Abstract:
A docking station is adapted to operate with a personal digital assistant. The docking station includes an image sensor configured to acquire images, a sensor microprocessor coupled to the sensor, a vision microprocessor coupled to the sensor microprocessor and an instruction memory and a data memory, a communication interface coupled to the vision microprocessor, and configured to interface with a digital personal assistant and a computer system interface and a power supply. A housing of the docking station encloses the image sensor, the sensor microprocessor, the vision microprocessor and memories, the communications interface, and a power supply. During operation, a personal digital assistant is physically and electronically coupling to a top oblique surface of the housing.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This is a continuation-in-part of U.S. patent application Ser. No. 09/415,635 filed on Oct. 12, 1999 filed by Yerazunis et al. incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to computer accessories, and more particularly to accessories adapted for use with digital personal assistant docking station devices. 
     BACKGROUND OF THE INVENTION 
     In the prior art, digital still cameras have been adapted to work with workstations, personal computers, and even lap-top devices. 
     In U.S. Pat. No. 5,708,853, Sanemitsu describes a Personal Computer Memory Card International Association (PCMCIA) card that includes an image input device. The card can be inserted into an PCMCIA slot of a lap-top computer. In one configuration, holes are formed in the casing of the lap-top so that an image input device can acquire a picture. The card requires that the computer device is equipped with PCMCIA “slot” and mounting frame. 
     There are a number of problems with this configuration. First, the PCMCIA standard requires that the dimensions of the slot be about 9×6×1.5 cm. For many modern PDA&#39;s, such as a PalmPilot (12×8×1.5), the slot and frame would consume nearly the entire interior of the PDA. In such applications, the card according to Sanemitsu would be totally unworkable. More recent PDA are even smaller than the PCMCIA card. 
     Second, the PCMCIA card has two connectors, front and back. The back  64  pins interface to the computer, and the front pins, which vary depending on the communications interface, need to be connected to some type of transmission controller connected to a communications line. Sanemitsu suggests an ISDN telephone line. This is a severe limitation making the device totally useless in most PDA type of environments where a communications line is not always available. In combination, the size of the PCMCIA card and the requirement for connection to a communication line make this solution completely impractical for modern mobile personal digital assistants. 
     In U.S. Pat. No. 5,948,086 Lin describes an electronic still camera that is adapted for use with a portable computer that is equipped with a housing for receiving a removable and rechargeable battery pack. This arrangement also has a number of problems similar to Sanemitsu&#39;s camera. First, the size of a rechargeable battery pack overwhelms any modern PDA. Second, this camera presumes that the device is equipped with a removable battery. This is not the case with most PDAs, which are powered by disposable batteries. 
     In other configurations, the camera is loosely tethered to the PDA. This presents an ergonomic problem since it is awkward to handle both the PDA and camera at the same time. 
     Therefore, it is desired to provide a camera system that can be used with a PDA in a rigid and ergonomic manner. 
     As a second characteristic, prior art cameras only acquire still or moving images. Other than controlling exposure, there is very little control of how the images are acquired. Therefore, there is a need for a camera that can be used with a PDA so that the PDA can control higher level camera functions, such as image enhancement, x-y projections, resolution, and the like. 
     SUMMARY OF THE INVENTION 
     The invention provides a docking station that is adapted to operate with a personal digital assistant. The docking station includes an image sensor configured to acquire images, a sensor microprocessor coupled to the sensor, a vision microprocessor coupled to the sensor microprocessor and an instruction memory and a data memory, a communication interface coupled to the vision microprocessor, and configured to interface with a digital personal assistant and a computer system interface and a power supply. 
     A housing of the docking station encloses the image sensor, the sensor microprocessor, the vision microprocessor and memories, the communications interface, and a power supply. During operation, a personal digital assistant is physically and electronically coupling to a top oblique surface of the housing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of a computer vision system adapted for use with a docking station of a personal digital assistant; 
     FIG. 2 is a back view of the computer vision system adapted for use with the docking station; 
     FIG. 3 is an front view of the computer vision system docking station and the personal digital assistant; 
     FIG. 4 is a side cut-away view of the computer vision system of the docking station of FIG. 1; 
     FIG. 5 is flow diagram of modes of operation of the docking station computer vision system; and 
     FIG. 6 is a flow diagram of operating modes of the docking station vision system. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1-3 respectively show side, back, and front views of a preferred embodiment for a computer vision system docking station (“cradle”)  100  adapted for use with a normally handheld personal digital assistant (PDA)  150 . The docking station includes a housing  105  a camera  106 , an on-off switch  107 , and a (serial RS232) connector  108 . 
     During operation, the PDA  150  is disposed on an upper surface  151  of the housing  105 . The vision system is housed entirely outside the PDA to retain the ergonomic operability of the PDA. During operation, the PDA  150  can be used to operate the computer vision system inside the housing  105 . Alternatively, the docking station vision system and PDA can be operated synchronously with a personal computer or workstation (not shown) connected to the docking station  100  via the connector  108 . 
     As shown in FIGS. 1 and 2, the PDA  150  to which the present computer vision system is adapted includes a display screen  151 , hardware buttons  152 - 155 , silk-screened buttons  156 - 159 , a scroll button  160 , and a writing surface  161 . The PDA shown is a PalmIII PalmPilot™ handheld computing device. It should be understood that the vision system can be adapted for use with other docking stations of similar handheld PDA devices. 
     FIG. 4 shows the arrangements of vision system components inside the housing  105  of the docking station  100 . A serial port and interface  102  is configured to mechanically and electrically connect with the PDA  150 , and with a personal computer via the serial connector  108 . The camera  106  is mounted on a circuit board  109 . Light enters the camera through a lens  101  focused on a solid state sensor  110 . Focusing can be accomplished by means of a bezel  103  surrounding the lens  101 . Processors and memories of the vision system, described in greater detail below, are also mounted on the circuit board  109 . A power supply, e.g., a battery  104  coupled to the circuit board  109  electrically operates the components of the vision system. 
     The computer vision system according to one embodiment of the invention uses an “Artificial Retina” (AR) for acquiring images, Mitsubishi Electric Inc. part number M64283FP. The AR is a CMOS image sensor with 128×128 pixels. The AR chip achieves high performance, up to 25 Hz for full frames, and higher for partial frames. Power consumption is 15 mW. The AR chip can execute 1D and 2D projection of an input image. The projection sums all pixels in columns in the vertical direction and rows in the horizontal direction. The image area is approximately 9 mm 2 . The relative small size (11×7 mm) and low cost of the AR makes this sensor ideal for PDA applications as described herein. 
     In another embodiment, the sensor is a color CMOS image sensor, Mitsubishi Electric part number M64289U. This sensor has a resolution of 352×288 pixels, and can acquire up to thirty frames per second. The sensor has exposure and gain control. 
     As another feature, the sensor is mounted on a single semiconductor substrate with a sensor microprocessor that can perform a number of low-level image processing tasks under user control. As is described below, the system according to the invention, allows the PDA to control the sensor&#39;s microprocessor. 
     FIG. 5 shows how the various components of the computer vision system and PDA interact. The computer vision system acquires images through the lens  101 . In the preferred embodiment as described above, the image sensor  110  uses CMOS technology, unlike the CCD devices of the prior art. The sensor  110  is co-resident and controlled by a camera sensor microprocessor  115  as described above. In addition, the system includes a vision microprocessor  120 . The vision microprocessor has access to an instruction memory  121  that stores programs, such as vision applications, and a data memory  122  for storing images. In one embodiment, the vision processor is a Mitsubishi Electric Inc., single chip, CMOS RISC microcomputer, part number M16C. 
     As a feature, the memories  121 - 122  can be downloaded with instructions and data from the PDA  150  to configure the computer vision system  100  for particular vision applications, such as object recognition, human-computer interfacing, pattern recognition, virtual reality and the like. Alternatively, the vision applications can be downloaded from a personal computer (PC)  130 , or any other computer via the serial interface  102  and the connector  108 . 
     The computer vision system and PDA  150  communicate via the serial interface  102 . A user interface of the PDA sends vision applications  191  and commands  192  to the computer vision system. In response to the commands and vision applications, the computer vision system sends images and status  193  and vision data  194  to the PDA. The PDA can send the data to other systems coupled to the connector  108 . 
     The PDA includes a microprocessor  170  for generating the commands and executing vision applications, and for processing and displaying the images, status information, and vision data. The PDA also includes a memory for storing the images as data objects  182  and  184 . The data objects can be picture objects  182  (still images), or video objects  184  (a sequence of images). The PDA also stores other data objects  181  and  183 . In the preferred implementation, the images acquired by the computer vision system are stored in the same format as the PDA&#39;s data objects. This formatting can be done by the vision processor  120 . 
     Operation 
     As shown in FIG. 6, a user operates the computer vision system and PDA by selecting  200  one of six basic modes, setup  201 , view-finder  202 , picture  203 , video  204 , programming  205 , and synchronize  206 . Operation is performed by using the buttons and the display of the PDA  150 , or some other attached computer. 
     In setup mode  201 , the PDA configures  210  computer vision system parameters  21   1 . Computer vision system parameters  211  include exposure, 1D or 2D edge extraction, gain control, frame rate, sensitivity, resolution, compression, and projection mode. Edge extraction is an important precursor step for object recognition tasks in a vision application. In projection mode, the pixels in horizontal rows and vertical columns are summed. This later feature enables, for example, motion, image analysis, and compression applications. The user can also crop images to selected areas of the sensor  110  by specifying a subset of the pixels as active. If the computer vision system has a black and white sensor, then one to eight bit of gray scale can be selected. For a color sensor, up to 24 bits of RGB values can be acquired. Compression can format a picture object as a JPEG file, and a video object as a MPEG file. Other compression standards are also possible. Even if the PDA can only display one or two bits of gray scale, the PDA can still acquire and store images of greater bit depth for display elsewhere. 
     In view-finder mode  202 , the computer vision system acquires images  220 , and the PDA displays the images  221  on the display screen  151 . However, current image data objects are stored only temporarily in the PDA&#39;s memory. 
     In picture mode  203 , the computer vision system acquires images  230 , the PDA temporarily stores and displays the images  231 , and permanently stores one selected image  232  as a picture object  182 . 
     In video mode  204 , the computer vision system acquires a sequence of images  240 , i.e., a video. The PDA displays the video  241 , and stores the video  242  as a video object  184 . In the case that the PDA memory is insufficient, picture and video objects can be up-loaded to the PC  130  or other type of computer using either the infra-red transceiver  170 , or the serial interface  102  when the computer vision system is not in use. 
     In programming mode  205 , the user selects a vision application to download  250  to the computer vision system. The application is executed  251 , and the PDA processes the vision data  252 . 
     In synchronize mode  206 , programs and data of the PDA  150  and vision system  100  can be synchronized with those of another computer system, for example, the PC  130 . 
     In addition, the user of the PDA can link the picture and video objects  182  and  184  to other data objects  181  and  183  managed by the PDA. For example, a picture of a person can be linked to the person&#39;s address, a business card object, a facsimile, a message, and the like. Similarly, other video objects can be linked to other objects managed by the PDA. 
     Although the invention has been described by way of examples of preferred embodiments, it is to be understood that various other adaptations and modifications may be made within the spirit and scope of the invention. Therefore, it is the object of the appended claims to cover all such variations and modifications as come within the true spirit and scope of the invention.