Patent Publication Number: US-7590545-B2

Title: Car management system and associated printer

Description:
FIELD OF THE INVENTION 
   The present invention relates to an information retrieval system for, and method of, retrieving information relating to a conveyance. 
   In this specification, unless the context clearly indicates otherwise, the term “conveyance” is to be understood in a broad sense as any suitable device for conveying persons and/or goods and includes road vehicles, aircraft, rail vehicles, waterborne craft, spacecraft, or the like. 
   BACKGROUND TO THE INVENTION 
   The integration of electronic management systems into vehicles has been increasing progressively with a corresponding reduction in the cost of components required to assemble such management systems. These management systems generally provide a host of functions including such things as monitoring of distance travelled and state of various fluids in the vehicle in order to determine when a service of the vehicle is due, manage ignition timings and other vehicle monitoring activities. 
   At present, as far as the applicant is aware, an output from a system of this nature is displayed as a readout on a dashboard of the vehicle. A user of the vehicle must interpret the readout in order to take appropriate action where necessary. For instance, if oil level in the vehicle is low a light may be illuminated on the dashboard indicating to a user that replenishment of the vehicle&#39;s oil supply is necessary. It may sometimes occur that the readout is transient in nature and does not re-occur, which can cause frustration at the time of servicing of the vehicle. Thus, it would be useful to have a means of recording information relating to the readout when such an event occurs for later analysis and, if necessary, remedial action to be taken. 
   CO-PENDING APPLICATIONS 
   Various methods, systems and apparatus relating to the present invention are disclosed in the following co-pending applications filed by the applicant or assignee of the present invention simultaneously with the present application: 
   
     
       
         
             
             
             
             
             
             
             
           
             
                 
                 
             
           
          
             
                 
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   The disclosures of these co-pending applications are incorporated herein by cross-reference. Each application is temporarily identified by its file reference. This will be replaced by the corresponding PCT Application Number when available. 
   RELATED PATENT APPLICATIONS AND PATENTS 
   
     
       
         
             
             
             
             
             
           
             
                 
             
           
          
             
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               PCT/AU01/00141 
             
             
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               PCT/AU01/00139 
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               PCT/AU01/00140 
             
             
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               6,260,953 
               6,267,469 
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               6,309,048 
               6,420,196 
               6,443,558 
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               6,378,989 
             
             
               6,848,181 
               6,634,735 
               PCT/AU98/00550 
               PCT/AU00/00095 
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               6,322,195 
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               6,460,778 
               6,305,788 
             
             
               PCT/AU00/00172 
               6,426,014 
               PCT/AU00/00338 
               6,364,453 
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               6,457,795 
               PCT/AU00/00581 
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               PCT/AU00/00582 
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               PCT/AU00/00587 
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               6,328,425 
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               PCT/AU00/00341 
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               PCT/AU00/00340 
               PCT/AU00/00749 
               6,417,757 
               PCT/AU01/01332 
               7,095,309 
             
             
               PCT/AU01/01318 
               6,854,825 
               PCT/AU00/00750 
               7,075,677 
               PCT/AU00/00751 
             
             
               6,428,139 
               PCT/AU00/00752 
               6,575,549 
               PCT/AU01/00502 
               PCT/AU00/00583 
             
             
               6,383,833 
               PCT/AU02/01120 
               PCT/AU00/00593 
               6,464,332 
               PCT/AU00/00333 
             
             
               PCT/AU00/01513 
               6,428,142 
               PCT/AU00/00590 
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               PCT/AU00/00592 
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               PCT/AU00/00584 
               6,322,194 
             
             
               PCT/AU00/00585 
               6,382,779 
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               PCT/AU00/01514 
             
             
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               PCT/AU00/01516 
               6,609,787 
             
             
               PCT/AU00/01517 
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               PCT/AU00/00594 
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               PCT/AU00/00595 
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               PCT/AU00/00596 
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               PCT/AU00/00598 
             
             
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               PCT/AU00/00516 
               6,795,215 
               PCT/AU00/00517 
             
             
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   SUMMARY OF THE INVENTION 
   According to a first aspect of the invention, there is provided an information retrieval system for retrieving information relating to a conveyance, the system including: 
   a data collecting means for collecting data relating to operational aspects of the conveyance; 
   a processing means, in communication with said data collecting means, for processing said collected data to provide formatted data suitable for printing; and 
   a printing unit, installed in said conveyance, for printing said formatted data to provide information relating to said conveyance. 
   The data collecting means may include a conveyance management sub-system which obtains details of predetermined operating parameters, such as fluid levels, fluid temperatures, etc., and related information of the conveyance, such as distance travelled, speed, etc. The sub-system may periodically produce information for viewing by the user without user intervention. In addition, or instead, the sub-system may include a user terminal to enable the user to access required information on demand. 
   The data collecting means may include a location determining unit for determining the location of the conveyance. The location determining unit may provide the location of the conveyance as a set of coordinates. Thus, the location determining unit may comprise a global positioning system (GPS) receiver. 
   The data collecting means may further include a locality data retrieval unit, which retrieves data relating to the location in response to the receipt of data from the location determining unit. The location data retrieval unit may comprise a locality information sub-system, which provides data relating to an establishment of relevance to a user of the conveyance. 
   The processing means may include a layout engine in communication with the data collecting means. The layout engine may lay out data elements to be communicated to the printer. 
   The processing means may comprise a data manipulating means in communication with the layout engine for manipulating the data to provide the formatted data. 
   The printing unit may include a printer controller, for receiving the formatted data to be printed, and a printer. The printer may be a full color printer. Preferably, the printer is a photo quality color printer. 
   Further, the printer may be an ink jet printer. The printer may therefore comprise a pagewidth ink jet printhead. The printhead may comprise an array of nozzles, said array being fabricated by microelectromechanical techniques. 
   According to a second aspect of the invention, there is provided a method of retrieving information relating to a conveyance, the method including the steps of: 
   collecting data relating to operational aspects of the conveyance; 
   processing said collected data to provide formatted data suitable for printing; and 
   printing said formatted data when required by a user, on a printing unit installed in said conveyance, to provide the user with information relating to said conveyance. 
   The method may include obtaining details of operating parameters and related information of the conveyance. The method may then include periodically producing information for viewing by the user without user intervention. In addition, or instead, the method may include enabling the user to access required information on demand. 
   Further, the method may include determining the location of the conveyance. The method may thus include providing the location of the conveyance as a set of co-ordinates. 
   Still further, the method may include retrieving data relating to a locality in which the conveyance is located. The method may include providing data relating to an establishment in the locality that is of relevance to the conveyance. 
   Additionally, the method may include laying out data elements to be printed. The method may include manipulating said data elements prior to printing the data to provide said formatted data. 
   According to a third aspect of the invention, there is provided an onboard information retrieval system for retrieving information relating to a vehicle, the system including: 
   a data collecting means for collecting data relating to operational aspects of the vehicle; 
   a processing means for processing said collected data to provide formatted data which is in a suitable format for printing; and 
   an onboard printing unit for printing said formatted data, on demand, to provide information relating to the locality. 
   In this specification, unless the context clearly indicates otherwise, the term “onboard” is to be understood in a broad sense as a device and its components, which are mounted in a conveyance or vehicle. 
   The information may include information relating to replenishable items of the vehicle. Further, the information may include information regarding establishments in a locality in which the vehicle is located which is of use in maintenance of the vehicle. The establishments may include service stations. 
   According to a fourth aspect of the invention, there is provided a method of retrieving information relating to a vehicle, the method including the steps of: 
   collecting data relating to operating aspects of the vehicle; 
   processing said collected data to provide formatted data which is in a suitable format for printing; and 
   printing said formatted data on an onboard printer to provide information relating to the vehicle. 
   The method may include providing information relating to replenishable items of the vehicle Further, the method may include providing information regarding establishments in a locality in which the vehicle is located which is of use in maintenance of the vehicle. Thus, the method may include providing information on the location of service stations in the locality. 
   According to a fifth aspect of the invention, there is provided an onboard information retrieval system for retrieving information relating to a vehicle, the system including: 
   a vehicle management system for providing information on various operating aspects of the vehicle; 
   a position sensing means carried by the vehicle for sensing the position of the vehicle in a locality and to provide location data; 
   a locality data retrieval unit for use in association with the position sensing means and for retrieving predetermined data relating to the locality; 
   a user terminal, operable by a user to obtain predetermined data; 
   a layout engine responsive to the user terminal for processing the predetermined data into data elements; 
   a pre-printing processing means which is connected to the layout engine and which processes the data to provide formatted data which is in a format which is suitable for printing; and 
   an onboard printer for printing the formatted data, on demand, to provide a hard copy of the information. 
   According to a sixth aspect of the invention, there is provided a method of retrieving information relating to a vehicle, the method including the steps of: 
   providing information on various operating aspects of the vehicle; 
   sensing the position of the vehicle in a locality and providing location data; 
   retrieving predetermined data relating to the locality; 
   obtaining desired data by means of a user terminal, operable by a user; 
   processing the predetermined data at least into data elements; 
   further processing the data to provide formatted data which is in a format which is suitable for printing; and 
   printing the formatted data, on demand, via an onboard printer to provide a hard copy of the information relating to the vehicle. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: 
       FIG. 1  shows a block diagram of an information retrieval system, in accordance with the invention, for retrieving information relating to a conveyance; 
       FIG. 2  shows a three dimensional view of a printer for use with the system; 
       FIG. 3  shows a three dimensional view of the printer with a cover removed; 
       FIG. 4  shows a three dimensional, exploded view of the printer, 
       FIG. 5  shows a sectional side view of the printer, 
       FIG. 6  shows a three dimensional view of a cartridge for the printer, 
       FIG. 7  shows a three dimensional, exploded view of the cartridge; 
       FIG. 8  shows a three dimensional, schematic view of a nozzle assembly for an ink jet printhead for the printer, 
       FIGS. 9 to 11  show a three dimensional, schematic illustration of an operation of the nozzle assembly of  FIG. 8 ; 
       FIG. 12  shows a three dimensional view of a nozzle array constituting the printhead; 
       FIG. 13  shows, on an enlarged scale, part of the array of  FIG. 12 ; 
       FIG. 14  shows a three dimensional view of the printhead including a nozzle guard; 
       FIG. 15  shows a schematic diagram of one embodiment of a position sensing system for use with the information retrieval system of  FIG. 1 ; 
       FIG. 16  shows a schematic diagram of another embodiment of a position sensing system for use with the information retrieval system of  FIG. 1 ; and 
       FIG. 17  shows a three dimensional view of an implementation of the information retrieval system 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
   Referring initially to  FIG. 1  of the drawings, reference numeral  10  generally designates an information retrieval system, in accordance with the invention, for retrieving information relating to a conveyance, more particularly, a motor vehicle. 
   The system  10  includes a vehicle management sub-system  12  that monitors operating parameters of the vehicle. More particularly, the sub-system  12  monitors fluid levels, fluid condition and various other parameters such as distance travelled by the vehicle, speed of the vehicle, stopping and starting of the vehicle, brake pad conditions, or the like. It is also now possible for vehicles to monitor other aspects of operating parameters such as suspension settings, tyre pressures, or the like. 
   The system  10  further includes a user terminal that enables a user of the system to request required information from the vehicle management sub-system  12 . The user terminal  26  includes a display and user interface. In addition to information being requested by the user via the user terminal  26 , the system  10  may, periodically, cause information to be displayed on the display of the user terminal  26  without any intervention by the user. 
   The system  10  further includes a data collecting means comprising a location determining unit  18  and a locality data retrieval sub-system  24 . The data collecting means collects data relating to a location of the motor vehicle and a locality in which the motor vehicle is positioned. 
   The location determining unit is, in one embodiment as shown in  FIG. 15 , a global positioning system (GPS) receiver  18 . The receiver  18  provides coordinates in the form of location data on an output line  20  to the vehicle management sub-system  12 . The data output on line  20  is also made available to the locality data retrieval sub-system  24 . The sub-system  24  is able to be interrogated by the user of the user terminal  26  so that relevant data regarding establishments in the locality that may be of use to the user can be displayed on the display of the user terminal  26 . The data regarding the locality would, typically, relate to locations of service stations, filling stations, motor spares stores, mechanical workshops, or the like which are in the locality in which the vehicle is positioned. The sub-system  24  produces the locality data on a data line  22  to the vehicle management sub-system  12 . 
   The system  10  includes a processing means  14  that processes data output from the vehicle management sub-system  12 . The processing means  14  includes a layout engine  28 . The sub-system  12  produces content and layout information based on details to be printed relating to vehicle management parameters. This content and layout information is sent via the sub-system  12  to the layout engine  28 . The layout engine  28  produces descriptions of one or more pages based on text and data content and any layout information provided. Each page is described by way of an appropriate page description language such as postscript or PDF. 
   The processing means further includes a rasterization module  34  that communicates with the layout engine via a data line  32 . A page compression module  38  is connected to an output of the rasterization module via a data line  36 . A page description output by the layout engine  28  on the data line  32  is fed to the modules  34  and  38  for rasterization, compression and output of data to be printed in a suitable format on data line  40 . 
   Data line  40  connects an output of the page compression module  38  to a printer controller  42  of a printing unit  16  of the system  10 . The printer controller  42  controls a printer  100  on which required information relating to management of the vehicle can be printed. 
   Certain of the components of the system  10  are now described in greater detail. 
   In the first embodiment of the receiver  18 , use is made of the global positioning system (GPS). The GPS consists of 24 satellites orbiting the earth in a fixed pattern such that from any point within range of the GPS, at least four satellites are visible. It is this line-of-sight to at least four satellites that enables the determination of a number of parameters relating to the location of the GPS receiver  18 . In  FIG. 15  of the drawings, four satellites  50 . 1 - 50 . 4  and their associated transmission foot prints  50 . 5  to  50 . 8 , respectively, are shown In a two dimensional projection. 
   Those skilled in the art will understand that each of the satellites  50 . 1 - 50 . 4  contains a high accuracy atomic clock and also ephemeris data. The ephemeris data and the current time are transmitted by each satellite  50 . 1 - 50 . 4  at fixed intervals so that they may be received by the GPS receiver  18 . By comparing the time at the GPS receiver  18  with the time received by way of the satellite transmissions, it is possible to calculate the distance between the receiver  18  and each of the satellites  50 . 1 - 50 . 4 . With the addition of the ephemeris data, the positions of the satellites  50 . 1 - 50 . 4  are also available. Given these two pieces of information, it is possible to narrow down the position of the receiver  18  to a point on a sphere centred on the satellites  50 . 1 - 50 . 4 . With four sets of data from the four satellites  50 . 1 - 50 . 4 , the intersections of each of these spheres  50 . 5 - 50 . 8  yields X, Y and Z co-ordinates of the GPS receiver  18  and also an accurate measure of UTC time. A transformation of these co-ordinates yields the receiver&#39;s position in terms of latitude, longitude and height above sea level. 
   To overcome the uncertainty of the GPS created by the introduction of “selective availability” into the GPS by the US military, an enhanced GPS, known as dGPS or differential GPS can be used. This uses a differential signal where it is available. dGPS uses a fixed reference base station equipped with a GPS receiver in addition to a portable receiver. The fixed receiver transmits a signal representing the error in the GPS signal that it receives to the portable receiver. The portable receiver then uses this signal to reduce the error in its position estimation. 
   In another embodiment of the invention, instead of using the GPS or in addition to it, a mobile phone network could, instead be used as shown in  FIG. 16 . It is only possible to use this network in populated areas in which a number of mobile phone base stations are located such as within the boundaries of a city. 
   A typical mobile telephone network consists of a number of base stations  60 . 1 - 60 . 6  ( FIG. 16 ). 
   Each base station  60 . 1 - 60 . 6  transmits in a predetermined area or foot print to define a cell. The distance between adjacent base stations is usually arranged so that the size of each cell is large enough to provide a degree of overlap between it and its neighboring cells. This allows a user to roam over the coverage area whilst still having access to telephone services since they are always in the area of at least one cell. 
   As a user moves within a cell, the strength of the signal that it receives from that cell varies depending on a number of factors including the distance from a base station  60 . 1 - 60 . 6 . As a user moves between cells, the handset typically switches from using the base station corresponding to the cell with a lower signal strength to a base station corresponding to a cell with a higher signal strength in order to maintain service quality. 
   Given the distribution of cells and the ability of a handset to emit a signal that may be received by more than one base station as it propagates, it is possible to conceive of a traffic controlling mechanism in which the location of a handset may be determined to within a certain degree of accuracy, possibly an accuracy of about ten meters. 
   A number of different techniques may be employed to locate the handset functioning as a receiver  18 . The selected technique depends mainly on the type of technology of the handset and its network. Generally, differences between the times of arrival of access bursts generated by the handset  18  can be used to triangulate the position of the receiver  18  by calculating the distance from three base stations to the receiver  18 . The reverse of this technique, whereby the receiver  18  determines its location based on access bursts generated by nearby base stations, can also be used by incorporating specialised location determining functionality into the receiver  18 . 
   It will be appreciated that a combination of mobile telephone networks and the GPS can be used yielding a system called Assistance-GPS. 
   The locality data retrieval sub-system  24  comprises a combination of a locality data server and a corresponding access mechanism. Once again, the type of access mechanism used will depend on the locality data server. 
   A locality data server is similar to a combination of the services that a tourist bureau, local newspaper and current events hotline may provide. The server maintains a database of a variety of up-to-date information from a large variety of sources that may be of interest to a target user of the system  10 . Information stored on the locality server is retrieved according to a number of categories including the time of day at which the request is made, the specific location of a user (including indications of their potential immediate destinations) the task that a user is involved in (as a tourist the goals of a user would be vastly different from a shopper) and general information about the user that may be provided by the user using the user terminal  26 . 
   Based on information supplied by the user via the user terminal  26 , locality information is supplied that is comprised of a number of elements that can be printed or of some other nature. This includes both images, text and potentially layout information that may be used or ignored by the user. In the context of this invention, the type of information that is made available to a user is in regard to the location of vehicle maintenance establishments in the locality such as filling stations, vehicle service establishments, or the like. 
   The server may be a shared resource, which is accessible by way of a network. In this way, the server can be updated regularly to provide information that is up-to-date and relevant. 
   A portable version of a locality data server is also possible such as by way of a subscription service in which media containing locality information is delivered to a user on a regular basis. This media may then be used with a corresponding reader and access mechanism to retrieve information that is relevant to the user&#39;s current requirements. 
   The layout engine  28  may be required to manipulate data sourced from a plurality of sources. This data may have no embedded layout information. Depending on the kind of content supplied, it may be necessary to firstly create a formatted description of the content, which can then be used to generate one or more pages of page description language. 
   The page description language to be generated by the layout engine  28  determines the kinds of data elements, and the structuring of elements that may be used to compose a page. For example, if the page description language used is postscript, then the elements that are used to describe the page include filled and stroked paths consisting of line segments and curves, text with corresponding font definitions, and images. 
   A template for laying out data may be dynamically generated by the layout engine  28  based on user choices, may be a static built-in template, or may even be obtained from some other source such as the source suppling the data. 
   A number of possibilities exist for layout and content descriptions that can be used to generate a set of consistent layouts for a page containing a number of elements, which may be both textual and graphical. 
   One example of a method of data layout that allows data to be sourced from a plurality of separate locations is through using a combination of XML (extensible Markup Language) and XSL (extensible Stylesheet Language). 
   XML allows content to be marked up by applying a set of tags to the content. The definition of each tag inparticular XML content is described in a separate scheme referenced by the XML. 
   XSL provides a method of transforming XML into another format (for example HTML) whilst simultaneously performing selection and filtering operations. 
   The combination of XML content and XSL as a layout specification allows for descriptions of one or more pages to be produced in a formatting language. The formatting language may then be translated into a page description language suitable for printing (ie, one that provides descriptions of objects, their locations and compositing details). 
   Another possible layout and content description which can be used is a document which is specified in HTML (Hyper Text Markup Language) which is supplied to the layout engine  28  for the purposes of creating a page description. One or more stylesheets specified according to CSS (Cascading Style Sheet) standard may also be supplied, allowing the layout engine  28  to associate a supplied style with a set of tags. If no style sheet is supplied a set of default styles internal to the layout engine  28  is adopted. 
   The HTML document is then translated into a page description language suitable for printing. 
   The rasterization module  34  is provided to convert from page description language into a format that can be sent to the print engine (not shown) of the printer  100 . This format may take a number of forms depending on the characteristics of the print engine such as the color gamut of the output device, the types of markers to be used, the number of markers being used (and their respective colors) and the medium being marked. 
   The page description received by the rasterization module  34  may also take a number of forms. Many page description languages are program oriented in that a page is described in a pragmatically generated manner. Other page description languages describe pages in terms of a set of objects placed on a page by way of a painter&#39;s algorithms. Still other page description languages describe a page in terms of a compositing model that defines a hierarchy of objects located on a page, each with a defined compositing order relative to a neighborhood of other objects. 
   A number of ways exist in which rasterization of a page, a set of pages, a sub-set of objects on a page or a sub set of objects on a number of pages may be processed by the rasterization module  34 . 
   One method of rasterization involves a divide-and-conquer approach in which the page description language is initially interpreted to form a model of the page. The page is scanned and objects are rasterized as they are encountered and then composited to form pixmap output for a portion of the page. The pixmap is then mapped into the color space of the output device or dithered (or error defused) to match the characteristics required by the output device. 
   Another method of rasterization which may be employed by the rasterization module  34  is to render each object in full or partially according to the type of object the coverage of the object with respect to the page (and the portion of the page currently being rendered) and caching aspects of the object For instance, if a character string is to be rasterized, each character in the string may be rasterized in full and then cached for later reuse whereas a filled rectangle may only be rasterized as necessary. 
   Depending on the output requirements for the rasterization module  34 , each page to be rasterized may be generated in its entirety or generated in a band wise fashion for forwarding to the page compression module  38 . In this way, if a page is larger than a certain size, and memory needs to be conserved, a page may be divided into a number of bands that may be rasterized on demand. 
   The page compression module  38  is provided to reduce the amount of rasterized page data that needs to be transferred to the printer controller  42 . The page data is compressed using one or more of a number of techniques that do not result in a visible degradation in the quality of the final printed image. 
   A method of compressing contone data is JPEG compression. With this compression technique, contone pixels are converted into a luminance/chrominance representation which may then efficiently be compressed by using quantization of a discrete cosine transformation of the data. This quantized version of the data is entropy coded to reduce large runs of zero valued elements resulting in an overall 10:1 reduction in data size with virtually no resulting significant loss of image quality. 
   The wavelet transform, as adopted by the JPEG 2000 standard, is a method used to compress contone data. Two different wavelet transforms are specified by JPEG 2000, namely, a 9/7 wavelet transform for lossy compression and a 5/3 3 wavelet transform for lossless compression. Given that the results of compression using the 9/7 wavelet transform are visually superior to the results of compression using the discrete cosine transform, it is reasonable to expect that a compression ratio of at least 50:1 can be achieved without significant degradation of the reconstructed image. 
   The scan order adopted by JPEG 2000 is a spiral scan of the original image, traversed one pixel at a time. This is not convenient for printing applications since it would require that the complete page be decoded and stored or that the page be decoded multiple times for printing to be carried out To remedy this, it may be possible to adopt an alternative scan order that traverses each image row in sequence such that each portion of the image received can be immediately decoded and printed independently of the receipt of the complete compressed page. 
   Compression of bilevel images may be performed by using the commonly known Group 3 or Group 4 fax algorithms. These algorithms exploit the two dimensional properties of typical bilevel images to achieve an average 30:1 compression. 
   The JBIG (Joint Bilevel Image Group) has defined a method for the compression of bilevel images called JBIG2 that is able to yield higher compression ratios than the older Group 3 and Group 4 fax algorithms with a more complex encoder/decoder combination Essentially JBIG2 relies on the encoder to successfully segment an input image into a number of regions that are compressed with techniques specialised according to the properties of the region being encoded. Regions that contain text elements are encoded using an algorithm that stores encoded versions of bitmaps corresponding to each character. Regions that contain half toned images (particularly for the case when ordered half toning has been used) are encoded by storing a dictionary of half toned patterns and the regions to which they apply. Regions that contain other elements such as line art are encoded into a compressed bitmap representation. 
   In certain instances, page compression may not be required. In that case, the page compression module  38  functions using null compression wherein the page is not compressed at all and the page compression module  38  functions as a pass through module. 
   The printer controller  42  is responsible for handling the hardware specific aspects of the printing process. This enables a number of different types of printing mechanisms or printers  100  to be adopted without changing details of the system further up the chain of print modules. 
   The printer controller  42  receives a rasterized version of each page which is usually compressed using one of the compression techniques described above. The page may be received in its entirety or in a band-wise fashion depending on the size of the page and the functioning of the preceding modules  34  and  38 . 
   In the printer controller  42 , the page data are progressively accessed in printer order, decompressed if required and organised into a format suitable for hardware of the printer  100  to enable the hardware of the printer  100  to program its printhead  300 . This recognition may include such factors as may be necessary to account for special characteristics of a particular printhead  300  such as up scaling and dithering of the print data and adjustments, if necessary, for the markers and paper being used. 
   Referring to  FIGS. 2 to 7  of the drawings, the printer  100  is described in greater detail. 
   The printer  100  includes a chassis  112  ( FIG. 3 ) which is covered by a top cover  116 . The printer  100  has an access opening  118  in the top cover. The access opening  118  is closed off by a flap  120 . The flap  120  is spring biased so that, when a cartridge  122  has been removed from the printer  100 , the flap is urged upwards to close off the access opening  118 . 
   The device which sends commands to the printer  100  can either be hard wired to the printer  100 , for example, via a wiring loom of the motor vehicle or, instead, the device may send commands to the printer  100  in a wireless manner. For this purpose, the printer  100  includes a port  124  able to detect wireless communications, such as infra-red communications. 
   The printer  100  incorporates a printhead  300  ( FIG. 3 ). The printhead  300  is a pagewidth ink jet printhead. More particularly, the printhead  300  is a four color printhead, or three color plus infra red ink, printhead which prints photo quality prints on print media stored in the cartridge  122 . The printhead  300  comprises an array of nozzles to provide printing at 1600 dpi. The nozzles of the printhead  300  are manufactured using the applicant&#39;s Memjet technology. The printhead is described in greater detail below. 
   The printhead  300  receives commands from a printed circuit board (PCB)  136  secured to the chassis  112 . 
   A pair of drive motors  138  and  140  is mounted on a sidewall  142  of the chassis  112 . The drive motor  138 , which is in the form of a stepper motor, drives a first drive arrangement in the form of a first gear train  144 . The first gear train  144  is mounted on a side molding  146  of the chassis  112 . 
   The drive motor  140 , which is also in the form of a stepper motor, drives a drive roller  148  via a second drive arrangement in the form of a second gear train  150 . 
   The printhead  300  receives ink from ink hoses  152  which communicate with an ink supply reservoir  154  ( FIG. 7 ) of the cartridge  122  via an ink supply manifold  156 , as will be described in greater detail below. 
   Referring to  FIG. 4  of the drawings, an exploded view of the printer  100  is illustrated. It is to be noted that the printhead  300  communicates with the PCB  136  via a TAB film  154 . 
   A slot  158  is defined in the side molding  146 . The slot  158  receives a corresponding formation of the cartridge  122  in it Further, a roller set  160  is mounted on a base  162  of the printer  100 . The roller set  160  comprises a rotatable axle  162 . A cog  164  is mounted proximate each end of the axle  162 . Each cog  164  engages a longitudinally extending rack  200 ,  202 , one on each side of the cartridge  122 , for inhibiting skewing of the cartridge  122  as it is inserted into, or withdrawn from, the printer  100 . 
   The first gear train  144  engages a pick up roller  168  of the printer  100 . The pick up roller  168  picks up print media in the form of a sheet of paper from a stack  170  of paper ( FIG. 5 ) in the cartridge  122  for feeding to the printhead  300  of the printer  100  when printing is to be effected. 
   As shown in greater detail in  FIG. 4  of the drawings, the first gear train  144  is powered by the stepper motor  138  via an axle  172  extending across the printer  100  to convey power from the stepper motor  138  to the first gear train  144 . A gear  174  is mounted against the molding  146  at one end of the axle  172 . The gear  174  drives a reduction gear set  176 . Further, the reduction gear set  176  communicates with a reversing mechanism  178 . Accordingly, the gear train  144  performs two functions. When the reversing mechanism  178  is not selected, the gear train  144  engages an upper rack  180  on the cartridge  122  for feeding the cartridge  122  into the printer  100  or ejecting the cartridge  122  from the printer  100 . Instead, when the reversing mechanism has been selected, it engages the pick up roller  168  or, more particularly, a gear  182  mounted at an end of the pick up roller  168 . The gear train  144  then serves to feed the paper to the drive roller  148  for conveying to the printhead  300 . 
   Referring now to  FIGS. 6 and 7  of the drawings, the cartridge  122  is described in greater detail. 
   The cartridge  122  comprises a base molding  190 . The base molding  190  is closed off by a metal cover  192 . The cover  192  has a pair of transversely spaced openings  194  defined in a front edge thereof. These openings  194  permit the pick up roller  168  of the printer  100  to engage a topmost sheet of the stack  170  of paper within the cartridge  122 . 
   A toothed rack  196  is provided on one side of the cartridge  122 . The toothed rack  196  defines the upper rack  180  which is engaged by a gear of the first gear train  144  for insertion of the cartridge  122  into, or its ejection from, the printer  100 . A rib  198  extends longitudinally along the side of the toothed rack  196 . The rib  198  is received in the slot  158  in the side molding  146  of the printer  100 . A lower surface of the toothed rack  196  also has one of the longitudinally extending racks  200  ( FIG. 7 ) for engagement with one of the cogs  164 . An opposed side of the base molding  190  of the cartridge  122  carries the other of the longitudinally extending racks  202  which engages the other cog  164  for inhibiting skewing of the cartridge  122  when it is inserted into, or ejected from, the printer  100 . 
   A feed slot  204  is defined at a front edge of the metal cover through which a sheet of paper to be printed is passed in use. The feed slot  204  is partially defined by a plastics strip  206  which inhibits more than one sheet of paper being fed to the printhead  300  at any one time. 
   A transversely extending trough  208  is defined outwardly of the strip  206 . The trough  208  accommodates a sprung roller  210  therein. The roller  210  is supported in the trough  208  via a plurality of clips  212 . 
   The roller  210  is biased upwardly relative to a base of the trough  208  via a plurality of leaf springs  214 . The leaf springs  214  are formed integrally with an L-shaped metal bracket  216  which partially forms the trough  208 . The roller  210  is a snap-fit in the clips  212 . 
   A platen  218  is accommodated in the base molding  190 . The platen  218  is spring biased via a plurality of leaf springs  220  which engage a floor  222  of the base molding  190  for urging the stack  170  of paper against the cover  192 . 
   The ink supply reservoir  154  includes an ink supply molding  224  formed integrally with the base molding  190 . The ink supply molding  224  defines a plurality of ink supply channels  226 . Each ink supply channel  226  contains a particular color of ink. In this context, the term “color” is to be understood as including inks which are invisible in the visible spectrum such as, for example, infra red inks. 
   The channels  226  are closed off by a flexible bladder-like membrane  228  which is heat-sealed to the molding  224 . It will be appreciated that, as ink is withdrawn from each channel  226 , the associated membrane  228  collapses into the channel  226  thereby inhibiting the ingress of air into that channel  226 . 
   Each channel  226  communicates with an ink outlet  230 . Each ink outlet  230  is in the form of a rupturable seal. 
   As shown in greater detail in  FIG. 4  of the drawings, the ink supply manifold  156  of the printer  100  includes pins  232 . These pins  232  communicate with the ink supply hoses  152 . When the cartridge  122  is inserted into the printer  100 , and the cartridge  122  is driven home by the gear train  144 , the pins  232  pierce the seals  230  to place the hoses  152  in communication with their associated ink supply channels  226 . 
   The cartridge  122  includes a quality assurance chip  234 . This chip  234  ensures correct communications between the cartridge  122  and the printer  100  and that the cartridge  122  is of the required quality. The chip  234  communicates with the printer  100  via chip contacts  236  mounted on the ink supply manifold  156  of the printer  100 . Thus, when the cartridge  122  is driven home by the gear train  144 , the chip  234  engages the contacts  236  for enabling communications to be established between the chip  234  and the circuit board  136  of the printer  100 . 
   The cartridge  122  is a disposable unit so that, once its ink supply and paper supply have been depleted, the cartridge is disposed of Instead, the cartridge  122  may be re-useable. In the latter case, once the supply of ink and paper in the cartridge  122  have been depleted and the cartridge  122  is ejected from the printer  100 , the used, empty cartridge  122  can be taken by a user to a supplier for a refund. It is to be noted that the cartridge  122  is automatically ejected from the printer  100  once its supply of paper and/or ink has been depleted. 
   Referring to  FIGS. 8 to 14  of the drawings, the printhead  300  is described in greater detail. The printhead  300  comprises an array, which will be described in greater detail below, of nozzle assemblies. In a particularly preferred form, the printhead includes Memjet technology as described in the patent applications and patents listed in the paragraph headed “Related Patent Applications and Patents”, at page 2, the disclosure of which is incorporated herein by way of explicit reference. 
   Referring to  FIG. 8  of the drawings, a nozzle assembly is illustrated and is designated generally by the reference numeral  400 . 
   The assembly  400  includes a silicon substrate or wafer  416  on which a dielectric layer  418  is deposited. A CMOS passivation layer  420  is deposited on the dielectric layer  418 . 
   Each nozzle assembly  400  includes a nozzle  422  defining a nozzle opening  424 , a connecting member in the form of a lever arm  426  and an actuator  428 . The lever arm  426  connects the actuator  428  to the nozzle  422 . 
   As shown in greater detail in  FIGS. 9 to 11  of the drawings, the nozzle  422  comprises a crown portion  430  with a skirt portion  432  depending from the crown portion  430 . The skirt portion  432  forms part of a peripheral wall of a nozzle chamber  434 . The nozzle opening  424  is in fluid communication with the nozzle chamber  434 . It is to be noted that the nozzle opening  424  is surrounded by a raised rim  436  which “pins” a meniscus  438  ( FIG. 9 ) of a body of ink  440  in the nozzle chamber  434 . 
   An ink inlet aperture  442  (shown most clearly in  FIG. 13  of the drawings) is defined in a floor  446  of the nozzle chamber  434 . The aperture  442  is in fluid communication with an ink inlet channel  448  defined through the substrate  416 . 
   A wall portion  450  bounds the aperture  442  and extends upwardly from the floor portion  446 . The skirt portion  432 , as indicated above, of the nozzle  422  defines a first part of a peripheral wall of the nozzle chamber  434  and the wall portion  450  defines a second part of the peripheral wall of the nozzle chamber  434 . 
   The wall  450  has an inwardly directed lip  452  at its free end which serves as a fluidic seal which inhibits the escape of ink when the nozzle  422  is displaced, as will be described in greater detail below. It will be appreciated that, due to the viscosity of the ink  440  and the small dimensions of the spacing between the lip  452  and the skirt portion  432 , the inwardly directed lip  452  and surface tension function as a seal for inhibiting the escape of ink from the nozzle chamber  434 . 
   The actuator  428  is a thermal bend actuator and is connected to an anchor  454  extending upwardly from the substrate  416  or, more particularly, from the CMOS passivation layer  420 . The anchor  454  is mounted on conductive pads  456  which form an electrical connection with the actuator  428 . 
   The actuator  428  comprises a pair of first, active beams  458  arranged above a pair of second, passive beams  460 . In a preferred embodiment, both pairs of beams  458  and  460  are of, or include, a conductive ceramic material such as titanium nitride (TiN). 
   Both pairs of beams  458  and  460  have their first ends anchored to the anchor  454  and their opposed ends connected to the arm  426 . When a current is caused to flow through the active beams  458  thermal expansion of the beams  458  result. As the passive beams  460 , through which there is no current flow, do not expand at the same rate, a bending moment is created causing the arm  426  and, hence, the nozzle  422  to be displaced downwardly towards the substrate  416  as shown in  FIG. 10  of the drawings. This causes ejection of ink through the nozzle opening  424  as shown at  462  in  FIG. 10  of the drawings. When the source of heat is removed from the active beams  458 , i.e. by stopping current flow, the nozzle  422  returns to its quiescent position as shown in  FIG. 11  of the drawings. When the nozzle  422  returns to its quiescent position, an ink droplet  464  is formed as a result of the breaking of an ink droplet neck as illustrated at  466  in  FIG. 11  of the drawings. The ink droplet  464  then travels on to the print media such as a sheet of paper. As a result of the formation of the ink droplet  464 , a “negative” meniscus is formed as shown at  468  in  FIG. 11  of the drawings. This “negative” meniscus  468  results in an inflow of ink  440  into the nozzle chamber  434  such that a new meniscus  438  is formed in readiness for the next ink drop ejection from the nozzle assembly  400 . 
   Referring now to  FIGS. 12 to 14  of the drawings, a part of the printhead  300  is described in greater detail. The printhead  300  is a four color printhead. Accordingly, the printhead  300  includes four groups  370  of nozzle assemblies, one for each color. Each group  370  has its nozzle assemblies  400  arranged in two rows  372  and  374 . One of the groups  370  is shown in greater detail in  FIG. 13  of the drawings. 
   To facilitate close packing of the nozzle assemblies  400  in the rows  372  and  374 , the nozzle assemblies  400  in the row  374  are offset or staggered with respect to the nozzle assemblies  400  in the row  372 . Also, the nozzle assemblies  400  in the row  372  are spaced apart sufficiently far from each other to enable the lever arms  426  of the nozzle assemblies  400  in the row  374  to pass between adjacent nozzles  422  of the assemblies  400  in the row  372 . It is to be noted that each nozzle assembly  400  is substantially dumbbell shaped so that the nozzles  422  in the row  372  nest between the nozzles  422  and the actuators  428  of adjacent nozzle assemblies  400  in the row  374 . 
   Further, to facilitate close packing of the nozzles  422  in the rows  372  and  374 , each nozzle  422  is substantially hexagonally shaped. 
   The substrate  416  has bond pads  376  arranged thereon which provide the electrical connections, via the pads  456 , to the actuators  428  of the nozzle assemblies  400 . These electrical connections are formed via the CMOS layer (not shown). 
   A nozzle guard  380  is mounted on the substrate  416  of the printhead  300 . The nozzle guard  380  includes a body member  382  having a plurality of passages  384  defined therethrough. The passages  384  are in register with the nozzle openings  424  of the nozzle assemblies  400  of the printhead  300  such that, when ink is ejected from any one of the nozzle openings  424 , the ink passes through the associated passage  384  before striking the print media. 
   The body member  382  is mounted in spaced relationship relative to the nozzle assemblies  400  by limbs or struts  386 . One of the struts  836  has air inlet openings  388  defined therein. 
   When the printhead  300  is in operation, air is charged through the inlet openings  388  to be forced through the passages  384  together with ink travelling through the passages  384 . The purpose of the air is to maintain the passages  384  clear of foreign particles. A danger exists that these foreign particles, such as dust particles, could fall onto the nozzle assemblies  400  adversely affecting their operation. With the provision of the air inlet openings  388  in the nozzle guard  380  this problem is, to a large extent, obviated. 
   In another embodiment of the invention, the printer  100  is built into and forms part of an in-car entertainment unit  500 , as shown in  FIG. 17  of the drawings. 
   The ICE unit  500 , in addition to a CD player  502  and a radio having controls  504 , includes a full color LCD  506 . The unit  500  functions as a satellite navigation unit and may also be used for receiving television signals. The unit  500  incorporates a printer  100  of the type described above. The unit  500  includes a bank of control buttons  508 . This bank of buttons  508  constitutes GPS controls and is used for satellite navigation purposes. In addition, the unit includes the user terminal  26  which is provided for controlling the printer  100  and the content printed by the printer  100 . 
   In use, a user of the system  10  uses the user terminal  26  to request required information from the vehicle management sub-system  12 . In addition, or instead, the sub-system  12  produces information which it regards as necessary to be brought to the attention of an operator of the vehicle and which is displayed on the display of the user terminal  26 . In producing this information, the sub-system  12  makes use of data produced by, inter alia, the location determining unit  18  and the locality data retrieval sub-system  24 . In addition, the sub-system  12  uses sensors within the vehicle to provide information regarding operating aspects of the vehicle. 
   A previously described, locality data is provided on data line  22  from the sub-system  24 . These locality data includes data such as the location of waypoints, for example, service stations which may be required to be visited by a user of the vehicle. The location data output on line  20  from the unit  18  is in the form of navigational positioning information which is used to determine the current location of the vehicle. 
   One possible application of the system  10  is its use in determining servicing requirements of the vehicle such as by making recommendations about scheduled servicing or reporting items which require servicing. 
   If the vehicle management sub-system  12  determines that the vehicle is due for a service such as a scheduled service it determines the location of the nearest suitable service station by using the location determining unit  18  and the sub-system  24 . The relevant data with the addition of the type of service required, as recommended by the vehicle management sub-system  12 , is displayed on the user terminal  26  and can be printed by the user via the printer  100  for reference by the user. 
   This information may be reproduced at any time by use of the user terminal  26  or may be produced automatically by the sub-system  12  in advance of a due date for a service. 
   The user may also request a printed copy of various details concerning a current state of serviceable items of the vehicle by means of the user terminal  26 . For example, the user may request a download of information regarding fluid levels of the vehicle such as brake fluid, oil, coolant, transmission fluid, or the like. Still further, where appropriate sensors are incorporated in the vehicle other mechanical details such as tyre pressures or suspension settings can be downloaded for replenishment or adjustment. 
   Another application of the system  10  is its use in record keeping for taxation purposes. Running costs associated with vehicles that are used both for business and personal use are, in certain jurisdictions, able to be reclaimed as a tax deduction or at least a portion of such use may be reclaimed for tax deduction purposes. In order to reduce the burden on a vehicle owner of maintaining a log book so that an apportionment between business and personal use can be made, the sub-system  12  can be programmed to automatically record usage. This is possible by having the sub-system  12  record start and end points of each journey made and the distance travelled between these points. 
   From a hard copy of trips undertaken during a financial year, the apportionment of travel between business and personal use can be easily evaluated. 
   Still further, for a fuel conscious driver the sub-system  12  can be programmed to periodically report fuel usage patterns in hard copy format such that trends may be observed by a driver. This will then enable the driver to adapt driving habits, change routes or attend to fine tuning of the vehicle in order to minimise fuel consumption. 
   Still another application of the system  10  is its use in hire vehicles such as taxis. Taxis commonly have metering systems that perform measurement of distance travelled and time elapsed in order to enable a fare to be calculated. These meters often have facilities for adding surcharges to the metered fare to account for details such as pre-booking fees, baggage handling fees, or the like. A taxi meter is, in fact, a form of vehicle management sub-system and its functions can be performed by the sub-system  12  of the system  10 . Thus, the system  10  can be used in a taxi for enabling a passenger conveyed in the taxi to obtain a receipt for their journey by way of the printer  100 . The receipt could contain additional information not generally available from existing metering systems such as the route taken, time elapsed, fare breakdown or the like. 
   Accordingly, it is an advantage of the invention that a system  10  is provided which facilitates the production of hard copies of information regarding operation of a vehicle. This facilitates servicing of the vehicle and also record keeping in respect of the vehicle for taxation purposes. Still further, the system  10  could be integrated into a vehicle where the vehicle is used for public hire purposes such as in the case of a taxi without the need for additional, separate taxi meters. 
   Although the invention has been described with reference to a number of specific embodiments, it will be appreciated by those skilled in the art that the invention can be embodied in many other forms.