JP2013228575A - Projector, and control method for projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further easily adjust the focus of a projector.SOLUTION: A projector 1 for projecting an image on a screen SC comprises: a zoom lens 25 configured to adjust the size of a projected image; a focus lens 24 configured to adjust the focus of the projected image with respect to the focus lens 24; a position detecting section 48 configured to detect a position of the zoom lens 25; and a focus control section 12 configured to limit a focus adjustment range for the focus lens 24 on the basis of the position of the zoom lens 25, detected by the position detecting section 48.

Description

  The present invention relates to a projector and a projector control method.

  Conventionally, a projector including a lens adjustment mechanism that performs focus adjustment and zoom adjustment is known (see, for example, Patent Document 1). This type of projector adjusts electric focus, electric zoom, and electric lens shift according to the operation of the remote controller.

JP 2011-227119 A

In a projector that does not have an autofocus mechanism, the user performs focus adjustment by operating the remote controller while visually confirming the focus state. However, it is not easy to determine in which direction the focus should be moved by looking at the out-of-focus state. For this reason, a user who is not familiar with the operation takes time to adjust the focus.
As an optical lens used in a projector, a varifocal lens in which a focus position moves when an optical magnification is changed is known. Employing a varifocal lens has advantages such as making the optical system compact and easily obtaining high optical performance, but it is also necessary to adjust the focus when the magnification is changed. In this case, it is necessary to adjust the focus in consideration of the direction of movement of the focus position accompanying the movement of the zoom, and it is not easy for an unfamiliar user to adjust.
The present invention has been made in view of the above-described circumstances, and an object thereof is to make it easier to adjust the focus of a projector.

In order to achieve the above object, a projector of the present invention is a projector that projects an image, a zoom lens that adjusts the size of the projected image, and a focus lens that adjusts the focus of the projected image; A position detection unit that detects a position of the zoom lens; and a focus control unit that limits a focus adjustment range of the focus lens based on the position of the zoom lens detected by the position detection unit. Features.
According to the present invention, by restricting the focus adjustment range based on the position of the zoom lens, a large deviation of the focus position can be prevented. Thereby, for example, when the focus adjustment is necessary due to the movement of the zoom lens, the focus adjustment can be completed quickly.

In the projector according to the aspect of the invention, the focus control unit may set the focus adjustment range to a range including at least a range corresponding to a projection distance set in advance in the projector.
According to the present invention, when the projection distance of the projector or the range of the projection distance is set in advance, the focus adjustment range is limited so that the focus can be adjusted within the range corresponding to the projection distance. For this reason, even if the focus adjustment range is limited, the focus adjustment range does not become practically narrow, so that quick focus adjustment is possible without impairing convenience.

In the projector according to the aspect of the invention, the position detection unit may detect the position of the zoom lens as an absolute position with respect to a reference provided in advance.
According to the present invention, since the position of the zoom lens can be detected as an absolute position, for example, a process for obtaining a relative position from a comparison with the position detected last time, the actual position of the zoom lens and the detected position are matched. Learning processing and adjustment for each projector are not necessary.

The present invention is the projector described above, further comprising an operation detection unit that detects an operation from the outside, and a drive unit that moves the focus lens, and the focus control unit is detected by the operation detection unit. According to an operation, the driving unit is operated within a range corresponding to the focus adjustment range.
According to the present invention, since the focus lens is moved within the limited focus adjustment range according to the user's operation, it is possible to prevent the user from being aware of the focus adjustment range and to prevent a large deviation of the focus position.

The present invention is the above projector, wherein the focus control unit limits the focus adjustment range based on a table that associates the position of the zoom lens detected by the position detection unit with the focus adjustment range. It is characterized by doing.
According to the present invention, the focus adjustment range corresponding to the position of the zoom lens can be quickly set.

Further, the present invention is the above projector, wherein the zoom lens and the focus lens are varifocal lenses (variable focus lenses) that change a focus position with a projected image when a position of the zoom lens is changed. ).
According to the present invention, it is possible to quickly complete the focus adjustment required in accordance with the movement of the zoom lens, so that the optical system of the projector can be reduced in size and the optical performance can be improved without impairing the convenience of the projector. realizable.

In order to achieve the above object, the projector control method of the present invention projects an image, detects the position of a zoom lens that adjusts the size of the projected image, and detects the position of the detected zoom lens. Based on the above, the focus adjustment range of the focus lens for adjusting the focus with the projected image is limited.
According to the present invention, by restricting the focus adjustment range based on the position of the zoom lens, a large deviation of the focus position can be prevented. Thereby, for example, when it is necessary to adjust the focus by moving the zoom lens, the focus can be quickly adjusted.

  According to the present invention, a large deviation of the focus position can be prevented, and the focus can be adjusted quickly.

It is a functional block diagram of a projector. It is explanatory drawing which shows a response | compatibility with the position of a focus lens, and the state of a zoom lens, (A) is a chart which showed the response | compatibility with a projection distance and the position of a focus ring for every zoom magnification, (B) is zoom. It is a chart showing correspondence between a lens position and a focus adjustment range. It is a figure which shows the structural example of the table which matched the position of the zoom lens, and the focus adjustment range. It is a flowchart which shows operation | movement of a projector.

Embodiments to which the present invention is applied will be described below with reference to the drawings.
FIG. 1 is a block diagram illustrating a functional configuration of a projector 1 according to the embodiment. The projector 1 that projects an image onto a screen SC (projection surface) projects an image onto the screen SC based on image data D input from an external image supply device (not shown) such as a personal computer or various image players. .
The image data D input to the projector 1 may be moving image (video) data or still image data. The projector 1 may project a video on the screen SC, or may display a still image on the screen SC. It is also possible to continue projecting. In the present embodiment, a configuration in which image data D, which is digital image data, is input to the projector 1 will be described. The projector 1 may be configured to A / D convert an analog image signal input from the outside and project an image based on the analog image signal.

The projector 1 includes a projection unit 20 (display unit) that forms an optical image, and an image processing system that electrically processes an image signal input to the projection unit 20, and these units are control units. It operates according to 10 controls.
The projection unit 20 includes a light source unit 21, a light modulation device 22, and a projection optical system 23. The light source unit 21 includes a light source such as a xenon lamp, an ultra-high pressure mercury lamp, an LED (Light Emitting Diode), and a laser light source. The light source unit 21 includes a reflector and an auxiliary reflector for guiding the light from the light source to the light modulation device 22, a dimming element (not shown) for dimming the light from the light source on the path to the light modulation device 22, and the like. You may prepare. A light source driving unit 34 is connected to the light source unit 21. The light source driving unit 34 controls power supply to the light source unit 21 according to control of the control unit 10 described later, and turns on and off the light source of the light source unit 21.

  The light modulation device 22 receives a signal from an image processing system, which will be described later, and modulates the light emitted from the light source unit 21 into image light. As a specific configuration of the light modulation device 22, for example, a system using three transmissive or reflective liquid crystal panels corresponding to each color of RGB can be cited. In this case, the light emitted from the light source unit 21 is incident on the light modulation device 22 after being separated into R, G, and B color light by a dichroic mirror or the like, and each color light is provided by the liquid crystal panel of each color included in the light modulation device 22. Is modulated, and then the respective color lights are combined by the cross dichroic prism and guided to the projection optical system 23. In the present embodiment, the light modulation device 22 includes a transmissive liquid crystal panel. The light modulation device 22 is driven by a light modulation device driving unit 33 described later, and forms an image by changing the light transmittance of each pixel arranged in a matrix.

The projection optical system 23 includes a focus lens 24 for adjusting the focus with the projection image on the screen SC, and a zoom lens 25 for adjusting the size (enlargement / reduction) of the projection image. . The light modulated by the light modulation device 22 is incident on the projection optical system 23, and this light is projected on the screen SC through the focus lens 24 and the zoom lens 25 to form a projected image.
The projection optical system 23 employs a varifocal lens composed of a plurality of lens groups including a focus lens 24 and a zoom lens 25. For this reason, when the zoom lens 25 is moved to change the projection magnification, the focus lens 24 is moved and the focus is adjusted.

The projection optical system 23 is provided with a focus adjustment unit 41 and a focus ring 42. The focus adjustment unit 41 includes a focus ring 42 connected to the focus lens 24 and a motor 43 that rotates the focus ring 42. The focus ring 42 is provided in a lens barrel (not shown) of the projection optical system 23. By rotating the focus ring 42, the focus lens 24 moves along the optical axis, and the focus can be adjusted. The focus adjustment unit 41 adjusts the focus by driving the motor 43 and rotating the focus ring 42 according to the control of the control unit 10 described later.
The zoom adjustment unit 45 includes a zoom ring 46 connected to the zoom lens 25, a motor 47 that rotates the zoom ring 46, and a position detection unit 48 (position detection unit) that detects the position of the zoom ring 46. . The zoom ring 46 is provided in a lens barrel (not shown) of the projection optical system 23. By rotating the zoom ring 46, the zoom lens 25 moves along the optical axis, and the zoom magnification can be adjusted. The zoom adjustment unit 45 adjusts the zoom magnification by driving the motor 47 and rotating the zoom ring 46 according to the control of the control unit 10 described later.
The motors 43 and 47 correspond to the driving means of the present invention. The motors 43 and 47 may be stepping motors or servomotors. Furthermore, the focus adjustment unit 41 and the zoom adjustment unit 45 may be configured using various drive sources such as an ultrasonic motor, a solenoid, and a linear actuator instead of the motor.

  The focus lens 24 and the zoom lens 25 indicate functions of a lens group included in the projection optical system 23, and are not limited to a configuration in which the focus lens 24 and the zoom lens 25 can be completely distinguished. That is, any configuration may be used in which zoom adjustment and focus adjustment are performed by moving some or all of the lenses of the projection optical system 23 along the optical axis. Therefore. When the focus ring 42 is rotated, part or all of the lens group of the projection optical system 23 is moved to change the focus position. When the zoom ring 46 is rotated, part or all of the lens group of the projection optical system 23 is rotated. It is sufficient that the zoom magnification is changed by moving. In the following description, the position of the focus ring 42 when in focus is referred to as a focus position, and the position of the zoom ring 46 when set to a magnification desired by the user is referred to as a zoom position.

The image processing system of the projector 1 is configured around a control unit 10 that controls the entire projector 1 in an integrated manner. The storage unit 15 stores data processed by the control unit 10, a control program executed by the control unit 10, and the like. A signal receiving unit 16 (operation detection unit) for detecting an operation by the remote controller 50, an operation unit 17 (operation detection unit) for detecting an operation on an operation panel (not shown), an image input unit 18 to which image data D is input, an image An image processing unit 31 that processes image data input to the input unit 18, and a light modulation device drive unit 33 that performs drawing by driving the light modulation device 22 based on an image signal output from the image processing unit 31. Yes.
The control unit 10 controls each unit of the projector 1 by reading and executing the control program stored in the storage unit 15. The control unit 10 detects the content of the operation performed by the user based on the operation information input from the signal receiving unit 16 or the operation unit 17, and the image processing unit 31 and the light modulation device driving unit 33 according to this operation. The light source driving unit 34, the focus adjusting unit 41, and the focus ring 42 are controlled to project an image on the screen SC.

The signal receiving unit 16 receives and decodes a radio signal transmitted from the remote controller 50 that operates the projector 1, and detects an operation on the remote controller. The signal receiving unit 16 generates operation information corresponding to the detected operation and outputs the operation information to the control unit 10.
The operation unit 17 detects a button operation on an operation panel (not shown) of the projector 1, generates operation information indicating the detected operation, and outputs the operation information to the control unit 10. Further, the operation unit 17 controls the lighting state of the indicator lamp of the operation panel (not shown) according to the operation state and the setting state of the projector 1 according to the control of the control unit 10.

  The image input unit 18 performs a scaling process on the image data D input from the outside, and outputs the processed image data to the image processing unit 31. Here, the image input unit 18 is, for example, a VISA (Video Electronics) such as a DVI (Digital Visual Interface) interface, a USB interface and a LAN interface to which a digital video signal is input, or an HDMI connector compliant with the HDMI (registered trademark) standard. It has an interface having connectors and the like conforming to the DisplayPort (trademark) standard established by Standards Association).

  The image processing unit 31 acquires the image data output from the image input unit 18 according to the control of the control unit 10, and determines the image size or resolution, whether the image is a still image or a moving image, and the frame rate in the case of a moving image. The attribute of the image data such as is determined. The image processing unit 31 develops an image in the frame memory 32 for each frame. Further, the image processing unit 31 performs resolution conversion processing when the resolution of the acquired image data is different from the display resolution of the liquid crystal panel of the light modulation device 22, and is instructed to zoom by operating the remote controller 50 or an operation panel (not shown). In such a case, enlargement / reduction processing is performed, and these processed images are developed in the frame memory 32. Thereafter, the image processing unit 31 outputs the image for each frame developed in the frame memory 32 to the light modulation device driving unit 33 as a display signal.

The control unit 10 executes functions of the projection control unit 11, the focus control unit 12, and the zoom control unit 13 by executing the control program stored in the storage unit 15.
The projection control unit 11 initializes each unit of the projector 1 according to the operation detected by the signal receiving unit 16 or the operation unit 17 and controls the light source driving unit 34, the image processing unit 31, and the light modulation device driving unit 33. Project an image.
The focus control unit 12 (focus control means) controls the focus adjustment unit 41 according to the operation detected by the signal reception unit 16 or the operation unit 17 and executes focus adjustment. On the operation panel (not shown) of the projector 1 and the remote controller 50, an operation for instructing focus adjustment is possible. This operation is an operation for designating the direction of focus adjustment and designating the amount of focus adjustment. In the configuration of the present embodiment, one operation is assigned to a specific key so as to instruct a predetermined adjustment amount, and focus adjustment is instructed by the operation of the key, and the focus adjustment amount is changed according to the number of operations. It has an increased configuration. Also, two keys corresponding to the positive direction and the negative direction of the focus adjustment direction are assigned, and when one of the keys is operated, the focus control unit 12 detects a focus adjustment instruction, specifies the focus adjustment direction, Get the focus adjustment amount. The focus control unit 12 moves the focus ring 42 by operating the motor 43 in accordance with the acquired focus adjustment direction and focus adjustment amount.
Further, the focus control unit 12 sets the focus adjustment range based on the adjustment position of the zoom ring 46, as will be described later. When the operation of the focus adjustment instruction detected by the signal receiving unit 16 or the operation unit 17 deviates from the focus adjustment range, the focus control unit 12 does not perform the focus adjustment corresponding to this operation. In other words, the focus control unit 12 limits the focus adjustment operation to the set focus adjustment range.

  The zoom control unit 13 controls the zoom adjustment unit 45 according to the operation detected by the signal reception unit 16 or the operation unit 17 and executes zoom adjustment. Here, in zoom adjustment, the direction of zoom adjustment (zoom magnification enlargement or reduction) and the amount of zoom adjustment are specified by operating the remote controller 50 or an operation panel (not shown). The zoom control unit 13 moves the zoom ring 46 by rotating the motor 47 in the forward direction or the reverse direction according to the designated direction and adjustment amount. Further, when zoom adjustment is performed, the zoom control unit 13 detects the position of the zoom ring 46 by the position detection unit 48, and specifies the position of the zoom lens 25, that is, the zoom magnification.

  The zoom control unit 13 can also detect the position of the zoom ring 46 as an absolute position based on a reference provided in advance by the position detection unit 48, and each time zoom adjustment is performed, the position of the zoom ring 46 is a relative position. It is also possible to detect as When detecting as the relative position, the zoom control unit 13 sets the initial state to the zero position, and every time zoom adjustment is performed, when the zoom magnification is increased, the zoom control unit 13 reduces the zoom magnification to the positive direction (+). Is the negative direction (-) and the adjustment amount is added. Each time the zoom control unit 13 changes the zoom magnification, the zoom control unit 13 adds the adjustment amount to the previous position of the zoom ring 46 and updates the current position of the zoom ring 46. As a specific configuration, for example, the motor 47 is a stepping motor, and the position detection unit 48 calculates the positive / negative of the adjustment amount and the adjustment amount based on the rotation direction of the motor 47 and the number of operation steps. In this case, the zoom control unit 13 always stores the position of the zoom ring 46 after the previous zoom magnification change in the storage unit 15. Further, the method of learning the correspondence between the actual movement amounts of the zoom ring 46 and the zoom lens 25 and the amount of rotation of the motor 47 by the zoom control unit 13, or the actual zoom lens 25 in advance for each projector 1. The detection accuracy can be improved by a method of setting a correction parameter by obtaining a correspondence between the amount of movement of the lens and the amount of rotation of the motor 47 by the zoom control unit 13.

On the other hand, when the position of the zoom ring 46 is detected as an absolute position, a position reference is provided in the position detection unit 48 in advance, and the position detection unit 48 determines the reference and the current position of the zoom ring 46. And the detected position is output to the zoom control unit 13. A specific configuration includes, for example, a configuration in which the position detection unit 48 includes a rotary encoder. In this case, there is an advantage that the zoom control unit 13 does not need to store the position of the zoom ring 46 after the previous adjustment. In addition, it is necessary to learn the correspondence between the actual movement amounts of the zoom ring 46 and the zoom lens 25 and the amount by which the zoom control unit 13 rotates the motor 47, or to set correction parameters for each individual in advance. In addition, there is an advantage that the position of the zoom ring 46 can be detected and the position of the zoom lens 25 can be specified with high accuracy.
In the zoom control unit 13 of the present embodiment, the position detection unit 48 detects the position of the zoom ring 46 as an absolute position.

Here, the operation of the focus control unit 12 will be described in detail.
FIG. 2 is an explanatory diagram showing the correspondence between the position of the focus lens 24 and the state of the zoom lens 25. FIG. 2A shows the projection from the projector 1 to the screen SC for each zoom magnification (position of the zoom lens 25). 6 is a chart showing the correspondence between the distance and the position of the focus ring, and FIG. 5B is a chart showing the correspondence between the position of the zoom ring and the focus ring set by the focus control unit 12; That is, the projection part of FIG. 4B shows the focus adjustment range of the focus lens 24.
The position of the focus lens 24 is defined by the position of the focus ring 42, and the position of the zoom lens 25 is defined by the position of the zoom ring 46. Therefore, in the following description, the position of the focus ring 42 is regarded as the position of the focus lens 24, and the position of the zoom ring 46 is regarded as the position of the zoom lens 25.

Normally, the focus position of the projector 1 varies depending on the projection distance. When the projection distance to the screen SC changes in the focused state (in-focus state), the focus needs to be readjusted. The FP shown in FIG. 2A indicates the position of the focus ring 42 in the focused state, and it is clear that the FP changes depending on the projection distance. Further, since the projection optical system 23 is composed of a varifocal lens, the position FP of the focus ring 42 in the focused state also changes depending on the position of the zoom ring 46.
In FIG. 2A, the change in the position FP when the zoom ring 46 is on the tele end side is shown in (1), and the change in the position FP when the zoom ring 46 is on the wide end side is shown in (2). The change in the position FP when the zoom ring 46 is near the center position is shown in (3).

As shown in FIG. 2A, the movement ranges A1, A2, and A3 of the focus ring 42 are different on the tele end side, the wide end side, and the vicinity of the intermediate position. That is, the range in which the focus ring 42 is moved for focusing differs depending on whether the zoom ring 46 is on the tele end side, the wide end side, or near the center position thereof. In the example of FIG. 2A, when the zoom ring 46 is near the center position, the adjustment position of the focus ring 42 is closer to one side of the movement range of the focus ring 42. Further, the adjustment position of the focus ring 42 when the zoom ring 46 is on the wide end side is close to the other side of the movement range of the focus ring 42.
Therefore, the focus control unit 12 of the projector 1 obtains the focus ring 42 adjustment range corresponding to the position of the zoom ring 46, and restricts to this range. In the projector 1, a projection distance to the screen SC is set in advance. This projection distance is determined as a practical projection distance range based on the light amount and resolution of the projector 1, the optical performance of the projection optical system 23, and the like. The range of the projection distance can be set to 0.8 m to 30 m, for example, but may be longer or shorter.
The focus control unit 12 sets the focus adjustment range so that the focus can be adjusted at least over the entire range of the projection distance range set in the projector 1 in advance. In the above example, the focus adjustment range is set so that the focus can be achieved anywhere the distance to the screen SC is between 0.8 m and 30 m.

  In FIG. 2B, for each position of the zoom ring 46, the lower limit of the focus adjustment range FA set by the focus control unit 12 is indicated by F1, and the upper limit is indicated by F2. In the focus adjustment range FA, it is possible to focus on the entire range of the set projection distance in the entire region between the wide end and the tele end of the zoom ring 46. Then, the focus control unit 12 sets a focus adjustment range FA corresponding to the position of the zoom ring 46 detected by the position detection unit 48 every time the focus adjustment is performed.

The focus control unit 12 may be configured to obtain the focus adjustment range by arithmetic processing, but may be set based on a table that is stored in advance in the storage unit 15 and sets the focus adjustment range.
FIG. 3 is a diagram illustrating a configuration example of a table in which the position of the zoom lens 25, that is, the position of the zoom ring 46 is associated with the focus adjustment range.
In the example of FIG. 3, the position of the zoom ring 46 is indicated by a numerical value of 0-100. The wide end is 0, and the tele end is 100. Further, the position of the focus ring 42 is set to a numerical value of 0 to 100, and the focus ring 42 can be moved between positions 0 to 100, and a specific range among these 0 to 100 is set as the focus adjustment range. The
For example, when the zoom ring 46 is at the position 49, the lower limit of the focus adjustment range (F1 in FIG. 2B) is set to position 4, and the upper limit of the focus adjustment range (F2 in FIG. 2B) is set to 34. . By referring to such a table, the focus control unit 12 can quickly set a focus adjustment range corresponding to the position of the zoom ring 46 detected by the zoom control unit 13 using the position detection unit 48. The projector 1 is configured to detect the position of the focus ring 42 by a position detector (not shown). The focus control unit 12 moves the focus ring 42 until the position detection unit (not shown) detects the movement amount indicated by the operation detected by the operation detection unit (the signal reception unit 16 and the operation unit 17).

FIG. 4 is a flowchart showing the operation of the projector 1, and particularly shows the operation when the focus control unit 12 performs the focus adjustment process.
The focus control unit 12 detects an operation indicating focus adjustment by the signal reception unit 16 or the operation unit 17 (step S11), and acquires the position of the zoom ring 46 detected by the position detection unit 48 by the zoom control unit 13 (step S11). S12). Next, the focus control unit 12 refers to the table stored in the storage unit 15 and acquires a focus adjustment range corresponding to the position of the zoom ring 46 acquired in step S12 (step S13).
Further, the focus control unit 12 acquires the current position of the focus ring 42 (step S14), and changes the moving direction of the focus ring 42 indicated by the operation detected by the signal receiving unit 16 or the operation unit 17, that is, the focus change. The direction is determined (step S15).

For example, as illustrated in FIG. 3, the change direction of the focus is determined based on whether the numerical value increases or decreases when the position of the focus ring 42 is expressed as a numerical value.
When the change direction of the focus ring 42 is the decreasing side, the focus control unit 12 determines whether or not the position of the focus ring 42 after the change is larger than the lower limit F1 of the focus adjustment range (step S16). When the position of the focus ring 42 after the change is larger than the lower limit F1 of the focus adjustment range (step S16; Yes), the focus control unit 12 operates the motor 43 to move the focus ring 42 (step S17). Exit.
On the other hand, when the position of the focus ring 42 after the change is equal to or less than the lower limit F1 of the focus adjustment range (step S16; No), the focus control unit 12 ends this process without moving the focus ring 42.

When the change direction of the focus ring 42 is the increasing side, the focus control unit 12 determines whether or not the position of the focus ring 42 after the change is smaller than the upper limit F2 of the focus adjustment range (step S18). When the changed position of the focus ring 42 is smaller than the upper limit F2 of the focus adjustment range (step S18; Yes), the focus control unit 12 operates the motor 43 to move the focus ring 42 (step S19), and this process Exit.
On the other hand, when the position of the focus ring 42 after the change is equal to or greater than the upper limit F2 of the focus adjustment range (step S18; No), the focus control unit 12 ends this process without moving the focus ring 42.

  The operation of FIG. 4 is performed each time a remote controller 50 or a key (not shown) on the operation panel is operated. The user adjusts the focus by operating the keys on the remote controller 50 or the operation panel while viewing the focus state of the projected image on the screen SC.

  As described above, according to the projector 1 according to the embodiment to which the present invention is applied, the projection unit 20 that projects an image, the zoom lens 25 that adjusts the size of the projected image, and the projected image The focus lens 24 for adjusting the focus of the zoom lens 25, the position detection unit 48 for detecting the position of the zoom lens 25, and the position of the zoom lens 25 detected by the position detection unit 48 restrict the focus adjustment range of the focus lens 24. The focus control unit 12 is provided, and the focus adjustment range is limited based on the position of the zoom lens 25, so that a large deviation of the focus position can be prevented. Thereby, for example, when the focus adjustment becomes necessary due to the movement of the zoom lens 25, the focus adjustment can be quickly completed. For example, if the user cannot determine the direction to change the focus, even if the focus is changed to the opposite side of the in-focus direction, the focus state is within the limited range, so it becomes too bad. There is nothing to do. Therefore, even if the user is unfamiliar, the focus can be adjusted quickly.

Further, since the focus control unit 12 sets the focus adjustment range to a range including at least a range corresponding to the projection distance set in advance in the projector 1, focus adjustment can be performed in a range corresponding to the preset projection distance. it can. For this reason, even if the focus adjustment range is limited, the focus adjustment range does not become practically narrow, so that quick focus adjustment is possible without impairing convenience.
Further, since the position detection unit 48 detects the position of the zoom lens 25 as an absolute position with respect to a reference provided in advance, for example, a process for obtaining a relative position from a comparison with a previously detected position, an actual zoom lens Learning processing for matching the position of 25 with the detected position, adjustment for each projector 1 and the like are not required.

Further, the projector 1 includes a signal receiving unit 16 and an operation unit 17, and a motor 43 that moves the focus lens 24, and the focus control unit 12 responds to an operation detected by the signal receiving unit 16 or the operation unit 17. Since the motor 43 is operated within a range corresponding to the focus adjustment range, it is possible to prevent the user from being aware of the focus adjustment range and to prevent a large deviation of the focus position.
Furthermore, the focus control unit 12 is stored in the storage unit 15 and quickly sets the focus adjustment range based on a table that associates the position of the zoom lens 25 detected by the position detection unit 48 with the focus adjustment range. it can.
The projection optical system 23 includes a zoom lens 25 and a focus lens 24, and constitutes a varifocal lens (variable focus lens) that changes the position of the focus with the projected image when the position of the zoom lens 25 is changed. Therefore, the optical system of the projector 1 can be reduced in size and the optical performance can be improved without impairing the convenience of the projector 1.

The above-described embodiment is merely an example of a specific mode to which the present invention is applied, and the present invention is not limited. The present invention can be applied as a mode different from the above-described embodiment. For example, in the above-described embodiment, the light modulation device 22 has been described by taking as an example a configuration using three transmissive liquid crystal panels corresponding to RGB colors, but the present invention is not limited to this. For example, a reflective liquid crystal panel may be used, or a configuration using three digital mirror devices (DMD) that modulate color lights of RGB colors may be used.
In the above-described embodiment, the configuration in which the focus ring 42 and the zoom ring 46 provided in the lens barrel (not shown) of the projection optical system 23 are moved to adjust the focus and change the zoom magnification is described as an example. The specific configuration of the mechanism for moving the focus lens 24 and the zoom lens 25 is arbitrary. In addition, the configuration in which the position detection unit 48 detects the zoom position, the configuration of the table that associates the detected zoom position with the focus adjustment range, and the like can be arbitrarily changed.

  Moreover, each function part shown in FIG. 1 shows the functional structure of the projector 1, Comprising: A specific mounting form in particular is not restrict | limited. In other words, it is not always necessary to individually implement hardware corresponding to each functional unit, and it is of course possible to implement a configuration in which the functions of some functional units are realized by software by the processor executing a program. There are other detailed configurations that can be arbitrarily changed.

  Further, in the present embodiment, when the adjusted position of the focus ring 42 is larger than the lower limit F1 in steps S16 and S18 of FIG. 4 showing the focus adjustment processing, or the adjusted position of the focus ring 42 is the upper limit F2. In the case of being larger, the description has been made on the assumption that the position of the focus ring 42 is adjusted in accordance with the movement amount indicated by the operation detected by the operation detection means (the signal receiving unit 16 and the operation unit 17). It is not limited. The focus adjustment range includes the lower limit F1 and the upper limit F2. When the adjusted position of the focus ring 42 is equal to or higher than the lower limit F1, or when the adjusted position of the focus ring 42 is equal to or lower than the upper limit F2, the focus ring The position of 42 may be adjusted.

  DESCRIPTION OF SYMBOLS 1 ... Projector, 10 ... Control part, 11 ... Projection control part, 12 ... Focus control part (focus control means), 13 ... Zoom control part, 15 ... Memory | storage part, 16 ... Signal receiving part (operation detection means), 17 ... Operation unit (operation detection means), 20 ... projection unit, 21 ... light source unit, 22 ... light modulator, 23 ... projection optical system, 24 ... focus lens, 25 ... zoom lens, 41 ... focus adjustment unit, 42 ... focus ring , 43... Motor (drive means), 45... Zoom adjustment section, 46... Zoom ring, 47... Motor, 48 .. position detection section (position detection means), 50.

Claims (7)

A projector for projecting an image,
A zoom lens that adjusts the size of the projected image;
A focus lens that adjusts the focus with the projected image;
Position detecting means for detecting the position of the zoom lens;
A focus control means for limiting a focus adjustment range of the focus lens based on the position of the zoom lens detected by the position detection means;
A projector comprising: The projector according to claim 1,
The focus control means sets the focus adjustment range to a range including at least a range corresponding to a projection distance preset in the projector. The projector according to claim 1 or 2, wherein
The position detection means detects the position of the zoom lens as an absolute position with respect to a reference provided in advance. It is a projector as described in any one of Claims 1-3, Comprising:
Operation detecting means for detecting an operation from the outside;
Drive means for moving the focus lens,
The focus control unit drives the driving unit within a range corresponding to the focus adjustment range in accordance with the operation detected by the operation detection unit. It is a projector as described in any one of Claims 1-4, Comprising:
The focus control unit limits the focus adjustment range based on a table that associates the position of the zoom lens detected by the position detection unit with the focus adjustment range. A projector according to any one of claims 1 to 5,
The zoom lens and the focus lens constitute a varifocal lens that changes a focus position with a projected image when the position of the zoom lens is changed. Project an image,
Detect the position of the zoom lens that adjusts the size of the projected image,
Limiting the focus adjustment range of the focus lens for adjusting the focus with the projected image based on the detected position of the zoom lens;
A projector control method characterized by the above.

Images