Digital Camera Patent Abstract
A digital camera that operates inside and in conjunction with a
non-digital camera, enabling the user to continue to use the non-digital
camera, controls and associated lens, flashes, etc. The digital
camera includes an imager which senses the image to be recorded
and a light detector which detects the existence of light due to
the opening of the shutter aperture of the non-digital camera. The
light detector controls the imager such that an image is recorded
and output from the imager when the light detector detects the opening
of the shutter aperture which occurs when the photographer depresses
the shutter button to take a picture. Preferably the digital camera
includes a memory for storage of the images recorded. These images
can then be subsequently output to an external device for further
processing or display.
Digital Camera Patent Claims
What is claimed is:
1. An apparatus to fit within a film cavity of a non-digital camera
comprising: a circuit board; a light detector located on the circuit
board to detect light due to the opening of a shutter aperture of
the non-digital camera; and an imager located on the circuit board
and coupled to the light detector and located adjacent to the shutter
aperture of the non-digital camera, said imager to sense radiated
energy reflective of an image received through a lens and shutter
aperture of the non-digital camera when the light detector detects
light due to the opening of the shutter aperture of the non-digital
camera, said imager to generate signals reflective of the image.
2. The apparatus as set forth in claim 1, further comprising a
memory to store digital data reflective of the image.
3. The apparatus of claim 2, further comprising a counter to provide
an image count to the memory for storage in association with the
4. The apparatus of claim 3, wherein the light detector to generate
a signal to increment the counter upon detection of light.
5. The apparatus as set forth in claim 1, further comprising a
passgate coupled to the light detector located between the imager
and a clock input to the imager, said passgate controlled by the
light detector such that when the light detector detects light due
to the opening of the shutter aperture of the non-digital camera,
the passgate is switched to permit clock signals to reach the imager
to drive the imager to output signals reflective of the image.
6. The apparatus as set forth in claim 1, wherein the light detector
to control power to the imager such that when the light detector
detects light due to the opening of the shutter aperture of the
non-digital camera, power is supplied to the imager to generate
signals reflective of the image.
7. The apparatus as set forth in claim 1, further comprising a
passgate coupled to an output of the imager such that when the light
detector detects light due to the opening of the shutter aperture
of the non-digital camera, output signals reflective of the image
are output from the imager.
8. The apparatus as set forth in claim 1, further comprising a
signal processor coupled to receive signals output by the imager.
9. The apparatus of claim 8, further comprising a single integrated
circuit comprising the light detector, the imager, and the signal
10. The apparatus of claim 9, wherein the single integrated circuit
comprises a complementary metal oxide semiconductor (CMOS) device.
11. The apparatus as set forth in claim 1, further comprising at
least one output port for outputting image data from the digital
camera to an external device.
12. The apparatus as set forth in claim 11, wherein the output
port comprises a wireless transmitter for transmitting image data
to a wireless receiver of an external device.
13. The apparatus as set forth in claim 11, wherein the output
port couples to a monitor, said apparatus further comprising analog
driver circuitry to drive the monitor to display the image on the
14. The apparatus as set forth in claim 11, wherein the output
port couples to the internet.
15. The apparatus of claim 1, further comprising an imager shutter
separate from the shutter aperture of the non-digital camera.
16. The apparatus of claim 15, further comprising a controller
to control the imager shutter independently of the shutter aperture
of the non-digital camera.
17. The apparatus of claim 1, further comprising a remote control
to provide control signals to control operation of the apparatus.
18. The apparatus of claim 1, further comprising a rail mechanism
to adjustably couple the circuit board into the non-digital camera.
19. A method for generating digital images using a non-digital
image camera comprising: specifying an image to be recorded by actuating
a shutter aperture of the non-digital camera, the actuation of the
shutter aperture opening the shutter aperture; controlling a shutter
of a photocard located in a film cavity of the non-digital camera
via a light detector of the photocard to permit light reflective
of the image to be received on an imager of the photocard; and controlling
the imager of the photocard to output signals reflective of the
image sensed based on the opening of the shutter aperture of the
non-digital camera and the shutter of the photocard.
20. The method as set forth in claim 19, further comprising translating
the signals to digital data, said digital data reflective of the
digital image sensed.
21. The method as set forth in claim 19, further comprising storing
in memory representations of the signals reflective of the image
22. The method as set forth in claim 18, further comprising processing
on the photocard the signals reflective of the image sensed to modify
23. The method as set forth in claim 19, further comprising outputting
the signals reflective of the image sensed to an external device.
24. The method as set forth in claim 23, wherein the external device
is a display device and the outputting comprises generating analog
signals to drive the display device in order to display the image.
25. The method as set forth in claim 23, wherein the external device
is a system that provides a connection to the internet.
26. The method of claim 19, further comprising controlling the
shutter of the photocard to operate faster than the shutter aperture
of the non-digital camera.
27. An apparatus comprising: a photocard for insertion into a non-digital
camera, the photocard including an integrated circuit comprising:
an imager to capture images through a shutter aperture of the non-digital
camera; a processor to process the images; a memory to store the
images; and an imager shutter separate from the shutter aperture
of the non-digital camera the image shutter controlled by a light
detector of the photocard.
28. The apparatus of claim 27, wherein the integrated circuit comprises
a complementary metal oxide semiconductor (CMOS) integrated circuit.
29. The apparatus of claim 27, further comprising a second memory
coupled to the integrated circuit.
30. The apparatus of claim 27, wherein the integrated circuit comprises
circuitry to generate an analog output to drive a monitor.
Digital Camera Patent Description
FIELD OF THE INVENTION
The present invention relates to photography and to electronics,
and more particularly to digital photographic equipment.
BACKGROUND OF THE INVENTION
A typical 35 millimeter camera boasts a range of features, from
the simple "point and shoot" camera function to functions
that provide sophisticated photographic effects. Photographers choose
35 millimeter cameras for a variety of reasons, including the variety
of cameras and features available and the standardization of accessories
such as additional lenses. Also, many experienced photographers
have an intuitive understanding of the effect that the features,
lenses, and other photographic equipment will have on light passing
through the lens and striking the film. For many photographers,
camera equipment represents a substantial investment both in terms
of cost and the time necessary to become familiar with the particular
features of a particular camera.
However, in some situations, a standard 35 mm camera is simply
inadequate. When extremely fast film is needed, for example, in
extremely dim light or when extremely fast objects are being photographed,
many cameras do not have a sufficiently fast shutter speed to capture
the image. Also, less-expensive cameras frequently are not upgradable.
Thus, photographers who purchase a simple, low cost camera having
a limited set of features typically cannot upgrade the camera to
include more features and end up purchasing a new camera having
the desired features.
These 35 millimeter film is sometimes difficult for a photographer
to handle. There is the risk of accidental exposure of film to light,
the risk of damaging a negative during developing, and the difficulty
in making a high-quality reproduction from a print when the negative
is unavailable are problems inherent in film-based photography.
Furthermore, 35 millimeter film is available only in 12, 24, and
36 exposures, a limitation that requires a photographer to change
film frequently. This is especially problematic when replacing film
in a camera is difficult or impossible process. For example an underwater
photographer cannot change the film in the camera when underwater;
therefore the photographer typically carries a number of cameras
in order to shoot more than one roll of pictures.
Digital camera technology has offered an alternative to ordinary
photographic equipment. Digital cameras capturing both still shots
and moving images allow modern photographers a lot of flexibility
to enhance and digitally process video frames by use of a computer,
but often require extremely expensive equipment beyond the price
range of many photographers. Such cameras are also wholly incompatible
with the "analog" film-based photography equipment in
which many photographers have invested time and money, and with
which many photographers are familiar.
The cost of starting all over with digital photographic equipment,
considering the large prior investment in time and money in standard
camera equipment, is a significant barrier to many photographers
who would otherwise utilize digital photography.
Therefore, it would be desirable to allow the owner of a standard
35 mm camera to "convert" the standard camera to a digital
camera, without having to modify the camera, without losing the
benefits of any features of the standard camera, and without requiring
owners of standard 35 mm cameras to forfeit their standard cameras
simply to enjoy the benefits of digital technology.
The present invention enables a photographer to easily convert
a camera to take digital photographs. The apparatus replaces film
and is structured to fit in the film compartment of a camera. The
apparatus is an electronic device having a light detector that detects
the opening and closing of the aperture of the camera, an imager
for detecting the image to be photographed, and a digital memory
unit for storing digitized information reflective of the photographic
images. The imager receives radiated energy through the lens of
the camera, allowing the external features such as telephoto and
other lenses, F-stop and aperture controls, etc., of the camera
to be used by the photographer to affect the image photographed.
The photocard can operate in a stand alone manner or can be coupled
to an external electronic device via a flat flexible wire that passes
out of the camera. The external device can be a general purpose
of photo processing system that enables the user to display, modify
and print out the images. Other external electronic devices may
have additional memory, power, or may be coupled to a NTSC converter
that converts the digital images to a television standard for viewing
on a television monitor or screen. In some embodiments, the electronic
device converts the digital images to one of a number of internet
or World Wide Web standards, and provides data either in a telephone
line or an ISDN format. In some embodiments, the external electronic
device includes a short-range wireless transmitter, for transmitting
images stored in the photocard's memory to a nearby television,
or for downloading digital photographs to an external memory or
to a magnetic medium such as a disk drive or tape drive.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects, features and advantages of the present invention will
be apparent to one skilled in the art from the following detailed
description in which:
FIG. 1 illustrates the camera body of a prior art 35 millimeter
FIG. 2 illustrates one embodiment of the apparatus of the present
FIG. 3 is a simplified block diagram of one embodiment of the photocard
of the present invention.
FIG. 4 is a block diagram of one embodiment of the photocard of
the present invention using off the shelf components.
FIG. 5 is a block diagram of one embodiment of the photocard of
the present invention using a CMOS imaging device.
FIG. 6 is a block diagram of one embodiment of the photocard of
the present invention embodied on an integrated silicon device.
FIG. 7 illustrates one embodiment of the apparatus of the present
invention as connected to an external device.
In the following description, for purposes of explanation, numerous
details are set forth in order to provide a thorough understanding
of the present invention. However, it will be apparent to one skilled
in the art that these specific details are not required in order
to practice the present invention. In other instances, well known
electrical structures and circuits are shown in block diagram form
in order not to obscure the present invention unnecessarily.
Referring now to FIG. 1, a prior art 35 millimeter camera 102 is
shown. Although such cameras are very well known, a brief overview
of typical camera functions will introduce a context in which embodiments
of the present invention may be more easily understood. A 35 millimeter
camera 102 has a film chamber 104 for receiving an unexposed roll
of film 106 into a substantially cylindrical film roll areas 108.
The film chamber 104 includes a thin, substantially flat area 112,
located behind the shutter aperture 114 and the cylindrical film
roll area 108 which provides a larger region at one end of the film
chamber 104 and a second cylindrical take up area 109. The film
chamber 104 is encloseable by a film chamber door 110 that is opened
to inset the unexposed roll of film 106. The flat area 112 may be
part of the film chamber door 110 in which film is held while the
shutter aperture 114 is open to expose a region 116 on the film
to light passing through the aperture 114.
When the film chamber door 110 is closed while film is properly
in place, a film take-up reel 118 rotates to draw onto the take-up
reel 118 a portion of the film. Thereafter, each time the shutter
button 120 is pushed to take a picture, the camera causes a shutter
aperture 114 to open and allow light to pass through the shutter
aperture 114 and expose a region of the film to the light.
As regions of the film are individually and sequentially exposed,
a film take-up reel 118 temporarily draws the exposed regions on
the film onto the take-up reel 118. In some cameras the take-up
reel 118 automatically advances to accept more of the exposed regions
of film, while in other cameras the take-up reel 118 must be mechanically
advanced by the user. Once substantially all the film has been advanced
onto the take-up reel 118 and the roll 106 is nearly empty, the
film take-up reel 118 releases the film, and the exposed film is
automatically or mechanically wound back into the roll 106. Then,
after the film is wound back into the roll 106, the film chamber
door 110 may be opened and the roll of used film removed.
FIG. 2 illustrates one embodiment of the present invention that
adapts a camera to take digital photographic images. The present
embodiment, an electronic camera-in-camera photocard, operates within
a 35 millimeter camera. It will be apparent to those skilled in
the art that the present invention can be used in other types of
cameras utilizing different film sizes.
Referring to FIG. 2, the photocard 202 shown in is inserted into
the film chamber 204 in place of film. Preferably, the photocard
202 is configured to fit into both the substantially flat area 212
and the cylindrical film roll area 208 of the film chamber 204.
Because the described embodiment of the present invention replaces
and thus obviates the need for film, the area 209 for receiving
an unexposed roll of film is also available. Thus, the photocard
202 can be configured to be thicker at both ends of the card such
that the thicker portions fit into areas 208 and/or 209. This provides
additional space in which circuitry or power supplies (e.g., batteries)
may be located. For example, a battery attachment is provided at
the opposite end of the circuit board, such that when cylindrical
batteries of a thin radius, such as AAA size batteries, are inserted
into the battery attachment, and the circuit board 230 is inserted
into the film chamber, the batteries occupy the space surrounding
the film take-up roll. In still other embodiments, a flat dial shaped
battery is included in a dial battery attachment coupled to the
circuit board. Other means of providing electrical power to the
circuit will be readily apparent to one of ordinary skill in the
art upon reference to the present disclosure.
The photocard 202 can be formed of one or more portions and includes
a circuit board 230, preferably approximately 1 to 2 millimeters
thick, which fits within the film chamber 204 of the camera when
the film chamber door 206 is closed. The film chamber door 206 of
the film chamber 204 closes to enclose the photocard 202, such that
a light detector of the photocard 202 is held in place in the substantially
flat area 212 behind the shutter aperture 214. Preferably, the circuit
board 230 is a printed circuit board and includes printed traces
or wires providing electric connections between various elements
mounted on the circuit board 230. Connections may be metal lines
etched, or deposited on the surface of the circuit board 230. In
some embodiments, bare die bonding or other means may be used to
fabricate circuitry directly onto the circuit board 230, while other
embodiments allow expandability by providing receptacles for surface
mounted components that includes various logic and memory storage
The circuit board 230 includes an imager 220, lens 232, memory
228 and other digital circuitry 224 that may include both embedded
logic and packaged integrated circuit devices. The digital circuitry
224 is distributed among several regions on the circuit board 230
and in several locations on the photocard. Some of the digital circuitry
224 is located on the surface of the photocard, while other portions
of the digital circuitry 224 are located internal to the cylindrical
The embodiment described for a particular model of camera. Because
different cameras have slightly different physical dimensions, it
is apparent that some embodiments of the present invention would
be designed specifically for particular models of standard cameras.
However, for the same film size camera it is contemplated that some
embodiments can be adjustable coupling the circuit board components
onto rails that are adjustable either by a spring loading or screw
mechanism that sets the length of the photocard to fit within the
length of the film chamber 204.
Referring to FIG. 3, a simplified block diagram of one embodiment
of the photocard is described. As mentioned above, the electronic
camera-in-camera photocard 300 includes an imager 305 (also shown
as element 220 in FIG. 2) that is mounted on the photocard. The
imager 305 captures the image the camera lens is directed at when
the shutter aperture 302 is opened. Coupled to or incorporated into
the imager 305 is a light detector 308 that detects the light that
enters through the shutter aperture 302 when the user operates the
shutter control 303 (e.g., depresses the button to take a picture)
and the shutter aperture 302 is opened to take a picture. The light
detector 308 controls the operation of the imager 305 such that
image data collected when the shutter is opened. In one embodiment
the light detector 308 controls the power to the imager 305. Alternately,
the light detector 308 controls a passgate which permits the clock
signal input that drives the imager 305 only when the shutter aperture
302 is open. In another embodiment, the light detector 308 controls
passgates located between the signal output of the imager 305 and
the inputs to analog to digital (A/D) converter 315. Thus, in this
embodiment, the imager 305 remains powered and operational, but
image data is only transferred out of the imager 305 when the shutter
is detected as opened.
Preferably the imager 305 is implemented as a digital imager fabricated
as a CCD (charged coupled device, also known as a bucket brigade
device). The CCD in some embodiments includes a large number of
small capacitors each having a small region of silicon between the
capacitor terminals. When light or other radiant energy strikes
the silicon, charge-hole pairs are formed in the silicon and are
quickly drawn to the capacitor terminals, providing electric connection
responsive to the incident light or other radiant energy.
It is contemplated that other imaging technologies can be used.
For example, CMOS devices and/or PN diodes that respond to incident
light, generating electronic signals detectable by a signal detector,
can be used. The advantage to using a CMOS imager is that most or
all of the functions of the photocard can be placed on a single
integrated circuit. Unlike a CCD, and as is illustrated in the embodiments
of FIGS. 5 and 6, a device fabricated using a CMOS process allows
both processing devices and light sensing devices to be fabricated
on a single chip, greatly reducing the cost and size of the overall
Furthermore, it is contemplated that the present invention can
extend to photograph images in other spectra: other technologies
responsive to radiant energy in any portion of the electromagnetic
spectrum can be used to transduce the radiant energy to electronic
signals detectable at the output of the imager. Thus, in some embodiments,
the imager 305 is fabricated such that electromagnetic energy other
than visible light may be detected, allowing photography in other
spectra. For example, the imager 305 can be configured to detect
a photograph subject's heat signature 305 such that "night
vision" photography can be performed. In particular, Mercury
Cadmium Telluride and other compounds, for example, respond electrically
to nonvisible radiant energy, particularly infrared energy, and
therefore allows photography in the corresponding spectra. Mercury
Cadmium Telluride has an especially low bandgap, making the compound
particularly suitable for photography in low energy and other nonvisible
Continuing with the present embodiment, the imager 305 is fabricated
using CCD technology and charge-hole pairs are moved at a transfer
rate through the silicon in the CCD device 305 to the A/D converter
315. Once converted to digital data, the data is stored in the memory
325. As the signals output from the CCD device 305 are output based
upon position (e.g., column by column), position information relative
to the matrix of the image sensed is maintained.
Because the size of each capacitor in a CCD imager is so small
compared to the normal 35 mm negative, the imager 305 occupies only
a small area on the photocard despite the large number of capacitors
needed to satisfy resolution requirements (i.e., the number of pixels).
Therefore, in some embodiments, an additional lens 304 (232 FIG.
2) provides further focus of light passing through the camera lens,
since the imager 305 is much smaller than the region of film normally
exposed in an exposure.
Digital circuitry 340, preferably a microcontroller or microprocessor,
provides a number of different functions. One function is the analysis
and translation of the digital data received from the A/D converter
of data words and other signals. It is contemplated that the digital
circuitry 340 performs some image processing to improve the image.
Such techniques, for example, edge detection or sharpening, cropping
and softening, are well known in the computer graphics art. In addition,
the digital circuitry 340, in some embodiments, structures the pixel
data into data words according to a specified output format. As
is apparent, the digital circuitry 340 can be configured to provide
prespecified output formats, for example, formats compatible with
predetermined computer or photo processing equipment that the digital
data may be downloaded to, as a selectable option.
Preferably the digitally converted signals received from the CCD
device 305 are configured into data words indicating the spatial
planar coordinates of an individual CCD capacitor, and the chrominance
and intensity of the light incident on the silicon of the CCD capacitor.
It will be recognized that various digital data structures may be
used to format the digital data. The data words thus collectively
represent a pixel map of an image frame as photographed by the imager
305 when the shutter aperture 302 of the camera is open.
Preferably a digital counter 320 provides a digital count-signal
indicating the number of times the shutter aperture of the camera
has opened since the counter was last reset. This count value is
indicative of the number of images collected since, for example,
the last download of images from the photocard to an external device.
In one embodiment, the counter 320 is a separate logic device coupled
to the light detector 308. The light detector 308, when light is
detected due to the opening of the shutter aperture 302, issues
a single, such as a clock signal, to increment the count maintained
by the counter. Alternately, the counter 320 can be embodied in
the digital circuitry 340 which maintains the count and increments
the count each time the digital circuitry 340 processes an image.
Preferably the signal representative of the count is appended to
the data words corresponding to the image received by the imager
220. Thus, data words generated on distinct openings of the shutter
aperture 302 may be distinguished from other data words generated
at the same planar spatial coordinates.
In one embodiment, a user of the photocard may, before or after
taking a picture, select an image representation option, such as
a color option, a gray-scale option, or a black-and-white option.
As is known to those skilled in the computer graphics art, the pixel
data representing the image can be displayed in color, gray scale,
etc. by performing different translations of the pixel data. Typically
a translation table, such as color lookup table, is used.
If the image representation option is specified at prior to taking
the picture, the data structure representative of the image sensed
would include a field which identifies the option selected for a
particular image or group of images. Although the camera photocard
could be configured to provide this capability, it is also contemplated
that this selection can be implemented as a post processing feature
that is provided by a device external to the photocard, after the
user down loads the images from the photocard. After download of
the images, the user can then select the desired image representation
option. It is noted that flexibility is achieved as the user can
produce multiple versions, for example, both black-and-white and
color versions, of the same photograph.
The pixel data and/or data words representative of the image are
stored in a memory 325. Preferably a reusable nonvolatile memory
is used. As will be described below, the contents of the memory
325 can be down-loaded to a larger memory or to other external devices
and the photocard reused. The ability to erase and reuse memory
325, in addition to the ability to store data in a compact space,
is extremely advantageous as the photocard may be reused, making
obsolete the recurring expense of buying rolls of film.
Preferably a flash electrical erasable programmable read only memory
(EEPROM) is used, although the present invention is not limited
as such and other types of EEPROMs can be used. In this embodiment,
the photocard may include a manually driven switch (such as a button)
to erase the memory after the images are downloaded. Alternately,
as part of the download process, the memory may be automatically
erased. It is readily apparent that other types of EEPROMs can be
used, and the erasure process required would have to be modified
Although it is preferred that the memory 325 is nonvolatile and
erasable, it is not limited as such and can be embodied as a volatile
or a non-erasable memory media. For example, the memory 325 can
be implemented in random access memory (RAM). However, the power
supply 335 would have to provide the power to maintain the image
information in the memory 325. Furthermore, a non-erasable media
could be used. In this embodiment, the memory would be configured
in a component that can be easily removed from the photocard in
order to swap out the memory component once it is completely used.
This embodiment may be advantageous for those users that wish to
have the convenience similar to a roll of film. A distinct difference,
however, is that the memory stores digital images and is capable
of storing more photographs than a standard roll of film.
It should be realized that due to the variety of memory 325 devices
available, different embodiments of the present invention allow
different numbers of exposures or images to be stored. Furthermore,
the photocard can be configured to generate different resolutions
(i.e., number of pixels per image) of images as well as the number
of bits per pixel. The resolution can be configured to vary according
to the embodiment of the photocard used; alternately, the photocard
could be configured to be field programmable, enabling the user
to selectively decrease the number of exposures the memory is capable
of storing for increased resolution. This resolution could be varied
from image to image, for an entire photographic session or consistently
applied to the images stored in the memory.
Power to the photocard 300 can be generated from a variety of sources.
For portability, it is preferred that the power supply 335 is a
battery. In one embodiment, the photocard is integrally formed with
a battery 234. Alternately, the power supply 335 includes a connection
to the camera battery and draws power from the camera battery typically
used to power the camera flash and other electrical components.
Preferably, additional batteries are provided as part of or adjacent
to the photocard 3000. These batteries would be stored in one or
both of the areas typically used to store a roll of film or take
up exposed film (areas 108, 109, FIG. 2). Because the image is stored
digitally in the memory and not on film, there is no danger of exposing
film, and the film chamber door may be opened to recharge or replace
the battery or other components without concern of damaging the
photographic images taken.
The photocard 300 further includes output circuitry 330 for reading
the images stored in the memory and downloading the images for viewing,
post processing, editing, printing or the like. In its simplest
form, the output circuitry 330 is a standard interface, such as
an RS-232 interface, and controller that downloads the entire memory
when the interface is connected to an external device, such as a
computer system or digital photo processing or editing system. In
this embodiment, the computer system would control the output circuit
330 to read the memory 325 and download the image information. Alternately,
some intelligence can be added to the output circuit 330, or the
digital circuitry 340 can be used to control the download of the
digital images. Furthermore, it is contemplated that the photocard
may include the necessary circuitry to drive certain equipment,
such as a monitor or printing device, to display or print the digital
images. In those embodiments, a processor or circuitry located on
the photocard would provide the logic to configure the data in a
compatible format. The photocard would also include, if needed,
additional circuitry to perform digital to analog conversion or
signals of prespecified levels compatible with the output device
the photocard is coupling to. Thus, the photocard could be used,
for example, to drive a monitor or a printer. The photocard could
also enable the user to fax images through a telephone line using
a coupled RJ-11 connector.
It is also contemplated that the photocard also includes circuitry
to perform direct pixel to NTSC conversion, NTSC being a standard
in the television industry. Furthermore, the photocard can be configured
with the necessary logic and connectors to providing outputs compatible
with a computer system and analog NTSC/PAL/SECAM output.
It can be seen that the photocard of the present invention provides
a number of distinct advantages to the user. The user can continue
to use the equipment he is familiar and comfortable with. In addition,
because the image is digitally stored, distortion in the image and
photographic errors can be corrected, minimizing the need to retake
photographs and increasing the capability of providing the perfect
photograph that can not be duplicated. The correction circuitry
may be located on the photocard (e.g., in the digital circuitry
340) and automatically enabled or may be part of a post processing
process executed on a photo editing or processing system. Image
correction can correct, for example, astigmatism, coma, aberration,
and other errors generated by the lens or imager.
But editability adds more than mere correction; editability also
facilitates creative expression by including features that extend
the capabilities of film-based technology, giving photographers
unprecedented control over the photographs produced. It is contemplated
that the photocard could also provide extremely high-precision and
high-resolution control, e.g., aperture sizes and magnifications,
over images, much more than would otherwise be allowed using only
the camera knobs and dials.
Selectable options and features may be selected by placing certain
switches on the card, such as dip switches, to specified states.
Alternately, a remote control device 370 is used. The remote control
370 communicates with the photocard to select options and perform
certain functions, such as the features and options discussed above,
including image processing functions, data configuration options,
output options and download options. Any type of remote control
technology can be used. In the present embodiment, the remote control
includes a radio receiver/transmitter that communicates with a radio
receiver/transmitter on the photocard. By including a receiver/transmitter
on both the photocard and the remote, the photocard can provide
feedback to the user, via the remote. Alternately, to save on space
and power consumption on the photocard, the remote can be configured
with a transmitter and the photocard can be configured solely with
The photocard could provide preprocessing functions that can mimic
virtually any effect a photographer might desire, even if the effect
is not achievable using ordinarily available photographic equipment.
For example, the photocard could include a user-programmable preprocessing
digital distorter, set by the user-photographer, that modifies the
signals sent from the imager. Digital distortion can produce effects
that cannot be achieved using film-based photography. In addition,
the photocard could include an internal timer that allows integration
of the image over time on the photocard itself, producing data that
exactly simulate a photographic image that would be produced using
film. This timer can be used to simulate opening a shutter extremely
fast, or can be used in conjunction with the camera's own shutter
speed to achieve varying results.
In particular, the photocard 300 can include control logic, which
may be separate logic or logic that is embodied in the digital circuitry
340, that controls a shutter of the imager (the imager shutter is
separate from the mechanical shutter aperture 302 of the camera).
Using this feature, the camera can be set to operate in accordance
with the mechanical shutter aperture speed or to operate at a speed
much faster than the mechanical shutter aperture speed is capable
of. Shutter speeds in ordinary cameras are normally limited to approximately
1/5,000 of a second, depending on the speed of the circuitry used.
In the photocard of the present invention, the shutter speeds of
the imager 305 can be set to approach 1/100,000 of a second. As
noted, the imager shutter speed can be set to coincide with the
mechanical shutter aperture speed of the camera. One way of achieving
this is to configure the connections between the light detector
308 and the images 305 such that when the light detector 308 detects
light, indicative that the shutter aperture 302 of the imager shutter
is opened, and when the light detector 308 no longer detects light,
indicative that the shutter aperture has closed, the imager shutter
It should be noted that the features above do not necessarily replace
the features of the camera itself; instead, these features augment
the camera's own controls, allowing a photographer an incredible
range of effects.
A more complete block diagram of one embodiment of the photocard
of the present invention is shown in FIG. 4. The photocard 400 includes
a CCD device 405 for detecting images when the shutter aperture
is opened. The CCD device 405 is powered by power supply 410, which
preferably also powers the other circuitry shown. The high voltage
generator 415, coupled to power supply 410 powers the CCD clock/column
driver 417. The clock/column driver 417 in conjunction with the
horizontal driver 420, drive the pixel signals output from the CCD
on a column by column basis. Automatic gain control 425 adjusts
the gain on the pixel signals received for subsequent processing.
The data is then converted to digital pixel data, by analog to digital
converter 430, and is temporarily stored in a buffer 435 which provides
an buffering mechanism to account for differing speeds of output
of the CCD and input of the signal processing component 440.
Signal processing is then performed on the digital pixel data to
enhance the image detected by the CCD device 405. Such techniques
are well known in the art of digital image processing, For example,
automatic white balance, automatic exposure control, gamma control
can be applied. In addition, the luminance and chrominance can be
separated for subsequent processing by the JPEG circuit 445. Although
the above processing is shown in FIG. 4 as a single function block
440, it is contemplated that the circuitry encompass multiple circuits.
Signal processing circuits and components are available from Samsung
Corporation and Hitachi Corporation.
The JPEG (Joint Picture Experts Group) circuit compresses the digital
images. JPEG is a standard for compression of digital photographic
images. The output of the JPEG circuit is processed by microcontroller
450 as indicated by the microcontroller instructions stored in the
nonvolatile memory 460 and uploaded to the instruction RAM 455 when
the photocard is powered.
The microcontroller 450 controls the storage of the pixel data
in the memory 465 and the subsequent output of the pixel data from
the memory 460 to a computer system, printer or photo processing
system, through the buffer 468 and output driver circuit 470, such
as one compatible with the RS-232 standard, or to drive a monitor
or other video device through the digital to analog converter 475
and sync circuit 480 to produce composite video signals reflective
of the digital images. Embodiments can also include driver hardware
and software to output the data through a telephone line connection,
such as one in accordance with the RJ-11 standard, to enable the
user to transmit or fax images over telephone lines.
The embodiment of FIG. 4 can be used for still photography or video.
The difference in application dictates the size of the memory as
video requires significantly more memory (roughly 100 Mbytes/minute).
However, using compression, such as compression techniques compatible
with the JPEG standard, the amount of memory needed can be reduced
to 20 Mbytes per minute of recording.
FIG. 5 illustrates an alternate embodiment which uses a CMOS imaging
chip which includes an on-board analog-to-digital converter, memory
and some processing circuitry. This embodiment provides a significant
space savings over the previous embodiment described. Referring
to FIG. 5, the photocard 500 includes a CMOS imager 505 that detects
an image when the mechanical shutter/aperture (not shown) and the
imager shutter (not shown) are opened. The CMOS imager 505, such
as one announced by VLSI Vision Limited, Edinburgh, Scotland, not
only senses the image received, but performs signal processing and
stores a limited amount of pixel data on chip. Thus, as can be seen
in FIG. 5, most of the additional circuitry for performing signal
processing is eliminated.
The pixel data output is received by the microcontroller 510 which
executes instructions stored in the program memory 520, which can
store the pixel data in memory 515 and subsequently output the pixel
data through buffer 525 and output circuit 535 and/or digital to
analog converter 530 and sync circuit 540. As the signal processing
and A/D conversion of the image is performed on the CMOS imaging
chip 505, the additional circuitry needed on the photocard is minimal.
It is contemplated that the features and functions described above
with respect to prior figures can be implemented in silicon on a
single chip. The resultant chip will incorporate the features of
the previous embodiments described; however, by integrating the
functions on a single chip, significant size and power and cost
savings will be realized. In addition, the speed and image quality
will be increased. FIG. 6 shows a simplified block diagram of a
photocard system which can be integrated onto a silicon component.
Referring to FIG. 6, the CMOS processor/imager 605 captures the
images, performs any signal/color processing needed and stores the
pixel data in the memory also integrated into the CMOS processor/imager
605. Additional memory 610 may also be provided if needed. The CMOS
imager/processor also includes the logic to generate output 615,
compatible with computer systems or analog output 620 for driving
a monitor. It is contemplated that the embodiment shown could include
other features or connect to external devices that may provide additional
As noted above, the photocard connects to an external device for
the download of the digital images. The external device can be a
variety of devices compatible with the output of the photocard.
For example, as shown herein, the photocard can be coupled to a
device having an RS-232 interface. This device could be a general
purpose computer or a computer specially configured to edit or process
digital images, a printer or photo processing equipment. The device
could simply be a mass storage device such as a disk drive. Other
devices are also contemplated. Additionally or alternately the device
could be a telephone, or can be a monitor or other analog equipment
that receives video reflective of the digital images, such as those
devices compatible with the NTSC or PAL standards.
Examples of external connections are shown in FIG. 7. Referring
now to FIG. 7, the present invention also includes embodiments that
have an external interface. A flexible flat wire 744 extends from
the photocard (not shown) which is located in the film chamber 204.
In an alternate embodiment, the wire 744 is replaced by a wireless,
such as a radio or infrared, connection. The flat wire is thin and
sturdy enough to enable the closure of the film chamber door and
to not be damaged by closure of the film chamber door. The flat
wire 744 connects to the external device 750 that, in various embodiments,
includes an external power supply, additional memory, and additional
circuitry. The additional circuitry, for example, can support or
supplement the functionality located on the photocard. Furthermore,
it is contemplated that the external device provides the connection
to external processors, monitors, and recorders, thereby eliminating
the need for the functionality to be located on the photocard. This
saves space and also provides a easy mechanism for providing for
additional connections without modifying the photocard.
In some embodiments, the external device 250 includes additional
memory to capture digitized data representing images or parts of
images as the images are taken. For example, the memory may be a
storage device such as a disk drive or the like. For the user that
intends to take a large quantity of pictures, the disk drive device
can be constructed to withstand rough handling and of a small enough
size to enable the user to clip the drive on his person, such as
his belt. Alternately, this data can be transferred to an antenna
circuit located external to the photocard for wireless transmission
to a remote receiver that may be coupled to a variety of types of
devices such as a television set or a video recorder, to a computer
system having a processor, to an internet-linked processor, to a
fax modem for transmission via telephone or ISDN lines, or to a
Using the photocard of the present invention, images can therefore
be transmitted quickly and efficiently to remote locations, can
be displayed on computer or television equipment, can be transmitted
via telephone lines as a fax, can be provided to the internet or
worldwide web rapidly, and can allow digital manipulation of images.
Facilities that allow rapid, high quality, high resolution printouts
of digital images recorded on digital cameras can easily be used
in accordance with the present invention to print out extremely
high quality prints of photographs recorded using the present invention,
using at least all of the digital enhancement techniques that may
be used with the expensive digital camera technologies.
As noted above, some embodiments of the present invention include
either a video-port, allowing either a direct wired, e.g., coaxial
connection, or an antenna for a wireless signal connection with
a typical television set. Other embodiments provide serial or parallel
data transfer to a computer system, either directly or via a peripheral
component. Additional intelligent components can be included in
other embodiments, allowing using connectability to digital networks
such as the internet. Still other embodiments allow connection to
an external memory that a photographer might wear on a belt or might
attach to an external surface of the camera. Such an external memory
may be magnetic rather than solid state, allowing much greater storage
capacity of digital images. Using wireless technology, other circuitry
included in other embodiments allows easy wireless downloading of
information to external hard drives or other computer equipment,
or to a receiver coupled to a television set. For example, in one
embodiment, a recreational user while on vacation, can fax photographs
of the vacation to friends and family via a telephone phone.
The invention has been described in conjunction with the preferred
embodiment. It is evident that numerous alternatives, modifications,
variations and uses will be apparent to those skilled in the art
in light of the foregoing description.