U.S. patent application number 16/195609 was filed with the patent office on 2019-05-23 for camera having a separate image capture module and a method of assembling the camera.
The applicant listed for this patent is Blackmagic Design Pty Ltd.. Invention is credited to Carsten Buettner, Michael Cornish, Stuart Elford, Simon Kidd, David Lunn, Grant Petty, Patrick Tolcher, John Vanzella.
Application Number | 20190158709 16/195609 |
Document ID | / |
Family ID | 49326957 |
Filed Date | 2019-05-23 |
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United States Patent
Application |
20190158709 |
Kind Code |
A1 |
Petty; Grant ; et
al. |
May 23, 2019 |
Camera Having a Separate Image Capture Module and a Method of
Assembling the Camera
Abstract
A camera including an image capture module, and at least one
other module. The image capture module is a sealed module and
includes: a housing; at least one image sensor to convert light
into electrical signals; an optical system associated with the
image sensor and arranged to transmit light through the housing to
the at least one image sensor; the image capture module and the at
least one other module being directly or indirectly mounted to each
other, and interoperable with each other to capture images. An
image capture module and method of construction of a camera are
also described.
Inventors: |
Petty; Grant; (Port
Melbourne, AU) ; Kidd; Simon; (Port Melbourne,
AU) ; Cornish; Michael; (Port Melbourne, AU) ;
Elford; Stuart; (Port Melbourne, AU) ; Lunn;
David; (Port Melbourne, AU) ; Vanzella; John;
(Port Melbourne, AU) ; Buettner; Carsten; (Port
Melbourne, AU) ; Tolcher; Patrick; (Port Melbourne,
AU) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Blackmagic Design Pty Ltd. |
Port Melbourne |
|
AU |
|
|
Family ID: |
49326957 |
Appl. No.: |
16/195609 |
Filed: |
November 19, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15490214 |
Apr 18, 2017 |
10154180 |
|
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16195609 |
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14391982 |
Oct 10, 2014 |
9661235 |
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PCT/AU2013/000381 |
Apr 12, 2013 |
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15490214 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04N 5/238 20130101;
H04N 5/2252 20130101; G03B 17/55 20130101; H04N 5/22525 20180801;
H04N 5/22521 20180801; H04N 5/2253 20130101; H04N 5/23216 20130101;
G03B 17/561 20130101; H04N 5/23293 20130101; H04N 5/2251 20130101;
H04N 5/2254 20130101; H04N 5/2257 20130101; G03B 17/14
20130101 |
International
Class: |
H04N 5/225 20060101
H04N005/225; H04N 5/232 20060101 H04N005/232; G03B 17/56 20060101
G03B017/56; G03B 17/14 20060101 G03B017/14; H04N 5/238 20060101
H04N005/238; G03B 17/55 20060101 G03B017/55 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 13, 2012 |
AU |
2012901461 |
Claims
1-20. (canceled)
21. A camera including: a body module including a body housing; at
least one image capture module, said at least one image capture
module including: a housing; at least one image sensor to convert
light into electrical signals; an optical system associated with
the image sensor and arranged to transmit light through the housing
to the at least one image sensor; and a lens mount including a
coupling to releasably engage a lens or other optical module to
connect the lens or other optical module to the image capture
module, wherein each image sensor has an imaging plane, said image
sensor being mounted within the image capture module such that the
imaging plane lies at a predefined distance from a plane of a
mounting face of the lens mount; said image capture module being
mounted to the body housing, and interoperable with the body module
to capture images; the body module further including a data
processing system to process image data received from an image
sensor of the image capture module; and a user interface subsystem
to enable user control of the image capture module.
22. The camera of claim 21 further including at least one second
image capture module.
23. The camera of claim 21 wherein any one or more of the following
subsystems is mounted within the housing of said body module: a
power supply subsystem arranged to supply power to the image
capture module; a thermal control subsystem arranged to dissipate
heat generated in the image capture module; and an input and/or
output subsystem to enable data or electrical connection to another
device.
24. The camera of claim 21 wherein the at least one image sensor is
mounted to the image capture module via an adjustable mounting
structure to allow adjustment of a position of the at least one
image sensor with respect to the housing and lens mount.
25. The camera of claim 24 wherein the at least one image sensor is
mounted on a substrate, and wherein the adjustable mounting
structure includes a series of adjustment screws holding the
substrate to the housing.
26. The camera of claim 25 wherein said adjustable mounting
structure further includes one or more spacers positioned between
the substrate and the housing to set the predefined distance
between the imaging plane and the plane of the mounting face of the
lens mount.
27. The camera of claim 26 wherein the optical system of the image
capture module includes one or more light transmissive elements in
front of and covering the at least one image sensor.
28. The camera of claim 27 wherein the one or more light
transmissive elements includes a light transmissive element
selected from a group including: one or more lenses; one or more
filters, one or more polarisers; and a light transmissive
cover.
29. The camera of claim 27 wherein the light transmissive element
covering the image sensor is spaced apart from the image sensor and
sealed to the housing.
30. The camera of claim 25 wherein the image capture module further
includes a rear seal sealing at least one of the substrate or the
image sensor to the housing.
31. The camera of claim 21 wherein the image capture module
additionally includes a cooling system arranged to cool the image
sensor and provide a thermal interface with the body module.
32. The camera of claim 31 wherein the cooling system is an active
cooling system in thermal communication with the image sensor
arranged to transfer heat away from the image sensor.
33. The camera of claim 21 wherein the image capture module
includes a generally tubular body with said lens mount located at
one end thereof and a substrate carrying the image sensor mounted
on or adjacent to another end thereof.
34. The camera of claim 31 wherein the thermal interface of the
image capture module is connected to the body module to transmit
heat generated in the image capture module for dissipation by the
body module.
35. The camera of claim 21 wherein the body housing is metal.
36. The camera of claim 35 wherein the metal body housing is
thermally connected to the image capture module, either directly or
via a heat transmitter such that heat generated in the image
capture module is transmitted to the metal body housing for
dissipation.
37. The camera of claim 21 wherein the body housing includes
ventilation openings to enable air to move through the body housing
and the camera includes a thermal control subsystem to cause
movement of said air for cooling.
38. The camera of claim 21 wherein the camera includes a data
storage subsystem to store at least data derived from an image
sensor of the image capture module, wherein the data storage
subsystem includes a removable solid state drive.
39. The camera of claim 21 wherein the housing of the image capture
module forms part of an external housing of the camera.
40. The camera of claim 35 wherein the metal is aluminium.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/490,214, filed Apr. 18, 2017, which is a
continuation of U.S. patent application Ser. No. 14/391,982, which
is now U.S. Pat. No. 9,661,235 issued on May 23, 2017, which is a
U.S. national phase of international patent application No.
PCT/AU2013/000381, filed Apr. 12, 2013, which claims priority to
Australian application No. AU2012901461, filed Apr. 13, 2012, the
disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to cameras and their
construction. The present invention is described in connection with
the construction of a video camera, but may additionally find
application in manufacture of digital still cameras.
BACKGROUND OF THE INVENTION
[0003] Manufacture of a camera is a complex process which presents
particular challenges. Some of these include:
[0004] The need to maintain sensor cleanliness often results in the
need to build the entire product in a clean room. With parts for
the body of the camera coming from a number of different sources,
the body parts of the camera are often not clean enough to enter a
clean room where the sensor is to be assembled. Presently the only
solution to this is that all components are manufactured to a
cleanliness standard that is often expensive, or unattainable.
[0005] Assembling the product to tight tolerances can be very
difficult, because the combination of multiple mechanical parts,
each with their own manufacturing tolerance, increases tolerance
stack-up. This can make it difficult to calibrate the sensor
position relative to the lens mount. The process of calibrating
such a complex device itself can be difficult and time consuming.
Moreover many of the steps are mechanical in nature and must be
repeated. This can create a bottle neck in the assembly
process.
[0006] Some of the manufacturing and calibration issues can be
addressed by the use of jigs to assist in certain manufacturing
steps, say to ensure the sensor is aligned to its substrate before
assembly and then glued in place. However, such jigs only complete
half the job of alignment, the sensor still requires physical
alignment to the body of the camera to ensure it aligns with the
lenses, this is a long arduous process that can add substantial
assembly time. U.S. Publication No. 2004/0121503 described a system
of this type.
[0007] These difficulties have flow on effects. For example to
create an alternate version of the product to support a different
lens systems etc., often requires a complete product and production
system redesign.
[0008] Highly skilled technicians are also required for the
assembly of the whole product, which increases cost.
[0009] Manufacturing mistakes that affect the product as it nears
completion can require complete disassembly of the whole product to
solve.
[0010] Moreover the inherent complexity of the device makes
servicing difficult. For example, currently to service a sensor
assembly of a camera, the whole camera must disassembled.
Disassembling of the camera can lead to contamination of the sensor
so must be performed under very controlled circumstances. In the
ideal situation, this would be a clean-room. Although in most cases
a camera that has been used in the field could not be made clean
enough to be worked on in a clean room, so this is not
practical.
[0011] Accordingly there is a need for a camera design that
addresses at least one of the foregoing drawbacks of the prior art
or at least provides a useful alternative to the conventional
approach to camera construction.
[0012] Reference to any prior art in the specification is not, and
should not be taken as, an acknowledgment or any form of suggestion
that this prior art forms part of the common general knowledge in
Australia or any other jurisdiction or that this prior art could
reasonably be expected to be ascertained, understood and regarded
as relevant by a person skilled in the art.
SUMMARY OF THE INVENTION
[0013] In broad concept a camera made in accordance with an
embodiment of the present invention includes a plurality of modules
each having a separate housing. The modules are coupled together
and at least one of data, electrical or thermal connection is made
between neighboring modules to complete the camera. At least one of
the modules is an image capture module that includes an image
sensor and optical system mounted to its housing, and forming a
sealed unit. The other module(s) can include a main body unit which
includes components for providing other functions to the completed
camera, such as data processing, power delivery, data storage,
thermal control and/or user interface functions.
[0014] Advantageously the image capture module is able to be
assembled separately to the other module(s) of the camera. The
modules can be connected together to complete construction of the
camera body. Most preferably the image capture module is integrated
in the camera during assembly of the other modules and provides at
least part of the camera housing.
[0015] This modular construction can allow each module to be
manufactured under different manufacturing conditions if needed.
Advantageously, the image capture module can be manufactured in
relatively better conditions (e.g. cleaner, low static, higher
precision) than the other module(s). For example the image capture
module can be assembled in a clean room environment, whereas the
main body module can be assembled in a routine electronics assembly
environment. Because the image capture module is a sealed unit it
can be assembled to the main body module (or other module) at final
assembly outside the clean room environment. Accordingly in one
form there is described a camera including an image capture module,
and at least one other module; said image capture module being a
sealed module and including: a housing; at least one image sensor
to convert light into electrical signals; an optical system
associated with the image sensor and arranged to transmit light
through the housing to the at least one image sensor; said image
capture module and said at least one other module being directly or
indirectly mounted to each other, and interoperable with each other
to capture images.
[0016] In a first aspect of the present invention there is provided
a camera including a body module including: a body housing and an
image capture module. The image capture module being a sealed
module and including: [0017] a housing; [0018] at least one image
sensor to convert light into electrical signals; [0019] an optical
system associated with the image sensor and arranged to transmit
light through the housing to the at least one image sensor; [0020]
a lens mount including a coupling to releasably engage a lens or
other optical module to connect the lens or other optical module to
the image capture module; [0021] said image capture module being
mounted directly or indirectly to the body housing, and
interoperable with the body module to capture images.
[0022] Preferably the image capture module includes a thermal
interface arranged to enable thermal connection between the image
capture module and the body module.
[0023] In a preferred form said at least one other module has a
housing to which is mounted any one or more of: [0024] a power
supply subsystem arranged to supply power to the image capture
module; [0025] data processing system(s) to process image data
received from an image sensor of the image capture module; [0026] a
thermal control subsystem arranged to dissipate heat generated in
the image capture module; [0027] a user interface subsystem to
enable user control of the image capture module; [0028] a data
storage subsystem to store data derived from an image sensor of the
image capture module; [0029] an input and or output subsystem to
enable data or electrical connection to another device.
[0030] In a preferred form the camera includes an electrical
connection between the image capture module and another module to
deliver electrical power to the image capture module.
[0031] In a preferred form the camera includes a data communication
connection between the image capture module and another module to
exchange data between the image capture module and the other
module. Said data could be, without limitation, image data received
from an image sensor of the image capture module; control data for
controlling the operation of the image capture module or an optical
module or lens connected, thereto; sensing data derived from
sensors mounted in the image capture module, or an optical module
or lens connected thereto.
[0032] In a preferred form the camera includes a thermal connection
between the image capture module and another module to transmit
heat generated in the image capture module for dissipation from the
other module. The thermal connection preferably includes at least
one heat-transfer element to draw heat away from the image capture
module. The heat transfer element could include one or more of a
Peltier cooler (or other active cooler) or heat pipe or the
like.
[0033] The image capture module preferably includes a lens mount on
one end thereof, said lens mount including a coupling to releasably
engage a lens or other optical module thereto. The lens mount can
have a mounting face against which a mating surface of a lens
abuts.
[0034] The image capture module can include at least one image
sensor, each having an imaging plane. The image sensor(s) is(are)
preferably mounted within the image capture module such that the
imaging plane lies at a predefined distance from a plane of the
mounting face of the lens mount. The predefined distance
corresponds to the type of lens mount.
[0035] The image sensor is mounted to the housing of the image
capture module via an adjustable mounting structure. The adjustable
mounting structure allows adjustment of the position of the image
sensor position with respect to the housing and lens mount.
[0036] Preferably the at least one image sensor is mounted on a
substrate. The adjustable mounting structure can include a series
of adjustment screws holding the substrate to the housing. Said
adjustable mounting means optionally including one or more spacers
positioned between the substrate and housing to set the predefined
distance between the imaging plane and the plane of the mounting
face of the lens mount.
[0037] The optical system of the image capture module includes one
or more light transmissive elements in front of and covering the
image sensor. The one or more light transmissive elements could be
any type of light transmissive element including but are not
limited to: [0038] one or more lenses; [0039] one or more filters;
[0040] one or more polarisers; [0041] a light transmissive
cover.
[0042] Preferably, the optical element covering the image sensor is
spaced apart from the image sensor and sealed to the housing.
[0043] The image capture module can additionally include a rear
seal sealing at least one or the substrate and/or image sensor to
the housing.
[0044] In this case, the optical element covering the image sensor,
at least the imaging plane of the image sensor and an inside wall
of the housing there between define the sealed volume within the
image capture module.
[0045] The camera can additionally include a cooling system
arranged to cool the image sensor. Preferably the cooling system is
part of the image capture module, although it may be part of
another module or form a connection between modules. The cooling
system can be an active cooling system. In one form the active
cooling can include a Peltier cooler mounted to the image capture
module in thermal contact with the image sensor arranged to
transfer heat away from the image sensor. The thermal contact can
be direct or indirect. The cooling system may form at least part of
the thermal connection between the image capture module and the
other module.
[0046] The image capture module preferably can include a generally
tubular body in which components are mounted. For example, the lens
mount is preferably mounted at one end and the substrate carrying
the image sensor on or adjacent to the other end thereof. In a
preferred form, the body housing is metal, and most preferably
aluminum, although other metallic and non-metallic materials can be
used. Most preferably the metal housing is of unitary construction
and machined from a single block of material.
[0047] The metal housing is preferably thermally connected to the
image capture module, either directly or via a heat transmitter
(e.g. a heat pipe or the like) such that heat generated in the
image capture module is transmitted to the metal housing for
dissipation.
[0048] As will be appreciated, direct contact in the context of
heat transmission can include contact via an intermediate substance
or material that aids thermal transmission between components, such
as thermal grease or the like.
[0049] The thermal control subsystem arranged to dissipate heat
generated in the image capture module and the other module
preferably includes a fan and ventilation openings to move air
through the housing of the other module.
[0050] The user interface subsystem preferably includes a
touchscreen and/or buttons.
[0051] The data storage subsystem to store at least data derived
from an image sensor of image capture module can include a
removable memory module. Preferably the removable memory module is
a solid state drive.
[0052] In a particularly preferred form the housing of the image
capture module forms part of the external housing of the
camera.
[0053] The camera of some embodiments can include one or more
second image capture modules. Such an arrangement can facilitate
capturing images from more than one viewpoint, as will be done to
create 3 dimensional video images. Preferably the image capture
module and the one or more second image capture module(s) are
substantially the same. Said image capture module and the second
image capture module(s) can be mounted relative to each other in a
predetermined position and orientation. Alternatively they can be
mounted in such a way that the predetermined relative position and
or orientation can be adjusted to suit image capture
requirements.
[0054] The present invention also provides a method of assembling a
camera, which includes separately assembling an image capture
module, and assembling the rest of the camera including the
pre-assembled image capture module. The image capture module
preferably includes part of the structural housing of the assembled
camera.
[0055] The assembly process preferably includes mechanically
mounting the pre-assembled image capture module to a main housing
of the camera. The method preferably includes making at least one
of the following connections between the image capture module and
another module of the camera; [0056] data connection; [0057]
electrical power connection; [0058] thermal connection.
[0059] The process of assembling the rest of the camera including
the pre-assembled image capture module, can include pre-assembling
another module and then assembling the modules to form the camera;
or integrating the pre-assembled image capture module into another
module during assembly of the other module.
[0060] The method can include making a thermal connection between
the image capture module at least one other component of the camera
for dissipation of heat generated by the image capture module.
Preferably the thermal connection is made between at least one
image sensor of the image capture module and a housing of the
camera.
[0061] The method can include calibrating a positioning of an
imaging plane of at least one image sensor of the image capture
module at a predetermined position with respect to a mounting plane
of a lens mount prior to assembling the rest of the camera
including the image capture module. In the case that the at least
one image sensor is mounted to the image capture module via an
adjustable mounting structure to allow adjustment of the position
of the at least one image sensor position with respect to lens
mount and the method can further includes fixing the position of
the adjustable mounting structure to attain the predetermined
position. The method can additionally or alternatively include
inserting a one or more spacers to set the predetermined position
of the at least one image sensor.
[0062] One or more second image capture modules can be
pre-assembled and/or mounted to another module (including the image
capture module) in the same or a similar manner.
[0063] In another aspect the present invention provides an image
capture module for a camera, such as a video camera, said image
capture module being a sealed module and including: a housing; at
least one image sensor to convert light into electrical signals; a
thermal interface configured to allow transmission of heat away
from the at least one image sensor.
[0064] Most preferably the thermal interface is adapted to be
coupled (directly or indirectly) to an element or structure of the
camera to transmit heat thereto. The image capture module can
include an optical system associated with the image sensor and
arranged to transmit light through the housing to the at least one
image sensor; a lens mount including a coupling to releasably
engage a lens or other optical module to connect the lens or other
optical module to the image capture module. The image capture
module is preferably arranged to be mounted directly or indirectly
to a camera body and interoperable therewith to capture images.
[0065] In another aspect there is provided an image capture module,
said image capture module being a sealed module and including: a
housing; at least one image sensor to convert light into electrical
signals; an optical system associated with the image sensor and
arranged to transmit light through the housing to the at least one
image sensor; a lens mount including a coupling to releasably
engage a lens or other optical module to connect the lens or other
optical module to the image capture module; said image capture
module being adapted to be integrated into a camera to video images
to be captured.
[0066] In either of the above aspects of the invention, the image
capture module may include at least one image sensor wherein each
image sensor has an imaging plane, said image sensor being mounted
within the image capture module such that the imaging plane lies at
a predefined distance from a plane of a mounting face of the lens
mount. The at least one image sensor may be mounted to the image
capture module via an adjustable mounting structure to allows
adjustment of the position of the at least one image sensor
position with respect to the housing and lens mount. The at least
one image sensor may be mounted on a substrate, wherein the
adjustable mounting structure includes a series of adjustment
screws holding the substrate to the housing. Said adjustable
mounting means may further include one or more spacers positioned
between the substrate and housing to set the predefined distance
between the imaging plane and the plane of the mounting face of the
lens mount. The optical system of the image capture module may
include one or more light transmissive elements in front of and
covering the at least one image sensor. The light transmissive
element covering the image sensor may be spaced apart from the
image sensor and sealed to the housing. The image capture module
may additionally include a rear seal sealing at least one or the
substrate and/or image sensor to the housing. The image capture
module can additionally include a cooling system arranged to cool
the image sensor and provide a thermal interface with another part
of the camera, preferably, the body of the camera or a heat
dissipation arrangement mounted therein. The cooling system may be
an active cooling system thermally coupled with the image sensor
arranged to transfer heat away from the image sensor. The image
capture module can include a generally tubular body with said lens
mount located at one end thereof and a substrate carrying the image
sensor mounted on or adjacent to the other end thereof. The thermal
interface of the image capture modules may be connected to the body
of the camera or a body module of the camera to transmit heat
generated in the image capture module for dissipation by the body
or body module.
[0067] In another aspect of the present invention there is provided
a camera including at least one of said image capture modules
[0068] As used herein, except where the context requires otherwise,
the term "comprise" and variations of the term, such as
"comprising", "comprises" and "comprised", are not intended to
exclude further additives, components, integers or steps.
[0069] Further aspects of the present invention and further
embodiments of the aspects described in the preceding paragraphs
will become apparent from the following description, given by way
of example and with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0070] Embodiments of the present invention will be described, by
way of non-limiting example only, with reference to the
accompanying drawings. In the drawings:
[0071] FIG. 1 is a schematic block diagram illustrating the main
functional blocks of a camera made in accordance with an embodiment
of the present invention;
[0072] FIG. 2A is a perspective view of the front of a camera made
in accordance with an embodiment of the present invention;
[0073] FIG. 2B shows a front, lower, perspective view of the camera
of FIG. 2A;
[0074] FIG. 2C shows a rear lower perspective view of the camera of
FIG. 2A;
[0075] FIG. 3 is a cross-sectional view through an image capture
module of the camera of FIG. 2A showing details of its
construction;
[0076] FIG. 4 is a horizontal cross-section through the image
capture module illustrated in FIG. 5 taken along line 6-6;
[0077] FIGS. 5 and 6 are front and rear exploded views of the image
capture module of FIGS. 3 and 4;
[0078] FIG. 7 is a cross-sectional view through a main body housing
of the camera of FIG. 2A, taken along a vertical plane, which
aligns with the plane of the cross-section through the image
capture module illustrated in FIG. 3;
[0079] FIG. 8 is a horizontal cross-section through the main body
housing illustrated in FIG. 7, along line 8-8;
[0080] FIG. 9 illustrates an assembled image capture module of the
type illustrated in FIGS. 3 and 4 being readied for insertion into
a receiving aperture of the main body housing illustrated in FIGS.
7 and 8.
[0081] FIG. 10 is a vertical cross section through an assembled
camera of the type illustrated in FIG. 2A, taken in the same plane
as the cross-sections of FIG. 3;
[0082] FIG. 11 is a horizontal cross-section through the camera
illustrated in FIG. 10, taken along line 11-11;
[0083] FIG. 12 is a cross-sectional view through another embodiment
of an image capture module of a camera;
[0084] FIG. 13 is a horizontal cross-section through the image
capture module illustrated in FIG. 12 taken along line 13-13;
[0085] FIGS. 14 and 15 are front and rear exploded views of the
image capture module of FIGS. 12 and 13; and
[0086] FIG. 16 is a vertical cross section through an assembled
camera that includes an image capture module of the type
illustrated in FIGS. 12 to 15, taken in the same plane as the
cross-section of FIG. 12;
[0087] FIG. 17 is a horizontal cross-section through the camera
illustrated in FIG. 16, taken along line 17-17; and
[0088] FIG. 18 is a schematic block diagram illustrating the main
functional blocks of a camera having a second image capture
module.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0089] FIG. 1 illustrates a schematic representation of a camera
100. The camera 100 is formed from two primary modules, an image
capture module 102 and a body module 104. The image capture module
102 forms a sealed optical and image capture system which is
configured to receive light and form an image in an image capture
sensor. The body module 104 houses the remaining functional
subsystems of the camera 100.
[0090] Turning firstly to the image capture module 102, which is
formed from an image capture module housing 106 in which is mounted
an optical system 108, imaging sensor 118 and supporting
electronics systems. The optical system 108 includes a cover lens
and optionally one or more focusing lenses 112 and 114. Light
enters the camera through an aperture 116 and passes through the
optical system 108 and is received at an image sensor 118. The
image sensor 118 can include one or more devices which convert
received light to electrical signals, for example a charge coupled
device (CCD) or complementary metal oxide semiconductor (CMOS)
pixel sensor. As will be appreciated a person skilled in the art
will be able to choose an image sensor having suitable operational
parameters (e.g. sensor size, resolution etc.) to suit
requirements.
[0091] The image capture module additionally includes on board data
storage in the form of memory 120, which stores operational
parameters related to the image sensor 118.
[0092] In order to facilitate the attachment of other optical
systems and lenses, the image capture module 102 additionally
includes a lens mount 122. The lens mount 122 is located adjacent
to aperture 116, facilitates the attachment of lenses to extend the
performance operation of the optical system 108. The lens mount may
additionally include electrical contacts (not shown in this view)
for providing an electrical or data interface with lenses or
systems attached thereto.
[0093] The image capture module 102 forms a sealed unit between:
the rear face of the outermost element in the optical system 108,
which in this case is face 124 of the cover lens 110 and the light
receiving face 126 of the image sensor 118. This ensures that the
imaging optics 108, and most importantly the sensor 118 is not
soiled by dust or other contaminants.
[0094] In one example, the inside face 128 of the sealed region 130
can be generally tubular and coated with an antireflective coating
so as to minimize stray reflections within the optical system. At a
first end thereof, the cover lens 110 is mounted, and sealed
against the inside surface 128 of the chamber 130, using an O-ring
132. At the other end of the region 130 is mounted the sensor 118
which is also sealed against the walls of the chamber 130 using a
seal 134.
[0095] The image capture module 102 additionally includes a cooling
system 136 which draws heat away from the imaging sensor 118 in
order to maintain correct operation of the sensor. In a preferred
form the temperature of the imaging sensor 118 is maintained at a
constant level, hence it is preferable to use an active cooler,
such as a Peltier cooler that can vary its cooling effectiveness to
suit variations in the temperature level of the imaging sensor
118.
[0096] In use, the image capture module 102 is mechanically
connected to the main body module 104. There are also data, power
and thermal connections between the two modules 102 and 104.
[0097] The main body module 104 includes a housing 138 in which is
mounted a variety of subsystems which interact with each other to
perform a majority of functions of the camera 100, as follows.
[0098] The module 104 houses a power supply module 140, which will
typically be a battery, providing power through a suitable power
supply circuit, but may additionally, or alternatively, receive
power from an external source, such as an AC power adaptor or
external battery or other external power source.
[0099] A data processing subsystem 142 is provided for both
controlling the operation of the camera generally as well as
processing image data received from the image processor 120 of the
image capture module 102.
[0100] Connected to the data processing system 142 is data storage
system 144. The data storage system 144 includes memory 146 which
provides working memory to store programs and data for use by the
data processing system 142; and also a data storage system 148, for
receiving and storing image data captured with the camera, and
associated data, e.g. metadata and the like. In some forms, the
data storage system 148 can include one or more removable data
storage units.
[0101] The main body module 104 also houses various interface
subsystems including a user interface subsystem 150 that comprises
a plurality of user actuatable controls for controlling the
operation of the camera 100. In this example, the primary user
interface is a touch screen, but the camera 100 may additionally
include a plurality of buttons or other control devices to allow
user control of the camera 100. Also provided is an input and/or
output subsystem 152 which comprises one or more input and/or
output ports for transferring data to and from external
devices.
[0102] The main body module 104 additionally includes a thermal
control subsystem 154. Thermal control subsystem 154 primarily
includes a fan 156 which draws air through ventilation openings 158
and 160 in the housing 138 of the main body module 104. The thermal
control subsystem 154 can also include one or more heat sinks,
radiators or other heat conductive elements 162 for enhancing
conductive heat transfer to the air passing through the ventilation
system. The imaging sensor 118 is optimally operated at a stable
temperature. Accordingly the thermal control subsystem 154 is
maintained in thermal contact with the image capture module 102 and
thus the imaging sensor 118 via a heat transmitting element such as
heat pipe 164. Additionally, a heat dissipating element 162 can be
connected to the external housing 138 of the main body module 104
such that the housing 138 itself can be used to dissipate heat to
the camera's surrounds.
[0103] FIGS. 2A through 2C are line drawings showing various
perspective views of a camera made with the general] construction
described in connection with FIG. 1. FIG. 2A shows a front
perspective view from above a camera designated generally as
reference numeral 200. The camera 200 includes an imaging module
202 and a main body module 204. As described in connection with
FIG. 1, the image capture module 202, called herein the `turret`
due to its squat, generally cylindrical form, houses the camera's
primary optical systems and imaging sensors. The turret 202
includes at its forward end a lens mount 206 including a mechanical
structure configured to receive a mechanical coupling on a lens to
be fitted to the mount 206. In one form the mechanical structure is
arranged to receive a bayonet style mount. The lens mount 206
additionally includes a series of electrical and data contacts 208.
A button 210 is also provided for disengaging a lens from the lens
mount 206. In examples of this camera, the lens mount may be made
according to a standard lens mount configuration such as an EF
mount (such as shown in FIGS. 2A to 11); MFT mount embodiment
illustrated in FIGS. 12 to 17; or other lens mount.
[0104] The turret 202 also includes a central bore 212 for
admitting light to the optical system mounted therein. The inside
wall of the bore 212 includes a series of ribs to prevent
reflections of off axis unfocussed light from the inside surface
214 of the bore from reaching the image sensor. Also provided, but
not visible in this view is an outer cover, in the form of an
optical filter to seal the sensitive parts of the turret 202.
[0105] The main body 204 of the camera 200 is generally rectangular
in front view and trapezoidal in profile. The turret 202 is mounted
centrally on the front face 216 of the body 204. One side 218 of
the body is provided a plurality of doors, e.g. door 220A, which
may be opened to reveal user controls or input/output ports, power
input ports, or the like. On the top 222 of the body 204 there is
provided a pair of loops 224 to which a carry strap may be
attached. The top face 222 also includes a series of recesses 226,
which may be threaded bores or similar and which are adapted for
receiving and mounting accessories to the camera body 204. The
front face 216 additionally includes a user interface button 228.
In this example the user interface button 228 is a "Record" button
which actuates recording by the camera.
[0106] FIG. 2B shows an underneath front perspective view of the
camera 200. In addition to those features already described in
connection with FIG. 2A, one can see an access panel 230 on the
side 232 of the body 204. The underside 234 of the body 204
additionally includes a pair of feet 236 on which the camera may be
rested. There is also provided ventilation panels 238 which include
a series of apertures through which air can pass to circulate
through the inside of the body module 204. A mounting structure 240
is also provided. The mounting structure 240 includes a pair of
bores for connecting the camera 200 to a standard tripod mount.
Accordingly, one of the bores is threaded and the other is adapted
for receiving a pin on a tripod mount.
[0107] FIG. 2C shows a rear perspective view of the camera 200, to
illustrate additional user interface controls visible in this view.
This rear view, shows the back side 242 of the body 204. Centrally
located within the rear side 242 is a display screen 244. The
display screen 244 can preferably be fitted with a touch sensor
interface to enable the user to input data to the camera 200. The
rear face 242 additionally includes buttons 246 and 248 and a row
of buttons 250 to provide additional user controls.
[0108] In this example, each of the modules making up the camera,
namely the turret 202 and body 204 include a main housing. The
housing is machined from aluminum in this example, although
alternatives, including but not limited to, cast magnesium or
plastics could also be used. In the case of the turret 202, the
housing is generally cylindrical in form, whereas the housing for
the body module 204 has a generally rectangular exterior shape with
rounded corners. These housings, the details of which will be
described below, provide a mechanically rigid structure to which
internal components can be mounted and also provide a rugged
exterior surface. Additionally, the housing of the body 204 can
additionally be used as a heat sink and heat dissipating device to
aid transfer of waste heat from the camera to the environment.
[0109] FIGS. 3 and 4 are cross-sectional views through the image
capture module or turret 202 of the camera illustrated in FIGS. 2A
to 2C; and FIGS. 5 and 6 are front and rear exploded views of the
image capture module 202; FIG. 3 illustrates a vertical
cross-section through the turret 202 and FIG. 4 is a horizontal
cross-section at line 6-6 illustrated in FIG. 3, looking upward.
FIGS. 3 to 6 will be described together using like numbering.
[0110] Turret 202 includes an external housing 300. The external
housing is machined from aluminum, although alternative
constructions, such as cast magnesium or plastic could also be
used. The housing 300 includes a generally cylindrical forward
portion 302 which merges via a radius 304 into a taper 306. The
taper 306 transitions into another cylindrical portion 308 at its
rear edge, and then the housing steps out into a short shoulder
310. The housing 300 has a central bore 312 which includes a series
of steps such that it reduces in radius from its front to rear.
Midway along the length of the bore 312 is a threaded section 314,
thread is used to engage an insert 316 which has a generally
cylindrical and threaded outer face 318 and a tapered inner face
320. The tapered inner face 320 includes a plurality of ridges or
grooves to form an antireflective internal face leading to the
image center of the camera.
[0111] At the front of the body 300 there is positioned a lens
mount 322. The lens mount 322 has a forward facing mounting surface
324 which abuts against lenses which are fitted to it. The lens
mount 322 also includes various mechanical details, e.g. 326 which
are used to engage a bayonet fitting on a lens which is attached to
the lens mount 322.
[0112] About three quarters of the way along the depth of bore 312
the bore steps inward at 328. The shoulder 328 supports an optical
filter 330 which in use filters out non-visible wavelengths of
light. The filter 330 is held in place by an O-ring seal 332, which
is received in a groove 335. The O-ring 332 is held in its groove
and the filter 330 is held in place and sealed against the O-ring
332 by the threaded insert 316 being screwed into the bore 312.
Following the filter 330 is an air gap 334. The air gap 334 has a
stepped profile and opens outward from shoulder 328. The peripheral
wall 336 of the air gap is defined by a rearwardly projecting
flange 338.
[0113] At the most rearward end of the turret 202 is an image
sensor assembly 340. The image sensor assembly 340 includes a
substrate 342 which, in this example is a printed circuit board
substrate, which carries an image sensing chip 344. The image
sensor assembly 340 is mounted to the housing 300 via a series of
screws 348. The screws are used to provide an adjustable mounting
for the image sensor assembly 340 when mounting it to the turret
housing 300. The mounting can additionally include one or more
spacers such as shims of thin metal or the like which can be used
to adjust the positioning of the sensor assembly 340 with respect
to the housing 300. In particular, it is important that the imaging
sensor 344 is correctly located with respect to the central axis of
the aperture 312 and that its position in a forwards and backwards
direction is set accurately with respect to the front mounting face
324 of the lens mount 322. In the case of an EF mount, the spacing
between the mounting face 324 and the imaging plane is nominally 44
mm. This length may vary depending on the configuration of the
optical system positioned between the lens mount and image sensor
344, as the inclusion of lenses may lengthen or shorten the
distance. Moreover the intention to use a different lens mount or
external lens system may dictate a different predetermined spacing.
The manufacturing tolerance of the housing 300 and sensor assembly
340, may require the position of the sensor assembly 340 to be
adjustable by a small fraction of a millimeter, say less than 0.2
mm. Although, better precision is desirable. In this case, the
spacers used can be metal shims of a thickness around 0.025 mm.
Although other sizes may be used.
[0114] Depending on the construction of the imaging sensor 344, the
imaging plane of the sensor may not be the front surface of the
imaging sensor. Instead, it may be set some distance back into the
depth of the imaging sensor. In this case it will not be possible
to use a mechanical method or jig to calibrate the mounting depth
to the imaging plane of the sensor directly. Therefore it will
either be necessary to determine the distance between the front
mounting face 324 of the lens mount 322 and a point on the imaging
sensor that lies at a known position with respect to the imaging
sensor's imaging plane to infer the position of the imaging plane,
or determine the position of the imaging plane by optical means,
such as by performing back focus calibration, in which the image
sensor position is adjusted such that a projected test image is
correctly focused on the sensor.
[0115] For example due to the construction of the sensor, the die
surface of the sensor, which defines the imaging plane of the
sensor, may be located at certain depth of beneath the front face
of the sensor, say 1 mm to 2 mm. This means that with the nominal
focal length of 44 mm of an EF lens mount, the distance to the face
of the imaging sensor from the lens mount surface needs to be
reduced from 44 mm by this offset.
[0116] In order to provide a seal on the rear side of the imaging
assembly, there is a seal 350 with a pair of upstanding sealing
flanges defining a U-shaped channel between them. The innermost
edge of the seal 350 surrounds the imaging sensor 344 and the
upstanding flanges form a seal against the flanges 338 of the
housing 300. This seal defines a sealed void between the rear-most
wall of the filter 330 and the imaging sensor 344. This space is
sealed against dirt, dust, moisture and other contaminants. The
rear face of the imaging assembly 340 additionally includes as
connector 352 which is configured to receive a multiconductor
connector to read out data from the imaging sensor 344 to the data
processing system located in the body 204. As can be seen best in
FIG. 3, the housing 300 additionally includes an angled channel 354
which is arranged to receive a series of wires for connecting the
electrical and data contacts of the lens mount 322 with the data
processing system of the camera. As can be seen best in FIG. 4, the
housing additionally includes a button arrangement 360 which forms
part of the release mechanism for a lens attached to the lens mount
322. The button includes a spring loaded button member 362 which
projects out of an aperture 364 in the housing 300 and is connected
to a pin 366. The pin 366, when extended, engages with a compatible
receiving hole in a lens attached to the lens mount 322 and
prevents the lens from rotating with respect to the lens mount 322,
to prevent unintended removal of the lens. The button 362 is
arranged to slide within a complementarity shaped cavity 364 to
guide it when the button 362 is pressed.
[0117] To better illustrate the construction of the image capture
module 202, front and rear exploded views are provided as FIGS. 5
and 6 respectively. In addition to the components shown in FIGS. 3
and 4, this view also illustrates a cooling system that can be
mounted thereto to transfer heat away from the imaging sensor. The
components will be briefly described beginning at the front of the
module 202, beginning with the lens mount 322.
[0118] The lens mount 322 comprises a mechanical mounting ring 322A
that provides mechanical structure to which a lens is mounted.
Spring 323 is used to retain the lens along with button assembly
360. Contact assembly 329 is used to make electrical and data
connections with lenses. The contact assembly 329 is mounted to the
housing 300 by screws 325. The mechanical mounting ring 322A is
mounted to the housing 300 with screws 321.
[0119] The filter 330 is inserted into the housing 300 and sealed
to it by O-ring 332. The O-ring is held in place by the insert
316.
[0120] Turning to the back side of the housing 300, there is first
located the seal 350 which engages the inside of the housing 300
and the image sensor 344 mounted on the substrate 342. The position
of the sensor is adjustable during manufacture and calibration by
placing one or more spacers, such as shims 351, between the housing
300 and the opposing face 341 of the substrate 342. The substrate
342 is held to the housing by screws 348. Element 355 is seal that
covers the back of a microphone (not illustrated) that is mounted
in the body housing. Next, a backing plate 351 is provided to
provide a mechanical mount for the cooling system 500 components.
The cooling system includes a Peltier cooler 1000 and a heat pipe
1004 mounted in thermal contact with the image sensor 344. The
backing plate 351 has a hole 357 through it to enable the cooler
1000 to directly contact the image sensor 344. The heat pipe 1004
is retained against the hot side of the cooler 1000 by a mounting
plate 1006 that is secured in place by screws 1008 and springs
1009.
[0121] FIGS. 7 and 8 show cross sectional views corresponding to
the cross sectional views of the turret 202 shown in FIGS. 3 and 4,
but instead show the body 204 of the camera 200. In side view the
body 204 is generally trapezoidal in shape, whereas in horizontal
cross section it is generally rectangular. The body module 204
includes a large circular recess 702, its front face, which in use,
receives the turret 202. The main body forming the housing 700 of
the body module 204 comprises a circumferential housing. The
housing includes a top wall 703, a bottom wall 704, side walls 706
and 708 (which are not shown in great detail due to the position of
this cross section and the provision of doors therein). The housing
700 additionally includes an integrally formed front wall 710, the
front and rear surfaces of the housing 700 are provided with covers
712 and 714 respectively. The covers 712 and 714 have, buttons and
other interface elements formed in them.
[0122] As can be seen best in FIG. 7, the bottom face of the
housing 700 includes a panel 714 which is provided with ventilation
therethrough. The rear face of the housing 700 includes a centrally
mounted display screen 716 which includes a display 718 and touch
sensitive interface 720. This is mounted on a mounting plate
substrate 722 which is affixed to the housing 700 and closes the
back of the housing 700. As can be seen in FIG. 8, each side of the
housing 700 includes short blind recesses 724. These recesses are
provided as mounting points for an external accessory such as a sun
shade or the like.
[0123] Turning now to FIG. 9, which shows a perspective view of the
housing 700, which as mentioned before could be machined from a
solid block of material such as aluminum; and turret assembly
202.
[0124] At this point it is worth noting that the turret assembly
202 is illustrated as being substantially complete, whereas the
housing 700 of the body module 204 is relatively incomplete by
comparison. This difference in stage of assembly between these two
modules illustrates an important advantage of preferred embodiments
of the present invention. Namely, that the turret can be
manufactured entirely separately from the body module 204. This has
various advantages compared to conventional camera manufacture, in
which once the body is provided, all optical components need to be
mounted separately within it and the camera built up around the
body. Instead, the preferred embodiments of the present invention
enables just the turret 202 to be assembled to its final form. The
turret 202 can be calibrated and tested for correct operation prior
to its being brought together with the other components of the
camera.
[0125] In some forms, the turret 202 will be provided with memory
(e.g. memory 120 in FIG. 1) for storing calibration data relating
to the image sensor. The response of the image sensor 118 is
imperfect at manufacture, resulting in pixels of the sensor having
a different light conversion efficiency.
[0126] Therefore, the camera will need to be calibrated to account
for this variation in performance. Calibration results in a
creation of calibration data, e.g. for each pixel on the sensor. In
image read out or processing this calibration data is used to
correct the raw data from the sensor, so as to create consistent
images.
[0127] Because the calibration data is unique to each sensor, and
in preferred embodiments of the present invention associate the
sensor with the image capture module, rather than a whole camera,
it can be advantageous to store this data along with the chip in
memory housed within the turret 202. This facilitates calibration
of the turret separately to the fully assembled camera, and also
enables replacement of the turret. Each time the camera is powered
up, the main processor will read its own configuration from its own
memory, then it will read the calibration information from the
memory of the turret 202.
[0128] Moreover, because the imaging plane of the image sensor
within the turret 202 is sealed after completion of manufacture of
the turret 202, it no longer needs to be handled in the manner
required during its manufacture. During its manufacture, ideally
the turret would be in a clean room facility and manufactured under
highly dust free and contaminant free environments. This is an
expensive process and requires well trained technicians to perform
it. By contrast, the body module 204 and the mounting of the turret
202 to the body module 204 can be performed in ordinary electronics
manufacturing facilities. Whilst these are clean and relatively
free of static and contaminants, they are not equivalent to the
conditions of a clean room. Accordingly assembly in this type of
environment is much cheaper than an equivalent assembly performed
in clean room facility.
[0129] An additional benefit of separately manufacturing and
assembling the image capture module 202 to the body module 204 is
that the separate testing of the image capture module 202 can be
performed. This prior testing reduces the likelihood of faulty
products being produced or at least narrows down the mode of
failure of the complete device to the body or its connection to the
turret 202, because the turret assembly 202 has already been tested
prior to its incorporation into the camera. Moreover, if the camera
needs to be serviced or dismantled or even in the event of complete
failure of the imaging system, this can be performed by removal of
the turret 202 from the body module 204. The damaged or faulty
turret 202 can be replaced by a functioning unit and reassembly of
the remaining components performed. If the camera was made by
conventional manufacturing techniques, the whole camera would need
to be disassembled and reassembled in an environment which is fit
for handling the sensitive optical components of the camera.
Ideally this would mean clean room conditions. However, with a
second hand camera which has been in the field, it is unlikely that
that camera could ever be brought up to a condition of cleanliness
that would allow its entry into a clean room for maintenance.
Certain embodiments of the present invention mitigate this problem
as only the turret needs to meet such stringent standards for
cleanliness if it is to be worked on for maintenance purposes or
refurbishment.
[0130] Returning now to FIG. 9 it can be seen, that the assembled
image capture module 202 is inserted through the aperture 702, from
behind, to mount the image capture module 202 to the housing 700 of
the main body module 204. The assembly process used in this example
includes integrating the pre-assembled image capture module into
the housing of the main body 204 at an early stage of its assembly.
The rest of the main body module 204 is then assembled around the
image capture module 202 such that the image capture module 202 is
integrated into the competed camera. Alternatively the
pre-assembled image capture module 202 could be mounted to a
pre-assembled main body module (or other module). In either case it
is necessary to make the necessary electrical, data and/or thermal
connections between the image capture module 202 and the other
components of the camera. In this example the thermal connection is
made by using the upper face 1005 of the heat pipe 1004 as a
thermal interface for the image capture module 202, by bringing the
thermal interface into contact with a component of the body module
204 so that heat is thus conducted out of the image capture module
202. In this case the heat is conducted to the body housing 700 of
the body module 204.
[0131] FIGS. 10 and 11 show cross-sectional views through an
assembled camera 200. The cross section of FIG. 10 is a vertical
cross section corresponding to the sections shown in FIGS. 3 and 7.
The horizontal cross section shown in FIG. 11 corresponds to the
horizontal cross sections of FIGS. 4 and 8. For clarity, only
components which have not previously been illustrated will be
numbered in these figures so as not to clutter the diagrams for the
reader.
[0132] As can be seen in FIGS. 10 and 11, the image capture
assembly or turret 202 is mechanically mounted to the main body
module 204.
[0133] As will be appreciated, the body module 204 carries
additional components in a completed camera 200. A selection of
these elements is illustrated for convenience. However, additional
components will be present in other embodiments of the present
invention. As will also be appreciated, the turret 202 will be
electrically connected to the power supply mounted within the body
204, the image capturing system will also be connected to a data
processing system within the body. As foreshadowed in relation to
FIG. 1, thermal connection is also made between the image capture
module 202 and the main body 204. In this embodiment the thermal
connection is formed by the combination of a Peltier cooling device
1000 which is mounted to the rear face of the imaging sensor 344
through a hole 345 in the substrate 342. The Peltier cooler 1000
draws heat from its face mounted to the image sensor 344 to its
rear face 1002. A heat pipe 1004 is mounted in physical contact
with the face 1002 of the Peltier cooler 1000. The heat pipe 1004
is an inverted L shape and extends upward from the Peltier cooler
1000 and meets the top wall 703 of the housing 700. The heat pipe
1004 acts to transfer heat from the hot side 1002 of the Peltier
cooler 1000 to the housing 700 via surface 1005 for dissipation to
the environment. As discussed before, this heat dissipation
function performed by the housing is enhanced by having a metal
housing. The heat pipe 1004 is held in contact with the Peltier
cooler by a mounting plate 1006 which is fastened in place by a
pair of sprung screws 1008. The housing module 204 additionally
houses the main circuit board 1010 which includes primary
electronics and processing systems of the camera. Mounted behind
circuit board 1010 is a generally rectangular bay 1012 which is
configured to receive a removable memory device such as a solid
state drive. The solid state drive is inserted and removed from the
bay 1010 by opening the door 230 (previously illustrated in FIG. 3)
which is mounted to the side of the housing 700. A series of
connectors and other input/output ports are located at 1012 and
accessed via door 1014. FIG. 11 additionally shows the position of
the battery 1016 in this embodiment.
[0134] FIGS. 12 to 17 illustrate embodiments of a second image
capture module and a camera made using this image capture module.
In FIGS. 12 to 17 elements of the second embodiment that have
corresponding elements in the embodiment of FIGS. 1 to 11 are
labelled with reference numerals that are common except for the
addition of an "A", and common components are like numbered, to aid
understanding. FIGS. 12 and 13 are cross-sectional views through
the image capture module or turret 202A; and FIGS. 14 and 15 are
front and rear exploded views of the image capture module 202A.
[0135] FIG. 12 illustrates a vertical cross-section through the
turret 202A and FIG. 13 is a horizontal cross-section at line 13-13
illustrated in FIG. 12, looking upward. FIGS. 12 to 15 will be
described together using like numbering.
[0136] As will be appreciated on initial inspection the turret 202A
is relatively short compared to the turret 202 of FIGS. 1 to 11.
Turret 202A includes an external housing 300A. The external housing
is machined from aluminum, although alternative constructions, such
as cast magnesium or plastic could also be used. The housing 300A
includes a short generally cylindrical forward portion 302A which
merges via a radius 304A into a taper 306A. The taper 306A
transitions into another cylindrical portion 308A at its rear edge,
and then the housing steps out into a short flange 310A. The
housing 300A has a central bore 312A which includes a series of
steps such that it reduces in radius from its front to rear. The
inner face 320A of the bore 312A includes a plurality of ridges or
grooves to form an antireflective internal face leading to the
image center of the camera.
[0137] At the front of the body 300A there is positioned a lens
mount 322A. The lens mount 322A has a forward facing mounting
surface 324A which abuts against lenses which are fitted to it. The
lens mount 322A also includes various mechanical details, e.g. 326A
which are used to engage a bayonet fitting on a lens which is
attached to the lens mount 322A.
[0138] Towards the rear end of the bore 312A a shoulder 328A is
provided that supports an optical filter 330A which in use filters
out non-visible wavelengths of light. In most embodiments this will
be an infrared filter. The filter 330A is held in place by an
O-ring seal 332A, which is received in a groove 335A. Following the
filter 330A is an air gap 334A. The peripheral wall 336A of the air
gap 334A is defined by a rearwardly projecting flange 338A.
[0139] At the most rearward end of the turret 202A is an image
sensor assembly 340A. The image sensor assembly 340A includes a
substrate 342A which, in this example is a printed circuit board
substrate, which carries an image sensing chip 344A. The image
sensor assembly 340A is mounted to the housing 300A via a series of
screws 348A. The screws are used to provide an adjustable mounting
for the image sensor assembly 340A when mounting it to the turret
housing 300A. The mounting can additionally include one or more
spacers such as shims 351A of thin metal or the like which can be
used to adjust the positioning of the sensor assembly 340A with
respect to the housing 300A. In particular, it is important that
the imaging sensor 344A is correctly located with respect to the
central axis of the aperture 312A and that its position in a
forwards and backwards direction is set accurately with respect to
the front mounting face 324A of the lens mount 322A. In the present
case, the turret 202A has a Micro Four Thirds mount (MFT mount)
thus, the spacing between the mounting face 324A and the imaging
plane is nominally 19.2 mm. This length may vary depending on the
configuration of the optical system positioned between the lens
mount and image sensor 344A, as the inclusion of lenses may
lengthen or shorten the distance. The manufacturing tolerance of
the housing 300A and sensor assembly 340A, may require the position
of the sensor assembly 340A to be adjustable by a small fraction of
a millimetre, say less than 0.2 mm. Although, better precision is
desirable. In this case, the spacers used can be metal shims of a
thickness around 0.025 mm. Although other sizes may be used.
[0140] In order to provide a seal on the rear side of the imaging
assembly, there is a seal 350A with a pair of upstanding sealing
flanges defining a U-shaped channel between them. The innermost
edge of the seal 350A surrounds the imaging sensor 344A and the
upstanding flanges form a seal against the flanges 338A of the
housing 300A. This seal defines a sealed void between the rear-most
wall of the filter 330A and the imaging sensor 344A. This space is
sealed against dirt, dust, moisture and other contaminants. The
rear face of the imaging assembly 340A additionally includes as
connector 352A which is configured to receive a multiconductor
connector to read out data from the imaging sensor 344A to the data
processing system located in the body of a camera into which the
turret 202A will be incorporated. As can be seen best in FIG. 15,
the housing 300A additionally includes a channel 354A which is
arranged to receive a series of wires 1202 for connecting the
electrical and data contacts of the lens mount 322A with the data
processing system of the camera. As can be seen best in FIG. 13,
the housing additionally includes a button arrangement 360A which
forms part of the release mechanism for a lens attached to the lens
mount 322A. The button includes a spring loaded button member 362A
which projects out of an aperture 364A in the housing 300A and is
connected to a pin 366A. The pin 366A, when extended, engages with
a compatible receiving hole in a lens attached to the lens mount
322 A and prevents the lens from rotating with respect to the lens
mount 322 A, to prevent unintended removal of the lens. The button
362A is arranged to slide within a complementarily shaped cavity
364A to guide it when the button 362A is pressed.
[0141] To better illustrate the construction of the image capture
module 202A, front and rear exploded views are provided as FIGS. 14
and 15 respectively. These views omit the cooling system
illustrated in connection with FIGS. 5 and 6, but an identical
cooling system can be mounted to this turret 202A to transfer heat
away from the imaging sensor. Alternatively a cooling mechanism can
form part of the body module 204A which is then thermally connected
to the image sensor 344A. In some embodiments, no active cooler may
be necessary is sufficient heat dissipation can be achieved without
it.
[0142] The lens mount 322A comprises a mechanical mounting ring
322AA that provides mechanical structure to which a lens is
mounted. Spring 323A is used to retain the lens along with button
assembly 360A. Contact assembly 329A is used to make electrical and
data connections with lenses. The mechanical mounting ring 322AA is
mounted to the housing 300A with screws (not shown).
[0143] The filter 330A is inserted into the housing 300A and sealed
to it by O-ring 332A.
[0144] Turning to the back side of the housing 300A, there is first
located the seal 350A which engages the inside of the housing 300A,
specifically the flange 336, and the image sensor 344A mounted on
the substrate 342A. The position of the sensor is adjustable during
manufacture and calibration by placing one or more spacers, such as
shims 351A, between the housing 300A and the opposing face 341A of
the substrate 342A. The substrate 342A is held to the housing by
screws 348A. Next, a backing plate 351A is provided to provide a
mechanical mount for the cooling system components.
[0145] FIGS. 16 and 17 show cross-sectional views through an
assembled camera 200A. The cross section of FIG. 16 is a vertical
cross section corresponding to the sections shown in FIG. 12. The
horizontal cross section shown in FIG. 13 corresponds to the
horizontal cross sections of FIG. 13. For clarity, only components
which have not previously been illustrated will be numbered in
these figures so as not to clutter the diagrams for the reader. The
camera body 204 is identical to the camera body illustrated in
FIGS. 10 and 11 and need not be described in detail. The image
capture assembly or turret 202A is mechanically mounted to the main
body module 204 in the same manner as the previous embodiment.
[0146] The examples given herein include two modules one of which,
is an image capture module. However, it will be appreciated that
the camera can be formed from more than two modules. By way of
example only a separate power supply module may be provided that
interfaces with one or more other modules of the camera. In some
embodiments a camera could include one or more second image capture
modules. The second image capture modules may be identical to the
first or different. The second image capture modules(s) could be
mounted to a common body module with the first image capture
modules. Such an arrangement may be used to capture images (video
or still) from multiple viewpoints, and could find particular use
in capturing images to enable the making of stereoscopic images,
such as might be performed in making three dimensional video.
[0147] FIG. 18 is a schematic block diagram illustrating the main
functional blocks of a camera having a second image capture module.
The camera 1800 is formed from three primary modules, being two
image capture modules 102 and a body module 104. The image capture
modules 102 each form sealed optical and image capture systems
which are configured to receive light and independently form an
image in an their respective image capture sensors. The body module
104 houses the remaining functional subsystems of the camera
1800.
[0148] Turning firstly to the image capture modules 102, each of
which are the same as the image capture module 102 described in
connection with FIG. 1, and components have been numbered with the
same reference numerals and will not be explained again. Generally
speaking each image capture module 102 is formed from an image
capture module housing 106 in which is mounted an optical system
108, imaging sensor 118 and supporting electronics systems.
[0149] The image capture modules 102 are mechanically connected to
the main body module 104. There are also data, power and thermal
connections between the image capture modules and the body module
104 (and possibly between the image capture modules in other
embodiments). The mechanical mounting of the image capture modules
with respect to each other and the body housing is done in such a
way that a predetermined separation and alignment exists between
the image capture modules 102. Most preferably the mounting is such
that the optical systems of the image capture modules are
relatively positioned and aligned such that the images captured by
each can be combined to create a three dimensional video. The
mounting mechanism may be adjustable to enable adjustment of the
relative positioning.
[0150] As will also be appreciated stereoscopic images could also
be captured using image capture modules with multiple image capture
sensors or specialized optical systems.
[0151] As can be seen with the foregoing the cameras made in
accordance with a preferred embodiment include an image capture
module(s) that includes an image sensor and optical system mounted
within the module's housing. The use of a separate module(s) of
this type can enhance manufacturability, testing and maintenance of
the camera, as the remainder of the camera e.g. one or more
additional modules or components do not need to be manufactured to
the same tolerance or in the same conditions as the image capture
module.
[0152] It will be understood that the invention disclosed and
defined in this specification extends to all alternative
combinations of two or more of the individual features mentioned or
evident from the text or drawings. All of these different
combinations constitute various alternative aspects of the
invention.
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