CN106993171B

CN106993171B - Projector with a light source

Info

Publication number: CN106993171B
Application number: CN201611257548.XA
Authority: CN
Inventors: 市枝博行; 浅见健一; 吉田宽治
Original assignee: Seiko Epson Corp
Current assignee: Seiko Epson Corp
Priority date: 2016-01-20
Filing date: 2016-12-29
Publication date: 2022-04-08
Anticipated expiration: 2036-12-29
Also published as: JP7067658B2; JP2021140166A; CN113556524B; CN106993171A; JP6878816B2; CN113556524A; JP2017129839A

Abstract

The invention provides a projector, which takes the design of the proper structure and arrangement of a built-in camera which does not fully consider the projection distance as the technical problem to be solved. The projector includes: a projection lens; a first imaging unit that images the projection surface; and a second imaging unit that images the projection surface at a wider angle of view than the first imaging unit. The first image pickup section is disposed to be offset by a first distance in a direction perpendicular to the optical axis with respect to the optical axis of the projection lens, and the second image pickup section is disposed to be offset by a second distance longer than the first distance in the direction perpendicular to the optical axis with respect to the optical axis of the projection lens.

Description

Projector with a light source

Technical Field

The present invention relates to a projector.

Background

Systems are known in which a built-in camera captures an image of a projection state of a projector, and measures a projection color, a projection position, and the like to automatically perform appropriate correction (patent documents 1 and 2).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2015-167341

Patent document 2: japanese patent laid-open No. 2014-197739

However, the projection distance of the projector is often set in various ways depending on the usage state of the projector. The built-in camera needs to be able to photograph the state of the screen (projection surface) regardless of the projection distance of the projector. However, in the past, it has been the actual situation that the design of the appropriate configuration and arrangement considering the projection distance has not been sufficiently made for the built-in camera.

Disclosure of Invention

The present invention has been made to solve at least part of the above problems, and can be realized as the following embodiments or application examples.

(1) According to an aspect of the present invention, there is provided a projector that projects an image onto a projection surface. The projector includes: a projection lens; a first imaging unit that images the projection surface; and a second imaging unit that images the projection surface at a wider angle of view than the first imaging unit. The first image pickup section is disposed to be offset by a first distance in a direction perpendicular to the optical axis with respect to the optical axis of the projection lens, and the second image pickup section is disposed to be offset by a second distance longer than the first distance in the direction perpendicular to the optical axis with respect to the optical axis of the projection lens.

According to the projector, since the second image pickup section for picking up an image of the projection surface with a wider angle of view is disposed at a position farther than the optical axis of the projection lens, it is possible to prevent the wide angle of view of the second image pickup section from interfering with the outer shape of the projection lens.

(2) The projector may further include: a lens mounting part to which a first projection lens for long-distance projection and a second projection lens for short-distance projection are replaceably mounted; a lens information acquisition unit that acquires projection lens identification information for identifying a projection lens attached to the lens attachment unit; and a control unit that causes the first imaging unit to image the projection surface when the projection lens identification information indicates that the first projection lens is attached to the lens attachment unit, and causes the second imaging unit to image the projection surface when the projection lens identification information indicates that the second projection lens is attached to the lens attachment unit.

According to this configuration, it is possible to take an image with an appropriate image pickup unit according to the attached projection lens.

(3) In the projector described above, the projection lens may be a zoom lens capable of changing a focal length, and the projector may further include: a lens information acquisition unit that acquires zoom information indicating a focal length of the projection lens; and a control unit that causes the first image pickup unit to pick up an image of the projection surface when the zoom information indicates that the focal distance is equal to or greater than a predetermined threshold value, and causes the second image pickup unit to pick up an image of the projection surface when the zoom information indicates that the focal distance is less than the threshold value.

According to this configuration, it is possible to perform imaging with an appropriate imaging unit according to the focal length of the projection lens.

(4) In the projector described above, the first image pickup section and the second image pickup section may have different appearances from each other.

According to this configuration, when a failure occurs in any one of the first image pickup unit and the second image pickup unit, the user of the projector can accurately determine which image pickup unit has a failure.

(5) The projector may further include an adjustment unit that adjusts the projection image projected onto the projection surface based on the captured image captured by the first imaging unit or the second imaging unit.

According to this configuration, the projection image projected on the projection surface can be appropriately adjusted based on the captured image captured by the first imaging unit or the second imaging unit.

The present invention can be implemented in various ways, for example, in various ways such as a projector and a control method thereof, a computer program for implementing the above functions, and a non-transitory storage medium (non-transitory storage medium) on which the computer program is recorded.

Drawings

Fig. 1 is a front view showing a state in which a projection lens for long-distance projection is mounted on a projector.

Fig. 2 is a perspective view of fig. 1 as viewed from above.

Fig. 3 is a front view showing a state where a projection lens for close-up projection is mounted on a projector.

Fig. 4 is a perspective view of fig. 3 as viewed from above.

Fig. 5 is a diagram showing an example of the appearance of the first camera and the second camera.

Fig. 6 is a diagram showing another example of the external appearance of the first camera and the second camera.

Fig. 7 is a diagram showing another example of the appearance of the first camera and the second camera.

Fig. 8 is a functional block diagram of the projector of the first embodiment.

Fig. 9 is a functional block diagram of the projector of the second embodiment.

Description of the reference numerals

100 … projector; 110 … front panel; 200 … projection; 210 … a first projection lens; 220 … second projection lens; 230 … lens mounting section; 240 … an optical modulation section; a 250 … light source; 260 … zoom lens; 300 … imaging part; 310 … a first camera; 320 … a second camera; 400 … control section; 500 … operating panel; 600 … projection image generating unit; 610 … projection image memory; 620 … adjustment part; 700. 700a … lens information acquisition unit; a CX … optical axis; d1, D2 … lens projection amount; l1 … first distance; l2 … second distance; LID … lens identification signal; SC … projection plane; theta 1 and theta 2 ….

Detailed Description

A. Arrangement of projection lens and built-in camera of projector

Fig. 1 is a front view showing a state where a first projection lens 210 for long-distance projection is mounted on a projector 100, and fig. 2 is a perspective view of fig. 1 as viewed from above. The front panel 110 of the projector 100 is provided with a first projection lens 210 and two built-in

cameras

310 and 320 for capturing images projected on a projection surface. The first projection lens 210 is replaceably attached to the lens mounting part 230. As shown in fig. 2, the barrel of the first projection lens 210 protrudes from the front panel 110 by a protruding amount D1.

The first camera 310 is a first image pickup unit for long-distance shooting, and the second camera 320 is a second image pickup unit for short-distance shooting. The

cameras

310 and 320 preferably have one or more differences among the following (1) to (3), with the following (1) being the most typical difference.

(1) The angle of view θ 2 (fig. 2) of the second camera 320 for close-distance photographing is wider than the angle of view θ 1 of the first camera 310 for long-distance photographing.

(2) The focus position of the second camera 320 for the short-distance photographing is closer than the focus position of the first camera 310 for the long-distance photographing.

(3) The resolution of the second camera 320 for the short-distance photographing is lower (the number of pixels is small) than that of the first camera 310 for the long-distance photographing.

The first camera 310 for telephoto photographing is disposed at a position separated by a first distance L1 in a direction perpendicular to the optical axis CX with respect to the optical axis CX of the first projection lens 210. The second camera 320 for close-range photographing is disposed at a position separated by a second distance L2 longer than the first distance L1 in a direction perpendicular to the optical axis CX with respect to the optical axis CX of the first projection lens 210. The reason for this will be described later.

Fig. 3 is a front view showing a state where the projector 100 is mounted with the second projection lens 220 for close-distance projection, and fig. 4 is a perspective view of fig. 3 as viewed from above. As shown in fig. 4, the barrel of the second projection lens 220 protrudes from the front panel 110 by a protruding amount D2. In a typical example, the protruding amount D2 of the second projection lens 220 for close-distance projection is larger than the protruding amount D1 (fig. 2) of the first projection lens 210 for long-distance projection. The reason for this is that the lens barrel tends to be longer as the second projection lens 220, which projects an image at a shorter distance, is larger than the lens aperture of the first projection lens 210.

As described above, the second camera 320 for short-distance photographing is disposed at a position farther from the

projection lenses

210 and 220 than the first camera 310 for long-distance photographing. The reason for this is that the angle of view of the second camera 320, which is generally used for short-distance photography, is wider than the angle of view of the first camera 310, which is generally used for long-distance photography, and therefore, if the second camera 320 is disposed at a position close to the projection lens 220, the barrel of the projection lens 220 enters the angle of view of the second camera 320, and therefore, it may be impossible to photograph the entire projected image on the screen surface. In addition, when the entire projection image on the screen surface can be photographed, if the barrel of the projection lens 220 enters the angle of view of the second camera 320, external light is reflected by the barrel of the projection lens 220 and the reflected light enters the second camera 320, which may cause large noise in the photographed image. The possibility of occurrence of such a problem is more significant when the projection amount D2 of the second projection lens 220 for short-distance projection is larger than the projection amount D1 (fig. 2) of the first projection lens 210 for long-distance projection, or when the aperture of the second projection lens 220 is larger than the aperture of the first projection lens 210. Here, in order to minimize the above-described influence while considering design in a limited space of the front panel 110 of the projector 100, the second camera 320 for short-distance photographing is disposed at a position farther from the optical axis CX of the

projection lenses

210 and 220 than the first camera 310 for long-distance photographing.

When the distance (projection distance) between the projector 100 and the projection surface is changed, the

cameras

310 and 320 are arranged so that the farther from the optical axes CX of the

projection lenses

210 and 220, the greater the change in the position of the projected image in the captured image. However, since the angle of view of the second camera 320 disposed farther from the optical axis CX of the

projection lenses

210 and 220 than the first camera 310 is wider than the angle of view of the first camera 310, the second camera can be accommodated within the angle of view even if the position of the projected image within the captured image changes.

The positional relationship of the

cameras

310 and 320 may be arranged in a horizontal direction (horizontal direction) as in the example of fig. 1 to 4, or may be arranged at any position such as a concentric position around the optical axis CX of the

projection lenses

210 and 220. When three or more cameras are provided in the projector, the cameras with wider field angles may be arranged in order so as to be located farther from the optical axis CX of the

projection lenses

210 and 220.

When the barrels of the

projection lenses

210 and 220 are inserted into the angles of view of the

cameras

310 and 320, the barrels of the

projection lenses

210 and 220 are preferably made of a material having low reflectivity (for example, a diffuse reflective material having fine irregularities).

The

cameras

310 and 320 are preferably disposed above the optical axes CX of the

projection lenses

210 and 220. The reason for this is that, when the projector 100 is used while being placed on a desk or the like, if the

cameras

310 and 320 are disposed on the lower side, the desk or the like may be brought into the field angles of the

cameras

310 and 320, and thus the entire projection image on the screen surface may not be captured. In addition, when the entire projection image can be captured, if a desk or the like enters the angle of view of the

cameras

310 and 320, external light is reflected at the desk or the like and the reflected light enters the

cameras

310 and 320, and a large noise may be generated in the captured image. In particular, such a problem is more likely to occur as the viewing angle of the second camera 320 is wider, and therefore, the second camera can be disposed at a position above the first camera 310.

Fig. 5, 6, and 7 are diagrams showing various examples of the external appearance of the first camera 310 and the second camera 320. In this example, the first camera 310 for long-distance photographing and the second camera 320 for short-distance photographing are designed to have appearances that can be easily recognized by naked eyes. In this way, when a failure occurs in any of the

cameras

310 and 320, the user of the projector 100 can clearly determine which camera has a failure, and can smoothly make a consultation with a support center. In addition, when a failure occurs in one camera, information for prompting replacement of the camera is displayed, and the appearance of the camera to be replaced can be characterized by characters, diagrams, or the like. Further, by displaying the appearance of the camera in use in characters, diagrams, or the like on a menu screen or the like, it is possible for the user to recognize which camera is currently in use.

B. Functional block diagram of projector of first embodiment

Fig. 8 is a functional block diagram of the projector of the first embodiment. The projector 100 includes a control unit 400, an operation panel 500, a projection unit 200, a projected image generation unit 600, a lens information acquisition unit 700, and an imaging unit 300. The image pickup section 300 includes the first camera 310 for long-distance photographing and the second camera 320 for short-distance photographing.

The control unit 400 controls each unit inside the projector 100. The control unit 400 has a function of causing either the first camera 310 or the second camera 320 to capture an image of the projection surface SC (screen surface) based on the information acquired by the lens information acquisition unit 700.

The projection image generating unit 600 has a function of generating a projection image projected on the projection surface SC by the projecting unit 200, and includes a projection image memory 610 for storing the projection image and an adjusting unit 620 for adjusting the projection image.

The adjustment unit 620 performs adjustment processing of the projection image projected on the projection surface SC based on the captured image captured by the first camera 310 or the second camera 320. The adjustment processing preferably includes, for example, keystone correction for correcting keystone distortion of the projection image, and color correction of the projection image. When the color of the projection image is corrected, a measurement pattern for measuring the color of the projection light is projected from the projection unit 200, the projection color is measured by the first camera 310 or the second camera, and the color of the projection light is corrected. Specifically, a gain value for adjusting the balance of red, green, and blue at a plurality of gray scales, a correction amount for correcting the luminance of gamma characteristics, correction data for correcting each point of in-plane color unevenness, and the like are calculated. Then, the adjustment section 620 performs correction using these correction values so that the projection light of the projector 100 has a desired hue.

The projection unit 200 has a function of projecting the projection image generated by the projection image generation unit 600 on the projection surface SC. The projector 200 has a light modulator 240 and a light source 250 in addition to the projection lens 210 and the projection mounting part 230 illustrated in fig. 1. The light modulation unit 240 forms projection image light by modulating light from the light source 250 according to the projection image data supplied from the projection image memory 610. The projection image light is color image light typically including visible light of three colors of RGB, and is projected on the projection surface SC by the projection lens 210. As the light source 250, various light sources such as a light emitting diode and a laser diode can be used in addition to a light source lamp such as an ultra-high pressure mercury lamp. The light modulation section 240 may be a transmissive or reflective liquid crystal panel, a digital micromirror device, or the like, or may be a configuration including a plurality of light modulation sections 240 of different color lights.

The lens information acquisition part 700 acquires projection lens identification information identifying the projection lens 210 (or 220) mounted on the lens mounting part 230. In the example of fig. 8, a physical or electrical determination bit is provided at a connection portion between the lens mounting unit 230 and the projection lens 210 (or 220), and a lens identification signal LID indicating a value of the determination bit is supplied from the lens mounting unit 230 to the lens information acquisition unit 700. The lens information acquiring unit 700 acquires projection lens identification information for identifying the projection lens 210 (or 220) currently mounted, based on the lens identification signal LID, and can supply the information to the control unit 400. The control unit 400 determines which of the two

projection lenses

210 and 220 is mounted on the lens mounting unit 230 based on the projection lens identification information. When the first projection lens 210 is attached to the lens attachment unit 230, the control unit 400 captures an image of the projection surface SC by the first camera 310. On the other hand, when the second projection lens 220 is mounted on the lens mounting portion 230, the second camera 320 captures an image of the projection surface SC. In this way, an appropriate camera can be selected from the

cameras

310 and 320 and shooting can be performed, depending on the projection lens actually mounted.

Further, the projection lens identification information for identifying the projection lens 210 (or 220) currently mounted can be acquired by receiving the lens identification signal LID from the lens mounting unit 230 in place of the lens information acquisition unit 700 in response to an instruction from the user using the operation panel 500 or a remote controller (not shown).

C. Functional block diagram of projector of second embodiment

Fig. 9 is a functional block diagram of the projector of the second embodiment. The difference from the first embodiment shown in fig. 8 is that a zoom lens 260 capable of changing a focal length (angle of view) is used instead of the replaceable projection lens 210, and the lens information acquiring unit 700a acquires zoom information indicating the focal length of the zoom lens 260, and the other configuration is the same as that of the first embodiment.

The lens information acquisition unit 700a acquires zoom information showing the focal length of the zoom lens 260. Specifically, for example, a sensor capable of detecting the zoom position of the zoom lens 260 is mounted in the zoom lens 260 in advance, and the zoom information is acquired based on the detected zoom position. When the zoom information shows that the focal length is equal to or greater than a predetermined threshold value, the control unit 400 images the projection surface SC by the first camera 310. On the other hand, when the zoom information shows that the focal distance is below the predetermined threshold, the projection plane SC is photographed by the second camera 320. In this way, a more suitable camera of the

cameras

310 and 320 can be selected and captured based on the actual focal distance.

The lens information acquiring unit 700a may acquire the focal point information by a method other than the above-described method in which the sensor detects the focal point position. For example, an image including a predetermined pattern may be projected on the projection surface SC, captured by the second camera 320 having a wide angle, and zoom information may be derived from the position or size of the pattern in the captured image.

The zoom information may be information that can replace the focal length, and is not limited to information that shows only the focal length itself. For example, information indicating the zoom ratio and information indicating the angle of view are also included in the "zoom information indicating the focal length". In other words, the zoom information may be information showing the zoom state of the zoom lens 260.

In the configuration in which the zoom lens 260 is replaceable as in the first embodiment, if the threshold value is changed according to the attached zoom lens, it is also possible to select an appropriate camera according to the attached zoom lens and the focal length and perform imaging. In this case, the lens information acquiring unit 700a acquires the projection lens identification information and the zoom information, and the control unit 400 selects an appropriate camera based on these pieces of information.

The present invention is not limited to the above-described examples and embodiments, and can be implemented in various forms without departing from the scope of the invention.

For example, when selecting a camera based on zoom information, the method is not limited to the method of directly comparing the focal length with the threshold value, and a table associated with the camera may be stored in a storage unit, not shown, in advance based on the comparison results of the plurality of zoom information with the threshold value, and the camera may be selected based on the acquired zoom information and the table.

For example, in a configuration in which a camera is selected based on zoom information, the size (imaging projection size) of a projection image in an imaging image of the second camera 320 at a wide angle in both the telephoto end and the wide-angle end of the zoom lens 260 is stored in advance in the storage unit, and the control unit 400 may estimate an actual imaging projection size by interpolating the two imaging projection sizes based on the acquired zoom information and may select the camera based on the estimated imaging projection size.

Further, the second camera 320 having a wide angle may capture a projection surface on which a predetermined image (for example, a full white image) is projected, detect the position and size of the projected image in the captured image, and select a camera according to the detected position and size of the projected image.

The lens

information acquiring units

700 and 700a may also acquire projection distance information indicating the distance (projection distance) between the projector 100 and the projection surface SC. In this case, the control unit 400 may select a camera based on the throw distance information, and may change the threshold value for selecting a camera based on the throw distance information. In order to acquire the projection distance information, triangulation using the projection image stored in the projection image memory 610 and the captured image obtained by capturing the projection image projected on the projection surface SC by the first camera 310 or the second camera 320 can be used. Further, a sensor capable of acquiring a focal position may be attached to the projection lens, and the projection distance may be calculated from the focal position, or a distance sensor may be provided to directly measure the projection distance.

Further, the configuration of the camera may be selected according to the adjustment content performed by the adjustment unit 620. For example, in a case where the projector is configured to project images in an array, when the projector is configured to adjust the projection image of the projector according to the projection image of another projector, the adjusting unit 620 needs to select a camera capable of capturing the projection image of the projector and capturing the projection image of another projector. On the other hand, when the adjustment is performed only based on the own projection image, the adjustment unit 620 may select at least a camera capable of capturing the own projection image. At this time, the adjustment information acquiring unit, not shown, acquires the adjustment content designated by the user via the operation panel 500 or the remote controller as the adjustment information, and the control unit 400 selects an appropriate camera based on the adjustment information. Further, the camera may be selected based on two kinds of information, i.e., projection lens identification information and adjustment information, two kinds of information, i.e., zoom information and adjustment information, or three kinds of information, i.e., projection lens identification information, zoom information and adjustment information.

Claims

1. A projector is characterized in that an image is projected on a projection surface,

the projector includes:

a projection lens;

a first imaging unit that images the projection surface;

a second imaging unit that images the projection surface at a wider angle of view than the first imaging unit;

a lens mounting part to which a first projection lens for long-distance projection and a second projection lens for short-distance projection are replaceably mounted;

a lens information acquisition unit that acquires projection lens identification information for identifying a projection lens attached to the lens attachment unit;

a front panel; and

a control part for controlling the operation of the display device,

the first image pickup section is disposed to be deviated from an optical axis of the projection lens by a first distance in a direction perpendicular to the optical axis,

the second image pickup section is configured to be displaced by a second distance longer than the first distance in a direction perpendicular to the optical axis with respect to the optical axis of the projection lens,

the first image pickup unit and the second image pickup unit are provided on the front panel,

a barrel of the projection lens protrudes from the front panel,

the control unit causes the first imaging unit to image the projection surface when the projection lens identification information indicates that the first projection lens is attached to the lens attachment unit,

when the projection lens identification information shows that the second projection lens is attached to the lens attachment section, the control section causes the second imaging section to image the projection surface.

2. A projector is characterized in that an image is projected on a projection surface,

the projector includes:

a projection lens which is a zoom lens capable of changing a focal length;

a first imaging unit that images the projection surface;

a lens information acquisition unit that acquires zoom information indicating a focal length of the projection lens;

a front panel; and

a control part for controlling the operation of the display device,

a barrel of the projection lens protrudes from the front panel,

the control unit causes the first imaging unit to image the projection surface when the zoom information shows that the focal length is equal to or greater than a predetermined threshold value,

when the zoom information shows that the focal length is less than the threshold, the control unit causes the second imaging unit to image the projection surface.

3. A projector is characterized in that an image is projected on a projection surface,

the projector includes:

a projection lens;

a first imaging unit that images the projection surface;

a lens information acquiring unit that acquires projection distance information indicating a distance between the projector and the projection surface;

a front panel; and

a control part for controlling the operation of the display device,

a barrel of the projection lens protrudes from the front panel,

the control unit selects whether to photograph the projection surface by the first image pickup unit or to photograph the projection surface by the second image pickup unit, based on the projection distance information acquired by the lens information acquisition unit.

4. A projector is characterized in that an image is projected on a projection surface,

the projector includes:

a projection lens;

a first imaging unit that images the projection surface;

an adjustment unit configured to perform adjustment processing on the projection image projected onto the projection surface by the projection lens based on the captured image captured by the first image capturing unit or the second image capturing unit;

a front panel; and

a control part for controlling the operation of the display device,

a barrel of the projection lens protrudes from the front panel,

the control portion selects whether to photograph the projection surface with the first image pickup portion or to photograph the projection surface with the second image pickup portion, according to whether the adjustment portion adjusts the projection image based on an image projected by a projector other than the projector or adjusts the projection image based on an image projected by the projector.

5. The projector according to any one of claims 1 to 4,

the first image pickup section and the second image pickup section have different appearances from each other.