Patent Application
20070077059
1. Field of Invention
This invention relates to image capture, transformation and reproduction.
2. Description of Related Art
Conventional printing systems provide users with a range of printing options. For example, conventional laser printers permanently fuse particles of toner onto durable sheets of paper. These conventional laser imaging systems offer low cost archival quality printing but are not generally suitable for mobile applications due to their high power requirements. Conventional ink-jet printers use ink nozzles to eject various color inks from tanks onto sheets of paper. Although ink jet printers are typically less expensive to purchase, the cost of ink usually results in higher printing costs.
Manufacturers of some conventional printing and scanning equipment have combined the function of scanning and printing into a single multi-function device. These conventional multi-function devices incorporate optical scanning devices with ink-jet or laser printers. These conventional multi-function devices are useful in reducing the space required in small home offices. However, these multi-function devices are not well suited to portable computing environments. For example, laser based multi-function devices typically consume large quantities of power in the heating of the imaging of the image drum and in heating the image toner particles.
Ink jet based multi-function devices also consume large quantities of valuable mobile power. Moreover the resultant image quality may not be appropriate for the intended purpose.
Conventional scanners scan images by recording the reflection of light from each portion of the page. Hand scanners capture images and use software to combine the images into a single image representative of the original. Other conventional scanners move the paper over a fixed array of photo-detectors or move an array of fixed photo-detectors across the image to be scanned. Good quality scanned images are difficult to produce with conventional hand scanners due to alignment problems. Better images are produced with conventional scanners incorporating a fixed array of photo-detectors. However, conventional fixed array photo-detectors require space un-available in a typical mobile environment. Thus, a portable low-power multi-function device that does not require a large amount of space would be useful.
Systems and method for a multi-function device that prints image information onto sheets of photo-addressable media is described. The multi-function device is comprised of an image acquisition component, an image generation component, optional image transformation components and an image projector to illuminate the photo-addressable medium with the optionally transformed image information. The effects of ambient light on the photo-addressable medium are reduced by tuning the response characteristics of the photo-addressable medium to respond to the wavelength of the projected light and/or to interpose band-pass filters that reduce non-projected light incident on the photo-addressable medium. Programmable characteristics of the photo-addressable medium are optionally be adjusted to compensate for ambient light. Registration marks on the photo-addressable medium allow the alignment of the projected image with the photo-addressable medium. Additional optional image transformations are applied to adjust the size of the information image, increase clarity and the like.
An illumination image is created based on the acquired image information 400 and the characteristics of the photo-addressable medium upon which the image is to be printed. For example, some photo-addressable media are photo-sensitive and change their optical contrast properties in response to incident illumination. Thus, in some exemplary embodiments, the illuminated areas of the photo-addressable medium are associated with higher optical contrast than un-illuminated areas. However, other types of photo-addressable media that reduce the optical contrast of illuminated areas can also be used in the practice of this invention. Thus, for these photo-addressable media, positive or negative illumination images may be required to produce the desired result.
The positive or negative illumination image is then applied or projected onto the photo-addressable medium. In various exemplary embodiments according to this invention, the illumination image is projected onto the photo-addressable medium using the Symbol Technologies laser based micro-projector or the like. However, it will be apparent that other sources of illumination, such as, light emitting diodes (LEDs), lamps, mirrors, liquid crystal based projectors, digital light projectors (DLP) and the like may also be used alone or in combination, without departing from the scope of this invention. Thus, in another exemplary embodiment, a red laser illumination source is coaxially combined with an infra-red laser illumination source to illuminate the photo-addressable media. The combined illumination source offers the advantage of an increase in optical power for recording the illumination image onto the photo-addressable medium. In some embodiments, the illumination source and the photo-addressable medium are selected to minimize ambient light interference. In other exemplary embodiments, a band-pass filter is used to reduce the interference effects of ambient light while the illumination image is recorded onto the photo-addressable medium.
In some cases, additional steps may be required to capture an illumination image on the photo-addressable medium. For example, one type of the Fuji Xerox e-paper requires the application of a power source for a specific time period. The power source may be applied using a portable power clip that incorporates a battery and a push button activation device or the like. When the photo-addressable medium is illuminated with the illumination image, the activation device applies power, and a programming voltage is applied to the photo-addressable medium. The projected illumination image applied to the photo-addressable medium transiently changes the conductivity of portions of the photo-addressable medium cause the photo-conductive portions of the photo-addressable medium to change to a second stable state. The second stable state is associated with optical characteristics different from the first stable state. The activation device is released and the power is removed. The bi-stable photo-addressable media records the projected illumination image in the optical contrast differences of the photo-addressable medium.
In various exemplary embodiments according to this invention, the acquired image 400 is optionally transformed to compensate for skewed photo-addressable media, key-stoning, to fit the acquired image within a specified area of the photo-addressable medium or the like.
In one exemplary embodiment, the image acquisition circuit 35 is activated to acquire an image from an image source. The image source may include, but is not limited to an image repository, a disk file, an embedded or external digital camera, an image scanning device, a software application capable of producing an image file, and/or any known or later developed source of images.
The acquired image is stored in memory 20 by the processor 30. The processor 30 activates the illumination image generation circuit 40 to determine an illumination image based on the acquired image. The illumination image circuit 40 creates an image of the appropriate positive or negative contrast areas to be projected onto the photo-addressable media. The determined illumination image is then projected onto the photo-addressable media by the illumination source 80. The illumination source 80 may be a point-source such as a laser, or a non-point source such as a digital light projector (DLP) or the like. Multiple illumination sources may be combined. In various exemplary embodiments, one or more illumination sources tuned to the response characteristics of the photo-addressable media are used. For example, in one embodiment, a red laser is coaxially combined with an infrared laser to provide a combined source of illumination with increased optical power for illuminating the photo-addressable medium with the illumination image.
In various other exemplary embodiments, an optional ambient illumination circuit 60 is activated. The ambient illumination circuit 60 determines the level of ambient illumination incident on the photo-addressable medium. Compensations that adjust the illumination image and/or the programming voltage applied to the photo-addressable medium are determined. For example, the illumination source may deliver less illumination to areas of the image already illuminated by ambient light since less additional energy is required to write the image in these areas. In still other exemplary embodiments, the required programming voltage applied to the photo-addressable media 300 to write the illumination image is adjusted based on the determined ambient illumination. That is, the voltage applied to image areas already receiving ambient illumination are reduced to compensate for the additional light.
The processor 30 optionally activates the optional transformation circuit 50 to determine transformations of the illumination image. The transformations may include, but are not limited to, determining a transformation of the illumination image to align or register the projected image with the current position of the photo-addressable media. In one exemplary embodiment according to this invention, the registration marks at the top left, top right, bottom left and bottom right are identified by activating the optional registration circuit 70. The registration marks are used to determine the orientation, alignment and inclination of the surface of the photo-addressable medium. The determined orientation of the registration marks is then used to determine compensating image transformations for key-stoning or non-perpendicular projection, de-skewing and the like.
In various embodiments, the optional registration circuit 70 is comprised of a camera that captures an image of the blank photo-addressable medium. However, it will be apparent that the registration circuit may use any known or later determined method of determining the registration and alignment of the photo-addressable medium without departing from the spirit or scope of this invention.
In various exemplary embodiments, the captured image is transformed by the multi-function device 100 to align the projected image with the photo-addressable medium. For example, registration marks may be positioned on the photo-addressable medium. A registration circuit within the multi-function device 100 detects the spatial position of the registration marks and uses the information to determine optional transformations that are applied to the image. The transformed image is then projected onto the photo-addressable medium using an illumination source. In various other exemplary embodiments, the illumination source is matched or tuned to the response characteristics of the photo-addressable medium. For example, in one embodiment, a projected image may be created by coaxially combining a red-light based micro-projector laser with an infra-red laser. A photo-addressable medium comprised of cholesteric crystals and a photo-conductor, is designed to respond to the wavelength of the combined source of illumination. The ambient light is less likely to contain both red laser and infra-red wavelengths thereby reducing ambient light effects on the photo-addressable medium.
In a second exemplary embodiment, the image is acquired from an image repository 520 containing images previously captured and downloaded from the camera 510. That is, the image repository may include an on-line photo-album or the like. An image is acquired from the image repository and transferred to the multi-function device 100. The acquired image is then optionally transformed based on the orientation of the photo-addressable media, ambient illumination, and the like. The optionally transformed image is then projected onto the photo-addressable medium 300.
In a third exemplary embodiment, the image is acquired from the internet repository 530. The internet repository 530 may be a file transfer protocol (FTP) based clip-art library, an HTML encoded web page and/or any known or later developed source of images. The image is downloaded using file transfer protocol (FTP), hypertext transfer protocol (HTTP), or the like to the multi-function device 100. The acquired image is optionally transformed and projected onto the photo-addressable medium 300 using the illumination source.
In a fourth exemplary embodiment according to this invention, the image is acquired from an image application 540. The image application 540 includes, but is not limited to, Adobe Photoshop, Corel Draw, Visio or the like. The acquired image is then transferred to the multi-function device 100, optionally transformed and applied or projected onto the photo-addressable medium 300 using an illumination source. As discussed above, various optional transformations may be applied to align the projected image with the photo-addressable medium, compensate for the effects of the ambient light and/or to perform any other useful image transformation.
In various other exemplary embodiments, a programming voltage is applied to the photo-addressable medium 300 as the transformed image is projected. The programming voltage and the projected image change the optical characteristics of photo-conductive portions of the photo-addressable medium 300 based on the projected image. For example, when the programming voltage is applied to a cholesteric light sensitive layer of material sandwiched between photoconductive materials, the increased conductivity of the photo-conductive material allows power to flow to the adjacent cholesteric crystal based material. This in turn effects a state change in the cholesteric material. The states are bistable states associated with differing optical characteristics. The cholesteric material retains the new stable state after the programming voltage is removed. A facsimile of the illumination image is thereby recorded on the photo-addressable medium 300.
The illumination image 400 is projected onto the photo-addressable medium using an illumination or light source. The illumination image illuminates the photo-addressable medium 300 all at once, or via one or more point sources. For example, in one exemplary embodiment, the output of a Symbol Technologies micro-projector laser is used to rasterize or write the illumination image 400 across the photo-addressable medium 300. A programming voltage is applied to the photo-addressable medium 300 to record the projected illumination image 400. When the programming voltage is removed, the illumination image 400 is retained by the photo-addressable medium 300. It will be apparent that various types of photo-addressable medium such as Fuji Xerox e-paper may also be used without departing from the spirit or scope of this invention.
The photo-addressable medium 300 is then removed from the clip board and used much like ordinary paper. In some exemplary embodiments according to this invention, the e-paper is erased by applying second programming voltage while shielding the paper from incident light.
In still other exemplary embodiments according to this invention, the multi-function device 101 includes an ambient illumination detector. The ambient illumination detector adjusts or transforms the illumination image 400 and/or the programming voltage to compensate for the amount of ambient light. The ambient illumination detector may be a photo-detector, a CCD, a digital camera or the like.
As discussed above, the acquired image 400 is optionally transformed to de-skew and/or align the acquired image 400 with the photo-addressable medium 300. In various embodiments, image transformations are applied to compensate for any unevenness of the photo-addressable medium 300. In still other exemplary embodiments, the programming voltage is automatically applied by the multi-function device 101 without user actuation of the activation button 330. Automatically determining when to apply the programming voltage facilitates the imaging process.
In some exemplary embodiments according to this invention, an optional user interface is provided via a liquid crystal display (LCD) or other display component. The user interface facilitates the selection of discrete images from the image repository or other image source. However, it should be apparent that a voice interface and/or any known or later developed user interface may also be used to select target images for acquisition, without departing from the scope of this invention.
In one exemplary embodiment, the photo-addressable medium 300 is Fuji Xerox's e-paper based photo-addressable medium. However, it will be apparent that any paper with a photo-sensitive ink may be used in the practice of this invention. In some embodiments, the photo-addressable medium is comprised of an organic photo-conductor, cholesteric material or the like. In still other embodiments, Hydroxy Gallium Pthalocyanine is used as a charge generation material. The Fuji Xerox e-paper based photo-addressable medium is comprised of bi-stable choleristic crystals sandwiched between a photoconductive material. A programming voltage is applied to the backplane in conjunction with a projected illumination image 400. The photo-conductive material allows selective current flow based on the projected illumination image 400. The optical quality of the cholesteric crystals exposed to the higher current records the incident illumination image by changing the state of the cholesteric crystals to a second stable state associated with different optical characteristics. The cholesteric crystals are bi-stable, and remain in the second state when the power is removed.
Stronger ambient illumination creates a problem by effectively exposing all of the photo-addressable medium. That is, if the ambient illumination is strong enough, then no differentiation between high and low contrast areas will be evident and the recorded image will not be perceived. These problems are addressed by selection of the photo-addressable medium in conjunction with the type of light or illumination used to project the illumination image. For example, the photo-addressable medium may be tuned to respond to specific wavelengths of laser light not otherwise found in ambient florescent, incandescent or natural sunlight. Multiple sources of illumination may be combined and/or filters may be used to further reduce the effects.
In step S300, a first image to be acquired from the image source is determined. The first image may be determined using a drop down dialog box, a cursor or pen gesture selection or the like. However, it should be apparent that any method of selecting a first image may be used in the practice of this invention. After the first image has been determined, control continues to step S400.
In step S400, a photo-addressable medium is determined. The photo-addressable medium may be Fuji Xerox's e-paper product, and/or any other known or later developed type of photo-addressable medium. Control then continues to step S500.
In step S500, a spatially variable illumination of the photo-addressable medium is determined based on the first image. The spatially variable illumination is provided by a point source laser such as the Symbol Technologies micro-projector laser or the like. The micro-projector laser device provides a compact and highly portable spatially variable source of illumination. However, it will be apparent that various other known or later developed types of spatially variable illumination sources may also be used without departing from the scope of this invention. After the spatially variable illumination has been determined, control continues to optional step S600.
In optional step S600, an optional second image is determined by applying the spatially variable illumination to the photo-addressable medium and storing an image of the resulting photo-addressable medium. The second image is based on the image projected onto the photo-addressable medium. The second image provides an indication of how the first image will look when recorded on the photo-addressable medium. The optional second image is recorded using a digital camera a charged coupled device (CCD) and/or any known or later developed means of capturing an image. The second image is used to determine that the projected image is mis-aligned with the optional registration marks on the photo-addressable medium. After the optional second image has been recorded, control continues to optional step S700.
In optional step S700, optional transformations of the first image are determined based on the optional second image. Thus, a mis-aligned or skewed image is corrected by transforming the image to compensate for the mis-alignment of the photo-addressable medium. Other optional transformations may be used to increase the size of text, increase the clarity of images and the like. After the optional transformations of the first image have been determined, control continues to step S800.
In step S800, optional compensations of the photo-addressable medium are determined based on the first and second images. For example, the second image may be used to detect that ambient light may wash-out the first projected image. Compensating reductions in the programming voltages applied to portions of the photo-addressable medium and the like are used to reduce the effect of the ambient light. Control then continues to step S900.
In step S900, the optionally transformed final image is projected onto the photo-addressable medium and any required programming voltages are applied. The projected image is then stably recorded onto the photo-addressable medium. In various other embodiments according to this invention, a band-pass filter is optionally interposed between the photo-addressable medium and any other source of illumination. The band-pass filter reduces the effect of the ambient illumination by selectively passing wavelengths associated with the spatially variable source of illumination.
It will be apparent that in various other exemplary embodiments according to this invention, the images may be located on the multi-function device 100, a laptop computer (not shown), an information repository (not shown) and/or any other location accessible via communications link 99.
Each of the circuits 10-70 of the multi-function device 100 described in
Moreover, the multi-function device 100 and/or each of the various circuits discussed above can each be implemented as software routines, managers or objects executing on a programmed general purpose computer, a special purpose computer, a microprocessor or the like. In this case, the multi-function device 100 and/or each of the various circuits discussed above can each be implemented as one or more routines embedded in the communications network, as a resource residing on a server, or the like. The multi-function device 100 and the various circuits discussed above can also be implemented by physically incorporating the multi-function device 100 into software and/or a hardware system, such as the hardware and software systems of a web server or a client device.
As shown in
The communication links 99 shown in
Further, it should be appreciated that the communication links 99 can be wired or wireless links to a network. The network can be a local area network, a wide area network, an intranet, the Internet, or any other distributed processing and storage network.
While this invention has been described in conjunction with the exemplary embodiments outlined above, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the exemplary embodiments of the invention, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention.
