WO2024047931A1

WO2024047931A1 - Optical path control device, display device, and optical path control method

Info

Publication number: WO2024047931A1
Application number: PCT/JP2023/015470
Authority: WO
Inventors: 裕之 ▲高▼田
Original assignee: 株式会社Ｊｖｃケンウッド
Priority date: 2022-08-31
Filing date: 2023-04-18
Publication date: 2024-03-07
Also published as: JP2024034291A

Abstract

The present invention suitably displays a moving image while suitably oscillating an oscillation part. The present invention comprises: an oscillation part that has an optical part on which light is incident; an actuator that is capable of oscillating the oscillation part; a driving part that applies a drive signal to the actuator, thereby causing the actuator to oscillate the oscillation part and controlling an optical path; and a control part that controls the driving part, wherein the control part sets, for each frame in which an image is displayed, the number of subframes in which some of pixels included in image data of a frame are displayed, and sets the oscillation speed of the oscillation part on the basis of the number of subframes.

Description

Optical path control device, display device, and optical path control method

The present invention relates to an optical path control device, a display device, and an optical path control method.

For example, in an image display device using a liquid crystal display element, in order to increase the resolution in a pseudo manner, one frame display period is divided into multiple subframe display periods, and each subframe display period is projected onto a screen. However, there is a technique that makes it appear as if more pixels than the number of pixels of the light modulation element are projected by controlling the light path control device so that the position of the light is shifted. For example, such a technique is described in Patent Document 1 below.

Patent No. 3863445

In this way, in a method in which one frame display period is divided into a plurality of subframe display periods, the projection position may be shifted by swinging the optical member using the optical path control device. In this case, it is required to appropriately display a moving image while appropriately swinging the swinging section.

In view of the above-mentioned problems, the present embodiment aims to provide an optical path control device, a display device, and an optical path control method that can appropriately display a moving image while appropriately swinging a swinging section.

An optical path control device according to an aspect of the present embodiment includes: a swinging section having an optical section into which light enters; an actuator capable of swinging the swinging section; and applying a drive signal to the actuator. A drive unit that controls an optical path by causing an actuator to swing the swing unit, and a control unit that controls the drive unit, and the control unit controls image data of the frame for each frame in which an image is displayed. The number of subframes for displaying some of the pixels included in the subframe is set, and the swinging speed of the swinging unit is set based on the number of subclaims.

An optical path control method according to an aspect of the present embodiment is an optical path control method for controlling an optical path by applying a drive signal to an actuator capable of swinging a swinging section having an optical section into which light enters, a step of setting the number of sub-frames for displaying some of the pixels included in the image data of the frame for each frame displaying the image data of the oscillating portion based on the number of the sub-claims; and setting a rocking speed.

According to the present embodiment, a moving image can be appropriately displayed while appropriately swinging the swinging section.

FIG. 1 is a schematic diagram showing a display device according to a first embodiment. FIG. 2 is a block diagram schematically showing the circuit configuration of the display device. FIG. 3 is a plan view showing the optical path control mechanism. FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3. FIG. 5 is a sectional view taken along the line VV in FIG. 3. FIG. 6 is an explanatory diagram illustrating a biaxial swing pattern of the optical section according to the first embodiment. FIG. 7 is an explanatory diagram showing a frame division configuration by the processing unit. FIG. 8 is an explanatory diagram for explaining an example of a drive signal setting method according to the first embodiment. FIG. 9 is a graph showing an example of the waveform of the drive signal when the motion vector is less than or equal to the threshold value. FIG. 10 is a graph showing an example of the swinging pattern of the swinging section when the motion vector is less than or equal to the threshold value. FIG. 11 is a graph showing an example of the waveform of the drive signal when the motion vector is larger than the threshold value. FIG. 12 is a graph showing an example of the swinging pattern of the swinging section when the motion vector is larger than the threshold value. FIG. 13 is a schematic diagram showing an example of image display when the motion vector is larger than the threshold value. FIG. 14 is a schematic diagram showing an example of image display when the motion vector is less than or equal to the threshold value. FIG. 15 is a schematic diagram showing an example of image display when the motion vector is less than or equal to the threshold value. FIG. 16 is a graph showing another example of the waveform of the drive signal. FIG. 17 is a graph showing another example of the swing pattern of the swing section. FIG. 18 is a schematic diagram showing another example of the order of displayed pixels. FIG. 19 is a block diagram schematically showing the circuit configuration of the display device according to the third embodiment.

The present embodiment will be described in detail below with reference to the accompanying drawings. Note that this embodiment is not limited to the following embodiment.

[Embodiment 1]
[Schematic configuration of display device]
FIG. 1 is a schematic diagram of a display device according to a first embodiment.

In this embodiment, as shown in FIG. 1, the display device 1 includes an optical path control device 10, an irradiation device 100, a video signal processing circuit (processing section) 160, and a control section 170 that controls the video signal processing circuit 160. and has. The irradiation device 100 is a device that irradiates light L for images. The optical path control device 10 is a device that controls the optical path of the light L. By shifting the optical axis of the light L, the optical path control device 10 shifts the position of the image displayed by the light L so that the resolution of the image by the irradiation device 100 (i.e., the number of pixels of the display element 106 described later) is higher than that of the image displayed by the light L. , increase the resolution of the projected image.

The irradiation device 100 includes a light source 101, polarizing

plates

105R, 105G, 105B,

display elements

106R, 106G, 106B, polarizing

plates

107R, 107G, 107B, a color synthesis prism 108, a projection lens 109, and a dichroic mirror 120. , 121,

reflective mirrors

130, 131,

lenses

140, 141, 142, 143, 144, 145, a polarization conversion element 150, and a video signal processing circuit 160. When the display element 106R, the display element 106G, and the display element 106B are not distinguished from each other, they are referred to as the display element 106.

The light source 101 is a light source that generates and irradiates light. The light source 101 emits incident light L0. In the following description, one light source 101 will be used as an example of a light source that irradiates the incident light L0, but other optical devices may be included for generating the incident light L0.

Incident light L0 from the light source 101 enters the lens 140. Lens 140 and lens 141 are, for example, fly-eye lenses. The illumination distribution of the incident light L0 is made uniform by the

lenses

140 and 141, and the incident light L0 is incident on the polarization conversion element 150. The polarization conversion element 150 is an element that aligns the polarization of the incident light L0, and includes, for example, a polarization beam splitter and a retardation plate. The polarization conversion element 150, for example, aligns the incident light L0 to p-polarized light.

The incident light L0 whose polarization has been aligned by the polarization conversion element 150 is irradiated onto the dichroic mirror 120 via the lens 142. Lens 142 is, for example, a condenser lens.

The dichroic mirror 120 separates the incident light L0 into yellow light LRG and blue light LB including components in the blue band. The yellow illumination light LRG separated by the dichroic mirror 120 is reflected by the reflection mirror 130 and enters the dichroic mirror 121.

The dichroic mirror 121 separates the incident yellow light LRG into red light LR including components in the red band and green light LG including components in the green band.

The red light LR separated by the dichroic mirror 121 is irradiated onto the polarizing plate 105R via the lens 143. The green light LG separated by the dichroic mirror 121 is irradiated onto the polarizing plate 105G via the lens 144. The blue light LB separated by the dichroic mirror 120 is reflected by the reflection mirror 131 and irradiated onto the polarizing plate 105B via the lens 145.

The polarizing

plates

105R, 105G, and 105B have a characteristic of reflecting either s-polarized light or p-polarized light and transmitting the other. For example, the polarizing

plates

105R, 105G, and 105B reflect s-polarized light and transmit p-polarized light. The polarizing

plates

105R, 105G, and 105B are also referred to as reflective polarizing plates.

The red light LR, which is p-polarized light, passes through the polarizing plate 105R and is irradiated onto the display element 106R. The green light LG, which is p-polarized light, passes through the polarizing plate 105G and is irradiated onto the display element 106G. The blue light LB, which is p-polarized light, passes through the polarizing plate 105B and is irradiated onto the display element 106B.

The display element 106R, display element 106G, and display element 106B are, for example, reflective liquid crystal display elements. In the following description, an example will be given in which the display element 106R, the display element 106G, and the display element 106B are reflective liquid crystal display elements, but the structure is not limited to the reflective type and uses a transmissive liquid crystal display element. You can also use it as Furthermore, various configurations using other display elements instead of liquid crystal display elements are also possible.

The display element 106R is controlled by the video signal processing circuit 160. The video signal processing circuit 160 drives and controls the display element 106R based on the red component image data. The display element 106R optically modulates the p-polarized red light LR under the control of the video signal processing circuit 160 to generate s-polarized red light LR. Display element 106G is controlled by video signal processing circuit 160. The video signal processing circuit 160 drives and controls the display element 106G based on the green component image data. The display element 106G optically modulates the p-polarized green light LG under the control of the video signal processing circuit 160 to generate s-polarized green light LG. Display element 106B is controlled by video signal processing circuit 160. The video signal processing circuit 160 drives and controls the display element 106B based on the blue component image data. The display element 106B optically modulates the p-polarized blue light LB based on the image data of the blue component under the control of the video signal processing circuit 160, and generates the s-polarized blue light LB.

The

polarizing plates

107R, 107G, and 107B have a characteristic of transmitting either s-polarized light or p-polarized light and reflecting or absorbing the other. For example, the

polarizing plates

107R, 107G, and 107B transmit s-polarized light and absorb unnecessary p-polarized light.

The s-polarized red light LR generated by the display element 106R is reflected by the polarizing plate 105R, passes through the polarizing plate 107R, and is irradiated onto the color synthesis prism 108. The s-polarized green light LG generated by the display element 106G is reflected by the polarizing plate 105G, passes through the polarizing plate 107G, and is irradiated onto the color synthesis prism 108. The s-polarized blue light LB generated by the display element 106B is reflected by the polarizing plate 105B, transmitted through the polarizing plate 107B, and irradiated onto the color synthesis prism 108.

The color synthesis prism 108 synthesizes the incident red light LR, green light LG, and blue light LB and irradiates it onto the projection lens 109 as light L for image display. The light L is projected onto a screen (not shown) or the like via the projection lens 109.

Although the irradiation device 100 has the above configuration, the configuration is not limited to the above description and may have any configuration.

The optical path control device 10 includes an optical path control mechanism 12, a control circuit (control section) 14, and a drive circuit (drive section) 16. The optical path control mechanism 12 is a mechanism that is driven by a drive circuit 16 to swing. The optical path control mechanism 12 is provided between the color synthesis prism 108 and the projection lens 109 in the direction along the optical path of the light L. The optical path control mechanism 12 swings while receiving the light L from the color combining prism 108, thereby shifting the traveling direction (optical path) of the light L and outputting the light L toward the projection lens 109. In this way, the optical path control device 10 controls the optical path of the light L so that the optical path of the light L is shifted. Note that the position where the optical path control mechanism 12 is provided is not limited to between the color combining prism 108 and the projection lens 109, and may be provided at any position.

[Functional configuration of display device]
FIG. 2 is a block diagram schematically showing the circuit configuration of the display device.

As shown in FIG. 2, the video signal processing circuit 160 controls the

display elements

106R, 106B, and 106G. A video signal including image data for controlling the

display elements

106R, 106B, and 106G and a synchronization signal is input to the video signal processing circuit 160. The video signal processing circuit 160 synchronizes the timing based on the synchronization signal and controls the

display elements

106R, 106B, and 106G based on the image data. Control circuit 14 has digital circuit 14A and converter 14B. A synchronization signal from the video signal processing circuit 160 is input to the digital circuit 14A. The digital circuit 14A generates a digital drive signal for driving the optical path control mechanism 12 while synchronizing the timing based on the synchronization signal. Converter 14B is a DA converter that converts a digital signal into an analog signal. The converter 14B converts the digital drive signal generated by the digital circuit 14A into an analog drive signal. The drive circuit 16 receives an analog drive signal from the converter 14B, amplifies the analog drive signal, and outputs it to the actuator 12B of the optical path control mechanism 12, which will be described later. The actuator 12B is driven according to a drive signal to swing a swinging section 12A (see FIG. 3), which will be described later.

The control unit 170 is a device that controls the drive circuit (drive unit) 16, and in this embodiment also controls the video signal processing circuit 160. The control unit 170 is, for example, a computer, and includes a storage unit and a processing unit (not shown). The storage unit included in the control unit 170 is a memory that stores various information such as calculation contents and programs of the processing unit, and includes, for example, a main storage device such as RAM (Random Access Memory) and ROM (Read Only Memory). , and an external storage device such as an HDD (Hard Disk Drive). The program for the processing unit stored in the storage unit may be stored in a recording medium readable by the control unit 170. Further, the processing unit included in the control unit 170 is a processing device that executes calculations, and includes a calculation circuit such as a CPU (Central Processing Unit), for example. The processing unit executes processing by the control unit 170 by reading and executing a program (software) from the storage unit. Note that the control unit 170 may execute the process using one CPU, or may include a plurality of CPUs and execute the process using the plurality of CPUs. Further, at least a part of the processing performed by the control unit 170 may be realized by a hardware circuit. The processing performed by the control unit 170 will be described later.

[Optical path control mechanism]
3 is a plan view showing the optical path control mechanism, FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3, and FIG. 5 is a sectional view taken along the line V-V in FIG. 3.

As shown in FIGS. 3 to 5, the optical path control mechanism 12 includes a swinging section 12A that includes an optical member (optical section) 20 into which the light L enters, and an actuator 12B that swings the swinging section 12A.

The actuator 12B swings around a first swing axis AX and a second swing axis BX along two directions intersecting (preferably orthogonal to) the direction in which the light L enters the optical member 20. 12A is rocked. The first swing axis AX and the second swing axis BX are preferably perpendicular to each other. Therefore, the optical path control mechanism 12 includes a first swing section 21 and a second swing section 22 as the swing section 12A, a first shaft section 23 along the first swing axis AX and a second swing axis BX, It has a second shaft portion 24, a first actuator 25 and a second actuator 26 as the actuator 12B, and a support portion 27.

The optical member 20 is a member that transmits the incident light L. The optical member 20 receives the light L from one surface, transmits the incident light L, and emits the light L from the other surface. The optical member 20 is a glass plate, but the material and shape may be arbitrary.

The first swinging section 21 has an optical member 20 and a first movable section 31. The first movable part 31 is a member that supports the optical member 20. The first movable part 31 is fixed to the optical member 20. Specifically, the first movable part 31 is a frame-shaped member made of a plate material with a through hole 31a formed in the center. The optical member 20 is fixed to the first movable part 31 while being fitted into the through hole 31 a of the first movable part 31 . Note that the optical member 20 is fixed to the first movable part 31 via a fixing member or an adhesive to be fixed to the first movable part 31; Any method may be used.

The second swinging section 22 is arranged outside the first swinging section 21. The second swinging section 22 has a second movable section 32 . The second movable part 32 is a member that supports the first movable part 31. The first movable part 31 is supported by the second movable part 32 so as to be swingable about the first swing axis AX. Specifically, the second movable part 32 is a frame-shaped member made of a plate material with a through hole 32a formed in the center. The first movable part 31 is swingably supported by the second movable part 32 while being disposed in the through hole 32a of the second movable part 32 with a predetermined gap therebetween. The first movable part 31 and the second movable part 32 are connected by a pair of first shaft parts 23 along the first swing axis AX. The first movable portion 31 swings about the first swing axis AX by elastically deforming the pair of second shaft portions 24 with respect to the second movable portion 32 so as to be twisted.

The support part 27 is arranged outside the second swing part 22. The support part 27 is a member that supports the second movable part 32. The second movable part 32 is supported by the support part 27 so as to be swingable about the second swing axis BX. Specifically, the support portion 27 is a frame-shaped member made of a plate material with a through hole 27a formed in the center. The second movable portion 32 is swingably supported by the support portion 27 while being disposed in the through hole 27a of the support portion 27 with a predetermined gap therebetween. The second movable part 32 and the support part 27 are connected by a pair of second shaft parts 24 along the second swing axis BX. The second movable portion 32 swings about the second swing axis BX by elastically deforming the pair of second shaft portions 24 with respect to the support portion 27 so as to be twisted.

The second movable part 32 (second swing part 22) swings about the second swing axis BX with the pair of second shaft parts 24 as fulcrums with respect to the support part 27. The first movable part 31 (first swing part 21) swings about the first swing axis AX with the pair of first shaft parts 23 as fulcrums relative to the second movable part 32. Therefore, the optical member 20 fixed to the second movable part 32 can swing around the first swing axis AX and the second swing axis BX. By swinging the optical member 20 around the first swing axis AX and the second swing axis BX, the optical path of the light L passing through the optical member 20 can be shifted due to a change in the attitude of the optical member 20. can.

In this embodiment, the first movable part 31, the second movable part 32, the first shaft part 23, and the second shaft part 24 are integrally formed. Therefore, the first movable part 31 swings relative to the second movable part 32 by elastically deforming the first shaft part 23 so as to be twisted in the circumferential direction. However, the first movable part 31, the second movable part 32, and the first shaft part 23 may be formed separately and connected. Further, one end and the other end in the axial direction of the second swing axis BX in the second movable part 32 are fixed so as to be connected to the support part 27, and the second shaft part is connected to each end of the second movable part 32. 24 respectively. However, the second shaft portions 24 may be provided at each end of the second movable portion 32, and each second shaft portion 24 may be fixed so as to be directly connected to the support portion 27. Furthermore, the second movable part 32, the second shaft part 24, and the support part 27 may be formed integrally.

The first actuator 25 swings the first movable part 31 (first swinging part 21) about the first swing axis AX with respect to the support part 27 using the pair of first shaft parts 23 as fulcrums. The first actuator 25 is arranged on both one side and the other side of the first swing axis AX in the radial direction (the axial direction of the second swing axis BX). The first actuator 25 includes a coil 41, a yoke 42, and a magnet 43.

The coil 41 is attached to the first movable part 31 and fixed to a coil attachment part 31b provided on the first movable part 31. The coils 41 are provided at both ends of the first movable portion 31 in the radial direction of the first swing axis AX (one side and the other side in the axial direction of the second swing axis BX). The yoke 42 is a member that forms a magnetic path. The yoke 42 is attached to the support part 27 and fixed to the support part 27. The yokes 42 are arranged at both ends of the first movable section 31 in correspondence with the coils 41, respectively. Magnet 43 is a permanent magnet. The magnet 43 is attached to the yoke 42 and fixed to the yoke 42. The magnets 43 are arranged adjacent to each coil 41 .

A drive signal from the drive circuit 16 (see FIG. 2) is input to the coil 41. In the example shown in FIG. 5, a magnet 43 is bonded to one side of a U-shaped yoke 42, and there is an air gap between the surface of the magnet 43 that is not bonded and the opposing U-shaped surface of the yoke 42. is formed. Coil 41 is placed within the air gap. When a drive signal is input to the coil 41, a current flows through the coil 41, which is a conductor located within the air gap (magnetic field) between the magnet 43 and the yoke 42, and force is generated in the coil 41. This force causes The first movable part 31 (first swing part 21) fixed to the coil 41 is caused to swing. That is, it can be said that the first actuator 25 is an electromagnetic actuator that includes a coil 41, a yoke 42, and a magnet 43.

The second actuator 26 swings the second movable part 32 (second swinging part 22) about the second swing axis BX with the pair of second shaft parts 24 as fulcrums relative to the support part 27. The second actuator 26 is arranged on both sides of the second swing axis BX in one direction and the other direction in the radial direction (the axial direction in the first swing axis AX). The second actuator 26 includes a coil 44, a yoke 45, and a magnet 46.

The coil 44 is attached to the second movable part 32 and fixed to a coil attachment part 32b provided on the second movable part 32. The coils 44 are provided at both ends of the second movable portion 32 in the radial direction of the second swing axis BX (one side and the other side in the axial direction of the first swing axis AX). The yoke 45 is a member that forms a magnetic path. The yoke 45 is attached to the support part 27 and fixed to the support part 27. The yoke 45 is arranged at both ends of the second movable section 32 in correspondence with the coil 44 . Magnet 46 is a permanent magnet. The magnet 46 is attached to the yoke 45 and fixed to the yoke 45. The magnets 46 are arranged adjacent to each coil 44 .

A drive signal from the drive circuit 16 (see FIG. 2) is input to the coil 44. In the example shown in FIG. 4, a magnet 46 is bonded to one side of a U-shaped yoke 45, and there is an air gap between the surface of the magnet 46 that is not bonded and the opposing U-shaped surface of the yoke 45. is formed. Coil 44 is placed within the air gap. When a drive signal is input to the coil 44, a current flows through the coil 44, which is a conductor located within the air gap (magnetic field) between the magnet 46 and the yoke 45, and force is generated in the coil 44, and this force causes The second movable part 32 (second swing part 22) fixed to the coil 44 is caused to swing. That is, it can be said that the second actuator 26 is an electromagnetic actuator that includes the coil 44, the yoke 45, and the magnet 46.

In the optical path control mechanism 12, the first movable part 31 provided with the optical member 20 swings, and the second movable part 32 supporting the first movable part 31 swings. It can be said that the movable part 31, the second movable part 32, and the

coils

41 and 44 constitute the swinging part 12A. That is, it can be said that the part of the optical path control mechanism 12 that swings with respect to the support section 27 refers to the swing section 12A. Note that the first shaft portion 23 also swings together with the second movable portion 32, and therefore is included in the swinging portion 12A. In addition, if a fixing member or adhesive for fixing the optical member 20 to the first movable part 31, a base or lead wire for passing current through the

coils

41, 44, etc. are provided, these are also attached to the support part. Since it swings with respect to 27, it is included in the swinging section 12A.

In this embodiment, the first actuator 25 swings the first movable part 31, and the second actuator 26 swings the second movable part 32. In this case, the

yokes

42 and 45 constituting each actuator 25 and 26 are fixed to the support portion 27. Therefore, when the second movable part 32 is swung by the second actuator 26, a gap is ensured between the first actuator 25 and the second movable part 32 so that they do not interfere with each other. Note that the first actuator 25 may be provided in the second movable part 32.

Although the

actuators

25 and 26 are of the so-called moving coil type in which the

coils

41 and 44 are arranged in the

movable parts

31 and 32, the

actuators

25 and 26 are not limited thereto. It may be of a so-called moving magnet type in which the

coils

41 and 44 are arranged on the support portion 27. In this case, since the

magnets

43 and 46 are oscillated together with the optical member 20, the

magnets

43 and 46 are included in the oscillating portion 12A instead of the

coils

41 and 44.

The optical path control mechanism 12 has the above-mentioned configuration, but is not limited to this, and can be any arbitrary structure that can shift the optical path of the light L by the optical section by swinging the optical section by an actuator to which a drive signal is applied. The configuration may be as follows.

[Pixel operation by optical path control mechanism]
Hereinafter, the operation when the first swinging section 21 and the second swinging section 22 are rocked will be explained. FIG. 6 is an explanatory diagram illustrating a biaxial swing pattern of the optical section according to the first embodiment.

The optical path control mechanism 12 of this embodiment causes the first swinging section 21 and the second swinging section 22 to swing using the actuator 12B according to the applied drive signal. In this embodiment, the first actuator 25 and the second actuator 26 constituting the actuator 12B move from the first angle D1 to the second angle around the first shaft portion AX and the second shaft portion BX, respectively, according to the drive signal. The first swing section 21 and the second swing section 22 are rocked so as to repeat the posture change to D2 and the posture change from the second angle D2 to the first angle D1. Due to the combination, the optical axis of the light L is repeatedly shifted from the first position to the second position, from the second position to the third position, from the third position to the fourth position, and from the fourth position to the first position. Note that the drive signal to be applied will be described later.

In other words, the image projected onto the screen by light L when the optical axis is in the first position and the image projected onto the screen by light L when the optical axis is in the second position are shifted by half a pixel. Similarly, when the optical axis is at the third and fourth positions, they are shifted by half a pixel. That is, the image projected onto the screen is always displayed shifted by half a pixel in either the upper, lower, left, or right diagonal. This increases the apparent number of pixels, making it possible to increase the resolution of the image projected onto the screen. Since the amount of shift of the optical axis is half a pixel of the image, the first angle D1 and the second angle D2 are set to angles that can shift the image by half a pixel. Note that the amount of shift of the image is not limited to half a pixel, but may be arbitrary, such as 1/4 or 1/8 of a pixel, for example. The first angle D1 and the second angle D2 may also be set appropriately according to the amount of shift of the image.

This will be explained in detail below. Here, the first swing axis AX direction and the second swing axis BX direction intersect orthogonally and are parallel to the pixel arrangement direction. As shown in FIG. 6, the image position P0 is the display position when the current value applied to the first actuator 25 and the second actuator 26 is 0, that is, when the displacement angle of the optical member 20 is 0. . In the A operation state, the optical member 20 is oscillated by a predetermined angle around the first oscillation axis AX by the first actuator 25, the image position P0 is shifted by 1/4 pixel in the direction of the second oscillation axis BX, and the second This is a state in which the optical member 20 is oscillated by a predetermined angle around the second oscillation axis BX by the actuator 26, and the image position P0 is shifted by 1/4 pixel in the direction of the first oscillation axis AX. In other words, the A operation state is an image in which the image position P0 is shifted to one side ABXa in the ABX direction, which is a combination of a vector directed in one direction in the first swing axis AX direction and a vector directed in one direction in the second swing axis BX direction. This is a state in which an image is displayed at position P1.

Similarly, in the B operation state, the image position P0 is shifted to one side ABXb in the ABX direction, which is a combination of a vector directed to one side in the first swing axis AX direction and a vector directed to one side in the second swing axis BX direction. This is a state in which an image is displayed at image position P2. Similarly, in the C operation state, the image position P0 is shifted to one side ABXc in the ABX direction, which is a combination of a vector directed to one side in the first swing axis AX direction and a vector directed to one side in the second swing axis BX direction. This is a state in which an image is displayed at image position P3. Similarly, in the D operation state, the image position P0 is shifted to one side ABXd in the ABX direction, which is a combination of a vector directed to one side in the first swing axis AX direction and a vector directed to one side in the second swing axis BX direction. This is a state in which an image is displayed at image position P4.

<Frame division configuration>
FIG. 7 is an explanatory diagram showing a frame division configuration by the processing unit. In this embodiment, the display period of one frame is divided into the display period of a plurality of subframes, and the plurality of subframes are displayed in the display period of one frame. As a result, the resolution of the display device is artificially increased, such as displaying image data with 8K resolution on a display device with 4K resolution, for example. Hereinafter, division into subframes will be described using as an example a case where image data having a resolution of 8K is displayed on a display device having a resolution of 4K.

A subframe is a divided frame that includes some of the pixels included in one frame. In other words, a subframe is a divided frame that displays image data of some pixels out of the image data of each pixel displayed in the display period of one frame. Note that the pixels included in each subframe in one frame do not overlap, and the subframes in one frame contain different pixels. In other words, image data of different pixels are displayed. do. In the example of FIG. 7, one frame constituting image data having a resolution of 8K is composed of a plurality of combinations of four pixels A, B, C, and D arranged in columns and rows. Each subframe is composed of image data to be displayed on a display device having 4K resolution. A plurality of pixels A, B, C, and D constituting one frame are divided into four subframes A, B, C, and D. In this case, sub-frame A is obtained by extracting only a plurality of pixels A that constitute one frame. In this case, subframe A displays only one pixel A at the positions of four pixels A, B, C, and D of the frame. Similarly, subframe B is obtained by extracting only the plurality of pixels B that constitute one frame. Sub-frame C is obtained by extracting only a plurality of pixels C constituting one frame. Sub-frame D is obtained by extracting only a plurality of pixels D constituting one frame. In this way, frame image data having 8K resolution is displayed as subframe image data having 4K resolution.

In this embodiment, the control unit 170 sets a subframe for each frame, and displays the image data included in the subframe set for that frame within the time to display that frame. , the display element 106 is controlled by the video signal processing circuit 160. That is, in this embodiment, the display period of one frame is divided into the display period of a plurality of subframes, and the plurality of subframes are displayed in the display period of one frame.

<Setting the swing speed for each frame>
In this way, in this embodiment, by displaying a plurality of subframes in one frame display period while swinging the swinging unit 12A, image data of subframes having a resolution of 4K, for example, can be changed into an image. Since the images are sequentially displayed at positions P1 to P4, the user can view an image with a pseudo 8K resolution. In this method of displaying an image by dividing it into subframes, it is required to appropriately display a moving image while appropriately swinging the swinging section 12A. On the other hand, in the present embodiment, the number of subframes is set for each frame, and the swinging speed of the swinging section 12A is set based on the number of subframes. It becomes possible to appropriately display a moving image while appropriately swinging the moving part 12A.

Although the method for setting the number of subframes for each frame may be arbitrary, in the first embodiment, the number of subframes is set based on the motion vector V of the motion area. Further, the method of controlling the swing speed of the swing unit 12A may be arbitrary, but in the first embodiment, the method is based on the motion vector V of the motion area (in other words, based on the number of subframes set from the motion vector V). ), the swinging speed of the swinging section 12A is set, and a drive signal that can realize the set swinging speed is set. This will be explained in detail below.

FIG. 8 is an explanatory diagram for explaining an example of a method of setting a drive signal according to the first embodiment. In FIG. 8, as an example of a moving image, frames F1 to F4 show a state in which an object 200 (an airplane) passes through a space in which an object 202 (building) is shown, and frames F5 to F6 show A group of images showing the state after the object 200 has passed is shown. In this example, the

objects

200 and 202, such as airplanes and buildings, are exemplified as objects that are determined to be motion areas, but the objects are not limited thereto and may be arbitrary. In this embodiment, the target object is a previously learned object that can move or change shape. Further, the data of the object is stored in a storage section included in the control section 170.

The control unit 170 acquires image data included in the frame when setting the drive signal. Specifically, if the frame to be displayed is the second frame, and the frame displayed before the second frame in time series is the first frame, the control unit 170 controls the image data (the first frame) included in the first frame. Image data for each pixel displayed in the display period of one frame) and image data included in the second frame (image data for each pixel displayed in the display period of the second frame) are acquired. Note that the first frame is a frame immediately before the second frame in chronological order, but is not limited to this, and is a frame displayed at an arbitrary timing before the second frame (for example, a frame displayed several frames earlier than the second frame). frame). Further, a plurality of frames before the second frame may be used as the first frame. In the example of FIG. 8, when frame F2 is to be displayed (second frame), the control unit 170 acquires image data of frame F2 and image data of frame F1 immediately before frame F2.

The control unit 170 extracts a target area from the image data in the first frame and the image data in the second frame, and obtains a motion vector between the target area in the first frame and the target area in the second frame. . Although the method of extracting the target area and the method of acquiring the motion vector may be arbitrary, in this embodiment, the control unit 170 extracts a common target from the image data in the first frame and the image data in the second frame. Extract the target area to be shown. The target area refers to an area where the same target object is shown in the first frame image and the second frame image. In other words, the target area in the first frame image refers to an area (pixel group) in the first frame image in which the target that is also included in the second frame image is captured; The target area in an image refers to an area (pixel group) in the second frame image in which an object that is also included in the first frame image is captured. In the example of FIG. 8, objects 200 and 202 are included in both the image of frame F1 and the image of frame F2. Therefore, in the example of FIG. 8, the control unit 170 extracts a region (pixel group) in which the target object 200 is included in the image data of the frame F1 as a target region for the target object 200 in the frame F1, and A region (pixel group) in which the target object 200 is included in the image data is extracted as a target region for the target object 200 in frame F2. Similarly, in the example of FIG. 8, the control unit 170 extracts a region (pixel group) including the target object 202 from the image data of the frame F1 as a target region for the target object 202 in the frame F1, and A region (pixel group) in which the target object 202 is included in the image data of F2 is extracted as a target region for the target object 202 in frame F2. Note that the method for extracting the target area from each image data may be arbitrary, and for example, a known image matching technique for extracting the same target from a plurality of images may be used. Note that when comparing the divided frames, if the entire angle of view is moving, the entire angle of view is determined as a moving area.

After extracting the target area, the control unit 170 calculates the motion vector V of the target area based on the target area in the first frame and the target area in the second frame. In this embodiment, the target area where the motion vector V is generated is treated as a motion area where the motion vector V (amount of motion) is generated. The motion vector V is an index indicating the amount of movement of the motion area (the amount of movement of the motion area) during the period from the first frame to the second frame. The control unit 170 calculates a motion vector V of the target area (motion area) from the position of the target area in the first frame image and the position of the target area in the second frame image. That is, for example, the control unit 170 calculates the difference between the position of the target area in the first frame image and the position of the target area in the second frame image in the image-based coordinate system based on the target area (movement). area) as the amount of movement (movement vector). When there are multiple target areas (motion areas), the control unit 170 calculates the motion vector V for each target area (motion area). In the example of FIG. 8, the control unit 170 calculates the motion vector V of the motion area of the target object 200 based on the position of the target object 200 in the first frame and the second frame. Similarly, the control unit 170 calculates the motion vector V of the motion area of the target object 202 based on the position of the target object 202 in the first frame and the second frame. Note that in addition to the amount of movement of the motion area, the control unit 170 may also calculate the movement direction of the motion area as a movement vector. That is, the motion vector V may indicate only the amount of motion of the motion region, or may indicate both the amount of motion of the motion region and the direction in which it moves (movement direction). The moving direction can be calculated from the position of the moving area within the first frame image and the position of the moving area within the second frame image in a coordinate system based on the image.

The control unit 170 sets the swinging speed of the swinging unit 12A in the second frame, that is, the waveform of the drive signal applied in the second frame in the first embodiment, based on the calculated motion vector of the motion area. The control unit 170 sets the waveform of the drive signal to be applied to the actuator 12B in the second frame based on the motion vector (movement amount) V of the motion area in the period from the first frame to the second frame. In this embodiment, the control unit 170 determines whether the motion vector (movement amount) V of the motion area is larger than a predetermined threshold value. More specifically, the control unit 170 controls the swinging speed of the swinging unit 12A due to the application of the drive signal when the motion vector V is larger than the threshold value, and the swing speed of the swinging unit 12A due to the application of the drive signal when the motion vector V is less than or equal to the threshold value. The waveform of the drive signal is set to be higher than the swinging speed of the swinging section 12A. Note that since the swing speed changes in proportion to the rate of change of the current value (voltage value) in the waveform of the drive signal, the control unit 170 controls the current value ( It can also be said that the waveform of the drive signal is set so that the rate of change of the current value (voltage value) is higher than the rate of change of the current value (voltage value) of the drive signal when the motion vector V is less than or equal to the threshold value. In other words, when the motion vector V is larger than the threshold value, the control unit 170 sets the waveform of the drive signal in the second frame to the first waveform to display a moving image. Then, when the motion vector V is less than or equal to the threshold value, the control unit 170 determines that a still image is to be displayed, and changes the waveform of the drive signal in the second frame so that the swinging speed of the swinging unit 12A is lower than the first waveform. (the rate of change of the current value is lower than the first waveform). Note that when there are multiple motion regions, the above determination is made using the motion vector V with the largest motion vector (movement amount) V among the motion regions. Further, the threshold value here may be set arbitrarily. In the example of FIG. 8, when the frame F2 is the display target (second frame), the motion vector V of the target object 200 is larger than the threshold value. Similarly, for frames F3 and F4, the motion vector V of the object 200 is larger than the threshold value. On the other hand, in frames F5 and F6, the object 200 is not photographed, and the motion vector V of the photographed object 202 is less than or equal to the threshold value. Therefore, in the example of FIG. 8, the rate of change of the current value in the drive signal in frames F2 to F4 is higher than the rate of change in the current value in the drive signal in frames F5 to F6.

Note that, as described above, the control unit 170 can also be said to set the swinging speed of the swinging unit 12A based on the number of subframes set based on the motion vector. In this case, the control unit 170 controls the swinging speed of the swinging unit 12A when the motion vector V is greater than the threshold (that is, when the number of subframes is greater than a predetermined threshold), such that the motion vector V is less than or equal to the threshold. The swinging speed of the swinging section 12A is set so as to be higher than the swinging speed of the swinging section 12A in the case (that is, when the number of subframes is less than or equal to a predetermined threshold value).

Hereinafter, examples of the waveform of the drive signal and the swing pattern of the swing section 12A based on the drive signal will be explained.

(Waveform of drive signal when motion vector is below threshold)
FIG. 9 is a graph showing an example of the waveform of the drive signal when the motion vector is below the threshold value, and FIG. 10 is a graph showing an example of the swinging pattern of the swinging section when the motion vector is below the threshold value. It is.

As shown in FIG. 9, the drive signal applied from the drive circuit 16 to the first actuator 25 is an electrical signal, and the current value changes over time. In other words, the waveform representing the change in the current value of the drive signal over time can be said to be the waveform of the drive signal. The waveform of the drive signal is shown by a solid line in FIG. The drive signal has the same waveform repeated every period T. The period T includes a period T1 and a period T2 that is subsequent to the period T1 and continuous with the period T1. Period T1 corresponds to a period in which an image (image not shifted by half a pixel) is displayed when the optical axis of light L is at the first position, and period T2 corresponds to a period when the optical axis of light L is at the second position. This corresponds to the period in which the image (image shifted by half a pixel) is displayed when the image is in the correct position.

When the motion vector V is less than or equal to the threshold, the period T1 and the period T2 each correspond to the display period of one frame, in other words, the period T corresponds to the display period of two frames. The waveform (second waveform) of the drive signal is set. In the example of FIG. 9, period T1 corresponds to frame F5, and period T2 corresponds to frame F6. In the second waveform, the current value changes from the first current value A1 to the second current value A2 in the first period TA1 of the period T1. Here, the intermediate position 0 between the first current value A1 and the second current value A2 is a position where the current value is zero. In the second waveform, the current value changes linearly over time from the first current value A1 to the second current value A2 in the first period TA1. That is, in the second waveform, the current value is the first current value A1 at the start timing of the first period TA1, and then the current value changes linearly from the first current value A1 until the end of the first period TA1. At the timing, the current value becomes the second current value A2. The first current value A1 is a current value that can hold the first swinging portion 21 at the first angle D1, and is set according to the numerical value of the first angle D1. The second current value A2 is a current value that can hold the first swinging portion 21 at the second angle D2, and is set according to the value of the second angle D2. The first current value A1 and the second current value A2 are current values with opposite signs, and may have the same absolute value. In FIG. 9, it is illustrated that the first current value A1 is negative and the second current value A2 is positive.

In the second waveform, the length of the first period TA1 is preferably a value corresponding to the natural frequency of the first swinging section 21. The first swinging section 21 refers to a portion of the optical path control mechanism 12 that swings relative to the support section 27 (in this embodiment, the optical member 20, the first movable section 31, and the coil 41). That is, it can be said that the length of the first period TA1 has a value corresponding to the natural frequency of the portion that swings with respect to the support portion 27. More specifically, the length of the first period TA1 is preferably approximately the same value as the natural period of the first swinging portion 21, and more preferably the same value as the natural period. Here, the natural period is the reciprocal of the natural frequency. Furthermore, "substantially the same value" means that a value that is slightly different from the natural period within the error range is also allowed. For example, even if the deviation from the natural period is within 5% of the value of the natural period, it may be determined as "approximately the same value." Hereinafter, the expression "substantially the same value" refers to the same meaning. Note that the value of the natural period (reciprocal of the natural frequency) is expressed as "1/f" [s] when the natural frequency is f [Hz].

In the second waveform, the current value is held at the second current value A2 in the second period TB1 of the period T1. The second period TB1 is a period subsequent to the first period TA1 and continuous with the first period TA1. Note that being held at the second current value A2 does not mean that the current value does not strictly change from the second current value A2, but may also deviate from the second current value A2 within a predetermined value range. May be included. The predetermined value here may be set arbitrarily, and may be, for example, a value of 10% of the second current value A2.

In this way, in the second waveform, the current value gradually changes from the first current value A1 to the second current value A2 in the period T1, and when the current value reaches the second current value A2, the current value changes to the second current value A2. 2 current value A2 is maintained.

In the second waveform, the current value changes from the second current value A2 to the first current value A1 in the third period TA2 of the period T2. The third period TA2 can be said to be a period subsequent to the second period TB1 and continuous to the second period TB1. More specifically, in the second waveform, the current value changes linearly over time from the second current value A2 to the first current value A1 in the third period TA2. That is, in the second waveform, the current value is the second current value A3 at the start timing of the third period TA2, and then the current value changes linearly from the second current value A2 to reach the second current value A3 in the third period TA2. At the end timing, the current value becomes the first current value A1.

In the second waveform, the length of the third period TA2 is preferably a value corresponding to the natural frequency of the first swinging section 21. More specifically, the length of the third period TA2 is preferably approximately the same value as the natural period (reciprocal of the natural frequency) of the first swinging portion 21, and more preferably the same value as the natural period. . In the third period TA2, the length of the third period TA2 is equal to the length of the first period TA1.

In the second waveform, the current value is held at the first current value A1 in the fourth period TB2 of the period T2. The fourth period TB2 is a period after the third period TA2 and continuous with the third period TA2. Further, the fourth period TB2 is a period that precedes the first period TA1 and is continuous with the first period TA1. The fourth period TB2 is equal to the second period TB1. Note that being held at the first current value A1 does not mean that the current value does not strictly change from the first current value A1, but may also deviate from the first current value A1 within a predetermined value range. May be included. The predetermined value here may be set arbitrarily, and may be, for example, a value of 10% of the first current value A1.

In this way, in the second waveform, the current value gradually changes from the second current value A2 to the first current value A1 in the period T2, and when the current value reaches the first current value A1, the current value changes to the first current value A1. 1 current value A1.

As described above, in this embodiment, the second waveform of the drive signal is trapezoidal, and the first period TA1 and third period TA2 in which the current value changes correspond to the natural frequency of the swinging section 12A. value.

Note that the broken line shown in FIG. 9 indicates the period during which the light L is irradiated. It is preferable that the irradiation device 100 does not irradiate the light L during the first period TA1 and irradiates the light L during the second period TB1. Further, it is preferable that the irradiation device 100 does not irradiate the light L during the third period TA2 and irradiates the light L during the fourth period TB2.

(Swinging pattern when the motion vector is below the threshold)
As shown in FIG. 10, the swing pattern of the first swing section 21 refers to the displacement angle (first swing) of the first swing section 21 for each time when a drive signal is applied to the first actuator 25. angle around the moving axis AX). In FIG. 10, the swing pattern is shown by a solid line.

In the second waveform, the current value of the drive signal changes from the first current value A1 to the second current value A2 in the first period TA1. Thereby, the displacement angle of the first swinging portion 21 changes from the first angle D1 to the second angle D2 in the first period TA1. Here, the intermediate position 0 between the first angle D1 and the second angle D2 is a position where the displacement angle of the first swinging portion 21 is zero.

In the second waveform, in the second period TB1, the current value of the drive signal is held at the second current value A2. As a result, the displacement angle of the first swinging portion 21 is maintained at the second angle D2 during the second period TB1. Note that being held at the second angle D2 does not mean that the displacement angle does not strictly change from the second angle D2, but also includes that the displacement angle deviates from the second angle D2 within a predetermined range. good. The predetermined value here may be set arbitrarily, and may be, for example, a value of 10% of the second angle D2.

In the second waveform, in the third period TA2, the current value of the drive signal changes from the second current value A2 to the first current value A1. As a result, the displacement angle of the first swinging section 21 changes from the second angle D2 to the first angle D1 in the third period TA2.

In the second waveform, in the fourth period TB2, the current value of the drive signal is held at the first current value A1. As a result, the displacement angle of the first swinging portion 21 is maintained at the first angle D1 during the fourth period TB2. Note that being held at the first angle D1 does not mean that the displacement angle does not strictly change from the first angle D1, but also includes that the displacement angle deviates from the first angle D1 within a predetermined range. good. The predetermined value here may be set arbitrarily, and may be, for example, a value of 10% of the first angle D1.

Note that the light L is irradiated during the second period TB1 and the fourth period TB2. Therefore, in the second period TB1, the first swinging portion 21 held at the second angle D2 is irradiated with the light L, and the optical path of the light L becomes the first position. In the fourth period TB2, the first swinging section 21 held at the first angle D1 is irradiated with the light L, the optical path of the light L is shifted to the second position, and the image is shifted by half a pixel.

Here, the drive signal applied to the first actuator 25 has been described as the drive signal applied from the drive circuit 16 to the actuator 12B. The same applies to the drive signal applied to the second actuator 26, so a description thereof will be omitted.

(Waveform of drive signal when motion vector is larger than threshold)
FIG. 11 is a graph showing an example of the waveform of the drive signal when the motion vector is larger than the threshold value, and FIG. 12 is a graph showing an example of the swinging pattern of the swinging part when the motion vector is larger than the threshold value. .

When the motion vector V becomes larger than the threshold value, the waveform (first waveform) of the drive signal is set so that the period T corresponds to the display period of one frame. In the example of FIG. 11, period T corresponds to frame F2. In the first waveform, the current value is held at zero during the first period TA1. In this embodiment, since the digital circuit 14A and the like include a digital switching circuit, the supply of current to the actuator 12B can be stopped, and the period in which the supply of current is stopped is the period in which the current value is zero. . In the first waveform, it is preferable that the length of the first period TA1 is a value corresponding to the natural frequency of the swinging section 12A. More specifically, the length of the first period TA1 is preferably approximately the same as half the natural period (reciprocal of the natural frequency) of the swinging portion 12A; It is more preferable that the value is the same as half of the value of . Note that the half value of the natural period is expressed as "1/(2·f)" [s] when the natural frequency is f [Hz].

In the first waveform, the current value is held at the second current value A2 in the second period TB1. The second period TB1 is a period subsequent to the first period TA1 and continuous with the first period TA1. That is, at the start timing of the second period TB1 (the timing at which the first period TA1 switches to the second period TB1), the current value switches from zero to the second current value A2, and the current value changes until the end timing of the second period TB1. is held at the second current value A2.

In this way, in the first waveform, the current value of the drive signal in the period T1 is held at zero in the first period TA1, the current value is switched to the second current value A2 at the start timing of the second period TB1, and the current value is maintained at zero in the first period TA1. The current value is held at the second current value A2 during the second period TB1.

In the first waveform, the current value is held at zero in the third period TA2. The third period TA2 can be said to be a period subsequent to the second period TB1 and continuous to the second period TB1. That is, at the start timing of the third period TA2 (timing when switching from the second period TB1 to the third period TA2), the current value switches from the second current value A2 to zero, and until the end timing of the third period TA2, the current value is held at zero. In the first waveform, it is preferable that the length of the third period TA2 has a value corresponding to the natural frequency of the swinging section 12A. More specifically, the length of the third period TA2 is preferably approximately the same as half the natural period (reciprocal of the natural frequency) of the swinging portion 12A; It is more preferable that the value is the same as half of the value of . In this embodiment, the length of the third period TA2 is equal to the length of the first period TA1.

In the first waveform, the current value is held at the first current value A1 in the fourth period TB2. The fourth period TB2 is a period after the third period TA2 and continuous with the third period TA2. That is, at the start timing of the fourth period TB2 (the timing at which the third period TA2 switches to the fourth period TB2), the current value switches from zero to the first current value A1, and the current value changes until the end timing of the fourth period TB2. is held at the first current value A1.

In this way, in the first waveform, the current value of the drive signal in the period T2 is held at zero in the third period TA2, and the current value is switched to the first current value A1 at the start timing of the fourth period TB2. During the fourth period TB2, the current value is held at the first current value A1.

Note that in the first waveform, the current value is held at zero in the first period TA1 following the fourth period TB2, as described above. That is, at the start timing of the first period TA1 (the timing at which the fourth period TB2 switches to the first period TA1), the current value switches from the first current value A1 to zero, and the current value changes until the end timing of the first period TA1. is held at zero.

The broken line in FIG. 11 indicates the period during which the light L is irradiated. It is preferable that the irradiation device 100 does not irradiate the light L during the first period TA1 and irradiates the light L during the second period TB1. Further, it is preferable that the irradiation device 100 does not irradiate the light L during the third period TA2 and irradiates the light L during the fourth period TB2.

(oscillation pattern when the motion vector is larger than the threshold)
At the start timing of the first period TA1, in the first waveform, the current value switches from the first current value A1 to zero, and the current value is maintained at zero until the end timing of the first period TA1. As a result, the displacement angle of the swinging portion 12A changes from the first angle D1 to the second angle D2 in the first period TA1. More specifically, the swinging part 12A, which has been twisted to the first angle D1 and held at the first current value A1, is untwisted and returns to the neutral position when the current becomes zero, and further inertial force is applied. , the second angle D2 is reached by being twisted to the second angle D2 on the opposite side.

At the start timing of the second period TB1, the current value of the first waveform switches from zero to the second current value A2, and the current value is maintained at the second current value A2 until the end timing of the second period TB1. As a result, the displacement angle of the swinging portion 12A is maintained at the second angle D2 during the second period TB1. That is, the swinging portion 12A that has been twisted to the second angle D2 is held at the second angle D2 because the force of returning to the neutral position and the force due to the second current value A2 are balanced.

At the start timing of the third period TA2, in the first waveform, the current value switches from the second current value A2 to zero, and the current value is maintained at zero until the end timing of the third period TA2. As a result, the displacement angle of the swinging portion 12A changes from the second angle D2 to the first angle D1 in the third period TA2.

At the start timing of the fourth period TB2, in the first waveform, the current value switches from zero to the first current value A1, and the current value is maintained at the first current value A1 until the end timing of the fourth period TB2. As a result, the displacement angle of the swinging portion 12A is maintained at the first angle D1 during the fourth period TB2.

As described above, in the example of the present embodiment, when the motion vector V is larger than the threshold, a stepped first waveform drive signal is applied, and when the motion vector V is less than or equal to the threshold, a trapezoidal drive signal is applied. A drive signal of a second waveform is applied. In both the first waveform and the second waveform, the current value changes in periods TA1 and TA2, and the periods TA1 and TA2 in the first waveform are shorter than the periods TA1 and TA2 in the second waveform. Therefore, it can be seen that in the first waveform shown in the example of this embodiment, the rate of change in the current value, in other words, the swinging speed of the swinging portion 12A is higher than the second waveform.

Note that the waveform of the drive signal set according to the motion vector V is not limited to those shown in the examples of FIGS. 8 to 12, and may be arbitrary. Further, in the above description, there are two types of waveforms of the drive signal that are set according to the motion vector V, but the present invention is not limited thereto. For example, three or more types of waveforms of the drive signal may be set depending on the motion vector V. In this case, the control unit 170 controls the swinging speed of the swinging unit to increase (the rate of change of the current value to ), it is preferable to set the waveform of the drive signal.

Further, in the example of this embodiment, the threshold value for the motion vector V is a constant value fixed for each frame or motion region, but is not limited to this, and may be set for each motion region. In this case, for example, the control unit 170 may set the threshold based on the area of the motion region. More preferably, the control unit 170 may set the threshold value to be smaller as the area of the motion region becomes larger. Thereby, the larger the movement area, the higher the swing speed can be set even if the amount of movement is small.

(Setting subframes according to motion vector)
In this embodiment, as described above, it is preferable to set the waveform of the drive signal for each frame and also set the number of subframes for each frame. Although the method for setting the number of subframes may be arbitrary, in this embodiment, the number of subframes is set based on the motion vector V. This will be explained in detail below.

When setting a subframe, the control unit 170 extracts a target region (motion region) and calculates a motion vector V of the motion region. The method for extracting the motion area and calculating the motion vector V is the same as that for setting the waveform of the drive signal, so the explanation will be omitted.

The control unit 170 sets the number of subframes for the second frame based on the calculated motion vector V of the motion area. That is, the control unit 170 sets the number of subframes of the second frame based on the motion vector (movement amount) V of the motion area in the period from the first frame to the second frame. In this embodiment, the control unit 170 determines whether the motion vector (movement amount) V of the motion area is larger than a predetermined threshold value. More specifically, the control unit 170 determines the number of subframes of the second frame when the motion vector V is larger than the threshold value from the number of subframes of the second frame when the motion vector V is less than or equal to the threshold value. Do more. In other words, when the motion vector V is larger than the threshold value, the control unit 170 sets the number of subframes of the second frame to the first predetermined number to display the moving image. Then, when the motion vector V is less than or equal to the threshold value, the control unit 170 sets the number of subframes of the second frame to a second predetermined number smaller than the first predetermined number to display a still image. Note that when there are multiple motion regions, the above determination is made using the motion vector V with the largest motion vector (movement amount) V among the motion regions. Further, the threshold value here may be set arbitrarily. In the example of FIG. 8, the number of subframes of frames F2 to F4 in which the motion vector V is greater than the threshold value is greater than the number of subframes in frames F5 to F6 in which the motion vector V is less than or equal to the threshold value.

Furthermore, when the motion vector V is larger than the threshold value, the control unit 170 can set the subframes so that all pixels included in the second frame are included in one of the respective subframes. preferable. In other words, in the example of FIG. 8, four

subframes

2A, 2B, 2D, and 2C are set in frame F2, and among the plurality of pixels A, B, C, and D that constitute frame F2, pixel A is Pixel B is included in subframe B, pixel C is included in subframe 2C, and pixel D is included in subframe 2D. The same applies to frames F3 and F4, so the explanation will be omitted.

Furthermore, when the motion vector V is less than or equal to the threshold, the control unit 170 sets the subframes so that only some pixels included in the second frame are included in each subframe. is preferred. In addition, in this case, the control unit 170 controls whether a pixel different from a pixel not included in a subframe of the second frame is included in one of the subframes in the frame (third frame) subsequent to the second frame. It is preferable to set the subframe so that the subframe is included. That is, in the example of FIG. 8, two

subframes

5A and 5B are set in frame F5, and among the plurality of pixels A, B, C, and D that constitute frame F5, pixel A is set in subframe 5A. pixel B is included in subframe 5B, and pixel C is included in subframe 2C. In frame F6,

subframes

6D and 6C are set, and among the plurality of pixels A, B, C, and D that constitute frame F5, pixel D that was not included in

subframes

5A and 5B is set in subframe 6D. , and pixel C is included in subframe 6C. Note that the pixel A and the pixel D, or the pixel B and the pixel C may be combined without being limited to being on the same line (side-by-side).

In the example of FIG. 8, the number of subframes (first predetermined number) when the motion vector V is greater than the threshold is 4, and the number of subframes (second predetermined number) when the motion vector V is less than or equal to the threshold is 2. However, the first predetermined number and the second predetermined number are not limited to this and may be arbitrary numbers. However, it is preferable that the first predetermined number and the second predetermined number are set according to the number of swing axes. Further, in the example of this embodiment, the number of subframes is set to one of two types of numbers, the first predetermined number and the second predetermined number, but the number is not limited thereto. For example, the number of subframes to be set may be set to any three or more types of numbers depending on the motion vector V. In this case, it is preferable that the control unit 170 increases the number of subframes as the motion vector (movement amount) V increases. For example, if the motion vector V is less than or equal to the first threshold, the number of subframes is one, and the motion vector V is greater than the first threshold and less than or equal to a second threshold that is higher than the first threshold. In this case, the number of subframes may be two, and if the motion vector V is larger than the second threshold, the number of subframes may be four.

Further, in the example of this embodiment, the threshold value for the motion vector V is a constant value fixed for each frame or motion region, but is not limited to this, and may be set for each motion region. In this case, for example, the control unit 170 may set the threshold based on the area of the motion region. More preferably, the control unit 170 may set the threshold value to be smaller as the area of the motion region becomes larger. As a result, the larger the motion area, the greater the number of subframes even if the amount of movement is small.

After setting the number of subframes for the second frame, the control unit 170 determines the pixels to be included in the set subframe, in other words, the pixels on which an image based on the image data is to be displayed during the display period of the subframe. is set for each subframe.

(Displaying images for each subframe)
After setting the subframe for the second frame, the control unit 170 outputs information on the set subframe to the video signal processing circuit 160. Thereby, the control unit 170 causes the video signal processing circuit 160 to cause the video signal processing circuit 160 to display the image of the image data included in the subframe set for the second frame within the time to display the second frame. The display element 106 is controlled. Furthermore, the control unit 170 causes the video signal processing circuit 160 to control the display element 106 so that each subframe set for the second frame is sequentially displayed within the time for displaying the second frame. be controlled. The display of images for each subframe will be described in more detail below.

(Image display when the motion vector is larger than the threshold)
FIG. 13 is a schematic diagram showing an example of image display when the motion vector is larger than the threshold value. In this embodiment, when the motion vector V is larger than the threshold value, in the second frame to be displayed, the subframes are arranged such that all pixels included in the second frame are included in one of the respective subframes. Set. Then, the video signal processing circuit 160 controls the

display elements

106R, 106G, and 106B so that the subframes set for the second frame are sequentially displayed during the time when the second frame is displayed. Then, the control circuit 14 generates a drive signal of the first waveform based on the synchronization signal input from the video signal processing circuit 160. The drive circuit 16 drives the actuator 12B based on this first waveform drive signal to swing the swinging section 12A. This will be explained in detail below.

In the examples shown in FIGS. 8 and 13, the video signal processing circuit 160 sequentially displays subframes 2A, 2B, 2D, and 2C divided into four parts within the time (60 Hz) for displaying the second frame (here, frame F2). The

display elements

106R, 106G, and 106B are controlled so that the display is displayed. At this time, the time for displaying each

subframe

2A, 2B, 2D, and 2C is 1/4 the time (240 Hz) for displaying the second frame (60 Hz).

At this time, as shown in FIGS. 2, 8, and 13, the control circuit 14 generates a first waveform drive signal based on the synchronization signal input from the video signal processing circuit 160, and the drive circuit 16

Actuators

25 and 26 are driven based on the drive signal. That is, as shown in FIG. 8, when displaying the subframe 2A, the drive circuit 16 applies a drive signal (see FIG. 11) corresponding to the first waveform in the period T1. Then, as shown in FIG. 13, the second actuator 26 swings the optical member 20 around the second swing axis BX, and shifts the image position P0 by 1/2 pixel in the direction of the first swing axis AX. Put into working condition. That is, the image is displayed at an image position P1 where the image position P0 is shifted to one ABXa in the ABX direction.

Thereafter, as shown in FIG. 8, when displaying subframe 2B, the drive circuit 16 continues to apply the drive signal (see FIG. 11) corresponding to the first waveform in period T1. Then, as shown in FIG. 13, the second actuator 26 swings the optical member 20 around the second swing axis BX, and shifts the image position P1 by 1/2 pixel in the first swing axis AX direction. Put into working condition. That is, the image is displayed at an image position P2 where the image position P0 is shifted to one ABXb in the ABX direction.

Thereafter, as shown in FIG. 8, when displaying subframe 2D, the drive circuit 16 applies a drive signal (see FIG. 11) corresponding to the first waveform in period T2. Then, as shown in FIG. 13, the first actuator 25 swings the optical member 20 (see FIG. 3) around the first swing axis AX, and moves the image position P2 by 1/2 in the direction of the second swing axis BX. Shift 2 pixels and enter D operation state. That is, the image is displayed at an image position P3 where the image position P0 is shifted to one side ABXd in the ABX direction.

Thereafter, as shown in FIG. 8, when displaying the subframe 2C, the drive circuit 16 continues applying the drive signal (see FIG. 11) corresponding to the first waveform in the period T2. Then, as shown in FIG. 13, the second actuator 26 swings the optical member 20 around the second swing axis BX, and shifts the image position P3 by 1/2 pixel in the direction of the first swing axis AX. Put into working condition. That is, the image is displayed at an image position P4 where the image position P0 is shifted to one side ABXc in the ABX direction.

(Image display when the motion vector is less than the threshold)
14 and 15 are schematic diagrams showing examples of image display when the motion vector is less than or equal to the threshold value. In this embodiment, when the motion vector V is less than or equal to the threshold value, in the second frame to be displayed, only some pixels included in the second frame are included in one of the respective subframes, and , in the frame (third frame) that follows the second frame, the subframes are divided so that pixels that are different from the pixels that were not included in the subframes of the second frame are included in one of the respective subframes. Set. Then, the video signal processing circuit 160 controls the

display elements

106R, 106G, and 106B so that the subframes set for the second frame are sequentially displayed during the time when the second frame is displayed, and the third frame is displayed. During the display time, the

display elements

106R, 106G, and 106B are controlled so that the subframes set for the third frame are sequentially displayed. The control circuit 14 then generates a second waveform drive signal based on the synchronization signal input from the video signal processing circuit 160. The drive circuit 16 drives the actuator 12B based on this second waveform drive signal to swing the swinging section 12A. This will be explained in detail below.

As shown in FIGS. 8 and 14, the video signal processing circuit 160 divides

subframes

5A, 5B, 5C, and 5D into four parts within the time (60 Hz) for displaying the second frame (here, frame F5). Among them,

display elements

106R, 106G, and 106B are controlled so that two

subframes

5A and 5B (first subframe group) are displayed sequentially. At this time, the time for displaying each

subframe

5A, 5B is 1/2 the time (120 Hz) for displaying frame F5 (60 Hz). Subsequently, as shown in FIGS. 8 and 15, the video signal processing circuit 160 divides the third frame (frame F6 in this case) into four

subframes

6A, 6B, and

Display elements

106R, 106G, and 106B are controlled so that two

subframes

6D and 6C (second subframe group) out of 6C and 6D are sequentially displayed. At this time, the time for displaying each

subframe

6D, 2C is 1/2 the time (120 Hz) for displaying the second frame (60 Hz).

At this time, as shown in FIGS. 2, 8, and 14, the control circuit 14 generates a second waveform drive signal based on the synchronization signal input from the video signal processing circuit 160, and the drive circuit 16

Actuators

25 and 26 are driven based on the drive signal. That is, as shown in FIG. 8, when displaying the subframe 5A, the drive circuit 16 sends a drive signal (see FIG. 9) corresponding to the second waveform in the period T1 to the first actuator 25 and the second actuator 26. Apply. Then, as shown in FIG. 14, the second actuator 26 swings the optical member 20 around the second swing axis BX, and shifts the image position P0 by 1/2 pixel in the direction of the first swing axis AX. Put into working condition. That is, the image is displayed at an image position P1 where the image position P0 is shifted to one ABXa in the ABX direction.

Thereafter, as shown in FIG. 8, when displaying subframe 5B, the drive circuit 16 continues to apply the drive signal (see FIG. 9) corresponding to the second waveform in period T1. Then, as shown in FIG. 14, the second actuator 26 swings the optical member 20 around the second swing axis BX, and shifts the image position P1 by 1/2 pixel in the first swing axis AX direction. Put into working condition. That is, the image is displayed at an image position P2 where the image position P0 is shifted to one ABXb in the ABX direction.

Thereafter, as shown in FIG. 8, when displaying the subframe 6D, the drive circuit 16 applies a drive signal (see FIG. 9) corresponding to the second waveform in period T2. Then, as shown in FIG. 15, the first actuator 25 swings the optical member 20 (see FIG. 3) around the first swing axis AX, and moves the image position P2 by 1/2 in the direction of the second swing axis BX. Shift 2 pixels and enter D operation state. That is, the image is displayed at an image position P3 where the image position P0 is shifted to one side ABXd in the ABX direction.

Thereafter, as shown in FIG. 8, when displaying the subframe 6C, the drive circuit 16 continues to apply the drive signal (see FIG. 9) corresponding to the second waveform in the period T2. Then, as shown in FIG. 14, the second actuator 26 swings the optical member 20 around the second swing axis BX, and shifts the image position P3 by 1/2 pixel in the direction of the first swing axis AX. Put into working condition. That is, the image is displayed at an image position P4 where the image position P0 is shifted to one side ABXc in the ABX direction.

As explained above, in this embodiment, the waveform of the drive signal in that frame is set based on the motion vector V of the motion area. In this way, since the waveform of the drive signal is set from the motion vector V of the motion area, the waveform of the drive signal can be set according to the motion vector V, that is, based on the determination result of whether the image is a moving image. A moving image can be appropriately displayed while appropriately swinging the moving part 12A. Furthermore, in this embodiment, the drive is performed such that the swinging speed of the swinging section 12A when the motion vector V is larger than the threshold value is higher than the swinging speed when the motion vector V is below the threshold value. Set the signal waveform. Therefore, for example, in the case of a moving image with a large motion vector V, it is possible to display the moving image smoothly by increasing the swing speed and increasing the frame rate while pseudo-improving the gradation value. can. On the other hand, when the number of subframes is large, the period of one subframe is shortened, so it is necessary to increase the swinging speed of the swinging section 12A, and the mechanical life of the optical path control device 10 is shortened due to fatigue. There is a risk that this may occur. In contrast, in the present embodiment, when the motion vector V is a still image with a low value, by lowering the rocking speed, fatigue can be suppressed and the lifespan can be prevented from being shortened.

(other examples)
In the above explanation, when the motion vector V is larger than the threshold value, the waveform of the drive signal is made stepwise as shown in FIG. 11, and when the motion vector V is less than the threshold value, the waveform of the drive signal is made stepwise. , a trapezoidal shape as shown in FIG. 9, but the waveforms of these drive signals are merely examples. Hereinafter, other examples of the waveform of the drive signal will be explained.

FIG. 16 is a graph showing another example of the waveform of the drive signal, and FIG. 17 is a graph showing another example of the swinging pattern of the swinging section. For example, when the motion vector V is larger than the threshold value, the waveform of the drive signal as shown in FIG. 16 may be set as the first waveform. As shown in FIG. 16, in the waveform of the drive signal of this example, in the first period TA1, the current value is held at the second current value A2, and then the current value is held at the first current value A1. That is, in the period TA1a of the first period TA1, the current value is held at the second current value A2, and in the period TA1b of the first period TA1, the current value is held at the first current value A1. . The period TA1b is a period subsequent to the period TA1a and continuous with the period TA1a. That is, at the start timing of the period TA1b (timing when switching from the period TA1a to the period TA1b), the current value switches from the second current value A2 to the first current value A1, and until the end timing of the period TA1b, the current value changes to the first current value. It is held at the value A1.

The length of the first period TA1 is preferably a value corresponding to the natural frequency of the swinging section 12A. The length of the first period TA1 is preferably approximately the same value as one-third of the natural period (reciprocal of the natural frequency) of the swinging portion 12A; More preferably, they are the same value. Note that the value of one-third of the natural period (reciprocal of the natural frequency) is expressed as "1/(3·f)" [s] when the natural frequency is f [Hz].

Furthermore, in the first period TA1, the length of the period TA1a and the length of the period TA1b have values corresponding to the natural frequency of the swinging portion 12A. It is preferable that the length of the period TA1a and the length of the period TA1b be the same. More specifically, the length of the period TA1a and the length of the period TA1b are preferably approximately the same value as one-sixth of the natural period (reciprocal of the natural frequency) of the swinging portion 12A, and the natural period More preferably, the value is the same as one-sixth of the value. Note that the value of one-sixth of the reciprocal of the natural frequency is expressed as "1/(6·f)" [s] when the natural frequency is f [Hz].

In the waveform of the drive signal in this example, the current value is held at the second current value A2 in the second period TB1. The second period TB1 is a period subsequent to the first period TA1 (period TA1b) and continuous with the first period TA1 (period TA1b). That is, at the start timing of the second period TB1 (timing when switching from period TA1b to second period TB1), the current value switches from the first current value A1 to the second current value A2, and until the end timing of the second period TB1, The current value is held at the second current value A2.

In this way, in this example, the drive signal in period T1 has a current value held at the second current value A2 during period TA1a, a current value switched to and held at the first current value A1 during period TA1b, and a current value switched to and held at the first current value A1 during period TA1b. At TB1, the current value is switched to and held at the second current value A2.

In the waveform of the drive signal of this example, in the third period TA2, the current value is held at the first current value A1, and then the current value is held at the second current value A2. That is, at the start timing of the period TA2a of the third period TA2 (the timing at which the second period TB1 switches to the period TA2a), the current value switches from the second current value A2 to the first current value A1, and at the end timing of the period TA2a. The current value is maintained at the first current value A1 until then. Period TA2b is a period subsequent to period TA2a and continuous with period TA2a. That is, at the start timing of the period TA2b (timing when switching from the period TA2a to the period TA2b), the current value switches from the first current value A1 to the second current value A2, and until the end timing of the period TA2b, the current value changes to the second current value. It is held at the value A2.

The length of the third period TA2 is preferably a value corresponding to the natural frequency of the swinging section 12A. The length of the third period TA2 is preferably approximately the same value as one-third of the natural period (reciprocal of the natural frequency) of the swinging portion 12A, and is equal to or equal to one-third of the natural period. More preferably, they are the same value. In this embodiment, the length of the third period TA2 is equal to the length of the first period TA1.

Furthermore, in the third period TA2, the length of the period TA2a and the length of the period TA2b have values corresponding to the natural frequency of the swinging section 12A. It is preferable that the length of period TA2a and the length of period TA2b be the same. More specifically, the length of the period TA2a and the length of the period TA2b are preferably approximately the same value as one-sixth of the reciprocal of the natural frequency of the swinging portion 12A, It is more preferable that the value is the same as the value of 1. In this embodiment, the length of period TA2a is equal to the length of period TA1a, and the length of period TA2b is equal to the length of period TA1b.

In the waveform of the drive signal of this example, the current value is held at the first current value A1 in the fourth period TB2. The fourth period TB2 is a period after the third period TA2 (period TA2b) and continuous with the third period TA2 (period TA2b). That is, at the start timing of the fourth period TB2 (the timing at which period TA2b switches to the fourth period TB2), the current value switches from the second current value A2 to the first current value A1, and until the end timing of the fourth period TB2, The current value is held at the first current value A1.

In this way, in this example, the drive signal in period T2 has a current value held at the first current value A1 during period TA2a, a current value switched to and held at the second current value A2 during period TA2b, and a current value switched to and held at the second current value A2 during period TA2b. At TB2, the current value is switched to and held at the first current value A1.

Note that in the period TA1a following the fourth period TB2, the current value is held at the second current value A2 as described above. That is, at the start timing of the period TA1a (the timing at which the fourth period TB2 switches to the period TA1a), the current value switches from the first current value A1 to the second current value A2, and until the end timing of the period TA1a, the current value changes to the second current value A2. 2 is held at the current value A2.

In this example, since the drive signal having the above waveform is applied, as shown in FIG. to the second angle D2. More specifically, in response to the force that tries to twist back at the first angle D1, a further force is applied in the direction that the second current value A2 tries to return, thereby accelerating the swinging section 12A in the direction of the second angle D2. If left as is, it will be twisted further than the second angle D2 due to inertia, so in this embodiment, the brake is applied by subsequently flowing the first current value A1. Therefore, the swinging portion 12A can be swinged at high speed.

At the start timing of the second period TB1, the current value of the drive signal switches from the first current value A1 to the second current value A2, and the current value is maintained at the second current value A2 until the end timing of the second period TB1. Ru. As a result, the displacement angle of the swinging portion 12A is maintained at the second angle D2 during the second period TB1.

In the drive signal, the current value switches from the second current value A2 to the first current value A1 at the start timing of the period TA2a, the current value is maintained at the first current value A1 until the end timing of the period TA2a, and the current value switches from the second current value A2 to the first current value A1 at the start timing of the period TA2b. At the timing, the current value switches from the first current value A1 to the second current value A2, and the current value is held at the second current value A2 until the end timing of the period TA2b. As a result, the displacement angle of the swinging portion 12A changes from the second angle D2 to the first angle D1 in the third period TA2 (periods TA2a, TA2b).

At the start timing of the fourth period TB2, the current value of the drive signal switches from the second current value A2 to the first current value A1, and the current value is maintained at the first current value A1 until the end timing of the fourth period TB2. Ru. As a result, the displacement angle of the swinging portion 12A is maintained at the first angle D1 during the fourth period TB2.

Although three types of examples of the waveform of the drive signal have been described so far, these waveforms may be set according to the motion vector V as follows. That is, for example, as explained in the above embodiment, when the motion vector V is less than or equal to the threshold, the trapezoid shape shown in FIG. 9 is formed, and when the motion vector V is larger than the threshold, the trapezoid shape shown in FIG. It may also be shaped like a staircase. For example, as explained in the other example above, when the motion vector V is less than or equal to the threshold, the trapezoid shape shown in FIG. 9 is formed, and when the motion vector V is larger than the threshold, the trapezoid shape shown in FIG. It may also have a shape like this. Further, for example, when the motion vector V is less than or equal to the threshold value, the shape may be a stepped shape as shown in FIG. 11, and when the motion vector V is greater than the threshold value, the shape may be formed as shown in FIG. 16. For example, if the motion vector V is less than or equal to the first threshold, the trapezoidal shape shown in FIG. If the motion vector V is larger than the second threshold, the shape may be a step shape as shown in FIG. 11, and if the motion vector V is larger than the second threshold, the shape may be a step shape as shown in FIG.

Furthermore, in the above description, the subframes were set so that the pixels A, B, D, and C were displayed in that order, but the order of the pixels to be displayed is not limited to this and may be arbitrary. FIG. 18 is a schematic diagram showing another example of the order of displayed pixels. For example, as shown in FIG. 18, subframes may be set so that pixels A, D, B, and C are displayed in this order.

[Embodiment 2]
In the second embodiment, the method of extracting a motion area and the method of obtaining a motion vector V are different from those in the first embodiment. In the second embodiment, descriptions of the same configuration and processing as in the first embodiment will be omitted.

In the second embodiment, the control unit 170 obtains the first frame of image data and the second frame of image data. Then, the control unit 170 determines the motion vector V and the motion area based on the image data of the first frame and the image data of the second frame (by comparing the image data of the first frame and the image data of the second frame). Calculate. Specifically, the control unit 170 determines a moving area of the image data, that is, an area where the motion vector V is generated, based on the image data of the first frame and the image data of the second frame. Extract as a motion area. That is, in the second embodiment, the control unit 170 calculates the motion vector V based on the image data of the first frame and the image data of the second frame, and calculates the motion vector V when the motion vector V is larger than a predetermined value (for example, less than zero). (large) area is extracted as a motion area. Note that the setting of subframes is not limited to using a motion vector V that includes both the amount of motion and the direction of motion, and only the magnitude of the motion (amount of motion) between the first frame and the second frame is used to determine the number of subframes. It may be used for setting. The method of calculating the motion vector V in the second embodiment may be arbitrary, and a known method may be used. For example, a block matching method may be used to calculate the motion vector V. In the block matching method, for example, an image is divided into a plurality of blocks, a correlation calculation between the first frame and the second frame is performed for each block, and a motion vector V is calculated from the correlation value in the correlation calculation. Then, a block whose motion vector V is larger than a predetermined value may be calculated as a motion area. Furthermore, the motion area, motion vector V, and motion amount in the second embodiment may be acquired from an external device via a communication unit (not shown). Further, the motion area is not limited to the area where the motion vector V occurs, but may be an area where the amount of motion occurs.

[Embodiment 3]
Embodiment 3 differs from the above embodiments in that the swinging speed of the swinging section is set based on the number of subframes. In Embodiment 3, descriptions of the same configurations and processes as in the above embodiments will be omitted.

FIG. 19 is a block diagram schematically showing the circuit configuration of the display device according to the third embodiment. The control section 170 includes a subframe setting section 172.

The subframe setting unit 172 sets the number of subframes for each frame. The subframe setting unit 172 may set the number of subframes using any method. For example, the subframe setting unit 172 may set the number of subframes based on the motion area and motion vector V calculated as in the first embodiment or the second embodiment. For example, the subframe setting unit 172 may obtain information on the category (type) of the program (content) displayed by the display device, and set the number of subframes according to the category of the program. The subframe setting unit 172 may acquire the information on the program category using any method. For example, the subframe setting unit 172 may acquire the program category information stored in the storage unit of the control unit 170, or the subframe setting unit 172 The program category may be acquired by communicating with a server in which the program category is stored via a communication unit provided with the program, or the category may be classified using a known method from the image data.

The subframe setting unit 172 may set the number of subframes based on any criteria depending on the category of the program. For example, when playing a program in a category that is expected to have a lot of movement or a high resolution, such as sports or movies, a large number of subframes may be set. Furthermore, for example, in the case of a category of programs such as information programs that have little movement or are expected to require low resolution, the number of subframes may be set to be small, giving priority to the lifespan of the device.

The control unit 170 sets the swinging speed of the swinging unit 12A based on the number of subframes. For example, the control unit 170 controls the swinging speed of the swinging unit 12A when the number of subframes is greater than a predetermined threshold, and the swinging speed of the swinging unit 12A when the number of subframes is less than or equal to a predetermined threshold. The swing speed of the swing section 12A is set so as to be higher than the speed. Then, the control unit 170 selects a drive signal waveform suitable for the rocking speed, that is, a drive signal waveform that can realize the set rocking speed, and applies the drive signal with the selected waveform.

(effect)
As described above, the optical path control device 10 according to the present embodiment includes a swinging section 12A having an optical member (optical section) 20 into which light enters, an actuator 12B capable of swinging the swinging section 12A, and a drive The control device includes a drive circuit (drive unit) 16 that controls the optical path by causing the actuator 12B to swing the swing unit 12A by applying a signal to the actuator 12B, and a control unit 170 that controls the drive circuit 16. The unit 170 sets, for each frame in which an image is displayed, the number of subframes for displaying some of the pixels included in the image data of the frame, and based on the number of subclaims, the swinging unit 12A Set the rocking speed. As a result, a moving image can be appropriately displayed while the swinging section 12A is swinging appropriately.

According to the optical path control device 10 of the present embodiment, the control unit 170 controls the swinging speed of the swinging unit 12A according to the drive signal when the number of subframes is greater than a predetermined threshold, and when the number of subframes is less than or equal to a predetermined threshold. The swinging speed of the swinging section 12A is set higher than the swinging speed of the swinging section 12A caused by the drive signal. As a result, in the case of a moving image with a large number of subframes, it is possible to display the moving image smoothly by increasing the swing speed and increasing the frame rate while pseudo-improving the gradation value. can. Furthermore, in an image with a small number of subframes, the swing speed can be lowered to improve the life of the device.

Further, the control unit 170 extracts a motion area indicating a common object from the image data in the first frame and the image data in the second frame after the first frame, and A motion vector with respect to the motion area in two frames is obtained, and based on the motion vector, the number of subframes in the second frame and the swing speed of the swing unit 12A are set. By setting the swinging speed based on the motion vector, the moving image can be displayed appropriately while swinging the swinging section 12A appropriately.

Further, the display device 1 according to the present embodiment includes an optical path control device 10 and a video signal processing circuit (processing unit) 160 that controls the display element 106 based on image data, and the control unit 170 The video signal processing circuit 160 controls the display element 106 so that the subframe set for the frame is displayed within the time period for displaying the frame. As a result, in the case of a still image with a low motion vector V, by lowering the rocking speed, fatigue can be suppressed and shortening of the life span can be suppressed.

Further, the driving unit 16 operates during first periods TA1 and TA2, which are periods in which images are displayed when the optical axis of the light is at the first position, and during periods when the optical axis of the light is at the second position. A drive signal with a waveform including second periods TB1 and TB2, which are continuous periods with the first periods TA1 and TA2 in which the images of , are displayed, is applied to the actuator 12B, and if the amount of movement is less than the threshold value, the first period TA1 and TA2 are displayed. In TA1 and TA2, the current value is gradually changed from the first current value to the second current value, and in the second period TB1 and TB2, a drive signal with a waveform that maintains the current value at the second current value is applied to the actuator 12B. However, when the amount of movement is larger than the threshold, the current value is switched from the first current value to zero at the start timing of the first periods TA1 and TA2, and the current value is set to zero until the end timing of the first periods TA1 and TA2. Driving a waveform in which the current value is switched from zero to the second current value at the start timing of the second periods TB1 and TB2, and the current value is held at the second current value until the end timing of the second periods TB1 and TB2. A signal is applied to actuator 12B. As a result, it becomes possible to appropriately display a moving image while appropriately swinging the swinging section 12A.

In addition, the drive unit 16 operates during first periods TA1 and TA2, which are periods in which images are displayed when the optical axis of the light is at the first position, and when the optical axis of the light is at the second position. A drive signal with a waveform including second periods TB1 and TB2, which are continuous periods with the first period in which the image of , the current value is gradually changed from the first current value to the second current value, and in the second periods TB1 and TB2, a drive signal with a waveform that maintains the current value at the second current value is applied to the actuator 12B to cause the actuator 12B to move. When the amount is larger than the threshold value, the current value is held at the first current value in the first period TA1, TA2, and then the current value is held at the second current value, and the current value is held at the second current value in the second period TB1, TB2. A drive signal having a waveform held at the first current value is applied to the actuator 12B. As a result, it becomes possible to appropriately display a moving image while appropriately swinging the swinging section 12A.

Furthermore, the control unit 170 obtains information on the type of content to be displayed, and sets the number of subframes according to the type of content. As a result, the swinging speed can be changed depending on the type of content, so fatigue can be suppressed and the lifespan can be prevented from being shortened.

Further, the optical path control method according to the present embodiment includes controlling an optical path by applying a drive signal to an actuator 12B that can swing a swinging section 12A having an optical member (optical section) 20 into which the light L is incident. A control method, comprising the steps of setting, for each frame in which an image is displayed, the number of subframes for displaying some of the pixels included in the image data of the frame, based on the number of subclaims, The method includes a step of setting the swinging speed of the swinging section 12A. As a result, a moving image can be appropriately displayed while the swinging section 12A is swinging appropriately.

In the embodiment described above, the optical member 20 is swingably supported by the first shaft section 23 along the first swing axis AX, and supported swingably by the second shaft section 24 along the second swing axis BX. Although the structure is such that it can be supported freely, the structure is not limited to this.

Although the display device 1 according to the present embodiment has been described so far, it may be implemented in various different forms other than the embodiment described above.

Each component of the illustrated display device 1 is functionally conceptual, and does not necessarily have to be physically configured as illustrated. In other words, the specific form of each device is not limited to what is shown in the diagram, and all or part of it may be functionally or physically distributed or integrated into arbitrary units depending on the processing load and usage status of each device. It's okay.

The configuration of the display device 1 is realized by, for example, a program loaded into a memory as software. The above embodiments have been described as functional blocks realized by cooperation of these hardware or software. That is, these functional blocks can be implemented in various forms using only hardware, only software, or a combination thereof.

The above-mentioned components include those that can be easily imagined by those skilled in the art and those that are substantially the same. Furthermore, the above configurations can be combined as appropriate. Furthermore, various omissions, substitutions, or changes in the configuration are possible without departing from the gist of the present embodiment.

The optical path control device, display device, and optical path control method of this embodiment can be used, for example, for image display.

1 Display device 10 Optical path control device 12 Optical path control mechanism 12A Swing section 12B Actuator 14 Control circuit 16 Drive circuit (drive section)
20 Optical member (optical part)
21 First swinging section 22 Second swinging section 23 First shaft section 24 Second shaft section 25 First actuator 26 Second actuator 27 Support section 31 First movable section 32 Second movable section 100 Irradiation device 106 Display element 160 Video signal processing circuit (processing section)
170 Control unit A1 First current value A2 Second current value AX First swing axis BX Second swing axis D1 First angle D2 Second angle L Light TA1, TA2 First period TB1, TB2 Second period V Motion vector

Claims

a swinging section having an optical section into which light enters;
an actuator capable of swinging the swinging section;
a drive unit that controls the optical path by applying a drive signal to the actuator to cause the actuator to swing the swing unit;
a control unit that controls the drive unit;
Equipped with
The control unit includes:
For each frame in which an image is displayed, the number of subframes for displaying some of the pixels included in the image data of the frame is set,
setting a swinging speed of the swinging unit based on the number of subframes;
Optical path control device.
The control unit makes the swinging speed of the swinging unit higher when the subframe is larger than a predetermined threshold than the swinging speed of the swinging unit when the subframe is less than or equal to the threshold. Item 1. The optical path control device according to item 1.
The control unit includes:
Obtaining the amount of motion from the image data in a first frame and the image data in a second frame after the first frame,
setting the number of subframes in the second frame based on the amount of motion;
The optical path control device according to claim 1 or claim 2.
An optical path control device according to claim 1 or claim 2,
a processing unit that controls a display element based on the image data,
The control unit includes:
causing the processing unit to control the display element so that the subframe set for the frame is displayed within the time for displaying the frame;
Display device.
The drive unit includes:
A first period in which an image is displayed when the optical axis of light is in the first position, and the first period in which an image is displayed when the optical axis of light is in the second position. Applying to the actuator a drive signal having a waveform including a second period that is a continuous period,
When the amount of movement is less than or equal to a threshold, the current value is gradually changed from a first current value to a second current value during the first period, and the current value is maintained at the second current value during the second period. Applying a drive signal having a waveform of The current value is maintained at zero until the start timing of the second period, the current value is switched from zero to the second current value, and the current value is changed to the second current value until the end timing of the second period. applying a drive signal of a waveform to be held to the actuator;
The optical path control device according to claim 3.
The drive unit includes:
A first period in which an image is displayed when the optical axis of light is in the first position, and the first period in which an image is displayed when the optical axis of light is in the second position. Applying to the actuator a drive signal having a waveform including a second period that is a continuous period,
When the movement amount is less than or equal to a threshold value, the current value is gradually changed from a first current value to a second current value during the first period, and the current value is maintained at the second current value during the second period. applying a drive signal having a waveform to the actuator, and when the amount of movement is larger than a threshold value, in the first period, the current value is held at the first current value, and then the current value is held at the second current value. and applying a waveform drive signal to the actuator to maintain the current value at the first current value during the second period;
The optical path control device according to claim 3.
The control unit includes:
Get information about the type of content displayed,
setting the number of subframes according to the type of content;
The optical path control device according to claim 1.
An optical path control method for controlling an optical path by applying a drive signal to an actuator capable of swinging a swinging section having an optical section into which light enters, the method comprising:
setting, for each frame in which an image is displayed, the number of subframes in which some of the pixels included in the image data of the frame are displayed;
setting a swinging speed of the swinging section based on the number of subframes;
including,
Optical path control method.