JP2004191946A - Picture display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a picture display device where luminous flux made to scan is made incident on an observer's retina 2 after it is influenced by an optical means 26, and by which an observer recognizes an accurate picture in spite of the intervention of the optical means. <P>SOLUTION: The picture display device is equipped with luminous flux output means 12, 14 and 16 outputting the luminous flux, a scanning means 24 for scanning the outputted luminous flux, the optical means 26 to which the luminous flux made to scan is radiated and which changes the advancing direction of the radiated luminous flux to a direction toward the observer's pupil, and a wave front curvature changing part 36 as a curvature correction means for correcting the wave front curvature of the luminous flux radiated to the optical means. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to an image display device that allows an observer to recognize an image by projecting the image on the retina of the observer.

  2. Description of the Related Art In recent years, various types of image display devices that allow an observer to recognize an image by scanning a light beam on the retina of the observer and projecting the image, that is, a so-called retinal scanning display have been proposed.

  For example, Patent Document 1 discloses a scanning optical element that scans a laser beam in a two-dimensional direction, and an optical unit that condenses the laser beam scanned by the scanning optical element in an eyeball of an observer (a focusing optical element). ) Is disclosed.

In this conventional image display apparatus, a half mirror having a part of a concave spheroid as a reflection surface is used as the optical means. In the spheroid, light emitted from one of the two focal points is always incident on the other focal point when reflected by the spheroid. In this conventional image display device, one of the two focal points of the spheroid is the reflection position of the laser beam on the scanning optical element, and the other focal point is the focal point of the laser beam in the eyeball by the optical unit. By setting the position, the laser light scanned by the scanning optical element can be surely focused in the eyeball.
JP-A-11-142763

  According to this type of image display device, a luminous point (light emitting point) is obtained by extending a light beam incident on the retina in a direction opposite to the incident direction and extending a distance equal to the radius of the wavefront curvature of the incident light beam. The observer is given a sense of vision as if there is. As a result, the observer feels a perspective corresponding to the wavefront curvature of the light beam projected on the retina.

  In this type of image display device, if the wavefront curvatures of the light beams incident on the retina coincide with each other for all pixels of the image, the image is displayed planarly to the observer. On the other hand, if the wavefront curvature of the light beam incident on the retina is changed for each pixel of the image, the image is displayed three-dimensionally for the observer.

  However, in the case of using the optical unit having the above-mentioned shape in the image display device disclosed in Patent Literature 1, since the curvature of the reflection surface is not constant over the entire optical unit, the light is reflected by the reflection surface. The degree of change of the wavefront curvature of the laser light with respect to the wavefront curvature of the laser light before reflection differs depending on the irradiation position (reflection position) of the laser light on the reflection surface. For this reason, the conventional image display device cannot make an observer recognize an accurate image.

  Thus, when using an image display device of the type in which the scanned light beam is incident on the retina of the observer after being affected by the optical means, conventionally, the wavefront curvature of the light beam is changed unexpectedly. This was due to deformation of the optical means due to temperature, changes in the wavelength of the light beam due to temperature, replacement of the optical means, etc., in addition to the optical characteristics of the optical means. Exists.

  In view of such circumstances, the present invention provides an image display apparatus in which a scanned light beam is incident on an observer's retina after being affected by optical means. The purpose of the present invention is to make it possible to recognize an accurate image.

  The following aspects are obtained by the present invention. Each mode is divided into sections, each section is numbered, and described in a format in which the numbers of other sections are cited as necessary. This is to facilitate understanding of some of the technical features that can be adopted by the present invention and combinations thereof, and the technical features that can be adopted by the present invention and combinations thereof are limited to the following embodiments. Should not be interpreted as That is, it should be construed that the technical features not described in the following embodiments but described in the present specification can be appropriately extracted and adopted as the technical features of the present invention.

  Furthermore, listing each section in a form that quotes the number of the other section does not necessarily prevent the technical features described in each section from being separated from and independent of the technical features described in the other sections. It is to be construed that the technical features described in the respective sections can be appropriately made independent according to their properties.

(1) An image display device that allows an observer to recognize an image by projecting the image on the retina of the observer,
Light beam output means for outputting a light beam;
Scanning means for scanning the light beam output by the light beam output means;
An optical unit that irradiates a light beam scanned by the scanning unit and changes a traveling direction of the irradiated light beam to a direction toward a pupil of an observer,
An image display device comprising: a curvature correction unit configured to correct a wavefront curvature of a light beam applied to the optical unit.

  According to this device, since the wavefront curvature of the light beam irradiated to the optical means can be corrected, when the wavefront curvature of the light beam irradiated to the optical means is affected by the optical means, the correction is performed from the optical means. It is possible to optimize the wavefront curvature of the light beam applied to the optical unit so that the wavefront curvature of the emitted light beam becomes a target value.

  Therefore, according to this device, it is easy for an observer to recognize an accurate image despite the presence of optical means that affects the wavefront curvature of the light beam.

  The term “curvature correction unit” in this section includes, for example, at least one of an irradiation position of a light beam irradiated to the optical unit, a physical quantity that affects the degree of change of the wavefront curvature of the light beam by the optical unit, and a type of the optical unit. Based on the above, the present invention can be implemented in a mode of correcting the wavefront curvature of the light beam irradiated on the optical unit.

  The “optical means” in this section and the following sections include, for example, mirrors, lenses, diffractive optical elements, and the like.

(2) The image display device according to (1), wherein the curvature correction unit performs the correction based on an irradiation position of a light beam irradiated to the optical unit.

  According to this device, the wavefront curvature of the light beam irradiated toward the pupil of the observer becomes the target value even if the degree of change in the wavefront curvature of the light beam varies depending on the irradiation position of the light beam irradiated on the optical means. As described above, it is possible to correct the wavefront curvature of the light beam applied to the optical unit.

  Therefore, according to this apparatus, it is easy for the observer to recognize an accurate image despite the degree of change in the wavefront curvature of the light beam depending on the irradiation position of the light beam applied to the optical means.

(3) The curvature correction unit is configured to adjust a pupil of an observer based on optical property information indicating a relationship between an irradiation position of a light beam applied to the optical unit and a degree of change in a wavefront curvature of the light beam by the optical unit. The image display device according to item (2), wherein the correction is performed such that the wavefront curvature of the traveling light flux becomes a target value.

  It is sufficient that the “optical characteristic information” in this section and each of the following sections can represent the relationship between the irradiation position of the light beam in the optical means and the degree of change in the wavefront curvature of the light beam. Therefore, the `` optical characteristic information '' may be, for example, information representing the relationship between the irradiation position of the light beam and the degree of change in the wavefront curvature, or, for example, information representing the relationship between the state of the scanning means and the degree of change in the wavefront curvature. Alternatively, the information may be information indicating the relationship between the irradiation position of the light beam and the refractive power of the optical unit.

(4) Further, the curvature correction means includes a storage means for storing optical characteristic information indicating a relationship between an irradiation position of a light beam irradiated to the optical means and a degree of change of a wavefront curvature of the light beam by the optical means. (2) The image display device according to (2), wherein the correction is performed based on the optical characteristic information stored in the storage unit such that the wavefront curvature of the light flux toward the pupil of the observer becomes a target value.

(5) The light beam output means includes:
Emitting means for emitting a light beam;
And a curvature modulating means for modulating the wavefront curvature of the light beam emitted from the emitting means, wherein the curvature correcting means performs the correction using the curvature modulating means. Image display device.

  According to this apparatus, since the wavefront curvature is corrected by modulating the wavefront curvature of the light beam, a plurality of emission units each emitting a plurality of types of light beams having different wavefront curvatures are provided for correction of the wavefront curvature. It is not essential to prepare them in advance.

  The term “curvature modulation means” in this section refers to a case where the wavefront curvature is modulated by changing a selected one of a plurality of emission means that respectively emit a plurality of types of light beams having different wavefront modulations. Can be easily implemented in a mode of continuously modulating. According to this aspect, it is easy to improve the correction accuracy of the wavefront curvature and improve the display accuracy of the image.

(6) Further, a control unit for controlling the curvature modulation unit for displaying the image is included, and the control unit includes, as the curvature correction unit, a part for performing the correction using the curvature modulation unit. Item).

  According to this device, it is possible to perform both display of an image and correction of the wavefront curvature using the same curvature modulation means, and display of the image and correction of the wavefront curvature using separate curvature modulation means. Compared with the case, the number of parts can be easily reduced.

(7) The light beam output means includes:
A plurality of emission units each emitting a plurality of light beams having different wavefront curvatures,
Selecting means for selecting a light beam to be emitted from among the plurality of light emitting means, wherein the curvature correcting means performs the correction using the selecting means. An image display device according to any one of the above.

  According to this device, in order to correct the wavefront curvature of the light beam, it is not necessary to change the wavefront curvature of the same light beam from one value to another value. Therefore, the time required for the change can be omitted, and as a result, the correction of the wavefront curvature can be easily performed in a shorter time.

  Therefore, according to this apparatus, for example, even when the depth to be recognized by the observer for each pixel greatly changes along the scanning direction, the wavefront curvature is set so as to quickly follow such a change in depth. Can be easily corrected.

(8) The image processing apparatus further includes a control unit that controls the selection unit to display the image, and the control unit includes, as the curvature correction unit, a part that performs the correction using the selection unit. 3. The image display device according to 1.

  According to this device, it is possible to perform both the display of an image and the correction of the wavefront curvature using the same selection unit, and when the display of the image and the correction of the wavefront curvature are performed using separate selection units, In comparison, the number of parts can be easily reduced.

(9) The image display device according to any one of (1) to (8), wherein the curvature correction unit performs the correction based on a physical quantity that affects a degree of change in a wavefront curvature of a light beam by the optical unit. .

  In the image display device according to any one of the above items (1) to (8), the degree to which the wavefront curvature of the light beam changes by the optical means can be changed by physical quantities related to the optical means, such as temperature and humidity.

  Based on such knowledge, in the device according to this section, the wavefront curvature of the light beam applied to the optical unit is corrected based on a physical quantity that affects the degree to which the wavefront curvature of the light beam changes by the optical unit. .

  Therefore, according to this image display device, it is easy to correct the wavefront curvature suitable for the actual optical characteristics of the optical means.

  The “physical quantity” in this section is not limited as long as it is a physical quantity that affects the degree of change of the wavefront curvature of the light beam by the optical means. Specifically, the “physical quantity” refers to, for example, a physical quantity representing characteristics of the optical unit itself, such as the temperature and / or humidity of the optical unit itself, or the temperature and / or humidity of air surrounding the optical unit, It may mean a physical quantity that is characteristic of the environment in which the optical means is located, such as the temperature and / or humidity of the air through which the light beam entering or exiting the optical means propagates. This “physical quantity” may be a physical quantity other than temperature or humidity.

(10) The curvature correction unit performs the correction based on the irradiation position of the light beam irradiated on the optical unit and a physical quantity that affects the degree of change of the wavefront curvature of the light beam by the optical unit (9). Item 10. The image display device according to Item 1.

  According to this device, the wavefront curvature of the light beam irradiated on the optical means is changed so as to be compatible with both the irradiation position and the physical quantity which affects the degree of change of the wavefront curvature of the light beam by the optical means. .

(11) Further, a detecting means for detecting the physical quantity is included,
The image display device according to (10), wherein the curvature correction unit performs the correction based on an irradiation position of a light beam irradiated to the optical unit and a physical quantity detected by the detection unit.

(12)
Detecting means for detecting the physical quantity;
A plurality of types of optical property information representing a relationship between an irradiation position of a light beam irradiated to the optical unit and a degree of change of a wavefront curvature of the light beam by the optical unit are stored according to a plurality of values that the physical quantity can take. Storage means,
(10) The image display according to (10), wherein the curvature correction unit performs the correction by using, from a plurality of types of optical characteristic information stored in the storage unit, information corresponding to a physical quantity detected by the detection unit. apparatus.

(13) The optical unit can be replaced with another type of optical unit having a different degree of changing the wavefront curvature of the light beam,
The image display device according to any one of (1) to (12), wherein the curvature correction unit performs the correction based on a type of the optical unit.

  According to this device, it is possible to use the type of the optical means properly according to the use or the like.

  Furthermore, according to this device, the correction of the wavefront curvature makes it possible to adapt to the type of optical means actually used, so that even if the optical means is replaced, the wavefront curvature will be improper. You don't have to.

(14) The image display device according to (13), wherein the curvature correction unit performs the correction based on an irradiation position of a light beam irradiated to the optical unit and a type of the optical unit.

  According to this device, the wavefront curvature of the light beam irradiated to the optical unit is changed so as to be compatible with both the irradiation position and the type of the optical unit.

(15) Further, optical characteristic information indicating a relationship between an irradiation position of a light beam irradiated to the optical unit and a degree of change of a wavefront curvature of the light beam by the optical unit can be changed according to a type of the optical unit. Including storage means for storing in
The image display device according to (14), wherein the curvature correction unit performs the correction using optical characteristic information changed according to the type of the optical unit.

  The term “change of optical property information” in this section means, for example, that a plurality of kinds of optical property information about a plurality of kinds of optical means are stored in advance in a “storage means”, and the optical property information is changed every time the optical means is replaced. It can be realized by selecting one to be used for wavefront curvature correction. Further, the "change of optical property information" is realized by changing the content of the "storage means" to the corresponding optical property information every time the optical means is replaced (for example, by replacing the recording medium). Is also possible.

(16) The scanning unit scans the light beam output by the light beam output unit in a main scanning direction and a sub-scanning direction, and among the main scanning direction and the sub-scanning direction, a light beam irradiated to the optical unit. The image display device according to any one of (1) to (15), wherein, in the main scanning direction, the change in the degree of change in the wavefront curvature of the light beam caused by the optical means due to the movement of the irradiation position is smaller.

  Generally, when displaying one image, the main scanning is repeatedly performed for a plurality of lines, whereas the sub-scanning is performed only once for one image.

  On the other hand, in the apparatus according to any one of the above items (1) to (15), the surface on which the light is irradiated to the optical means extends in two directions intersecting each other, and the irradiation of the light irradiated on the optical means is performed. The change in the degree of change in the wavefront curvature of the light beam due to the optical means due to the movement of the position may differ between the two directions.

  In this case, the response speed of the wavefront curvature to a command to change the wavefront curvature is reduced by selecting one of the two directions, in which the degree of change of the wavefront curvature is small, in the direction of the main scanning with a high scanning frequency. It becomes easy to do.

  Based on such knowledge, in the apparatus according to this section, the degree of change in the wavefront curvature of the light beam due to the movement of the irradiation position of the light beam irradiated on the optical means in the main scanning direction and the sub-scanning direction Is smaller in the main scanning direction.

(17) The light beam output means is provided for each of a plurality of wavelengths different from each other, and the image display device further combines the plurality of light beams respectively output by the plurality of light beam output means to form the scanning means. (1) The image display device according to any one of (1) to (16), further comprising a combining unit that outputs the curvatures of the light beams, wherein the curvature correction unit individually corrects the wavefront curvature of the light beam output by each of the light beam output units.

  According to this device, a light beam of a desired color can be obtained by combining a plurality of light beams having different wavelengths.

  In this device, the wavefront curvature of each light beam is changed before the synthesis of a plurality of light beams. On the other hand, the wavefront curvature of the synthesized light beam is synthesized using a wavefront modulating means after the plurality of light beams are synthesized into one light beam. May be changed.

  However, in this configuration, the wavefront curvature of the light flux, which is each component of the combined light flux, changes to different degrees depending on the wavelength of each component when passing through the above-described wavefront modulation means and other means (for example, a lens). I do. Therefore, in order to finally set the wavefront curvature of the light flux, which is each component of the combined light flux, to a desired value, it is necessary to correct the wavefront curvature of each light flux for each wavelength before synthesis, and for that purpose, In addition to the above-described curvature modulation means, it is necessary to provide a curvature modulation means for correcting the wavefront curvature of each light beam for each wavelength before combining.

  On the other hand, according to the device according to this section, since a configuration is adopted in which the wavefront curvatures of the respective light beams are modulated independently of each other before combining a plurality of light beams having different wavelengths, each light beam is synthesized before the combination. It is sufficient to correct the wavefront curvature in advance, and it is not essential to correct the wavefront curvature after the synthesis.

(18) An image display device that allows an observer to recognize an image by projecting the image on the retina of the observer,
A light beam output unit that outputs a light beam, an output unit that outputs the light beam, and a curvature modulation unit that modulates a wavefront curvature of the light beam output from the output device;
Scanning means for scanning the light beam output by the light beam output means;
An optical unit that irradiates a light beam scanned by the scanning unit and changes a traveling direction of the irradiated light beam to a direction toward a pupil of an observer,
A storage unit that stores optical characteristic information indicating a relationship between an irradiation position of a light beam applied to the optical unit and a degree of change in wavefront curvature of the light beam by the optical unit,
Based on the optical characteristic information stored in the storage unit, the curvature modulation unit corrects the wavefront curvature of the light beam applied to the optical unit so that the wavefront curvature of the light beam toward the pupil of the observer becomes a target value. And an image display device including a curvature correction unit.

  According to this device, the wavefront curvature of the light beam irradiated toward the pupil of the observer becomes the target value even if the degree of change in the wavefront curvature of the light beam varies depending on the irradiation position of the light beam irradiated on the optical means. As described above, it is possible to correct the wavefront curvature of the light beam applied to the optical unit.

  Therefore, according to this apparatus, it is easy for the observer to recognize an accurate image despite the degree of change in the wavefront curvature of the light beam depending on the irradiation position of the light beam applied to the optical means.

  Further, according to this device, the wavefront curvature of the light beam emitted from the emission unit is modulated, so that the wavefront curvature is corrected.

  Hereinafter, some embodiments to which the present invention is applied will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of a retinal scanning display 10 as an image display device according to the first embodiment of the present invention.

  The retinal scanning display 10 is for causing an observer to recognize an image projected on the retina by irradiating a laser beam as a light beam to a pupil 2 of the observer. As shown in FIG. 1, the retinal scanning display 10 outputs laser light of each color (each wavelength region) of red (R), green (G), and blue (B), and outputs the laser light. An R laser output unit 12, a G laser output unit 14, and a B laser output unit 16 capable of modulating the output intensity and wavefront curvature of the laser beam.

  As shown in FIG. 1, the retinal scanning display 10 further includes a total reflection mirror 18 and a partial transmission mirror for synthesizing the three color laser beams output from the laser output units 12, 14, and 16. 20 and a partially transmitting mirror 22. The total reflection mirror 18 reflects the laser light output from the R laser output unit 12. The partially transmitting mirror 20 allows the laser light from the total reflection mirror 18 to pass therethrough and reflects the laser light output from the G laser output unit 14 so as to be coaxial with the laser light. The partially transmitting mirror 22 reflects the laser light output from the B laser output unit 16 so that the laser light from the partially transmitting mirror 20 passes therethrough and is coaxial with the laser light.

  As shown in FIG. 1, the retinal scanning display 10 further scans the laser beam combined by the three mirrors 18, 20, and 22 in a two-dimensional direction, and is scanned by the scanning mirror 24. And a throw-in mirror 26 for reflecting the reflected laser light to enter the pupil 2 of the observer.

  The retinal scanning display 10 further includes, as shown in FIG. 1, a storage section 28 for storing various information, adjustment of the output intensity and wavefront curvature of the laser light output from each of the laser output sections 12, 14, and 16. And a control unit 30 for performing scanning of the laser beam by the scanning mirror 24. The scanning mirror 24 is configured as an oscillating mirror that vibrates in a two-dimensional direction (main scanning direction and sub-scanning direction) by a driving unit 241, and scanning is controlled via the driving unit 241 under the control of the control unit 30.

  Here, a specific configuration of each of the laser output units 12, 14, 16 will be described. However, the R laser output unit 12 will be described as a representative, and the other laser output units 14 and 16 have the same configuration, and thus the description will be omitted.

  As shown in FIG. 2, the R laser output unit 12 emits red laser light (parallel light) in accordance with a command from the control unit 30 (an example of a light emitting unit) 32, and emits light from the emitting unit 32. An intensity modulation unit 34 that modulates the output intensity of the laser light according to a command value from the control unit 30 and a wavefront curvature modulation unit 36 that modulates the wavefront curvature of the laser light that has passed through the intensity modulation unit 34 are provided. One example of the emission unit 32 is configured to include a semiconductor laser device as a light source. One example of the intensity modulator 34 is an AOM as a light intensity modulator.

  The wavefront curvature modulator 36 includes a half mirror 38 on which laser light is incident from the intensity modulator 36, a convex lens (an example of a light converging unit) 40 having a focal length f for converging the laser light from the half mirror 38, and a movable mirror. 42. The movable mirror 42 has a reflection surface 42a that reflects the laser light incident from the convex lens 40 in a direction opposite to the incident direction and returns the half mirror 38 to the laser light. By being moved, the optical path distance between the reflection surface 42a and the convex lens 40 can be changed.

  As shown in FIG. 2, the half mirror 38 has a cube shape in which two right-angle prisms each having a dielectric multilayer film formed on a slope 38 a are bonded to each other. Approximately 50% is reflected in the orthogonal direction and approximately 50% is transmitted. Therefore, when the laser light from the intensity modulator 34 enters the half mirror 38, about 50% of the laser light is reflected by the inclined surface 38a and enters the convex lens 40 provided on the emission side of the half mirror 38. I do. Further, about 50% of the amount of the laser light that has entered the half mirror 38 from the convex lens 40 by being reflected by the reflection surface 42a passes through the slope 38a, and is output as output light from the R laser output unit 12. .

  As shown in FIG. 2, the movable mirror 42 is formed by bonding a reflection plate 44 and a piezoelectric actuator 46 in which piezoelectric piezoelectric elements are stacked. The reflection plate 44 is formed by applying a mirror coating of a metal film to a surface of a light transmitting plate material such as a glass plate. The piezoelectric actuator 46 is driven by applying a drive voltage from the control unit 30, and moves the position of the reflection plate 44 according to the drive voltage in the normal direction of the reflection surface 42 a (direction indicated by an arrow z in FIG. 2). To change the optical path distance between the reflecting surface 42a and the convex lens 40.

  Here, the control of the optical path distance will be described with reference to FIG.

  When a drive voltage is not applied from the control unit 30 to the piezoelectric actuator 46, as shown in FIG. 3A, the optical path distance, which is the distance between the reflection surface 42 a and the principal point of the convex lens 40, is increased. Is adjusted in advance to be equal to the focal length f. Therefore, in this state, the laser light incident on the convex lens 40 from the half mirror 38 is refracted and converged when passing through the convex lens 40, and focuses on the reflection surface 42a. The converged incident laser light is reflected on the reflecting surface 42a in the same direction as the incident laser light, and as a result, becomes diffused light which is diffused at the same angle as the convergent angle of the converged light, and is incident on the convex lens 40 again. Then, the light is refracted at the same angle as that at the time of convergence and is converted into parallel light. That is, the incident laser light is collimated by the convex lens 40.

  On the other hand, when a drive voltage is applied from the control unit 30 to the piezoelectric actuator 46, as shown in FIG. 3B, the piezoelectric actuator 46 is driven and the reflection surface 42a moves to the convex lens 40 side, and the movement When the distance is represented by d, the optical path distance between the reflection surface 42a and the principal point of the convex lens 40 changes from f to f−d.

  Therefore, in this state, the laser light incident on the convex lens 40 from the half mirror 38 is refracted and converged when passing through the convex lens 40 in the same manner as described above, but the reflection surface 42a is longer than the focal length f of the convex lens 40. Since the laser beam has moved to a position closer to the convex lens 40 by d, the laser beam is not focused on the reflection surface 42a. After being reflected by the reflection surface 42a, the laser light is focused at a position advanced by a distance d, that is, at a position of a distance f-2d from the principal point of the convex lens 40, and then becomes a diffused light and returns to the convex lens 40 again. Incident.

  Therefore, although the laser beam is refracted when passing through the convex lens 40 and its divergence angle is reduced, the laser beam passes through the convex lens 40 without being converted into parallel light, that is, without being collimated. As a result, the wavefront curvature of the laser light changes. Here, “the wavefront curvature of the laser light changes” means that the wavefront curvature of the laser light at a certain fixed position (for example, on the retina of the observer) changes.

  Here, the reason why the laser output units 12, 14, 16 modulate the wavefront curvature of the laser light in the retinal scanning display 10 will be briefly described.

  In general, light emitted from a light source propagates as a so-called spherical wave of light that travels in all directions at the same speed and in the same phase around the light emitting point. This spherical wave is projected onto the retina of the observer with a different radius of curvature according to the distance between the light emitting point and the observer, and the observer feels a perspective according to the radius of curvature.

  Therefore, in the present embodiment, by modulating the wavefront curvature of the laser light incident on the pupil 2 of the observer to change the position of the apparent light emitting point (see FIG. 3B) of the laser light, The viewer is made to recognize the depth of the image with a more natural feeling.

  According to the wavefront curvature modulation unit 36 of the present embodiment, for example, when the focal length f of the convex lens 40 is 4 mm, the observer can move the reflection surface 42a of the movable mirror 42 by about 30 μm from infinity to about 30 cm. Perspective can be recognized within a range up to a distance. When the focal length f of the convex lens 40 is 2 mm, the observer can recognize the perspective within a range from about 30 cm to infinity only by moving the reflecting surface 42 a of the movable mirror 42 by about 10 μm.

  As shown in FIG. 4, the scanning mirror 24 includes a frame 48 in which two shaft portions 48a and 48b formed coaxially are rotatably supported by a support (not shown). Further, there is provided a scanning plate 50 in which two shaft portions 50 a and 50 b formed coaxially are rotatably supported by a frame 48. That is, the scanning plate 50 is supported by a support (not shown) so as to be swingable about two axes that intersect at right angles to each other. The scanning plate 50 has a reflection surface 50c that reflects the laser light combined by the total reflection mirror 18 and the partial transmission mirrors 20 and 22 shown in FIG.

  The scanning mirror 24 is driven by the driving unit 241 shown in FIG. One example of the driving unit 241 is a method using magnetism. When this method is adopted, for example, the movable member is provided with a coil, and the stationary member is provided with a permanent magnet.

  The drive unit 241 swings the frame 48 around the x-axis and the scanning plate 50 around the y-axis independently of each other based on a command from the control unit 30. Thereby, the direction of the reflection surface 50c of the scanning plate 50 changes, and the laser light reflected by the reflection surface 50c is scanned in the two-dimensional direction. Specifically, the scanning plate 50 swings around the y-axis a plurality of times while the frame 48 swings around the x-axis once, and the laser beam mainly swings around the y-axis. Scanning is performed in the sub-scanning direction by swinging about the x-axis in the scanning direction.

  As shown in FIG. 1, the input mirror 26 is configured as a half mirror, thereby reflecting the laser beam scanned by the scanning mirror 24 toward the pupil 2 of the observer, and having a function of reflecting the laser light from the front of the observer. And a function of transmitting light.

  As shown in FIG. 5, the reflecting surface 26a for reflecting the laser light on the input mirror 26 is formed as a concave surface extending in the longitudinal direction (the direction indicated by the arrow L) and the short direction (the direction indicated by the arrow S). Have been. This curved surface is formed as a part of the spheroid. The input mirror 26 is positioned in front of the observer's eyes such that the reflection point of the laser beam on the reflection surface 50c of the scanning mirror 24 is located at one of the two focal points of the spheroid and the pupil 2 of the observer is located at the other. Is used by being attached to the head. In the mounted state, the laser light scanned by the scanning mirror 24 surely enters the pupil 2 of the observer and is focused on the retina.

  As described above, since the reflecting surface 26a of the casting mirror 26 is a curved surface but not a spherical surface, its curvature is not constant over the entire reflecting surface 26a, and changes depending on the position on the reflecting surface 26a. Specifically, as shown in FIG. 5, the reflection surface 26a forms a part of an ellipse on a cross section parallel to the longitudinal direction, and forms a part of a perfect circle on a cross section parallel to the short direction. Has formed.

  Therefore, the curvature of the reflection surface 26a changes greatly as it moves along the longitudinal direction, and changes less as it moves along the transverse direction. On the other hand, if the curvature of the reflection surface 26a differs depending on the position, the degree of change of the wavefront curvature of the laser light reflected by the reflection surface 26a with respect to the wavefront curvature of the laser light before reflection also differs depending on the position.

  Based on such knowledge, in the retinal scanning display 10, the short direction (direction indicated by the arrow S in FIG. 5) of the input mirror 26 is selected as the main scanning direction, while the longitudinal direction (in FIG. (Direction indicated by arrow L) is selected as the sub-scanning direction, and then scanning mirror 24 scans the laser beam.

  Therefore, according to the present embodiment, the wavefront curvature of the laser light changes before and after the reflection on the reflection surface 26a, and the degree of the change corresponds to the movement of the reflection point (irradiation position) of the laser light on the reflection surface 26a. However, the frequency of the change is less than when the longitudinal direction of the input mirror 26 is selected in the main scanning direction and the short direction is selected in the sub-scanning direction.

  As shown in FIG. 1, the control unit 30 receives an image signal (video signal) from an external device (not shown) such as a computer and performs control for causing an observer to recognize an image represented by the image signal. Do.

  Specifically, the control unit 30 causes the laser beam to be output from the emission unit 32 of each of the laser output units 12, 14, 16 based on the image signal, and controls the intensity of the output laser beam by the intensity modulation unit 34. The laser beam is modulated so that the color of the image represented by the image signal is represented, and the wavefront curvature of the laser light is represented by the wavefront curvature modulator 36 so that the depth of the image represented by the image signal is represented. Is modulated. The control unit 30 further drives the scanning mirror 24 to scan the laser beam in the two-dimensional direction.

  As a result, the laser light output from each of the laser output units 12, 14, 16 is combined by the total reflection mirror 18 and the partial transmission mirrors 20, 22, and then scanned by the scanning mirror 24 in the two-dimensional direction. The light is reflected by the input mirror 26 and enters the pupil 2 of the observer. As a result, the image represented by the image signal is projected on the retina of the observer, and the image is recognized by the observer.

  In order for the observer to recognize the depth of the image represented by the image signal, each of the laser output units 12 and 12 is set so that the wavefront curvature of the laser light incident on the pupil 2 of the observer becomes a target value corresponding to the depth. It is necessary to modulate the wavefront curvature of the laser light output from 14 and 16. However, since the wavefront curvature of the laser light changes to a different degree depending on the reflection position on the reflection surface 26a when the laser light is reflected on the reflection surface 26a of the casting mirror 26, each wavefront curvature is determined based on only the depth of the image represented by the image signal. If the wavefront curvature of the laser light output from the laser output units 12, 14, 16 is simply modulated, the wavefront curvature of the laser light incident on the pupil 2 of the observer cannot be set as the target value.

  Therefore, in this embodiment, prior to the incidence of the laser light on the input mirror 26, the control unit 30 considers the change in the wavefront curvature when the laser light is reflected by the reflection surface 26a of the input mirror 26, and It is designed so that the wavefront curvature of the laser light output from the output units 12, 14, 16 is corrected in advance.

  Hereinafter, the modulation of the wavefront curvature of the laser light output from each of the laser output units 12, 14, 16 will be described. However, only the wavefront curvature modulation by the R laser output unit 12 will be described, and the wavefront curvature modulation by the other laser output units 14 and 16 has the same content, and thus the description will be omitted.

  As shown in the schematic diagram of FIG. 6, the laser light output from the R laser output unit 12 is scanned in the main scanning direction and the sub-scanning direction by the scanning mirror 24, reflected by the reflection surface 26a of the input mirror 26, and observed. The pupil 2 of the person.

  Here, various symbols are defined as follows.

a: radius of curvature of the wavefront of the laser beam output from the R laser output unit 12: angle of the reflection surface 50c of the scanning mirror 24 in the main scanning direction α: angle of the reflection surface 50c of the scanning mirror 24 in the sub-scanning direction m: R The travel distance R of the laser light from the laser output unit 12 to the reflection surface 26a of the input mirror 26: the reflection surface curvature n which is the curvature of the curved surface at the irradiation position of the laser light on the reflection surface 26a of the input mirror 26: the reflection of the input mirror 26 Traveling distance b of laser light from surface 26a to pupil 2 of the observer: radius of curvature of wavefront of laser light in pupil 2 of the observer

  Here, since the traveling distances m and n and the curvature R of the reflection surface change depending on the angles θ and α of the reflection surface 50c of the scanning mirror 24, the functions m (θ, α), which are functions of the angles θ and α, respectively. It is expressed as a function n (θ, α) and a function R (θ, α).

  Further, since the wavefront curvature radius b is a value corresponding to the depth of the image recognized by the observer, the wavefront curvature radius b is similarly expressed as a function b (θ, α) of the angles θ and α.

  In addition, in this embodiment, since the image is displayed two-dimensionally for the observer, the wavefront curvature radius b is determined so that the image has the same depth for all pixels. . On the other hand, when the present invention is implemented in a mode in which the image is displayed three-dimensionally to the observer, the wavefront curvature is set so that not all pixels constituting the image have the same depth. The radius b is determined.

  Further, in the present embodiment, the wavefront curvature radius a is a value adjusted to make the wavefront curvature radius b a desired value. Therefore, the wavefront curvature radius a is also a function b (θ, α) of the angles θ and α. α).

  The value of the wavefront curvature radius b when the angles θ and α are constant values is approximately expressed by the following equation (1).

  b = R (a + m) / (R-2 (a + m)) + n Expression (1)

  Therefore, given the respective values of the traveling distances m and n, the reflection surface curvature R, and the wavefront curvature radius b, the wavefront curvature radius a can be obtained from the following equation (2).

  a = R (b−n) / (R + 2 (b−n)) − m Equation (2)

  As shown in FIG. 7, the storage unit 28 shown in FIG. 1 stores, as information unique to the retinal scanning display 10, the value of the traveling distance m in association with each pixel constituting the image represented by the image signal. The value of the traveling distance n and the value of the reflection surface curvature R are stored in advance as optical characteristic information. The value of the reflection surface curvature R is a value that uniquely indicates the degree of change in the wavefront curvature of the laser light between before and after reflection on the reflection surface 26a. The position of each pixel is defined by angles θ and α.

  Specifically, the storage unit 28 stores the travel distance m (θ, α) for each value of the angles θ and α corresponding to each pixel, as conceptually shown in FIG. ) Is stored as a table, and for the travel distance n, as conceptually shown in FIG. 6B, the travel distance n (θ, α) for each value of the angles θ and α corresponding to each pixel The values are stored as a table, and as for the reflection surface curvature R, the reflection surface curvature R (θ, α) for each value of the angles θ and α corresponding to each pixel is conceptually represented in FIG. The values are stored as a table.

  Then, the control unit 30 performs a wavefront curvature modulation process for modulating the wavefront curvature of the laser light output from the R laser output unit 12 by referring to each table stored in the storage unit 28.

  As shown in FIG. 1, the control unit 30 is mainly configured by a computer 52. Computer 52 is configured to include a processor 54 and storage 56, as is well known. In the storage 56, a wavefront curvature modulation program executed by the processor 54 to perform the above-described wavefront curvature modulation processing is stored in advance.

  FIG. 8 is a flowchart conceptually showing the contents of the wavefront curvature modulation program. An image signal including a depth signal is input to the control unit 30 in image units, and the wavefront curvature modulation program is executed each time the image signal is input to the control unit 30. .

  When the wavefront curvature modulation program is started, first, in step S110 (hereinafter simply referred to as “S110”; the same applies to other steps), an image is generated based on the depth signal included in the input image signal. Is generated, a table representing the value (target value) of the wavefront radius of curvature b for each of the angles θ and α corresponding to the respective pixels constituting the pixel.

  Next, in S120, the contents of the tables of the traveling distances m and n and the reflection surface curvature R stored in the storage unit 28 are read from the storage unit 28.

  Subsequently, in S130, based on the table of the wavefront curvature radius b created in S110 and the tables of the traveling distances m and n and the reflection surface curvature R read in S120, for each value of the angles θ and α, The value of the wavefront radius of curvature a is calculated using the above equation (2). Further, a table representing the value of the wavefront radius of curvature a for each value of the angles θ and α is created from the calculated values.

  Thereafter, in S140, based on the table of the wavefront curvature radius a created in S130, for each value of the angles θ and α, the displacement value for displacing the reflecting surface 42a of the movable mirror 42 to obtain each wavefront curvature radius a. z is calculated. Further, a table representing the displacement value z for each of the angles θ and α is created from the calculated values.

  The calculation of the displacement value z can be performed as follows.

  When the focal length f of the convex lens 40 is fixed, the wavefront curvature radius a of the laser light output from each of the laser output units 12, 14, 16 is equal to the reflection surface 42a of the movable mirror 42 as in the following equation (3). It becomes a function for the displacement value z, and has a relationship as shown in the graph of FIG. This function is not a simple inverse function.

  a = g (z) Equation (3)

  Therefore, given the value of the wavefront curvature radius a, the displacement value z can be obtained from the following equation (4).

z = g ^-1 (a) Equation (4)

  After the table of the displacement values z is created in S140 in this way, the process proceeds to S150 in FIG. In S150, based on the table of the displacement value z, the position of the reflecting surface 42a of the movable mirror 42 is adjusted in accordance with the change of the angles θ and α of the reflecting surface 50c while being synchronized with the scanning of the laser beam by the scanning mirror 24. Controlled.

  In addition, it should be noted that the actual values of the angles θ and α of the reflection surface 50c are determined by arranging detectors for detecting the laser beam at the main scanning direction area end position and the sub-scanning direction area end position of the reflection surface 50c, respectively. In each of the main scanning direction and the sub-scanning direction, it can be obtained by measuring the elapsed time from the time when the laser light is detected by each detector.

  When the scanning of the laser light for one image corresponding to the input image signal and the position control of the reflection surface 42a are completed, one execution of the wavefront curvature modulation program is completed.

  As is clear from the above description, in the present embodiment, each of the laser output units 12, 14, and 16 constitutes an example of the "light beam output means" in the above item (1), and the scanning mirror 24 corresponds to the "light beam output means" in the same item. The scanning mirror constitutes an example of the “scanning means”, the input mirror 26 constitutes an example of the “optical means” in the same paragraph, and the control unit 30 controls the “curvature correction means” in the above paragraph (1), (2) or (3). This constitutes an example.

  Further, in the present embodiment, the storage unit 28 forms an example of the “storage unit” in the above item (4), and the emission unit 32 forms an example of the “emission unit” in the above item (5). The modulating unit 36 constitutes an example of the “curvature modulating unit” in the same paragraph, and the control unit 30 constitutes an example of the “curvature correcting unit” in the same paragraph.

  Furthermore, in the present embodiment, the control unit 30 constitutes an example of the “control unit” in the above item (6), and the scanning mirror 24 constitutes an example of the “scanning unit” in the above item (16). The laser output units 12, 14, 16 constitute one example of the "plurality of light beam output means" in the above item (17), and the total reflection mirror 18 and the partially transmitting mirrors 20, 22 cooperate with each other in the "composition means". And the control unit 30 constitutes an example of the "curvature correction means" in the same section.

  Further, in the present embodiment, each of the laser output units 12, 14, 16 constitutes an example of the "light beam output means" in the above item (18), and the scanning mirror 24 constitutes an example of the "scanning means" in the same item. Then, the input mirror 26 constitutes an example of the “optical means” in the same section, the storage section 28 constitutes an example of the “storage section” in the same section, and the control section 30 constitutes an example of the “curvature correction section” in the same section. It constitutes.

  As is clear from the above description, according to the present embodiment, even if the degree of change of the wavefront curvature of the laser light differs depending on the reflection position of the laser light on the reflection surface 26a of the input mirror 26, the pupil 2 of the observer is not affected. Since it is easy to always set the wavefront curvature of the incident laser light to the target value, it is easy for the observer to accurately recognize the image represented by the image signal.

  Furthermore, according to the present embodiment, since the wavefront curvature of the laser light output from each of the laser output units 12, 14, 16 can be continuously changed by each movable mirror 42, the laser light enters the pupil 2 of the observer. Fine adjustment of the wavefront curvature of the laser beam to be performed becomes easy.

  Furthermore, in the present embodiment, the short direction of the input mirror 26 is set as the main scanning direction, and the long direction is set as the sub-scanning direction, so that the scanning mirror 24 scans the laser light. Therefore, according to the present embodiment, the frequency at which the degree of change in the wavefront curvature of the laser light due to the reflection of the reflection surface 26a changes during the scanning of the laser light is reduced, and as a result, the laser output units 12, 14, 16 It is not necessary to increase the speed of modulating the wavefront curvature of the output laser light.

  Furthermore, in the present embodiment, a wavefront curvature modulation section 36 is provided corresponding to the emission section 32 of each of the laser output sections 12, 14, 16, and each laser beam is synthesized before the laser light emitted from each emission section 32 is synthesized. The wavefront curvature of light is modulated. Therefore, according to the present embodiment, it is not indispensable to provide a configuration for correcting the wavefront curvature of the laser light emitted from each emission unit 32 separately from the wavefront curvature modulation unit 36.

  Specifically, it is assumed that the wavefront curvatures of the laser beams of the three colors emitted from the emission units 32 are modulated using a common wavefront curvature modulation unit for the laser lights after the laser lights are combined. When employed, for example, when it is necessary that the laser beams pass through a lens common to the laser beams after the synthesis, each output beam is corrected in order to correct a shift or chromatic aberration that occurs in the degree of change in the wavefront curvature of each laser beam. It is necessary to separately provide a configuration for individually correcting the wavefront curvature of each laser beam emitted from the unit 32.

  On the other hand, according to the present embodiment, it is not essential to provide such a configuration separately.

  In addition, in this embodiment, a plurality of types of tables are stored in the storage unit 28 in the present embodiment, but the contents of the tables may be changed to another table.

  That is, for example, instead of using the table of the reflection surface curvature R, a table indicating the refractive power of the reflection surface 26a of the input mirror 26 or a table indicating the rate at which the wavefront curvature of the laser light is changed by the reflection surface 26a is used. Is also good.

  Further, in the present embodiment, each table is created based on the angles θ and α of the reflection surface 50c of the scanning mirror 24, but instead of the angles θ and α, the laser incident on the pupil 2 of the observer is used. It may be created based on the incident angle of light or the reflection position of the laser light on the reflection surface 26a of the input mirror 26.

  Further, for example, if a table that allows the wavefront curvature radius a to be directly calculated from the angles θ and α of the reflection surface 50c of the scanning mirror 24 and the wavefront curvature radius b is used, the calculation process can be simplified easily. It becomes.

  Next, a retinal scanning display 60 as an image display device according to a second embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 10, a retinal scanning display 60 according to the present embodiment includes a temperature sensor 62 in addition to the configuration of the retinal scanning display 10 according to the first embodiment shown in FIG.

  Further, in the retinal scanning display 60 according to the present embodiment, the storage unit 28 stores a plurality of table groups each including a table of the traveling distances m and n and a table of the reflection surface curvature R.

  Hereinafter, the present embodiment will be described in detail. Components in common with the retinal scanning display 10 shown in FIG. 1 will be denoted by the same reference numerals in FIG. 10 and will not be described in detail. .

  As shown in FIG. 10, in the present embodiment, the temperature sensor 62 is mounted on the front surface 26b (or the reflection surface 26a) of the input mirror 26. The temperature sensor 62 is provided to detect the temperature of the closing mirror 26.

  As shown in FIG. 10, in the present embodiment, a plurality of sets of tables stored in the storage unit 28 are prepared in association with a plurality of representative values of the temperature of the input mirror 26. The shape of the reflecting surface 26a of the input mirror 26 slightly changes depending on the temperature of the input mirror 26, and as a result, the degree of change of the wavefront curvature of the laser light by the reflecting surface 26a also changes. Therefore, in the present embodiment, a plurality of sets of table groups corresponding to a plurality of representative values that the temperature of the input mirror 26 can take are prepared.

  The control unit 30 uses the table group associated with the representative temperature closest to the temperature detected by the temperature sensor 62 among the plurality of sets of table groups stored in the storage unit 28, so that the wavefront curvature modulation unit The modulation of the laser beam by 36 is performed.

  Therefore, according to the present embodiment, even if the degree of change of the wavefront curvature of the laser light by the input mirror 26 changes depending on the temperature of the input mirror 26, the wavefront curvature of the laser light conforms to the actual optical characteristics of the input mirror 26. The wavefront curvature of the laser light output by the laser output units 12, 14, 16 is modulated so that the final value of the laser light accurately matches the target value.

  Therefore, according to the present embodiment, in addition to the same effects as those of the retinal scanning display 10 according to the first embodiment, the image represented by the image signal is always accurately recognized by the observer regardless of the temperature of the input mirror 26. The effect of being able to do is obtained.

  As is apparent from the above description, in the present embodiment, the temperature of the input mirror 26 constitutes an example of the “physical quantity” in the above item (9), (10) or (11), and the temperature sensor 62 The storage section 28 constitutes an example of the “storage section” in the above item (12), and the control section 30 constitutes an example of the “detection section” in the above item (11) or (12). This constitutes an example of the "curvature correction means" in the item (10), (11) or (12).

  In addition, in the retinal scanning display 60 according to the present embodiment, a plurality of sets of tables associated with the temperature of the input mirror 26 are prepared, but a change in the optical characteristics of the input mirror 26 is taken into consideration. The group of tables to be referred to for performing the wavefront modulation is not limited to this. For example, a humidity sensor for detecting the humidity of the air surrounding the input mirror 26 is provided, and the present invention can be implemented using a plurality of sets of tables associated with the detected humidity of the humidity sensor.

  In addition, in this embodiment, the input mirror 26 configured as a half mirror constitutes an example of the “optical means” in the above item (1), but the optical means is configured as a diffractive optical element. It is possible to carry out the present invention in an embodiment.

  In this embodiment, for example, when the temperature of the medium through which the light beam propagates changes, the wavelength of the light beam changes, and accordingly, by focusing on the fact that the wavefront curvature of the light beam emitted from the diffractive optical element changes, the light beam is changed. The present invention can be implemented using a plurality of sets of tables associated with the temperature detected by the temperature sensor that detects the temperature of the medium through which the light propagates.

  Next, a retinal scanning display 70 as an image display device according to a third embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 11, the retinal scanning display 70 according to the present embodiment has the same basic configuration as the retinal scanning display 10 according to the first embodiment shown in FIG.

  However, in the present embodiment, the input mirror 26 to be used is replaceable with any one of a plurality of types. Accordingly, in the present embodiment, an exchange switch 72 to be operated by the observer when the input mirror 26 is exchanged is provided.

  Further, in the retinal scanning display 70 according to the present embodiment, according to the second embodiment shown in FIG. 10, the storage unit 28 includes a table group including three tables of the traveling distances m and n and the reflection surface curvature R. Multiple sets are stored. Further, the tables are associated with a plurality of types of input mirrors 26.

  Hereinafter, the present embodiment will be described in more detail. However, constituent elements common to the retinal scanning display 10 shown in FIG. 1 are denoted by the same reference numerals in FIG. I do.

  In the present embodiment, the input mirror 26 is detachably mounted on a frame (not shown) of the retinal scanning display 70, and the observer who is the user can replace the input mirror 26 according to the application. Is possible. Therefore, for example, when the observer wants to change the viewing angle of an image scanned on the retina by the retinal scanning display 70, the observer replaces the input mirror 26 with the reflecting surface 26a having a shape having a desired viewing angle. It is possible.

  If the shape of the reflecting surface 26a of the input mirror 26 is different, the degree of change in the wavefront curvature of the laser light by the input mirror 26 is also different. Therefore, the storage unit 28 is associated with a plurality of types of exchangeable input mirrors 26, The plurality of table groups described above are stored in advance.

  If the input mirror 26 is replaced by the observer, it is necessary to input the fact to the control unit 30. For this reason, in the present embodiment, the exchange switch 72 is provided to allow the observer to perform an operation for specifying a newly selected one of the plurality of types of exchangeable mirrors 26 that can be exchanged. The exchange switch 72 is connected to the control unit 30.

  The control unit 30 controls the wavefront curvature modulation unit 36 by using the table group corresponding to the input mirror 26 of the type specified by the exchange switch 72 among the plurality of table groups stored in the storage unit 28. Modulates laser light.

  Therefore, according to the present embodiment, even if the input mirror 26 is replaced by the observer, as long as the observer can perform a selection operation for selecting the currently used input mirror 26 via the exchange switch 72. The wavefront curvature of the laser light output from the laser output units 12, 14, 16 is modulated so as to conform to the optical characteristics of the input mirror 26 and to accurately match the final value of the wavefront curvature of the laser light with the target value. Will be done.

  As is apparent from the above description, according to the present embodiment, in addition to the same effects as those of the retinal scanning display 10 according to the first embodiment, the type of the input mirror 26 can be used while maintaining the image reproduction accuracy. The effect of being able to exchange according to it is acquired.

  In addition, in this embodiment, in the present embodiment, a plurality of sets of tables corresponding to a plurality of types of the input mirrors 26 are stored in the storage unit 28 in advance. The method of exchanging optical characteristic information used by the control unit 30 is not limited to this.

  For example, when the storage medium from which data is read in the storage unit 28 is replaceable, when replacing the input mirror 26, the storage medium is replaced with a storage medium storing optical characteristic information corresponding to the input mirror 26. By doing so, it is possible to achieve the purpose.

  As is apparent from the above description, in the present embodiment, the input mirror 26 constitutes an example of the “optical means” in the item (13), and the control section 30 performs the “curvature correction” in the item or the item (14). It constitutes an example of "means".

  Further, in the present embodiment, the storage unit 28 constitutes an example of the “storage unit” in the item (15), and the control unit 30 constitutes an example of the “curvature correction unit” in the item.

  Next, a fourth embodiment of the present invention will be described. However, this embodiment is different from the above-described first to third embodiments only in the configuration of the laser output unit and common to other elements. Therefore, only different elements will be described in detail, and common elements will be described. Will be referred to using the same reference numerals, and a detailed description thereof will be omitted.

  In each of the first to third embodiments, for example, as shown in FIG. 2, the wavefront curvature modulating unit 36 modulates the wavefront curvature of the laser light for each laser light of each color. On the other hand, in the present embodiment, for each laser beam of each color, there are provided a plurality of optical systems for generating a plurality of laser beams having different wavefront curvatures under an invariable wavefront curvature, respectively. By changing the selected one, the wavefront curvature of the laser light is modulated.

  FIG. 12 shows only a main part of the retinal scanning display according to the present embodiment in an optical path diagram. In the present embodiment, as in the first to third embodiments, three laser output units are provided in order to emit laser beams of three colors and perform wavefront modulation. Since the configurations of the laser output units are basically common to each other, FIG. 12 representatively shows a laser output unit 80 which is one of the laser output units.

As schematically shown in FIG. 12, the laser output unit 80 includes a laser emitter and an optical system for each of a plurality of discrete wavefront curvatures.
Specifically, in order to emit a parallel laser beam, that is, a laser beam having a wavefront curvature of 0, a first laser emitting unit 82 that emits the laser beam as a parallel beam and two lenses are coaxially fixed at a fixed distance. And a total reflection mirror 98. In the first fixed lens array 90, when the laser light from the first laser emitting device 82 enters one lens, the laser light is emitted from the other lens toward the total reflection mirror 98 as parallel light.

  The laser output unit 80 further includes a second laser emitting unit 84 that emits laser light as parallel light in order to emit laser light that is diffused from the parallel light, that is, laser light having a larger wavefront curvature than the parallel light, Are provided with a second fixed lens array 92 coaxially arranged at a fixed distance shorter than the first fixed lens array 90, and a partial transmission mirror 100 coaxial with the total reflection mirror 98.

  In the second fixed lens array 92, when the laser light from the second laser emitting device 84 enters one lens, the laser light is emitted from the other lens toward the partially transmitting mirror 100 as the first diffused light. The partially transmitting mirror 100 reflects the first diffused light incident thereon, and transmits parallel light incident from the total reflection mirror 98 along an optical axis common to the parallel light.

  The laser output unit 80 further includes a third laser emitting unit 86 that emits laser light as parallel light in order to emit laser light that is diffused from the first diffused light, that is, laser light that has a larger wavefront curvature than the first diffused light. A third fixed lens array 94 in which two lenses are coaxially arranged at a fixed distance shorter than the second fixed lens array 92; and a partial transmission mirror 102 coaxial with the total reflection mirror 98 and the partial transmission mirror 100. I have.

  In the third fixed lens array 94, when the laser light from the third laser emitter 86 enters one lens, the laser light is emitted from the other lens toward the partially transmitting mirror 102 as the second diffused light. The partially transmitting mirror 102 reflects the second diffused light incident thereon, and converts the parallel light or the first diffused light incident from the total reflection mirror 98 or the partially transmitted mirror 100 into light common to the parallel light or the first diffused light. Transmit along the axis.

  The laser output unit 80 further includes a fourth laser emitting unit 88 that emits laser light as parallel light in order to emit laser light that is diffused from the second diffused light, that is, laser light that has a larger wavefront curvature than the second diffused light. A fourth fixed lens array 96 in which two lenses are coaxially arranged at a fixed distance shorter than the third fixed lens array 94; and a partial transmission mirror 104 coaxial with the total reflection mirror 98 and the partial transmission mirrors 100 and 102. Have.

  In the fourth fixed lens array 96, when the laser light from the fourth laser emitting device 88 enters one lens, the laser light is emitted from the other lens toward the partially transmitting mirror 104 as third diffused light. The partially transmitting mirror 104 reflects the third diffused light incident thereon, and converts the parallel light, the first diffused light or the second diffused light incident from the total reflection mirror 98 and the partially transmitted mirror 102 or 104 into the parallel light and the second diffused light. The light is transmitted along an optical axis common to the first diffused light and the second diffused light.

  Each of the parallel light, the first diffused light, the second diffused light, and the third diffused light is then irradiated to a corresponding one of the three mirrors 18, 20, and 22 shown in FIG.

  The control unit 30 controls the output intensity (including ON / OFF of each of the laser emitters 82, 84, 96, 88) of the laser light emitted from each of the laser emitters 82, 84, 86, 88.

  According to the laser output unit 80, the laser light emitted from each of the laser emitters 82, 84, 86, 88 passes through different fixed lens rows 90, 92, 94, 96 and is output. In each of the fixed lens rows 90, 92, 94, and 96, the intervals between the two lenses belonging to each are different from each other. , 86, 88 are modulated such that the wavefront curvatures of the respective laser beams incident from them become different from each other.

  Therefore, according to the present embodiment, by selecting any one of the laser emitters 82, 84, 86, 88 that output laser light by the control unit 30, the laser light output from the laser output unit 80 is selected. It is easy to instantaneously change the wavefront curvature.

  As is clear from the above description, in the present embodiment, a plurality of laser emitters 82, 84, 86, and 88, a plurality of fixed lens rows 90, 92, 94, and 96 corresponding to the laser emitters 82, 84, 86, and 88, and a corresponding mirror. The combination with 100, 102, 104, 106 constitutes an example of the “plurality of emission means” in the above item (7), and the control section 30 constitutes an example of the “selection means” in the same item.

  In addition, in this embodiment, a plurality of laser lights having different wavefront curvatures can be generated independently of each other for each color laser light, and any one of the laser lights is selected. To be incident on the scanning mirror 24.

  On the other hand, for example, it is theoretically possible to operate the laser output unit 80 in such a manner that a plurality of laser beams are simultaneously emitted from the plurality of laser emitters 82, 84, 86, 88. According to this aspect, a plurality of laser beams having a plurality of types of wavefront curvatures can be combined into one laser beam and output. For this reason, according to this aspect, an observer recognizes an image in which a plurality of images having different depths are superimposed (for example, an image such as a composite image in which a translucent image is superimposed before a certain image). Can be done.

  Further, in any of the above-described embodiments, the traveling direction of the laser beam scanned by the scanning mirror 24 is changed to the direction toward the pupil 2 of the observer by the input mirror 26 as a reflection unit. Although a convergent configuration is employed, other configurations can be employed to achieve the same purpose.

  For example, it is possible to adopt a configuration in which the traveling direction of the laser beam scanned by the scanning mirror 24 is changed to a direction toward the pupil 2 of the observer by a lens serving as a refraction unit so that the laser beam converges. It is also possible to adopt a configuration in which the traveling direction of the laser beam is changed by an element to converge.

  In any of the configurations, when the degree of change in the wavefront curvature of the laser light is different depending on the irradiation position of the laser light irradiated from the scanning mirror 24 to the lens or the diffractive optical element, If the wavefront curvature of the laser light output from the laser output units 12, 14, 16 is corrected according to the present invention, an observer can recognize an accurate image despite the above-described optical characteristics of the lens or the diffractive optical element. be able to.

  In addition, in any of the above-described embodiments, a swing mirror capable of two-dimensional scanning is used as the scanning mirror 24 as the scanning unit, but the scanning unit is not limited to this. is not.

  For example, instead of the scanning mirror 24, a first scanning mirror that deflects laser light only in the main scanning direction and a second scanning mirror that deflects laser light only in the sub-scanning direction are used. It is possible to adopt a configuration in which the laser light synthesized by the partially transmitting mirrors 20 and 22 is incident on the input mirror 26 via the first scanning mirror and the second scanning mirror in order. In this case, the order in which the laser light passes through the first scanning mirror and the second scanning mirror may be any order.

  As described above, some of the embodiments of the present invention have been described in detail with reference to the drawings. However, these are exemplifications, and based on the knowledge of those skilled in the art, including the aspects described in the section of [Disclosure of the Invention]. The present invention can be implemented in other forms with various modifications and improvements.

FIG. 1 is a diagram showing a schematic configuration of a retinal scanning display according to a first embodiment of the present invention. FIG. 2 is a diagram illustrating a schematic configuration of an R laser output unit in FIG. 1. FIG. 3 is an optical path diagram for explaining an operation of a wavefront curvature modulation unit in an R laser output unit in FIG. 2. FIG. 2 is a perspective view illustrating an appearance of a scanning mirror in FIG. 1. FIG. 2 is a perspective view for explaining a scanning direction of laser light in the retinal scanning display of FIG. 1. FIG. 2 is a schematic diagram of the retinal scanning display of FIG. 1. (A), (b) and (c) are diagrams conceptually showing three tables in FIG. 1. 2 is a flowchart conceptually showing the contents of a wavefront curvature modulation program executed by a computer of a control unit in FIG. 1. 9 is a graph for explaining a relationship between a displacement value z and a wavefront curvature radius a in the wavefront curvature modulation program of FIG. 8. FIG. 6 is a diagram illustrating a schematic configuration of a retinal scanning display according to a second embodiment of the present invention. FIG. 11 is a diagram illustrating a schematic configuration of a retinal scanning display according to a third embodiment of the present invention. FIG. 14 is an optical path diagram showing a schematic configuration of a laser output unit in a retinal scanning display according to a fourth embodiment of the present invention.

Explanation of reference numerals

12, 14, 16 Laser output unit 20 Total reflection mirror 20, 22 Partial transmission mirror 24 Scanning mirror 26 Input mirror 28 Storage unit 30 Control unit 32 Emission unit 36 Curvature modulation means 62 Temperature sensors 82, 84, 86, 88 Laser emitter 90,92,94,96 Fixed lens array

Claims (18)

An image display device that allows the observer to recognize the image by projecting the image on the observer's retina,
Light beam output means for outputting a light beam;
Scanning means for scanning the light beam output by the light beam output means;
An optical unit that irradiates a light beam scanned by the scanning unit and changes a traveling direction of the irradiated light beam to a direction toward a pupil of an observer,
An image display device comprising: a curvature correction unit configured to correct a wavefront curvature of a light beam applied to the optical unit.   The image display device according to claim 1, wherein the curvature correction unit performs the correction based on an irradiation position of a light beam applied to the optical unit.   The curvature correction means, based on optical property information indicating the relationship between the irradiation position of the light beam irradiated to the optical means and the degree to which the wavefront curvature of the light beam changes by the optical means, the light flux toward the pupil of the observer. The image display device according to claim 2, wherein the correction is performed such that a wavefront curvature becomes a target value.   Further, a storage means for storing optical property information indicating a relationship between the irradiation position of the light beam irradiated to the optical means and the degree of change in the wavefront curvature of the light beam by the optical means, wherein the curvature correction means includes: 3. The image display device according to claim 2, wherein the correction is performed based on the optical characteristic information stored in the storage unit such that the wavefront curvature of the light flux toward the pupil of the observer becomes a target value. The luminous flux output means,
Emitting means for emitting a light beam;
The image display according to any one of claims 1 to 4, further comprising a curvature modulating means for modulating a wavefront curvature of a light beam emitted from the emitting means, wherein the curvature correcting means performs the correction using the curvature modulating means. apparatus.   6. The image processing apparatus according to claim 5, further comprising a control unit that controls the curvature modulation unit to display the image, wherein the control unit includes, as the curvature correction unit, a part that performs the correction using the curvature modulation unit. Image display device. The luminous flux output means,
A plurality of emission units each emitting a plurality of light beams having different wavefront curvatures,
5. A selecting means for selecting a light beam to be emitted from the plurality of emitting means, wherein the curvature correcting means performs the correction using the selecting means. Image display device.   The image according to claim 7, further comprising a control unit that controls the selection unit to display the image, wherein the control unit includes, as the curvature correction unit, a part that performs the correction using the selection unit. Display device.   9. The image display device according to claim 1, wherein the curvature correction unit performs the correction based on a physical quantity that affects a degree of change of a wavefront curvature of a light beam by the optical unit. 10.   10. The curvature correction unit according to claim 9, wherein the correction unit performs the correction based on an irradiation position of a light beam irradiated to the optical unit and a physical quantity that affects a degree of change in a wavefront curvature of the light beam by the optical unit. Image display device. Further, it includes a detecting means for detecting the physical quantity,
The image display device according to claim 10, wherein the curvature correction unit performs the correction based on an irradiation position of a light beam irradiated to the optical unit and a physical quantity detected by the detection unit. further,
Detecting means for detecting the physical quantity;
A plurality of types of optical property information representing a relationship between an irradiation position of a light beam irradiated to the optical unit and a degree of change of a wavefront curvature of the light beam by the optical unit are stored according to a plurality of values that the physical quantity can take. Storage means,
11. The image display device according to claim 10, wherein the curvature correction unit performs the correction by using information corresponding to a physical quantity detected by the detection unit among a plurality of types of optical characteristic information stored in the storage unit. . The optical means can be replaced with another type of optical means having a different degree of changing the wavefront curvature of the light beam,
The image display device according to claim 1, wherein the curvature correction unit performs the correction based on a type of the optical unit.   14. The image display device according to claim 13, wherein the curvature correction unit performs the correction based on an irradiation position of a light beam irradiated to the optical unit and a type of the optical unit. Further, optical characteristic information indicating a relationship between an irradiation position of a light beam irradiated to the optical unit and a degree of change of a wavefront curvature of the light beam by the optical unit is stored so as to be changeable according to a type of the optical unit. Including storage means,
The image display device according to claim 14, wherein the curvature correction unit performs the correction using optical characteristic information changed according to a type of the optical unit.   The scanning unit scans the light beam output by the light beam output unit in a main scanning direction and a sub-scanning direction, and among the main scanning direction and the sub-scanning direction, an irradiation position of the light beam irradiated to the optical unit. The image display device according to any one of claims 1 to 15, wherein a smaller change in the degree of change of the wavefront curvature of the light beam caused by the optical means due to the movement of the optical unit is the main scanning direction.   The light beam output means is provided for each of a plurality of wavelengths different from each other, and the image display device further combines the plurality of light beams output by the plurality of light beam output means and outputs the combined light beam to the scanning means. 17. The image display device according to claim 1, further comprising a combining unit, wherein the curvature correcting unit individually corrects a wavefront curvature of the light beam output from each of the light beam output units. An image display device that allows the observer to recognize the image by projecting the image on the observer's retina,
A light beam output unit that outputs a light beam, an output unit that outputs the light beam, and a curvature modulation unit that modulates a wavefront curvature of the light beam output from the output device;
Scanning means for scanning the light beam output by the light beam output means;
An optical unit that irradiates a light beam scanned by the scanning unit and changes a traveling direction of the irradiated light beam to a direction toward a pupil of an observer,
A storage unit that stores optical characteristic information indicating a relationship between an irradiation position of a light beam applied to the optical unit and a degree of change in wavefront curvature of the light beam by the optical unit,
Based on the optical characteristic information stored in the storage unit, the curvature modulation unit corrects the wavefront curvature of the light beam applied to the optical unit so that the wavefront curvature of the light beam toward the pupil of the observer becomes a target value. And an image display device including a curvature correction unit.

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