HK1152761B - Light source device and projector - Google Patents

Description

Light source device and projector

Technical Field

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

Background

Nowadays, a data projector as an image projection apparatus that projects a screen or a video image of a personal computer, an image based on image data stored in a memory card or the like, and the like onto a screen is widely used. The projector condenses light emitted from a light source onto a micromirror display element called a DMD (digital micromirror device) or a liquid crystal panel, and displays a color image on a screen.

In such a projector, a high-luminance discharge lamp has been mainly used as a light source, but in recent years, studies and proposals have been made on the use of a light-emitting diode, a laser diode, an organic EL, a fluorescent substance, or the like as a light source. For example, japanese patent application laid-open No. 2004-341105 proposes a light source device including: a solid-state light source that emits ultraviolet light as excitation light; and a fluorescent wheel composed of a disk-shaped transparent base material on which a fluorescent layer is disposed that receives the emitted ultraviolet light as excitation light and converts the ultraviolet light into visible light.

Jp 2004-341105 a proposes that a visible light reflecting film that transmits ultraviolet light and reflects visible light is formed on a wheel surface of a fluorescent wheel on which ultraviolet light is incident, whereby the incident ultraviolet light is irradiated to a phosphor layer disposed on the wheel surface on the emission side to generate fluorescence and the fluorescence is emitted to the emission side, and further, the fluorescence emitted from the phosphor layer to the incidence surface side is reflected to the emission side by the visible light reflecting film, whereby the amount of fluorescence emitted from the fluorescent wheel can be increased.

In order to prevent the optical member from being damaged by the excitation light irradiation, a blue laser diode or the like that emits light in the blue wavelength band as the excitation light may be used for the solid-state light source of the light source device. In this case, the fluorescent wheel is configured to: a diffusion layer is formed on the wheel surface, etc., to transmit the fluorescent wheel and use the blue wavelength band light as it is.

Further, since the incident surface of the fluorescent wheel used in such a light source device needs to be formed with a reflective film that transmits light in the blue wavelength band and reflects other visible light, it takes time and labor for manufacturing, which is a factor of increasing the cost.

Therefore, the following structure is considered as a light source device: the wheel base material is formed of a metal plate or the like, and light in the blue wavelength band, which is excitation light, and fluorescence in the red, green, or the like emitted from the fluorescent material are reflected by the reflection surface of the metal plate, thereby sequentially emitting light in the red, green, and blue wavelength bands.

However, in this case, since the optical paths of the light in the red, green, and blue wavelength bands are not necessarily made the same, when the layer of the red or green phosphor is irradiated with the blue excitation light, the reflected light from the light source in the blue wavelength band is not necessarily mixed with the emitted fluorescence in the red or green wavelength band, and thus there is a problem that the color purity is not good.

Further, since the incident surface and the emission surface of the fluorescent wheel for blue wavelength band light are the same, there is a problem that: in order to separate the optical path on which the blue light source light is incident from the optical path on which the blue light source light is emitted, it is necessary to make the optical layout or the optical components have a special configuration.

Disclosure of Invention

In view of the above-described problems of the prior art, it is an object of the present invention to provide a light source device and a projector including the light source device, in which a light source light emitted from a luminescent wheel and an emission light path of each color luminescent light can be separated by using the luminescent wheel itself as a reflective plate and providing a transmissive portion for transmitting the light source light in a part of the reflective plate without providing a special reflective layer for reflecting only light of a predetermined wavelength band on the luminescent wheel surface, and which can be manufactured easily with a simple structure and can emit each color light with high color purity.

The light source device of the present invention includes: a light-emitting panel having a plurality of segment regions on a substrate, at least one of the segment regions being a reflecting portion on which a phosphor layer is formed to receive excitation light and emit light of a predetermined wavelength band, at least one of the segment regions being a transmitting portion through which the light is transmitted; a light source for irradiating excitation light to the phosphor layer of the light emitting panel; a dichroic mirror disposed between the light source and the light emitting panel, and transmitting the excitation light and reflecting the fluorescent light from the phosphor; and a plurality of reflecting mirrors and/or dichroic mirrors that can condense the excitation light transmitted through the transmission portion of the light-emitting panel and the fluorescent light reflected by the dichroic mirror on the same optical path and irradiate the same direction.

Drawings

The present invention will be more fully understood from the detailed description given below and the accompanying drawings, which are given by way of illustration only, and are not intended to limit the scope of the present invention.

Fig. 1 is a perspective view showing an external appearance of 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. 4 is a schematic front view and a schematic top view showing a partial cross section of a luminescent wheel according to an embodiment of the present invention.

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

Fig. 6 is a schematic diagram showing the deformation of the optical paths of the light source light and the fluorescent light in the light source device according to the embodiment of the present invention.

Fig. 7 is a table showing an example of combination of optical axis changing mirrors in the light source device according to the embodiment of the present invention.

Detailed Description

Hereinafter, preferred embodiments for carrying out the present invention will be described with reference to the drawings. However, in the embodiments described below, various limitations that are technically preferable for carrying out the present invention are added, but the scope of the present invention is not limited to the following embodiments and the illustrated examples.

Hereinafter, embodiments for carrying out 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 that guides light from the light source device 63 to the display element 51, a projection side optical system 90 that projects an image emitted from the display element 51 on a screen, and a projector control unit that controls the light source device 63 and the display element 51.

The light source device 63 has a luminescent wheel 71 as a luminescent plate. The fluorescent wheel 71 has three sector-shaped segment regions adjacent to each other on a base material capable of being controlled by rotation. Two of the three segment regions are reflective portions, and a layer 131G of a phosphor that receives excitation light and emits light in a green wavelength band and a layer 131R of a phosphor that emits light in a red wavelength band are provided in the reflective portions. The remaining one of the segment regions is a transmissive portion for transmitting light.

Specifically, the transmissive portion and the reflective portion for transmitting the excitation light are arranged in the circumferential direction, and the plurality of phosphor layers 131 for emitting light of different wavelength bands are formed in the circumferential direction in the reflective portion. The light source device 63 further includes: a wheel motor 73 as a driving device for rotating the fluorescent wheel 71; a light source 72 that irradiates the phosphor layer 131 of the phosphor wheel 71 with excitation light; a first optical axis conversion mirror 1 as a dichroic mirror, which is disposed between the light source 72 and the fluorescent wheel 71, transmits the excitation light and reflects the fluorescent light from the fluorescent body; and a plurality of reflecting mirrors and/or dichroic mirrors that can condense the excitation light transmitted through the transmission part of the fluorescence wheel 71 and the fluorescence reflected by the first optical axis conversion mirror 1 on the same optical path and irradiate them in the same direction.

The light source 72 that irradiates the excitation light to the luminescent wheel 71 is a laser emitter that emits laser light in the blue wavelength band, and the luminescent material forming the luminescent material layer 131 is plural. As described above, the plurality of phosphors are a phosphor that emits light in the red wavelength band and a phosphor that emits light in the green wavelength band.

Further, a diffusion layer 141 for diffusing excitation light is formed on the diffusion plate 140 serving as a transmission part of the luminescent wheel 71.

The light source device 63 includes a light collecting optical system formed of a plurality of lenses and mirrors, each of which is disposed between the light source 72 and the luminescent wheel 71, and on a path of the luminescent light emitted from the luminescent wheel 71 or the light source light transmitted through the luminescent wheel 71, and which collects light by being matched with a mirror such as a dichroic mirror.

Further, the condensing optical system includes: a first optical axis conversion mirror 1 as a dichroic mirror, which is disposed between the luminescent wheel 71 and the light source 72, transmits light source light without changing the optical axis of the light source light emitted from the light source 72, and converts the direction of the optical axis of the luminescent light emitted from the layer 131 of the luminescent material; a second optical axis conversion mirror 2 as a normal mirror for converting the direction of the optical axis of the light source light transmitted through the diffusion layer 141 of the fluorescent wheel 71; a third optical axis conversion mirror 3 for further converting the optical axis of the fluorescence converted by the first optical axis conversion mirror 1; and a fourth optical axis conversion mirror 4 that transmits the light source light without converting the optical axis of the light source light converted by the second optical axis conversion mirror 2, and further converts the fluorescence converted by the third optical axis conversion mirror 3, thereby condensing the fluorescence and the light source light on the same optical path.

Specifically, the first optical axis conversion mirror 1 is disposed between the fluorescent wheel 71 and the light source 72 on the optical axis of the light source 72, and the second optical axis conversion mirror 2 is disposed at a position opposite to the light source 72 with respect to the fluorescent wheel 71 on the optical axis of the light source 72; the third optical axis conversion mirror 3 is disposed on the optical axis of the fluorescence converted by the first optical axis conversion mirror 1, and the fourth optical axis conversion mirror 4 is disposed to face the second optical axis conversion mirror 2 and the third optical axis conversion mirror 3.

The second to fourth optical axis conversion mirrors 2 to 4 are composed of two reflection mirrors for converting the optical axes of the light source light or the fluorescent light, and one dichroic mirror for transmitting the light source light without converting the optical axis of the light source light and converting the optical axis of the fluorescent light.

The second optical axis conversion mirror 2 is a reflecting mirror that converts the optical axis of the light source light that has passed through the diffusion layer 141 of the fluorescent wheel 71 by 90 degrees, the third optical axis conversion mirror 3 is a reflecting mirror that converts the optical axis of the fluorescent light converted by the first optical axis conversion mirror 1 by 90 degrees, and the fourth optical axis conversion mirror 4 is a dichroic mirror that converts the optical axis of the fluorescent light converted by the third optical axis conversion mirror 3 by 90 degrees without changing the optical axis of the light source light converted by the second optical axis conversion mirror 2.

< example >

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is an external perspective view of a projector 10. In the present embodiment, the left and right represent the left and right directions with respect to the projection direction, and the front and rear represent the front and rear directions with respect to the traveling 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 for covering a projection port is provided on a side of a front panel 12 which is a side plate in front of a main body casing, and the front panel 12 has a plurality of exhaust holes 17. Although not shown, the projector 10 includes an Ir receiving unit that receives a control signal from a remote controller.

Further, a key/indicator portion 37 is provided on the top panel 11 as the main body case. The key/indicator unit 37 is provided with 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, a key or indicator such as an overheat indicator for notifying when the light source device, the display element, the control circuit, or the like is overheated, and the like.

Further, on the back surface of the main body case, various terminals 20 such as an input/output connector portion including a USB terminal, a D-SUB terminal for inputting image signals, an S terminal, an RCA terminal, and the like, and a power adapter plug are provided on the back 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 a block diagram of fig. 2. The projector control unit is constituted by a control unit 38, an input/output interface 22, an image conversion unit 23, a display encoder 24, a display drive unit 26, and the like. The image signals of various specifications input from the input/output connector section 21 are converted into image signals of a predetermined format suitable for display by the image conversion section 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 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 in accordance with the image signal output from the display encoder 24. When the light source 72 of the light source device 63 is turned on, the light beam emitted from the light source device 63 enters the display element 51 through the light source side optical system, and a light image is formed by the reflected light of the display element 51 controlled by the display driving unit 26, whereby a display image is projected on a screen, not shown, through the projection system lens group as the projection side optical system. The movable lens group 97 of the projection optical system is driven by the lens motor 45 for zoom adjustment and focus adjustment.

The image compression/expansion unit 31 performs recording processing of: the luminance signal and the color difference signal of the image signal are data-compressed by ADCT and huffman coding, and are sequentially written into the memory card 32 which is a removable recording medium. Further, the image companding unit 31 performs the following processing in the playback mode: the image data recorded in the memory card 32 is read out, each image data constituting a series of moving pictures is expanded in units of 1 frame, and the image data is output to the display encoder 24 via the image conversion unit 23, so that the moving pictures and the like can be displayed based on the image data stored in the memory card 32.

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

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

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

The control unit 38 controls the power supply control circuit 41, and the power supply control circuit 41 turns on the light source 72 of the light source device 63 when the power switch button is operated. Further, the control unit 38 causes the cooling fan drive control circuit 43 to detect the temperature by 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. Further, the control unit 38 performs control such that: the cooling fan drive control circuit 43 keeps the rotation of the cooling fan even after the projector main body is powered OFF (turned OFF) by a timer or the like, and further powers OFF the projector main body 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, in the projector 10, a light source control circuit board 102 on which a power circuit module 101 and the like are mounted is disposed near the right side panel 14, a Sirocco fan type blower 110 is disposed substantially at the center, a control circuit board 103 is disposed near the blower 110, a light source device 63 is disposed near the front panel 12, and an optical system unit 70 is disposed near the left side panel 15. In the projector 10, the partition wall 120 hermetically partitions the interior of the housing 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, and the blower 110 is disposed such that the intake port 111 is located in the intake-side space chamber 121 and the exhaust port 113 is located at the boundary between the exhaust-side space chamber 122 and the intake-side space chamber 121.

The optical system unit 70 has a substantially コ -shaped configuration including 3 modules, i.e., an illumination-side 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-side module 80 located between the illumination-side module 78 and the left side panel 15.

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

The image generation block 79 includes, as the light source side optical system 62: an optical axis changing mirror 74 for changing the optical axis direction of the bundle of rays emitted from the light guide device 75; a plurality of condensing lenses for condensing the light reflected by the optical axis changing mirror 74 to the display element 51; and an irradiation mirror 84 that irradiates the display element 51 with the light flux that has passed through the condenser lenses at a predetermined angle. Further, 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 high in temperature.

The projection side module 80 has a lens group of a projection side optical system 90 that emits light reflected by the display element 51 and forms an image to a screen. The projection-side optical system 90 includes a fixed lens group 93 built in a fixed lens barrel and a movable lens barrel group 97 built in a movable lens barrel, and is a variable focus lens having a zoom function, and the movable lens group 97 is moved by a lens motor to perform zoom adjustment and focus adjustment.

In the internal structure of the projector 10, components lower in temperature than the light source device 63 are disposed in the intake-side spatial chamber 121. Specifically, a light source control circuit substrate 102, a blower 110, a control circuit substrate 103, an image generation module 79 of the optical system unit 70, a projection side module 80 of the optical system unit 70, and a condenser lens in the illumination side module 78 of the optical system unit 70 are arranged.

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

Further, the light source device 63 includes: a fluorescent wheel 71 as a light emitting plate that emits light in wavelength bands of red, green, and blue, which are three primary colors of light, by irradiation with light; a wheel motor 73 as a driving device for rotationally driving the fluorescent wheel 71; a plurality of light sources 72 that irradiate the fluorescent wheel 71 with light in a blue wavelength band; and a plurality of mirrors for guiding the light of red, green, and blue wavelength bands emitted from the fluorescent wheel 71 to the light guide device 75.

The plurality of light sources 72 are arranged such that the optical axis of each light source 72 is substantially perpendicular to the optical axis of the light guide device 75. The fluorescent wheel 71 is disposed near the front panel 12 so as to face the light source 72. Specifically, the optical axis of the light source 72 is arranged perpendicular to the wheel surface of the fluorescent wheel 71. That is, the rotation shaft of the wheel motor 73 that rotates the fluorescent wheel 71 is parallel to the optical axis of the light source 72. The fluorescent wheel 71 is configured to emit red and green fluorescent light toward the light source 72 and transmit blue wavelength band light from the light source 72.

As shown in fig. 4, the luminescent wheel 71 serving as the luminescent plate has three sector-shaped segment regions on a disk-shaped base material. Two of the three segment regions are reflective portions, and the remaining one segment region is a transmissive portion. Specifically, the fluorescent wheel 71 is: the reflector plate 130 as a sector-shaped reflector in which the red phosphor layer 131R and the green phosphor layer 131G are disposed adjacent to each other in the circumferential direction as the two types of phosphor layers 131 emitting light of different wavelength bands, and the diffuser plate 140 as a sector-shaped transmission portion disposed adjacent to the diffuser layer 141 and the phosphor layer 131 are integrally formed by being joined and fixed to a motor shaft provided on the rotating shaft of the wheel motor 73. In addition, the boundary surface between the reflection plate 130 and the diffusion plate 140 is also joined.

In addition, the fluorescent wheel 71 is: a circular opening is formed in the center portion, which corresponds to the shape of a cylindrical rotating shaft as a connecting portion with the wheel motor 73, the rotating shaft is inserted into the circular opening, and the motor hub (hub) is joined to the vicinity of the center portion of the reflection plate 130 and the diffusion plate 140, thereby firmly connecting and integrating the two.

Thus, 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 a wheel motor 73 as a driving device which is driven and controlled by the control unit 38 of the projector control unit.

The reflection plate 130 as the reflection portion is formed of an opaque base material made of a heat conductive member such as a copper plate or aluminum. The reflection plate 130 is formed by silver vapor deposition or the like on the entire surface of the light source 72 side on which the phosphor layer 131 is mounted, and forms a reflection layer that reflects blue light source light from the light source 72 and red and green wavelength band fluorescence generated by the phosphor. On the reflective layer, a phosphor layer 131 is formed. This reflective layer can be easily formed because one surface of the reflective plate 130 is mirror-finished.

In addition, two kinds of strip-shaped phosphor layers 131 are formed adjacent to each other in the circumferential direction by coating in the vicinity of the outer periphery of the sector-shaped reflector 130 having a major arc (major arc) which is an arc of at least half a circle. On the reflecting plate 130, a red phosphor layer 131R containing a phosphor which absorbs light from the light source 72 as excitation light by being irradiated with the light source light and is excited to emit light of a wavelength band of red as a primary color is formed, and a green phosphor layer 131G containing a phosphor which absorbs light from the light source 72 as excitation light and emits light of a wavelength band of green as a primary color is similarly formed adjacent to the red phosphor layer 131R. The phosphor layer 131 is composed of a phosphor crystal and a binder.

The diffusion plate 140 serving as a transmission unit is made of a transparent base material such as a glass base material or a transparent resin base material, and has a diffusion layer 141 over the entire surface on the light source 72 side. Specifically, the diffuser plate 140 is formed by applying an optical treatment such as roughening treatment by blast (blast) processing or the like to one entire surface of a fan-shaped transparent base material having a minor arc (minor arc) of about one-third of the circumference. Thereby, the diffusion layer 141 is formed, and the diffusion layer 141 adds a diffusion effect to the blue light source light when the incident blue light source light transmits the diffusion plate 140.

Further, the diffusion plate 140 is disposed adjacent to the reflection plate 130 in the circumferential direction, and thus the diffusion layer 141 is disposed adjacent to the phosphor layer 131. 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. In addition, the diffusion layer 141 may be formed on the surface on the opposite side instead of the diffusion layer 141 on the light source 72 side.

The light source 72 irradiates light to the phosphor layer 131 and the diffusion layer 141 disposed in the vicinity of the outer periphery of the phosphor wheel 71, is configured as a laser emitter or a blue light emitting diode, and emits blue wavelength band light as visible light having a wavelength shorter than the red and green wavelength band light emitted from the red and green phosphor layers 131R and 131G.

By disposing the light source 72 so as to face the luminescent wheel 71 having the luminescent material layer 131 and the diffusion layer 141 in this manner, it is possible to separate the luminescent light emitted from the luminescent material layer 131 formed in the reflection portion of the luminescent wheel 71 from the light source light transmitted through the diffusion plate 140 which is the transmission portion of the luminescent wheel 71. That is, by sequentially irradiating the phosphor layer 131 and the diffusion layer 141 of the rotating luminescent wheel 71 with blue light source light, when the light source light emitted from the light source 72 is irradiated to the phosphor layer 131 of the luminescent wheel 71 as excitation light, the luminescent light is emitted on the light source 72 side, and when the light source light emitted from the light source 72 is irradiated to the diffusion layer 141 of the transmission portion of the luminescent wheel 71, the light source light is diffused and transmitted on the opposite side of the light source 72.

Since the reflecting layer is formed on the surface of the reflecting plate 130 as the reflecting portion on which the phosphor layers 131 are arranged, if the light source light having directivity is irradiated from the light source 72 to the red phosphor layer 131R, the phosphor of the red phosphor layer 131R absorbs the blue light as the excitation light and emits the fluorescence of the red wavelength band in all directions. The red fluorescent light emitted toward the light source 72 is incident on the light guide device 75 via the condensing optical system having a mirror, and the red fluorescent light emitted toward the opaque base material is reflected by the reflective layer, and most of the reflected light is incident on the light guide device 75 as the light emitted from the fluorescent wheel 71 via the condensing optical system having a mirror.

Further, since the blue light source light irradiated to the reflective layer without being absorbed by the phosphor of the red phosphor layer 131R is also reflected by the reflective layer and can be emitted again to the red phosphor layer 131R side to excite the phosphor, the utilization efficiency of the blue light source light can be improved and bright light emission can be achieved.

The blue light source light that is reflected by the reflective layer without being absorbed by the phosphor and returns from the red phosphor layer 131R to the light source 72 side travels from the red phosphor layer 131R to the light source 72 side together with the red phosphor. However, the blue light source light is separated from the red fluorescent light by a dichroic mirror that is an optical axis converter that reflects the red light and transmits the blue light. That is, of the light emitted from the fluorescent wheel 71 toward the light source 72, only the red fluorescent light is reflected by the dichroic mirror and enters the light guide device 75 via another mirror or lens of the condensing optical system.

Similarly, if the light from the light source 72 is irradiated to the layer 131G of the green phosphor, the green wavelength band fluorescence emitted from the green phosphor emits light as bright as the red fluorescence, is reflected by the optical axis conversion mirror and separated from the blue light source light on the return light source 72 side, and then enters the light guide device 75 via another mirror or lens of the condensing optical system.

Further, if light source light such as laser light in the blue wavelength band is irradiated from the light source 72 to the diffusion layer 141, since the diffusion layer 141 exerts a diffusion effect on the incident blue light source light, blue light which is diffused light similar to light (red light and green light) emitted from the fluorescent material layer 131 is emitted from the diffusion layer 141, and the blue light is incident on the light guide device 75 via a condensing optical system having a mirror.

Accordingly, if the light source 72 emits light source light having directivity while rotating the fluorescent wheel 71, light in the red, green, and blue wavelength bands sequentially enters the light guide device 75 from the fluorescent wheel 71 through the condensing optical system having a mirror, and the DMD, which is the display element 51 of the projector 10, displays the light of each color in a time-division manner in accordance with data, thereby generating a color image on the screen.

As shown in fig. 5, the light source device 63 includes a collimator lens 150, and the collimator lens 150 is disposed on the light emitting side of the light source 72 on the optical axis and converts light emitted from the light source 72 into parallel light. The light source device 63 includes a light collecting optical system including first to fourth optical axis conversion mirrors 1 to 4, and a plurality of convex lenses or the like, the first to fourth optical axis conversion mirrors 1 to 4 reflecting or transmitting light of a predetermined wavelength band emitted from the fluorescent wheel 71 to collect light of each color emitted from the fluorescent wheel 71 on the same optical path, and the plurality of convex lenses or the like collecting light beams emitted from the fluorescent wheel 71 and incident on the light guide device 75.

The following describes the condensing optical system of the present embodiment. The light collecting optical system includes 4 optical axis conversion mirrors, and the 4 optical axis conversion mirrors are arranged at predetermined positions so that the optical axes of the red and green fluorescent lights emitted and separated from the fluorescent wheel 71 in different directions coincide with the optical axis of the blue light source light, and the red and green lights and the blue light are collected on the same optical path. The optical axis conversion mirror is configured by a dichroic mirror disposed between the light source 72 and the fluorescent wheel 71, which transmits the excitation light and reflects the fluorescent light from the fluorescent material, and a plurality of reflection mirrors and dichroic mirrors, which condense the excitation light transmitted through the transmission portion of the fluorescent wheel 71 and the fluorescent light reflected by the dichroic mirror on the same optical path and can irradiate light in the same direction.

Specifically, the condensing optical system includes: a first optical axis conversion mirror 1 as a dichroic mirror, which is disposed between the luminescent wheel 71 and the light source 72, transmits light source light without changing the optical axis of the light source light emitted from the light source 72, and converts the direction of the optical axis of the luminescent light emitted from the layer 131 of the luminescent material; a second optical axis conversion mirror 2 for converting the direction of the optical axis of the light source light transmitted through the diffusion layer 141 of the fluorescent wheel 71; and third and fourth optical axis conversion mirrors 3 and 4 for further converting the optical axis of the fluorescence converted by the first optical axis conversion mirror 1 and the optical axis converted by the second optical axis conversion mirror 2, thereby making the optical axes of the fluorescence and the light source light coincide with each other and converging the fluorescence and the light source light on the same optical path.

In the present embodiment, the first optical axis conversion mirror 1 is a dichroic mirror, is disposed between the light source 72 and the fluorescent wheel 71 on the optical axis of the light source 72, and converts the optical axes of the red and green fluorescent lights emitted from the fluorescent wheel 71 by 90 degrees without changing the optical axis of the blue light source light emitted from the light source 72. That is, the first optical axis conversion mirror 1 transmits blue light source light, which is excitation light, emitted from the light source 72, and reflects red and green wavelength band fluorescent light emitted from the fluorescent material of the fluorescent material layer 131 of the fluorescent wheel 71 while changing the direction thereof at an angle of 90 degrees.

The second optical axis converter 2 is a normal reflecting mirror, and is disposed at a position opposite to the light source 72 with respect to the fluorescent wheel 71 on the optical axis of the light source 72, and converts the optical axis of the blue light source light transmitted through the diffusion layer 141 in the transmission portion of the fluorescent wheel 71 by 90 degrees. That is, the second optical axis converter 2 redirects and reflects the blue wavelength band light emitted from the fluorescent wheel 71 at an angle of 90 degrees. Further, the second optical axis conversion mirror 2 may be a dichroic mirror capable of reflecting light in the blue wavelength band, instead of a reflecting mirror.

The third optical axis converter 3 is a reflecting mirror, and is disposed opposite to the first optical axis converter 1 on the optical axes of the red and green fluorescent lights converted by the first optical axis converter 1, and converts the optical axes of the fluorescent lights converted by the first optical axis converter 1 by 90 degrees. That is, the third optical axis conversion mirror 3 further redirects and reflects the red and green fluorescence reflected by the first optical axis conversion mirror 1 at an angle of 90 degrees. Further, the third optical axis conversion mirror 3 may be a dichroic mirror capable of reflecting red and green light, instead of a reflecting mirror.

The fourth optical axis converter 4 is a dichroic mirror, and is disposed to face the second optical axis converter 2 and the third optical axis converter 3, and converts the optical axes of the red and green fluorescent lights converted by the third optical axis converter 3 by 90 degrees without changing the optical axis of the blue light source light converted by the second optical axis converter 2. That is, the fourth optical axis converter 4 is disposed at a position where the optical axis of the blue light source light reflected by the second optical axis converter 2 intersects the optical axes of the red and green wavelength band fluorescent lights reflected by the third optical axis converter 3, and transmits the blue light source light reflected by the second optical axis converter 2 to travel straight, while the red and green wavelength band fluorescent lights reflected by the third optical axis converter 3 are redirected at an angle of 90 degrees and reflected.

Thus, the blue light source light transmitted through the fourth optical axis conversion mirror 4 and the red and green fluorescent lights reflected by the fourth optical axis conversion mirror 4 are collected on the same optical path, and the lights of all the colors are emitted in the same direction.

As described above, by arranging the 4 optical axis conversion mirrors 1 to 4 in the light collecting optical system, the optical axes of the respective color lights emitted from the fluorescent wheel 71 are converted to coincide with the optical axis of the light guide device 75, and the respective color lights can be collected on the same optical path and irradiated in the same direction, so that the emitted lights of the respective colors from the fluorescent wheel 71 can be sequentially incident on the light guide device 75.

The light collecting optical system is formed of a lens and a mirror, in which a plurality of lenses for collecting light by combining with a mirror such as a dichroic mirror are arranged between the light source 72 and the luminescent wheel 71 and on the path of the luminescent light from the luminescent wheel 71 and the light source light transmitted through the luminescent wheel 71. Thus, the light beam whose traveling direction is changed by the mirror can be condensed by the lens, and the light can be efficiently incident on the light guide device 75.

Specifically, the blue light emitted from the plurality of light sources 72 is collimated by the collimator lens 150 if the light source 72 is a blue light emitting diode, or collimated by the collimator lens 150 if the light source 72 is a blue laser emitter, and is condensed by the first convex lens 153a disposed between the collimator lens 150 and the first optical axis converter 1. Further, by disposing the condenser lens groups 155 near both the front and back surfaces of the luminescent wheel 71, the light of the blue wavelength band condensed by the first convex lens 153a is irradiated to the luminescent wheel 71 in a state of being further condensed by the condenser lens groups 155, and the respective light fluxes emitted from both the front and back surfaces of the luminescent wheel 71 are also condensed.

Further, since the second convex lens 153b is disposed between the second optical axis conversion mirror 2 and the fourth optical axis conversion mirror 4, the third convex lens 153c is disposed between the first optical axis conversion mirror 1 and the third optical axis conversion mirror 3, the fourth convex lens 153d is disposed between the third optical axis conversion mirror 3 and the fourth optical axis conversion mirror 4, and the light guide device incident lens 154 is disposed between the fourth optical axis conversion mirror 4 and the light guide device 75, the light emitted from the fluorescent wheel 71 enters the light guide device 75 as a condensed bundle of rays.

Therefore, the blue light source light emitted from the light source 72 through the collimator lens 150 is condensed by the first convex lens 153a, passes through the first optical axis converter 1, is further condensed by the condenser lens group 155, and is irradiated to the phosphor layer 131 or the diffusion layer 141 of the phosphor wheel 71.

Then, when the light source light is irradiated to the diffusion layer 141 of the diffusion plate 140 as the transmission part of the luminescent wheel 71, the blue light source light which has transmitted the diffusion layer 141 and becomes the diffused light is condensed by the condensing lens group 155 disposed on the luminescent wheel 71 in the reverse direction of the light source 72 side, and is irradiated to the second optical axis changing mirror 2. The blue light source light is reflected by the second optical axis conversion mirror 2, condensed by the second convex lens 153b, transmitted through the fourth optical axis conversion mirror 4, condensed by the light guide device incident lens 154, and then incident on the light guide device 75.

When the light source light is applied to the phosphor layer 131 of the reflector 130 as a reflection portion of the phosphor wheel 71, the red or green wavelength band phosphor light is emitted toward the light source 72. Then, the fluorescence is condensed by the condenser lens group 155 on the light source 72 side of the fluorescence wheel 71, and is irradiated to the first optical axis conversion mirror 1. Here, the fluorescence is reflected by the first optical axis conversion mirror 1, and the blue light source light that is not absorbed and reflected by the phosphor of the phosphor layer 131 is transmitted through the first optical axis conversion mirror 1. This can separate the red or green fluorescent light from the blue light source light, thereby preventing the color purity from being lowered.

The fluorescence reflected by the first optical axis conversion mirror 1 is condensed by the third convex lens 153c and is applied to the third optical axis conversion mirror 3. Then, the fluorescence is reflected by the third optical axis conversion mirror 3, condensed by the fourth convex lens 153d, and then applied to the fourth optical axis conversion mirror 4. The fluorescence is further reflected by the fourth optical axis converter 4, condensed by the light guide device entrance lens 154, and enters the light guide device 75.

As described above, according to the present invention, the light source light emitted from the luminescent wheel 71 and the emission light path of the luminescent light of each color can be separated by providing the luminescent wheel 71 itself as the reflection plate 130 without providing a special reflection layer that reflects only light of a predetermined wavelength band on the surface of the luminescent wheel 71, and providing the diffusion plate 140 having the diffusion layer 141 that transmits and diffuses the light source light as the transmission portion in a part of the reflection plate 130. This makes it possible to provide the light source device 63 having a simple structure and easy to manufacture, and the projector 10 including the light source device 63.

Further, although a small amount of blue light source light reflected from the fluorescent wheel 71 is present in the light emitted from the fluorescent wheel 71 in addition to the red or green fluorescent light, the blue light source light reflected from the fluorescent wheel 71, which is mixed in the fluorescent light of the red or green wavelength band, can be eliminated by disposing the first optical axis conversion mirror 1 as a dichroic mirror between the light source 72 and the fluorescent wheel 71, so that it is possible to provide the light source device 63 capable of emitting each color light having high color purity in which the light source light is surely prevented from being mixed in the fluorescent light, and the projector 10 including the light source device 63.

Further, by using a laser emitter of a blue wavelength band for the light source 72, the phosphor can be efficiently excited and emitted. Further, the phosphor layer 131 having at least a phosphor emitting light in a red wavelength band and a phosphor emitting light in a green wavelength band is formed on the phosphor wheel 71, whereby light in red and green wavelength bands as primary colors can be generated. Further, by providing the diffusion layer 141 in the transmission portion, the laser light having directivity can be diffused and transmitted, and the light in the blue wavelength band, which is the primary color, can be made to enter the light guide device 75 as diffused light similar to the fluorescence.

In addition, the diffuser 141 may not be provided in the transmissive portion, but the transmissive portion may be formed of a space that is a normal glass plate or a through hole surrounded by a frame, and the diffuser may be fixedly disposed on the optical path of the blue light source light such as on the side of the light source 72 in front of the luminescent wheel 71 or between the luminescent wheel 71 and the second optical axis conversion mirror 2. In the light source device 63, when the light source 72 is a blue light emitting diode, the diffusion layer 141 may not be provided on the light path of the transmission portion or the blue light source light.

The optical axis conversion mirrors 1 to 4 used for the condensing optical system of the light source device 63 may have various types and installation methods.

Next, another modified example of the arrangement structure of the optical axis changing mirrors 1 to 4 will be described with reference to fig. 6 and 7.

Fig. 6(a) is a schematic diagram showing an optical path L of light source light emitted from the light source 72 and an optical path F of fluorescent light emitted upon receiving the light source light in the optical layout of the light source device 63 (see fig. 5). That is, in the first optical layout shown in fig. 6(a), as shown in fig. 7, the first optical axis conversion mirror 1 is a dichroic mirror that transmits blue light source light and reflects red and green fluorescent light. The second optical axis converter 2 is a reflecting mirror that reflects the blue light source light. The third optical axis converter 3 is a reflecting mirror that reflects red and green fluorescent light, and the fourth optical axis converter 4 is a dichroic mirror that transmits blue light source light and reflects red and green fluorescent light.

The optical layout may be a second optical layout (see fig. 6(b)) that is: as shown in fig. 7, the fourth optical axis conversion mirror 4 of the first optical layout is a dichroic mirror that reflects blue light source light and transmits red and green fluorescent light.

Further, a third optical layout may be adopted in which the second optical axis conversion mirror 2 is a dichroic mirror that transmits blue light source light and reflects red and green fluorescent light, and the fourth optical axis conversion mirror 4 is a reflecting mirror (see fig. 6 (c)). This allows only the fluorescence to be repeatedly reflected, and the light source light and the fluorescence can be condensed on the same optical path on the optical axis of the light source 72.

In addition, the second optical axis conversion mirror 2 in the third optical layout may be a dichroic mirror that reflects blue light source light and transmits red or green fluorescent light, thereby forming a fourth optical layout (see fig. 6(d)) which is another optical layout.

Further, the light collection optical system of the light source device 63 may adopt a fifth optical layout (see fig. 6(e)) that: the second optical axis conversion mirror 2 is a reflecting mirror that converts the optical axis of the blue light source light transmitted through the diffusion layer 141 of the diffusion plate 140 of the fluorescent wheel 71 by 90 degrees, the fourth optical axis conversion mirror 4 is a reflecting mirror that converts the optical axis of the blue light source light converted by the second optical axis conversion mirror 2 by 90 degrees, and the third optical axis conversion mirror 3 is a dichroic mirror that converts the optical axis of the blue light source light converted by the fourth optical axis conversion mirror 4 by 90 degrees without changing the optical axes of the red and green fluorescent lights converted by the first optical axis conversion mirror 1.

In addition, a sixth optical layout (see fig. 6 f) which is another optical layout may be configured, that is: the third optical axis conversion mirror 3 in the fifth optical layout is a dichroic mirror that transmits blue light source light and reflects red and green fluorescent light.

Further, the second to fourth optical axis conversion mirrors 2 to 4 are not limited to the case where the second to fourth optical axis conversion mirrors 2 to 4 are configured by 2 mirrors for converting the optical axes of the light source light or the fluorescent light and 1 dichroic mirror for converting one of the optical axes of the light source light and the fluorescent light without converting the other, and the second to fourth optical axis conversion mirrors 2 to 4 may adopt a seventh optical layout (see fig. 6(g)) having 3 mirrors for converting the optical axis of the blue light source light, and the red and green fluorescent lights and the blue light source light are condensed on the same optical path mainly by repeatedly reflecting the blue light source light.

In this manner, various optical layouts can be adopted by variously combining the characteristics of the second to fourth optical axis conversion mirrors 2 to 4 and arranging them at predetermined positions and angles. Therefore, not only the light source device 63 and the projector 10 having high color purity and easy to manufacture can be provided as described above, but also the degree of freedom in arrangement of the apparatus such as the projector 10 to which such a light source device 63 is mounted can be improved.

According to the present invention, the light source device and the projector including the light source device can be provided which are simple in structure, easy to manufacture, and capable of emitting light of respective colors having high color purity by separating the light source light emitted from the luminescent wheel from the emission light path of the luminescent light of respective colors by using the luminescent wheel itself as a reflecting plate without providing a special reflecting layer which reflects only light of a predetermined wavelength band on the surface of the luminescent wheel and providing a transmitting portion which transmits the light source light on a part of the reflecting plate.

The present invention is not limited to the above-described embodiments, and can be freely modified and improved without departing from the scope of the invention. For example, the phosphor layer 131 disposed on the reflection plate 130 is not limited to the case where the red and green phosphor layers 131R and 131G are disposed, and the phosphor layer 131 capable of emitting light in a wavelength band of an auxiliary color such as yellow may be further disposed.

The number of optical axis conversion mirrors disposed in the light source device 63 is not limited to 4, and 5 or more optical axis conversion mirrors may be disposed to condense the separated light source light and fluorescence light on the same optical path. However, it is preferable to provide 4 optical axis conversion mirrors 1 to 4 because a simple and compact light source device 63 can be realized.

In the above-described embodiment, a dichroic mirror is used for the purpose of converting the optical axis direction or selecting the transmission or reflection of light in accordance with the wavelength, but the present invention is not limited to this, and for example, another alternative means such as a dichroic prism may be used instead of the dichroic mirror.

Further, the luminescent wheel 71 may not be formed in a disk shape, but may be formed as a rectangular luminescent plate and fixedly disposed. At this time, by disposing an adjusting device for changing the irradiation direction of the light from the light source 72 between the light source 72 and the light emitting panel or by providing a light source driving device for driving to change the position and/or the irradiation direction of the light source 72, the irradiation points of the light from the light source 72 are sequentially positioned in each segment region, whereby the light of each color can be incident on the light guide device 75 via the condensing optical system. As the adjustment device, for example, a light polarizer using a KTN crystal, an acoustic optical element, a MEMS mirror, or the like can be used.

Claims (18)

1. A light source device is provided with:

a light emitting plate having a plurality of segment regions on a substrate, at least one of the segment regions being a reflection portion on which a phosphor layer that receives excitation light and emits light of a predetermined wavelength band is formed, and at least one of the segment regions being a transmission portion through which light is transmitted;

a light source for irradiating excitation light to the phosphor layer of the light emitting panel;

a first optical axis conversion mirror disposed between the light source and the light emitting panel, and transmitting excitation light and reflecting fluorescence from the phosphor; and

and second to Nth optical axis conversion mirrors which converge the excitation light transmitted through the transmission part of the light emitting panel and the fluorescence reflected by the first optical axis conversion mirror on the same optical path and irradiate in the same direction, wherein N is an integer greater than 2.

2. The light source device according to claim 1,

the light source is a laser light emitter with a blue waveband.

3. The light source device according to claim 2,

the phosphor forming the phosphor layer is composed of at least a phosphor emitting light of a red wavelength band and a phosphor emitting light of a green wavelength band.

4. The light source device according to claim 2,

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

5. The light source device according to claim 3,

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

6. The light source device according to any one of claims 1 to 3, wherein,

the second to nth optical axis conversion mirrors are disposed on paths of the fluorescence from the light emitting panel and the light source light transmitted through the light emitting panel, and cooperate with the first optical axis conversion mirror to condense the light, thereby forming a condensing optical system.

7. The light source device according to claim 6, wherein,

a diffusion layer for diffusing the excitation light is formed in the transmission portion of the light emitting panel;

a first optical axis conversion mirror that transmits light source light emitted from the light source without changing an optical axis of the light source light and converts a direction of an optical axis of the fluorescent light emitted from the phosphor layer;

the second to nth optical axis conversion mirrors are the following mirrors:

a second optical axis conversion mirror which is a dichroic mirror or a reflecting mirror for converting the direction of the optical axis of the light source light transmitted through the diffusion layer of the light emitting panel; and

and a third optical axis converter and a fourth optical axis converter for further converting the optical axis of the fluorescence converted by the first optical axis converter or the optical axis converted by the second optical axis converter, thereby condensing the fluorescence and the light source light on the same optical path.

8. The light source device according to claim 7, wherein,

the first optical axis conversion mirror is disposed on the optical axis of the light source between the light emitting panel and the light source;

the second optical axis conversion mirror is disposed on the optical axis of the light source at a position opposite to the light source with respect to the light emitting panel;

the third optical axis conversion mirror is disposed on the optical axis of the fluorescence converted by the first optical axis conversion mirror;

the fourth optical axis conversion mirror is disposed opposite to the second optical axis conversion mirror and the third optical axis conversion mirror.

9. The light source device according to claim 7, wherein,

the second to fourth optical axis conversion mirrors are the following mirrors:

2 reflecting mirrors for converting the optical axes of the light source light or the fluorescent light; and

and 1 dichroic mirror for converting one of the light source light and the fluorescence light without converting the other.

10. The light source device according to claim 8,

the second to fourth optical axis conversion mirrors are the following mirrors:

2 reflecting mirrors for converting the optical axes of the light source light or the fluorescent light; and

and 1 dichroic mirror for converting one of the light source light and the fluorescence light without converting the other.

11. The light source device according to claim 9, wherein,

the second optical axis conversion mirror is a reflecting mirror for converting the optical axis of the light source light transmitted through the diffusion layer of the light emitting panel by 90 degrees;

the third optical axis conversion mirror is a reflecting mirror for converting the optical axis of the fluorescence converted by the first optical axis conversion mirror by 90 degrees;

the fourth optical axis conversion mirror is a dichroic mirror that does not change the optical axis of the light source light converted by the second optical axis conversion mirror and converts the optical axis of the fluorescent light converted by the third optical axis conversion mirror by 90 degrees.

12. The light source device according to claim 10,

the second optical axis conversion mirror is a reflecting mirror for converting the optical axis of the light source light transmitted through the diffusion layer of the light emitting panel by 90 degrees;

the third optical axis conversion mirror is a reflecting mirror for converting the optical axis of the fluorescence converted by the first optical axis conversion mirror by 90 degrees;

the fourth optical axis conversion mirror is a dichroic mirror that does not change the optical axis of the light source light converted by the second optical axis conversion mirror and converts the optical axis of the fluorescent light converted by the third optical axis conversion mirror by 90 degrees.

13. The light source device according to claim 9, wherein,

the second optical axis conversion mirror is a reflecting mirror for converting the optical axis of the light source light transmitted through the diffusion layer of the light emitting panel by 90 degrees;

the fourth optical axis conversion mirror is a reflecting mirror for converting the optical axis of the light source light converted by the second optical axis conversion mirror by 90 degrees;

the third optical axis conversion mirror is a dichroic mirror that does not change the optical axis of the fluorescence converted by the first optical axis conversion mirror and converts the optical axis of the light source light converted by the fourth optical axis conversion mirror by 90 degrees.

14. The light source device according to claim 10,

the second optical axis conversion mirror is a reflecting mirror for converting the optical axis of the light source light transmitted through the diffusion layer of the light emitting panel by 90 degrees;

the fourth optical axis conversion mirror is a reflecting mirror for converting the optical axis of the light source light converted by the second optical axis conversion mirror by 90 degrees;

the third optical axis conversion mirror is a dichroic mirror that does not change the optical axis of the fluorescence converted by the first optical axis conversion mirror and converts the optical axis of the light source light converted by the fourth optical axis conversion mirror by 90 degrees.

15. The light source device according to claim 7, wherein,

the second to fourth optical axis conversion mirrors are 3 reflection mirrors for converting the optical axes of the light source lights.

16. The light source device according to claim 8,

the second to fourth optical axis conversion mirrors are 3 reflection mirrors for converting the optical axes of the light source lights.

17. The light source device according to claim 1,

the light emitting panel is in a disk shape, and the light source device includes a driving device for rotating the light emitting panel in a circumferential direction.

18. A projector is provided with:

the light source device according to claim 1;

a display element;

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

a projection-side optical system that projects an image emitted from the display element onto a screen; and

and a projector control unit for controlling the light source device and the display element.