KR101202724B1 - Light source unit and projector - Google Patents

Abstract

In order to provide a light source unit capable of stable projection without generating heat even when the phosphor is used continuously for a long time, and in order to provide a projector including the light source unit, the projector of the present invention includes a light source unit, a display element, and a light guide. It comprises an optical system, a projection-side optical system, and a light source control means for controlling the light source unit, and the light source unit excites an excitation light irradiation device that emits excitation light and an emission light from the excitation light irradiation device. A fluorescent wheel that emits fluorescent light in a green wavelength band as light, and a light source-side optical system that focuses light emitted from each fluorescent light source and each light source device on a predetermined surface, and the light source control means includes an excitation light irradiation device; Excitation light so that the time required when the red light source device and the blue light source device are sequentially turned on once does not become an integer multiple of the time required for the fluorescent wheel to rotate once Time-division control of the scanning device, red light source device, a blue light source device and also controls the rotation speed of the fluorescent wheel.

Description

Light source unit and projector {LIGHT SOURCE UNIT AND PROJECTOR}

The present invention relates to a light source unit and a projector including the light source unit.

Today, many data projectors are used as image projection apparatuses for projecting a screen, a video image of a personal computer, an image by image data stored in a memory card, or the like onto a screen. The projector condenses the light emitted from the light source to a micromirror display element called a DMD (digital micromirror device) or a quartz plate to display a color image on the screen.

In such a projector, conventionally, the use of a high-brightness discharge lamp which emits white light as a light source and projecting a color image by coloring a white wheel with a color wheel has been mainstream. However, a projector having a configuration in which a color wheel is colored on such white light has a problem in that the utilization efficiency of the light beam emitted from the light source is low because only the predetermined wavelength band light is extracted and projected from the white light. In addition, high-brightness discharge lamps have a short lifespan.

Therefore, in recent years, the development and proposal of the projector which used the solid state light emitting element (semiconductor light emitting element), such as a light emitting diode (LED), a laser diode (LD), or organic EL, as a light source, has been made | formed. For example, Japanese Patent Application Laid-open No. 2004-341105 proposes a light source unit having a fluorescent wheel in which phosphors are placed in a circumferential direction on a transparent disc and an ultraviolet light emitting diode as a solid light emitting element. ought. The light source unit in the proposal of Japanese Patent Application Laid-open No. 2004-341105 is irradiated with ultraviolet rays as excitation light from the back side to the fluorescent wheel, and is emitted from the surface side of the fluorescent wheel. The fluorescent light is used as the light source light.

In the invention described in Japanese Patent Application Laid-Open No. 2004-341105, the red phosphor, the green phosphor, and the blue phosphor are excited by ultraviolet rays, and the fluorescent light emitted from the phosphor is switched ON / OFF by a micromirror of the display element. By doing so, an image is generated. Therefore, the utilization efficiency of the light beam emitted from the light source can be improved as compared with the case where the white light emitted from the discharge lamp is colored with the color wheel.

However, in the above-described projector, since the phosphors of three colors are arranged in the circumferential direction of the fluorescent wheel and the irradiated light is continuously irradiated to the fluorescent wheel, the phosphor generates heat and the luminous efficiency of the phosphor decreases. And red, green, and blue fluorescent light have a problem that luminance unevenness may occur and a high quality image cannot be projected. In addition, red, green, and blue phosphors have a problem in that luminance and saturation differ depending on the color, and the color to be projected cannot be reproduced. In addition, since the excitation light source is always turned on, there is a problem that the deterioration of the excitation light source is accelerated and the product life is shortened.

Japanese Patent Application Publication No. 2004-341105

The present invention has been made in view of the problems of the prior art, and an object thereof is to provide a light source unit capable of stable projection without generating heat even when the phosphor is used continuously for a long time, and a projector having the light source unit. have.

In the light source unit of the present invention, an excitation light irradiation device for emitting excitation light and a phosphor for emitting fluorescent light of a predetermined wavelength band using the emission light from the excitation light irradiation device as excitation light are provided at least in the circumferential direction. The fluorescent wheel, two kinds of light source devices for emitting light having a wavelength band different from the wavelength band emitted from the fluorescent wheel, fluorescent light emitted from the fluorescent wheel and light emitted from the two kinds of light source devices are prescribed. And a light source control means for time-division-controlling the excitation light irradiation device and the two kinds of light source devices, and controlling rotation of the fluorescent wheel, wherein the light source control means includes: When the time required when the excitation light irradiation device and the two kinds of light source devices are sequentially turned on once is required for the fluorescent wheel to rotate one time. Time-division control of the said excitation light irradiation apparatus and said two types of light source devices, and the rotational speed of the said fluorescent wheel are controlled so that it may not become an integer multiple of the inside.

In the light source unit of the present invention, the phosphor attached to the fluorescent wheel is a green phosphor that receives the emitted light from the excitation light irradiation device and emits fluorescent light of a green wavelength band, and the two kinds of light source devices. The present invention is characterized by comprising a red light source device for emitting red wavelength band light and a blue light source device for emitting blue wavelength band light.

Further, in the light source unit of the present invention, the light source control means is required when the excitation light irradiation device and the two kinds of light source devices light up one time in sequence once for the fluorescent wheel to rotate one time. The time-division control of the excitation light irradiation device and the two kinds of light source devices such that the number divided by time becomes an irrational number, and the rotational speed of the fluorescent wheel are controlled.

The projector of the present invention is a fluorescence in which an excitation light irradiation device for emitting excitation light and a phosphor for emitting fluorescent light of a predetermined wavelength band using the emission light from the excitation light irradiation device as excitation light are placed in at least the circumferential direction. Two kinds of light source devices emitting light of a wavelength band different from the wavelength band emitted from the wheel, the fluorescent wheel, fluorescent light emitted from the fluorescent wheel, and light emitted from the two light sources And a light source control means for time-division-controlling the excitation light irradiation device and the two kinds of light source devices, and controlling the rotation of the fluorescent wheel, wherein the light source control means comprises: the excitation light source; The time required for generating an image of one frame using light from the light irradiation apparatus and the two kinds of light source apparatuses is reduced by one rotation of the fluorescent wheel. Time-division control of the excitation light irradiation apparatus and the two kinds of light source devices and control the rotational speed of the fluorescent wheel so as not to be an integral multiple of the time required to light the light source unit, and modulating the light from the light source unit A display element to be generated, a light guide optical system for guiding light from the light source unit to the display element, a projection side optical system for projecting an image emitted from the display element to the screen, the light source unit and the display element And projector control means for controlling the light and the like.

According to the present invention, it is possible to provide a light source unit capable of stable projection without generating heat even when the phosphor is used continuously for a long time, and a projector having the light source unit.

Although this invention can fully understand from the following detailed description and an accompanying drawing, these are for description only and do not limit the scope of the present invention.
1 is an external perspective view of a projector according to an exemplary embodiment of the present invention.
2 is a functional circuit block diagram of a projector according to an embodiment of the present invention.
3 is a schematic plan view showing the internal structure of a projector according to an embodiment of the present invention.
4 is a front schematic view and a cross-sectional schematic view of a fluorescent wheel according to an embodiment of the present invention.
5 is a view showing a relationship between the turn-on period of each light source of the light source unit and the rotation of the fluorescent wheel according to an embodiment of the present invention.
DON 6 is a diagram showing the relationship between the lighting cycle of each light source of the light source unit and the rotation of the fluorescent wheel according to the embodiment of the present invention.

EMBODIMENT OF THE INVENTION Below, the preferable form for implementing this invention is demonstrated with reference to drawings. However, in the embodiments described below, various technically preferable limitations are made in order to carry out the present invention, but the scope of the invention is not limited to the following examples and illustrated examples.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated. The projector 10 of the present invention includes a light source unit 60, a display element 51, a light guide optical system 170 for guiding light from the light source unit 60 to the display element 51, and a display element ( And a projection-side optical system 220 for projecting the image emitted from 51 onto the screen, and projector control means for controlling the light source unit 60, the display element 51 and the like.

The light source unit 60 includes at least an excitation light irradiation device 70 that emits excitation light and a phosphor that emits fluorescent light of a predetermined wavelength band using the emitted light from the excitation light irradiation device 70 as excitation light. From the fluorescent wheel 101 placed in the circumferential direction, two kinds of light source devices 120 and 300 for emitting light having a wavelength band different from the wavelength band emitted from the fluorescent wheel 101, and the fluorescent wheel 101. The light source side optical system 140 for condensing the emitted fluorescent light and the light emitted from the two kinds of light source devices 120 and 300 on a predetermined surface, the excitation light irradiation device 70 and the two kinds of the light source devices 120, Time-division control of 300, and light source control means for controlling the rotation of the fluorescent wheel 101.

The phosphor attached to the fluorescent wheel 101 is a green phosphor that receives the emitted light from the excitation light irradiation device 70 and emits the fluorescent light of the green wavelength band. The two kinds of light source devices 120 and 300 are a red light source device 120 that emits red wavelength band light and a blue light source device 300 that emits blue wavelength band light. In addition, the excitation light irradiation apparatus 70 includes an excitation light source 71 serving as a laser light emitter for emitting blue wavelength band light, and the red light source device 120 serves as a red light emitting diode for emitting red wavelength band light. A circle 121 is provided, and the blue light source device 300 includes a blue light source 301 as a blue light emitting diode that emits blue wavelength band light.

The light source control means is provided by sequentially adjusting the excitation light source 71 of the excitation light irradiation device 70, the red light source 121 of the red light source device 120, and the blue light source 301 of the blue light source device 300. The time-divided control of each light source 71, 121, 301 and the wheel motor 110 are controlled so that the time required when the lighting is turned on is not an integer multiple of the time required for the fluorescent wheel 101 to rotate once. The rotation speed of 101 is controlled.

In addition, in the light source unit 60 of the present invention, the light source control means uses the time required for the fluorescent wheel 101 to rotate one time by the excitation light source 71, the red light source 121, and the blue light source 301. Time-division control of the excitation light source 71, the red light source 121, and the blue light source 301, respectively, so that the number divided by the necessary time when the light is sequentially turned on once is controlled, and the rotation speed of the fluorescent wheel 101 is further controlled. To control.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 is an external perspective view of the projector 10. In the present embodiment, the left and right in the projector 10 represent the left and right direction with respect to the projection direction, and the front and rear represent the front and rear direction with respect to the screen side direction of the projector 10 and the traveling direction of the light beam.

And the projector 10 is a substantially rectangular parallelepiped shape, as shown in FIG. 1, and the lens cover 19 which covers the projection opening on the side of the front panel 12 used as the side plate of the front of a projector housing. In addition, a plurality of intake holes 18 are formed in the front panel 12. Although not shown, an Ir receiving unit for receiving a control signal from a remote controller is provided.

In addition, the upper panel 11 of the housing is provided with a key / indicator portion 37, and the key / indicator portion 37 has a power indicator for notifying on or off of a power switch key or a power supply, and on / off of projection. Keys and indicators, such as a projection switch key for switching a key, a column indicator for notifying when a light source unit, a display element, a control circuit, or the like are overheated, are disposed.

In addition, on the rear surface of the housing, various terminals 20, such as an input / output connector portion provided with a USB terminal, a D-SUB terminal for image signal input, an S terminal, an RCA terminal, and the like, are provided on the rear panel. In addition, a plurality of intake holes 18 are formed in the back panel. In addition, a plurality of exhaust holes 17 are formed in the right side panel which is the side plate of the housing | casing which is not shown in figure, and the left side panel 15 which is the side plate shown in FIG. Intake holes 18 are also formed in the corners of the left panel 15 near the rear panel. In addition, a plurality of intake holes or exhaust holes are formed in the vicinity of the front, back, left and right panels of the lower panel, not shown.

Next, the projector control means of the projector 10 will be described using the block diagram of FIG. The projector control means is comprised of the control part 38, the input / output interface 22, the image conversion part 23, the display encoder 24, the display drive part 26, etc., and the various standards input from the input / output connector part 21. The image signal is converted into a picture signal of a predetermined format suitable for display by the image conversion unit 23 via the input / output interface 22 and the system bus SB, and then output to the display encoder 24.

The display encoder 24 expands and stores the input image signal in the video RAM 25, and then generates a video signal from the stored contents of the video RAM 25 and outputs it to the display driver 26.

The display driver 26 functions as a display element control means, and appropriately drives the display element 51, which is a spatial light modulation element (SOM), at a frame rate corresponding to the image signal output from the display encoder 24. The light beam emitted from the light source unit 60 is irradiated to the display element 51 through the light guide optical system to form an optical image with the reflected light of the display element 51, and the image is displayed on a screen (not shown) through the projection-side optical system described later. Displays the projection. And the movable lens group 235 of this projection side optical system is driven by the lens motor 45 for zoom adjustment and focus adjustment.

In addition, the image compression decompression unit 31 records and records the luminance signal and the color difference signal of the image signal sequentially in the memory card 32 which becomes a removable recording medium by data compression by a process such as ADCT and Huffman coding. The process is performed. In addition, the image compression decompression unit 31 reads the image data recorded in the memory card 32 in the reproduction mode, decompresses each image data constituting a series of moving images in units of one frame, and this image data. Is outputted to the display encoder 24 via the image conversion section 23, and processing for enabling display of moving pictures or the like is performed based on the image data stored in the memory card 32.

The control part 38 is responsible for the operation control of each circuit in the projector 10, and is comprised by RAM etc. which fixedly store operation programs, such as a CPU and various settings, and are used as ROM and a work memory.

The operation signal of the key / indicator portion 37 constituted by a main key and an indicator or the like provided on the upper panel 11 of the housing is sent directly to the control portion 38, and the key operation signal from the remote controller is an Ir receiving portion. A code signal received at 35 and demodulated by Ir processing section 36 is output to control section 38.

The voice processing unit 47 is connected to the control unit 38 via the system bus SB. The audio processing unit 47 includes a sound source circuit such as a PCM sound source, and in the projection mode and the reproduction mode, the audio data is analogized, and the speaker 48 is driven to make a loud and loud sound.

In addition, the control part 38 controls the light source control circuit 41 as a light source control means, The light source control circuit 41 has the light source unit 60 which the light source light of the predetermined wavelength band requested | required at the time of image generation | generation. The light emission of the excitation light irradiation device, the red light source device, and the blue light source device of the light source unit 60 is individually controlled to be emitted from the light source unit 60.

In addition, the control unit 38 causes the cooling fan drive control circuit 43 to perform temperature detection by a plurality of temperature sensors provided in the light source unit 60 and the like, thereby controlling the rotational speed of the cooling fan from the result of the temperature detection. have. Further, the control unit 38 continues the rotation of the cooling fan even after the projector is powered off by a timer or the like in the cooling fan drive control circuit 43, or depending on the result of the temperature detection by the temperature sensor, Control such as turning off the power supply is also performed.

Next, the internal structure of this projector 10 is demonstrated. 3 is a schematic plan view showing the internal structure of the projector 10. As shown in FIG. 3, the projector 10 includes a control circuit board 241 in the vicinity of the right panel 14. This control circuit board 241 is provided with a power supply circuit block, a light source control block, and the like. In addition, the projector 10 includes a light source unit 60 on the side of the control circuit board 241, that is, substantially in the center of the projector housing. In addition, the projector 10 includes an optical system unit 160 between the light source unit 60 and the left panel 15.

The light source unit 60 is an approximate center portion in the left and right direction of the projector housing and is arranged in the vicinity of the rear panel 13 and the light beams emitted from the excitation light irradiation apparatus 70. The blue light source device disposed in the vicinity of the front panel 12 so as to be parallel to the fluorescent light emitting device 100 disposed in the vicinity of the front panel 12 on the optical axis and the beam of light emitted from the fluorescent light emitting device 100 ( 300, the red light source device 120 disposed between the excitation light irradiation device 70 and the fluorescent light emitting device 100, and the emission light from the fluorescent light emitting device 100 or the red light source device 120 from the red light source device 120. And a light source-side optical system 140 for converting the optical axes of the exit light and the blue light source device 300 to be the same optical axis, and condensing light of each color to the entrance hole of the light tunnel 175, which is a predetermined surface. do.

The excitation light irradiation apparatus 70 converts the optical axis of the excitation light source 71 arranged so that the rear panel 13 and the optical axis are parallel, and the optical axis of the emitted light from the excitation light source 71 in the direction of the front panel 12. Between the reflection mirror group 75, the condenser lens 78 for condensing the emitted light from the excitation light source 71 reflected by the reflection mirror group 75, and the excitation light source 71 and the right panel 14. The heat sink 81 arrange | positioned in between is provided.

The excitation light source 71 is formed by arranging a plurality of blue laser diodes in a matrix form, and on the optical axis of each blue laser diode, a collimator lens 73 for converting the emitted light from each blue laser diode into parallel light. Are arranged respectively. The reflection mirror group 75 is formed by arranging a plurality of reflection mirrors in a stepped manner, and reduces the cross-sectional area of the light beam emitted from the excitation light source 71 in one direction to emit it to the condensing lens 78.

A cooling fan 261 is disposed between the heat sink 81 and the rear panel 13, and the excitation light source 71 is cooled by the cooling fan 261 and the heat sink 81. In addition, a cooling fan 261 is disposed between the reflective mirror group 75 and the back panel 13, and the cooling fan 261 allows the reflective mirror group 75, the condenser lens 78, and the like. Is cooled.

The fluorescent light emitting device 100 rotates the fluorescent wheel 101 and the fluorescent wheel 101 arranged parallel to the front panel 12, that is, orthogonal to the optical axis of the emitted light from the excitation light irradiation device 70. A wheel motor 110 for driving and a condensing lens group 111 for condensing a beam of light emitted from the fluorescent wheel 101 toward the rear panel 13 are provided.

The fluorescent wheel 101 is a disk-shaped metal base, as shown in FIG. In the fluorescent wheel 101, an annular fluorescent light emitting region which emits fluorescent light in the green wavelength band using the emitted light from the excitation light source 71 as the excitation light is formed as a recess, and the fluorescent wheel 101 is excited. It functions as a fluorescent plate which receives light and fluorescently emits light. In addition, the surface of the excitation light source 71 side of the fluorescent wheel 101 including the fluorescent light emitting region is mirror-processed by silver deposition or the like to form a reflecting surface for reflecting light, and a layer of green phosphor on the reflecting surface. 103 is provided.

And the emitted light from the excitation light irradiation apparatus 70 irradiated to the green phosphor layer 103 of the fluorescent wheel 101 excites the green phosphor in the green phosphor layer 103, and is omnidirectional from the green phosphor. The fluorescence emitted light beam is reflected directly on the excitation light source 71 side or on the reflection surface of the fluorescent wheel 101 and then emitted to the excitation light source 71 side. In addition, the excitation light, which is not absorbed by the phosphor of the phosphor layer 103, is irradiated onto the metal substrate and is incident on the phosphor layer 103 again to excite the phosphor layer 103. Therefore, by making the surface of the recessed part of the fluorescent wheel 101 a reflective surface, the utilization efficiency of the excitation light emitted from the excitation light source 71 can be improved, and light emission can be made brighter.

Among the excitation light reflected from the reflection surface of the fluorescent wheel 101 to the phosphor layer 103 side, the excitation light emitted by the excitation light source 71 side without being absorbed by the phosphor is the first dichroic mirror 141 described later. ), And the fluorescent light is reflected by the first dichroic mirror 141, so that excitation light is not emitted to the outside. 3, the cooling fan 261 is arrange | positioned between the wheel motor 110 and the front panel 12, and the fluorescent wheel 101 is cooled by this cooling fan 261. As shown in FIG. .

The red light source device 120 is provided with the red light source 121 arrange | positioned so that the excitation light source 71 and an optical axis may be parallel, and the condensing lens group 125 which collects the emitted light from the red light source 121. As shown in FIG. And this red light source device 120 is arrange | positioned so that the optical axis and the green wavelength band light emitted from the excitation light irradiation apparatus 70 and the light emitted from the fluorescent wheel 101 may cross | intersect. The red light source 121 is a red light emitting diode as a semiconductor light emitting element that emits red wavelength band light. In addition, the red light source device 120 includes a heat sink 130 disposed on the right panel 14 side of the red light source 121. A cooling fan 261 is disposed between the heat sink 130 and the front panel 12, and the red light source 121 is cooled by the cooling fan 261.

The blue light source device 300 includes a blue light source 301 disposed in parallel with the optical axis of the emitted light from the fluorescent light emitting device 100, and a condensing lens group 305 for condensing the emitted light from the blue light source 301. Equipped. And this blue light source device 300 is arrange | positioned so that the emission light from the red light source device 120 and an optical axis may cross | intersect. The blue light source 301 is a blue light emitting diode as a semiconductor light emitting element that emits blue wavelength band light. In addition, the blue light source device 300 includes a heat sink 310 disposed on the front panel 12 side of the blue light source 301. A cooling fan 261 is disposed between the heat sink 310 and the front panel 12, and the blue light source 301 is cooled by the cooling fan 261.

The light source side optical system 140 includes a condenser lens for condensing the light beams in the red, green, and blue wavelength bands, and a dichroic mirror for converting the optical axes of the light beams in each color wavelength band to make the same optical axis. Specifically, the optical axis of the blue wavelength band light emitted from the excitation light irradiation device 70 and the green wavelength band light emitted from the fluorescent wheel 101 intersects with the optical axis of the red wavelength band light emitted from the red light source device 120. The first dichroic mirror 141 which transmits blue and red wavelength band light, reflects the green wavelength band light, and converts the optical axis of the green wavelength band light by 90 ° in the direction of the left panel 15 at a position to It is arranged.

The blue wavelength band light is transmitted at positions where the optical axis of the blue wavelength band light emitted from the blue light source device 300 intersects with the optical axis of the red wavelength band light emitted from the red light source device 120. A second dichroic mirror 148 is disposed to reflect the band light and convert the optical axes of the green and red wavelength band light by 90 degrees toward the rear panel 13. A condenser lens is disposed between the first dichroic mirror 141 and the second dichroic mirror 148.

The optical system unit 160 includes an illumination generation block 161 located on the left side of the excitation light irradiation apparatus 70 and an image generation block located near the position where the rear panel 13 and the left panel 15 intersect each other ( 165 and the three blocks of the projection side block 168 located between the light source side optical system 140 and the left panel 15 are substantially U-shaped.

The illumination side block 161 includes a part of the light guide optical system 170 for guiding the light source light emitted from the light source unit 60 to the display element 51 included in the image generating block 165. As the light guide optical system 170 of the illumination side block 161, the light tunnel 175 which makes the light beam emitted from the light source unit 60 into the light beam of uniform intensity distribution, and the incident surface of this light tunnel 175 The optical axis of the condenser lens 173 for condensing the light source light, the condenser lens 178 for condensing the light emitted from the light tunnel 175, and the optical axis of the light beam emitted from the light tunnel 175 is converted in the direction of the image generating block 165. And an optical axis conversion mirror 181 to be used.

The image generation block 165 is a light guide optical system 170 that transmits the light condenser lens 183 for condensing the light source light reflected by the optical axis conversion mirror 181 to the display element 51, and the light condenser lens 183 is transmitted through the light converging lens 183. The irradiation mirror 185 irradiates a light beam to the display element 51 at a predetermined angle. The image generating block 165 also includes a DMD serving as the display element 51, and a heat sink for cooling the display element 51 between the display element 51 and the back panel 13. 190 is disposed, and the display element 51 is cooled by the heat sink 190. In the vicinity of the front surface of the display element 51, a condenser lens 195 as the projection side optical system 220 is disposed.

The projection side block 168 has a lens group of the projection side optical system 220 that emits ON light reflected by the display element 51 to the screen. The projection-side optical system 220 includes a fixed lens group 225 incorporated in the fixed barrel and a movable lens group 235 embedded in the movable barrel to form a variable focus lens having a zoom function. By moving the movable lens group 235 by a motor, zoom adjustment and focus adjustment are enabled.

Next, the light source control method in the light source unit 60 comprised in this way is demonstrated. As described above, in the projector 10 of the present embodiment, the emitted light from the red light source 121 for the red wavelength band light and the excitation light irradiation device 70 for the green wavelength band light is emitted as excitation light. The fluorescent wheel 101 is configured to emit light from the blue light source 301 to the blue wavelength band light.

The red light source 121, the excitation light source 71, and the blue light source 301 are time-divisionally controlled by the light source control circuit 41 as the light source control means, and the red wavelength band light, the green wavelength band light, and the blue wavelength band are controlled. Each wavelength band light is sequentially emitted to the display element 51 in the order of light. Each light source 71, 121, 301 is duty driven by the light source control circuit 41. That is, when each light source 71, 121, 301 is lighted in order of red light source 121 lighting, excitation light source 71 lighting, blue light source 301 lighting, and the predetermined light source is lighted, another light source This lights out state.

Therefore, since each light source 71, 121, 301 may have a time that is not lit, the average current value can be kept low, and even when a high voltage is applied to each light source 71, 121, 301 at the time of lighting. Compared with the case where the light is always lit, the rate at which the semiconductor light emitting element deteriorates over time can be suppressed, and the lifespan can be extended. In addition, since a high voltage can be applied to each of the light sources 71, 121, and 301, the output of each light source 71, 121, and 301 at the time of light emission can be increased to project an image of high brightness.

In the light source unit 60 as described above, each of the light sources 71, 121, and 301 is time-divisionally driven, and thus, the phosphors attached to the fluorescent wheel 101 which emits the excitation light from the excitation light source 71 and emit light. The excitation light is irradiated within a range based on the lighting time of the excitation light source 71 and the rotational speed of the fluorescent wheel 101 in one frame. On the other hand, the fluorescent material has a characteristic that the luminous efficiency is lowered when the temperature exceeds a predetermined temperature, particularly 100 ° C. Therefore, when the exiting light from the excitation light source 71 is always irradiated at the same position of the fluorescent wheel 101, the temperature of the phosphor located at the portion to which the excitation light is irradiated increases, the luminous efficiency is lowered and the amount of the fluorescent light is reduced. This may cause a decrease in luminance in the projected image.

In addition, when the emitted light from the excitation light source 71 is always irradiated to the same position of the fluorescent wheel 101, the phosphor located at the portion to which the excitation light is irradiated is likely to deteriorate, and the phosphor may be squeezed or peeled off. have.

In the present invention, in order to prevent such local temperature rise of the phosphor, the rotation period (cycle) of the fluorescent wheel 101 is not an integer multiple of the time division period (frame) of each light source 71, 121, 301. The rotation of the fluorescent wheel 101 and the lighting of the red light source 121, the excitation light source 71, and the blue light source 301 are controlled. That is, as shown in FIG. 5, one frame of lighting cycles of each of the light sources 71, 121, and 301, which is a case where the red light source 121, the excitation light source 71, and the blue light source 301 each light one by one sequentially. The time-division control of each light source 71, 121, 301 and the wheel motor 110 are controlled so that the time required for the cycle does not become an integral multiple of the time required for one cycle of the fluorescent wheel 101. The rotation speed is controlled.

In this way, each light source 71, 121, 301 is controlled to be turned on and the rotation speed of the fluorescent wheel 101 is controlled so that the position at which the light beam emitted from the excitation light source 71 is irradiated to the fluorescent wheel 101 is determined. Since the fluctuation varies depending on the number of frames of the light sources 71, 121, and 301, excitation light is always irradiated to a predetermined location of the fluorescent wheel 101 so that the fluorescent wheel 101 locally retains heat. This can be prevented from occurring.

In addition, since the fluorescent wheel 101 can be prevented from becoming locally hot, the luminous efficiency of the phosphor can be kept constant at all times, and the luminance unevenness can be prevented from occurring in the projected image even when used continuously for a long time. .

And in the above-mentioned embodiment, each light source 71, 121, 301 so that the time required for one frame of each light source 71, 121, 301 does not become an integral multiple of the time required for one cycle of the fluorescent wheel 101. ) And the fluorescent wheel 101, the rotation speed of the fluorescent wheel 101 is always constant, and only the lighting time of each light source 71, 121, 301 is controlled, or the fluorescent wheel 101 is controlled. The objective of this embodiment can be attained even if the rotational speed of the control panel and the lighting time of each of the light sources 71, 121, and 301 are configured to be variably controlled.

5, when the time required for one frame in which the red light source 121, the excitation light source 71, and the blue light source 301 each light up is shorter than the time required for one cycle of the fluorescent wheel 101, Although it is described with reference to FIG. 6, even when one frame, which is the lighting period of each light source 71, 121, 301 is longer than the time required for one cycle of the fluorescent wheel 101, each light source 71, 121. And the same effect can be obtained by controlling each light source 71, 121, 301 and the fluorescent wheel 101 so that the time required for one frame of the 301 may not be an integral multiple of the time required for one cycle of the fluorescent wheel 101. have.

For example, when the amount of light in the red wavelength band is insufficient, it is possible to control that the lighting time of the red light source 121 is longer than the lighting time of the excitation light source 71 or the blue light source 301. Also in this case, the above-described effects can be obtained by making the time required for one frame of each light source 71, 121, 301 not be an integral multiple of the time required for one cycle of the fluorescent wheel 101.

In addition, each light source 71, 121, 301 and the fluorescent wheel 101 so that the time required for one frame of each light source 71, 121, 301 does not become an integral multiple of the time required for one cycle of the fluorescent wheel 101. In the case of controlling, the number obtained by dividing the time required for one cycle of the fluorescent wheel 101 by the time required for one frame of each light source 71, 121, 301 is an irrational number (a being a ratio of two constants a and b). each light source 71, 121, 301 and the fluorescent wheel 101 by controlling the number of digits that cannot be represented by / b (a number that cannot be represented by b ≠ 0)) or a rational number close to an irrational number, that is, a large number of digits after the decimal point. By repeating the lighting of (71, 121, 301) a plurality of times, the possibility of synchronizing with the fluorescent wheel 101 cycle can be reduced, and the effect of preventing the fluorescent wheel 101 from locally retaining heat can be enhanced. have.

Then, each light source 71, 121, 301 and the number of times required for one cycle of the fluorescent wheel 101 divided by the time required for one frame of each light source 71, 121, 301 are rational ratios. In the case of controlling the fluorescent wheel 101, it is very preferable to make the fractional part of the rational number three digits or more. This is because the display element 51 used in the present embodiment can display a color image of about 30 to 60 frames in one second, so that the lighting cycle and the fluorescent wheel 101 cycle of each light source 71, 121, 301 are performed. This is to prevent synchronization for a few seconds.

In addition, although the above-mentioned embodiment mentions the fluorescent wheel 101 which emits green wavelength band light, and the light source unit 60 provided with the red light source 121 and the blue light source 301, it limits to this structure. If the light source unit 60 is provided with the fluorescent wheel 101 and two kinds of light sources capable of emitting light having a wavelength band different from the predetermined wavelength band light emitted from the fluorescent wheel 101, all kinds of light sources. The same control method can be applied to the unit 60.

In addition, the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope without departing from the gist of the embodiment. Incidentally, the functions executed in the above-described embodiments may be performed in combination as appropriate. The above-described embodiments include various steps, and various inventions can be extracted by appropriate combinations of the plurality of configuration requirements disclosed. For example, even if some of the configuration requirements are deleted from the overall configuration requirements shown in the embodiment, if an effect can be obtained, a configuration from which this configuration requirement has been deleted can be extracted as the invention.

Claims (4)

An excitation light irradiation device for emitting excitation light;
A fluorescent wheel in which a fluorescent material for emitting fluorescent light of a predetermined wavelength band by using the emitted light from the excitation light irradiation device as excitation light is disposed at least in the circumferential direction;
Two kinds of light source devices for emitting light of a wavelength band different from the wavelength band emitted from the fluorescent wheel;
A light source side optical system for condensing the fluorescent light emitted from the fluorescent wheel and the light emitted from the two kinds of light source devices on a predetermined surface; And
Time-division control of the excitation light irradiation device and the two kinds of light source devices, and light source control means for controlling rotation of the fluorescent wheel
Including,
The light source control means includes the excitation light so that the number of times required for one rotation of the fluorescent wheel is divided by the time required when the excitation light irradiation device and the two kinds of light source devices are sequentially turned on one by one. A light source unit for time-division control of the irradiation apparatus and the two kinds of light source devices, and for controlling the rotational speed of the fluorescent wheel. The method of claim 1,
The phosphor attached to the fluorescent wheel is a green phosphor that receives the emitted light from the excitation light irradiation device and emits fluorescent light of a green wavelength band,
The two kinds of light source devices are a light source unit that is a red light source device that emits red wavelength band light and a blue light source device that emits blue wavelength band light. delete An excitation light irradiation device for emitting excitation light and a phosphor for emitting fluorescent light of a predetermined wavelength band using the emission light from the excitation light irradiation device as excitation light include at least a fluorescent wheel placed in a circumferential direction, and the fluorescent wheel. Two kinds of light source devices for emitting light of a wavelength band different from the wavelength band emitted from the light source, and a light source side for condensing the fluorescent light emitted from the fluorescent wheel and the light emitted from the two kinds of light source devices on a predetermined surface And a light source control means for time-division-controlling an optical system, the excitation light irradiation device, and the two kinds of light source devices, and controlling the rotation of the fluorescent wheel,
The light source control means includes the excitation light so that the number of times required for one rotation of the fluorescent wheel is divided by the time required when the excitation light irradiation device and the two kinds of light source devices are sequentially turned on one by one. A light source unit for time-division control of the irradiation apparatus and the two kinds of light source devices, and for controlling the rotational speed of the fluorescent wheel;
A display element for generating an image by modulating the light from the light source unit;
A light guide optical system for guiding light from the light source unit to the display element;
A projection-side optical system for projecting an image emitted from the display element onto a screen; And
Projector control means for controlling the light source unit and the display element
Projector comprising a.

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