Source: https://patents.google.com/patent/JP2011053540A/en
Timestamp: 2020-01-27 06:03:07
Document Index: 617933321

Matched Legal Cases: ['arts 145', 'art 145', 'arts 145', 'arts 145', 'art 145', 'art 145', 'art 145', 'arts 145', 'arts 145', 'art 145']

JP2011053540A - Retina-scanning type image display device - Google Patents
Retina-scanning type image display device Download PDF
JP2011053540A
JP2011053540A JP2009203770A JP2009203770A JP2011053540A JP 2011053540 A JP2011053540 A JP 2011053540A JP 2009203770 A JP2009203770 A JP 2009203770A JP 2009203770 A JP2009203770 A JP 2009203770A JP 2011053540 A JP2011053540 A JP 2011053540A
JP2009203770A
2009-09-03 Application filed by Brother Industries Ltd, ブラザー工業株式会社 filed Critical Brother Industries Ltd
2009-09-03 Priority to JP2009203770A priority Critical patent/JP2011053540A/en
2011-03-17 Publication of JP2011053540A publication Critical patent/JP2011053540A/en
A retinal scanning image display apparatus capable of realizing high-speed modulation by external modulation of input light without causing a significant increase in power consumption or an increase in the size of the apparatus.
A driving signal generating unit that generates a driving signal according to image information, a light source unit 110 that emits laser light having an intensity according to the driving signal, and a two-dimensional laser beam emitted from the light source unit 110. A scanning section that scans in the direction, and a projection section that projects an image by projecting laser light scanned by the scanning section onto the retina of the eye of the observer. The light source section 110 includes a light source 120 and a light source 120. And a magneto-optic modulator 140 that modulates the intensity of the laser light emitted from the light source based on the drive signal.
The present invention relates to a retinal scanning image display apparatus that recognizes an afterimage of light scanned on the retina as an image by irradiating the retina while scanning weak light at high speed.
For example, in an image display device or the like, a semiconductor excitation solid laser (DPSS laser) or the like is used as a light source. Such a semiconductor-pumped solid-state laser has a limited response to high-speed modulation because of its low response speed. For this reason, conventionally, there is a technique using an external modulator that indirectly modulates input light from the outside.
Some of these external modulators utilize the acousto-optic effect. An external modulator using an acoustooptic effect is provided with an acoustooptic element composed of an acoustooptic medium made of glass or the like and a piezoelectric element. In such an external modulator, an ultrasonic wave propagates through the acousto-optic medium by applying an electrical signal to the piezoelectric element, whereby the light passing through the acousto-optic medium is diffracted.
As an example of an image display device including a light source that emits light modulated by such an external modulator, there is a retinal scanning image display device (see, for example, Patent Document 1). The retinal scanning image display device is an image display device that allows an observer to recognize an afterimage of light scanned on the retina as an image by irradiating the viewer's retina while scanning weak light at high speed.
JP 2008-089931 A
In an external modulator using the acousto-optic effect, ultrasonic waves are used for light diffraction. Therefore, in order to perform high-speed modulation that can ignore the delay in the propagation speed of ultrasonic waves, It is necessary to make it enter with a small aperture. For this reason, in the external modulator using the acoustooptic effect, the optical system is complicated, alignment is difficult, and it is difficult to reduce the size of the modulator. Further, an acoustooptic device for obtaining an acoustooptic effect has a problem that power consumption is relatively large.
On the other hand, the retinal scanning image display device is used by being mounted on the observer's head or is carried around, and there is a demand for low power consumption and miniaturization.
The present invention has been made in view of the circumstances as described above, and is a retina capable of realizing high-speed modulation by external modulation of input light without causing a significant increase in power consumption and an increase in size of the apparatus. A scanning image display device is provided.
In order to solve the above-described problem, a retinal scanning image display device according to claim 1 emits a driving signal generation unit that generates a driving signal according to image information and a light beam having an intensity according to the driving signal. A light source unit, a scanning unit that scans a light beam emitted from the light source unit in a two-dimensional direction, and a projection unit that projects an image by projecting the light beam scanned by the scanning unit onto the retina of an observer's eye; The light source unit includes a light source and a magneto-optic modulator that modulates the intensity of the light beam emitted from the light source based on the drive signal.
The retinal scanning image display device according to claim 2 is the retinal scanning image display device according to claim 1, wherein the magneto-optic modulator has a plurality of cells whose transmittance can be independently controlled. Are arranged two-dimensionally in a plane substantially orthogonal to the incident direction of the light beam, and a control signal is input to each cell unit based on the drive signal to transmit light incident on each cell unit And a control unit that controls the rate and modulates the intensity of the light beam emitted from the light source.
The retinal scanning image display device according to claim 3 is the retinal scanning image display device according to claim 2, wherein the control unit is configured to control each cell unit according to a control signal input to each cell unit. It controls whether the light incident on the light is transmitted or blocked.
The retinal scanning image display device according to claim 4 is the retinal scanning image display device according to claim 2 or 3, wherein the control unit transmits light among the plurality of cell units. The control signal is controlled so that the cell portions are adjacent to form a single transmission region.
Further, the retinal scanning image display device according to claim 5 is the retinal scanning image display device according to claim 4, wherein the control unit is configured such that the center of the transmission region substantially coincides with the optical axis position of the light beam. Thus, the control signal is controlled.
The retinal scanning image display device according to claim 6 is the retinal scanning image display device according to any one of claims 2 to 5, wherein the light source unit emits a light beam emitted from the light source. At least a part of the magneto-optic modulator is configured to be incident on all the entrances.
The retinal scanning image display device according to claim 7 is the retinal scanning image display device according to any one of claims 2 to 6, wherein the light source includes a red laser that emits a red light beam; A green laser that emits a green light beam and a blue laser that emits a blue light beam, and sequentially emits the red light beam, the green light beam, and the blue light beam in a time-sharing manner; The intensity of each of the green light beam and the blue light beam is sequentially modulated.
Further, the retinal scanning image display device according to claim 8 is the retinal scanning image display device according to any one of claims 2 to 6, wherein the light source includes a red laser that emits a red light beam; A green laser that emits a green light beam and a blue laser that emits a blue light beam, and the magneto-optic modulator is provided in each of the red laser, the green laser, and the blue laser. is there.
The retinal scanning image display device according to claim 9 is the retinal scanning image display device according to any one of claims 2 to 6, wherein the light source includes a semiconductor laser that emits a red light beam, A solid-state laser that emits a green light beam; and a semiconductor laser that emits a blue light beam. The drive signal generation unit responds to the image information for each of the semiconductor laser and the magneto-optic modulator. Output a driving signal to emit a light beam whose intensity is modulated according to the driving signal from each of the semiconductor lasers, and the intensity of the light beam emitted from the solid-state laser is determined according to the driving signal by the magneto-optic modulator. Modulation.
The retinal scanning image display device according to claim 10 is the retinal scanning image display device according to any one of claims 2 to 9, wherein the cell portions are formed in a 16 × 16 matrix. The control unit controls the cell unit to control the intensity of the light flux to 256 gradations.
The retinal scanning image display device according to claim 11 is the retinal scanning image display device according to any one of claims 1 to 10, wherein the magneto-optic modulator is emitted from the light source. A first linearly polarizing plate, a second linearly polarizing plate having a polarization characteristic orthogonal to the polarizing property of the first linearly polarizing plate, the first linearly polarizing plate, and the A magneto-optical element sandwiched between the second linearly polarizing plates is disposed.
According to the retinal scanning image display apparatus of the present invention, high-speed modulation by external modulation can be realized for input light without significantly increasing power consumption or increasing the size of the apparatus.
1 is a diagram illustrating an appearance of a retinal scanning image display device according to an embodiment of the present invention. It is a figure which similarly shows the electrical structure and optical structure of a retinal scanning type | mold image display apparatus. It is a figure which shows the structure of a light source part. It is a top view of a magneto-optic modulator. It is a side view of a magneto-optic modulator. It is explanatory drawing which shows an example of the polarization | polarized-light when a magneto-optical effect is acquired in a magneto-optical modulator. It is explanatory drawing which shows an example of the polarization | polarized-light when a magneto-optical effect is not acquired in a magneto-optical modulator. It is a top view which shows the other structural example of a magneto-optical modulator. It is a side view which shows the other structural example of a magneto-optical modulator. It is a figure which shows the cell part group formed in a 16x16 matrix form. It is a figure which shows an example of the ON / OFF pattern of the cell part group accompanying the intensity | strength change of a light beam. It is a figure which shows an example of the ON / OFF pattern of the cell part group accompanying the intensity | strength change of a light beam. It is a figure which shows the other structure of a light source part. It is a figure which shows the other structure of a light source part.
The present invention focuses on the fact that a retinal scanning image display device can display a bright image with a relatively small amount of light, and adopts a configuration including a magneto-optical element as an external modulator in the retinal scanning image display device. . Embodiments of the present invention will be described below.
[Configuration of Retina Scanning Image Display Device]
First, the configuration of a retinal scanning image display apparatus (hereinafter referred to as “RSD”) according to an embodiment of the present invention will be specifically described with reference to FIGS.
[Appearance of RSD1]
As shown in FIG. 1, the RSD 1 according to the present embodiment uses the retina of the eye of the observer (the user wearing the RSD 1) as the projection target, and projects the scanned laser light from the pupil and projects it onto the retina. As a result, the viewer is made to visually recognize the image. That is, the RSD 1 is an image display device that causes the viewer to recognize an afterimage of the light scanned on the retina as an image by irradiating the viewer's retina while scanning weak light at high speed.
The RSD 1 includes a control unit 2, a transmission cable unit 3, and a head mounting tool 4. The control unit 2 emits laser light having an intensity corresponding to the image signal as image light. The transmission cable unit 3 includes an optical fiber cable 50 (see FIG. 2) that transmits image light emitted from the control unit 2. The head mounting tool 4 is a part for mounting the RSD 1 on the observer's head, and scans the image light transmitted by the transmission cable unit 3 and projects the image light to the observer. It is a part for displaying.
The control unit 2 incorporates a storage unit (see FIG. 2, content storage unit 14), and forms an image signal based on the content information and the like stored in the storage unit. The control unit 2 emits laser light having an intensity according to the formed image signal to the transmission cable unit 3 as image light.
The head mounting tool 4 includes a support member 6 configured in a substantially glasses shape and a projection unit 10 supported by the support member 6. The projection unit 10 is provided on the side of the front portion 7 of the support member 6. The projection unit 10 scans the image light transmitted by the transmission cable unit 3 so that the observer can recognize it as a display image.
The projection unit 10 scans the image light intensity-modulated for each color of R (red), G (green), and B (blue) in the control unit 2 in a two-dimensional direction, and enters the eye Y of the observer. . In the projection unit 10, a half mirror 9 is provided at a position corresponding to the front of the observer's eye Y (a position facing the eye Y). By this half mirror 9, the external light Lx passes through the half mirror 9 and enters the observer's eye Y, and the image light Ly emitted from the projection unit 10 is reflected by the half mirror 9 and enters the observer's eye Y. To do. Thereby, the observer can visually recognize the image by the image light Ly superimposed on the outside scene by the external light Lx.
As described above, the RSD 1 of the present embodiment is a see-through type RSD that projects image light while scanning the eye Y of the observer while transmitting external light. The RSD as an example of the retinal scanning image display apparatus according to the present invention is not necessarily a see-through type RSD.
[Electrical configuration and optical configuration of RSD1]
Next, the electrical configuration and optical configuration of the RSD 1 will be described with reference to FIG. As shown in FIG. 2, the control unit 2 provided in the RSD 1 includes a control unit 30 that performs overall control of the overall operation of the RSD 1 and a light source unit 11 to which the image signal S is supplied from the control unit 30. Yes. The light source unit 11 reads out image information from the image signal S supplied from the control unit 30 in units of pixels, and R (red), G (green), and B (blue) based on the read image information in units of pixels. Laser light whose intensity is modulated for each color is generated and emitted.
The control unit 30 controls the entire RSD 1 by executing a predetermined process according to a control program stored therein. The control unit 30 includes a CPU, flash memory, RAM, VRAM, a plurality of input / output I / Fs, and the like, which are connected to a data communication bus, and transmit / receive various information via the bus. I do.
The light source unit 11 is provided with an image signal supply circuit 13 that generates a signal or the like as an element for synthesizing an image. The control unit 30 is based on image data supplied from a device (not shown) externally connected via an input / output terminal or the like, or content information stored in advance in the content storage unit 14 having a relatively large storage area. Receives input of image data. The control unit 30 generates an image signal S based on the image data, and sends the image signal S to the image signal supply circuit 13. Based on the image signal S, the image signal supply circuit 13 generates each signal as an element for forming a display image in units of pixels. That is, in the present embodiment, the image signal supply circuit 13 functions as a drive signal generation unit that generates a drive signal according to image information.
Here, the content information stored in the content storage unit 14 includes at least one of data for displaying characters, data for displaying images, and data for displaying moving images. Is. For example, the content information is a document file, an image file, a moving image file, or the like used on a personal computer or the like. The content storage unit 14 can be, for example, a magnetic storage medium such as a hard disk, an optical recording medium such as a CD-R, a flash memory, or the like.
Further, the light source unit 11 is provided with a light source unit 110 that outputs a laser beam (light beam) having an intensity corresponding to a drive signal (hereinafter referred to as “light source drive signal”) 60 generated by the image signal supply circuit 13. Yes. The light source unit 110 includes a light source 120 and a magneto-optic modulator 140 that modulates the intensity of laser light emitted from the light source 120 based on the light source drive signal 60. That is, the light source unit 110 modulates the light from the light source 120 by the magneto-optic modulator 140 and emits it to the optical fiber cable 50.
The light source 120 generates red laser light, green laser light, and blue laser light as the emitted laser light. Therefore, the light source 120 includes a red laser generation unit 121 that generates red laser light, a green laser generation unit 122 that generates green laser light, and a blue laser generation unit 123 that generates blue laser light. The light source drive signal 60 includes an R drive signal 60r that is a control signal for the red laser generator 121, a G drive signal 60g that is a control signal for the green laser generator 122, and a control signal for the blue laser generator 123. A B drive signal 60b is included (see FIG. 3).
The magneto-optic modulator 140 is an external modulator using a magneto-optic effect. That is, the magneto-optical modulator 140 indirectly modulates the red laser light, the green laser light, and the blue laser light that are input light from the light source 120 from the outside based on the light source drive signal 60, Modulates the intensity of laser light of each color. Modulated light Lc, which is laser light modulated by the magneto-optic modulator 140, is collected by the coupling optical system 77 and guided to the optical fiber cable 50. The optical fiber cable 50 is accommodated in the transmission cable portion 3 (see FIG. 1).
Further, the image signal supply circuit 13 receives a horizontal drive signal 61 used in the horizontal scanning unit 80 provided in the projection unit 10 and a vertical drive signal 62 used in the vertical scanning unit 90 also provided in the projection unit 10. Output each. The horizontal drive signal 61 and the vertical drive signal 62 are transmitted by a drive signal transmission cable included in the transmission cable unit 3.
The projection unit 10 is located between the light source unit 11 and the eye Y of the observer in the RSD 1. The projection unit 10 is provided with a collimating optical system 79, a horizontal scanning unit 80, a first relay optical system 85, a vertical scanning unit 90, and a second relay optical system 95. The collimating optical system 79 collimates the laser light generated by the light source unit 11 and emitted through the optical fiber cable 50. The horizontal scanning unit 80 reciprocally scans the laser beam collimated by the collimating optical system 79 in the horizontal direction for image display. The vertical scanning unit 90 scans the laser beam scanned in the horizontal direction by the horizontal scanning unit 80 in the vertical direction. The first relay optical system 85 is provided between the horizontal scanning unit 80 and the vertical scanning unit 90. The second relay optical system 95 is for emitting laser light scanned in the horizontal and vertical directions by the horizontal scanning unit 80 and the vertical scanning unit 90 to the pupil 101a of the observer.
The horizontal scanning unit 80, the vertical scanning unit 90, and the first relay optical system 85 are arranged in the horizontal direction so that the laser light incident from the optical fiber cable 50 can be projected as an image onto the retina 101b of the observer. And an optical system for scanning in the vertical direction to obtain a scanning light beam. That is, in the present embodiment, the configuration including the horizontal scanning unit 80 and the vertical scanning unit 90 functions as a scanning unit that scans the light beam emitted from the light source unit 110 in a two-dimensional direction. Therefore, in the following description, the horizontal scanning unit 80 and the vertical scanning unit 90 are collectively referred to as a scanning unit.
The horizontal scanning unit 80 includes a resonance type deflection element 81 and a horizontal scanning drive circuit 82. The deflection element 81 has a deflection surface for scanning the laser beam in the horizontal direction. The horizontal scanning drive circuit 82 generates a drive signal that resonates the deflection element 81 and swings the deflection surface (reflection surface) of the deflection element 81 based on the horizontal drive signal 61.
On the other hand, the vertical scanning unit 90 includes a non-resonant deflection element 91 and a vertical scanning drive circuit 92. The deflection element 91 has a deflection surface (reflection surface) for scanning the laser beam in the vertical direction. The vertical scanning drive circuit 92 generates a drive signal for swinging the deflection surface of the deflection element 91 in a non-resonant state based on the vertical drive signal 62. The vertical scanning unit 90 vertically scans a laser beam for forming an image from the first horizontal scanning line toward the last horizontal scanning line for each frame of the image to be displayed. Thereby, a two-dimensionally scanned image is formed. Here, the “horizontal scanning line” means one scanning in the horizontal direction by the horizontal scanning unit 80.
The first relay optical system 85 that relays the laser light between the horizontal scanning unit 80 and the vertical scanning unit 90 receives the laser light scanned in the horizontal direction by the deflection surface of the deflection element 81 included in the horizontal scanning unit 80. Then, the light is converged on the deflection surface of the deflection element 91 included in the vertical scanning unit 90. Then, the laser beam converged on the deflection surface of the deflection element 91 is scanned in the vertical direction by the deflection surface of the deflection element 91 to be formed as image light Ly. The laser light as the image light Ly is transmitted through the second mirror optical system 95 in which two lenses 95a and 95b having positive refractive power are arranged in series to the half mirror 9 positioned in front of the eye Y of the observer. It is reflected and enters the observer's pupil 101a. Thereby, the display image according to the image signal S is projected on the retina 101b. In this way, the observer recognizes the image light Ly as a display image.
Further, in the second relay optical system 95, the respective laser beams are made substantially parallel to each other by the lenses 95a and converted into convergent laser beams. The laser light converted by the lens 95a is converted into substantially parallel laser light by the lens 95b, and the center line of these laser lights is converted so as to converge on the pupil 101a of the observer. This lens 95b is an eyepiece optical system that projects image light Ly (laser light) scanned by the scanning unit into the observer's eye Y and projects an image corresponding to the image signal S onto the observer's retina 101b. Function. As described above, in the present embodiment, the configuration including the second relay optical system 95 and the half mirror 9 projects the light beam scanned by the scanning unit onto the retina 101b of the observer's eye Y to project an image. It functions as a part.
[Configuration of light source section]
Next, the configuration of the light source unit 110 will be described with reference to FIGS. 3, 4, and 5. As shown in FIG. 3, the light source unit 110 includes a light source 120, a beam diameter expanding optical system 150, and a magneto-optic modulator 140.
(Light source 120)
The light source 120 includes a red laser generator 121, a green laser generator 122, and a blue laser generator 123. The red laser generation unit 121 includes an R laser 124 that is a solid-state laser that generates red laser light Lr, and an R laser driver 125 that drives the R laser 124.
The green laser generator 122 and the blue laser generator 123 are also configured in the same manner as the red laser generator 121. That is, the green laser generator 122 includes a G laser 126 that is a solid-state laser that generates the green laser light Lg, and a G laser driver 127 for driving the G laser 126. The blue laser generation unit 123 includes a B laser 128 that is a solid-state laser that generates the blue laser light Lb, and a B laser driver 129 for driving the B laser 128.
As described above, the drive signals 60r, 60g, and 60b for the laser generators 121, 122, and 123 include laser ON / OFF signals. That is, in the red laser generator 121, ON / OFF of the red laser light Lr is controlled by the R drive signal 60r. Similarly, in the green laser generator 122, ON / OFF of the green laser light Lg is controlled by the G drive signal 60g, and in the blue laser generator 123, ON / OFF of the blue laser light Lb is controlled by the B drive signal 60b. OFF is controlled.
Laser beams Lr, Lg, and Lb emitted from the lasers 124, 126, and 128 are incident on the dichroic mirrors 131, 132, and 133. Thereafter, the laser beams Lr, Lg, and Lb are selectively reflected and transmitted with respect to the wavelength by these dichroic mirrors 131, 132, and 133, and enter the magneto-optical modulator 140 through the beam diameter expanding optical system 150. . The laser beams emitted from each of the red laser generation unit 121, the green laser generation unit 122, and the blue laser generation unit 123 are emitted in a time division manner.
Specifically, the red laser light Lr emitted from the R laser 124 is incident on the dichroic mirror 131, passes through the dichroic mirror 131, and forms emitted light from the light source 120. Further, the green laser light Lg emitted from the G laser 126 is incident on the dichroic mirror 132 and is reflected by the dichroic mirror 132 toward the dichroic mirror 131. Thereafter, the green laser light Lg incident on the dichroic mirror 131 is reflected by the dichroic mirror 131 toward the beam diameter expanding optical system 150 to form light emitted from the light source 120.
Further, the blue laser light Lb emitted from the B laser 128 is incident on the dichroic mirror 133 and is reflected by the dichroic mirror 133 toward the dichroic mirror 132. Thereafter, the blue laser light Lb incident on the dichroic mirror 132 passes through the dichroic mirror 132 and then enters the dichroic mirror 131. Thereafter, the blue laser light Lb incident on the dichroic mirror 131 is reflected by the dichroic mirror 131 toward the beam diameter expanding optical system 150 to form light emitted from the light source 120. The configuration of the optical system for emitting the laser beams Lr, Lg, and Lb from the lasers 124, 126, and 128 as the emitted light from the light source 120 is the same as the laser beams Lr and Lr emitted from the lasers 124, 126, and 128, respectively. There is no limitation as long as Lg and Lb can be selectively reflected and transmitted with respect to the wavelength.
The light source 120 sequentially emits the red laser light Lr, the green laser light Lg, and the blue laser light Lb in a time division manner. That is, as shown in FIG. 3, the light source 120 repeatedly irradiates the three colors of laser beams Lr, Lg, and Lb in a predetermined order, for example, every preset unit time. In the light source unit 110 that sequentially emits the three colors of laser beams Lr, Lg, and Lb in this manner, the driver 146 has the intensities of the red laser beam Lr, the green laser beam Lg, and the blue laser beam Lb. Are sequentially modulated. That is, the three-color laser beams Lr, Lg, and Lb emitted in order from the light source 120 are sequentially subjected to intensity modulation in the magneto-optic modulator 140 in accordance with the order of emission.
As described above, in the light source unit 110 of the present embodiment, the emission and intensity modulation processing for each of the three colors of laser beams Lr, Lg, and Lb is sequentially distributed and performed for each unit time. By such time-division processing for each color of the laser light, one magneto-optic modulator 140 is shared by the three colors of laser light Lr, Lg, and Lb.
In such time division processing for each color of laser light, the order of emission of laser light of each color and intensity modulation is not particularly limited. In the time division processing for each color of the laser light, the laser driver corresponding to the laser light of each color is used to switch the emission of the laser light per unit time, that is, the emission / stop of the laser light of each color. This is performed based on drive signals 60r, 60g, and 60b input to 125, 127, and 129, respectively. The control signal for ON / OFF control of the laser light of each color is sent from the driver 146 for controlling the intensity modulation of the laser light in the magneto-optic modulator 140 to each of the laser drivers 125, 127, and 129. The structure input with respect to it may be employ | adopted.
(Beam Diameter Expansion Optical System 150)
The beam diameter expanding optical system 150 expands the beam diameters of the laser beams Lr, Lg, and Lb emitted from the light source 120, and converts the laser beam whose beam diameter is expanded by the magnifying lens 151 into parallel light. A collimating lens 152. In other words, the laser beams Lr, Lg, and Lb emitted from the light source 120 are diverged by the magnifying lens 151 in the relay optical system 150 to increase the beam diameter, and are collimated by the collimator lens 152.
(Magneto-optic modulator 140)
The magneto-optic modulator 140 is a magneto-optic spatial modulator, and includes a magneto-optic element 141 and a coil 142. The magneto-optical element 141 has a laminated structure composed of a plurality of layers, for example, about several millimeters thick, and is configured to transmit light.
The magneto-optical element 141 has a magnetic layer made of a magneto-optical material having a magneto-optical effect such as a magnetic garnet film or a one-dimensional magneto-photonic crystal. This magnetized layer gives rotation of the polarization direction corresponding to the direction of magnetization to incident light by the magneto-optic effect (Faraday effect).
The coil 142 is for generating a magnetic field with respect to the magneto-optical element 141. That is, the coil 142 is a means for applying a magnetic field to the magneto-optical element 141. The coil 142 is disposed adjacent to the magneto-optic element 141 on the light incident side (left side in FIG. 3) of the magneto-optic element 141. In this embodiment, the coil 142 is disposed on the light incident side with respect to the magneto-optical element 141, but may be disposed on the opposite side, that is, on the light emitting side (right side in FIG. 3). . The coil 142 has a thin film coil 144.
As shown in FIG. 4, the thin film coil 144 is a conductive wire wound in a spiral shape, and generates a magnetic field for setting the direction of magnetization in the magneto-optical element 141. The thin film coil 144 is disposed so as to be adjacent to the magneto-optical element 141 in a posture in which the film surface is substantially parallel to the light incident surface.
The coil 142 generates a magnetic field with respect to the magneto-optical element 141 in the thin film coil 144 by receiving supply of electric current. Then, by controlling the current supplied to the thin film coil 144, that is, the magnetic field generated by the thin film coil 144, the rotation amount (rotation angle) of the polarization direction given to the light transmitted through the magneto-optical element 141 is controlled. Is adjusted.
In addition, the magneto-optical modulator 140 includes a driver 146 for controlling the operation of the magneto-optical element 141. Specifically, the driver 146 controls the direction and the magnitude of the current supplied to the thin film coil 144 included in the coil 142, whereby the rotation amount of the polarization direction given to the light transmitted by the magneto-optical element 141 is controlled. (Rotation angle) is controlled.
Therefore, the driver 146 includes a power supply unit 146 a that supplies current to the thin film coil 144 of the coil 142. The thin-film coil 144 of the coil 142 is energized through, for example, a terminal formed at an end of the thin-film coil 144 or a wiring connected to a conductive portion of the magneto-optical element 141 or the like. Connected to. The power supply unit 146 a supplies a pulse current to the thin film coil 144. However, the current supplied from the power supply unit 146a to the thin film coil 144 may be a direct current.
The driver 146 controls the magneto-optical element 141 based on the drive signal 60a that is a modulation signal. That is, the drive signal 60a is a signal for adjusting the rotation of the polarization direction according to the direction of magnetization given to the light incident on the magneto-optical element 141. The drive signal 60a is included in the light source drive signal 60 (see FIG. 2) sent from the image signal supply circuit 13 to the light source unit 110. That is, the magneto-optic modulator 140 modulates the intensity of the laser light emitted from the light source 120 based on the light source drive signal 60 by the driver 146 that receives the drive signal 60a.
In the RSD 1 of the present embodiment, the coil 142 having the thin film coil 144 is used as a configuration for generating a magnetic field with respect to the magneto-optical element 141. However, the present invention is not limited to this. Therefore, as a configuration for generating a magnetic field with respect to the magneto-optical element 141, for example, a configuration using a magnetic material, or a magneto-optical element 141 interposed between electrodes and magnetized by an electrode sandwiching the magneto-optical element 141 is used. The structure etc. which generate | occur | produce the magnetic field with respect to the optical element 141 may be sufficient.
In the magneto-optic modulator 140, polarizing plates 147 and 148 having polarization directions orthogonal to each other are provided on the light incident side (left side in FIG. 3) and the light exit side (right side in FIG. 3) of the magneto-optical element 141. Is provided. The polarizing plates 147 and 148 are linear polarizing plates that linearly polarize incident light, and their polarization directions are orthogonal to each other.
A polarizing plate (hereinafter referred to as “incident side polarizing plate”) 147 provided on the light incident side of the magneto-optical element 141 is provided on the incident side of the magneto-optical element 141 on the optical path of the laser light emitted from the light source 120. The coil 142 is provided at a position at a predetermined interval on the rear side (left side in FIG. 3) in the traveling direction of the laser beam. Further, a polarizing plate (hereinafter referred to as “emission-side polarizing plate”) 148 provided on the light emission side of the magneto-optical element 141 is relative to the magneto-optical element 141 on the optical path of the laser light emitted from the light source 120. The laser beam is provided at a position at a predetermined interval on the front side (right side in FIG. 3) in the traveling direction of the laser beam. However, the incident side polarizing plate 147 may be provided so as to be adjacent to the coil 142, and the emission side polarizing plate 148 may be provided so as to be adjacent to the magneto-optical element 141.
As described above, the magneto-optic modulator 140 according to this embodiment includes the incident-side polarizing plate 147 as the first linear polarizing plate and the polarization of the incident-side polarizing plate 147 on the optical path of the laser light emitted from the light source 120. An output side polarizing plate 148 as a second linear polarizing plate having a polarization characteristic orthogonal to the characteristics, and a magneto-optical element 141 sandwiched between the incident side polarizing plate 147 and the output side polarizing plate 148 are disposed. To do. However, the polarization directions of the incident-side polarizing plate 147 and the outgoing-side polarizing plate 148 do not necessarily need to be orthogonal to each other, and can be appropriately adjusted to an appropriate angular relationship.
The operation of the magneto-optical modulator 140 having the above configuration will be described with reference to FIGS. In the magneto-optic modulator 140, a pulse current is supplied to the thin film coil 144 by the driver 146 according to the drive signal 60a. As a result, a magnetic field is applied to the magneto-optical element 141 by the thin film coil 144. Thus, the direction of magnetization in the magneto-optical element 141 is rotated by the magnetic field applied to the magneto-optical element 141.
As shown in FIG. 6A, the laser light emitted from the light source 120 includes only a polarization component P1 in a certain direction (vertical direction in the figure) by the incident-side polarizing plate 147 from a state including various polarization components. To be filtered. The laser light that has passed through the incident side polarizing plate 147 enters the magneto-optical element 141. In the magneto-optical element 141, the magnetization of the magneto-optical element 141 is changed with respect to the incident laser light by a magneto-optical effect (Faraday effect) obtained by passing a current from the power supply unit 146 a of the driver 146 to the thin-film coil 144. A rotation of the polarization direction according to the direction is given.
That is, as shown in FIG. 6B, when the rotation angle of the polarization direction of the incident light in the magneto-optical element 141 is the angle θ, the laser light including only the polarization component P1 (see FIG. 6A) is The light is modulated to a polarization component P2 having a polarization direction in a direction rotated by an angle θ with respect to the polarization direction of the polarization component P1. The laser light modulated by passing through the magneto-optical element 141 is filtered by the output side polarizing plate 148.
Specifically, as described above, the polarization direction of the output side polarizing plate 148 is orthogonal to the polarization direction of the incident side polarizing plate 147. For this reason, as shown in FIG. 6C, according to the output side polarizing plate 148, from the laser beam including only the polarization component P2 (see FIG. 6B) obtained by transmitting through the magneto-optical element 141. Then, a polarization component P3 in the direction (left-right direction in the figure) orthogonal to the polarization direction of the polarization component P1 (see FIG. 10A) obtained by transmitting through the incident-side polarizing plate 147 is obtained. The laser beam having the polarization component P3 is emitted from the magneto-optic modulator 140 as light forming the modulated light Lc (see FIG. 3).
<Corrected because 146a in FIG. 3 is a current source>
On the other hand, when no current is passed from the power supply unit 146a of the driver 146 to the thin film coil 144, that is, when the magneto-optical effect (Faraday effect) cannot be obtained in the magneto-optical element 141, the laser light emitted from the light source 120 is magneto-optical. Emission from the modulator 140 is hindered. That is, as shown in FIG. 7A, the laser beam of the polarization component P1 emitted from the light source 120 and obtained by passing through the incident-side polarizing plate 147 is also transmitted through the magneto-optical element 141. The rotation of the polarization direction according to the direction of magnetization in the optical element 141 is not given. That is, as shown in FIG. 7B, the laser light transmitted through the magneto-optical element 141 remains in the state of the polarization component P1.
Therefore, as shown in FIG. 7C, the laser light that has passed through the magneto-optical element 141 is filtered by the output side polarizing plate 148 and cannot pass through the output side polarizing plate 148. That is, the laser beam of the polarization component P1 that has passed through the magneto-optical element 141 does not include the polarization component obtained by transmitting through the output-side polarizing plate 148. Therefore, the light that passes through the output-side polarizing plate 148, that is, magneto-optics. The outgoing light from the modulator 140 cannot be obtained. As a result, in this case, the modulated light Lc (see FIG. 3) cannot be obtained.
As described above, in the magneto-optical modulator 140, the incident light is modulated by the magneto-optical element 141, whereby the polarization component of the output-side polarizing plate 148 (FIG. 6C, the polarization component P3) is obtained as the modulated light Lc. Reference light) is obtained. Accordingly, the intensity of the modulated light Lc varies depending on the magnitude of the angle θ that is the rotation angle of the polarization direction with respect to the incident light by the magneto-optical element 141. That is, the magnitude of the amplitude of the polarization component P3 (FIG. 6C) corresponding to the intensity as the brightness of the modulated light Lc is multiplied by sin θ with respect to the magnitude of the amplitude of the polarization component P1 or the polarization component P2. It corresponds to the value. In practice, according to the magneto-optic modulator 140, the intensity (brightness) of the incident light is several percent based on the magnitude of the angle θ that is the rotation angle of the polarization direction with respect to the incident light by the magneto-optical element 141. A weak light having a thickness). That is, in FIG. 6 and FIG. 7, the broken-line circle surrounding the polarization component virtually indicates the beam diameter of the laser light.
As described above, the intensity of the laser light emitted from the light source 120 is modulated by the magneto-optical effect (Faraday effect) obtained in the magneto-optical element 141. That is, by controlling the modulation of the laser beam in the magneto-optical element 141, the laser beam that enters the magneto-optical modulator 140 and passes through the incident-side polarizing plate 147, the magneto-optical element 141, and the emitting-side polarizing plate 148 is controlled. The transmittance is controlled. That is, the magneto-optic modulator 140 having the magneto-optic element 141 is configured as a transmission type magneto-optic spatial modulator that transmits and modulates incident light.
The laser light that has passed through the output-side polarizing plate 148 in the magneto-optic modulator 140 is emitted from the magneto-optic modulator 140 as modulated light Lc, is incident on the optical fiber cable 50 by the coupling optical system 77, and is transmitted by the optical fiber cable 50. Guided to the projection unit 10.
As described above, in this embodiment, the driver 146 provided in the magneto-optic modulator 140 inputs the control signal to the magneto-optical element 141 based on the light source drive signal 60 and transmits the light incident on the magneto-optic element 141. It functions as a control unit that controls the rate and modulates the intensity of the laser light emitted from the light source 120. Here, the control signal input to the magneto-optical element 141 from the driver 146 includes a control signal for the current to the thin film coil 144.
In the magneto-optic modulator 140, the intensity of the laser beam to be modulated is controlled to, for example, 256 gradations. That is, in this case, the magnitude of the current supplied to the thin film coil 144 by the driver 146 is controlled in 256 steps, so that the rotation amount (rotation angle) of the polarization direction given to the light transmitted by the magneto-optical element 141 is increased. ) Is controlled in 256 steps.
That is, the intensity of the laser light emitted from the emission-side polarizing plate 148 is divided into 255 levels from a state of 0 (a state where the modulated light Lc cannot be obtained). Then, the rotation amount (rotation angle) of the polarization direction in the magneto-optical element 141 controlled by the magnitude of the current supplied to the thin film coil 144 is controlled in 256 steps so as to correspond to each intensity of the laser light. Is done. Thereby, the intensity of the laser beam modulated in the magneto-optic modulator 140 is controlled to 256 gradations.
As described above, the magneto-optical element 141 provided in the magneto-optical modulator 140 may be divided into a plurality of segments. Hereinafter, a configuration in which the magneto-optical element 141 is divided into a plurality of segments (hereinafter referred to as “divided configuration”) will be described with reference to FIGS. 8 to 12.
As shown in FIGS. 8 and 9, in the divided configuration, the magnetization layer of the magneto-optical element 141 rotates the polarization direction according to the magnetization direction with respect to incident light by the magneto-optic effect (Faraday effect). Has a plurality of cells 143. The plurality of cells 143 are arranged in a two-dimensional matrix. For each cell 143, the direction of magnetization is set independently.
In the divided configuration, the coil 142 includes a thin film coil 144 provided corresponding to each of the plurality of cells 143 constituting the magneto-optical element 141. That is, in the divided configuration, the coil 142 has at least as many thin-film coils 144 as the number of cells 143 included in the magneto-optical element 141. The thin film coil 144 generates a magnetic field for setting the direction of magnetization in each cell 143 independently. The thin film coil 144 is disposed so as to be adjacent to each cell 143 in a posture in which the film surface is substantially parallel to the light incident surface.
The coil 142 receives a supply of electric current, and generates a magnetic field for each cell 143 corresponding to each thin film coil 144 in each thin film coil 144. By controlling the current supplied to each thin film coil 144, that is, the magnetic field generated by each thin film coil 144, the transmittance of each cell 143 included in the magneto-optical element 141 can be controlled independently. Done. That is, by adjusting the current supplied to the coil 142, the amount of rotation (rotation angle) in the polarization direction given to the light transmitted through each cell 143 is adjusted.
As described above, the magneto-optic modulator 140 according to the present embodiment includes a plurality of cell units 145 including the cells 143 and the thin film coils 144 corresponding to each other as a plurality of magnetization setting elements capable of independently controlling the transmittance. . In the magneto-optic modulator 140, the plurality of cell portions 145 are two-dimensionally arranged on a plane substantially orthogonal to the incident direction of the laser light.
That is, the plurality of cell units 145 included in the magneto-optic modulator 140 are arranged in a two-dimensional matrix corresponding to the arrangement of the cells 143 of the magneto-optical element 141. The arrangement direction of the plurality of cell portions 145 is a direction along a plane substantially orthogonal to the optical axis L0 of the laser light emitted from the light source 120 (see FIG. 3).
In the divided configuration, the driver 146 controls the operation of each cell unit 145. Specifically, the driver 146 controls the direction and magnitude of the current supplied to each thin film coil 144, thereby rotating the amount of rotation (rotation angle) of the polarization direction given to the light transmitted by each cell unit 145. ) To control. Therefore, in the divided configuration, the power supply unit 146a supplies current to each thin film coil 144 independently. Each thin film coil 144 is supplied with power so that it can be energized independently through, for example, a terminal formed at the end of the thin film coil 144 or a wiring connected to a conductive portion in the magneto-optical element 141. Connected to the unit 146a.
Further, the control of each cell unit 145 by the driver 146 is performed based on the drive signal 60a. That is, in the split configuration, the drive signal 60 a is a signal for adjusting the rotation of the polarization direction according to the direction of magnetization given to the light incident on each cell 143.
As described above, in the divided configuration, the driver 146 inputs a control signal for each cell unit 145 to control the transmittance of light incident on each cell unit 145 and modulate the intensity of the laser beam emitted from the light source 120. Functions as a control unit. Here, the control signal input from the driver 146 to each cell unit 145 includes a control signal for the current to the thin film coil 144. Therefore, the driver 146 specifies the thin film coils 144 corresponding to the cells 143 of the magneto-optical element 141 by selecting them in a two-dimensional matrix arrangement, and sends an independent signal to each thin film coil 144.
For example, the operation of the magneto-optic modulator 140 in the divided configuration is as follows. That is, in the magneto-optic modulator 140, a pulse current is selectively supplied to the plurality of thin film coils 144 by the driver 146 according to the drive signal 60a. Thereby, a magnetic field is independently applied to each cell 143 of the magneto-optical element 141 by the thin film coil 144. Thus, the direction of magnetization in each cell 143 is independently rotated by the magnetic field applied to each cell 143. Therefore, in the divided configuration, each cell unit 145 is controlled independently when the magneto-optical effect (Faraday effect) is obtained (see FIG. 6) and when it is not obtained (see FIG. 7).
In the divided configuration, the driver 146 controls whether light incident on each cell unit 145 is transmitted or blocked by a control signal input to each cell unit 145. That is, when transmitting light incident on the cell unit 145, the driver 146 energizes the thin film coil 144 in each cell unit 145 of the magneto-optical element 141 in accordance with a control signal input to the cell unit 145 as described above. As a result, the polarization direction of the laser beam of the polarization component P1 transmitted through the incident side polarizing plate 147 is changed to the polarization component P2. As a result, the laser beam of the polarization component P3 that has passed through the emission-side polarizing plate 148 is obtained as the light that forms the modulated light Lc.
On the other hand, when blocking the light incident on the cell unit 145, the driver 146 does not energize the thin film coil 144 in each cell unit 145 of the magneto-optical element 141 by the control signal input to the cell unit 145 as described above. As a result, the laser beam of the polarization component P1 transmitted through the incident side polarizing plate 147 is transmitted while maintaining the polarization direction. As a result, the laser light transmitted through the cell unit 145 cannot be transmitted through the output side polarizing plate 148 but is blocked at the output side polarizing plate 148.
As described above, the driver 146 can obtain the modulated light Lc from the magneto-optic modulator 140 by the control signal for the cell unit 145, specifically, the control signal for the current to the thin film coil 144 constituting the cell unit 145. The case where the light incident on the cell unit 145 is transmitted and the case where the light incident on the cell unit 145 is blocked are controlled independently for each cell unit 145. Hereinafter, for each cell unit 145, a state in which incident light is transmitted, that is, a state in which the polarization direction of light incident on the cell unit 145 is changed is set to “ON”, and a state in which incident light is blocked, that is, a cell. The state in which the polarization direction of the incident light in the unit 145 is not changed is set to the “OFF” state.
In other words, in the split configuration, the driver 146 selectively switches ON and OFF for the plurality of cell units 145 independently at each cell unit 145. However, in the case where the cell portion 145 transmits the incident light, the amount of rotation (rotation angle) of the polarization direction given to the light transmitted through the cell 143 is adjusted by adjusting the current supplied to the coil 142. That is, the intensity (brightness) of the modulated light Lc can be adjusted.
In the divided configuration, the time division processing for each color of the three colors of laser beams Lr, Lg, and Lb is performed, so that the emission and modulation of the three colors of laser beams are performed in a time division manner. The color of is expressed.
In the magneto-optic modulator 140 of the present embodiment, the cell portions 145 arranged in a two-dimensional matrix are formed in a 16 × 16 matrix, and the cell portion 145 is controlled by the driver 146. The intensity of the laser beam is preferably controlled to 256 gradations. That is, in this case, as shown in FIG. 10, the 256 cell portions 145 are vertically 16 along a plane substantially orthogonal to the optical axis L0 of the laser light emitted from the light source 120 (see FIG. 3). They are arranged in the form of 16 columns (16 rows). In FIG. 10, each square indicates a cell portion 145 including a cell 143 and a thin film coil 144.
Then, as shown in FIG. 10, the cell portions 145 arranged two-dimensionally in a 16 × 16 matrix form have a laser beam intensity of 256 light transmitted through the magneto-optic modulator 140 by the driver 146, that is, the intensity of the modulated light Lc is 256. Control is performed so as to achieve gradation. That is, for 256 cell units 145, the intensity of the laser light transmitted through the magneto-optic modulator 140 in 256 steps from the state in which the number of ON cell units 145 is zero to the state in which the number of ON cell units 145 is 255. Is adjusted. In other words, for 256 cell units 145, magneto-optical modulation is performed in 256 steps from the state in which all cell units 145 are OFF to the state in which all the remaining cell units 145 except for one cell unit 145 are ON. The intensity of the laser light transmitted through the device 140 is adjusted.
Therefore, the “gradation” regarding the intensity of the laser light here is determined by the number of cell portions 145 in the ON state (or OFF state). In the following, the intensity of the laser beam controlled to 256 gradations is represented by the number of ON cell portions 145 in the 256 cell portions 145. That is, in this case, the intensity of the laser beam is represented by 256 numerical values from “0” to “255” corresponding to the number of the cell portions 145 in the ON state. Hereinafter, for convenience, the cell unit 145 in the ON state is referred to as “ON cell unit 145a”, and the cell unit 145 in the OFF state is referred to as “OFF cell unit 145b”.
In FIG. 11, in the cell unit 145 group arranged in a 16 × 16 matrix, the ON cell unit 145a is represented by a non-colored color, and the OFF cell unit 145b is represented by a colored square. As shown in FIG. 11A, when the intensity of the laser beam is “0”, the 256 cell portions 145 are all OFF cell portions 145b. That is, there is no ON cell unit 145a in 256 cell units 145. Therefore, in this case, the laser light incident from the light source 120 cannot be transmitted through the cell unit 145 in the magneto-optic modulator 140 and is blocked.
As shown in FIG. 11B, when the intensity of the laser beam is “1”, one cell unit 145 among the 256 cell units 145 becomes the ON cell unit 145a. In FIG. 11B, as one ON cell portion 145a, a substantially central cell portion 145 located at the eighth position from the left and the eighth position from the top in the 16 × 16 matrix arrangement is used.
Similarly, FIG. 11C shows a state where the intensity of the laser beam is “20”, and FIG. 11D shows a state where the intensity of the laser beam is “169”. 11C and 11D, as an example of an array of a plurality of ON cell portions 145a, a state where ON cell portions 145a having a numerical value representing the intensity of laser light at each intensity stage are scattered. Show. That is, in FIGS. 11C and 11D, in the cell unit 145 group arranged in a 16 × 16 matrix, the number of ON cell units 145a corresponding to the numerical value indicating the intensity of the laser beam at each intensity level. Are randomly present.
FIG. 11E shows a state where the intensity of the laser beam is “255”. In this case, of the 256 cell units 145, 255 cell units 145 become ON cell units 145a, and only one cell unit 145 becomes an OFF cell unit 145b. In FIG. 11 (e), as the OFF cell portion 145b, the cell portion 145 in the upper right corner located at the 16th from the left and the first from the top in the 16 × 16 matrix arrangement is used. The state where the intensity of the laser beam shown in FIG. 11E is “255” corresponds to the state where the intensity of the laser beam controlled to 256 gradations is the highest.
Thus, the position of the ON cell unit 145a is not particularly limited in each intensity step of the laser light controlled by the number of the ON cell units 145a. That is, for example, as shown in FIG. 11B, when the intensity of the laser beam is “1”, when one ON cell portion 145a exists regardless of the position in the 16 × 16 matrix arrangement, The intensity of the laser light is “1”.
Therefore, the cell unit 145 used as the ON cell unit 145a in each intensity step of the laser beam is, for example, a random arrangement or an arrangement that regularly changes whenever the intensity changes, thereby forming a 16 × 16 matrix. It is controlled so that 256 cell portions 145 arranged in a uniform manner are used. Such control contributes to extending the life of the cell unit 145 from the relationship with the aging of the cell unit 145.
As described above, in the magneto-optic modulator 140, the intensity of the laser beam is controlled to 256 gradations by the ON / OFF control of the cell units 145 arranged in a 16 × 16 matrix by the driver 146. However, a state in which all 256 cell portions 145 become ON cell portions 145a can be used as the laser light intensity stage. By adding such an intensity step to the intensity step of the laser beam controlled to 256 gradations as described above, it is possible to realize 257 gradations from 0 to 256 ON cell portions 145a. Become.
In addition, regarding the intensity of the laser light, as an ON / OFF pattern of the cell unit 145 group arranged in a 16 × 16 matrix at each stage, a plurality of ON cell units 145a are adjacent to each other in a single region. It is preferably controlled to form. That is, in this case, the driver 146 controls the control signal so that the ON cell unit 145a that is the cell unit 145 that transmits light among the plurality of cell units 145 is adjacent to form a single transmission region. An example of the ON / OFF pattern of the cell unit 145 group in such a case will be described with reference to FIG. In FIG. 12, as in FIG. 11, in the cell unit 145 group arranged in a 16 × 16 matrix, the ON cell unit 145a is represented by non-colored and the OFF cell unit 145b is represented by a colored square.
FIGS. 12A and 12B show the case where the intensity of the laser beam is “0” and “1”, as in FIGS. 11A and 11B. Then, as shown in FIG. 12C, when the intensity of the laser beam is “20”, the 20 ON cell portions 145a are arranged at approximately the center in the cell portion 145 group arranged in a 16 × 16 matrix. Are present in the form of 4 vertical columns and 5 horizontal columns (5 rows). In FIG. 12C, as the 20 ON cell portions 145a, the cell portions 145 included in the 7-10th range from the left and the 6-10th range from the top in the 16 × 16 matrix arrangement are used. ing. A collection region of the ON cell portions 145a in the group of cell portions 145 arranged in a 16 × 16 matrix is present as a single transmission region 145c formed by a plurality of adjacent ON cell portions 145a.
That is, the transmissive region 145c is a portion that exists as an island-like portion formed by adjoining two or more ON cell portions 145a in a group of cell portions 145 arranged in a 16 × 16 matrix. is there. Therefore, with regard to the transmissive region 145c, a single region means a region where the OFF cell portion 145b does not exist within the range surrounded by the outer edge of the region formed by the plurality of ON cell portions 145a. For this reason, for example, the plurality of ON cell portions 145a arranged in a ring shape are not included in the ON cell portion 145a forming the transmission region 145c.
Therefore, as shown in FIG. 12D, when the intensity of the laser beam is “169”, 169 ON cell portions 145a are transmitted in, for example, 13 columns in the vertical direction and 13 columns in the horizontal direction (13 rows). It exists as area | region 145c. FIG. 12E shows a state in which the intensity of the laser beam is “255” as in the case of FIG. As shown in FIG. 12 (e), in a state where 255 cell parts 145 other than one OFF cell part 145b are ON cell parts 145a, the area part of 255 ON cell parts 145a is transparent. It exists as area | region 145c.
Moreover, it is preferable that the arrangement shape of the ON cell part 145a that forms the transmission region 145c is a rotationally symmetric shape. In this case, as the shape of the transmission region 145c, for example, a regular polygonal shape such as a square or a regular pentagon, a circular shape, or the like is employed. As described above, since the shape of the transmission region 145c is a rotationally symmetric shape, the ON / OFF control of the 256 cell units 145 by the driver 146 can be facilitated.
Further, the transmission region 145c is preferably formed so that the center position thereof substantially coincides with the position of the optical axis L0 (see FIG. 3) of the laser light emitted from the light source 120. That is, in the configuration in which the laser beam is transmitted so that the direction of the optical axis L0 is substantially perpendicular to the two-dimensional plane on which 256 cell portions 145 are arranged, the position of the optical axis L0 is the transmission region 145c. It is preferable to substantially coincide with the center position in the two-dimensional plane. In this case, the driver 146 controls the control signal so that the center of the transmission region 145c substantially coincides with the position of the optical axis L0 of the laser beam.
Here, as the center of the transmissive region 145c, for example, the cell portion 145 located at the center of the circumscribed rectangle or the center of the circumscribed circle with respect to the transmissive region 145c is associated. Specifically, for example, in the case where the intensity of the laser beam is “9”, when nine ON cell portions 145a arranged in a 3 × 3 matrix are formed as the transmission region 145c, eight ONs are formed. The position of the central ON cell part 145a surrounded by the cell part 145a is the central position of the transmission region 145c. That is, in this case, the position where the transmission region 145c is formed is the control signal from the driver 146 so that the center ON cell portion 145a of the nine ON cell portions 145a substantially coincides with the position of the optical axis L0 of the laser beam. Controlled by. Here, also from the viewpoint of facilitating the specification of the cell portion 145 corresponding to the center of the transmission region 145c, it is preferable that the transmission region 145c has a rotationally symmetric shape as described above.
Further, the number of cell portions 145 formed in a matrix in the magneto-optic modulator 140 may be an integer multiple in the vertical and horizontal directions with respect to the 16 × 16 arrangement. Accordingly, the number of cell portions 145 formed in a matrix may be, for example, a 32 × 32 arrangement in which the 16 × 16 arrangement is doubled in the vertical and horizontal directions.
In the case where the cell portions 145 are formed in a 32 × 32 matrix, the intensity of the laser light can be controlled to 256 gradations by increasing the ON cell portions 145a by four from zero. That is, when the number of ON cell units 145a is 0, the number of ON cell units 145a in each strength stage is a multiple of 4 from the state where there are no ON cell units 145a. The intensity of the laser beam can be adjusted in 256 steps depending on the number of 145a.
Therefore, the state in which 1020 (= 4 × 255) ON cell portions 145a exist in the cell portions 145 arranged in 32 × 32 is the state in which the intensity is the highest with respect to the intensity of the laser light controlled to 256 gradations. Correspond. Even when the cell portions 145 are formed in a 32 × 32 matrix, a state in which all 1024 (= 32 × 32) cell portions 145 become ON cell portions 145a is used, so that 257 gradations are used. Can be realized.
When the cell portions 145 are formed in a 32 × 32 matrix, the number of the cell portions 145 increases in comparison with the 16 × 16 arrangement, so that the cell portions 145 are formed by the adjacent ON cell portions 145a. As described above, the accuracy of the center position corresponding to the position of the optical axis L0 of the laser beam and the rotationally symmetric shape can be improved for a single transmission region.
In the 32 × 32 arrangement of the cell unit 145, examples of the increment pattern of four from the zero state for the ON cell unit 145a include the following modes. That is, as the first step of the strength step, the 4 × 2 cell portions 145 located at the center in the 32 × 32 arrangement are turned ON. Next, as the second stage, two four cell portions 145 are turned on outside the pair of opposing sides in the square formed by the 2 × 2 four ON cell portions 145a. Subsequently, as the third stage, two four cell portions 145 are turned on outside the pair of opposite sides of the square formed by the 2 × 2 four ON cell portions 145a. . As the fourth stage, the cell parts 145 existing at the four corners in the 4 × 4 array including the 12 ON cell parts 145a in the third stage are turned ON. In this way, the ON / OFF control of the cell unit 145 is performed so that the rotationally symmetric shape is maintained with respect to the shape of a single transmission region at each intensity level of the laser light.
In the magneto-optic modulator 140 of the present embodiment, the light source unit 110 is configured such that at least a part of the light beam emitted from the light source 120 is incident on all the entrances of the magneto-optic modulator 140. Is preferred. Here, the entrance of the magneto-optic modulator 140 is an opening that is provided on the laser beam entrance side in each cell unit 145 and allows the laser beam to enter the cell unit 145. Therefore, as shown in FIG. 10, the entrance 145 d of the magneto-optic modulator 140 is provided in each cell unit 145. That is, in the configuration in which the cell portions 145 are formed in a 16 × 16 matrix, the magneto-optic modulator 140 has 256 incident ports 145d.
In this way, the beam diameter of the laser light is adjusted so that the laser light emitted from the light source 120 is incident on all the incident ports 145d with respect to the incident port 145d of the magneto-optic modulator 140. Specifically, the beam diameter of the laser light emitted from the light source 120 is adjusted by a magnifying lens 151 (see FIG. 3) constituting the relay optical system 150 between the light source 120 and the magneto-optic modulator 140. That is, the beam diameter of the laser light emitted from the light source 120 is adjusted so that the incident apertures 145d of all the cell portions 145 are included in the irradiation range of the laser light whose beam diameter is expanded by the magnifying lens 151. .
Further, in the adjustment of the beam diameter of the laser beam for the cell unit 145 group, the intensity distribution (for example, Gaussian distribution) of the laser beam is considered. For example, the difference in intensity of the irradiated laser light is relatively small between the cell portion 145 irradiated with the vicinity of the optical axis L0 of the laser light and the cell portion 145 forming the peripheral portion of the transmission region 145c. In addition, the beam diameter of the laser light applied to the cell unit 145 group is adjusted.
Further, regarding the intensity distribution of the laser light, the degree of intensity modulation by each cell unit 145 can be controlled by the intensity distribution. In this case, for example, the driver 146 controls the control signal according to the intensity distribution of the laser light incident on the magneto-optic modulator 140 so that the intensity of the modulated light emitted from each cell unit 145 becomes substantially uniform. .
That is, the laser beam generally has a predetermined distribution such as a distribution that approximates a Gaussian distribution with respect to its intensity. Therefore, based on the intensity distribution of the laser light incident on the magneto-optic modulator 140, the modulation amount by each cell unit 145 in the cell unit 145 group, that is, the magnitude of the current supplied to each thin film coil 144 of the coil 142 is determined. Control.
Specifically, when the intensity distribution (cross-sectional intensity distribution) of the laser light incident on the magneto-optic modulator 140 is, for example, a Gaussian distribution, the intensity of the laser light is highest at the portion of the optical axis L0 and decreases toward the periphery. . Therefore, in order to make the intensity of the laser beam emitted from each cell unit 145 uniform, the cell located in the portion through which the central portion of the laser beam (the vicinity of the optical axis L0) passes according to the intensity distribution of the laser beam. The magnitude of the current supplied to each cell unit 145 is controlled so that the intensity of the modulated light is higher in the cell unit 145 located in the portion where the peripheral portion of the laser beam is transmitted than the unit 145.
As described above, the modulation amount of the intensity of the incident light by each cell unit 145 is controlled according to the distribution of the intensity of the laser light incident on the magneto-optic modulator 140, so that the magneto-optic modulator 140 becomes independent. Thus, in the configuration having the plurality of cell portions 145 whose transmittance can be controlled, it is possible to reduce the intensity variation of the modulated light Lc emitted from the magneto-optic modulator 140 due to the intensity distribution of the laser light.
As described above, in the light source unit 110 included in the RSD 1 of the present embodiment, the magneto-optic modulator 140 is shared by the three colors of laser light, that is, the red laser light Lr, the green laser light Lg, and the blue laser light Lb. Yes. That is, in the light source unit 110 of the present embodiment, the intensity of the laser light generated by each of the laser generation units 121, 122, and 123 included in the light source 120 is incident by one magneto-optical modulator 140 that enters through a predetermined optical system. A modulated configuration is employed. For such a configuration, a magneto-optical modulator 140 may be provided for each color of laser light. That is, in the light source unit 110, the magneto-optic modulator 140 may be provided for each of the three primary colors.
A configuration in which the magneto-optic modulator 140 is provided independently for each of the laser beams of the three primary colors (hereinafter referred to as “this configuration”) will be described with reference to FIG. In the following description, the same reference numerals are used for the components common to the already described embodiments, and the description thereof is omitted as appropriate.
As shown in FIG. 13, in the light source unit 210 according to the present configuration, the light source 220 includes a red laser generation unit 121, a green laser generation unit 122, and a blue laser generation unit 123. A magneto-optic modulator 140 is provided. That is, the magneto-optical modulator 140r for the red laser generator 121, the magneto-optical modulator 140g for the green laser generator 122, and the magneto-optical modulator 140b for the blue laser generator 123, respectively. Is provided.
The beam diameter of the red laser beam Lr emitted from the red laser generator 121 is expanded by the magnifying lens 151 in the relay optical system 150 provided between the red laser generator 121 and the magneto-optic modulator 140r. After being collimated by the collimator lens 152, it is incident on the magneto-optic modulator 140r. The laser light incident on the magneto-optic modulator 140r is intensity-modulated by the magneto-optic effect (Faraday effect) under the ON / OFF control of the cell unit 145 by the driver 146, and is emitted as the modulated light Ld of the red laser light Lr. The
Similarly, the green laser light Lg emitted from the green laser generator 122 enters the magneto-optical modulator 140g via the relay optical system 150 provided between the green laser generator 122 and the magneto-optical modulator 140g. The intensity is modulated and emitted as the modulated light Le of the green laser light Lg. Further, the blue laser light Lb emitted from the blue laser generator 123 is incident on the magneto-optic modulator 140b via the relay optical system 150 provided between the blue laser generator 123 and the magneto-optic modulator 140b. Modulated and emitted as modulated light Lf of the blue laser light Lb.
As shown in FIG. 13, the modulated lights Ld, Le, and Lf for the laser beams of the respective colors are incident on the dichroic mirrors 261, 262, and 263. Thereafter, the modulated light Ld, Le, and Lf are selectively reflected and transmitted with respect to the wavelength by these dichroic mirrors 261, 262, and 263, and are emitted as emitted light Lo.
Specifically, the modulated light Ld of the red laser light Lr is transmitted through the dichroic mirror 261 to form outgoing light Lo. The modulated light Le of the green laser light Lg is incident on the dichroic mirror 262 and reflected by the dichroic mirror 262 toward the dichroic mirror 261. Thereafter, the modulated light Le incident on the dichroic mirror 261 is reflected by the dichroic mirror 261 to form outgoing light Lo.
The modulated light Lf of the blue laser light Lb is incident on the dichroic mirror 263 and reflected by the dichroic mirror 263 toward the dichroic mirror 262. Thereafter, the modulated light Lf incident on the dichroic mirror 262 passes through the dichroic mirror 262 and then enters the dichroic mirror 261. Thereafter, the modulated light Lf incident on the dichroic mirror 261 is reflected by the dichroic mirror 261 to form outgoing light Lo.
The emitted light Lo formed by the modulated lights Ld, Le, and Lf for the laser beams Lr, Lg, and Lb of each color is condensed by the coupling optical system 77 and guided to the optical fiber cable 50 (see FIG. 2). The configuration of the optical system for emitting the modulated lights Ld, Le, and Lf for the laser lights Lr, Lg, and Lb of the respective colors as the emitted light Lo is such that the modulated lights Ld, Le, and Lf are selectively reflected with respect to the wavelength. -It will not be limited if it is the structure which can be permeate | transmitted.
In this configuration, a modulation signal (see FIG. 3, drive signal 60a) for controlling the magneto-optical element 141 is independently sent to the magneto-optical modulator 140 corresponding to each color laser beam. That is, as shown in FIG. 13, a drive signal 60x as a modulation signal for the red laser light Lr is input to the driver 146 provided in the magneto-optic modulator 140r corresponding to the red laser light Lr. Similarly, a drive signal 60y as a modulation signal for the green laser light Lg is input to the driver 146 provided in the magneto-optic modulator 140g corresponding to the green laser light Lg, and the magnetism corresponding to the blue laser light Lb. A drive signal 60z as a modulation signal for the blue laser light Lb is input to the driver 146 provided in the optical modulator 140b.
Thus, in this configuration, the light source 220 includes the red laser generation unit 121, the green laser generation unit 122, and the blue laser generation unit 123, and the laser generation units for the laser beams Lr, Lg, and Lb of the respective colors. Corresponding magneto-optic modulators 140r, 140g, 140b are provided, respectively.
In the RSD 1 of the present embodiment, a configuration in which the magneto-optic modulator 140 is provided only for the green laser light Lg (hereinafter referred to as “another configuration”) may be employed. Another configuration will be described with reference to FIG.
As illustrated in FIG. 14, in the light source unit 310 according to another configuration, the light source 320 includes a red laser generation unit 121, a green laser generation unit 122, and a blue laser generation unit 123. A magneto-optic modulator 140 g is provided only for the green laser generator 122.
Therefore, in another configuration, the green laser generator 122 has a solid-state laser 326 as a laser driven by the laser driver 327 that receives the G drive signal 60g. In addition, the red laser generation unit 121 includes a semiconductor laser 324 that emits red laser light Lr as a laser driven by a laser driver 325 that receives the R drive signal 60x ′. Similarly, the blue laser generator 123 includes a semiconductor laser 328 that emits blue laser light Lb as a laser driven by a laser driver 329 that receives the B drive signal 60z ′.
Then, as described above, the green laser light Lg emitted from the green laser generation unit 122 is incident on the magneto-optical modulator 140g via the relay optical system 150, is intensity-modulated, and becomes modulated light Le of the green laser light Lg. Emitted. Further, the red laser light Lr emitted from the red laser generator 121 is intensity-modulated according to the R drive signal 60x ′ including the modulation signal, and is emitted as the modulated light Lh via the relay optical system 150. Similarly, the blue laser light Lb emitted from the blue laser generator 123 is intensity-modulated according to the B drive signal 60z ′ including the modulation signal, and emitted as modulated light Li via the relay optical system 150.
Then, the modulated lights Lh, Le, and Li for the laser beams of the respective colors are selectively reflected and transmitted with respect to the wavelengths by the dichroic mirrors 261, 262, and 263, and are emitted as the emitted light Lo. Exit. The red laser light Lr emitted from the red laser generator 121 and the blue laser light Lb emitted from the blue laser generator 123 may be configured to be emitted without passing through the relay optical system 150. Good.
As described above, in the RSD 1 according to the present embodiment, the magneto-optical element has a characteristic that the visible light transmittance is low (several percent), and a retinal scanning image that can display a bright image with a small amount of light. In the display device, the intensity of the laser beam can be modulated by the magneto-optic modulator as an external modulator including the magneto-optic element. The magneto-optical element 141 is divided into cells 143 as a plurality of segments, so that digital gradation expression is performed. Such gradation expression by the plurality of cells 143 is performed as necessary gradation expression. In the retinal scanning-type image display device, a laser beam having a relatively small beam diameter is used, and accordingly, the magneto-optical element 141 is also miniaturized. Since the magneto-optical element 141 for modulating the intensity of the laser light is reduced in size, high responsiveness can be obtained and high-speed modulation can be performed. Further, in the retinal scanning type image display device, since the amount of light necessary for displaying an image is small, even if the magneto-optical element 141 is small, the problem of heat due to low transmittance hardly occurs. .
In addition, although RSD1 of this embodiment uses a laser beam as light projected on the retina of an observer's eye, it is not limited to this. That is, in the retinal scanning image display apparatus according to the present invention, the light projected onto the retina of the observer's eye may be a collimated light beam.
As described above, according to the RSD 1 according to the present embodiment, the following effects can be expected.
(1) The RSD 1 of this embodiment includes an image signal supply circuit 13 that generates a light source drive signal 60 according to image information, and a light source unit 110 (210) that emits laser light having an intensity according to the light source drive signal 60. The horizontal scanning unit 80 and the vertical scanning unit 90 that scan the laser light emitted from the light source unit 110 (210) in a two-dimensional direction, and the laser light scanned by these scanning units is the retina 101b of the eye Y of the observer. And the second relay optical system 95 and the half mirror 9 for projecting an image. The light source unit 110 includes a light source 120 (220) and a magneto-optic modulator 140 that modulates the intensity of the laser light emitted from the light source 120 (220) based on the light source drive signal 60. As a result, high-speed modulation by external modulation can be realized for input light without significantly increasing power consumption or increasing the size of the apparatus.
That is, the RSD 1 of the present embodiment includes a magneto-optic modulator 140 that utilizes the magneto-optic effect as a configuration for performing intensity modulation of laser light. For this reason, the RSD 1 of the present embodiment is advantageous in terms of power consumption, simplicity of the apparatus configuration, and the like in comparison with a configuration in which an external modulator using an acousto-optic effect is provided as an external modulator of laser light. is there. Further, the properties of the magneto-optical element, such as low visible light transmittance and low contrast, make it possible to display a retinal scanning display that can display a bright image with a small amount of light compared to an image display device such as a projector. There is no problem in the device.
(2) Also, in the RSD 1 of the present embodiment, the magneto-optic modulator 140 has a plurality of cell units 145 whose transmittance can be controlled independently on a plane substantially orthogonal to the incident direction of the laser light. Two-dimensional arrangement is performed, a control signal is input to each cell unit 145 based on the drive signal 60a to control the transmittance of light incident on each cell unit 145, and the laser beam emitted from the light source 120 (220) is controlled. A driver 146 for modulating the intensity is provided. Thereby, digital gradation expression is possible for the laser light whose intensity is modulated by the magneto-optic modulator 140.
(3) In the RSD 1 of the present embodiment, the driver 146 controls whether the light incident on each cell unit 145 is transmitted or blocked by a control signal input to each cell unit 145. Thereby, since control of each cell part 145 becomes binary control (ON / OFF control), control can be facilitated.
(4) Further, in the RSD 1 of the present embodiment, the driver 146 sends a control signal so that the cell portion 145 that transmits light among the plurality of cell portions 145 is adjacent to form a single transmission region 145c. Control. As a result, optical defects such as diffraction hardly occur with respect to the laser light transmitted through the cell unit 145 group, and a good beam shape can be obtained. In addition, the control of each cell unit 145 can be facilitated.
(5) In the RSD 1 of the present embodiment, the driver 146 controls the control signal so that the center of the transmission region 145c substantially coincides with the position of the optical axis L0 of the laser beam. As a result, it is possible to efficiently use the laser power of the laser light incident on the cell unit 145 group.
(6) In the RSD 1 of the present embodiment, the light source unit 110 (210) causes at least a part of the laser light emitted from the light source 120 (220) to enter all the entrances 145d of the magneto-optic modulator 140. Is configured to do. As a result, all of the plurality of cell portions 145 can be used as portions for intensity modulation of laser light, and the number of intensity modulation patterns can be ensured.
(7) In the RSD 1 of the present embodiment, the light source 120 includes the R laser 124 that emits the red laser light Lr, the G laser 126 that emits the green laser light Lg, and the B laser that emits the blue laser light Lb. 128, and sequentially emits the red laser light Lr, the green laser light Lg, and the blue laser light Lb in a time-sharing manner, and the driver 146 outputs each of the red laser light Lr, the green laser light Lg, and the blue laser light Lb. The intensity of the is sequentially modulated. As a result, the three color laser beams Lr, Lg, and Lb can share one magneto-optic modulator 140, and the cell unit 145 group can be intensity-modulated with different ON / OFF patterns for each color of the laser beam. It becomes.
(8) In the RSD 1 of the present embodiment, the light source 220 includes the R laser 124 that emits the red laser light Lr, the G laser 126 that emits the green laser light Lg, and the B laser that emits the blue laser light Lb. 128, and the magneto-optical modulator 140 is provided in each of the R laser 124, the G laser 126, and the B laser. This makes it easy to perform intensity modulation according to the intensity distribution that changes for each color (by wavelength) for the laser light incident on the magneto-optic modulator 140.
(9) In the RSD 1 of the present embodiment, the light source 320 includes the semiconductor laser 324 that emits the red laser Lr, the solid-state laser 326 that emits the green laser light Lg, and the semiconductor laser 328 that emits the blue laser light Lb. The image signal supply circuit 13 outputs drive signals 60x ′, 60z ′, and 60y corresponding to the image information to the semiconductor lasers 324 and 328 and the magneto-optic modulator 140g, respectively. Laser light Lr and Lb whose intensity is modulated in accordance with the drive signals 60x ′ and 60z ′ are emitted from the semiconductor lasers 324 and 328, and the intensity of the green laser light Lg emitted from the solid-state laser 326 is output by the magneto-optic modulator 140g. Modulation is performed according to the drive signal 60y. Thereby, the green laser light Lg can be easily adjusted to a desired intensity.
(10) Further, in the RSD 1 of the present embodiment, the cell unit 145 is formed in a 16 × 16 matrix, and the driver 146 controls the cell unit 145 so that the intensity of the laser beam is 256 gradations. To control. This facilitates control of the plurality of cell units 145 and facilitates handling of 8-bit images.
(11) Further, in the RSD 1 of the present embodiment, the magneto-optic modulator 140 includes the incident side polarizing plate 147 and the polarization of the incident side polarizing plate 147 on the optical path of the laser light emitted from the light source 120 (220). An output side polarizing plate 148 having a polarization characteristic orthogonal to the characteristics, and a magneto-optical element 141 sandwiched between the incident side polarizing plate 147 and the output side polarizing plate 148 are disposed. Thereby, intensity modulation using the magneto-optical effect can be performed with a simple configuration.
1 RSD (retinal scanning image display device)
9 Half mirror 13 Image signal supply circuit (drive signal generator)
60 Light source drive signal (drive signal)
80 Horizontal scanning unit (scanning unit)
90 Vertical scanning unit (scanning unit)
95 Second relay optical system 101b Retina 110 Light source 120 Light source 124 R laser (red laser)
126 G laser (green laser)
128 B laser (blue laser)
140 Magneto-optical modulator 141 Magneto-optical element 145 Cell unit 145c Transmission region 145d Entrance 146 Driver (control unit)
147 Incident side polarizing plate (first linear polarizing plate)
148 Output side polarizing plate (second linear polarizing plate)
210 light source unit 220 light source 310 light source unit 320 light source 324 semiconductor laser 326 solid state laser 328 semiconductor laser L0 optical axis Y eye
A drive signal generation unit that generates a drive signal according to image information, a light source unit that emits a light beam having an intensity according to the drive signal, and a scanning unit that scans the light beam emitted from the light source unit in a two-dimensional direction; A projection unit that projects an image by projecting the light beam scanned by the scanning unit onto the retina of the observer's eye,
The light source unit includes a light source and a magneto-optic modulator that modulates the intensity of a light beam emitted from the light source based on the drive signal.
In the magneto-optic modulator, a plurality of cell portions whose transmittance can be independently controlled are two-dimensionally arranged in a plane substantially orthogonal to the incident direction of the light beam,
A control unit that inputs a control signal for each cell unit based on the drive signal, controls the transmittance of light incident on each cell unit, and modulates the intensity of the light beam emitted from the light source; The retinal scanning image display apparatus according to claim 1, wherein
3. The retinal scanning image according to claim 2, wherein the control unit controls whether light incident on each cell unit is transmitted or blocked by a control signal input to each cell unit. 4. Display device.
The said control part controls the said control signal so that the cell part which permeate | transmits light among these cell parts may be adjoined, and it may become one united permeation | transmission area | region. The retinal scanning image display device described.
5. The retinal scanning image display apparatus according to claim 4, wherein the control unit controls the control signal so that a center of the transmission region substantially coincides with an optical axis position of the light beam.
The said light source part is comprised so that at least one part of the light beam radiate | emitted from the said light source may inject into all the entrances of the said magneto-optical modulator, The any one of Claims 2-5 characterized by the above-mentioned. 2. A retinal scanning image display device according to 1.
The light source includes a red laser that emits a red light beam, a green laser that emits a green light beam, and a blue laser that emits a blue light beam, and time-divides the red light beam, the green light beam, and the blue light beam. In order,
The retinal scanning image display apparatus according to claim 2, wherein the control unit sequentially modulates the intensity of each of the red light beam, the green light beam, and the blue light beam.
The light source includes a red laser that emits a red light beam, a green laser that emits a green light beam, and a blue laser that emits a blue light beam,
The retinal scanning image display apparatus according to claim 2, wherein the magneto-optic modulator is provided in each of the red laser, the green laser, and the blue laser.
The light source includes a semiconductor laser that emits a red light beam, a solid-state laser that emits a green light beam, and a semiconductor laser that emits a blue light beam,
The drive signal generation unit outputs a drive signal corresponding to the image information to each of the semiconductor laser and the magneto-optic modulator, and a light beam whose intensity is modulated from each semiconductor laser according to the drive signal And the intensity of the light beam emitted from the solid-state laser is modulated in accordance with the drive signal by the magneto-optic modulator. Type image display device.
The cell part is formed in a 16 × 16 matrix,
The retinal scanning image display apparatus according to claim 2, wherein the control unit controls the cell unit to control the intensity of the light flux to 256 gradations.
The magneto-optic modulator has, on the optical path of a light beam emitted from the light source, a first linear polarizing plate and a second straight line having a polarization characteristic orthogonal to the polarization characteristic of the first linear polarizing plate. 11. The polarizing plate and a magneto-optical element sandwiched between the first linear polarizing plate and the second linear polarizing plate are arranged. 11. Retina scanning image display device.
JP2009203770A 2009-09-03 2009-09-03 Retina-scanning type image display device Pending JP2011053540A (en)
JP2009203770A JP2011053540A (en) 2009-09-03 2009-09-03 Retina-scanning type image display device
JP2011053540A true JP2011053540A (en) 2011-03-17
ID=43942582
JP2009203770A Pending JP2011053540A (en) 2009-09-03 2009-09-03 Retina-scanning type image display device
JP (1) JP2011053540A (en)
2009-09-03 JP JP2009203770A patent/JP2011053540A/en active Pending