JP5250980B2 - Projector and image correction method for the projector - Google Patents

Description

  The present invention relates to a projector and an image correction method for the projector.

2. Description of the Related Art Conventionally, there is known a projector that modulates light emitted from a light source according to image information to form an optical image, enlarges and projects the formed optical image on a screen, and displays the image.
Such a projector is configured to be able to adjust the zoom state in order to change the size of the projected image displayed on the screen (see, for example, Patent Document 1).
The projector described in Patent Document 1 is configured such that the zoom state can be manually adjusted by operating a lever provided on the projection lens.

JP 2003-215702 A

However, in the projector described in Patent Document 1, since the amount of light emitted from the light source does not change, if the size of the projected image is increased by adjusting the zoom state, the illuminance of the optical image to be enlarged and projected decreases. Is blurred. On the other hand, if the size of the projected image is reduced by adjusting the zoom state, the illuminance of the optical image to be enlarged and projected becomes high and the image becomes too clear. Therefore, when the size of the projection image is changed by adjusting the zoom state, there is a problem that the projection image is not displayed on the screen in an appropriate state.
This problem is the same when the size of the projected image is changed by moving the screen closer to or away from the projector.

  An object of the present invention is to provide a projector capable of displaying a projection image on a screen in an appropriate state when the size of the projection image is changed, and an image correction method for the projector.

The projector according to the present invention includes a light source device, a light modulation device that modulates light emitted from the light source device according to image information to form an optical image, and projection optics that enlarges and projects the formed optical image onto a screen. A projector including a device and a control device that controls each of the devices, the imaging device configured to capture a projection image that is controlled by the control device and displayed on the screen, and the control device includes the imaging device An image size calculating unit that calculates a size of the projection image based on a captured image picked up by an image, and an edge that corrects an edge portion in the image information according to the size of the projection image calculated by the image size calculating unit and a correction means, the image size calculating means, in the captured image captured by the imaging device, pairs corresponding to the projection image A corresponding image recognition unit that recognizes an image, a center position calculation unit that calculates a center position of the corresponding image, a center position of the entire captured image, and a center position of the corresponding image calculated by the center position calculation unit; Based on the deviation calculated by the deviation calculating unit, a distance detecting unit for detecting a projection distance from the projection optical device to the screen, and calculating the area of the corresponding image Rukoto includes an area calculation section, and the projection distance detected by the distance detecting unit, and the size calculating unit that calculates the size of the projection image based on the area of the corresponding image to be calculated by the area calculation section It is characterized by.

  According to such a configuration, since the image size calculation means calculates the size of the projection image based on the captured image captured by the imaging device, the positional relationship between the projector and the screen is not fixed Even so, the size of the projected image can be detected. Therefore, since the edge correction means can correct the edge portion in the image information according to the size of the projection image, it is possible to display the projection image on the screen in an appropriate state balanced as a whole.

In the present invention, the image size calculation means includes a corresponding image recognition unit for recognizing a corresponding image corresponding to the projection image and a center position for calculating a center position of the corresponding image in a captured image captured by the imaging device. Based on a calculation unit, a deviation calculation unit that calculates a deviation between the center position of the entire captured image and the center position of the corresponding image calculated by the center position calculation unit, and the deviation calculated by the deviation calculation unit A distance detection unit that detects a projection distance from the projection optical device to the screen, an area calculation unit that calculates an area of the corresponding image, a projection distance detected by the distance detection unit, and the area calculation unit Ru and a size calculating unit that calculates the size of the projection image based on the area of the corresponding image calculated by.

According to such a configuration, since the projector includes the imaging device, the positional relationship between the projector and the imaging device is fixed. Here, the deviation between the center position of the entire captured image captured by the image capturing apparatus and the center position of the corresponding image corresponding to the projected image in the captured image is such that the projection distance from the projection optical apparatus to the screen increases. Since there is a proportional relationship that becomes smaller, the distance detection unit can detect the projection distance based on this deviation.
In addition, since the size per pixel in the captured image can be calculated by detecting the projection distance, the size calculation unit calculates the size of the projection image based on the area of the corresponding image calculated by the area calculation unit. Can be calculated.

In the present invention, the edge correcting unit, the constant edge enhancement filter for emphasize edges in the image information, and change depending on the size of the previous SL the projected image calculated by the image size calculating means, the It is preferable to correct an edge portion in the image information with an edge enhancement filter whose constant has been changed.

  According to such a configuration, for example, by changing the constants of the edge enhancement filter so that the degree of enhancement of the edge portion in the image information increases as the size of the projection image increases, the overall balance is further increased. The projected image can be displayed on the screen in the appropriate state.

In the present invention, the edge correcting unit, a smoothing constant of a filter for smoothing the edges of the image information, and change depending on the size of the previous SL the projected image calculated by the image size calculating means, It is preferable to correct an edge portion in the image information with a smoothing filter whose constant has been changed.

  According to such a configuration, for example, the balance of the smoothing filter is changed so that the degree of smoothing of the edge portion in the image information becomes smaller as the size of the projection image becomes larger, thereby further improving the balance as a whole. The projected image can be displayed on the screen in an appropriate state where the image has been removed.

In the present invention, includes a light amount adjuster for adjusting the amount of light emitted from the light source device, the control device, the light quantity adjusting device in accordance with the size of the projected image calculated by prior Symbol image size calculating means It is preferable that a light amount control means for adjusting a light amount of light emitted from the light source device is provided.

  According to such a configuration, since the projector includes the light amount control unit, for example, when the size of the projection image is increased, even if the illuminance of the optical image to be enlarged and projected becomes low and the image is blurred, the light source device By increasing the amount of light emitted from the projector, it is possible to display a projected image on the screen in an appropriate state that is balanced as a whole. On the other hand, when the size of the projected image is reduced, even if the illuminance of the optical image to be enlarged and projected is high and the image is too clear, by reducing the amount of light emitted from the light source device as a whole, A projected image can be displayed on the screen in a balanced and appropriate state.

An image correction method for a projector of the present invention includes a light source device, a light modulation device that modulates light emitted from the light source device according to image information to form an optical image, and the formed optical image is enlarged on a screen. An image correction method for a projector comprising a projection optical device for projecting and a control device for controlling the devices, an imaging step for imaging a projection image displayed on the screen, and an imaging imaged by the imaging step wherein an image size calculating step of calculating the size of the projection image based on the image, and an edge correction step for correcting an edge portion in the image information according to the size of the projected image calculated by the image size calculating step The image size calculation step corresponds to the projection image in the captured image captured in the imaging step. A corresponding image recognition step for recognizing the corresponding image, a center position calculating step for calculating a center position of the corresponding image, a center position of the entire captured image, and the corresponding image calculated in the center position calculating step. A deviation calculating step for calculating a deviation from a center position; a distance detecting step for detecting a projection distance from the projection optical device to the screen based on the deviation calculated in the deviation calculating step; and Size calculation for calculating the size of the projection image based on the area calculation step for calculating the area, the projection distance detected in the distance detection step, and the area of the corresponding image calculated in the area calculation step And a step .

  According to such a configuration, it is possible to enjoy the same operations and effects as those of the projector described above.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[First Embodiment]
[Configuration of projector]
FIG. 1 is a block diagram illustrating a schematic configuration of the projector 1.
The projector 1 modulates light emitted from a light source according to image data (image information) to form an optical image, and enlarges and projects the formed optical image on a screen Sc, as shown in FIG. The image projection device 2 and the control device 3 are roughly configured.

As shown in FIG. 1, the image projection apparatus 2 includes a light source device 21, a liquid crystal panel 22 as a light modulation device, and a projection optical device 23.
The light source device 21 emits light toward the liquid crystal panel 22 and includes a light source lamp 24 constituted by a high-pressure discharge lamp and a lamp driver 25.
A lamp driver 25 as a light amount adjusting device applies a driving voltage based on a control signal from the control device 3 to drive the light source lamp 24. The light source lamp 24 can adjust the amount of emitted light by adjusting the drive voltage applied by the lamp driver 25.
The light source device 21 may employ various self-light emitting elements such as a light emitting diode, a laser diode, an organic EL element, and a silicon light emitting element.

The liquid crystal panel 22 is a transmissive liquid crystal panel, and changes the arrangement of liquid crystal molecules sealed in a liquid crystal cell (not shown) to transmit or block the light emitted from the light source lamp 24 into image data. In response to this, an optical image is formed, and this optical image is emitted to the projection optical device 23.
The projection optical device 23 is configured as a combined lens in which a plurality of lenses including a zoom lens 26 and a focus lens 27 are housed in a cylindrical lens barrel (not shown), and an optical image emitted from the liquid crystal panel 22 is screened. The projected image is enlarged and projected toward Sc, and a projected image based on the emitted optical image is displayed on the screen Sc.

The zoom lens 26 as a zoom adjustment device is supported by a zoom ring (not shown), and moves in the optical axis direction in the lens barrel by rotating the zoom ring about the optical axis of the zoom lens 26. Thereby, the zoom lens 26 adjusts the zoom state of the projection image displayed on the screen Sc. Specifically, the zoom lens 26 can be adjusted so that the image displayed on the screen Sc is enlarged by moving the zoom lens 26 to the liquid crystal panel 22 side, and displayed on the screen Sc by moving the zoom lens 26 to the screen Sc side. It is possible to adjust so that the image to be reduced becomes smaller.
The focus lens 27 as a focus adjusting device is supported by a focus ring (not shown), and moves in the optical axis direction in the lens barrel by rotating the focus ring about the optical axis of the focus lens 27. Thereby, the focus lens 27 adjusts the focus state of the projection image displayed on the screen Sc.

As shown in FIG. 1, the projection optical device 23 includes a zoom detection device 28 that detects a zoom state adjusted by the zoom lens 26, and a focus detection device 29 that detects a focus state adjusted by the focus lens 27. Is provided.
The zoom detection device 28 and the focus detection device 29 are configured by, for example, a rotary encoder or the like, and detect the zoom state and the focus state by detecting the rotation amounts of the zoom ring and the focus ring with the rotary encoder or the like.

  The projector 1 includes operation means (not shown) such as operation buttons and a remote controller. The user of the projector 1 can rotate the zoom ring to move the zoom lens 26 forward and backward with respect to the optical axis of the projection optical device 23 by operating this operation means, and is displayed on the screen Sc. The zoom state of the projected image can be adjusted. Further, the user of the projector 1 can rotate the focus ring to move the focus lens 27 forward and backward with respect to the optical axis of the projection optical device 23 by operating this operation means, and is displayed on the screen Sc. The focus state of the projected image can be adjusted. Furthermore, the user of the projector 1 can set whether or not to perform an image correction method of the projector 1 described later by operating this operation means.

  Although not shown, the projector 1 includes three liquid crystal panels 22 corresponding to the three colors RGB. The light source device 21 includes a color light separation optical system that separates light emitted from the light source lamp 24 into three colors of light. Furthermore, the projection optical device 23 has a combining optical system that generates an optical image representing a color image by combining three color optical images. As for the configuration of such an optical system, various general projector optical system configurations can be used.

  The control device 3 includes, for example, a CPU (Central Processing Unit) and the like, and controls the entire projector 1. As shown in FIG. 1, the main device 31, an image size acquisition unit 32, and an edge Emphasis filter generation means 33, image processing means 34, and light amount control means 35 are provided. These components 31 to 35 are connected by a bus (not shown) so that necessary information can be transmitted.

The main memory 31 stores a program, data, and the like for executing predetermined processing by the control device 3.
For example, the main memory 31 stores projection image size information in which the zoom state adjusted by the zoom lens 26 and the focus state adjusted by the focus lens 27 are associated with the size of the projection image displayed on the screen Sc. Has been.

Further, for example, the main memory 31 stores edge enhancement filter constant information in which the size of the projection image and the constants of the edge enhancement filter generated by the edge enhancement filter generation means 33 described later are associated with each other. Examples of the edge enhancement filter for enhancing the edge portion in the image data include an edge enhancement filter using a Laplacian filter.
Further, the edge enhancement filter constant information is associated so that the degree of enhancement of the edge portion in the image data increases as the size of the projected image displayed on the screen Sc increases.

The image size acquisition unit 32 causes the zoom detection device 28 to detect the zoom state adjusted by the zoom lens 26 and causes the focus detection device 29 to detect the focus state adjusted by the focus lens 27. The image size acquisition unit 32 acquires the size of the projection image associated with the projection image size information stored in the main memory 31 based on the zoom state and the focus state.
The edge enhancement filter generation unit 33 acquires the edge enhancement filter constant associated with the edge enhancement filter constant information stored in the main memory 31 based on the size of the projection image acquired by the image size acquisition unit 32. Then, an edge enhancement filter based on the obtained constant is generated.

The image processing unit 34 includes, for example, a GPU (Graphics Processor Unit) and the like, and performs image processing. The image processing unit 34 includes an image generation unit 341, an image quality adjustment unit 342, and a video memory 343.
The image generation unit 341 samples the input image data signal and generates image data in units of frames.
Note that the image data signal may be externally input from a PC (Personal Computer) or the like via a connection terminal (not shown) of the projector 1, and further, a projector incorporating a DVD (Digital Versatile Disk) playback device or the like. In that case, it may be input via an internal bus.

The image quality adjustment unit 342 performs image processing based on the edge enhancement filter generated by the edge enhancement filter generation unit 33 on the image data generated by the image generation unit 341. Then, the image quality adjustment unit 342 stores the image processed image data in the video memory 343.
Then, the image processing unit 34 outputs the image data stored in the video memory 343 to the image projecting device 2, and the image projecting device 2 forms an optical image based on the image data stored in the video memory 343 to form a screen. Enlarge and project to Sc.
In the present embodiment, the edge correction unit includes an edge enhancement filter generation unit 33 and an image quality adjustment unit 342. That is, the edge correction unit corrects the edge portion in the image data according to the zoom state detected by the zoom detection device 28.

When the size of the projection image acquired by the image size acquisition unit 32 increases, the light amount control unit 35 outputs a control signal for increasing the amount of light emitted from the light source device 21 to the lamp driver 25. On the other hand, when the size of the projection image acquired by the image size acquisition unit 32 becomes small, the light amount control unit 35 outputs a control signal for reducing the light amount of light emitted from the light source device 21 to the lamp driver 25.
The lamp driver 25 adjusts the amount of light emitted from the light source lamp 24 by adjusting the drive voltage applied to the light source lamp 24 based on the control signal output from the light amount control means 35. That is, the light amount control means 35 adjusts the light amount of light emitted from the light source device 21 in accordance with the zoom state detected by the zoom detection device 28.

[Projector image correction method]
Next, an image correction method of the projector 1 will be described with reference to FIG.
FIG. 2 is a flowchart showing an image correction method of the projector 1.
When the user of the projector 1 operates the operation button or the like of the operation means and the setting for performing the image correction method of the present invention is performed from the menu screen or the like, the projector 1 performs the following steps S1 to S1. S6 is executed.
First, when the user of the projector 1 operates an operation button or the like of the operation unit to adjust the zoom state and the focus state of the image displayed on the screen Sc, the zoom lens 26 and the focus lens 27 are moved in the lens barrel. Are moved forward and backward with respect to the optical axis (step S1).
When the zoom lens 26 and the focus lens 27 advance and retract, the image size acquisition unit 32 causes the zoom detection device 28 and the focus detection device 29 to detect the zoom state and the focus state (step S2: zoom detection step).

When the zoom state and the focus state are detected, the image size acquisition unit 32 acquires the size of the projection image associated with the projection image size information stored in the main memory 31 based on the zoom state and the focus state. (Step S3).
When the size of the projection image is acquired by the image size acquisition unit 32, the edge enhancement filter generation unit 33 is associated with the edge enhancement filter constant information stored in the main memory 31 based on the size of the projection image. An edge enhancement filter constant is acquired, and an edge enhancement filter based on the acquired constant is generated (step S4: edge correction step).

When the edge enhancement filter is generated by the edge enhancement filter generation unit 33, the image quality adjustment unit 342 performs image processing based on the edge enhancement filter on the image data generated by the image generation unit 341 (Step S5: Edge). Correction step).
When the image processing is performed by the image quality adjustment unit 342, the light amount control unit 35 outputs a control signal corresponding to the size of the projection image acquired by the image size acquisition unit 32 to the lamp driver 25 to output from the light source device 21. The amount of emitted light is adjusted (step S6).
By executing the above steps, as the size of the projected image displayed on the screen Sc increases, the degree of emphasizing edge portions in the image data increases, and the amount of light emitted from the light source device 21 increases. Therefore, the projector 1 can display an image on the screen Sc in an appropriate state.

The projector 1 according to the present embodiment has the following effects.
(1) Since the edge correction unit corrects the edge portion in the image data in accordance with the zoom state detected by the zoom detection device 28, the projection image is displayed on the screen Sc in an appropriate state that is balanced as a whole. Can do.
(2) Since the projector 1 includes the zoom detection device 28 and the focus detection device 29, when the projection image is in focus, the projector 1 determines from the projection optical device 23 according to the focus state detected by the focus detection device 29. The projection distance to the screen Sc can be obtained. Therefore, even if the positional relationship with the screen Sc is not fixed, the projected image is based on the zoom state detected by the zoom detection device 28 and the focus state detected by the focus detection device 29. The size of can be detected.

(3) The edge correction means changes the constants of the edge enhancement filter so that the degree of enhancement of the edge portion in the image data increases as the size of the projection image increases. In such a state, the projected image can be displayed on the screen Sc.
(4) The light amount control unit 35 increases the light amount of light emitted from the light source device 21 when the size of the projection image acquired by the image size acquisition unit 32 increases, and when the size of the projection image decreases, the light source device Since the amount of light emitted from 21 is reduced, it is possible to display an image on the screen Sc in an appropriate state that is balanced as a whole.

[Second Embodiment]
A projector 1A according to a second embodiment of the invention will be described.
In the following description, parts that have already been described are assigned the same reference numerals and description thereof is omitted.
The projector 1 according to the first embodiment includes the edge enhancement filter generation unit 33, and the main memory 31 associates the size of the projection image with the constants of the edge enhancement filter generated by the edge enhancement filter generation unit 33. The obtained edge enhancement filter constant information is stored.
On the other hand, as shown in FIG. 3, the projector 1 </ b> A according to the present embodiment includes the smoothing filter generation unit 36. The main memory 31 generates the projection image size and the smoothing filter generation unit 36. The smoothing filter constant information in which the constant of the smoothing filter to be associated is associated is stored.

In addition, as a smoothing filter for smoothing the edge part in image data, the smoothing filter using a median filter etc. can be illustrated.
Further, the smoothing filter constant information is associated so that the degree of smoothing the edge portion in the image data decreases as the size of the projected image displayed on the screen Sc increases.

FIG. 3 is a block diagram showing a schematic configuration of the projector 1A.
The smoothing filter generation unit 36 acquires the constant of the smoothing filter associated with the smoothing filter constant information stored in the main memory 31 based on the size of the projection image acquired by the image size acquisition unit 32. Then, a smoothing filter based on the obtained constant is generated.
Then, the image quality adjustment unit 342A performs image processing based on the smoothing filter generated by the smoothing filter generation unit 36 on the image data generated by the image generation unit 341.
In the present embodiment, the edge correction unit includes the smoothing filter generation unit 36 and the image quality adjustment unit 342A.

Next, an image correction method of the projector 1A will be described with reference to FIG.
FIG. 4 is a flowchart showing an image correction method of the projector 1A.
First, the projector 1A executes steps S1 to S3 in the same manner as the projector 1 in the first embodiment.
When the size of the projection image is acquired by the image size acquisition unit 32, the smoothing filter generation unit 36 associates with the smoothing filter constant information stored in the main memory 31 based on the size of the projection image. A constant of the obtained smoothing filter is obtained, and a smoothing filter based on the obtained constant is generated (step S14: edge correction step).

When the smoothing filter is generated by the smoothing filter generation unit 36, the image quality adjustment unit 342A performs image processing based on the smoothing filter on the image data generated by the image generation unit 341 (step S15: edge). Correction step).
Then, projector 1A executes step S6 in the same manner as projector 1.
By executing the above steps, as the size of the projected image displayed on the screen Sc increases, the degree of smoothing of the edge portion in the image data decreases, and the light emitted from the light source device 21 is reduced. Since the amount of light increases, the projector 1A can display an image on the screen Sc in an appropriate state.

In this embodiment as well, the same actions and effects as (1), (2), and (4) of the first embodiment can be obtained, and the following actions and effects can be obtained.
That is, since the edge correction means changes the constant of the smoothing filter so that the degree of smoothing of the edge portion in the image data becomes smaller as the size of the projection image becomes larger, the balance correction as a whole is more appropriately balanced. In such a state, the projected image can be displayed on the screen Sc.

[Third Embodiment]
A projector 1B according to a third embodiment of the invention will be described.
The projectors 1, 1 </ b> A according to the first and second embodiments include a focus lens 27 and a focus detection device 29, and the image size acquisition means 32 is a zoom state detected by the zoom detection device 28 and a focus detection device. The size of the projection image is acquired based on the focus state detected by the control unit 29.
On the other hand, as shown in FIG. 5, the projector 1B includes a distance detection device 4 that detects a projection distance from the projection optical device 23 to the screen Sc, and an image size acquisition unit 32B, and an image size acquisition unit 32B. Is different in that the size of the projection image is acquired based on the zoom state detected by the zoom detection device 28 and the projection distance detected by the distance detection device 4.

FIG. 5 is a block diagram showing a schematic configuration of the projector 1B.
The distance detection device 4 includes a transmitter and a receiver that transmit and receive ultrasonic waves, and measures the time until the ultrasonic waves transmitted from the transmitter are reflected by an object and received by the receiver. It is a sensor that measures the distance to the object, and is provided at a position that detects the distance to the object in the projection direction of the projection optical device 23. That is, the distance detection device 4 can detect the projection distance from the projection optical device 23 to the screen Sc. Note that the sensor is not limited to a sensor that detects a distance using ultrasonic waves, and may be a sensor that detects a distance using infrared rays, for example.

The image size acquisition unit 32B causes the zoom detection device 28 to detect the zoom state adjusted by the zoom lens 26 and causes the distance detection device 4 to detect the projection distance from the projection optical device 23 to the screen Sc. Then, the image size acquisition means 32B acquires the size of the projection image associated with the projection image size information stored in the main memory 31 based on the detected zoom state and projection distance.
In the present embodiment, the projection image size information stored in the main memory 31 includes the zoom state adjusted by the zoom lens 26, the projection distance detected by the distance detection device 4, and the projection image displayed on the screen Sc. Is associated with the size of.

Next, an image correction method of the projector 1B will be described with reference to FIG.
FIG. 7 is a flowchart showing an image correction method of the projector 1B.
First, when the user of the projector 1B operates an operation button or the like of the operation unit to adjust the zoom state of the image displayed on the screen Sc, the zoom lens 26 moves forward and backward in the lens barrel with respect to the optical axis. (Step S21).
When the zoom lens 26 advances and retreats, the image size acquisition unit 32B causes the zoom detection device 28 and the distance detection device 4 to detect the zoom state and the projection distance (step S22: zoom detection step).

When the zoom state and the projection distance are detected, the image size acquisition unit 32B acquires the size of the projection image associated with the projection image size information stored in the main memory 31 based on the zoom state and the projection distance. (Step S23).
Then, projector 1B executes steps S4 to S6 in the same manner as projector 1.
By executing the above steps, the projector 1B can display an image on the screen Sc in an appropriate state.

In this embodiment as well, the same actions and effects as (1), (3), and (4) of the first embodiment can be obtained, and the following actions and effects can be obtained.
In other words, since the projector 1B includes the distance detection device 4, the projection distance from the projection optical device 23 to the screen Sc can be detected. Thereby, even when the positional relationship between the projector 1B and the screen Sc is not fixed, the size of the projection image can be detected. Therefore, since the edge correction means can correct the edge portion in the image data according to the size of the projection image, the projection image can be displayed on the screen Sc in an appropriate state balanced as a whole.

[Fourth Embodiment]
A projector 1C according to a fourth embodiment of the invention will be described.
In the projector 1B according to the third embodiment, the image size acquisition unit 32B acquires the size of the projection image based on the zoom state adjusted by the zoom lens 26 and the projection distance detected by the distance detection device 4. .
On the other hand, as shown in FIG. 7, the projector 1 </ b> C according to the present embodiment includes the imaging device 5 and the image size calculation unit 37, and the projection image based on the captured image captured by the imaging device 5. It differs in that the size is calculated.

FIG. 7 is a block diagram showing a schematic configuration of the projector 1C.
The imaging device 5 is configured by a CCD (Charge Coupled Device) camera that can be controlled by the control device 3, and is provided in a projection direction of the projection optical device 23, that is, at a position where a projection image displayed on the screen Sc can be captured. Yes. In addition, not only a CCD camera but a CMOS (Complementary Metal Oxide Semiconductor) camera etc. may be adopted, for example.

The image size calculation unit 37 calculates the size of the projection image based on the captured image captured by the imaging device 5.
Here, FIG. 8 is a diagram showing the principle of the projection image size calculation method by the image size calculation means 37.
8 shows the optical path of the optical image enlarged and projected by the projection optical device 23 and the position of the screen Sc arranged on this optical path. In FIG. 8, the projection distance from the projection optical device 23 to the screen Sc is exemplified as a long distance (FIG. 8A), a medium distance (FIG. 8B), and a short distance (FIG. 8C). To do.
Further, the diagram on the right side in FIG. 8 shows a captured image Im captured by the imaging device 5 at each distance.

For example, when an image data signal composed of a pattern of the same color is input to the image processing unit 34 and an optical image based on this pattern is enlarged and projected on the image projection apparatus 2, as shown in FIG. A projected image is displayed on the screen. At this time, in the captured image Im captured by the imaging device 5, the center position P of the corresponding image S corresponding to the projection image displayed on the screen Sc is apart from the projection distance from the projection optical device 23 to the screen Sc. The closer to the center position C of the captured image Im.
Specifically, the distance between CPs in the captured image Im captured in FIG. 8B is shorter than the distance between CPs in the captured image Im captured in FIG. 8C. In addition, the distance between CPs in the captured image Im captured in FIG. 8A is shorter than the distance between CPs in the captured image Im captured in FIG. 8B.
Here, the distance between the CPs and the projection distance from the projection optical device 23 to the screen Sc are in a proportional relationship.

In order to calculate the size of the projection image based on the above-described principle, the image size calculation unit 37 includes a corresponding image recognition unit 371, a center position calculation unit 372, and a deviation calculation unit 373, as shown in FIG. , A distance detection unit 374, an area calculation unit 375, and a size calculation unit 376.
The corresponding image recognition unit 371 recognizes the corresponding image S corresponding to the projection image displayed on the screen Sc in the captured image Im captured by the imaging device 5. Specifically, the corresponding image S is cut out from the captured image Im by performing image processing of binarization processing and labeling processing on the captured image Im.
The center position calculation unit 372 calculates the center position P of the corresponding image S.

The deviation calculation unit 373 calculates the deviation between the center position C of the entire captured image Im and the center position P of the corresponding image S calculated by the center position calculation unit 372, that is, the distance between CPs.
The distance detection unit 374 detects the projection distance from the projection optical device 23 to the screen Sc based on the deviation calculated by the deviation calculation unit 373.
In the present embodiment, the deviation calculated by the deviation calculator 373 and the projection distance from the projection optical device 23 to the screen Sc are associated with each other and stored in the main memory 31.

The area calculation unit 375 calculates the area of the corresponding image S. Specifically, the number of pixels of the corresponding image S cut out by the corresponding image recognition unit 371 is calculated.
The size calculation unit 376 calculates the size of the projection image based on the projection distance detected by the distance detection unit 374 and the area of the corresponding image S calculated by the area calculation unit 375. Specifically, when the projection distance is detected by the distance detection unit 374, the size per pixel in the captured image Im can be calculated from the projection distance. Therefore, if the area of the corresponding image S is multiplied by the size per pixel, the size of the projection image can be calculated.
In the present embodiment, the projection distance from the projection optical device 23 to the screen Sc and the size per pixel in the captured image Im are associated and stored in the main memory 31.

Next, an image correction method of the projector 1C will be described with reference to FIG.
FIG. 9 is a flowchart showing an image correction method of the projector 1C.
When the user of the projector 1C operates an operation button or the like of the operation unit and the setting for performing the image correction method of the present invention is performed from the menu screen or the like, the projector 1C performs the following steps S31 to S31. S32 and S4 to S6 are executed.
First, the image size calculation means 37 inputs an image data signal composed of the same color pattern to the image processing means 34 and causes the image projection apparatus 2 to enlarge and project an optical image based on this pattern. Thereby, a projection image is displayed on the screen Sc. Then, the image size calculation unit 37 causes the imaging device 5 to capture the projection image displayed on the screen Sc and acquire the captured image Im (step S31: imaging step).

When the captured image Im is acquired, the image size calculating unit 37 calculates the size of the projection image based on the captured image Im (step S32: image size calculating step).
Here, step S32 performs the following steps S321-S326.
The corresponding image recognition unit 371 recognizes the corresponding image S corresponding to the projection image displayed on the screen Sc in the captured image Im (step S321).
When the corresponding image recognition unit 371 recognizes the corresponding image S, the center position calculation unit 372 calculates the center position P of the corresponding image S (step S322).

When the center position of the corresponding image S is calculated, the deviation calculating unit 373 calculates a deviation between the center position P of the entire captured image Im and the center position P of the corresponding image S calculated by the center position calculating unit 372. (Step S323).
When the deviation is calculated by the deviation calculation unit 373, the distance detection unit 374 detects the projection distance from the projection optical device 23 to the screen Sc based on the deviation (step S324).
When the projection distance is detected, the area calculation unit 375 calculates the area of the corresponding image S (step S325).
When the area of the corresponding image S is calculated, the size calculation unit 376 calculates the size of the projection image based on the projection distance detected by the distance detection unit 374 and the area of the corresponding image S calculated by the area calculation unit 375. Is calculated (step S326).

When the size of the projection image is calculated by the image size calculation unit 37, the projector 1C executes steps S4 to S6 in the same manner as the projector 1.
By executing the above steps, the projector 1C can display an image on the screen Sc in an appropriate state.

In this embodiment as well, the same actions and effects as (1), (3), and (4) of the first embodiment can be obtained, and the following actions and effects can be obtained.
That is, since the image size calculation unit 37 calculates the size of the projection image based on the captured image Im captured by the imaging device 5, the positional relationship between the projector 1C and the screen Sc is not fixed. Even if it exists, the size of the projected image can be detected. Therefore, since the edge correction means can correct the edge portion in the image data according to the size of the projection image, the projection image can be displayed on the screen Sc in an appropriate state balanced as a whole.

[Modification of Embodiment]
It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within a scope that can achieve the object of the present invention are included in the present invention.
In the first embodiment and the second embodiment, the edge correction unit corrects the edge portion in the image data according to the zoom state and the focus state. However, the edge correction unit may correct only according to the zoom state. In short, the edge correction means may correct the edge portion in the image information according to the zoom state.
In each of the embodiments described above, the constant of the edge enhancement filter or the smoothing filter is a constant associated with the edge enhancement filter constant information or the smoothing filter constant information stored in the main memory 31 based on the size of the projection image. However, the constant may be calculated using a function based on the size of the projection image. In short, it is only necessary that the constant of each filter can be changed according to the size of the projection image.

In each of the embodiments, the edge enhancement filter or the smoothing filter is used alone. For example, the edge enhancement filter is used in a range where the size of the projection image is larger than a predetermined size, and the range is smaller than the predetermined size. A smoothing filter may be used. In short, it is only necessary that the edge portion in the image information can be corrected according to the size of the projection image.
In each of the above embodiments, the lamp driver 25 is used as the light amount adjusting device. However, for example, a diaphragm or the like that reduces the amount of light emitted from the light source device may be used. It is sufficient that the amount of light emitted from the light source device can be adjusted. Furthermore, the projector does not have to include the light amount adjusting device and the light amount control unit. In short, it is sufficient if the projector can display an image on the screen in an appropriate state that is balanced as a whole.

In the fourth embodiment, the image size calculation unit 37 inputs an image data signal composed of the same color pattern to the image processing unit 34, and an optical image based on the same color pattern is input to the image projection device 2. However, for example, an image data signal composed of a pattern in which a rectangular region having a color different from the background image is provided at the center position of the background image of the same color may be input. Depending on the configuration of the pattern, the projection image can be easily recognized.
In the fourth embodiment, the image size calculation unit 37 includes the corresponding image recognition unit 371, the center position calculation unit 372, the deviation calculation unit 373, the distance detection unit 374, the area calculation unit 375, and the size calculation unit 376. However, the image size may be calculated by a configuration other than this. For example, the center position calculation unit 372, the deviation calculation unit 373, and the distance detection unit 374 may be omitted by using the distance detection device 4 in the third embodiment together, in short, based on the captured image. It is only necessary that the size of the projected image can be calculated.

In each of the above-described embodiments, the transmissive liquid crystal panel 22 is employed. However, the present invention is not limited to this, and a reflective liquid crystal panel may be employed or a digital micromirror device (DMD) may be employed. Good. DMD is a trademark of Texas Instruments Incorporated.
In each of the above embodiments, the three liquid crystal panels 22 are provided. However, the present invention is not limited to this, and only one liquid crystal panel 22 is provided. Two liquid crystal panels 22 are provided. Four or more liquid crystals are provided. The panel 22 may be provided.

  The present invention can be used for a projector, and in particular, can be suitably used for a projector capable of changing the size of a projection image.

1 is a block diagram showing a schematic configuration of a projector according to a first embodiment of the invention. 6 is a flowchart showing an image correction method for the projector according to the embodiment. The block diagram which shows schematic structure of the projector which concerns on 2nd Embodiment of this invention. 6 is a flowchart showing an image correction method for the projector according to the embodiment. The block diagram which shows schematic structure of the projector which concerns on 3rd Embodiment of this invention. 6 is a flowchart showing an image correction method for the projector according to the embodiment. The block diagram which shows schematic structure of the projector which concerns on 4th Embodiment of this invention. The figure which shows the principle of the size calculation method of the projection image by the image size calculation means which concerns on the said embodiment. 6 is a flowchart showing an image correction method for the projector according to the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,1A, 1B, 1C ... Projector, 3 ... Control device, 4 ... Distance detection device, 5 ... Imaging device, 21 ... Light source device, 22 ... Liquid crystal panel (light modulation device), 23 ... Projection optical device, 25 ... Lamp Driver (light quantity adjustment device), 26 ... zoom lens (zoom adjustment device), 27 ... focus lens (focus adjustment device), 28 ... zoom detection device, 29 ... focus detection device, 33 ... edge enhancement filter generation means (edge correction means) , 35... Light quantity control means, 36... Smoothing filter generation means (edge correction means), 342, 342 A ... Image quality adjustment section (edge correction means), 371 ... Corresponding image recognition section, 372 ... Center position calculation section, 373. Deviation calculation unit, 374 ... distance detection unit, 375 ... area calculation unit, 376 ... size calculation unit, S4, S5, S14, S15 ... edge correction step, 2, S22 ... zoom detection step, S31 ... imaging step, S32 ... image size calculating step, Sc ... screen.

Claims (5)

A light source device; a light modulation device that modulates light emitted from the light source device in accordance with image information to form an optical image; a projection optical device that magnifies and projects the formed optical image onto a screen; A projector comprising a control device for controlling
An imaging device controlled by the control device and capturing a projection image displayed on the screen;
The controller is
Image size calculation means for calculating the size of the projection image based on a captured image captured by the imaging device;
Edge correction means for correcting edge portions in the image information according to the size of the projection image calculated by the image size calculation means ,
The image size calculation means
A captured image captured by the imaging device, a corresponding image recognition unit that recognizes a corresponding image corresponding to the projection image;
A center position calculator for calculating the center position of the corresponding image;
A deviation calculator that calculates a deviation between the center position of the entire captured image and the center position of the corresponding image calculated by the center position calculator;
A distance detection unit that detects a projection distance from the projection optical device to the screen based on the deviation calculated by the deviation calculation unit;
An area calculation unit for calculating the area of the corresponding image;
Projector characterized by Rukoto comprises a projection distance detected by the distance detecting unit, and the size calculating unit that calculates the size of the projection image based on the area of the corresponding image to be calculated by the area calculation section . The projector according to claim 1 , wherein
The edge correction unit changes a constant of an edge enhancement filter for enhancing an edge portion in the image information according to the size of the projection image calculated by the image size calculation unit, and the constant is changed. A projector, wherein an edge portion in the image information is corrected by an edge enhancement filter. In the projector according to claim 1 or 2 ,
The edge correction unit changes a constant of a smoothing filter for smoothing an edge portion in the image information according to the size of the projection image calculated by the image size calculation unit, and the constant is changed. A projector characterized in that an edge portion in the image information is corrected by a smoothing filter. The projector according to any one of claims 1 to 3 ,
A light amount adjusting device for adjusting the amount of light emitted from the light source device;
The controller is
A projector comprising: a light amount control unit that causes the light amount adjusting device to adjust a light amount of light emitted from the light source device according to a size of the projection image calculated by the image size calculating unit. A light source device; a light modulation device that modulates light emitted from the light source device in accordance with image information to form an optical image; a projection optical device that magnifies and projects the formed optical image onto a screen; An image correction method for a projector comprising a control device for controlling
An imaging step of imaging a projected image displayed on the screen;
An image size calculating step for calculating a size of the projection image based on a captured image captured by the imaging step;
An edge correction step of correcting an edge portion in the image information according to the size of the projection image calculated by the image size calculation step ,
The image size calculating step includes:
A corresponding image recognition step for recognizing a corresponding image corresponding to the projection image in the captured image captured in the imaging step;
A center position calculating step for calculating a center position of the corresponding image;
A deviation calculating step for calculating a deviation between the center position of the entire captured image and the center position of the corresponding image calculated in the center position calculating step;
A distance detecting step for detecting a projection distance from the projection optical device to the screen based on the deviation calculated in the deviation calculating step;
An area calculating step for calculating an area of the corresponding image;
A size calculation step of calculating a size of the projection image based on the projection distance detected in the distance detection step and the area of the corresponding image calculated in the area calculation step. Image correction method.

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