JP2010224493A - Light source device and projection device - Google Patents

Abstract

An object of the present invention is to suppress the occurrence of a color braking phenomenon while using a light source and a color wheel having sufficient brightness for practical use.
A semiconductor laser 17 that emits spot light, a phosphor color wheel 19 in which a plurality of color filters are divided and arranged on a rotating disk, and a color wheel 19 that reflects the spot light within a predetermined angle range. Are sequentially scanned, and the polygon mirror 18 as a scanning body for emitting a plurality of colors of fluorescence from the color wheel 19 in a time-sharing manner, and synchronization for synchronizing the rotation phase of the color wheel 19 and the scanning phase of the polygon mirror 18 And a projection light processing unit 24 as a control unit.
[Selection] Figure 1

Description

  The present invention relates to a light source device and a projection device suitable for a projector device of a DLP (Digital Light Processing) (registered trademark) system.

  In a DLP projector, for example, a lamp, a color wheel that separates incident light into R, G, and B light in a time-sharing manner, a rod-type integrator that emits light emitted from the color wheel as planar light, and An optical engine having a tablet lens, a mirror, a relay lens, an image generating element, and a projection lens, to increase the transmittance of the color wheel and to obtain a uniform surface light by the integrator A configuration in which a collimator lens that collimates outgoing light from the light source and a microlens array attached to the outgoing surface side of the color wheel is considered. (Patent Document 1)

JP 2008-134433 A

  In the single-plate type DLP projector including the technology described in the above patent document, the occurrence of a color breaking phenomenon called a color breaking phenomenon is unavoidable at the timing when the color filter is switched on the optical axis as the color wheel rotates. It becomes.

In order to suppress this color braking phenomenon, it is necessary to increase the color switching speed of the light source, but there is a limit in the method using the color wheel. For example, when the rotation speed of the color wheel is 9000 rpm and the number of color segments of the same color per rotation of the color wheel is 2, when the color repetition frequency at 1 × speed is 60 Hz,
((9000 [rpm] / 60 [sec]) × 2) / 60 [Hz] = 5
Thus, the upper limit is 5 times speed.

  By the way, in a projector using an LED (light emitting diode) as a light source, an LED that emits light of R, G, and B colors is driven in a time-sharing manner, so that a color wheel becomes unnecessary, and the color repetition speed is limited by the switching speed of the LED. Is done.

  The manufacturer of the image generating element has reported that 48 times speed (2880 Hz when the color repetition frequency of 1 time speed is 60 Hz) is possible as a color repetition speed when using an LED as a light source. It has been confirmed that the color braking phenomenon can be suppressed almost completely at a speed.

  However, when an LED is used as a light source, practical brightness as a projector cannot be obtained at present in terms of light emission luminance.

  The present invention has been made in view of the above circumstances, and its object is to suppress the occurrence of a color braking phenomenon while using a light source and a color wheel having sufficient brightness for practical use. It is an object of the present invention to provide a light source device and a projection device that are capable of performing the above.

  The invention according to claim 1 is a light source that emits spot light, a color wheel in which a plurality of color filters are divided and arranged on a rotating disk, and spot light from the light source is reflected within a predetermined angle range. A scanning body that sequentially scans the color filters of the color wheel and emits light of a plurality of colors from the color wheel in a time-sharing manner; and a synchronization control unit that synchronizes the rotation phase of the color wheel and the scanning phase of the scanning body; It is characterized by comprising.

  According to a second aspect of the present invention, in the first aspect of the invention, the synchronization control unit is configured such that the scanning direction of the scanning body coincides with the moving direction of the color filter at the reflected light irradiation position of the color wheel. The color wheel is rotated.

  According to a third aspect of the present invention, in the first aspect of the present invention, the light source is one of a semiconductor laser and a fiber laser.

  According to a fourth aspect of the present invention, in the first aspect of the present invention, the scanning body includes a polygon mirror in which a plurality of plane mirrors are arranged along a peripheral wall surface.

  The invention according to claim 5 is the invention according to claim 3, wherein the number of color filters of the color wheel matches the number of plane mirrors of the polygon mirror that constitutes the scanning body. The rotation speed of the polygon mirror constituting the scanning body and the color wheel are rotated synchronously at the same rotation speed.

  According to a sixth aspect of the present invention, there is provided a light source that emits spot light, a color wheel in which a plurality of color filters are divided and arranged on a rotating disk, and spot light from the light source is reflected within a predetermined angle range so that the color is reflected. A scanning body that sequentially scans the color filter of the wheel and emits light of a plurality of colors from the color wheel in a time-sharing manner, and a synchronization control unit that synchronizes the rotation phase of the color wheel and the scanning phase of the scanning body A light source unit and a projection unit that forms and projects a light image for each of a plurality of colors of light emitted in a time-sharing manner from the color wheel of the light source.

  According to the present invention, it is possible to suppress the occurrence of a color braking phenomenon while using a light source and a color wheel having sufficient brightness for practical use.

The block diagram which shows the structure of the electronic circuit of the data projector apparatus which concerns on one Embodiment of this invention. The figure which shows the positional relationship of light source light, a polygon mirror, and the fluorescence color wheel mainly concerning the embodiment. The figure which shows the structure of the fluorescence color wheel which concerns on the same embodiment. The figure explaining the scanning with respect to one fluorescence filter in the fluorescence color wheel by the polygon mirror which concerns on the same embodiment on a plane.

  A DLP data projector apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a schematic functional configuration of an electronic circuit included in the data projector device 10 according to the embodiment.
Reference numeral 11 denotes an input / output connector unit including, for example, a pin jack (RCA) type video input terminal, a D-sub15 type RGB input terminal, and a USB (Universal Serial Bus) connector.

  Image signals of various standards input from the input / output connector unit 11 are input to an image conversion unit 13 which is also generally referred to as a scaler, through an input / output interface 12 (I / F) 12 and a system bus SB.

  The image conversion unit 13 unifies the input image signal into an image signal of a predetermined format suitable for projection, and stores it in the video RAM 14 which is a buffer memory for projection as appropriate, and then sends it to the projection image processing unit 15.

  At this time, data such as symbols indicating various operation states for OSD (On Screen Display) is also superimposed on the image signal by the video RAM 14 as necessary, and the processed image signal is sent to the projection image processing unit 15.

  The projection image processing unit 15 performs spatial processing by faster time-division driving that multiplies, for example, a frame rate of 60 [frames / second], the number of color components, and the number of display gradations according to the transmitted image signal. The micromirror element 16 which is a static light modulation element (SLM) is driven to display.

  The micromirror element 16 is turned on / off individually at a high speed by tilting angles of a plurality of micromirrors arranged in an array, for example, XGA (horizontal 1024 × vertical 768 dots). Form an image.

  On the other hand, laser light of an ultraviolet region, for example, a wavelength of 340 [nm] is generated by the oscillation of the semiconductor laser 17 and reflected by the peripheral wall surface of the polygon mirror 18 which is a rotating polygon mirror. The reflected light from the polygon mirror 18 is applied to one point on the circumference of the phosphor color wheel 19 which is a rotating body.

  For example, the phosphor color wheel 19 regularly divides and arranges three-color phosphors that emit fluorescence of R (red), G (green), and B (blue) when irradiated with ultraviolet light on the peripheral edge side of the bottom surface. Configured. By irradiating the laser beam reflected by the polygon mirror 18, R, G, B fluorescence is emitted from the phosphor color wheel 19 in a time-sharing manner.

  The light emitted from the phosphor color wheel 19 is converted into a light beam having a substantially uniform luminance distribution by irregular reflection inside the integrator 20. The light emitted from the integrator 20 is further converted into parallel light by the light source lens system 21 and then totally reflected by the mirror 22 and applied to the micromirror element 16.

  Then, an optical image is formed by the reflected light from the micromirror element 16, and the formed optical image is projected and displayed on a screen (not shown) to be projected via the projection lens unit 23.

  The semiconductor laser 17 oscillates ultraviolet laser light by excitation of the projection light processing unit 24. The projection light processing unit 24 is further connected to a motor (M) 25, a marker sensor 26, a motor (M) 27, and a marker sensor 28.

  The motor 25 rotates the polygon mirror 18, and its phase is controlled by the projection light processing unit 24. The marker sensor 26 is arranged to face the rotation peripheral end of the polygon mirror 18, and outputs a pulse as a detection signal at a timing facing a marker (not shown) arranged at one point on the polygon mirror 18 side. The projection light processing unit 24 detects the rotational phase and period of the polygon mirror 18 based on the pulse from the marker sensor 26.

  The motor 27 rotates the phosphor color wheel 19, and its phase is controlled by the projection light processing unit 24. The marker sensor 28 is arranged to face the rotation peripheral end of the phosphor color wheel 19, and a pulse as a detection signal at a timing facing a marker (not shown) arranged at one point of the peripheral end on the phosphor color wheel 19 side. Is output. The projection light processing unit 24 detects the rotational phase and period of the phosphor color wheel 19 based on the pulse from the marker sensor 28.

  The projection light processing unit 24 controls the rotational phases of the polygon mirror 18 and the phosphor color wheel 19 according to the image data given from the projection image processing unit 15.

  The CPU 29 controls all the operations of the above circuits. The CPU 29 is connected to the main memory 30 and the program memory 31. The main memory 30 is composed of DRAM. The program memory 31 is composed of an electrically rewritable nonvolatile memory, and stores an operation program, various fixed data, and the like. The CPU 29 executes a control operation in the data projector device 10 using the main memory 30 and the program memory 31.

Further, the CPU 29 executes various projection operations in accordance with key operation signals from the operation unit 32.
The operation unit 32 includes a key operation unit provided in the main body of the data projector device 10 and a laser light receiving unit that receives infrared light between a remote controller (not shown) dedicated to the data projector device 10. The operation unit 32 directly outputs a key operation signal based on the operated key to the CPU 29.

  The CPU 29 is further connected to the audio processing unit 33 via the system bus SB. The sound processing unit 33 includes a sound source circuit such as a PCM sound source, converts the sound data given during the projection operation into an analog signal, and outputs it from the speaker unit 34.

Next, the operation of the above embodiment will be described.
2 to 4 mainly show the configuration of the polygon mirror 18 and the phosphor color wheel 19 in detail.
FIG. 2 shows a polygon mirror 18 that reflects a spot beam B of laser light oscillated by the semiconductor laser 17 and a phosphor color wheel 19 that emits R, G, and B fluorescence in a time-sharing manner by irradiation of the reflected light. A structure, positional relationship, and each rotation direction are shown.

  The polygon mirror 18 is disposed so that the incident angle of each laser beam from the semiconductor laser 17 to each plane mirror formed on the peripheral wall surface of the polygon mirror 18 is 45 °. Therefore, the laser beam has an emission angle of 45 °, and as a result, the laser beam is bent by 90 ° by the polygon mirror 18 and irradiated to the peripheral edge of the bottom surface of the phosphor color wheel 19.

  Here, the polygon mirror 18 is composed of, for example, a 72-angle polygon mirror whose peripheral surface is composed of 72 plane mirrors. Corresponding to this, the phosphor color wheel 19 regularly divides and arranges 72 (= 24 each × RGB 3 colors) fluorescent color filters regularly at the peripheral edge of the bottom surface.

  Then, the projection light processing unit 24 controls the motor 25 and the motor 27 so that the polygon mirror 18 and the phosphor color wheel 19 have the same cycle and the rotation phases thereof coincide. FIG. 2 shows a case where both the polygon mirror 18 and the phosphor color wheel 19 rotate so that the peripheral end portions on the side visible in the drawing move along the arrows R1 and R2.

  The projection light processing unit 24 controls the rotational speed and phase of the polygon mirror 18 and the phosphor color wheel 19 according to the outputs of the marker sensor 26 and the marker sensor 28.

  FIG. 3 illustrates a specific configuration of the phosphor color wheel 19. 3A is a plan view of the disc-shaped phosphor color wheel 19, and FIG. 3B is a side view. As shown in the figure, the phosphor color wheel 19 is integrally formed by adhering a dichroic filter 19b having the same diameter on one surface of a disc-shaped transparent substrate 19a, and slightly on the other surface side from the transparent substrate 19a. A small-diameter fluorescent plate 19c is also attached.

  As shown in the drawing, the fluorescent plate 19c is regularly arranged with 72 substantially rectangular fluorescent color filters 19cR, 19cG, 19cB,. These fluorescent color filters 19cR, 19cG, 19cB,... Emit fluorescent light of R, G, B when the fluorescent material is excited by irradiation of the laser light reflected by the polygon mirror 18, and the fluorescent color wheel 19 is used. , R, G, B fluorescence is emitted to the integrator 20 in a time-sharing manner.

Next, scanning of the fluorescent color filters 19cR, 19cG, 19cB,... Of the phosphor color wheel 19 as the polygon mirror 18 rotates will be described.
FIG. 4 illustrates a state in which the laser light from the semiconductor laser 17 is reflected by the peripheral end surface of the rotating polygon mirror 18 and is applied to the fluorescent color filters 19cR, 19cG, 19cB,. FIG.

  When the polygon mirror 18 has a 72-corner thin prismatic shape as described above, the central angle φ of the peripheral end surface with respect to one plane mirror is 5 °. However, in this figure, for the sake of easy understanding visually, an 18-sided polygon mirror having a central angle φ of 20 ° is drawn.

  It is assumed that the polygon mirror 18 rotates about the point O in the direction of the arrow R1, and at the same time, the phosphor color wheel 19 also rotates in the direction of the arrow R2. The spot beam B from the semiconductor laser 17 is reflected at the point position P0 on the peripheral end face of the polygon mirror 18 and irradiates the phosphor color wheel 19 side.

  When one plane mirror of the polygon mirror 18 reaches a position P11 in the drawing, reflection by the mirror is started. In synchronization with the reflected light S at that time, one of the fluorescent color filters 19cR, 19cG, 19cB,... Of the phosphor color wheel 19 becomes a position P21 in the drawing, and the spot beam B is irradiated to the color filter. Is started.

  Thereafter, since the polygon mirror 18 and the phosphor color wheel 19 move in substantially the same direction on the plane of this figure with respect to the spot beam B from the semiconductor laser 17, the reflected light from the polygon mirror 18 is reflected by the phosphor color wheel 19. The same color filter is scanned.

  Then, when one plane mirror of the polygon mirror 18 reaches a position P12 in the drawing, the reflection at the mirror is finished. In synchronization with the reflected light E at that time, the corresponding color filter of the phosphor color wheel 19 becomes a position P22 in the figure, and the irradiation of the spot beam B to the color filter is also terminated.

  When the width along the rotation direction of one color filter constituting the phosphor color wheel 19 is W, the color filter is scanned by the width W over the moving stroke D.

  Therefore, when focusing attention on one color filter, for example, if “D = 2W”, when the speed when one color filter moves in the direction of the arrow R2 is V, the width W is V / Scan across the width W at a speed of 2.

  In this way, the rotational speed and both phases of the polygon mirror 18 and the phosphor color wheel 19 are accurately controlled by the motor 25, so that the spot beam B reflected by the polygon mirror 18 passes through the color filter of the phosphor color wheel 19. The scanning is performed slowly at a speed lower than the rotation speed.

  Actually, the polygon mirror 18 and the phosphor color wheel 19 are not the same center axis as shown in FIG. 2 but each rotation axis has a predetermined angle, and the bottom surface of the polygon mirror 18 is accurate. Is a polygon, not a circle, and the diameter of the center point and the end of one plane mirror are different from each other. Therefore, when the color filter of the phosphor color wheel 19 is scanned by the reflected light of the plane mirror, The trajectory crosses a substantially rectangular color filter with a slight arc.

  Compared to the above, when switching the spot beam B from the semiconductor laser 17 after reflection by one plane mirror of the polygon mirror 18 and reflection by the next plane mirror, the reflected light is reflected within a very short time. Will be scanned from the E direction to the S direction.

  Therefore, it is possible to sufficiently enhance the effect of suppressing the occurrence of the color break phenomenon called color breaking phenomenon.

When the polygon mirror 18 and the phosphor color wheel 19 are rotated synchronously including the phase at 7200 rpm, for example, the repetition frequency of the time-division fluorescent light emitted from the phosphor color wheel 19 is:
(7200 [rpm] / 60 [sec]) x (72 [segment] / 3 [color])
= 2880 [Hz]
= 60 [Hz] x 48 [Double speed]
Thus, a 48 × single plate type DLP projector can be realized. This double speed number is equal to the double speed number reported by the manufacturer of the micromirror element that the color braking phenomenon can be practically completely suppressed.

  As described above in detail, according to this embodiment, while using a light source having sufficient brightness in practice and a color wheel for obtaining a plurality of primary color lights in a time-sharing manner using light from the light source, The occurrence of the braking phenomenon can be sufficiently suppressed.

  In the above embodiment, the rotation direction of the polygon mirror 18 and the rotation direction of the phosphor color wheel 19 irradiated with the reflected light with respect to the spot beam B from the semiconductor laser 17 are the same. Accordingly, the scanning speed of the phosphor color wheel 19 with respect to one color filter is relatively decreased, and the scanning speed at the time of switching from one color filter to the next color filter is increased. The occurrence of the color braking phenomenon can be suppressed more reliably.

  Furthermore, in the above embodiment, the polygon mirror 18 is used as a scanning body that reflects the spot beam B from the semiconductor laser 17 and simultaneously scans and irradiates the color filter of the phosphor color wheel 19. Accordingly, it is possible to increase the speed with a simple structure, and it is possible to reliably suppress the occurrence of the color braking phenomenon while keeping the manufacturing cost of the apparatus low.

  Moreover, in the said embodiment, the number of the plane mirrors of the polygon mirror 18 and the number of the color mirrors of the fluorescent substance color wheel 19 shall be the same, and the rotational speed shall also be the same. Thereby, the synchronous control with respect to the polygon mirror 18 and the fluorescent substance color wheel 19 becomes easy, and the burden of the projection light processing part 24 can be reduced.

  In the above embodiment, the peripheral surface of the polygon mirror 18 is constituted by a 72-angle polygon mirror composed of 72 plane mirrors, and the phosphor color wheel 19 also surrounds 72 fluorescent color filters in the same manner as the bottom peripheral edge. However, the present invention is not limited to this as long as the number of plane mirrors of the polygon mirror 18 and the number of color mirrors of the phosphor color wheel 19 are the same.

  Further, the polygon mirror 18 and the phosphor color wheel 19 are rotated synchronously at 7200 rpm. However, if the rotation speed of the polygon mirror 18 and the rotation speed of the phosphor color wheel 19 are the same, different rotation speeds may be used. Absent.

  In the above embodiment, the example of the semiconductor laser 17 has been described, but a fiber laser may be used.

  Further, in the above embodiment, the case where the scanning body that reflects and scans the spot beam B from the semiconductor laser 17 with respect to the phosphor color wheel 19 is configured by the polygon mirror 18 has been described, but the present invention is limited to the polygon mirror 18. In addition, for example, a galvano mirror called a galvano scanner may be used, or a reflection operation in a broad sense that the deflection scanning by an AOD (Acousto-Optic Deflector) is bent in the optical axis. If it is understood, even if AOD is used, it can be similarly applied.

  In addition, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention in the implementation stage. Further, the functions executed in the above-described embodiments may be combined as appropriate as possible. The above-described embodiment includes various stages, and various inventions can be extracted by an appropriate combination of a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, if the effect is obtained, a configuration from which the constituent requirements are deleted can be extracted as an invention.

  DESCRIPTION OF SYMBOLS 10 ... Data projector apparatus, 11 ... Input / output connector part, 12 ... Input / output interface (I / F), 13 ... Image conversion part (scaler), 14 ... Video RAM, 15 ... Projection image processing part, 16 ... Micromirror element (SLM), 17 ... semiconductor laser, 18 ... polygon mirror, 19 ... phosphor color wheel, 19a ... transparent substrate, 19b ... dichroic filter, 19c ... fluorescent plate, 19cR, 19cG, 19cB ... fluorescent color filter, 20 ... integrator, 21 DESCRIPTION OF SYMBOLS ... Light source lens system, 22 ... Mirror, 23 ... Projection lens unit, 24 ... Projection light processing part, 25 ... Motor (M), 26 ... Marker sensor, 27 ... Motor (M), 28 ... Marker sensor, 29 ... CPU, 30 ... Main memory, 31 ... Program memory, 32 ... Operation unit, 33 ... Audio processing unit, 34 ... S Over mosquito part, SB ... system bus.

Claims (6)

A light source that emits spot light;
A color wheel in which a plurality of color filters are divided and arranged on a rotating disk, and
A scanning body that reflects spot light from the light source within a predetermined angle range, sequentially scans the color filter of the color wheel, and emits light of a plurality of colors from the color wheel in a time-sharing manner;
A light source device, comprising: a synchronization control unit that synchronizes a rotation phase of the color wheel and a scanning phase of the scanning body.   The light source according to claim 1, wherein the synchronization control unit rotates the color wheel so that a scanning direction of the scanning body and a moving direction of the color filter at a reflected light irradiation position of the color wheel coincide with each other. apparatus.   2. The light source device according to claim 1, wherein the light source is one of a semiconductor laser and a fiber laser.   2. The light source device according to claim 1, wherein the scanning body includes a polygon mirror in which a plurality of plane mirrors are arranged along a peripheral wall surface. The number of color filters of the color wheel and the number of plane mirrors of the polygon mirror constituting the scanning body are the same,
4. The light source device according to claim 3, wherein the synchronization control unit rotates the polygon wheel constituting the scanning body and the color wheel in synchronization with each other at the same rotation speed. A light source that emits spot light, a color wheel in which a plurality of color filters are divided and arranged on a rotating disk, and spot light from the light source is reflected within a predetermined angle range to sequentially scan the color filters of the color wheel. A light source unit including a scanning body that emits light of a plurality of colors from the color wheel in a time-sharing manner, and a synchronization control unit that synchronizes the rotation phase of the color wheel and the scanning phase of the scanning body;
A projection apparatus comprising: a projection unit configured to form and project an optical image for each of a plurality of colors of light emitted in a time-sharing manner from the color wheel of the light source.

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