Abstract:
A detachable cartridge unit and an auxiliary unit combined forms a functional component for a data processing system. The cartridge unit is configured to receive a variety of auxiliary units in order to form different functional components and perform different functions. The circuit board of the cartridge unit contains circuits and components common to each functional component. The auxiliary unit contains components and circuits unique to the function that the auxiliary unit represents. The cartridge unit comprises a circuit board, a housing containing the circuit board, a first connector coupled to the circuit board for connecting to a data processing system, a second connector coupled to the circuit board, and a grip movably connected to the housing with a hinge. The auxiliary unit includes an auxiliary circuit board, an auxiliary connector coupled to the auxiliary circuit board for detachably connecting to the second connector, an auxiliary housing containing the auxiliary circuit board, a guide for guiding the auxiliary connector to connect to the second connector via a predetermined path, and an auxiliary grip movably connected to the auxiliary housing with a hinge.

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to function expansion of a data processing system and, more specifically, to providing a detachable auxiliary unit to a removable cartridge unit of a data processing system. 
   BACKGROUND OF THE INVENTION 
   Data processing systems like personal computers use removable add-on cards or cartridges containing circuit boards to add additional software and/or hardware to the data processing system. For example, a computerized automotive service system needs to perform a variety of tests on different models of vehicles. The automotive service system requires additional circuits, drivers, software, interfaces, communication protocols, and parameters for different vehicle models to correctly conduct the tests. When a new test is to be performed or another vehicle model is to be tested, an add-on card or a cartridge corresponding to the previous test is removed and a new one corresponding to the new test is plugged into the computerized automotive service system via a receiving slot or socket to provide necessary hardware or software or both to the system. These removable add-on cards or cartridges provide flexible system architecture to perform different types of functions. 
   However, the use of add-on cards or cartridges to add additional hardware and/or software poses concerns of cost. There are circuits and components common to every add-on card or cartridge. According to conventional design, these common circuits and components have to be provided on every add-on card or cartridge. As the number of add-on cards or cartridges increases, the cost for these redundant circuits and components increases proportionally. These redundant components can increase the cost of add-on cards or cartridges up to 20%. 
   SUMMARY OF THE INVENTION 
   Accordingly, there exists a need to provide flexible hardware architecture for a data processing system to adapt to different purposes of use. There is also a need to add or remove additional hardware or software to and from a data processing system, and at the same time, reduce the cost for using the same. 
   These and other needs are addressed by the present invention. The present invention provides improved design architecture to supply additional functionality to a data processing system and, at the same time, reduce the cost of using the same. The invention also increases protection to components disposed on the add-on cards or cartridges. 
   An embodiment of the present invention comprises two portions: a cartridge unit and an auxiliary unit. The cartridge unit and the auxiliary unit together form a functional component of a data processing system. The cartridge unit comprises a circuit board, a housing containing the circuit board, a first connector coupled to the circuit board for connecting to a data processing system, a second connector coupled to the circuit board, and a grip movably connected to the housing with a hinge. The auxiliary unit includes an auxiliary circuit board, an auxiliary connector coupled to the auxiliary circuit board for detachably connecting to the second connector, an auxiliary housing containing the auxiliary circuit board, a guide for guiding the auxiliary connector to connect to the second connector via a predetermined path, and an auxiliary grip movably connected to the auxiliary housing with a set of hinges. 
   The cartridge unit may be adapted to removably attach to a data processing system, such as a computer or a computerized automotive service system. The cartridge unit is configured to receive a variety of auxiliary units in order to form a variety of functional components to perform different functions. The circuit board of the cartridge unit may contain circuits and components common to each functional component, such as interface circuits, a microprocessor, and other supporting logic and circuits that are common to different functional components. The auxiliary unit may contain components and circuits unique to the function that the functional unit represents, such as supporting logic and circuits as well as memory devices, such as an EPROM (Erasable Programmable Read Only Memory), for storing data and code unique to the function that the auxiliary unit represents. 
   In operation, an auxiliary unit is connected to the cartridge unit to provide a specific function. When a new function or software is required in the data processing system, the auxiliary unit having the function that is no longer needed is removed from the cartridge unit and a new auxiliary unit corresponding to the new function is attached to the cartridge unit. 
   According to one embodiment, the auxiliary circuit board is enclosed by the auxiliary housing to avoid electrostatic charge from damaging the components affixed thereon. 
   Both the auxiliary unit and the cartridge unit may have a grip to assist disengaging the units from the objects to which the units are connected. The grip may be part of a surface cover that has a lip portion extending passing a set of hinges with which the surface cover connects to the housing. The grip, as part of the surface cover, is capable of rotating about the hinges. In operation, when an operator holds the grip and rotates the grip about the hinges, the lip portion contacts the object to which the unit is connected. As a result, the surface cover works as a lever and the contact point works as a fulcrum to assist disengaging the unit from the object. 
   Various advantages of the present invention will become readily apparent from the following detailed description, simply by way of illustration of the invention and not limitation. As will be realized, the invention is capable of other and different embodiments and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawing and description are to be regarded as illustrative in nature, and not as restrictive. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements and in which: 
       FIG. 1  illustrates a vehicle diagnostic system upon which an embodiment of the invention may be implemented. 
       FIG. 2  illustrates a block diagram of a cartridge unit and auxiliary unit implemented according to the present invention. 
       FIG. 3  shows a perspective view of a cartridge unit and an auxiliary unit implemented according to the present invention. 
       FIG. 4  shows a perspective view of an auxiliary unit together with a cartridge unit after the auxiliary unit is connected to the cartridge unit. 
       FIG. 5  is an exploded view of a cartridge unit implemented according to the present invention. 
       FIG. 6  is an exploded view of an auxiliary unit implemented according to the present invention. 
       FIGS. 7   a ,  7   b  and  7   c  show how a cartridge unit is detached from a scanner. 
       FIGS. 8   a ,  8   b  and  8   c  illustrate how an auxiliary unit is detached from a cartridge unit. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1  illustrate a vehicle diagnostic system upon which an embodiment of the invention may be implemented. In  FIG. 1 , a scanner  103  is connected to a vehicle computer  101  and a cartridge unit  205 . An auxiliary unit  240  is connected to cartridge unit  205 . 
   Vehicle computer  101  is an on-board data processing system of a vehicle, such as a computer, coupled to a variety of sensors that are used to monitor various vehicle operation parameters. The parameters are useful for determining the operation status of the vehicle. Scanner  103  is a data processing system configured for downloading data or parameters from vehicle computer  101  and may be capable of executing instructions, processing and storing data obtained from vehicle computer  101 , and generating control signals to control vehicle computer  101 . Scanner  103  may include interface circuits to interface with vehicle computer  101 ; a processor, such as a embedded controller, for executing instructions and processing signals and data; a memory device, such as ROM or RAM or both for storing, instructions, communication protocols used with different types of vehicle, and/or data obtained from vehicle computer  101 . 
   In operation, scanner  103  connects to an input/output port of vehicle computer  101  to access vehicle parameters stored in vehicle computer  101 . The vehicle parameters may include parameters unique to the vehicle, such as model, year, maker, as well as parameters collected by sensors indicating the operation status of the vehicle, such as engine temperature, battery voltage, oil level, brake fluid level, and so on. A data bus  105  and a control bus  107  are provided between scanner  103  and vehicle computer  101  to facilitate transmission of control signals and data therebetween. Control bus  107  and data bus  105  may also share the same physical transmission path by using time multiplexing or coding techniques, such as arranging control signals and data in packets. 
   Vehicle computer  101 , in response to a specific control signal received from scanner  103  via control bus  107 , sends operation parameters collected by the sensors to scanner  103  via data bus  103 . The operation parameters are then stored in the memory device of scanner  103  and are accessible by the processor of scanner  103 . 
   Scanner  103  has a receiving device, such as a socket, a slot, a connector or the like, for detachably receiving a cartridge unit  205  that has an auxiliary unit  240  coupled thereto. Cartridge unit  205  and auxiliary unit  240  together form a functional component of scanner  103 . The circuit board of cartridge unit  205  may contain circuits and components common to each functional component, while auxiliary unit  240  may contain components and circuits unique to the functional component. For example, each auxiliary unit may represent specifications, testing requirements, communication protocols, and/or testing procedures of a specific vehicle model. Cartridge unit  205  communicate with scanner  103  via a data bus  109  and a control bus  111 , and with auxiliary unit  240  via a data bus  207  and a control bus  209 . 
     FIG. 2  illustrates a block diagram of cartridge unit  205  and auxiliary unit  240  implemented according to the present invention. Cartridge unit  205  includes circuits and components common to each functional component, such as a controller  204  coupled to an interface circuit  202 , a ROM  210 , a RAM  212 , a first connector  232 , a second connector  234 , and a buffer circuit  206 . RAM  210  is used for temporally store data or instructions, and is accessible by processor  204 . Controller  204  is typically driven by microcode stored in ROM  212 . ROM  212  stores static data or instructions or both, as well as communication protocols that are unique to different vehicle models. ROM  212  could be replaced by other types of non-volatile memory such as EEPROM or flash EEPROM. 
   Auxiliary unit  240  may contain circuits and components unique to each functional component of scanner  103 , such as an EPROM  201 , an interface and decoding circuit (not shown), and a connector  245 . EPROM  201  may store necessary data and software code unique to a specific vehicle model. For example, EPROM  201  may store procedural instructions of conducting diagnostic process for different models of vehicles, and/or communication protocols used in communicating with the vehicle computer of a specific vehicle model. Cartridge unit  205  is configured to receive a variety of auxiliary units in order to form different functional components and perform different functions. Therefore, scanner  103  can be updated by providing new auxiliary units for new vehicle models. 
   After auxiliary unit  240  connects to cartridge unit  205 , connectors  234  and  245  form signal paths between cartridge unit  205  and auxiliary unit  240 . A control bus  209  and a data bus  207  are provided to facilitate communication between controller  204  and EPROM  201 . Control signals generated by controller  204  are placed on control bus  209  and are decoded by the interface and decoding circuit of auxiliary unit  240 . Based on the contents of the control signals, data or instructions or both stored in the EPROM  201  is released to data bus  207  and accessible by controller  204 . 
   As illustrated in  FIG. 2 , cartridge unit  205  connects to scanner  103  with first connector  232  and receives control signals therefrom. Controller  204  interfaces with scanner  103  via interface circuit  202  and with auxiliary unit  240  via buffer circuit  206 . 
   In operation, auxiliary unit  240  is connected to cartridge unit  205  to provide a specific function to scanner  103 . For example, the combination of auxiliary unit  240  and cartridge unit  205  provides communication protocols and test procedures corresponding to a specific vehicle model. By attaching such cartridge unit  205  and auxiliary unit  240  to scanner  103 , scanner  103  can properly communicate with vehicle computer  101  of the specific model of vehicle by accessing the specific communication protocol stored in EPROM  201  of auxiliary unit  240 . For instance, if a 1997 Ford Taurus is to be tested, auxiliary unit  240  corresponding to 1997 Ford Taurus is located and connected to cartridge unit  205 . The units are then attached to scanner  103 . Auxiliary unit  240  corresponding to 1997 Ford Taurus stores communication protocols and test procedures that are unique to the vehicle in EPROM  201 . Upon connection of cartridge unit  205  and auxiliary unit  240  to scanner  103 , scanner  103  gains access to data stored in EPROM  201  by issuing control signals to cartridge unit  205 . The control signals may be decoded by controller  204  or other decoding circuits. In response to a control signal requesting access data representing communication protocols, controller  204  may in turn generate control signals to auxiliary unit  240 . The control signals may include address data corresponding to the memory location in which the communication protocols are stored. 
   The control signals are then decoded by the interface and decoding circuit of auxiliary unit  240 . Based on the content of the control signals, data corresponding to communication protocol used by the vehicle computer of 1997 Ford Taurus are made available on data bus  207  and in turn on data buses  109 , and accessible by scanner  103 . With the communication protocol, scanner  103  can properly communicate with the vehicle computer on board of the 1997 Ford Taurus under test. When another vehicle model is to be tested, a corresponding auxiliary unit is attached to cartridge unit  205  to provide proper communication protocols to scanner  103 . 
     FIG. 3  shows a perspective view of a cartridge unit  205  and auxiliary unit  240  implemented according to the present invention. Cartridge unit  205  has a housing  210  for housing a circuit board  230  on which the components described in  FIG. 2  are disposed. A grip  220  is rotatably connected to housing  210  with a set of hinges  222 . Circuit board  230  is coupled to a first connector  232  and a second connector  234 , and a pathway  212  is formed beneath circuit board  230 . 
   Auxiliary unit  240  has a guide  242  connected to an auxiliary housing  246 . Guide  242  may be plate-shaped, substantially U-shaped, L-shaped, or of any other shape that is capable to fit into and travel along pathway  212  disposed in cartridge unit  205 . Housing  246  may be disposed vertically on one end of guide  242  and house a circuit board on which EPROM  201  and other circuitry are disposed. A grip  249  is pivotably connected to housing  246 . 
   Housing  210  and  246  protect the components on circuit board from being damaged by electrostatic charge during engagement or disengagement of the auxiliary unit. Electrostatic charge accumulated on a human body may sometimes reach levels of over 1000 volts. The transfer of a static charge from a human body to a circuit board can cause serious damages to the electronic circuitry. During the frequent engagement and disengagement of the auxiliary unit and the cartridge unit, touching of the circuit board by the operator is unavoidable. Having the circuit board contained in the housing shields the circuit board from contacts of the operator and thus prevents the circuit board from being damaged by the electrostatic charge transferred from the human body. 
   In order to form a functional component of scanner  103 , auxiliary unit  240  has to connect to cartridge unit  205 . In operation, the tip portion of guide  242  is inserted into matching pathway  212  disposed in cartridge unit  205 . By moving auxiliary unit  240  along the direction indicated by the arrow shown in  FIG. 3 , guide  242  travels along pathway  212  and brings connector  245  to a position close to second connector  234  for connecting to second connector  234 .  FIG. 4  shows a perspective view of an auxiliary unit together with a cartridge unit after the auxiliary unit is connected to the cartridge unit. In one embodiment, after auxiliary unit  240  is connected to cartridge unit  205 , grip  249  and grip  220  form a substantially flat surface. 
     FIG. 5  is an exploded view of a cartridge unit implemented according to the present invention. Housing  210  may comprise a cover  252  and a lower portion  251 . Cover  252 , lower portion  251  and circuit board  230  may be assembled together with a set of screws  253 . Lower portion  251  has a tongue portion  299 . In one embodiment, circuit board  230  is disposed near the upper portion inside housing  210  so that pathway  212  is formed beneath circuit board  230 . 
   First connector  232  may be provided at one end of circuit board  230  and extend to the exterior of housing  210  for connecting to a data processing system, such as a scanner  103  as described above. First connector  232  may be a connecting device, such as a male connector, female connector, golden fingers or the like, for connecting to a matching connecting device disposed on scanner  103 . Second connector  234  may be disposed on the other end of circuit board  230  for receiving a matching connector of auxiliary unit  240 . Second connector  234  may be a connecting device, such as a male connector or female connector or golden fingers or the like, for connecting to a matching connecting device. 
   Grip  220  may pivotably connect to housing  210  with a set of hinges  222 . Grip  220  may have a lip portion  225  extends past hinges  222 . Grip  220  may have an opening  298  with the size and shape substantially equal to grip  249  of auxiliary unit  240  in order to receive grip  249  upon auxiliary unit  240  connects to cartridge unit  205 . 
     FIG. 6  is an exploded view of an auxiliary unit  240  implemented according to the present invention. A body portion  264  and a cover  262  together form housing  246  and houses circuit board  244 . Body portion  264  and cover  262  may be assembled by a set of screws  266 . Connector  245  is coupled to circuit board  244  and exposed from housing  246 . Grip  249  may be pivotably connected to body portion  264  with a set of hinges  248  and may have a lip portion  247  extending past hinges  248 . 
     FIGS. 7   a ,  7   b  and  7   c  show how cartridge unit  205  is detached from scanner  103 . In  FIG. 7   a , cartridge unit  205  is inserted into a slot  703  disposed on scanner  103  and connected to a connector  701  with connector  232 . Grip  220  has a lip portion  225  extending past hinges  222 .  FIG. 7   b  shows the disengagement of cartridge unit  205  from scanner  103 . In order to disengage cartridge unit  205  from scanner  103 , grip  220  is rotated about hinges  222 . After grip  220  is rotated to a certain angle, lip portion  225  contacts a portion of scanner  103  at point A. The combination of the contact at point A and the continued rotation of grip  220  about hinges  222  forms a lever, with fulcrum at point A, load from connectors  232  and  701 , and effort from the rotation of grip  220 . Therefore, the rotation of grip  220  assists disengagement of connector  232  from connector  701 .  FIG. 7   c  shows the removal of cartridge unit  205  from scanner  103  after connector  232  being disengaged from connector  701 . 
     FIGS. 8   a ,  8   b  and  8   c  illustrate how auxiliary unit  240  is detached from cartridge unit  205 . For better illustration,  FIGS. 8   a ,  8   b  and  8   c  also show scanner  103  to which cartridge unit  205  is attached. In  FIG. 8   a , auxiliary unit  240  is connected to connector  234  of cartridge unit  205  with connector  245 . Grip  249  has a lip portion  247  extending past hinges  248 .  FIG. 8   b  shows the disengagement of auxiliary unit  240  from cartridge unit  205 . In order to disengage auxiliary unit  240  from cartridge unit  205 , auxiliary grip  249  is rotated about hinges  248 . After auxiliary grip  249  is rotated to a certain angle, lip portion  247  contacts tongue portion  299  at point A. The combination of the contact at point A and the continued rotation of grip  249  about hinges  248  forms a lever, with fulcrum at point A, load from connectors  234  and  245 , and effort from the rotation of grip  249 . Therefore, the rotation of grip  249  assists disengagement of connector  245  from connector  234 .  FIG. 8   c  shows the removal of auxiliary unit  240  from cartridge unit  205  after connector  245  being disengaged from connector  234 . 
   While this invention has been described in connection with an exemplary embodiment, it is to be understood that the invention is not limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.