JP5157835B2 - Image display device - Google Patents

Description

  The present invention relates to an image display device.

  In recent years, projectors using a laser light source have been developed with the increase in output of semiconductor lasers and the appearance of blue semiconductor lasers. Since this type of projector has a narrow wavelength range of the laser light source, the color reproduction range can be sufficiently widened, and the size and the number of components can be reduced. This has great potential as a next-generation projector. However, when performing display on a projector using a laser light source, light spots and dark spots are distributed in a striped pattern or a spotted pattern due to light interference caused by a scatterer such as a screen, so-called “scintillation (or“ speckle ”). The phenomenon called "" may also occur.

  Scintillation causes an adverse effect such as giving a viewer a glare and giving an uncomfortable feeling when viewing an image. In particular, since laser light is highly coherent, scintillation is likely to occur. However, not only a laser light source but also a lamp light source, in recent years, the coherence of light has been increased by shortening the arc, and a technique for removing scintillation has become important. Therefore, techniques for reducing scintillation as described below have been proposed (see, for example, Patent Documents 1-3).

Patent Document 1 discloses an image generation apparatus in which a light scattering element including a diffraction grating corresponding to each wavelength is arranged at a position where a one-dimensional intermediate image is formed by a light modulation device. In this image generating apparatus, speckle can be reduced by shifting the imaging position of the one-dimensional intermediate image corresponding to each wavelength in the direction corresponding to the scanning direction of the scanning optical system. Patent Documents 2 and 3 disclose image display devices that change the drawing position (pixel position) at regular intervals when scanning light. In this image display apparatus, since the speckle pattern changes by changing the drawing position, speckle felt by human eyes can be reduced.
JP 2008-8777 A JP 2003-255252 A JP 2005-292380 A

However, the speckle reduction measures described in Patent Documents 1-3 have the following problems.
In the image generation apparatus of Patent Document 1, a projection optical system for projecting a one-dimensional intermediate image on a light scattering element is required, which causes a problem that the apparatus becomes large. In particular, in the case of a scanning-type image generation apparatus such as that disclosed in Patent Document 1, a projection optical system is essentially unnecessary. Nevertheless, the presence of the projection optical system complicates the entire optical system and increases the number of parts. Further, in the devices of Patent Documents 2 and 3, even if the drawing position is shifted at regular intervals, the speckle pattern at an arbitrary point on the screen is always constant, so the speckle reduction effect is not sufficient. .

  SUMMARY An advantage of some aspects of the invention is that it provides an image display device that can reliably suppress speckle without increasing the size of the device.

  In order to achieve the above object, an image display device of the present invention includes a light source that emits laser light, and a scanning unit that draws an image by scanning the laser light in a two-dimensional direction on a projection surface. And the scanning means performs a laser beam scanning motion for scanning the laser beam on the projection surface at a predetermined cycle, and a motion having a constant period other than a multiple of the scanning period of the laser beam, the laser beam By performing a laser beam incident angle changing motion including either a motion having a constant period other than a divisor of the scanning period or a motion not having a constant period, the scanning means applies a predetermined drawing point on the projection surface. The incident angle of the laser beam varies with time.

  In the image display device of the present invention, the scanning means performs a laser beam scanning movement for performing a laser beam scanning, and performs a laser beam incident angle changing movement, so that it enters a predetermined drawing point on the projection surface. The incident angle of the laser light changes with time. At this time, if a motion having a constant period that is a multiple or a divisor of the scanning period of the laser beam is applied to the scanning unit, the scanning period of the laser beam and the period of the motion applied to the scanning unit are synchronized. . In this case, depending on the drawing point, the laser beam may always be incident from the same angle, and the speckle cannot be completely suppressed.

  On the other hand, in the image display device of the present invention, the scanning means has a movement having a constant period other than a multiple of the scanning period of the laser light as the laser light incident angle change movement, Since either the movement with a fixed period or the movement without a fixed period is performed, the scanning period of the laser beam and the period of the laser beam incident angle change movement are always in an asynchronous state. Therefore, since laser light is incident on all drawing points from different angles depending on time, different speckle patterns are generated, and these speckle patterns are temporally averaged to increase the SN ratio of image light. Thus, according to the image display apparatus of the present invention, speckle can be reliably suppressed without complicating the optical system.

In the image display device of the present invention, a mirror having a reflecting surface for reflecting the laser beam can be used as the scanning unit.
According to this configuration, for example, a configuration in which the scanning unit performs the laser beam incident angle changing motion by a method such as applying vibration to the mirror can be realized relatively easily.

In the image display device of the present invention, the laser beam incident angle changing motion is a translational motion having a moving component in the normal direction of the reflecting surface, or a rotation axis on an axis different from the scanning axis of the mirror. A rotational motion is desirable.
According to this configuration, it is possible to effectively change the incident angle of the laser beam with respect to a predetermined drawing point on the projection surface.

In the image display device of the present invention, when a resonance type mirror is used as the mirror, a resonance motion of a first resonance mode is used as the laser beam scanning motion, and the first resonance mode is used as the translation motion or the rotation motion. It is desirable to use a resonance motion of the second resonance mode different from the above.
According to this configuration, a large vibration can be obtained only by applying relatively small energy to the scanning means, and a highly efficient image display apparatus can be realized.

In the above configuration using the resonance motion of the second resonance mode, a drive signal having a waveform in which a waveform having the resonance frequency of the second resonance mode is superimposed on the waveform of the drive signal of the mirror used for scanning of the laser light. The scanning means is preferably supplied.
In the present invention, as a specific means for imparting a laser beam incident angle change motion to the mirror, for example, a configuration in which the mirror is vibrated by a driving means such as a piezoelectric element may be used. Without using any means, the above movement can be imparted to the mirror simply by crafting the drive signal supplied to the scanning means, which is reasonable.

In the image display device of the present invention, the scanning means scans the laser light at a relatively high speed in one direction on the projection surface, and scans of the high-speed scanning means on the projection surface. A low-speed scanning unit that scans the laser light at a relatively low speed in a direction perpendicular to the direction, at least one of the high-speed scanning unit and the low-speed scanning unit is configured to perform the laser light incident angle change motion. Can be adopted.
According to this configuration, since two-stage scanning means, that is, a high-speed scanning means and a low-speed scanning means, are used, and at least one of them only needs to perform the laser beam incident angle changing motion, the motion can be controlled easily and reliably. .

In the above configuration using two scanning means, both the high speed scanning means and the low speed scanning means perform the laser light incident angle changing motion, and the period of the laser light incident angle changing motion of the high speed scanning means and the low speed scanning. The period of the laser beam incident angle change movement of the means is in a relationship other than a multiple or a relationship other than a divisor, or the laser beam incident angle change motion of the high speed scanning unit, the laser beam incident angle change of the low speed scanning unit It is desirable that at least one of the movements does not have a certain period.
According to this configuration, both the high-speed scanning means and the low-speed scanning means perform the laser beam incident angle changing movement, and the movement cycle of the high-speed scanning means and the movement period of the low-speed scanning means are other than a multiple or a factor other than a divisor. Or because at least one of the laser beam incident angle changing motions of the two scanning means does not have a constant period, the asynchronous state is reliably maintained over the entire projection surface, and speckle is more reliably suppressed. be able to.

Alternatively, one of the high-speed scanning unit and the low-speed scanning unit performs the laser beam incident angle changing motion, and the one scanning unit performs the laser beam incident angle changing motion on the projected surface. It is desirable to correct the deviation of the drawing point by controlling the scanning of the scanning means on the side not performing the laser beam incident angle changing motion, or the light emission timing of the light source.
In the present invention, since the scanning means performs a laser beam incident angle changing motion in addition to the laser beam scanning motion, the drawing position when the projection surface is irradiated with the laser beam is deviated from the normal drawing point, and the image is distorted. It is done. On the other hand, according to the above configuration, since the deviation of the drawing point is corrected by the scanning control of the scanning means on the side not performing the laser beam incident angle changing motion or the light emission timing of the light source, the image without distortion Can be obtained.

In the image display device of the present invention, the scanning unit is a biaxial scanning unit that scans the laser beam in a horizontal direction and a vertical direction on the projection surface, and the biaxial scanning unit changes the incident angle of the laser beam. A configuration for performing exercise can be employed.
According to this configuration, since only one stage of the biaxial scanning unit is used and the laser beam incident angle changing motion is performed, the parts of the image display device can be simplified and downsized.

In the above-described configuration using the biaxial scanning means, the deviation of the drawing point on the projection surface caused by the biaxial scanning means performing the laser beam incident angle changing motion is controlled by the scanning of the biaxial scanning means. Alternatively, it is desirable to correct by the light emission timing of the light source.
According to this configuration, an image without distortion can be obtained as described above.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
The image display device of this embodiment is an image display device that draws an image on a screen using laser light sources that respectively emit red light, green light, and blue light, and is an example that uses two-stage scanning means. .
FIG. 1 is a perspective view showing a schematic configuration of the image display apparatus of the present embodiment. FIG. 2 is a perspective view showing a MEMS mirror used in the image display apparatus. FIG. 3 is a diagram showing a waveform of a drive signal supplied to the MEMS mirror. FIG. 4 is a diagram illustrating a change in the incident angle of light on the screen when the MEMS mirror performs a laser beam incident angle changing motion. FIG. 5 is a front view showing the position of each drawing point on the screen. In the following drawings, the dimensional ratio and scale may be changed for each component in order to make each component easy to see.

  As shown in FIG. 1, the image display device 1 according to the present embodiment includes a light source unit 2, a MEMS mirror 3 (high-speed scanning unit), and a galvano mirror 4 (low-speed scanning unit). The light source unit 2 includes a red laser light source 2R that emits red laser light (center wavelength: 620 nm), a green laser light source 2G that emits green laser light (center wavelength: 530 nm), and a blue laser light (center wavelength: 460 nm). And a cross dichroic prism 5. In addition, the wavelength of the laser beam of each color is only an example. The cross dichroic prism 5 combines the laser beams of the respective colors emitted from the laser light sources 2R, 2G, and 2B.

  As shown in FIG. 1, the MEMS mirror 3 is a scanning mirror installed on the side closer to the light source unit 2 among the two scanning mirrors. The MEMS mirror 3 emits laser light emitted from the light source unit 2 in the horizontal direction H during scanning in two directions (vertical direction V and horizontal direction H) when an image is drawn on the screen 7 (projected surface). It functions as a horizontal scanning scanner, and is responsible for high-speed scanning. On the other hand, the galvanometer mirror 4 is a scanning mirror installed on the side close to the screen 7 of the two scanning mirrors. The galvanometer mirror 4 functions as a vertical scanning scanner that scans the laser light reflected by the MEMS mirror 3 in the vertical direction V, and is responsible for low-speed scanning.

  The screen 7 used in this embodiment is capable of displaying a so-called VGA (Video Graphics Array) image formed by pixels in the horizontal direction 640 × vertical direction 480. The “pixels on the screen” referred to here are irradiation areas on the projection surface corresponding to one pixel which is the minimum unit constituting the projection image.

  As shown in FIG. 2, the MEMS mirror 3 includes a mirror portion 9, a frame portion 10, and a beam portion 11 that are integrally formed from, for example, a silicon substrate. The mirror unit 9 is formed in a disc shape and has a smooth reflecting surface that reflects incident light. Moreover, the mirror part 9 is rotatably supported inside the frame part 10 by a beam part 11 extending in the diameter direction of the disk. Although not shown, the mirror portion 9 is provided with a coil, and the frame portion 10 is provided with a magnet. That is, the MEMS mirror 3 is configured such that the mirror unit 9 is driven by electromagnetic induction when a current is passed through the coil. Specifically, by supplying a sinusoidal drive signal (current) to the coil, the coil receives the Lorentz force and the beam portion 11 is twisted, and the mirror portion 9 is within a predetermined rotation angle range around the beam portion 11. Rotate reciprocating motion (swing motion). The rotation of the mirror unit 9 is a laser beam scanning motion, and the laser beam is scanned on the screen 7 in the horizontal direction. In the following description, a surface in which the reflecting surface of the mirror unit 9 and the upper surface of the frame unit are in the same plane when the mirror unit 9 is not rotating is referred to as a “main surface of the MEMS mirror”.

  In the present embodiment, a drive signal having a waveform in which another sine wave having a different period from one sine wave is superimposed is not applied to the coil, but a sinusoidal drive signal is simply applied to the coil of the MEMS mirror 3. To supply. Specifically, as shown in FIG. 3, the waveform of the sine wave indicated by the one-dot chain line W2 is superimposed on the waveform of the sine wave-like drive signal having a short cycle indicated by the solid line W1 used for scanning of the laser beam. Drive signal S is generated and supplied to the coil. Here, the frequency of the sine wave indicated by the solid line W1 corresponds to the resonance frequency of the first resonance mode inherent to the MEMS mirror 3, and the frequency of the sine wave indicated by the one-dot chain line W2 is the resonance of the second resonance mode. It corresponds to the frequency. That is, since a general MEMS mirror has a plurality of specific resonance modes in addition to the resonance mode used for laser beam scanning, in this embodiment, other than the resonance mode used for rotational reciprocating motion for laser beam scanning. This means that the mirror unit 9 is vibrated using the resonance mode. Further, the cycle of the sine wave indicated by the solid line W1 and the cycle of the sine wave indicated by the one-dot chain line W2 are not in a multiple or divisor relationship.

  When such a drive signal S is supplied to the coil, resonance in two different resonance modes inherent to the MEMS mirror 3 occurs, and as a result, as shown in FIG. Rotational reciprocating motion in the direction), and vibration of the mirror portion in the normal direction of the main surface of the MEMS mirror (reciprocating motion in the direction indicated by arrow B) occurs. That is, the mirror unit 9 has a normal direction of the main surface of the MEMS mirror 3, that is, when the mirror unit 9 is not rotating (when the reflecting surface of the mirror unit 9 is on the same plane as the upper surface of the frame unit 10). Translational motion with a moving component occurs in the normal direction of the reflecting surface. Further, as described above, since the period of the two waveforms W1 and W2 for generating the two motions included in the drive signal S is not a multiple or divisor, the reciprocating motion and vibration of the mirror unit 9 are vibrated. Are not synchronized with each other and are always out of phase.

  At this time, the overall operation of the image display device 1 will be described. Laser light emitted from each of the red laser light source 2R, the green laser light source 2G, and the blue laser light source 2B is synthesized by the cross dichroic prism 5 and is combined with the MEMS mirror 3. It is injected towards. The light reflected by the MEMS mirror 3 is scanned on the screen 7 by a rotational motion (arrow C) about the rotational axis parallel to the paper surface of FIG. At this time, the mirror unit 9 of the MEMS mirror 3 vibrates in the arrow B direction while rotating and reciprocating in the arrow A direction around the rotation axis perpendicular to the paper surface of FIG. Even when P (pixels) is irradiated, there are cases where the laser light follows a solid line L1 and a broken line L2 depending on time (frame), and the incident angle to the screen 7 changes.

  Assuming that the MEMS mirror is vibrated in synchronization with the rotational reciprocating motion of the laser beam, the laser beam may always be incident from the same angle depending on the drawing point (pixel), and the speckle cannot be completely suppressed. . On the other hand, in the image display device 1 of the present embodiment, the rotational reciprocation and vibration of the mirror unit 9 of the MEMS mirror 3 are always in an asynchronous state. Laser light is incident. Therefore, different speckle patterns are generated, and these speckle patterns are temporally averaged to increase the SN ratio of image light. Thus, according to the image display device of the present embodiment, speckle can be reliably suppressed without complicating the optical system.

  In addition, the resonance type MEMS mirror 3 is provided as a scanning unit, the resonance motion in the first resonance mode is used for rotating and reciprocating the mirror portion 9, and the resonance motion in the second resonance mode for vibrating the mirror portion 9. Therefore, a large vibration can be obtained only by applying relatively small energy to the MEMS mirror, and a highly efficient image display device can be realized. In addition, an electric signal for vibrating the mirror unit 9 is not supplied separately, but the waveform of the second resonance mode is superimposed on the waveform of the first resonance mode of the driving signal for laser beam scanning. The above-described motion can be imparted to the mirror unit 9 by simply devising a drive signal supplied to the MEMS mirror 3 without using special vibration imparting means such as an element, which is reasonable.

  In addition, as a result of vibrating the mirror unit 9, not only the incident angle changes but also the position of the drawing point may shift. As in this embodiment, a vibration other than the rotational reciprocating motion for high-speed scanning is applied to the MEMS mirror 3 in the previous stage, while a special motion other than the rotational reciprocating motion for low-speed scanning is applied to the downstream galvanometer mirror. If not, for example, as shown in FIG. 5, each drawing point on the screen 7 is shifted in the horizontal direction H to a position P2 indicated by a broken line with respect to a normal drawing point position P1 indicated by a solid line. In this case, it is sufficient that the degree of deviation is within the allowable range, but if the allowable range is exceeded, the image may be distorted. In that case, each drawing point is set to a normal position by giving the same vibration as that of the MEMS mirror 3 in the preceding stage to the latter stage galvanometer mirror 4 or by finely adjusting the light emission timing of each laser light source 2R, 2G, 2B. Can be corrected. In the present embodiment, vibration is applied only to the MEMS mirror 3 on the high-speed scanning side, and the drawing position can be corrected by the galvano mirror 4 on the low-speed scanning side, so that correction can be easily performed and accuracy can be improved.

  Since the resonance frequency of each mode in one MEMS mirror is known in advance at the time of design, if the positional relationship between the image display device 1 and the screen 7 is determined, the positional deviation of each drawing point on the screen 7 is It can be calculated in advance. Therefore, if the control of the galvanometer mirror 4 and the adjustment of the light emission timings of the laser light sources 2R, 2G, and 2B are performed in accordance with a predetermined control rule, an image display device free from pixel deviation can be realized.

[Modification 1-1]
In the above embodiment, the configuration example in which the normal direction of the reflection surface is applied to the mirror portion 9 of the MEMS mirror 3 has been described. However, instead of the configuration example, the rotational reciprocating motion for scanning of the mirror portion 9 is performed. It is good also as a structure which gives the rotational motion centering on the rotating shaft different from a rotating shaft, and the effect similar to the said embodiment is acquired also in that case. FIG. 6 shows a configuration example in which a reciprocating motion about the rotation axis extending in the direction orthogonal to the extending direction of the beam portion 11 occurs on the main surface of the MEMS mirror 3. That is, in the case of this MEMS mirror 3, while the reciprocating motion (indicated by the arrow A) of the mirror portion 9 around the beam portion 11 (rotation axis a) for scanning the laser light is generated, the rotation axis a Thus, a reciprocating motion (indicated by an arrow D) of the mirror portion 9 about the vertical rotation axis d occurs. The reciprocating motion of the mirror unit 9 about the rotation axis d is generated using a resonance mode different from the resonance mode used for the reciprocating motion of the mirror unit 9 for scanning the laser beam, as in the above embodiment. Can be made. In addition, the resonance mode can be realized by superimposing a predetermined waveform on a drive signal for scanning with laser light, as in the above embodiment.

  In the case of this modification, as shown in FIG. 7, each drawing point on the screen 7 is moved with respect to the normal drawing point position P1 indicated by the solid line by the reciprocating motion of the mirror unit 9 about the rotation axis d. It shifts in the vertical direction V to the position P2 indicated by the broken line. In this case, it is sufficient that the degree of deviation is within the allowable range, but if the allowable range is exceeded, the image may be distorted. In that case, each drawing point can be corrected to a normal position by finely adjusting the scanning angle of the latter-stage galvanometer mirror 4 by the amount of deviation by the former-stage MEMS mirror 3.

  In this modified example, when one drawing point is shifted to the adjacent drawing point position instead of a slight shift as shown in FIG. 7, the latter galvanometer mirror 4 for correcting the drawing point position is used. The image signal corresponding to each drawing point supplied to each laser light source 2R, 2G, 2B is rearranged without control, and the drawing is performed at a timing when a predetermined drawing point position is passed according to the locus of the drawing point on the screen 7. It is good also as a structure which irradiates the laser beam corresponding to a point. In this case, control of image signals supplied to the laser light sources 2R, 2G, and 2B becomes complicated, but control of the galvanometer mirror 4 at the subsequent stage is extremely easy.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS.
FIG. 8 is a perspective view showing the overall configuration of the image display apparatus of this embodiment, and FIG. 9 is a front view showing the MEMS mirror.
8 and 9, the same reference numerals are given to the same components as those in FIGS. 1 and 2 used in the description of the first embodiment, and detailed description thereof will be omitted.

  As shown in FIG. 8, the image display device 21 of the present embodiment includes a red laser light source 2R, a green laser light source 2G, a blue laser light source 2B, a cross dichroic prism 5, and a MEMS mirror 22 (scanning means). The image is displayed by scanning the laser beam two-dimensionally on the screen 7 by the MEMS mirror 22.

  As illustrated in FIG. 9, the MEMS mirror 22 includes a mirror unit 31, a first frame unit 33, a second frame unit 35, a first beam unit 32, and a second beam unit 34. It is a mirror. The mirror part 31 is supported by the first frame part 33 by the first beam part 32 extending in the x direction, and the first frame part 33 including the mirror part 31 is secondly supported by the second beam part 34 extending in the y direction. It is supported by the frame part 35. With this configuration, the first frame portion 33 including the mirror portion 31 rotates and reciprocates around the second beam portion 34 as a central axis (indicated by an arrow E), and scans the laser light in the horizontal direction H on the screen 7 (low speed). scanning). Further, the mirror portion 31 rotates and reciprocates around the first beam portion 32 with the first beam portion 32 as a central axis (indicated by an arrow F), and scans the laser beam in the vertical direction V on the screen 7 (high-speed scanning). ).

  Here, in the case of the present embodiment as well, as in the first embodiment, the drive signal as shown in FIG. 3 is supplied to the coil of the MEMS mirror 22 so that the entire mirror portion 31 or the first frame portion 33 is scanned with the laser beam. Therefore, a reciprocating motion in a predetermined resonance mode is generated, and a translational motion in the normal direction of the main surface of the MEMS mirror 22 or a rotating motion around an axis different from the rotational axis of the reciprocating motion is generated.

  Also in the image display device 21 of the present embodiment, the same effect as that of the first embodiment that speckles can be reliably suppressed without complicating the optical system is obtained.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, an example in which translational motion or rotational motion is applied only to the scanning mirror on the front stage (high-speed scanning) is shown, but motion may be applied only to the scanning mirror on the rear stage (low-speed scanning). In this case, the positional deviation of the drawing point may be corrected by controlling the scanning mirror on the preceding stage or by adjusting the light emission timing of the laser light source.

  Alternatively, motion may be applied to both the front and rear scanning mirrors. In that case, it is desirable that the period of motion of the scanning mirror at the front stage and the period of motion of the scanning mirror at the rear stage have a relationship other than a multiple or a relationship other than a divisor. According to this configuration, since the asynchronous state of the movement of each scanning mirror is reliably maintained, speckle can be more reliably suppressed.

  In the above-described embodiment, an example in which translational motion or rotational motion having a constant period is applied to the scanning mirror has been described. However, motion that does not have a constant period (in other words, a random period) is applied to the scanning mirror. It is good also as a structure to provide. In this case, since the movement does not synchronize with the rotational reciprocation of the scanning mirror for scanning the laser beam, speckle can be reliably suppressed.

  In the above-described embodiment, a configuration has been described in which a driving signal other than laser beam scanning is generated in the scanning mirror by applying a driving signal in which two different resonance waveforms are superimposed on the scanning mirror. Instead of this configuration, the drive signal applied to the scanning mirror may be a signal having only a laser beam scanning waveform, and may be provided with a means for separately providing vibration such as a piezoelectric element. In addition, as a laser beam scanning means, a MEMS mirror, a galvanometer mirror, a polygon mirror, or the like can be used.

1 is a perspective view showing an image display device according to a first embodiment of the present invention. It is a perspective view which shows the MEMS mirror used for an image display apparatus. It is a figure which shows the waveform of the drive signal supplied to a MEMS mirror. It is a figure which shows the path | route of the light to a screen when a motion is provided to the MEMS mirror. It is a figure which shows the position of the drawing point on a screen. It is a perspective view which shows the motion of the MEMS mirror as a modification. It is a figure which shows the position of the drawing point on the screen in the case of FIG. It is a perspective view which shows the image display apparatus of 2nd Embodiment of this invention. It is a perspective view which shows the MEMS mirror used for an image display apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,21 ... Image display apparatus, 2 ... Light source part, 2R, 2G, 2B ... Laser light source, 3 ... MEMS mirror (high-speed scanning means), 4 ... Galvano mirror (low-speed scanning means), 7 ... Screen (projection surface) 22 MEMS mirror (scanning means).

Claims (10)

A light source that emits light;
A mirror having a reflecting surface for reflecting the light, the prior SL light by scanning a two-dimensional direction on the projection surface and a scanning means for drawing the image,
It said scanning means, before Symbol while performing optical scanning movement Ru is scanned in a predetermined cycle on the projection surface light, motion having a constant period other than a multiple of the scanning period of the previous SL light, scanning before Symbol light motion having a constant period other than a divisor of the period, by performing any of including a light incidence angle variation motion of motion without a fixed period before Symbol for a given drawing point of the projection surface from said scanning means The incident angle of light changes with time ,
The light incident angle changing motion is a translational motion having a moving component in the normal direction of the reflecting surface, or a rotational motion around a rotational axis on an axis different from the scanning axis of the mirror. Image display device. It said mirror is a mirror of the resonant, resonant motion of the first resonance mode is used as a pre-Symbol light scanning motion, the translational motion or resonant motion of the first resonance mode different from the second resonance mode as the rotational motion The image display device according to claim 1 , wherein the image display device is used. Drive signal waveform is superimposed having a resonance frequency of said second resonant mode waveform of the drive signal of the mirror used to scan the front Symbol light, to claim 2, characterized in that it is supplied to the scanning means The image display device described. Said scanning means, said a high-speed scanning means for scanning a pre-Symbol light relatively fast in one direction on the projection surface, the front in the scanning direction perpendicular to the direction of the fast scan means on a projection surface SL Low-speed scanning means for scanning light at a relatively low speed,
The high-speed scanning means, at least one of the image display apparatus according to any one of claims 1 to 3, characterized in that the pre-Symbol light incident angle variation motion of the slow scan unit. The high-speed scanning means performs both the previous SL light incident angle variation motion of the slow scan means, the period and the multiple of the light incident angle change motion cycle as the slow scan means at a light incidence angle variation motion of the high-speed scanning means Or at least one of the light incident angle changing motion of the high speed scanning means and the light incident angle changing motion of the low speed scanning means does not have a constant period. The image display device according to claim 4 . The high-speed scanning means, one carries out the pre-Symbol light incident angle variation motion, the drawing on the projection surface caused by one of the scanning means performs the pre-Symbol light incident angle variation motion of said slow scan means the displacement of the point, the control of the scanning of the scanning means prior Symbol light incident angle variation motion is not performed side, or the image display apparatus according to claim 4, characterized in that to correct the light emission timing of the light source. It said scanning means is a biaxial scanning means for scanning a pre-Symbol light in the horizontal direction and the vertical direction on the projection surface,
The image display apparatus according to any one of claims 1 to 3, characterized in that the two-axis scanning means performs pre-Symbol light incident angle variation motion. The deviation of the recording points on the projection surface caused by the two-axis scanning means performs pre-Symbol light incident angle variation motion, control of the scanning of the two-axis scanning means, or is corrected by the light emission timing of the light source The image display device according to claim 7 . A light source that emits light;
High-speed scanning means for scanning the light at a relatively high speed in one direction on the projection surface, and scanning the light at a relatively low speed in a direction perpendicular to the scanning direction of the high-speed scanning means on the projection surface. Scanning means for drawing an image by scanning the light in a two-dimensional direction on the projection surface,
The scanning means performs a light scanning motion in which the light is scanned on the projection surface in a predetermined cycle, and has a constant cycle other than a multiple of the light scanning cycle, and a divisor of the light scanning cycle. The incident angle of the light with respect to a predetermined drawing point on the projection surface from the scanning unit is changed over time by performing a light incident angle changing motion including any one of a motion having a constant period and a motion having no constant period. Change,
At least one of the high-speed scanning unit and the low-speed scanning unit performs the light incident angle change motion,
The shift of the drawing point on the projection surface caused by one of the scanning means performing the light incident angle changing motion, the scanning control of the scanning means on the side not performing the light incident angle changing motion, or An image display device, wherein correction is performed according to the light emission timing of a light source. A light source that emits light;
Scanning means for drawing the image by scanning the light in a two-dimensional direction on the projection surface;
The scanning means performs a light scanning motion in which the light is scanned on the projection surface in a predetermined cycle, and has a constant cycle other than a multiple of the light scanning cycle, and a divisor of the light scanning cycle. The incident angle of the light with respect to a predetermined drawing point on the projection surface from the scanning unit is changed over time by performing a light incident angle changing motion including any one of a motion having a constant period and a motion having no constant period. Change,
The scanning means is a biaxial scanning means for scanning the light in a horizontal direction and a vertical direction on the projection surface;
The deviation of the drawing point on the projection surface caused by the biaxial scanning unit performing the light incident angle changing motion is corrected by the scanning control of the biaxial scanning unit or the light emission timing of the light source. An image display device characterized by the above.

Images