HK1152995A - Light source device, projection apparatus, and projection method - Google Patents

Description

Light source device, projection device and projection method

Technical Field

The present invention relates to a light source device, a projection device, and a projection method suitable for a projector device and the like.

Background

For example, in patent document 1 (japanese laid-open patent publication No. 2004-341105), in a projection display device, since planar light sources emitting R, G, B primary color lights and spatial light modulators corresponding to the planar light sources are required for color display, the number of components increases, and it is not possible to achieve reduction in size, weight, and price of the entire device. Therefore, the following techniques are considered: a light emitting diode that emits ultraviolet light is used as a light source, a visible light reflecting film having a characteristic of transmitting ultraviolet light and reflecting visible light is formed on a surface of a color wheel (color wheel) on a light source side, from which ultraviolet light is irradiated, and phosphor layers that emit visible light corresponding to R, G, B by irradiation of ultraviolet light are formed on a back surface side of the color wheel.

However, including the above patent documents, fig. 5 exemplifies that the color of light emitted from the light source side changes when a single light source and a color wheel are used. Fig. 5A shows a configuration of the color wheel 1 including the color filters 1R, 1G, and 1B of R, G, B whose center angles are set to 120 ° respectively. The rotational position of the color wheel inserted in the optical path from the light source is represented by an angle of 0 to 360 ° of the rotational phase corresponding to the image frame.

In the color wheel 1, as shown in the drawing, a color filter 1R of a color of B (blue) 1B, R (red) and a color filter 1G of a color of G (green) are cyclically disposed in the optical path from the light source in this order. Fig. 5B shows the color of the light source light irradiated to a micro mirror (micro mirror) element for displaying an image and the color of the light source light emitted from the color wheel 1.

As shown in fig. 5B, using a single light source, the light transmitted by each color filter is selected by the color wheel 1 and irradiated to the micromirror element to form an optical image by the reflected light thereof. Therefore, the color of the light source light irradiated on the micromirror element is consistent with the color of the light source light emitted from the color wheel.

As shown in fig. 5A, since the color wheel 1 is configured such that the center angle of each of the color filters 1B, 1R, and 1G is fixed, it is physically impossible to change the width of each field period of B, R, G during one 360 ° rotation of the color wheel 1.

Therefore, there is a problem that it is impossible to cope with a change in the transmission band characteristic of the color filter due to a change in time, and it is impossible to cope with various use situations desired by the user when it is desired to enhance the brightness of the image more than the adjustment of the color balance and the color reproducibility.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and an object thereof is to cope with a desired color environment such as color balance and brightness of a projected image as needed.

In order to achieve the above object, one aspect of the present invention is a light source device including: a first light source emitting light in a first wavelength band; a light source light generation unit that generates light of a plurality of colors by time division using the first light source; a second light source that generates light of a second wavelength band different from the first wavelength band; and a light source control unit that generates each light emitted by the light source light generation unit and the second light source in one cycle, and controls a driving timing of each of the first and second light sources so that a light emission timing and a light emission period of each light can be adjusted.

In order to achieve the above object, one aspect of the present invention is a projection apparatus including: a first light source emitting light in a first wavelength band; a light source light generation unit that generates light of a plurality of colors by time division using the first light source; a second light source that generates light of a second wavelength band different from the first wavelength band; a light source control unit that generates each light emitted from the light source light generation unit and the second light source in one cycle, and controls a driving timing of each of the first and second light sources so that a light emission timing and a light emission period of each light can be adjusted; an input unit that inputs an image signal; and a projection unit that forms a color light image corresponding to the image signal input by the input unit for each light using each light emitted based on the control of the light source control unit, and projects the color light image.

In order to achieve the above object, one aspect of the present invention is a projection method for use in a projection apparatus, the projection apparatus including: a first light source emitting light in a first wavelength band; a light source light generating unit that generates light of a plurality of colors by time division using the first light source; a second light source that generates light of a second wavelength band different from the first wavelength band; an input unit which inputs an image signal; and a projection unit that forms a color light image corresponding to the image signal input by the input unit using each light and projects the color light image, wherein the projection method includes a light source control step of generating each light emitted from the light source light generation unit and the second light source in one cycle and controlling a driving timing of each of the first and second light sources so that a light emission timing and a light emission period of each light can be adjusted.

Drawings

Fig. 1 is a block diagram showing an overall functional circuit configuration of a data projector device according to an embodiment of the present invention.

Fig. 2 is a diagram mainly showing a specific optical configuration of a light source system according to an embodiment of the present invention.

Fig. 3 is a diagram showing the configuration of the color wheel, and the timing of each projection operation in the standard mode and the green enhancement mode according to the embodiment of the present invention.

Fig. 4 is a diagram showing the configuration of the color wheel, the timing of each projection operation in the standard mode, and the timing of each projection operation in the brightness enhancement mode according to another operation example of the embodiment of the present invention.

Fig. 5 shows a relationship between a color wheel structure used in a general DLP (registered trademark) type projector apparatus and a color of light emitted from the color wheel.

Detailed Description

An embodiment of the present invention applied to a DLP (registered trademark) type data projector device will be described below with reference to the drawings.

Fig. 1 is a block diagram showing a schematic functional configuration of an electronic circuit provided in the data projector 10 according to the present embodiment.

Reference numeral 11 denotes an input/output connector including, for example, a video input terminal of pin jack (RCA) type, an RGB input terminal of D-sub15 type, and a usb (universal serial bus) connector.

The image signals of various specifications input from the input/output connector unit 11 are input to the image conversion unit 13 via an input/output interface (I/F)12 and a system bus SB.

The image conversion unit 13 converts the input image signal into an image signal of a predetermined format suitable for projection, writes the image signal into a video RAM14 serving as a buffer memory for suitable display, reads the written image signal, and sends the read image signal 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 read from the video RAM14, processed in a superimposing manner, and written into the video RAM14 as necessary. Then, the read processed image signal is sent to the projection image processing unit 15.

The projection image processing unit 15 performs display driving of the micromirror elements 16 as the Spatial Light Modulator (SLM) by faster time division driving of multiplying a frame rate (frame rate) of a predetermined format, for example, 120 frames/second, the number of division of color components, and the number of display gradation steps, based on the transmitted image signal.

The micromirror element 16 forms a light image by reflected light thereof by performing on/off operations at high speed for each of the tilt angles of a plurality of fine mirrors arranged in an array, for example, XGA (1024 pixels in horizontal direction × 768 pixels in vertical direction).

On the other hand, R, G, B of the primary color light is cyclically emitted from the light source 17 in time division. The light of R, G, B primary colors from the light source 17 is reflected by the mirror 18 and is irradiated on the micromirror element 16.

The reflected light from the micromirror device 16 forms an optical image, and the formed optical image is projected and displayed on a projection screen, not shown, which is an object to be projected, via the projection lens unit 19.

The specific optical configuration of the light source unit 17 will be described later, and includes 2 types of light sources, i.e., a semiconductor laser 20 that emits blue laser light and an LED21 that emits red light.

The blue laser beam emitted from the semiconductor laser 20 is reflected by the reflecting mirror 22 and then transmitted through the dichroic mirror 23 to irradiate 1 spot on the circumference of the color wheel 24. The color wheel 24 is rotated by a motor 25. On the circumference of the color wheel 24 irradiated with the laser light, the green phosphor reflecting plate 24G and the blue transmission diffusion plate 24B are formed in a ring shape.

When the green phosphor reflecting plate 24G of the color wheel 24 is positioned at the laser light irradiation position, green light is excited by the irradiation of the laser light, and the excited green light is reflected by the color wheel 24 and then reflected by the dichroic mirror 23. Thereafter, the green light is further reflected by the dichroic mirror 28, turned into a light beam having a substantially uniform luminance distribution by an integrator 29, reflected by the mirror 30, and sent to the mirror 18.

As shown in fig. 1, when the blue transmissive diffuser 24B of the color wheel 24 is located at the laser light irradiation position, the laser light is diffused by the blue transmissive diffuser 24B, transmitted through the color wheel 24, and then reflected by the mirrors 26 and 27, respectively. Thereafter, the blue light passes through the dichroic mirror 28, is converted into a light beam having a substantially uniform luminance distribution by an integrator 29, is reflected by a reflecting mirror 30, and is sent to the reflecting mirror 18.

The red light emitted from the LED21 is transmitted through the dichroic mirror 23, reflected by the dichroic mirror 28, turned into a light beam having a substantially uniform luminance distribution by the integrator 29, reflected by the reflecting mirror 30, and sent to the reflecting mirror 18.

As described above, the dichroic mirror 23 has spectral characteristics of transmitting blue light and red light, and reflecting green light.

The dichroic mirror 28 has a spectral characteristic of transmitting blue light and reflecting red light and green light.

The projection light processing unit 31 totally controls the light emission timing of each of the semiconductor laser 20 and the LED21 of the light source unit 17 and the rotation of the color wheel 24 by the motor 25. The projection light processing unit 31 controls the light emission timing of each of the semiconductor laser 20 and the LED21 and the rotation of the color wheel 24 in accordance with the timing of the image data supplied from the projection image processing unit 15.

The CPU32 executes control operations in the data projector apparatus 10 using a main memory 33 formed of a DRAM and a program memory 34 formed of an electrically rewritable nonvolatile memory in which an operation program, various types of fixed data, and the like are stored.

The CPU32 executes various projection operations in accordance with a key operation signal from the operation unit 35.

The operation unit 35 includes a key operation unit provided in the main body of the data projector apparatus 10 and a laser receiving unit that receives infrared light between a remote controller (not shown) dedicated to the data projector apparatus 10, and directly outputs a key operation signal based on a key operation performed by a user with the key operation unit of the main body or the remote controller to the CPU 32.

The operation unit 35 includes, for example, a FOCUS key (FOCUS), a ZOOM key (ZOOM), an input image switching key (IMPUT), a MENU key (MENU), cursor (←, →, ↓, and ↓) keys, a set key (ENTER), and a cancel key (ESC), in addition to the key operation unit and the remote controller.

The CPU32 is also connected to the audio processing unit 36 via the system bus SB. The sound processing unit 36 includes a sound source circuit such as a PCM sound source, and simulates sound data supplied during a projection operation, and drives the speaker 37 to emit sound for sound amplification or to emit a beep sound as necessary.

Fig. 2 mainly shows an example of the configuration of a specific optical system of the light source unit 17. The figure shows the structure around the light source unit 17 in a planar layout.

For example, 3 semiconductor lasers 20A to 20C having the same emission characteristics are provided. The laser light of each of the semiconductor lasers 20A to 20C is blue, and the emission wavelength thereof is, for example, about 450 nm.

The blue light oscillated by the semiconductor lasers 20A to 20C is substantially collimated by the lenses 41A to 41C, reflected by the mirrors 22A to 22C, transmitted through the dichroic mirror 23 via the lenses 42 and 43, and irradiated onto the color wheel 24 via the lens group 44.

In the present embodiment, the lenses 42 and 43 and the lens group 44 form a light collecting optical system that collects the substantially collimated blue light at a position system of the color wheel 24 on the optical axis.

On the color wheel 24, as described above, the blue transmissive diffusion plate 24B and the green phosphor reflective plate 24G are located on the same circumference to form a circular ring.

When the green phosphor reflector 24G of the color wheel 24 is positioned at the blue light irradiation position, green light in a wavelength band centered around a wavelength of about 530 nm, for example, is excited by the irradiation. The green light thus excited is reflected by the reflection surface of the color wheel 24, passes through the lens group 44, and is then reflected by the dichroic mirror 23.

The green light reflected by the dichroic mirror 23 is further reflected by the dichroic mirror 28 via the lens 45, and is guided to the integrator 29 via the lens 46. In the present embodiment, the lens group 44, the lens 45, and the lens 46 are designed such that: the beam size of the green light excited by the color wheel 24 is converged within the opening size of the integrator 29 and guided to the light guiding optical system of the integrator 29. The magnification of the light guide optical system is designed to substantially coincide with the ratio of the size of the opening of the integrator 29 to the size of the light irradiated on the color wheel 24.

The green light is converted into a light beam having a substantially uniform luminance distribution by the integrator 29, reflected by the mirror 30 via the lens 47, and sent to the mirror 18 via the lens 48.

The green light reflected by the mirror 18 is irradiated on the micromirror element 16 via the lens 49. Then, a green component light image is formed by the green light reflected light, and is projected to the outside through the lens 49 and the projection lens unit 19.

When the blue transmissive diffuser 24B of the color wheel 24 is positioned at the blue light irradiation position, the blue light is diffused by the blue transmissive diffuser 24B with a lower diffusivity than the green light excited by the substantially completely diffused light and is transmitted through the color wheel 24. Then, the light is reflected by the mirror 26 after passing through the lens 50 located on the back surface side.

The motor 25 for rotating the color wheel 24 is disposed on the same side as the lens 50, and the lens 50 collects the blue light transmitted through the color wheel 24. Since the blue light transmitted through the color wheel 24 has a lower diffusivity than the green light reflected by the color wheel 24, the lens 50 can be made smaller than the lens group 44, and the lens group 44 condenses the green light reflected by the color wheel 24.

The blue light is reflected by the mirror 27 after passing through the lens 51, passes through the dichroic mirror 28 after passing through the lens 52, and is guided to the integrator 29 through the lens 46. In the present embodiment, the lenses 50, 51, 52 and the lens 46 are designed such that: the light beam size of the blue light after passing through the color wheel 24 is converged within the opening size of the integrator 29 and guided to the light guiding optical system of the integrator 29. The magnification of the light guide optical system is designed to substantially coincide with the ratio of the size of the opening of the integrator 29 to the size of the light irradiated on the color wheel 24.

Then, the integrator 29 converts the blue light into a light beam having a substantially uniform luminance distribution, and the light beam is reflected by the mirror 30 via the lens 47, and is sent to the mirror 18 via the lens 48.

The blue light after being reflected by the mirror 18 is irradiated on the micromirror element 16 via the lens 49. Then, a light image of a blue component is formed by the reflected light of the blue light, and is projected to the outside through the lens 49 and the projection lens unit 19.

On the other hand, the LED21 emits red light of a wavelength of 620[ nm ], for example. The red light emitted from the LED21 passes through the dichroic mirror 23 via the lens group 53, is reflected by the dichroic mirror 28 via the lens 45, and is guided to the integrator 29 via the lens 46. In the present embodiment, the lens group 53, the lens 45, and the lens 46 are designed such that: and a light guide optical system for guiding the light beam of the red light emitted with the light emission size of the LED21 to the integrator 29 while being confined within the opening size of the integrator 29. The magnification of the light guide optical system is designed to substantially coincide with the ratio of the size of the opening of the integrator 29 to the light emission size of the LED 21.

The integrator 29 converts the red light into a light beam having a substantially uniform luminance distribution, and then reflects the light beam by the mirror 30 via the lens 47, and sends the light beam to the mirror 18 via the lens 48.

The LED21 is disposed close to the semiconductor lasers 20A to 20C and has an optical axis parallel to the optical axes of the semiconductor lasers 20A to 20C. With this arrangement, although not shown, the heat sink provided on the rear surface of the LED21 for cooling the LED21 and the heat sink provided on the rear surface of the semiconductor lasers for cooling the semiconductor lasers 20A to 20C can be easily integrated, and the size of the entire device can be reduced and the number of components can be reduced.

The red light reflected by the mirror 18 is irradiated onto the micromirror element 16 via the lens 49. The reflected light of the red light forms a light image of a red component, and the light image is projected to the outside through the lens 49 and the projection lens unit 19.

The operation of the above embodiment will be described below.

In the present embodiment, as shown in fig. 3A, the blue transmissive diffuser plate 24B constituting the color wheel 24 is disposed on a circumference having a center angle of about 150 ° at a position corresponding to a rotational phase of 0 ° to 150 ° in an image frame. On the other hand, the green phosphor reflective plate 24G is disposed on a circumference having a central angle of about 210 ° at a position where the rotational phase is about 150 ° to 360 ° (0 °).

Here, the standard mode and the green enhancement mode can be switched as two color modes.

In the standard mode, as shown in fig. 3B, the time ratio during projection of the B, R, G primary color images constituting a 1-frame projected color image is made 1: 1.

The periods during which B, R, G primary color images are projected are defined as a B field, an R field, and a G field, respectively.

That is, when the center angle of the color wheel 24 is changed to 360 degrees at which the color wheel 24 rotates once at a constant speed, the time ratio B: R: G of the B field, the R field, and the G field is 120 °: 120 °.

In the other green enhancement mode, as shown in fig. 3C, the time ratio during projection of B, R, G primary color images constituting a 1-frame color image is set to 10: 11: 15.

That is, when the center angle of the color wheel 24 is changed to 360 ° of one rotation of the color wheel 24 which rotates at a constant speed, the time ratio B: R: G of the B field, the R field, and the G field is 100 °: 110 °: 150 °.

The operation control associated with the color mode switching is executed by the projection light processing unit 31 in addition to the overall control performed by the CPU 32.

Fig. 3B shows the relationship between the color of the optical image formed by the micromirror element 16, the light emission timing of the LED21, the light emission timings of the semiconductor lasers 20A to 20C, and the output of the color wheel 24 in the standard mode.

In the standard mode, during a period corresponding to a B field of 120 ° at the center angle of the color wheel 24 at the beginning of 1 frame, blue light is emitted by oscillation of the semiconductor lasers 20A to 20C as indicated by CW output in fig. 3B. The blue light transmitted through the color wheel 24 is diffused by the diffuser plate 24B and then irradiated onto the micromirror element 16.

At this time, an image corresponding to blue is displayed by the micromirror device 16, and a blue light image is formed by the reflected light thereof and projected to an external projection target via the projection lens unit 19. During this time, the LED21 is off.

Thereafter, the LED21 is lit in synchronization with the temporary stop of the oscillation of the semiconductor lasers 20A to 20C. Then, during an R field period corresponding to 120 ° at the center angle of the color wheel 24, red light is emitted by the lighting of the LED21 and impinges on the micromirror element 16 as shown by the R-LED of fig. 3.

At this time, an image corresponding to red is displayed by the micromirror device 16, and a red light image is formed by the reflected light thereof and projected to an external projection target via the projection lens unit 19.

During this period, the oscillation of the semiconductor lasers 20A to 20C is temporarily stopped. Therefore, when the semiconductor lasers 20A to 20C oscillate, the blue transmissive diffuser 24B and the green fluorescent reflector 24G of the color wheel 24 are present at the positions on the optical axis, but since the oscillation of the semiconductor lasers 20A to 20C is temporarily stopped, neither blue light nor green light as light source light is generated.

Thereafter, the oscillation in the semiconductor lasers 20A to 20C is started again in synchronization with the turning off of the LED 21. Thereafter, in a G field period corresponding to 120 ° at the center angle of the color wheel 24, the reflected light of green excited by the green phosphor reflective plate 24G of the color wheel 24 is irradiated on the micromirror element 16 as light source light.

At this time, an image corresponding to green is displayed by the micromirror device 16, and a green light image is formed by the reflected light thereof and projected to an external projection target via the projection lens unit 19.

Further, the color wheel 24 rotates to end the G field and 1 frame period. Thereafter, when the blue transmissive diffuser plate 24B is again positioned on the optical axis from the semiconductor lasers 20A to 20C instead of the green fluorescent reflector plate 24G, the period of the B field of the next frame is defined.

In this way, the oscillation and lighting timings of the semiconductor lasers 20A to 20C and the LED21 are controlled in synchronization with the rotation of the color wheel 24 on which the blue transmission diffusion plate 24B and the green fluorescent reflection plate 24G are formed. Thus, green light and blue light generated by oscillation of the semiconductor lasers 20A to 20C and red light generated by lighting of the LED21 are cyclically generated in a time division manner and are irradiated onto the micromirror element 16.

The operation in the green enhancement mode will be described below.

Fig. 3C shows the relationship between the color of the optical image formed by the micromirror element 16, the light emission timing of the LED21, the light emission timings of the semiconductor lasers 20A to 20C, and the output of the color wheel 24 in the green-enhanced mode.

In the green enhancement mode, in the first field period of 1 frame, corresponding to 100 ° at the center angle of the color wheel 24, blue light is emitted by oscillation of the semiconductor lasers 20A to 20C as indicated by CW output in fig. 3C. The blue light transmitted through the color wheel 24 is diffused by the diffuser plate 24B and then irradiated onto the micromirror element 16.

At this time, an image corresponding to blue is displayed by the micromirror device 16, and a blue light image is formed by the reflected light thereof and projected to an external projection target via the projection lens unit 19. During this time, the LED21 is off.

Thereafter, the lighting of the LED21 is started in synchronization with the temporary stop of the oscillation of the semiconductor lasers 20A to 20C. Thereafter, during an R field period corresponding to 110 ° at the center angle of the color wheel 24, red light is emitted by the lighting of the LED21 as shown by the R-LED of fig. 3C and impinges on the micromirror element 16.

At this time, an image corresponding to red is displayed by the micromirror device 16, and a red light image is formed by the reflected light thereof and projected to an external projection target via the projection lens unit 19.

During this period, the oscillation of the semiconductor lasers 20A to 20C is temporarily stopped. Therefore, when the semiconductor lasers 20A to 20C oscillate, the blue transmissive diffuser 24B and the green fluorescent reflector 24G of the color wheel 24 are present at the positions on the optical axis, but since the oscillation of the semiconductor lasers 20A to 20C is temporarily stopped, neither blue light nor green light as light source light is generated.

Thereafter, the oscillation in the semiconductor lasers 20A to 20C is started again in synchronization with the LED21 being turned off. Thereafter, in a G field period corresponding to 150 ° at the center angle of the color wheel 24, the reflected light of green excited by the green phosphor reflective plate 24G of the color wheel 24 is irradiated on the micromirror element 16 as light source light.

At this time, an image corresponding to green is displayed by the micromirror device 16, and a green light image is formed by the reflected light thereof and projected to an external projection target via the projection lens unit 19.

Then, the color wheel 24 rotates to end the G field and 1 frame period. Thereafter, when the blue transmissive diffuser plate 24B is positioned on the optical axis from the semiconductor lasers 20A to 20C instead of the green fluorescent reflector plate 24G, a B-field period of the next frame is obtained.

In this way, the oscillation and lighting timings of the semiconductor lasers 20A to 20C and the LED21 are controlled in synchronization with the rotation of the color wheel 24 on which the blue transmission diffusion plate 24B and the green fluorescent reflection plate 24G are formed. Thus, green light and blue light generated by oscillation of the semiconductor lasers 20A to 20C and red light generated by lighting of the LED21 are cyclically generated in a time division manner and are irradiated onto the micromirror element 16.

Further, the R field to be turned on by the LED21 is arranged in synchronization with the boundary timing from the blue transmission diffusion plate 24B to the green fluorescent reflection plate 24G constituting the color wheel 24, and as in the case of the standard mode and the green enhancement mode, the light emission timings of the semiconductor lasers 20A to 20C and the LED21 can be controlled to adjust the time length of each field period of B, R, G in 1 frame period.

As described above, according to the present embodiment, the length of time allocated to each color component can be arbitrarily adjusted regardless of the optical system using the color wheel, and a desired color environment such as color balance and brightness of a projected image can be freely accommodated.

In particular, in the green enhancement mode, the projection time of a green image based on G (green) light closer to the luminance component is set longer than that of the other primary color components. As a result, not only the overall green color is enhanced, but also the brightness of the entire image is increased, and a brighter image is projected.

In the above-described embodiment, the semiconductor lasers 20A to 20C are used as the light sources for generating the B (blue) light and the G (green) light by using the color wheel 24, whereby stable operation excellent particularly in response speed and light intensity can be performed. Further, it is possible to improve merchantability by using appropriate elements according to the light source of the data projector device.

Meanwhile, in the fluorescent substance currently used, the conversion efficiency of the wavelength from the blue laser light to the red light is low, and thus a sufficient light emission luminance cannot be obtained. Therefore, by using the red LED as the 2 nd light source element, the period of each primary color image field can be adjusted as described above, and projection display of a red image can be performed with sufficient light emission luminance.

(other operation examples)

Next, another operation example according to the present embodiment will be described.

In the present operation example, as shown in fig. 4A, the blue transmissive diffuser plate 24B constituting the color wheel 24 is disposed on a circumference having a center angle of 150 ° at a position where the rotational phase corresponding to the image frame is 0 ° to 150 °. On the other hand, the green phosphor reflective plate 24G is disposed on a circumference having a central angle of about 210 ° at a position where the rotational phase is about 150 ° to 360 ° (0 °).

Here, as the two color modes, switching can be made between the standard mode and the brightness enhancement mode.

In the standard mode, the time ratio during projection of the primary color images of B, R, G constituting the projected 1-frame color image is made to be 1: 1.

That is, the color wheel 24 rotating at a lateral speed rotates once 360 °, and if the center angle of the color wheel 24 is replaced, the time ratio B: R: G of the B field, the R field, and the G field is 120 °: 120 °.

In the other luminance enhancement mode, in addition to the primary color images of R, G, B constituting the 1-frame color image, an image of Y (yellow) is projected. The time ratio of the periods during which the primary color images are projected B, R, G, Y is made to be 1: 1.

The period during which the Y primary color image is projected is defined as a Y field.

That is, the color wheel 24 rotating at a transverse speed rotates once 360 °, and if the center angle of the color wheel 24 is changed, the time ratio B: R: G: Y of the R field, G field, B field, and Y field T is 90 °: 90 °.

The operation control associated with the color mode switching is executed by the projection light processing unit 31 in addition to the overall control performed by the CPU 32.

Fig. 4B shows the relationship between the color of the optical image formed by the micromirror element 16, the light emission timing of the LED21, the light emission timings of the semiconductor lasers 20A to 20C, and the output of the color wheel 24 in the standard mode.

In the standard mode, in the first frame of 1 frame, during a B field period corresponding to a center angle of the color wheel 24 of 120 °, blue light is emitted by oscillation of the semiconductor lasers 20A to 20C as indicated by CW output in fig. 4B. The blue light transmitted through the color wheel 24 is diffused by the diffuser plate 24B and then irradiated onto the micromirror element 16.

At this time, an image corresponding to blue is displayed by the micromirror device 16, and a blue light image is formed by the reflected light thereof and projected to an external projection target via the projection lens unit 19. During this time, the LED21 is off.

Thereafter, the lighting of the LED21 is started in synchronization with the temporary stop of the oscillation of the semiconductor lasers 20A to 20C. Thereafter, in the R field period corresponding to the center angle of the color wheel 24 of 120 °, red light is emitted by the lighting of the LED21 as shown by the R-LED of fig. 4B and is irradiated on the micromirror element 16.

At this time, an image corresponding to red is displayed by the micromirror device 16, and a red light image is formed by the reflected light thereof and projected to an external projection target via the projection lens unit 19.

During this period, the oscillation of the semiconductor lasers 20A to 20C is temporarily stopped. Therefore, when the semiconductor lasers 20A to 20C oscillate, the blue transmissive diffuser 24B and the green fluorescent reflector 24G of the color wheel 24 are present at the positions on the optical axis, but since the oscillation of the semiconductor lasers 20A to 20C is temporarily stopped, neither blue light nor green light as light source light is generated.

Thereafter, the oscillation in the semiconductor lasers 20A to 20C is started again in synchronization with the LED21 being turned off. Then, in a G field period corresponding to a central angle of 120 ° of the color wheel 24, green reflected light excited by the green phosphor reflective plate 24G of the color wheel 24 is irradiated as light source light onto the micromirror element 16.

At this time, an image corresponding to green is displayed by the micromirror device 16, and a green light image is formed by the reflected light thereof and projected to an external projection target via the projection lens unit 19.

Then, the color wheel 24 rotates to end the G field and 1 frame period. Thereafter, when the blue transmissive diffuser plate 24B is again positioned on the optical axis from the semiconductor lasers 20A to 20C instead of the green fluorescent reflector plate 24G, the period of the B field of the next frame is defined.

In this way, the oscillation and lighting timings of the semiconductor lasers 20A to 20C and the LED21 are controlled in synchronization with the rotation of the color wheel 24 on which the blue transmission diffusion plate 24B and the green fluorescent reflection plate 24G are formed. Thus, green light and blue light generated by oscillation of the semiconductor lasers 20A to 20C and red light generated by lighting of the LED21 are cyclically generated in a time division manner and are irradiated onto the micromirror element 16.

The operation in the luminance enhancement mode will be described below.

Fig. 4C shows the relationship between the color of the optical image formed by the micromirror element 16, the light emission timing of the LED21, the light emission timings of the semiconductor lasers 20A to 20C, and the output of the color wheel 24 in the luminance enhancement mode.

In the brightness enhancement mode, in the first field period of 1 frame corresponding to the center angle of the color wheel 24 of 90 °, blue light is emitted by oscillation of the semiconductor lasers 20A to 20C as indicated by CW output in fig. 4C. The blue light transmitted through the color wheel 24 is diffused by the diffuser plate 24B and then irradiated onto the micromirror element 16.

At this time, an image corresponding to blue is displayed by the micromirror device 16, and a blue light image is formed by the reflected light thereof and projected to an external projection target via the projection lens unit 19. During this time, the LED21 is off.

Thereafter, the lighting of the LED21 is started in synchronization with the temporary stop of the oscillation of the semiconductor lasers 20A to 20C. Thereafter, in the R field period corresponding to the center angle of the color wheel 24 of 90 °, red light is emitted by the lighting of the LED21 as shown by the R-LED of fig. 4C and is irradiated on the micromirror element 16.

At this time, an image corresponding to red is displayed by the micromirror device 16, and a red light image is formed by the reflected light thereof and projected to an external projection target via the projection lens unit 19.

During this period, the oscillation of the semiconductor lasers 20A to 20C is temporarily stopped. Therefore, when the semiconductor lasers 20A to 20C oscillate, the blue transmissive diffuser 24B and the green fluorescent reflector 24G of the color wheel 24 are present at the positions on the optical axis, but since the oscillation of the semiconductor lasers 20A to 20C is temporarily stopped, neither blue light nor green light as light source light is generated.

Thereafter, the oscillation in the semiconductor lasers 20A to 20C is started again in synchronization with the LED21 being turned off. Then, in a G field period corresponding to a center angle of the color wheel 24 of 90 °, the reflected light of green excited by the green phosphor reflective plate 24G of the color wheel 24 is irradiated on the micromirror element 16 as light source light.

At this time, an image corresponding to green is displayed by the micromirror device 16, and a green light image is formed by the reflected light thereof and projected to an external projection target via the projection lens unit 19.

Then, the color wheel 24 rotates so that the G field ends. Next, the lighting of the LED21 is started without stopping the oscillation of the semiconductor lasers 20A to 20C. Thereafter, during the Y field period corresponding to the center angle of the color wheel 24 being 90 °, red light is emitted by the lighting of the LED21 as shown by the R-LED of fig. 4C.

Therefore, the micromirror element 16 is irradiated with yellow light generated by a mixed color of red light formed by the lighting of the LED21 and green light formed by the reflection of the green phosphor reflector 24G of the color wheel 24.

At this time, an image corresponding to yellow is displayed by the micromirror device 16, and a yellow light image is formed by the reflected light thereof and is projected to an external projection target via the projection lens unit 19.

Then, the color wheel 24 rotates to end the Y field and 1 frame period. Thereafter, when the blue transmissive diffuser plate 24B is again positioned on the optical axis from the semiconductor lasers 20A to 20C instead of the green fluorescent reflector plate 24G, the period of the B field of the next frame is defined.

In this way, the oscillation and lighting timings of the semiconductor lasers 20A to 20C and the LED21 are controlled in synchronization with the rotation of the color wheel 24 on which the blue transmission diffusion plate 24B and the green fluorescent reflection plate 24G are formed. Thus, green light and blue light generated by oscillation of the semiconductor lasers 20A to 20C, red light generated by lighting the LED21, and yellow light based on a mixed color are cyclically generated in a time division manner and irradiated onto the micromirror element 16.

Further, the R field to be lit by the LED21 is arranged in synchronization with the boundary timing from the blue transmission diffusion plate 24B to the green fluorescent reflection plate 24G constituting the color wheel 24, and as shown in the above-described standard mode and the luminance enhancement mode, the light emission timings of the semiconductor lasers 20A to 20C and the LED21 are controlled to set B, R, G fields in the 1-frame period and the Y field as necessary, whereby the time lengths of these field periods can be adjusted.

Thus, in the present operation example, it is possible to correspond to a desired color environment such as color balance and luminance of a projected image as needed.

In particular, in the luminance enhancement mode shown in the other operation example, since the yellow image projection time based on the Y (yellow) color closer to the luminance component is newly provided than the primary color components of the light sources are used individually, the luminance of the entire image can be greatly improved, and a bright image can be projected.

Although not shown in the above operation example, the period of time for forming the corresponding optical image may be set by emitting red light from the LED21 at the same time when the blue transmission/diffusion plate 24B of the color wheel 24 is positioned on the optical path from the semiconductor lasers 20A to 20C, and emitting M (magenta) light from the mixed color.

In addition, when focusing on the lighting period of the LED21 shown by R-RED in fig. 4C described above, lighting of the LED21 is required for the R field and the Y field in 1 frame, and lighting and extinguishing of the LED21 are performed in 2 cycles for 2 fields in total of the R field and the Y field.

In this way, by increasing the driving frequency of the LED21 to shorten the continuous lighting time, it is possible to maintain stable light emission driving at high luminance in consideration of the characteristics of the LED21 whose light emission luminance is reduced by the heat resistance generated by continuous driving.

In the above embodiment, the semiconductor lasers 20A to 20C emit blue laser light, the color wheel 24 generates blue light and green light, and the LED21 emits red light. However, the present invention is not limited to this, and the LED21 may be a semiconductor laser that emits red laser light, for example. In this case, a diffusion plate for diffusing the red laser light to generate red light needs to be positioned on the optical axis of the semiconductor laser that emits the red laser light.

That is, when the luminance balance of the primary color light which can be emitted by one light source is not suitable for practical use, the present invention can be applied to a light source unit using a plurality of light sources which compensates for the luminance balance by using another light source, and a projection apparatus using such a light source unit.

The above-described embodiment describes a case where the present invention is applied to a DLP (registered trademark) type data projector apparatus. However, the present invention is also applicable to, for example, a liquid crystal projector or the like that forms an optical image using a single-color liquid crystal panel.

The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the scope of the main contents thereof. In addition, the functions performed in the above-described embodiments may be implemented by appropriate combinations. The above embodiments include various stages, and various inventions can be obtained by appropriate combinations of the disclosed structural elements. For example, even if some of the constituent elements shown in the embodiments are deleted, the configuration in which the constituent elements are deleted can be obtained as the invention as long as the effects can be obtained.

Claims (10)

1. A light source device is characterized by comprising:

a first light source emitting light in a first wavelength band;

a light source light generation unit that generates light of a plurality of colors by time division using the first light source;

a second light source that generates light of a second wavelength band different from the first wavelength band; and

and a light source control unit that generates each light emitted by the light source light generation unit and the second light source in one cycle, and controls a driving timing of each of the first and second light sources so that a light emission timing and a light emission period of each light can be adjusted.

2. A projection device is characterized by comprising:

a first light source emitting light in a first wavelength band;

a light source light generation unit that generates light of a plurality of colors by time division using the first light source;

a second light source that generates light of a second wavelength band different from the first wavelength band;

a light source control unit that generates each light emitted from the light source light generation unit and the second light source in one cycle, and controls a driving timing of each of the first and second light sources so that a light emission timing and a light emission period of each light can be adjusted;

an input unit that inputs an image signal; and

and a projection unit that forms a color light image corresponding to the image signal input by the input unit for each light using each light emitted based on the control of the light source control unit, and projects the color light image.

3. The projection device of claim 2,

the first light source emits laser light of a blue wavelength band, and the light source light generating unit is a color wheel in which a phosphor layer that generates a green wavelength band using the laser light as excitation light and a diffusion layer that diffuses and transmits the laser light are arranged at least in a circumferential direction.

4. A projection device according to claim 3,

the second light source is a light emitting diode or a laser light source emitting light in a red waveband.

5. The projection device of claim 2,

the projector is provided with at least two or more light source control units and color modes with different control conditions of the projection units corresponding to the light source control units, and switches the color modes.

6. The projection device of claim 5,

the color mode includes a color mode in which: the generation of the laser oscillation in the blue wavelength band is stopped in at least one light emission period of the light emitting diode that emits the light in the red wavelength band, the light emission period being a light emission period including a period that spans the phosphor layer and the diffusion layer at an irradiation position of the laser light in one cycle of the color wheel.

7. The projection device of claim 6,

the color patterns include two color patterns having different ratios of light emission periods of primary colors RGB.

8. The projection device of claim 6,

the color pattern partially repeats at least one of the plurality of colors of light emitted by the light source light generation unit and a light emission period of the light of the second light source to emit light of a mixed color,

the projection unit includes: and a color mode for forming and projecting a light image of a color corresponding to the light in synchronization with the light emission timing of the mixed color light.

9. The projection device of claim 8,

the color mode includes a color mode in which: the driving timings of the first and second light sources are controlled so that a period in which the second light source emits light alone and a period in which the first and second light sources emit light together to generate mixed color light are separated in time.

10. A projection method for a projection apparatus, the projection apparatus having: a first light source emitting light in a first wavelength band; a light source light generating unit that generates light of a plurality of colors by time division using the first light source; a second light source that generates light of a second wavelength band different from the first wavelength band; an input unit which inputs an image signal; and a projection unit for forming and projecting a color light image corresponding to the image signal input by the input unit by using each light,

the projection method includes a light source control step of generating each light emitted from the light source light generating unit and the second light source in one cycle and controlling the driving timing of each of the first and second light sources so that the light emission timing and the light emission period of each light can be adjusted.