JP2013122564A - Shutter device, projector unit, and shutter plate drive control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly stop a shutter plate in such a rotation position as not to intercept projection light of a projector.SOLUTION: A shutter device includes: a shutter plate which has intercepting parts and transmitting parts alternately arranged in the same surface peripheral direction around a rotation axis; a shutter driving part which rotationally drives the shutter plate in both forward and backward rotation directions; a rotation position detection unit which detects a rotation position of the shutter plate; an inversion time counting unit which counts a time from an inversion time point of the shutter plate; and a torque deriving unit which rotationally drives the shutter driving part with a prescribed torque set to a value equal to or lower than a maintaining torque when stopping processing of the shutter plate is started, and causes the shutter driving part to rotationally drive the shutter plate with a torque resulting from gradual increase of the prescribed torque until a next inversion time point tafter the time counted by the inversion time counting unit exceeds a preliminarily determined first time (t-t).

Description

  The present invention relates to a shutter device that shields or transmits light emitted to project an image, a projector unit, and a shutter plate drive control method.

  In recent years, demand for displaying moving images using projectors such as home theater use and 3D display has increased, and accordingly, the demand for performance has also increased. When a hold type light modulation device such as a liquid crystal panel is used as the light modulation function unit of the projector, if the display content is changed in the moving image, an afterimage of the display content of the previous frame remains or the display content of the next frame is rewritten. The rise time required, and the human tracking eye movement and the time integration effect of the eyes acted, causing image blurring.

  In order to improve such image blurring, for example, a technique for shielding an image rewriting period in a projector with a mechanical shutter is disclosed (for example, Patent Documents 1 and 2). With this technique, the image display period by the projector can be made intermittent to improve the quality of the moving image.

JP 2002-148712 A JP 2006-30493 A

  However, with the above mechanical shutter, the projection light is intermittently shielded and the light amount of the entire image is attenuated, so even images that do not require shielding during the rewriting period, such as still images and moving images with little change in display contents. If the mechanical shutter is applied, the amount of light is unnecessarily suppressed. Therefore, simply adopting the techniques of Patent Document 1 and Patent Document 2 described above cannot sufficiently deal with images that do not require such rewrite period shielding.

  In addition, it is conceivable to remove the projection light shielding means as described in Patent Document 2, but the work itself is troublesome, and when the projector is installed at a location that is out of reach, such as the ceiling, There is also a problem that the shielding means cannot be easily removed. In addition, it is conceivable to separately provide a stopping means such as a stopper for stopping the projection light at a rotational position where the projection light is not shielded. However, a new mechanism needs to be added, resulting in an increase in cost.

  Therefore, the inventor of the present application provides a sufficient amount of light even for an image that does not require shielding during the rewriting period by stopping the mechanical shutter at a predetermined rotational position that does not shield the projection light of the projector. I came up with it. However, if the torque of the motor when rotating the mechanical shutter is not fully taken into account, the overrun at the rotation position that does not block the projection light of the projector will increase and it will take time until it stops completely, or the cogging of the motor There is a possibility that the mechanical shutter may stop in the middle of the stop process due to insufficient rotational torque relative to the torque.

  SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and it is an object of the present invention to provide a shutter device, a projector unit, and a shutter plate drive control method capable of smoothly stopping a shutter plate at a rotational position that does not block the projection light of the projector. It is said.

In order to solve the above problems, the present invention provides the following shutter device, projector unit, and shutter plate drive control method.
(1) A shutter plate that shields light emitted from a light source and a transmissive portion that transmits the light are alternately arranged in the same circumferential direction around the rotation axis, and forwardly rotates the shutter plate. And a shutter driving unit that rotates in both the reverse and reverse directions, and the shielding unit and the transmission unit of the shutter plate at a predetermined position corresponding to the light source in accordance with the rotational driving of the shutter plate by the shutter driving unit. A rotation position detection unit that detects which position is to be positioned, a reversal timing unit that measures a time from the reversal time of the shutter plate with reference to a detection result of the rotation position detection unit, and a shutter plate At the start of the stop process, the shutter drive unit has a predetermined torque set to a value equal to or less than a maintenance torque that is a torque when the torque in the forward rotation direction and the torque in the reverse rotation direction are balanced to enter the stop state. The shutter plate is driven to rotate in a direction opposite to the current rotation direction, and from the predetermined torque until the next reversal time after the time measured by the reversing time measuring unit exceeds a predetermined first time. And a torque deriving unit that causes the shutter driving unit to rotationally drive the shutter plate with a gradually increased torque.
(2) The shutter device according to (1), wherein the torque deriving unit gradually reduces torque that causes the shutter driving unit to rotationally drive the shutter plate from torque at the time of reversal.
(3) The shutter device according to (2), wherein the torque deriving unit sets the torque immediately after reversal to a torque having an absolute value equal to that of the torque immediately before reversal and a reverse rotation direction.
(4) The shutter device according to any one of (1) to (3), wherein the torque deriving unit derives the torque after the reversal based on the torque gradually increased until the next reversal.
(5) When the time measured by the reversing time measuring unit does not exceed a predetermined first time, the torque deriving unit calculates the torque after reversing based on the current torque and the torque before reversing. The shutter device according to any one of (1) to (4), wherein the shutter device is derived.
(6) A projector having a projection unit that projects an image, a shielding unit that shields light emitted from the projection unit, and a transmission unit that transmits the light alternately in the circumferential direction on the same plane around the rotation axis The shutter plate arranged, a shutter drive unit that rotationally drives the shutter plate in both forward and reverse directions, and a predetermined position corresponding to the projection unit as the shutter plate is driven to rotate by the shutter drive unit. A rotation position detection unit that detects which of the shielding unit and the transmission unit of the shutter plate is positioned, and a detection result of the rotation position detection unit, and from the time of reversal of the shutter plate A reverse timing unit for measuring the time of the rotation and a maintenance torque which is a torque when the torque in the forward rotation direction and the torque in the reverse rotation direction are balanced when the stop process of the shutter plate starts. The shutter drive unit is driven to rotate the shutter plate in a direction opposite to the current rotation direction with a predetermined torque set to a value less than or equal to a predetermined time, and the time measured by the reversing time measuring unit is a predetermined first time. And a torque deriving unit that causes the shutter driving unit to rotationally drive the shutter plate with a torque gradually increased from the predetermined torque until the next reversal point.
(7) A shutter plate that shields light emitted from a light source and a transmission portion that transmits the light are alternately arranged in the same circumferential direction around the rotation axis, and forwardly rotates the shutter plate. A shutter plate drive control method for driving and controlling the shutter plate using a shutter drive unit that rotationally drives in both reverse and reverse directions, and corresponds to the light source as the shutter plate is rotationally driven by the shutter drive unit. It is detected which of the shielding part and the transmission part of the shutter plate is positioned at a predetermined position, and the detection result of the rotational position detection part is referred to, and the shutter plate from the reversal point of time is detected. Time is measured and set to a value equal to or less than the maintenance torque, which is the torque when the torque in the forward rotation direction and the torque in the reverse rotation direction are balanced to enter the stop state at the start of the shutter plate stop process. The shutter driving unit is driven to rotate the shutter plate in a direction opposite to the current rotation direction with a predetermined torque, and after the time measured by the reversing time measuring unit exceeds a predetermined first time, Until the time of reversal, the shutter plate drive control method is characterized in that the shutter plate is rotated by the shutter drive unit with a torque gradually increased from the predetermined torque.

  According to the present invention, it is possible to smoothly stop the shutter plate at a rotational position where the projection light of the projector is not blocked.

It is explanatory drawing which showed the schematic relationship of the projector unit. It is the block diagram which showed the structure of the shutter apparatus. It is an external view for demonstrating the shape of a shutter board | plate. It is a functional block diagram showing the operation of the shutter control unit. It is a timing chart for demonstrating operation | movement of a shutter control part. It is explanatory drawing for demonstrating a shutter board stop process. It is the timing chart which showed the typical example of transition of the torque in a shutter board stop process. It is a flowchart for demonstrating the flow of a shutter plate drive control method. It is explanatory drawing which showed the other example of the shutter plate stop process.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

(First embodiment: projector unit 100)
FIG. 1 is an explanatory diagram showing a schematic relationship of the projector unit 100. The projector unit 100 includes a projector 110 and a shutter device 120.

  The projector 110 is a device that displays an image by projecting the image onto a screen or the like. Further, the projector 110 can display one image as a still image, or can display it as a moving image by continuously switching a plurality of images in units of frames.

  The shutter device 120 blocks or transmits light projected on the projector 110. In projector 110, if the display content changes frequently, an afterimage of the display content of the previous frame may remain, or a rise time may be required to rewrite the display content of the next frame, which may cause moving image blurring. There is. Therefore, the shutter device 120 improves the image quality of the moving image by intentionally blocking the light of the projector 110 at such display content rewriting timing.

  In the present embodiment, the shutter device 120 switches and executes two processes of (1) shutter plate rotation processing and (2) shutter plate stop processing. (1) The shutter plate rotation process is a process that is applied to a moving image with a large change in display contents, and only projects the light to be transmitted intermittently onto the screen by rotating the shutter plate described later. (2) Shutter plate stop processing is applied to images that do not need to be shielded during the rewriting period, such as still images and moving images with little change in display content. This is a process of projecting onto a screen. The shutter device 120 will be specifically described below.

(Shutter device 120)
2 is a block diagram showing the configuration of the shutter device 120, FIG. 3 is an external view for explaining the shape of the shutter plate, and FIG. 4 is a functional block diagram showing the operation of the shutter control unit. It is. The shutter device 120 includes a shutter plate 150, a shutter drive unit 152, a rotational position detection unit 154, a reverse timing unit 156, a reception unit 158, and a shutter control unit 160.

  The shutter plate 150 is formed in a disc shape and is rotatably supported in a posture that is perpendicular to the light projected by the projector 110. In the shutter plate 150, as shown in FIG. 3A, slits that radiate from the rotary shaft 180 toward the outer peripheral side in the radial direction are formed at equal intervals around the rotary shaft 180 in the same plane circumferential direction. .

  Here, the tangible region sandwiched between the slits in the circumferential direction of the shutter plate 150, which is indicated by hatching in FIG. 3, is a shielding portion 182 that shields the light projected by the projector 110, as shown in FIG. When the shielding unit 182 is positioned on the projection unit 186 of the projector 110, the light projected by the projector 110 is shielded and is not displayed on the screen. On the other hand, the slit is a transmission unit 184 that transmits the light projected by the projector 110. When the transmission unit 184 is positioned on the projection unit 186 of the projector 110 as shown in FIG. Light is displayed on the screen. As described above, the transmission portions 184 and the shielding portions 182 are alternately arranged on the shutter plate 150.

  The shutter drive unit 152 is configured by an electric motor (motor), fixes the electric motor main body, and rotationally drives the shaft (not shown) of the shutter plate 150 in both the forward and reverse directions around the rotation shaft 180.

  The rotational position detection unit 154 is configured by, for example, a photo interrupter, and is a shielding unit on the shutter plate 150 at the position of the projection unit 186 of the projector 110 corresponding to the light source as the shutter plate 150 is rotationally driven by the shutter drive unit 152. It is detected which of 182 and transmissive part 184 is located. Specifically, as illustrated in FIG. 3A, the rotational position detection unit 154 is fixed at a position corresponding to the projection unit 186 of the projector 110. Then, the rotational position detection unit 154 outputs “1” as a shielding signal in the state of FIG. 3B in which the light of the light emitting unit of the rotational position detection unit 154 is shielded by the shielding unit 182 and does not reach the light receiving unit. In the state of FIG. 3C in which the light from the light emitting unit of the position detecting unit 154 reaches the light receiving unit, “0” is output as the shielding signal.

  As a means for detecting the rotational position of the shutter plate 150, for example, it is conceivable to use an encoder with high angular resolution. However, since the shaft of the shutter plate 150 is thin, the encoder cannot be installed effectively, and even if installed, the cost increases. In addition, the encoder can only grasp the relative rotational position based on the initial position, but the rotational position detecting unit 154 of the present embodiment can grasp the absolute rotational position of the transmission unit 184 of the shutter plate 150. It is suitable for the application.

  The inversion time measuring unit 156 is configured by a hardware counter, refers to the detection result of the rotational position detection unit 154, and the time from the time when the shielding unit 182 and the transmission unit 184 in the shutter plate 150 are inverted, that is, the shielding signal is “1”. The time after inversion from “0” to “0” or after inversion from “0” to “1” is measured. The measured time is reset at the next inversion.

  The receiving unit 158 is connected to the projector 110 for communication, and receives a synchronization signal and an ON / OFF signal from the projector 110. The synchronization signal indicates the frame timing of the image projected by the projector 110. The ON / OFF signal indicates ON / OFF of rotation of the shutter plate 150, that is, whether (1) shutter plate rotation processing or (2) shutter plate stop processing is performed.

  The shutter control unit 160 is composed of a semiconductor integrated circuit including a CPU (Central Processing Unit), reads programs and parameters for operating the CPU itself from the ROM, and cooperates with the RAM as a work area and other electronic circuits. Thus, the entire shutter device 120 is managed and controlled. The shutter control unit 160 also functions as a rotation state deriving unit 170, a torque deriving unit 172, and a torque control unit 174 as shown in FIG. Hereinafter, the operation of each functional part in (1) shutter plate rotation processing and (2) shutter plate stop processing will be described.

<(1) Shutter plate rotation processing>
Referring to FIG. 4, the rotation state deriving unit 170 determines the angular velocity (or the number of rotations) and the phase of the shutter plate 150 based on the shielding signal output from the rotation position detection unit 154 and the time measured by the inversion timing unit 156. To derive. Further, the rotation state deriving unit 170 can also derive the angle and the number of rotations by integrating the angular velocities.

  When the ON / OFF signal received from the projector 110 is ON, that is, when shutter plate rotation processing is instructed, the torque deriving unit 172 receives the angular velocity and phase of the shutter plate 150 derived by the rotation state deriving unit 170, and the reception. Based on the synchronization signal received by projector 158 from projector 110, the torque required for shutter drive unit 152 is derived so that the synchronization signal and the shielding signal are synchronized while maintaining a predetermined phase relationship.

  FIG. 5 is a timing chart for explaining the operation of the shutter control unit 160. FIG. 5 shows a time response of the luminance 190 of the projected light at an arbitrary pixel of the projected image when the hold type light modulation device is used. As can be understood by referring to the time response of the luminance 190, in the time region indicated by hatching in FIG. 5, an afterimage of the display content of the previous frame remains or a rise time is required to rewrite the display content of the next frame. To do. Therefore, it is desirable to temporarily block the projection of the image during that time.

  Therefore, the projector 110 sets the time required for the start-up for the afterimage of the display content of the previous frame to remain or the rewrite to the display content of the next frame as the shielding time, and the time after the display content is stabilized as the transmission time. The synchronization signal shown in FIG. 5 is transmitted to the shutter device 120. The torque deriving unit 172 of the shutter device 120 is arranged such that the shielding unit 182 is positioned at the projection unit 186 of the projector 110 during the shielding time of the synchronization signal, and the transmission unit 184 is the projection unit 186 of the projector 110 during the transmission time. The torque is derived so as to be positioned at (so that the shield signal is synchronized with the synchronization signal).

  The torque control unit 174 causes the shutter driving unit 152 to rotationally drive the shutter plate 150 according to the torque derived by the torque deriving unit 172. In this way, the image projected during the shielding time of the synchronization signal is shielded by the shielding portion 182 of the shutter plate 150 and is not physically displayed on the screen.

  Here, if the rising period indicated by hatching in FIG. 5 cannot be completely shielded, a gradual change in luminance will be seen by the user and image blur will occur. In this embodiment, by completely blocking the rising period for rewriting the display contents of the next frame, the brightness of the projected image can be displayed as if it appears to be sharply changed, and the image blur is reduced. It becomes possible to suppress.

<(2) Shutter plate stop processing>
FIG. 6 is an explanatory diagram for explaining the shutter plate stop process. By the above-described (1) shutter plate rotation process, unnecessary projection during the shielding time can be avoided. However, in the shutter plate rotation process, the light amount of the entire image is attenuated due to intermittent shielding of the projection light. Therefore, for images that do not need to be shielded during the rewriting period, such as still images and moving images with little luminance change, the interval between the transmission portions 184 of the shutter plate 150 is assumed to be larger than the area occupied by the projection portion 186. 6, the shutter plate 150 is stopped at a rotational position where the transmission part 184 of the shutter plate 150 does not overlap the projection light, and the light from the projector 110 is continuously projected onto the screen.

  In the front view of the projector 110 in FIG. 6, the direction in which the shutter plate 150 is rotated clockwise is CW (forward rotation), and the direction in which the shutter plate 150 is rotated counterclockwise is CCW (reverse rotation). The rotational position detection unit 154 uses “1” as the shielding signal when the shielding unit 182 shields the light from the projection unit 186 and “0” when the transmission unit 184 transmits the light from the projection unit 186. Is output. Further, the rotational position detection unit 154 is offset from the projection unit 186 by a predetermined angle to the CCW in order to detect a position where the polarity is reversed. For example, when the shutter signal is reversed to “1” from “0” when the shutter signal is reversed from “0” to “1” in the case where the shutter signal 150 is rotated to CW by using such a shield signal, the shutter plate 150 is shown in FIG. Can be positioned as follows. On the contrary, when the shutter plate 150 is rotating in the CCW, if the shutter plate 150 is stopped when the shielding signal is reversed from “1” to “0”, the shutter plate 150 is moved as shown in FIG. Can be positioned.

  When the ON / OFF signal received from the projector 110 is OFF, that is, when the shutter plate stop process is instructed, the torque deriving unit 172 outputs the angular velocity of the shutter plate 150 derived by the rotation state deriving unit 170 and the inversion timing unit. Based on the time measured by 156 and the shielding signal from the rotational position detector 154, the torque required for the shutter driver 152 is derived so that the shutter plate 150 is finally stopped at the position shown in FIG. Then, the torque control unit 174 controls the torque of the shutter driving unit 152 with the torque derived by the torque deriving unit 172. Hereinafter, a specific torque transition in the shutter plate stop process will be described.

  When the shutter plate stop process is instructed from the projector 110, the shutter plate stop process of the shutter plate 150 that has been driven to rotate by the shutter plate rotation process is started. Here, first, the brake process of the shutter drive unit 152 that is rotationally driven is performed, and the brake process is continued until the angular velocity of the shutter plate 150 becomes less than a predetermined first threshold value. Then, when the angular velocity of the shutter plate 150 becomes less than the first threshold, the torque deriving unit 172 starts a stop process for stopping the shutter plate 150 at the position of FIG.

  The purpose of the shutter plate stop process is to stop the shutter signal at the rotation position where the shielding signal is reversed from “0” to “1” when the shutter plate 150 is rotated to CW, as described above, or the shutter plate 150. Is stopped at the rotational position where the shielding signal is reversed from “1” to “0”. Therefore, the torque deriving unit 172 crosses the final rotation position (target position) of interest, reverses the direction of torque control, and crosses the final rotation position again. By repeating such an operation a plurality of times, the torque becomes a maintenance torque that is a torque when the torque in the forward rotation direction and the torque in the reverse rotation direction are balanced, and the shutter plate 150 becomes the final target. It will stop at the rotational position. Such a period from straddling the final rotational position to straddling again, that is, a period between polarity inversions is hereinafter referred to as an inversion period. Further, until the final rotational position is reached, while the torque control direction (CW or CCW) is the same, the rotational drive is performed with substantially the same torque (the rotational drive is performed with the same torque for at least a predetermined period). ). Such torque is referred to as drive torque in each rotational drive.

  FIG. 7 is a timing chart showing a typical example of torque transition in the shutter plate stop process. 7A shows the transition of the shielding signal, FIG. 7B shows the transition of the absolute value of the torque derived by the torque deriving section 172, and FIG. 7C shows the transition of the torque deriving section 172. FIG. 7D shows the transition of the rotational position of the shutter plate 150. FIG. The transition of the torque (absolute value and control direction) shown in FIG. 7B and FIG. 7C corresponds to the torque commanded by the torque control unit 174 to the shutter drive unit 152. Here, the torque deriving unit 172 By describing the torque derived from the above, detailed description of the torque used for the torque control unit 174 and the shutter drive unit 152 is omitted.

  As shown by A in FIG. 7B, the torque deriving unit 172 sets a predetermined torque (drive torque) set to a value equal to or less than the maintenance torque at the start of the stop process of the shutter plate 150, and the shutter drive unit 152. In addition, the shutter plate 150 is rotationally driven in a direction opposite to the current rotational direction. The torque deriving unit 172 changes the driving torque stepwise as shown in FIG. 7B every time the polarity of the shielding signal is reversed as shown in FIG. 7A, and finally settles to the maintenance torque. . This step change will be described in detail later.

  Thus, by starting the torque at the start of the shutter plate stop process from a value lower than the maintenance torque, it is possible to reduce the overrun of the rotational position when the rotational position detector 154 reverses the polarity. Therefore, compared with a case where the torque is started from a value higher than the maintenance torque, it is possible to reach the final rotational position quickly and smoothly without accompanying any apparent vibration.

数式１）

数式２）
ここで、定数Ｋ_１は、シャッタ駆動部１５２やシャッタ板１５０の慣性モーメント等に応じて予め定められた正の値であり、時点ｔ_１は、シャッタ駆動部１５２やシャッタ板１５０の慣性モーメント等に応じて予め定められる。時点ｔ_Ｓは、反転期間の開始時点であり、時点ｔ_ｒは反転期間の終了時点である。かかる時点ｔ_Ｓ、ｔ_１、ｔ_ｒは、各反転期間に対する相対的な時刻なので、反転期間毎に適用される。したがって、ここでは、１の反転期間について時点ｔ_Ｓ、ｔ_１、ｔ_ｒを定義しているが、各反転期間について同様の時点が存在することになる。また、ここでは定数Ｋ_１や第１時間（ｔ_１−ｔ_Ｓ）を固定値としているが、遮蔽信号による極性反転回数や後述する反転時のトルクＴ_Ｅと駆動トルクＴ_Ｂｎとの差分から動的に決定されるとしてもよい。 However, if the drive torque is intentionally set low as described above, the drive torque is insufficient with respect to the cogging torque of the motor, and the rotation of the shutter plate 150 is driven halfway along the path until the rotation position detector 154 reverses the polarity. There is a risk of stopping. Therefore, the torque deriving unit 172 of the present embodiment, as indicated by B in FIG. 7B, performs torque T as shown in Equation 1 below until a predetermined first time (time point t ₁ -time point t _S ). after maintaining the to the drive torque _{T Bn,} the time measured by the inverted clock section 156 _{(t-t S)} until time _{t r} the next inverted from beyond the first hour _(t 1 -t _S), The torque T is gradually increased from the drive torque _TBn based on the following formula 2.

Formula 1)

Formula 2)
Here, the constant K ₁ is a positive value determined in advance according to the moment of inertia of the shutter driving unit 152 and the shutter plate 150, and the time point t ₁ is the moment of inertia of the shutter driving unit 152 and the shutter plate 150. It is predetermined according to. Time t _S is the start time of the inversion period, and time _tr is the end time of the inversion period. Since the time points t _S , t ₁ , and _tr are relative times with respect to each inversion period, they are applied for each inversion period. Therefore, here, time points t _S , t ₁ , _tr are defined for one inversion period, but similar time points exist for each inversion period. Also, here it is a fixed value constants K ₁ and the first hour (t 1 _{-t S)} has a kinematic from the difference between the torque T _E when the inversion of the polarity inversion frequency and below by shielding signal and the drive torque T _Bn It may be determined automatically.

However, as indicated by C in FIG. 7B, at the start of the shutter plate stop process, the timing for increasing the torque is different from the first time (t ₁ -t _S ). Unlike the shutter plate stop process that repeats the inversion period with inversion, at the start of the shutter plate stop process, the rotation position is determined by the timing at which the projector 110 instructs the shutter plate stop process (the ON / OFF signal is turned OFF). The time until the detection unit 154 next determines polarity reversal is different. Therefore, at the start of the shutter plate stop process, when the shutter plate stop process is instructed from the projector 110, the shutter plate stop process is smoothly performed regardless of the rotation position of the shutter plate 150. Timing for increasing the torque is provided separately.

数式３）
ここでは、今回の駆動トルクＴ_Ｂｎに、反転までに漸増したトルクの５０％を加算して次回の駆動トルクＴ_Ｂｎ＋１を導出している。ただし、加算する割合（％）は５０％に限らず、任意の％を設定することができる。 Further, the drive torque _TBn is derived as follows. Torque derivation section 172, as in FIG. 7 B, based on the torque increasing until the next reversal (difference between the torque T _E when inverted driving torque T _Bn), as in Equation 3, after the reversal The (next) driving torque _{TBN + 1} is derived.

Formula 3)
Here, the current drive torque T _Bn, is derived for the next driving torque T _{Bn + 1} by adding 50% of the torque increasing up inversion. However, the ratio (%) to be added is not limited to 50%, and an arbitrary% can be set.

数式４） When the time (t−t _S ) measured by the reversing time measuring unit 156 does not exceed the first time (t ₁ −t _S ), the torque deriving unit 172 displays the current (current) Based on the drive torque T _Bn and the drive torque T _Bn−1 before the reversal (previous), the drive torque T _{Bn + 1} after the reversal (next time) is derived.

Formula 4)

As can be understood with reference to Equation 3 and Equation 4, if the torque deriving unit 172 does not reach the rotational position where the polarity is reversed by the first time (t ₁ -t _S ), the torque is insufficient. Therefore, it is determined that the arrival is delayed or the rotational drive of the shutter plate 150 is stopped in the middle of the path, and the torque is increased and the rotational drive is performed, so that the next incremental increase in the torque T _{Bn + 1} is performed. reflect. On the other hand, when reaching the rotational position where the polarity is reversed before reaching the first time (t ₁ -t _S ), it is determined that the torque is sufficient, and the current drive torque is determined from the previous drive torque _TBn−1. to determine the next drive torque T _{Bn + 1} to follow the changing trend of the torque to the T _Bn.

When the rotation position detection unit 154 detects polarity reversal, the torque control direction of the shutter drive unit 152 is reversed (CW → CCW or CCW → CW). At this time, the torque deriving unit 172, the torque T immediately after reversal, equal to the torque T _E of the inverted immediately before changing its polarity only.

数式５）
ただし、定数Ｋ_２は、シャッタ駆動部１５２やシャッタ板１５０の慣性モーメント等に応じて予め定められた負の値である。 Further, the torque deriving unit 172 gradually decreases the torque T from the torque T _E after the reversal (the reversal point) based on the following Equation 5 until the torque T reaches the target drive torque T _En from the reversal point. To do.

Formula 5)
However, the constant K ₂ is a negative value predetermined according to the moment of inertia of the shutter driving unit 152 and the shutter plate 150 or the like.

Further, when the gradually reduced torque reaches the target driving torque T _Bn (driving torque T _{Bn + 1} derived before inversion), the torque deriving unit 172 maintains the driving torque T _Bn . Therefore, the second time (t ₂ −t _S ) required for the gradual reduction of the torque is (T _B −T _E ) / K ₂ , and the time for maintaining the torque T at the driving torque T _Bn in Equation 1 is To be precise, t ₂ <t ≦ t ₁ . Here, since the constant K ₂ fixed, but so that the time t ₂ is varied, the time point t ₂ is fixed and may be changed K ₂ accordingly.

As can be understood with reference to FIG. 7 (b) and (c), the torque T immediately after reversal, equal to the torque T _E of the inverted immediately before, are reversed only control direction. With such a configuration, it is possible to apply a torque that has the same absolute value as that of the rotational drive torque of the shutter drive unit 152 immediately before reversal but in the opposite direction of rotation, so that the shutter plate 150 can be appropriately braked as a kickback. Furthermore, the rotation drive in the reverse direction can be started smoothly. In addition, the command to the shutter drive unit 152 can be completed with only the polarity inversion command, and the processing load can be reduced.

Further, for example, it may be equal to a constant K ₁ using the constant K ₂ for use in decreasing in equation 5 incrementally in equation 2. By doing so, the energy in the reverse direction immediately after the reversal can be made closer to the energy when the shutter plate 150 is rotationally driven just before the reversal (corresponding to the integral value of the torque). It becomes possible to start more smoothly.

By the shutter plate stop process as described above, the rotation of the shutter plate 150 at the time of reversal is stopped in the section of t _S <t ≦ t ₂ , and the shutter plate 150 is driven to rotate in the reverse direction in the section of t ₂ <t. is allowed, if the polarity is inverted to a second time _(t 2 -t _S) longer than the first hour _{(t 1 -t S), t} 1 in the interval of <t ≦ _{t r,} further increase the torque, shutter The plate 150 can be quickly reached the inversion position. In this way, it is possible to smoothly stop the shutter plate at a rotational position that does not block the projection light of the projector.

(Shutter plate drive control method)
FIG. 8 is a flowchart for explaining the flow of the shutter plate drive control method. Here, in particular, (2) shutter plate stop processing will be described. Here, the rotational position detection unit 154 always detects which of the shielding unit 182 and the transmission unit 184 is located on the projection unit 186 as a shielding signal, and the inversion timing unit 156 detects the detection result of the rotational position detection unit 154. It is assumed that the time after the shielding part 182 and the transmission part 184 are always reversed is measured.

When the shutter 110 is instructed from the projector 110, first, the brake process of the shutter drive unit 152 that is rotationally driven to CCW is performed (S200). Then, it is determined whether or not the angular velocity of the shutter plate 150 is less than a predetermined first threshold value α (S202). While the angular velocity of the shutter plate 150 is equal to or greater than the first threshold value α (NO in S202), the brake process S200. repeat. If the angular velocity of the shutter plate 150 is less than the first threshold value α (YES in S202), the torque deriving unit 172 sets the torque to a predetermined driving torque _TBn equal to or lower than the maintenance torque, resets the reverse timing unit 156, The current value of the shielding signal at that time is stored as the previous value of the shielding signal, and the shutter plate stop process is started (S204).

  When the first threshold value α is relatively large, the shutter plate stop process is started in a state in which the rotational drive of the shutter plate 150 still remains, and when the first threshold value α is relatively small, the rotation of the shutter plate 150 is nearly stopped. After that, the shutter plate stop process is started. In the present embodiment, since the resolution of the shielding signal per rotation of the rotational position detector 154 is low, there is a limit on the lower limit, but it is desirable that the first threshold value α is somewhat small.

Subsequently, the torque deriving unit 172 determines whether or not the time measured by the inversion time measuring unit 156 exceeds a predetermined third time (t ₃ −t _S ) (S 206), and the third time (t ₃ − If (t _S ) is exceeded (YES in S206), the torque T is gradually increased from the drive torque _TBn based on Equation 2 (S208). If the time measured by the inversion time measuring unit 156 does not exceed the third time (t ₃ -t _S ) (NO in S206), the rotation drive is continued while the torque T is maintained at the drive torque _TBn .

  Then, the torque deriving unit 172 refers to the previous value of the shielding signal and the current value of the current shielding signal, the previous value of the shielding signal is “1”, and the current value of the shielding signal is “0”. It is determined whether there is, that is, whether an inversion position from the shielding part 182 to the transmission part 184 has been reached (S210). The torque deriving unit 172 updates the previous value of the shielding signal with the current value of the shielding signal (S212) until the shielding signal is reversed (NO in S210), and repeats the processing from the time counting time determination step S206, If the shielding signal is inverted (YES in S210), the process proceeds to the next step S214 in which the inversion period is repeated.

Subsequently, the torque deriving unit 172 compares the previous value of the shielding signal with the current value of the shielding signal, and determines whether the two values are different (S214). If the two values are different (YES in S214), the torque deriving unit 172 determines that the polarity reversal position has been reached, and maintains the torque T (absolute value) before and after reversal, while controlling the torque. Only reverse (CW → CCW or CCW → CW), and the inversion flag is set to “1” (S216). Further, the torque deriving unit 172 derives the next driving torque T _{Bn + 1} based on Equation 3 or Equation 4 (S218). The reverse flag is a flag for gradually decreasing the torque T at the start of the reverse period. Further, the first time, because there is no driving torque _{T Bn-1} of the pre-reversal (previous), the driving torque _{T Bn} driving torque _{T Bn-1} = current before inversion in equation 4 (previous) (this time). Here, the torque deriving unit 172 derives the next drive torque T _{Bn + 1} , which corresponds to the current drive torque T _Bn in the new inversion period. While the two values are equal (NO in S214), the inversion step S216 and the drive torque deriving step S218 are not executed. Then, the torque deriving unit 172 updates the previous value of the shielding signal with the current value of the shielding signal (S220).

Next, the torque deriving unit 172 determines whether or not the current torque T is larger than the target drive torque _TBn and the reverse flag is “1” (S222). If current torque T is greater than drive torque _TBn and the reverse flag is “1” (YES in S222), torque deriving unit 172 gradually decreases torque T based on Equation 5 (S224). Further, if the current torque T is equal to or less than the driving torque _TBn or the reverse flag is “0” (NO in S222), the torque deriving unit 172 sets the reverse flag to “0” (S226), Control proceeds to the next step S228.

After setting the reversal flag to “0”, the torque deriving unit 172 determines whether or not the time measured by the reversal timing unit 156 exceeds the first time (t ₁ −t _S ) ( _S 228). If the time (t ₁ -t _S ) has not been exceeded (NO in S228), the torque T is maintained at the target drive torque _TBn (S230). If the time measured by the reversing time measuring unit 156 exceeds the first time (t ₁ -t _S ) (YES in _S 228), the torque T is gradually increased from the drive torque T _Bn based on Equation 2 (S 232). .

  Thus, the torque T converges to the maintenance torque when the torque in the forward rotation direction and the torque in the reverse rotation direction are balanced to enter the stop state, and the shutter plate 150 stops in a form that is pushed from both the CW and CCW directions. .

(Another example of shutter plate stop processing)
FIG. 9 is an explanatory view showing another example of the shutter plate stop process. As described above, unlike the shutter plate stop process in which the inversion period is repeated with inversion, the time (t _r −t) until the rotation position detection unit 154 next determines the polarity inversion at the start of the shutter plate stop process. _S ) differs depending on the timing at which the shutter 110 is instructed from the projector 110. For example, FIG. 9 illustrates a case where the time until the rotational position detection unit 154 next determines polarity reversal is longer than the typical example illustrated in FIG.

Referring to FIG. 9, since the time until the rotational position detector 154 next determines the polarity reversal is long, the gradual increase period of the torque T becomes long (overrun becomes large), and the drive torque _TBn becomes the maintenance torque. It is over. Then, the torque T is not gradually increased in the second inversion period, and converges to the maintenance torque in the third inversion period. In this way, depending on the timing when the shutter 110 is instructed from the projector 110, it can be understood that although the rotational speed and overrun at the first inversion timing are different, the final rotational position is reached quickly and smoothly. .

  By the shutter device 120 and the shutter plate drive control method described above, the shutter plate 150 is moved to a rotational position where the projection light of the projector 110 is not blocked, and the shutter plate 150 does not fall into a useless overrun or stop in the middle. It is possible to smoothly stop the 150 transmitting portions 184 so that they are appropriately positioned on the projecting portion 186 of the projector 110. In addition, since the stop state is maintained with the maintenance torque even after the stop, the projected light is not blocked by the disturbance. Therefore, regardless of whether a moving image with a large change in display content, a still image, a moving image with a small change in display content, or an image that does not need to be shielded during the rewriting period, the user has a high visual effect. Can be seen.

  In addition, a program that causes a computer to function as the shutter device 120 (shutter controller 160) and a computer-readable flexible disk, magneto-optical disk, ROM, EPROM, EEPROM, CD, DVD, BD, and the like on which the program is recorded are recorded. A storage medium is also provided. Here, the program refers to data processing means described in an arbitrary language or description method.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  Note that each step in the shutter plate drive control method of the present specification does not necessarily have to be processed in time series in the order described in the flowchart, and may include processing in parallel or by a subroutine.

  The present invention can be used in a shutter device that shields or transmits light emitted to project an image, a projector unit, and a shutter plate drive control method.

DESCRIPTION OF SYMBOLS 100 ... Projector unit 110 ... Projector 120 ... Shutter apparatus 150 ... Shutter board 152 ... Shutter drive part 154 ... Rotation position detection part 156 ... Inversion time measuring part 170 ... Rotation state deriving part 172 ... Torque deriving part 174 ... Torque control part 182 ... Shielding Part 184 ... Transmission part

Claims (7)

A shutter plate that shields light emitted from a light source and a transmissive portion that transmits the light, the shutter plates being alternately arranged around the rotation axis in the same circumferential direction;
A shutter drive unit that rotationally drives the shutter plate in both forward and reverse directions;
A rotational position for detecting which of the shielding portion and the transmission portion of the shutter plate is positioned at a predetermined position corresponding to the light source in accordance with the rotational driving of the shutter plate by the shutter driving portion. A detection unit;
An inversion timing unit that refers to the detection result of the rotational position detection unit and measures the time from the inversion point of the shutter plate,
At the start of the shutter plate stop process, the shutter drive unit is supplied with a predetermined torque set to a value equal to or lower than a maintenance torque, which is a torque when the torque in the forward rotation direction and the torque in the reverse rotation direction are balanced to enter the stop state. The shutter plate is rotationally driven in a direction opposite to the current rotational direction, and gradually increases from the predetermined torque until the next reversal time after the time measured by the reversal timing unit exceeds a predetermined first time. A torque deriving unit that causes the shutter driving unit to rotationally drive the shutter plate with the torque that has been caused;
A shutter device comprising:   2. The shutter device according to claim 1, wherein the torque deriving unit gradually reduces torque that causes the shutter driving unit to rotationally drive the shutter plate from torque at the time of reversal.   The shutter device according to claim 2, wherein the torque deriving unit sets the torque immediately after reversal to a torque having an absolute value equal to that of the torque immediately before reversal and a reverse rotation direction.   4. The shutter device according to claim 1, wherein the torque deriving unit derives the torque after the reversal based on the torque gradually increased until the next reversal. 5.   When the time measured by the reversing time measuring unit does not exceed a predetermined first time, the torque deriving unit derives the torque after reversing based on the current torque and the torque before reversing. The shutter device according to claim 1, wherein: A projector having a projection unit for projecting an image;
A shutter plate that shields light emitted from the projection unit and a transmission unit that transmits the light, the shutter plates being alternately arranged around the rotation axis in the same surface circumferential direction;
A shutter drive unit that rotationally drives the shutter plate in both forward and reverse directions;
Rotation to detect which of the shielding part and the transmission part of the shutter plate is located at a predetermined position corresponding to the projection part as the shutter driving part is driven to rotate by the shutter driving part. A position detector;
An inversion timing unit that refers to the detection result of the rotational position detection unit and measures the time from the inversion point of the shutter plate,
At the start of the shutter plate stop process, the shutter drive unit is supplied with a predetermined torque set to a value equal to or lower than a maintenance torque, which is a torque when the torque in the forward rotation direction and the torque in the reverse rotation direction are balanced to enter the stop state. The shutter plate is rotationally driven in a direction opposite to the current rotational direction, and gradually increases from the predetermined torque until the next reversal time after the time measured by the reversal timing unit exceeds a predetermined first time. A torque deriving unit that causes the shutter driving unit to rotationally drive the shutter plate with the torque that has been caused;
A projector unit comprising: A shutter plate that shields light emitted from a light source and a transmission portion that transmits the light are alternately arranged in the same circumferential direction around the rotation axis, and the shutter plate is rotated forward and reverse. A shutter plate drive control method for driving and controlling the shutter plate using a shutter drive unit that rotationally drives in both directions,
Detecting which of the shielding part and the transmission part of the shutter plate is positioned at a predetermined position corresponding to the light source in accordance with the rotational driving of the shutter plate by the shutter driving unit,
Referring to the detection result of the rotational position detector, measure the time from the reversal point of the shutter plate,
At the start of the shutter plate stop process, the shutter drive unit is supplied with a predetermined torque set to a value equal to or lower than a maintenance torque, which is a torque when the torque in the forward rotation direction and the torque in the reverse rotation direction are balanced to enter the stop state. Rotate the shutter plate in the direction opposite to the current rotation direction,
From the time when the time measured by the reversing time measuring unit exceeds a predetermined first time until the next reversal time point, the shutter driving unit is driven to rotate the shutter plate with a torque gradually increased from the predetermined torque. A shutter plate drive control method characterized by the above.

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