JP2006350015A - Scanner, display and method of driving - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve durability of a scanner even when an inexpensive bearing is used as the bearing arranged in a galvano scanner. <P>SOLUTION: In the scanner, an auxiliary motor control part 154 controls an auxiliary motor driving circuit 155 on the basis of a signal which is supplied from a rotary encoder 151 and expresses the rotation angle of a shaft 161, and drives an auxiliary motor 93. The auxiliary motor driving circuit 155 generates a driving current for driving the auxiliary motor 93 on the basis of the control by the auxiliary motor control part 154 and supplies the driving current to the auxiliary motor 93. The auxiliary motor 93 turns the shaft 161 on the basis of the driving current from the auxiliary motor driving circuit 155. The present invention is applicable to a display which displays a picture by scanning light. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a scanning device, a display device, and a driving method, and more particularly, to a scanning device, a display device, and a driving method that can improve durability.

  A galvano scanner (scanning device) that scans incident light is incorporated and used in a laser processing machine, a laser marker that marks a semiconductor, or a laser show that scans a laser and emits it into the atmosphere. .

  As shown in FIG. 1, a conventional galvano scanner (scanning device) includes a scanning mirror 11 that reflects incident light and a galvano motor 12 that rotates the scanning mirror 11. 11 is provided.

  The galvano motor 12 rotates the scanning mirror 11 by rotating the shaft 21 so as to reciprocate in the direction indicated by the arrow A1 (the left-right direction in the figure), and scans the light incident on the scanning mirror 11. Therefore, the light incident on the scanning mirror 11 indicated by the arrow B1 changes in the direction reflected by the scanning mirror 11 according to the rotation angle of the scanning mirror 11, as indicated by arrows B11 to B13.

  The performance of such a galvano scanner is mainly determined by factors such as scanning speed, scanning acceleration, and inertia (moment of inertia) of the scanning mirror 11. If the inertia of the scanning mirror 11 is large, the scanning speed and scanning acceleration are larger. It becomes difficult to get. In addition, when the inertia of the scanning mirror 11 is large, the bearing (bearing) for supporting the shaft 21 disposed inside the galvano motor 12 becomes heavily worn, and the durability of the galvano scanner decreases. .

  However, since the beam diameter of a laser is generally narrowed down, a relatively small mirror is used as the scanning mirror 11 of the galvano scanner that scans the laser. Therefore, the inertia size of the scanning mirror 11 is galvano. There was no significant impact on scanner durability. Further, when the galvano scanner is used to control the position of the mirror (scanning mirror 11) that reflects light, that is, to control the angle at which light is reflected and deflected, the scanning mirror 11 is frequently rotated. Since there is no need, the durability of the galvano scanner is rarely a problem.

  Further, in a conventional galvano scanner, a rotating plate provided with a radial pattern is rotated integrally with a scanning mirror, and light is emitted from an LED (Light Emitting Diode) to provide the rotating plate and the radial pattern. In some cases, the rotation angle of the scanning mirror is measured by passing the fixed plate and receiving the light (for example, see Patent Document 1).

  Incidentally, in recent years, a display device using a laser as a light source has been developed as a device using a galvano scanner. In this display device, the light from the light source is condensed and modulated so that the light emitted from the light source becomes thin linear light, and further, the modulated light is scanned by a galvano scanner. Is displayed. When such a display device is used for industrial use, the life (usable time) of the display device can be extended by periodic maintenance or replacement of parts, but when used as a home display device. In general, since regular maintenance and component replacement are not performed, the display device is required to have a durability of about 50,000 hours so that the display device can be operated for a long time without performing maintenance or component replacement.

JP 2003-307700 A

  However, in the above-described display device using the galvano scanner, in order to display an image, the scanning mirror 11 of the galvano scanner reflects and scans light having a certain area (cross-sectional area). 11, a relatively large mirror is used. Therefore, since the inertia of the scanning mirror 11 is also increased, the wear of the bearings arranged inside the galvano motor 12 becomes severe, and the durability of the galvano scanner is lowered.

  In particular, in a galvano scanner used in a display device, the scanning mirror 11 rotates within a narrow angle range of about 10 to 15 degrees, so that only a small part of the bearing disposed inside the galvano motor 12 is worn. Unfortunately, the wear of such bearings has reduced the durability of the galvano scanner.

  For example, the ball bearing shown in FIG. 2 is arranged inside the galvano motor 12, and when the shaft 21 rotates, the inner ring 41 fitted with the shaft 21 is also rotated in conjunction with the movement. Has been made.

  In FIG. 2, the ball bearing has an annular inner ring 41 disposed in an annular outer ring 42, and a spherical rolling element 43 between the inner ring 41 (the outer surface 51 of the inner ring 41) and the outer ring 42. -1 to rolling elements 43-8 are arranged. Further, since the outer ring 42 is fixed, the inner ring 41 rotates together with the shaft 21 when the shaft 21 fitted inside the inner ring 41 rotates clockwise or counterclockwise in the figure. Furthermore, the rolling elements 43-1 to 43-8 rotate in a direction opposite to the direction in which the shaft 21 rotates. Hereinafter, the rolling elements 43-1 to 43-8 are simply referred to as the rolling elements 43 when it is not necessary to distinguish them individually.

  Here, in FIG. 2, when the inner diameter of the inner ring 41 is 8 mm, the outer diameter is 10 mm, the inner diameter of the outer ring 42 is 16 mm, the outer diameter is 18 mm, and the diameter of each rolling element 43 is 3 mm, the shaft 21 is only 15 degrees. When rotating, the outer surface 51 of the inner ring 41 moves by 1.31 (= 2 × 3.14 × 5 × 15/360) mm, so that the rolling element 43 having a diameter of 3 mm is 50 (= (1 .31 / (2 × 3.14 × 1.5)) × 360) degrees only.

  Accordingly, only a specific part of the surface of the rolling element 43 is always in contact with the surface of the inner ring 41 or a specific part of the surface of the outer ring 42. Only the surface or the portion in contact with the surface of the outer ring 42 was worn (slipped), which was a major factor in reducing the durability of the galvano scanner.

  Further, lubricating oil (grease) is supplied to the ball bearing (bearing) from a predetermined location, and in the ball bearing, the rolling element 43 rotates only within an angular range of about 50 degrees. The lubricating oil could not be spread over the entire surface of the rolling element 43. Therefore, the lubricating oil may not spread over the surface of the inner ring 41 or the surface of the rolling element 43 in contact with the surface of the outer ring 42, and the surface of the rolling element 43 may be further worn due to the lack of lubricating oil. possible.

  As described above, in the conventional display device, since there are many factors that reduce the durability of the galvano scanner, it is difficult to improve the durability of the galvano scanner.

  In addition, bearing manufacturers do not guarantee the durability of bearings, but according to the results of durability tests by general galvano scanner manufacturers, the lifetime (usable time) of galvano scanners is currently It was about 10,000 hours, and the durability of about 50,000 hours required when using the display device for home use could not be realized.

  Therefore, it is possible to use an industrial bearing that guarantees high durability as a bearing disposed inside the galvano motor 12, but even in such a highly durable bearing, until the endurance time is reached. Furthermore, such bearings are very expensive because they are used in special industrial applications.

  The present invention has been made in view of such a situation, and is intended to improve durability even when an inexpensive bearing is used as a bearing disposed inside a galvano scanner. is there.

  One aspect of the present invention is a first driving unit that rotates the shaft so as to reciprocate within a predetermined angle range, and a reflecting unit that is provided on the shaft and reflects incident light so as to scan the light. And a rotation control means for controlling the rotation of the shaft so as to rotate the shaft one or more times.

  The scanning device may further include second driving means for rotating the shaft, and the rotation control means may control the rotation of the shaft by the second driving means.

  The first driving means can rotate the shaft by changing the polarity of the coil provided in the first driving means.

  The scanning device further includes a determination unit that determines whether or not the axis reaches the dead point, and the rotation control unit reverses the polarity of the coil when it is determined that the axis reaches the dead point, The rotation of the shaft can be controlled by changing the polarity of another coil provided at a position close to the coil.

  The scanning device is further provided with a determination unit that determines whether the axis reaches the dead point or whether the axis passes the dead point, and the rotation control unit determines that the axis reaches the dead point. If so, the first drive means is controlled so that the coil is not polarized, and if it is determined that the axis has passed the dead center, the first drive means is controlled so that the coil is polar. Thus, the rotation of the shaft can be controlled.

  In one aspect of the present invention, the shaft of a scanning device that rotates the shaft so as to reciprocate within a range of a predetermined angle and reflects incident light by the reflecting means provided on the shaft to scan the light is provided. In this driving method, the rotation of the shaft is controlled so as to be rotated one or more times.

  In one aspect of the present invention, the shaft of a scanning device that rotates the shaft so as to reciprocate within a range of a predetermined angle and reflects incident light by the reflecting means provided on the shaft to scan the light. The rotation of the shaft is controlled so that is rotated one or more times.

  In one aspect of the present invention, a light source that emits light, a driving unit that rotates the shaft to reciprocate within a predetermined angle range, and a shaft that is provided on the shaft and emitted from the light source so as to scan the light. A light reflecting means for reflecting the modulated light; a projection means for projecting the light reflected by the reflecting means to display an image; and controlling the rotation of the shaft so as to rotate the shaft one or more times. And a rotation control means.

  In one aspect of the present invention, the light is emitted, rotated so that the shaft reciprocates within a predetermined angle range, and the emitted light is scanned by the reflecting means provided on the shaft. The modulated light is reflected and the reflected light is projected to display an image. Then, the rotation of the shaft is controlled so that the shaft rotates one or more times.

  According to the present invention, the durability of the galvano scanner can be improved. In particular, the durability can be improved even when an inexpensive bearing is used as the bearing disposed inside the galvano scanner.

  Embodiments of the present invention will be described below. Correspondences between the configuration requirements of the present invention and the embodiments described in the detailed description of the present invention are exemplified as follows. This description is to confirm that the embodiments supporting the present invention are described in the detailed description of the invention. Accordingly, although there are embodiments that are described in the detailed description of the invention but are not described here as embodiments corresponding to the constituent elements of the present invention, It does not mean that the embodiment does not correspond to the configuration requirements. Conversely, even if an embodiment is described here as corresponding to a configuration requirement, that means that the embodiment does not correspond to a configuration requirement other than the configuration requirement. It's not something to do.

  One aspect of the present invention includes a first driving unit (for example, a galvano motor 92 in FIG. 6) that rotates a shaft (for example, the shaft 101 in FIG. 6) to reciprocate within a predetermined angle range, Reflecting means (for example, the scanning mirror 91 in FIG. 6) that is provided and reflects incident light so as to scan the light, and a rotation control means that controls the rotation of the shaft so as to rotate the shaft one or more times. (For example, the auxiliary motor control unit 154 in FIG. 6).

  The scanning device is further provided with second driving means for rotating the shaft (for example, the auxiliary motor 93 in FIG. 6), and the rotation control means (for example, the auxiliary motor control unit 154 in FIG. 6) has the second driving means. The rotation of the shaft by the driving means can be controlled.

  The first driving means (for example, the galvano motor 92 in FIG. 12) has a shaft (for example, FIG. 12) by changing the polarity of the coil (for example, the coil 211 in FIG. 13) provided in the first driving means. The shaft 101) can be rotated.

  The scanning device is further provided with a determination unit (for example, the determination unit 321 in FIG. 12) for determining whether or not the axis (for example, the axis 101 in FIG. 12) reaches the dead point, and a rotation control unit (for example, FIG. 12, the coil control unit 322 or the auxiliary coil control unit 323) reverses the polarity of the coil (for example, the coil 211 in FIG. 13) and closes the coil when it is determined that the axis reaches the dead point. The rotation of the shaft can be controlled by changing the polarity of another coil (for example, the auxiliary coil 341 in FIG. 13) provided in.

  The scanning device includes determination means (for example, a determination unit 191 in FIG. 9) that determines whether an axis (for example, the axis 101 in FIG. 9) reaches the dead point or whether the axis has passed the dead point. ), And the rotation control means (for example, the galvano motor control unit 181 in FIG. 9), when it is determined that the axis reaches the dead point, the coil (for example, the coil 211 in FIG. 10) does not have polarity. The first driving means (for example, the galvano motor 92 in FIG. 9) is controlled, and when it is determined that the shaft has passed the dead center, the first driving means is controlled so that the coil has a polarity. Thus, the rotation of the shaft can be controlled.

  One aspect of the present invention is that a shaft (for example, the shaft 101 in FIG. 6) is rotated so as to reciprocate within a predetermined angle range, and reflecting means (for example, the scanning mirror 91 in FIG. 6) provided on the shaft. Thus, the rotation of the shaft is controlled so that the shaft of the scanning device that reflects the incident light and scans the light (for example, the light deflection unit 74 in FIG. 6) is rotated one or more times (for example, in FIG. 8). Step S42) A driving method.

  One aspect of the present invention is a driving unit that rotates a light source (for example, the light source 71 in FIG. 3) that emits light and a shaft (for example, the shaft 101 in FIG. 6) to reciprocate within a predetermined angle range. For example, a galvano motor 92 in FIG. 6 and a reflection unit (for example, a scanning mirror in FIG. 6) that is provided on the shaft and reflects the modulated light that is emitted from the light source so as to scan the light. 91), projection means for projecting light reflected by the reflection means to display an image (for example, the enlarged projection system 75 in FIG. 3), and the rotation of the shaft so as to rotate the shaft one or more times. It is a display device provided with rotation control means (for example, auxiliary motor control part 154 of Drawing 6).

  The present invention can be applied to an image output device such as a printer, an image reading device such as a scanner, and a front projection type or rear projection type display device that scans light to display an image.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 3 is a diagram illustrating a configuration example of a display device to which the present invention is applied.

  The display device 61 is configured to include a light source 71, a modulation unit 72, a projection optical system 73, a light deflection unit 74, and an enlarged projection system 75, and the display device 61 supplies light for displaying an image to the screen 76. Projection is performed to display a two-dimensional image on the screen 76.

  The light source 71 is made of, for example, a semiconductor laser or a solid-state laser, and emits red (R), green (G), and blue (B) light (laser), and the emitted light is a lens (not shown). The light is incident on the modulation unit 72 through the like. For example, each of red, green, and blue light emitted from the light source 71 is condensed into a linear light by a lens (not shown) and is incident on the modulation unit 72.

  The modulation unit 72 includes, for example, GLV (Grating Light Valve) (trademark) for modulating each of red, green, and blue light, modulates the light incident from the light source 71, and converts the modulated light. The light is incident on the projection optical system 73 via a dichroic mirror (not shown).

  For example, the GLV constituting the modulation unit 72 includes a movable ribbon electrode (hereinafter referred to as a movable ribbon electrode) having a reflective film formed on the surface thereof, and a fixed ribbon electrode (hereinafter referred to as a movable ribbon electrode) having a reflective film formed on the surface thereof. (Referred to as a fixed ribbon electrode) and a common electrode made of a polysilicon thin film on a silicon substrate.

  The movable ribbon electrode and the fixed ribbon electrode are alternately arranged on the common electrode along the longitudinal direction of the linear light incident from the light source 71, and the movable ribbon electrode is in a state where no driving voltage is applied. And each reflective surface (surface in which the reflective film is formed) of a fixed ribbon electrode is made so that the height from a common electrode may become equal.

  Further, when a driving voltage is applied to the movable ribbon electrode, an electrostatic force is generated between the movable ribbon electrode and the common electrode, and the movable ribbon electrode moves or deforms according to the electrostatic force, and the reflecting surface of the movable ribbon electrode The height from the common electrode to the reflecting surface of the fixed ribbon electrode is different (no longer coincident). Therefore, of the light incident from the light source 71, there is an optical path difference between the light reflected on the reflecting surface of the fixed ribbon electrode and the light reflected on the reflecting surface of the movable ribbon electrode, and the GLV functions as a reflective diffraction grating. Then, diffracted light including a predetermined order is generated. In this way, the diffracted light generated in the GLV as the modulation unit 72 is spatially modulated, and the modulated red, green, and blue light is synthesized by, for example, a dichroic mirror (not shown) and projected. The light enters the optical system 73.

  Here, an example in which GLV is used as the modulation unit 72 has been described, but not limited to GLV, a reflective liquid crystal element, DMD (Digital Micromirror Device) (trademark), or the like may be used.

  The projection optical system 73 includes, for example, a plurality of mirrors and the like, and separates (blocks) a diffracted light component of a specific order from the light incident from the modulation unit 72 and does not separate the light (diffracted light). ) Is incident on the light deflection unit 74.

  The light deflection unit 74 is configured by, for example, a galvano scanner (scanning device) or the like, and the light deflection unit 74 scans the light incident from the projection optical system 73 by rotating the scanning mirror of the galvano scanner, A two-dimensional image is formed. The magnifying projection system 75 is composed of, for example, one or a plurality of lenses, and a two-dimensional image obtained through the light deflecting unit 74 is enlarged as an intermediate image and projected onto the screen 76. Display the image.

  For example, as shown in FIG. 4, the light deflection unit 74 that scans the light incident from the projection optical system 73 includes a scanning mirror 91 that reflects the incident light, a galvano motor 92 that rotates the scanning mirror 91, and a scanning mirror. It is comprised so that the auxiliary motor 93 which rotationally drives 91 may be included.

  In the drawing, an arrow A31 indicates a direction in which the scanning mirror 91 is rotated. An arrow B31 indicates a direction in which the light from the projection optical system 73 is incident on the scanning mirror 91, and an arrow B32 indicates a direction in which the light reflected by the scanning mirror 91 is incident on the enlarged projection system 75. ing.

  The galvano motor 92 is composed of, for example, a 2-pole or 4-pole servo motor, and is provided on the shaft 101 by rotating the shaft 101 provided on the galvano motor 92 so as to reciprocate in the direction indicated by the arrow A31. The scanning mirror 91 is rotated.

  For example, the galvano motor 92 rotates the shaft 101 within a predetermined angle range of 90 degrees or less, scans the light incident on the scanning mirror 91 from the direction of the arrow B31, and expands the projection system. 75 is incident. As indicated by an arrow B31, the direction in which the light incident on the scanning mirror 91 from the projection optical system 73 is reflected by the scanning mirror 91 changes according to the rotation angle of the scanning mirror 91. It is reflected in the direction shown and enters the enlarged projection system 75.

  The auxiliary motor 93 is disposed in the vicinity of the galvano motor 92. For example, a shaft (not shown) of the auxiliary motor 93 is connected to the shaft 101 by a coupler or the like so that the shaft is coaxial with the shaft 101 of the galvano motor 92. That is, a scanning mirror 91 is provided at one end of the shaft 101 of the galvano motor 92, and the other end of the shaft 101 of the galvano motor 92 is connected to a shaft (not shown) of the auxiliary motor 93. Yes.

  The shaft of the auxiliary motor 93 and the shaft 101 of the galvano motor 92 are not connected so as to be coaxial, but the driving force of the auxiliary motor 93 is applied to the galvano motor 92 via a transmission unit such as a gear or a belt. It may be transmitted to the shaft 101.

  The auxiliary motor 93 rotates the shaft 101 of the galvano motor 92 by rotating a shaft (not shown). As a result, the scanning mirror 91 provided on the shaft 101 also rotates in conjunction with the shaft 101.

  As described above, the light deflection unit 74 is provided with the auxiliary motor 93, and the shaft 101 of the galvano motor 92 can be rotated by rotationally driving the shaft of the auxiliary motor 93. For example, one or a plurality of ball bearings 111 shown in FIG. 5 are arranged inside the galvano motor 92, and when the shaft of the auxiliary motor 93 is driven to rotate, the inner ring 121 into which the shaft 101 is fitted is also a shaft. It is made to rotate in conjunction with the movement of 101.

  In FIG. 5, the ball bearing 111 includes an annular inner ring 121 disposed in an annular outer ring 122, and a spherical rolling element between the inner ring 121 (the outer surface 131 of the inner ring 121) and the outer ring 122. 123-1 to rolling elements 123-8 are arranged. Further, since the outer ring 122 is fixed, when the shaft 101 fitted inside the inner ring 121 rotates (or rotates) in the clockwise or counterclockwise direction in the drawing, the inner ring 121 is moved to the shaft 101. Together with this, the rolling elements 123-1 to 123-8 rotate (or rotate) in a direction opposite to the direction in which the shaft 101 rotates. Hereinafter, the rolling elements 123-1 to 123-8 are simply referred to as the rolling elements 123 when it is not necessary to distinguish them individually.

  For example, if the shaft 101 is rotated by rotating the shaft of the auxiliary motor 93 (not shown) by the auxiliary motor 93, the inner ring 121 is also rotated, and thus the rolling element 123 is also rotated. Therefore, the inner ring on the surface of the rolling element 123 is rotated. A portion (contact point) in contact with 121 or the outer ring 122 can be changed. As a result, it is possible to prevent the rolling element 123 from slipping on the surface and to distribute the lubricant evenly over the surface of the rolling element 123.

  That is, by rotating the shaft of the auxiliary motor 93, the position of the surface of the rolling element 123 that becomes a contact point with the inner ring 121 or the outer ring 122 can be changed, and the durability of the ball bearing 111 can be improved.

  FIG. 6 is a block diagram showing a more detailed configuration example of the light deflection unit 74 shown in FIG. In the figure, portions corresponding to those in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  More specifically, the light deflection unit 74 includes a scanning mirror 91, a galvano motor 92, an auxiliary motor 93, a rotary encoder 151, a galvano motor control unit 152, a galvano motor drive circuit 153, an auxiliary motor control unit 154, and an auxiliary motor drive circuit. 155.

  The shaft 161 provided in the auxiliary motor 93 is connected to the shaft 101 so that one end thereof is coaxial with the shaft 101 of the galvano motor 92, and the other end of the shaft 161 is a rotary encoder. 151.

  The rotary encoder 151 detects the rotation angle (or rotation angle) of the shaft 161 connected to the rotary encoder 151, that is, the rotation angle of the scanning mirror 91. Then, the rotary encoder 151 generates a signal indicating the detected rotation angle (or rotation angle) and supplies the signal to the galvano motor control unit 152 and the auxiliary motor control unit 154.

  The galvano motor control unit 152 controls the galvano motor drive circuit 153 based on the signal indicating the rotation angle of the shaft 161 supplied from the rotary encoder 151 to drive the galvano motor 92.

  The galvano motor driving circuit 153 generates a driving current for driving the galvano motor 92 based on the control of the galvano motor control unit 152, and supplies the generated driving current to the galvano motor 92. The scanning mirror 91 is rotated by driving.

  For example, the galvano motor drive circuit 153 supplies the generated drive current to a coil (not shown) of the galvano motor 92. The galvano motor 92 is attached to a magnet (not shown) by generating a magnetic field in the coil so that the built-in coil has S or N polarity according to the drive current from the galvano motor drive circuit 153. The shaft 101 is rotated.

  The auxiliary motor control unit 154 controls the auxiliary motor drive circuit 155 based on the signal indicating the rotation angle of the shaft 161 supplied from the rotary encoder 151 to drive the auxiliary motor 93.

  The auxiliary motor drive circuit 155 generates a drive current for driving the auxiliary motor 93 based on the control of the auxiliary motor control unit 154, and supplies the generated drive current to the auxiliary motor 93. The shaft 161 (scanning mirror 91) is rotated by driving.

  For example, the auxiliary motor drive circuit 155 supplies the generated drive current to a coil (not shown) of the auxiliary motor 93. The auxiliary motor 93 is attached to a magnet (not shown) by generating a magnetic field in the coil so that the built-in coil has S or N polarity according to the drive current from the auxiliary motor drive circuit 155. The shaft 161 is rotated.

  In FIG. 6, the shaft 161 of the auxiliary motor 93 is connected to the shaft 101 of the galvano motor 92, but the shaft 101 of the galvano motor 92 is connected to the auxiliary motor 93 and the rotary encoder 151 without providing the shaft 161. It is good also as a structure connected to.

  Next, an image display process, which is a process in which the display apparatus 61 displays an image in response to a user's operation after the display apparatus 61 described above is activated, will be described with reference to a flowchart of FIG.

  When the display device 61 is activated by a user operation, the display device 61 performs an operation confirmation process in step S11. Although details of the operation confirmation process will be described later, in the operation confirmation process, the display device 61 confirms whether each unit of the display device 61 operates normally. At this time, the light deflecting unit 74 rotates the scanning mirror 91 once to prevent the surface of the rolling element 123 of the ball bearing 111 disposed inside the galvano motor 92 from slipping and the lubricating oil It should be evenly distributed over the surface of the rolling element 123.

  In step S12, the display device 61 performs a process according to the user's operation. For example, when the user instructs display of a predetermined image, the light source 71 emits red, green, and blue light (laser), and causes the emitted light to enter the modulator 72. The modulator 72 modulates the light incident from the light source 71 and causes the light to enter the projection optical system 73. Further, the projection optical system 73 separates the diffracted light component of a specific order from the light incident from the modulation unit 72 and causes the light that has not been separated to enter the light deflection unit 74.

  When light enters the scanning mirror 91 of the light deflecting unit 74 from the projection optical system 73, the galvano motor control unit 152 is based on a signal indicating the rotation angle of the shaft 161 supplied from the rotary encoder 151. 153 is controlled to drive the galvano motor 92. The galvano motor driving circuit 153 generates a driving current for driving the galvano motor 92 based on the control of the galvano motor control unit 152, and supplies the generated driving current to the galvano motor 92. 92 is driven to rotate the scanning mirror 91.

  When the galvano motor control unit 152 rotates the scanning mirror 91, the light incident on the scanning mirror 91 is reflected so as to be scanned by the scanning mirror 91 to form a two-dimensional image. The enlargement projection system 75 enlarges the two-dimensional image obtained through the light deflecting unit 74 as an intermediate image, projects it onto the screen 76, and displays the two-dimensional image on the screen 76.

  When the display device 61 performs a process according to the user's operation, in step S13, the display device 61 determines whether to turn off the power. That is, in step S13, the display device 61 determines whether or not the user has instructed to turn off the power.

  If it is determined in step S13 that the power is not turned off, the user is not instructed to turn off the power. Therefore, the process returns to step S12, and the display device 61 performs a process according to the user's operation.

  On the other hand, if it is determined in step S13 that the power supply is to be turned off, the user has instructed the power supply to be turned off. Therefore, the process proceeds to step S14, and the display device 61 performs an operation confirmation process. Note that the operation confirmation process in step S14 is the same process as the operation confirmation process in step S11, and a description thereof will be omitted.

  When the operation confirmation process is performed in step S14, the process proceeds to step S15, where the display device 61 turns off the power of the display device 61 and the image display process ends.

  In this way, when the display device 61 is activated, the display device 61 performs an operation confirmation process and rotates the scanning mirror 91 once. Then, the display device 61 displays an image according to the user's operation, and when the power-off is instructed, the display device 61 performs an operation confirmation process again, rotates the scanning mirror 91 once, and then turns on the power of the display device 61. Turn off.

  It has been described that the operation confirmation process is performed immediately after the display device 61 is activated and immediately before the display device 61 is turned off and the scanning mirror 91 is rotated once, but immediately after the display device 61 is activated, and Not only just before the power of the display device 61 is turned off, but also when the display device 61 is not displaying an image on the screen 76, the operation confirmation processing may be performed periodically. Alternatively, the operation confirmation process may be performed just after the display device 61 is activated or just before the display device 61 is turned off, and the scanning mirror 91 may be rotated once.

  Next, an operation confirmation process corresponding to the process of step S11 or the process of step S14 of FIG. 7 will be described with reference to the flowchart of FIG.

  In step S41, the display device 61 performs a function check of each unit of the display device 61, and confirms whether each unit of the display device 61 operates normally.

  When it is confirmed that each part of the display device 61 operates normally, in step S42, the auxiliary motor control unit 154 drives the auxiliary motor 93 and rotates the shaft 161 of the auxiliary motor 93 once, and the process ends. .

  For example, in step S <b> 42, the auxiliary motor control unit 154 controls the auxiliary motor drive circuit 155 to drive the auxiliary motor 93 based on a signal indicating the rotation angle of the shaft 161 supplied from the rotary encoder 151.

  The auxiliary motor drive circuit 155 generates a drive current for driving the auxiliary motor 93 based on the control of the auxiliary motor control unit 154, and supplies the generated drive current to the auxiliary motor 93. The shaft 161 is rotated once. As a result, the shaft 101 of the galvano motor 92 connected coaxially to the shaft 161 of the auxiliary motor 93 makes one rotation, and similarly, the scanning mirror 91 provided on the shaft 101 also makes one rotation.

  Therefore, for example, if the ball bearing 111 shown in FIG. 5 is arranged inside the galvano motor 92, the inner ring 121 in which the shaft 101 is fitted is linked with the movement of the shaft 101 of the galvano motor 92. Rotate once.

  Here, for example, when the inner diameter of the inner ring 121 is 8 mm, the outer diameter is 10 mm, the inner diameter of the outer ring 122 is 16 mm, the outer diameter is 18 mm, and the diameter of each rolling element 123 is 3 mm, the shaft 101 (inner ring 121) is 1 When rotated, the outer surface 131 of the inner ring 121 moves by 31.4 (= 2 × 3.14 × 5) mm, so that the rolling element 123 having a diameter of 3 mm is 1200 (= (31.4 / (2 It is rotated (rotated) by 3.14 × 1.5)) × 360) degrees. That is, when the inner ring 121 rotates once, each rolling element 123 rotates about 3 rotations and 120 degrees (= 1200/360).

  In this case, each rolling element 123 can be substantially rotated by 120 degrees by rotating the shaft 101 of the galvano motor 92 once. As a result, the position of the portion (contact point) in contact with the inner ring 121 or the outer ring 122 on the surface of the rolling element 123 can be changed. It can be made to spread evenly over the surface of 123.

  In this way, the light deflecting unit 74 rotates the shaft 101 (scanning mirror 91) of the galvano motor 92 once to rotate the inner ring 121 on the surface of the rolling element 123 of the ball bearing 111 disposed inside the galvano motor 92. Alternatively, the position of the portion in contact with the outer ring 122 is changed.

  As described above, the auxiliary motor 93 is provided as a mechanism for rotating the scanning mirror 91 once in the light deflecting unit 74, and the operation confirmation process is performed immediately after the display device 61 is activated and immediately before the display device 61 is turned off. Thus, the scanning mirror 91 is periodically rotated once to prevent the ball bearing 111 disposed inside the galvano motor 92 from slipping on the surface of the rolling element 123, and the lubricating oil is used to prevent the rolling element 123 from moving. It can be distributed evenly on the surface.

  Thereby, the durability of the ball bearing 111 arranged inside the galvano motor 92 can be further improved, and even when an inexpensive ball bearing 111 is used as the bearing arranged inside the galvano motor 92, The durability of the galvano motor 92 (light deflection unit 74) can be improved.

  In the operation confirmation process, it has been described that the scanning mirror 91 is rotated once. Further, as described above, the auxiliary motor 93 is provided in the light deflection unit 74 as a mechanism for rotating the scanning mirror 91. However, instead of the auxiliary motor 93, a hydraulic cylinder, an air cylinder or the like is provided to rotate the scanning mirror 91. May be.

  Furthermore, it is possible to rotate the shaft 101 of the galvano motor 92 once only by controlling the driving of the galvano motor 92 without providing the auxiliary motor 93 in the light deflection unit 74. In this case, the light deflection unit 74 is configured as shown in FIG. 9, for example. 9, parts corresponding to those in FIG. 6 are denoted by the same reference numerals, and description thereof is omitted as appropriate.

  The light deflection unit 74 shown in FIG. 9 includes a scanning mirror 91, a galvano motor 92, a rotary encoder 151, a galvano motor drive circuit 153, and a galvano motor control unit 181.

  The rotary encoder 151 is connected to the shaft 101 of the galvano motor 92 and detects the rotation angle (or rotation angle) of the shaft 101, that is, the rotation angle of the scanning mirror 91. Then, the rotary encoder 151 generates a signal indicating the detected rotation angle (or rotation angle) and supplies the signal to the galvano motor control unit 181.

  The galvano motor control unit 181 controls the galvano motor drive circuit 153 to drive the galvano motor 92. The galvano motor control unit 181 includes a determination unit 191.

  The determination unit 191 of the galvano motor control unit 181 determines whether or not the shaft 101 reaches the dead center based on the signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151 or determines whether the shaft 101 is dead. It is determined whether or not it has passed.

  For example, a magnet is attached (fitted) to the shaft 101 of the galvano motor 92, and the polarity of S or N is set inside the galvano motor 92 according to the drive current from the galvano motor drive circuit 153. A coil for generating a magnetic field is provided so as to take on. The galvano motor 92 inverts the polarity of the coil in accordance with the drive current from the galvano motor drive circuit 153, and rotates (or rotates) the shaft 101 using the force that the coil and the magnet attract. Here, the dead point is a state in which, for example, when the shaft 101 is rotated (or rotated), the coil and the magnet attract each other and no torque is generated on the shaft 101 even if the polarity of the coil is reversed ( Or the position of the axis | shaft 101 used as the direction which the axis | shaft 101 rotates becomes unknown.

  The galvano motor control unit 181 determines whether the galvano motor control unit 181 determines whether the shaft 101 has reached the dead point or whether the shaft 101 has passed the dead point. The motor drive circuit 153 is controlled to drive the galvano motor 92.

  Further, the determination unit 191 of the galvano motor control unit 181 determines whether or not the shaft 101 has made one rotation based on the signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151. When it is determined that the shaft 101 has made one rotation, the galvano motor control unit 181 controls the galvano motor drive circuit 153 to suppress the supply of drive current from the galvano motor drive circuit 153 to the galvano motor 92. The drive of the motor 92 is stopped.

  Inside the galvano motor 92, for example, as shown in FIG. 10A, an annular coil 211 made of an iron core and a winding wound around the iron core is disposed. An annular magnet 212 is fitted, and the magnet 212 is disposed so as to be surrounded by the coil 211.

  The coil 211 is composed of four parts of windings 221 to 224 (divided into four equal parts), and each of the windings 221 to 224 corresponds to the driving current supplied from the galvano motor driving circuit 153. Thus, the magnetic field is generated so that each winding has S or N polarity.

  For example, the galvano motor drive circuit 153 supplies the coil 211 with one of currents having different polarities (hereinafter referred to as positive current and negative current) as the drive current. For example, when a positive current is supplied as a drive current to the coil 211, a magnetic field is generated so that the winding 221 and the winding 223 (on the side of the magnet 212) have N polarity, and the winding 222 and the winding 211 are wound. The magnetic field is generated so that the wire 224 (on the magnet 212 side) has the polarity of S. Similarly, when a negative current is supplied as a drive current to the coil 211, the winding 221 and the winding A magnetic field is generated so that 223 (of the magnet 212 side) has an S polarity, and a magnetic field is generated so that the winding 222 and the winding 224 (of the magnet 212 side) have an N polarity. .

  The magnet 212 is divided into regions 231 to 234 (divided into four equal parts), and the region 231 and the region 233 of the magnet 212 have an S polarity as indicated by the symbol “S” in the figure. It is magnetized in advance so as to take on. Similarly, the region 232 and the region 234 of the magnet 212 are pre-magnetized so as to have N polarity as indicated by the symbol “N” in the drawing.

  Therefore, for example, when the galvano motor drive circuit 153 supplies a positive current as a drive current to the coil 211, the polarities of the winding 221 and the winding 223 (on the magnet 212 side) of the coil 211 are as shown in FIG. 10B. N, and the polarity of winding 222 and winding 224 (on the side of magnet 212) is S.

  Then, since each of the windings 221 to 224 of the coil 211 and each of the regions 231 to 234 of the magnet 212 are attracted to each other, the magnet 212 and the shaft 101 fitted to the magnet 212 are shown in the figure. Start rotating in the clockwise direction.

  Then, the galvano motor driving circuit 153 draws the coil 211 into the coil 211 immediately before the winding 221 of the coil 211 and the region 231 of the magnet 212 are attracted to rotate the shaft 101 and the shaft 101 (magnet 212) reaches the dead point. The supply of drive current is suppressed. In other words, the galvano motor drive circuit 153 supplies the drive current to the coil 211 in the state shown in FIG. 10B immediately before the magnet 212 is rotated clockwise by 45 degrees in the figure. Suppress.

  In this case, as shown in FIG. 10C, when the shaft 101 (magnet 212) reaches the dead point, the coil 211 is not supplied with a drive current (the drive current is not flowing). Each of the windings 221 to 224 of 211 has no polarity. Therefore, the shaft 101 (magnet 212) continues to rotate due to inertia.

  Further, when the shaft 101 (magnet 212) passes through the dead point, the galvano motor drive circuit 153 reverses the polarity of the drive current. That is, the galvano motor drive circuit 153 supplies a negative current as a drive current to the coil 211.

  When a negative current as a drive current is supplied to the coil 211, the polarity of the winding 221 and the winding 223 of the coil 211 is S, and the polarity of the winding 222 and the winding 224 is N as shown in FIG. 10D. Become.

  Then, the winding 221 of the coil 211 and the region 234 of the magnet 212, the winding 222 and the region 231, the winding 223 and the region 232, and the winding 224 and the region 233 attract each other, so that the magnet 212 (shaft 101). Further rotates in the clockwise direction in the figure.

  The galvano motor drive circuit 153 supplies the drive current to the coil 211 immediately before the winding 221 of the coil 211 and the region 234 of the magnet 212 attract each other and the shaft 101 (magnet 212) reaches the dead point. Suppress. When supply of the drive current to the coil 211 is suppressed, when the shaft 101 (magnet 212) reaches the dead point again as shown in FIG. 10E, the drive current is not supplied to the coil 211 (drive current). Therefore, each of the windings 221 to 224 of the coil 211 has no polarity. Therefore, the shaft 101 (magnet 212) continues to rotate due to inertia.

  As described above, the galvano motor control unit 181 controls the galvano motor drive circuit 153 based on the signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151. Then, the galvano motor drive circuit 153 suppresses the supply of the drive current to the coil 211 of the galvano motor 92 immediately before the shaft 101 reaches the dead center based on the control of the galvano motor control unit 181, and the shaft 101 is dead. After passing the point, the polarity of the drive current is reversed (the polarity of the coil 211 is reversed), the drive current is supplied again to the coil 211 of the galvano motor 92, and the shaft 101 (scanning mirror 91) is rotated. The galvano motor drive circuit 153 repeats these series of processes until the shaft 101 rotates once.

  Next, with reference to the flowchart of FIG. 11, an operation confirmation process that is a process corresponding to the process of step S <b> 11 of FIG. 7 or the process of step S <b> 14 by the light deflection unit 74 illustrated in FIG. 9 will be described.

  In step S <b> 71, the display device 61 performs a function check of each unit of the display device 61 to confirm whether each unit of the display device 61 operates normally.

  When it is confirmed that each part of the display device 61 operates normally, in step S72, the galvano motor control unit 181 is based on the signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151. The drive circuit 153 is controlled to supply a drive current to the galvano motor 92.

  The galvano motor driving circuit 153 generates, for example, a positive current as a driving current based on the control of the galvano motor control unit 181 and supplies the positive current to the coil 211 of the galvano motor 92. When a positive current as a drive current is supplied to the coil 211, for example, as shown in FIG. 10B, the windings 221 and 223 of the coil 211 have a polarity N, and the windings 222 and 224 have a polarity. Since S becomes S, the shaft 101 (magnet 212) starts to rotate in the clockwise direction in the drawing.

  At this time, the rotary encoder 151 detects the rotation angle of the shaft 101 of the galvano motor 92, generates a signal indicating the detected rotation angle, and supplies the signal to the galvano motor control unit 181.

  When a driving current is supplied from the galvano motor driving circuit 153 to the galvano motor 92, in step S73, the determination unit 191 of the galvano motor control unit 181 generates a signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151. Based on this, it is determined whether or not the shaft 101 reaches the dead point.

  For example, the determination unit 191 of the galvano motor control unit 181 has a predetermined shaft 101 further predetermined from the current position of the shaft 101 indicated by the signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151. If it reaches the dead point, it is determined that the dead point is reached.

  If it is determined in step S73 that the dead point is not reached, the process returns to step S73, and the determination process is repeated until it is determined that the dead point is reached. In this case, the driving current is continuously supplied from the galvano motor driving circuit 153 to the galvano motor 92.

  On the other hand, if it is determined in step S73 that the dead point is reached, the process proceeds to step S74, where the galvano motor control unit 181 controls the galvano motor drive circuit 153 to drive the galvano motor drive circuit 153 to drive the galvano motor 92. The supply of current is suppressed.

  Since the galvano motor driving circuit 153 suppresses the supply of the driving current to the galvano motor 92 based on the control of the galvano motor control unit 181, for example, as shown in FIG. Not supplied, and each of the windings 221 to 224 is in a state of no polarity.

  When the supply of the drive current to the galvano motor 92 is suppressed, in step S75, the determination unit 191 of the galvano motor control unit 181 determines the shaft based on the signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151. It is determined whether 101 has passed the dead point.

  For example, the determination unit 191 of the galvano motor control unit 181 determines the current position of the shaft 101, which is indicated by the signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151, from the position of the dead point. When the position is rotated by a predetermined angle, it is determined that the dead point has been passed.

  If it is determined in step S75 that the dead point has not been passed, the process returns to step S75, and the determination process is repeated until it is determined that the dead point has been passed. In this case, the supply of drive current from the galvano motor drive circuit 153 to the galvano motor 92 continues to be suppressed.

  On the other hand, if it is determined in step S75 that the dead point has been passed, the process proceeds to step S76, where the determination unit 191 of the galvano motor control unit 181 uses the signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151. Based on this, it is determined whether or not the shaft 101 (scanning mirror 91) has made one rotation.

  If it is determined in step S76 that the shaft 101 has not made one rotation, the shaft 101 is still rotated, so the processing returns to step S72 and the above-described processing is repeated. In this case, for example, the process returns to step S72, and the galvano motor drive circuit 153 determines the polarity of the drive current supplied to the galvano motor 92 until the supply of the drive current is suppressed under the control of the galvano motor control unit 181. Drive currents having different polarities are generated and supplied to the galvano motor 92.

  Therefore, for example, when a positive current is supplied as a drive current to the galvano motor 92 until the supply of the drive current is suppressed, the galvano motor drive circuit 153 generates a negative current as the drive current, Supply.

  In this case, for example, as shown in FIG. 10D, the polarity of the winding 221 and the winding 223 of the coil 211 is S, and the polarity of the winding 222 and the winding 224 is N. The shaft 101 further rotates in the clockwise direction in the drawing.

  On the other hand, if it is determined in step S76 that the shaft 101 (scanning mirror 91) has made one rotation, the shaft 101 of the galvano motor 92 is not rotated any further, and the operation confirmation process ends.

  In this manner, the galvano motor control unit 181 controls the galvano motor drive circuit 153 based on the signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151, and the galvano motor control unit 181 immediately before the shaft 101 reaches the dead point. The supply of drive current to the coil 211 of the motor 92 is suppressed, the shaft 101 is rotated by inertia, and when the shaft 101 passes through the dead point, the polarity of the drive current is reversed and the coil of the galvano motor 92 is again turned on. The drive current is supplied to 211, the shaft 101 is rotated, and the rotation of the shaft 101 is controlled. Then, these processes are repeated to rotate the shaft 101 (scanning mirror 91) of the galvano motor 92 once.

  As described above, when the supply of the drive current to the coil 211 of the galvano motor 92 is suppressed immediately before the shaft 101 of the galvano motor 92 reaches the dead center, the shaft 101 continues to rotate due to inertia. However, since the rotary encoder 151 provided in the optical deflection unit 74 such as a galvano scanner can detect the rotation angle of the shaft 101 with high accuracy, it is difficult to control the rotation of the shaft 101. The motor control unit 181 can control the rotation of the shaft 101 of the galvano motor 92 with higher accuracy, and as a result, can rotate the shaft 101 once.

  As described above, the rotation angle of the shaft 101 of the galvano motor 92 is detected by the rotary encoder 151, and based on the detected rotation angle, the rotation of the shaft 101 of the galvano motor 92 is controlled to periodically scan the mirror 91. By rotating the roller once, the surface of the rolling element 123 of the ball bearing 111 disposed inside the galvano motor 92 with a simpler configuration is prevented from slipping, and the lubricating oil is evenly distributed on the surface of the rolling element 123. You can make it go around.

  Thereby, the durability of the ball bearing 111 arranged inside the galvano motor 92 can be further improved, and even when an inexpensive ball bearing 111 is used as the bearing arranged inside the galvano motor 92, The durability of the galvano motor 92 (light deflection unit 74) can be improved.

  In the operation confirmation process, it has been described that the shaft 101 (scanning mirror 91) of the galvano motor 92 is rotated once, but it may be rotated one or more times, such as two times or three times. Further, by providing one or a plurality of auxiliary coils at positions close to the coil 211 shown in FIG. 10, the supply of drive current to the galvano motor 92 is not suppressed, that is, the shaft 101 is rotated by inertia. The shaft 101 can be rotated once without causing the rotation.

  In this case, the light deflection unit 74 is configured as shown in FIG. 12, for example. In FIG. 12, portions corresponding to those in FIG. 9 are denoted by the same reference numerals, and description thereof is omitted as appropriate.

  The optical deflection unit 74 shown in FIG. 12 includes a scanning mirror 91, a galvano motor 92, a rotary encoder 151, a galvano motor control unit 301, and a galvano motor drive circuit 302.

  The galvano motor control unit 301 controls the galvano motor drive circuit 302 to drive the galvano motor 92. The galvano motor control unit 301 includes a determination unit 321, a coil control unit 322, and an auxiliary coil control unit 323.

  The determination unit 321 of the galvano motor control unit 301 determines whether or not the shaft 101 reaches the dead center based on the signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151.

  The coil control unit 322 or the auxiliary coil control unit 323 of the galvano motor control unit 301 drives the galvano motor based on the determination result of whether or not the shaft 101 reaches the dead point by the determination unit 321 of the galvano motor control unit 301. The circuit 302 is controlled and the galvano motor 92 is driven.

  For example, the coil control unit 322 controls the galvano motor drive circuit 302 based on the determination result of the determination unit 321 and supplies the drive current supplied to the coil disposed inside the galvano motor 92 to the galvano motor drive circuit 302. (Hereinafter also referred to as coil drive current) is generated and supplied to the coil of the galvano motor 92.

  Further, for example, the auxiliary coil control unit 323 controls the galvano motor drive circuit 302 based on the determination result of the determination unit 321, so that the galvano motor drive circuit 302 has an auxiliary coil disposed inside the galvano motor 92. A drive current to be supplied (hereinafter also referred to as an auxiliary coil drive current) is generated and supplied to the auxiliary coil of the galvano motor 92.

  Further, the determination unit 321 of the galvano motor control unit 301 determines whether or not the shaft 101 has made one rotation based on the signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151. When it is determined that the shaft 101 has made one rotation, the coil control unit 322 or the auxiliary coil control unit 323 of the galvano motor control unit 301 controls the galvano motor drive circuit 302 to change from the galvo motor drive circuit 302 to the galvano motor 92. The supply of the coil driving current or the auxiliary coil driving current is suppressed, and the driving of the galvano motor 92 is stopped.

  Inside the galvano motor 92, for example, as shown in FIG. 13A, a coil 211 and a magnet 212 to which the shaft 101 of the galvano motor 92 is fitted are arranged. An auxiliary coil 341 made of, for example, an iron core and a winding wound around the iron core is disposed at a position adjacent to the boundary between the winding 221 and the winding 224.

  That is, the internal configuration of the galvano motor 92 shown in FIG. 13A is a configuration in which an auxiliary coil 341 is newly arranged in the internal configuration of the galvano motor 92 shown in FIG. 10A. In FIG. 13, the same reference numerals are given to the portions corresponding to those in FIG. 10, and description thereof will be omitted as appropriate.

  In FIG. 13A, the windings 221 to 224 of the coil 211 are in a state of no polarity. Coil driving current from the galvano motor driving circuit 302 is supplied to the windings 221 to 224 of the coil 211, and each of the windings 221 to 224 corresponds to the coil driving current from the galvano motor driving circuit 302. Thus, the magnetic field is generated so that each winding has S or N polarity.

  For example, one of currents having different polarities (hereinafter referred to as a positive current and a negative current) is supplied from the galvano motor driving circuit 302 to the coil 211 as a coil driving current. For example, when a positive current is supplied to the coil 211 as a coil drive current, a magnetic field is generated so that the winding 221 and the winding 223 (on the magnet 212 side) have N polarity, and the winding 222 and The magnetic field is generated so that the winding 224 (on the magnet 212 side) has the polarity of S. Similarly, when a negative current is supplied to the coil 211 as a coil driving current, the winding 221 and The magnetic field is generated so that the winding 223 (on the magnet 212 side) has an S polarity, and the magnetic field is generated so that the winding 222 and the winding 224 (on the magnet 212 side) have an N polarity. ing.

  Similarly, in FIG. 13A, the auxiliary coil 341 has no polarity. The auxiliary coil 341 is supplied with an auxiliary coil driving current from the galvano motor driving circuit 302, and the auxiliary coil 341 has S or N polarity according to the auxiliary coil driving current from the galvano motor driving circuit 302. Generate a magnetic field.

  For example, the galvano motor drive circuit 302 is supplied to the auxiliary coil 341 with any one of currents having different polarities (hereinafter referred to as positive current and negative current) as the auxiliary coil drive current. For example, when a positive current is supplied to the auxiliary coil 341 as the auxiliary coil driving current, the auxiliary coil 341 generates a magnetic field so that the magnet 212 side of the auxiliary coil 341 has N polarity, and the auxiliary coil 341 generates a magnetic field. When a negative current is supplied as the auxiliary coil drive current, the auxiliary coil 341 generates a magnetic field so that the magnet 212 side of the auxiliary coil 341 has an S polarity.

  For example, when the galvano motor driving circuit 302 supplies a positive current as a coil driving current to the coil 211 in the state shown in FIG. 13A, as shown in FIG. 13B, the winding 221 and the winding 223 of the coil 211 (magnets thereof) The polarity on the 212 side) is N, and the polarity on the winding 222 and the winding 224 (on the magnet 212 side) is S.

  Then, each of the windings 221 to 224 of the coil 211 and each of the regions 231 to 234 of the magnet 212 attract each other, so that the magnet 212 (shaft 101) rotates in the clockwise direction in the drawing. start.

  Then, as shown in FIG. 13C, the galvano motor driving circuit 302 has the coil 211 at the moment when the winding 221 of the coil 211 and the region 231 of the magnet 212 are attracted and the shaft 101 (magnet 212) reaches the dead point. The polarity of the coil drive current supplied to the coil 211 is reversed, and an auxiliary coil drive current having the same polarity as the polarity of the coil drive current supplied to the coil 211 is supplied to the auxiliary coil 341.

  Therefore, in this case, as shown in FIG. 13D, a negative current as a coil driving current is supplied from the galvano motor driving circuit 302 to the coil 211, and a negative current as an auxiliary coil driving current is supplied to the auxiliary coil 341. Is done. Thereby, the polarity of the winding 221 and the winding 223 (on the magnet 212 side) of the coil 211 is S, and the polarity of the winding 222 and the winding 224 (on the magnet 212 side) is N. The polarity of the auxiliary coil 341 (on the side of the magnet 212) is S.

  In FIG. 13D, since the polarity of the winding 221 and the auxiliary coil 341 is S, and the polarity of the region 231 of the magnet 212 facing the winding 221 of the coil 211 is also S, the auxiliary coil 341 and the region 231 repel each other. Due to the matching force, the magnet 212 (shaft 101) rotates in the clockwise direction in the figure.

  That is, the region 231 of the magnet 212 is a dead center position with respect to the winding 221 of the coil 211, but the region 231 is a position close to the winding 221, and the winding 221 and the winding 224. Since the auxiliary coil 341 disposed at a position close to the boundary between the auxiliary coil 341 and the auxiliary coil 341 is not a dead center position, the magnet 212 is moved in the figure by the force of repulsion between the auxiliary coil 341 and the region 231. Rotate around.

  The galvano motor drive circuit 302 reverses the polarity of the coil drive current supplied to the coil 211 at the moment when the magnet 212 (shaft 101) rotates and the shaft 101 (magnet 212) reaches the dead center again. The polarity of the auxiliary coil driving current supplied to the auxiliary coil 341 is reversed.

  Then, as shown in FIG. 13E, the polarities of the winding 221 and the winding 223 of the coil 211 are N, and the polarities of the winding 222 and the winding 224 are S. Further, the polarity of the auxiliary coil 341 is N. At this time, since the polarity of the region 234 of the magnet 212 facing the winding 221 of the coil 211 is also N, the magnet 212 (the shaft 101) is caused to rebound by the force of repulsion between the region 234 and the auxiliary coil 341. Continue to rotate clockwise.

  As described above, the galvano motor control unit 301 controls the galvano motor drive circuit 302 based on the signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151. The galvano motor driving circuit 302 supplies the galvano motor 92 with a coil driving current and an auxiliary coil driving current having the same polarity to the galvano motor 92 under the control of the galvano motor control unit 301. Further, the galvano motor control unit 301 controls the galvano motor drive circuit 302 to invert the polarity of the coil drive current and the auxiliary coil drive current supplied to the galvano motor 92 every time the shaft 101 reaches the dead point. (Reversing the polarities of the coil 211 and the auxiliary coil 341) rotates the shaft 101 (scanning mirror 91) once.

  Next, with reference to the flowchart of FIG. 14, the operation confirmation process, which is a process corresponding to the process of step S11 of FIG. 7 or the process of step S14, by the optical deflection unit 74 shown in FIG.

  In step S <b> 101, the display device 61 performs a function check of each unit of the display device 61 and confirms whether each unit of the display device 61 operates normally.

  When it is confirmed that each part of the display device 61 operates normally, in step S102, the coil control unit 322 of the galvano motor control unit 301 generates a signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151. Based on this, the galvano motor driving circuit 302 is controlled, and the galvano motor 92 is supplied with a coil driving current.

  The galvano motor driving circuit 302 generates a coil driving current based on the control of the galvano motor control unit 301 and supplies it to the coil 211 of the galvano motor 92. For example, when the galvano motor driving circuit 302 generates a positive current as a coil driving current and supplies the positive current to the coil 211 of the galvano motor 92, the winding 221 and the winding 223 of the coil 211 as shown in FIG. The polarity is N, the polarity of the winding 222 and the winding 224 is S, and the shaft 101 (magnet 212) starts to rotate in the clockwise direction in the figure.

  At this time, the rotary encoder 151 detects the rotation angle of the shaft 101 of the galvano motor 92, generates a signal indicating the detected rotation angle, and supplies the signal to the galvano motor control unit 301.

  When the coil driving current is supplied from the galvano motor driving circuit 302 to the galvano motor 92, the determination unit 321 of the galvano motor control unit 301 is a signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151 in step S103. Based on the above, it is determined whether or not the shaft 101 reaches the dead point.

  For example, the determination unit 321 of the galvano motor control unit 301 further determines a predetermined shaft 101 in advance from the current position of the shaft 101 indicated by the signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151. When it reaches the dead point when it is rotated by the angle of, it is determined that the dead point is reached.

  If it is determined in step S103 that the dead point is not reached, the process returns to step S103, and the determination process is repeated until it is determined that the dead point is reached. In this case, the coil driving current is continuously supplied from the galvano motor driving circuit 302 to the galvano motor 92.

  On the other hand, if it is determined in step S103 that the dead point is reached, the process proceeds to step S104, where the coil control unit 322 of the galvano motor control unit 301 controls the galvano motor drive circuit 302 so that the galvano motor drive circuit 302 becomes galvano. The polarity of the coil drive current supplied to the motor 92 is reversed.

  In step S <b> 105, the auxiliary coil control unit 323 of the galvano motor control unit 301 controls the galvano motor driving circuit 302 to invert the polarity of the auxiliary coil driving current that the galvano motor driving circuit 302 supplies to the galvano motor 92. When the auxiliary coil driving current is not supplied from the galvano motor driving circuit 302 to the galvano motor 92 (for example, in the state shown in FIG. 13C), the auxiliary coil control unit 323 displays the galvano motor driving circuit 302. In addition, an auxiliary coil drive current having the same polarity as the coil drive current is supplied to the galvano motor 92.

  For example, when it is determined that the shaft 101 reaches the dead point in the state shown in FIG. 13C, the galvano motor driving circuit 302 supplies the galvano motor 92 (coil 211) to the galvano motor control unit 301 based on the control. Since the polarity of the coil driving current to be reversed is reversed and the auxiliary coil 341 is supplied with the auxiliary coil driving current having the same polarity as the coil driving current, as shown in FIG. 13D, the polarity of the windings 221 to 224 of the coil 211 Are reversed, the auxiliary coil 341 has polarity, the polarity of the winding 221, the winding 223, and the auxiliary coil 341 is S, and the polarity of the winding 222 and the winding 224 is N. As a result, the shaft 101 (magnet 212) continues to rotate in the clockwise direction in the drawing.

  When the polarity of the auxiliary coil drive current supplied to the galvano motor 92 is reversed, the determination unit 321 of the galvano motor control unit 301 is based on the signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151 in step S106. Thus, it is determined whether or not the shaft 101 reaches the dead point.

  If it is determined in step S106 that the dead point is not reached, the process returns to step S106, and the determination process is repeated until it is determined that the dead point is reached. In this case, the coil drive current and the auxiliary coil drive current are continuously supplied from the galvano motor drive circuit 302 to the galvano motor 92.

  On the other hand, if it is determined in step S106 that the dead point is reached, the process proceeds to step S107, and the determination unit 321 of the galvano motor control unit 301 is based on the signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151. Thus, it is determined whether or not the shaft 101 (scanning mirror 91) has made one rotation.

  If it is determined in step S107 that the shaft 101 has not made one rotation, the shaft 101 is still rotated, so the processing returns to step S104 and the above-described processing is repeated.

  On the other hand, if it is determined in step S107 that the shaft 101 has made one rotation, the shaft 101 of the galvano motor 92 is not rotated any more, so the process proceeds to step S108, where the coil control unit 322 of the galvano motor control unit 301 is Then, the galvano motor driving circuit 302 is controlled to suppress the supply of the coil driving current to the galvano motor 92.

  In step S109, the auxiliary coil control unit 323 of the galvano motor control unit 301 controls the galvano motor drive circuit 302 to suppress the supply of the auxiliary coil drive current to the galvano motor 92, and the operation confirmation process ends.

  When the galvano motor driving circuit 302 suppresses the supply of the coil driving current and the auxiliary coil driving current to the galvano motor 92, the windings 221 to 224 and the auxiliary coil 341 of the coil 211 are not in a state of having a polarity. The shaft 101 stops rotating.

  In this way, the galvano motor control unit 301 performs the coil driving current to the galvano motor 92 and the galvano motor 92 each time the shaft 101 reaches the dead point based on the signal indicating the rotation angle of the shaft 101 supplied from the rotary encoder 151. The axis 101 is rotated once by reversing the polarity of the auxiliary coil driving current.

  As described above, the rotation angle of the shaft 101 of the galvano motor 92 is detected by the rotary encoder 151, and the polarities of the coil drive current and the auxiliary coil drive current supplied to the galvano motor 92 are reversed based on the detected rotation angle. The surface of the rolling element 123 of the ball bearing 111 disposed inside the galvano motor 92 by controlling the rotation of the shaft 101 (scanning mirror 91) of the galvano motor 92 and periodically rotating the scanning mirror 91 once. In addition, the lubricating oil can be distributed evenly over the surface of the rolling element 123.

  Thereby, the durability of the ball bearing 111 arranged inside the galvano motor 92 can be further improved, and even when an inexpensive ball bearing 111 is used as the bearing arranged inside the galvano motor 92, The durability of the galvano motor 92 (light deflection unit 74) can be improved.

  Although an example in which one auxiliary coil 341 is provided inside the galvano motor 92 has been described, a plurality of auxiliary coils may be provided. Further, it has been described that the auxiliary coil driving current is supplied to the galvano motor 92 and the polarity of the auxiliary coil driving current is reversed at the moment when the shaft 101 reaches the dead point. However, only when the shaft 101 reaches the dead point. The auxiliary coil drive current having the same polarity as the coil drive current may be supplied to the galvano motor 92.

  Furthermore, although it has been described that the shaft 101 (scanning mirror 91) of the galvano motor 92 is rotated once in the operation confirmation process, it may be rotated one or more times, such as two times or three times.

It is a figure which shows the structure of the conventional galvanometer scanner. It is a figure which shows the structure of the bearing arrange | positioned inside a galvano scanner. It is a figure which shows the structural example of the display apparatus to which this invention is applied. It is a figure which shows the structural example of the optical deflection | deviation part of FIG. It is a figure which shows the structural example of the bearing arrange | positioned inside a galvano motor. It is a block diagram which shows the more detailed structural example of an optical deflection | deviation part. It is a flowchart explaining the process of an image display. It is a flowchart explaining the process of operation confirmation. It is a block diagram which shows the other structural example of an optical deflection | deviation part. It is a figure for demonstrating control of the drive of a galvano motor. It is a flowchart explaining the process of operation confirmation. It is a block diagram which shows the further another structural example of an optical deflection | deviation part. It is a figure for demonstrating control of the drive of a galvano motor. It is a flowchart explaining the process of operation confirmation.

Explanation of symbols

  71 light source, 72 modulation unit, 74 light deflection unit, 75 enlargement projection system, 91 scanning mirror, 92 galvano motor, 93 auxiliary motor, 101 axis, 151 rotary encoder, 152 galvano motor control unit, 153 galvano motor drive circuit, 154 auxiliary Motor control unit, 155 auxiliary motor drive circuit, 161 axis, 181 galvano motor control unit, 191 determination unit, 211 coil, 212 magnet, 301 galvano motor control unit, 302 galvano motor drive circuit, 321 determination unit, 322 coil control unit, 323 Auxiliary coil controller, 341 Auxiliary coil

Claims (7)

In a scanning device that scans light,
First driving means for rotating the shaft so as to reciprocate within a predetermined angle range;
A reflecting means provided on the axis for reflecting the incident light so as to scan the light;
And a rotation control means for controlling the rotation of the shaft so as to rotate the shaft one or more times. A second driving means for rotating the shaft;
The scanning device according to claim 1, wherein the rotation control unit controls rotation of the shaft by the second driving unit. The scanning device according to claim 1, wherein the first driving unit rotates the shaft by changing a polarity of a coil provided in the first driving unit. Determination means for determining whether or not the axis reaches a dead point;
When it is determined that the axis reaches the dead point, the rotation control unit reverses the polarity of the coil and changes the polarity of another coil provided at a position close to the coil, thereby The scanning device according to claim 3, wherein rotation of the shaft is controlled. Determination means for determining whether the axis reaches a dead point or whether the axis has passed the dead point;
When it is determined that the axis reaches the dead point, the rotation control unit controls the first driving unit so that the coil does not have polarity, and it is determined that the axis has passed the dead point. 4. The scanning device according to claim 3, wherein the rotation of the shaft is controlled by controlling the first driving unit so that the coil has a polarity. 5. In a driving method of a scanning device in which a shaft is rotated so as to reciprocate within a range of a predetermined angle, and incident light is reflected by a reflecting means provided on the shaft to scan the light.
A driving method for controlling rotation of the shaft so as to rotate the shaft one or more times. A light source that emits light;
Drive means for rotating the shaft so as to reciprocate within a predetermined angle range;
Reflecting means that is provided on the axis and reflects the modulated light that is emitted from the light source so as to scan the light;
Projecting means for projecting light reflected by the reflecting means to display an image;
And a rotation control means for controlling rotation of the shaft so as to rotate the shaft one or more times.

Images