U.S. patent application number 11/898987 was filed with the patent office on 2008-01-31 for projection type image display system, projector, program, information storage medium and image projection method.
This patent application is currently assigned to SEIKO EPSON CORPORATION. Invention is credited to Hideki Matsuda.
Application Number | 20080024514 11/898987 |
Document ID | / |
Family ID | 29405341 |
Filed Date | 2008-01-31 |
United States Patent
Application |
20080024514 |
Kind Code |
A1 |
Matsuda; Hideki |
January 31, 2008 |
Projection type image display system, projector, program,
information storage medium and image projection method
Abstract
To provide a projection type image display system, projector,
program, information storage medium and image projection method
which can project an image applicable to viewing environment of a
changed projection position, a liquid crystal projector is provided
with: a sensor for sensing a projection target area and outputting
sensing information; an edge detection section for outputting
detection information based on the sensing information; a
projectable area determination section for determining a
projectable area based on the detection information; a projection
area selecting section for selecting a projection area from the
projectable area; a sensing data generation section for generating
sensing data applicable to viewing environment of the selected
projection area, based on the sensing information of the selected
projection area; an LUT data generation section for generating LUT
data; a correction section for correcting image information based
on the generated LUT data; and an image projection section for
projecting an image onto the projection area based on the corrected
image information.
Inventors: |
Matsuda; Hideki;
(Fujimi-machi, JP) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 320850
ALEXANDRIA
VA
22320-4850
US
|
Assignee: |
SEIKO EPSON CORPORATION
4-1, NISHI-SHINJUKU 2-CHOME SHINJUKU-KU
TOKYO
JP
163-0811
|
Family ID: |
29405341 |
Appl. No.: |
11/898987 |
Filed: |
September 18, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10438897 |
May 16, 2003 |
7292252 |
|
|
11898987 |
Sep 18, 2007 |
|
|
|
Current U.S.
Class: |
345/589 ;
345/619; 345/682; 348/745; 348/759; 348/E17.005; 348/E5.137;
348/E5.139 |
Current CPC
Class: |
H04N 5/7416 20130101;
H04N 17/04 20130101; H04N 9/3185 20130101; H04N 2005/745 20130101;
H04N 9/3194 20130101; H04N 5/74 20130101 |
Class at
Publication: |
345/589 ;
345/619; 345/682; 348/745; 348/759; 348/E05.139 |
International
Class: |
G09G 5/02 20060101
G09G005/02; G09G 5/373 20060101 G09G005/373; G09G 5/38 20060101
G09G005/38; H04N 5/74 20060101 H04N005/74; H04N 9/31 20060101
H04N009/31 |
Foreign Application Data
Date |
Code |
Application Number |
May 20, 2002 |
JP |
2002-144670 |
May 2, 2003 |
JP |
2003-127026 |
Claims
1. A projection type image display system comprising: a sensing
section which senses a projection target area and outputs sensing
information; a detection section which performs edge detection
based on the sensing information and outputting detection
information which indicates edge in a sensed image; a projection
area selection section which selects a projection area having no
obstacle in the projectable target area, based on the detection
information and selection by a user or a predetermined criterion;
an adjustment section which adjusts input image information such
that an image is displayed on the projection area; an image
correction data generation section which generates image correction
data used to correct the image depending on viewing environment,
based on the sensing information; a correction section which
corrects color and brightness of the input image information, based
on the image correction data; and an image projection section which
projects an image onto the projection area based on the input image
information corrected by the correction section.
2. The projection type image display system as defined in claim 1,
wherein: the image correction data generation section detects
viewing environment of the projection area and generates the image
correction data, based on the sensing information of the projection
area selected by the projection area selection section.
3. The projection type image display system as defined in claim 2,
wherein: the image projection section has a spatial light
modulator; and the adjustment section associates the projection
target area based on the sensing information with a pixel area of
the spatial light modulator to adjust the input image information
so that the position of an image is adjusted.
4. The projection type image display system as defined in claim 2,
wherein: the image projection section has a spatial light
modulator; and the adjustment section associates the projection
target area based on the sensing information with a pixel area of
the spatial light modulator to adjust the input image information
so that the size of an image is adjusted.
5. The projection type image display system as defined in claim 3,
wherein: the sensing section repeatedly performs the sensing
operation at a predetermined timing and outputs the sensing
information; the detection section outputs the detection
information based on the newest sensing information; and the
projectable area determination section determines the projectable
area based on the newest detection information.
6. A projection type image display system comprising: a sensing
section which senses a projection target area and outputs sensing
information; a detection section which performs color-distribution
detection based on the sensing information and outputs detection
information which indicates color distribution in a sensed image; a
projection area selection section which selects a projection area
having no obstacle in the projectable area, based on the detection
information and selection by a user or a predetermined criterion;
an adjustment section which adjusts input image information such
that an image is displayed on the projection area; an image
correction data generation section which generates image correction
data used to correct the image depending on viewing environment,
based on the sensing information; a correction section which
corrects color and brightness of the input image information, based
on the image correction data; and an image projection section which
projects an image onto the projection area based on the input image
information corrected by the correction section.
7. The projection type image display system as defined in claim 6,
wherein: the image correction data generation section detects
viewing environment of the projection area and generates the image
correction data, based on the sensing information of the projection
area selected by the projection area selection section.
8. The projection type image display system as defined in claim 7,
wherein: the image projection section has a spatial light
modulator; and the adjustment section associates the projection
target area based on the sensing information with a pixel area of
the spatial light modulator to adjust the input image information
so that the position of an image is adjusted.
9. The projection type image display system as defined in claim 7,
wherein: the image projection section has a spatial light
modulator; and the adjustment section associates the projection
target area based on the sensing information with a pixel area of
the spatial light modulator to adjust the input image information
so that the size of an image is adjusted.
10. The projection type image display system as defined in claim 8,
wherein: the sensing section repeatedly performs the sensing
operation at a predetermined timing and outputs the sensing
information; the detection section outputs the detection
information based on the newest sensing information; and the
projectable area determination section determines the projectable
area based on the newest detection information.
11. A computer-readable storage medium storing computer-executable
instructions, wherein said computer-executable instructions cause a
computer to function as: a sensing section which senses a
projection target area and outputting sensing information; a
detection section which performs edge detection based on the
sensing information and outputs detection information which
indicates edge in a sensed image; a projection area selection
section which selects a projection area having no obstacle in the
projectable area, based on the detection information and selection
by a user or a predetermined criterion; an adjustment section which
adjusts input image information such that an image is displayed on
the projection area; an image correction data generation section
which generates image correction data used to correct the image
depending on viewing environment, based on the sensing information;
a correction section which corrects color and brightness of the
input image information, based on the image correction data; and an
image projection section which projects an image onto the
projection area based on the input image information corrected by
the correction section.
12. The computer-readable storage medium as defined in claim 11,
wherein: the image correction data generation section detects
viewing environment of the projection area and generates the image
correction data, based on the sensing information of the projection
area selected by the projection area selection section.
13. The computer-readable storage medium as defined in claim 12,
wherein: the image projection section has a spatial light
modulator; and the adjustment section associates the projection
target area based on the sensing information with a pixel area of
the spatial light modulator to adjust the input image information
so that the position of an image is adjusted.
14. The computer-readable storage medium as defined in claim 12,
wherein: the image projection section has a spatial light
modulator; and the adjustment section associates the projection
target area based on the sensing information with a pixel area of
the spatial light modulator to adjust the input image information
so that the size of an image is adjusted.
15. The computer-readable storage medium as defined in claim 13,
wherein: the sensing section repeatedly performs the sensing
operation at a predetermined timing and outputs the sensing
information; the detection section outputs the detection
information based on the newest sensing information; and the
projectable area determination section determines the projectable
area based on the newest detection information.
16. A computer-readable storage medium storing computer-executable
instructions, wherein said computer-executable instructions cause a
computer to function as: a sensing section which senses a
projection target area and outputting sensing information; a
detection section which performs color-distribution detection based
on the sensing information and outputs detection information which
indicates color distribution in a sensed image; a projection area
selection section which selects a projection area having no
obstacle in the projectable area, based on the detection
information and selection by a user or a predetermined criterion;
an adjustment section which adjusts input image information such
that an image is displayed on the projection area; an image
correction data generation section which generates image correction
data used to correct the image depending on viewing environment,
based on the sensing information; a correction section which
corrects color and brightness of the input image information, based
on the image correction data; and an image projection section which
projects an image onto the projection area based on the input image
information corrected by the correction section.
17. The computer-readable storage medium as defined in claim 16,
wherein: the image correction data generation section detects
viewing environment of the projection area and generates the image
correction data, based on the sensing information of the projection
area selected by the projection area selection section.
18. The computer-readable storage medium as defined in claim 17,
wherein: the image projection section has a spatial light
modulator; and the adjustment section associates the projection
target area based on the sensing information with a pixel area of
the spatial light modulator to adjust the input image information
so that the position of an image is adjusted.
19. The computer-readable storage medium as defined in claim 17,
wherein: the image projection section has a spatial light
modulator; and the adjustment section associates the projection
target area based on the sensing information with a pixel area of
the spatial light modulator to adjust the input image information
so that the size of an image is adjusted.
20. The computer-readable storage medium as defined in claim 18,
wherein: the sensing section repeatedly performs the sensing
operation at a predetermined timing and outputs the sensing
information; the detection section outputs the detection
information based on the newest sensing information; and the
projectable area determination section determines the projectable
area based on the newest detection information.
Description
[0001] This is a Continuation of application Ser. No. 10/438,897
filed May 16, 2003. The disclosure of the prior application is
hereby incorporated by reference herein in its entirety.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0002] Japanese Patent Application No. 2002-144670, filed on May
20, 2002 and Japanese Patent Application No. 2003-127026, filed on
May 2, 2003, are hereby incorporated by reference in their
entirety.
BACKGROUND
[0003] The present invention relates to a projection type image
display system, projector, program, information storage medium and
image projection method which can change a projection position.
[0004] Projection type image display systems such as liquid crystal
projectors and the like have been used in classrooms, movie
theaters, meeting rooms, exhibition grounds and domestic living
rooms.
[0005] When an image is projected using a liquid crystal projector
or the like and if there is an obstacle between an image projecting
section and a projection plane, the image will not be well viewed
by the obstacle on which the projected light impinges or which
obstructs the view.
[0006] For example, a domestic living room is usually used not only
by the user of a liquid crystal projector or the like, but also by
the user's family. Even if the user has secured any larger area of
wall surface as a projection area, anyone of his or her family may
place a furniture or houseplant in front of that wall surface such
that the furniture or houseplant will hide part of the projection
area intended by the user.
[0007] Moreover, if a liquid crystal projector or the like is used
to project a product introduction image or an advertisement image
in an exhibition ground or the like, the image may be partially
hidden behind any person who has unintentionally entered the
projection area.
[0008] In such a case, it is usual that the user moves the liquid
crystal projector or the like or changes the direction of
projection from the liquid crystal projector or the like to avoid
the obstacle and to project the image properly. However, the
movement of the liquid crystal projector or the like is troublesome
while at the same time, the calibration must be tried again.
[0009] When the liquid crystal project or the like is used to
project an image, moreover, the user may want to project the image
onto the desired portion of the projection area depending on the
situation in the projection.
[0010] For example, in a room into which a living room and kitchen
are unified, the user may usually project an image onto the wall of
the living room and sometimes want to project another image
illustrating a recipe onto the wall of the kitchen.
[0011] For presentation, a right-handed presenter may more easily
point an image through a pointer when the image is displayed on the
right side as viewed from audience while a left-handed presenter
may more easily point the image through the pointer when the image
is displayed on the left side as viewed from the audience.
[0012] In such a case, it is preferred that the user shifts the
image projection position to perform a more effective presentation.
However, it takes time that the projector is manually adjusted in
projection position and re-calibrated each time when one presenter
is replaced by another.
[0013] In order to display an image intended by the user,
furthermore, it is necessary that the color and brightness of an
image are corrected in consideration of the influences of ambient
light (illuminating light or sunlight) and projection plane.
[0014] In recent years, the partial illumination has been adopted
even in home. If the projection position has been changed without
change of the settings in the liquid crystal projector or the like,
therefore, the image appearance intended by the user may highly be
varied since the influence of the ambient light to the image is
variable depending on the projection position.
SUMMARY
[0015] The present invention is made in view of the above-mentioned
problems and may provide a projection type image display system,
projector, program, information storage medium and image projection
method which can easily change projection position.
[0016] According to a first aspect of the present invention, there
is provided a projection type image display system and a projector
each of which comprising:
[0017] a sensing means for sensing a projection target area and
outputting sensing information;
[0018] a detection means for performing edge detection or
color-distribution detection based on the sensing information and
outputting detection information which indicates edge in a sensed
image or color distribution in a sensed image;
[0019] a projectable area determination means for determining a
projectable area having no obstacle in the projection target area,
based on the detection information;
[0020] a projection area selection means for selecting a projection
area from the projectable area, based on selection by a user or a
predetermined criterion;
[0021] an adjustment means for adjusting input image information
such that an image is displayed on the projection area; and
[0022] an image projection means for projecting an image onto the
projection area based on the adjusted input image information.
[0023] According to a second aspect of the present invention, there
is provided a projection type image display system and a projector
each of which comprising:
[0024] a sensing section which senses a projection target area and
outputs sensing information;
[0025] a detection section which performs edge detection or
color-distribution detection based on the sensing information and
outputs detection information which indicates edge in a sensed
image or color distribution in a sensed image;
[0026] a projectable area determination section which determines a
projectable area having no obstacle in the projection target area,
based on the detection information;
[0027] a projection area selection section which selects a
projection area from the projectable area, based on selection by a
user or a predetermined criterion;
[0028] an adjustment section which adjusts input image information
such that an image is displayed on the projection area; and
[0029] an image projection section which projects an image onto the
projection area based on the adjusted input image information.
[0030] According to a third aspect of the present invention, there
is provided a computer-readable program which causes a computer to
function as:
[0031] a sensing means for sensing a projection target area and
outputting sensing information;
[0032] a detection means for performing edge detection or
color-distribution detection based on the sensing information and
outputting detection information which indicates edge in a sensed
image or color distribution in a sensed image;
[0033] a projectable area determination means for determining a
projectable area having no obstacle in the projection target area,
based on the detection information;
[0034] a projection area selection means for selecting a projection
area from the projectable area, based on selection by a user or a
predetermined criterion;
[0035] an adjustment means for adjusting input image information
such that an image is displayed on the projection area; and
[0036] an image projection means for projecting an image onto the
projection area based on the adjusted input image information.
[0037] According to a fourth aspect of the present invention, there
is provided an information storage medium storing a
computer-readable program which causes a computer to function
as:
[0038] a sensing means for sensing a projection target area and
outputting sensing information;
[0039] a detection means for performing edge detection or
color-distribution detection based on the sensing information and
outputting detection information which indicates edge in a sensed
image or color distribution in a sensed image;
[0040] a projectable area determination means for determining a
projectable area having no obstacle in the projection target area,
based on the detection information;
[0041] a projection area selection means for selecting a projection
area from the projectable area, based on selection by a user or a
predetermined criterion;
[0042] an adjustment means for adjusting input image information
such that an image is displayed on the projection area; and
[0043] an image projection means for projecting an image onto the
projection area based on the adjusted input image information.
[0044] According to a fifth aspect of the present invention, there
is provided an image projection method comprising:
[0045] sensing a projection target area to output sensing
information;
[0046] performing edge detection or color-distribution detection
based on the sensing information and outputting detection
information which indicates edge in a sensed image or color
distribution in a sensed image;
[0047] determining a projectable area having no obstacle in the
projection target area, based on the detection information;
[0048] selecting a projection area from the projectable area based
on user selection or a predetermined criterion;
[0049] adjusting input image information such that an image is
displayed on the projection area; and
[0050] projecting an image onto the projection area based on the
adjusted input image information.
[0051] In the projection type image display systems and the like
according to the present invention, a user can more easily change
the projection position since the projectable area including no
obstacle (e.g., a desk, audience or the like) can automatically be
determined.
[0052] Each of the projection type image display systems and
projectors may further comprise:
[0053] an image correction data generation means for generating
image correction data used to correct an image depending on viewing
environment, based on the sensing information; and
[0054] a correction means for correcting the input image
information adjusted by the adjustment means, based on the image
correction data,
[0055] wherein the image projection means projects an image onto
the projection area based on the input image information corrected
by the correction means.
[0056] Each of the program and information storage medium may
further causes a computer to function as:
[0057] an image correction data generation means for generating
image correction data used to correct an image depending on viewing
environment, based on the sensing information; and
[0058] a correction means for correcting the input image
information adjusted by the adjustment means, based on the image
correction data,
[0059] wherein the image projection means projects an image onto
the projection area based on the input image information corrected
by the correction means.
[0060] The image projection method may further comprise:
[0061] generating image correction data used to correct an image
depending on viewing environment, based on the sensing
information;
[0062] correcting the input image information based on the image
correction data; and
[0063] projecting an image onto the projection area based on the
input image information corrected by the correction means.
[0064] Thus, in the projection type image display systems and the
like, an image can be corrected depending on viewing environment of
the projection position by generating the image correction data
based on the result of sensing of the projection target area and
using the image correction data to correct the input image
information.
[0065] In each of the projection type image display systems,
projectors, program and information storage medium, the image
correction data generation means may detect viewing environment of
the projection area and generate the image correction data, based
on the sensing information of the projection area selected by the
projection area selection means.
[0066] The image projection method may further comprise detecting
viewing environment of the projection area and generating the image
correction data, based on the sensing information of the selected
projection area.
[0067] Thus, in the projection type image display system and the
like, an image view can be kept constant by correcting the image
depending on viewing environment of the projection position even if
the projection position is changed.
[0068] In each of the projection type image display system,
projector, program and information storage medium, the image
projection means may have a spatial light modulator; and the
adjustment means may associate the projection target area based on
the sensing information with a pixel area of the spatial light
modulator to adjust the input image information so that at least
one of the position and size of an image is adjusted.
[0069] The image projection method may further comprise associating
the projection target area based on the sensing information with a
pixel area of a spatial light modulator adjust at least one of the
position and size of an image.
[0070] Thus, in the projection type image display systems and the
like, an image can be projected with its appropriate size since the
association of the projection target area with the pixel area of
the spatial light modulator can automatically be carried out.
[0071] In each of the projection type image display systems,
projectors, program and information storage medium,
[0072] the sensing means may repeatedly perform the sensing
operation at a predetermined timing and output the sensing
information;
[0073] the detection means may output the detection information
based on the newest sensing information; and
[0074] the projectable area determination means may determine the
projectable area based on the newest detection information.
[0075] The image projection method may further comprise:
[0076] repeatedly performing the sensing operation and outputting
the detection information at a predetermined timing, and
[0077] determining the projectable area based on the newest
detection information.
[0078] If the position or the like, of an obstacle is changed (or
if the projection area is hidden by audience, for example), the
projection type image display systems and the like according to the
present invention enables to perform automatic adjustment to
project an image on the projection area having no obstacles by
repeating the sensing and edge detection at a predetermined timing.
So a user can more easily change the projection position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0079] FIG. 1 is a schematic diagram showing a projection area
according to one embodiment of the present invention;
[0080] FIG. 2 is a functional block diagram showing a projection
type image display system in a liquid crystal projector according
to one embodiment of the present invention;
[0081] FIG. 3 is a flow chart showing an image projecting procedure
according to one embodiment of the present invention;
[0082] FIG. 4 is a hardware block diagram showing a projection type
image display system in a liquid crystal projector according to one
embodiment of the present invention; and
[0083] FIG. 5 is a functional block diagram showing another
projection type image display system in a liquid crystal projector
according to one embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0084] The present invention applied to a projection type image
display system that uses a liquid crystal projector is described
below by way of example, with reference to the accompanying
drawings. Note that the embodiment described below do not in any
way limit the scope of the present invention defined by the claims
laid out herein. Similarly, all the elements of the embodiment
below should not be taken as essential requirements defined by the
claims herein.
System Configuration
[0085] There will be described a case when a liquid crystal
projector is arranged in a domestic living room to project an image
onto the wall.
[0086] FIG. 1 is a schematic diagram showing a projection area
according to one embodiment of the present invention.
[0087] When the wall is used as a projection target area 10 onto
which an image is projected and if any obstacle such as a picture
20, a foliage plant 22 or the like, the wall may be hidden behind
the obstacle. Thus, the liquid crystal projector may not adequately
display an image.
[0088] In particular, because the living room is used by a
plurality of members in the family, the picture 20 and/or foliage
plant 22 may frequently be moved by any of the members. It is
therefore difficult to secure the projection area adequately at all
times.
[0089] Moreover, the image appearance is variable depending on the
position of a fluorescent lamp 50. In recent years, the partial
illumination has taken in home. The image appearance is variable
depending on the position onto which the liquid crystal projector
projects an image in the living room.
[0090] The liquid crystal projector according to this embodiment
senses the projection target area 10 through a CCD sensor for
performing edge detection, determines a plurality of projection
areas 40-1 to 40-3 which satisfy a predetermined aspect ratio and
decides one of the projection areas 40 on selection of the user to
project an image thereonto.
[0091] Furthermore, the liquid crystal projector according to this
embodiment realizes an ideal image appearance by correcting the
color and brightness of the image in consideration of the influence
of an ambient light (an illuminating light from the fluorescent
lamp 50 or sunlight) in a viewing environment (or an environment
under which the image is actually viewed under the influence of the
light from the fluorescent lamp 50 as well as the influence of the
color in the projection area) and the influence of the projection
plane (such as the color of the projection area, spectral
reflection factor and the like).
[0092] Thus, the user can reproduce an ideal image appearance even
if the image projection position has been changed.
Functional Blocks
[0093] Functional blocks in a projection type image display system
included in a liquid crystal projector for realizing the
aforementioned functions will be described below.
[0094] FIG. 2 is a functional block diagram showing a projection
type image display system in a liquid crystal projector according
to one embodiment of the present invention.
[0095] The projection type image display system comprises a sensor
60, an input signal processing section 110, a correction section
120, a D/A converter section 180, an image projection section 190,
a projection-area-to pixel-area association section 130, a
projection area determination section 140, a calibration signal
generation section 150, a sensing data generating section 170, an
LUT data generation section 160 and an aspect-ratio determination
section 132.
[0096] The input signal processing section 110 converts R1-, G1-
and B1-signals constituting analog R-, G- and B-signals which are a
kind of input image information from PC (Personal Computer) or the
like into digital R2-, G2- and B2-signals.
[0097] The input signal processing section 110 comprises an A/D
converter section 112 for performing such an analog to digital
conversion and an image position/size adjustment section 114 which
is part of an adjustment mean for adjusting the position and size
of the image (which may adjust only the position or size of the
image).
[0098] However, the A/D converter section 112 and D/A converter
section 180 are unnecessary if only digital type R-, G- and
B-signals are used in the projection type image display system.
[0099] The calibration signal generation section 150 generates
digital R2-, G2- and B2-signals for projection of calibration
images.
[0100] In such a manner, the calibration can be made solely by the
liquid crystal projector by internally generating calibration
signals within the liquid crystal projector without inputting
calibration signals from any external input device such as a PC or
the like into liquid crystal projector. The calibration image
signals may be inputted from PC or the like directly into the
projector 20 without provision of the calibration signal generation
section 150.
[0101] The correction section 120 comprises a 3D-LUT
(three-dimensional lookup table) storage section 122 and a 1D-LUT
(one-dimensional lookup table) storage section 124. The correction
section 120 corrects the color of an image using 3D-LUT and the
brightness of the image using 1D-LUT. 3D-LUT and 1D-LUT are kinds
of image correction data. The image correction data may be in the
form of a matrix, for example.
[0102] The correction section 120 corrects the color, brightness
and the like of the image to form output R3-, G3- and B3-signals,
based on the R2-, G2- and B2-signals from the input signal
processing section 110 or the calibration signal generation section
150.
[0103] The D/A converter section 180 converts the R3-, G3- and
B3-signals from the correction section 120 into analog R4-, G4- and
B4-signals.
[0104] The image projection section 190 comprises a drive section
191, a spatial light modulator 192 and a source of light 193 and a
lens 195.
[0105] The drive section 191 drives the spatial light modulator 192
based on the R4-, G4- and B4-signals from the D/A converter section
180. The image projection section 190 projects the light from the
light source 193 through the spatial light modulator 192 and lens
195.
[0106] In this embodiment, furthermore, the projection area
decision region 140 included in the liquid crystal projector
comprises a projection area selecting section 142, a projectable
area determination section 144, an edge detection section 146 and a
projection-range detection section 148.
[0107] The projection-range detection section 148 detects the range
of the projection target area 10 (which will also be referred to
the projection range 10A), based on sensing information represented
by X-, Y- and Z-values (tristimulus values of XYZ) from the sensor
60 which is a sensing means for sensing the projection target area
10. The X-, Y- and Z-values used herein are machinery independence
colors which are based on the International Standard defined by the
International Commission on Illumination (CIE).
[0108] For convenience, FIG. 1 shows the projection target area 10
which has the same size as the projection range 10A. Moreover, the
projection range 10A is intended to indicate the range in the
projection target area 10 irradiated by a projection light.
[0109] The edge detection section 146 performs the edge detection
and outputs detection information, based on the X-, Y- and Z-values
of the whole projection range 10A on the projection target area
10.
[0110] The projectable area determination section 144 determines
projection areas 40-1 to 40-3 which have no obstacle such as
picture 10 or the like within the projection range 10A on the
projection target area 10 and also which have a size equal to or
larger than a fixed size satisfying the aspect ratio, based on the
detection information and an aspect ratio determined by the
aspect-ratio determination section 132 (for example, 16:9, 4:3 or
the like). For simplicity, FIG. 1 shows three representative
projection areas 40-1 to 40-3, but more projection areas 40 can
actually be determined. Moreover, only one projection area may be
determined. The projectable area determination section 144 detects
a portion of the projection area surrounded by a boarder line on
the outermost side thereof as a projectable area 30.
[0111] If there is any projection area which does not overlap with
other projection areas, a plurality of projectable areas 30 may be
detected.
[0112] The projection area selecting section 142 selects one of the
projection areas 40-1 to 40-3 contained in the projectable area 30
according to user's instruction of selection (e.g., through a
remote controller in the liquid crystal projector).
[0113] The projection-area-to-pixel area association section 130,
which is part of the adjusting means, associates the projection
area in the projection range 10A on the projection target area 10
with the pixel area of the spatial light modulator 192, based on
the projection range 10A on the projection target area 10 detected
by the projection-range detection section 148 and the projection
area selected by the projection area selecting section 142. More
particularly, the projection-area-to-pixel area association section
130 determines a ratio between the projection range 10A on the
projection target area 10 and the pixel area of the spatial light
modulator 192.
[0114] In place of this technique, the projection-area-to-pixel
area association section 130 may associates coordinates within the
projection range 10A (or coordinates on a light-receiving element
in the sensor 60) with coordinates on the projected image (or
calibration image). This is because the coordinates on the
projected image can be transformed into coordinates on the pixel
area of the spatial light modulator 192 through a predetermined
transformation.
[0115] The relationship between a pixel in the projected image and
a pixel portion of the spatial light modulator 192 has been known
by the image projection section 190.
[0116] The image position/size adjustment section 114 adjusts the
input image information to regulate the position and size of the
image, based on the ratio determined by the
projection-area-to-pixel area association section 130 and the
positional information in the projection range 10A on the
projection target area 10 in the projection area selected by the
projection area selecting section 142.
[0117] Furthermore, the liquid crystal projector according to this
embodiment comprises a sensing data generation section 170 for
computing the mean value in the projection area from X-, Y- and
Z-values for each pixel from the sensor 60 when a plurality of
calibration images are projected, to correct the influence of the
ambient light, and an LUT data generation section 160 for updating
or generating 3D-LUT stored in the 3D-LUT storage section 122 and
1D-LUT stored in the 1D-LUT storage section 124, based on X-, Y-
and Z-values for each calibration image.
[0118] The sensing data generation section 170 computes the mean
value of X-, Y- and Z-values of pixels in the projection area,
based on the sensing information from the sensor 60 and information
indicating the projection area from the projection area
determination section 140.
[0119] The LUT data generation section 160, which is an image
correction data generating means, then generates 3D-LUT and 1D-LUT
based on the computed mean value. The LUT data generation section
160 may generate the image correction data corresponding to a
device using a device profile which has been held in the LUT data
generation section 160.
[0120] In such a manner, the image information can be corrected
depending on the viewing environment in the projection area by
generating the image correction data based on the mean value of the
X-, Y- and Z-values which is sensing information for each of the
pixels forming the projection area.
Flow of Image Processing
[0121] A flow of image processing with the use of these sections
and portions will now be described in connection with a flow
chart.
[0122] FIG. 3 is a flow chart showing an image projecting procedure
according to one embodiment of the present invention.
[0123] First of all, the calibration signal generation section 150
produces calibration signals so that a plurality of single-colored
calibration images (for example, white-, red-, green-, blue-, gray-
and black-colored calibration images) will be displayed; the
correction section 120 corrects color temperature and the like on
the basis of normal liquid crystal projector settings; and the
image projection section 190 sequentially projects the calibration
images based on the corrected image information.
[0124] The sensor 60 measures X-, Y- and Z-values of each pixel (or
a pixel in sensor 60 used to output the calibration image
measurement through the sensor 60) in outputs measured value of the
calibration image) in a calibration image displayed on the
projection target area 10 (step S1).
[0125] The projection-range detection section 148 then detects the
projection range 10, based on the difference for each pixel between
X-, Y- and Z-values when the white-colored calibration image is
displayed and X-, Y- and Z-values when the black-colored
calibration image is displayed (step S2). In this case, it is
preferably assumed, for example, that pixels having the difference
equal to or more than 5 cd/m.sup.2 are included in the projection
range 10A on the projection target area 10. In place of the sensing
information (X-, Y- and Z-values) when the black-colored
calibration image is displayed, the sensing information in the
projection range 10A on the projection target area 10 when the
black-colored calibration image is not displayed may be used.
[0126] The edge detection section 146 performs the edge detection,
based on the X-, Y- and Z-values measured when the black-colored
calibration image is displayed (step S3). More particularly, the
edge detection section 146 is based on the X-, Y- and Z-values of
the pixel in the projection range 10A detected by the
projection-range detection section 148.
[0127] The projectable area determination section 144 then
determines a projectable area 30 (i.e., an area including at least
one projection area), based on the image aspect ratio from the
aspect-ratio determination section 132 and the edge detection data
from the edge detection section 146. More particularly, the
projectable area determination section 144 detects the edge
detection data in the projection range 10A from its left and upper
location to its right and lower location to specify an area which
satisfies a desired aspect ratio (i.e., one projection area). For
example, if there is a polygon-shaped projectable area 30 as shown
in FIG. 1, a plurality of projection areas 40-1 to 40-3 will be
selected (step S4).
[0128] The projection area determination section 140 outputs
information indicative of these projection areas 40-1 to 40-3
selected by the projectable area determination section 144 toward
the input signal processing section 110; and the image projection
section 190 projects a selecting image for causing a user to select
one of the projection areas 40-1 to 40-3. In this case, the input
signal processing section 110 may have stored image information
used to generate the selecting image.
[0129] The projection area selecting section 142 then selects one
of the projection areas 40-1 to 40-3, based on a predetermined
criterion (for example, it is at the upper end, lower end, left end
or right end) or a user's instruction (step S5).
[0130] The sensing data generation section 170 computes the mean
value of X-, Y- and Z-values of each of the pixels forming the
projection area in each calibration image, based on the sensing
information from the sensor 60 and information indicating the
projection area from the projection area determination section 140.
Moreover, the LUT generating section 160 generates 3D-LUT and
1D-LUT based on the computed mean value (step S6) and updates the
LUT data by storing them in the 3D-LUT and 1D-LUT storage sections
122, 124, respectively (step S7).
[0131] The projection-area-to-pixel area association section 130
then associates the projection area with the pixel area of the
spatial light modulator 192 (step S8). In this case, the image may
be resized so that the entire range of the image represented by the
image signals is projected onto the selected projection area.
Alternatively, the image may be trimmed so that part of the image
represented by the image signals is projected onto the selected
projection area.
[0132] The image position/size adjustment section 114 then uses
this association to adjust the digitally converted input image
signals so that the position and size of the image will be adjusted
and outputs digital signals (R2, G2, B2).
[0133] Furthermore, the correction section 120 uses these digital
signals (R2, G2, B2) to correct the image information so that the
image takes the color and brightness corresponding to the viewing
environment on the projection area; and the D/A converter section
180 performs the digital conversion against the image information
(R3, G3, B3) from the correction section 120 and outputs analog
signals (R4, G4, B4).
[0134] The drive section 191 then drives the spatial light
modulator 192 based on these analog signals (R4, G4, B4); and the
image projection section 190 outputs a light from the light source
193 through the spatial light modulator 192 and lens 195 to project
the image.
[0135] In such a manner, the image projection section 190 can
project the image corrected relating to its color and brightness
onto the projection area (step S9).
[0136] As described, this embodiment can permit the user to change
the projection position in a more simple and easy manner since the
liquid crystal projector can automatically determine any suitable
projectable area 30 on which there is no obstacle (for example,
desk, audience or the like).
[0137] For presentation, a right-handed presenter may more easily
point an image through a pointer when the image is displayed on the
right side as viewed from audience while a left-handed presenter
may more easily point the image through the pointer when the image
is displayed on the left side as viewed from the audience.
[0138] Even in such a case, this embodiment permits the user to
project the image onto any preferred position without need of any
manual adjustment for the projector's projection position.
[0139] According to this embodiment, furthermore, the liquid
crystal projector can project the image after the color and
brightness thereof have been corrected for the viewing environment
of the projection area selected from the projectable area by
generating the sensing data from the computed mean values of the
X-, Y- and Z-values of each of the pixels forming the projection
area in each calibration image, based on the sensing information
from the sensor 60 and the information indicative of the projection
area from the projection area determination section 140 and by
using the image correction data generated based on this sensing
data.
[0140] Thus, the liquid crystal projector can more simply and
easily change the projection position, for example, even if the
projection area 40 is continuously changed for display, since no
calibration must be re-tried each time when the projection area is
change.
[0141] According to this embodiment, furthermore, the liquid
crystal projector can project the image with its appropriate size
onto an appropriate position since the association of the
projection range 10A on the projection target area 10 with the
pixel area in the spatial light modulator 192 can automatically be
carried out.
Hardware Configuration
[0142] For example, the following things can be applied to the
respective hardware parts above mentioned.
[0143] FIG. 4 is a hardware block diagram showing a projection type
image display system in a liquid crystal projector according to one
embodiment of the present invention.
[0144] For example, the A/D converter section 112 may be
implemented by an A/D converter 930 or the like; the D/A converter
section 180 may be implemented by a D/A converter 940 or the like;
the drive section 191 may be implemented by a ROM 960 or the like
stored a liquid crystal light valve drive driver; the spatial light
modulator 192 may be implemented by a liquid crystal panel 920 or a
liquid crystal light valve or the like; the correction section 120,
projection area selecting section 142, projectable area
determination section 144, edge detection section 146,
projection-range detection section 148, projection-area-to-pixel
area association section 130, aspect-ratio determination section
132, sensing data generation section 170 or LUT generating section
160 may be implemented by an image processing circuit 970 or CPU
910 or the like; the calibration signal generation section 150 may
be implemented by a RAM 950 or the like; and the sensor 60 may be
implemented by a multi-pixel sensor which can derive X-, Y- and
Z-values such as a CCD sensor or a CMOS sensor or the like. These
components arc configured to mutually deliver the information
therebetween through a system bus 980. Moreover, these components
could be implemented in a hardware manner such as circuits or in a
software manner such as drivers.
[0145] In addition, these functions could be implemented by a
computer within the liquid-crystal projector reading out a program
from an information storage medium 300.
[0146] The information storage medium 300 could be a CD-ROM,
DVD-ROM, ROM, RAM, or HDD, by way of example, and the method of
reading the program therefrom could be a direct method or an
indirect method.
[0147] Instead of the information storage medium 300, it is also
possible to download a program that implements the above-described
functions, from a host device over a network, in order to implement
the above-described functions.
Modifications
[0148] Although one embodiment of the present invention has been
described, the present invention is not limited to this
embodiment.
[0149] For example, the projectable area determination section 144
determines the projectable area 30 based on the edge detection
information in a sensed image from the edge detecting section 146
in the above embodiment, but the projectable area 30 may be
determined based on information other than the edge detection
information. The projectable area determination section 144 may
determine the projectable area 30 based on color distribution in a
sensed image.
[0150] Since the X-, Y- and Z-values relating to an obstacle such
as the foliage plant 22 are different from the X-, Y- and Z-values
in the projectable area 30 in the sensed image of FIG. 1, the
projectable area 30 can be selected by detecting distribution of
X-, Y- and Z-values representing colors. The technique of selecting
the projectable area 30 based on color distribution will be
described below.
[0151] FIG. 5 is a functional block diagram of a projection type
image display system in a liquid crystal projector according to one
embodiment of the present invention.
[0152] In this embodiment, the edge detecting section 146 is
replaced by a color-distribution detection section 147 which
outputs detection information indicating color distribution in a
sensed image (which may be the whole or part of the sensed image)
from the sensor 60, and the projectable area determination section
144 is replaced by a projectable area determination section
145.
[0153] After the processing in the project region detection section
148 (step S2) described in connection with FIG. 3, the
color-distribution detection section 147 detects color distribution
in the project region 10A based on the sensing information (X-, Y-
and Z-values) relating to a portion corresponding to the project
region 10A in the sensed image.
[0154] More particularly, the color-distribution detection section
147 generates a histogram (or frequency distribution) of X-, Y- and
Z-values for a predetermined image processing unit (such as one
pixel or a pixel block including a fixed number of pixels in
horizontal and vertical directions).
[0155] The color-distribution detection section 147 then detects a
range of X-value (XP1-XP2) having upper frequency in the histogram
of X value. Similarly, the color-distribution detection section 147
detects a range of Y-value (YP1-YP2) having upper frequency and a
range of Z-value (ZP1-ZP2) having upper frequency. These ranges are
optional, so they may be identical with one another or different
from one another.
[0156] The color-distribution detection section 147 outputs the
color-distribution information (XP1-P2, YP1-YP2 and ZP1-ZP2) toward
the projectable area determination section 145.
[0157] The projectable area determination section 145 then
determines the projectable area 30, based on an aspect ratio of an
image from the aspect ratio determination section 132 and the
detection information of color distribution from the
color-distribution detection section 147.
[0158] Specifically, the projectable area determination section 145
selects an area AX having an X-value corresponding to the range of
X-value (XP1-XP2) from the color-distribution detection section
147, based on the sensing information relating to the projection
area 10A in the sensed image. Note that the sensing information has
an ordinate position, an abscissa position, X-value, Y-value and
Z-value for each coordinate position. Therefore, the projectable
area determination section 145 can use the X-value as a search key
to detect the ordinate and abscissa positions in the coordinates
having the X-value, so that it can select the area AX. Areas AY and
AZ for Y- and Z-values can be selected similarly.
[0159] According to such a procedure, the projectable area
determination section 145 selects the area AX having the X-value in
the range of X-value (XP1-XP2), the area AY having the Y-value in
the range of X-value (YP1-YP2) and the area AZ having the Z-value
in the range of Z-value (ZP1-ZP2) in addition to an area AA in
which the areas AX, AY and AZ overlap each other (e.g., the
projectable area 30 in FIG. 1).
[0160] In such a manner, the projectable area 30 can be selected.
The remaining procedure portion may be accomplished by the steps
after the above-mentioned step S3 in FIG. 3.
[0161] By using such a technique based on the color distribution,
the liquid crystal projector according to this embodiment can
select an area satisfying the aspect ratio from among an area which
has the same color and has not been influenced (or influenced) by
the environment, as a projection area, even if part of the
projection target area 10 has been influenced by that environment
(due to the fluorescent lamp 50 or the like).
[0162] The liquid crystal projector according to this embodiment
can perform the processing more quickly (or more efficiently) since
the edge detection can be omitted by adopting the technique based
on the color distribution.
[0163] Note that the technique of detecting color distribution is
not limited to the aforementioned technique. For example, the range
of X-, Y- or Z-value may be determined by calculating these values
with different coefficient values or by using a certain function.
Moreover, the indexes for detecting color distribution may be in
the form of R-, G- and B-values, other than the X-, Y- and
Z-values.
[0164] When part of the projection target area 10 reflects no light
projected from the liquid crystal projector, such as when the
liquid crystal projector is used outdoors and part of the
projection target area 10 is an empty space, or when the liquid
crystal projector is used in a classroom and part of the projection
target area 10 is a glass window, the liquid crystal projector may
perform the following processing.
[0165] When the liquid crystal projector projects a rectangular
image, the projection area can be determined by a process in which
projecting and imaging of points or lines representing four corners
of the rectangular image is repeatedly performed while narrowing
the projection range, and the four corners in the sensed image is
associated with the coordinates of the four corners in the spatial
light modulator 192 at the point of detection of the points or
lines representing the four corners by the sensor 60.
[0166] Although the liquid crystal projector in the above
embodiment uses a monochromatic black calibration image for the
edge detection or other processing, sensing information indicating
differences between the X-, Y- and Z-values of a monochromatic
white calibration image as a sensed image and the X-, Y- and
Z-values of a monochromatic black calibration image as a sensed
image may be used for the edge detection or other processing.
[0167] Even if the projection target area 10 is influenced by the
environment differently by location, the liquid crystal projector
can perform the detection of color distribution and the like in a
state the difference is reduced.
[0168] The user's selection of the projection area may be carried
out through a button or remote controller on the main body of the
liquid crystal projector or through action or voice of the
user.
[0169] Moreover, the liquid crystal projector according to this
embodiment may perform the trapezoid skew correction or automatic
focus adjustment when the image is projected.
[0170] Furthermore, the projection area may have any configuration
other than the rectangle-shaped configuration as in the
aforementioned embodiment, such as a circular configuration.
[0171] In addition, the liquid crystal projector of this embodiment
may repeatedly perform such an image projection as shown in FIG. 9
at a predetermined timing (e.g., with a predetermined time interval
or at a time point when one presenter is replaced by another).
[0172] Thus, the liquid crystal projector can automatically perform
such an adjustment that the image can be projected onto a
projection area having no obstacle by repeating the sensing and
edge detection operations at a predetermined timing when the
position of an obstacle has been changed, more particularly, when
the projection area is hidden by audience. Thus, the user can more
simply and easily change the projection position. The liquid
crystal projector may further determine the projection area
depending on the position of the obstacle.
[0173] In addition, the liquid crystal projector of this embodiment
may repeat such a process as shown by steps S1 to S9 in FIG. 3 if
the image processing of FIG. 3 is repeated at the predetermined
timing. Alternatively, the liquid crystal projector may repeat such
a process as shown by steps S3 to S9 by performing only the sensing
operation for the projection target area 10 on non-display (or the
projected black-colored calibration image) at step 1 and omitting
the procedure of step S2.
[0174] In the former case, thus, the liquid crystal projector can
not only perform such an adjustment that the image is projected
onto a projecting area 40 having no obstacle, for example, when a
new obstacle enters the projection area, but also project the image
after it has been corrected for a new viewing environment when the
older viewing environment has been changed. In the latter case, the
liquid crystal projector can more simply and easily change the
projection position without giving troublesome feelings to
observers due to display of the colored calibration images, since
the image can be projected onto the new projection area having no
obstacle merely by performing the sensing operation for the
projection target area 10 on non-display.
[0175] Although the preferred embodiment has been described as to
the liquid crystal projector which determine the maximum
projectable area 30 after one or more projection areas 40
satisfying the aspect ratio have been selected, one or more
projection areas 40 satisfying the aspect ratio within the
projectable area 30 may be selected after the projectable area 30
having no obstacle has been determined based on the edge detection
data.
[0176] Although the preferred embodiment has been described as to
the liquid crystal projector which generates the image correction
data based on the mean value of X-, Y- and Z-values on the
projection area determined by the projection area determination
section 140, image correction data (e.g., 3D-LUT, 1D-LUT and the
like) may be generated based on the mean value of the X-, Y- and
Z-values for each selectable projection area (for example, each of
the projection areas 40-1 to 40-3 shown in FIG. 1). It may be then
stored to correction section 120. The input image information may
be then corrected while switching one changing image correction
data to be applied to another, depending on selection of the
projection area.
[0177] Thus, the liquid crystal projector can apply the image
correction data acceptable to the viewing environment within a
reduced time period since it is not required to update the image
correction data at each time when the projection area is changed,
even though it is frequently changed.
[0178] The projection type image displaying system according to
this embodiment may be applied to any one of various projectors
such as a projector using a digital micromirror device (DMD) and
the like, other than the aforementioned liquid crystal projector.
For example, the aforementioned spatial light modulator may be in
the form of an instrument consisting of a DMD tip and a color
filter. By the way, DMD is a trademark possessed by the U.S. Texas
Instruments. In addition, the projector is not limited to be of
front projection type, but it may be of back projection type.
[0179] The present invention can effectively be used even when an
image is projected in the business such as a meeting room, a
medical building-site, an advertisement spot, an education spot, a
movie theater, an exhibition ground, rather than for the
aforementioned domestic living rooms.
[0180] In addition, the aforementioned function of the projector
type image displaying system may be implemented by a single liquid
crystal projector or by a plurality of distributed processing
devices (e.g., a liquid crystal projector and personal
computers).
* * * * *