Light irradiation device and image projection device

Abstract

To shorten a spoke period during which color reproducibility of color selection light emitted from a light irradiation device cannot be obtained.SOLUTION: A light irradiation device has: a color selection moving member that moves a plurality of color selection units so that the color selection units sequentially cross a superimposed light path through which superimposed light passes which is obtained by superimposing a plurality of rays of individual light F1, F2; and an emission unit that sequentially emits rays of color selection light obtained through incident of the superimposed light on the plurality of color selection units. An incident spot S21 on the color selection moving member in one of the rays of individual light constituting the superimposed light is shifted in a direction A in which the plurality of color selection units crosses the superimposed light path, relative to an incident spot S22 on the color selection moving member in the other of the rays of individual light. The light irradiation device has a control unit that performs emission control of not causing the emission unit to emit color selection light obtained from one of the rays of individual light, while causing the emission unit to emit color selection light obtained from the other of the rays of individual light, in a period (T3-T1) during which a boundary part 53b present between the plurality of color selection units crosses an incident spot portion W1 on the color selection moving member consisting only of one of the rays of individual light.SELECTED DRAWING: Figure 7

Description

[Technical field]

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

[0002] Conventionally, a light irradiation device has been known that has a color selection movement member that moves a plurality of color selection sections corresponding to different colors so that the color selection sections sequentially cross a superimposed light path through which superimposed light, which is obtained by superimposing a plurality of individual lights that pass through a plurality of different individual light paths, passes, and an emission section that sequentially emits each color selected light obtained when the superimposed light is incident on each of the plurality of color selection sections.

[0003] For example, Patent Document 1 discloses an illumination device used in a projector (image projection device) that irradiates each emitted light (individual light) from two light source modules onto each phosphor wheel and spatially combines the fluorescence excited in each phosphor region on each phosphor wheel with an optical element. In this illumination device, the spatially combined light beam (superimposed light) enters each filter region (color selection section) of a filter wheel (color selection moving member), and light (color selected light) with a wavelength selected in each filter region is sequentially emitted toward an image generation section. As a result, the illumination device emits four colors of light, red light, green light, blue light, and yellow light, by switching them over time, to the image generation section. Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a light irradiation device in which a superimposed light obtained by superimposing multiple individual lights that pass through multiple different individual optical paths is incident on a color selection moving member, there was a problem that there was a long spoke period during which the color reproducibility of the color selection light emitted from the light irradiation device could not be obtained. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, the present invention provides a light irradiation device having a color selection moving member that moves a plurality of color selection sections so that a plurality of color selection sections corresponding to different colors sequentially cross a superimposed light path through which a superimposed light obtained by superimposing a plurality of individual lights that pass through a plurality of different individual light paths passes, and an emission section that sequentially emits each color selected light obtained when the superimposed light is incident on each of the plurality of color selection sections, wherein an incident spot on the color selection moving member for a portion of the individual lights that constitute the superimposed light is shifted in a direction crossing the plurality of color selection sections relative to an incident spot on the color selection moving member for other individual lights that constitute the superimposed light, and the device has a control unit that performs emission control to emit color selected light based on the other individual lights from the emission section while not emitting color selected light based on the portion of the individual lights from the emission section during a period when a boundary portion existing between the plurality of color selection sections crosses an incident spot portion on the color selection moving member consisting only of the portion of the individual lights. Effect of the Invention

[0006] According to the present invention, in a light irradiation device in which a superimposed light obtained by superimposing a plurality of individual lights passing through a plurality of different individual optical paths is incident on a color selection moving member, it is possible to shorten the spoke period during which color reproducibility of the color selection light emitted from the light irradiation device cannot be obtained. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of an image projection device including an illumination device according to an embodiment. [Diagram 2] FIG. 2 is a plan view showing a schematic configuration of the lighting device. [Diagram 3] FIG. 4 is an explanatory diagram showing an example of a phosphor wheel in the lighting device. [Figure 4] FIG. 2 is an explanatory diagram showing an example of a color wheel in the lighting device. [Diagram 5] FIG. 2 is a hardware configuration diagram of an image projection apparatus according to an embodiment. [Figure 6] 1 is an explanatory diagram of when a boundary of a color wheel crosses an incident spot of non-overlapping light on a color wheel. [Figure 7] 1 is an explanatory diagram of when a boundary of a color wheel crosses an incident spot of superimposed light on a color wheel. [Figure 8] (a) is an explanatory diagram showing a drive current waveform and a light output waveform when adjusting the synchronization timing of a phosphor wheel and a color wheel; (b) is an explanatory diagram showing a light output waveform when a first light source unit of two light source units is turned on and a second light source unit is turned off; and (c) is an explanatory diagram showing a light output waveform when a second light source unit of two light source units is turned on and a first light source unit is turned off. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment in which a light irradiation device according to the present invention is applied to an illumination device of a projector, which is an image projection device, will be described. The present invention is also applicable as a light irradiation device for image projection devices other than projectors (for example, head-up displays, etc.), and is also applicable as a light irradiation device other than image projection devices.

[0009] FIG. 1 is a diagram showing an example of the configuration of an image projection device 100 including an illumination device 10 as a light irradiation device according to this embodiment. In the following description, the X, Y, and Z directions are perpendicular to each other, the X and Y directions are horizontal, and the Z direction is vertical, but this is not limited to this configuration.

[0010] The image projection device 100 includes an illumination device 10 and a DMD (Digital Micromirror Device) 101 as an image generation unit that generates an image by modulating illumination light from the illumination device 10. The image projection device 100 also includes an illumination optical system 102 that illuminates the light output from the illumination device 10 substantially uniformly and guides it to the DMD 101, and a projection optical system 103 that enlarges and projects the light spatially modulated by the DMD 101 onto a projection surface 104.

[0011] The DMD 101 generates an image from the illumination light from the illumination device 10 by reflecting the incident light beam with micro mirrors arranged on the surface. Note that, in addition to the DMD 101, the image generating section may also be configured to use a liquid crystal panel such as a transmissive liquid crystal element or a reflective liquid crystal element.

[0012] The projection optical system 103 is an optical system located downstream of the DMD 101 in the optical path, and projects light toward a projection surface 104, which is a screen. The illumination optical system 102 is an optical system for guiding illumination light from the illumination device 10 toward the DMD 101. These optical systems are composed of optical elements including lenses and mirrors, and are disposed within a housing 105 of the image projection device 100.

[0013] FIG. 2 is a plan view showing a schematic configuration of the lighting device 10 (a view of the lighting device 10 seen from above). As shown in FIG. 2, the illumination device 10 has a first light source unit LS1, a second light source unit LS2, a prism 2 as a superimposing optical element, a color wheel 53 as a color selection movement member, and a rod integrator 3 which is an output section as a light homogenizing element.

[0014] Prism 2, which is a superimposing optical element, is a polyhedron having four or more faces. Among the faces of prism 2, the face on which light F1 from first light source unit LS1 is incident is reflective face 2A, and the face on which light F2 from second light source unit LS2 is incident is transmissive face 2B.

[0015] It is preferable to make the transmission surface 2B, through which the light F2 from the second light source unit LS2 of the prism 2 passes, a diffusing surface. By making it a diffusing surface, it is possible to eliminate unevenness in color and brightness of the light passing through the diffusing surface. Note that instead of providing a diffusing surface on the prism 2, a separate diffusing plate may be provided to eliminate unevenness in color and brightness.

[0016] The prism 2 reflects the light F1 from the first light source unit LS1 on the reflecting surface 2A and transmits the light F2 from the second light source unit LS2 on the transmitting surface 2B, combining (superimposing) the light F1 and the light F2 and guiding them to the rod integrator 3 as a light beam (superimposed light) traveling in approximately the same direction.

[0017] In this embodiment, the prism 2 is used as the superimposing optical element, but any optical element that can superimpose (combine) the light F1 and F2 from two or more light source units in approximately the same direction and guide them to the rod integrator 3 may be used.

[0018] The rod integrator 3 is a rod-shaped glass and is an optical element that homogenizes the light by reflecting the incident light multiple times inside. Specifically, the illuminance and light intensity distribution of the light F1 and F2 that are superimposed (combined) by the prism 2 and passed through the color wheel 53 are homogenized, and the light is output as the illumination light L that is the outgoing light.

[0019] In this embodiment, a rod integrator 3 with excellent efficiency and high output is used as the light uniformizing element, but a prismatic light tunnel with mirrors bonded to four sides, a fly's eye lens, or the like may also be used as the light uniformizing element.

[0020] Next, the first light source unit LS1 and the second light source unit LS2 will be described. Since the first light source unit LS1 and the second light source unit LS2 have substantially the same configuration, here we will explain each element of the first light source unit LS1, and the elements that make up the second light source unit LS2 will be numbered the same and explanations will be omitted as appropriate.

[0021] The first light source unit LS1 includes an LED light source 11 serving as a light source of excitation light, a collimator lens 12 arranged facing the LED light source 11, a light source optical system 13, a condensing element 14, a microlens array 19, and a dichroic mirror 15. The first light source unit LS1 also includes a disk-shaped phosphor wheel 17 serving as a wavelength conversion movable member, a first condensing optical system 16, and a second condensing optical system 18.

[0022] The LED light source 11 is a multi-chip laser diode unit in which a plurality of light emitting parts are arranged in a one-dimensional or two-dimensional array.

[0023] A collimator lens 12 is disposed at a position facing each light-emitting portion of the LED light source 11, and converts the excitation light emitted from each light-emitting portion into a parallel light beam. The light source optical system 13 is a lens that collects the excitation light that has been made parallel by the collimator lens 12. Here, the center of the light source generally coincides with the optical axis of the excitation light emitted from the light source. Therefore, the light source optical system 13 is provided so that the center of the light source and the optical axis of the light source optical system 13 are aligned.

[0024] The condensing element 14 is a lens with negative power arranged after the light source optical system 13, and reduces the condensing property of the light source optical system 13. The light flux that has been transmitted through the condensing element 14 and has its condensing property reduced is incident on a microlens array 19, which serves as a light profile adjustment element. The microlens array 19 homogenizes the light intensity distribution of the irradiation spot of the light irradiated at a desired position on the phosphor wheel 17.

[0025] Of the light beams transmitted through the microlens array 19, only light of a specific wavelength is reflected by the dichroic mirror 15, and an illumination spot is generated at a desired position on the phosphor wheel 17 by the first focusing optical system 16. In other words, the phosphor wheel 17 is provided in the vicinity of the illumination spot. Note that a reflective diffractive optical element (DOE) may be used instead of the dichroic mirror 15.

[0026] FIG. 3 is an explanatory diagram showing an example of the phosphor wheel 17. As shown in FIG. The phosphor wheel 17 is a disk-shaped member configured to rotate at high speed around the rotation axis 17a by a drive motor. The phosphor wheel 17 of this embodiment has two phosphor regions 17A and 17B that are wavelength conversion parts coated with phosphor, and an excitation light reflection region 17C that is a reflection part that reflects excitation light. As the phosphor wheel 17 rotates, these regions 17A, 17B, and 17C move across the irradiation spot S1 of the light focused by the first focusing optical system 16, and the two phosphor regions 17A and 17B and the excitation light reflection region 17C are sequentially switched at the position of the irradiation spot S1.

[0027] In this embodiment, blue light with a central wavelength of 455 nm in emission intensity is used as the excitation light emitted from the LED light source 11. Therefore, when the excitation light reflection region 17C of the phosphor wheel 17 is located at the position of the irradiation spot S1, the blue light is output as it is without wavelength conversion. On the other hand, when the first phosphor region 17A of the phosphor wheel 17 is located at the position of the irradiation spot S1, yellow light that has been wavelength-converted into yellow fluorescence is output. Also, when the second phosphor region 17B of the phosphor wheel 17 is located at the position of the irradiation spot S1, green light that has been wavelength-converted into green fluorescence is output.

[0028] In this embodiment, the phosphor wheel 17 is shown as being divided into two phosphor regions 17A, 17B and an excitation light reflecting region 17C, but it may also be configured with one phosphor region or three or more phosphor regions, or may be configured with two or more excitation light reflecting regions.

[0029] 2, the light beam output from phosphor wheel 17 passes through first focusing optical system 16 again, and is then focused by second focusing optical system 18 constituted by a relay lens system. Thereafter, if it is light F1 from first light source unit LS1, it is turned back by reflecting surface 2A of prism 2, passes through color wheel 53, and enters rod integrator 3. If it is light F2 from second light source unit LS2, it is transmitted through transmitting surface 2B of prism 2, similarly passes through color wheel 53, and enters rod integrator 3.

[0030] FIG. 4 is an explanatory diagram showing an example of the color wheel 53. As shown in FIG. Color wheel 53 is a disk-shaped member arranged on the optical path (superimposed optical path) between prism 2 and rod integrator 3, and configured to rotate at high speed around rotation axis 53a in the direction of arrow A in the figure by a drive motor. Color wheel 53 may also be arranged on the downstream side (exit side) of the optical path of rod integrator 3.

[0031] The color wheel 53 of this embodiment has color selection regions as a plurality of light transmission filter sections having different spectral transmittances. Specifically, it has four color selection regions: a yellow region 53A that outputs yellow light, a red region 53B that outputs red light, a green region 53C that outputs green light, and a blue region 53D that outputs blue light. Note that some of these color selection regions 53A, 53B, 53C, and 53D may be transmission sections that transmit light as they are.

[0032] When the color wheel 53 rotates, these color selection areas 53A, 53B, 53C, and 53D move to cross the optical path (incident spot S2) of the light beam (superimposed light) formed by superimposing (combining) the lights F1 and F2 from the light source units LS1 and LS2 by the prism 2. As a result, the four color selection areas 53A, 53B, 53C, and 53D are switched in sequence on the optical path (incident spot S2), and light that is time-shared into yellow, red, green, and blue is output to the rod integrator 3.

[0033] The color wheel 53 is controlled to rotate in synchronization with the phosphor wheel 17 at the same rotation speed as the phosphor wheel 17. When light time-divided into yellow, green, and blue light by the phosphor wheel 17 is sequentially incident on the color wheel 53 as in this embodiment, the color wheel 53 is controlled to rotate as follows. That is, the color wheel 53 is controlled to rotate so that the yellow region 53A of the color wheel 53 corresponds to half of the first phosphor region 17A corresponding to the yellow of the phosphor wheel 17, the red region 53B of the color wheel 53 corresponds to the remaining half of the first phosphor region 17A corresponding to the yellow of the phosphor wheel 17, the green region 53C of the color wheel 53 corresponds to the second phosphor region 17B corresponding to the green of the phosphor wheel 17, and the blue region 53D of the color wheel 53 corresponds to the excitation light reflection region 17C corresponding to the blue of the phosphor wheel 17.

[0034] The blue region 53D of the color wheel 53 is preferably configured with a transmissive diffusion plate. By configuring the blue region 53D as a transmissive diffusion plate, it is possible to reduce the coherence of the LED light source 11, and to reduce speckles on the projection surface 104. On the other hand, the yellow region 53A of the color wheel 53 may be configured with a transmissive plate that transmits the wavelength region of the yellow fluorescence emitted by the first phosphor region 17A as it is. For example, the red region 53B of the color wheel 53 is provided with a dichroic mirror that transmits the red wavelength region of the yellow fluorescence emitted by the first phosphor region 17A of the phosphor wheel 17 and reflects the other wavelengths. Also, the green region 53C of the color wheel 53 may be configured with a transmissive plate that transmits the wavelength region of the green fluorescence emitted by the second phosphor region 17B as it is.

[0035] In this way, the yellow, red, green, and blue lights time-shared by phosphor wheel 17 and color wheel 53 are sequentially incident on rod integrator 3, and each light is homogenized by rod integrator 3 and then guided to DMD 101. Then, based on image data provided via external device connection I / F 818 or the like (see FIG. 5), DMD 101 forms an image corresponding to each color, and projection optical system 103 projects the enlarged image onto projection surface 104.

[0036] The image projection device 100 of this embodiment can be used in a variety of applications, including commercial use (projection display for business, meetings, presentations, etc.), home use, medical use (projection display of monochrome medical images such as X-ray images and MRI (magnetic resonance imaging) images), public use (projection display of various kinds of guidance, advertisements, signage, etc. in public places, stores, and transportation facilities), and installation in factories.

[0037] Furthermore, the image projection device 100 of this embodiment has projection modes corresponding to the above-mentioned respective uses (color mode, video mode, image mode, medical mode for projecting medical images, public mode for projecting guidance or signage outdoors or in a store, etc.) Depending on the change of mode, the control of the driving method and driving amount of the light source, power, cooling, output, etc. may be automatically changed.

[0038] FIG. 5 is a diagram showing the hardware configuration of the image projection device 100 according to this embodiment. 5, the image projection device 100 includes a CPU (Central Processing Unit) 801, a ROM (Read Only Memory) 802, and a RAM (Random Access Memory) 803. The image projection device 100 also includes a media I / F (Interface) 807, an operation unit 808, a power switch 809, a bus line 810, a network I / F 811, an LED (Light Emitting Diode) drive circuit 814, an external device connection I / F (Interface) 818, a fan drive circuit 819, a cooling fan 820, and the like.

[0039] The CPU 801 controls the overall operation of the image projection device 100. The ROM 802 stores programs and data used to drive the CPU 801. The RAM 803 is used as a work area for the CPU 801. The media I / F 807 controls reading and writing (storing) data from and to a portable recording medium 806.

[0040] The operation unit 808 has various keys, buttons, LEDs, etc. arranged thereon, and is used by the user to perform various operations other than turning on / off the power of the image projection device 100. For example, the operation unit 808 accepts instruction operations such as operations to adjust the size of the projection image, operations to adjust the color tone, operations to adjust the focus, operations to adjust the keystone, etc., and outputs the contents of the accepted operations to the CPU 801. The power switch 809 is a switch for switching the power of the image projection device 100 on / off.

[0041] The bus line 810 is an address bus, a data bus, or the like for electrically connecting the components such as the CPU 801 shown in Fig. 8. The network I / F 811 is an interface for data communication using a communication network such as the Internet. The LED drive circuit 814 controls the turning on and off of the LED light source 11 under the control of the CPU 801.

[0042] A PC (Personal Computer) is directly connected to the external device connection I / F 818, and control signals and image data are exchanged between the external device connection I / F 818 and the PC. The fan drive circuit 819 is connected to the CPU 801 and the cooling fan 820, and drives / stops the cooling fan 820 based on a control signal from the CPU 801. The cooling fan 820 rotates to exhaust air from inside the image projection device 100, thereby cooling the inside of the image projection device 100.

[0043] Furthermore, when power is supplied to the CPU 801, the CPU 801 starts up according to a control program previously stored in the ROM 802, and sends a control signal to an LED drive circuit 814 to turn on the LED light source 11. The CPU 801 also sends a control signal to a fan drive circuit 819 to rotate a cooling fan 820 at a predetermined rated speed. When the supply of power from the power supply circuit starts, the image projection device 100 puts the DMD 101 into a state in which it can display an image, and furthermore, power is supplied from the power supply circuit to various other components.

[0044] Furthermore, when the power switch 809 of the image projection device 100 is turned OFF, the power switch 809 sends a power OFF signal to the CPU 801, and when the CPU 801 detects the power OFF signal, it sends a control signal to the LED drive circuit 814 to turn off the LED light source 11. After that, when a predetermined time has elapsed, the CPU 801 sends a control signal to the fan drive circuit 819 to stop the cooling fan 820, and also ends its own control process, and finally sends an instruction to the power circuit to stop the supply of power from the power source.

[0045] Next, the spoke periods occurring in the lighting device 10 of this embodiment will be described. Illumination device 10 of the present embodiment moves four color selection areas 53A, 53B, 53C, and 53D on color wheel 53 so as to cross the optical path of light incident on color wheel 53, and sequentially emits light of each color (color-selected light) output from each area. In such illumination device 10, spoke periods occur during which the color reproducibility of the light of each color output from color wheel 53 cannot be obtained.

[0046] More specifically, there is a boundary 53b between each of the color selection regions 53A, 53B, 53C, and 53D on the color wheel 53. The width of the boundary 53b (the length of the boundary 53b in the rotation direction A of the color wheel 53) is usually smaller than the width of the incident spot S2 of the light incident on the color wheel 53, as shown in FIG. 6. Therefore, during a period T' (=T2'-T1') in which the boundary 53b crosses the incident spot S2 of the light incident on the color wheel 53, light is simultaneously incident on two color selection regions (e.g., the yellow region 53A and the red region 53B) that straddle the boundary 53b, and light in which the colors of the two color selection regions are mixed is output from the color wheel 53 and emitted from the lighting device 10. Note that, although the incident spot S2 is shown as a perfect circle in FIG. 6, the spot shape is actually determined by the arrangement of the light source device, etc.

[0047] Such mixed color light does not provide color reproducibility for any of the colors in the color selection regions 53A, 53B, 53C, and 53D on the color wheel 53. Therefore, the period T' during which the boundary portion 53b crosses the incident spot S2 of the light incident on the color wheel 53 is stored as a spoke period, for example, in the ROM 802 of the image projection device 100, and the CPU 801 of the image projection device 100 processes the light in the spoke period as a non-use period during which it is not used for color reproduction of the image.

[0048] In general, if the spoke period T' (=T2'-T1') is long, the usable period of the light emitted from the lighting device 10 (light irradiation device) becomes short, resulting in inefficiency. In particular, when the light emitted from the lighting device 10 is used for image projection as in this embodiment, if the spoke period T' is long, the time required for color reproduction of each color in the projected image becomes short, affecting color reproducibility on the image, particularly reproduction of gradation. Specifically, artifacts occur and color gradation cannot be reproduced smoothly. For this reason, in the past, the spoke period T' was shortened as much as possible by reducing the width of the boundary portion 53b or the width of the incident spot S2.

[0049] However, in a configuration such as that of this embodiment in which a light beam (superimposed light) formed by superimposing light F1, F2 (individual light) from each light source unit LS1, LS2 that passes through multiple different optical paths (individual optical paths) is incident on color wheel 53, the spoke period is often longer than in a configuration in which non-superimposed light (light consisting of only one individual light) is incident on color wheel 53.

[0050] More specifically, in this configuration, it is difficult to completely overlap the light beams F1 and F2 from the light source units LS1 and LS2 (to form a single incident spot as shown in FIG. 6) on the color wheel 53. Therefore, as shown in FIG. 7, the incident spot S21 on the color wheel 53 for the light F1 from the first light source unit LS1 is shifted in the direction crossing the four color selection regions 53A, 53B, 53C, and 53D on the color wheel 53 (i.e., the rotation direction A of the color wheel 53) with respect to the incident spot S22 on the color wheel 53 for the light F2 from the second light source unit LS2.

[0051] In this shifted state, the width W of the incident spot of the superimposed light of the lights F1 and F2 is greater than the width W' of the incident spot S2 of the non-superimposed light (light consisting of only one individual light). Therefore, in a configuration in which the superimposed light of the lights F1 and F2 is incident on the color wheel 53, the period (T2-T1) during which the boundary portion 53b crosses the incident spot of the light incident on the color wheel 53 is longer than the period T' (=T2'-T1') in a configuration in which the non-superimposed light is incident on the color wheel 53. This will result in a longer spoke period.

[0052] Here, a period during which the boundary 53b crosses the incident spot portions W1 and W2 on the color wheel 53, which are made up of only the individual light beams F1 and F2 that constitute the superimposed light of the light beams F1 and F2, will be considered. For example, looking at the period (T3-T1) during which the boundary 53b crosses the portion W1 of the incident spot S21 consisting only of the light F1, during this period (T3-T1), the boundary 53b exists within the incident spot S21 of the light F1, and the light F1 is simultaneously incident on two color-selective regions (e.g., the yellow region 53A and the red region 53B) that straddle the boundary 53b. Therefore, the color-selected light by the light F1 becomes a mixed state, and the entire color-selected light of the superimposed light including the light F1 also becomes a mixed state. Therefore, if the color-selected light by the superimposed light of the lights F1 and F2 is to continue to be emitted during this period (T3-T1), this period (T3-T1) must be treated as a spoke period.

[0053] However, during this period (T3-T1), the boundary 53b does not exist within the incident spot S22 of the other light F2. Therefore, the color-selected light by the other light F2 is not mixed. Therefore, in this embodiment, during the period (T3-T1) when the boundary 53b crosses the portion W1 of the incident spot S21 on the color wheel 53 consisting of only one light F1 constituting the superimposed light of the lights F1 and F2, emission control is performed to emit the color-selected light by the other light F2 from the rod integrator 3 while not emitting the color-selected light by the one light F1 from the rod integrator 3. This emission control can be easily realized, for example, by light source control in which the LED light source 11 of the second light source unit LS2 of the other light F2 is turned on while only the LED light source 11 of the first light source unit LS1 of the one light F1 is turned off.

[0054] As a result, during the period (T3-T1), only the color-selected light by the unmixed light F2 is emitted from the rod integrator 3, not including the color-selected light by the mixed light F1. As a result, since unmixed color-selected light is emitted during this period (T3-T1), it is no longer necessary to treat this period (T3-T1) as a spoke period. Therefore, the spoke period can be made shorter than when color-selected light by the superimposed light of the lights F1 and F2 is continuously emitted during this period (T3-T1).

[0055] The same is true for the period (T2-T4) in which the boundary 53b crosses the portion W2 of the incident spot S22 consisting only of the light F2. That is, during this period (T2-T4), the boundary 53b exists within the incident spot S22 of the light F2, and the light F2 is simultaneously incident on two color-selective regions (e.g., the yellow region 53A and the red region 53B) that straddle the boundary 53b. Therefore, the color-selected light by the light F2 becomes a mixed state, and the entire color-selected light of the superimposed light including the light F2 also becomes a mixed state. Therefore, if the color-selected light by the superimposed light of the lights F1 and F2 is to be continuously emitted during this period (T2-T4), this period (T2-T4) must be treated as a spoke period.

[0056] However, during this period (T2-T4), the boundary 53b does not exist within the incident spot S21 of the other light F1. Therefore, the color-selected light by the other light F1 is not mixed. Therefore, in this embodiment, during the period (T2-T4) when the boundary 53b crosses the portion W2 of the incident spot S22 on the color wheel 53 consisting of only one light F2 constituting the superimposed light of the lights F1 and F2, emission control is performed to emit the color-selected light by the other light F1 from the rod integrator 3 while not emitting the color-selected light by the one light F2 from the rod integrator 3. This emission control can be easily realized, for example, by light source control in which the LED light source 11 of the first light source unit LS1 of the other light F1 is turned on while only the LED light source 11 of the second light source unit LS2 of the one light F2 is turned off.

[0057] As a result, during the period (T2-T4), only the color-selected light by the unmixed light F1 is emitted from the rod integrator 3, not including the color-selected light by the mixed light F2. As a result, since unmixed color-selected light is emitted during this period (T2-T4), it is no longer necessary to treat this period (T2-T4) as a spoke period. Therefore, the spoke period can be made shorter than when color-selected light by the superimposed light of the lights F1 and F2 is continuously emitted during this period (T2-T4).

[0058] In addition, during the period (T4-T3) when the boundary 53b crosses the portion W3 where the incident spots S21 and S22 of the lights F1 and F2 overlap each other, the boundary 53b exists in both the incident spots S21 and S22, and the color-selected light by both the lights F1 and F2 is in a mixed color state. Therefore, during this period (T4-T3), it is not possible to emit unmixed color-selected light, and therefore this period is treated as a spoke period. Therefore, the spoke period T in this embodiment is only the period (T4-T3) when the boundary 53b crosses the portion W3 where the incident spots S21 and S22 of the lights F1 and F2 overlap each other.

[0059] The spoke period T in this embodiment is shorter than the spoke period T' when the incident spots S21, S22 of the lights F1, F2 on the color wheel 53 are overlapped so as to completely overlap (when a single incident spot is formed as shown in FIG. 6). Therefore, if priority is given to shortening the spoke period, the incident spots S21, S22 of the lights F1, F2 on the color wheel 53 may be intentionally shifted. The amount of shift in this case is appropriately set by comparing the advantage of a shorter spoke period with the disadvantage of a smaller overlapping area of ​​the incident spots of the lights F1, F2.

[0060] In this embodiment, in order to perform light source control to shorten the spoke period as described above, it is necessary to synchronize the operations of the LED light source 11, the phosphor wheel 17, the color wheel 53, and the DMD 101. For example, in a period in which a blue image is displayed, blue light is appropriately generated over that period by synchronization between the phosphor wheel 17 and the color wheel 53, and the operation of the DMD 101 must also be synchronized so that the DMD 101 operates to appropriately display a blue image during this period. Furthermore, in this embodiment, in order to perform light source control to shorten the spoke period, it is also necessary to synchronize the operations of the LED light sources 11 of the two light source units LS1 and LS2.

[0061] There are various methods for adjusting synchronization, but one example is shown below. First, as shown in FIG. 8(a), the drive current waveforms and light output waveforms of the LED light sources 11 of the two light source units LS1 and LS2 are observed with an oscilloscope. For example, assume that the LED light sources 11 of the two light source units LS1 and LS2 are turned on during the display period of a blue image. In this case, the same drive current waveform is input to the LED light sources 11 of the two light source units LS1 and LS2, and adjustments are made so that the excitation light reflection area 17C of the phosphor wheel 17 and the blue area 53D of the color wheel 53 pass through the spots S1 and S2 during the turn-on period of the LED light sources 11 of the two light source units LS1 and LS2. Specifically, as shown in FIG. 8, the light output waveform has periods Ts1 and Ts2 in which the light output drops before and after the period in which high light output is obtained, so the timing of the phosphor wheel 17 and the color wheel 53 is adjusted so that these two periods Ts1 and Ts2 have the same time width. If this timing is not optimized, the timing of adjacent colors will be shifted and the correct color will not be reproduced.

[0062] Next, in this embodiment, the first light source unit LS1 of the two light source units LS1 and LS2 is turned on, and the second light source unit LS2 is turned off, and the optical output waveform at that time is observed with an oscilloscope. Then, as shown in FIG. 8(b), the timings t1 and t4 at which the optical output drops are measured. Also, the second light source unit LS2 of the two light source units LS1 and LS2 is turned on, and the first light source unit LS1 is turned off, and the optical output waveform at that time is observed with an oscilloscope. Then, as shown in FIG. 8(c), the timings t3 and t2 at which the optical output drops are measured. These timings t1 to t4 correspond to the timings T1 to T4 shown in FIG. 7. Therefore, the spoke period T (= t4 - t3) can be obtained from these timings t1 to t4, and the spoke period can be shortened by performing light source control of the two light source units LS1 and LS2 based on these timings t1 to t4.

[0063] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the spirit of the present invention described in the claims, unless otherwise specifically limited in the above description.

[0064] The above description is merely an example, and each of the following aspects provides unique effects. [First aspect] The first aspect is a light irradiation device (e.g., lighting device 10) having a color selection movement member (e.g., color wheel 53) that moves a plurality of color selection units (e.g., color selection areas 53A, 53B, 53C, and 53D) corresponding to different colors so that the color selection units sequentially cross a superimposed light path through which a superimposed light obtained by superimposing a plurality of individual lights (e.g., light F1 from a first light source unit LS1 and light F2 from a second light source unit LS2) that pass through a plurality of different individual light paths passes, and an emission unit (e.g., rod integrator 3) that sequentially emits each color selected light (e.g., yellow light, red light, green light, and blue light) obtained by the superimposed light being incident on each of the plurality of color selection units, and the light irradiation device (e.g., lighting device 10) has a part of the individual lights (e.g., light F1) that constitute the superimposed light. The superimposed light is characterized in that the incident spot (e.g., S21) on the color selection moving member in the superimposed light is shifted in the direction in which the multiple color selection sections cross (e.g., the rotation direction A of the color wheel 53) relative to the incident spot (e.g., S22) on the color selection moving member for other individual lights (e.g., light F2) that constitute the superimposed light, and the superimposed light is characterized in that the control unit (e.g., CPU 801, etc.) performs emission control to emit color selected light based on the other individual lights from the emission unit while not emitting color selected light based on the portion of the individual lights from the emission unit during a period (e.g., T3-T1) in which a boundary portion 53b existing between the multiple color selection units crosses an incident spot portion (e.g., W1) on the color selection moving member consisting only of the portion of the individual lights. In general, in a light irradiation device that moves a plurality of color selection sections on a color selection moving member so as to cross the optical path of light incident on the color selection moving member and sequentially emits each color-selected light emitted from each color selection section, a spoke period occurs during which color reproducibility of the emitted color-selected light is not obtained. To explain in detail, a boundary section exists between the plurality of color selection sections on the color selection moving member, and the width of the boundary section is usually smaller than the width of the incident spot of light incident on the color selection moving member. Therefore, during the period during which the boundary section crosses the incident spot of light incident on the color selection moving member, light is simultaneously incident on two color selection sections straddling the boundary section, and the color-selected light of the two color selection sections is emitted from the light emitting device in a mixed state. Such mixed color light does not obtain color reproducibility for any of the color-selected light. Therefore, this period is treated as a spoke period, and a downstream device (e.g., an image projection device) that receives the emitted light from the light irradiation device (each color-selected light outputted sequentially) processes the emitted light from the light irradiation device as, for example, a non-use period during which the emitted light from the light irradiation device is not used for color reproduction of an image. Therefore, if the spoke period is long, the period during which the light emitted from the light irradiation device is used in the downstream device will be short, resulting in inefficiency. Therefore, in the past, efforts were made to shorten the spoke period as much as possible by reducing the width of the boundary portion or the width of the incident spot. However, in a configuration in which multiple individual lights passing through multiple different individual light paths are superimposed and the superimposed light is incident on a color selection moving member, as in the lighting device described in Patent Document 1, the spoke period is often longer than in a configuration in which non-superimposed light (light consisting of only one individual light) is incident on a color selection moving member. In detail, in this configuration, it is difficult to superimpose multiple individual lights passing through multiple individual light paths so that the incident spots on the color selection moving member completely overlap. Therefore, the incident spots on the color selection moving member of some individual lights constituting the superimposed light are shifted in the direction in which the multiple color selection parts on the color selection moving member cross, relative to the incident spots on the color selection moving member of other individual lights. The incident spot width of the superimposed light in this shifted state (the length of the incident spot in the crossing direction) is larger than the incident spot width of non-superimposed light (light consisting of only one individual light). Therefore, in a configuration in which superimposed light is incident on the color selection moving member, the period during which the boundary crosses the incident spot of the light incident on the color selection moving member is longer than in a configuration in which non-superimposed light is incident on the color selection moving member, and the spoke period is correspondingly longer. Here, when considering the period in which the boundary crosses the incident spot portion on the color selection moving member, which is made up of only a portion of the individual light constituting the superimposed light, the boundary exists within the incident spot of the portion of the individual light, and the portion of the individual light is simultaneously incident on the two color selection portions that straddle the boundary. Therefore, the color selection light due to the portion of the individual light is in a mixed state, and the entire color selection light of the superimposed light including the portion of the individual light is also in a mixed state, so this period is also treated as a spoke period. However, during this period, the other individual lights constituting the superimposed light do not have a boundary within their incident spots, and only one of the color selection portions is present. Therefore, the color selection light due to the other individual lights is not mixed. Therefore, in this aspect, during the period when the boundary portion crosses the incident spot portion on the color selection moving member that is composed of only a portion of the individual light that constitutes the superimposed light, emission control is performed such that the color selection light of the other individual light is emitted from the emission portion while the color selection light of the portion of the individual light is not emitted from the emission portion. As a result, the color selection light emitted from the emission portion during this period is composed only of the color selection light of the other individual light that is not mixed, without including the color selection light of the portion of the individual light that is mixed. As a result, during this period, the color selection light that is not mixed is emitted from the emission portion, and it becomes unnecessary to treat it as a spoke period, so that the spoke period can be shortened.

[0065] [Second aspect] The second aspect is characterized in that the first aspect has a plurality of light sources (e.g., a first light source unit LS1 and a second light source unit LS2) that respectively output the plurality of individual lights, and the emission control includes controlling the light sources that output some of the individual lights to stop outputting, thereby preventing color-selected light based on some of the individual lights from being emitted from the emission section. According to this, the above-mentioned extraction control can be realized by a simple control.

[0066] [Third aspect] A third aspect is a configuration in which, in the second aspect, the multiple light sources include a blue light source (e.g., LED light source 11) that outputs blue light in the blue wavelength region, and a wavelength conversion section (e.g., phosphor regions 17A, 17B) that emits wavelength-converted light in a wavelength band longer than the blue wavelength region when the blue light is incident on it, and a reflection section (e.g., excitation light reflection region 17C) that reflects the blue light have a wavelength conversion moving member (e.g., phosphor wheel 17) that moves the wavelength conversion section and the reflection section so that they sequentially cross individual optical paths through which the blue light passes, and the movement of the wavelength conversion moving member is synchronized with the movement of the color selection moving member. According to this, in a light irradiation device that sequentially emits blue light and light in a wavelength band having a wavelength longer than the blue wavelength region, it is possible to shorten the spoke period.

[0067] [Fourth aspect] A fourth aspect is characterized in that, in any of the first to third aspects, the incident spot portion is, among each of the incident spots on the color selection moving member in the plurality of individual lights constituting the superimposed light, a portion of the incident spot located on the most upstream side in the direction crossed by the boundary portion, or a portion of the incident spot located on the most downstream side, or both. This facilitates emission control to shorten the spoke period.

[0068] [Fifth aspect] A fifth aspect is characterized in that in any one of the first to fourth aspects, the plurality of color selection sections include a plurality of light transmitting filter sections having different spectral transmittances. This makes it easy to obtain a plurality of color selection sections.

[0069] [Sixth aspect] The sixth aspect is characterized in that in an image projection device 100 including a light irradiation device (e.g., a lighting device 10) and an image generating unit (e.g., a DMD 101) that generates an image using light emitted from the light irradiation device, the light irradiation device is any one of the light irradiation devices of the first to fifth aspects. This makes it possible to provide an image projection device with a short spoke period. [Explanation of symbols]

[0070] 2: Prism 3: Rod integrator 10: Lighting equipment 11:LED light source 12: Collimator lens 13:Light source optical system 14: Light collecting element 15:Dichroic mirror 16:First condensing optical system 17: Phosphor wheel 17A: First phosphor region 17B: Second phosphor region 17C: Excitation light reflection area 17a: Rotation axis 18:Second condensing optical system 19: Microlens array 53: Color Wheel 53A: Yellow area 53B: Red area 53C: Green area 53D: Blue area 53a: Rotating shaft 53b: Boundary part 100: Image projection device 101:DMD 102: Illumination optical system 103: Projection optical system 104: Projection surface 105: Housing LS1: First light source unit LS2: Second light source unit S1: Irradiation spot S2, S21, S22: Incident spots T, T': spoke period [Prior art documents] [Patent documents]

[0071] [Patent Document 1] JP 2014-160233 A

Claims

1. a color selection moving member that moves a plurality of color selection units corresponding to different colors so that the color selection units sequentially cross a superimposed light path through which a superimposed light obtained by superimposing a plurality of individual lights that pass through a plurality of different individual light paths passes; an emission unit that sequentially emits each color selected light obtained by the superimposed light being incident on each of the plurality of color selection units, an incidence spot on the color selection moving member of a portion of the individual light beams constituting the superimposed light is shifted in a direction across the plurality of color selection units with respect to an incidence spot on the color selection moving member of another individual light beam constituting the superimposed light, a control unit that performs emission control to prevent color-selected light based on the portion of the individual light from being emitted from the emission unit while emitting color-selected light based on the other individual light from the emission unit during a period in which a boundary portion between the plurality of color selection units crosses an incident spot portion on the color selection moving member consisting of only the portion of the individual light, the control unit performing emission control to prevent color-selected light based on the portion of the individual light from being emitted from the emission unit.

2. The light irradiation device according to claim 1 , a plurality of light sources each outputting the plurality of individual lights; The light irradiation device is characterized in that the emission control includes controlling so that color-selected light based on the portion of the individual light is not emitted from the emission section by stopping output from a light source that outputs the portion of the individual light.

3. The light irradiation device according to claim 2, the plurality of light sources includes a blue light source that outputs blue light in a blue wavelength region, a wavelength conversion unit that emits wavelength-converted light in a wavelength band having a wavelength longer than a blue wavelength region when the blue light is incident thereon and a reflecting unit that reflects the blue light, the wavelength conversion unit and the reflecting unit having a wavelength conversion movement member that moves the wavelength conversion unit and the reflecting unit so that the wavelength conversion unit and the reflecting unit sequentially cross individual optical paths through which the blue light passes; A light irradiation device, characterized in that the movement of said wavelength conversion movable member is synchronized with the movement of said color selection movable member.

4. The light irradiation device according to any one of claims 1 to 3, The light irradiation device is characterized in that the incident spot portion is, among each of the incident spots on the color selection moving member in the multiple individual lights that constitute the superimposed light, a portion of the incident spot that is located on the most upstream side in the direction in which the boundary portion crosses, or a portion of the incident spot that is located on the most downstream side, or both.

5. The light irradiation device according to any one of claims 1 to 3, The light irradiation device according to claim 1, wherein the plurality of color selection sections include a plurality of light transmission filter sections having different spectral transmittances.

6. A light irradiation device; an image generating unit that generates an image using the light emitted from the light irradiation device, 4. An image projection device, comprising the light projection device according to claim 1 as said light projection device.

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