JP6992508B2 - Image display device, image projection device, image display method, and image pickup device - Google Patents

Description

The present invention relates to an image display device, an image projection device, an image display method, and an image pickup device.

Conventionally, there is a technique of reciprocating an image display element in a direction orthogonal to gravity to increase the resolution of a projected image (see, for example, Patent Document 1).

However, in Patent Document 1, when the image display element is reciprocated in a plane including the direction of gravity, the reciprocating motion is affected by gravity, and there is a possibility that the high-resolution projected image may not be a desired projected image. be.
The present invention has been made in view of the above, and an image display device capable of reciprocating without being affected by gravity even when the image display element is reciprocated in a plane including the direction of gravity. The purpose is to provide.

According to the image projection device of one aspect of the present invention, the image display element movably supported in a plane including the direction of gravity, the first actuator for reciprocating the image display element, and the image display element. It includes a second actuator that applies a constant force against gravity to the image display element during the reciprocating movement, and a driving force generating unit that controls the driving of the first actuator and the second actuator. It is provided with an image display device characterized by the above.

According to the present invention, even when the image display element is reciprocated in a plane including the direction of gravity, the reciprocating motion without being affected by gravity is possible.

It is a perspective view (A) of an image projection device and a side view (B) of an image projection device. It is a figure which showed the arrangement and composition of an optical engine and a light source unit. It is a figure which shows the structural example of an optical engine. It is an overall view (perspective view) of a high resolution module. It is an exploded perspective view of a high resolution module. It is an exploded perspective view of a position detection part. It is an exploded side view of a position detection part. It is a figure which shows the detailed structure of the driving force generation part. It is a figure which shows the configuration example of the movable unit which displayed only the movable part. It is a figure which shows the configuration example of the fixed unit which displayed only the fixed part. It is a figure explaining the structure of a movable plate. It is explanatory drawing of PWM control of a voice coil. It is explanatory drawing of PWM control of a voice coil (gravity component). It is a flowchart which shows the control procedure of an image display element unit. It is a flowchart which shows the modification of the control procedure shown in FIG.

Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In each drawing, the same components may be designated by the same reference numerals and duplicate explanations may be omitted. Further, in the following, although the explanation is made on the premise that the image is projected, the projection includes the projection.

1A is a perspective view of the image projection device 1 according to the present embodiment, and FIG. 1B is a side view of the image projection device 1. Note that FIG. 1B shows a state in which the projected light emitted from the image projection device 1 is applied to the screen (projected object) 2 on which the image is projected.
The image projection device 1 is a device that generates an image based on image data input from a personal computer, a video camera, or the like, and projects and displays the image on a screen 2, or the like. Liquid crystal projectors, which are widely known as image projection devices 1, have recently been improved in resolution, improved in brightness due to higher efficiency of light source lamps, and reduced in price. In addition, compact and lightweight projectors using DMDs (Digital Micro-mirror Devices) have become widespread, and these projectors have come to be widely used not only in offices and schools but also in homes. In particular, front-type projectors have become more portable and are being used for small meetings with several people.

The projector, which is the image projection device 1, is required to be able to project a large screen image (larger screen of the projection screen) and to make the "projection space required outside the projector" as small as possible. In recent years, the performance of optical engines has improved, and projectors capable of achieving a projection distance of 1 to 2 m and a projection size of 60 inches to 80 inches have become mainstream. In the case of the projector with a long projection distance in the past, there was a conference desk between the projector and the screen 2, and the projector was placed behind the conference desk, but in recent years, the conference has been shortened due to the shortening of the projection distance. It has become possible to place it on the front side of the desk, and the space behind the projector can be freely used. Since the projector houses a light source lamp and a large number of electronic boards inside, the internal temperature of the projector will rise with the passage of time after the start-up. This is remarkable in recent years when the size of the projector housing is becoming smaller, and as a countermeasure, the intake port 11 and the intake port 11 are shown in FIG. 1 (A) so as not to exceed the heat resistant temperature of the components inside the projector. An air cooling system in which an exhaust port 12 is provided and a forced air flow is used is generally adopted.

FIG. 2 is a diagram showing the arrangement and configuration of the optical engine 3 and the light source unit 4 with the exterior cover of the image projection device 1 removed. In this embodiment, a high-pressure mercury lamp is used as the light source unit 4. As a path for the light emitted from the light source unit 4 to form an image on the screen 2, the light from the light source unit 4 is first applied to the illumination unit 3a described later of the optical engine 3. In the lighting unit 3a, the irradiated white light is separated into RGB, and the separated light is guided to an image display element unit 8 described later, which is an example of an image display device. After that, the light guided to the image display element unit 8 is image-formed according to the modulation signal, and is magnified and projected by the projection unit 3b described later to reach the screen 2.

FIG. 3 is a diagram showing a configuration example of the optical engine 3. As shown in FIG. 3, the optical engine 3 according to the present embodiment mainly includes a lighting unit 3a, a projection unit 3b, and the like. The illumination unit 3a is an example of the illumination optical means, and guides the light emitted from the light source unit 4 to the DMD 213 provided in the image display element unit 8. Further, the projection unit 3b is an example of the projection means, and the image generated by the DMD 213 (image display element unit 8) is enlarged and projected on the screen 2.

In the optical engine 3 of the present embodiment, first, the white light emitted from the light source unit 4 is converted into each color of RGB by the disk-shaped color wheel 5. After that, the light emitted from the color wheel 5 is guided into the lighting unit 3a by the light tunnel 6 formed by laminating the plate glass into a tubular shape, and the chromatic aberration is caused by the two relay lenses 7 arranged immediately after the light tunnel 6. Is corrected, and the light is focused on the image display element unit 8 provided with the DMD 213 by the flat mirror 10 and the concave mirror 9. The DMD 213 has a substantially rectangular mirror surface composed of a plurality of micromirrors, and by driving each micromirror in a time-division manner based on the video data, the projected light is processed and reflected on a predetermined video. It has a structure. Here, it can be considered that the DMD 213, which is an example of the light modulation element, generates an image by using the light emitted from the light source unit 4. Further, the image projection device 1 of the present embodiment is a projector in which the DMD 213 faces the screen 2.

There are two types of reflection directions for the DMD 213, and the light used for forming the video data is reflected to the projection lens, and the light discarded without being used is reflected to the OFF light plate. The light used for forming the video data is reflected toward the projection unit 3b, is magnified when passing through the plurality of projection lenses, and is projected onto the screen 2 as magnified video light. The relay lens 7, concave mirror 9, plane mirror 10, image display element unit 8, and projection unit 3b inside the lighting unit 3a are held on the incident side by a housing (not shown) so as to cover each component. The mating surface of the housing has a dustproof structure sealed with a sealing material.
Further, the image projection device 1 of the present embodiment includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The CPU controls the operation of the image projection device 1 by expanding the program stored in the ROM or the like into the RAM and executing the program.

Next, the high-resolution module 21 which is an example of the configuration of the image display element unit 8 will be described. FIG. 4 is an overall view (perspective view) of the high resolution module 21. The high resolution module 21 is a module used for the image forming unit of the image projection device 1. The image projection device 1 is a device that generates an image based on image data input from a personal computer, a video camera, or the like, and projects and displays the image on a screen or the like. As described above, the image projection device 1 is becoming higher in resolution, the brightness is improved due to the higher efficiency, and the price is lowered. While small and lightweight devices are becoming widespread, LCD TVs are also becoming higher in resolution. FPDs (Flat Panel Display), which can display high-definition images such as 4K and 8K, are becoming widely used not only in general households but also in business applications such as signage.

Generally, it can be said that the resolution of a DLP (Digital Lite Processing) projector using a DMD depends on the resolution of the DMD itself, which is an image display element. The DMD has a structure in which Micro-Mirrors are spread, and the resolution is determined by the number of Micro-Mirrors. Therefore, it can be said that it is easiest to increase the resolution by increasing the DMD itself and increasing the number of Micro-Mirrors. However, in that case, it becomes necessary to increase the lighting area in accordance with the increase in the size of the DMD, which not only makes it impossible to divert the existing optical engine and forces a new design, but also leads to an increase in the cost of optical parts other than the DMD. Problems arise. Therefore, it is required to reduce the size and pitch of the Micro-Mirror without changing the size of the DMD.

However, there is a limit to reducing the size and pitch of the Micro-Mirror, and there are many technical issues such as the possibility of having to increase the size of the DMD in order to achieve high resolution. There is a background that cannot be realized. Therefore, in the following, instead of increasing the resolution of the DMD itself, we propose a method of creating an intermediate image in the projected image by moving the DMD by half a pixel and increasing the resolution of the projected image without changing the resolution of the DMD itself. do. Hereinafter, the specific method will be described.

FIG. 5 is an exploded perspective view of the high resolution module 21. As shown in FIG. 5, the high-resolution module 21 is mainly composed of a position detection unit 211 including a DMD 213 and a driving force generation unit 212 including a heat sink 24. Subsequently, a detailed configuration of the position detection unit 211 and the driving force generation unit 212 will be described.

6A and 6B are diagrams showing a detailed configuration of the position detection unit 211. FIG. 6A is an exploded perspective view of the position detection unit 211, and FIG. 6B is an exploded side view of the position detection unit 211. As shown in FIGS. 6A and 6B, the position detection unit 211 corresponding to the second floor portion includes the DMD 213, the DMD substrate 23 including the Hall element 25, the Hall element magnet 42, and the movable plate 61 which is a movable plane 3. It consists of one plate. As a specific configuration of these three plates, the positions and spacings of the two plates are fixed by arranging the columns 36 between the top plate 31 and the base plate 32, and the movable plate 61 is arranged between them. It is composed.
As a method of supporting the movable plate 61, balls 34 are arranged between the movable plate 61 and the top plate 31 and between the movable plate 61 and the base plate 32 for the purpose of reducing friction during movement, and the balls are arranged from two directions at a total of three points. It is configured to be supported by sandwiching it with 34. Regarding the adjustment of the clearance between the movable plate 61 and the ball 34, the clearance is adjusted by the pushing amount of the adjusting screw 37.

FIG. 7 is a diagram showing a detailed configuration of the driving force generation unit 212. As shown in FIG. 7, the driving force generation unit 212 includes a driving magnet 33 attached to the base plate 32, a flexible substrate 26 with a voice coil 22 arranged opposite to the driving magnet 33, and a heat sink 24. The starting magnet 33 and the voice coil 22 function as an actuator such as a VCM (Voice Coil Motor).
Here, the movable unit 81 displaying only the movable portion from the position detection unit 211 and the driving force generation unit 212 and the fixed unit 91 displaying only the fixed portion are shown in FIGS. 8 and 9 below, respectively.

As shown in FIG. 8, the movable unit 81 includes a DMD board 23 and a movable plate 61 included in the position detection unit 211, a flexible board 26 with a voice coil 22 and a heat sink 24 included in the driving force generation unit 212. It is composed of. A DMD cover 27 is provided on the front surface of the DMD 213, and this component is attached for the purpose of preventing the DMD 213 from being unintentionally removed from the DMD socket when an unexpected external force is applied to the DMD 213.
Further, the DMD cover 27 is configured to be coated with black to prevent the DMD 213 from coming off and at the same time to take measures against stray light. Further, a major feature here is that the voice coil 22 is arranged inside the heat sink 24. As is clear from FIG. 8, the center of gravity of the movable portion is in the vicinity of the heavy heat sink 24. In order to stabilize the driving performance, it is desirable that the center of gravity of the movable part and the driving force generation point coincide with each other (= no moment is generated), so the above-mentioned configuration is used. A more specific arrangement of the voice coil 22 will be described later with reference to FIG.

Subsequently, the configuration of the fixed unit 91 shown in FIG. 9 will be described below. As shown in FIG. 9, it can be said that most of the fixed unit 91 is composed of the position detection unit 211. Specifically, the component corresponding to the driving force generating unit 212 is only the driving magnet 33 for generating the driving force, and the two plates of the top plate 31 and the base plate 32 connected via the support column 36 and the movable plate. Most of the fixing unit 91 is composed of parts included in the position detecting portion 211, such as a magnet 42 for a Hall element for detecting the position of the portion and a ball 34 for improving the slidability of the movable portion.
The ball 34 on the base plate 32 side is housed in the ball holding portion 38, and on the top plate 31 side, a round hole is provided in the top plate 31 and the ball 34 is arranged inside the round hole. The ball receiving portion 35 is configured to cover the round hole. The main function of the ball 34 is to hold the movable plate 61 without impairing the driving performance of the movable plate 61, and the movable plate 61 is supported by being sandwiched between the two balls 34 from both sides. From the viewpoint of drive performance, it is desirable to provide a minute clearance between the ball 34 and the movable plate 61, and as a method of realizing this, an adjusting screw 37 is provided and the clearance is adjusted by the pushing amount thereof. be.

FIG. 10 is a diagram illustrating a configuration of a movable plate 61 constituting the movable unit 81. The conventional movable plate is composed of four voice coils 52 to 55, two each in the X-axis direction and the Y-axis direction, which are the plane directions of the heat sink 24, and all voice coils as shown in FIG. 11 are PWMed. By controlling, a driving force was generated, and the image display element unit 8 was moved to a predetermined position. In this case, depending on the timing of the PWM control, a section T in which the current value becomes zero occurs, and the image display element unit 8 is always subjected to gravity.

However, in this embodiment, as shown in FIG. 10, the voice coil 56 for generating the driving force corresponding to the gravity is arranged on the movable plate 61 so as to oppose the gravity of the image display element unit 8. Then, by controlling the voice coil 56 with a constant current value as shown in FIG. 12 during the reciprocating motion of the DMD 213, a constant driving force corresponding to the gravity of the image display element unit 8 is always generated. That is, in this embodiment, an actuator (first) which is composed of voice coils 52 to 55 and a starting magnet 33 provided corresponding to these, moves the image display element unit 8 to a predetermined position, and shifts the pixels. Actuator), a voice coil 56, and a starting magnet 33 provided corresponding to the voice coil 56), and an actuator (second) that generates a force against the gravity of the image display element unit 8 during the reciprocating movement of the DMD 213. By adopting the structure having the actuator), it was decided to eliminate the influence of gravity while generating the driving force for shifting the pixels. Specifically, during the reciprocating movement of the first actuator, DMD213, which reciprocates the DMD213 and DMD213 of the image display element unit 8 supported so as to be movable in a plane including the direction of gravity, the DMD213 opposes gravity. The configuration includes the second actuator that applies a constant force, the first actuator, and the driving force generation unit 212 that controls the driving of the second actuator.
With this configuration, even in a state where no driving force is generated by another voice coil (PWM OFF state), the image display unit does not freely fall and blurring of the projected image can be prevented. In FIG. 10, since the voice coil 56 is arranged between the voice coil 54 and the voice coil 55 at the position of the center of gravity of the movable unit 81, a constant driving force corresponding to the gravity of the image display element unit 8 is stabilized. Can be generated. Further, by providing the first actuator and the second actuator, more actuators are driven than in the case where a force against gravity is generated and controlled only by the first actuator, so that the heat generation source is dispersed. It is possible to reduce the size of each actuator.

Further, when the image display element unit 8 is vertically driven, it is necessary to generate the driving force for gravity by the voice coils 52 to 55 in the conventional configuration. However, according to the configuration of this embodiment, since the voice coil 56 generates the driving force for gravity, the voice coils 52 to 55 need only generate the same driving force during vertical driving as during horizontal driving, and the image is displayed. There is no need to separate the control methods of the units.

FIG. 13 is a flowchart showing a control procedure of the image display element unit 8 of the image projection device 1 in this embodiment. As shown in FIG. 13, when the power of the image projection device 1 is turned on (step S1), the high-resolution module 21 reads the main body setting specified by the operator and sets the drive shaft of the image display element unit 8. Initial settings related to image projection such as settings are made, and the standby state is set (step S2).
The high-resolution module 21 determines whether or not the initially set image display element unit 8 is vertically driven (step S3). When the image display element unit 8 determines that the image display element unit 8 performs vertical drive (step S3; Yes), the high resolution module 21 turns on the voice coil 56 (step S4). When the image display element unit 8 determines that the image display element unit 8 does not perform vertical drive (step S3; No), the high resolution module 21 waits until the image display element unit 8 is vertically driven.

After that, the high resolution module 21 determines whether or not the power of the image projection device 1 is turned off (step S5), and repeats the above steps until the power of the image projection device 1 is turned off.
As described above, in this embodiment, the free fall of the image display element unit 8 can be prevented by constantly generating the driving force for the gravity of the image display element unit 8 by using the voice oil 56. As a result, it is possible to prevent the projected image from shifting, so that a clear image can always be provided.

Specifically, a voice coil 56 controlled by a constant current is arranged on the movable plate 61 of the image display element unit 8, and the arranged voice coil 56 generates a driving force for the gravity of the image display element unit 8. Even when the driving force is not generated, such as when PWM is OFF, the driving force generated by the boil coil 56 and the gravity of the image display element unit 8 can be offset to prevent the image display element unit 8 from freely falling. It is possible to provide a clear image without causing any deviation in the projected image.

FIG. 14 is a flowchart showing a modified example of the control procedure shown in FIG. In FIG. 14, the image projection device 1 is provided with a detection unit such as an acceleration sensor, and the detection unit is used to calculate the inclination of the image projection device 1 main body so that the operator drives the image display element unit 8 in the initial setting. It is possible to automatically determine whether or not to turn on the boil coil 56 without setting the axis.
In FIG. 14, as in the case of FIG. 13, when the power of the image projection device 1 is turned on (step S11), the high resolution module 21 calculates the tilt angle of the main body from the value detected by the detection unit. At the same time, the main body settings other than the drive shaft of the image display element unit 8 designated by the operator are read, the initial settings related to the image projection are performed, and the standby state is set (step S21).

The high-resolution module 21 determines whether or not the initially set image display element unit 8 is vertically driven by determining whether or not the inclination detected and calculated by the detection unit is equal to or greater than a predetermined threshold value. (Step S3). When the high-resolution module 21 determines that the inclination of the image display element unit 8 is equal to or greater than a predetermined threshold value and performs vertical drive (step S3; Yes), the voice coil 56 is turned on and detected by the detection unit. A driving force having a magnitude against gravity is always generated according to the magnitude of the inclination (step S4). When the image display element unit 8 determines that the image display element unit 8 does not perform vertical drive (step S3; No), the high resolution module 21 waits until the image display element unit 8 is vertically driven.
After that, as in the case of FIG. 13, the high resolution module 21 determines whether or not the power of the image projection device 1 is turned off (step S5), and repeats the above steps until the power of the image projection device 1 is turned off.

As described above, in the modification shown in FIG. 14, the detection unit detects the inclination of the image display element unit 8, and the high resolution module 21 vertically drives the apparatus main body if the inclination is equal to or more than a predetermined threshold value. The boil coil 56 is automatically turned on, and a driving force having a magnitude against gravity is always generated according to the magnitude of the inclination. Therefore, no matter what angle the image projection device 1 main body is tilted, it is not necessary for the operator to manually set the drive shaft in the initial setting, and the labor for the initial setting can be reduced.

In this embodiment, the voice coil 56 for generating the driving force for the gravity of the image display element unit 8 is arranged on the movable plate 61 of the image display element unit 8 constituting the image projection device 1. explained. However, it is also possible to apply the same technology to the image stabilization technology of the image sensor. Specifically, the image display element unit 8 of the image image sensor 1 is replaced with an image sensor unit, and the image sensor is subjected to gravity separately from the actuator that applies a force to move the image sensor according to the detection result of the gyro sensor or the acceleration sensor. By providing an actuator that applies a countervailing force, it is possible to correct camera shake more accurately than before.

Further, in this embodiment, it is decided to control the voice coil 56 with a constant current value in consideration of the influence of gravity when the detection unit detects the inclination. However, when the detection unit detects the tilt, if an external factor such that the tilt changes with time is added, for example, the image projection device 1 main body may be moved up and down to project, or a mobile robot or the like may be used. When the image projection device 1 is mounted on a moving body and it is moved and projected, the change in the speed of movement is regarded as the change in the strength of an external factor, and the voice coil 56 is controlled according to the change. A constant current value may be varied to generate a force against gravity. For example, when the image projection device 1 is moved up and down, it is affected by the acceleration moving in the up and down direction in addition to gravity, so that it is compared with the case where the inclination is simply detected as in the example shown in FIG. The voice coil 56 is controlled by a current value having a magnitude corresponding to a change in the moving speed. By such control, even if an external factor other than gravity is applied, the influence can be eliminated and a clear image can be provided.

Although the image projection device according to the embodiment has been described above, the present invention is not limited to the above embodiment, and various modifications and improvements can be made within the scope of the present invention.

1 Image projection device 2 Screen 3 Optical engine 4 Light source unit 5 Color wheel 6 Light tunnel 7 Relay lens 8 Image display element unit 9 Concave mirror 10 Flat mirror 10
21 High resolution module 211 Position detection unit 212 Driving force generation unit 213 DMD
24 Heat sink 52-55 Voice coil 56 Voice coil (gravity)
61 Movable plate 81 Movable unit 91 Fixed unit

Japanese Unexamined Patent Publication No. 2016-085363

Claims (8)

An image display element that is movably supported in a plane including the direction of gravity,
The first actuator that reciprocates the image display element and
A second actuator that applies a constant force against gravity to the image display element during the reciprocating motion of the image display element.
A driving force generating unit that controls the driving of the first actuator and the second actuator,
An image display device comprising. It is equipped with a detector that detects the tilt of the image display device.
The driving force generation unit generates a force against the gravity of the second actuator based on the detection result of the detection unit.
The image display device according to claim 1. The driving force generating unit generates the countering force according to the inclination detected by the detecting unit.
The image display device according to claim 2. The detection unit detects a change in the moving speed of the image display device and detects a change in the moving speed of the image display device.
The driving force generating unit generates the countering force according to the changing moving speed.
The image display device according to claim 2 or 3. An image display element that is movably supported in a plane including the direction of gravity,
The first actuator that reciprocates the image display element and
A second actuator that applies a constant force against gravity to the image display element during the reciprocating motion of the image display element.
A driving force generating unit that controls the driving of the first actuator and the second actuator,
A projection unit that projects an image generated by the image display element controlled by the first actuator and the second actuator onto a projection surface by the driving force generation unit.
An image projection device characterized by comprising. The first actuator reciprocates the image display element movably supported in a plane including the direction of gravity.
The second actuator applies a constant force against gravity to the image display element during the reciprocating motion of the image display element.
An image display method characterized by that. An image sensor that is movably supported in a plane including the direction of gravity,
The first actuator that reciprocates the image sensor and
A second actuator that applies a constant force against gravity to the image sensor during the reciprocating motion of the image sensor.
A driving force generating unit that controls the driving of the first actuator and the second actuator,
An image sensor unit characterized by being equipped with. It is equipped with a detection unit that detects the tilt of the image sensor.
The driving force generation unit generates a force against the gravity of the second actuator based on the detection result of the detection unit.
The image pickup element unit according to claim 7.

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