JP2012181339A - Image projection device, control method of the same and control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image projection device capable of accurately returning a focus lens to a position before a reset where a state in focus is maintained, after the reset.SOLUTION: A projector 100 includes: a storage part 104 for storing a reference movement amount F from a set position set on an optical axis of a projector lens 111 to a reference position to which a focus lens 111a is moved based on input operation, and reference temperature C when the focus lens is moved to the reference position; and a control part 105 for controlling a driving part 101 so as to, when the focus lens is returned from a position where the focus lens was retracted at the time of reset, move the focus lens from the set position by a movement amount obtained by adding a correction movement amount B, corresponding to a difference between temperature at the time of the reset and the reference temperature C, to the reference movement amount.

Description

  The present invention relates to an image projection apparatus such as a liquid crystal projector, a control method thereof, and a control program.

  If the temperature changes after the user moves the focus lens of the projection lens to the in-focus position, the temperature correction function that maintains the in-focus state by moving the focus lens in the direction of the optical axis by an amount corresponding to the temperature change An image projection apparatus including the above is known. On the other hand, an image projection apparatus having a reset function for returning a focus lens to a focus position before reset after reset such as restart is also known. For example, Patent Document 1 stores the amount of movement from the in-focus position to the mechanical end when the photographic lens is moved from the in-focus position to the mechanical end during reset and returned to the in-focus position, and after reaching the mechanical end. A camera that returns to the in-focus position based on the amount of movement is disclosed.

Japanese Patent Laid-Open No. 7-261071

  However, since Patent Document 1 does not consider the temperature, the return position of the focus lens is shifted from the in-focus position by the amount of change between the temperature before resetting and the temperature at resetting, and the projected image is out of focus.

  An object of the present invention is to provide an image projection apparatus, a control method thereof, and a control program capable of accurately returning a focus lens to a position where the focus state before reset is maintained after reset.

  An image projection apparatus according to the present invention is an image projection apparatus that projects an image through a projection lens, and obtains a driving unit that drives a focus lens of the projection lens and a movement amount of the focus lens by the driving unit. Movement amount acquisition means, temperature detection means for detecting temperature, and movement amount acquisition from a set position set on the optical axis of the projection lens to a reference position where the focus lens is moved based on an input operation Storage means for storing a reference movement amount that is a movement amount acquired by the means, a reference temperature that is a temperature detected by the temperature detection means when moved to the reference position, and the focus lens is retracted at reset When returning from the position, the temperature detected by the temperature detection means at the time of reset and the reference temperature stored in the storage means The focus lens is moved from the set position by a movement amount obtained by adding a first correction movement amount for correcting fluctuations in the focus position of the focus lens corresponding to the difference between the reference movement amount stored in the storage means. Control means for controlling the drive means so as to be moved.

  According to the present invention, it is possible to provide an image projection apparatus that can accurately return the focus lens to a position that maintains the in-focus state before the reset, and a control method and control program thereof.

It is a block diagram of the image projection apparatus of this invention. Example 1 It is a flowchart for demonstrating the control method of the control part shown in FIG. 1 in focus drive. Example 1 It is a flowchart for demonstrating the control method of the control part shown in FIG. 1 in reset drive. (Example 2) It is a flowchart for demonstrating the control method of the control part in focus drive. Example 1 It is a flowchart for demonstrating the control method of the control part in reset drive. (Example 2)

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

  FIG. 1 is a block diagram of a projector 100 (image projection apparatus) according to the first embodiment. The projector 100 is an image projection apparatus that projects light (that is, an image) modulated by an image display element such as a liquid crystal panel in accordance with an input image signal onto a projection surface such as a screen through a projection lens 111 as a projection image. is there. In this case, the light emitted from the light source 115 passes through the illumination optical system 114 and forms an image in the color separation / synthesis system 113.

  The projector 100 includes a drive unit 101, a movement amount acquisition unit 102, a temperature sensor 103, a storage unit 104, a control unit 105, a projection lens 111, a lens mount 112, a color separation / synthesis system 113, a light source (lamp) 115, and an exhaust port 116. Have.

  The drive unit (drive unit) 101 drives the focus lens 111 a of the projection lens 111.

  The movement amount acquisition unit (movement amount acquisition means) 102 acquires the movement amount (relative amount) of the focus lens 111a on the optical axis, and is configured by a rotary encoder in this embodiment. The projector 100 of this embodiment is configured at low cost because it does not use acquisition means that can acquire the absolute position of the focus lens 111a. The rotary encoder of the present embodiment includes a disk-shaped scale having a large number of openings formed in the circumferential direction and rotating with the movement of the focus lens 111a, and a light emitting element and a light receiving element having an optical path on the opening. Have. The amount of movement of the focus lens 111a is obtained by counting the number of H level and L level pulses output from the light receiving element.

  The temperature sensor 103 is temperature detecting means for detecting temperature. In the present embodiment, the temperature sensor 103 is disposed in the lens mount 112, the color separation / synthesis system 113, and the exhaust port 116, and the lens mount 112, the color separation / synthesis system 113, and the exhaust port 116 are arranged. Detect temperature.

  The storage unit (memory) 104 stores a control program for a control method to be described later and various types of data used therein, for example, the movement amount of the focus lens 111a acquired by the movement amount acquisition unit 102, the temperature detected by the temperature sensor 103, and the like. Remember.

  A control unit (control unit) 105 controls each unit of the image projection apparatus, and is configured as a microcomputer in this embodiment. The control unit 105 acquires information from the movement amount acquisition unit 102, the temperature sensor 103, and the storage unit 104, and controls the drive unit 101 based on these information.

  When the user performs an input operation to move the focus lens 111a to the reference position, the control unit 105 controls the drive unit 101 according to the input operation. Here, the reference position is an arbitrary position on the optical axis of the projection lens 111, for example, a focus position of the focus lens 111a.

  First, as a premise, a set position is set at an arbitrary position on the optical axis of the projection lens 111. The setting position is a home position from which the movement amount of the focus lens 111a is calculated. When the focus lens 111a is at the setting position, the movement amount of the focus lens 111a acquired by the movement amount acquisition unit 102 is zero. This is because the movement amount acquisition unit 102 can only acquire a movement amount that is not an absolute position but a relative amount.

  Then, the control unit 105 stores in the storage unit 104 a reference movement amount that is a movement amount from the set position to the reference position and a reference temperature that is a temperature of the focus lens 111a detected by the temperature sensor 103 at that time.

  The projector 100 also has a temperature correction function and a reset function.

  In the temperature correction, the control unit 105 is driven so as to move the focus lens 111a from the reference position by the correction movement amount A corresponding to the temperature change when the focus lens 111a changes in temperature after moving to the reference position. The unit 101 is controlled.

  The correction movement amount A is a change in the focus position of the focus lens 111a depending on the difference between the current temperature detected by the temperature sensor 103 and the temperature detected by the temperature sensor 103 (reference temperature C described later) when the temperature is moved to the reference position. Is a movement amount (second correction movement amount) for correcting. The current temperature is a temperature detected by the temperature sensor 103 at the current position of the focus lens 111a. The current position of the focus lens 111a is usually one of a reference position, a position corrected for temperature from the reference position, and a set position.

  In this embodiment, the temperature sensor 103 detects the temperature at a position slightly away from the focus lens 111 a and estimates the temperature of the focus lens 111 a from the three temperature sensors 103. Of course, a temperature sensor may be arranged in the vicinity of the focus lens 111a.

  On the other hand, the reset is performed by operating a reset switch (not shown), restarting, turning on the power, or the like. When the reset operation is performed, the control unit 105 causes the focus lens 111a to be retracted from the current position (that is, the reference position or the temperature corrected position) to the retracted position (for example, the mechanical end or other position). The drive unit 101 is controlled.

  For example, when there is no temperature correction after the focus lens 111a is moved to the reference position, the current position is the reference position, and therefore the control unit 105 causes the focus lens 111a to be retracted from the reference position to the retracted position. To control. Then, the control unit 105 returns the focus lens 111a to the position before reset from the position retracted at the time of reset after reset.

  As described above, the position before reset is the reference position or a position where the temperature correction is performed on the reference position, which is the focus position of the focus lens 111a. And the position returned after reset is a position which maintained the focus state before reset.

  That is, if the temperature of the focus lens 111a before and after the reset is the same, the position returned after the reset is the same as the position before the reset. However, if the temperature of the focus lens 111a before and after the reset is different, the position returned after the reset is a position where the temperature correction corresponding to the temperature change is applied to the position before the reset. The temperature change here is a difference between the temperature detected by the temperature sensor 103 at the time of reset (current temperature) and the temperature detected by the temperature sensor 103 before the reset (reference temperature).

  A description will be given of the control performed by the control unit 105 at the time of resetting when there is no temperature correction before resetting. If there is no temperature correction before resetting, the position before resetting is the reference position. In this case, the control unit 105 controls the drive unit 101 to move the focus lens from the set position by a predetermined movement amount. Here, the “predetermined movement amount” is a reference movement amount that is a correction movement amount B for correcting fluctuations in the focus position of the focus lens corresponding to the difference between the temperature at reset (current temperature) and the reference temperature. The amount of movement added to. The correction movement amount B is a movement amount (first correction movement amount) for correcting the fluctuation of the focus position of the focus lens 111a based on the difference between the temperature at the time of reset and the reference temperature. As a result, the position where the focus lens 111a returns can maintain the same in-focus state as the position before the reset, and the projected image can maintain the focused state.

  On the other hand, when the temperature correction is performed before the reset, the position before the reset is a position obtained by correcting the temperature of the reference position. Assuming that the movement amount from the set position to the reference position is the movement amount L, in this case, the control unit 105 obtains a movement amount obtained by subtracting the correction movement amount A from the movement amount L, and adds the correction movement amount B to the movement amount. The drive unit 101 is controlled to move the focus lens from the set position by the amount of movement. As a result, the position where the focus lens 111a returns after resetting can maintain the same in-focus state as the position before resetting, and the projected image can maintain the focused state.

  Note that the combination of the addition and subtraction calculation of the correction movement amount A and the correction movement amount B with respect to the movement amount L or the reference position is not limited to the description in the embodiment. In view of the moving direction of the focus lens with reference to the reference position, it may be determined whether to add or subtract the correction movement amount.

  FIG. 2 is a flowchart for explaining a control method executed by the control unit 105 in focus driving for driving the focus lens 111a and focusing, and “S” is an abbreviation of a step. The control method shown in FIG. 2 and the following drawings can be embodied as a control program for causing a computer to realize the function.

  First, the control unit 105 controls the drive unit 101 to move the focus lens 111a by a specified amount (S201). Next, the control unit 105 determines whether the drive of the focus lens 111a is performed by the user or by temperature correction (S202).

  In the case of driving by a user input operation, the control unit 105 sets the focus driving flag to ON (S203), sets the corrected movement amount A to 0, and stores it in the storage unit 104 (S204). In addition, the control unit 105 stores a movement amount (reference movement amount) from a setting position (not shown) to a reference position with the position of the focus lens 111a at this time as a reference position (focusing position) F in the storage unit 104. Next, the control unit 105 stores the temperature (for example, 23 ° C.) of the focus lens 111a detected by the temperature sensor 103 at this time as the reference temperature C in the storage unit 104 (S205).

  On the other hand, when the temperature rises to 30 ° C. after the focus lens 111a moves to the reference position (focus position) at 23 ° C., focus drive is performed by temperature correction. When focus driving is performed by temperature correction, the control unit 105 stores the movement amount of the focus lens 111a from the reference position in the storage unit 104 as the correction movement amount A (S206), and proceeds to S205.

  The movement amount at this time is a movement amount for correcting a defocus due to a difference (temperature change) of 23 ° C. which is a temperature when the focus lens 111a is moved from the current temperature 30 ° C. to the reference position. . In this embodiment, the current temperature (30 ° C.) is not stored as the reference temperature C in the focus drive by temperature correction, but this temperature may be stored.

  The process ends after S205 or S206.

  FIG. 3 is a flowchart for explaining a control method executed by the control unit 105 in reset driving for returning the focus lens 111a from the retracted position after resetting, and “S” is an abbreviation of step.

  As a premise, the control unit 105 measures the movement amount L from the position of the focus lens 111a before the reset to the set position using the movement amount acquisition unit 102 (S301). Next, the control unit 105 determines whether the last focus driving is performed by the user or by temperature correction (S302).

  In the case of focus drive by temperature correction, the control unit 105 loads the corrected movement amount A from the storage unit 104 (S303), and sets the reference movement amount F based on the corrected movement amount A and the movement amount L to F = L−. A is calculated as A (S304), and the reference movement amount F is stored in the storage unit 104 (S305). In the above example, the reference movement amount F is the reference position (focus position) at 23 ° C.

  On the other hand, in the case of focus drive by the user, the control unit 105 loads the reference movement amount F stored in the storage unit 104 because the reference movement amount F is the same as the previously calculated value (S306).

  After S305 or S306, the control unit 105 reads the reference temperature C stored in the storage unit 104 (S307). In the above example, the reference temperature C is 23 ° C. Next, the control unit 105 calculates a corrected movement amount B corresponding to the difference between the reference temperature C and the current temperature detected by the temperature sensor 103 at the time of reset (S308). When the temperature sensor 103 detects the current temperature in S308, the focus lens 111a is located at the set position.

  Next, the control unit 105 adds the reference movement amount F and the correction movement amount B to calculate the return movement amount P (S309), sets the focus movement flag to OFF (S310), and moves the focus lens 111a to the return position P. Move (S311).

  According to the present embodiment, the focus lens can be accurately returned to the position that maintains the in-focus state before the reset after the reset whether or not the temperature correction is applied before the reset.

  Another advantage of the present invention is that the focus lens can be moved to an appropriate position even in an image projection apparatus such as a liquid crystal projector that does not have an AF function.

  The image projection apparatus according to the second embodiment has the same configuration as that in FIG. 1, but is different from the first embodiment in that the projection lens 111 can be replaced. In this embodiment, the control content depends on whether the projection lens 111 has a temperature correction mode (or whether the temperature correction mode is valid or invalid), or has a mode corresponding to the reset function (or whether the mode is valid or invalid). Has changed.

  FIG. 4 is a flowchart for explaining a control method executed by the control unit 105 in the focus drive similar to FIG. 2, and “S” is an abbreviation of a step. FIG. 4 is the same as FIG. 2 except that S207 is performed after S201.

  That is, similarly to S201, the control unit 105 controls the drive unit 101 to move the focus lens 111a by a specified amount (S201). When the control unit 105 drives the focus lens 111 a based on temperature characteristics, the drive amount is calculated using parameters stored in the storage unit 104.

  Next, the control unit 105 determines from the storage unit 104 whether the focus correction of the currently mounted focus lens 111a is valid or invalid (S207). The control unit 105 proceeds to S202 if the focus correction is valid, and ends the process if the focus correction is invalid.

  FIG. 5 is a flowchart for explaining a control method executed by the control unit 105 in reset driving, and “S” is an abbreviation of a step.

  First, the control unit 105 determines from the storage unit 104 whether the focus correction of the currently mounted focus lens 111a is valid or invalid (S312). If the focus correction is invalid, the control unit 105 ends the process. If the focus correction is valid, the control unit 105 loads the correction movement amount calculation parameter from the storage unit 104 after performing S301 to S307 (S313), and uses it in S308. . Thereafter, S309 to S311 are performed.

  In this embodiment, the storage unit built in the image projection apparatus main body is used. However, the storage unit may be arranged inside the interchangeable projection lens 111.

  Even in this embodiment, in an image projection apparatus having an interchangeable projection lens, the focus lens is accurately maintained after the reset in a focused state before the reset even if the temperature correction is not applied before the reset. Can be restored.

  Although the temperature detection means may detect the temperature of the focus lens itself, the temperature of the focus lens is estimated by detecting the temperature of the optical system located closer to the light source than the lens mount part of the projection lens and the projection lens. May be. In this case, the temperature of the focus lens may be determined by using the temperature detected by the temperature detection unit and information that can be used to estimate the temperature of the focus lens stored in the storage unit in advance.

  As mentioned above, although the preferable Example of this invention was described, this invention is not limited to these Examples, A various deformation | transformation and change are possible within the range of the summary.

  The image projection apparatus can be applied to a projector application.

100 Projector (image projection device)
101 Drive unit (drive means)
102 Movement amount acquisition unit (movement amount acquisition means)
104 Storage section (storage means)
105 Control unit (control means)
116 Temperature sensor (temperature detection means)

Claims (9)

An image projection device that projects an image through a projection lens,
Driving means for driving a focus lens of the projection lens;
A movement amount acquisition means for acquiring a movement amount of the focus lens by the driving means;
Temperature detecting means for detecting the temperature;
A reference movement amount, which is a movement amount detected by the movement amount acquisition means, from a setting position set on the optical axis of the projection lens to a reference position where the focus lens is moved based on an input operation; Storage means for storing a reference temperature, which is a temperature detected by the temperature detection means when moved to a reference position;
When the focus lens is returned from the position retracted at the time of reset after the reset, the focus lens corresponding to the difference between the temperature detected by the temperature detection means at the time of reset and the reference temperature stored in the storage means. The drive unit is controlled to move the focus lens from the set position by a movement amount obtained by adding a first correction movement amount for correcting fluctuations in the focal position to the reference movement amount stored in the storage unit. Control means;
An image projection apparatus comprising: The projection lens has a mode for returning the focus lens to a focus position at the time of the reset,
The image projection apparatus according to claim 1, wherein the control unit controls the driving unit to return the focus lens to a focus position when the mode is valid. The control unit corrects a change in a focus position of the focus lens corresponding to a difference between the temperature detected by the temperature detection unit and the reference temperature after the focus lens is moved to the reference position. Controlling the driving means to move the focus lens from the reference position by a second correction movement amount of
The storage means further stores the second correction movement amount,
The control means, after resetting, causes the driving means to move the focus lens from the set position by a movement amount obtained by adding the first correction movement amount to the reference movement amount and subtracting the second correction movement amount. The image projection apparatus according to claim 1, wherein the image projection apparatus is controlled. The projection lens has a temperature correction mode for correcting a change in a focus position of the focus lens due to a temperature change after the focus lens is moved to the reference position;
The control means controls the driving means to move the focus lens from the reference position by the second correction movement amount when the temperature correction mode is enabled. 4. The image projection apparatus according to 3. The projection lens is configured to be replaceable with the image projection device,
The image projection apparatus according to claim 1, wherein the storage unit is provided in the projection lens. A control method for an image projection apparatus, comprising: a driving unit that drives a focus lens of a projection lens; a movement amount acquisition unit that acquires a movement amount of the focus lens by the driving unit; and a temperature detection unit that detects a temperature. And
Obtaining a reference movement amount that is a movement amount from a setting position set on the optical axis of the projection lens to a reference position to which the focus lens is moved based on an input operation;
Detecting the temperature when moved to the reference position as a reference temperature by the temperature detecting means;
When the focus lens is returned from the position retracted at the time of reset after resetting, the variation of the focus position of the focus lens corresponding to the difference between the temperature detected by the temperature detecting means at the time of reset and the reference temperature is corrected. Controlling the driving means to move the focus lens from the set position by a movement amount obtained by adding a first correction movement amount for the reference movement amount;
A control method characterized by comprising: After the focus lens is moved to the reference position, a second correction movement for correcting a change in the focus position of the focus lens corresponding to the difference between the temperature detected by the temperature detection means and the reference temperature. Controlling the drive means to move the focus lens from the reference position by an amount;
Controlling the driving means to move the focus lens from the set position by a movement amount obtained by adding the first correction movement amount to the reference movement amount and subtracting the second correction movement amount;
The control method according to claim 6, further comprising: In an image projection apparatus comprising: a driving unit that drives a focus lens of a projection lens; a movement amount acquisition unit that acquires a movement amount of the focus lens by the driving unit; a temperature detection unit that detects a temperature; and a computer. On the computer,
A function for acquiring a reference movement amount, which is a movement amount from a setting position set on the optical axis of the projection lens to a reference position to which the focus lens is moved based on an input operation, from the movement amount acquisition unit;
A function of acquiring from the temperature detection means as a reference temperature a temperature when moved to the reference position;
When the focus lens is returned from the position retracted at the time of reset after resetting, the variation of the focus position of the focus lens corresponding to the difference between the temperature detected by the temperature detecting means at the time of reset and the reference temperature is corrected. A function of controlling the driving means to move the focus lens from the set position by a movement amount obtained by adding a first correction movement amount for the reference movement amount;
Control program to realize. After the focus lens is moved to the reference position, a second correction movement for correcting a change in the focus position of the focus lens corresponding to the difference between the temperature detected by the temperature detection means and the reference temperature. A function of controlling the driving means to move the focus lens from the reference position by an amount;
A function of controlling the driving means to move the focus lens from the set position by a movement amount obtained by adding the first correction movement amount to the reference movement amount and subtracting the second correction movement amount;
The control program according to claim 8 for realizing further.