Abstract:
An image processing apparatus includes a first image pick-up unit, a projecting unit that projects imaging light, an optical unit that transmits part of light entering from a first image pick-up direction and guides the part of the light to the first image pick-up unit while reflecting part of the imaging light projected from the projecting unit and outputting the reflected light in the first image pick-up direction, and reflects part of light entering from a second image pick-up direction and guides the part of the light to the first image pick-up unit while transmitting part of the imaging light projected from the projecting unit and outputting the part of the imaging light in the second image pick-up direction, and an attenuating unit that is movably placed between two positions.

Description:
BACKGROUND 
     1. Technical Field 
     The present invention relates to an image processing apparatus that has an image pick-up unit that picks up an image of an object, and a projecting unit that projects imaging light onto the image pick-up region of the image pick-up unit. 
     2. Related Art 
     There have been known techniques for sending instructions from a remote place with the use of images. By those techniques, an image of a predetermined region picked up by a camera is transmitted to a remote place, and an annotation image based on an instruction from the remote place is projected onto the image pick-up region of the camera by a projector. 
     In those techniques, the camera and the projector are housed in a casing and are shielded from external light, and the optical system of the camera and the optical system of the projector are designed to share the same optical axis with the help of a half mirror, so that each one of the image pick-up ranges of the camera corresponds to a projecting range. 
     In a case where the camera and the projector are housed in a casing, and the optical system of the camera and the optical system of the projector are designed to share the same optical axis with the help of a half mirror, as described above, the imaging light not to be used for projection among the imaging light emitted from the projector toward the half mirror might scatter as stray light in the casing and enter the camera. Therefore, a light attenuating member called a “trap” to absorb and attenuate the imaging light not to be used for projection is placed in such a position as to receive the imaging light not to be used for projection, as opposed to the half mirror. 
     SUMMARY 
     According to an aspect of the present invention, there is provided an image processing apparatus including: a first image pick-up unit; a projecting unit that projects imaging light; an optical unit that transmits part of light entering from a first image pick-up direction and guides the part of the light to the first image pick-up unit while reflecting part of the imaging light projected from the projecting unit and outputting the reflected light in the first image pick-up direction, and reflects part of light entering from a second image pick-up direction and guides the part of the light to the first image pick-up unit while transmitting part of the imaging light projected from the projecting unit and outputting the part of the imaging light in the second image pick-up direction; and an attenuating unit that is movably placed between a position in which imaging light transmitted through the optical unit can be received and a position in which imaging light reflected by the optical unit can be received, and attenuates the received imaging light. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the present invention will be described in detail based on the following figures, wherein: 
         FIGS. 1A and 1B  schematically show the structures of image processing units that are parts of image processing apparatuses; 
         FIG. 2  shows a first specific example structure of an optical trap; 
         FIG. 3  shows a second specific example structure of an optical trap; 
         FIGS. 4A and 4B  are side views of an image processing unit; 
         FIG. 5  shows an example of the angle of the projecting direction of the projector with respect to the projection face of the screen; 
         FIG. 6  is a side view of an image processing apparatus having an image processing unit above an object; 
         FIG. 7  is a side view of an image processing apparatus having an image processing unit placed in the same horizontal plane as an object; 
         FIG. 8  is a side view of an image processing apparatus having a mirror placed on the line extending in the projecting direction of the projector of the image processing unit; 
         FIG. 9  is a side view of an image processing apparatus in which the projecting direction of the projector is horizontal, and the image processing unit is placed in such a position that the screen exists on the line extending in the projecting direction; 
         FIG. 10  is a side view of an image processing apparatus in which the projector projects light diagonally downward, and the image processing unit is placed in such a position that the screen exists on the line extending in the projecting direction; 
         FIG. 11  is a side view of an image processing apparatus having the image processing unit located in such a position that a mirror exists in the image pick-up range of the camera; and 
         FIG. 12  is a side view of an image processing apparatus in which the mirror is eliminated from the image pick-up range of the camera. 
     
    
    
     DETAILED DESCRIPTION 
     A description will now be given, with reference to the accompanying drawings, of exemplary embodiments of the present invention.  FIGS. 1A and 1B  schematically show the structures of image processing units that are parts of image processing apparatuses employed in this exemplary embodiment. Each of the image processing units  10  shown in  FIGS. 1A and 1B  picks up an image of an object  300 , and projects the picked-up image. Each image processing unit  10  includes a half mirror  12  as an optical member, a camera  14  as a first image pick-up unit, a projector  16  as a projecting unit, an optical trap  18  as an attenuating unit, and a casing  11  that shields those components from external light. 
     The casing  11  includes a light incoming/outgoing unit  11 A that allows incoming light in the horizontal direction and emits part of the light of the image projected from the projector  16 , and a light incoming/outgoing unit  11 B that allows incoming light from below and emits part of the light of the image projected from the projector  16 . The optical trap  18  is selectively provided for the two light incoming/outgoing units  11 A and  11 B, and shields each of the light incoming/outgoing units  11 A and  11 B. 
     In  FIGS. 1A and 1B , the half mirror  12  is located in a position within the image pick-up range of the camera  14  and within the projection range of the imaging light of the projector  16 . The camera  14  pikes up an image of an object placed under the camera  14 . In  FIG. 1A , the camera  14  receives the light of the object  300  passing through the half mirror  12 , and picks up the image of the object  300  placed on a floor or the like. In  FIG. 1B , the camera  14  receives the light of the object  300  reflected by the half mirror  12 , and picks up the image of the object  300  placed on a table or the like. Meanwhile, the projector  16  projects imaging light in the horizontal direction. The projector  16  projects the imaging light corresponding to an image obtained by the camera  14  onto a screen or the like (not shown) via the half mirror  12 . 
     The optical trap  18  is of a movable type, and attenuates light. More specifically, in a case where the camera  14  receives the light of the object  300  passing through the half mirror  12  and picks up the image of the object  300 , the optical trap  18  is located on a side face of the image processing unit  10 , or on the line extending in the projecting direction of the projector  16 , so as to prevent light unnecessary for the image pick-up from being reflected by the half mirror  12  and entering the camera  14 . In a case where the camera  14  receives the light of the object  300  reflected by the half mirror  12  and picks up the image of the object  300 , the optical trap  18  is located below the image processing unit  10 , or on the line extending in the image pick-up direction of the camera  14 , so as to prevent the unnecessary light from passing through the half mirror  12  and entering the camera  14 . 
       FIGS. 2 and 3  illustrate the structures of the optical traps  18  in detail. The optical trap  18  shown in  FIG. 2  includes a concave mirror  104 , a vertical plate  107 , a horizontal plate  108 , and light attenuation filters  109 ,  110 , and  111 . Imaging light passing through the half mirror  12  is reflected by the concave mirror  104 . The vertical plate  107  is located in the area on which light reflected by the concave mirror  104  is focused. The horizontal plate  108  is attached to the end portion of the vertical plate  107  farther away from the half mirror  12 . 
     The light attenuation filter  110  is formed in the vertical plate  107 . The light attenuation filter  110  has a ND coat to restrain light transmission, an AR coat to restrain light reflection, and the likes. The light reflected by the concave mirror  104  is attenuated by the light attenuation filter  110 , but part of the reflected light is again reflected and reaches the light attenuation filter  109  formed on the concave mirror  104 . The light attenuation filter  109  has the same structure as the light attenuation filter  110 . Light that reaches the light attenuation filter  109  is attenuated, but part of the light is reflected and reaches the light attenuation filter  110 . Thereafter, the light reflection between the light attenuation filter  109  and the light attenuation filter  110  is repeated, so as to gradually attenuate light. The light attenuation filter  109  may be provided entirely or partially over the concave mirror  104 . 
     On the other hand, the optical trap  18  shown in  FIG. 3  includes a light attenuation filter  124  and a non-reflector  125 . Imaging light passing through the half mirror  12  is attenuated by the flat-type light attenuation filter  124 , but part of the imaging light is reflected by the half mirror  12 . The non-reflector  125  having a section in a rectangular shape minus a side is located in the position where light reflected by the light attenuation filter enters. The non-reflector  125  absorbs the reflected light. The light receiving face of this optical trap  18  may be formed with a fabric such as velvet. 
       FIGS. 4A and 4B  are side views of the image processing unit  10 . An attachment base  22  as a first adjustment mechanism has the camera attached thereto, and the projector  16  attached thereto, with the projecting direction of the projector  16  being adjustable. The optical trap  18  is formed in an optical trap unit  20 . 
     As the projecting direction of the projector  16  is adjustable, the direction of projecting imaging light is adjusted so that the half mirror  12  cannot exist in the projecting range, as shown in  FIG. 4B . In this manner, the imaging light can be projected directly onto a screen  200 . 
     In a case where the projection face of the screen  200  extends in the vertical direction, the imaging light projecting direction of the projector  16  in the image processing unit  10  in the situation shown in  FIG. 4A  is perpendicular to the projection face of the screen. Accordingly, a circular luminance distribution is observed, or a so-called hot spot is formed, on the center of the projected image. However, the projector  16  is tilted as shown in  FIG. 4B , so that the imaging light projecting direction of the projector  16  cannot form a right angle with respect to the projection face of the screen  200 , as shown in  FIG. 5 . In this manner, a hot spot cannot be formed on the screen  200 . 
     In the case where the imaging light projecting direction of the projector  16  in the image processing unit  10  is not perpendicular to the projection face of the screen  200 , as shown in  FIG. 5 , trapezoid distortion might be caused in the image projected on the screen  200 . In such a case, the projection lens (not shown) build in the projector  16  is shifted in a predetermined direction, and imaging light having the distortion corrected is projected. In this manner, the trapezoid distortion is corrected. 
     The tilt angle of the projector  16  is set by a personal computer (PC) or the like that controls the attachment base  22 , for example. The tilt angle is input from the PC to the projector  16 . Based on the tilt angle, the imaging light is corrected. Alternatively, a gyro is attached to the projector  16 , and a tilt angle detected by the gyro is input to the projector  16 . Based on the tilt angle, the projector  16  corrects the imaging light. In a case where trapezoid distortion is caused in the image picked up by the camera  14 , the image can be corrected in the same manner as above. 
     A camera  30  shown in  FIG. 4B  picks up an image of the screen  200  having an image projected thereon through imaging light projection. If the camera  14  is designed to be movable and can pick up an image of the screen  200  having an image projected thereon, the camera  30  is unnecessary. With dust and stains on the half mirror  12  being taken into consideration, however, it is desirable to have a camera that picks up an image of the screen  200 . 
       FIGS. 6 and 7  are side views of a first image processing apparatus having the image processing unit  10  mounted thereon. The image processing unit  10  is placed on an elevating movable shelf  40  as a second adjustment mechanism that is slidably attached to a stand  41 . In this manner, the image processing unit  10  can move up and down. 
     In  FIG. 6 , an object  300 - 1  is placed under the image processing unit  10  located in a position A. In this case, the optical trap  18  is placed on a side face of the image processing unit  10 , or on the line extending in the projecting direction of the projector  16 , as shown in  FIG. 1A . The camera  14  receives the light of the object  300 - 1  passing through the half mirror  12 , and picks up the image of the object  300 - 1 . The imaging light from the projector  16  is reflected by the half mirror  12 , and is projected downward. The movable shelf may be designed to tilt the image processing unit  10 . 
     In  FIG. 7 , on the other hand, an object  300 - 2  is not placed under the image processing unit  10 . In this case, the image processing unit  10  moves down to a position in the same horizontal plane as the object  300 - 2  (position B). The optical trap  18  is placed below the image processing unit  10 , or on the line extending in the image pick-up direction of the camera  14 , as shown in  FIG. 1B . The camera  14  receives the light of the object  300 - 2  reflected by the half mirror  12 , and picks up the image of the object  300 - 2 . The imaging light from the projector  16  passes through the half mirror  12 , and is projected in the horizontal direction. 
       FIGS. 8 ,  9 , and  10  are side views of a second image processing apparatus having the image processing unit  10  mounted thereon. As in the first image processing apparatus, the image processing unit  10  is placed on the movable shelf  40 , and can move up and down. In a case where the image processing unit  10  is located in a position C, a mirror  50  as a reflecting means is provided on the line extending in the projecting direction of the projector  16 . 
     In the case where the image processing unit  10  is located in the position C as shown in  FIG. 8 , the optical trap  18  is placed under the image processing unit  10 , or on the line extending in the image pick-up direction of the camera  14 , as shown in  FIG. 1B . The camera  14  receives the light of the object  300 - 1  that is reflected by the mirror  50  and passes through the half mirror  12 . The camera  14  then picks up the image of the object  300 - 1 . In a case where the image processing unit is located in a position D, the optical trap  18  is placed on a side face of the image processing unit  10 , or on the line extending in the projecting direction of the projector  16 . The camera  14  receives the light of the object  300 - 2  reflected by the half mirror  12 , and picks up the image of the object  300 - 2 . 
     In  FIG. 9 , the image processing unit  10  is located in a position E. In this case, the optical trap  18  is placed under the image processing unit  10 , or on the line extending in the image pick-up direction of the camera  14 , as shown in  FIG. 1B . The imaging light from the projector  16  passes through the half mirror  12 , and is horizontally projected onto the screen  200 . 
     In  FIG. 10 , the image processing unit  10  is located in a position F. This image processing unit  10  is tilted so that imaging light that is emitted from the projector  16  and passes through the half mirror  12  is projected diagonally downward. In this case, the optical trap  18  is placed under the image processing unit  10 , or on the line extending in the image pick-up direction of the camera  14 , as shown in  FIG. 1B . The imaging light from the projector  16  passes through the half mirror  12 , and is projected diagonally downward. In this manner, the imaging light is projected onto the screen  200 . 
       FIG. 11  is a side view of a third image processing apparatus having the image processing unit  10  mounted thereon. Unlike the second image processing apparatus, the third image processing apparatus has a contact sensor  60  that detects the location of the image processing unit  10  placed on the movable shelf  40 . More specifically, in a case where the image processing unit  10  is located in such a position that the mirror  50  exists in the image pick-up range of the camera  14 , the contact sensor  60  is located in such a position that can be brought into contact with the image processing unit  10 . 
     In the situation shown in  FIG. 11 , when the contact sensor  60  is brought into contact with the image processing unit  10  located in a position G, a detection signal to this effect is sent to the projector  16 . When the projector  16  receives the detection signal, or when the mirror  50  exists in the image pick-up range of the camera  14 , the projector  16  mirror-reverses the image picked up by the camera  14 , and projects the imaging light corresponding to the mirror-reversed image. In this manner, a non-reversed image is projected on the screen. If the detection signal is not received by the projector  16 , or if the mirror  50  does not exist in the image pick-up range of the camera  14 , the projector  16  projects the imaging light corresponding to the image picked up by the camera  14 . 
       FIG. 12  is a side view of a fourth image processing apparatus having the image processing unit  10  mounted thereon. Unlike the second image processing apparatus, the fourth image processing apparatus has the mirror  50  that can be flipped up, and a contact sensor  70  that detects the location of the image processing unit  10  placed on the movable shelf  40 . More specifically, in a case where the image processing unit  10  is located in such a position that the mirror  50  exists in the imaging light projecting range of the projector  16 , the contact sensor  70  is placed in such a position that can be brought into contact with the image processing unit  10 . 
     In the situation shown in  FIG. 12 , when the contact sensor  70  is brought into contact with the image processing unit  10  located in the position G, a detection signal to this effect is sent to the projector  16 . When the projector  16  receives the detection signal, or when the mirror  50  exists in the imaging light projecting range of the projector  16 , the projector  16  stops projecting the imaging light. Alternatively, when the projector  16  receives the detection signal, the projector  16  performs a control operation to flip up the mirror  50 , and thus eliminates the mirror  50  from the imaging light projecting range of the projector  16 . The mirror  50  might be flipped up by hand. 
     As described above, in the image processing apparatus employed in this exemplary embodiment, the imaging light projecting direction of the projector  16  of the image processing unit  10  is restricted. As a result, even when the image pick-up direction of the camera  14  is restricted, the camera  14  can pick up an image of the object, receiving the light passing through the half mirror  12  or the light reflected by the half mirror  12 . Accordingly, the camera  14  has two image pick-up directions, and a greater degree of freedom is allowed in the image pick-up. 
     Also, by virtue of the movable optical trap  18 , light unnecessary for image pick-up cannot reach the camera  14 , and an image of the object  300  can be properly picked up. 
     Further, since the imaging light projecting direction of the projector  16  can be adjusted, the half mirror  12  can be eliminated from the projecting range. In this manner, an image can be projected directly on the screen  200 . Also, since the position and the setting angle of the image processing unit  10  are adjustable in the vertical direction, the positional relationship between the image processing unit  10  and the object  300  can be set suitably for picking up an image of the object and projecting the imaging light. 
     In the above described exemplary embodiment, in a case where the image processing unit  10  is located in such a position that the mirror  50  exists in the image pick-up range of the camera  14 , the image picked up by the camera  14  is mirror-reversed. In a case where the image processing unit  10  is located in such a position that the mirror  50  exists in the imaging light projecting range of the projector  16 , the projection of imaging light from the projector  16  is stopped, or the mirror  50  is flipped up. However, it is also possible to restrict the location of the image processing unit  10 , so that the image processing unit  10  cannot move to such a position that the mirror  50  enters the image pick-up range of the camera  14  or the imaging light projecting range of the projector  16 , or that the image processing unit  10  cannot stand still in such positions. 
     Although the image processing unit  10  is placed on the movable shelf  40  slidably attached to the stand  41  in the above described exemplary embodiment, the image processing unit  10  may be mounted on a horizontal surface of a table, a floor, or a box-like base, or may be attached to a vertical face such as the face of a wall. Alternatively, the image processing unit  10  may be attached to a ceiling. 
     The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The exemplary embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents. 
     CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2006-217508 filed Aug. 9, 2006.