Head mounted device

Abstract

To provide a head-mounted device capable of reducing power consumption.SOLUTION: A head-mounted device includes a detector configured to detect an opening degree of an eye, a display including a light emitter configured to emit light, and a controller configured to control brightness of the light based on the opening degree.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to head-mounted devices. [Background technology]

[0002] Patent Document 1 discloses a mobile device. In this mobile device, when the viewer's line of sight is not directed onto the liquid crystal display panel, all matrix elements of the backlight are turned off. When the viewer's line of sight is directed onto the liquid crystal display panel, the viewpoint position on the liquid crystal display panel is calculated, and of all the matrix elements constituting the backlight, only those matrix elements corresponding to the vicinity of the calculated viewpoint position are turned on. This allows the mobile device to save power (paragraphs 0011, 0012, 0016, 0017, and 0023). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-209610 Summary of the Invention [Problem to be solved by the invention]

[0004] In the mobile device disclosed in Patent Document 1, the liquid crystal display panel remains lit even when the viewer blinks and is no longer looking at the liquid crystal display panel, which makes it difficult to achieve sufficient power saving in the mobile device.

[0005] In view of this problem, an aspect of the present disclosure has been made. An object of the present disclosure is to provide, for example, a head-mounted device that can reduce power consumption. [Means for solving the problem]

[0006] A head-mounted device according to one aspect of the present disclosure includes a detection unit that detects the degree of eye opening, a display having a light-emitting unit that emits light, and a controller that controls the brightness of the light based on the degree of opening. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a perspective view schematically illustrating a head-mounted device of a first embodiment and a person wearing the head-mounted device. [Figure 2] FIG. 2 is a block diagram of a main body provided in the head-mounted device of the first embodiment. [Figure 3] 1 is a timing chart showing the waveform of a gate start pulse signal output by a timing controller provided in a head-mounted device of the first embodiment, the waveform of a gate scan signal output by a gate driver provided in the head-mounted device, and the change over time in the state of a backlight provided in the head-mounted device. [Figure 4] 5 is a flowchart showing the flow of control performed by a timing controller provided in the head-mounted device of the first embodiment. [Figure 5] 10 is a timing chart showing the time change in the state of a backlight provided in a head-mounted device of a comparative example. [Figure 6] 4 is a timing chart showing the time change in the state of a backlight provided in the head-mounted device of the first embodiment. [Figure 7] 10A and 10B are diagrams showing changes in the state of a backlight provided in a head-mounted device of the second embodiment during blinking. [Figure 8] 10 is a flowchart showing the flow of control performed by a timing controller provided in the head-mounted device of the second embodiment. [Figure 9] 10A and 10B are diagrams showing the state of a backlight provided in a head-mounted device of the third embodiment and changes in the brightness of light emitted by the backlight during blinking. [Figure 10]10 is a flowchart showing the flow of control performed by a timing controller provided in the head-mounted device of the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same or equivalent elements are designated by the same reference numerals, and redundant description will be omitted.

[0009] 1. First embodiment 1.1 Appearance of the head-mounted device FIG. 1 is a perspective view schematically illustrating a head-mounted device of the first embodiment and a person wearing the head-mounted device.

[0010] The head-mounted device 1 of the first embodiment shown in FIG. 1 is mounted on the head 202 of a person 201 and displays an image to be recognized by the person 201. The head-mounted device 1 is a goggle-type head-mounted device. The head-mounted device 1 may be a head-mounted device other than a goggle-type head-mounted device. For example, the head-mounted device 1 may be a glasses-type head-mounted device, a helmet-type head-mounted device, or the like.

[0011] The head-mounted device 1 is a cross-reality (XR) device. The XR device may be a virtual reality (VR) device, an augmented reality (AR) device, a mixed reality (MR) device, an alternate reality (SR) device, or the like.

[0012] As shown in FIG. 1, the head-mounted device 1 comprises a main body 11 and a strap 12 .

[0013] The main body 11 is placed in front of the eyes of the head 202 and displays an image that is viewed by the eyes.

[0014] The strap 12 secures the main body 11 to the head 202. This allows the strap 12 to maintain the main body 11 positioned in front of the head 202. The strap 12 may be replaced with other types of fastening mechanisms. For example, the strap 12 may be replaced with temples.

[0015] 1.2 Inside the head-mounted device FIG. 2 is a block diagram of a main body provided in the head-mounted device of the first embodiment.

[0016] As shown in FIG. 2, the main body 11 includes a system 21, which includes a gaze detection sensor 22 and a display 23 for each of the left and right eyes.

[0017] The gaze detection sensor 22 detects the gaze of the eyes and the degree of eye opening, and outputs gaze information 31 indicating the detected gaze and opening degree information 32 indicating the detected degree of eye opening.

[0018] The gaze detection sensor 22 includes an image sensor and a processing circuit (not shown). The image sensor captures an image of the eye and its surroundings. As a result, the image sensor generates image data representing an image including the image of the eye. The image processing circuit processes the generated image data to generate gaze information 31 and eye opening degree information 32. The image processing circuit recognizes the eye image and detects the gaze and eye opening degree from the recognized eye image. The image sensor may be a charge-coupled device (CCD) image sensor, a complementary metal-oxide semiconductor (CMOS) image sensor, or the like.

[0019] The system 21 outputs opening degree information 32 and image information 33. The opening degree information 32 is added to the image information 33. The system 21 is composed of a processing circuit, a microcontroller, etc. The microcontroller has a processor and a memory. The processor executes a program stored in the memory to cause the microcontroller to perform all or part of the processing performed by the system 21.

[0020] Display 23 emits light to display an image according to output image information 33. Display 23 adjusts the brightness of the emitted light to a brightness according to output opening degree information 32.

[0021] In recent years, most head-mounted devices have been equipped with a gaze detection sensor. For this reason, it is often unnecessary to provide an additional gaze detection sensor in the head-mounted device in order to provide the head-mounted device with the function of emitting light having a brightness corresponding to the opening degree information 32. However, when providing this function to a head-mounted device that does not have a gaze detection sensor, it is necessary to provide the head-mounted device with an additional gaze detection sensor.

[0022] 1.3 Display As shown in FIG. 2, the display 23 includes a backlight 41, a liquid crystal panel 42, and a timing controller 43.

[0023] The backlight 41 emits light.

[0024] The liquid crystal panel 42 modulates the emitted light to display an image.

[0025] The timing controller 43 controls the liquid crystal panel 42 in accordance with the image information 33. As a result, the timing controller 43 causes the liquid crystal panel 42 to modulate light in accordance with the image information 33.

[0026] The timing controller 43 controls the backlight 41 according to the eye opening degree information 32. As a result, the timing controller 43 causes the backlight 41 to emit light according to the eye opening degree information 32. The timing controller 43 controls the brightness of the light based on the eye opening degree represented by the eye opening degree information 32. As a result, the brightness of the light can be adjusted to a brightness appropriate for the eye opening degree. As a result, the power consumption of the backlight 41 can be reduced. When the eye opening degree indicates that the eyes are closed, the timing controller 43 dims the brightness of the light. As a result, when the person 201 is unable to recognize an image displayed on the display 23 due to blinking or the like, the brightness of the light can be dimmed. As a result, the power consumption of the backlight 41 can be reduced without preventing the person 201 from recognizing an image displayed on the display 23. Dimming the brightness of the light is performed by turning off the backlight 41 to turn off the display 23. Dimming the brightness of the light may also be performed by dimming the backlight 41 to dim the display 23.

[0027] 1.4 Backlight The backlight 41 is an edge-type backlight. Therefore, as shown in Fig. 2, the backlight 41 includes light-emitting diodes (LEDs) 51, a light guide plate 52, and an LED driver 53. The backlight 41 may also be a direct-type backlight.

[0028] The LED 51 emits light.

[0029] The light guide plate 52 guides light that has entered an end surface of the light guide plate 52, and emits the guided light from the main surface of the light guide plate 52. The emitted light illuminates the display region 42a of the liquid crystal panel 42. The light guide plate 52 illuminates the display region 42a of the liquid crystal panel 42 substantially uniformly.

[0030] The LED driver 53 drives the LED 51 to cause the LED 51 to emit light.

[0031] The timing controller 43 can control the timing at which the LED driver 53 turns on the LED 51. The timing controller 43 turns on the LED 51 when the eye opening degree represented by the eye opening degree information 32 indicates that the eyes are open. The timing controller 43 turns off the LED 51 when the eye opening degree indicates that the eyes are closed.

[0032] 1.5 LCD panel 2, the liquid crystal panel 42 includes a liquid crystal panel main body 61, a gate driver 62, and a source driver 63. The liquid crystal panel main body 61 includes n gate lines, m source lines, and m×n pixels (not shown). The m×n pixels are arranged in a display area 42a of the liquid crystal panel 42. n and m are integers of 2 or greater.

[0033] The gate driver 62 drives a gate line selected from the n gate lines, thereby bringing the m pixels connected to the selected gate line into a state in which a voltage can be written.

[0034] The source driver 63 drives m source lines. As a result, the source driver 63 writes voltages into m pixels that are connected to the m source lines and are ready to receive voltages. As a result, the source driver 63 sets the light transmittance of the m pixels to a light transmittance that corresponds to the written voltage.

[0035] The timing controller 43 controls the gate driver 62. The gate driver 62 selects and drives n gate lines in sequence according to the control.

[0036] The timing controller 43 controls the source driver 63. In accordance with this control, the source driver 63 drives m source lines with a voltage according to one line of image information included in the image information 33 and corresponding to the selected gate line, writes a voltage according to the image information for that one line to m pixels connected to the selected gate line, and sets the light transmittance of the m pixels to the light transmittance according to the image information for that one line.

[0037] As a result, the gate driver 62 and the source driver 63 write voltages according to the image information 33 to the m×n pixels in accordance with the control performed by the timing controller 43, and set the light transmittance of the m×n pixels to the light transmittance according to the image information 33. In this way, the timing controller 43 causes the liquid crystal panel 42 to modulate light according to the image information 33.

[0038] 1.6 Turning the backlight on and off Figure 3 is a timing chart showing the waveform of a gate start pulse signal output by a timing controller provided in the head-mounted device of the first embodiment, the waveform of a gate scan signal output by a gate driver provided in the head-mounted device, and the change over time in the state of a backlight provided in the head-mounted device.

[0039] In the timing chart of FIG. 3, the horizontal axis represents time, and the vertical axis represents the level of the gate start pulse signal, the level of the gate scan signal, and the state of the backlight 41.

[0040] 3, one frame 71, which is each of the multiple frames, includes a panel scan period 81, a liquid crystal response period 82, and lighting timing 83. The gate start pulse signal includes one gate start pulse 91 within one frame 71. The gate scan signal includes n gate pulses 92 within one frame 71.

[0041] The panel scan period 81 starts in synchronization with the timing controller 43 inputting a gate start pulse 91 to the gate driver 62. During the panel scan period 81, the gate driver 62 inputs n gate pulses 92 to n gate lines, respectively, to sequentially drive the n gate lines. This causes voltages corresponding to the image information 33 to be written to m×n pixels. During the panel scan period 81, the backlight 41 is turned off. Hereinafter, inputting n gate pulses 92 to n gate lines, respectively, to sequentially drive the n gate lines will also be referred to as "panel scan."

[0042] The liquid crystal response period 82 is a period following the panel scan period 81. During the liquid crystal response period 82, the m×n pixels respond to the written voltages and have light transmittances corresponding to the written voltages. During the liquid crystal response period 82, the backlight 41 is turned off.

[0043] The lighting timing 83 is a period following the liquid crystal response period 82. At the lighting timing 83, the timing controller 43 turns on the backlight 41 when the eye opening degree represented by the eye opening degree information 32 indicates that the eyes are open, and turns off the backlight 41 when the eye opening degree indicates that the eyes are closed. When turning on the backlight 41, the timing controller 43 turns on the backlight 41 at a set duty ratio, for example, a 10% duty ratio. The timing controller 43 may turn on the backlight 41 at a first brightness when the eye opening degree indicates that the eyes are open, and may turn on the backlight 41 at a second brightness that is darker than the first brightness when the eye opening degree indicates that the eyes are closed.

[0044] The gaze detection sensor 22 constitutes a detection unit that detects the degree of eye opening. The backlight 41 constitutes a light-emitting unit that emits light. The timing controller 43 constitutes a controller that controls the brightness of the light emitted by the backlight 41 based on the degree of eye opening represented by the eye opening degree information 32. The liquid crystal panel 42 is an example of a light modulation type panel that modulates the emitted light. Therefore, the liquid crystal panel 42 may be replaced with another type of light modulation type panel. The liquid crystal panel 42 and the backlight 41 may be replaced with a self-luminous panel. When the liquid crystal panel 42 and the backlight 41 are replaced with a self-luminous panel, the self-luminous panel constitutes the light-emitting unit that emits light. Furthermore, the timing controller 43 constitutes a controller that controls the brightness of the light emitted by the self-luminous panel based on the degree of eye opening. An element other than the timing controller 43 may constitute a controller that controls the brightness of the light emitted by the backlight 41 based on the degree of eye opening represented by the eye opening degree information 32.

[0045] 1.7 Control Flow FIG. 4 is a flowchart showing the flow of control performed by the timing controller provided in the head-mounted device of the first embodiment.

[0046] The timing controller 43 executes steps S101 to S104 shown in FIG.

[0047] In step S101, the timing controller 43 inputs a gate start pulse 91 to the gate driver 62 to start one frame 71.

[0048] In the following step S102, the timing controller 43 causes the gate driver 62 to perform a panel scan.

[0049] In the following step S103, the timing controller 43 determines whether the eyes are completely closed based on the degree of eye opening represented by the degree-of-eye-opening information 32. If it is determined that the eyes are completely closed, step S101 is executed without executing step S104. If it is determined that the eyes are even slightly open, step S104 is executed and then step S101 is executed.

[0050] In the following step S104, the timing controller 43 turns on the backlight 41.

[0051] If the eyes are completely closed according to steps S101 to S104, steps S101 to S103 are repeatedly executed, but step S104 is not executed. If the eyes are not completely closed, steps S121 to S124 are repeatedly executed. Therefore, whether or not step S104 is executed depends on whether or not the eyes are completely closed.

[0052] Through steps S101 to S104, if the eyes are closed due to blinking or the like, timing controller 43 ends one frame 71 with backlight 41 turned off at lighting timing 83. If the eyes are open, timing controller 43 turns on backlight 41 at lighting timing 83 and then ends one frame 71. This makes it possible to reduce the power consumption of head-mounted device 1 by the amount of power required to turn on backlight 41 when the eyes are closed.

[0053] The timing controller 43 determines whether to turn on the backlight 41 during a liquid crystal response period 82 included in a pre-lighting period 84 before the lighting timing 83, and turns on or off the backlight 41 according to the determination made at the lighting timing 83 after the pre-lighting period 84. The liquid crystal response period 82, during which the determination as to whether to turn on the backlight 41 is made, is a period after the panel scan period 81. Therefore, the timing controller 43 causes the gate driver 62 to perform a panel scan regardless of the determination.

[0054] 1.8 Comparison between Comparative Example and First Embodiment Fig. 5 is a timing chart showing the time change in the state of a backlight provided in a head-mounted device of a comparative example. Fig. 6 is a timing chart showing the time change in the state of a backlight provided in a head-mounted device of the first embodiment.

[0055] In the timing charts of FIGS. 5 and 6, the horizontal axis represents time, and the vertical axis represents the state of the backlight.

[0056] 5, in the comparative example, the backlight is turned on repeatedly at a fixed cycle, always turning on once per frame 71. Therefore, the backlight is turned on in both frames 71 that belong to period 101 when the eyes are open and frames 71 that belong to period 102 when the eyes are closed due to blinking or the like.

[0057] 6, in the first embodiment, backlight 41 repeatedly lights up at a constant cycle during period 101 when the eyes are open, but stops repeatedly lighting up at a constant cycle during period 102 when the eyes are closed due to blinking or the like. Therefore, backlight 41 lights up during frames 71 that belong to period 101 when the eyes are open, but does not light up during frames 71 that belong to period 102 when the eyes are closed due to blinking or the like.

[0058] 1.9 Estimation of the reduction rate of backlight power consumption The average blinking frequency is said to be 10 to 30 times per minute. The average blinking duration is said to be 0.1 to 0.3 seconds. Therefore, for the following cases 1 to 5, we estimated the number of frames in which the backlight 41 was not lit and the reduction rate of power consumption of the backlight 41 due to the presence of frames in which the backlight 41 was not lit.

[0059] Case 1: The blinking cycle is 10 times per minute and the blinking time is 0.1 seconds. Case 2: The blinking cycle is 15 times per minute and the blinking time is 0.1 seconds. Case 3: The blinking cycle is 15 times per minute and the blinking time is 0.15 seconds. Case 4: The blinking cycle is 20 times per minute and the blinking time is 0.2 seconds. Case 5: The blinking cycle is 30 times per minute and the blink duration is 0.3 seconds.

[0060] In the calculation, the frame frequency was 120 Hz and the number of lighting timings 83 included in one minute was 7200. The results of the calculation are shown in Table 1.

[0061] [Table 1]

[0062] As shown in Table 1, in Case 1, where the blink frequency is 10 times per minute, which is the lower limit of the range of typical blink frequencies, and the blink duration is 0.1 seconds, which is the lower limit of the range of typical blink durations, the reduction rate of power consumption by backlight 41 is 1.7%. In Case 3, where the blink frequency is 15 times per minute, which is the average blink frequency, and the blink duration is 0.15 seconds, which is the average blink duration, the reduction rate of power consumption by backlight 41 is 3.8%. In this way, by having frames in which backlight 41 is not lit, the power consumption of backlight 41 can be reduced.

[0063] 1.10 Eye-gaze detection sensor The gaze detection sensor 22 must detect changes in the degree of eye opening due to blinking, etc. For this reason, the image sensor provided in the gaze detection sensor 22 must be driven at a frequency that can track changes in the degree of eye opening due to blinking, etc., and must be driven at, for example, 90 to 120 Hz. When the image sensor is driven at 120 Hz, each frame captured by the image sensor has a length of approximately 8 ms.

[0064] The time that the eyes are closed during a blink is approximately 0.1 to 0.3 seconds. Therefore, in order to detect changes in the degree of eye opening due to blinking with high accuracy, gaze detection sensor 22 must detect whether the eyes are open at intervals that are sufficiently shorter than this time, for example, at intervals of 80 ms or less. Therefore, when each frame captured by an image sensor has a length of approximately 8 ms, gaze detection sensor 22 must detect whether the eyes are open every 10 frames, preferably every few frames such as every two or three frames, and more preferably every frame.

[0065] The gaze detection sensor 22 only needs to detect whether the eyes are open or not. Therefore, in the gaze detection sensor 22, if the image processing circuit detects the eyeball, iris, or pupil, it is determined that the eyes are open, and if the image processing circuit does not detect the eyeball, iris, or pupil, it is determined that the eyes are closed.

[0066] 2. Second embodiment The following describes the differences between the second embodiment and the first embodiment. For points that are not described, the second embodiment also employs the same configuration as that employed in the first embodiment.

[0067] FIG. 7 is a diagram showing changes in the state of the backlight provided in the head-mounted device of the second embodiment during blinking.

[0068] In the second embodiment, as shown in FIG. 7 , when the eye opening degree represented by the eye opening degree information 32 decreases over time from OP1 to OP7, the timing controller 43 turns on the backlight 41 when the eye opening degree is greater than a first specific eye opening degree OP5, and turns off the backlight 41 when the eye opening degree is less than the first specific eye opening degree OP5. When the eye opening degree increases over time from OP8 to OP14, the timing controller 43 turns off the backlight 41 when the eye opening degree is less than a second specific eye opening degree OP9, and turns on the backlight 41 when the eye opening degree is greater than the second specific eye opening degree OP9. The first specific eye opening degree OP5 and the second specific eye opening degree OP9 indicate that the eyes are not completely closed. The first specific eye opening degree OP5 is an eye opening degree at which the person 201 cannot recognize an image displayed on the display 23. The second specific eye opening degree OP9 is one step smaller than the eye opening degree OP10 at which person 201 can recognize the image displayed by display 23. Therefore, the second specific eye opening degree OP9 is preferably smaller than the first specific eye opening degree OP5.

[0069] Therefore, when the degree of eye opening represented by the degree-of-eye-opening information 32 becomes smaller than the first specific degree of eye opening OP5, the timing controller 43 turns off the backlight 41. Also, when the degree of eye opening becomes larger than the second specific degree of eye opening OP9, the timing controller 43 turns on the backlight 41.

[0070] As a result, the timing controller 43 changes the state of the backlight 41 from an on state to an off state while the eyes are closing in the first half of a blink. The timing controller 43 changes the state of the backlight 41 from an off state to an on state while the eyes are opening in the second half of a blink. As a result, the backlight on period during which the backlight 41 is on is shortened to the period during which the eye opening degree changes from an opening degree OP1 indicating that the eyes are fully open to a first specific opening degree OP5 and the period during which the eye opening degree changes from a second specific opening degree OP9 to an opening degree OP14 indicating that the eyes are fully open. Furthermore, the off period during which the backlight 41 is off is extended to the period during which the eye opening degree changes from the first specific opening degree OP5 to a fourth specific opening degree OP9 via opening degrees OP7 / OP8 indicating that the eyes are fully open. This further reduces the power consumption of the backlight 41.

[0071] The backlight-on period includes a period when the eyes are not completely closed, but the field of view of the eyes is significantly darkened during this period. Therefore, even if backlight 41 is turned off during this period, person 201 is not substantially prevented from recognizing the image displayed on display 23.

[0072] FIG. 8 is a flowchart showing the flow of control performed by the timing controller provided in the head-mounted device of the second embodiment.

[0073] In the second embodiment, the timing controller 43 executes steps S111 to S117. It is assumed that the eyes are fully open when step S111 is executed.

[0074] In step S111, the timing controller 43 inputs a gate start pulse 91 to the gate driver 62. In response to this, the timing controller 43 starts one frame 71.

[0075] In the following step S112, the timing controller 43 causes the gate driver 62 to perform a panel scan.

[0076] In the following step S113, timing controller 43 determines whether the degree of eye opening represented by the degree-of-eye-opening information 32 is smaller than the first specific degree of eye opening OP5. If it is determined that the degree of eye opening is smaller than the first specific degree of eye opening OP5, step S114 is executed. If it is determined that the degree of eye opening is larger than the first specific degree of eye opening OP5, step S117 is executed, followed by step S111.

[0077] In step S117, the timing controller 43 turns on the backlight 41.

[0078] When the eyes are gradually closed through steps S111 to S113 and S117, steps S111 to S113 and S117 are repeatedly executed before the degree of eye opening becomes smaller than the first specific degree of eye opening OP5. Therefore, backlight 41 is turned on. After the degree of eye opening becomes smaller than the first specific degree of eye opening OP5, the repeated execution of steps S111 to S113 and S117 is stopped, and steps S114 to S116 are executed.

[0079] In step S114, the timing controller 43 inputs a gate start pulse 91 to the gate driver 62 to start one frame 71.

[0080] In the following step S115, the timing controller 43 causes the gate driver 62 to perform a panel scan.

[0081] In the following step S116, timing controller 43 determines whether the eye opening degree represented by opening degree information 32 is greater than a second specific opening degree OP9. If it is determined that the eye opening degree is greater than the second specific opening degree OP9, step S117 is executed, followed by step S111. If it is determined that the eye opening degree is less than the second specific opening degree OP9, step S114 is executed.

[0082] When the eyes are opening through steps S114 to S116 and S117, steps S114 to S116 are repeatedly executed, and step S117 is not executed, before the degree of eye opening becomes greater than the second specific degree of eye opening OP9. As a result, the backlight 41 does not light up. After the degree of eye opening becomes greater than the second specific degree of eye opening OP9, the repeated execution of steps S114 to S116 is stopped, and step S117 is executed. As a result, the backlight 41 lights up.

[0083] According to steps S111 to S117, the backlight 41 is turned on in step S117 when it is determined in step S113 that the eye opening degree is greater than the first specific eye opening degree OP5, and when it is determined in step S116 that the eye opening degree is greater than the second specific eye opening degree OP9. The timing controller 43 turns off the backlight 41 and ends one frame 71 during the period from when the eye opening degree represented by the eye opening degree information 32 reaches the first specific eye opening degree OP5 to when the eye opening degree reaches the second specific eye opening degree OP9. Furthermore, the timing controller 43 turns on the backlight 41 and ends one frame 71 during the period before the eye opening degree reaches the first specific eye opening degree OP5 and the period after the eye opening degree reaches the second specific eye opening degree OP9. This allows the power consumption of the head-mounted device 1 to be reduced by the amount of power required to turn on the backlight 41 when the eyes are closed.

[0084] In the second embodiment, the gaze detection sensor 22 detects the degree of eye opening so as to identify which of three or more different stages of eye opening the eye is in. For this reason, in the gaze detection sensor 22, for example, an image processing circuit detects the area of ​​the eyeball, and the degree of eye opening is determined based on the area of ​​the detected eyeball area. Furthermore, if the area of ​​the eyeball area detected in the next frame is smaller than the area of ​​the eyeball area detected in the previous frame, it is determined that the degree of eye opening is decreasing over time. Furthermore, if the area of ​​the eyeball area detected in the next frame is larger than the area of ​​the eyeball area detected in the previous frame, it is determined that the degree of eye opening is increasing over time.

[0085] When the degree of eye opening is determined based on the area of ​​the eyeball region, the degree of eye opening when the area of ​​the eyeball region is at its maximum is determined as the degree of eye opening OP1 / OP14, which indicates that the eye is fully open. The degree of eye opening when the area of ​​the eyeball region is at its minimum is determined as the degree of eye opening OP7 / OP8, which indicates that the eye is fully closed. The degree of eye opening when the area of ​​the eyeball region is, for example, 0.2 times the maximum is determined as the first specific degree of eye opening OP5. Furthermore, the degree of eye opening when the area of ​​the eyeball region is, for example, 0.1 times the maximum is determined as the second specific degree of eye opening OP9.

[0086] 3 Third embodiment The following describes the differences between the third embodiment and the second embodiment. For points that are not described, the third embodiment also employs the same configuration as that employed in the second embodiment.

[0087] FIG. 9 is a diagram showing the state of a backlight provided in a head-mounted device of the third embodiment and changes in the luminance of light emitted by the backlight during blinking.

[0088] In the third embodiment, as shown in FIG. 9, when the degree of eye opening represented by the degree of eye opening information 32 decreases over time from degree of eye opening OP1 to degree of eye opening OP7, the timing controller 43 turns on the backlight 41 brightly when the degree of eye opening is greater than the first specific degree of eye opening OP5, turns on the backlight 41 dimly when the degree of eye opening is less than the first specific degree of eye opening OP5 but greater than the third specific degree of eye opening OP6, and turns off the backlight 41 when the degree of eye opening is less than the third specific degree of eye opening OP6. Furthermore, when the eye opening degree represented by the eye opening degree information 32 increases over time from the eye opening degree OP8 to the eye opening degree OP14, the timing controller 43 turns off the backlight 41 when the eye opening degree is smaller than the fourth specific eye opening degree OP9, turns on the backlight 41 dimly when the eye opening degree is larger than the fourth specific eye opening degree OP9 but smaller than the second specific eye opening degree OP10, and turns on the backlight 41 brightly when the eye opening degree is larger than the second specific eye opening degree OP10. The first specific eye opening degree OP5, the second specific eye opening degree OP10, the third specific eye opening degree OP6, and the fourth specific eye opening degree OP9 indicate that the eyes are not completely closed. The first specific eye opening degree OP5 and the second specific eye opening degree OP10 are eye opening degrees at which the person 201 cannot recognize the image displayed on the display 23. The third specific eye opening degree OP6 and the fourth specific eye opening degree OP9 are eye opening degrees that are one step smaller than the eye opening degrees OP5 and OP10 at which person 201 can recognize the image displayed by display 23. Therefore, the third specific eye opening degree OP6 and the fourth specific eye opening degree OP9 are smaller than the first specific eye opening degree OP5 and the second specific eye opening degree OP10. The brightness of the light emitted by backlight 41 when backlight 41 is dimly lit is lower than the brightness of the light emitted by backlight 41 when backlight 41 is brightly lit.

[0089] Therefore, after the eye opening degree represented by the eye opening degree information 32 becomes smaller than the first specific eye opening degree OP5, the timing controller 43 gradually decreases the brightness of the light emitted by the backlight 41 as the eye opening degree becomes smaller. Furthermore, before the eye opening degree becomes larger than the second specific eye opening degree OP10, the timing controller 43 gradually increases the brightness of the light emitted by the backlight 41 as the eye opening degree becomes larger. The timing controller 43 may continuously decrease the brightness of the light emitted by the backlight 41 as the eye opening degree becomes smaller. The timing controller 43 may continuously increase the brightness of the light emitted by the backlight 41 as the eye opening degree becomes larger. This makes it less likely that the person 201 will notice a change in the brightness of the light emitted by the display 23.

[0090] 4 Fourth embodiment The following describes the differences between the fourth embodiment and the first embodiment. For points that are not described, the fourth embodiment also employs the same configuration as that employed in the first embodiment.

[0091] FIG. 10 is a flowchart showing the flow of control performed by the timing controller provided in the head-mounted device of the fourth embodiment.

[0092] In the fourth embodiment, the timing controller 43 executes steps S121 to S124 shown in FIG.

[0093] In step S121, the timing controller 43 inputs a gate start pulse 91 to the gate driver 62 to start one frame 71.

[0094] In the following step S123, the timing controller 43 determines whether the eyes are completely closed. If it is determined that the eyes are completely closed, step S121 is executed without executing steps S123 and S124. If it is determined that the eyes are even slightly open, step S121 is executed after steps S123 and S124 are executed.

[0095] In step S124, the timing controller 43 causes the gate driver 62 to perform a panel scan.

[0096] In the following step S124, the timing controller 43 turns on the backlight 41.

[0097] According to steps S121 to S124, if the eyes are completely closed, steps S121 and S122 are repeatedly executed, but steps S123 and S124 are not executed. If the eyes are not completely closed, steps S121 to S124 are repeatedly executed. Therefore, whether or not steps S123 and S124 are executed depends on whether or not the eyes are completely closed.

[0098] In the fourth embodiment, the timing controller 43 determines whether to turn on the backlight 41 before the panel scan period 81, and if the backlight 41 is to be turned off according to the determination, the timing controller 43 causes the gate driver 62 to stop performing panel scanning during the panel scan period 81. This makes it possible to reduce the power consumption of the head-mounted device 1 by the amount of power required for the gate driver 62 to perform panel scanning when the eyes are closed.

[0099] The present disclosure is not limited to the above-described embodiments, and may be replaced with a configuration that is substantially the same as the configuration shown in the above-described embodiments, a configuration that has the same effect, or a configuration that can achieve the same purpose. [Explanation of symbols]

[0100] 1 Head-mounted device 11 Main unit 12 Straps 21 System 22 Eye gaze detection sensor 23 Display 31 Gaze information 32 Opening information 33 Image information 41 Backlight 42 LCD panel 43 Timing Controller 51 Light Emitting Diode (LED) 52 Light guide plate 53 LED drivers 61 LCD panel body 62 Gate Driver 63 Source Driver 71 1 frame 81 Panel Scan Period 82 LCD response time 83 Lighting timing 84 Pre-lighting period 91 Gate Start Pulse 92 Gate Pass 101 The Period When Eyes Are Open 201 people 202 Head 102 Eyes Closed

Claims

1. a detection unit that detects the degree of eye opening; a display having a light-emitting portion that emits light; a controller that controls the brightness of the light based on the degree of opening; A head-mounted device comprising:

2. Controlling the brightness based on the degree of opening includes dimming the brightness when the degree of opening indicates that the eyes are closed. The head-mounted device of claim 1 .

3. The dimming includes turning off the display.

3. The head-mounted device of claim 2.

4. the light-emitting unit is a backlight, The display includes a liquid crystal panel that modulates the light. A head-mounted device according to any one of claims 1 to 3.

5. Controlling the brightness based on the degree of opening includes determining the brightness based on the degree of opening during a pre-lighting period included in each frame, and controlling the brightness according to the determination at a lighting timing after the pre-lighting period included in each frame.

5. The head-mounted device of claim 4.

6. the controller sequentially drives a plurality of gate lines of the liquid crystal panel during a panel scan period included in the pre-lighting period; Making the determination during the pre-lighting period includes making the determination after the panel scan period.

6. The head-mounted device of claim 5.

7. the controller sequentially drives a plurality of gate lines of the liquid crystal panel during a panel scan period included in the pre-lighting period; performing the determination during the pre-lighting period includes performing the determination before the panel scan period, The controller stops sequentially driving the plurality of gate lines during the panel scan period when the brightness is to be reduced according to the determination.

6. The head-mounted device of claim 5.

8. Controlling the brightness based on the degree of opening includes dimming the brightness when the degree of opening is smaller than a specific degree of opening that indicates that the eyes are not completely closed.

3. A head-mounted device according to claim 1 or 2.

9. the specific opening degree is a first specific opening degree, Controlling the brightness based on the degree of opening includes increasing the brightness when the degree of opening exceeds a second specific opening that indicates that the eye is not completely closed.

9. The head-mounted device of claim 8.

10. The second specific opening degree is smaller than the first specific opening degree.

10. The head-mounted device of claim 9.

11. Controlling the brightness based on the degree of opening includes, when the degree of opening is smaller than a set degree of opening, decreasing the brightness as the degree of opening becomes smaller. A head-mounted device according to any one of claims 1 to 3.

12. The detection unit detects the degree of opening at time intervals of 80 ms or less. A head-mounted device according to any one of claims 1 to 3.

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