Video display apparatus and adjustment method thereof

Abstract

To provide a video display device capable of displaying a clear video by adjusting visibility without making a user sense the focus change and the field angle change of the video caused by the driving of an optical element.SOLUTION: The image display apparatus includes image display units 102a and 102b, optical elements 103a and 103b, and movement driving unit 12 that changes relative positions of image display units 102a and 102b and optical elements 103a and 103b. Movement driver 12 includes prediction value acquirer 113 that acquires a prediction value related to a relative positional change between video displays 102a and 102b and optical elements 103a and 103b, allowable value acquirer 114 that acquires an allowable value related to the positional change, and control mode selector 116 that selects any one of a plurality of control modes for controlling the movement driver based on a comparison result between the prediction value and the allowable value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a video display device and an adjustment method thereof. [Background technology]

[0002] Image display devices include those worn on the user's head and those worn like glasses. In image display devices, a display unit is placed near the user's eyes, and parallax images are displayed for each of the user's left and right eyes. The parallax images contain depth information indicating whether the user is looking at something far away or close up, and by viewing the displayed parallax images, the user can obtain a three-dimensional image of the object displayed in the parallax images.

[0003] In this image display device, the user's line of sight is adjusted to the position of the stereoscopic image generated by the images displayed for each eye. At this time, the focal position is fixed to each of the left and right images on the display screen. This results in an unnatural state that would not occur when viewing a real object. For this reason, technologies such as those described in Patent Document 1 have been developed. In Patent Document 1, the diopter adjustment for depth information corresponding to the position of the user's point of gaze when viewing an image is performed by driving optical elements included in the display optical system in accordance with individual differences and the usage status of the image display device. This makes it possible to reduce the sense of discomfort felt during stereoscopic viewing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-32278 Summary of the Invention [Problem to be solved by the invention]

[0005] When adjusting the diopter for depth information according to the position of the user's gaze point while viewing an image, the optical element is moved by a drive distance according to the amount of depth change, but it is desirable for the user to not notice the drive of the optical element as much as possible. To achieve this, it is necessary to complete the drive of the optical element within the response delay time of the human eye (the delay time until the human eye starts to respond, during which time it becomes unable to respond).

[0006] However, if the driving distance of the optical element is long and the driving time exceeds the user's response delay time, the user will sense changes in focus and angle of view due to the driving of the optical element. This will cause discomfort to the user as they sense the driving of the optical element. This problem will also occur when using a device configuration such as that described in Patent Document 1.

[0007] The present disclosure aims to provide an image display device and an adjustment method thereof that can adjust the diopter and display clear images without the user being aware of changes in focus or angle of view of the image due to relative movement between the image display unit and the optical element. [Means for solving the problem]

[0008] The image display device of the present disclosure includes an image display unit, an optical element, and a movement drive unit that changes the relative position between the image display unit and the optical element. The movement drive unit has a predicted value acquisition unit, a tolerance acquisition unit, and a control mode selection unit. The predicted value acquisition unit acquires a predicted value regarding a change in the relative position. The tolerance acquisition unit acquires a tolerance regarding the change in the relative position. The control mode selection unit selects one of a plurality of control modes for controlling the movement drive unit based on a comparison result between the predicted value and the tolerance.

[0009] The method for adjusting an image display device according to the present disclosure includes a first step, a second step, and a third step for changing the relative position between an image display unit and an optical element. The first step acquires a predicted value for a change in the relative position. The second step acquires an allowable value for the change in the relative position. The third step selects one of a plurality of control modes for controlling movement driving of the relative position based on a comparison result between the predicted value and the allowable value. [Effects of the Invention]

[0010] According to the present disclosure, an image display device is realized that can adjust the visibility and display clear images without the user being aware of changes in the focus or angle of view of the image due to relative movement between the image display unit and the optical element. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram showing a schematic configuration of a video display device according to a first embodiment. [Figure 2] 10A and 10B are schematic diagrams for explaining a state when an optical element is moved by a diopter change drive unit. [Figure 3] FIG. 1 is a schematic diagram of a user and a spherical object viewed from above. [Figure 4] FIG. 1 is a schematic diagram of a user and a spherical object viewed from above. [Figure 5] FIG. 4 is a characteristic diagram showing the relationship between a response delay time and a drive time. [Figure 6] FIG. 10 is a characteristic diagram showing the transition of the drive speed when driving an optical element. [Figure 7] FIG. 10 is a characteristic diagram showing the transition of the drive speed when driving an optical element. [Figure 8] 10 is a characteristic diagram for explaining a situation in which the first control mode or the second control mode is selected by comparing the allowable drive time with the predicted drive time. FIG. [Figure 9] 5 is a flowchart showing a method for adjusting visibility in the image display device according to the first embodiment. [Figure 10]FIG. 10 is a schematic diagram showing a schematic configuration of a video display device according to a second embodiment. [Figure 11] 10 is a flowchart showing a method for adjusting visibility in an image display device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] -Basic configuration of the image display device in various embodiments- Before specifically disclosing the embodiments, the basic configuration of the image display device in each embodiment will be described.

[0013] The device includes an image display unit, an optical element, and a movement drive unit that changes the relative position between the image display unit and the optical element. The movement drive unit has a predicted value acquisition unit, a tolerance acquisition unit, and a control mode selection unit. The predicted value acquisition unit acquires a predicted value regarding changes in the relative position. The tolerance acquisition unit acquires a tolerance regarding changes in the relative position. The control mode selection unit selects one of a plurality of control modes for controlling the movement drive unit based on a comparison result between the predicted value and the tolerance value. By appropriately selecting the control mode based on the comparison result between the predicted value and the tolerance value, it is possible to adjust the focal length to a stereoscopic image caused by parallax and display a clear image without the user being aware of changes in the focus or angle of view of the image due to the relative movement between the image display unit and the optical element.

[0014] Specifically, the predicted value is at least one of a predicted drive distance of the relative position change and a predicted drive time required for the relative position change, and the allowable value is at least one of an allowable drive distance of the relative position change and a allowable drive time required for the relative position change.

[0015] The image display device of the present disclosure further includes a gaze detection unit that detects changes in the user's gaze direction. The movement drive unit further includes a gaze position acquisition unit that acquires the gaze position from the detection result of the gaze detection unit, a memory unit that stores the gaze position, and a gaze change amount acquisition unit that acquires the gaze change amount from the gaze position acquired by the gaze position acquisition unit and the gaze position stored in the memory unit. With this configuration, the control mode is selected taking into consideration the gaze movement delay time obtained from the gaze change amount. This realizes an image display device that can more reliably adjust the focal length to display clear stereoscopic images due to parallax without the user being able to sense changes in the focus or angle of view of the image due to relative drive between the image display unit and the optical element.

[0016] -Specific Description of Various Embodiments- Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the following embodiments do not limit the invention according to the claims. Although multiple features are described in the various embodiments, not all of these multiple features are necessarily essential, and multiple features may be combined arbitrarily. Furthermore, in the drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0017] [First embodiment] A first embodiment of the present disclosure will be described below.

[0018] (Configuration of video display device) FIG. 1 is a schematic diagram showing a schematic configuration of a video display device according to a first embodiment. This image display device comprises image display means 11 for displaying an image, movement driving means 12, and control means 13. Control means 13 controls image display means 11 and movement driving means 12 in an integrated manner.

[0019] Image display devices come in two types: one worn on the user's head, and one worn like glasses. In either type, the image display device can be fixed near the user's left eye 201a and right eye 201b. The user's left eye is designated 201a and right eye 201b, and the symbols a and b are added to the reference numerals of components related to the left eye 201a and right eye 201b, respectively, to distinguish between them.

[0020] The image display means 11 includes an image acquisition section 100, a display processing section 101, a pair of image display sections 102a and 102b, and a pair of optical elements 103a and 103b. The image acquisition unit 100 acquires image data for display via an external device, a network, or the like. The display processing unit 101 performs processing such as adjusting the display magnification of the image data acquired by the image acquisition unit 100. The display units 102a and 102b receive the image data processed by the display processing unit 101 and display the image. For example, the image data may be divided into separate image data for the image display units 102a and 102b and displayed. This configuration is not limited to this, and a configuration in which the screen of one image display unit is divided into two and image data is displayed on the divided screens may also be used. This image processing tailored to the right and left eyes allows the user to view the image without any discomfort. The optical elements 103a and 103b have lenses corresponding to the left eye 201a and the right eye 201b, respectively. The images displayed on the image display units 102a and 102b are displayed on the left eye 201a and the right eye 201b through the optical elements 103a and 103b.

[0021] The movement driving means 12 is a movement driving unit that changes the relative positions of the image display units 102a, 102b and the optical elements 103a, 103b, and in this embodiment, moves the optical elements 103a, 103b relative to the image display units 102a, 102b. The movement driving means 12 has diopter change driving units 104a, 104b, a depth acquisition unit 110, a depth storage unit 111, a driving distance acquisition unit 112, a predicted value acquisition unit 113, a tolerance acquisition unit 114, a user information recording unit 115, a control mode selection unit 116, and a drive instruction unit 117.

[0022] In the above-mentioned image display means 11 and movement drive means 12, the image acquisition unit 100, display processing unit 101, depth acquisition unit 110, drive distance acquisition unit 112, predicted value acquisition unit 113, tolerance value acquisition unit 114, control mode selection unit 116, and drive instruction unit 117 are obtained as follows: That is, these components are realized by one or more processors such as a central processing unit (CPU) reading and executing a program.

[0023] Diopter change drivers 104a and 104b have vibration actuators with drive sources such as ultrasonic motors, and are connected to optical elements 103a and 103b, respectively, to move optical elements 103a and 103b. Optical elements 103a and 103b are moved within sections (illustrated by arrows 104a1 and 104b1) along their optical axes by diopter change drivers 104a and 104b. Diopter change drivers 104a and 104b each have a position detection sensor, which acquires position information of optical elements 103a and 103b within that section.

[0024] 2A and 2B are schematic diagrams for explaining the state when the optical elements 103a and 103b are moved by the diopter change driving units 104a and 104b, respectively. (a) shows the state when the optical elements 103a and 103b are moved to the vicinity of the image display units 102a and 102b, respectively, and (b) shows the state when the optical elements 103a and 103b are moved to the vicinity of the eyes 201a and 201b, respectively.

[0025] When a user of the image display device, who is an observer, views the image display units 102a and 102b with their eyes 201a and 201b through the optical elements 103a and 103b, the observer sees virtual images 105a and 105b. The positions of the virtual images 105a and 105b in the directions of the optical axes 103a1 and 103b1, based on the positions of the user's eyes 201a and 201b, are defined as the virtual image formation position i.

[0026] As shown in FIGS. 2(a) and 2(b), the virtual image formation position i can be changed by changing the positions of the optical elements 103a and 103b. For example, as the optical elements 103a and 103b move closer to the image display units 102a and 102b, the virtual image formation position i moves closer to the eyes 201a and 201b. Conversely, as the optical elements 103a and 103b move closer to the eyes 201a and 201b, the virtual image formation position i moves farther away from the eyes 201a and 201b. Therefore, by moving the lenses 103a and 103b using the diopter change drive units 104a and 104b, the diopter can be adjusted, i.e., the image of a distant object or a nearby object can be viewed without blurring, according to the visual acuity of the user's eyes 201a and 201b. The displayed image contains depth information indicating whether the point of gaze is near or far. When this depth information matches the viewer's visibility, the image appears clear to the user.

[0027] When a user watches an image, the depth of the gaze point changes in two ways: one accompanied by a change in the user's line of sight, and one not accompanied by a change in the line of sight. A case where the depth at the point of gaze changes without the user's line of sight changing will be explained using Figure 3. Figure 3 is a schematic diagram of a user and a spherical object viewed from above. Figure 3(a) shows the spherical object at the point of gaze moving from a depth of 100 to a depth of 90 while the user's line of sight remains unchanged toward the center. The user's point of gaze remains on the spherical object. The side closer to the user is considered the near side, and the side farther away is considered the back side. Here, the depth values ​​are expressed as relative values ​​rather than absolute values, with the values ​​decreasing as they approach the front.

[0028] The arrow extending from the user to the spherical object indicates the user's line of sight. While the user continues to gaze at a spherical object located in the center in front of them, the spherical object moves toward them. At this time, the line of sight does not change, but the depth of the gaze point does. If the depth of the spherical object before movement is 100 and the depth of the spherical object after movement is 90, the depth change is 10. The optical element is driven by a drive distance corresponding to the depth change. Normally, the drive speed of the optical element is set to the maximum possible drive speed. This is because if the drive speed is slow, there will be times when the displayed parallax image is out of focus. If the depth change is small, the drive time required to drive the optical element will also be shorter.

[0029] Figure 3(b) shows a case where the depth change is large. It shows a spherical object moving from a depth of 100 to a depth of 20. This can occur when the spherical object moves quickly, or when switching scenes in the video, causing the spherical object to suddenly appear in front of the user's eyes, or when another spherical object suddenly appears in front of the user's eyes. In such cases, only the depth of the gaze point changes without changing the user's gaze direction. In the case of Figure 3(b), the depth change is 80, and the driving distance is longer than in the case shown in Figure 3(a). If the optical element is driven at the same speed as in Figure 3(a), the driving time will also be longer due to the increased driving distance. As described above, there are cases where the depth at the gaze point changes without changing the user's gaze direction.

[0030] Next, we will use Figure 4 to explain how depth changes as the user's gaze direction changes. Figure 4 is a schematic diagram of a user and a spherical object viewed from above. Figure 4(a) shows how the user's gaze point shifts from a spherical object located at a depth of 100 to a spherical object located at a depth of 90. There are two cases: the spherical object moves from a depth of 100 to a depth of 90, and the gaze direction changes from an object located at a depth of 100 to another object located at a depth of 90. In these cases, the depth changes as the gaze direction changes. In Figure 4(a), the depth change is 10. Figure 4(b) shows how the user's gaze point shifts from a spherical object located at a depth of 100 to a spherical object located at a depth of 20. The depth change in Figure 4(b) is 80, and the driving distance is longer than in Figure 4(a). In Figure 4(b), driving the lens at the same speed as in Figure 4(a) also requires a longer driving time. As described above, the depth may change as the user's line of sight changes.

[0031] Figure 5 is a characteristic diagram showing the relationship between response delay time and drive time. Figure 5(a) shows the relationship between a person's response delay time and the lens drive time when the amount of depth change is small. The horizontal axis represents time, and the vertical axis represents depth. After a depth change occurs, the drive distance optical element is driven according to the amount of depth change. After a depth change occurs, a response delay occurs in the human eye when looking at the gaze point. If the drive of the optical element is completed within this response delay time, the user will not notice any change in focus or angle of view of the image due to the drive of the optical element.

[0032] Figure 5(b) shows the relationship between the user's response delay time and lens drive time when the depth change amount is large. After the depth change occurs, the lens is driven a distance corresponding to the depth change amount. After the depth change occurs, a response delay occurs in the user's eyes when looking at the gaze point. When the depth change amount is large, that is, when the optical element drive distance is large, the drive time also becomes long and the optical element drive cannot be completed within the response delay time. Because the optical element drive continues even during times when the user can respond, the user will perceive changes in focus and angle of view. Even if the optical element drive adjusts the focal length of the image and makes it appear clear, if the user perceives changes in focus or angle of view, the image will appear unnatural and uncomfortable.

[0033] The depth acquisition unit 110 acquires depth from the image acquired by the image acquisition unit 100, and the depth storage unit 112 stores the depth acquired by the depth acquisition unit 110. The depth acquisition unit 110 calculates a depth change amount based on the depth stored in the depth storage unit 111 and the depth acquired by the depth acquisition unit 112. The driving distance acquisition unit 112 calculates a driving distance of the diopter change driving units 104a and 104b based on the depth change amount calculated by the depth acquisition unit 110. The positions of the optical elements 103a and 103b corresponding to the depth may be calculated using a predetermined function. Alternatively, instead of performing a calculation, a table showing the relationship between the depth change amount and the driving distance may be stored, and the driving distance may be determined using this table.

[0034] The predicted value acquisition unit 113 calculates a predicted value Dp of the drive amount of the diopter change drive units 104a and 104b using the drive distance L obtained by the drive distance acquisition unit 112. As the predicted value Dp, a predicted drive time Tp predicted under the conditions of the drive distance L and the drive speed V is used. Instead of the predicted drive time Tp, the drive distance L may be used as it is as the predicted drive distance Lp. Below, a case where the predicted drive time Tp is used as the predicted value Dp will be described.

[0035] The method of calculating the predicted drive time Tp will be described with reference to Fig. 6. Fig. 6 is a characteristic diagram showing the transition of the drive speed when driving the optical element. The vertical axis represents the drive speed, and the horizontal axis represents time.

[0036] As shown in FIG. 6, the robot accelerates from the start of driving to a first speed V1 at an acceleration a during an acceleration time Ta. The acceleration time at this time is calculated as Ta=V1 / a. The distance La traveled during the acceleration time Ta is La=1 / 2×Ta×V1 After reaching the first speed V1, constant speed driving continues at the first speed V1 for the period of constant speed driving time T1. After the constant speed driving time T1 has elapsed, the motor decelerates at a deceleration rate (absolute value of negative acceleration) b for deceleration time Tb until it stops. The deceleration time at this time is calculated as Tb=V1 / b. The distance Lb traveled during the deceleration time T1 is Lb=1 / 2×Tb×V1 The constant speed driving time T1 is calculated as follows: T1 = (L - La - Lb) / V1 The error correction time until the drive is stopped is Te. Te may be a constant value or may vary depending on the speed, acceleration, and deceleration. The predicted drive time Tp is given by Tp = Ta + T1 + Tb + Te It can be calculated as follows.

[0037] 6 illustrates an example in which the predicted drive time Tp is calculated based on trapezoidal drive, but it may also be calculated based on another speed transition.Furthermore, the drive time corresponding to the drive speed and drive distance may be measured and stored in advance, and the predicted drive time Tp may be calculated based on the drive time for the stored drive distance.

[0038] The tolerance value acquisition unit 114 calculates a tolerance value Dt based on the depth change amount d obtained by the depth acquisition unit 110 and the user information stored in the user information recording unit 115. The tolerance value Dt is an allowable drive time Tt. Instead of the allowable drive time Tt, a predicted drive distance Lt based on the drive distance L may be used. Below, a case where the allowable drive time Tt is used as the tolerance value Dt will be described.

[0039] The calculation method of the predicted drive time Tp will be explained using Fig. 7. Fig. 7 is a characteristic diagram showing the transition of the drive speed when driving the optical element. The vertical axis represents the drive speed, and the horizontal axis represents time. The allowable drive time Tt is calculated based on the convergence adjustment delay time Tv and the focus adjustment delay time Tf.

[0040] Figure 7(a) shows the convergence accommodation delay time Tv with respect to the depth change amount d. The convergence accommodation delay time Tv is expressed as the sum of the response delay time until the eyes start convergence accommodation and the accommodation time during which the eyes are performing convergence accommodation. The response delay time of convergence accommodation is a value obtained by multiplying a fixed value Tv0 by a personal information coefficient α1, which has a value that varies depending on age. Since the convergence accommodation time of the eyes is proportional to the depth change amount d, it is a value obtained by multiplying the depth change amount d by a personal information coefficient α2, which has a value that varies depending on age. From the above, the convergence accommodation delay time Tv is Tv=α1×Tv0+α2×d It can be expressed as:

[0041] To obtain the convergence adjustment delay time, instead of performing the calculation as described above, a table showing the relationship between the depth change amount and the convergence adjustment delay time may be stored, and the convergence adjustment delay time may be determined using this table.

[0042] Figure 7(b) shows the focus adjustment delay time Tf versus the depth change amount d. The focus adjustment delay time Tf is expressed as the sum of the response delay time until the eyeball (crystalline lens) starts focus adjustment and the accommodation time during focus adjustment. The focus adjustment delay time Tf is calculated by multiplying Tf0, which is a fixed value, by a personal information coefficient β1, which has a value that varies depending on age. Since the focus adjustment time of the eyeball is proportional to the depth change amount d, the focus adjustment delay time Tf is calculated by multiplying the depth change amount d by a personal information coefficient β2, which has a value that varies depending on age. From the above, the focus adjustment delay time Tf is calculated as follows: Tf=β1×Tf0+β2×d It can be expressed as:

[0043] To obtain the focus adjustment delay time, instead of performing the calculation as described above, a table showing the relationship between the depth change amount and the focus adjustment delay time may be stored, and the focus adjustment delay time may be determined using this table.

[0044] The allowable drive time Tt is the time period during which the human eye cannot respond due to convergence adjustment and focus adjustment, and within this time, the user cannot perceive changes in focus or angle of view in the image caused by the drive of the optical elements. Convergence adjustment and focus adjustment are performed simultaneously in parallel, and the user cannot perceive changes unless both adjustments are completed, so the longer of the convergence adjustment delay time Tv and focus adjustment delay time Tf is used as the allowable drive time Tt. From the above, the allowable drive time Tt is Tt = max(Tv,Tf) It is expressed as:

[0045] Alternatively, the allowable drive time Tt is Tt=min(Tv,Tf) The allowable drive time Tt may be set to be shorter by expressing it as follows. Furthermore, without being limited to these, it is also possible to multiply Tv and Tf by a predetermined ratio and add them together. By multiplying by a predetermined ratio in this way, the allowable drive time Tt can be expressed in detail, and it becomes possible to more accurately compare and determine the predicted value Dp and the allowable value Dt. In the above case, the allowable drive time Tt is calculated by using the ratios α3 and β3 as follows: Tt = α3 × Tv + β3 × Tf It is expressed as:

[0046] A fixed value may be used as the allowable drive time Tt. Alternatively, instead of performing calculations, a table showing the relationship between the depth change amount and the allowable drive time, or the relationship between the convergence adjustment delay time and the focus adjustment delay time and the allowable drive time, may be stored and used to determine the allowable drive time.

[0047] When the drive distance L is used as the allowable drive distance Lt instead of the allowable drive time Tt as the allowable value Dt, it is possible to calculate the allowable drive distance Lt when the trapezoidal drive is performed using the allowable drive time Tt. Alternatively, a table showing the relationship between the allowable drive time Tt and the allowable drive distance Lt may be stored and used to determine the allowable drive distance Lt.

[0048] The control mode selection unit 116 compares the predicted value Dp obtained by the predicted value acquisition unit 113 with the allowable value Dt obtained by the allowable value acquisition unit 114 to select a control mode. When the predicted drive time Tp is used as the predicted value Dp, the allowable drive time Tt is used as the allowable value Dt. When the predicted drive distance Lp is used as the predicted value Dp, the allowable drive distance Lt is used as the allowable value Dt. The drive instruction unit 117 transmits information about the control mode selected by the control mode selection unit 116 to the control device 13.

[0049] If the predicted value Dp is smaller than the allowable value Dt, the control mode selection unit 116 selects the first control mode. If the predicted value Dp is larger than the allowable value Dt, the control mode selection unit 116 selects the second control mode. In the first control mode, the diopter change drive units 104a and 104b are driven using first parameters including a first speed, a first acceleration, and a first deceleration. In the second control mode, the diopter change drive units 104a and 104b are driven using second parameters including a second speed, a second acceleration, and a second deceleration. Here, each second parameter is equal to or smaller than the corresponding first parameter, and at least one of the second parameters is smaller than the corresponding first parameter. Note that if the predicted value Dp and the allowable value Dt are the same value, either the first control mode or the second control mode is selected. In this case, which control mode is selected is specified in advance.

[0050] 8 is a characteristic diagram for explaining a situation in which the first control mode or the second control mode is selected by comparing the allowable drive time with the predicted drive time, where (a) shows the first control mode and (b) shows the second control mode. In FIG. 8, the horizontal axis represents time, with white arrows indicating the occurrence of depth changes, dashed arrows indicating predicted drive times, and solid arrows indicating allowable drive times. The predicted drive time is calculated using the first speed, first acceleration, and first deceleration for the first control mode.

[0051] 9(a), since the predicted drive time falls within the allowable drive time, the control mode selection unit 116 selects the first control mode and drives the optical elements 103a and 103b at the first speed, first acceleration, and first deceleration. As a result, the drive of the optical elements 103a and 103b is completed within the allowable drive time, and the diopter change drive units 104a and 104b can perform diopter adjustment without the user noticing changes in focus or angle of view.

[0052] 9(b), since the predicted drive time exceeds the allowable drive time, the control mode selection unit 116 selects the second control mode and drives the optical elements 103a and 103b at the second velocity, second acceleration, and second deceleration. At this time, at least one of the second velocity, second acceleration, and second deceleration uses values ​​smaller than the first velocity, first acceleration, and first deceleration.

[0053] By using the second control mode, even if the drive continues beyond the allowable drive time, the focus change and the angle of view change caused by the drive of the optical elements 103a and 103b are gradual, making it difficult for the user to perceive the change in focus or angle of view. This is based on a characteristic known as human change blindness. Change blindness is a characteristic in which people have difficulty perceiving changes over a long period of time. People can perceive changes by remembering the state before and after the change and recognizing the moment of the change. In contrast, when the change is gradual, it is difficult to remember the state before and after the change or recognize the moment of the change, making it difficult to perceive the change. In this embodiment, this characteristic is utilized to adopt values ​​smaller than the first speed, first acceleration, and first deceleration for one or more of the second speed, second acceleration, and second deceleration. As the drive time of the diopter change drive units 104a and 104b becomes longer, the focus change and the angle of view change caused by the drive of the optical elements 103a and 103b become gradual, making it difficult for the user to perceive the change. This allows the diopter change driving units 104a and 104b to perform diopter adjustment without the user perceiving a change in focus or angle of view.

[0054] (Method for adjusting visibility in image display device) A method for adjusting the visibility in the image display device according to this embodiment will be described below. FIG. 9 is a flowchart showing a method for adjusting the visibility in the image display device according to this embodiment.

[0055] In step S101, a change in the depth of the gaze point occurs. The depth may be the value at the center of the image as shown in Figure 2, or a representative value to which the focal length should be adjusted at each time may be pre-programmed. Then, the process proceeds to step S102.

[0056] In step S102, the depth acquisition unit 110 acquires the depth after the change. The acquired depth is stored in the depth storage unit 111. The depth acquisition unit 110 calculates the depth change amount d based on the acquired depth and the depth stored in the depth storage unit 111. The process proceeds to step S103.

[0057] In step S103, the driving distance acquisition unit 112 calculates the driving distance L of the diopter change driving units 104a and 104b based on the depth change amount obtained by the depth acquisition unit 110. The driving distance L may be calculated using a function for the positions of the optical elements 103a and 103b corresponding to the depth, or the driving distance L may be determined using a table showing the relationship between the depth change amount and the driving distance. The process proceeds to step S104.

[0058] In step S104, the predicted value acquisition unit 113 calculates a predicted value Dp from the drive distance L obtained by the drive distance acquisition unit 112. As the predicted value Dp, a predicted drive time Tp calculated from the drive distance is used. Note that the drive distance may be used as the predicted drive distance Lp as is. The process proceeds to step S105.

[0059] In step S105, the tolerance acquisition unit 114 acquires user information from the user information recording unit 115. The user information may include age, eyesight, whether or not the user uses vision correction devices, etc. The process proceeds to step S106.

[0060] In step S106, the tolerance acquisition unit 114 calculates a tolerance Dt based on the depth change amount d obtained by the depth acquisition unit 110 and the user information stored in the user information recording unit 115. The tolerance is, for example, the tolerance drive time Tt. The method for calculating the tolerance drive time Tt is as described above, and the tolerance drive time Tt is calculated based on the convergence accommodation delay time Tv and the focus adjustment delay time Tf. The process proceeds to step S107.

[0061] Instead of obtaining the allowable drive time Tt by calculation as described above, it may be determined using a table showing the relationship between the depth change amount and the convergence adjustment delay time or a table showing the relationship between the depth change amount and the focus adjustment delay time. Furthermore, when the drive distance L is used as the allowable drive distance Lt instead of the allowable drive time Tt as the allowable value Dt, for example, the allowable drive distance Lt when trapezoidal drive is performed at the first speed V may be calculated using the allowable drive time Tt.

[0062] In step S107, the control mode selection unit 116 compares the predicted value Dp obtained by the predicted value acquisition unit 113 with the predicted value Dt obtained by the tolerance acquisition unit 114 to select a control mode. When the predicted drive time Tp is used as the predicted value Dp, the tolerance value Dt is used as the tolerance value. When the predicted drive distance Lp is used as the predicted value Dp, the tolerance value Dt is used as the tolerance value. When the predicted value Dp is smaller than the tolerance value Dt, the control mode selection unit 116 selects the first control mode and proceeds to step S108.

[0063] In step S108, under the control of the control device 13, the diopter change drive units 104a and 104b drive the optical elements 103a and 103b in the first control mode (first speed, first acceleration, and first deceleration) selected in step S107.

[0064] In step S107, if the predicted value Dp is greater than the allowable value Dt, the control mode selection unit 116 selects the second control mode, and the process proceeds to step S109.

[0065] In step S109, under the control of the control device 13, the diopter change driving units 104a and 104b drive the optical elements 103a and 103b in the second control mode (second speed, second acceleration, and second deceleration) selected in step S107.

[0066] As described above, according to this embodiment, an image display device is realized that can display clear images by adjusting the focal length to a stereoscopic image created by parallax, without the user being able to sense changes in the focus or angle of view of the image caused by driving the optical elements.

[0067] In this embodiment, there are two cases: one in which the allowable drive time Tp and the predicted drive time Tt are acquired and compared to select a control mode; and one in which the allowable drive distance Lp and the predicted drive distance Lt are acquired and compared to select a control mode. In this embodiment, the control mode is selected by comparing whether the time required for a position change (drive time) exceeds the user's response delay time. Therefore, a more accurate determination can be made by calculating and comparing the time rather than comparing only the distance. In consideration of this, the present invention is not limited to the above two cases, and it is also possible to use both, for example.

[0068] Specifically, first, the allowable driving distance Lp and the predicted driving distance Lt are sequentially acquired in steps S102 to S106, and then the two are compared in step S107. If necessary, for example, when it is determined that the comparison results lack accuracy due to the use of a predetermined threshold, the allowable driving time Tp and the predicted driving time Tt are compared in steps S102 to S107 to select a control mode. This allows for accurate selection of the control mode while reducing the amount of calculations.

[0069] [Variations] A modified example of this embodiment will be described below, which discloses an image display device configured to accommodate users with different visual acuity between their left and right eyes.

[0070] The image display device of this modified example has the same schematic configuration as that shown in FIG. 1 described in the first embodiment. A method for adjusting the diopter of the image display device according to this modification will be described below with reference to FIG. 9 of the first embodiment. An example will be shown in which the diopter is adjusted for the left eye first, and then for the right eye. For example, a selector switch (not shown) can be used to set the left eye adjustment mode, the right eye adjustment mode, or the binocular adjustment mode as in the first embodiment.

[0071] 9 are assumed to be performed while the user is gazing at one point regardless of the user's eyesight. Therefore, when adjusting the diopter for each eye, it is sufficient to first perform steps S101 and S102 once, and it is not necessary to perform steps S101 and S102 for each eye.

[0072] In this modification, a change in depth of the gaze point occurs in step S101. In step S102, the depth acquisition unit 110 acquires the depth after the change. The acquired depth is stored in the depth storage unit 111. The depth acquisition unit 110 calculates the depth change amount d based on the acquired depth and the depth stored in the depth storage unit 111.

[0073] <Left eye adjustment mode> In step S103, for the left eye 201a, the driving distance acquisition unit 112 calculates the driving distance La of the diopter change driving unit 104a on the left eye 201a side based on the depth change amount obtained by the depth acquisition unit 110. In step S104, the predicted value acquisition unit 113 calculates a predicted value Dpa for the left eye 201a from the driving distance La obtained by the driving distance acquisition unit 112. In step S105 , the tolerance acquisition unit 114 acquires user information from the user information recording unit 115 . In step S106, the tolerance acquisition unit 114 calculates the tolerance Dta for the left eye 201a based on the depth change amount d obtained by the depth acquisition unit 110 and the user information stored in the user information recording unit 115.

[0074] In step S107, the control mode selection unit 116 compares the predicted value Dpa obtained by the predicted value acquisition unit 113 with the predicted value Dta obtained by the tolerance acquisition unit 114 to select a control mode. When the predicted drive time Tpa is used as the predicted value Dpa, the tolerance value Dta is used as the tolerance time Tta. When the predicted drive distance Lpa is used as the predicted value Dpa, the tolerance value Dta is used as the tolerance distance Lta. When the predicted value Dpa is smaller than the tolerance value Dta, the control mode selection unit 116 selects the first control mode and proceeds to step S108.

[0075] In step S108, based on the control of the control device 13, the diopter change drive unit 104a on the left eye 201a side drives the optical element 103a on the left eye 201a side in the first control mode (first speed, first acceleration, and first deceleration) selected in step S107. In step S107, if the predicted value Dpa is greater than the allowable value Dta, the control mode selection unit 116 selects the second control mode, and the process proceeds to step S109.

[0076] In step S109, based on the control of the control device 13, the diopter change drive unit 104a on the left eye 201a side drives the optical element 103a on the left eye 201a side in the second control mode (second speed, second acceleration, and second deceleration) selected in step S107.

[0077] <Right eye adjustment mode> In step S103, for the right eye 201b, the driving distance acquisition unit 112 calculates the driving distance Lb of the diopter change driving unit 104b on the right eye 201b side based on the depth change amount obtained by the depth acquisition unit 110. In step S104, the predicted value acquisition unit 113 calculates a predicted value Dpb for the right eye 201b from the driving distance Lb obtained by the driving distance acquisition unit 112. In step S105 , the tolerance acquisition unit 114 acquires user information from the user information recording unit 115 . In step S106, the tolerance acquisition unit 114 calculates a tolerance Dtb for the right eye 201b based on the depth change amount d obtained by the depth acquisition unit 110 and the user information stored in the user information recording unit 115.

[0078] In step S107, the control mode selection unit 116 compares the predicted value Dpb obtained by the predicted value acquisition unit 113 with the predicted value Dtb obtained by the tolerance acquisition unit 114 to select a control mode. When the predicted drive time Tpb is used as the predicted value Dpb, the tolerance value Dtb is used as the tolerance time Ttb. When the predicted drive distance Lpb is used as the predicted value Dpb, the tolerance value Dtb is used as the tolerance time Ltb. When the predicted value Dpb is smaller than the tolerance value Dtb, the control mode selection unit 116 selects the first control mode and proceeds to step S108.

[0079] In step S108, based on the control of the control device 13, the diopter change drive unit 104b on the right eye 201b side drives the optical element 103b on the right eye 201b side in the first control mode (first speed, first acceleration, and first deceleration) selected in step S107. In step S107, if the predicted value Dpb is greater than the allowable value Dtb, the control mode selection unit 116 selects the second control mode, and the process proceeds to step S109.

[0080] In step S109, based on the control of the control device 13, the diopter change drive unit 104b on the right eye 201b side drives the optical element 103b on the right eye 201b side in the second control mode (second speed, second acceleration, and second deceleration) selected in step S107.

[0081] As described above, this modification enables accurate diopter adjustment for each eye, even if the user has different visual acuity between their left and right eyes. In other words, an image display device is realized that can display clear images by adjusting the focal length of a stereoscopic image caused by parallax for each eye, without the user being aware of changes in focus or angle of view of the image due to the driving of the optical elements.

[0082] In this modification, steps S103 to S106 may be executed first in the left eye adjustment mode, and then steps S103 to S106 may be executed in the right eye adjustment mode, and then steps S107 to S109 may be executed simultaneously for both the left and right eyes.

[0083] Furthermore, in this modified example, as in the first embodiment, it is possible to perform both the case where the allowable drive time Tp and the predicted drive time Tt are obtained and compared to select the control mode, and the case where the allowable drive distance Lp and the predicted drive distance Lt are obtained and compared to select the control mode.

[0084] [Second embodiment] Next, a second embodiment of the present disclosure will be described. FIG. 10 is a schematic diagram showing the general configuration of the image display device according to this embodiment.

[0085] (Configuration of video display device) In the image display device of this embodiment, as shown in FIG. 10, in addition to the configuration of the first embodiment shown in FIG. 1, the image display means 11 has gaze detection units 107a and 107b, and the movement driving means 12 has a gaze position acquisition unit 118, a gaze position memory unit 119, and a gaze change amount acquisition unit 120.

[0086] The gaze detection units 107a and 107b have a camera and an infrared illumination unit, and are arranged closer to the user's eyes 201a and 201b than the optical elements 103a and 103b. In the gaze detection units 107a and 107b, the camera illuminates the eyes 201a and 201b with infrared light using the infrared illumination unit to acquire eyeball images and detect changes in the gaze point and gaze direction of the user's eyes 201a and 201b. The gaze position acquisition unit 118 determines the position of the gaze point from the detection results by the gaze detection units 107a and 107b. The gaze position storage unit 119 stores the position of the gaze point obtained by the gaze position acquisition unit 118. The gaze change amount acquisition unit 120 calculates a gaze change amount e from the gaze position stored in the gaze position storage unit 119 and the gaze position calculated by the gaze position acquisition unit 118. The line of sight change amount e may be the angle of change in the line of sight direction, the movement distance of the gaze point in the image space, or the movement distance on the image display units 102a and 102b.

[0087] (Method for adjusting visibility in image display device) A method for adjusting the visibility in the image display device according to this embodiment will be described below. Fig. 11 is a flowchart showing a method for adjusting the visibility of the image display device according to this embodiment. In Fig. 11, the same components as those in Fig. 1 are given the same reference numerals, and detailed explanations will be omitted.

[0088] In step S201, a change in depth of the gaze point occurs. As the depth, a value at the center of the image may be used as shown in FIG. 2, or a representative value to which the focal length should be adjusted for each time may be pre-programmed. Also, as shown in FIG. 3, the gaze position obtained by gaze position acquisition unit 118 may be used as the gaze point, and a change in depth of the gaze point may be detected. Then, the process proceeds to step S202.

[0089] Steps S202 to S205 are the same as steps S102 to S105 in FIG. 9 of the first embodiment.

[0090] In step S206, the gaze change amount acquisition unit 120 calculates the gaze change amount e from the gaze position acquired by the gaze position acquisition unit 118. The process proceeds to step S207.

[0091] In step S207, the tolerance calculation unit 114 calculates a tolerance Dt based on the depth change amount d obtained by the depth calculation unit 110, the user information stored in the user information recording unit 115, and the line of sight change amount e obtained by the line of sight change amount acquisition unit 120. The tolerance Dt is calculated as a tolerance drive time Tt. The tolerance drive time Tt is calculated based on the convergence accommodation delay time Tv, the focus accommodation delay time Tf, and the line of sight movement delay time Tm. The convergence accommodation delay time Tv and the focus accommodation delay time Tf are acquired in the same manner as in the first embodiment.

[0092] The gaze movement delay time Tm is the response delay time after a change in gaze direction occurs. The gaze movement response delay time Tm is the sum of a fixed value Tm0 multiplied by a personal information coefficient γ1, which has a different value for each age, and the gaze change amount e multiplied by a personal information coefficient γ2, which has a different value for each age, since it is proportional to the gaze change amount e as it also depends on the distance of the gaze movement. From the above, the gaze movement delay time Tm is Tm = γ1 × Tv0 + γ2 × e The amount of change in the line of sight e may be the angle of change in the line of sight direction or the distance of change.

[0093] The allowable drive time Tt is calculated based on the convergence accommodation delay time Tv, the focus adjustment delay time Tf, and the line of sight movement delay time Tm. It is considered that line of sight movement occurs first, followed by convergence accommodation and focus adjustment. Therefore, the allowable drive time Tt is the sum of the convergence accommodation delay time Tv, the focus adjustment delay time Tf, and the line of sight movement delay time. The larger of the convergence accommodation delay time Tv and the focus adjustment delay time Tf is used. From the above, the allowable drive time Tt is Tt = max(Tv,Tf) + Tm It is expressed as:

[0094] Alternatively, the allowable drive time Tt is Tt = min(Tv,Tf) + Tm The allowable drive time Tt may be set to be shorter by expressing it as follows. Furthermore, it is not limited to these, and Tv, Tf, and Tm may be multiplied by a predetermined ratio and added together. By multiplying by a predetermined ratio in this way, the allowable drive time Tt can be expressed in detail, and it becomes possible to more accurately compare and determine the predicted value Dp and the allowable value Dt. In the above case, the allowable drive time Tt is calculated using the ratios α3, β3, and γ3 as follows: Tt = α3 × Tv + β3 × Tf + γ3 × Tm It is expressed as:

[0095] A fixed value may be used as the allowable drive time Tt. Alternatively, instead of performing calculations, a table showing the relationship between the depth change amount and the allowable drive time, or the relationship between the convergence adjustment delay time and the focus adjustment delay time and the allowable drive time, may be stored and used to determine the allowable drive time.

[0096] When the drive distance L is used as the allowable drive distance Lt instead of the allowable drive time Tt as the allowable value Dt, it is possible to calculate the allowable drive distance Lt when the trapezoidal drive is performed using the allowable drive time Tt. Also, a table showing the relationship between the allowable drive time Tt and the allowable drive distance Lt may be stored and used to determine the allowable drive distance Lt. When the predicted drive time Tp is used as the predicted value Dp, the allowable drive distance Lt is used as the allowable value Dt.

[0097] Steps S208 to S210 following step S207 are similar to steps S107 to S109 in FIG. 9 of the first embodiment.

[0098] As described above, according to this embodiment, the control mode is selected taking into consideration the line-of-sight movement delay time obtained from the line-of-sight change amount, thereby realizing an image display device that can more reliably display clear images by adjusting the focal length to a stereoscopic image caused by parallax, without the user being aware of changes in focus or angle of view of the image due to the driving of the optical elements.

[0099] In this embodiment, as in the first embodiment, it is possible to select a control mode by acquiring and comparing the allowable drive time Tp and the predicted drive time Tt, and by acquiring and comparing the allowable drive distance Lp and the predicted drive distance Lt. This allows for accurate selection of the control mode while reducing the amount of calculation.

[0100] Furthermore, in this embodiment, similar to the modification of the first embodiment, the diopter adjustment for the left eye and the diopter adjustment for the right eye may be performed independently to accommodate users with different visual acuity between the left and right eyes. This realizes an image display device that can display clear images by adjusting the focal length for a stereoscopic image caused by parallax for each of the left and right eyes, without the user being aware of changes in focus or angle of view of the image due to the driving of the optical elements.

[0101] In the above-described embodiments and modifications, consideration may be given to reducing the drive noise generated when the diopter change drive units 104a and 104b drive and move 103a and 103b. If the drive speed is high during diopter adjustment of the image display device, drive noise is generated. Therefore, in the embodiments and modifications, for example, a threshold value for the drive time required for drive at a drive speed at which the user does not perceive (or is not bothered by) the drive noise is predefined. When the control mode selection unit 116 selects the first control mode during diopter adjustment, drive is performed at a first speed, first acceleration, and first deceleration that satisfy the threshold value or greater within the allowable drive time range. By controlling in this manner, diopter adjustment can be performed without the user perceiving changes in the focus or angle of view of the image due to relative movement between the image display unit and the optical element, while suppressing drive noise generated during diopter adjustment, thereby enabling clear images to be displayed.

[0102] The disclosure of the various embodiments and modifications includes the following configurations and methods. (Configuration 1) A video display unit; an optical element; a movement driving unit that changes the relative position of the image display unit and the optical element; It is equipped with The movement drive unit is a predicted value acquisition unit that acquires a predicted value regarding a change in the relative position; a tolerance acquisition unit that acquires a tolerance regarding a change in the relative position; a control mode selection unit that selects one of a plurality of control modes for controlling the movement drive unit based on a comparison result between the predicted value and the allowable value; having Video display device. (Configuration 2) the predicted value is at least one of a predicted driving distance of the change in the relative position and a predicted driving time required for the change in the relative position; 2. The image display device according to claim 1. (Configuration 3) the tolerance is at least one of a tolerance distance for the change in the relative position and a tolerance time required for the change in the relative position; 3. The image display device according to configuration 1 or 2. (Configuration 4) The tolerance value is a value obtained using user information of the user. 4. The image display device according to configuration 3. (Configuration 5) The user information includes the user's eye convergence accommodation time, focus accommodation time, age, and visual acuity. 5. The image display device according to configuration 4. (Configuration 6) the allowable driving time is a response delay time of the user's eyes, and the allowable driving distance is a distance obtained using the allowable driving time; 4. The image display device according to configuration 3. (Configuration 7) the movement driving unit further includes a depth acquisition unit that acquires a depth change amount from the image displayed on the image display unit, the predicted value and the tolerance value are values ​​obtained using the depth variation amount; 7. The image display device according to any one of configurations 1 to 6. (Configuration 8) the plurality of control modes include a first control mode in which the movement drive unit is driven with each of first parameters including a first drive speed, a first acceleration, and a first deceleration when the relative position between the image display unit and the optical element changes; The image display device according to any one of configurations 1 to 7. (Configuration 9) The control mode selection unit When the predicted value is smaller than the allowable value, the first control mode is selected; 9. The image display device according to configuration 8. (Configuration 10) the plurality of control modes include a second control mode in which the movement drive unit is driven with second parameters including a second drive speed, a second acceleration, and a second deceleration when the relative position between the image display unit and the optical element changes; each of the second parameters is less than or equal to a corresponding one of the first parameters; At least one of the second parameters is smaller than a corresponding one of the first parameters; 9. The image display device according to configuration 8. (Configuration 11) The control mode selection unit When the predicted value is greater than the allowable value, the second control mode is selected. 11. The image display device according to configuration 10. (Configuration 12) The device further includes a line-of-sight detection unit that detects a change in the line-of-sight direction of the user, The movement drive unit is a gaze position acquisition unit that acquires a gaze position from a detection result of the gaze detection unit; a storage unit that stores the gaze position; a line-of-sight change amount acquisition unit that acquires a line-of-sight change amount from the line-of-sight position acquired by the line-of-sight position acquisition unit and the line-of-sight position stored in the storage unit; Further comprising: 12. The image display device according to any one of configurations 1 to 11. (Configuration 13) It has a left eye side adjustment mode and a right eye side adjustment mode, The movement drive unit is In the left eye adjustment mode, the predicted value acquisition unit acquires the predicted value regarding the change in the relative position for the left eye side of the user, the tolerance acquisition unit acquires the tolerance regarding a change in the relative position for the left eye side of the user, In the right eye adjustment mode, the predicted value acquisition unit acquires the predicted value regarding the change in the relative position for the right eye side of the user, the tolerance acquisition unit acquires the tolerance regarding a change in the relative position for the right eye of the user, the control mode selection unit selects one of the plurality of control modes sequentially or simultaneously for the left eye side and the right eye side of the user based on a comparison result between the predicted value and the allowable value. 13. The image display device according to any one of configurations 1 to 12. (Method 1) When changing the relative position of the image display unit and the optical element, obtaining a prediction of a change in the relative position; obtaining a tolerance for changes in the relative position; selecting one of a plurality of control modes for controlling the movement driving of the relative position based on a comparison result between the predicted value and the allowable value; having A method for adjusting a video display device. [Explanation of symbols]

[0103] 201a: Left eye 201b: Right eye 11: Image display means 12: Movement driving means 13: Control device 100: Video acquisition unit 101: Display processing unit 102a, 102b: Video display unit 103a, 103b: Optical elements 104a, 104b: Diopter change drive unit 110: Depth acquisition unit 111: Depth storage unit 112: Drive distance acquisition unit 113: predicted value acquisition unit 114: allowable value acquisition unit 115: user information recording unit 116: Control mode selection unit 117: Drive instruction unit

Claims

1. A video display unit; an optical element; a movement driving unit that changes the relative position of the image display unit and the optical element; It is equipped with The movement drive unit is a predicted value acquisition unit that acquires a predicted value regarding a change in the relative position; a tolerance acquisition unit that acquires a tolerance regarding a change in the relative position; a control mode selection unit that selects one of a plurality of control modes for controlling the movement drive unit based on a comparison result between the predicted value and the allowable value; having Video display device.

2. the predicted value is at least one of a predicted driving distance of the change in the relative position and a predicted driving time required for the change in the relative position; 2. The image display device according to claim 1.

3. the tolerance is at least one of a tolerance distance for the change in the relative position and a tolerance time required for the change in the relative position; 2. The image display device according to claim 1.

4. The tolerance value is a value obtained using user information of the user.

4. The image display device according to claim 3.

5. The user information includes the user's eye convergence accommodation time, focus accommodation time, age, and visual acuity.

5. The image display device according to claim 4.

6. the allowable driving time is a response delay time of the user's eyes, and the allowable driving distance is a distance obtained using the allowable driving time; 4. The image display device according to claim 3.

7. the movement driving unit further includes a depth acquisition unit that acquires a depth change amount from the image displayed on the image display unit, the predicted value and the tolerance value are values ​​obtained using the depth variation amount; 2. The image display device according to claim 1.

8. the plurality of control modes include a first control mode in which the movement drive unit is driven with each of first parameters including a first drive speed, a first acceleration, and a first deceleration when the relative position between the image display unit and the optical element changes; 2. The image display device according to claim 1.

9. The control mode selection unit When the predicted value is smaller than the allowable value, the first control mode is selected; 9. The image display device according to claim 8.

10. the plurality of control modes include a second control mode in which the movement drive unit is driven with second parameters including a second drive speed, a second acceleration, and a second deceleration when the relative position between the image display unit and the optical element changes; each of the second parameters is less than or equal to a corresponding one of the first parameters; At least one of the second parameters is smaller than a corresponding one of the first parameters; 9. The image display device according to claim 8.

11. The control mode selection unit When the predicted value is greater than the allowable value, the second control mode is selected. The image display device according to claim 10.

12. The device further includes a line-of-sight detection unit that detects a change in the line-of-sight direction of the user, The movement drive unit is a gaze position acquisition unit that acquires a gaze position from a detection result of the gaze detection unit; a storage unit that stores the gaze position; a line-of-sight change amount acquisition unit that acquires a line-of-sight change amount from the line-of-sight position acquired by the line-of-sight position acquisition unit and the line-of-sight position stored in the storage unit; Further comprising:

2. The image display device according to claim 1.

13. It has a left eye side adjustment mode and a right eye side adjustment mode, The movement drive unit is In the left eye adjustment mode, the predicted value acquisition unit acquires the predicted value regarding the change in the relative position for the left eye side of the user, the tolerance acquisition unit acquires the tolerance regarding a change in the relative position for the left eye side of the user, In the right eye adjustment mode, the predicted value acquisition unit acquires the predicted value regarding the change in the relative position for the right eye side of the user, the tolerance acquisition unit acquires the tolerance regarding a change in the relative position for the right eye of the user, the control mode selection unit selects one of the plurality of control modes sequentially or simultaneously for the left eye side and the right eye side of the user based on a comparison result between the predicted value and the allowable value.

2. The image display device according to claim 1.

14. When changing the relative position of the image display unit and the optical element, obtaining a prediction of a change in the relative position; obtaining a tolerance for changes in the relative position; selecting one of a plurality of control modes for controlling the movement driving of the relative position based on a comparison result between the predicted value and the allowable value; having A method for adjusting a video display device.

Images