JP2012177867A - Intermittent display device and projection display system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intermittent display device which allows a shutter for intermittent display to be stopped at a proper position and is capable of inexpensively switching between the presence and the absence of the shutter in accordance with the use state of a projection display device.SOLUTION: An intermittent display device 3 is capable of intermittently displaying an image formed by projection light projected by a projection display device and includes: a shutter 5 which is rotatable to periodically shield the projection light; a motor unit 7 which drives the shutter 5; a rotation phase detection unit 6 which detects a rotation phase of the shutter 5 to output a signal with a polarity corresponding to the rotation phase; and a control unit 4 which controls the shutter 5 in accordance with a polarity of a shielding signal so that, when the shutter 5 in a rotating state is to be stopped, the shutter 5 is stopped at a position not to shield the projection light.

Description

  The present invention relates to an intermittent display device and a projection display system.

  In recent years, the demand for moving image display on a projection display device (projector) such as home theater use or 3D display has increased, and 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 device of a projection type display device, there is a rising period and afterimage period until each pixel is rewritten next. There is a problem that the time integration effect acts to cause image blur in the moving image.

  In order to improve this image blur, the image is formed by shielding the image in that period with a shutter or the like provided inside or outside the projection display device in synchronization with the rising period or afterimage period at the rewrite timing of each pixel. An intermittent display method for improving the image quality of a moving image by apparently shortening the display period of the image has been proposed (see, for example, Patent Documents 1 and 2).

JP 2002-148712 A JP 2006-30493 A

  The intermittent display method described above is unnecessary for the display of still images and the like that do not require moving image display performance because the amount of light on the entire screen is reduced and darkened by blocking the projection light for a certain period. For this reason, it is necessary to switch the presence or absence of a shutter according to a use condition.

  However, Patent Documents 1 and 2 do not fully consider switching between the presence and absence of a shutter. In particular, in Patent Document 2, when the intermittent display is unnecessary, the entire intermittent display device including the shutter is assumed to be moved or removed. For this reason, when the projection type display device is installed at a position such as the ceiling that is out of reach of normal hands, it is difficult to switch the presence or absence of the shutter.

  In addition, a method of separately providing a stop device such as a stopper that stops the shutter blade at a position where the projection light is not shielded is conceivable. However, there is a problem that the cost increases accordingly.

  In view of the above problems, an object of the present invention is to provide an intermittent display in which the shutter for intermittent display can be stopped at an appropriate position, and the presence or absence of the shutter can be switched at low cost according to the use state of the projection display device. An apparatus and a projection display system are provided.

  According to one aspect of the present invention, the intermittent display device (3) is capable of intermittently displaying an image of projection light projected by the projection display device (1), and periodically blocks the projection light. A rotatable shutter (5), a motor unit (7) for driving the shutter (5), and a rotational phase detector for detecting a rotational phase of the shutter (5) and outputting a signal having a polarity corresponding to the rotational phase. (6) and control for controlling the shutter (5) so that the shutter (5) stops at a position where the shutter (5) does not shield the projection light according to the polarity of the shielding signal when the shutter (5) is stopped from the rotation state. An intermittent display device (3) comprising a unit (4) is provided.

  In one aspect of the present invention, the control unit (4) drives the shutter (5) so as to approach the position where the shutter (5) does not shield the projection light according to the polarity of the shielding signal. , A processing time measurement module (104) for measuring the stop processing time for driving the shutter (5) by the drive module (101), a determination is made as to whether or not the stop processing time has reached a predetermined threshold, and the stop processing time A processing time determination module (105) that stops the shutter (5) when it is determined that the predetermined threshold value has been reached may be provided.

  In one aspect of the present invention, the control unit (4) drives the shutter (5) so as to approach the position where the shutter (5) does not shield the projection light according to the polarity of the shielding signal. An inversion determination module (201) for determining whether or not the polarity of the shielding signal has been inverted, an inversion number calculation module (202) for calculating the number of inversions determined to have inverted the polarity of the shielding signal, and the number of inversions An inversion number determination module (203) that determines whether or not the predetermined threshold value has been exceeded and stops the shutter (5) when it is determined that the inversion number has exceeded the predetermined threshold value may be provided.

  In one aspect of the present invention, the control unit (4) drives the shutter (5) so as to approach the position where the shutter (5) does not shield the projection light according to the polarity of the shielding signal. , An inversion interval measuring module (301) for measuring the polarity inversion interval until the polarity of the shield signal is inverted, and determining whether the polarity inversion interval is less than a predetermined threshold and determining that the polarity inversion interval is less than the predetermined threshold In such a case, a reverse interval determination module (302) for stopping the shutter (5) may be provided.

  In one aspect of the present invention, the control unit (4) drives the shutter (5) so as to approach the position where the shutter (5) does not shield the projection light according to the polarity of the shielding signal. A torque change module (401) that changes the drive torque of the motor unit (7) every time the polarity of the shielding signal is reversed, and determines whether the drive torque is less than a predetermined threshold, and the drive torque is less than the predetermined threshold And a torque determination module (402) for stopping the shutter (5).

  In one aspect of the present invention, the control unit (4) stores the polarity of the shielding signal detected when the shutter (5) is stopped, and is detected during the stop period of the shutter (5). A polarity change determination module (501) for determining whether or not the polarity of the shielded signal is different from the polarity of the shield signal stored in the storage unit (42), and is detected during the stop period of the shutter (5). If it is determined that the polarity of the shielded signal is different from the polarity of the shielded signal detected when the shutter (5) is stopped, the shutter (5) stop process may be re-executed.

  In one aspect of the present invention, the control unit (4) calculates the number of rotations of the shutter (5) based on the polarity of the shielding signal, and whether the number of rotations is less than a predetermined threshold. And a rotation number determination module (103) for determining whether the rotation number is less than a predetermined threshold, and the drive module (101) may decelerate the rotation of the shutter (5).

  According to another aspect of the present invention, a projection display device (1) that projects projection light and an intermittent display device (3) that can intermittently display images of projection light, the projection light being periodically emitted. The shutter (5) that can be rotated so as to be shielded, the motor unit (7) that drives the shutter (5), and the rotation phase of the shutter (5) are detected, and a signal having a polarity corresponding to the rotation phase is output. When the rotation phase detector (6) and the shutter (5) are stopped from the rotation state, the shutter (5) is stopped so that the shutter (5) stops at a position where the projection light is not blocked according to the polarity of the shielding signal. A projection display system characterized by comprising an intermittent display device (3) provided with a control unit for controlling the above.

  ADVANTAGE OF THE INVENTION According to this invention, the shutter for intermittent display can be stopped in an appropriate position, and the intermittent display apparatus and projection type display system which can switch the presence or absence of a shutter cheaply according to the use condition of a projection type display apparatus Can be provided.

It is the schematic which shows an example of the projection type display system which concerns on the 1st Embodiment of this invention. It is a graph which shows the relationship between the time response of the brightness | luminance of the projection light which concerns on the 1st Embodiment of this invention, and a shielding state. It is the schematic for demonstrating the stop position used as the transmission state of the shutter which concerns on the 1st Embodiment of this invention. It is a block diagram which shows an example of the control part which concerns on the 1st Embodiment of this invention. It is a flowchart for demonstrating an example of the shutter stop method which concerns on the 1st Embodiment of this invention. It is a block diagram which shows an example of the control part which concerns on the 2nd Embodiment of this invention. It is a flowchart for demonstrating an example of the shutter stop method which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows an example of the control part which concerns on the 3rd Embodiment of this invention. It is a flowchart for demonstrating an example of the shutter stop method which concerns on the 3rd Embodiment of this invention. It is a flowchart for demonstrating an example of the interruption process of the shutter stop method which concerns on the 3rd Embodiment of this invention. It is a block diagram which shows an example of the control part which concerns on the 4th Embodiment of this invention. It is a flowchart for demonstrating an example of the shutter stop method which concerns on the 4th Embodiment of this invention. It is a block diagram which shows an example of the control part which concerns on the 5th Embodiment of this invention. It is a flowchart for demonstrating an example of the shutter stop method which concerns on the 5th Embodiment of this invention.

  Next, first to fifth embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  The first to fifth embodiments described below exemplify devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is The material, shape, structure, arrangement, etc. are not specified below. The technical idea of the present invention can be variously modified within the scope of the claims.

(First embodiment)
A projection display system according to an embodiment of the present invention includes a projection display device (projector) 1 and an intermittent display device (mechanical shutter unit) 3 as shown in FIG.

  The projection display device 1 includes a main body 11 and a projection lens 12 attached to the main body 11. The main body 11 includes a light source 13 and a hold-type light modulator 14 that modulates light from the light source 13. The projection lens 12 projects the projection light (video) modulated by the light modulation unit 14 toward a screen (not shown).

  The intermittent display device 3 displays an image intermittently by shielding the projection light projected from the projection display device 1 at a predetermined timing. The intermittent display device 3 receives the rotation phase detection unit 6, the control unit 4 that receives the synchronization signal and the shielding signal output from the projection display device 1 and the rotation phase detection unit 6, and the drive signal from the control unit 4. A motor unit 7 that is connected to the motor unit 7, a shaft 8 having one end connected to the motor unit 7, and a shutter 5 connected to the other end of the shaft 8.

  The shutter 5 is disposed on the optical path of the projection light projected from the projection display device 1. The shutter 5 is rotatable so as to periodically shield the projection light from the projection display device 1. The shutter 5 includes a shielding part (blade) 51 and a transmission part 52 between adjacent shielding parts 51. The interval between the adjacent shielding portions 51 is larger than the vertical width of the projection light. The size and number of the shielding part 51 and the transmission part 52 are set as appropriate.

  The rotation phase detection unit 6 detects the rotation phase of the shutter 5 at a specific position within the circumference of the shutter 5 (projection light shielding state), and outputs a shielding signal having a polarity corresponding to the rotation phase to the control unit 4. As the rotation phase detection unit 6, for example, a photo interrupter composed of a light emitting element and a light receiving element can be used.

  The control unit 4 receives the synchronization signal of the projected image output from the projection display device 1 and the shielding signal output from the rotation phase detection unit 6, and the phase relationship between the synchronization signal and the shielding signal is constant. A drive signal for driving the shutter 5 is output to the motor unit 7 so as to synchronize while maintaining the above.

  The motor unit 7 rotationally drives the shutter 5 by rotationally driving the shaft 8 in accordance with the drive signal from the control unit 4.

  In FIG. 2, the example of the relationship between the time response of the brightness | luminance of the projection light in a certain coordinate of a projection screen, and the shielding state by the shutter 5 is shown. When the hold-type light modulator 14 is used, there is a rising period until the next rewriting for each pixel, and the luminance does not change sharply, but rises slightly gently as shown in the graph of FIG. Since the gradual change in luminance during the rising period becomes an image blur, it is the role of the shutter 5 to physically shield it.

  As shown as “shielding period” in FIG. 2, when the rising period is completely shielded, the projected image appears to have a sharp change in brightness, and thus there is no image blur. On the other hand, if the shielding period cannot completely shield the rising period, a gradual change in luminance will be seen, resulting in image blurring. Therefore, control is performed by the control unit 4 shown in FIG. 1 so that the shielding period by the shutter 5 and the timing of the luminance change of the projection light completely coincide.

  As described above, the shutter 5 that eliminates image blur works effectively for moving images with a large change in luminance. However, when the shutter 5 blocks the projection light in a still image that does not change in luminance, the amount of light on the entire screen is lost. There is a problem of darkening. In order to avoid this problem without physically removing the shutter 5, as shown in FIG. 3, it is only necessary to stop at an appropriate position where the shielding part 51 of the shutter 5 is not exposed to the projection light. As a generally conceivable method, use of a stopper that physically stops the movement of the shutter 5 can be mentioned, but this leads to an increase in cost. The first embodiment of the present invention is characterized in that the shutter 5 is stopped at an appropriate position without using a dedicated instrument such as a stopper.

  As shown in FIG. 2, if the shielding signal is “High” when the projection light is shielded and “Low” when the projection light is not shielded, the projection light is projected on the screen 100% without being shielded. When the shutter 5 rotates in the direction of the arrow shown in FIG. 3, the shutter signal may be stopped in a state where the shielding signal is switched from “High” to “Low” at the lower end of the projection light. Therefore, the rotational phase detector 6 detects the shielding state of the shutter 5 at the lower end of the projection light. Then, the control unit 4 controls the shutter 5 to stop at the timing when the shielding signal is switched from “High” to “Low”.

  When the control unit 4 shown in FIG. 1 stops the shutter 5 from the rotation state, the shutter 5 stops at a position where the shutter 5 does not block the projection light according to the polarity of the shielding signal output from the rotation phase detection unit 6. Thus, a drive signal for driving the shutter 5 is output to the motor unit 7.

  As illustrated in FIG. 4, the control unit 4 includes a central processing unit (CPU) 41 and a storage unit 42. The CPU 41 logically includes a drive module 101, a rotation speed calculation module 102, a rotation speed determination module 103, a processing time measurement module 104, and a processing time determination module 105.

  The drive module 101 outputs a drive signal for decelerating the rotational drive of the shutter 5 when stopping the shutter 5. Furthermore, after the shutter 5 decelerates, the drive module 101 drives the shutter 5 so as to approach the position where the shutter 5 does not shield the projection light according to the polarity of the shielding signal output from the rotational phase detector 6. The drive signal is output.

  The rotation speed calculation module 102 calculates the rotation speed of the shutter 5 based on the change time of the polarity of the shielding signal output from the rotation phase detector 6.

  The rotation speed determination module 103 reads the predetermined threshold value α from the storage unit 42 and determines whether the rotation speed of the shutter 5 calculated by the rotation speed calculation module 102 is less than the predetermined threshold value α.

  The processing time measurement module 104 is a time (hereinafter referred to as “stop processing”) after the rotational speed determination module 103 determines that the rotational speed is less than the predetermined threshold value α and the drive module 101 starts the stop processing after the shutter 5 is decelerated. It functions as a timer that measures (counts) time.

  The processing time determination module 105 reads the predetermined threshold β from the storage unit 42, determines whether or not the stop processing time measured by the processing time measurement module 104 has reached the predetermined threshold β, and the stop processing time When it is determined that the predetermined threshold value β has been reached, a drive signal for stopping the shutter 5 is output to the motor unit 7 or the output of the drive signal for rotating the shutter 5 is stopped.

  The storage unit 42 stores a rotation speed threshold value α read by the rotation speed determination module 103, a stop processing time threshold value β read by the processing time measurement module 104, and the like. As the storage unit 42, for example, a memory, a magnetic disk, an optical disk, or the like can be employed.

  Next, an example of a method for stopping the shutter 5 according to the first embodiment of the present invention will be described with reference to the flowchart of FIG. For example, when the control unit 4 receives a signal for starting the stop process from the projection display device 1, the stop process starts.

  (A) First, in step S101, a braking process is performed to stop the shutter 5 from the rotating state. In the braking process, the drive module 101 outputs a drive signal for decelerating the rotation of the shutter 5 to the motor unit 7 to reduce the rotation speed of the shutter 5. In step S <b> 102, the rotation speed calculation module 102 calculates the rotation speed of the shutter 5 based on the shielding signal output from the rotation phase detection unit 6. Further, the rotation speed determination module 103 determines whether or not the rotation speed of the shutter 5 calculated by the rotation speed calculation module 102 is less than a predetermined threshold value α. When it is determined that the threshold value α is equal to or greater than the predetermined threshold value α, the process returns to step S101 and the braking process is continued. On the other hand, if it is determined in step S102 that the rotation speed of the shutter 5 is less than the predetermined threshold value α, the process proceeds to step S103.

  (B) In step S103, the processing time measurement module 104 starts measuring (counting) the stop processing time. In step S104, the rotational phase detector 6 detects the rotational phase of the shutter 5 (the shielding state of transmitted light), and outputs a shielding signal corresponding to the rotational phase. The drive module 101 determines whether the polarity of the shielding signal output from the rotational phase detector 6 is “High” or “Low”. If it is determined as “High”, since the projection light is blocked, in step S105, the drive module 101 outputs a drive signal so that the shutter 5 rotates in the normal direction. On the other hand, if “Low” is determined in step S104, the projection light is transmitted. Therefore, in step S106, the drive module 101 outputs a drive signal so that the shutter 5 rotates in the reverse direction. . In this way, by outputting a forward or reverse drive signal according to the polarity of the shielding signal, the shutter 5 gradually approaches a position where the polarity of the shielding signal output by the rotational phase detector 6 is just switched. .

  (C) In step S107, the processing time determination module 105 determines whether or not the stop processing time measured by the processing time measurement module 104 has exceeded a predetermined threshold value β. If it is determined that the predetermined threshold β has been exceeded, it is determined that the shutter 5 has been subjected to the desired position control, and the processing time determination module 105 performs a drive complete stop process for stopping the shutter 5 in step S108.

  The drive complete stop process is more specifically described when a DC motor is used. The drive output from the drive module 101 is stopped, and if the motor or motor driver IC has an ON / OFF control terminal, it is turned OFF. Or the power supply to the motor or the motor driver IC is stopped so that the motor cannot be driven completely. Even in cases other than the DC motor, the same processing as that of the DC motor is performed.

  According to the projection display system according to the first embodiment of the present invention, the threshold value α of the rotation speed of the braking process, the drive output set in steps S105 and S106, and the determination in step S107 are used. By setting the timer count threshold β to an appropriate value, the stop position control of the shutter 5 can be performed with sufficient accuracy. Therefore, when intermittent display for displaying a still image is not necessary, the shielding unit 51 of the shutter 5 can be stopped at a position where it is not exposed to the projection light without providing a dedicated stop device. As a result, the presence or absence of the shutter 5 can be switched at a low cost according to the usage state of the projection display device 1.

  The series of procedures shown in FIG. 5 can be executed by controlling the projection display system shown in FIG. 1 by a program of an algorithm equivalent to FIG. This program may be stored in the storage unit 42, for example. In addition, the program can be stored in a computer-readable recording medium, and the recording medium can be read into the storage unit 42 to execute a series of procedures according to the embodiment of the present invention. Here, the “computer-readable recording medium” means a medium that can record a program such as a computer memory, a magnetic disk, and an optical disk. Specifically, a memory card, a CD-ROM, and the like are included in the “computer-readable recording medium”.

(Second Embodiment)
In the projection display system according to the second embodiment of the present invention, as shown in FIG. 6, the CPU 41 of the control unit 4 includes, in addition to the drive module 101, the rotation speed calculation module 102, and the rotation speed determination module 103. The present embodiment is different from the first embodiment in that an inversion determination module 201, an inversion count calculation module 202, and an inversion count determination module 203 are provided.

  The inversion determination module 201 determines whether or not the polarity of the shielding signal output from the rotation phase detection unit 6 is inverted.

  The inversion count calculation module 202 functions as a timer for calculating (counting) the number of times that the polarity of the shielding signal is determined to be inverted by the inversion determination module 201 (hereinafter referred to as “inversion count”).

  The inversion number determination module 203 reads a predetermined threshold β from the storage unit 42, determines whether the inversion number calculated by the inversion number calculation module 202 exceeds the predetermined threshold β, and the inversion number is equal to the predetermined threshold value. When it is determined that β is exceeded, the shutter 5 is stopped.

  Since the other configuration of the projection display system according to the second embodiment of the present invention is substantially the same as that of the first embodiment of the present invention, a duplicate description is omitted.

  Next, an example of a method for stopping the shutter 5 according to the second embodiment of the present invention will be described with reference to the flowchart of FIG.

  (A) First, in the same manner as the steps S101 and S102 shown in FIG. 5, the braking process is performed in steps S201 and S202. When the number of rotations of the shutter 5 is less than the predetermined threshold value α, the process proceeds to step S203.

  (B) In step S203, the number of inversions calculated (counted) by the inversion number calculating module 202 is cleared. In step S <b> 204, the drive module 101 determines whether the polarity of the shielding signal output from the rotational phase detection unit 6 is “High” or “Low”. If it is determined as “High”, since the projection light is blocked, the drive module 101 outputs a drive signal so that the shutter 5 rotates in the normal rotation in step S205. If it is determined as “Low”, since the projection light is transmitted, in step S206, the drive module 101 outputs a drive signal so that the shutter 5 rotates in the reverse direction.

  (C) In each of steps S207 and S208, the reversal determination module 201 determines whether or not the previous shielding state is reversed (different) from this time. If it is determined that the rotation has been reversed, the reversal count calculation module 202 adds 1 to the counted reversal count in steps S209 and S210, respectively. In step S211, the inversion number determination module 203 determines whether or not the inversion number calculated by the inversion number calculation module 202 has exceeded a predetermined threshold value β. If it is determined that the threshold value β has been exceeded, the shutter 5 determines that the desired position control has been performed, and a drive complete stop process is performed in step S212.

  According to the projection display system according to the second embodiment of the present invention, the threshold value α of the rotation speed of the braking process, the drive output set in steps S205 and S206, and the determination in step S211 are used. The stop position control of the shutter 5 can be performed with sufficient accuracy by setting the threshold value β of the inversion number calculation module 202 to be an appropriate value.

(Third embodiment)
In the projection display system according to the third embodiment of the present invention, as shown in FIG. 8, the CPU 41 of the control unit 4 includes, in addition to the drive module 101, the rotation speed calculation module 102, and the rotation speed determination module 103. The difference from the first embodiment of the present invention is that it includes an inversion interval measurement module 301 and an inversion interval determination module 302.

  The inversion interval measurement module 301 measures an interval until the polarity of the shielding signal output from the rotation phase detector 6 is inverted (hereinafter referred to as “polarity inversion interval”).

  The inversion interval determination module 302 reads the predetermined threshold β from the storage unit 42, determines whether the polarity inversion interval measured by the inversion interval measurement module 301 is less than the predetermined threshold β, and the polarity inversion interval is the predetermined threshold. If it is determined that it is less than β, the shutter 5 is stopped.

  The other configuration of the projection display system according to the third embodiment of the present invention is substantially the same as that of the first embodiment of the present invention, and thus the duplicated description is omitted.

  Next, an example of a method for stopping the shutter 5 according to the third embodiment of the present invention will be described with reference to the flowchart of FIG.

  (A) First, in the same manner as the steps S101 and S102 shown in FIG. 5, the braking process is performed in steps S301 and S302. When the number of rotations of the shutter 5 is less than the predetermined threshold value α, the process proceeds to step S303.

  (B) In step S303, the inversion interval measurement module 301 starts an interrupt process for measuring the polarity inversion interval. This measurement is processed in parallel independently of the subsequent routines, and the polarity inversion interval is updated as needed. The interrupt process will be described with reference to the flowchart of FIG. First, in step S309, when the polarity of the shielding signal output from the rotation phase detection unit 6 is inverted, the inversion interval measurement module 301 ends the measurement of the polarity inversion interval that was started in the previous interruption. In step S310, the measured polarity inversion interval is stored in the storage unit. In step S311, the inversion interval measurement module 301 newly starts measuring the polarity inversion interval. An interruption occurs whenever the polarity reversal of the shielding signal is triggered, and the polarity reversal interval is always updated to the latest by performing the above processing.

  (C) In step S304 shown in FIG. 9, the drive module 101 determines the polarity of the shielding signal output from the rotational phase detector 6. In the case of “High”, since the projection light is shielded, in step S305, the drive module 101 outputs a drive signal so that the shutter 5 rotates in the normal rotation. In the case of “Low”, since the projection light is transmitted, in step S306, the drive module 101 outputs a drive signal so that the shutter 5 rotates in the reverse direction. In this way, by outputting a forward or reverse drive signal according to the polarity of the shielding signal, the shutter 5 gradually approaches the position where the shielding signal in the rotational phase detection unit 6 is just switched, and the movement of the shutter 5 Converges toward a predetermined stop position, so that the polarity inversion interval of the shielding signal is gradually reduced.

  (D) In step S307, the inversion interval determination module 302 reads the latest polarity inversion interval from the storage unit 42, and determines whether the polarity inversion interval is less than a predetermined threshold β. If it is less than the predetermined threshold β, the shutter 5 determines that the desired position control has been performed, and in step S308, complete driving stop processing including termination of the polarity inversion interval measurement interrupt is performed.

  According to the projection display system according to the third embodiment of the present invention, the threshold value α of the rotation speed of the braking process, the drive output set in steps S305 and S306, and the determination in step S307 are used. By setting the threshold value β of the polarity inversion interval of the shielding signal to an appropriate value, the stop position control of the shutter 5 can be performed with sufficient accuracy.

(Fourth embodiment)
In the first to third embodiments of the present invention, depending on the system, there is a possibility that the position control cannot be completely converged with a fixed driving torque. Therefore, in the fourth embodiment of the present invention, an example in which the drive torque is changed during the shutter 5 stop process will be described.

  In the projection display system according to the fourth embodiment of the present invention, as shown in FIG. 11, the CPU 41 of the control unit 4 includes, in addition to the drive module 101, the rotation speed calculation module 102, and the rotation speed determination module 103. The point provided with the torque change module 401 and the torque determination module 402 is different from the first embodiment of the present invention.

  The torque changing module 401 changes the driving torque of the motor unit 7 every time the polarity of the shielding signal output from the rotation phase detecting unit 6 is reversed.

  The torque determination module 402 determines whether or not the driving torque of the motor unit 7 is less than the predetermined threshold value β, and stops the shutter 5 when it is determined that the driving torque is less than the predetermined threshold value β.

  Since the other configuration of the projection display system according to the fourth embodiment of the present invention is substantially the same as that of the first embodiment of the present invention, the redundant description is omitted.

  Next, an example of a method for stopping the shutter 5 according to the fourth embodiment of the present invention will be described with reference to the flowchart of FIG.

  (A) First, the braking process is performed in steps S401 and S402 in the same manner as the steps S101 and S102 shown in FIG. If the number of rotations of the shutter 5 is less than the predetermined threshold value α, the process proceeds to step S403.

  (B) In step S403, the drive module 101 determines whether the polarity of the shielding signal output from the rotational phase detector 6 is “High” or “Low”. If it is determined as “High”, in step S <b> 404, the inversion determination module 201 determines whether or not the previous shielding state is inverted with respect to this time. If reversed, in each step S406, the torque changing module 401 performs a process of reducing the driving torque of the motor.

  (C) After that, if it is determined in step S403 that the shielding signal is “High”, in step S408, the drive module 101 outputs a drive signal in the normal rotation direction. On the other hand, if it is determined in step S403 that the shielding signal is “Low”, in step S409, the drive module 101 outputs a drive signal in the reverse direction. If the setting of the drive torque is changed in steps S406 and S407, it is reflected at this time. Since the driving torque gradually decreases every time the shielding signal is reversed, the shutter 5 stops toward the target position while slowing down the movement. This process facilitates the convergence of the shutter 5 operation in the stop process.

  (D) Thus, in step S410, the torque determination module 402 determines whether or not the motor drive torque is less than a predetermined threshold value β. If it is determined that it is less than the predetermined threshold β, it is determined that the shutter 5 has been subjected to the desired position control, and the torque determination module 402 performs a drive complete stop process in step S411.

  According to the projection display system according to the fourth embodiment of the present invention, the threshold value α of the number of revolutions of the braking process, the reduction range of the driving torque in steps S406 and S407, and the determination in step S410 are used. The stop position control of the shutter 5 can be performed with sufficient accuracy by setting the threshold value β of the driving torque to be an appropriate value.

(Fifth embodiment)
In the first to fourth embodiments of the present invention, since no stop device dedicated to the shutter 5 is provided, after the shutter 5 is stopped at a desired position, some force is applied from the outside, and the shutter 5 is moved from a predetermined position. There is a possibility to move. In the fifth embodiment of the present invention, a process for returning to a desired stop position again when the shutter 5 moves from a predetermined position will be described.

  As shown in FIG. 13, the projection type display system according to the fifth embodiment of the present invention is such that the CPU 41 of the control unit 4 further includes a polarity change determination module 501. Different from form.

  The polarity change determination module 501 determines whether the polarity of the shielding signal detected during the stop period of the shutter 5 is different from the polarity of the shielding signal when the shutter 5 is stopped. The storage unit 42 stores the polarity of the shielding signal detected when the shutter 5 is stopped. When the polarity change determination module 501 determines that the polarity of the shield signal detected during the shutter 5 stop period is different from the polarity of the shield signal stored in the storage unit 42, the shutter 5 stop process is re-executed. To do.

  Since the other configuration of the projection display system according to the fifth embodiment of the present invention is substantially the same as that of the first embodiment of the present invention, a duplicate description will be omitted.

  Next, an example of a method for stopping the shutter 5 according to the fifth embodiment of the present invention will be described with reference to the flowchart of FIG.

  (A) After the shutter 5 is stopped at a desired position by the procedure of steps S101 to S108 shown in FIG. 5, the polarity of the shielding signal at that time is stored in the storage device in step S501.

  (B) In step S502, the polarity change determination module 501 constantly monitors (polls) the polarity of the shielding signal output by the rotation phase detector 6, and the polarity of the shielding signal output when the shutter 5 is stopped. It is determined whether it has changed. If the polarity has changed, it is determined that the shutter 5 has moved, and the complete drive stop is canceled in step S503.

  (C) Thereafter, the shutter 5 can be stopped again at a desired position by performing the shutter 5 stop processing in steps S101 to S108 shown in FIG.

  According to the projection display system according to the embodiment of the present invention, after the shutter 5 is stopped, even if some force is applied from the outside and the shutter 5 moves from a predetermined position, the shutter 5 is returned to an appropriate stop position again. Can do.

  In place of the procedure of steps S101 to S108 shown in FIG. 5, the procedure of steps S201 to S212 shown in FIG. 7, the procedure of steps S301 to S308 shown in FIG. 9, or the steps S401 to S401 shown in FIG. You may perform the procedure of S411.

(Other embodiments)
As described above, the present invention has been described according to the first to fifth embodiments. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, it is possible to provide an inexpensive and simple stopper that suppresses the shielding portion 51 of the shutter 5 and stop the shutter 5 with the stopper so that the shutter 5 does not move after the stop position control is completed. .

  The intermittent display device 3 shown in FIG. 1 may be detachably attached to the projection display device 1. In addition, all or part of the components of the intermittent display device 3 can be incorporated in the projection display device 1. Further, the projection display device 1 may be configured to include the intermittent display device 3.

  Further, the modules of the CPU 51 described in each of the first to fifth embodiments can be used in appropriate combination with each other.

  As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

  The intermittent display device and the projection display system according to the present invention can improve the moving image performance and ensure the brightness at the time of displaying a still image, and thus can be used for a projector used in a home theater or a presentation.

1. Projection type display device (projector)
3. Intermittent display device (mechanical shutter)
DESCRIPTION OF SYMBOLS 4 ... Control part 5 ... Shutter 6 ... Rotation phase detection part 7 ... Motor part 8 ... Shaft 11 ... Main body 12 ... Projection lens 13 ... Light source 14 ... Light modulation part 41 ... Central processing unit (CPU)
DESCRIPTION OF SYMBOLS 42 ... Memory | storage part 51 ... Shielding part 52 ... Transmission part 101 ... Drive module 102 ... Rotational speed calculation module 103 ... Rotational speed determination module 104 ... Processing time measurement module 105 ... Processing time determination module 201 ... Inversion determination module 202 ... Inversion number calculation Module 203... Reverse count determination module 301. Reverse interval measurement module 302. Reverse interval determination module 401. Torque change module 402. Torque determination module 501. Polarity change determination module

Claims (8)

An intermittent display device capable of intermittently displaying an image of projection light projected by a projection display device,
A shutter rotatable to periodically shield the projection light;
A motor unit for driving the shutter;
A rotational phase detector that detects a rotational phase of the shutter and outputs a signal having a polarity corresponding to the rotational phase;
A controller that controls the shutter so that the shutter stops at a position where the projection light is not shielded according to the polarity of the shielding signal when the shutter is stopped from the rotation state. Display device. The control unit is
A driving module that drives the shutter so that the shutter approaches a position where the projection light is not shielded according to the polarity of the shielding signal;
A processing time measuring module for measuring a stop processing time for driving the shutter by the driving module;
A processing time determination module that determines whether or not the stop processing time has reached a predetermined threshold and stops the shutter when it is determined that the stop processing time has reached a predetermined threshold. The intermittent display device according to claim 1, wherein the display device is an intermittent display device. The control unit is
A driving module that drives the shutter so that the shutter approaches a position where the projection light is not shielded according to the polarity of the shielding signal;
An inversion determination module for determining whether the polarity of the shielding signal is inverted;
An inversion number calculating module for calculating an inversion number determined that the polarity of the shielding signal is inverted;
And a reversal number determination module for stopping the shutter when it is determined whether or not the reversal number exceeds a predetermined threshold value and the reversal number exceeds a predetermined threshold value. Item 8. An intermittent display device according to Item 1. The control unit is
A driving module that drives the shutter so that the shutter approaches a position where the projection light is not shielded according to the polarity of the shielding signal;
An inversion interval measuring module for measuring a polarity inversion interval until the polarity of the shielding signal is inverted;
A reversal interval determination module that determines whether or not the polarity reversal interval is less than a predetermined threshold and stops the shutter when the polarity reversal interval is determined to be less than a predetermined threshold. Item 8. An intermittent display device according to Item 1. The control unit is
A driving module that drives the shutter so that the shutter approaches a position where the projection light is not shielded according to the polarity of the shielding signal;
A torque changing module that changes the driving torque of the motor unit each time the polarity of the shielding signal is reversed;
2. A torque determination module that determines whether or not the drive torque is less than a predetermined threshold and stops the shutter when the drive torque is determined to be less than the predetermined threshold. The intermittent display device described. The control unit is
A storage unit for storing the polarity of the shielding signal detected when the shutter is stopped;
A polarity change determination module that determines whether the polarity of the shielding signal detected during the shutter stop period is different from the polarity of the shielding signal stored in the storage unit;
When it is determined that the polarity of the shielding signal detected during the shutter stop period is different from the polarity of the shielding signal detected when the shutter is stopped, the shutter stop process is re-executed. The intermittent display device according to claim 1, wherein: The control unit is
A rotational speed calculation module for calculating the rotational speed of the shutter based on the polarity of the shielding signal;
A rotation speed determination module that determines whether or not the rotation speed is less than a predetermined threshold;
5. The intermittent display device according to claim 2, wherein the drive module decelerates the rotation of the shutter until it is determined that the rotation speed is less than a predetermined threshold value. A projection display device for projecting projection light;
An intermittent display device capable of intermittently displaying an image of the projection light, wherein the shutter is rotatable so as to periodically shield the projection light, a motor unit that drives the shutter, and a rotation phase of the shutter And a position where the shutter does not block the projection light according to the polarity of the shielding signal when the shutter is stopped from the rotating state. A projection display system comprising: an intermittent display device including a control unit that controls the shutter so as to stop.

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