Patent Application
20130293657
This invention pertains to the field of printing and more particularly to a method of printing an image that conveys information to both a sighted person and a visually-impaired person.
Since the invention of the printing press, printed images have become a common way to communicate information. Printed images can include text, as well as other types of image content such as photographic images and graphical image elements (e.g., pie charts, logos and computer generated artwork).
While printed images are effective to communicate information to sighted persons, there is a significant minority of the human population who suffer from visual impairment, including blindness. Printed images have little or no value for this population segment.
A variety of methods have been developed for communicating information to visually impaired individuals. The Braille system is a method that is widely used by people who are visually-impaired to enable them to read and write. Braille was devised in 1825 by Louis Braille, and involves forming tactile characters using patterns of raised dots. Each Braille character, or cell, is made up of six dot positions, arranged in a rectangle containing two columns of three dots each. A dot may be raised at any of the six positions to form sixty-four possible arrangements (including the arrangement in which no dots are raised). Conventionally, Braille characters are “printed” using devices that emboss the desired dot patterns into a receiver such as paper.
In recent years, various systems have been developed for forming tactile patterns, including Braille characters, using electrographic printing technology. For example, commonly-assigned, U.S. Patent Application Publication 2008/0159786 to Tombs et al., entitled “Selective printing of raised information by electrography,” and commonly-assigned U.S. Pat. No. 8,064,788 to Zaretsky et al., entitled “Selective printing of raised information using electrography,” describe methods for printing raised information with a tactile feel using toner particles having a substantially larger size than standard size marking particles that are used to form printed images.
Commonly-assigned U.S. Patent Application Publication 2011/0200360 to Tyagi et al., entitled “System to print raised printing using small toner particles,” and commonly-assigned U.S. Patent Application Publication 2011/0200933 to Tyagi et al., entitled “Raised printing using small toner particles,” disclose methods to print raised letters using small toner particles that involve using multiple layers of toner.
Commonly-assigned U.S. Patent Application Publication 2011/0200932 to Tyagi et al., entitled “Raised letter printing using large yellow toner particles,” discloses a method to produce prints with raised letters by forming multi-color toner images and fusing the print one or more times.
A variety of other methods are also known in the art for forming tactile image content. For example, commonly-assigned U.S. Pat. No. 5,125,996 to Campbell et al., entitled “Three dimensional imaging paper,” discloses an imaging paper having dispersed throughout hollow expanding synthetic thermoplastic polymeric microspheres. Tactile information can be provided by using a scanning laser beam (or some other thermal source) to cause discrete areas of the paper to expand.
Zychem Ltd of Middlewich, Cheshire, UK have developed a product known as Zytex2 Swell Paper onto which images can be printed and made into tactile diagrams. This product can be used to form, Braille or other forms of tactile patterns. An image can be printed onto the paper, and when the paper is heated using one of our Zyfuse heating machines, the black parts of the image swell up to become tactile. This approach has the limitation that the tactile features are constrained to have a direct correspondence to the black image regions.
U.S. Pat. No. 4,972,501 to Horyu, entitled “Image processing apparatus,” discloses an apparatus to enable a blind person to read characters written on a paper. The apparatus includes a photo-sensor which is used to scan the printed text. The scanned image pattern is converted to mechanical vibrations using piezoelectric elements or LEDs.
Commonly-assigned U.S. Pat. No. 6,755,350 to Rochford et al., entitled “Sensual label,” and commonly-assigned U.S. Pat. No. 7,014,910 to Rochford et al., entitled “Sensual label,” discloses a pressure sensitive adhesive label including at least one tactile or olfactory feature. Tactile features are provided by a textured overcoat later. The form of the tactile and olfactory features can be chosen to be related to visual content included on the label.
U.S. Pat. No. 7,290,951 to Tanaka et al., issued Sep. 7, 2006, entitled “Braille layout creation method, Braille layout creation system, program, and recording medium,” discloses a Braille layout creation method where Braille characters are embossed into an object frame, in association with corresponding printed text characters.
U.S. Patent Application Publication 2002/0003469 to Gupta, entitled “Internet browser facility and method for the visually impaired,” discloses a method for facilitating internet browsing for the visually impaired. The method involves using a matrix of movable tactile elements to display a representation of a file containing hypertext links. Text is translated to Braille and graphics images are converted to a dot matrix representation, with selective simplification.
There remains a need for a method to effectively convey information pertaining to photographs and graphics, to both sighted persons and visually impaired persons.
The present invention represents a method for printing an image to convey information to both a sighted person and a visually-impaired person, comprising:
printing an image including image content on a receiver medium using one or more visible colorants, the printed image being viewable by the sighted person, wherein the image content includes photographic image content, artwork image content or graphical image content;
defining a vocabulary of different tactile patterns, each tactile pattern having a defined meaning; and
providing tactile patterns on the surface of the printed image, the tactile pattern provided at a particular location being selected from the predefined vocabulary such that when a visually-impaired person touches the tactile pattern at the particular location, the tactile pattern conveys information about the corresponding image content at the particular location to the visually-impaired person.
This invention has the advantage that the resulting image provides tactile information that can be sensed by a visually impaired person, while simultaneously providing an image that is viewable by a sighted person.
It has the additional advantage that the tactile information is presented in a spatially-correlated arrangement such that the tactile pattern at a particular location conveys information about the corresponding image content at that location, thereby enabling the visually-impaired person to understand the spatial relationships between the different elements of the image.
It is to be understood that the attached drawings are for purposes of illustrating the concepts of the invention and may not be to scale.
The invention is inclusive of combinations of the embodiments described herein. References to “a particular embodiment” and the like refer to features that are present in at least one embodiment of the invention. Separate references to “an embodiment” or “particular embodiments” or the like do not necessarily refer to the same embodiment or embodiments; however, such embodiments are not mutually exclusive, unless so indicated or as are readily apparent to one of skill in the art. The use of singular or plural in referring to the “method” or “methods” and the like is not limiting. It should be noted that, unless otherwise explicitly noted or required by context, the word “or” is used in this disclosure in a non-exclusive sense.
In accordance with the present invention, printed images are produced having image content that is visible to a sighted person. Any method known in the art can be used to produce the printed images, including using printing presses (e.g., offset or gravure printing presses) or ink jet printers.
One common method for printing images on a receiver medium that can be used in accordance with the present invention is referred to as “electrography” (or “electrophotography”). In this method, an electrostatic image is formed on a dielectric member by uniformly charging the dielectric member and then discharging selected areas of the uniform charge to yield an image-wise electrostatic charge pattern. Such discharge is typically accomplished by exposing the uniformly charged dielectric member to actinic radiation provided by selectively activating particular light sources in an LED array or a laser device directed at the dielectric member. After the image-wise charge pattern is formed, the pigmented (or in some instances, non-pigmented) marking particles are given a charge, substantially opposite the charge pattern on the dielectric member and brought into the vicinity of the dielectric member so as to be attracted to the image-wise charge pattern to develop such pattern into a visible image.
Thereafter, a suitable receiver medium (e.g., cut sheet of plain bond paper) is brought into juxtaposition with the marking particle developed image-wise charge pattern on the dielectric member. A suitable electric field is applied to transfer the marking particles to the receiver medium in the image-wise pattern to form the desired print image on the receiver medium. The receiver medium is then removed from its operative association with the dielectric member and subjected to heat and/or pressure to permanently fix the marking particle print image to the receiver medium. In some embodiments, plural marking particle images of, for example, different color particles can be overlaid on one receiver medium (before fixing) to form a multi-color printed image on the receiver medium.
The electrographic printer engine 100 has a series of electrographic printing modules 10A, 10B, 10C, 10D, 10E and 10F. As discussed below, each of the electrographic printing modules 10A, 10B, 10C, 10D, 10E forms an electrostatic image, employs a developer having a carrier and toner particles to develop the electrostatic image, and transfers a developed image onto a receiver medium 200. Where the toner particles of the developer are pigmented, the toner particles are also referred to as “marking particles.” The receiver medium 200 may be a sheet of paper, cardboard, plastic, or other material to which it is desired to print an image or a predefined pattern.
The embodiment of an electrographic printer engine 100 shown in
After moving the receiver medium through the electrographic printing modules 10A, 10B, 10C, 10D, 10E and 10F, the transport belt 210 moves the receiver medium 200 with the multi-colored image to a fusing assembly 30. The fusing assembly 30 includes a heated fusing roller 31 and an opposing pressure roller 32 that form a fusing nip to apply heat and pressure to the receiver medium 200. In some embodiments, the fusing assembly 30 also applies a fusing oil, such as silicone oil, to the fusing roller 31. Additional details of the developing and fusing process are described in U.S. Patent Application Publication 2008/0159786, which is incorporated by reference.
In the illustrated embodiment, the same transport belt 210 is used for transferring the receiver medium 200 through the electrographic printing modules 10A, 10B, 10C, 10D, 10E and 10F and for moving the receiver medium 200 through the fusing assembly 30 so that the process speed for fusing and the process speed for applying raised and print images are the same. Alternatively, separate transport mechanisms can be provided for applying images and fusing images allowing the image applying and fusing process speeds to be set independently.
The electrographic printing modules 10A, 10B, 10C, 10D, 10E and 10F are controlled using electrographic process-set points, control parameters, and algorithms appropriate for the developer for printing using the marking particles and carrier particles of the print image. The set-points, control parameters, and algorithms can be implemented in logic forming part of a logic and control unit (LCU) 123. The LCU 123 may include (or may interact with) logic and control components (LCC) 124 associated with the individual electrographic printing modules 10A, 10B, 10C, 10D, 10E. The LCCs 124 receive signals from various sensors (e.g., a meter 121 for measuring the uniform electrostatic charge and a meter 122 for measuring the post-exposure surface potential within a patch area of a patch latent image formed from time to time in a non-image area on the photoconductive imaging member) and send control signals to the primary charging subsystems 108, the exposure subsystems 106, and the development station subsystems 107.
The illustrated electrographic printer engine 100 includes six electrographic printing modules 10A, 10B, 10C, 10D, 10E and 10F, and accordingly up to six images can be formed on the receiver medium 200 in one pass. For example, electrographic printing modules 10A, 10B, 10C and 10D can be driven with image information to form black, yellow, magenta, and cyan, images, respectively. As is known in the art, a spectrum of colors can be produced by combining the primary colors cyan, magenta, yellow, and black, and subsets thereof in various combinations. The developers in the development station of electrographic printing modules 10A, 10B, 10C and 10D employ pigmented marking particles of the respective color corresponding to the color of the image to be applied by a respective electrographic printing modules 10A, 10B, 10C and 10D. The remaining two electrographic printing modules 10E and 10F, can be provided with marking particles having alternate colors to provide improved color gamut, non-pigmented colorless particles to provide a clear layer protection glossy print capability or to provide tactile features in accordance with the present invention. For example, in some embodiments the fifth electrographic printing modules 10E is provided with developer having red pigmented marking particles and the sixth electrographic printing modules 10F is provided with developer having non-pigmented particles.
Alternatively, in some embodiments the tactile features can be printed with multiple layers of a single color (e.g., with two layers of colorless toner). In this case, both electrographic printing modules 10E and 10F can be provided with the same type of toner. Additional fusing modules (not shown) can preferably be placed between electrographic printing modules 10D and 10E and between electrographic printing modules 10E and 10F. This enables multiple colorless images to be printed in register, thereby creating a final stack height sufficient to provide raised tactile features on selected areas of the receiver medium 200. In order to provide a tactile feel, it is desirable to achieve a post fusing stack height of at least 20 μm on a receiver medium. However, 40 to 50 μm and greater stack heights are often desirable for some applications, and in some cases even greater stack heights including heights of 100 μm and more are desirable.
The term particle size, as used herein, refers to developer and carrier, as particles as well as marking and non-marking particles. The mean volume weighted diameter is measured by conventional diameter measuring devices, such as a Coulter Multisizer, sold by Coulter, Inc. and the mean volume weighted diameter is the sum of the mass of each particle times the diameter of a spherical particle of equal mass and density, divided by total particle mass.
In one mode of practicing this invention, the use of “clear” non-marking toner particles allows tactile features to be provided without affecting overall print density.
The present invention will now be described with reference to
In some embodiments, the printing apparatus used to print the printed visible image 310 uses an electrographic printer engine 100, such as that described with respect to
An analyze image step 315 is used to analyze the image data for the input image 300 to determine associated image information 320. In a preferred embodiment, the analyze image step 315 segments the input image 300 into a plurality of image regions 325, and the image information 320 specifies the type of image content in each of the image regions 325.
In some embodiments, the analyze image step 315 is performed using an automatic algorithm executing on a digital image processing system. The automatic algorithm can include an automatic image segmentation process for segmenting the input image 300 into the image regions 325, and a semantic analysis process that identifies the type of image content in each of the image regions. Processes for automatically segmenting an input image 300 into a plurality of image regions 325, and for determining the type of image content are well-known in the image understanding art.
In other embodiments, the analyze image step 315 is performed manually by a user. For example, a user interface can be provided enabling the user to define image regions 325, for example by drawing a series boundary lines that separate the image regions 325. Once the user has defined the image regions 325, a user interface can be provided enabling the user to associate a type of image content with each image region.
Returning to a discussion of
A select corresponding tactile patterns step 330 is used to select tactile patterns 335 to be formed as a function of location on the printed visible image 310. In some embodiments, the select corresponding tactile patterns step 330 selects a tactile pattern 335 to be used for each of the image regions 325 determined by the analyze image step 315.
A form tactile patterns on printed image step 345 is then used to form a tactile image including the selected tactile patterns 335 onto the receiver medium of the printed visible image 310, thereby providing a visible/tactile image 350 in accordance with the present invention. It should be noted that it is not required that the tactile image information be formed onto the receiver medium after the printed visible image 310 has been printed. In some embodiments, the tactile image information can be formed onto the receiver medium before the printed visible image 310 has been printed, or can be formed concurrently with the printed visible image 310 being printed.
In accordance with the present invention, the visible/tactile image 350 includes visible image information that can be viewed by a sighted person, as well as tactile information that can be touched by a visually-impaired person to enable them to “view” the image as well. The tactile information provides the visually-impaired person with information pertaining to the printed visible image 310 viewed by the sighted person in a spatially-correlated arrangement.
The form tactile patterns on printed image step 345 can form the tactile patterns 335 using any method known in the art. In some cases, the tactile patterns can be provided using the printing device that was used to form the printed visible image 310. In other embodiments, the tactile patterns 335 can be formed using a separate texturing device (e.g., a mechanical embossing device).
In some embodiments, the printed visible image 310 is formed using an electrographic printing system, such as that described with respect to
In other embodiments, the form tactile patterns on printed image step 345 can employ an expandable (i.e., “swellable”) receiver medium that can be selectively activated to provide tactile features. One approach for fabricating a receiver medium of this type is described in the aforementioned commonly-assigned U.S. Pat. No. 5,125,996 to Campbell et al., entitled “Three dimensional imaging paper,” which is incorporated herein by reference. This approach involves dispersing hollow expanding synthetic thermoplastic polymeric microspheres within the receiver medium (or coated on the receiver medium). Tactile features can then be formed by using a scanning laser beam (or some other thermal energy source) to selectively apply thermal energy, thereby causing the microspheres in discrete areas of the paper to expand and form a tactile feature.
In a variation of this approach, a printing process can be used to selectively apply an expandable material (e.g., a solution including hollow expanding synthetic thermoplastic polymeric microspheres) to the surface of the printed visible image 310 in accordance with the tactile patterns 335. The expandable material can then be activated (e.g., using heat) to form the tactile features.
Another approach that the form tactile patterns on printed image step 345 can use to form the tactile patterns 335 is to employ a mechanical embossing process. Such methods are well-known in the art for forming Braille characters, or other forms of tactile patterns that are used for a wide variety of applications (e.g., greeting cards). A wide variety of mechanical embossing techniques can be used. For example, some mechanical embossing techniques form tactile patterns by creating an embossing plate with surface relief that can be pressed against the receiver medium thereby deforming it to form the tactile features. In other embodiments, the receiver medium can be embossed by passing it under a series of mechanical pins that can be selectively activated to press against the receiver medium, thereby forming tactile patterns by creating depressions in the surface of the receiver medium.
In other embodiments, the form tactile patterns on printed image step 345 can form the tactile patterns 335 using a printing process, such as screen printing, that is capable of applying a thick layer of an ink, or some other type of substance, to provide the tactile features.
Preferably, the formation of the tactile patterns does not substantially change the color of the printed visible image 310 so that the appearance of the visible/tactile image 350 is not noticeably different from the appearance of the printed visible image 310 to a human observer. A good rule of thumb is that the colors are preferably not changed by more about 3 ΔE* units, as measured using the well-known CIELAB color system. However, in some embodiments larger color differences can be accepted. If the color differences are significant, it may be desirable to use color management to adjust the color of the printed visible image 310 so that the visible/tactile image 350 has a desired average color value.
In some embodiments, the region boundaries 610 between the image regions 325 can be printed as raised tactile features in the tactile image 600 to provide the visually-impaired person with a clear delineation between the image regions 325.
In some embodiments, the tactile patterns 335 in the tactile pattern vocabulary 340 that are associated with the different types of image content can be fixed across a particular population of images. This enables the visually-impaired person to learn to interpret the meaning of the different tactile patterns 335, much like they can learn to interpret the meaning of Braille character patterns. The population of images using a particular tactile pattern vocabulary 340 can be as small as a pair of images printed on a particular page, or can be as large as all of the images in a particular image collection or all of the images used in a particular application. If the method of the present invention becomes widely used, it may become desirable to define a standard tactile pattern vocabulary 340 (
In other embodiments, the tactile patterns 335 in the tactile pattern vocabulary 340 that are associated with the different types of image content can be defined on an image-by-image basis. In this case, it can be valuable to provide a legend 615 on the visible/tactile image 350 that defines the meaning of the tactile patterns 335 used for that particular image. The legend 615 can include sample tactile patterns 620, together with Braille labels 625 specifying the associated meaning (e.g., the associated type of image content). The legend 615 can optionally included text labels 630 that are viewable by a sighted person corresponding to the Braille labels 625. This can enable a sighted person who is unfamiliar with Braille to understand the meaning of the different tactile patterns 335. Defining a tactile pattern vocabulary 340 that is customized to the image content of a particular image has the advantage that it can be used to convey more specific information that is relevant to the particular image than it would be practical to address using a more limited standardized tactile pattern vocabulary 340. However, it has the disadvantage that the visually impaired person would need to learn the meanings for a new set of tactile patterns 335 for each image.
In some embodiments, the tactile patterns 335 in the tactile pattern vocabulary 340 are customized on an image-by-image basis according to the image content in the input image 300. This enables the meanings of the tactile patterns to be more specific to the image content of a particular input image than would be possible using a standard tactile pattern vocabulary 340. For example, different tactile patterns 335 can be defined for each person in a particular image, rather than using a more generic “person” tactile pattern. The legend 615 can then associate the names of the persons with the corresponding tactile patterns 335.
It can be desirable for the tactile patterns 335 to be representative of the visual image content in the different image regions 325. For example, a tactile pattern 335 can be determined for the water image region 500 (
In some embodiments, the tactile patterns 335 in the tactile pattern vocabulary 340 can be determined by analyzing the image content in the input image 300 and determining tactile patterns 335 that are representative of visible patterns in the image content. For example, in one such embodiment, a representative portion of a particular image region 325 (i.e., an “image tile”) is identified. Preferably, the identified representative portion should have a visually uniform texture. A luminance image is then determined containing only gray scale image information. A sharpening step is then applied to enhance the image detail in the luminance image. A tone scale adjustment (e.g., histogram equalization) is then applied to stretch the tone levels out to use the full range of available code values, and to increase the contrast to exaggerate the texture effects. In some embodiments, a thresholding step (e.g., a halftoning operation such as error diffusion) can be used to binarized the resulting tactile pattern 335.
A caption 635 can optionally be provided in association with the visible/tactile image 350. The caption 635 preferably includes both a visible text caption 640 viewable by a sighted person, as well as a Braille caption 645 that can be sensed by a visually-impaired person. The caption 635 can include various information pertaining to the visible/tactile image 350. Examples, of such information would include a date/time identifier (e.g., “2003”), a weather identifier (e.g., “sunny,” a season identifier (e.g., “summer”), a geography identifier (e.g., “mountain lake,” or “canyon,” or “seashore”), a location identifier (e.g., “Wall St., NY City,” or “Disney World,” or “Grand Tetons National Park”) or an identity of a person or object pictured in the visible/tactile image 350 (e.g., “Debbie”). The information presented in the caption 635 can provide additional insight to the visually-impaired person regarding the content of the visible/tactile image 350. While the caption 635 in
In some embodiments, additional information can be included in the tactile image 600 to supplement the tactile patterns 335. For example, a Braille label 650 can be added that provides additional information pertaining to the image content of the input image 300. For example, the Braille label 650 shown in
In other embodiments, rather than using homogeneous textures in each image region 325 as shown in
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
