JP2006115607A - Motor device and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor device and a projector that can perform rotation control of a rotor with high accuracy, can be easily manufactured, and can reduce manufacturing costs.
A motor device includes a stator 4521 having a bearing 4524, and a rotor 4522 having a rotating shaft 4522A supported by the bearing 4524 and configured to be rotatable with respect to the stator 4521. It converts energy into mechanical rotational energy. This motor apparatus includes a case 4523A that is provided on the rotor 4522 and has a polygonal cross section around the rotation shaft 4522A.
[Selection] Figure 3

Description

  The present invention relates to a motor device and a projector.

2. Description of the Related Art Conventionally, several configurations for implementing rotor rotation control (speed control, phase control) have been proposed and put into practical use in motor devices that convert electrical energy into mechanical rotational energy.
For example, in a DC brushless motor, a configuration using a Hall element is often used.
In this configuration, a hall element is provided in the motor device, and the magnetic pole position of the rotor is detected by the hall element. And a control apparatus performs rotation control of a rotor based on the signal output from a Hall element.
For example, a configuration using a rotary encoder is known.
In this configuration, a rotary encoder is provided on the rotor, and the rotational speed of the rotor is detected by the rotary encoder. And a control apparatus performs rotation control of a rotor based on the signal output from a rotary encoder according to rotation of a rotor.
Furthermore, for example, a configuration using a photo interrupter is known (see, for example, Patent Document 1).
In this configuration, a slit is provided in the outer peripheral portion of the reflector that rotates in synchronization with the rotor. Further, the photo interrupter is arranged so as to sandwich the outer peripheral portion of the reflecting plate. The photo interrupter detects the edge of the slit depending on whether or not the light from the light emitting element is received by the light receiving element through the slit. Then, the control device detects the rotational speed of the rotor according to the signal output from the photo interrupter, and performs the rotational control of the rotor based on the rotational speed.
Furthermore, for example, a configuration using a photo reflector is known (see, for example, Patent Document 2).
In this configuration, the motor device is formed of an outer rotor type motor device, and the detection disk is disposed on the opening surface of the rotor. Further, the surface of the detection disk is mirror-finished, and a light-absorbing scale is formed by applying a light absorber on the surface at regular intervals along a predetermined circumference. And a photo reflector is arrange | positioned so as to oppose a light reflective scale. The photo reflector detects the rotational position of the rotor depending on whether light from the light emitting element is reflected by the detection disk and received by the light receiving element. The control device detects the rotational speed of the rotor in accordance with the signal output from the photoreflector, and performs the rotational control of the rotor based on the rotational speed.

Japanese Patent Laid-Open No. 6-22584 Japanese Patent Laid-Open No. 11-89204

However, in the configuration using the Hall element, the characteristics of the Hall element are likely to change with temperature. For this reason, the rotation control of the rotor cannot be performed with high accuracy in a place where the temperature environment is severe. In addition, in order to perform the rotation control of the rotor with high accuracy even in a place where the temperature environment is severe, control for correcting the temperature characteristic of the Hall element is required, and the control structure becomes complicated.
Further, in the configuration using the rotary encoder, it is necessary to dispose the rotary encoder on the rotor. When manufacturing the motor device, the manufacturing becomes difficult and the manufacturing cost cannot be reduced.
Furthermore, in the configuration described in Patent Document 1, in order to perform the rotation control of the rotor with high accuracy, it is necessary to provide slits in the reflection plate with high accuracy, which makes it difficult to manufacture the reflection plate. For this reason, when manufacturing a motor apparatus, the manufacture becomes difficult and the manufacturing cost cannot be reduced.
Furthermore, in the configuration described in Patent Document 2, it is necessary to perform mirror finishing on the surface of the detection disk, and in order to perform the rotation control of the rotor with high accuracy, the light absorber is increased at regular intervals. Since it is necessary to apply with high accuracy, it becomes difficult to manufacture the motor device, and the manufacturing cost cannot be reduced.

  An object of the present invention is to provide a motor device and a projector that can perform rotation control of a rotor with high accuracy, can be easily manufactured, and can reduce manufacturing costs.

A motor device according to the present invention includes a stator having a bearing, and a rotor having a rotating shaft supported by the bearing and configured to be rotatable with respect to the stator. A motor device for converting to mechanical rotational energy, comprising a polygonal columnar portion provided on the rotor and having a polygonal cross section around the rotation axis.
Here, as the motor device, a DC motor (brushless DC motor, DC motor with brush), which is configured to include a stator and a rotor and converts electric energy into mechanical rotation energy, Any motor such as an AC motor may be employed.
According to the present invention, since the rotor constituting the motor device is provided with the polygonal columnar portion, for example, light or sound waves are emitted toward the side end surface of the polygonal columnar portion, and either side of each side end surface The rotation state of the rotor can be detected by detecting light reflected by the end face or sound waves. If the rotation control of the rotor is performed based on the detected rotation state of the rotor, the rotation control of the rotor can be performed with high accuracy.
In addition, according to the present invention, since the rotation control of the rotor can be performed with high accuracy only by providing the polygonal columnar portion in the rotor, the manufacture of the motor device is facilitated and the manufacturing cost is reduced. Can be planned.

In the motor device of the present invention, a rotation state detection device that detects a rotation state of the rotor and outputs rotation state information relating to the rotation state, and a rotation state information output from the rotation state detection device A control device that performs rotation control, and the rotation state detection device irradiates a light beam in a direction orthogonal to the columnar axis in the polygonal columnar portion when the rotor rotates, and forms the polygonal columnar shape. It is preferable to detect the rotational state of the rotor by detecting the light beam reflected by the side end face of the part.
Here, as the rotation state detection device, for example, a photo reflector in which a light emitting diode and a phototransistor are combined as one element can be adopted.
According to the present invention, the rotation state detector rotates the rotor by emitting a light beam toward the side end surface of the polygonal columnar portion and detecting the light beam reflected on one of the side end surfaces. The state can be detected. Based on the rotation state of the rotor detected by the rotation state detection device, the rotation control of the rotor can be performed with high accuracy by the control device.
In addition, each side end face of the polygonal columnar portion is made a reflective surface that can reflect a light beam, and a rotation state detector that emits the light beam and detects reflected light can be used to detect the rotation state of the rotor with a simple configuration. This can be implemented, and in manufacturing the motor device, the manufacturing can be further facilitated, and the manufacturing cost can be further reduced.

In the motor device of the present invention, it is preferable that at least one of the side end faces of the polygonal columnar portion is subjected to a light shielding process.
By the way, when all the side end surfaces of the polygonal columnar part function as reflecting surfaces, the rotation state information output from the rotation state detecting device when the rotor makes one rotation is output by the number of each side end surface. The Rukoto.
In the present invention, since at least one of the side end surfaces of each side end surface of the polygonal columnar portion is subjected to a light shielding process, the rotation state information output from the rotation state detection device when the rotor makes one rotation is: The number of side end surfaces subjected to the light shielding process is lost. For this reason, the phase control of the rotor can be satisfactorily performed by the control device by using the timing at which the rotation state information is not output among the output timings of the rotation state information output from the rotation state detection device.

In the motor device of the present invention, the rotor is disposed outside the stator, and the polygonal columnar portion accommodates the rotor and the stator therein and rotates in synchronization with the rotor. The motor housing is preferably formed on at least a part of the motor housing.
According to the present invention, the motor device is constituted by an outer rotor type motor in which the rotor is disposed outside the stator. For this reason, inertia becomes large and it becomes the structure which is easy to rotate the to-be-rotated body used as the rotation object of a motor apparatus at constant speed.
In addition, by configuring with an outer rotor type motor in this way, the motor housing can be rotated in synchronization with the rotor, and the rotated body can be connected to the motor housing and rotated. Therefore, the connection surface between the rotated body and the motor device can be made large, and the rotated body can be rotationally driven while maintaining the support state of the rotated body satisfactorily.
Furthermore, since the motor housing can be rotated in synchronism with the rotor, a polygonal columnar portion can be formed on at least a part of the motor housing. The manufacturing cost can be further reduced.

The projector according to the present invention is a projector that modulates a light beam emitted from a light source according to image information and projects the modulated light beam in an enlarged manner, and forms an image of the light beam emitted from the light source at a predetermined position. And a plurality of light beam incident side end surfaces on which light beams emitted from the illumination optical device are incident are configured to be rotatable about a predetermined rotation center axis and refract the light beams passing through the interior to rotate the light beams. A prism that changes the exit position of the light source, the motor device that supports the prism and rotationally drives the prism about the rotation center axis, and modulates the light flux through the prism according to image information to obtain an optical image. And a hold type light modulation device that continues to form a preceding optical image until the subsequent image information is input, and an optical image formed by the hold type light modulation device A projection optical device for enlarging and projecting, and the illumination optical device forms a light beam in a predetermined illumination region on an image forming region in the hold type light modulation device, and the motor device rotationally drives the prism. Thus, the emission position of the light beam emitted from the illumination optical device and changed through the prism is changed, and the illumination area is scrolled at a predetermined cycle on the image forming area.
Here, the scrolling means crossing from one end side to the other end side of the image forming area.
According to the present invention, since the projector includes the motor device described above, the projector can enjoy the same effects as the motor device described above. In addition, since the motor device that can be manufactured easily and can reduce the manufacturing cost is provided, the manufacturing cost of the projector can be reduced.

By the way, in the hold type light modulation device, since the image formed in each display period is continuously displayed, there is a problem in that the human tracking eye movement and the time integration effect of the eye act to cause image blurring (“ "Video performance evaluation technology for displays" LCD Vol. 6, No. 4, 2002 Norio Oma, Tatsuo Uchida).
In the present invention, since the motor device can perform the rotation control of the rotor with high accuracy, by rotating the prism, the motor device emits light from the illumination optical device and is connected to a predetermined region on the image forming region in the hold type light modulation device. The illuminated area to be imaged can be scrolled at a predetermined cycle on the image forming area. That is, the non-illuminated area that is not irradiated with the light flux, which is an area other than the illuminated area, can be scrolled at a predetermined cycle on the image forming area. As a result, when a moving image is formed by the hold type light modulation device, it is possible to hide a predetermined period in each display period of each optical image constituting the moving image in the non-illuminated area. It becomes. For this reason, the display period of the optical image formed by the hold type light modulation device can be shortened, the action of the human tracking eye movement and the time integration effect of the eye can be reduced, and the moving image performance can be improved.

In the projector according to the aspect of the invention, it is preferable that the number of side end surfaces of the polygonal columnar portion constituting the motor device is an integral multiple of the number of light incident side end surfaces of the prism.
According to the present invention, since the number of side end surfaces of the polygonal columnar portion constituting the motor device is set to an integral multiple of the number of the light beam incident side end surfaces of the prism, the prism is driven to rotate on the image forming area. Control for synchronizing the scrolling of the illumination area with, for example, vertical scanning of an optical image formed by a hold-type light modulation device can be easily performed.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[Configuration of projector]
FIG. 1 is a diagram schematically showing a schematic configuration of the projector 1.
The projector 1 modulates a light beam emitted from a light source according to image information to form an optical image, and enlarges and projects the formed optical image on a screen. As shown in FIG. 1, the projector 1 includes an exterior housing 2, a projection lens 3 as a projection optical device, an optical unit 4, and a control device 5 (not shown).
Although not shown in FIG. 1, in the exterior casing 2, in a space other than the projection lens 3 and the optical unit 4, a cooling unit configured by a cooling fan or the like that cools the inside of the projector 1, the projector 1. It is assumed that a power supply unit and the like for supplying electric power to the internal components are disposed.

The exterior housing 2 is made of synthetic resin or the like, and is formed in a substantially rectangular parallelepiped shape in which the projection lens 3, the optical unit 4, and the control device 5 (not shown) are housed and disposed inside as shown in FIG. Yes. Although not shown, the outer casing 2 includes an upper case that configures the top, front, back, and side surfaces of the projector 1 and a lower case that configures the bottom, front, and back surfaces of the projector 1, respectively. The upper case and the lower case are fixed to each other with screws or the like.
The exterior housing 2 is not limited to being made of synthetic resin, and may be formed of other materials, for example, metal.

The optical unit 4 is a unit that optically processes a light beam emitted from a light source under the control of the control device 5 to form an optical image (color image) corresponding to image information. As shown in FIG. 1, the optical unit 4 has a substantially L shape in plan view that extends along the back surface of the exterior housing 2 and extends along the side surface of the exterior housing 2. . The detailed configuration of the optical unit 4 will be described later.
The projection lens 3 enlarges and projects the optical image (color image) formed by the optical unit 4 on a screen (not shown). The projection lens 3 is configured as a combined lens in which a plurality of lenses are housed in a cylindrical lens barrel, and the relative position of the plurality of lenses is changed so that the focus adjustment and magnification adjustment of an optical image to be enlarged and projected can be performed. It is configured.
Although not shown, the control device 5 includes an arithmetic processing device such as a CPU (Central Processing Unit) and controls the entire projector 1 based on a signal input from an external device. The control structure of the control device 5 will be described later.

[Detailed configuration of optical unit]
As shown in FIG. 1, the optical unit 4 includes an illumination optical device 41, a color separation optical device 42, a relay optical device 43, an optical device 44, an optical scanning device 45, and these devices 41 to 45 inside. And an optical component casing 46 to be housed.
The illumination optical device 41 is an optical system for forming an image of illumination light in an illumination area that is a predetermined area on an image forming area of a liquid crystal panel, which will be described later, constituting the optical device 44. As shown in FIG. 1, the illumination optical device 41 includes a light source device 411, a first lens array 412, a second lens array 413, a polarization conversion element 414, and a superimposing lens 415.

  As shown in FIG. 1, the light source device 411 includes a light source lamp 416 that emits a radial light beam, a reflector 417 that reflects the emitted light emitted from the light source lamp 416 and converges the light to a predetermined position, and the reflector 417 converges the light. And a collimating concave lens 418 that collimates the luminous flux with respect to the illumination optical axis A. As the light source lamp 416, a halogen lamp, a metal halide lamp, or a high-pressure mercury lamp is frequently used. Further, the reflector 417 is composed of an ellipsoidal reflector having a spheroidal surface, but may be composed of a parabolic reflector having a rotational paraboloid. In this case, the collimating concave lens 418 is omitted.

The first lens array 412 has a configuration in which small lenses having a substantially rectangular outline when viewed from the optical axis direction are arranged in a matrix. Each small lens splits the light beam emitted from the light source device 411 into a plurality of partial light beams.
The second lens array 413 has substantially the same configuration as the first lens array 412, and has a configuration in which small lenses are arranged in a matrix. The second lens array 413, together with the superimposing lens 415, forms an image of each small lens of the first lens array 412 in an illumination area which is a predetermined area on an image forming area of a liquid crystal panel described later of the optical device 44. have.

The polarization conversion element 414 is disposed between the second lens array 413 and the superimposing lens 415, and converts light from the second lens array 413 into substantially one type of polarized light.
Specifically, each partial light converted into approximately one type of polarized light by the polarization conversion element 414 is finally a predetermined area on an image forming area of a liquid crystal panel (to be described later) of the optical device 44 by the superimposing lens 415. It is almost superimposed on the area. In a projector using a liquid crystal panel of a type that modulates polarized light, only one type of polarized light can be used, and therefore approximately half of the light from the light source device 411 that emits randomly polarized light cannot be used. For this reason, by using the polarization conversion element 414, the light emitted from the light source device 411 is converted into substantially one type of polarized light, and the light use efficiency in the optical device 44 is increased.

As shown in FIG. 1, the color separation optical device 42 includes two dichroic mirrors 421 and 422, which are emitted from the illumination optical device 41 by the dichroic mirrors 421 and 422, and the field lens 423, the optical scanning device 45, and the field lens. It has a function of separating a plurality of partial light fluxes via 424 into three color lights of red, green, and blue.
As shown in FIG. 1, the relay optical device 43 includes two relay lenses 431 and 432 and reflection mirrors 433 to 437, and each color light separated by the color separation optical device 42 is described later in the optical device 44. It leads to the liquid crystal panel. Then, the relay optical device 43 sets the geometric optical path length of each color light reaching from the dichroic mirror 421 to each liquid crystal panel to be described later of the optical device 44 to the same size. Further, the two relay lenses 431 and 432 are respectively arranged on the optical path of red light and the optical paths of green and blue light. That is, since the number of relay lenses arranged in the optical path of red light, the optical path of green light, and the optical path of blue light is the same, the inversion states of the optical images of red light, green light, and blue light are the same, When red light, green light, and blue light are combined, combined light having no color unevenness can be formed.

  At this time, in the dichroic mirror 421 of the color separation optical device 42, among the light beams emitted from the illumination optical device 41, the green light component and the blue light component are transmitted, and the red light component is reflected. The red light reflected by the dichroic mirror 421 is reflected by the reflection mirror 433, is reflected by the reflection mirrors 434 and 435 via the relay lens 431, passes through the field lens 419, and reaches a later-described red light liquid crystal panel. To do. The field lens 419 converts each partial light beam emitted from the second lens array 413 into a light beam parallel to the central axis (principal ray). The same applies to the field lens 419 provided on the light incident side of the other liquid crystal panel for green light and blue light, and the field lenses 423 and 424 provided in the upstream and downstream of the optical path of the optical scanning device 45.

  Further, the green light and the blue light transmitted through the dichroic mirror 421 are reflected by the reflection mirror 436, enter the dichroic mirror 422 after passing through the relay lens 432. Of the green light and blue light incident on the dichroic mirror 422, the green light is reflected by the dichroic mirror 422, reflected by the reflecting mirror 433, passes through the field lens 419, and reaches a later-described green light liquid crystal panel. To do. On the other hand, the blue light passes through the dichroic mirror 422, is reflected by the reflection mirror 437, passes through the field lens 419, and reaches a later-described blue light liquid crystal panel.

As shown in FIG. 1, the optical device 44 includes three liquid crystal panels 441 (a red light side liquid crystal panel 441R, a green light side liquid crystal panel 441G, and a blue light side liquid crystal panel as a hold type light modulation device. 441B), three incident side polarization plates 442, three emission side polarization plates 443, and a cross dichroic prism 444.
As shown in FIG. 1, the three incident side polarizing plates 442 are respectively arranged in the rear stage of the optical path of each field lens 419. The incident-side polarizing plates 442 receive the respective color lights whose polarization directions are aligned in approximately one direction by the polarization conversion element 414. Of the incident light beams, the polarization directions of the light beams aligned by the polarization conversion element 414 are substantially the same. It transmits only polarized light in the same direction and absorbs other light beams. Although not shown in the drawing, these incident side polarizing plates 442 have a configuration in which a polarizing film is pasted on a translucent substrate such as sapphire or quartz.

As shown in FIG. 1, the three liquid crystal panels 441 are respectively arranged on the rear side of the optical path of each incident side polarizing plate 442. Although not shown, these liquid crystal panels 441 have a configuration in which a liquid crystal, which is an electro-optical material, is hermetically sealed between a pair of transparent glass substrates. The alignment state of the liquid crystal at the pixel position is controlled to modulate the polarization direction of the polarized light beam emitted from each incident side polarizing plate 442.
As shown in FIG. 1, the three exit-side polarizing plates 443 are respectively arranged in the rear stage of the optical path of each liquid crystal panel 441. These exit-side polarizing plates 443 have substantially the same configuration as the incident-side polarizing plate 442, and although not shown, have a configuration in which a polarizing film is attached to a light-transmitting substrate. The polarizing film constituting the exit side polarizing plate 443 is disposed so that the transmission axis that transmits the light beam is substantially orthogonal to the transmission axis that transmits the light beam at the incident side polarizing plate 442.

  The cross dichroic prism 444 is an optical element that is arranged in the latter stage of the light path of the exit-side polarizing plate 443, and forms a color image by combining optical images modulated for each color light emitted from each exit-side polarizing plate 443. The cross dichroic prism 444 has a square shape in plan view in which four right angle prisms are bonded together, and two dielectric multilayer films are formed on the interface where the right angle prisms are bonded together. These dielectric multilayer films reflect each color light emitted from the liquid crystal panels 441R and 441B via the respective emission side polarizing plates 443, and pass through the color light emitted from the liquid crystal panel 441G and the emission side polarizing plates 443. In this manner, the color lights modulated by the liquid crystal panels 441 are combined to form a color image.

Under the control of the control device 5, the optical scanning device 45 scrolls the illumination region that is emitted from the illumination optical device 41 and forms an image on a predetermined region on the image formation region of the liquid crystal panel 441 on the image formation region (image formation region). The image from the one end side to the other end side) to prevent blurring of the moving image. The detailed configuration of the optical scanning device 45 will be described later.
The optical component casing 46 is formed of a synthetic resin molded product, and as shown in FIG. 1, a predetermined illumination optical axis A is set therein, and the above-described devices 41 to 45 are connected to the illumination optical axis A. Store and place in position. The optical component casing 46 is not limited to being made of synthetic resin, but may be made of other materials. Although not shown, the optical component casing 46 is composed of a container-shaped component storage member that stores the devices 41 to 45 described above, and a lid-shaped member that closes the opening of the component storage member. .

[Configuration of optical scanning device]
FIG. 2 is an exploded perspective view schematically showing a schematic configuration of the optical scanning device 45.
As shown in FIG. 1, the optical scanning device 45 is disposed between the illumination optical device 41 and the color separation optical device 42. Then, the optical scanning device 45 is driven and controlled by the control device 5, so that an illumination area that is emitted from the illumination optical device 41 and forms an image on a predetermined area on the image formation area of the liquid crystal panel 441 is displayed on the image formation area. Scroll to prevent blurring of moving images. As shown in FIG. 2, the optical scanning device 45 includes a prism 451 and a motor 452.

  As shown in FIG. 2, the prism 451 has a four-beam-incidence-side end surface 451 </ b> A on its side surface and is formed in a square column shape with a square cross section, and is one end surface of two end surfaces that intersect the four light-beam-incidence side end surfaces 451 </ b> A. Is rotatably supported by the motor 452. As will be described in detail later, the light beam passing through the prism 451 is refracted by the rotation of the prism 451, and the emission position of the light beam in the prism 451 is changed. The light beam is emitted from the illumination optical device 41 and formed on the liquid crystal panel 441. The illumination area imaged on the area is scrolled on the image forming area.

FIG. 3 is a diagram illustrating a configuration of the motor 452. In FIG. 3, in order to show the internal configuration of the motor 452, the upper case in the drawing is omitted.
The motor 452 supports the prism 451 in a horizontal direction orthogonal to the direction in which the prism 451 is applied with its own weight, and is controlled by the control device 5 so that the prism 451 is centered on a predetermined rotation center axis R (FIG. 2) in the horizontal direction. Rotating drive. As shown in FIG. 3, the motor 452 is constituted by an outer rotor type brushless DC motor.
Specifically, the motor 452 includes a stator 4521 as a stator, a rotor 4522 as a cup-shaped rotor that rotates outside the stator 4521, and a motor housing 4523 that houses the stator 4521 and the rotor 4522 inside. .
The rotor 4522 has a rotation shaft 4522A at the center, and an annular permanent magnet 4522B is fixed to a cup-shaped inner wall surface. Permanent magnet 4522B is multi-polarized so that N poles and S poles are alternately arranged at predetermined intervals in the circumferential direction. The rotation shaft 4522A is rotatably supported by a bearing 4524 that passes through the stator 4521.
As this bearing 4524, for example, a ball bearing, a metal bearing, or a dynamic pressure bearing can be adopted.

The motor housing 4523 includes a case 4523A as a cup-shaped polygonal columnar portion that is connected to the rotor 4522 and rotates together with the rotor 4522 so that the columnar axis coincides with the rotation axis 4522A, and a case 4523A across a flange 4525 that is a stationary member. The back cap 4523B is disposed on the opposite side and connected to the rotary shaft 4522A.
In the case 4523A, an end surface intersecting a predetermined rotation center axis R functions as a support surface 4523A1 (FIGS. 2 and 3) that supports the prism 451. The support surface 4523A1 and the four light beam incident side end surfaces 451A of the prism 451 One end surface of the two intersecting end surfaces is connected so as to coincide with the center position of the support surface 4523A1 in plan view and the columnar axis of the prism 451. As shown in FIG. 2 or FIG. 3, the case 4523A has a regular octagonal cross section centered on the rotation shaft 4522A. And each side end surface of case 4523A is comprised so that the light beam inject | emitted from the rotation state detection apparatus mentioned later can be reflected. In the present embodiment, although not specifically illustrated, one of the eight side end faces is subjected to a light shielding process so that a light beam emitted from a rotation state detection device described later is not reflected. Has been. The detailed configuration of the rotation state detection device will be described at the same time when the control structure of the control device 5 is described.
The back cap 4523B has a substantially disk shape and prevents dust and the like from entering the motor 452 from the outside.

The stator 4521 is fixed to the flange 4525 with screws 4526, and includes a plurality of stator cores 4521A arranged radially and a plurality of stator coils 4521B wound around the respective stator cores 4521A. Stator 4521 is arranged such that the tip of each stator core 4521A faces permanent magnet 4522B at a predetermined interval. The stator coil 4521B is electrically connected to a motor control unit (described later) of the control device 5, and is driven by multiphase energization by the motor control unit. The permanent magnet 4522B, that is, the rotor 4522 is rotationally driven by the rotating magnetic field generated by the multiphase energization driving.
As shown in FIG. 1, the optical scanning device 45 described above is used for optical components such that the flange 4525 is supported by the optical component casing 46 and the rotation center axis R is orthogonal to the illumination optical axis A. Arranged in the housing 46.

4 and 5 are diagrams showing a state in which the illumination area is scrolled on the image forming area by the optical scanning device 45. FIG. FIG. 4 is a diagram of the prism 451 viewed from the rotation center axis R direction. FIGS. 5A to 5G show the illumination areas in a state where the rotation position of the prism 451 is positioned at each position shown in FIGS. 4A to 4G. 4 and 5 show a case where the projector 1 is in a normal installation state (an installation state that is not a ceiling suspension). The upper direction in the figure indicates the top side of the projector 1, and the lower direction in the figure indicates the bottom side of the projector 1. The same applies to the following description.
When the motor 452 is driven by the drive control by the control device 5 and the rotational position of the prism 451 is in the state shown in FIG. 4A, that is, the optical axis of the light beam emitted from the illumination optical device 41 is either When orthogonal to the light beam incident side end surface 451A, the light beam passes through the prism 451 without being refracted. Then, as shown in FIG. 5A, the light beam emitted from the illumination optical device 41 forms an image in a region at a substantially central portion in the vertical direction on the image forming region G of the liquid crystal panel 441. That is, in the illumination optical device 41, as shown in FIG. 5A, the horizontal width dimension of the illumination area L is the same as the horizontal width dimension of the image forming area G of the liquid crystal panel 441. The vertical width dimension is set to be smaller than the vertical width dimension of the image forming area G, and the illumination area L is set to form an image in a substantially central portion of the image forming area G in the vertical direction. In the present embodiment, the illumination area L for the entire area of the image forming area G is obtained by setting the aspect ratio of each small lens constituting the first lens array 412 and the second lens array 413 of the illumination optical device 41 to a predetermined ratio. Is set to be 50%.

  When the prism 451 is rotated in the direction of arrow R1 in FIG. 4 from the state shown in FIG. 4A to the state shown in FIG. 4B, the light beam emitted from the illumination optical device 41 is the prism. The light is refracted upward inside 451, and the emission position of the light beam from prism 451 moves upward. The illumination area L on the image forming area G also moves upward as shown in FIG.

  Here, when the prism 451 is further rotated in the arrow R1 direction from the state shown in FIG. 4B to the state shown in FIG. 4C, the light beam emitted from the illumination optical device 41 is the prism 451. The two light flux incident side end faces 451A are incident to each other. Here, as shown in FIG. 4C, the light beam incident on one light beam incident side end face 451A is refracted upward in the prism 451 as in the state shown in FIG. 4B. On the other hand, the light beam incident on the other light beam incident side end surface 451A is refracted downward in the prism 451 as shown in FIG. In this way, in the state shown in FIG. 4C, the light beam emitted from the illumination optical device 41 is separated into two light beams inside the prism 451. And the illumination area | region L on the image formation area G will also be isolate | separated into the upward direction side and the downward direction side, as shown in FIG.5 (C). That is, by rotating the prism 451, the illumination area L moves to the upper side of the image formation area G as shown in FIG. 5B, and then when the prism 451 is further rotated, the illumination area L becomes the image formation area G. The vertical width dimension on the upper side is reduced while moving upward, and further appears upward from the lower end of the image forming region G by the reduced vertical width dimension.

Then, from the state shown in FIG. 4C, when the prism 451 is sequentially rotated in the direction of the arrow R1 so as to be in the states shown in FIGS. 4D to 4F, the illumination region L becomes as shown in FIG. As shown in (F) to (F), the vertical width dimension on the upper side gradually decreases, and the vertical width dimension on the lower side gradually increases. Further, when the state shown in FIG. 4G is obtained by rotating the prism 451 by 90 ° from the state shown in FIG. 4A, the illumination region L is as shown in FIG. The position is the same as the position of the illumination area L shown in A).
That is, the illumination area L scrolls in the vertical direction on the image forming area G by rotating the prism 451 by 90 ° from the predetermined position.
As described above, the optical scanning device 45 scrolls the illumination region L on the image forming region G at a predetermined cycle by the rotation of the prism 451 under the control of the control device 5.

[Control structure by control device]
FIG. 6 is a block diagram showing a control structure by the control device 5.
The control device 5 controls the entire projector 1 based on a signal input from an external device. Hereinafter, the control structure of the liquid crystal panel 441 and the motor 452 by the control device 5 will be mainly described, and description and illustration of the other control structures will be omitted.
As shown in FIG. 6, the control device 5 includes a video signal input unit 51, a liquid crystal panel drive control unit 52, a frame memory 53, and a motor control unit 54.
The video signal input unit 51 is a part for inputting video signals output from various external devices. As shown in FIG. 6, the video signal input unit 51 includes a first input unit 511 and a second input unit 512.
The first input unit 511 is a portion to which a plurality of image signals output from a personal computer or the like are provided, and includes a first video selector 511A and an ADC (Analog to Digital Converter) 511B as shown in FIG. .
The first video selector 511A selects and outputs one of a plurality of input image signals in accordance with a selection signal given from the liquid crystal panel drive control unit 52. The image signal output from the first video selector 511A includes three color analog image signals of red (R), green (G), and blue (B), a horizontal synchronization signal, and a vertical synchronization signal. Yes. Such an image signal is called a component signal.
The ADC 511B converts the three analog image signals output from the first video selector 511A into digital image signals by the AD conversion circuit in the ADC 511B. The digital image signal is temporarily recorded in the frame memory 53 in synchronization with the horizontal synchronization signal and the vertical synchronization signal included in the image signal output from the first video selector 511A. The recorded digital image signal is sequentially rewritten according to the digital image signal output from the ADC 511B.

The second input unit 512 is a part to which a plurality of video signals output from a video recorder, a television, or the like is given, and includes a second video selector 512A and a video decoder 512B as shown in FIG.
The second video selector 512A selects and outputs one of the input video signals according to the selection signal given from the liquid crystal panel drive control unit 52. These video signals are image signals in which a luminance signal, a color signal, and a synchronization signal are superimposed, and are called composite signals.
The video decoder 512B separates the horizontal synchronization signal and the vertical synchronization signal from the composite signal output from the second video selector 512A and converts them into three digital image signals of R, G, and B. The digital image signal is temporarily recorded in the frame memory 53 in synchronization with the separated horizontal synchronization signal and vertical synchronization signal. The recorded digital image signal is sequentially rewritten according to the digital image signal output from the video decoder 512B.

The liquid crystal panel drive control unit 52 appropriately reads the digital image signal output from the video signal input unit 51 and sequentially stored in the frame memory 53, performs a predetermined process on the read digital image signal, and performs the process. A drive signal as image information corresponding to the image is output to each liquid crystal panel 441 to form a predetermined optical image. Examples of the predetermined processing in the liquid crystal panel drive control unit 52 include image size adjustment processing such as enlargement / reduction, trapezoidal distortion correction processing, image quality adjustment processing, and gamma correction processing. Since each of these processes is a well-known technique, detailed description is abbreviate | omitted.
The liquid crystal panel drive control unit 52 generates and generates a vertical synchronization signal and a horizontal synchronization signal for forming an optical image in the liquid crystal panel 441 based on the synchronization signal included in the component signal and the composite signal. The digital image signal stored in the frame memory 53 is appropriately read out in synchronization with the vertical synchronizing signal and horizontal synchronizing signal.
Further, the liquid crystal panel drive control unit 52 outputs the generated vertical synchronization signal to the motor control unit 54.

Next, the control operation of the liquid crystal panel 441 by the above-described liquid crystal panel drive control unit 52 will be described.
FIG. 7 is a diagram for explaining the control operation of the liquid crystal panel 441 by the liquid crystal panel drive control unit 52. 7 shows a case where the projector 1 is in a normal installation state (an installation state that is not ceiling-suspended), as in FIGS. 4 and 5. The upper direction in the figure indicates the top side of the projector 1, and the lower direction in the figure indicates the bottom side of the projector 1. The same applies to the following description.
When the liquid crystal panel drive control unit 52 forms an optical image in the image forming region G of the liquid crystal panel 441, image information corresponding to each pixel on the scanning line HL1 based on the generated horizontal synchronization signal and vertical synchronization signal. Are read from the frame memory 53. Further, the liquid crystal panel drive control unit 52 performs a predetermined process on the read image information to generate a drive signal. Then, the liquid crystal panel drive control unit 52 outputs a drive signal to the scanning line HL1, and sequentially enters each pixel (not shown) on the scanning line HL1 according to image information from one end side to the other end side of the scanning line HL1. A so-called horizontal scan is performed in which the luminous flux is modulated to form display light. Then, so-called vertical scanning is performed in which the horizontal scanning is sequentially performed on each of the scanning lines HL2, HL3,... HLE (uppermost scanning line in the vertical direction). In the present embodiment, the vertical scanning direction is set to the direction from the bottom to the top as shown in FIG. 7, but the present invention is not limited to this, and the direction may be set to the direction from the top to the bottom. By performing the vertical scanning described above, display light is formed on each pixel in the entire range of the image forming region G, and an optical image (one screen) is formed. Then, by repeating the horizontal scanning and the vertical scanning at a predetermined horizontal scanning period and a vertical scanning period (field period), a plurality of optical images are continuously formed to form a moving image.

FIG. 8 is a diagram illustrating an example of a driving state of the liquid crystal panel 441. In FIG. 8, the driving state of the predetermined pixel is shown, the horizontal axis is the driving time of the predetermined pixel, and the vertical axis is the luminance of the predetermined pixel.
The liquid crystal panel 441 to which the drive signal is output from the liquid crystal panel drive control unit 52 is driven as follows.
That is, the liquid crystal panel 441 changes the alignment state of the liquid crystal corresponding to the predetermined pixel in accordance with the drive signal output from the liquid crystal panel drive control unit 52, and the light beam emitted from the illumination optical device 41 passes through the liquid crystal. As a result, light is modulated to form display light. At this time, the predetermined pixels of the liquid crystal panel 441 continue to display the display light formed over each vertical scanning period (hereinafter referred to as a display period) as shown in FIG. When a moving image is formed by being carried out, human tracking eye movement and eye time integration effect act, and image blur tends to occur. In the liquid crystal panel 441, since the response time of the device exists until the liquid crystal is aligned, the display light of the predetermined pixel reaches the target transmitted light amount with a certain time delay from the signal application as shown in FIG. For this reason, in the first half of each display period, the luminance tends to be insufficient and blurry.

FIG. 9 is a diagram illustrating a configuration of the rotation state detection device 55.
FIG. 10 is a diagram illustrating a signal output from the rotation state detection device 55.
Here, before describing the configuration of the motor control unit 54, the configuration of the rotation state detection device 55 will be described.
The rotation state detecting device 55 detects the rotation state of the prism 451 by detecting the rotation state of the rotor 4522 constituting the motor 452. Then, the rotation state detection device 55 outputs a signal based on the detected rotation state to the motor control unit 54. As shown in FIG. 9, the rotation state detection device 55 is composed of a photo reflector in which a light emitting diode 55A that emits infrared rays and a phototransistor 55B that detects reflected light of the emitted infrared rays are combined into one element. Is done. As shown in FIG. 9, the rotation state detection device 55 is arranged at a position where infrared rays can be emitted with respect to the side end surface of the case 4523 </ b> A constituting the motor 452 in a direction orthogonal to the rotation center axis R. Is done.

When the motor 452 is driven and the rotor 4522 (case 4523A) rotates, the side end surface of the case 4523A that is not subjected to the light shielding process faces the rotation state detection device 55 as shown in FIG. As shown in A), the infrared light emitted from the light emitting diode 55A is reflected by the side end face and detected by the phototransistor 55B. Then, the phototransistor 55B outputs a predetermined signal as rotation state information to the motor control unit 54, as shown in FIG.
On the other hand, when the motor 452 is driven and the rotor 4522 (case 4523A) is rotating, if the side end surface of the case 4523A does not face the rotation state detection device 55, as shown in FIG. Infrared light emitted from the light emitting diode 55 </ b> A is not detected by the phototransistor 55 </ b> B, and a predetermined signal is not output to the motor control unit 54. The same applies to the case where the side end surface of the case 4523A subjected to the light shielding process faces the rotation state detection device 55.
As described above, the case 4523A has a regular octagonal cross section and has eight side end surfaces, and one of the eight side end surfaces is subjected to a light shielding process. For this reason, the rotation state detection device 55 outputs a predetermined signal based on the rotation state to the motor control unit 54 every time the case 4523A rotates 45 °, and when the case 4523A rotates once, the side end face subjected to the light shielding process is displayed. Except for this, the predetermined signal is output to the motor controller 54 seven times.

  In the present embodiment, the rotation state detection device 55 forms an image when the prism 451 is in the state shown in FIG. 4B, that is, the upper end of the illumination area L is shown in FIG. 5B. When the upper end of the region G coincides with the upper end, the side end surfaces of the case 4523A subjected to the light shielding process are arranged to face each other. With this arrangement, when the motor 452 is driven and the rotor 4522 (case 4523A) rotates, and the side end surface adjacent to the side end surface subjected to the light shielding process in the case 4523A faces the rotation state detection device 55, The prism 451 is in the state shown in FIG. 4F, that is, the lower end of the illumination area L is in agreement with the lower end of the image forming area G as shown in FIG.

The motor control unit 54 is electrically connected to the stator coil 4521B of the motor 452. Then, the motor control unit 54 drives the motor 452 by sequentially energizing the stator coil 4521B, and performs drive control to cause the prism 451 to scroll the illumination area L described above at a predetermined cycle.
Here, when performing the drive control, the motor control unit 54 scrolls the illumination area L by the prism 451 based on the vertical synchronization signal output from the liquid crystal panel drive control unit 52. Synchronize with vertical scan. In addition, the motor control unit 54 is electrically connected to the rotation state detection device 55, and based on a signal output from the rotation state detection device 55, a scroll cycle of the illumination region L by the prism 451 (hereinafter referred to as a scroll cycle). Adjust).
As shown in FIG. 6, the motor control unit 54 includes an arithmetic processing unit 541 and a motor driving unit 542.

  The motor driving unit 542 sequentially energizes the stator coil 4521 </ b> B of the motor 452 to drive the motor 452. Further, the motor drive unit 542 changes the voltage value applied to the stator coil 4521B in accordance with the control command output from the arithmetic processing unit 541, and changes the rotational speed and rotational position (phase) of the rotor 4522 in the motor 452. It is configured to be changeable.

FIG. 11 is a diagram illustrating a processing state of a signal output from the rotation state detection device 55 by the arithmetic processing unit 541.
The arithmetic processing unit 541 calculates a scroll cycle based on a signal output from the rotation state detection device 55 according to the rotation of the prism 451 driven by the motor 452.
Specifically, the arithmetic processing unit 541 includes a comparator circuit (not shown) that normalizes an analog signal output from the rotation state detection device 55 and a clock generation circuit (not shown) that outputs a clock signal at a predetermined frequency. Yes.
The arithmetic processing unit 541 uses the comparator circuit to shape the analog signal output from the rotation state detection device 55 into a pulse signal as shown in FIG. At this time, as described above, when the case 4523A makes one rotation, the rotation state detection device 55 outputs a predetermined signal seven times except for the side end surface subjected to the light shielding process. Therefore, the arithmetic processing unit 541 recognizes seven pulses P1 to P7 every time the case 4523A makes one rotation, as shown in FIG. Further, the position P0 at which the pulse between the pulses P1 and P7 is missing is recognized as the rotation state detection device 55 facing the side end face subjected to the light shielding process among the side end faces of the case 4523A.
The arithmetic processing unit 541 recognizes how many seconds the minimum interval between the pulses P1 to P7 shown in FIG. 11 is based on the clock signal output from the clock generation circuit. As described above, the scrolling of the illumination area L by the prism 451 is performed every time the prism 451 rotates 90 °. For this reason, as described above, by recognizing how many seconds the minimum interval between the pulses P1 to P7 is, the interval between the signals output every time the prism 451 rotates 45 ° in the rotation state detection device 55. Is recognized, and the number of seconds at which the prism 451 rotates by 90 ° is calculated, that is, the scroll period is calculated.

  In addition, the arithmetic processing unit 541 calculates the vertical scanning cycle of the liquid crystal panel 441 based on the vertical synchronization signal output from the liquid crystal panel drive control unit 52. Specifically, based on the clock signal, it is recognized how many seconds the vertical synchronization signal is output from the liquid crystal panel drive control unit 52, and the vertical scanning period of the vertical scanning in the liquid crystal panel 441 is calculated.

Then, the arithmetic processing unit 541 outputs a control command for synchronizing the scroll of the illumination area L by the prism 451 to the vertical scanning in the liquid crystal panel 441 to the motor driving unit 542.
Specifically, the arithmetic processing unit 541 compares the calculated scroll cycle with the vertical scanning cycle, and outputs a control command for making the scroll cycle and the vertical scanning cycle the same. That is, the arithmetic processing unit 541 outputs a control command for increasing the rotation speed of the prism 451 to the motor driving unit 542 when the scroll cycle is longer than the vertical scanning cycle. In addition, when the scroll period is smaller than the vertical scanning period, the arithmetic processing unit 541 outputs a control command for reducing the rotation speed of the prism 451 to the motor driving unit 542.
As described above, the motor control unit 54 performs so-called feedback control for driving and controlling the motor 452 based on the signal output from the rotation state detection device 55.

In addition, the arithmetic processing unit 541 adjusts the rotational position (phase) of the motor 452 using the position P0 where the pulse is missing, so that the scroll of the illumination area L by the prism 451 and the vertical scanning in the liquid crystal panel 441 are in the same phase. A control command to this effect is output to the motor drive unit 542.
Specifically, the arithmetic processing unit 541 includes the timing of the pulse P1 adjacent to the position P0 where the pulse is missing, among the signals output from the rotation state detection device 55, and the vertical synchronization output from the liquid crystal panel drive control unit 52. A control command to make the signal input timing substantially the same is output to the motor drive unit 542.
Here, as described above, the rotation state detection device 55 has the prism 451 in the state shown in FIG. 4F when the side end surface adjacent to the side end surface subjected to the light shielding process in the case 4523A is opposed, that is, As shown in FIG. 5F, the end of the illumination area L in the moving direction is coincident with the lower end of the image forming area G, and a signal based on the rotation state is output to the motor control unit 54. It is configured. Therefore, when the motor control unit 54 performs control to make the timing of the pulse P1 adjacent to the position P0 where the pulse is missing and the input timing of the vertical synchronization signal output from the liquid crystal panel drive control unit 52 substantially the same. In this case, at the timing when the vertical synchronization signal is input, the end of the illumination area L on the rear side in the moving direction is positioned at the lower end of the image forming area G, that is, the vertical scanning start position on the image forming area G. Positioned.

FIG. 12 is a diagram illustrating the state of the display light of the pixels under the control of the motor control unit 54. In FIG. 12, as in FIG. 8, the horizontal axis represents the pixel driving time, and the vertical axis represents the pixel luminance.
By the control by the motor control unit 54 described above, the prism 451 performs scrolling of the illumination region L that crosses from the lower end to the upper end on the image forming region G in conjunction with vertical scanning in the liquid crystal panel 441. Performed in the vertical scanning cycle. In other words, the prism 451 interlocks with the vertical scanning in the liquid crystal panel 441 and crosses from the lower end to the upper end on the image forming region G (light flux that is a region excluding the illumination region). Scrolling is performed in a vertical scanning cycle in a region where no light is irradiated (see FIG. 5). At this time, since the ratio of the illumination area L to the entire area of the image formation area G is 50%, in each pixel in the image formation area G, the first half of each display period is not displayed in the non-illumination area NL. The latter half of each display period is displayed in the illumination area L. That is, as shown in FIG. 12, each pixel in the image forming region G is in a non-display state in which the luminance is substantially 0 in the first half of each display period, and the luminance is a desired value in the second half of each display period. Is displayed.

The motor device 100 according to the present invention is configured by the motor 452, the rotation state detection device 55, and the motor control unit 54 described above.
In the above description, only the drive control of the liquid crystal panel 441 and the drive control of the motor 452 when the projector 1 is installed in a normal state have been described. However, when the projector 1 is installed in a ceiling state, The control device 5 performs control for reversing the vertical scanning direction shown in FIG. 7 and for reversing the rotation direction of the prism 451 shown in FIGS. 4 and 5.

In the embodiment described above, the motor 452 constituting the motor device 100 is provided with the case 4523A having a regular octagonal cross section that rotates in synchronization with the rotor 4522. Therefore, the rotational state detection device 55 uses the side end surface of the case 4523A. The rotational state of the rotor 4522 can be detected by detecting the light beam emitted toward one of the side end surfaces and reflected by one of the side end surfaces. Then, based on the rotation state of the rotor 4522 detected by the rotation state detection device 55, the motor control unit 54 can perform rotation control (speed control, phase control) of the rotor 4522 with high accuracy.
Further, the rotational state of the rotor 4522 can be obtained simply by using the rotational state detection device 55 that forms the case 4523A in a regular octagonal column shape, makes each side end surface a reflective surface capable of reflecting the light beam, and emits the light beam and detects the reflected light. This can be detected with a simple configuration, and when the motor device 100 is manufactured, the manufacturing can be facilitated and the manufacturing cost can be reduced.

  Here, since one side end surface of the side end surfaces of the case 4523A is subjected to light shielding processing, the signal output from the rotation state detection device 55 when the case 4523A makes one rotation is subjected to light shielding processing. Only one is missing depending on the side end face. For this reason, the motor control unit 54 performs good adjustment control (phase control) of the rotational position of the rotor 4522 using the position P0 where the pulse is missing among the normalized pulse signals output from the rotational state detection device 55. Can be implemented.

Further, since the motor 452 is constituted by an outer rotor type brushless DC motor, the inertia is increased, and the prism 451 which is the rotation target of the motor 452 can be easily rotated at a constant speed. Therefore, the rotation speed of the prism 451 can be easily controlled, and the scrolling of the illumination area L by the prism 451 can be easily and well synchronized with the vertical scanning of the optical image on the liquid crystal panel 441.
Furthermore, the prism 451 can be fixed to the case 4523A by configuring the motor 452 with an outer rotor type brushless DC motor in this way. For this reason, the connection surface between the case 4523A and the prism 451 can be made large, and the prism 451 can be rotationally driven while maintaining a good support state of the prism 451.

  Since the motor control unit 54 can control the rotation of the rotor 4522 with high accuracy, by rotating the prism 451, the motor control unit 54 emits light from the illumination optical device 41 to a predetermined area on the image forming area G in the liquid crystal panel 441. The illumination area L to be imaged can be scrolled on the image forming area G at a predetermined cycle. That is, the non-illuminated area NL that is not irradiated with the light beam, which is an area excluding the illuminated area L, can be scrolled on the image forming area G at a predetermined cycle. Thus, when a moving image is formed on the liquid crystal panel 441, a predetermined period in each display period of each optical image constituting the moving image can be set to a non-display state in the non-illumination region NL. . For this reason, the display period of the optical image formed by the liquid crystal panel 441 can be shortened, the action of the human tracking eye movement and the time integration effect of the eyes can be reduced, and the moving image performance can be improved.

Here, since the number of side end surfaces of the case 4523A is formed to be twice the number of light beam incident side end surfaces 451A of the prism 451, the motor control unit 54 causes the prism 451 to scroll the illumination area L. Control synchronized with vertical scanning in the liquid crystal panel 441 can be easily performed.
In this way, by synchronizing the scrolling of the illumination area L with the vertical scanning, it is possible to continue the predetermined period during the display period of the predetermined pixel in the image forming area G to be in the non-display state. Moreover, the same period in each display period in each pixel on the plurality of scanning lines HL1, HL2, HL3,. Therefore, the improvement of the moving image performance can be continued, and further, the moving image performance can be improved over the entire optical image range.

Further, the motor control unit 54, based on the rotation state of the prism 451 detected by the rotation state detection device 55, causes the illumination region L by the prism 451 to be substantially the same as the vertical scanning period of the vertical scanning in the liquid crystal panel 441. So-called feedback control is performed to adjust the scroll period. As a result, the scroll cycle can be constantly monitored, and the scroll cycle can be matched with the vertical scanning cycle of the vertical scanning in the liquid crystal panel 441 in a favorable and reliable manner.
Further, the rotation state detection device 55 corresponds to the pulse P1 adjacent to the position P0 where the pulse is missing when the end on the rear side in the moving direction of the illumination area L matches the lower end of the image forming area G. Since the motor control unit 54 is configured to output a signal, when the motor control unit 54 performs control to make the timing of the pulse P1 and the input timing of the vertical synchronization signal substantially the same, the timing at which the vertical synchronization signal is input The end of the illumination area L on the rear side in the movement direction, that is, the end of the non-illumination area NL on the front side in the movement direction can be positioned at the start position of the vertical scanning on the image forming area G. Accordingly, the non-illumination area NL can be scrolled in accordance with the display timing of each pixel on each scanning line HL1, HL2, HL3,..., HLE in the image forming area G. For this reason, in each pixel on each scanning line HL1, HL2, HL3,..., HLE in the image forming region G, the first half portion in each display period may be set in a non-display state in the non-illumination region NL. it can. Therefore, the initial rising portion and afterimage portion of the display period in the liquid crystal panel 441 can be actively hidden, and the moving image performance can be greatly improved.

Furthermore, in this embodiment, since the ratio of the illumination area L to the entire area of the image forming area G is set to 50%, it is possible to perceive an improvement in the image quality of the moving image.
Further, by arranging the optical scanning device 45 between the illumination optical device 41 and the color separation optical device 42, the illumination regions L can be scrolled on the image forming regions G of the three liquid crystal panels 441, respectively. . Therefore, for example, compared to a configuration in which three optical scanning devices 45 are provided corresponding to the three liquid crystal panels 441, the minimum number of optical scanning devices 45 can be used, and the manufacturing cost of the projector 1 can be reduced. In addition, the projector 1 can be downsized.

Although the present invention has been described with reference to preferred embodiments, the present invention is not limited to the above-described embodiments, and various improvements and design changes can be made without departing from the scope of the present invention. It is.
In the above embodiment, the motor 452 is constituted by an outer rotor type brushless DC motor, but the present invention is not limited to this. As the motor, any motor such as a brushed DC motor or an AC motor may be adopted as long as it is an electric motor that converts electrical energy into mechanical rotational energy.
In the above embodiment, the polygonal columnar part (case 4523A) is formed to have a regular octagonal cross section. Just do it. When the rotation target is the prism 451 as in the above embodiment, it is preferable that n is an integer multiple of the number of the light beam incident side end faces 451A of the prism 451.
In the above-described embodiment, the polygonal columnar portion has been described as the case 4523A. However, a configuration in which the polygonal columnar portion is provided in another portion such as the rotation shaft 4522A that rotates in synchronization with the rotor 4522 may be employed. Further, the back cap 4523B of the motor housing 4523 may be formed in a polygonal column shape to form a polygonal columnar part.

In the embodiment, the rotation state detection device 55 is configured by a photo reflector, but the present invention is not limited to this. For example, a configuration may be adopted in which sound waves are emitted toward the side end surface of the case 4523A and reflected sound waves are detected. In addition, the configuration is not limited to the photoreflector configured by the light emitting diode 55A and the phototransistor 55B as long as the configuration is configured to detect the reflected light beam emitted toward the side end face of the case 4523A.
In the embodiment, the light shielding process is performed on only one of the side end surfaces of the case 4523A. However, the present invention is not limited to this, and a configuration in which the light shielding process is performed on two or more side end surfaces may be employed. .

In the embodiment described above, the motor control unit 54 controls the rotation of the motor 452 to scroll the illumination area L in the prism 451 so that the first half of the display period in each pixel is not displayed. However, the present invention is not limited to this, and it may be configured to perform rotation control in which other portions are not displayed.
In the above-described embodiment, the motor control unit 54 performs the drive control in which the first half portion of each pixel during the display period is not displayed based on the vertical synchronization signal. However, the present invention is not limited to this. For example, the drive control may be performed based on the horizontal synchronization signal together with the vertical synchronization signal. In such a configuration, by using the horizontal synchronization signal, the phase of scrolling the illumination area L by the prism 451 can be changed, and the period of non-display state can be shifted in each display period of each pixel. The desired period can be hidden.
In the embodiment, the detection position of the rotation state detection device 55 is not limited to the detection position described in the embodiment, and may be set to other detection positions. Furthermore, you may comprise so that the detection position of the rotation state detection apparatus 55 can be changed suitably. In such a configuration, the phase of scrolling of the illumination area L by the prism 451 can be changed as described above.
In the present invention, if the scrolling of the illumination area L and the vertical scanning are synchronized, the scrolling of the illumination area L and the vertical scanning are not in the same phase, but have a certain phase difference as described above. Good. In the above embodiment, the configuration in which the scroll cycle and the vertical scanning cycle of the vertical scanning are the same has been described. However, the present invention is not limited to this, and the scroll cycle and the vertical scanning cycle may have an integer ratio relationship. .

In the embodiment, the ratio of the illumination area L to the entire area of the image forming area G is set to 50%. However, the ratio is not limited to this, and is preferably 50% or less.
Further, although the ratio is set by setting the aspect ratio of each small lens constituting the first lens array 412 and the second lens array 413 to a predetermined ratio, the present invention is not limited to this.
For example, by setting the aspect ratio of each small lens constituting the first lens array 412 and the second lens array 413 to a predetermined ratio, the entire area of the image forming area G is set to be an illumination area. A ratio of the illumination area L to the entire area of the image forming area G is obtained by attaching a light shielding member to each small lens constituting the first lens array 412 and the second lens array 413 and shielding the light by the light shielding member. You may employ | adopt the structure which changes.
Further, by setting the aspect ratio of the small lenses constituting the first lens array 412 and the second lens array 413 to a predetermined ratio, the entire area of the image forming area G is set to be an illumination area. An optical element that compresses the light beam emitted from the illumination optical device 41 in the vertical direction is disposed on the downstream side of the optical path of the illumination optical device 41, and the light beam is compressed by the optical element. You may employ | adopt the structure which changes the ratio of the illumination area | region L with respect to the whole area | region.

In the above-described embodiment, only the example of the projector 1 using the three liquid crystal panels 441 has been described. However, the present invention is a projector using only one liquid crystal panel, a projector using only two liquid crystal panels, or 4 The present invention can also be applied to a projector using two or more liquid crystal panels.
In the embodiment, a transmissive liquid crystal panel having a different light incident surface and light emitting surface is used. However, a reflective liquid crystal panel having the same light incident surface and light emitting surface may be used.
In the above embodiment, only an example of a front type projector that projects from the direction of observing the screen has been described, but the present invention is also applicable to a rear type projector that projects from the side opposite to the direction of observing the screen. Is possible.
In the embodiment, the case where the rotation center axis R is set in the horizontal direction has been described. However, the present invention may be applied to the case where the rotation center axis R is installed in the vertical direction.
In the above-described embodiment, only the example in which the optical scanning device 45 is applied to the projector 1 has been described. However, the present invention can also be applied to a laser beam printer, a digital copying machine, a facsimile, a laser display, and the like.

In the above-described embodiment, the prism 451 is employed as the rotation target of the motor 452, but the following may be employed as the rotation target.
13 and 14 are diagrams showing a modification of the embodiment.
For example, you may employ | adopt the wheel 551 shown in FIG. 13 as a rotation object.
The wheel 551 has a disk shape extending in a direction orthogonal to the optical axis of the incident light beam, and is made of a translucent member such as glass.
As shown in FIG. 13, the surface of the wheel 551 has two spirals C1 and C2 (so-called Archimedes spirals) whose distance from the rotation center position RO gradually increases according to the rotation angle θ of the wheel 551. ) Is formed. A shielding film 551A that shields a part of the light beam incident on the wheel 551 is formed between the spiral C1 and the spiral C2.
Then, the wheel 551 is fixed to the case 4523A of the motor 452 so that the rotation shaft 4522A of the motor 452 coincides with the rotation center position RO of the wheel 551.
In such a state, by driving the motor 452 and rotating the wheel 551, the shielding film 551A moves up and down on the region LO of the incident light beam, which is similar to FIG. 6 described in the above embodiment. On the image forming area G, the illumination area L and the non-illumination area NL are scrolled up and down.
In addition, as the rotation control of the wheel 551 described above, the wheel 551 is controlled based on the vertical synchronization signal and the signal output from the rotation state detection device 55, similarly to the control by the motor control unit 54 described in the above embodiment. It is assumed that the scrolling of the illumination area L is synchronized with the vertical scanning of the liquid crystal panel 441. Similarly to the control by the motor control unit 54 described in the above embodiment, if the control using the position PO where the pulse is missing is performed, the rotation position (phase) of the wheel 551 can be controlled, and each pixel can be controlled. In each display period, a desired period can be hidden.

Further, for example, a wheel 651 shown in FIG.
The wheel 651 is, for example, a projector equipped with a DMD (Digital Micro miller Device: trademark of TI) that modulates a light beam emitted from a light source according to image information by controlling an incident angle of a micromirror. This is a color wheel that emits light beams in different wavelength regions in a time-division format.
Specifically, the wheel 651 is composed of a translucent member having a disk shape extending in a direction orthogonal to the optical axis of the incident light beam, and is divided into four fan shapes separated along the rotation direction of the wheel 651. Three transmissive color filters 651R, 651G, and 651B are formed in the region. Here, the transmissive color filter 651R transmits light in the red wavelength region and transmits only red light by reflecting or absorbing light in other wavelength regions. Similarly, the transmissive color filters 651G and 651B transmit light in the green and blue wavelength regions, respectively, and reflect or absorb light in other wavelength regions to transmit only green light or blue light. Further, in the four fan-shaped regions, the portions other than the transmissive color filters 651R, 651G, and 651B are translucent regions 651W, and the translucent regions 651W can increase the luminance in the projected image. The brightness of the projected image can be ensured.
The color filters 651R, 651G, and 651B are not limited to the three color filters of red, green, and blue, but may be three transmissive color filters of cyan, magenta, and yellow.

Then, the wheel 651 is fixed to the case 4523A of the motor 452 so that the rotation shaft 4522A of the motor 452 coincides with the rotation center position RO of the wheel 651.
Note that the rotation control of the wheel 651 described above is based on the synchronization signal of the image signal and the signal output from the rotation state detection device 55 in substantially the same manner as the control by the motor control unit 54 described in the above embodiment. The wheel 651 is controlled to rotate at a constant frequency in synchronization with the synchronization signal. Similarly to the control by the motor control unit 54 described in the above embodiment, if the control using the position PO where the pulse is missing is performed, the rotation position (phase) of the wheel 651 can be controlled, and the DMD can be controlled. When the light modulation of a predetermined color is performed, the rotation position of the wheel 651 can be set to the rotation position of the predetermined color.

Although the best configuration for carrying out the present invention has been disclosed in the above description, the present invention is not limited to this. That is, the invention has been illustrated and described primarily with respect to particular embodiments, but may be configured for the above-described embodiments without departing from the scope and spirit of the invention. Various modifications can be made by those skilled in the art in terms of materials, quantity, and other detailed configurations.
Therefore, the description limited to the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such is included in this invention.

  The motor device of the present invention can perform the rotation control of the rotor with high accuracy, can be easily manufactured and can reduce the manufacturing cost, and can improve the moving image performance by adopting the prism as the rotation target. And can be used for projectors used in presentations.

FIG. 2 is a diagram schematically showing a schematic configuration of a projector in the embodiment. The disassembled perspective view which shows typically schematic structure of the optical scanning device in the said embodiment. The figure which shows the structure of the motor in the said embodiment. The figure which shows the state in which an illumination area scrolls on an image formation area with the optical scanning device in the said embodiment. The figure which shows the state in which an illumination area scrolls on an image formation area with the optical scanning device in the said embodiment. The block diagram which shows the control structure by the control apparatus in the said embodiment. The figure for demonstrating control operation of the liquid crystal panel by the liquid crystal panel drive control part in the said embodiment. The figure which shows an example of the drive state of the liquid crystal panel in the said embodiment. The figure which shows the structure of the rotation state detection apparatus in the said embodiment. The figure which shows the signal output from the rotation state detection apparatus in the said embodiment. The figure which shows the processing state of the signal output from a rotation state detection apparatus by the arithmetic processing part in the said embodiment. The figure which shows the state of the display light of a pixel by control of the motor control part in the said embodiment. The figure which shows the modification of the said embodiment. The figure which shows the modification of the said embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Projector, 3 ... Projection lens (projection optical apparatus), 41 ... Illumination optical apparatus, 54 ... Motor control part (control apparatus), 55 ... Rotation state detection apparatus, 100 ...・ Motor device, 441, 441R, 441G, 441B ... Liquid crystal panel (hold type light modulation device), 451 ... Prism, 451A ... End face on the light incident side, 4521 ... Stator (stator), 4522 ... Rotor (rotor), 4522A ... Rotating shaft, 4523 ... Motor housing, 4523A ... Case (polygonal column), 4524 ... Bearing, G ... Image forming area, L ..Lighting area, R ... Rotation center axis

Claims (6)

A stator having a bearing and a rotor having a rotating shaft supported by the bearing and configured to be rotatable with respect to the stator are configured to convert electrical energy into mechanical rotational energy. A motor device that performs
A motor device comprising a polygonal columnar portion provided on the rotor and having a polygonal cross section around the rotation axis. The motor device according to claim 1,
A rotation state detection device that detects a rotation state of the rotor and outputs rotation state information related to the rotation state, and a control device that performs rotation control of the rotor based on the rotation state information output from the rotation state detection device And
The rotation state detection device irradiates a light beam in a direction perpendicular to the columnar axis in the polygonal columnar portion and detects a light beam reflected on a side end surface in the polygonal columnar portion while the rotor is rotating. By doing so, the rotation state of the rotor is detected. The motor device according to claim 2,
A motor device characterized in that at least one of the side end surfaces of the polygonal columnar portion is subjected to a light shielding process. In the motor apparatus in any one of Claims 1-3,
The rotor is disposed outside the stator;
The said polygonal columnar part is formed in at least one part of the motor housing which accommodates the said rotor and the said stator inside, and rotates synchronizing with the said rotor, The motor apparatus characterized by the above-mentioned. A projector that modulates a light beam emitted from a light source in accordance with image information and enlarges and projects the modulated light beam,
An illumination optical device that forms an image of the light beam emitted from the light source at a predetermined position, and a plurality of light beam incident side end surfaces on which the light beam emitted from the illumination optical device is incident, and is rotatable about a predetermined rotation center axis The prism configured to be refracted so as to refract a light beam passing through the inside and change the emission position of the light beam, and to support the prism and to rotate the prism about the rotation center axis. 4. The motor device according to any one of 4 and a hold type that modulates the light flux through the prism according to image information to form an optical image and continues to form a preceding optical image until the subsequent image information is input A light modulation device, and a projection optical device that magnifies and projects an optical image formed by the hold type light modulation device,
The illumination optical device forms an image of a light flux on a predetermined illumination area on an image forming area in the hold type light modulation device,
The motor device rotates the prism to change the emission position of the light beam emitted from the illumination optical device and through the prism, and scrolls the illumination region on the image forming region at a predetermined cycle. A projector characterized by that. The projector according to claim 5, wherein
The number of the side end surfaces of the polygonal columnar portion constituting the motor device is an integral multiple of the number of light beam incident side end surfaces of the prism.

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