JP2014071230A - Image display device, control method, program, and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display device capable of displaying an image appropriately taking characteristics of sight of a user into consideration.SOLUTION: An image display device includes a sight information acquisition part and a display control part. The sight information acquisition part acquires information about sight of a user. The display control part causes a display part to display an image on a display part so as to generate a virtual image in a focal position of a line of sight of the user. Then, the display control part adjusts the image on the basis of the acquisition result of the sight information acquisition part and causes the display part to display it.

Description

  The present invention relates to a technique for displaying an image.

  2. Description of the Related Art Conventionally, a technique for adjusting an image so as to reduce the burden on the eyes of an observer is known. For example, Patent Document 1 discloses a technique for measuring brightness of an image for the left eye and an image for the right eye, respectively, and controlling the difference to be a predetermined value or less in image adjustment of a stereoscopic display. ing. In addition, Patent Document 2 discloses a technique related to the present invention.

JP2012-073434A Japanese Patent Application Laid-Open No. 07-321087

  In the technique described in Patent Document 1 and the like, since the visual characteristics of the observer are not taken into consideration, an image cannot be displayed so as to reduce the burden on the eyes according to the observer having various eye characteristics. .

  The present invention has been made to solve the above-described problems, and mainly provides an image display device capable of displaying an image appropriately in consideration of the visual characteristics of an observer. Objective.

  In the first aspect of the present invention, the image display device includes a visual information acquisition unit that acquires information related to the user's vision, and an image display unit that generates a virtual image at the focal position of the user's line of sight. A display control unit to be displayed on the display unit, wherein the display control unit adjusts the image based on the acquisition result of the visual information acquisition unit and displays the image on the display unit.

  According to a tenth aspect of the present invention, there is provided a control method executed by the image display device, wherein a visual information acquisition step of acquiring information related to a user's vision and a virtual image are generated at a focal position of the user's line of sight. The display control step for displaying the image on the display unit, and in the display control step, the image is adjusted based on the acquisition result in the visual information acquisition step and displayed on the display unit. It is characterized by making it.

  The invention according to claim 11 is a program executed by the image display device, wherein a virtual information is generated at a visual information acquisition unit that acquires information relating to a user's vision and a focus position of the user's line of sight. In addition, the image display device is caused to function as a display control unit that displays an image on a display unit, and the display control unit adjusts the image based on an acquisition result of the visual information acquisition unit, and displays the image on the display unit. It is characterized by being displayed.

It is a schematic block diagram of a head mounted display system. It is a block diagram which shows the functional structure of a head mounted display. The positional relationship between the eyeball and the pupil is shown. The schematic structure of a head mount unit is shown. The data structure of user information is shown. It is a flowchart which shows the process sequence at the time of starting of a head mounted display. The schematic diagram of position adjustment of a virtual image in case eye positions are right eye positions is shown. The schematic diagram of the position adjustment of the virtual image when there is an oblique position in one eye is shown. The positional relationship between the displayable range and the effective area Rtag is shown. A procedure for adjusting the focal position and the effective area during content viewing will be described. It is a flowchart which shows the procedure of a focus position adjustment process. It is a flowchart which shows the procedure of an effective area adjustment process.

  According to a preferred embodiment of the present invention, the image display device obtains an image so that a virtual image is generated at a focal information position of the user's line of sight, and a visual information acquisition unit that acquires information related to the user's vision. A display control unit to be displayed on the display unit, and the display control unit adjusts the image based on the acquisition result of the visual information acquisition unit and displays the image on the display unit.

  The image display device includes a visual information acquisition unit and a display control unit. The visual information acquisition unit acquires information related to the user's vision. The display control unit displays an image on the display unit so that a virtual image is generated at the focal position of the user's line of sight. And a display control part adjusts an image based on the acquisition result of a visual information acquisition part, and displays it on a display part. As described above, the image display apparatus can reduce the burden on the eyes of the user by displaying the image on the display unit so that a virtual image is generated at the focal position of the user's line of sight. Moreover, the image display apparatus can display an image suitable for each user having various visual characteristics by adjusting the image based on the visual information of the user.

  In one aspect of the image display device, the image display device further includes the display unit that is attached to a user's head and displays an image at a position where the user can visually recognize the image. As described above, the present invention can be suitably applied to a head mounted display that is a display exclusively for the user to be worn on the head.

  In another aspect of the image display device, the visual information acquisition unit acquires the eye position information of the user, and the display control unit adjusts the position of the virtual image based on the eye position information. As described above, the image is displayed on the display unit. Thereby, even if the user has eye position characteristics such as oblique position, the burden on the user's eyes can be suitably reduced.

  In another aspect of the image display device, the display unit includes a right eye display unit and a left eye display unit, and the display control unit includes the right eye display unit and the left eye. An image is displayed on each display unit. In general, visual characteristics may differ between the left eye and the right eye. Therefore, according to this aspect, the image display device can make the virtual image visible by appropriately adjusting the images to the left and right eyes in consideration of the characteristics of the left and right eyes.

  In another aspect of the image display device, the visual information acquisition unit acquires the moving object visual acuity information of the user, and the display control unit determines the luminance or / and / or the image based on the moving object visual acuity information. Adjust the contrast. According to this aspect, the image display apparatus can appropriately suppress eye fatigue when viewing the moving image content.

  In another aspect of the image display device, the display control unit divides the image into a plurality of regions based on the moving body visual acuity information, and changes the brightness or / and contrast for each region. adjust. According to this aspect, the image display apparatus can appropriately suppress eye fatigue when viewing the moving image content.

  In another aspect of the image display device, the luminance or / and the contrast are adjusted so that the region farther from the focal position of the user's line of sight becomes less noticeable. By doing in this way, the image display apparatus can suppress eye fatigue suitably.

  In another aspect of the image display device, the image display device relates to a user identification information acquisition unit that acquires identification information for identifying a user, and the user's vision acquired by the visual information acquisition unit. And a storage unit that stores information in association with the identification information. According to this aspect, the image display apparatus can preferably record and use visual information for each user.

  In another aspect of the image display device, the identification information is iris information of the user's eyes. According to this aspect, the image display apparatus can preferably identify the user.

  According to another preferred embodiment of the present invention, there is provided a control method executed by the image display device, the visual information acquiring step for acquiring information relating to the user's vision, and the virtual image at the focal position of the user's line of sight A display control step of displaying an image on a display unit so as to be generated, and in the display control step, the image is adjusted based on an acquisition result in the visual information acquisition step, Display on the display. By executing this control method, the image display apparatus can appropriately display an image in consideration of the visual characteristics of the observer.

  According to another preferred embodiment of the present invention, the program is executed by the image display device, and a visual information acquisition unit that acquires information related to a user's vision and a virtual image at a focal position of the user's line of sight The image display device is caused to function as a display control unit that displays an image on a display unit so as to be generated, and the display control unit adjusts the image based on an acquisition result of the visual information acquisition unit, Display on the display unit. By executing this program, the image display apparatus can appropriately display an image in consideration of the visual characteristics of the observer.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[Configuration of head mounted display system]
FIG. 1 is a schematic configuration diagram of a head mounted display system according to the present embodiment. Hereinafter, the head-mounted display is appropriately expressed as “HMD”. As shown in FIG. 1, the HMD system mainly includes an HMD 1, a headphone 2, a head mount (HM) unit 3, a head fixing device 4, an external playback device 5, and an operation unit 6. Hereinafter, the vertical direction (that is, the main scanning direction) of the image displayed by the HMD 1 is the Y-axis direction, the horizontal direction (that is, the sub-scanning direction) of the image is the X-axis direction, and the direction perpendicular to the XY plane is the Z-axis direction. The positive direction of each axis is determined as shown in the figure.

  The HMD 1 is attached to the user's head by the head fixing device 4 and displays an image or the like output from the external playback device 5 so that the user can visually recognize the virtual image. The headphone 2 is attached to the user's ear and outputs audio data and the like output from the external player 5. The HM unit 3 controls the entire HMD system such as display control of the HMD 1 and sound output control of the headphones 2. The external player 5 reads the content stored in the hard disk or storage medium and outputs the content image or audio data to the HM unit 3. The operation unit 6 is a remote controller used when the user performs various operations.

  FIG. 1 shows a state in which the HMD 1, the headphones 2, the external player 5 and the HM unit 3 are connected by wire, but instead of this, a communication standard such as BlueTooth (registered trademark). Wireless connection may be made according to Further, the operation unit 6 may be a key, a button, or the like provided in the HMD 1 or the HM unit 3.

[Configuration of HMD]
FIG. 2 is a block diagram illustrating a functional configuration of the HMD 1. FIG. 2 schematically shows the arrangement of the components of the HMD 1 when the HMD 1 is observed from the positive direction of the Y axis. As illustrated in FIG. 2, the HMD 1 mainly includes a right-eye display unit 11R, a left-eye display unit 11L, eye information measurement units 12R and 12L, and a communication unit 13.

  The right-eye display unit 11R displays an image that the user visually recognizes with the right eye. The left-eye display unit 11L displays an image that is visually recognized by the user with the left eye. The display unit 11R for the right eye and the display unit 11L for the left eye have, for example, a transparent screen and a light source that emits light constituting the display image to the screen, and a virtual image is displayed to the user based on the reflected light of the screen. Make it visible. In addition, the right-eye display unit 11R and the left-eye display unit 11L are configured to be able to adjust the distance from the eye to the visually recognized virtual image (also referred to as “virtual image distance Lv”). Moreover, the display part 11R for right eyes and the display part 11L for left eyes are comprised so that position adjustment is possible according to a user's eye width and virtual image distance Lv. Further, the right-eye display unit 11R and the left-eye display unit 11L correspond to stereoscopic image display.

  The eye information measurement unit 12R performs measurement of each visual function of the user's right eye (also referred to as “visual inspection”). The eye information measurement unit 12L performs a visual inspection of the user's left eye. Further, the eye information measuring units 12R and 12L have an imaging unit, and acquire iris information of the user's eyes. The communication unit 13 performs communication with the HM unit 3.

  Here, the visual inspection performed by the eye information measurement units 12R and 12L will be specifically described.

  The visual examination includes, for example, a visual acuity examination, an eye position examination, an objective refraction examination, and the like. Visual acuity tests are performed on the left eye, right eye, and both eyes. The visual acuity test includes a static visual acuity test and a moving visual acuity test. In the static visual acuity test, the eye information measuring units 12R and 12L perform measurement using a commonly used Landolt ring, Snellen target using alphabet, E chart, and other hiragana or katakana. The dynamic visual acuity test includes a dynamic visual acuity (DVA) visual acuity test that identifies lateral movement, and a dynamic visual acuity (KVA) visual acuity test that identifies longitudinal movement. The eye position inspection is an inspection to detect the presence or absence of strabismus or oblique position (potential strabismus) and its degree (ie, misalignment), and is performed on the left, right, and both eyes. Test, Hirschberg test, etc. are used. Similar to the autorefractometer, the objective refraction test is a test that measures the presence and degree of amblyopia, hyperopia, and astigmatism by measuring the objective refractive power and the corneal curvature radius. In the visual inspection, the eye information measurement units 12R and 12L cause the right-eye display unit 11R and the left-eye display unit 11L to display an inspection image or the like as necessary. Further, the eye information measuring units 12R and 12L appropriately request the user to input to the operation unit 6 in the visual acuity test or the like, and recognize the inspection result based on the operation information transmitted from the operation unit 6.

  When calculating the inspection result of the visual inspection described above, the eye information measurement units 12R and 12L may cause the server storing the visual inspection program to calculate the inspection result. In this case, the eye information measurement units 12R and 12L transmit the measurement result necessary for calculating the test result to the above-described server via the communication unit 13, and receive the test result calculated by the server.

  Next, a specific example of visual inspection performed by the eye information measurement units 12R and 12L will be described with reference to FIG. Here, an example of eye position examination will be described as an example. First, the case of monocular measurement for the left eye having an oblique position will be described.

  FIG. 3A shows the positional relationship between the eyeball 8L and the pupil 9L when an object such as an inspection mark is displayed at the front position with respect to the left eye by the left eye display unit 11L and visually recognized by the left eye. Indicates. In this case, as shown in FIG.

  FIG. 3B shows the positional relationship between the eyeball 8L and the pupil 9L when the left eye field of view is blocked from a state in which the object is viewed only with the left eye. In FIG. 3B, the position of the pupil 9L at the time of FIG.

  As shown in FIG. 3B, in this case, the pupil 9L is displaced by the width indicated by the arrow AR in the negative X-axis direction. Therefore, in this case, the eye information measurement unit 12L recognizes that the eye position shift has occurred by the width indicated by the arrow AR based on the image obtained by photographing the left eye. As described above, the eye information measurement units 12R and 12L perform monocular measurement on each eye.

  Further, in addition to monocular measurement, the eye information measurement units 12R and 12L perform binocular measurement that measures a shift in eye position that occurs in one or both eyes when the object is visually recognized by both eyes. In the case of binocular measurement, the eye information measuring units 12R and 12L store in advance information indicating a normal eye position with respect to the display position of the object to be watched, and each eye when the object is being stared is stored. By comparing with the eye position, the presence / absence and degree of eye position shift of each eye is detected.

  Here, preferably, in the monocular measurement and the binocular measurement, the eye information measurement units 12R and 12L change the display position of the object to be visually observed and measure the eye position deviation a plurality of times. For example, the eye information measurement units 12R and 12L display the target object in order at each of the four corners of the displayable range of the left-eye display unit 11L and the right-eye display unit 11R, and measure the eye position deviation. And memorize it as a test result. In another example, the eye information measurement units 12R and 12L divide the displayable range in the XY plane of the left-eye display unit 11L and the right-eye display unit 11R into a plurality of blocks, and display an object for each block. Then, the eye position deviation is measured and stored as a test result. In these examples, preferably, the eye information measuring units 12R and 12L may change the distance in the Z-axis direction of the object to be displayed with respect to the eyes, and measure the eye position deviation for each distance. That is, in this case, the eye information measurement units 12R and 12L measure the eye position deviation for each virtual image distance Lv. As described above, the eye information measurement units 12R and 12L preferably change the display position of the object to be displayed in the X, Y, and Z axis directions and measure the eye position shift at each display position.

  In the binocular measurement, when the eye information measurement units 12R and 12L detect eye misalignment at the display positions of all objects, it is highly likely that the eye in which the eye misalignment has occurred is a homeostatic perspective. If the presence / absence of eye misalignment changes depending on the display position of the object, it is determined that there is a high possibility that the eye where the eye misalignment has occurred is an intermittent strabismus. When the HM unit 3 to be described later has such a perspective tendency, in order to prevent the burden from concentrating on the right eye (effect), the position of the virtual image is reduced so as to reduce the burden of the effect. Make adjustments.

[Configuration of HM unit]
FIG. 4 shows a schematic configuration of the HM unit 3. As shown in FIG. 4, the HM unit 3 mainly includes a communication unit 31, a control unit 32, and a storage unit 33.

  The communication unit 31 communicates with the external playback device 5 and the HMD 1 to transmit / receive images, audio data, and other information. In addition, the communication unit 31 receives operation information from the operation unit 6.

  The control unit 32 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), and controls the entire HM unit 3 by executing a control program stored in the ROM or the like. To do. For example, the control unit 32 adjusts the image quality of an image transmitted to the HMD 1 based on the visual information of the user wearing the HMD 1 or controls the HMD 1 so as to adjust the position of a virtual image to be visually recognized by the user. To do. The control unit 32 functions as a “visual information acquisition unit” and a “user identification information acquisition unit” in the present invention together with the eye information measurement units 12R and 12L. The control unit 32 functions as a “display control unit” in the present invention.

  The storage unit 33 stores visual inspection information (also referred to as “user information”) for each user transmitted from the eye information measurement units 12R and 12L. In addition, the storage unit 33 stores a map of adjustment values relating to image quality suitable for each combination of visual information and a map of adjustment values of virtual image positions suitable for each combination of visual information. Each adjustment value stored in the above-described map is determined in advance so as to be an experimentally or theoretically suitable value for the associated visual information.

  FIG. 5A shows the data structure of user information stored in the storage unit 33. As shown in FIG. 5 (A), the user information has items of user identification information, visual information, and other use time recording areas for each user (here, users A and B). The user identification information is information for discriminating the user wearing the HMD1, and may be, for example, the glow information measured by the eye information measurement units 12R and 12L, and each user operates when using the HMD1. The user ID or the like input to the unit 6 or the like may be used. The visual information is information indicating the inspection result of the visual inspection performed by the eye information measuring units 12R and 12L. The other use storage area stores the viewing time of the viewed content, information on the eye position during viewing, and the like.

  FIG. 5B is a diagram showing in detail the items included in the visual information. As shown in FIG. 5B, the storage unit 33 stores, as visual information, glow information, static visual acuity of each of the left and right eyes, and a DVA value and a KVA value indicating moving visual acuity. Further, the storage unit 33 stores, as visual information, information on the positions of the left and right eyes, and the presence and extent of objective refractive errors such as amblyopia, hyperopia, and astigmatism for each of the left and right eyes. To do.

[Control at startup]
Next, processing executed when the user wears the HMD 1 and activates the HMD 1 will be described with reference to FIG. FIG. 6 is an example of a flowchart showing a processing procedure when the HMD 1 is activated. Schematically, the control unit 32 of the HM unit 3 performs a visual inspection to perform registration processing of the user based on the user identification information acquired from the user when the user is not registered. If the user is registered, the corresponding user information is read from the storage unit 33.

  First, the control unit 32 acquires user identification information of a user wearing the HMD 1 (step S101). For example, the control unit 32 causes the eye information measurement units 12R and 12L to measure the iris of the user's eye, and acquires the glow information indicating the measurement result from the eye information measurement units 12R and 12L as user identification information.

  Next, the control unit 32 determines whether or not the acquired user identification information has been registered (step S102). That is, the control unit 32 determines whether or not user information including the user identification information is stored in the storage unit 33. When the user identification information has been registered (step S102; Yes), the control unit 32 acquires user information including visual information and the like from the storage unit 33 (step S106). Thereafter, the control unit 32 adjusts the image quality of the image displayed by the right-eye display unit 11R and the left-eye display unit 11L, the display position of the virtual image, and the like based on the visual information.

  On the other hand, when the acquired user identification information has not been registered (step S102; No), the control unit 32 notifies the user through the headphones 2 that a new registration procedure is to be performed (step S103). Then, the control unit 32 causes the eye information measurement units 12R and 12L to perform a visual inspection of the user (step S104). In this case, the eye information measurement units 12R and 12L perform the visual inspection described in the section [Configuration of HMD], and transmit the inspection result of the visual inspection to the control unit 32.

  Next, the control unit 32 associates the inspection result of the visual inspection with the user identification information and stores it in the storage unit 33 as user information (step S105). Thereafter, the control unit 32 adjusts the image quality of the image displayed by the display unit 11R for the right eye and the display unit 11L for the left eye, the display position of the virtual image, and the like based on the visual information acquired by the visual inspection.

[Position adjustment of virtual image]
Next, a method for adjusting the display position of the virtual image when the user views content with the HMD 1 will be described. Schematically, the control unit 32 moves the display position of the virtual image in the Z-axis direction based on visual acuity and refractive error information included in the visual information, and also displays the virtual image display position based on the eye position information and the like. Is moved on the XY plane. This will be described with reference to FIGS.

  FIG. 7 shows a schematic diagram of position adjustment of the virtual image when the eye position is the right eye position. In FIG. 7, the lines of sight 40A and 40B before and after shifting the virtual image “Iv” in the Z-axis direction and the focal position “Pf” of each line of sight are shown. In FIG. 7 and FIG. 8 described later, for convenience, the width of the virtual image Iv in the X-axis direction is drawn smaller than the actual width.

  The control unit 32 changes the position of the virtual image Iv in the Z-axis direction based on information on visual acuity obtained by visual inspection and information on objective refractive errors such as amblyopia and hyperopia. For example, when the control unit 32 determines that the eyesight tends to be weak or amblyopic, the position of the virtual image Iv is on the Z axis negative direction side as compared with the case where the eyesight tends to be strong or hyperopic. Set. In addition, when the control unit 32 detects an operation on the operation unit 6 for enlarging the virtual image Iv, the control unit 32 sets the position of the virtual image Iv on the Z axis negative direction side.

  On the other hand, when the eye position is the right eye position, as shown in FIG. 7, the focus position Pf of the line of sight and the center position of the virtual image Iv exist on the auxiliary line 42 that passes through the middle of the left and right eyes and is parallel to the Z axis. As described above, when both eyes are in the normal eye position, the control unit 32 sets the center position of the virtual image Iv to a position that overlaps the auxiliary line 42 and suppresses the burden on one eye.

  FIG. 8 shows a schematic diagram of virtual image position adjustment when one eye has an oblique position. In FIG. 8, the lines of sight 40C and 40D before and after shifting the position of the virtual image Iv in the Z-axis direction and its focal position Pf are shown.

  As shown in FIG. 8, in this case, the control unit 32 causes the virtual image Iv to be on the X axis more than the position shown in FIG. 7 so that the focal position Pf is the most natural position (that is, less burden on both eyes). The screen is shifted to the positive direction. As a result, the focal position Pf is shifted to the X axis positive direction side from the focal position Pf shown in FIG. Thereby, when a user visually recognizes virtual image Iv, it can control that load is biased to one eye.

  Here, a specific method for correcting the display position of the virtual image Iv based on the eye position deviation will be described. The control unit 32 refers to a predetermined map based on the virtual image distance Lv of the virtual image Iv to be displayed and the information on the eye position deviation in the case of the virtual image distance Lv, and corrects the position of the virtual image Iv on the XY plane. Determine the amount. The above-described map is, for example, a map that defines the eye position deviation and an appropriate correction amount for the eye position deviation for each virtual image distance Lv, and is stored in advance in the storage unit 33 or the like. The correction amount recorded in the map is set to an appropriate correction value for each eye position shift based on, for example, experiments.

  In general, the eye position is affected by refractive errors such as amblyopia, hyperopia, and astigmatism. Therefore, as described above, the control unit 32 can determine the correction amount of the position of the virtual image Iv more accurately by determining the correction amount of the position of the virtual image Iv based on the virtual image distance Lv in addition to the eye position shift. it can.

  As described above, the control unit 32 can appropriately suppress the fatigue of the user's eyes and the like by adjusting the position of the virtual image Iv in consideration of the characteristics of the user's eye position. Also, in general, when displaying a stereoscopic image, the image viewed with the left eye is different from the image viewed with the right eye, so that the image is viewed without considering the characteristics of the user's eye position. In particular, the burden on the user's eyes is particularly large. Therefore, according to the present embodiment, the control unit 32 can suitably reduce the load on the user's eyes even when displaying a stereoscopic image.

[Image quality adjustment]
Next, an image quality adjustment method when a user views content with the HMD 1 will be described. Schematically, the control unit 32 sets an area centered on the focal position Pf (also referred to as “effective area Rtag”) based on the information on the moving body visual acuity obtained by visual inspection, and outside the effective area Rtag. Reduce the brightness or / and contrast of At this time, the control part 32 sets the effective area | region Rtag to the area | region estimated that a user can visually recognize a moving body suitably in the case of a moving image content. Thereby, the video in the effective area Rtag is suitably viewed while suitably reducing the burden on the user's eyes.

  FIG. 9A shows the position of the effective area Rtag relative to the image displayable range “Rmax”. In FIG. 9A, the user is facing the front, and the focus position Pf of the line of sight coincides with the center of the displayable range Rmax.

  As shown in FIG. 9A, the control unit 32 sets a rectangular effective area Rtag at a position where the center of the effective area Rtag overlaps the focal position Pf. The control unit 32 also includes the width of the effective area Rtag in the X-axis direction (also simply referred to as “horizontal width”) and the width in the Y-axis direction (also simply referred to as “vertical width”) included in the user information. It sets based on the DVA value and KVA value which show visual acuity. Here, based on the DVA value and the KVA value, the control unit 32 determines the above-described vertical width and horizontal width so that the effective area Rtag matches the area where it is estimated that the user can preferably see the moving object. To do. Specifically, the control unit 32 refers to a map or expression indicating the appropriate width and height of the effective area Rtag for each DVA value and KVA value, and determines the width of the effective area Rtag in the X-axis direction and the Y-axis direction. decide. The above-described map or the like is created based on an experiment or the like and stored in the storage unit 33 in advance.

  Then, the control unit 32 reduces the luminance or / and the contrast of each pixel corresponding to the displayable range Rmax area (see the shaded area) outside the effective area Rtag. As described above, the control unit 32 can appropriately reduce eye fatigue during viewing by making the area other than the effective area Rtag corresponding to the range in which the user can visually recognize the moving object inconspicuous.

  In addition, when the focus position Pf of the line of sight moves, the control unit 32 changes the effective region Rtag according to the focus position Pf. FIG. 9B shows the position of the effective area Rtag within the displayable range Rmax when the user shifts his / her line of sight in the positive X-axis direction.

  As shown in FIG. 9B, in this case, the focus position Pf is also shifted in the X-axis positive direction because the user has shifted the line of sight in the X-axis positive direction. In this case, first, the control unit 32 recognizes the focal position Pf by causing the eye information measurement units 12R and 12L to detect the line-of-sight direction and the eye width of each eye, for example. Then, the control unit 32 shifts the effective region Rtag in the right direction so that the center position of the effective region Rtag overlaps the recognized focal position Pf. By doing in this way, even if it is a case where a user's eyes | visual_axis moved, the effective area | region Rtag can be defined exactly.

  Preferably, the control unit 32 may reduce the effective area Rtag in accordance with the content viewing time. In general, as the viewing time of the content becomes longer, fatigue of the user's eyes accumulates and the dynamic visual acuity relatively decreases. Therefore, the control unit 32 can set the effective region Rtag appropriately corresponding to the decrease in the moving visual acuity by reducing the effective region Rtag according to the viewing time of the content. In this case, for example, the control unit 32 makes the effective area Rtag smaller by referring to a map or the like of a coefficient by which the vertical width and the horizontal width of the effective area Rtag are multiplied for each viewing time of the content.

[Processing when viewing content]
The control unit 32 calculates the distance from the eye to the focal position Pf (that is, the virtual image distance Lv) at predetermined intervals during the reproduction of the content, and when the virtual image distance Lv is equal to or greater than a predetermined threshold, the effective region Reduce Rtag. This will be specifically described with reference to the flowcharts of FIGS.

  FIG. 10 is a flowchart showing a procedure for adjusting the focal position Pf and the effective area Rtag when viewing content. The control unit 32 repeatedly executes the processing of the flowchart shown in FIG. 10 according to a predetermined cycle when viewing the content.

  First, the control unit 32 acquires eye position information and line-of-sight information related to the line-of-sight direction from the eye information measurement units 12R and 12L (step S201). Next, the control unit 32 executes a focus position adjustment process shown in FIG. 11 described later (step S202). And the control part 32 performs the effective area | region adjustment process shown in FIG. 12 mentioned later (step S203). Then, the control unit 32 performs image quality adjustment based on the effective area Rtag adjusted in step S203 (step S204). Specifically, as described in the section [Image quality adjustment], the control unit 32 reduces the luminance or / and the contrast other than the effective area Rtag.

  FIG. 11 is a flowchart showing the procedure of the focus position adjustment process executed in step S202 of FIG.

  First, the control unit 32 determines whether or not the deviation of the eye position acquired in step S201 with respect to the eye position detected during the visual inspection is within an allowable range (step S301). Specifically, the control unit 32 determines whether or not the magnitude of the above-described eye position shift is smaller than a predetermined value. The predetermined value described above is set based on an experiment or the like in the magnitude of the eye position deviation that does not affect the user viewing the image. And when the above-mentioned eye position shift is in an allowable range (Step S301; Yes), control part 32 ends processing of a flow chart.

  On the other hand, when the above-described eye misalignment exceeds the allowable range (step S301; No), the control unit 32 calculates an adjustment value indicating the distance and direction to move the focal position Pf from the eye misalignment. The position of the virtual image is moved based on the adjustment value (step S302). For example, the control unit 32 refers to the map for correcting the display position of the virtual image described in the section [Adjustment of the position of the virtual image], and calculates the adjustment value described above based on the eye position shift. And the control part 32 memorize | stores the above-mentioned adjustment value in the memory | storage part 33 with the elapsed time from content viewing start (step S303). In this case, the storage unit 33 preferably records these pieces of information in the “other use recording area” of the user information shown in FIG.

  FIG. 12 is a flowchart showing the procedure of the effective area adjustment process executed in step S203 of FIG.

  First, the control unit 32 recognizes the focal position Pf (that is, the position of the virtual image) based on the line-of-sight information acquired in step S201, and calculates the virtual image distance Lv. And the control part 32 determines whether the virtual image distance Lv is below a predetermined threshold value (step S401). The above threshold is a threshold for determining whether or not the effective region Rtag needs to be adjusted, and is determined based on, for example, experiments. If the virtual image distance Lv is equal to or smaller than the threshold (step S401; Yes), the control unit 32 determines that there is no need to adjust the effective area Rtag and ends the process of the flowchart.

  When the virtual image distance Lv exceeds the threshold (step S401; No), the control unit 32 calculates an adjustment value by which the vertical width and the horizontal width of the effective area Rtag are multiplied according to the virtual image distance Lv, and is effective based on the adjustment value. The region Rtag is adjusted (step S402). At this time, the control unit 32 determines the adjustment value so that the effective area Rtag is reduced as the virtual image distance Lv is longer. In general, when the virtual image distance Lv is long, the range in which the user is gazing is relatively small. Therefore, the control part 32 can adjust the effective area | region Rtag appropriately by this process. And the control part 32 memorize | stores the above-mentioned adjustment value in the memory | storage part 33 with the elapsed time from content viewing start (step S403). In this case, the storage unit 33 preferably records these pieces of information in the “other use recording area” of the user information shown in FIG.

  Preferably, when the virtual image distance Lv becomes smaller than the threshold value again from the state where the virtual image distance Lv is larger than the threshold value, the control unit 32 determines the size of the effective area Rtag reduced based on the adjustment value in step S402. It is good to return to the size before applying the value.

  As described above, in the HMD system according to the present embodiment, the control unit 32 of the HM unit 3 acquires the visual information of the user by the eye information measurement units 12R and 12L. Moreover, the control part 32 displays an image on the display part 11R for left eyes and the display part 11L for left eyes so that a virtual image is produced | generated in the focus position of a user's eyes | visual_axis. At this time, the control part 32 adjusts an image based on the acquired visual information, and displays it on the display part 11R for right eyes or the display part 11L for left eyes. Thereby, the HMD system can appropriately display an image in consideration of the visual characteristics of the observer.

[Modification]
In the description of FIG. 9 in the section [Image quality adjustment], the control unit 32 adjusts the brightness or / and contrast by dividing the displayable range Rmax into the effective area Rtag and the other areas. Instead of this, the control unit 32 may divide the displayable range Rmax into three or more regions. Even in this case, the control unit 32 makes the brightness or / and the contrast smaller in the region farther from the focal position Pf so as to be inconspicuous. Thereby, the control part 32 can make the part which a user does not pay attention inconspicuous, and can reduce the burden of eyes.

  In FIG. 9, the effective area Rtag is rectangular, but is not limited thereto, and may be any shape such as an ellipse. For example, when the effective area Rtag is an ellipse, the control unit 32 determines adjustment values to be multiplied by the major axis and the minor axis of the effective area Rtag instead of determining the adjustment values to be multiplied by the vertical width and the horizontal width of the effective area Rtag. By determining, the size of the effective area Rtag is adjusted.

  The present invention can be suitably applied to a head-mounted display and other display systems for observing each individual.

1 HMD
2 Headphones 3 HM unit 4 Head fixing device 5 External player 6 Operation unit

Claims (12)

A visual information acquisition unit that acquires information about the user's vision;
A display control unit that displays an image on a display unit so that a virtual image is generated at a focal position of the user's line of sight;
With
The display control unit adjusts the image based on an acquisition result of the visual information acquisition unit and displays the image on the display unit.   The image display apparatus according to claim 1, further comprising the display unit that is mounted on the head of the user and displays an image at a position where the user can visually recognize the image. The visual information acquisition unit acquires eye position information of the user,
The image display device according to claim 1, wherein the display control unit displays the image on the display unit so that a position of the virtual image is adjusted based on the eye position information. . The display unit includes a right-eye display unit and a left-eye display unit,
The image display according to any one of claims 1 to 3, wherein the display control unit displays an image on each of the right-eye display unit and the left-eye display unit. apparatus. The visual information acquisition unit acquires the moving body vision information of the user,
5. The image display device according to claim 1, wherein the display control unit adjusts luminance or / and contrast of the image based on the moving object visual acuity information. 6.   The said display control part divides | segments the said image into several area | region based on the said moving body visual acuity information, and adjusts so that a brightness | luminance or / and contrast may differ for every said area | region. The image display device described.   The image display apparatus according to claim 6, wherein the display control unit adjusts the luminance or / and contrast so that the region farther from the focal position of the user's line of sight becomes less conspicuous. A user identification information acquisition unit for acquiring identification information for identifying a user;
8. The storage unit according to claim 1, further comprising a storage unit that stores information relating to the user's vision acquired by the visual information acquisition unit in association with the identification information. Image display device.   The image display apparatus according to claim 8, wherein the identification information is glow information of a user's eyes. A control method executed by an image display device,
A visual information acquisition process for acquiring information about the user's vision;
A display control step of displaying an image on a display unit so that a virtual image is generated at a focal position of the user's line of sight,
In the display control step, the image is adjusted based on the acquisition result in the visual information acquisition step and displayed on the display unit. A program executed by the image display device,
A visual information acquisition unit that acquires information about the user's vision;
The image display device functions as a display control unit that displays an image on a display unit so that a virtual image is generated at a focal position of the user's line of sight,
The display control unit adjusts the image based on an acquisition result of the visual information acquisition unit, and displays the image on the display unit.   A storage medium storing the program according to claim 11.

Images