Abstract:
An optical floppy disc constructed of microfilm, thermoplastic or paper and bears digital and/or graphic information. Digital information may be stored in radial lines each of which comprises the digital information to be retrieved and line addresses at the end of a line or dispersed within a line. Digital information may also be stored in a plurality of coaxial circular tracks and be retrieved by addressing the track and portion of the track containing the desired information. Information retrieval systems, both continuously rotating and start-stop systems are provided for reading the various types of discs. Of particular importance is the use of a disc as an easily up-dateable catalog.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is related to co-pending applications, assigned to the same assignee, namely Ser. No. 922,798, filed July 7, 1978, now U.S. Pat. No. 4,213,040 and Ser. No. 956,426, filed Oct. 31, 1978, now U.S. Pat. No. 4,254,329. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to communications systems, and more particularly to microfilm systems in which data is stored in digital and/or graphic form on a circular storage media, such as microfilm, thermoplastics or paper, and is optically scanned by light transmission, light reflection or light refraction apparatus. 
     2. Description of the Prior Art 
     In Gokey et al Ser. No. 922,798, filed July 7, 1978 and Gokey et al Ser. No. 956,426, filed Oct. 31, 1978, a microfiche system is disclosed in which a microfiche card bears digitally encoded information and is read by an optical scanner which indexes the card to a desired address and optically scans the data content at that address. Also disclosed in these applications is a viewer microfiche, bearing graphic information (including drawings, alphanumeric, etc, other than digital information) which is addressed by digital codes for viewing on a screen. Each of the microfiche, both the digital microfiche and the viewer microfiche, were provided with indicia to correct for skew and to provide tracking alignment. 
     Murakoshi, in his U.S. Pat. No. 3,792,440, discloses a film disc memory which photographically stores clock signals in the radial direction and index signals in the circular direction to control the x-y movement of a microfiche transport to properly position a desired frame in the light path of a viewer. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to store and retrieve information of the type set forth in the Gokey et al applications on a microdisc such that skew and tracking indicia are obviated. 
     Another object of the invention is to provide an economical data storage and retrieval system which may readily be constructed of presently available components and which is, in both construction and operation, cost effective and highly versatile. 
     Another object of the invention is to provide an information storage and retrieval system in which both digital information and graphic information may be stored on and retrieved from the same disc. 
     As used herein, the term disc refers to a storage medium which may be microfilm, thermoplastic (diazo), paper or the like, and optical scanning may therefore include light reflection, light refraction or light transmission. However, for the sake of simplicity, only microfiche storage and light transmission reading are discussed herein. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects, features and advantages of the invention, its organization, construction and operation will be best understood from the following detailed description, taken in conjunction with the accompanying drawings, on which: 
     FIG. 1 is a plan view of a digital optical floppy disc which bears digital information along radial lines thereof; 
     FIG. 2 is a graphic illustration of the distribution of data along a radial line, including a pair of flags and a line address; 
     FIG. 3 is another graphic illustration of a different data distribution along a radial line, including a pair of flags and distributed address information; 
     FIG. 4 is a simplified block diagram of a system for retrieving data from a disc of the type illustrated in FIG. 1; 
     FIG. 5 is a plan view of an optical floppy disc which bears digital information in circular tracks and which has a radial index to be read by a separate index sensor; 
     FIG. 6 is a simplified schematic diagram of apparatus for retrieving data from a disc of the type illustrated in FIG. 5; 
     FIG. 7 is a plan view of an optical floppy disc storing graphic information and digital information; 
     FIG. 8 is a diagrammatic and schematic illustration of a system for reading a digital disc, a viewer disc, or a combination digital/viewer disc; 
     FIG. 9 illustrates an embodiment of a different scanner for use with a system of FIG. 7; 
     FIG. 10 illustrates another embodiment of the scanner of FIG. 9, with two variations, namely a polygonal mirror arrangement and a polygonal prism arrangement; 
     FIGS. 11, 12, 13 are flow charts for the command processing, the index routine and the data retrieval routine as employed in a model of the system embodying the principles of the present invention; and 
     FIG. 14 is a schematic block diagram of a microprocessor and the data recovery and timing circuits employed in practicing the invention in accordance with the flow charts of FIGS. 9-11. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Inasmuch as the drive apparatus for the microdisc may be constructed from a diskette or floppy disc drive, constructed to run at, for example, 24 or 30 RPM, and inasmuch as only the microfiche type of microdisc is discussed in detail herein, the disc will be referred to as an optical floppy disc. 
     Referring to FIG. 1, an optical floppy disc is generally illustrated at 10 as having a peripheral edge 12 and a hub opening 14 for clamping the same in a disc drive. Digital text is generally illustrated at 16 as extending between a pair of flags 18 and 20. A plurality of such radially extending lines of data are provided about the disc, only one being illustrated for purpose of simplicity. 
     In the alternative, the disc may have a plurality of information bands, as illustrated at 22 and 24, each of which bands includes a plurality of radially extending lines of digital data. 
     As illustrated in FIG. 2, the text 16 may comprise a beginning flag 18, a terminal flag 20, and an address 26 which may comprise a plurality of bits. 
     As illustrated in FIG. 3, it is not necessary for the address 26 to be located in a particular position along the data line, but may be dispersed within the data line, as illustrated at 28, 30 and 32, it only being necessary that sensor cells be assigned to the specific address locations. 
     On a 4&#34; disc, 256 bits/line were provided with a 6 mill bit spacing, including flags, and a 6 mill radial bit length. Many codes may be used, and in a particular construction, an 8-bit Ascii code was employed. 
     An optical floppy disc of the type illustrated in FIG. 1 may be driven continuously and optically scanned to provide the desired output data, as illustrated in FIG. 4 in which the disc 10 is driven at a constant speed by a drive motor 34 and is illuminated by a lamp 36. An optical sensor, such as a Reticon RL-1728H, manufactured by Reticon Corporation, Sunnyvale, Calif., may be driven by a sensor driver 40, to radially scan each radial line as it passes beneath the sensor, so that the sensor 38 constantly loads the information of each line, bit-by-bit, and line-by-line, into a comparison device 44. The comparison device 44 receives an address by way of an input 42 and compares the desired address with the addresses and respective data received from the sensor 38. Upon address agreement, the comparison device 44 feeds the information by way of an output 46 to a utilization device 48, such as a display unit, which may include a decoder. 
     FIG. 5 illustrates a circular data storage format by which twice the bit density may be achieved over radial bit orientation, for a given size of disc. 
     In FIG. 5, an optical floppy disc is generally illustrated at 50 as comprising a plurality of circular tracks, only three of which are illustrated, namely the tracks 52, 54 and 60. 
     As an illustration, the track 52 may contain 200 bits, the track 54 may contain 1000 bits and the track 60 may contain 2000 bits. In order to access the desired information, for example the information between bits 800 and 900 in the track 54, the disc 50 is also provided with an index 62 which defines a zero point for all tracks. The index 62, since the same is radial, may be read by a single photocell, as indicated at 64. As the disc rotates, therefore, the address of the desired information tells the system to enable the sensor cell associated with the track 54, to read all bits on the track 54, to throw away bits 1-799 and bits 901-1000 and maintain bits 800-900. This is accomplished through a simple counting process all referenced to the index 62. 
     FIG. 6 illustrates in an extremely simplified form, a system for reading the information on an optical floppy disc of the type illustrated in FIG. 5. In FIG. 6, an optical floppy disc 50 is constantly rotated by a drive motor 66 and is illuminated by a lamp 68. The index 62 of FIG. 5 is sensed by a separate photocell 70 once each revolution to inform a control circuit 78 of the exact position of the disc. The control circuit 78 receives an address at 76 which includes a track selection, for example the track 54, and the desired bits on the track to inform an internal counter in the control circuit 78. Inasmuch as the track selection circuit 74 only permits that portion of the sensor 72 associated with the track 54 to feed data to the control circuit 78, and as the counter has been instructed to throw away the bits prior to and subsequent to the desired data, only the desired data is output at 80 for further utilization, such as for decoding and display. 
     Up to this point, the optical floppy disc has been a continuously rotating disc, although the disc 10 of FIG. 1 could be read in a start-stop mode of operation in which the disc is moved to the desired address, stopped and read. Also, up to this point, only a digital structure has been discussed. The microdisc, preferably in the form of an optical floppy disc, may also bear graphic information, such as pictures, drawings, alphanumerical information or the like, in which case the start-stop mode is preferred. Referring to FIG. 7, an optical floppy disc 82 is generally illustrated as comprising a plurality of pictures arranged in a plurality of circular bands, here the bands A, B and C, so that the pictures are located at Al-An, Bl-Bn and Cl-Cn, each of which has a peripherally arranged address which lies at a predetermined angle with respect to the physical location thereof, here 180°. The angle is arbitrary and depends upon the particular construction of the reader. The reader, therefore, when addressed, rotates the disc 82, scans for the desired address, and positions the desired graphic information angularly with respect to a projection system. The projection system is a multi-position system, designed for radial movement, depending upon which band is selected, A, B or C, as will be evident from the discussion below. 
     As indicated in FIG. 7, digital data may be interspersed with the graphic information or placed in a separate area on the disc, and formed as in FIG. 1, as indicated at 16, 22, 24. 
     A disc of the type illustrated in FIG. 7 is shown in FIG. 8 in a system which is designed to read all of the types of discs discussed above, depending upon the type of drive employed and the programming provided to a system controller. A start-stop operation is, of course, preferred for the viewer-type optical floppy disc and will be discussed immediately below, followed with a discussion of modifications for reading discs of the type illustrated in FIG. 1 and FIG. 5 with a continuous rotation of such discs. 
     In FIG. 8, an optical floppy disc 82 is illustrated in the environment of a reader which includes both a digital scanner and an optical projection system. 
     As to the scanner, a light source 84 is provided on one side of the disc to direct light through a collimating lens 86 and through the disc 82 for scanning by an optical sensor, such as the aforementioned Reticon RL-1728H, or a Fairchild CCD 110. The sensor 88 is controlled to scan radially of the disc and reads the digital information back to a system controller 90, which operates via a program to control a coarse positioning motor 92, either a d.c. motor or a stepping motor, and a fine or vernier stepping motor 102 for fine positioning. 
     The motor 92 is connected to a shaft 94 which mounts a gear 96 by way of an overrunning clutch 98, and which has a hub (not shown) for clamping the disc 82, in cooperation with the disc clamp (not shown) at 100, as is well known to those skilled in the magnetic diskette art. The clutch may be, for example, a model JB-L-57, manufactured by the Winfred M. Berg Co., East Rockaway, Long Island, N.Y. 
     The vernier stepping motor 102 operates a worm gear 104 which is engaged with teeth 106 of the gear 96 for fine positioning. 
     Referring to the projection system, a light source 108 projects light through the disc 82 and through a projection lens system 112 to image on a viewer screen, projection screen or television camera, symbolically illustrated at 114. The projection lens 112 is positioned to one of a plurality of radial positions, in accordance with the address, by a three-position actuator 116. 
     All of the foregoing operations are under the control of the system controller 90 and a program stored therein. The system controller 90 comprises a sensor driver and video data processing unit 118, motor driver circuits 120, system power supplies 122 and a microprocessor 124, and will be discussed in greater detail below. 
     Suffice it here to say that the data input from a user activates the system controller to cause the motors 92 and 102 to position the disc 88 at a desired location. Then, the light sources 84 and 108 are switched on by the controller (not shown) or the light paths thereof are de-blanked by electromechanical apparatus (not shown) as well known to those skilled in the art, and the digital and/or graphic information is read via the sensor 88 and the projection and viewing apparatus 112, 114. The digital information read by the sensor 88 is processed and output to the user and this information is available in conjunction with the graphic information displayed by the device 114. 
     The scanner apparatus 84, 86, 88 may be replaced by a flying spot type scanner of the type illustrated in FIG. 9 which comprises a light source 126, a lens 128, a mirror 130 which is oscillated at the scan frequency by a servo motor 132, a corrective optics 138 for correcting the variable scan path length, a lens 134 and a photodetector 136. With the flying spot scanner, and in a system for continuously rotating the disc, assuming a disc of the type illustrated in FIG. 1, the scan path may be skewed with respect to the data lines in order to obtain higher speeds. 
     Another flying spot scanner is illustrated in FIG. 10 and has two variations. 
     In the first variation, a constantly rotating pentagonal mirror 140 replaces the servo components 130, 132 and receives a light beam 138 for effecting the scan. 
     In the second variation, a polygonal element 140&#39;, depending on the refractive properties of the material employed, receives a coherent beam 142, as from a laser, and bends the beam, through refraction, prior to the same exiting the element 140&#39;. 
     Referring back to FIG. 8, an optical floppy system was built and operated in which the projection components were not employed. Also, the motor 92 was a continuously operating motor and data of the type illustrated in FIG. 1 was retrieved. The flow charts of FIGS. 11, 12 and 13 illustrate the console command processor operations, the index routine and the data retrieve routine for that system. The block diagram of FIG. 14 complements these flow charts and illustrates the system controller 90 as employed in the test model. It should be pointed out that the test model was operated locally via an ASCII keyboard and remotely via telephone lines. As mentioned above, the flow charts show only portions of the system operation and the entire process is set forth below by way of the program utilized in the controller. 
     Referring to FIGS. 11-14, the console command operations are initiated with a start input to clear the memory and load pointers into the system, as indicated at 144. Directions are then printed at 146 and the system asks for a command at 148. If the command is determined valid at 150, a determination of the correct routine is provided at 154. If the command is not valid, a loop asking for a second command is provided, including a printing of error codes at 152. 
     In this example, the index routine receives a start instruction and the system operates in response to receipt of a flag at 156 to obtain 88 scans from the disc at 158. This scan information is decoded to data 160 and the first 22 tracks are printed as index information 162. The system then prints directions 164 and waits for a second flag 166, the system then delays past the index tracks 168, decodes 88 more scans to data and compiles a cross-referenced table of addresses at 172. At the conclusion of the index routine, a warm start signal is provided back to the command process to initiate a request for another command. Upon receiving a start indication for the data retrieval routine, the system checks for a legal address at 174 and, if the same is not found, a print error code is initiated at 176 and a warm start is again provided to ask for another command at 148. 
     Assuming a correct address, the requested track is obtained at 178, and a retry loop is provided, at 180, if the requested track is not found. 
     The system then checks for parity errors at 182, records such errors in a table 184 and provides the same to check for ASCII data or prices 186. It should be mentioned that this particular system was designed to output ASCII information or digital information which relates to prices of spare parts of equipment, such as farm equipment. 
     If ASCII is output, ASCII characters are printed at 188 and a determination is made at 190 as to whether the entire ASCII information has been obtained. If the ASCII information has been completely obtained, a warm start is sent to the console command processor; if not, the next track is obtained at 192. 
     In a case in which price line information is output, a determination is made as to which price was requested, at 192, and the output data is recovered and the proper price is printed, before a warm start is again indicated. 
     Referring to FIG. 14, in particular, the microprocessor data recovery and timing circuits are illustrated as comprising a plurality of components which are interconnected by way of an 8-bit data bus 196 and a 16-bit address bus 198. These components include a microprocessor 200, a video interface 202, a disc controller 204 for controlling a disc drive 206, a random access memory 208, a telephone interface 210, a sensor 212, driven by a 6φ clock 214, and 8-bit shift register (serial in-parallel out) 220, an operational amplifier 216, an operational amplifier 218, a parallel interface 222 and an ASCII keyboard 224. In addition system timing and power supplies are, of course, included. 
     The following table sets forth the component employed in the structure of FIG. 14, their manufacturers and model numbers. 
     
         ______________________________________REFNO.    NAME             MODEL NO. &amp; MFG.______________________________________200    Microprocessor   Zilog Z-80, Zilog                   Cupertino, California202    Video Interface  IMSAI VIO,                   IMS Associates,                   Inc. California204    Disc Controller  IMSAI DIO,                   IMS Associates,                   Inc. California206    Floppy Disc Unit PerSci, Inc.                   Marina Del Rey,                   California208    Random Access Memory                   Type 2102-IL,  (384 units,49,152 Bytes)                   National Electric                   Co., (NEC), Japan210    Telephone Interface                   D.C.Hayes Telephone                   Interface Card212    SENSOR           RL-17284,                   Reticon Corporation,                   Sunnyvale, California214    60 Clock         Custom Built by Newslog                   International, Inc.,                   Whitewater, Wisconsin216    Op-Amp(High Gain,Low                   CAIOA,  Noise,High Speed)                   Reticon Corporation                   Sunnyvale, California218    Op-Amp(High Speed)                   LM311,                   National Semiconductor                   Santa Clara, California222    Parallel Interface                   IMSAI PIO-6-6,                   IMS Associates,                   Inc. California______________________________________ 
    
     In addition an ASCII keyboard and a S-100 bus system was employed. 
     In a slightly different form, the system was constructed using the following components. 
     
         ______________________________________Quantity  Component______________________________________1      Technical Design Laboratories 280 CPU Card1      IMSAI 8080 Frzme/Power Supply (modified) -2 Vector Graphics 8K,  250 ns Semiconductor Memory4      Digital Research 8K, 250 ns Semiconductor Memory1      Custom Built 3k, 250 ns Semiconductor Memory1      Cromenco 8K EPROM Memory Board1      IMSAI MIO Multiple I/O Board1      Processor Technology 3P + S I/O Card1      Processor Technology VDMI 16 × 64 Video  Display Card1      IMSAI PIO 6--6 Parallel Interface Card1      IMSAI Intelligent Breadboard1      IMSAI VIO 24 × 80 Video Display Card1      Sanyo 14 inch Video Monitor1      IMSAI DIO Disc Controller and Data Separator1      PerSci 277 Dual 8 inch Floppy Disc Drive1      D.C. Hayes Auto Dial/Answer Modem1      Custom Built System Timing Card1      ASCII Keyboard______________________________________ 
    
     In order for one skilled in the art to better understand the invention, the model system discussed above was operated in accordance with the following program. Of course, for different modes of operation, and different types of discs, such as circular format and graphic information, other programs may be used. It should be pointed out that this particular program was set up for 30 rpm or 24 rpm operation of the disc drive and for operation with either IMSAI or NYLAC components. ##SPC1## ##SPC2## ##SPC3## ##SPC4## 
     It was disclosed above that the radially oriented data could be stored skewed so that the data could be scanned such that the sensor could be skewed or a light beam could be radially displaced across the data line within the time of the skew as defined by the speed or rotation of the disc. In addition, we have determined that the data may be stored, generally radially, but extending more specifically in arcuate lines so that the scanner is constructed either in an arcuate form or includes a beam which travels radially and circumferentially, that is in a radially, arcuately directed manner. In other words, the light beam, for a flying spot scanner, would sweep radially and circumferentially so as to scan an arcuate radial line of data. 
     Of course, faster data retrieval is obtained through the use of a constantly rotating disc. Therefore, scanning in accordance with a skewed data format, an arcuate data format or a circular data format is preferred to start-stop operation. It is readily apparent, however, that a continuous rotation cannot be employed for the projection of graphic information unless the projected image is first stored and then reproduced. 
     Although we have described our invention by reference to particular illustrative embodiments thereof, many changes and modifications of the invention may become apparent to those skilled in the art without departing from the spirit and scope of the invention. We therefore intend to include within the patent warranted hereon all such changes and modifications as may reasonably and properly be included within the scope of our contribution to the art.