Generally, the present invention relates to handheld printers. Particularly, it relates to improving print quality in handheld printers of the type able to print in random motion patterns. In one aspect, reference indicia on media are used to relocate a lost printer position and/or update (validate) printer position while either inactive or actively printing. In another, particular types and styles of reference indicia are contemplated. Still other aspects relate to media having reference indicia and supply items with reference indicia for use with the media.
As is known, handheld printers afford mobile convenience to users. Unlike their immobile or stationary counterparts, users determine the navigation path of a given swath of printing. In some instances, this includes random movement over a media. In others, it includes back-and-forth movement attempting to simulate a stationary printer. Regardless, successful handheld printing dictates that image information relative to the printer location be available at all times. However, all users do not navigate in the same fashion. Nor do they navigate at the same speed or orientation. For at least these reasons, handheld printers rely heavily on sensor inputs, such as those from optical sensors or encoders, for printing images. Yet, sensor inputs are sometimes limited in their capabilities and print jobs are interrupted due to lost or inaccurate printer location calculations.
In turn, if the printer location ever becomes lost, the printer can either quit printing or guess at location. If printing quits, users have incomplete print jobs. If locations are guessed, print quality suffers. In either, poor results are obtained. In the event printer locations are not completely lost, but simply inaccurate, print quality suffers because of inappropriately placed print patterns being deposited on the media.
Accordingly, there exists a need in the art for robust, multi-directional and random printing handheld printers having improved print quality. Particularly, there are needs by which handheld printers are able to validate or recalibrate positioning during printing and/or reacquire positioning to complete an interrupted or lost print job. Naturally, any improvements should further contemplate good engineering practices, such as relative inexpensiveness, stability, low complexity, ease of manufacturing, etc.
The above-mentioned and other problems become solved by applying the principles and teachings associated with the hereinafter described handheld printing with reference indicia. Specifically, methods and apparatus contemplate handheld printers manipulated randomly or predictably over a media on which an image is printed. In this regard, various reference indicia on the media serve to assist in reacquiring a lost printer position or validate/update other positions.
Representatively, a handheld printer includes one or more position sensors, a controller and an inkjet printhead that are coordinated to print an image. Also, the controller correlates the location of the printhead to the image and, when lost, communicates to a direction indicator of the printer to provide user notification of where to move the housing to reacquire the location. Especially, the direction indicator points to the location of a reference indicia on the media. Once over the reference indicia, the printer reads or views the information therein and location is reacquired. Embodiments of the reference indicia include guide and location patterns, with the guide pattern pointing to the location pattern. The reference indicia is variously provided, but representatively includes being printed by the printer as printing operations begin, being pre-printed on the media or applied to the media as a supply item.
For validating or recalibrating other than completely lost positions, reference indicia representatively include related tick marks of substantially equal size and shape with substantially equal spacing there between.
Supply items for applying reference indicia on the media include a substrate with reference indicia thereon. The substrate has a planar size substantially smaller than the media. The reference indicia is also pre-selected to substantially match a reference indicia stored in the printer.
These and other embodiments, aspects, advantages, and features of the present invention will be set forth in the description which follows, and in part will become apparent to those of ordinary skill in the art by reference to the following description of the invention and referenced drawings or by practice of the invention. The aspects, advantages, and features of the invention are realized and attained by means of the instrumentalities, procedures, and combinations particularly pointed out in the appended claims.
The accompanying drawings incorporated in and forming a part of the specification, illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention. In the drawings:
In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention and like numerals represent like details in the various figures. Also, it is to be understood that other embodiments may be utilized and that process, mechanical, electrical and/or other changes may be made without departing from the scope of the present invention. In accordance with the present invention, a handheld printer for printing with reference indicia is hereafter described.
With reference to
In
At once surface 118 of the housing 112 is a portion 119 of a flexible circuit, especially a tape automated bond (TAB) circuit 120. At 121, another portion 121 is adhered to surface 122. Electrically, the TAB circuit 120 supports a plurality of input/output (I/O) connectors 124 for connecting an actuator chip 125, also known as a heater chip, to the handheld printer during use. Pluralities of electrical conductors 126 exist on the TAB circuit to connect and short the I/O connectors 124 to the input terminals (bond pad 128) of the actuator chip 125 and skilled artisans know various techniques for facilitating this. In an exemplary embodiment, the TAB circuit is a polyimide material and the electrical conductors and connectors are copper or aluminum-copper. For simplicity,
At 132, the actuator chip 125 contains at least one ink via that fluidly connects to the ink of the compartment 116. During printhead manufacturing, the actuator chip 125 is attached to the housing with any of a variety of adhesives, epoxies, etc., as is well know in the art. To eject ink, the actuator chip contains columns (column A-column D) of fluid firing actuators, such as thermal heaters. In other actuator chips, the fluid firing actuators embody piezoelectric elements, MEMs devices, and the like. In either, this crowded figure simplifies the actuators as four columns of six dots or darkened circles but in practice the actuators might number several dozen, hundred or thousand. Also, vertically adjacent ones of the actuators may or may not have a lateral spacing gap or stagger there between. In general, however, the actuators have vertical pitch spacing, such as about 1/300th, 1/600th, 1/1200th,or 1/2400th of an inch along the longitudinal extent of a via. Further, the individual actuators are typically formed as a series of thin film layers made via growth, deposition, masking, patterning, photolithography and/or etching or other processing steps on a substrate, such as silicon. A nozzle member with pluralities of nozzle holes, not shown, is adhered to or fabricated as another thin film layer on the actuator chip such that the nozzle holes generally align with and are positioned above the actuators to eject ink.
With reference to
Among other things, the controller 22 also includes a stored to-be-printed representation of an image 32. In turn, it correlates the position of the printhead, especially individual actuators, to the image. It then prints the image with ink 35 on the media 16 according to the image pattern 36 in the pixels 38. A has-been-printed image 34 may also be stored or accessed by the controller to keep track of future printing and to determine whether the image has been printed completely or not. In structure, the controller embodies an ASIC, discrete IC chips, firmware, software, a microprocessor, combinations thereof or the like. Alternatively, the to-be-printed image 32 is dynamically updated to remove pixels that have been printed so that the has-been printed information 34 is merged with the to-be-printed information. In either, the controller further includes a memory stored reference indicia 39 for comparison, in some instances, to the reference indicia of the media to reacquire a lost printer position or validate other than lost positions.
With reference to
Regardless of how obtained, the inset shows a magnified representative of the reference indicia including both a location pattern 40 and a guide pattern 41. As is seen, the location pattern is generally central to the reference indicia periphery 43 while the guide pattern 41 surrounds the location pattern. The guide pattern also includes indicators 45, such as arcs or chevrons, which are used in combination with the optical sensor(s) 20 to direct the printer, especially sensors, over at least a portion of the location pattern. In this manner, once the sensor can observe the location pattern and communicate same with the controller 22, including comparison to the stored reference indicia (
With reference to
If the printer location is unknown, or lost, a reacquisition mode of printing is entered at step 210. In this regard, it is preferred that printing of the image ceases so that poor print quality will not result. Then, at step 212, directions to the reference indicia are indicated. In this regard, the position indicators 17 (
Next, users follow the position indicators until the printer is eventually positioned over the reference indicia, step 214. Automatically, the controller will then observe the reference indicia, especially the location pattern, and reacquire the location of the printer. Normal printing of the image then occurs by moving the printer back to a position on the media requiring printing, step 208. Eventually, the complete image is fully printed.
With reference to
For example,
Also,
Alternatively,
In still other alternate embodiments,
In any embodiment, certain advantages of the invention over the prior art are readily apparent. For example, the invention at hand provides updating/validating printer positioning during printing or reacquiring positioning, if lost, to complete an interrupted print job. Alternatively, the invention contemplates supply items for application to media or pre-adorned media with reference indicia for use with handheld printing. Less intuitively, use of reference indicia during handheld printing minimizes accumulated position errors. Better print quality then results. Also, because simple reference indicia can assist in printing, robustness is added and manufacturing costs are minimized.
Finally, one of ordinary skill in the art will recognize that additional embodiments are also possible without departing from the teachings of the present invention. This detailed description, and particularly the specific details of the exemplary embodiments disclosed herein, is given primarily for clarity of understanding, and no unnecessary limitations are to be imported, for modifications will become obvious to those skilled in the art upon reading this disclosure and may be made without departing from the spirit or scope of the invention. Relatively apparent modifications, of course, include combining the various features of one or more figures with the features of one or more of other figures.