Drive control system, head mounted display, and drive control method

Abstract

The present invention stabilizes the rotation of a DC motor (423) for vibration used in a head mounted display (12). This drive control system (100) comprises: a vibration unit (42) that is provided in the HMD 12 having a display panel (38) disposed in front of the user's eyes when worn and includes at least the DC motor (423); and a motor control unit (60) that outputs a drive signal for controlling the driving force for driving the vibration unit (42). The motor control unit (60) outputs a first drive signal (DP1) for driving the vibration unit (42) with a first driving force during a predetermined start-up period (T1), and outputs, after the start-up period (T1) has passed, a second drive signal (DP2) which is composed of a plurality of single pulses to be intermittently output, and is for driving the vibration unit (42) with a second driving force that is smaller than the first driving force,.

Description

Drive control system, head-mounted display, and drive control method

[0001] The present invention relates to a drive control system, a head-mounted display, and a drive control method.

[0002] As disclosed in Patent Literature 1, head-mounted displays are used to present moving images such as game footage and movies. When a head-mounted display is used, moving images are displayed in front of the user's eyes, providing the user with a highly realistic sensation.

[0003] International Publication No. 2015 / 137165

[0004] There is a demand for a more realistic experience when using a head-mounted display. To this end, it is conceivable to use a vibration motor, for example, to generate vibrations corresponding to the image. Since vibration motors vary from one another, the degree of vibration may differ depending on the vibration motor installed in the head-mounted display. Therefore, PWM control may be used to adjust for vibration errors due to individual differences. However, when PWM control is used, the driving force supplied to the vibration motor decreases depending on the duty ratio. Depending on the orientation of the head-mounted display, the vibration motor may be affected by gravity, making it impossible to generate the desired vibration.

[0005] The present invention has been made in view of the above-mentioned circumstances, and one of its objects is to stabilize the rotation of a vibration motor used in a head-mounted display.

[0006] In order to solve the above problems, the drive control system of the present invention has a vibration unit including at least a motor, which is provided in a head-mounted display having a display panel that is placed in front of the user's eyes when worn, and a motor control unit that outputs a drive signal that controls the drive force that drives the vibration unit, wherein the motor control unit outputs a first drive signal that drives the vibration unit with a first drive force during a predetermined start-up period, and after the start-up period has elapsed, outputs a second drive signal that is composed of a plurality of intermittently output short pulses that drives the vibration unit with a second drive force that is smaller than the first drive force.

[0007] Furthermore, the head-mounted display of the present invention is a head-mounted display equipped with a display panel that is placed in front of the user's eyes when worn, and has a vibration unit including at least a motor, and a motor control unit that outputs a drive signal that controls the drive force that drives the vibration unit, wherein the motor control unit outputs a first drive signal that drives the vibration unit with a first drive force during a predetermined start-up period, and after the start-up period has elapsed, outputs a second drive signal that is composed of a plurality of intermittently output short pulses that drives the vibration unit with a second drive force that is smaller than the first drive force.

[0008] Furthermore, the drive control method of the present invention is a drive control method for controlling the drive force that drives a vibration unit including at least a motor, which is provided in a head-mounted display having a display panel that is placed in front of the user's eyes when worn, and outputs a first drive signal that drives the vibration unit with a first drive force during a predetermined start-up period, and after the start-up period has elapsed, outputs a second drive signal consisting of a plurality of intermittently output short pulses that drives the vibration unit with a second drive force that is smaller than the first drive force.

[0009] FIG. 1 is a diagram showing an example of the overall configuration of an entertainment system according to the present embodiment. FIG. 2 is a diagram showing an example of the configuration of an entertainment device according to the present embodiment. FIG. 3 is a diagram showing an example of the configuration of a head-mounted display according to the present embodiment. FIG. 4 is a plan view of a vibration unit provided in the head-mounted display according to the present embodiment, seen from above. FIG. 5 is a side view of a vibration unit provided in the head-mounted display according to the present embodiment, seen from the side. FIG. 6 is a diagram showing an example of the configuration of a drive control system included in the entertainment system according to the present embodiment. FIG. 7 is a diagram explaining drive control immediately after start-up of a DC motor according to the present embodiment. FIG. 8 is a diagram explaining drive control when the target rotation frequency of a DC motor according to the present embodiment is changed. FIG. 9 is a diagram schematically showing an example of drive control in the present embodiment. FIG. 10 is a diagram showing a table relating to target rotation frequencies and start-up periods at start-up. FIG. 11 is a diagram showing a table relating to target rotation frequencies and start-up periods when the target rotation frequency is changed. FIG. 12 is a diagram showing an approximate curve based on an approximate formula used to determine a duty ratio in the present embodiment.

[0010] Hereinafter, an embodiment of the present invention (hereinafter referred to as the present embodiment) will be described with reference to the drawings.

[0011] [Overview of the Overall Configuration of Entertainment System 10] Fig. 1 is a diagram showing an example of the overall configuration of an entertainment system according to this embodiment. As shown in Fig. 1, the entertainment system 10 according to this embodiment may include, for example, a head-mounted display (hereinafter also referred to as HMD) 12, an entertainment device 14, a relay device 16, a display 18, a camera microphone unit 20, and a controller 22. Note that the overall configuration of the entertainment system 10 shown in Fig. 1 is an example and is not limited thereto, and any system may be used as long as it includes at least the HMD 1.

[0012] [Overview of the Overall Configuration of the Entertainment Device 14] Fig. 2 is a diagram showing an example of the configuration of an entertainment device according to this embodiment. The entertainment device 14 according to this embodiment may include, for example, a processor 50, a storage unit 52, a communication unit 54, and an input / output unit 56, as shown in Fig. 2.

[0013] The entertainment device 14 may be a computer such as a game console, a DVD player, or a Blu-ray (registered trademark) player. The entertainment device 14 according to this embodiment may generate video and audio by executing a game program or playing content stored in a memory or recorded on an optical disc. The entertainment device 14 according to this embodiment may then output a video signal representing the generated video and an audio signal representing the generated audio to a display 18 via a relay device 16.

[0014] The processor 50 may be, for example, a program-controlled device such as a CPU that operates according to a program installed in the entertainment device 14 .

[0015] The storage unit 52 may be, for example, a storage element such as a ROM or a RAM, or a hard disk drive. The storage unit 52 may store programs executed by the processor 50. The communication unit 54 may be, for example, a communication interface such as a wireless LAN module. The input / output unit 56 may be an input / output port such as an HDMI (registered trademark) (High-Definition Multimedia Interface) port or a USB port.

[0016] The various functions of the entertainment device 14 may be implemented in the HMD 12 .

[0017] 1, the HMD 12 may have a main body 121 and a wearing band 122. The wearing band 122 may be annular and surround the user's head as a whole. The main body 121 may house the display panel 38 and the like and may include a housing 44 that forms the exterior of the main body 121. The wearing band 122 may be connected to the upper part of the main body 121.

[0018] 3 is a diagram showing an example of the configuration of the head-mounted display according to this embodiment. As shown in FIG. 3, the HMD 12 may include a processor 30, a storage unit 32, a communication unit 34, an input / output unit 36, a display panel 38, a sensor unit 40, and a vibration unit 42.

[0019] The processor 30 may be, for example, a program-controlled device such as a microprocessor that operates according to a program installed in the HMD 12. The storage unit 32 may be, for example, a storage element such as a ROM or a RAM. The storage unit 32 may store programs executed by the processor 30. The communication unit 34 may be, for example, a communication interface such as a wireless LAN module. Note that while FIG. 1 shows an example in which the HMD 12 can communicate with the entertainment device 14 via wireless communication, a configuration in which wired communication is possible may also be used. The input / output unit 36 ​​may be, for example, an input / output port such as an HDMI (registered trademark) (High-Definition Multimedia Interface) port or a USB port.

[0020] The display panel 38 may be, for example, a liquid crystal display or an organic EL display, and may display images generated by the entertainment device 14. The display panel 38 may be placed in front of the eyes of the user when the user wears the HMD 12. The display panel 38 may receive, for example, a video signal output by the entertainment device 14 and relayed by the relay device 16, and output an image represented by the video signal.

[0021] The display panel 38 may be configured to display a three-dimensional image by displaying, for example, an image for the left eye and an image for the right eye. The display panel 38 is not limited to a panel that displays three-dimensional images, and may be a panel that is only capable of displaying two-dimensional images. The sensor unit 40 may be, for example, an acceleration sensor or a motion sensor. The sensor unit 40 may output measurement results of the attitude, rotation amount, movement amount, etc. of the HMD 12 to the processor 30.

[0022] [Configuration of vibration unit 42] Next, the configuration of the vibration unit 42 included in the HMD 12 will be described with reference to Figures 4A and 4B. Figure 4A is a plan view of the vibration unit included in the head-mounted display according to this embodiment, viewed from above. Figure 4B is a side view of the vibration unit included in the head-mounted display according to this embodiment, viewed from the side. Here, the side refers to a direction substantially perpendicular to the display panel 38.

[0023] The vibration unit 42 is driven (vibrates) in accordance with instructions received from the entertainment device 14 and outputs from the sensor unit 40. As shown in Fig. 1, the vibration unit 42 may be provided, for example, at the front of the wearing band 122. Note that Fig. 1 shows the arrangement of the vibration unit 42 and also shows its shape schematically. The vibration unit 42 may be provided in the HMD 1 so as to vibrate the HMD 1, and is not limited to the arrangement shown in Fig. 1.

[0024] The vibration unit 42 may vibrate, for example, when an object or game character operated by the user takes some action or receives an impact. The vibration of the vibration unit 42 causes the wearing band 122 to vibrate, and the vibration is transmitted to the user's head. This allows the user to have a realistic experience.

[0025] 4A and 4B , the vibrating unit 42 is preferably a vibrating device constituting a so-called eccentric motor, including a rotating shaft 421, a weight 422 that rotates together with the rotating shaft 421, and a DC motor 423 that rotates the rotating shaft 421. The weight 422 is preferably attached to the rotating shaft 421 and has a center of gravity at a position away from the rotating shaft 421. The DC motor 423 is preferably a general-purpose motor that includes at least a coil, a rotor, and a stator.

[0026] The rotation shaft 41 is preferably disposed so as to extend in a direction along the display surface of the display panel 38. In other words, the rotation shaft 41 is preferably disposed so that its axis O extends in a direction substantially parallel to the display panel 38. Specifically, the rotation shaft 41 is preferably disposed so as to face the up-down direction of the display panel 38. With this arrangement, the vibration of the vibrating unit 42 occurs in a direction substantially perpendicular to the up-down direction of the display panel 38.

[0027] 5 is a diagram showing an example of the configuration of the drive control system 100 included in the entertainment system according to this embodiment. The drive control system 100 according to this embodiment may include a motor control unit 60, a driver circuit 70, and a vibration unit 42.

[0028] The motor control unit 60 may output a drive signal, which is a pulse signal that controls the drive force supplied from the driver circuit 70, in response to the image displayed on the display panel 38 or the detection by the sensor unit 40 (hereinafter referred to as the image, etc.). Note that the motor control unit 60 is not limited to one that outputs a drive signal in response to the image, etc., and may be capable of outputting a drive signal independent of the image, etc. For example, the motor control unit 60 may be capable of outputting a drive signal based on an input operation to the controller 22 that is not reflected in the display on the display panel 38. The motor control unit 60 may be included in the HMD 12. In this case, the motor control unit 60 may be implemented primarily as the processor 30. Note that the motor control unit 60 may also be included in the entertainment device 14, in which case the motor control unit 60 may be implemented primarily as the processor 50.

[0029] The driver circuit 70 supplies a drive voltage corresponding to a drive signal output from the motor control unit 60 to the coil of the DC motor 423, thereby driving the DC motor 423. The driver circuit 70 includes a switch or the like that is a transistor, and is preferably configured to be able to supply a drive voltage to the DC motor 423 by switching the switch ON and OFF according to the drive signal output from the motor control unit 60. The driver circuit 70 is preferably included in the HMD 12.

[0030] [Drive Control: Immediately After Start-Up] Next, drive control immediately after start-up of the DC motor of this embodiment will be described with reference to Fig. 6. Fig. 6 is a diagram illustrating drive control immediately after start-up of the DC motor of this embodiment.

[0031] The DC motor 423 included in the vibration unit 42 starts rotating when a drive voltage is supplied, and after a predetermined period of time, the desired target rotation frequency is reached. Individual differences may occur in the DC motors 423. Specifically, even when the same drive voltage is supplied to the coils of the DC motors 423, variations in rotation frequency may occur for each DC motor 423. Therefore, the vibrations transmitted to the user's head may vary for each HMD 12.

[0032] Therefore, for example, it is conceivable to perform PWM (Pulse Width Modulation) control and calibration for each DC motor 423. However, PWM control tends to result in variations in the time from when the DC motor 423 is started until it reaches a target rotation frequency. Furthermore, PWM control may result in insufficient driving force immediately after starting the DC motor 423, which may cause the DC motor 423 to malfunction. This is because the rotation shaft 421 and the weight 422 are susceptible to the influence of gravity depending on the orientation and posture of the head of the user wearing the HMD 12. For example, if the rotation shaft 421 is positioned so as to extend horizontally, the rotation shaft 421 and the weight 422 become difficult to rotate due to the influence of gravity.

[0033] Therefore, in this embodiment, a constant drive voltage (power supply voltage) is supplied during a predetermined start-up period T1 immediately after the start-up of the DC motor 423, and PWM control is performed during a stable period T2 after the start-up period T1 has elapsed.

[0034] In this embodiment, the start-up period T1 is a predetermined period immediately after the DC motor 423 starts from a stopped state and before the rotation frequency stabilizes. The start-up period T1 is preferably set in advance according to the target rotation frequency of the DC motor 423. The start-up period T1 is preferably set to be longer as the target rotation frequency of the DC motor 423 increases. Note that FIG. 6 shows an example in which the target rotation frequency of the DC motor 423 is F1 [Hz]. The drive voltage supplied during the start-up period T1 is preferably set to the same value regardless of individual differences between the DC motors 423.

[0035] The stable period T2 is a period after the start-up period T1 has elapsed, during which the rotation frequency of the DC motor 423 has stabilized.

[0036] During the start-up period T1, the motor control unit 60 outputs a first drive signal DP1 that drives the vibration unit 42 with a first drive force. That is, during the start-up period T1, a switch included in the driver circuit 70 is constantly turned on to supply power supply voltage. This allows the vibration unit 42 to be driven with a greater drive force than when PWM control is used. Therefore, the DC motor 423 can be rotated normally regardless of the posture of the vibration unit 42, i.e., the orientation of the rotation shaft 421. Furthermore, the time required to reach the target rotation frequency can be kept constant regardless of individual differences in the DC motor 423. Furthermore, the rotation frequency of the DC motor 423 can be made to reach the target rotation frequency in a short period of time.

[0037] During the stable period T2, the motor control unit 60 performs PWM control to output a second drive signal DP2 that drives the vibration unit 42 with a second drive force that is smaller than the first drive force. That is, during the stable period T2, the switch included in the driver circuit 70 may be alternately turned on and off at predetermined intervals. The second drive signal DP2 is a signal made up of a plurality of short pulses that are output intermittently.

[0038] Here, the second driving force that vibrates the vibrating unit 42 under PWM control is determined according to the duty ratio of the second driving signal DP2. Here, the duty ratio indicates the proportion of a single pulse output within a predetermined period. In FIG. 6, the second driving signal DP2 has a duty ratio of 3 / 6.

[0039] The duty ratio of the second drive signal DP2 may be set for each DC motor 423 in accordance with individual differences between DC motors 423. For example, in a DC motor that tends to have a low rotation frequency, the duty ratio of the second drive signal DP2 may be set high.

[0040] [Drive Control: When Target Rotational Frequency is Changed] Next, drive control when the target rotational frequency of the DC motor of this embodiment is changed will be described with reference to Fig. 7. Fig. 7 is a diagram illustrating drive control when the target rotational frequency of the DC motor of this embodiment is changed.

[0041] FIG. 7 shows an example in which the target rotation frequency is changed from the state in which the rotation frequency has reached the target rotation frequency F1 [Hz] shown in FIG. 6 to F2 (>F1) [Hz].

[0042] In this embodiment, a constant drive voltage (power supply voltage) is supplied during a predetermined start-up period T11 when the target rotation frequency is changed, and PWM control is performed during a stable period T12 after the start-up period T11 has elapsed.

[0043] The motor control unit 60 outputs the third drive signal DP3 shown in FIG. 7 during a predetermined start-up period T11 when the target rotation frequency is changed. That is, the power supply voltage is supplied by keeping the switch included in the driver circuit 70 in a constant ON state. This makes it possible to keep the time required to reach the second target rotation frequency F2 constant regardless of individual differences in the DC motor 423. Furthermore, the rotation frequency of the DC motor 423 can reach the changed target rotation frequency in a short period of time.

[0044] During the stable period T12, the motor control unit 60 performs PWM control to output the fourth drive signal DP4 shown in FIG. 7 . That is, during the stable period T12, the switch included in the driver circuit 70 is alternately turned ON / OFF at predetermined intervals. The fourth drive signal DP4 is a signal composed of a plurality of short pulses that are output intermittently. FIG. 7 shows the fourth drive signal DP4 with a duty ratio of 4 / 6. The duty ratio of the fourth drive signal DP4 may be set for each DC motor 423 depending on the individual differences of the DC motor 423.

[0045] [Drive Control: Braking] When the supply of drive voltage is stopped, the DC motor 423 continues to rotate due to inertia and then stops. In this case, it takes time for the vibration of the vibrating unit 42 to stop, and the vibration becomes dull.

[0046] Therefore, in this embodiment, a configuration is adopted in which the motor control unit 60 outputs a braking signal in response to the video, etc., thereby forcibly and quickly stopping the rotation of the DC motor 423. For example, the DC motor 423 may be braked by connecting the coil of the DC motor 423 to the ground to eliminate the drive voltage, or the DC motor 423 may be braked electromagnetically by induced electromotive force generated by short-circuiting the coil terminals.

[0047] Fig. 6 shows an example in which the motor control unit 60 outputs a braking signal during a braking period T3 after a stable period T2, and Fig. 7 shows an example in which the motor control unit 60 outputs a braking signal during a braking period T13 after a stable period T12.

[0048] The braking period T13 is not limited to the period required for the rotation of the DC motor 423 to completely stop, but may be any period required for the rotation to weaken to the point where the user no longer feels the vibration.

[0049] 6 and 7, by adopting a configuration in which the rotation of the DC motor 423 is forcibly stopped by applying a braking force rather than waiting for it to stop due to inertia, it is possible to add sharpness to the vibration, thereby providing the user with a more realistic experience.

[0050] [Drive Control: Delay Suppression, etc.] Further, delay suppression, etc. in this embodiment will be described with reference to Fig. 8. Fig. 8 is a diagram schematically illustrating an example of drive control in this embodiment. Arrows in Fig. 8 indicate the output timing of drive instructions or braking instructions that are output in accordance with images displayed on the display panel 38, etc. For example, the arrow indicated with "25" indicates the timing at which a drive instruction is issued to output a drive signal with a target rotation frequency of 25 Hz.

[0051] In this embodiment, the motor control unit 60 is configured to input a drive instruction to be output in response to the image displayed on the display panel 38 during the braking period T3 during which the braking signal is being output. Furthermore, the motor control unit 60 waits until the braking period T3 has elapsed before starting to output a drive signal based on the drive instruction. That is, rather than immediately starting to output a drive signal based on the drive instruction after inputting the drive instruction, the motor control unit 60 accepts a reservation for outputting a drive signal based on the drive instruction. Even when a drive instruction is output during the braking period T3, the configuration of waiting until the braking period T3 has elapsed before outputting the next drive signal allows for more dynamic vibrations. Furthermore, by accepting a reservation for the next drive in advance, the motor control unit 60 can start outputting the next drive signal immediately after the braking period T3 has elapsed, thereby minimizing delays in outputting the next drive signal. As a result, the user can enjoy a more realistic experience.

[0052] In addition, in this embodiment, when drive instructions are issued consecutively, the operation based on the later drive instruction is prioritized. That is, when drive instructions are input multiple times during the braking period T3 in which a braking signal is being output, the motor control unit 60 outputs the next drive signal based on the drive instruction input last. Specifically, as shown in FIG. 8 , if a drive instruction to output a drive signal having a target rotation frequency of 25 Hz is input, and before the braking period T3 has elapsed, a drive instruction to output a drive signal having a target rotation frequency of 10 Hz is input, priority is given to outputting the drive signal having a target rotation frequency of 10 Hz.

[0053] Furthermore, in this embodiment, when a braking instruction is input after a drive instruction is input, the motor control unit 60 prioritizes braking. That is, when a braking instruction is input after a reservation for output of the next drive signal has been accepted, the reservation for output of the drive signal based on the drive instruction is canceled. This makes it possible to prevent vibration from continuing for a long period of time. As a result, it is possible to prevent the user from feeling uncomfortable due to the vibration continuing for a long period of time. Note that the braking instruction may be output when a predetermined period of time has elapsed since the most recent braking instruction was output, regardless of the situation of the video, etc.

[0054] [Table Related to Start-Up Period] Next, the relationship between the target rotation frequency and the start-up period will be described with reference to Fig. 9A and Fig. 9B. Fig. 9A is a diagram showing a table related to the target rotation frequency and the start-up period at startup. Fig. 9B is a diagram showing a table related to the target rotation frequency and the start-up period when the target rotation frequency is changed.

[0055] In this embodiment, as shown in FIGS. 9A and 9B , a configuration is adopted in which a table relating to the target rotation frequency and the rise-up period at startup and a table relating to the target rotation frequency and the rise-up period when the target rotation frequency is changed are managed separately. This is because, even if the target rotation frequency is the same, the required rise-up period differs between startup and when the target rotation frequency is changed. In other words, even if the target rotation frequency is the same, the rise-up period T1 and the rise-up period T11 differ. Managing the tables separately in this way allows for simplification of the tables. These tables may be stored, for example, in the storage unit 32.

[0056] As described above, the ramp-up period T1 shown in Fig. 6 may be set in advance according to the target rotation frequency. Fig. 9A shows an example in which the ramp-up periods T1 corresponding to target rotation frequencies of 10, 15, 20, and 25 Hz are t11, t12, t13, and t14 ms, respectively. Here, the relationship is t11 < t12 < t13 < t14. In other words, the ramp-up period T1 is set to be longer as the target rotation frequency increases.

[0057] The ramp-up period T11 shown in Fig. 7 may be set in advance depending on the target rotation frequency before and after the change. Fig. 9B shows the ramp-up period T11 when the target rotation frequency before the change is 10, 15, or 20 Hz and the target rotation frequency after the change is 15 to 25 Hz in 1 Hz increments. The ramp-up period T11 shown in Fig. 9B has the relationship t21<t22< ...<t211, and t212<t213 < ...<t217.

[0058] In this embodiment, if the difference between the target rotation frequency before and after the change is small, the start-up period T11 is not provided. For example, when driving is performed in accordance with a drive instruction to output a drive signal with a target rotation frequency of 15 Hz, if a drive instruction is output to output a drive signal with a target rotation frequency of 15 to 19 Hz, the start-up period T11 is not provided. By adopting this configuration, it is possible to reduce power consumption due to the unnecessary occurrence of the start-up period T11.

[0059] [Method of Determining Duty Ratio] Next, an example of a method of determining the duty ratio of the second drive signal DP2 for each DC motor 423 will be described with reference to FIG. 10. FIG. 10 is a diagram showing an approximate curve based on an approximate formula used to determine the duty ratio in this embodiment. The vertical axis of FIG. 10 represents the rotation frequency, and the horizontal axis represents the duty ratio of the second drive signal DP2. In FIG. 10, for example, "x14" represents the duty ratio required to obtain a rotation frequency of 14 Hz. Although not shown or described, the duty ratio of the fourth drive signal DP4 shown in FIG. 7 may also be determined using a similar method.

[0060] As described above, individual differences may occur in the DC motor 423, and therefore it is necessary to determine in advance the duty ratio of the second drive signal DP2 output during the stable period T2 for each DC motor 423 in accordance with these individual differences. For example, determining the duty ratio for each target rotation frequency between 10 and 25 Hz requires 16 adjustments, which is unproductive. The adjustments are performed to determine the duty ratio for each target rotation frequency in accordance with the individual differences.

[0061] Furthermore, if the adjustment work is performed multiple times depending on the number of target rotation frequencies, the driving time of the DC motor 423 during the adjustment work will be long. In a new or unused DC motor 423, the rotating shaft 421 breaks in as the motor rotates, and the rotation performance changes during the adjustment work. Therefore, if the adjustment work takes a long time, there is a possibility that accurate adjustment will not be possible.

[0062] Therefore, in this embodiment, the burden of the adjustment work is reduced by determining the duty ratio for each target rotation frequency using an approximation formula. Specifically, as shown in FIG. 10 , for example, appropriate duty ratios are first determined for target rotation frequencies of 14 Hz and 20 Hz. An approximation formula is then generated based on the two pieces of determined information. Then, the error between a curve (dashed line in FIG. 10 ) based on a relational expression previously generated according to the ideal performance of the DC motor 423 and an approximate curve (solid line in FIG. 10 ) based on the generated approximation formula is determined. If the error is within an acceptable range, appropriate duty ratios for target rotation frequencies other than 14 Hz and 20 Hz can be determined based on the generated approximation formula. The generation of the approximation formula and the error determination can be performed by a general-purpose computer (not shown).

[0063] By adopting the above-described method for determining the duty ratio, productivity can be improved and the precision of fitting can be improved.

Claims

1. a vibration unit including at least a motor, the vibration unit being provided in a head-mounted display having a display panel that is placed in front of the user's eyes when the head-mounted display is worn; a motor control unit that outputs a drive signal that controls a drive force that drives the vibration unit; and the motor control unit outputs a first drive signal that drives the vibration unit with a first drive force during a predetermined start-up period, and after the start-up period has elapsed, outputs a second drive signal that drives the vibration unit with a second drive force that is smaller than the first drive force and is composed of a plurality of intermittently output short pulses; the motor control unit is capable of outputting a braking signal that generates a braking force that brakes the driving of the vibration unit, when a drive instruction to output the drive signal in accordance with an image displayed on the display panel is input during a braking period in which the brake signal is being output, the motor control unit waits for the braking period to elapse before outputting the drive signal. Drive control system.

2. A vibration unit including at least a motor, which is provided in a head-mounted display having a display panel that is placed in front of a user's eyes when worn; a motor control unit that outputs a drive signal that controls a drive force that drives the vibration unit; and the motor control unit outputs a first drive signal that drives the vibration unit with a first drive force during a predetermined start-up period, and after the start-up period has elapsed, outputs a second drive signal that drives the vibration unit with a second drive force that is smaller than the first drive force and is composed of a plurality of intermittently output short pulses; the motor control unit is capable of outputting a braking signal that generates a braking force that brakes the driving of the vibration unit, when the motor control unit inputs a drive instruction to output the drive signal in accordance with an image displayed on the display panel multiple times during a braking period in which the brake signal is being output, the motor control unit outputs the next drive signal based on the drive instruction input last. Drive control system.

3. the predetermined start-up period includes a start-up period when changing the target rotation frequency of the motor. The drive control system according to claim 1 or 2.

4. the predetermined start-up period is set in advance according to a target rotation frequency of the motor; The drive control system according to claim 1 or 2.

5. the motor includes a rotating shaft and a weight that rotates together with the rotating shaft; the rotation axis is provided to extend in a direction along the display surface of the display panel. The drive control system according to claim 1 or 2.

6. A head-mounted display having a display panel that is placed in front of a user's eyes when worn, a vibration unit including at least a motor; a motor control unit that outputs a drive signal that controls a drive force that drives the vibration unit; and the motor control unit outputs a first drive signal that drives the vibration unit with a first drive force during a predetermined start-up period, and after the start-up period has elapsed, outputs a second drive signal that drives the vibration unit with a second drive force that is smaller than the first drive force and is composed of a plurality of intermittently output short pulses; the motor control unit is capable of outputting a braking signal that generates a braking force that brakes the driving of the vibration unit, when a drive instruction to output the drive signal in accordance with an image displayed on the display panel is input during a braking period in which the brake signal is being output, the motor control unit waits for the braking period to elapse before outputting the drive signal. Head-mounted display.

7. A drive control method for controlling a drive force for driving a vibration unit including at least a motor, the vibration unit being provided in a head-mounted display having a display panel that is placed in front of a user's eyes when the display panel is worn, comprising: outputting a first drive signal that drives the vibration unit with a first drive force during a predetermined start-up period; After the start-up period has elapsed, a second drive signal is output, the second drive signal being composed of a plurality of intermittently output single pulses, and driving the vibration unit with a second drive force that is smaller than the first drive force; outputting a braking signal that generates a braking force that brakes the driving of the vibration unit; When a drive instruction to output the drive signal in accordance with an image displayed on the display panel is input during a braking period in which the braking signal is being output, the drive signal is output after waiting for the braking period to elapse. Drive control method.