JP2010117541A - Beam scanning-type display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problem: in a display device such as a HMD (head-mounted display), it is difficult to maintain the optimum beam waist position of scanning beams all over the view field. <P>SOLUTION: The beam scanning-type display device includes: a light source which emits the beam; a wavefront shape-changing means for changing the wavefront shape of the beam emitted from the light source; a scanning means for scanning the beam from the wavefront shape-changing means; and a deflecting means for changing the direction of the beam scanned by the scanning means to advance toward the user's eyes. The wavefront shape-changing means includes an optical component which oscillates solely in synchronism with the operation of the scanning means, and includes a line-of-sight detecting means for detecting the line-of-sight of the user who operates the beam scanning type display device, and the driving width of the optical component which oscillates solely in the wavefront shape-changing means is changed in accordance with the detection result obtained by the line-of-sight detecting means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a display device such as an HMD (head mounted display).

  Conventionally, in a display device such as an HMD (head-mounted display), there is a method (hereinafter referred to as a laser scanning method) in which laser light is two-dimensionally scanned and directly drawn on the retina of the eye. (For example, refer to Patent Document 1). Laser scanning display devices include a retinal scanning display, a retinal irradiation display, a direct retina display, a laser scanning display, a direct-view display device, an RSD (Retina Scanning Display), and a VRD (Virtual Retina Display). ), Etc.

  FIG. 1 shows an example of the structure of a glasses-type HMD. In FIG. 1, laser sources 101 and 110 for emitting laser light to a spectacle frame, wavefront changing means 102 and 109 for controlling the wavefront of the laser light, and scanning means 103 and 108 for scanning the laser light in a two-dimensional direction are mounted. Yes. The laser light is projected toward the spectacle lens by the scanning means, reflected by the deflecting means 104 and 107 provided on the surface of the spectacle lens, is incident on the user's eye, and forms an image on the retina. Here, a half mirror, a hologram optical element (HOE), or the like is used for the deflecting means 104 and 107, and the user can view both the outside scenery and the image drawn by the laser at the same time. . For the scanning means 103 and 108, a mirror device that scans laser light in a two-dimensional direction by vibrating a single single-plate mirror in a uniaxial or biaxial direction is used.

A method of giving perspective to an image displayed to the user by changing the wavefront curvature of the laser light is also considered (see, for example, Patent Document 2).
JP 10-301055 A JP 2004-191946 A

  However, in a laser scanning display device, in order to realize a wide viewing angle and high resolution, it is necessary to change the beam waist position of the scanning beam in accordance with the scanning of the laser beam. Here, the beam waist is a place where the diameter of the laser beam becomes the smallest. In this specification, the beam waist position is treated as the position of the beam waist viewed from the scanning means.

  In order to realize high resolution in a laser scanning display device, it is necessary to reduce the beam spot diameter on the retina. Since the human eye is a condensing lens, when a parallel laser beam (laser beam with an infinite curvature radius) is incident on the eye, the incident light is focused on a small spot on the retina. Therefore, it is possible to depict a high-resolution video on the retina. In order to make a beam incident on the user's eye into parallel light in a glasses-type laser scanning display device, it is necessary to change the beam waist position of the scanning beam in accordance with the movement of the scanning means. By changing the position of the beam waist of the scanning beam in accordance with the location where the scanning beam from the scanning unit is incident on the deflecting unit, the laser beam from the deflecting unit toward the user's eyes can be converted into parallel light. FIG. 3 shows an example of the optimum beam waist position of the scanning beam by the scanning means for making the laser beam toward the user's eye into parallel light in the glasses-type display device. The deflecting unit 104 is a hologram mirror designed to collect light at the pupil position 305 of the user, and the scanning unit 103 obliquely enters the laser beam 304 with respect to this deflecting unit. At this time, the beam waist position of the laser beam is changed in accordance with the incident position of the laser beam 304 on the deflecting means 104. An example of an appropriate beam waist position of the laser beam 304 is shown by a line 301, and the beam waist position of the laser beam 304 is positioned on the line 301 even if the direction of the laser beam 304 changes due to the movement of the scanning unit 103. By controlling so as to make it possible, the beam incident on the pupil can be made into parallel light.

  However, when displaying a wide-field image to the user in the beam scanning display device, it is difficult to keep the beam waist position of the scanning beam optimal over the entire field of view. The beam waist position of the scanning beam needs to be changed following the operation of the scanning unit, but when displaying a high-quality image, the scanning unit operates at high speed (for example, 100 Hz or more). When following a scanning means that operates at high speed, it is difficult to give a complicated operation to the lens or mirror. Therefore, the optical parts used for the wavefront shape changing means can be driven at high speed with simple single vibration. Used. FIG. 2 shows a detailed structural diagram of a beam scanning type HMD. Here, reference numerals 201 and 202 denote lenses included in the wavefront shape changing unit, which respectively change the horizontal beam waist position and the vertical beam waist position of the scanning beam with an amplitude D in synchronization with the movement of the scanning unit 103. Single vibration drive.

  However, in the method of simply vibrating the optical component, there is a problem that it is difficult to keep the beam waist position of the scanning beam optimal over the entire field of view of the image.

  4 and 5 show the optimum beam waist position 401 and the beam waist position 402 of the scanning beam realized by the single vibration lens 201. FIG. 4 and 5, the horizontal axis indicates the viewing angle (field angle) of the pixel displayed to the user, and the vertical axis indicates the beam waist position of the scanning beam displaying the pixel corresponding to the viewing angle. The value of the beam waist position on the vertical axis is expressed by the distance from the scanning means 103 to the beam waist position of the scanning beam. 4 shows an example when the driving width of the single vibration lens 201 is small, and FIG. 5 shows an example when the driving width of the single vibration lens 201 is large.

  As shown in FIG. 4, when the driving width of the single vibration lens 201 is small, the deviation between the optimum beam waist position 401 and the beam waist position 402 is small at both ends of the field of view (40 degrees on the right side and 40 degrees on the left side). In other words, at this time, the beam waist position realized by the simple vibrating lens 201 is optimal at both ends of the user's visual field, and thus the pixels in the visual field of this portion are displayed without blur on the user's retina. On the other hand, the gap between 401 and 402 is large at the center of the visual field. At this time, since the beam waist position of the scanning beam for drawing the pixel at the center of the visual field is shifted from the optimum beam waist position, the pixel at the center of the visual field is blurred on the retina of the user. That is, the user displays an image in which both ends of the screen are clear and the center of the screen is blurred.

  Further, as shown in FIG. 5, when the driving width of the single vibration lens 201 is large, there is little deviation between the optimum beam waist position 401 and the beam waist position 402 in the center of the visual field. In other words, at this time, the beam waist position realized by the single vibration lens 201 is optimal, so that the pixel in the center of the visual field is displayed without blur on the retina of the user. On the other hand, the gap between 401 and 402 is large at both ends of the field of view. At this time, since the beam waist position of the scanning beam for drawing the pixels at both ends of the field of view is shifted from the optimum beam waist position, the pixels at both ends of the field of view are blurred on the user's retina. That is, the user displays an image with a clear center in the screen and blurred both ends of the screen.

  That is, when changing the beam waist position of the scanning beam at high speed by driving the optical component with a single vibration, the waist position of the scanning beam can be optimally maintained only in a part of the field of view, and the user's eyes in other parts. Since the beam heading toward is not parallel light, there arises a problem that the resolution on the retina is degraded.

  Patent Documents 1 and 2 do not consider the problem caused by the operation of such wavefront shape changing means.

  FIG. 10 shows an example of an image displayed to the user. In FIG. 10, reference numeral 1001 denotes a displayable area where the beam scanning display device can display an image. The beam scanning display device of the present invention can display an image of an arbitrary size in the displayable area 1001. FIG. 10 shows an example in which a display image 1003 is displayed on the entire displayable area 1001. In this example, a very wide viewing angle image with a horizontal viewing angle of 100 degrees is displayed to the user. As described above, it is difficult to optimally set the beam waist position of the scanning beam for such a wide-field display image 1003 so that all pixels are clearly visible to the user. However, as a human visual characteristic, a person can clearly recognize an image only in an area of about ± 5 degrees (center visual field) with the line of sight as the central view. In FIG. 10, an example of the central visual field at a certain point of time of the user is indicated by 1002. At this time, among the pixels of the display image 1003, the user can clearly recognize only the portion of the central visual field 1002, and even if the pixels in other regions are blurred, the user is blurred. I can not recognize that. That is, the current central visual field 1002 is specified from the user's line-of-sight direction, and the beam waist position of the scanning beam is controlled so that the pixels included in the central visual field 1002 among the pixels of the display image 1003 are clearly visible to the user. If possible, since the user cannot recognize the blur of the pixel, the display image can be prevented from being deteriorated.

  The present invention solves the above-described problem. In the beam scanning display device, the drive width of the optical component of the wavefront shape changing means is appropriately changed while sequentially determining the area where the pixels need to be clearly displayed in the image. The purpose is to prevent the deterioration of the image recognized by the user.

In order to solve the above-described conventional problems, a beam scanning display device of the present invention includes:
A light source that outputs a beam;
Wavefront shape changing means for changing the wavefront shape of the beam from the light source;
Scanning means for scanning the beam from the wavefront shape changing means;
Deflecting means for changing the beam scanned by the scanning means in a direction toward the user's eyes;
A beam scanning display device comprising:
The wavefront shape changing unit includes an optical component that is driven by simple vibration in synchronization with the operation of the scanning unit.

  With this configuration, the beam waist position of the scanning beam can be changed following the operation of the high-speed scanning means, and the display image can be improved in image quality.

In the scanning region where the scanning beam is incident on the deflecting unit,
Do vertical scanning faster than horizontal scanning,
The wavefront shape changing means is synchronized with the scanning in the horizontal direction of the scanning means,
The optical component is driven by a single vibration.

  With this configuration, the speed of the single vibration drive can be reduced, and the operation of the wavefront shape control means can be simplified.

In addition, the beam scanning display device of the present invention includes line-of-sight detection means for detecting the line of sight of the user,
The wavefront shape changing unit changes the amplitude of the optical component that simply vibrates in accordance with the detection result of the line-of-sight detection unit.

  With this configuration, it is possible to prevent blurring of image quality displayed in a portion where the user's visual acuity is high.

The scanning means of the present invention injects a beam obliquely to the deflecting means,
In the scanning region where the scanning beam is incident on the deflecting means,
The intersection of the scanning area and the user's line of sight is the gaze point, and the longer the gaze distance, which is the distance between the gaze point and the scanning means,
The wavefront shape changing means makes the amplitude of the optical component smaller than when the gaze distance is short.

  With this configuration, it is possible to prevent the image in the range of the central visual field of the user from being blurred as the user's line of sight moves.

  In the beam scanning display device of the present invention, the gaze distance is a horizontal distance between the gaze point and the scanning unit.

  With this configuration, the wavefront shape control means can be operated following the horizontal direction in which the change in the optimum beam waist position is large.

The wavefront shape changing means of the present invention is
In the scanning area where the scanning beam is incident on the deflection unit, according to the image display position where the image is displayed in the scanning area,
The drive width of the optical component that simply vibrates is changed.

  With this configuration, when the beam scanning display device displays an image only in a part of a region where the image can be displayed, it is possible to prevent the display image from being blurred without extra processing such as eye gaze detection. Become.

Further, the scanning means of the present invention makes a beam incident on the deflecting means obliquely,
The longer the display distance, which is the distance between the image display position and the scanning means,
The wavefront shape changing means makes the amplitude of the optical component smaller than when the display distance is short. With this configuration, the image is blurred depending on the position where the image is displayed in the scanning region. It becomes possible to prevent this.

In addition, the beam scanning display device of the present invention includes line-of-sight detection means for detecting the line of sight of the user,
The image display position in the scanning area is
When exceeding the range of the central visual field centered on the gazing point that is the intersection of the user's line of sight and the scanning area, the wavefront shape changing unit is configured to detect the vibration of the optical component that simply vibrates according to the detection result of the line of sight detection unit. The drive width is changed.

  With this configuration, when a small image is displayed in the scanning area, it is possible to perform processing for preventing the display image from blurring without performing extra processing such as eye gaze detection.

  By appropriately changing the drive width of the optical component of the wavefront shape changing means while sequentially determining the area where the pixels need to be clearly displayed in the image, deterioration of the image recognized by the user is prevented.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a configuration diagram (a plan view and a side view) of a glasses-type HMD (head-mounted display) in Embodiment 1 of the present invention. FIG. 2 is a detailed view of a part of FIG.

  In the configuration diagrams of FIGS. 1 and 2, each component and its relationship are described.

  The light sources 101 and 110 output beams. As shown in FIG. 2, the output beam is a laser beam obtained by combining the laser beams output from the red laser light source 211, the blue laser light source 212, and the green laser light source 213, and the output from each color laser light source is appropriately set. By modulating, laser light of any color can be output. Furthermore, an image can be displayed on the retina of the user's eye by performing modulation in conjunction with wavefront shape changing means and scanning means described later.

  In FIG. 2, 211 is a red semiconductor laser light source, 212 is a blue semiconductor laser light source, 213 is an infrared semiconductor laser light source, and SHG (Second Harmonic Generation: Second Harmonic Generation) that converts infrared light into green. ) Although shown as a combination of elements, 213 may be a green semiconductor laser light source, or each light source may be a solid laser, liquid laser, gas laser, or light emitting diode.

  In FIG. 2, the laser light is modulated by each laser light source, but the means for modulating the light output from the laser light source may be used in combination with the laser light source to modulate the laser light.

  The light sources 101 and 110 may include the light detection means 214 in FIG. The light detection means can detect the user's line-of-sight direction by detecting the intensity of the reflected light from the cornea of the user's eye. Most of the beams deflected in the direction of the eye by the deflecting means are incident on the corneal surface obliquely, but the beam from the front with respect to the eyeball is incident perpendicular to the corneal surface. Since the reflectance is relatively high, the line-of-sight direction can be detected by detecting the intensity of the reflected light.

  The wavefront shape changing means 102 and 109 change the wavefront shapes of the beams from the light sources 101 and 110, respectively, so that the spot sizes of the beams deflected by the deflecting means 104 and 107 described later are within a predetermined range. To do.

  The “spot size” of the beam will be described below as a spot size on the retina of the user's eye, but may be a spot size on the pupil, a spot size on the cornea, or a spot size on the deflecting means. The spot size on the retina is the same as the pixel size to be displayed.

  The “wavefront shape” is a three-dimensional shape of a beam wavefront, and includes flat, spherical, and aspherical shapes.

  In FIG. 2, the focal length horizontal component changing means 201 and the focal length vertical component changing means 202 are arranged in series in the optical path, so that the horizontal curvature and the vertical curvature of the wavefront shape are independent. Can be changed. Reference numeral 201 denotes a horizontal cylindrical lens, and 202 denotes a vertical cylindrical lens, which respectively changes the curvature in the horizontal direction and the vertical direction by being driven by simple vibrations, thereby changing the beam waist in the horizontal direction and the vertical direction of the scanning beam. Change the position.

  The wavefront shape changing means in FIG. 2 uses a cylindrical lens to change the wavefront shape. However, as another means, a combination of a cylindrical lens and a mirror is used, and the mirror is driven by a single vibration to thereby generate a beam of the scanning beam. A method of changing the waist position may be used (FIG. 9). In this case, by configuring the mirror as a MEMS (Micro-Electro-Mechanical-System) mirror, it is possible to drive at higher speed.

  A diffractive optical element may be used instead of the cylindrical lens. In this case, since the optical element is thin and light, it is possible to drive at higher speed.

  Further, a method of changing the beam waist position of the scanning beam by using a liquid crystal lens, a deformable lens such as a liquid lens, an EO element (electro-optical conversion element), or the like may be used. In this case, it is not necessary to directly move the position of the lens or mirror, so that high-speed control is possible and the display device does not generate extra vibration.

  Scanning means 103 and 108 two-dimensionally scan the beams from the wavefront shape changing means 102 and 109, respectively. The scanning means is a single-plate small mirror that can change the angle two-dimensionally, and is a MEMS (Micro-Electro-Mechanical-System) micromirror.

  The scanning unit may be realized by a combination of two or more types of scanning units, such as for horizontal scanning and vertical scanning.

  The scanning means is not limited to a method of physically tilting the mirror, but a method of moving a lens or rotating a diffraction element, a liquid crystal lens, a deformable lens, an AO element (acoustooptic element), an EO element ( A method using a deflection element such as an electro-optical conversion element) may also be used.

  The deflecting units 104 and 107 change the directions of the beams scanned by the scanning units 103 and 108, respectively, toward the user's eyes. In the deflecting means 104 and 107, for example, a photopolymer layer is formed on the inner side (eye side) of the spectacle lens, a Lippmann volume hologram is formed on the photopolymer layer, and the beam from the scanning means is transmitted to the user's eye. It is made to be diffracted and focused on the pupil. The photopolymer layer may be formed with multiple holograms reflecting red, green, and blue light from each light source, or three layers of holograms corresponding to each color light may be laminated. Good. In addition, by using the wavelength selectivity of the hologram, only light of the light source wavelength is diffracted, and light of wavelengths other than the light source wavelength that occupies most of the light from the outside world is not affected by diffraction, It can be a transmissive display.

  The deflection means is not limited to deflection by a diffraction element such as a hologram, and may be a mirror such as a concave mirror or a lens such as a convex lens. In this case, it is easier to manufacture the deflection means than when a hologram is used as the deflection means.

  The control means 105 and 111 include an integrated circuit that controls each part of the HMD. The outputs of the lasers and the operations of the wavefront shape changing means and the scanning means are performed by the control means 105 and 111. The control means 105 and 108 include means for determining the contents to be displayed to the user.

  FIG. 6 shows a functional block diagram of the control means 105 and 111 in the present embodiment. Details of each functional block will be described later.

  Note that the control means 105 and 111 may include a communication means for receiving a video / audio signal by wireless connection with a peripheral device such as a mobile phone. Further, the control means 105, 111 may be provided with a memory storing an image to be presented to the user, or an image to be presented to the user may be acquired from an external device wirelessly.

  The control means 105 and 111 may be one, and the control means 105 or 111 may control the operations of the laser light source, the wavefront shape changing means, the scanning means, and the headphones corresponding to the left and right eyes. In this case, since only one control means is required, the cost can be reduced and the display device can be reduced in weight.

  The headphone units 106 and 112 include speakers and output sound.

  The headphone unit may include a battery that supplies power to each unit of the HMD.

  In addition, each means and each part in FIG. 1 may be incorporated in one HMD, or may not be incorporated. For example, all the components in FIG. 1 may be included in one HMD, or the headphone unit may not be provided. Moreover, each part may be distributed. For example, the control means may be partly included in the scanning means and the wavefront shape changing means. 1 may be shared by a plurality of devices. For example, the laser light source may be shared by two HMDs.

  Hereinafter, an example will be described in which the drive width of the wavefront shape changing unit is appropriately changed to prevent the image quality from being deteriorated while sequentially determining the area in the image where the pixels need to be clearly displayed in the present embodiment. For the sake of simplicity, only the display on the left eye of the user will be described in the HMD, but the same processing is performed for the right eye.

  In this embodiment, the image quality displayed to the user is prevented from being deteriorated by executing steps 701 to 703 shown in FIG.

(Step 701) Optimization Region Determination In this step, the optimization region determination means 601 determines an optimization region in which an image should be clearly displayed by optimizing the beam waist position of the scanning beam in the displayable region 1001. To do. In this step, two processes are performed: display image determination and line-of-sight position determination.

Determination of Display Image First, the optimization area determination unit 601 acquires the position in the displayable area, the horizontal size, and the vertical size of the image displayed to the user from the image management unit 604. The display image 1003 is not only displayed in the entire displayable area 1001 as shown in FIG. 10, but may be displayed only in a part of the displayable area 1002 as shown in FIG. The display as shown in FIG. 11 is performed when the display image 1003 does not hinder the user from visually recognizing the outside world, for example, when the HMD is worn outdoors. Here, if the size of the display image 1003 is smaller than the central visual field and the position is fixed, the beam scanning display device always uses the beam waist in the region where the display image 1003 is displayed regardless of the line of sight of the user. What is necessary is just to control so that a position may be optimized.

  Here, when the horizontal size A and the vertical size B of the display image 1003 acquired from the image management unit 604 are smaller than the size D of the central visual field 1003 held by the optimization region determination unit 601, optimization is performed. The area determination unit 601 determines the display position of the display image 1003 acquired from the image management unit 604 as the optimization area X.

  When the size A in the horizontal direction and the size B in the vertical direction of the display image 1003 acquired from the image management unit 604 exceed the size D of the central visual field 1003 held by the optimization region determination unit 601, the optimization region determination The means 601 determines the user's line-of-sight position.

  Note that the size D of the central visual field held by the optimization region determining unit 601 may be a size corresponding to a general visual field angle (about 10 degrees) converted to a size within the displayable region 1001. However, it may be set by an individual user from the input device of the HMD. In the latter case, it is possible to perform processing in consideration of individual differences in the size of the central visual field.

The determination of the line-of-sight position The optimization area determination unit 601 acquires the user's line-of-sight direction from the line-of-sight detection unit 605 and determines the location of the central visual field 1002 within the displayable area 1001. The line-of-sight detection means 605 determines the current user's line-of-sight direction using the output of the photodetector 214 that detects the reflected light from the user's retina or cornea.

  The optimization region determination unit 601 determines, as the optimization region X, the viewing angle that matches the user's line-of-sight direction acquired from the line-of-sight detection unit 605.

  When the optimization region determination unit 601 determines the optimization region X, the information is notified to the drive width determination unit 602.

(Step 702) Drive Width Determination In this step, the drive width determination unit 602 determines the necessity of changing the drive width of the optical component in the wavefront shape changing unit 102 from the value of the optimization region X determined in the previous step. .

  In the present embodiment, the drive width determination unit 602 first determines the drive width of the wavefront shape changing unit 102 for optimizing the beam waist position of the optimization region X determined in the previous step. In the present embodiment, as shown in FIG. 2, the horizontal beam waist position is independently controlled by the single vibration lens 201, and the vertical beam waist position is independently controlled by the single vibration lens 202. Therefore, the necessity of changing the driving width of the wavefront shape changing means is performed in each of the horizontal direction and the vertical direction.

  The drive width determination unit 602 holds a relationship table between the drive widths of the wavefront shape changing unit as shown in FIG. 8 and the regions optimized thereby. The example of FIG. 8 is an example relating to the horizontal beam waist position. For example, in order to optimize the horizontal beam waist position of the portion where the horizontal viewing angle is 0 degrees (the center of the displayable area 1001), This indicates that the driving width of the wavefront shape changing means (in this embodiment, the driving width of the single vibration lens 201 for the horizontal direction) needs to be ± 0.4 mm. The drive width determination means 602 determines the drive width α0 of the wavefront shape control means for optimizing the horizontal beam waist position of the optimization region X from this relation table.

  The drive width determination unit 602 holds the same relationship table as in FIG. 8 for the vertical beam waist position, thereby driving the wavefront shape changing unit for optimizing the vertical beam waist position of the optimization region X. The width (driving width of the single vibration lens 202 for the vertical direction in this embodiment) β0 is determined.

  After the determination of α0 and β0, the beam drive width determination means 602 sets the current drive width α1 of the horizontal vibration lens 201 and the drive width β1 of the vertical vibration lens 202 to α0 and β0, respectively. Compare.

  If the values of α0 and α1 and β0 and β1 coincide with each other, the beam driving width determination unit 602 determines that the beam waist position has already been optimized and ends the processing. In other cases, the beam driving width determination unit 602 notifies the driving distance changing unit 603 of the values of α0 and β0.

(Step 703) Drive Width Change In this step, the drive width change means 603 controls the single vibration lenses 201 and 202 of the wavefront shape change means to operate with the drive widths α0 and β0 determined in step 702.

  The drive width changing unit notifies the wavefront shape changing unit 102 of the values of α1 and β1, thereby changing the drive widths of the single vibration lenses 201 and 202 and optimizing the beam waist position in the optimization region.

  By performing the above processing, it is possible to always clearly display the pixel in the central field of view of the user or a specific portion within the displayable area while changing the beam waist position at high speed by simply vibrating the optical component. It becomes possible, and a wide-field video display can be realized.

  In the present embodiment, the wavefront shape changing means 102 uses a method of causing the simple vibrating lenses 201 and 202 to vibrate simply as shown in FIG. 2, but as shown in FIG. Alternatively, a method of driving with a single vibration may be used. At this time, the relationship table shown in FIG. 8 shows not the lens driving distance but the mirror driving distance and the horizontal or vertical region in which the beam waist position is optimized thereby. 602 will be held. In this case, it is possible to improve the frame rate and the number of pixels of the image to be displayed by operating the mirror at high speed.

(Embodiment 2)
In the present embodiment, when a HUD (Head Up Display) mounted on a vehicle or an aircraft is realized by a beam scanning display device, by changing the drive width of the optical component of the wavefront shape changing means, the image quality can be improved. A method for preventing the decrease will be exemplified.

  FIG. 12 is a side view of a laser scanning type HUD (head-up display) according to Embodiment 2 of the present invention, and FIG. 13 is a bird's-eye view.

  A laser scanning unit 1202 is embedded inside the car 1201. The laser scanning unit 1202 is attached below the windshield 1203 of the car, and is arranged inside the instrument panel in the present embodiment to save space of the display device.

  The laser scanning unit 1202 may be arranged outside the instrument panel, not inside the instrument panel. In this case, the laser scanning unit 1202 can be easily replaced and the position can be changed.

  The light scanned by the laser scanning unit 1202 is reflected by the deflecting unit 104 attached to the windshield 1203, passes through the half mirror 1204, and reaches the eyeball 1206 of the driver 1205 so that an image is visually recognized. In such a HUD, it is possible to see the map information and warning information displayed by the laser scanning unit 1202 while confirming the scenery of the outside world through the windshield 1203, thereby improving the safety and convenience of the driver. Become. The reflected light of the laser projected on the user's retina is reflected by the half mirror 1204 installed in front of the user's eyes and detected by the light detection means 214.

  In this embodiment, the laser scanning unit 1202 includes a light source 101, a wavefront shape changing unit 102, a scanning unit 103, and a control circuit 105. As shown in FIG. 13, the laser scanning unit 1202 is installed not on the user's front but on the side mirror side, and projects laser light obliquely onto the windshield 1203. By adopting such a configuration, it is possible to increase the degree of freedom of the place where the laser scanning unit 1203 is arranged, and there is an effect of improving the design of the vehicle.

  The deflecting means 104 may be freely attached to and detached from the windshield 1203. In this case, when the display on the display is unnecessary, the changing means 104 is removed, so that the transparency of the windshield 1203 can be maintained and the safety of the driver can be improved.

  The deflecting unit 104 may reflect the light from the scanning unit not toward one of the eyes of the user but to the eyes of the user. In this case, the video can be displayed on both eyes of the user by one change means 104.

  In the embodiment of the present invention, a half mirror 1304 is installed in front of the user's eyes so that the reflected light from the user's retina is reflected to the light detection unit 214. The half mirror 1304 is attached to the car ceiling 1307 by a support bar 1308, and this structure detects the spot size on the user's retina without forcing the device to be mounted on the user's head. Can do. The half mirror 1304 and the light detector 214 may be installed not on the ceiling of the car but on the driver's glasses or hat. In this case, even if the driver's head moves back and forth, the possibility that the head contacts the half mirror is reduced, so that the driver's safety can be improved.

  The control means 105 includes an integrated circuit that controls each part of the HUD. The output of each laser and the operations of the wavefront shape changing means, the scanning means, and the photodetector are performed by the control means 105. The control means 105 also includes a function for controlling the operation of the wavefront shape changing means. In this embodiment, the light detection means 214 is arranged on the ceiling and the control circuit 105 is installed inside the instrument panel. However, the communication between the light detection means 214 and the control circuit 105 has a wired cable inside the car. May be performed by wireless communication.

  In the present embodiment, the beam scanning display apparatus of FIG. 12 executes steps 701 to 3 shown in FIG. 7 and changes the driving width of the optical component of the wavefront shape changing unit, so that the user notices the deterioration of the image quality. To prevent that. The contents of the processing in steps 701 to 703 are the same as those in the seventh embodiment.

  Although only one user's eye is shown in FIG. 12, another set of laser scanning unit 1202, changing means 104, and light detecting means 214 is prepared, and the curvature radius of the beam is controlled for both eyes. May be.

  The control processing in each embodiment described above is performed by the CPU interpreting and executing predetermined program data stored in a storage device (ROM, RAM, hard disk, etc.) that can execute the processing procedure described above. Realized. In this case, the program data may be introduced into the storage device via the recording medium, or may be directly executed from the recording medium. The recording medium refers to a recording medium such as a semiconductor memory such as a ROM, a RAM, or a flash memory, a magnetic disk memory such as a flexible disk or a hard disk, an optical disk such as a CD-ROM, DVD, or BD, or a memory card such as an SD card. . The recording medium is a concept including a communication medium such as a telephone line or a conveyance path.

  The beam scanning display device according to the present invention has a beam diameter changing means and the like, and can be applied to uses such as a display device, a display system, a display method, and a display program.

1 is a configuration diagram of a beam scanning display device according to a first embodiment of the present invention. 1 is a detailed configuration diagram of a beam scanning display device according to Embodiment 1 of the present invention. The figure which shows the example of the beam waist position of the incident laser for making incident light to an eyeball into parallel light The figure which shows the example of the optimal beam waist position and the beam waist position realized by the single vibration lens The figure which shows the example of the optimal beam waist position and the beam waist position realized by the single vibration lens Functional block diagram of control means in Embodiment 1 of the present invention The flowchart which changes the drive width of the wavefront shape change means in this invention The figure which shows the example of the relationship table of the area | region where the drive width of the wave-front shape change means in Embodiment 1 of this invention and a beam waist position are optimized 1 is a detailed configuration diagram of a beam scanning display device according to Embodiment 1 of the present invention. The figure which shows the example of the display image and center visual field in Embodiment 1 of this invention. The figure which shows the example of the display image and center visual field in Embodiment 1 of this invention. Configuration diagram of a beam scanning display device in a second embodiment of the present invention Bird's-eye view of the beam scanning display device in the second embodiment of the present invention

Explanation of symbols

101 Left-eye light source 102 Left-eye wavefront shape changing means 103 Left-eye scanning means 104 Left-eye deflection means 105 Left-eye control means 106 Left-eye headphone unit 110 Right-eye light source 109 Right-eye wavefront shape changing means 108 right-eye scanning means 107 right-eye deflection means 111 right-eye control means 112 right-eye headphone unit 201 focal length horizontal component changing means 202 focal length vertical component changing means 211 red laser light source 212 blue laser light source 213 green laser light source 214 Photodetection means

Claims (8)

A light source that outputs a beam;
Wavefront shape changing means for changing the wavefront shape of the beam from the light source;
Scanning means for scanning the beam from the wavefront shape changing means;
A beam scanning display device comprising: deflection means for changing a beam scanned by the scanning means in a direction toward the user's eye;
The beam scanning display device, wherein the wavefront shape changing unit includes an optical component that is driven by simple vibration in synchronization with the operation of the scanning unit. In the scanning region where the scanning beam is incident on the deflection unit, the scanning unit
Do vertical scanning faster than horizontal scanning,
The wavefront shape changing means is synchronized with the scanning in the horizontal direction of the scanning means,
The beam scanning display device according to claim 1, wherein the optical component is driven by a single vibration. Provided with gaze detection means for detecting the gaze of the user,
3. The beam scanning display device according to claim 1, wherein the wavefront shape changing unit changes the amplitude of a single vibration optical component in accordance with a detection result of the line-of-sight detection unit. The scanning means obliquely enters the deflecting means;
In the scanning region where the scanning beam is incident on the deflecting means,
The intersection of the scanning area and the user's line of sight is the gaze point, and the longer the gaze distance, which is the distance between the gaze point and the scanning means,
The beam scanning display device according to claim 3, wherein the wavefront shape changing unit reduces the amplitude of the optical component as compared with a case where the gaze distance is short. The beam scanning display device according to claim 4, wherein the gaze distance is a horizontal distance between the gaze point and the scanning unit. The wavefront shape changing means is
In the scanning area where the scanning beam is incident on the deflection unit, according to the image display position where the image is displayed in the scanning area,
3. The beam scanning display device according to claim 1, wherein the driving width of the optical component that vibrates is changed. The scanning means obliquely enters the deflecting means;
The longer the display distance, which is the distance between the image display position and the scanning means,
The beam scanning display device according to claim 6, wherein the wavefront shape changing unit makes the amplitude of the optical component smaller than when the display distance is short. Provided with gaze detection means for detecting the gaze of the user,
The image display position in the scanning area is
When exceeding the range of the central visual field centered on the gazing point that is the intersection of the user's line of sight and the scanning area, the wavefront shape changing unit is configured to detect the vibration of the optical component that simply vibrates according to the detection result of the line of sight detection unit. 8. The beam scanning display device according to claim 7, wherein the driving width is changed.

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