JP6413409B2 - Lighting device, projector, and projector control method - Google Patents

Description

  The present invention relates to an illumination device, a projector, and a projector control method.

  In recent years, a light source device using a phosphor has been used in a projector (see, for example, Patent Document 1). In this light source device, the uniformity of the excitation light intensity irradiated to the phosphor layer is enhanced by using a homogenizer.

JP2012-118302A

  However, in the above prior art, for example, when the intensity of the excitation light is reduced due to some cause such as deterioration or failure of the excitation light source, there is a problem that the fluorescence intensity is reduced and the display image becomes dark.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an illumination device, a projector, and a projector control method capable of suppressing a decrease in fluorescence intensity.

According to the first aspect of the present invention, the light source device that emits the excitation light, the first multi-lens array on which the excitation light is incident, and the second multi-lens provided at the rear stage of the first multi-lens array. Fluorescence is generated by the excitation light emitted from the lens array, the condensing optical system provided after the second multi-lens array, and the condensing optical system provided after the condensing optical system. and a phosphor layer which, when the intensity of the excitation light is lower than a predetermined intensity, by widening the spacing between the first multi-lens array and the second multi-lens array, the phosphor layer lighting device is provided comprising a gap adjusting device Ru to shrink the size of the spot of the excitation light formed thereon.

  According to the illumination device according to the first aspect, when the intensity of the excitation light is reduced for some reason, the interval between the multi-lens array between the first multi-lens array and the second multi-lens array is increased. Thus, the size of the excitation light spot formed on the phosphor layer can be reduced. As a result, the area of the fluorescent light emitting region is reduced, so that the fluorescent light generated in the fluorescent material layer is efficiently taken in by the optical system provided in the subsequent stage of the fluorescent material layer. Therefore, by improving the use efficiency of the fluorescence, it is possible to reduce the influence due to the intensity reduction (output reduction) of the excitation light.

  Hereinafter, the size of the excitation light spot formed on the phosphor layer may be referred to as the excitation light size. In addition, the distance between the first multi-lens array and the second multi-lens array may be referred to as an inter-lens distance.

In the first aspect, it is preferable that an optical sensor for detecting the intensity of fluorescence emitted from the phosphor layer is further provided, and the interval adjusting device adjusts the interval based on a signal from the optical sensor.
According to this configuration, the intensity of excitation light can be indirectly detected from the intensity of fluorescence.

In the first aspect, it is preferable that an optical sensor for detecting the intensity of the excitation light is further provided, and the interval adjusting device adjusts the interval based on a signal from the optical sensor.
According to this configuration, the interval can be accurately adjusted based on the intensity of the excitation light.

In the first aspect, it is preferable to further include a light source control device capable of controlling the intensity of the excitation light among the first intensity, the second intensity, and the third intensity.
According to this configuration, for example, the intensity of the excitation light can be adjusted between the normal driving, the energy saving driving, and the OFF driving states. Although the intensity of the excitation light is reduced during energy saving driving, the use efficiency of fluorescence can be increased by adjusting the size of the excitation light, so that the influence due to the decrease in the intensity of the excitation light can be reduced.

  According to the second aspect of the present invention, an illumination device that emits illumination light, a light modulation device that forms image light by modulating the illumination light according to image information, and projection optics that projects the image light And a projector in which the illumination device is the illumination device according to the first aspect.

  According to the projector according to the second aspect, since the illumination device according to the first aspect is provided, a decrease in brightness of the display image due to a decrease in excitation light intensity is reduced. Therefore, the projector can perform display with excellent image quality.

According to the third aspect of the present invention, a light source device that emits excitation light, a first multi-lens array on which the excitation light is incident, and a second multi-lens that is provided after the first multi-lens array. In a control method of a projector including a lens array, a condensing optical system provided at a subsequent stage of the second multi-lens array, and a phosphor layer provided at a subsequent stage of the condensing optical system. A step of detecting the intensity of the fluorescence emitted from the phosphor layer, and a size of the spot of the excitation light formed on the phosphor layer when the intensity of the fluorescence is smaller than a predetermined intensity. so as to reduce, control method of a projector including the steps of greater than a predetermined distance the spacing between the first multi-lens array and the second multi-lens array is provided

  According to the projector control method of the third aspect, the excitation light size can be reduced by increasing the inter-lens distance when the excitation light intensity decreases due to some cause. Thereby, the fluorescence produced | generated by the fluorescent substance layer comes to be efficiently taken in with the optical system provided in the back | latter stage of a fluorescent substance layer. Therefore, by improving the use efficiency of the fluorescence, it is possible to reduce the influence due to the intensity reduction (output reduction) of the excitation light.

According to the fourth aspect of the present invention, the light source device that emits the excitation light, the first multi-lens array on which the excitation light is incident, and the second multi-lens provided at the subsequent stage of the first multi-lens array. In a control method of a projector including a lens array, a condensing optical system provided at a subsequent stage of the second multi-lens array, and a phosphor layer provided at a subsequent stage of the condensing optical system. there are, step a, the second intensity intensity of the excitation light from the first intensity to change the intensity of the excitation light to a second intensity less than the first intensity or al the first intensity Between the first multi-lens array and the second multi-lens array so as to reduce the size of the spot of the excitation light formed on the phosphor layer. Is greater than the predetermined interval And Kusuru steps, the control method of a projector including a is provided.

  According to the projector control method of the fourth aspect, for example, when the intensity of the excitation light is suppressed by selecting the energy saving drive mode, the excitation light size can be reduced by increasing the distance between the lenses. Thereby, the fluorescence produced | generated by the fluorescent substance layer comes to be efficiently taken in with the optical system provided in the back | latter stage of a fluorescent substance layer. Therefore, by improving the use efficiency of the fluorescence, it is possible to reduce the influence due to the intensity reduction (output reduction) of the excitation light.

FIG. 2 is a plan view illustrating a schematic configuration of the projector according to the first embodiment. The figure which shows schematic structure of the illuminating device which concerns on 1st Embodiment. The figure which shows schematic structure of a space | interval adjustment apparatus. The figure which shows schematic structure of a sensor unit. The front view which showed the arrangement position of the mirror with respect to a polarization converting element. FIG. 3 is a flowchart showing the operation of the projector according to the first embodiment. The flowchart figure which shows operation | movement of the projector of 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In addition, in the drawings used in the following description, in order to make the features easy to understand, there are cases where the portions that become the features are enlarged for the sake of convenience, and the dimensional ratios of the respective components are not always the same as the actual ones. Absent.

(First embodiment)
First, an example of a projector according to the present embodiment will be described. The projector according to the present embodiment is a projection type image display device that displays a color image (image) on a screen (projection surface) SCR. The projector 1 uses three light modulation devices corresponding to each color light of red light, green light, and blue light. The projector uses a semiconductor laser (laser light source) that can obtain light with high luminance and high output as the light source of the illumination device.

(projector)
FIG. 1 is a plan view showing a schematic configuration of a projector according to the present embodiment. As shown in FIG. 1, the projector 1 includes an illumination device 2, a color separation optical system 3, a light modulation device 4R, a light modulation device 4G, a light modulation device 4B, a combining optical system 5, and a projection optical system 6. It has.

  The color separation optical system 3 is for separating the illumination light WL into red light LR, green light LG, and blue light LB. The color separation optical system 3 includes a first dichroic mirror 7a and a second dichroic mirror 7b, a first total reflection mirror 8a, a second total reflection mirror 8b, a third total reflection mirror 8c, and a first A relay lens 9a and a second relay lens 9b are roughly provided.

  The first dichroic mirror 7a has a function of separating the illumination light WL from the illumination device 2 into red light LR and other light (green light LG and blue light LB). The first dichroic mirror 7a transmits the separated red light LR and reflects other light (green light LG and blue light LB). On the other hand, the second dichroic mirror 7b has a function of separating other light into green light LG and blue light LB. The second dichroic mirror 7b reflects the separated green light LG and transmits the blue light LB.

  The first total reflection mirror 8a is disposed in the optical path of the red light LR, and reflects the red light LR transmitted through the first dichroic mirror 7a toward the light modulation device 4R. On the other hand, the second total reflection mirror 8b and the third total reflection mirror 8c are arranged in the optical path of the blue light LB, and guide the blue light LB transmitted through the second dichroic mirror 7b to the light modulation device 4B. The green light LG is reflected from the second dichroic mirror 7b toward the light modulation device 4G.

  The first relay lens 9a and the second relay lens 9b are arranged on the light emission side of the second total reflection mirror 8b in the optical path of the blue light LB. The first relay lens 9a and the second relay lens 9b function to compensate for the optical loss of the blue light LB caused by the optical path length of the blue light LB being longer than the optical path lengths of the red light LR and the green light LG. have.

  The light modulation device 4R modulates the red light LR according to the image information, and forms image light corresponding to the red light LR. The light modulation device 4G modulates the green light LG according to the image information, and forms image light corresponding to the green light LG. The light modulation device 4B modulates the blue light LB according to the image information, and forms image light corresponding to the blue light LB.

  For example, a transmissive liquid crystal panel is used for the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B. In addition, a pair of polarizing plates (not shown) are arranged on the incident side and the emission side of the liquid crystal panel so that only linearly polarized light in a specific direction passes therethrough.

  Further, a field lens 10R, a field lens 10G, and a field lens 10B are disposed on the incident side of the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B, respectively. The field lens 10R, the field lens 10G, and the field lens 10B are for parallelizing the red light LR, the green light LG, and the blue light LB incident on the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B, respectively. It is.

  Image light from the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B is incident on the combining optical system 5. The combining optical system 5 combines the image light corresponding to the red light LR, the green light LG, and the blue light LB, and emits the combined image light toward the projection optical system 6. For example, a cross dichroic prism is used for the combining optical system 5.

  The projection optical system 6 includes a projection lens group, and enlarges and projects the image light combined by the combining optical system 5 toward the screen SCR. As a result, an enlarged color image is displayed on the screen SCR.

(Lighting device)
Then, the illuminating device 2 which concerns on one Embodiment of this invention is demonstrated. FIG. 2 is a diagram showing a schematic configuration of the illumination device 2. As shown in FIG. 2, the illuminating device 2 is an optical system including an array light source 21A, a collimator optical system 22, an afocal optical system 23, a homogenizer optical system 24, a distance adjusting device 40, and a polarization separation element 50A. The element 25A, the first pickup optical system 26, the fluorescent light emitting element 27, the phase difference plate 28, the second pickup optical system 29, the diffuse reflection element 30, the integrator optical system 31, and the polarization conversion element 32 And a superimposing optical system 33.

  An array light source 21A, a collimator optical system 22, an afocal optical system 23, a homogenizer optical system 24, an optical element 25A, a phase difference plate 28, a second pickup optical system 29, and a diffuse reflection element 30 Are arranged side by side on the optical axis ax1 in a state where their optical centers coincide with the optical axis ax1 shown in FIG. On the other hand, the fluorescent light emitting element 27, the first pickup optical system 26, the optical element 25A, the integrator optical system 31, the polarization conversion element 32, and the superimposing optical system 33 have their optical centers in FIG. The optical axis ax <b> 2 is aligned with the optical axis ax <b> 2. The optical axis ax1 and the optical axis ax2 are in the same plane and are orthogonal to each other.

  The array light source 21A corresponds to the light source device in the claims. The array light source 21A includes a first semiconductor laser 211 that is a first light source and a second semiconductor laser 212 that is a second light source. The plurality of first semiconductor lasers 211 and the plurality of second semiconductor lasers 212 are arranged in an array in one plane orthogonal to the optical axis ax1.

  The first semiconductor laser 211 emits blue light BL ′. The first semiconductor laser 211 emits laser light having a peak wavelength of 460 nm, for example, as blue light BL ′. The second semiconductor laser 212 is a laser light source for excitation light that emits excitation light BL. The second semiconductor laser 212 emits laser light having a peak wavelength of 440 nm, for example, as the excitation light BL.

  The excitation light BL and the blue light BL ′ are emitted from the array light source 21A toward the polarization separation element 50A.

  Excitation light BL and blue light BL ′ emitted from the array light source 21 </ b> A enter the collimator optical system 22. The collimator optical system 22 converts the excitation light BL and the blue light BL ′ emitted from the array light source 21 </ b> A into parallel light beams. The collimator optical system 22 is composed of, for example, a plurality of collimator lenses 22a arranged in an array. The plurality of collimator lenses 22a are arranged corresponding to the plurality of first semiconductor lasers 211 and the plurality of second semiconductor lasers 212, respectively.

  Each excitation light BL and blue light BL ′ converted into a parallel light beam by passing through the collimator optical system 22 is incident on the afocal optical system 23. The afocal optical system 23 adjusts the beam diameters of the excitation light BL and the blue light BL ′. The afocal optical system 23 includes, for example, a convex lens 23a and a concave lens 23b.

  Excitation light BL and blue light BL ′ whose beam diameters are adjusted by passing through the afocal optical system 23 are incident on the homogenizer optical system 24. The homogenizer optical system 24 includes a first multi-lens array 24a and a second multi-lens array 24b. The first multi-lens array 24a includes a plurality of small lenses 24am, and the second multi-lens array 24b includes a plurality of small lenses 24bm corresponding to the plurality of small lenses 24am.

  The excitation light BL and blue light BL ′ that have passed through the homogenizer optical system 24 are incident on the optical element 25A. The optical element 25A is composed of, for example, a dichroic prism having wavelength selectivity. The dichroic prism has an inclined surface K that forms an angle of 45 ° with the optical axis ax1. The inclined surface K forms an angle of 45 ° with respect to the optical axis ax2. The optical element 25A is arranged so that the intersection of the optical axes ax1 and ax2 orthogonal to each other coincides with the optical center of the inclined surface K.

  On the inclined surface K, a polarization separation element 50A having wavelength selectivity is provided. The polarization separation element 50A separates the excitation light BL and the blue light BL 'into an S polarization component and a P polarization component for the polarization separation element 50A.

  In addition, the polarization separation element 50A has a color separation function that transmits fluorescent light YL, which is second light having different wavelength bands, from excitation light BL and blue light BL ′, which will be described later, regardless of the polarization state. Yes.

  Here, the excitation light BL and the blue light BL ′ are coherent linearly polarized light. Further, the excitation light BL and the blue light BL 'have different polarization directions when entering the polarization separation element 50A.

  Specifically, the polarization direction of the excitation light BL coincides with the polarization direction of the S polarization component reflected by the polarization separation element 50A. On the other hand, the polarization direction of the blue light BL ′ coincides with the polarization direction of the P-polarized component transmitted by the polarization separation element 50A.

  Therefore, the excitation light BL incident on the polarization separation element 50A is reflected toward the fluorescent light emitting element 27 as S-polarized excitation light BLs. On the other hand, the blue light BL ′ incident on the polarization separation element 50 </ b> A is transmitted toward the diffuse reflection element 30 as P-polarized blue light BL′p.

  The S-polarized excitation light BLs emitted from the polarization separation element 50 </ b> A is incident on the first pickup optical system 26. The first pickup optical system 26 condenses a plurality of light beams (excitation light BLs) emitted from the second multi-lens array 24 b toward the phosphor layer 34, and on the phosphor layer 34. Superimpose. The first pickup optical system 26 corresponds to the condensing optical system in the claims.

  The first pickup optical system 26 includes, for example, a pickup lens 26a and a pickup lens 26b. The excitation light BLs emitted from the first pickup optical system 26 enters the fluorescent light emitting element 27. The fluorescent light emitting element 27 includes a phosphor layer 34, a substrate 35 that supports the phosphor layer 34, and a fixing member 36 that fixes the phosphor layer 34 to the substrate 35.

  The phosphor layer 34 is fixed to the substrate 35 by a fixing member 36 provided between the side surface of the phosphor layer 34 and the substrate 35. The surface of the phosphor layer 34 opposite to the side on which the excitation light BLs is incident is in contact with the substrate 35.

  The phosphor layer 34 includes a phosphor that is excited by absorbing the excitation light BLs having a wavelength of 440 nm, and the phosphor excited by the excitation light BLs is, for example, in a wavelength region of 500 to 700 nm as the second light. Fluorescent light (yellow light) YL having a peak wavelength is generated.

  It is preferable to use a material having excellent heat resistance and surface processability for the phosphor layer 34. As such a phosphor layer 34, for example, a phosphor layer in which phosphor particles are dispersed in an inorganic binder such as alumina, or a phosphor layer in which phosphor particles are sintered without using a binder is suitable. Can be used.

  On the side of the phosphor layer 34 opposite to the side on which the excitation light BLs is incident, a reflecting portion 37 as a first reflecting element is provided. The reflection unit 37 has a function of reflecting a part of the fluorescent light YL among the fluorescent light YL generated by the phosphor layer 34.

  A heat sink 38 is disposed on the surface of the substrate 35 opposite to the surface that supports the phosphor layer 34. In the fluorescent light emitting element 27, since heat can be radiated through the heat sink 38, thermal deterioration of the phosphor layer 34 can be prevented.

  Of the fluorescent light YL generated in the phosphor layer 34, a part of the fluorescent light YL is reflected by the reflecting portion 37 and emitted to the outside of the phosphor layer 34. In addition, among the fluorescent light YL generated in the fluorescent material layer 34, another part of the fluorescent light YL is emitted outside the fluorescent material layer 34 without passing through the reflecting portion 37. In this way, the fluorescent light YL is emitted from the phosphor layer 34.

  The fluorescent light YL emitted from the phosphor layer 34 is non-polarized light whose polarization direction is not uniform. The fluorescent light YL passes through the first pickup optical system 26 and then enters the polarization separation element 50A. The fluorescent light YL is transmitted from the polarization separation element 50 </ b> A toward the integrator optical system 31.

  The P-polarized blue light BL′p emitted from the polarization separation element 50 </ b> A enters the phase difference plate 28. The phase difference plate 28 is composed of a ¼ wavelength plate (λ / 4 plate) disposed in the optical path between the polarization separation element 50 </ b> A and the diffuse reflection element 30. Accordingly, the P-polarized blue light BL′p emitted from the polarization separation element 50A is incident on the phase difference plate 28 and converted into circularly-polarized blue light BL′c, and then the second pickup optical. The light enters the system 29.

  The second pickup optical system 29 condenses the blue light BL′c toward the diffuse reflection element 30 and includes, for example, a pickup lens 29a.

  The diffuse reflection element 30 diffuses and reflects the blue light BL′c emitted from the second pickup optical system 29 toward the polarization separation element 50A. Among them, as the diffuse reflection element 30, it is preferable to use an element that causes Lambert reflection of the blue light BL′c incident on the diffuse reflection element 30.

  The blue light BL′c diffusely reflected by the diffuse reflection element 30 is again incident on the phase difference plate 28, converted into S-polarized blue light BL ′s, and then incident on the polarization separation element 50 </ b> A. The S-polarized blue light BL ′s is reflected from the polarization separation element 50 </ b> A toward the integrator optical system 31.

  As a result, the blue light BL's is used as the illumination light WL together with the fluorescent light YL transmitted through the polarization separation element 50A. That is, the blue light BL's and the fluorescent light YL are emitted from the polarization separation element 50A in the same direction. Thereby, illumination light (white light) WL in which blue light BL's and fluorescent light (yellow light) YL are mixed is obtained.

  The illumination light WL emitted from the polarization separation element 50A enters the integrator optical system 31. The integrator optical system 31 includes, for example, a lens array 31a and a lens array 31b. The lens arrays 31a and 31b are composed of a plurality of lenses arranged in an array.

  The illumination light WL that has passed through the integrator optical system 31 enters the polarization conversion element 32. The polarization conversion element 32 includes a polarization separation film and a retardation plate. The polarization conversion element 32 converts the non-polarized fluorescent light YL into S-polarized light.

  The illumination light WL that has become S-polarized light by the polarization conversion element 32 enters the superimposing optical system 33. The superimposing optical system 33 superimposes the illumination light WL emitted from the polarization conversion element 32 in the illuminated area. For example, the superimposing optical system 33 includes a superimposing lens 33a. Thereby, the illuminance distribution in the illuminated area is made uniform.

  By the way, in the illumination device 2, when the intensity of the excitation light BLs emitted from the second semiconductor laser 212 decreases with time due to some cause such as failure or deterioration with time, the intensity of the fluorescent light YL decreases, and the screen The image projected on the SCR becomes dark.

  With respect to this problem, the illumination device 2 of the present embodiment includes a distance adjusting device 40 for adjusting the distance between the first multi-lens array 24a and the second multi-lens array 24b. In the initial state, the second multi-lens array 24b is disposed at the focal position of the small lens 24am included in the first multi-lens array 24a. In this case, a secondary light source image is formed on the second multi-lens array 24b. However, when the inter-lens distance is increased, the secondary light source image is formed at a position closer to the first multi-lens array 24a than to the second multi-lens array 24b. The light transmitted through each of the plurality of small lenses 24bm included in the second multi-lens array 24b is collected by the first pickup optical system 26 and forms an image at the tip of the phosphor layer 34. Corresponding to the difference in the formation position of the secondary light source image, the image formation position is closer to the phosphor layer 34 when the distance between the lenses is expanded than in the initial state. Therefore, the size of each light incident on the phosphor layer 34 is smaller when the inter-lens distance is increased than in the initial state. In this manner, the interval adjusting device 40 is formed on the phosphor layer 34 by changing the interval (inter-lens distance) between the first multi-lens array 24a and the second multi-lens array 24b. The spot size (excitation light size) of the excitation light BLs to be adjusted is adjusted.

  Next, a specific configuration of the interval adjusting device 40 will be described. FIG. 3 is a diagram showing a schematic configuration of the interval adjusting device 40.

  As shown in FIG. 3, the interval adjusting device 40 includes a base 51, a first holding part 52 that holds the lower part of the first multi-lens array 24a, and a first part that holds the lower part of the second multi-lens array 24b. 2 holding part 53, drive mechanism 54, sensor unit 60, and control device 55 which controls drive mechanism 54 based on the detection result of sensor unit 60 are included. The first holding unit 52 and the second holding unit 53 hold the lens arrays 24a and 24b at positions that do not block incident light on the lens.

  The base part 51 supports the first holding part 52 and the second holding part 53. The first holding part 52 is fixed to the upper surface 51 a of the base part 51. The second holding part 53 is disposed on the upper surface 51 a of the base part 51 in a state where a predetermined interval is held with respect to the first holding part 52. The second holding part 53 can be moved on the upper surface 51 a of the base part 51 by a driving mechanism 54 described later, and the distance between the second holding part 53 and the first holding part 52 can be adjusted. A spring member 56 is disposed between the first holding part 52 and the second holding part 53. The second holding portion 53 is in a state of being biased by a spring member 56 so as to increase the interval.

  The drive mechanism 54 includes a screw portion 54a and a drive portion 54b that drives the screw portion 54a. The screw portion 54 a is in contact with the side surface of the second holding portion 53 at the tip end portion. The drive part 54 b moves the screw part 54 a relative to the attachment part 57 on the upper surface 51 a of the base part 51. Thereby, as for the screw part 54a, the front-end | tip part moves along the left-right direction in FIG.

  When the tip of the screw portion 54a moves to the right in FIG. 3, the second holding portion 53 moves to the right. Further, when the distal end portion of the screw portion 54a moves leftward, the second holding portion 53 moves to the left side by the urging force of the spring member 56. In this way, the distance adjusting device 40 adjusts the distance between the lenses.

  In the present embodiment, the interval adjusting device 40 adjusts the inter-lens distance according to the intensity of the excitation light BLs. The interval adjusting device 40 includes a sensor unit 60 as a means for detecting the intensity of the excitation light BLs. The sensor unit 60 indirectly detects a change in the output of the excitation light BLs by detecting the intensity of the fluorescent light YL.

  In the present embodiment, a light amount monitoring mirror 42 is provided on the optical path between the integrator optical system 31 and the polarization conversion element 32. The light quantity monitor mirror 42 is disposed so as to form an angle of 45 ° with respect to the optical axis ax2. The light quantity monitor mirror 42 transmits a part of the incident light and reflects the rest. The light transmitted through the light quantity monitor mirror 42 enters the polarization conversion element 32, and the light reflected by the light quantity monitor mirror 42 enters the sensor unit 60. A detailed configuration of the sensor unit 60 will be described later.

FIG. 4 is a diagram showing a schematic configuration of the sensor unit 60. FIG. 5 is a front view showing the arrangement position of the mirror with respect to the polarization conversion element 32.
As shown in FIG. 4, the sensor unit 60 includes a sensor unit 61 and an optical filter 62. The optical filter 62 has an optical characteristic of transmitting the fluorescent light YL component of the illumination light WL and absorbing the blue light BL ′s component of the illumination light WL.

  The sensor unit 61 detects the light amount of the fluorescent light YL separated by the optical filter 62 out of the illumination light WL reflected by the light amount monitor mirror 42. The sensor unit 61 is electrically connected to the control device 55 and transmits a detection result. Based on the detection result of the sensor unit 61, the control device 55 controls the interval adjustment operation by the interval adjustment device 40 (drive mechanism 54) as described later.

  As shown in FIG. 5, the light quantity monitoring mirror 42 is held by a holding member 48 that is disposed so as to avoid the light incident region R of the polarization conversion element 32. The light incident region R of the polarization conversion element 32 is a region where each of a plurality of small light beams emitted from the integrator optical system 31 is incident.

  In the present embodiment, the light quantity monitoring mirror 42 is provided on the optical path of one light beam Z among the plurality of small light beams emitted from the integrator optical system 31. For this reason, even if a part of the illumination light WL is extracted by the light quantity monitoring mirror 42, illuminance unevenness does not occur on the light modulation devices 4R, 4G, and 4B that are the illuminated areas. Therefore, the light quantity monitoring mirror 42 is not necessarily a transflective mirror.

  Here, it is assumed that the amount of light emitted from the second semiconductor laser 212 is reduced due to a change with time when the projector is used. The concept of the countermeasure of the present embodiment for the decrease in the intensity of the fluorescent light YL that occurs in this case will be described based on the flowchart of FIG.

  The control device 55 indirectly detects the output change of the excitation light BLs based on the intensity change of the fluorescent light YL transmitted from the sensor unit 60. When the intensity of the fluorescent light YL decreases (step S1), the illuminance on the screen SCR decreases (step S2). When the control device 55 determines that the intensity of the fluorescent light YL (excitation light BLs) is lower than a predetermined intensity (threshold) (steps S1 and S2 in FIG. 6), an interval adjustment operation by the drive mechanism 54 is executed.

  The drive mechanism 54 moves the tip of the screw portion 54a to the left in FIG. Then, the second holding unit 53 moves to the left side, and between the first multi-lens array 24 a held by the first holding unit 52 and the second multi-lens array 24 b held by the second holding unit 53. (Step S3 in FIG. 6). Thereby, the size of the excitation light BLs is reduced (step S4 in FIG. 6).

  When the size of the excitation light BLs irradiated on the phosphor layer 34 is reduced, the size of the fluorescence light YL generated by the phosphor layer 34 is also reduced. Then, the fluorescent light YL emitted from the phosphor layer 34 is more efficiently taken into the subsequent optical system such as the first pickup optical system 26, the integrator optical system 31, and the superimposing lens 33a. That is, the utilization efficiency of the fluorescent light YL in the subsequent optical system is improved (step S5).

  Therefore, according to the illumination device 2 of the present embodiment, the utilization efficiency of the fluorescent light YL in the optical system provided in the subsequent stage of the phosphor layer 34 is improved by the control of the control device 55. Therefore, the influence by the intensity | strength fall of excitation light BLs is reduced, and the output fall of illumination light WL can be reduced.

  In the projector 1 of the present embodiment, the illuminance on the screen SCR is increased by the control of the control device 55 (step S6 in FIG. 6), and display with excellent image quality can be performed.

(Second Embodiment)
Next, the lighting device according to the second embodiment will be described. In the first embodiment, the case where the distance adjusting device 40 adjusts the distance between the lenses based on the detection result (excitation light output) of the sensor unit 60 has been described as an example. The function of the control device 55 is different from that in which the interval is adjusted without using 60 detection results. In the following description, the same reference numerals are given to the same configurations and members as in the first embodiment, and the detailed description thereof is omitted.

In the present embodiment, the control device 55 also functions as a light source control device that controls the intensity of the excitation light BLs among the first intensity, the second intensity, and the third intensity.
Here, the first intensity corresponds to the intensity of the excitation light BLs during normal driving, and the second intensity corresponds to the intensity of the excitation light BLs during low power consumption driving (hereinafter sometimes referred to as eco mode driving). The third intensity corresponds to the intensity (zero) of the excitation light BLs when the illumination device 2 is powered off. The second intensity is set lower than the first intensity (for example, about 20% to 50%).

  For example, the control device 55 controls the second intensity so as to control the intensity of the excitation light BLs among the first intensity, the second intensity, and the third intensity in accordance with an instruction from the user. The output of the semiconductor laser 212 is controlled.

  The control device 55 drives the excitation light BLs at the first intensity when performing normal driving according to the user's instruction, and supplies the excitation light BLs at the second intensity when performing eco-mode driving according to the user's instruction. The excitation light BLs is set to the third intensity (zero) when the power is turned off in accordance with a user instruction.

  Note that, as an instruction from the user, for example, an electrical signal generated when a switch provided in the projector 1 is switched by the user, or directly transmitted from the user to the control device 55 via an external device (computer). An electrical signal can be exemplified.

  Here, a specific flow at the time of eco-mode driving will be described based on the flowchart of FIG.

  For example, when the drive mode is changed (set) from the normal drive to the eco mode drive according to a user instruction, the control device 55 changes the intensity of the excitation light BLs from the first intensity to the second intensity (see FIG. 7 step S11). Accordingly, the output of the second semiconductor laser 212 that emits the excitation light BLs decreases (step S12 in FIG. 7).

  In response to the change in the intensity of the excitation light BLs from the first intensity to the second intensity (the output of the excitation light BLs has decreased), the control device 55 determines the interval by the interval adjustment device 40 (drive mechanism 54). Perform the adjustment operation.

  The distance adjusting device 40 increases the distance between the lenses (step S13 in FIG. 7), and thereby the size of the excitation light BLs is reduced (step S14 in FIG. 7).

  As a result, the fluorescent light YL emitted from the phosphor layer 34 is more efficiently captured by the subsequent optical system such as the first pickup optical system 26, the integrator optical system 31, and the superimposing lens 33a. . Therefore, according to the present embodiment, the utilization efficiency of the fluorescent light YL in the optical system provided in the subsequent stage of the phosphor layer 34 is improved by the control of the control device 55 (step S15 in FIG. 7). Moreover, since the fluorescent light YL can be efficiently generated even in the eco mode drive, the energy saving performance is excellent.

  As described above, since the projector according to the present embodiment includes the lighting device that has improved energy saving performance during the eco mode driving (step S16 in FIG. 7), the energy saving performance is high and the image quality is excellent.

  In addition, this invention is not necessarily limited to the thing of the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.

  For example, in the first embodiment, the case where the sensor unit 60 (the light amount monitoring mirror 42) detects the intensity of the fluorescent light YL in the optical path between the integrator optical system 31 and the polarization conversion element 32 is taken as an example. However, the position where light is extracted is not limited to this. For example, the reflected light of the screen SCR may be detected.

  In the first embodiment, the case where the sensor unit 60 detects the output change of the excitation light BLs indirectly by detecting the intensity of the fluorescent light YL is taken as an example. However, the intensity of the excitation light BLs is detected. Alternatively, the intensity of the excitation light BLs may be directly detected using a sensor unit. When the intensity of the excitation light BLs is directly detected, the reflected light from the half mirror disposed at the location where the excitation light BLs from the second semiconductor laser 212 is gathered may be detected.

  In the above-described embodiment, the second semiconductor laser 212 that emits laser light having a peak wavelength of 440 nm is used as the laser light source for excitation light, and the laser light having a peak wavelength of 460 nm is emitted to the laser light source for blue light. Although the case where the first semiconductor laser 211 is used has been illustrated, the peak wavelengths of the excitation light BL and the blue light BL ′ are not necessarily limited to such examples.

  In the above-described embodiment, the projector 1 including the three light modulation devices 4R, 4G, and 4B is exemplified. However, the projector 1 may be applied to a projector that displays a color image (image) with one light modulation device.

In addition, the shape, number, arrangement, material, and the like of the various components of the lighting device and the projector are not limited to the above-described embodiment, and can be changed as appropriate.
Moreover, although the example which mounted the illuminating device by this invention in the projector was shown in the said embodiment, it is not restricted to this. The lighting device according to the present invention can also be applied to lighting fixtures, automobile headlights, and the like.

  BL, BLs ... excitation light, 1 ... projector, 2 ... illumination device, 4R, 4G, 4B ... light modulation device, 6 ... projection optical system, 21A ... array light source (light source device), 24a ... first multi-lens array, 24b ... second multi-lens array, 26 ... first pickup optical system (condensing optical system), 34 ... phosphor layer, 40 ... interval adjustment device, 55 ... control device (light source control device), 60 ... sensor unit (Light sensor).

Claims (7)

A light source device that emits excitation light;
A first multi-lens array on which the excitation light is incident;
A second multi-lens array provided after the first multi-lens array;
A condensing optical system provided at a subsequent stage of the second multi-lens array;
A phosphor layer provided at a subsequent stage of the condensing optical system and generating fluorescence by the excitation light emitted from the condensing optical system ;
When the intensity of the excitation light is lower than a predetermined intensity, the gap formed between the first multi-lens array and the second multi-lens array is widened to form the phosphor layer. lighting device and a clearance adjusting device which Ru is reducing the size of the spot of the excitation light. Further comprising a light sensor for detecting the intensity of the fluorescence emitted from the phosphor layer,
The lighting device according to claim 1, wherein the interval adjusting device adjusts the interval based on a signal from the optical sensor. An optical sensor for detecting the intensity of the excitation light;
The lighting device according to claim 1, wherein the interval adjusting device adjusts the interval based on a signal from the optical sensor. The intensity of the excitation light, a first intensity, the first and the lower second intensity than the intensity, the less than the second intensity third light source that can be controlled with the strength The illumination device according to any one of claims 1 to 3, further comprising a control device. An illumination device that emits illumination light;
A light modulation device that forms image light by modulating the illumination light according to image information;
A projection optical system for projecting the image light,
The projector is the lighting device according to any one of claims 1 to 4. A light source device that emits excitation light, a first multi-lens array on which the excitation light is incident, a second multi-lens array that is provided at a subsequent stage of the first multi-lens array, and the second multi-lens A control method of a projector including an illumination device having a condensing optical system provided at a subsequent stage of the array, and a phosphor layer provided at a subsequent stage of the condensing optical system,
Detecting the intensity of fluorescence emitted from the phosphor layer;
When the fluorescence intensity is smaller than a predetermined intensity , the first multi-lens array and the second multi-lens are arranged so as to reduce the size of the spot of the excitation light formed on the phosphor layer. A method for controlling the projector, the method comprising: setting a distance between the arrays to be larger than a predetermined distance. A light source device that emits excitation light, a first multi-lens array on which the excitation light is incident, a second multi-lens array that is provided at a subsequent stage of the first multi-lens array, and the second multi-lens A control method of a projector including an illumination device having a condensing optical system provided at a subsequent stage of the array, and a phosphor layer provided at a subsequent stage of the condensing optical system,
And changing the intensity of the excitation light to a second intensity less than the first intensity or al the first intensity,
In response to the intensity of the excitation light being changed from the first intensity to the second intensity, the size of the spot of the excitation light formed on the phosphor layer is reduced. A method of controlling the projector, comprising: making an interval between the first multi-lens array and the second multi-lens array larger than a predetermined interval.

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