Light irradiation device and image projection device

Abstract

The invention relates to a light irradiation apparatus and an image projection apparatus. The light irradiation device includes a color selection moving member that moves a plurality of color selection units to sequentially cross an overlapping light path through which overlapping light formed by overlapping a plurality of individual light beams (F1, F2) passes, and an emission unit that sequentially emits color selection light formed by the overlapping light beams entering the plurality of color selection units. An incident spot (S21) of individual light constituting a part of the superimposed light on the color selection moving member is shifted in a transverse direction (A) of the plurality of color selection units with respect to an incident spot (S22) of other individual light constituting the superimposed light on the color selection moving member, and a control unit is provided that performs emission control such that the incident spot (S21) is smaller than the incident spot (S22) of the individual light constituting the superimposed light on the color selection moving member in the transverse direction (A) of the plurality of color selection units. During a period (T3-T1) in which a boundary portion (53b) existing between the plurality of color selection portions crosses an incident spot portion (W1) on the color selection moving member comprising only a portion of the individual light, color selection light of another individual light is emitted from the emission portion, and color selection light of a portion of the individual light is not emitted from the emission portion.

Description

Technical Field

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

[0002] In the past, there is known a light irradiation device having a color selection moving component that moves a plurality of color selection parts corresponding to different colors in a manner that sequentially crosses an overlapping light path through which overlapping light passes, the overlapping light being formed by overlapping a plurality of separate lights passing through a plurality of different separate light paths; and an emitting part that sequentially emits each color selection light obtained by the overlapping light being incident on the plurality of color selection parts respectively.

[0003] For example, Patent Document 1 discloses a lighting device as a light irradiation device for a projector (image projection device), which irradiates each emitted light (individual light) from two light source modules onto each phosphor wheel, and spatially synthesizes the fluorescence excited in each phosphor region on each phosphor wheel through an optical element. In this lighting device, the spatially synthesized light beams (overlapping light) are incident on each filter region (color selection section) of a filter wheel (color selection moving member), and the light (color selection light) selected by wavelength in each filter region is sequentially emitted to an image generation section. As a result, in the lighting device, four colors of light, such as red light, green light, blue light, and yellow light, are emitted to the image generation section while switching in time.

[0004] However, in a light irradiation device that causes superimposed light formed by superimposing a plurality of individual lights passing through a plurality of different individual optical paths to be incident on a color selection moving member, there is a problem that the spoke period is long and the color reproducibility of the color selection light emitted from the light irradiation device cannot be obtained.

[0005] [Patent Document 1] (Japanese) Patent Publication No. 2014-160233 Summary of the invention

[0006] In order to solve the above-mentioned problems, the light irradiation device of the present invention is characterized in that it includes: a color selection moving part that moves a plurality of color selection parts corresponding to different colors to sequentially intersect the overlapping light path through which the overlapping light passes, the overlapping light being formed by overlapping a plurality of separate lights that pass through a plurality of different separate light paths, and an emission part that sequentially emits each color selection light obtained by the overlapping light being respectively incident on the plurality of color selection parts, wherein an incident light spot of a separate light constituting a part of the overlapping light on the color selection moving part is offset in a direction of intersecting the plurality of color selection parts relative to an incident light spot of other separate lights constituting the overlapping light on the color selection moving part, and a control part that performs emission control in such a manner that, while a boundary part existing between the plurality of color selection parts intersects an incident light spot part on the color selection moving part constituted only by the portion of separate lights, the color selection light of the other separate lights is emitted from the emission part, while the color selection light of the portion of separate lights is not emitted from the emission part.

[0007] According to the present invention, in a light irradiation device that causes superimposed light formed by superimposing a plurality of individual lights passing through a plurality of different individual optical paths to be incident on a color selection moving member, a spoke period during which color selection light emitted from the light irradiation device fails to achieve color reproducibility can be shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 FIG. 1 is a diagram showing an example of a configuration of an image projection device including an illumination device according to an embodiment.

[0009] Figure 2 Shown is a top view of the general structure of the lighting device.

[0010] Figure 3 FIG. 1 is an explanatory diagram of an example of a fluorescent wheel in the lighting device.

[0011] Figure 4 FIG. 1 is an explanatory diagram of an example of a color wheel in the lighting device.

[0012] Figure 5 FIG. 2 is a diagram showing a hardware configuration of an image projection device according to an embodiment of the present invention.

[0013] Figure 6 FIG. 1 is an explanatory diagram showing a case where the boundary of the color wheel intersects the incident light spot of non-overlapping light on the color wheel.

[0014] Figure 7 FIG. 1 is an explanatory diagram showing a case where the boundary of the color wheel intersects the incident light spot of the superimposed light on the color wheel.

[0015] Figure 8(a) is an illustration of the driving current waveform and the light output waveform when adjusting the synchronization timing of the phosphor wheel and the color wheel, (b) is an illustration of the light output waveform when the first light source unit of the two light source units is turned on and the second light source unit is turned off, and (c) is an illustration of the light output waveform when the second light source unit of the two light source units is turned on and the first light source unit is turned off. DETAILED DESCRIPTION

[0016] Hereinafter, an embodiment in which the light irradiation device according to the present invention is applied to an illumination device of a projector as an image projection device will be described.

[0017] Furthermore, the present invention can also be applied as a light irradiation device for an image projection device other than a projector (for example, a head-up display, etc.), and can also be applied as a light irradiation device other than an image projection device.

[0018] Figure 1 FIG. 1 is a schematic diagram showing an example of a configuration of an image projection device 100 including an illumination device 10 as a light irradiation device according to the present embodiment.

[0019] In the following description, the X direction, the Y direction, and the Z direction are directions perpendicular to each other, the X direction and the Y direction are horizontal directions, and the Z direction is represented as a vertical direction, but the present invention is not limited to this configuration.

[0020] The image projection device 100 includes an illumination device 10 and a digital micromirror device (DMD) 101 as an image generation unit that modulates illumination light from the illumination device 10 to generate an image. In addition, 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 amplifies the light spatially modulated by the DMD 101 and projects it onto a projection surface 104.

[0021] DMD101 generates an image from the illumination light of illumination device 10 by reflecting incident light beams through micro mirrors arranged on the surface. In addition, as an image generating unit, a liquid crystal panel using a transmissive liquid crystal element or a reflective liquid crystal element may be used instead of DMD101.

[0022] The projection optical system 103 is an optical system located on the downstream side of the optical path of the DMD 101 and used for projecting onto a projection surface 104 as a screen. The illumination optical system 102 is an optical system for guiding illumination light from the illumination device 10 to the DMD 101. These optical systems are composed of optical elements including lenses and reflectors, and are arranged in a housing 105 of the image projection device 100.

[0023] Figure 2 FIG. 1 is a plan view showing a schematic configuration of the lighting device 10 (a view showing the lighting device 10 as viewed from above).

[0024] like Figure 2 As shown, the lighting device 10 includes 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 moving member, and an optical integrator rod 3 as an emission portion of a light uniformizing element.

[0025] The prism 2 as the superimposing optical element is a polyhedron having four or more faces. Among the faces of the prism 2, the face into which the light F1 from the first light source unit LS1 enters is a reflecting face 2A, and the face into which the light F2 from the second light source unit LS2 enters is a transmitting face 2B.

[0026] It is preferred that the transmission surface 2B of the prism 2 that transmits the light F2 from the second light source unit LS2 is set as a diffusion surface. By forming the diffusion surface, the color or brightness unevenness of the light passing through the diffusion surface can be eliminated. In addition, instead of setting the diffusion surface on the prism 2, a diffusion plate can be set separately to eliminate the color or brightness unevenness.

[0027] The prism 2 reflects the light F1 from the first light source unit LS1 through the reflection surface 2A, transmits the light F2 from the second light source unit LS2 through the transmission surface 2B, combines (overlaps) the light F1 and the light F2, and guides them toward the optical integrator rod 3 as light beams (overlapping light) heading in approximately the same direction.

[0028] In the present embodiment, the prism 2 is used as the superimposing optical element, but any optical element may be used as long as it can superimpose (combine) the lights F1 and F2 from two or more light source units in substantially the same direction and guide them to the rod integrator 3 .

[0029] The rod integrator 3 is a rod-shaped glass optical element that makes incident light uniform by multiple reflections inside. Specifically, it makes the illumination and light intensity distribution of the lights F1 and F2 overlapped (synthesized) by the prism 2 and passed through the color wheel 53 uniform and outputs them as outgoing light, i.e., illumination light L.

[0030] In this embodiment, the rod integrator 3 having high efficiency and high output is used as the light uniformizing element. However, a prism-shaped light tunnel having reflective mirrors attached to four sides, a fly-eye lens, or the like may also be used as the light uniformizing element.

[0031] Next, the first light source unit LS1 and the second light source unit LS2 will be described.

[0032] The first light source unit LS1 and the second light source unit LS2 have substantially the same configuration, and therefore, each element of the first light source unit LS1 is described here, and each element constituting the second light source unit LS2 is also denoted by the same reference numerals, and the description thereof is appropriately omitted.

[0033] The first light source unit LS1 includes an LED light source 11 as a light source of excitation light, a collimating lens 12 arranged opposite to the LED light source 11, a light source optical system 13, a focusing element 14, a microlens array 19, and a dichroic mirror 15. In addition, the first light source unit LS1 also includes a disk-shaped fluorescent wheel 17 as a wavelength conversion moving part, a first focusing optical system 16, and a second focusing optical system 18.

[0034] The LED light source 11 is a multi-chip laser diode unit in which a plurality of light emitting units are arranged in a one-dimensional or two-dimensional array.

[0035] A collimating lens 12 is arranged 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 for focusing the excitation light that has become parallel light through the collimating lens 12. Here, the center of the light source is generally consistent with the optical axis of the excitation light emitted from the light source. Therefore, the light source optical system 13 is arranged so that the center of the light source is consistent with the position of the optical axis of the light source optical system 13.

[0036] The focusing element 14 is a lens with negative refractive power disposed at the rear stage of the light source optical system 13, and relaxes the focusing property of the light source optical system 13. The light beam having the light focusing property relaxed by the focusing element 14 enters the microlens array 19 as a light profile adjustment element. The microlens array 19 makes the light intensity distribution of the irradiation spot of the light irradiated to the desired position on the fluorescent body wheel 17 uniform.

[0037] Among the light beams transmitted through the microlens array 19, only the light of a specific wavelength is reflected by the dichroic mirror 15, and generates an irradiation spot at a desired position on the phosphor wheel 17 through the first condensing optical system 16. In other words, the phosphor wheel 17 is provided near the irradiation spot. In addition, a reflective diffractive optical element (DOE) may be used instead of the dichroic mirror 15.

[0038] Figure 3FIG. 1 is an explanatory diagram of an example of the fluorescent substance wheel 17 .

[0039] The phosphor wheel 17 is a disk-shaped member configured to rotate at high speed around a rotating shaft 17a by a driving motor. The phosphor wheel 17 of this embodiment has two phosphor regions 17A and 17B coated with phosphor as wavelength conversion parts, and an excitation light reflection region 17C as a reflection part that reflects excitation light. By the rotation of the phosphor wheel 17, these regions 17A, 17B, and 17C move in a manner that crosses 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.

[0040] In the present embodiment, blue light having a central wavelength of 455 nm in luminous intensity is used as the excitation light emitted from the LED light source 11. Therefore, when the excitation light reflecting region 17C of the phosphor wheel 17 is located at the position of the irradiation spot S1, the blue light is directly output 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 after wavelength conversion to yellow fluorescence is output. In addition, when the second phosphor region 17B of the phosphor wheel 17 is located at the position of the irradiation spot S1, green light after wavelength conversion to green fluorescence is output.

[0041] In addition, the phosphor wheel 17 of this embodiment is divided into two phosphor regions 17A and 17B and an excitation light reflecting region 17C, but it may also be a structure having one phosphor region or three or more phosphor regions, a structure having two or more excitation light reflecting regions, etc.

[0042] like Figure 2 As shown, the light beam output from the fluorescent body wheel 17 passes through the first condensing optical system 16 again, and then is condensed by the second condensing optical system 18 composed of a relay lens system. After that, if it is the light F1 from the first light source unit LS1, it is reflected by the reflection surface 2A of the prism 2, passes through the color wheel 53, and enters the light integrator rod 3. If it is the light F2 from the second light source unit LS2, it passes through the transmission surface 2B of the prism 2, and also passes through the color wheel 53, and enters the light integrator rod 3.

[0043] Figure 4 FIG. 5 is an explanatory diagram of an example of the color wheel 53 .

[0044] The color wheel 53 is disposed on the optical path (overlapping optical path) between the prism 2 and the rod integrator 3, and is a disc-shaped component configured so as to be rotated at high speed in the direction of arrow A in the figure with the rotation axis 53a as the center by a driving motor. Alternatively, the color wheel 53 may be disposed on the downstream side (exit side) of the optical path of the rod integrator 3.

[0045] The color wheel 53 of this embodiment has color selection areas as a plurality of light transmission filter parts having different spectral transmittances. Specifically, it has four color selection areas, namely, a yellow area 53A that outputs yellow light, a red area 53B that outputs red light, a green area 53C that outputs green light, and a blue area 53D that outputs blue light. In addition, some of these color selection areas 53A, 53B, 53C, and 53D may be transmission parts that directly transmit light.

[0046] When the color wheel 53 rotates, the color selection areas 53A, 53B, 53C, and 53D move in a manner that crosses the optical path (incident light spot S2) of the light beams (overlapping light) of the light F1 and F2 from the light source units LS1 and LS2 that are overlapped (synthesized) by the prism 2. Thus, on the optical path (incident light spot S2), the four color selection areas 53A, 53B, 53C, and 53D are switched in sequence, and the time-divided yellow, red, green, and blue lights are output to the rod integrator 3.

[0047] The color wheel 53 is rotationally controlled at the same rotation speed as the fluorescent body wheel 17 so as to be synchronized with the fluorescent body wheel 17. As in the present embodiment, when the light time-divided into yellow, green, and blue light by the fluorescent body wheel 17 is sequentially incident on the color wheel 53, the color wheel 53 is rotationally controlled as follows. That is, the color wheel 53 is rotationally controlled so that the yellow region 53A of the color wheel 53 corresponds to the half of the first fluorescent body region 17A corresponding to the yellow color of the fluorescent body wheel 17, the red region 53B of the color wheel 53 corresponds to the remaining half of the first fluorescent body region 17A corresponding to the yellow color of the fluorescent body wheel 17, the green region 53C of the color wheel 53 corresponds to the second fluorescent body region 17B corresponding to the green color of the fluorescent body wheel 17, and the blue region 53D of the color wheel 53 corresponds to the excitation light reflecting region 17C corresponding to the blue color of the fluorescent body wheel 17.

[0048] The blue region 53D of the color wheel 53 is preferably formed of a transmissive diffuser. By using the blue region 53D as a transmissive diffuser, the coherence of the LED light source 11 can be reduced, and the speckle on the projection surface 104 can be reduced. On the other hand, the yellow region 53A of the color wheel 53 can also be formed of a transmissive plate that directly transmits the wavelength region of the yellow fluorescence emitted by the first phosphor region 17A. The red region 53B of the color wheel 53 is configured with a dichroic mirror, for example, to transmit the red wavelength region of the yellow fluorescence emitted by the first phosphor region 17A of the phosphor wheel 17 and reflect the other wavelengths. In addition, the green region 53C of the color wheel 53 can also be formed of a transmissive plate that directly transmits the wavelength region of the green fluorescence emitted by the second phosphor region 17B.

[0049] Thus, the yellow, red, green and blue lights which have passed through the fluorescent wheel 17 and the color wheel 53 are incident on the light integrator rod 3 in sequence, and each light is uniformly guided to the DMD 101 by the light integrator rod 3. Then, according to the external device connection I / F 818 etc. (refer to Figure 5 ) is used to form images corresponding to each color through DMD101, and the enlarged image is projected onto the projection surface 104 through the projection optical system 103.

[0050] The image projection device 100 of this embodiment can be used in various situations, such as business use (projection display for business, conferences, presentations, etc.), home use, medical use (projection display of monochrome medical images such as X-ray images and magnetic resonance imaging (MRI) images), public use (projection display of various guides, advertisements, signs, etc. in public places, stores, and transportation agencies), and factory installation.

[0051] In addition, the image projection device 100 of this embodiment has projection modes corresponding to the above-mentioned various uses (color mode, dynamic image mode, image mode, medical mode for projecting medical images, public mode for projecting guides or signs outdoors or in stores, etc.). According to the change of the mode, the driving method and driving amount control of the light source, power, cooling, output, etc. can be automatically changed.

[0052] Figure 5 FIG. 2 is a diagram showing a hardware configuration of the image projection device 100 according to the present embodiment.

[0053] like Figure 5 As shown, the image projection device 100 includes a central processing unit (CPU: Central Processing Unit) 801, a read-only memory (ROM: Read Only Memory) 802 and a random access memory (RAM: Random Access Memory) 803. The image projection device 100 also includes a medium I / F (interface) 807, an operation unit 808, a power switch 809, a bus 810, a network I / F 811 and a light emitting diode (LED: Light Emitting Diode), a drive circuit 814, an external device connection I / F (interface) 818, a fan drive circuit 819, a cooling fan 820, etc.

[0054] The CPU 801 controls the overall operation of the image projection device 100. The ROM 802 stores programs and data for driving the CPU 801. The RAM 803 is used as a work area for the CPU 801. The medium I / F 807 controls reading or writing (storing) of data to a portable recording medium 806.

[0055] The operation unit 808 is provided with various keys, buttons, LEDs, etc., 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 adjustment operations of the size of the projected image, adjustment operations of the color tone, adjustment operations of the focus, and adjustment operations of the keystone correction, and outputs the accepted operation content to the CPU 801. The power switch 809 is a switch for switching the power of the image projection device 100 on / off.

[0056] Bus 810 is used to electrically connect Figure 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 lighting and extinguishing of the LED light source 11 under the control of the CPU 801.

[0057] The external device connection I / F 818 is directly connected to a personal computer (PC) and obtains control signals and image data from 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 according to the control signal from the CPU 801. The cooling fan 820 exhausts the air inside the image projection device 100 by rotating, thereby cooling the inside of the image projection device 100.

[0058] When power is supplied, the CPU 801 starts up according to the control program pre-stored in the ROM 802, and supplies a control signal to the LED drive circuit 814 to light up the LED light source 11. In addition, a control signal is supplied to the fan drive circuit 819 to rotate the cooling fan 820 at a predetermined rated speed. When the image projection device 100 starts to supply power from the power circuit, the DMD 101 becomes capable of displaying an image, and further, power is supplied from the power circuit to various other components.

[0059] In addition, when the power switch 809 is turned off, the image projection device 100 sends a power off signal from the power switch 809 to the CPU 801, and when the CPU 801 detects the power off signal, it provides a control signal to the LED drive circuit 814 to extinguish the LED light source 11. Then, when a predetermined time has passed, the CPU 801 provides a control signal to the fan drive circuit 819 to stop the cooling fan 820, and the CPU 101 itself ends its control processing, and finally provides an instruction to the power circuit to stop the supply of power.

[0060] Next, the spoke period generated by the lighting device 10 in this embodiment will be described.

[0061] The lighting device 10 of this embodiment moves the four color selection areas 53A, 53B, 53C, and 53D on the color wheel 53 so as to intersect the optical path of the light incident on the color wheel 53, and sequentially emits the light of each color output from each area (color selection light). In such a lighting device 10, a spoke period occurs in which the color reproducibility of the light of each color output from the color wheel 53 cannot be obtained.

[0062] Specifically, there is a boundary 53b between the color selection areas 53A, 53B, 53C, and 53D on the color wheel 53. Figure 6 As shown, 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. Therefore, during the period T' (= T2'-T1') when the boundary 53b crosses the incident spot S2 of the light incident on the color wheel 53, the light is simultaneously incident on two color selection areas (for example, the yellow area 53A and the red area 53B) across the boundary 53b, and the light after the colors of the two color selection areas are mixed is output from the color wheel 53 and emitted from the lighting device 10. In addition, during Figure 6 In the figure, the incident light spot S2 is represented by a true circle, but in fact the shape of the light spot is determined by the configuration of the light source device, etc.

[0063] Such mixed color light cannot obtain color reproducibility for any color of each color selection area 53A, 53B, 53C, 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 during the spoke period as an unused period not used for color reproduction of the image.

[0064] Generally speaking, if the spoke period T' (= T2'-T1') is long, the usable period of the emitted light from the lighting device 10 (light irradiation device) becomes shorter, which is inefficient. In particular, as in the present embodiment, when the emitted light from the lighting device 10 is used for image projection, if the spoke period T' is long, the time required for color reproduction of each color in the projected image becomes shorter, which affects the color reproduction of the image, especially the grayscale reproduction. Specifically, artifacts are generated, and the color gradation cannot be smoothly reproduced. Therefore, in the past, the spoke period T' was shortened as much as possible by reducing the width of the boundary portion 53b or reducing the width of the incident light spot S2.

[0065] However, as in the present embodiment, in a configuration in which a light beam (overlapping light) formed by overlapping light F1, F2 (separate light) from each light source unit LS1, LS2 passing through a plurality of different light paths (separate light paths) is incident on the color wheel 53, the spoke period is more likely to become longer than in a configuration in which non-overlapping light (light consisting of only one single light) is incident on the color wheel 53.

[0066] Specifically, in this configuration, it is difficult to overlap the lights F1 and F2 from the light source units LS1 and LS2 in such a way that the incident light spots on the color wheel 53 completely overlap (eg, Figure 6 As shown in FIG. 1 , the incident light spot is formed into a single incident light spot. Therefore, Figure 7 As shown, the incident light spot S21 of the light F1 from the first light source unit LS1 on the color wheel 53 is offset in the transverse direction (i.e., the rotation direction A of the color wheel 53) relative to the incident light spot S22 of the light F2 from the second light source unit LS2 on the color wheel 53.

[0067] The width W of the incident spot of the overlapping light of the light F1 and F2 in the offset state is larger than the width W' of the incident spot S2 of the non-overlapping light (the light composed of only one single light). Therefore, in the configuration in which the overlapping light of the light 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 the configuration in which the non-overlapping light is incident on the color wheel 53, and the spoke period is correspondingly longer.

[0068] Here, observation is made while the boundary 53 b crosses the incident spot portions W1 and W2 on the color wheel 53 composed of only the individual lights F1 and F2 that constitute a part of the superimposed light of the lights F1 and F2.

[0069] For example, when observing the period (T3-T1) in which the boundary 53B crosses the part W1 of the incident light spot S21 composed of only the light F1, the boundary 53b exists in the incident light spot S21 of the light F1 during the period (T3-T1), and the light F1 is simultaneously incident on two color selection areas (for example, the yellow area 53A and the red area 53B) straddling the boundary 53b. Therefore, the color selection light of the light F1 becomes a mixed color state, and the color selection light including the overlapping light of the light F1 also becomes a mixed color state as a whole. Therefore, in the case where the color selection light of the overlapping light of the light F1 and the light F2 continues to be emitted during the period (T3-T1), it is necessary to treat the period (T3-T1) as a spoke period.

[0070] However, during this period (T3-T1), for the other light F2, there is no boundary portion 53b in its incident light spot S22. Therefore, the color selection light of the other light F2 is not mixed. Therefore, in the present embodiment, for the period (T3-T1) in which the boundary portion 53b crosses the portion W1 of the incident light spot S21 on the color wheel 53 consisting of only one light F1 of the overlapping lights constituting the lights F1 and F2, emission control is performed such that the color selection light of the other light F2 is emitted from the light integrator rod 3, and the color selection light of the one light F1 is not emitted from the light integrator rod 3. This emission control can be easily realized by, for example, light source control to light up the LED light source 11 of the second light source unit LS2 of the other light F2 and turn off only the LED light source 11 of the first light source unit LS1 of the one light F1.

[0071] Thus, during the period (T3-T1), the color selection light including the color-mixed light F1 and only the color selection light F2 without color mixing is emitted from the light integrator rod 3. As a result, since the color selection light without color mixing is emitted during the period (T3-T1), it is not necessary to process it as a spoke period. Thus, compared with the case where the color selection light of the overlapping light F1 and F2 is continuously emitted during the period (T3-T1), the spoke period can be shortened.

[0072] The same is true for the period (T2-T4) in which the boundary 53b crosses the portion W2 of the incident light spot S22 composed of only the light F2. That is, during this period (T2-T4), the boundary 53b exists in the incident light spot S22 of the light F2, and the light F2 is simultaneously incident on two color selection areas (for example, the yellow area 53A and the red area 53B) straddling the boundary 53b. Therefore, the color selection light of the light F2 becomes a mixed color state, and the color selection light including the overlapping light of the light F2 also becomes a mixed color state as a whole. Therefore, in the case where the color selection light of the overlapping light of the light F1 and F2 is continuously emitted during this period (T2-T4), it is necessary to treat this period (T2-T4) as a spoke period.

[0073] However, in this period (T2-T4), for the other light F1, there is no boundary portion 53b in its incident light spot S21. Therefore, the color selection light of the other light F1 is not mixed. Therefore, in this embodiment, for the period (T2-T4) in which the boundary portion 53b crosses the portion W2 of the incident light spot S22 on the color wheel 53 composed of only one light F2 of the overlapping lights constituting the lights F1 and F2, the emission control is performed so that the color selection light of the other light F1 is emitted from the light integrator rod 3, and the color selection light of the one light F2 is not emitted from the light integrator rod 3. This emission control can be easily realized by, for example, light source control to light up the LED light source 11 of the first light source unit LS1 of the other light F1 and turn off only the LED light source 11 of the second light source unit LS2 of the one light F2.

[0074] Thus, during the period (T2-T4), the color selection light including the color-mixed light F2 and only the color selection light F1 without color mixing is emitted from the light integrator rod 3. As a result, since the color selection light without color mixing is emitted during the period (T2-T4), it is not necessary to process it as a spoke period. Thus, compared with the case where the color selection light of the overlapping light F1 and F2 is continuously emitted during the period (T2-T4), the spoke period can be shortened.

[0075] In addition, for the period (T4-T3) when the incident light spots S21 and S22 of the light F1 and F2 are overlapped with each other, the boundary portion 53b exists in any of the incident light spots S21 and S22, and the color selection light of any of the light F1 and F2 is in a mixed color state. Therefore, the color selection light without mixed color cannot be emitted during this period (T4-T3), so it is treated as a spoke period. Therefore, the spoke period T of this embodiment is only the period (T4-T3) when the incident light spots S21 and S22 of the light F1 and F2 are overlapped with each other.

[0076] The spoke period T of this embodiment is greater than the case where the incident light spots S21 and S22 of the light F1 and F2 on the color wheel 53 completely overlap (eg Figure 6 The spoke period T' is shorter in the case of a single incident light spot (shown in FIG. 1 ). Therefore, if the spoke period is shortened first, the incident light spots S21 and S22 of the lights F1 and F2 on the color wheel 53 may be intentionally staggered. The amount of staggering at this time is appropriately set by comparing the advantage of a shorter spoke period and the disadvantage of a smaller overlapping area of ​​the incident light spots of the lights F1 and F2.

[0077] In the present embodiment, in order to implement the light source control for shortening 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, during the display of a blue image, in order to appropriately generate blue light during the period by synchronizing the phosphor wheel 17 and the color wheel 53, and for the DMD 101 to operate in a manner that appropriately displays a blue image during the period, it is also necessary to synchronize the operation of the DMD 101. Moreover, in the present embodiment, in order to further implement the light source control for shortening 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.

[0078] There are many methods for adjusting synchronization, and one example is shown below.

[0079] First, if Figure 8 As shown in (a), the driving current waveform and light output waveform of the LED light sources 11 of the two light source units LS1 and LS2 are observed with an oscilloscope. For example, suppose that the LED light sources 11 of the two light source units LS1 and LS2 are turned on during the display of a blue image. At this time, the same driving current waveform is input to the LED light sources 11 of the two light source units LS1 and LS2, and during the lighting period of the LED light sources 11 of the two light source units LS1 and LS2, 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 light spots S1 and S2. Specifically, as Figure 8 As shown in FIG. 1 , in the light output waveform, periods Ts1 and Ts2 of light output decrease are generated before and after the period of obtaining high light output, 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 the timing is not optimized, the timing of adjacent colors will be offset, and the correct color cannot be reproduced.

[0080] Next, in this embodiment, the light output waveform at this time is observed using an oscilloscope in a state where 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. Figure 8 As shown in (b), the timing t1 and t4 of the light output drop at this time are measured. In addition, the light output waveform at this time is observed with an oscilloscope while 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. Then, as Figure 8 As shown in (c), the timings t3 and t2 when the light output decreases are measured. These timings t1 to T4 are related to Figure 7Therefore, the spoke period T (= t4 - t3) can be obtained from the timings t1 to t4, and the spoke period can be shortened by controlling the light sources of the two light source units LS1 and LS2 based on the timings t1 to t4.

[0081] Although preferred embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned specific embodiments, and various modifications and changes can be made within the scope of the concept of the present invention as described in the scope of rights unless otherwise specified in the above description.

[0082] The above description is just an example, and the following various methods all have unique effects.

[0083] [First method]

[0084] The first mode is a light irradiation device (e.g., lighting device 10), comprising: a plurality of color selection parts (e.g., color selection areas 53A, 53b, 53C, 53D) corresponding to different colors are moved to sequentially cross the overlapping light paths through which overlapping light passes, wherein the overlapping light is formed by overlapping a plurality of separate light paths that are different from each other (e.g., light F1 from a first light source unit LS1 and light F2 from a second light source unit LS2), and an emission part (e.g., a light integrator rod 3), which sequentially emits each color selection light (e.g., yellow light, red light, green light, blue light) obtained by respectively injecting the overlapping light into the plurality of color selection parts, wherein the light irradiation device is characterized in that it also has a control part (e.g., CPU 801, etc.), which performs The emission control is that an incident light spot (e.g., S21) of a single light (e.g., light F1) constituting a part of the overlapping light on the color selection movable part is offset in a transverse direction of the plurality of color selection parts (e.g., a rotation direction A of the color wheel 53) relative to an incident light spot (e.g., S22) of other single light (e.g., light F2) constituting the overlapping light on the color selection movable part, and during a period (e.g., T3-T1) in which a boundary portion 53b existing between the plurality of color selection parts transverses an incident light spot portion (e.g., W1) on the color selection movable part constituted only by the portion of the single light, the color selection light of the other single light is emitted from the emission part, while the color selection light of the portion of the single light is not emitted from the emission part.

[0085] Generally, in a light irradiation device that moves a plurality of color selection parts on a color selection moving member in a manner that crosses the optical path of light incident on the color selection moving member and sequentially emits each color selection light emitted from each color selection part, a spoke period occurs in which the color reproducibility of the emitted color selection light cannot be obtained. Specifically, there is a boundary part between the plurality of color selection parts on the color selection moving member, and the width of the boundary part is generally smaller than the width of the incident light spot of the light incident on the color selection moving member. Therefore, during the period in which the boundary part crosses the incident light spot of the light incident on the color selection moving member, the light is simultaneously incident on two color selection parts across the boundary part, and the color selection lights of the two color selection parts are emitted from the light emitting device in a mixed color state. Such mixed color light cannot obtain color reproducibility for any color selection light. Therefore, this period is regarded as a spoke period, and in a subsequent device (e.g., an image projection device) that receives the emitted light (the color selection lights sequentially output) from the light irradiation device, for example, the emitted light from the light irradiation device is treated as an unused period that is not used for color reproduction of an image. Therefore, if the spoke period is long, the use period of the emitted light from the light irradiation device in the subsequent device becomes short, which is inefficient. Therefore, in the past, the spoke period was shortened as much as possible by reducing the width of the boundary portion or the width of the incident light spot.

[0086] However, in a configuration in which a plurality of individual lights passing through a plurality of different individual light paths are overlapped and incident on the color selection moving part, as in the lighting device described in Patent Document 1, the spoke period is often longer than in a configuration in which non-overlapping light (light consisting of only one individual light) is incident on the color selection moving part. Specifically, in this configuration, it is difficult to overlap a plurality of individual lights passing through a plurality of individual light paths in such a way that the incident light spots on the color selection moving part completely overlap. Therefore, the incident light spots on the color selection moving part of a part of the individual lights constituting the overlapped light are shifted in a direction transverse to the plurality of color selection parts on the color selection moving part relative to the incident light spots on the color selection moving part of the other individual lights. The width of the incident light spot of the overlapped light in this shifted state (the length of the incident light spot in the transverse direction) is greater than the width of the incident light spot of the non-overlapping light (light consisting of only one individual light). Therefore, in the configuration in which overlapping light is incident on the color selection moving member, compared with the configuration in which non-overlapping light is incident on the color selection moving member, the period in which the boundary crosses the incident light spot of the light incident on the color selection moving member becomes longer, and the spoke period becomes longer accordingly.

[0087] Here, if we observe the period when the boundary portion crosses the incident light spot portion on the color selection moving part composed of only a part of the individual light constituting the overlapping light, then the boundary portion exists in the incident light spot of the part of the individual light, and the part of the individual light simultaneously enters the two color selection portions across the boundary portion. Therefore, the color selection light of the part of the individual light becomes a mixed color state, and the color selection light of the overlapping light including the part of the individual light also becomes a mixed color state as a whole, so this period is also treated as a spoke period. However, during this period, for the other individual light constituting the above-mentioned overlapping light, there is no boundary portion in its incident light spot, and only one of the color selection portions exists. Therefore, the color selection light of the other individual light is not mixed.

[0088] Therefore, in this method, for the period when the boundary portion crosses the incident light spot portion on the color selection moving part composed of only the individual light constituting a part of the overlapping light, emission control is performed such that the color selection light of other individual light is emitted from the emission portion, and the color selection light of a part of the individual light is not emitted from the emission portion. Therefore, the color selection light emitted from the emission portion during this period is composed of only the color selection light of other individual light that is not mixed in color, without including the color selection light of the part of the individual light that is mixed in color. As a result, during this period, the color selection light that is not mixed in color is emitted from the emission portion, and since it is not necessary to treat it as a spoke period, the spoke period can be shortened.

[0089] [Second method]

[0090] The second method is that in the first method, there are multiple light sources (for example, a first light source unit LS1 and a second light source unit LS2) that respectively output the multiple individual lights. In the emission control, the light source that outputs the part of the individual lights is stopped from outputting, so that the color selection light of the part of the individual lights is not emitted from the emission portion.

[0091] Thereby, the above-mentioned injection control can be realized by simple control.

[0092] [Third Method]

[0093] The third mode is in the second mode, characterized in that: the multiple light sources include a blue light source (such as LED light source 11) that outputs blue light in a blue wavelength region, and a wavelength conversion moving component having a movable wavelength conversion portion (such as phosphor wheel 17) and a reflecting portion, so that the wavelength conversion portion (such as phosphor regions 17A, 17B) that emits wavelength converted light of a wavelength band longer than the blue wavelength region by injecting the blue light and the reflecting portion (such as excitation light reflecting region 17C) that reflects the blue light sequentially cross the separate optical path through which the blue light passes, and the movement of the wavelength conversion moving component is synchronized with the movement of the color selection moving component.

[0094] Thus, in a light irradiation device that sequentially emits blue light and light of a wavelength band longer than the blue wavelength region, the spoke period can be shortened.

[0095] [Fourth Method]

[0096] The fourth mode is any one of the first to third modes, characterized in that: the incident light spot portion is a portion of the incident light spot located on the upstream side of the direction transverse to the boundary portion, or a portion of the incident light spot located on the downstream side, or both, among each incident light spot on the color selection movable component in the multiple separate lights constituting the overlapping light.

[0097] This makes it easier to control the injection while shortening the spoke period.

[0098] [Fifth Method]

[0099] A fifth aspect is any one of the first to fourth aspects, wherein the plurality of color selection sections include a plurality of light transmission filter sections having spectral transmittances different from each other.

[0100] Thereby, a plurality of color selection sections can be easily obtained.

[0101] [Sixth Method]

[0102] The sixth method is characterized in that, in an image projection device 100 having a light irradiation device (e.g., an illumination device 10) and an image generating unit (e.g., DMD 101) that generates an image using light emitted from the light irradiation device, any one of the first to fifth methods is used as the light irradiation device.

[0103] Thus, it is possible to provide an image projection device having a short spoke period.

Claims

1. A light irradiation device, characterized in that include: a color selection moving member that moves a plurality of color selection portions corresponding to mutually different colors to sequentially cross a superimposed optical path through which superimposed light passes, the superimposed light being formed by superimposing a plurality of individual lights passing through a plurality of mutually different individual optical paths; and an emitting unit that sequentially emits each color selected light obtained by the superimposed light being incident on the plurality of color selecting units respectively, The incident light spot of the single light constituting a part of the superimposed light on the color selection moving member is offset in a transverse direction of the plurality of color selection parts relative to the incident light spots of the other single light constituting the superimposed light on the color selection moving member. And it has a control unit, which performs emission control in which, while a boundary portion existing between the plurality of color selection portions intersects an incident light spot portion on the color selection movable member composed of only the portion of the single light, the color selection light of the other single lights is emitted from the emission unit, while the color selection light of the portion of the single light is not emitted from the emission unit.

2. The light irradiation device according to claim 1, characterized in that: having a plurality of light sources for respectively outputting the plurality of individual lights, In the emission control, the light source that outputs the part of the individual light stops outputting the light, so that the color selection light of the part of the individual light is not emitted from the emission unit.

3. The light irradiation device according to claim 2, characterized in that: The plurality of light sources include a blue light source that outputs blue light in a blue wavelength region, and a wavelength conversion moving part having a movable wavelength conversion part and a reflecting part, so that the wavelength conversion part that emits wavelength converted light of a wavelength band longer than the blue wavelength region by injecting the blue light and the reflecting part that reflects the blue light sequentially cross the single optical path through which the blue light passes, The movement of the wavelength conversion moving part is synchronized with the movement of the color selection moving part.

4. The light irradiation device according to any one of claims 1 to 3, characterized in that: The incident light spot portion is the portion of the incident light spot located on the most upstream side in the direction intersecting the boundary portion, the portion of the incident light spot located on the most downstream side, or both of the portions of the incident light spot located on the most upstream side, among the incident light spots on the color selection moving part in the multiple separate lights constituting the overlapping light.

5. The light irradiation device according to any one of claims 1 to 3, characterized in that: The plurality of color selection portions include a plurality of light-transmitting filter portions having spectral transmittances different from each other.

6. An image projection device, characterized in that include: Light irradiation device and an image generating unit that generates an image using the light emitted from the light irradiation device, As the light irradiation device, the light irradiation device according to any one of claims 1 to 3 is used.

Images