue wavelength band light, fluorescence containing green wavelength band light (light L2 shown by the dashed line in Figure 8) is emitted. Here, the light emitted in the red emission region 104 and the green emission region 106 consists of fluorescence containing red wavelength band light or fluorescence containing green wavelength band light, and excitation light that is not irradiated into the red emission region 104 or the green emission region 106 and is reflected by the mirrored surface of the fluorescence wheel 101 (hereinafter referred to as "residual excitation light").

[0051] The red wavelength band light emitted in the red emission region 104 and the green wavelength band light emitted in the green emission region 106 are diffused at an angle of approximately 120° and emitted towards the composite member 200 via the first focusing lens 142. The red wavelength band light and green wavelength band light emitted towards the composite member 200 are incident on the dichroic mirror surface 204 of the composite member 200, reflected by the dichroic mirror surface 204 towards the color wheel device 150, and incident on the color wheel 151.

[0052] When the red-transmitting region 154 is located at the second irradiation spot SP2, the red wavelength band light incident on the color wheel 151 passes through the red-transmitting region 154 to enhance its color purity and is emitted toward the microlens array 90. Similarly, when the green-transmitting region 156 is located at the second irradiation spot SP2, the green wavelength band light incident on the color wheel 151 passes through the green-transmitting region 156 to enhance its color purity and is emitted toward the microlens array 90. In this way, red wavelength band light and green wavelength band light can be used as light sources.

[0053] The residual excitation light reflected by the fluorescent wheel 101 is emitted towards the composite member 200 via the first focusing lens 142 and incident on the dichroic mirror surface 204. When the switching diffraction grating 202 is in the ON state, the residual excitation light incident on the dichroic mirror surface 204 is transmitted through the dichroic mirror surface 204 and the switching diffraction grating 202 without bending and is removed.

[0054] In this embodiment, a configuration in which the fluorescent wheel device 100 is provided with a red light-emitting region 104 and a green light-emitting region 106 is illustrated. However, the fluorescent wheel device 100 may also be provided with a yellow light-emitting layer that emits fluorescence including yellow wavelength band light. In this case, blue wavelength band light, which is the excitation light, is irradiated onto the yellow light-emitting layer, causing yellow wavelength band light to be emitted, and the emitted yellow wavelength band light is reflected towards the color wheel device 150 by the dichroic mirror surface 204. When the red light-transmitting region 154 is located at the second irradiation spot SP2, the red wavelength band light is transmitted through the red light-transmitting region 154 and the other green wavelength band light is reflected and removed. When the green light-transmitting region 156 is located at the second irradiation spot SP2, the green wavelength band light is transmitted through the green light-transmitting region 156 and the other red wavelength band light is reflected and removed.

[0055] As described above, the light source device 60 according to this embodiment includes an excitation light irradiation device 70 that emits blue wavelength band light, a switching diffraction grating 202 that is provided so that the blue wavelength band light emitted from the excitation light irradiation device 70 is incident at an angle tilted with respect to the excitation light incident surface 200a, and which changes in time division between an optical path that transmits the incident blue wavelength band light in a first direction D1 and an optical path that transmits it in a second direction D2, a fluorescence wheel device 100 that is provided so that the blue wavelength band light in the second direction D2 that has passed through the switching diffraction grating 202 is incident, and which has a red emission region 104 that emits fluorescence including red wavelength band light when irradiated with blue wavelength band light, and a dichroic mirror surface 204 provided between the switching diffraction grating 202 and the fluorescence wheel device 100 that reflects the red wavelength band light emitted in the red emission region 104 and transmits the blue wavelength band light that has passed through the switching diffraction grating 202.

[0056] As a result of the above configuration, the light source device 60 makes the first direction changed by the switching diffraction grating 202 approximately equal to the direction in which red wavelength band light is reflected by the dichroic mirror surface 204. This causes the blue wavelength band light transmitted through the switching diffraction grating 202 in the first direction D1 and the blue wavelength band light transmitted through the switching diffraction grating 202 in the second direction D2 to be emitted by the fluorescent wheel device 100, and the red wavelength band light reflected by the dichroic mirror surface 204 to be guided to the same side. As a result, the optical paths of the blue wavelength band light and the red wavelength band light are the same, eliminating the need to separately arrange lens members, mirror members, etc., to guide one wavelength band light independently from the other wavelength band light. Therefore, the light source device 60 can be miniaturized.

[0057] Furthermore, in the light source device 60, the switching diffraction grating 202 changes either the optical path that bends and transmits the incident blue wavelength band light in a first direction D1 or the optical path that transmits it in a second direction D2, with the first direction D1 being approximately equal to the direction in which the red wavelength band light is reflected by the dichroic mirror surface 204. This provides a specific configuration in which the blue wavelength band light transmitted through the switching diffraction grating 202 in the first direction D1 and the red wavelength band light reflected by the dichroic mirror surface 204 are guided to the same side.

[0058] Furthermore, the light source device 60 is equipped with a fluorescent wheel device 100 as a fluorescent light emission device. This makes it possible to suppress the concentration of heat generated by the irradiation of excitation light on a part of the phosphor layer provided on the fluorescent wheel device 100.

[0059] Furthermore, in the light source device 60, a dichroic mirror surface 204 is provided on the side of the switching diffraction grating 202 facing the fluorescent wheel device 100. This reduces the number of components compared to when the switching diffraction grating 202 and the dichroic mirror surface 204 are separate components.

[0060] Furthermore, in the light source device 60, the fluorescent wheel device 100 has a green emission region 106 that emits fluorescence including green wavelength band light when irradiated with blue wavelength band light, and the dichroic mirror surface 204 reflects the green wavelength band light emitted in the green emission region 106. As a result, the optical path of the green wavelength band light can be the same as that of the blue wavelength band light and the red wavelength band light, and the display colors of the light source device 60 can be increased while the device can be miniaturized.

[0061] Furthermore, the light source device 60 includes a color wheel device 150 having a blue-transmitting region 152 that transmits blue wavelength band light, a red-transmitting region 154 that transmits red wavelength band light and reflects other wavelength band light, and a green-transmitting region 156 that transmits green wavelength band light and reflects other wavelength band light. The color wheel device 150 is configured so that blue wavelength band light transmitted through the dichroic mirror surface 204 in a first direction D1, and red wavelength band light and green wavelength band light reflected by the dichroic mirror surface 204 are incident on it. This makes it possible to increase the color purity of the red wavelength band light transmitted through the red-transmitting region 154 and the green wavelength band light transmitted through the green-transmitting region 156, and also allows the blue wavelength band light, red wavelength band light, and green wavelength band light transmitted through the color wheel device 150 to be guided along the same optical path.

[0062] Furthermore, the light source device 60 is equipped with a color wheel device 150 as a filter device. This provides a specific configuration for controlling the color wheel device 150 so that the corresponding blue transmission region 152, red transmission region 154, and green transmission region 156 are positioned in a time-division manner at the locations where blue wavelength band light, red wavelength band light, and green wavelength band light are incident, respectively.

[0063] Furthermore, in the light source device 60, the color wheel device 150 has a blue-transmitting region 152 that transmits and diffuses blue wavelength band light as a transmitting region. As a result, the blue wavelength band light transmitted through the blue-transmitting region 152 can be made into a luminous flux of approximately the same magnitude as the red wavelength band light and the green wavelength band light.

[0064] Furthermore, the projection device 10 according to this embodiment includes the 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 surface, and a control unit 38 that controls the light source device 60 and the display element 50. This makes it possible to make the optical paths of the blue wavelength band light, red wavelength band light, and green wavelength band light guided from the light source device 60 to the projection optical system 220 the same optical path, thereby realizing a projection device 10 in which the light source device 60 has been miniaturized.

[0065] Furthermore, the projection device 10 includes a switching diffraction grating 202 that changes the optical path under the control of the control unit 38, acting as an optical path changing unit. This allows us to provide a specific configuration for the optical path changing unit.

[0066] The embodiments described above 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 variations are included in the scope and essence of the invention, as well as in the claims of the invention and its equivalents.

[0067] For example, in the above embodiment, a configuration was illustrated in which, when the switching diffraction grating is in the off state, blue wavelength band light passes through the switching diffraction grating while bending in a first direction, and when the switching diffraction grating is in the on state, blue wavelength band light passes through the switching diffraction grating in a second direction without bending. However, a configuration in which, when the switching diffraction grating is in the on state, blue wavelength band light passes through the switching diffraction grating while bending in a first direction, and when the switching diffraction grating is in the off state, blue wavelength band light passes through the switching diffraction grating in a second direction without bending is also possible.

[0068] Furthermore, although the above embodiment illustrates a configuration in which the switching diffraction grating and the dichroic mirror surface are provided on the same composite member, a configuration in which a dichroic mirror having the same function as the dichroic mirror surface is provided as a separate member from the switching diffraction grating is also possible. In this case, the switching diffraction grating and the dichroic mirror can be arranged at different positions and angles, making it easier to design the optical paths for blue wavelength band light and red wavelength band light.

[0069] Furthermore, although a switching diffraction grating was used as an example of the optical path changing unit in the above embodiment, the device is not limited to this. The optical path changing unit can be any device that can electrically change the optical path of incident blue wavelength band light to either an optical path that transmits in a first direction or an optical path that transmits in a second direction.

[0070] The invention described in the first claim of this application is listed below. [1] A light source that emits light in the first wavelength band, An optical path changing unit is provided such that the first wavelength band light emitted from the light source is incident at an angle inclined with respect to the incident surface, and which changes either the optical path that transmits the incident first wavelength band light in a first direction or the optical path that transmits it in a second direction in a time-division manner. A fluorescence emission device having a first emission region that is provided so as to receive the first wavelength band light in the second direction that has passed through the optical path changing section, and which emits fluorescence including the second wavelength band light when irradiated with the first wavelength band light, The device includes a mirror portion provided between the optical path changing section and the fluorescent light emitter, which reflects the second wavelength band light emitted in the first light emission region and transmits the first wavelength band light that has passed through the optical path changing section. Light source device. [2] The optical path changing unit changes either the optical path that bends and transmits the incident first wavelength band light in the first direction or the optical path that transmits it in the second direction, The first direction is approximately equal to the direction in which the second wavelength band light is reflected by the mirror portion. The light source device according to claim 1. [3] The light source device according to [2] above, wherein the fluorescent light-emitting device is a fluorescent wheel device. [4] The light source device according to [3], wherein the mirror portion is a dichroic mirror surface provided on the side of the optical path changing portion that is on the side of the fluorescent wheel device. [5] The fluorescence emission device has a second emission region which emits fluorescence including light in the third wavelength band when irradiated with light in the first wavelength band, The mirror portion reflects the third wavelength band light emitted in the second light emission region. A light source device as described in any of the above [1] to [4]. [6] A filter device having a transmission region that transmits light in the first wavelength band, a first filter region that transmits light in the second wavelength band and reflects light in other wavelength bands, and a second filter region that transmits light in the third wavelength band and reflects light in other wavelength bands. The filter device is configured such that the first wavelength band light transmitted through the mirror in the first direction, and the second wavelength band light and the third wavelength band light reflected by the mirror are incident on it. The light source device described in [5] above. [7] The light source device according to [6], wherein the filter device is a color wheel device. [8] The light source device according to [7], wherein the transmission region of the color wheel device is a transmission-diffusion region that transmits and diffuses light in the first wavelength band. [9] The light source device described in [8] above, A display element that generates image light, A projection optical system that projects the image light emitted from the display element onto a projection object, The system comprises a control unit that controls the light source device and the display element, Projection device.

[10] The control unit controls the change of the optical path in the optical path changing unit, The optical path changing unit is a switching diffraction grating that changes the optical path under the control of the control unit. The projection apparatus described in [9] above. [Explanation of Symbols]

[0071] 10 Projection device 12 Front panel 12a Projection opening 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 / decompression unit 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 speakers 50 display elements 57 Power connector 60 Light source device 70 Excitation light irradiation device 71 Blue laser diode 72 Collimator lens 80 Red-green light source device 90 Microlens arrays 100 Fluorescence wheel devices 101 Fluorescent Wheel 104 Red Emitting Region 106 Green light-emitting area 110 motor 130 Heatsink 140 Light Source Optical System 142 First focusing lens 150 Color wheel device 151 Color Wheel 152 Blue Transparency Area 154 Red transmission area 156 Green transmission area 160 Motor 170 Light Guide Optics 174 Concave lens 175 Second focusing lens 185 Illumination mirror 195 Condenser lens 200 Composite member 200a Excitation light incident surface 200b Excitation light emission surface 202 Switching diffraction grating 204 Dichroic mirror surface 220 Projection optical system 225 Fixed lens group 235 Movable lens group 242 Control circuit board 261 Cooling fan D1 1st direction D2 2nd direction L1, L2 Optical SB System Bus SP1: First irradiation spot SP2: Second irradiation spot

Claims

1. A light source that emits light in the first wavelength band, An optical path changing unit is provided such that the first wavelength band light emitted from the light source is incident at an angle inclined with respect to the incident surface, and which changes either the optical path that transmits the incident first wavelength band light in a first direction or the optical path that transmits it in a second direction in a time-division manner. A fluorescence emission device having a first emission region that is provided so as to be incident on the first wavelength band light in the second direction that has passed through the optical path changing section, and which emits fluorescence including the second wavelength band light when irradiated with the first wavelength band light, The optical path changing section and the fluorescent light emitter are provided with a mirror section that reflects the second wavelength band light emitted in the first light emission region and transmits the first wavelength band light that has passed through the optical path changing section, The aforementioned fluorescence emission device is a fluorescence wheel device, The mirror portion is a dichroic mirror surface provided on the side of the optical path changing portion facing the fluorescent wheel device. Light source device.

2. The optical path changing unit changes either the optical path that transmits the incident first wavelength band light in the first direction or the optical path that transmits it in the second direction. The first direction is substantially equal to the direction in which the second wavelength band light is reflected by the mirror portion. The light source device according to claim 1.

3. The fluorescence emission device has a second emission region that emits fluorescence including light in the third wavelength band when irradiated with light in the first wavelength band, The mirror portion reflects the third wavelength band light emitted in the second light-emitting region. The light source device according to claim 1 or 2.

4. The filter device comprises a transmission region that transmits light in the first wavelength band, a first filter region that transmits light in the second wavelength band and reflects light in other wavelength bands, and a second filter region that transmits light in the third wavelength band and reflects light in other wavelength bands. The filter device is configured such that the first wavelength band light transmitted through the mirror in the first direction, and the second wavelength band light and the third wavelength band light reflected by the mirror are incident on it. The light source device according to claim 3.

5. The light source device according to claim 4, wherein the filter device is a color wheel device.

6. The light source device according to claim 5, wherein the transmission region of the color wheel device is a transmission-diffusion region that transmits and diffuses light in the first wavelength band.

7. The light source device according to claim 6, A display element that generates image light, A projection optical system that projects the image light emitted from the display element onto a projection object, The system comprises a control unit that controls the light source device and the display element, Projection device.

8. The optical path changing unit is a switching diffraction grating that changes the optical path under the control of the control unit. The projection apparatus according to claim 7.

Images