HK1152760B - Light source unit utilizing laser for light source and projector - Google Patents

Description

Light source device using laser light as light source and projector

Cross-referencing

The present invention is the whole contents of japanese patent application No. 2009-155452 filed on 30.6.2009 in 2009, including the specification, claims, drawings and abstract of the specification.

Technical Field

The present invention relates to a light source device using a laser beam as a light source and a projector including the light source device.

Background

In these days, data projectors are widely used as image projection apparatuses for reading and projecting image data or video data stored in a screen or a video image of a personal computer, or in a memory card or the like onto a screen. The projector condenses light emitted from a light source on a micromirror display element called a DMD (digital micromirror device) or a liquid crystal panel, thereby displaying a color image on a screen.

In such a projector, a high-luminance discharge lamp has been mainly used as a light source, and in recent years, many developments and proposals have been made to use a light emitting diode, a laser diode, an organic EL, a phosphor, or the like as a light source. For example, a light source device described in japanese patent application laid-open No. 2004-341105 includes: a fluorescent wheel (luminescent center) comprising a plate-like transparent base material on which a fluorescent layer is disposed; and a solid light source emitting ultraviolet rays, wherein the fluorescent wheel receives the ultraviolet rays and converts the ultraviolet rays into visible light. In the light source device described in jp 2004-341105 a, ultraviolet light as excitation light is irradiated to the phosphor layer formed on the phosphor wheel, and fluorescent light in red, green, and blue wavelength bands can be emitted.

However, since the emission efficiency of the red phosphor is much lower than that of the other phosphors, there is a problem that the luminance of red is insufficient.

Disclosure of Invention

In view of the above-described problems of the conventional art, an object of the present invention is to provide a light source device capable of improving the brightness of a screen, and a projector including the light source device, the light source device including: a fluorescent wheel having a fluorescent material of a type having a good luminous efficiency; a light source for exciting the phosphor; and a monochromatic light source that emits light in a wavelength band corresponding to a phosphor having a relatively low luminous efficiency.

One aspect of the present invention is a light source device including: a light emitting panel having a plurality of fan-shaped regions, each of the fan-shaped regions being formed with at least a layer of a phosphor that receives excitation light and emits light of a predetermined wavelength band and a transmission portion that transmits light; a first light source that irradiates the phosphor with excitation light; a second light source that emits light of a wavelength band different from the fluorescent light emitted from the phosphor layer and the excitation light emitted from the first light source; a condensing optical system that condenses light emitted from the light emitting panel and light emitted from the second light source on the same optical path; and a light source control unit that controls light emission of the first light source and the second light source.

Another aspect of the present invention is a projector including: a light source device; a display element; a light source side optical system for guiding light from the light source device to the display element; a projection optical system for projecting an image emitted from the display element onto a screen; and a projector control unit that controls the light source device and/or the display element, wherein the light source device is the light source device described in the above-described aspect.

The above objects, other objects, features and advantages of the present invention will become more apparent from the attached drawings and the following detailed description.

Drawings

Fig. 1 is an external perspective view showing a projector including a light source device according to an embodiment of the present invention.

Fig. 2 is a diagram showing a functional circuit module of a projector including a light source device according to an embodiment of the present invention.

Fig. 3 is a schematic plan view showing an internal structure of a projector including a light source device according to an embodiment of the present invention.

Fig. 4A and 4B are a front view and a top view partially in cross section of a fluorescent wheel according to an embodiment of the present invention.

Fig. 5 is a schematic plan view showing a light source device according to an embodiment of the present invention.

Fig. 6A and 6B are schematic front views of fluorescent wheels showing the first light source extinction range according to the embodiment of the present invention.

Fig. 7A, 7B, and 7C are timing charts showing the on-off timings of the first light source and the second light source of the light source control unit of the embodiment of the present invention.

Fig. 8A and 8B are schematic front views of fluorescent wheels in other forms in the light source device according to the embodiment of the present invention.

Fig. 9 is a schematic plan view showing a light source device according to a modification of the present invention.

Fig. 10 is a front view schematically showing a luminescent wheel of a light source device according to a modification of the present invention.

Detailed Description

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The following embodiments are intended to variously limit the techniques for carrying out the present invention, and the scope of the present invention is not limited to the following embodiments and the illustrated examples.

First, an outline of the configuration of the projector of the present invention will be described.

The projector 10 includes: a light source device 63; a display element 51; a cooling fan; a light source side optical system 62 for guiding light from the light source device 63 to the display element 51; a projection optical system 90 that projects an image emitted from the display element 51 on a screen; a projector control unit that controls the light source device 63 and/or the display element 51; and a light source control circuit 41 as light source control means for controlling the lighting timing of the first light source 72 and the second light source 82 of the light source device 63.

In the light source device 63, a dichroic mirror 151 that transmits the light source light transmitted through the luminescent wheel 71 and the luminescent light emitted from the luminescent wheel 71 and reflects the light from the second light source 82 is disposed at a position where the optical axis of the first light source 72 and the optical axis of the second light source 82 intersect. The fluorescent wheel 71 is prevented from being irradiated with light from the second light source 82 by the dichroic mirror 151.

The light source device 63 includes: a fluorescent wheel 71 having two semicircular sector-shaped regions adjacent to each other on a rotationally controllable transparent substrate, wherein a layer 131 of a fluorescent material that receives excitation light and emits light in a green wavelength band is formed in a first region 1 that is one sector-shaped region, and a transmission portion that transmits light is formed in a second region 2 that is the other sector-shaped region; a first light source 72 for irradiating the phosphor with excitation light in a visible light region; a second light source 82 that emits light of a wavelength band different from the fluorescent light emitted from the phosphor layer 131 and the excitation light emitted from the first light source 72; and a condensing optical system that condenses the light emitted from the luminescent wheel 71 and the light emitted from the second light source 82 on the same optical path.

The transparent base material is formed of a glass base material or a transparent resin base material, and a dichroic layer 132 that transmits excitation light and reflects light of other wavelength bands is formed by a coating layer on the surface of the transparent base material on the side of the layer 131 where the fluorescent material of the first region 1 is arranged.

In the second region 2 of the transparent base material, a diffusion layer 141 for diffusing transmitted light is formed. Further, a reflective coating layer is formed on the entire surface of the transparent base material on the side opposite to the side where the layer 131 having the fluorescent material is disposed.

The first light source 72 is a laser light emitter that emits light in a blue wavelength band shorter than the wavelength of light in a green wavelength band emitted from the green phosphor layer 131. The second light source 82 is a light emitting diode that emits light in the red wavelength band.

In order to prevent the light from the first light source 72 from being emitted from the luminescent wheel 71 as a result of the light from the first light source 72 being emitted so that the irradiation region 7 spans two fan-shaped regions at the boundary between the first region 1 and the second region 2, the light source control unit turns off the first light source 72 and turns on the second light source 82.

Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1 is an external perspective view of a projector 10. In the present embodiment, the left and right are the left and right directions indicating the projection direction with respect to the projector 10, and the front and rear are the front and rear directions indicating the proceeding direction of the light beam emitted from the projector 10. As shown in fig. 1, the projector 10 has a substantially rectangular parallelepiped shape, and a lens cover 19 that covers a projection opening is provided on a side of a front panel 12 that is a side plate in front of a main body case, and a plurality of exhaust holes 17 are provided in the front panel 12. Although not shown, the remote controller further includes an Ir receiving unit that receives a control signal from the remote controller.

A key indicator portion 37 is provided on the top panel 11 of the main body case, and a key and/or an indicator such as a power switch key, a power indicator for notifying on or off of power, a projection switch key for switching on and off of projection, and an overheat indicator for notifying when the light source device, the display element, the control circuit, or the like is overheated are arranged on the key indicator portion 37.

Various terminals 20 such as an input/output connection unit provided with a USB terminal, a D-SUB terminal for inputting image signals, an S terminal, and an RCA terminal, and a power adapter plug are provided on the rear surface of the main body case on the rear surface panel. Further, a plurality of intake holes 18 are formed in the vicinity of the lower portion of the right side plate 14, which is a side plate of the main body casing not shown, and the left side plate 15, which is a side plate shown in fig. 1.

Next, a projector control unit of the projector 10 will be described with reference to the block diagram of fig. 2.

The projector control unit includes a control unit 38, an input/output interface 22, an image conversion unit 23, a display encoder (エンコ - ダ)24, a display drive unit 26, and the like, and image signals of various specifications input from the input/output connection unit 21 are converted by the image conversion unit 23 via the input/output interface 22 and a System Bus (SB) so as to be unified into image signals of a predetermined format suitable for display, and then output to the display encoder 24.

The display encoder 24 expands and stores the input image signal in the video RAM25, generates a video signal from the stored content of the video RAM25, and outputs the video signal to the display driver 26.

The display driving unit 26 drives the display element 51, which is a spatial light modulator (SOM), at an appropriate frame rate based on the image signal output from the display encoder 24, and a light beam emitted from the light source device 63 enters the display element 51 through the light source side optical system, thereby forming a light image by reflected light of the display element 51, and the image is projected and displayed on a screen, not shown, through the projection lens group, which is a projection side optical system. The lens motor 45 drives the movable lens group 97 of the projection-side optical system to perform zoom adjustment or focus adjustment.

The image compression/extension unit 31 performs data compression of the luminance signal and the color difference signal of the image signal by ADCT and huffman coding, and performs recording processing of sequentially writing the compressed signals into a memory card 32 which is a removable recording medium. The image compressing/extending unit 31 reads the image data recorded in the memory card 32 in the playback mode, expands each image data constituting a series of moving images in units of 1 frame, outputs the image data to the display encoder 24 via the image converting unit 23, and performs processing enabling display of moving images and the like based on the image data stored in the memory card 32.

The control unit 38 controls operations of circuits in the projector 10, and includes a CPU, a ROM in which operation programs such as various settings (settings) are fixedly stored, a RAM used as a work memory (work memory), and the like.

An operation signal of a key indicator unit 37 composed of a main key, an indicator and the like provided on the top panel 11 of the main body casing is directly sent to the control unit 38, a key operation signal from the remote controller is received by the Ir receiving unit 35, and a code signal demodulated by the Ir processing unit 36 is output to the control unit 38.

The control unit 38 is connected to the sound processing unit 47 via a System Bus (SB). The sound processing unit 47 includes a sound source circuit such as a PCM sound source, and simulates sound data in a projection mode and a reproduction mode, and drives a speaker 48 to amplify and reproduce sound.

The control unit 38 controls a light source control circuit 41 as a light source control unit, and the light source control circuit 41 controls the light emission of the first light source and the second light source of the light source device 63 based on the image signal. The control unit 38 causes the cooling fan drive control circuit 43 to detect the temperature using a plurality of temperature sensors provided in the light source device 63 and the like, and controls the rotation speed of the cooling fan based on the result of the temperature detection.

The control unit 38 controls the cooling fan drive control circuit 43 to maintain the rotation of the cooling fan by a timer or the like even after the power supply to the projector main body is turned off, or controls the projector main body to turn off the power supply based on the result of temperature detection by the temperature sensor.

Next, the internal structure of the projector 10 will be described.

Fig. 3 is a schematic plan view showing an internal structure of the projector 10.

As shown in fig. 3, the projector 10 has a power control circuit board 102 on which a power circuit module 101 and the like are mounted, a sirocco fan-type blower 110 disposed substantially at the center, a control circuit board 103 disposed near the blower 110, a light source device 63 disposed near the front panel 12, and an optical system mechanism 70 disposed near the left panel 15 in the vicinity of the right panel 14. The projector 10 is configured such that the inside of the housing is divided into an intake-side space chamber 121 on the rear panel 13 side and an exhaust-side space chamber 122 on the front panel 12 side by a partitioning partition wall 120 in an airtight manner, the blower 110 is disposed such that the intake port 111 is located in the intake-side space chamber 121, and the discharge port 113 is located at the boundary between the exhaust-side space chamber 122 and the intake-side space chamber 121.

The optical system mechanism 70 includes 3 modules, that is, an illumination module 78 located in the vicinity of the light source device 63, an image generation module 79 located on the rear panel 13 side, and a projection module 80 located between the illumination module 78 and the left side panel 15, and the optical system mechanism 70 is substantially shaped like "コ".

The illumination module 78 includes a part of the light source optical system 62, and the light source optical system 62 guides light emitted from the light source device 63 to the display element 51 included in the image generation module 79. The light source optical system 62 included in the illumination side module 78 includes a light guide device 75 for making the light flux emitted from the light source device 63 a light flux having a uniform intensity distribution, and a condenser lens for condensing the light transmitted through the light guide device 75.

The image generation block 79 includes, as the light source side optical system 62: an optical axis changing mirror 74 that changes the optical axis direction of the light beam emitted from the light guide device 75; a plurality of condensing lenses for condensing the light reflected by the optical axis changing mirror 74 on the display element 51; and an illumination mirror 84 for illuminating the display element 51 with the light beam transmitted through the condenser lens at a predetermined angle. The image generation module 79 includes a DMD which is the display element 51, and a display element cooling device 53 for cooling the display element 51 is disposed on the rear panel 13 side of the display element 51, thereby preventing the display element 51 from becoming hot.

The projection module 80 has a lens group of a projection optical system 90 that irradiates light reflected by the display element 51 to form an image to a screen. As the projection optical system 90, a variable focus lens having a zoom function is used, which includes a fixed lens group 93 built in a fixed barrel and a movable lens group 97 built in a movable barrel, and the projection optical system 90 can perform zoom adjustment and/or focus adjustment by moving the movable lens group 97 by a lens motor.

In the internal structure of the projector 10, components having a temperature lower than that of the light source device 63, specifically, the light source control circuit board 102, the blower 110, the control circuit board 103, the image generation module 79 of the optical system mechanism 70, the projection-side module 80 of the optical system mechanism 70, and the condenser lens of the illumination-side module 78 of the optical system mechanism 70 are disposed in the suction-side spatial chamber 121.

On the other hand, the relatively high-temperature light source device 63, the light guide device 75 included in the illumination side module 78 of the optical system mechanism 70, and the exhaust temperature reduction device 114 are disposed in the exhaust side spatial chamber 122.

The light source device 63 further includes: a fluorescent wheel 71 that emits light in wavelength bands of green and blue as primary colors by irradiation with light; a wheel motor 73 as a driving device for rotationally driving the fluorescent wheel 71; a first light source 72 for emitting light of a blue wavelength band to the fluorescent wheel 71; and a second light source 82 that emits light in a red wavelength band as a primary color.

The first light source 72 is disposed such that the optical axis of the first light source 72 is substantially orthogonal to the optical axis of the light guide device 75. Further, the second light source 82 is disposed such that the optical axis of the second light source 82 is substantially parallel to the optical axis of the light guide device 75. The fluorescent wheel 71 is disposed such that the optical axis of the first light source 72 is orthogonal to the wheel surface of the fluorescent wheel 71. That is, the rotation axis of the wheel motor 73 that rotates the fluorescent wheel 71 is parallel to the optical axis of the first light source 72.

The first light source 72 is a laser emitter that emits light in a blue wavelength band of visible light having a wavelength shorter than that of green wavelength band light emitted from the phosphor layer 131, as well as light in the phosphor layer 131 and the diffusion layer 141 disposed near the outer periphery of the phosphor wheel 71. In addition, the second light source 82 is a red light emitting diode that emits light in a red wavelength band.

As shown in fig. 4A and 4B, the fluorescent wheel 71 is a thin circular transparent base material having a fluorescent material layer 131, a circular opening corresponding to the shape of a cylindrical rotating shaft, which is a connecting portion to be connected to the wheel motor 73, is formed in the central portion of the transparent base material, and a motor hub (motor hub) is brought into contact with the vicinity of the central portion of the transparent base material by inserting the rotating shaft into the circular opening, whereby the fluorescent wheel 71 and the rotating shaft of the wheel motor 73 are firmly connected.

Therefore, the fluorescent wheel 71 is integrally rotated in the circumferential direction at a rotational speed of about 120 times per second or the like by the wheel motor 73 as a driving device which is drive-controlled by the control section 38 of the projector control unit. That is, the fluorescent wheel 71 can be rotationally controlled.

The transparent substrate has two semicircular sector-shaped regions adjacent to each other, and is formed of a glass substrate, a transparent resin substrate, or the like. The transparent base material has a phosphor layer 131 formed in a first region 1, which is one of the fan-shaped regions, and a second region 2, which is the other fan-shaped region, is a transmissive portion for transmitting light from the first light source 72.

In addition, a band-shaped concave portion is formed in the vicinity of the outer peripheral portion of the first region 1 of the transparent base material, and the phosphor layer 131 is formed in the concave portion. The phosphor layer 131 is a layer containing light of a wavelength band of green that is a primary color generated when excited, and the phosphor layer 131 is irradiated with light from the first light source 72 and absorbs light from the first light source 72 as excitation light. By forming the phosphor layer 131 in this manner, the luminescent wheel 71 can function as a luminescent plate. The phosphor layer 131 is composed of a phosphor crystal and a binder.

A dichroic layer 132 that transmits excitation light and reflects light of another wavelength band is formed by coating (coating) on the surface of the portion of the transparent base material in the first region 1 where the phosphor layer 131 is formed, and the phosphor layer 131 is formed on the dichroic layer 132. The dichroic layer 132 may be formed not only in the portion of the phosphor layer 131 but also over the entire first region 1. The dichroic layer 132 may be formed on the surface of the transparent base material on the first light source 72 side, as long as it is provided between the first light source 72 and the phosphor layer 131.

The second region 2 as a transmission part has a diffusion layer 141 on a surface opposite to the first light source 72 side. Specifically, the diffusion layer 141 is a layer that exerts a diffusion effect when incident blue light source light is transmitted by subjecting the second region 2 of the transparent base material to an optical treatment such as sandblasting, for example, sandblasting.

The diffusion layer 141 may be formed by fixing a band-shaped solid material as an optical material, in addition to the case of applying an optical treatment to the surface of the transparent base material. Note that the diffusion layer 141 may be formed on the surface on the first light source 72 side instead of the diffusion layer 141 on the surface on the opposite side to the first light source 72.

Further, a non-reflective coating layer, not shown, is formed by a coating layer on the entire surface of the transparent substrate on the first light source 72 side.

The fluorescent wheel 71 may be formed into a circular shape by forming a transparent base material by two filter sheets corresponding to the two sector regions, forming the fluorescent material layer 131 and the diffusion layer 141 by the respective filter sheets, and then integrating them by bonding or attaching members.

In this way, the phosphor layer 131 and the diffusion layer 141 are disposed adjacent to each other in the circumferential direction in the two fan-shaped regions. Therefore, when the blue light source light is sequentially irradiated to the phosphor layer 131 and the diffusion layer 141 of the rotating phosphor wheel 71, the phosphor light of the green wavelength band is emitted from the phosphor wheel 71 when irradiated to the phosphor layer 131 of the phosphor wheel 71, and the blue light source light is diffused and transmitted when irradiated to the diffusion layer 141 of the transmission portion of the phosphor wheel 71.

Further, since the dichroic layer 132 is formed on the surface of the transparent base material in the first region 1 on which the phosphor layer 131 is disposed, and the non-reflective coating is formed on the surface on the first light source 72 side, when the light from the first light source 72 is irradiated to the first region 1, the blue light source light is transmitted to the transparent base material without being emitted to the first light source 72 side by the non-reflective coating on the incident surface of the first region 1. The blue light source light transmitted through the transparent base transmits through the dichroic layer 132 and is irradiated to the phosphor layer 131.

The phosphor of the phosphor layer 131 absorbs the blue light source light as excitation light and emits the green wavelength band phosphor light in all directions. Then, the green fluorescent light emitted to the side opposite to the first light source 72 enters the light guide device 75 via a light collecting optical system described later, the green fluorescent light emitted to the transparent base material side is reflected by the dichroic layer 132, and most of the reflected light enters the light guide device 75 as the light emitted from the fluorescent wheel 71 via the light collecting optical system.

When the diffusion layer 141 is irradiated with the laser light of the blue wavelength band from the first light source 72, since the blue light source light having entered the diffusion layer 141 exerts a diffusion effect, the same blue light as the light emitted from the fluorescent material layer 131 (green fluorescent light) as diffused light is emitted from the diffusion layer 141, and the blue light enters the light guide device 75 via the condensing optical system.

As shown in fig. 5, the light source device 63 includes a collimator lens 150 disposed on the emission side of the first light source 72, and converting the light emitted from the first light source 72 into parallel light. The light source device 63 includes a light collecting optical system including a dichroic mirror 151 and a reflecting mirror 152, and a lens or the like for collecting the light flux emitted from the fluorescent wheel 71 and incident on the light guide device 75, and the dichroic mirror 151 and the reflecting mirror 152 reflect or transmit light of a predetermined wavelength band emitted from the fluorescent wheel 71, convert the optical axes of blue light and green light from the fluorescent wheel 71 and the optical axis of red light from the second light source 82, and collect the respective color lights on the same optical path.

Next, the condensing optical system of the present embodiment will be explained.

The dichroic mirror 151 is disposed at a position where the optical axis of the first light source 72 and the optical axis of the second light source 82 intersect, transmits the blue light emitted from the first light source 72 and transmitted through the transmission portion of the fluorescent wheel 71 and the green light emitted from the fluorescent wheel 71, reflects the red light emitted from the second light source 82, and changes the direction by an angle of 90 degrees.

The reflecting mirror 152 is disposed at a position where the optical axis of the first light source 72 and the optical axis of the light guide device 75 intersect, and reflects the blue light and the green light from the fluorescent wheel 71 and the red light reflected by the dichroic mirror 151, and changes their directions by an angle of 90 degrees toward the light guide device 75 side.

Further, by disposing the condenser lens group 155 near the emission surface of the luminescent wheel 71, the light flux emitted from the luminescent wheel 71 is condensed and irradiated to the dichroic mirror 151.

Similarly, by disposing the condenser lens group 155 near the emission surface of the second light source 82, the light flux emitted from the second light source 82 is condensed and irradiated to the dichroic mirror 151. Further, since the light guide device incident lens 154 is disposed between the dichroic mirror 151 and the reflecting mirror 152, the respective color lights enter the light guide device 75 as light beams further condensed.

Therefore, when the luminescent wheel 71 is rotated and light is emitted from the first light source 72 and the second light source 82 at different timings, light in wavelength bands of red, green, and blue is sequentially incident on the light guide device 75 from the luminescent wheel 71 via the condensing optical system, and the DMD, which is the display element 51 of the projector 10, displays the light of each color in a time-division manner based on data, thereby generating a color image on a screen.

The turning on/off operation of the first light source 72 and the second light source 82 is time-division controlled by the light source control means. The light source control circuit 41 as the light source control means irradiates light from the first light source 72 to one boundary between the first area 1 and the second area 2, thereby turning off the first light source 72 and turning on the second light source 82 so that the fluorescent wheel 71 does not emit the synthesized light of the wavelength bands of two colors.

Specifically, as shown in fig. 6A, the range in which the first light source 72 is turned off is determined such that the substantially circular irradiation region 7 of the light from the first light source 72 is not located at a position across the first region 1 and the second region 2. As shown in the figure, the first light source extinction range is a range surrounded by a tangent to the irradiation region 7 of the light from the fluorescent wheel 71 in the vicinity of one boundary of the first region 1 and the second region 2. The tangent line is an imaginary line indicating a predetermined position of the fluorescent wheel 71, the first light source turning-off range is a fan-shaped region having a boundary line between the first region 1 and the second region 2 as a center and an acute central angle, and the light source control unit turns off the first light source 72 when the region is located on a central axis of the first light source 72 fixedly arranged.

That is, the light source control unit turns off the first light source 72 when the tangent line is positioned at the center of the irradiation region 7 of the fixedly arranged first light source 72 by moving the tangent line by rotating the fluorescent wheel 71, and turns on the first light source 72 when the other tangent line is positioned at the center of the irradiation region 7. In other words, when the fluorescent wheel 71 rotates and the boundary moves to a position where it contacts the circular irradiation region 7, the first light source 72 is turned off, and when the boundary passes through the irradiation region 7 and moves to another position where it contacts the irradiation region 7, the first light source 72 is turned on.

Therefore, the light source control unit turns off the first light source 72 so as to turn off the first light source 72 in a range larger than the first light source turning-off range when the boundary of the first region 1 and the second region 2 of the rotating fluorescent wheel 71 approaches the irradiation region 7 of the first light source 72. Then, when the boundary between the first region 1 and the second region 2 exceeds the irradiation region 7 of the first light source 72, the first light source 72 is turned on again. As a result, color mixing of light at one boundary between the first region 1 and the second region 2 can be prevented.

Further, as shown in fig. 6B, by setting the range in which the first light source 72 is turned off to a range larger than the size of the incident surface of the light guide device 75, it is possible to reliably prevent color mixing of light from the fluorescent wheel 71 incident on the light guide device 75 in this range, and to obtain good color reproducibility.

The first light source turning-off range is configured to turn off the first light source 72 and turn on the second light source 82 so that color mixing does not occur at one boundary of the two sector regions. However, not limited to this, in order to prevent color mixing at both boundaries of the two sector regions, the light source device 63 may be configured to emit light of a predetermined wavelength band in order of red, green, red, and blue by turning off the first light source 72 and turning on the second light source 82.

Next, the timings of turning on and off the first light source 72 and the second light source 82 are described in accordance with the timing charts shown in fig. 7A, 7B, and 7C.

The wheel angle in the figure indicates the position on the wheel surface (specifically, the position of the wheel surface arranged at the center of the irradiation region 7) when the position of one boundary line between the first region 1 and the second region 2 in the fluorescent wheel 71 shown in fig. 6A and 6B is set as a reference (0 degrees) by an angle, and this position moves together with the rotation of the fluorescent wheel 71.

Fig. 7A is a diagram illustrating control for emitting light in wavelength bands of red, green, and blue from the light source device 63 at substantially equal intervals. First, the light source control unit turns on the first light source 72 when the wheel position at the wheel angle of 60 degrees is located at the center of the irradiation region 7. Thus, the light emitted from the first light source 72 is irradiated to the phosphor layer 131 formed in the first region 1 of the phosphor wheel 71, and thus the green fluorescent light (G) emitted from the phosphor wheel 71 is emitted from the light source device 63 and enters the light guide device 75.

When the fluorescent wheel 71 rotates and the wheel position at the wheel angle of 180 degrees reaches the center of the irradiation region 7, the diffusion layer 141 of the second region 2 is irradiated with light from the first light source 72. Thereby, the blue light source light (B) diffused and transmitted through the transmission portion of the fluorescent wheel 71 is emitted from the light source device 63 and enters the light guide device 75.

Further, when the wheel position at the wheel angle of 300 degrees before the boundary of the first area 1 and the second area 2 is located at the center of the irradiation area 7 of the first light source 72, the light source control unit turns off the first light source 72 and turns on the second light source 82. Thereby, only the red light source light (R) from the second light source 82 is emitted from the light source device 63 and enters the light guide device 75.

When the wheel position at the wheel angle of 60 degrees is located at the center of the irradiation region 7 of the first light source 72, the light source control unit turns on the first light source 72 again and turns off the second light source 82. Thereby, the green fluorescent light (G) is emitted from the light source device 63.

Therefore, light in wavelength bands of red (R), green (G), and blue (B) is sequentially emitted from the light source device 63, and the projector 10 time-divisionally displays the incident light of each color on the display element 51 based on data, thereby generating a color image on a screen.

In addition, in order to prevent a situation where both the first light source 72 and the second light source 82 become a non-lit state, resulting in a low luminance, the light source control unit controls the lighting and extinction timings of the first light source 72 and the second light source 82 in such a manner that one of the first light source 72 and the second light source 82 is lit up immediately before the other is extinguished.

Further, since the second light source 82 that emits red light is provided as a monochromatic light source, the first light source 72 and the second light source 82 can be controlled by the light source control unit, respectively, and therefore the lighting time of the first light source 72 and the second light source 82 can be freely changed, so that the light source device 63 having a wide bright mode can be provided.

The first light source 72 and the second light source 82 may be simultaneously turned on only for a predetermined time, and light in wavelength bands of magenta (M) and yellow (Y) may be emitted from the light source device 63 as complementary colors. Specifically, as shown in fig. 7B, when the first light source 72 is turned on and blue light source light is irradiated to the first region 1, green light (R) is emitted, and when the light source light is irradiated to the second region 2 by rotation, blue light (B) is emitted. When the second light source 82 is turned on after the blue light is emitted for a predetermined time, the blue light transmitted through the fluorescent wheel 71 and the red light emitted from the second light source 82 can be combined, and the light (M) in the band of magenta color that is stable is emitted from the light source device 63 and enters the light guide device 75.

After the magenta light (M) is emitted for a predetermined time, when only the first light source 72 is turned off, the red light (R) from the second light source 82 is emitted from the light source device 63. After emitting red light (R) for a predetermined time, if the second light source 82 is not turned off and the first light source 72 is turned on, red light from the second light source 82 and green light emitted from the luminescent wheel 71 are combined, and stable light of a yellow (Y) wavelength band is emitted from the light source device 63 and enters the light guide device 75.

In this way, the light source control unit controls the lighting of the first light source 72 and the second light source 82, respectively, and performs control of simultaneously lighting the first light source 72 and the second light source 82 for a predetermined time at a predetermined timing so that the light emitted from the luminescent wheel 71 upon receiving the light from the first light source 72 and the light emitted from the second light source 82 are combined only for the predetermined time. As a result, not only primary-color wavelength band light but also complementary-color wavelength band light can be emitted from the light source device 63, and the luminance of the light source device 63 can be improved to improve color reproducibility.

As shown in fig. 7C, the light source control means can freely adjust the luminance by controlling the lighting time of the first light source 72 and the second light source 82 so as to shorten the emission time of each color light. The color scheme can be adjusted by controlling the first light source 72 or the second light source 82 by the light source control means so as to suppress the light source output only when light of a predetermined wavelength band is emitted.

As shown in fig. 4A and 4B and fig. 6A and 6B, the fluorescent wheel 71 is not limited to the case where it is formed to have two fan-shaped regions, and may have various configurations. For example, as shown in fig. 8A, three fan-shaped regions may be formed on a transparent substrate, a layer 131 of a green phosphor emitting green light (G) may be provided on the first region 1, the second region 2 may be formed as a transmissive portion having a diffusion layer 141 transmitting blue light (B), and the third region 3 may be formed as a non-transmissive portion not transmitting light source light from the first light source 72 by covering and providing a mask 145.

In this way, by forming a non-transmissive portion that does not transmit light from the first light source 72 in a predetermined fan-shaped region and irradiating the second light source 82 with light from the first light source 72 cut off by the non-transmissive portion, red light (R) from the second light source 82 can be emitted from the light source device 63 in a state where the first light source 72 is constantly on.

As shown in fig. 8B, three fan-shaped regions may be formed on the transparent base material, the green phosphor layer 131G may be provided on the first region 1, the cyan phosphor layer 131C capable of emitting light of a wavelength band of cyan, which is a complementary color, may be provided on the second region 2, and the third region 3 may be formed as a transmissive portion.

In this way, not only the layer 131 of the phosphor emitting the green wavelength band of the fluorescent light, but also the layer 131 of the phosphor emitting light of various wavelength bands may be provided. As shown in the drawing, when the center of the irradiation region of the first light source 72 is located in the range from the wheel angle 330 degrees to the wheel angle 30 degrees, only the red band light (R) from the second light source 82 is emitted from the light source device 63 by setting the first light source lighting range from the wheel angle 30 degrees to the wheel angle 330 degrees and setting the second light source lighting range from the wheel angle 270 degrees to the wheel angle 90 degrees.

When the center of the irradiation region is in the range from the wheel angle of 30 degrees to the wheel angle of 90 degrees, the light source device 63 emits yellow wavelength band light (Y) in which the green wavelength band light from the fluorescent wheel 71 and the red wavelength band light from the second light source 82 are combined. When the center of the irradiation region is located in the range from the wheel angle of 90 degrees to the wheel angle of 150 degrees, only the green band light (G) from the fluorescent wheel 71 is emitted from the light source device 63.

When the center of the irradiation region is in the range from the wheel angle of 150 degrees to the wheel angle of 210 degrees, only the cyan-green wavelength band light (C) from the luminescent wheel 71 is emitted from the light source device 63, and when the center of the irradiation region is in the range from the wheel angle of 210 degrees to the wheel angle of 270 degrees, only the blue wavelength band light (B) transmitted through the transmission part of the luminescent wheel 71 is emitted from the light source device 63.

When the center of the irradiation region is in the range from the wheel angle of 270 degrees to the wheel angle of 330 degrees, light (M) in the magenta wavelength band, which is a combination of the light in the blue wavelength band transmitted through the transmission part of the fluorescent wheel 71 and the light in the red wavelength band from the second light source 82, is emitted from the light source device 63.

By arranging a plurality of different types of phosphor layers 131 or controlling the lighting timing of the first light source 72 and the second light source 82 in a plurality of combinations in this way, the light source device 63 capable of emitting light of a plurality of wavelength bands can be provided.

The type and location of the light source are not limited to those described above, and a blue light emitting diode may be used as the first light source 72, and a laser light emitter that emits laser light in the red wavelength band may be used as the second light source 82. Further, the first light source 72 uses a blue laser emitter to emit excitation light with high output to efficiently excite the phosphor, and the second light source 82 uses a red light emitting diode to reduce the cost of the product.

In addition, as shown in fig. 5, the optical arrangement (layout) is not limited to the case where the light from the second light source 82 does not irradiate the fluorescent wheel 71, and as shown in fig. 9, the second light source 82 may be disposed on the first light source 72 side so that the light from the second light source 82 also irradiates the fluorescent wheel 71. In this case, a dichroic mirror 151 that transmits light from the first light source 72 and reflects light from the second light source 82 is disposed between the fluorescent wheel 71 and the first light source 72 at a position where the optical axis of the first light source 72 and the optical axis of the second light source 82 intersect. That is, the light from the second light source 82 can also illuminate the fluorescence wheel 71.

In this case, as shown in fig. 10, the luminescent wheel 71 includes: a first region 1 having a layer 131 of a phosphor that receives light from the first light source 72 and emits fluorescent light; a second region 2 as a transmission part having a diffusion layer 141 that transmits light from the first light source 72; and a third region 3 as a transmission part through which light from the second light source 82 is transmitted. Then, the light source device 63 can sequentially emit the respective color lights by turning on the first light source 72 (turning off the second light source 82) to irradiate the first region 1 and the second region 2 with light, and turning on the second light source 82 (turning off the first light source 72) to irradiate the third region 3 with light.

In the case where the second light source 82 is a laser light emitter, by forming the diffusion layer 141 in the second region 2 and the third region 3, the laser light with high directivity emitted from the first light source 72 and the second light source 82 can be transmitted as diffused light similar to the fluorescent light emitted from the first region 1. Also in this case, the diffusion layer 141 provided on the second region 2 and the third region 3 may be formed according to the characteristics of the irradiated light, and may be subjected to optical processing of different specifications.

Further, it may be formed such that: the transmission section of the luminescent wheel 71 is formed by a normal glass plate or a through hole space having a frame formed therearound without providing the diffusion layer 141, and an optical member for providing a diffusion effect is fixedly disposed on the optical path of the laser beam on the first light source 72 side closest to the luminescent wheel 71 or on the emission side of the luminescent wheel 71. When the first light source 72 and the second light source 82 of the light source device 63 are both light emitting diodes, the diffusion layer 141 may not be provided on the transmission portion and/or the optical path.

As described above, according to the present invention, the projector 10 includes: a first light source 72 that excites the phosphor; a fluorescent wheel 71 having a fluorescent material of a type having a good luminous efficiency; the second light source 82 is a monochromatic light source that emits light of a red wavelength band corresponding to the phosphor having a relatively low emission efficiency, for example, a red phosphor is not formed on the fluorescent wheel 71. Thus, the light source device 63 capable of improving the brightness of the screen and the projector 10 including the light source device 63 are provided.

Further, since the light source light is irradiated to the luminescent wheel 71 at a predetermined timing, the irradiation time of the luminescent wheel 71 is reduced as compared with the case where the light is always irradiated to the luminescent wheel 71, and the temperature rise can be suppressed. Therefore, the decrease in the luminous efficiency due to the temperature increase of the phosphor can be suppressed, and the luminous efficiency of the phosphor can be improved.

Further, by using the laser emitter of the blue wavelength band for the first light source 72, the phosphor can be efficiently excited and emitted. Further, by forming the phosphor layer 131 having at least a phosphor that emits light of a green wavelength band on the phosphor wheel 71, light of a green wavelength band as a primary color can be generated. Further, by providing the diffusion layer 141 on the transmission section, the laser light having directivity can be diffused and transmitted, and the light in the blue wavelength band of the primary color can be made incident on the light guide device 75 as diffused light similar to the fluorescent light.

Further, the present invention is not limited to the above embodiments, and for example, a configuration may be adopted in which the light source control unit is not provided in the projector 10, but the light source control units are provided in the light source devices 63, respectively. Further, as a mirror having a characteristic that the dichroic mirror 151 shown in fig. 5 reflects light from the fluorescent wheel 71 and transmits light from the second light source 82, an optical arrangement in which the light guide device 75 is disposed on the optical axis of the second light source 82 may also be employed. Further, as a mirror having a characteristic of causing dichroic mirror 151 shown in fig. 9 to reflect light from first light source 72 and transmit light from second light source 82, an optical arrangement in which the positions of first light source 72 and second light source 82 are exchanged may also be employed.

In the above-described embodiment, the first light source 72 uses a laser light emitter in the blue wavelength band, but is not limited thereto, and a laser light emitter in the ultraviolet wavelength band may be used, for example. In this case, it is preferable to dispose a phosphor layer that emits light of a wavelength band different from that of the light of the wavelength band emitted from the phosphor layer 131 formed in the reflection portion, in the transmission portion of the phosphor wheel 71.

In the above-described embodiment, the dichroic mirror is used to change the optical axis direction and select transmission and reflection according to the wavelength, but the present invention is not limited to this, and other replacing means such as a dichroic prism may be used instead of the dichroic mirror.

In this way, as shown in fig. 5 and 9, since the light source device 63 can adopt various optical arrangements, not only can the luminance of the screen be improved as described above, but also the degree of freedom in arrangement of the equipment such as the projector 10 to which such a light source device 63 is mounted can be achieved.

The sector-shaped region formed on the transparent substrate is not limited to the formation of an equal division, and 4 or more regions may be formed in an unequal division. Further, the following configuration may be adopted: a layer 131 of a phosphor that emits light in the red wavelength band is provided in the third region 3 shown in fig. 10, and when the third region 3 is located at the center of the irradiation region, both the first light source 72 and the second light source 82 are turned on, and the second light source 82 is used as an auxiliary light source that increases the amount of red light. Note that the second light source 82 is not limited to a light source emitting light in the red wavelength band, and a light source emitting light in a wavelength band other than light in the red wavelength band, which is different from the fluorescent light emitted from the phosphor layer 131 and the excitation light emitted from the first light source 72, may be used.

The fluorescent wheel 71 is not limited to a circular plate shape, and may be fixedly disposed by forming a rectangular light emitting plate. In this case, an adjusting device for changing the irradiation direction of the light from the first light source 72 or a light source driving device for driving the first light source 72 so as to change the position and/or the irradiation direction is disposed between the first light source 72 and the light emitting panel, and the light of each color can be made incident on the light guide device 75 by the condensing optical system by sequentially positioning the irradiation point of the light from the first light source 72 in each of the fan-shaped regions. As the adjustment device, a light beam splitter using, for example, a KTN crystal, an acoustic-optical device (acoustic-optical device), a MEMS mirror, or the like can be used.

The present invention is not limited to the above embodiments, and can be freely modified and improved without departing from the scope of the present invention.

Although various exemplary embodiments have been described, the present invention is not limited to the above-described embodiments. The scope of the invention is therefore intended to be limited solely by the contents of the appended claims.

Claims (11)

1. A light source device has:

a light emitting panel having a plurality of fan-shaped regions, each of the fan-shaped regions being formed with at least a layer of a phosphor that receives excitation light and emits light of a predetermined wavelength band and a transmission portion that transmits light;

a first light source that irradiates the phosphor with excitation light;

a second light source that emits light of a wavelength band different from the fluorescence light emitted from the phosphor layer and the excitation light emitted from the first light source;

a condensing optical system that condenses light emitted from the light emitting panel and light emitted from the second light source on the same optical path; and

a light source control unit for controlling the light emission of the first light source and the second light source,

the light emitting plate is a fluorescent wheel composed of a base material capable of being controlled in rotation,

the light source device is characterized in that,

the light source control unit is configured to turn off the first light source and turn on the second light source so that at least one boundary of adjacent sector regions is not irradiated with light from the first light source,

in the base material having two adjacent sector regions, one sector region is formed with the layer of the phosphor, and the other sector region is used as the transmission section,

the light source control means is configured to turn off the first light source and turn on the second light source at a position where the irradiation region crosses the two fan-shaped regions in order to prevent the synthesized light of the dichromatic wavelength band from being emitted from the light emitting panel by the irradiation of the light from the first light source at least one of the boundaries of the two fan-shaped regions,

the light source control means turns off the first light source in a fan-shaped region in which a central angle between a boundary line of the two fan-shaped regions is an acute angle, turns off the first light source when one of connection lines connecting a center of the fluorescent wheel and a tangent line to an outer periphery of the substantially circular irradiation region of the light from the first light source is located at a boundary of the two fan-shaped regions, and turns on the first light source when the other of connection lines connecting the center of the fluorescent wheel and a tangent line to an outer periphery of the substantially circular irradiation region of the light from the first light source is located at a boundary of the two fan-shaped regions.

2. The light source device according to claim 1,

the first light source is a blue-band laser emitter.

3. The light source device according to claim 2,

the phosphor is a phosphor that receives excitation light and emits light in at least a green wavelength band.

4. The light source device according to claim 2 or 3,

a diffusion layer for diffusing light from the first light source is formed in the transmission portion of the light emitting panel.

5. The light source device according to claim 1,

a phosphor layer is formed on the transmission portion of the light emitting panel, and the phosphor layer receives excitation light from the first light source and emits light of a wavelength band different from a predetermined wavelength band light emitted from the phosphor layer.

6. The light source device according to claim 2 or 3,

the second light source is a light emitting diode of a red wavelength band.

7. The light source device according to claim 1,

the substrate is a transparent substrate, and a dichroic layer that transmits the excitation light and reflects light of other wavelength bands is formed on the surface of a sector region of the transparent substrate in which the layer of the phosphor is disposed.

8. The light source device according to claim 1,

the light collecting optical system further includes a dichroic mirror disposed at a position where an optical axis of the first light source and an optical axis of the second light source intersect, the dichroic mirror transmitting light from the light emitting panel and reflecting light from the second light source, or reflecting light from the light emitting panel and transmitting light from the second light source,

the light from the second light source is prevented from being irradiated to the light emitting panel.

9. The light source device according to claim 8,

the light source control means controls the first light source and the second light source to be turned on, respectively, and controls the first light source and the second light source to be turned on simultaneously so that the light emitted from the light emitting panel upon receiving the light from the first light source and the light emitted from the second light source are combined only for a predetermined time.

10. The light source device according to claim 1,

the condensing optical system further includes a dichroic mirror disposed at a position where an optical axis of the first light source and an optical axis of the second light source intersect, the dichroic mirror transmitting light from the first light source and reflecting light from the second light source, or reflecting light from the first light source and transmitting light from the second light source,

the light source device is configured to transmit light from the second light source to the transmission portion of the light emitting panel.

11. A projector is characterized by comprising:

a light source device;

a display element;

a light source side optical system for guiding light from the light source device to the display element;

a projection optical system for projecting an image emitted from the display element onto a screen; and

a projector control unit for controlling the light source device and/or the display element,

the light source device according to claim 1.