Patent Application
20050018005
Image forming devices such as laser printers, copy machines, and facsimile machines employ electro photographic processes to produce printed images on paper or other print media. In laser printers, a source image is rasterized to form a bitmap image for subsequent rendering to a final printed image. A source image can include a number of elements. Examples include text, vector, and/or continuous tone or graphic elements such as a photo. When a source image is rasterized creating a bitmap image, the various elements are converted to pixel patterns that approximate the source image.
Once a bitmap image is generated from a source image, it can be printed by modulating and scanning a laser beam across a charged surface of a photoconductive drum in a succession of scan lines. Each scan line is divided into pixel areas, and the modulated laser beam causes some pixel areas to be exposed to a light pulse and some not. Where a pixel area is illuminated, the photosensitive drum is discharged so that, when it is subsequently toned, the toner adheres to the discharged areas and is repelled by the still charged areas. The toner adhering to the discharged areas is then transferred and fixed to paper or other print media.
Because of its digital nature, a printed bitmap image does not perfectly reflect the source image. For example, printed image edges that are either not parallel or not perpendicular to the scan direction of the laser can appear stepped or jagged. This is especially noted in text and line art. Because resolution is also limited, a bitmap representation of a graphical element such as a photo can appear degraded.
Various image enhancement techniques have been developed to improve the quality of a printed bitmap image. Among many others, these enhancement techniques include: edge smoothing, fine line broadening, anti-aliasing, and resolution doubling. In a laser printer, for example, one or more techniques can, when implemented, modulate the laser to produce a pixel smaller than a standard pixel size. The techniques may also indicate that the laser output is to be offset from the pixel center. Parameters for a particular image enhancement technique can dictate pixel size and offset position.
In addition to improving the quality of printed images, printer manufacturers are also faced with reducing the cost associated with printing those images. One of the more significant operation costs of a laser printer is that of imaging material such as toner or ink. Recognizing this, various imaging enhancement techniques have been developed to conserve imaging material.
For a given image forming device, developing criteria for selecting among a variety of available image enhancement techniques and for selecting optimal parameters for implementing those techniques is a complex process. Numerous factors must be taken into account. Some of these factors include:
Because there are so many complex factors involved in developing criteria for selecting image enhancement techniques, the introduction of a new image forming device to consumers can be significantly delayed. To decrease delays, one possible solution involves using image enhancement techniques, parameters, and selection criteria (collectively and individually referred to as image enhancement data) previously developed for a similar but older device design when first introducing a new design to consumers. The older image enhancement data will not be optimal for the new design. However, image enhancement data, once developed for the new design, can be deployed later as an upgrade.
As with the deployment of other upgrades, deploying new image enhancement data for use by image forming devices already sold and in use can lead to a number of logistical problems. The consumer is usually responsible for implementing the upgrade. The consumer must first learn of the upgrade and then take steps required to install the upgrade—whether that be installing new programming or new hardware. Consumers who are not aware of an upgrade will not benefit. Consumers who learn of an upgrade but are not sophisticated enough to implement it also will not benefit. If acquiring or installing installation proves to be difficult or time consuming, those consumer's who choose to take time to implement an upgrade can be seriously inconvenienced.
INTRODUCTION: An image forming device can use a variety of image enhancement techniques to improve the quality of printed output and to reduce the amount of imaging material required to produce the printed output. The particular technique or techniques used at a given time as well as the parameters for implementing those techniques depend upon a number of complex factors. In the description that follows image enhancement techniques, parameters for implementing image enhancement techniques, and selection criteria are at time referred to individually and collectively as image enhancement data. Consequently, developing image enhancement data that is optimal for a given image forming device is a difficult and time consuming task. To avoid delaying the introduction of a new image forming device to the market, it is often beneficial initially to initially use image enhancement data previously developed for a similar but older design. Once image enhancement data is developed specifically for the new design, it can be released as an upgrade.
Many image forming devices such as laser and ink printers use replaceable cartridges. The cartridges contain imaging material such as toner or ink as well as components for dispensing the imaging material. As the imaging material is depleted, the cartridge is removed and replaced. To maintain a supply of imaging material, consumers expect to periodically remove and replace cartridges. Memory integrated into a cartridge can be programmed to supply newly developed image enhancement data. Once the cartridge is installed, the memory can be accessed and read and the image forming device upgraded to use the new image enhancement data.
In addition to supplying upgrades, integrating image enhancement data within a printer cartridge allows a manufacturer to more efficiently capitalize on the subjective preferences of a demographic. Different cartridge models for the same printer can be developed with image enhancement data designed specifically for a given demographic. For example, certain groups of people prefer printed text to appear thicker and bolder. Others prefer finer lines. For a given printer, one cartridge model can be produced with image enhancement data that causes printed text to appear thicker and bolder, and another cartridge model can be produced with image enhancement data that causes printed text to appear relatively fine. Each cartridge model can then be marketed to its intended demographic.
TERMINOLOGY: The terms image forming device, image enhancement techniques, parameters, and selection criteria are used throughout the following description. An image forming device is any device that can produce a printed image on paper or any other print media. Examples include, ink printers, laser printers, facsimile machines, copiers, and all-in-one or multi-function printers. Image enhancement techniques include any techniques that can improve the quality of printed output as well as any techniques that can reduce the amount of imaging material such as toner or ink toner used to produce the printed output. A parameter is data used to implement an image enhancement technique.
Selection criteria are criteria used to determine which image enhancement technique or techniques to use at a given time and/or to determine a parameter or parameters for implementing the particular image enhancement technique or techniques. The determinations can be based upon any number of factors including, but not limited to, whether an image includes text, graphics, or both, the environment in which the image forming device is operating, the level of remaining imaging material, and the extent to which the limited life components of the image forming device have been used. Limited life components are those components of an image forming device that degrade or wear though use affecting print quality. Often, limited life components are integrated within the same cartridge containing the imaging material.
COMPONENTS: The physical and logical components of various embodiments of the invention will now be described with reference to the block diagrams of
As shown in
Image forming device 10 also includes device printing components 22, device memory 24, device I/O logic 26, and CPU (Central Processing Unit) 28. Device printing components 22, when used in conjunction with cartridge printing components 16, represent hardware capable of dispensing a consumable from reservoir 14 onto print media in the form of a desired print image. The printed image can include any combination of text and/or graphics. Device memory 24 represents any memory device or combination of memory devices that can store programming and other data used to guide cartridge and device printing components 16 and 22 in the production of a printed image. Device logic 26 represents generally any programming that enables programming stored in device memory 24 to communicate with cartridge 12 and access cartridge memory 18. Device logic 26 is responsible for both reading data from and writing data to cartridge memory 18. CPU 28 represents any processor capable of executing instructions from programming stored in device memory 24 and cartridge memory 18. At least some of the executed instructions guide cartridge and device printing components 16 and 22 to form a desired image on print media.
In operation, charging device 16B places a uniform electrostatic charge on photoconductive drum 16A. Light from laser 22A is scanned across photoconductive drum 16A in a pattern of a desired print image. Where exposed to the light, photoconductive drum 16A is discharged creating an electrostatic version of the desired print image. Developer 16 transfers charged toner particles from toner reservoir 14A to photoconductive drum 16A. The charged toner particles are repelled by the charged portions of photoconductive drum 16A but adhere to the discharged portions. Charge roller 22B charges or discharges media sheet 30. As media sheet passes across photoconductive drum 16A, toner particles are then transferred from photoconductive drum 16A to media sheet 30. Fuser rollers, thermally fix the transferred toner particles to media sheet 30. Discharge lamp 22D removes the remaining charge on photoconductive drum 16A, and wiper 16D removes any residual toner particles remaining on photoconductive drum 16A.
In the example of
Referring now to
As an example, image enhancement data 32 and 34 may each include one or more conditions each associated with electronic data identifying one or more image enhancement techniques and/or parameters, if any, for implementing image enhancement techniques. A condition is a circumstance or set of circumstances that when met indicate the image enhancement technique(s) and any parameter(s) associated with that condition are to be implemented. The following are examples of conditions and associated techniques.
Technique execution logic 36 represents any programming capable of implementing an image enhancement technique. Technique execution logic 56 may perform this function by determining if cartridge image enhancement data 32 is present and enhancing an image by implementing techniques according to parameters, if any, identified by cartridge image enhancement data 32. If cartridge image enhancement data 32 is not present, technique execution logic 36 may implement techniques according to parameters, if any, identified by default image enhancement data 34. It is noted that the techniques implemented and/or the parameters may be identified by cartridge image enhancement data 32 and default image enhancement data 34. In one embodiment, default image enhancement data 34 may not be present. In such a case, technique execution logic 36 may determine that cartridge image enhancement data 32 is also not present and disable all image enhancement capabilities. In another embodiment, technique execution logic 36 can simultaneously execute image enhancement data 32 and 34.
For example, when executing image enhancement data 32 and/or 34, technique execution logic 36 determines when a condition contained in image enhancement data 32 or 34 is met, and then implements the image enhancement technique(s) according to parameter(s), if any, associated with that condition. It may be determined that more than one condition has been met at a given time. Technique execution logic 36, depending on which condition is met, can digitally enhance a rasterized image before it is printed and it can enhance a printed image in real time by affecting the operation of printing components 16 and/or 22 as the image is being printed. Preferably, real time aspects of technique execution logic 36, such as those that directly affect the modulation and deflection of laser 22A (
Printing logic 38 represents generally any programming capable of controlling the production of a printed page. Printing logic 38 is responsible for using technique execution logic 36 to execute image enhancement data 32 and/or 34 and for using cartridge and device printing components 16 and 22 to generate printed output.
Image enhancement data sets 46-50, each represent generally any data used for image enhancement. More specifically, each image enhancement data set 46-50 can include image enhancement techniques, parameters, and/or selection criteria for selecting an image enhancement technique or for selecting from among image enhancement techniques. The term “set” is used only to help the reader distinguish one group of image enhancement data from another. Again, it is noted that The phrase “selecting an image enhancement technique” can mean selecting a particular image enhancement technique or selecting parameters for implementing an image enhancement technique. The phrase “selecting from among image enhancement techniques” can mean selecting a particular image enhancement technique from a plurality of techniques or selecting a parameter or parameters from a plurality of parameters for implementing an image enhancement technique.
Image enhancement data set 46, for example, may identify all available image enhancement techniques and/or parameters most demanding on cartridge printing components 16. Image enhancement data set 48 may identify all available image enhancement techniques and/or parameters less demanding on cartridge printing components 16. Image enhancement data set 50 may not identify all available image enhancement techniques. For those it does identify, it may specify parameters that are least demanding on cartridge printing components 16.
Data set selection criteria 52 represents electronic data that can be processed with one or more state variables 40-44 to select from among image enhancement data sets 46-50. As the values of state variables 40-44 change, processing data set selection criteria 52 will result in a different image enhancement data 46, 48, or 50 being selected.
Referring to
Technique execution logic 56, as defined above, represents generally any programming capable of implementing an image enhancement technique. Technique execution logic 56 may perform this function by implementing techniques according to parameters, if any, identified by image enhancement data sets 46-50. It is noted that the techniques implement and/or the parameters may be identified by image enhancement data sets 46-50.
State monitor 58 represents generally any combination of hardware and/or programming capable of monitoring the state of cartridge printing components 16 and/or device printing components 22 and updating state variables 40-44 accordingly. With reference to
Printing logic 60 represents generally any programming capable of controlling the production of a printed page. Printing logic 50 is responsible for using technique selection logic 54 to select image enhancement data set 46, 48, or 50, using technique execution logic 56 to execute the selected image enhancement data set 46, 48, or 50, and using cartridge and device printing components 16 and 22 to generate printed output.
To select image enhancement data set 46, 48, or 50, technique selection logic 56 processes entries 62 in a hierarchical order dictated by priority field 64 data of entries 62. When processing a given entry 62, technique selection logic 54 determines if a condition required by data in state condition field 66 for that entry 62 is being met. If that condition is being met, technique selection logic 54 selects mage enhancement data set 46, 48, or 50 identified by data in set identifier field 68 for that entry 62. Technique selection logic 54 then stops processing further entries 62. If the condition is not being met, technique selection logic 54 continues processing subsequent entries 62 in an order dictated by priority field 64 data. One image enhancement data set 46, 48, or 50 may be identified as a default to be selected if none of the conditions required by data in state condition field 66 for all entries 62.
State variables 40-44 and data set selection criteria 52 could instead be stored in device memory 24B. Preferably, state variables 40-44 are stored in cartridge memory 18B. If cartridge 12 is removed from image forming device 10 and inserted into a different image forming device (not shown) then state variables 40-44 remain with cartridge 12. Where state variables 40-44 are maintained in device memory 24, they do not follow cartridge 12 when it is removed and used elsewhere. Technique selection logic 54 may be stored in cartridge memory 18 and then loaded into device memory 24 to be utilized by printing logic 60 as needed. Similarly, image enhancement data sets 46-50, while stored in cartridge memory 18, may also be loaded into device memory 24 to be utilized by technique selection logic 54 and technique execution logic 56.
The block diagrams of
Also, the present invention can be embodied in any computer-readable media for use by or in connection with an instruction execution system such as a computer/processor based system or an ASIC (Application Specific Integrated Circuit) or other system that can fetch or obtain the logic from computer-readable media and execute the instructions contained therein. “Computer-readable media” can be any media that can contain, store, or maintain programs and data for use by or in connection with the instruction execution system. Computer readable media can comprise any one of many physical media such as, for example, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor media. More specific examples of suitable computer-readable media include, but are not limited to, a portable magnetic computer diskette such as floppy diskettes or hard drives, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory, or a portable compact disc.
OPERATION: The operation of embodiments of the present invention will now be described with reference to the flow diagrams of
Referring first to
With reference to
Referring now to
A print job or jobs are then printed using the selected image enhancement data set (step 88). Referring back to
The state of cartridge 12 is monitored (step 90). For example, step 90 can involve identifying a toner or ink level. It can involve measuring the use of cartridge printing components 16 such as the duration to which photoconductive drum 16A has been exposed to laser 22A as well as the number pf printed pages. State variables 40-44 are updated accordingly (step 92).
Although the flow chart of
CONCLUSION: The present invention has been shown and described with reference to the foregoing exemplary embodiments. It is to be understood, however, that other forms, details, and embodiments may be made without departing from the spirit and scope of the invention which is defined in the following claims.
