U.S. patent application number 11/366494 was filed with the patent office on 2006-07-06 for image capture module and image capture apparatus for inputting shape of object on three dimensional space.
This patent application is currently assigned to KABUSHIKI KAISHA TOSHIBA. Invention is credited to Miwako Doi, Akira Morishita, Takahiro Murata, Shunichi Numazaki, Naoko Umeki.
Application Number | 20060146175 11/366494 |
Document ID | / |
Family ID | 17063292 |
Filed Date | 2006-07-06 |
United States Patent
Application |
20060146175 |
Kind Code |
A1 |
Numazaki; Shunichi ; et
al. |
July 6, 2006 |
Image capture module and image capture apparatus for inputting
shape of object on three dimensional space
Abstract
An image capture module and an image capture apparatus for
inputting shape of an object in three dimensional space, including
a light emitting section which emits light to the object for
reflection by the object and imaging of reflected light on a
photo-receiving plane of a reflected light image detecting section
via an image capture optical system. The reflected light image
detecting section detects a reflected light image indicative of a
distribution of intensity of the reflected light. The light may be
irradiated evenly to the object and the shape of the object may be
detected correctly even if the object has irregularity by disposing
the light emitting section closely to the image capture optical
system. The object may be illuminated evenly by the light from a
light emitting section having plural light emitting elements by
disposing the light emitting elements symmetrically about the image
capture optical system. The object may be illuminated more evenly
by the light from the light emitting elements by using reflecting
elements which surround respective light emitting elements and
focus light toward the object.
Inventors: |
Numazaki; Shunichi;
(Kanagawa-ken, JP) ; Murata; Takahiro;
(Kanagawa-ken, JP) ; Doi; Miwako; (Kanagawa-ken,
JP) ; Morishita; Akira; (Tokyo, JP) ; Umeki;
Naoko; (Kanagawa-ken, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
KABUSHIKI KAISHA TOSHIBA
Minato-ku
JP
|
Family ID: |
17063292 |
Appl. No.: |
11/366494 |
Filed: |
March 3, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10612957 |
Jul 7, 2003 |
7042490 |
|
|
11366494 |
Mar 3, 2006 |
|
|
|
09146957 |
Sep 4, 1998 |
6628335 |
|
|
10612957 |
Jul 7, 2003 |
|
|
|
Current U.S.
Class: |
348/360 ;
348/E5.029 |
Current CPC
Class: |
G06F 3/042 20130101;
H04N 5/374 20130101; H04N 2013/0081 20130101; H04N 5/2256 20130101;
G06F 3/0304 20130101 |
Class at
Publication: |
348/360 |
International
Class: |
H04N 5/225 20060101
H04N005/225 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 5, 1997 |
JP |
9-240692 |
Claims
1. An imaging apparatus comprising: a casing including an optical
filter; a plurality of light sources, in the casing, each
configured to emit an invisible light to be reflected by an object;
a two dimensional image sensor, in the casing, surrounded by the
light sources and configured to receive the reflected invisible
lights from the object through the optical filter; and an image
processing unit that obtains three dimensional image information
from a plurality of images, wherein the optical filter selectively
transmits the invisible lights and blocks a visible light.
2. The imaging apparatus according to claim 1, wherein the light
sources are infrared LEDs.
3. The imaging apparatus according to claim 1, wherein the two
dimensional image sensor is a CCD image sensor.
4. The imaging apparatus according to claim 1, wherein a number of
the light sources is more than or equal to 3.
5. The imaging apparatus according to claim 1, wherein the light
sources are arranged symmetrically about a center of the two
dimensional image sensor.
6. The imaging apparatus according to claim 1, further comprising:
a control mechanism configured to control the two dimensional image
sensor to generate a first image when the light sources are
emitting the invisible lights and a second image when the light
sources are not emitting the invisible lights.
7. The imaging apparatus according to claim 6, wherein the three
dimensional image information of the external object is obtained
from the first image and the second image.
8. A portable imaging apparatus configured to be placed on a desk,
comprising: a casing including an optical filter at a top surface
of the casing; at least two light sources, in the casing, each
configured to upwardly emit an invisible light, through the optical
filter, to be reflected by an external object; an image sensor,
disposed in the casing, surrounded by the light sources, and
configured to downwardly receive the reflected invisible lights
from the external object through the optical filter; and an image
processing unit that obtains three dimensional image information
form a plurality of images, wherein the optical filter is
configured to selectively transmit light having a predetermined
wavelength corresponding to the light sources in the casing.
9. The image apparatus according to claim 8, wherein the light
sources are infrared LEDs.
10. The imaging apparatus according to claim 8, wherein the image
sensor is a CCD image sensor.
11. The imaging apparatus according to claim 10, further
comprising: a control mechanism configured to control the CCD image
sensor to generate a first image when the light sources are
emitting the invisible lights and a second image when the light
sources are not emitting the invisible lights.
12. The imaging apparatus according to claim 11, wherein three
dimensional image information of the external object is obtained
from the first image and the second image.
13. The imaging apparatus according to claim 8, wherein the light
sources are arranged symmetrically around the imaging sensor.
14. The imaging apparatus according to claim 13, further
comprising: a control mechanism configured to control the image
sensor to generate a first image when the light sources are
emitting the invisible lights and a second image when the light
sources are not emitting the invisible lights.
15. The imaging apparatus according to claim 14, wherein three
dimensional image information of the external object is obtained
from the first image and the second image.
16. The imaging apparatus according to claim 8, wherein a number of
the light sources is more than or equal to 3.
17. The imaging apparatus according to claim 8, wherein the light
sources are arranged symmetrically about a center of the image
sensor.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Divisional of co-pending U.S. patent
application Ser. No. 10/612,957, filed Jul. 7, 2003, which is a
Divisional of U.S. application Ser. No. 09/146,957, filed Sep. 4,
1998, now U.S. Pat. No. 6,628,335, and claims priority to Japanese
Patent Application No. 9-240692, filed Sep. 5, 1997. The entire
contents of these applications are incorporated herein by reference
in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an image capture module and
an image capture apparatus including light emitting sections to
input a shape of an object on a three-dimensional space.
[0004] 2. Discussion of the background
[0005] Although a mouse is usually used as an input device of a
computer, the mouse is a two-dimensional pointing device for moving
a cursor, for selecting a menu and the like. The mouse operates on
two-dimensional information so that it is difficult to make a
selection on an object having a depth such as an object within a
three-dimensional space. It has been also difficult to add mouse
driven natural motion to characters in creating animation.
[0006] In order to solve the above-mentioned problems, the present
inventors have invented a device that allows a shape of an object,
motion, distance information and the like to be inputted in
non-contact mode of operation. This device obtains an image of
reflected light by operating in synchronism with light emitting
sections an image capture sensor having two capacitors in a
photo-receiving cell that corresponds to one pixel. Electric charge
generated by a photoelectric converting section of the
photo-receiving cell by receiving the light is accumulated
selectively in either one of the two capacitors. Then, electric
charge generated by receiving light while the light emitting
section emits light is accumulated in the first capacitor and
electric charge generated by receiving light while the light
emitting section does not emit light is accumulated in the second
capacitor. Image data of only reflected light which is a difference
between the quantities of electric charge of the two capacitors may
be obtained by providing a mechanism for outputting the difference
between the two quantities of electric charge in reading the charge
from the cell.
SUMMARY OF THE INVENTION
[0007] The present invention provides an image capture module for
inputting a shape of an object on a three-dimensional space,
including a light emitting section configured to irradiate light to
the object to be imaged; and image capture section, disposed in the
vicinity of the light emitting section, configured to detect the
light emitted by the emitting device and reflected by the
object.
[0008] In the image capture module, the light emitting section is
disposed in the vicinity of and around the image capture section so
as to be geometrically symmetrical. The light emitting section is
disposed at positions where the light irradiated from the light
emitting section does not directly enter the image capture
section.
[0009] The image capture module further includes a reflecting
device, mounted around the light emitting section, and configured
to irradiate light emitted from the light emitting section in an
object image capture range. The light emitting section has a
directivity that illuminates a range wider than the image capture
range and illuminates more brightly the peripheral part of the
image capture range than the center of the image capture range.
[0010] The image capture module further includes a filtering
device, mounted in front of the light emitting section or the image
capture section, for protecting the light emitting section or the
image capture section. The filtering device selectivity passes a
wavelength of light to be inputted.
[0011] The image capture module further includes a casing for
concealing and storing the whole of the light emitting section and
the image capture section. The casing has a connector for
exchanging signals with an internal circuit of the image capture
section.
[0012] The image capture module further includes a rotary shaft,
mounted to the image capture module, for rotatably moving the image
capture module. The connector is disposed near the rotary
shaft.
[0013] The present invention is also directed to an image capture
section configured to input to a shape of an object on a
three-dimensional space, including an image capture module,
containing a light emitting section configured to irradiate light
to an object to be imaged; and an image capture section, disposed
in the vicinity of the light emitting section, configured to detect
the light emitted from the light emitting section and reflected by
the object, and a mechanism configured to move the image capture
module within predetermined range of an angle of elevation.
[0014] The image capture apparatus further includes handles,
attached to the image capture module, configured to move the image
capture module, and a casing configured to conceal and store an
external circuit of the image capture module.
BRIEF DESCRIPTION OF DRAWINGS
[0015] A more complete appreciation of the invention and many of
the attendant advantages thereof will be readily obtained as the
same becomes better understood by reference to the following
detailed description when considered in connection with the
accompanying drawings, wherein:
[0016] FIG. 1 is a block diagram showing a structure of an
inputting device having a light emitting section and image capture
sensor according to the present invention;
[0017] FIG. 2 is a schematic block diagram showing a reflected
light image detecting section of the present invention;
[0018] FIG. 3 is a diagram illustrating an effect of the
relationship between positions of the light emitting sections and
the image capture optical system of the invention;
[0019] FIGS. 4a and 4b are plan and sectional views showing a
structure of the image capture module of the present invention;
[0020] FIGS. 5a and 5b are diagrams illustrating changes in
directivity characteristics of the light emitting section obtained
by using a reflecting plate according to the present invention;
[0021] FIG. 6 is an illustration of light reflected by the
reflecting plate of the present invention;
[0022] FIG. 7 is an illustration of light reflected by the
reflecting plate of the present invention;
[0023] FIGS. 8a-8h are illustrations of various arrangements of the
image capture optical system and the light emitting sections of the
present invention;
[0024] FIG. 9 is a sectional view showing a concealed image capture
module of the present invention;
[0025] FIG. 10 is an illustration of the image capture apparatus of
the present invention in which the image capture module is made
movable;
[0026] FIG. 11 is an illustration of the image capture apparatus of
the present invention having handles for moving the image capture
module of the present invention; and
[0027] FIG. 12 is an illustration of the image capture apparatus of
the present invention having a handle for moving the image capture
module of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0028] The fundamental principle and the basic structure of an
image capture section according to the present invention is first
explained. The image capture section has a light emitting section
configured to emit invisible light to an object and an image
capture section configured to detect the light reflected from the
object. The image capture device detects only the light emitted by
the light emitting section and reflected by the object and to the
end separates reflected light from external light such as room
light or sun light by operating the light emitting section and the
image capture section in synchronism.
[0029] Referring now to the drawings, wherein like reference
numerals designate identical or corresponding parts throughout the
several views, FIG. 1 shows the basic structure of the inventive
image capture section and FIG. 2 shows a more detailed structure of
a reflected light image detecting section 4 in the image capture
section. The light emitted from the light emitting section 1 is
reflected by the object 2, e.g., a hand, and the reflected light of
the object 2 is imaged on a photo-receiving plane of the reflected
light image detecting section 4 via an image-capture optical system
3, e.g., a lens. The reflected light image detecting section 4
detects a reflected light image indicative of a distribution of
intensity of the reflected light. How to take out only the
reflected light by the reflected light image detecting section 4
separately from the external light is hereinafter described.
[0030] The reflected light image detecting section 4 continuously
outputs a quantity of reflected light of each pixel of the
reflected light image. The output from the reflected light image
detecting section 4 is amplified by an amplifier 5, is converted to
digital data by an A/D converter section 6 and is then stored in a
memory 7. The data stored in the memory 7 is read at predetermined
timing. The read data is sent to a computer via an I/F circuit 8 to
be processed. A timing controller section 9 controls operation of
the image detecting section 4, A/D converter section 6, memory 7
and I/F circuit 8.
[0031] Next, the structure of the reflected light image detecting
section 4 will be explained in detail by using FIG. 2. In the
reflected light image detecting section 4, photo-receiving cells
15, each corresponds to one pixel of an image, are arrayed
two-dimensionally. Although it is similar to other image-capture
elements such as a CCD image sensor in that respect, it is
different from the CCD in that it includes a mechanism configured
to separate reflected light from the external light and take out
only reflected light within the structure of the cell. The cell 15
includes a photo-electric converter section 10, an accumulating
direction control section 11, a first charge accumulating section
12, a second charge accumulating section 13 and a selective output
section 14.
[0032] The photo-electric converter section 10 converts incident
light into electric charge. The first and second charge
accumulating sections 12 and 13 accumulate the electric charge
generated by the photo-electric converter section 10. The
accumulating direction control section 11 controls to which of the
first and second charge accumulating sections 12 and 13 the
electric charge generated by the photo-electric converter section
10 should be accumulated. The selective output section 14 selects
either the first charge accumulating section 12 or the second
charge accumulating section 13 and reads its electric charge to the
outside of the cell.
[0033] The following operation is carried out in order to obtain
one reflected light image. At first, the light emitting section 1
emits light in pulses. During the emission, electric charge
generated by the photo-electric converter section 10 is accumulated
in the first charge accumulating section 12. Then, while the light
emitting section 1 is not emit light, electric charge generated by
the photo-electric converter section 10 is accumulated in the
second charge accumulating section 13.
[0034] That is, the electric charge obtained by receiving the
reflected light and the external light such as room light and sun
light is accumulated in the first charge accumulating section 12
and the electric charge obtained by receiving only the external
light is accumulated in the second charge accumulating section 13.
When the electric charge is to be read from the cell, the two
quantities of accumulated electric charge are read sequentially to
take out a difference there between by a differential circuit 17.
Only the reflected light may be taken out by subtracting the
quantity of accumulated electric charge of the second charge
accumulating section 13 is from the quantity of accumulated
electric charge of the first charge accumulating section 12.
[0035] The relationship between positions of the light emitting
section and the image capture section is important for the image
capture section of the present invention. When there are objects at
the same distance, it is desirable to be able to illuminate the
surfaces of the objects equally. In other words, it is then
desirable that the intensity of illumination be equal.
[0036] Further, the photo-receiving cells 15 may be a CCD image
sensor. In this case, the CCD image sensor is controlled to output
alternately electric charge generated by receiving light while the
light emitting section emits and does not emit.
First Embodiment
[0037] In FIG. 3, reflected light from an object 25 is detected by
an image capture element (not shown) via the image capture optical
system 3. Assume that there are two light emitting sections at
positions A1 and A2. An LED is used as a light emitting element in
each light emitting section.
[0038] When the object 25 has a concave shape in which the center
thereof is dented, there is a portion 26 at the dented part where
the light emitting from the light emitting section A1 does not
reach. Similarly, there is a portion 27 where the light emitting
from the light emitting section A2 does not reach. The illuminance
of these portions is low because only the light of one light
emitting section strikes as compared to the other part where the
light from both of the light emitting sections strike. Accordingly,
a part in the reflected light image corresponding to that portion
becomes dark.
[0039] Further, light from neither of the light emitting sections
A1 and A2 reaches a portion 28 and no reflected light returns to
photo-receiving cells from the portion 28 at all. Therefore, the
reflected light image appears as if it has a hole at the
center.
[0040] When the light emitting sections are located at positions B1
and B2, not at the positions A1 and A2, light reaches also to the
concave portion at the center of the object 25, so that such a
problem do not arise.
[0041] The same applies also to a case when an object has a convex
shape whose center protrudes. Because light of only one light
source reaches the outer slant portions, the illuminance there
drops with the result that such portions are darkened relative to
the other portions. To avoid the occurrence of darkened portions,
it is important the all of points on an object to be picked up be
coupled in a straight line to the light source and not be
obstructed by the other part of the same object.
[0042] To that end, it is preferable to dispose light emitting
sections as close as possible to the image capture optical system.
This is important for the device emitting light from the light
source, detecting its reflected light as an image and processing
each pixel value of the image in connection with distance as
described in the present embodiment.
[0043] FIGS. 4a and 4b show the image capture module constructed by
disposing the light emitting sections close to the image capture
optical system, wherein FIG. 4a is a plan view in which the image
capture module is seen from the top (from the object side) and FIG.
4b is a sectional view when the image capture module is seen just
from the side.
[0044] The image capture module shown in FIG. 4a includes the image
capture optical system 3 at the center and eight light emitting
sections on a concentric circle around that. Here, the light
emitting sections are composed of LEDs 30.
[0045] In FIG. 4b, the image capture optical system 3 is located at
the center and is surrounded by the LEDs 30. The image capture
element is located below the image capture optical system 3.
Covering the image capture module is part of a frame or a casing 32
for fixing the relationship of positions of the LEDs 30 and the
image capture optical system 3.
[0046] In the first embodiment, an angle of view of the image
capture optical system 3 is set large for the reason explained
hereinafter. Because the image capture section forms an image by
detecting light emitted from the light emitting sections and
reflected by the object, the further the distance to the object,
the smaller the quantity of reflected light to be received becomes.
The distance to the object is desirable to be short for higher S/N.
However, the shorter the distance, the narrower a range where an
image can be detected becomes.
[0047] Suppose that a gesture inputting apparatus is to be
constructed by utilizing the inventive device to input and analyze
a shape of hand, for example. In such a case, the image-capture
range must be sufficient to include the whole hand and to allow a
certain degree of the hand movement. In particular, the image
capture range must be at least 30 cm square. A diagonal distance of
the image capture range of 30 cm square is about 42 cm. When it is
realized by using an optical system having about 50 degrees of
angle of view, the distance to the object is around 45 cm. When it
is realized by an optical system whose angle of view is about 70
degrees, the distance to the object is around 30 cm.
[0048] Because the quantity of received light is inversely
proportional to a square of the distance to the object when the
quantity of emitted light of the light emitting sections is equal
as described above, the quantity of reflected light is reduced by
half or less when the distance to the object increases 45 cm from
35 cm. Accordingly, the angle of view of the image capture optical
system is desirable set to be large.
[0049] Because this image capture section is arranged so as to form
an image by receiving the light emitted by the light emitting
section and reflected from the object, the light emitted by the
light emitting section should not enter the photo-receiving element
directly. Accordingly, the light emitting sections should be
disposed at positions where the light thereof will not enter the
image capture element directly.
[0050] As a method for realizing that disposition, the positional
relationship between the light emitting sections 30 and the image
capture optical system 3 should be defined so that the light will
not enter the image capture optical system 3 directly. Otherwise a
blocking member that blocks only the direct light without affecting
the irradiation of light to the object or the imaging of the
reflected light should be provided. The image capture module shown
in FIGS. 4a and 4b combines both such structures.
[0051] Each LED of the light emitting section shown in FIG. 4b is
surrounded by a reflecting element in the form of a sloped recess
33 cut aslant around each LED so that the surface of the sloped
recess reflects the light of each LED. Although the LED 30 has a
wide directivity and illuminates a range exceeding far beyond the
image capture range, the light illuminated beyond the image capture
range will not reach the image capture element even if it is
reflected by the object. The quantity of reflected light may be
increased and the S/N may be approved by directing the light
emitted toward the outside of the image capture range within the
image capture range by the reflecting element.
[0052] Further, the use of the reflecting element allows the
brightness of the peripheral part to be enhanced more than that of
the center and to prevent the S/N at the peripheral part from
dropping. This point will be explained further in detail in
connection with FIG. 5.
[0053] The LED is constructed by concealing an LED chip, i.e., a
light emitting body, by resin having an effect of lens. Although
the LED chip itself emits light in omnidirectionally, various
directive characteristics may be given to the LED by changing the
lens effect of the concealing resin.
[0054] FIG. 5a shows a light emitting directivity characteristic of
an LED suitable for the present embodiment. This LED has a wide
directivity and is capable of illuminating a wide range. As it is
apparent from FIG. 5a, the intensity of emission is gradually
reduced as the direction of emission deviates from the front
direction and is reduced almost to a half in the direction deviated
by 50 degrees from the front direction.
[0055] Then, the reflecting element 33 is mounted in relation to
the LED as shown in FIG. 6. The LED 30 is located at the center of
and surrounded by the reflecting element 33. Light emission from
the LED is reflected and the directivity thereof is changed by the
reflecting element 33. FIG. 5b shows a directive characteristic of
the emission which has been changed by utilizing such reflecting
element. Here, the reflecting element is disposed so that light
emitted at an angle of 40 degrees or more from the front direction
is reflected. Thus, the intensity of emission in the peripheral
direction becomes greater than that of the front direction.
[0056] However, because the LED light emission may not be always
directed to the center of the object space. For example, there may
be a case when the slope and the shape of the reflecting element
are better not to be symmetrical. While the symmetrical slope may
be created just by creating a conical hole from the top, an
asymmetrical slope may be created by creating a conical hole from
the diagonal direction deviated from the orientation of the
LED.
[0057] For instance, it is desirable to set the angle of the slope
on the lens side at 38 degrees and that of the opposite slope at
about 35 degrees (both are angles from the direction of the optical
axis) when a distance from the center of the lens to the LED is 20
mm and in order to illuminate a space of 20 cm square distance from
the lens by 20 cm.
[0058] Further, the reflection characteristic of the reflecting
element 33 is not limited in specular reflection. Usually, the
accuracy of the position of the LED chip is not high and it is not
reasonable to mount the LED high-accurately. Then, the reflecting
element which has reflection characteristic of specular reflection
makes loss of the illuminance for the object space by the error of
the position of the LED.
[0059] In this case, the surface of the reflecting element may be
diffuse reflection surface. In this way, the reflecting light
reflected by the reflecting element diffuses any direction. So, the
reflecting element of diffuse reflection surface is resolved the
loss of the illuminance for the object space by the error of the
position of the LED.
[0060] The shape of the reflecting element is arranged by a
directivity characteristic of an LED, a characteristic of the
surface of the reflecting element and the desirable characteristic
of the emission. One of the desirable shape of the reflecting
element is a shape 63 as, shown in FIG. 7. It is supposed that LED
exists a starting point in this graph of FIG. 7. A direction of
lengthwise axis the front direction of the LED. This graph shows a
right side of a sectional view. The shape of this reflecting
element has a characteristic mentioned below.
[0061] A light 64 of the 50 degrees direction from the center is
reflected by the vertically reflecting element. And, the light 64
is reflected to the direction 50 degrees. A light 65 of the
direction more than 50 degrees from the LED is reflected to the
vertical direction according to the degrees increased. A light 66
of the 90 degrees direction from the center is reflected to the
vertical direction by the reflecting element of 45 degrees. And,
the light 66 is reflected to the vertical direction. The light of
the direction which is from 50 degrees to 90 degrees is reflected
uniformly to the opposite side which is from 50 degrees to 0
degree.
[0062] Because of the LED is a small surface light source which is
not a point light source, the reflecting element which has specular
reflection of this shape may be loss of the illuminance for the
object space by the error of the position and the shape of the LED.
So, the surface of the reflecting element has the characteristic of
the diffuse reflection. In the case of the specular reflection, the
illuminance is bright for the reflected light reflects to the
vertical direction from the 90 degrees direction. So, it is
desirable that the reflecting element is designed for the reflected
light reflects to the direction shifted from 90 degrees.
[0063] Next, difference possible arrangements of the plurality of
LEDs will be explained in relation to FIGS. 8a-8h which show
examples of arrangements corresponding to different numbers of
LEDs. Generally, the LEDs are arranged symmetrically about the
center of the lens, except in the case 40 where only a single LED
is provided, as shown in FIG. 8a.
[0064] It is desirable to be able to illuminate the space to be
detected by uniform light as much as possible. When all of the LEDs
are disposed on one side of the lens, the side of the space to be
detected as far from the LEDs is darkened as compared to the
opposite side.
[0065] Although FIG. 8a-8f show exemplary arrangements 40 through
45 in which 2, 3, 4, 6 and 8 LEDs are used, the number of LEDs of
the invention is not limited to those numbers. Although the LEDs
cannot be disposed symmetrically except when there is only one LED,
it is effective to dispose them closely to the lens.
[0066] Also, the LEDs may be disposed at the bilaterally
symmetrical positions in the examples 46 and 47 shown in FIGS. 8g
and 8h, they need not be disposed evenly around the image capture
optical system. This arrangement may be adopted when the image
capture range is rectangular and is lengthy in the horizontal
direction. An advantage of this arrangement is that because the
LEDs are mounted at the two places to the right and left, the LEDs
may be mounted per group on a small substrate, thus allowing the
substrate to be miniaturized and facilitating the packaging.
Second Embodiment
[0067] This image capture module allows a device to be manipulated
in a non-contact manner when it is not desirable to manipulate the
device directly by hand because the hands are dirty for example.
However, there has been a possibility that this image capture
module may malfunction when exposed in an environment where it is
liable to get wet by water or to become dirty by mud for
example.
[0068] Further, the quality of the detected image deteriorates when
foreign substances such as mud and dust are lodged between the
image capture optical system and the image capture sensor.
Therefore, it is very important for the device that might be used
in such an adverse environment to construct the image capture
module so that it will not affected by such substances.
[0069] FIG. 9 shows an image capture module having a concealed
structure to solve such problems. In FIG. 9, the LEDs 30, i.e., the
light emitting section, the image capture optical system 3, the
image capture sensor 31 and some circuit parts are stored in a
concealed casing 52.
[0070] The image capture optical system 3, the LEDs 30 and the
image capture element 31 mounted on a substrate 51 as well as their
positional relationship are fixed by the casing 52. A peripheral
circuit is mounted on the substrate 51 as necessary. Cables for
emitting the LEDs are led out of the substrate.
[0071] Preferably, the upper part thereof is covered by an optical
filter 50 which selectively transmits light of wavelength to be
received to form an image. Because near infrared rays are used in
the present embodiment, a near infrared ray transmission filter is
used here. This filter will not transmit visible light, so that the
user is unable to see the inside beyond the filter.
[0072] The image capture optical system, the substrate on which the
image capture element is mounted, and the LEDs are concealed by the
casings 52 and 53 as well as the optical filter 50.
[0073] It is advantageous to use the optical filter also from the
following viewpoint. When the near infrared LED is used as the
light emitting section, the user cannot see the light. However, in
one embodiment a small fluorescent lamp may be used instead of the
near infrared LED in order to assure a much larger quantity of
light. However, because the user can see the light when the
fluorescent lamp is used, a filter for cutting the visible light
must be used to prevent the glare.
[0074] Meanwhile, an optical filter for filtering out light other
than that of predetermined wavelength in order to reduce the amount
of external light such as room light and sun light may be used
together in the image capture optical system. It is, however,
cumbersome to mount the similar optical filters in the light
emitting section and the image capture optical system.
[0075] Then, it is preferable to dispose the light emitting section
and the image capture optical system as close as possible and to
cover the front face thereof by the optical filter filtering out
light other than that of the predetermined wavelength. The cost may
be also lowered by disposing the image capture optical system and
the light emitting section closely.
[0076] The image capture module includes the image capture sensor,
forming an electrical circuit together with several accompanying
electronic parts. Therefore, the internal circuit must be connected
with the external circuit when the image capture module is
concealed. Although it is possible to connect the cables directly
with the external circuit, it is preferable to provide a connector
54 for connecting to the outside in order to facilitate the
assembly of the image capture module to other equipments.
[0077] The image capture section of the present invention may be
used as an input device of various equipments. A designer of an
equipment with which the inventive image capture section of the
present invention is to be assembled can use the device of the
present invention as an input device of arbitrary information by
arranging the equipment so as to detect the shape of a hand, for
example, by the image capture module, to include an image processor
to convert the image into data which can be used as controllable
information and then to take out only the data to the outside of
the connector 54. The equipment can be used in an environmentally
hostile application by utilizing a water-proof or anti-dust
connector.
[0078] Preferably, the image capture section is installed so as to
be able to change the image capture direction. When it is used as a
device for inputting the shape and the motion of moving hand, for
example, the position where the hand can be readily moved differs
depending on person. In such a case, it is preferable to arrange
the device so that the user can control the image capture
direction.
[0079] The simplest structure which allows the image capture
direction to be controlled is to arrange the image capture module
so that it is rotatably mounted on a rotary shaft extending in the
direction vertical to the optical axis of the image capture optical
system in the present embodiment. In that case, when the connector
is mounted at a position distant from the rotary shaft, the
position of the connector may largely changes due to the rotation.
Then, the cable connecting from the connector to the other circuit
must be made longer. In order to avoid this problem, the connector
is positioned as close to the rotary shaft as possible. Thereby,
the cable connecting the image capture module with the external
circuit may be shortened. It also avoids a long cable from becoming
entangled with other parts when the image capture module is moved.
In FIG. 9, the image capture module is constructed so that the
rotary shaft 55 is close to the connector 54.
Third Embodiment
[0080] FIG. 10 shows an image capture section arranged such that an
angle of deviation of the image capture module can be controlled in
a range from 30 degrees to 90 degrees. Because the image capture
section allows the image capture direction to be controlled, each
user can control its direction.
[0081] This device is arranged so that it can be placed on a desk
and be manually manipulated by user. Normally, it can be used
readily with the user making such manipulation by resting his/her
elbow upon the desk. Then, the position of hand may differ
depending on the length from the elbow to the tip of the hand. The
above-mentioned mechanism can accommodate differences in location
of the hand due to the noted user manipulation.
[0082] FIGS. 11 and 12 show image capture sections having attached
handles 60 and 61 for changing the angle of the image capture
module. When one touches the image capture optical system or the
optical filter in changing the direction of the image capture
section, the contacted part may be stained, thus deteriorating the
quality of image detected. Then, the handles are attached so that
the user by using the handles need not erroneously touch the image
capture optical system or the optical filter.
[0083] The handle 60 is attached around the top of the LEDs of the
image capture module in FIG. 11. The handle is attached at the
position when it will not block the path of the light emitted by
the light emitting section, reflected by the object and reaching to
the image capture element. The handles are attached on the right
and left sides to allow users of both right-hander and left-hander
to manipulate the module readily.
[0084] FIG. 12 shows a casing when the handle 61 is attached on the
side of the main body. The image capture module moves in linkage by
sliding the handle along a groove 62. Although the handle is
attached only at the right side in the figure, the handle may be
attached on the both sides as a matter of course.
[0085] Obviously, numerous modifications and variations of the
present invention are possible in light of the above teachings. It
is therefore to be understood that within the scope of the appended
claims, the invention may be practiced than as specifically
described herein.
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