CA1066949A - Impact line printer having graphics plotting capability - Google Patents
Impact line printer having graphics plotting capabilityInfo
- Publication number
- CA1066949A CA1066949A CA248,713A CA248713A CA1066949A CA 1066949 A CA1066949 A CA 1066949A CA 248713 A CA248713 A CA 248713A CA 1066949 A CA1066949 A CA 1066949A
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- CA
- Canada
- Prior art keywords
- character
- dot
- horizontal
- graphics
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/485—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by the process of building-up characters or image elements applicable to two or more kinds of printing or marking processes
- B41J2/505—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by the process of building-up characters or image elements applicable to two or more kinds of printing or marking processes from an assembly of identical printing elements
- B41J2/515—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by the process of building-up characters or image elements applicable to two or more kinds of printing or marking processes from an assembly of identical printing elements line printer type
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J19/00—Character- or line-spacing mechanisms
- B41J19/14—Character- or line-spacing mechanisms with means for effecting line or character spacing in either direction
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D9/00—Recording measured values
- G01D9/02—Producing one or more recordings of the values of a single variable
- G01D9/04—Producing one or more recordings of the values of a single variable with provision for multiple or alternative recording
- G01D9/06—Multiple recording, e.g. duplicating
- G01D9/08—Multiple recording, e.g. duplicating giving both graphical and numerical recording
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Record Information Processing For Printing (AREA)
Abstract
Abstract of the Disclosure An impact line printer of the type forming alphanumeric characters by printing dots at selected dot positions within a dot matrix is provided with means for selecting a graphics plotting mode of operation. Either the printing mode or the graphics plotting mode of operation is selected on a character-by-character basis. The dot matrix within which alphanumeric characters are printed in the printing mode of operation is expanded, when the graphics plotting mode of operation is selected, to include additional dot positions at which dots may be printed to significantly increase dot resolution.
Description
~66~9 Background and Summary of the Invention The prior art alphanumeric impact line printer described in U.S.
patent No. 3,782,278 issued January 1, 1974, David L. Barnett et al, forms characters by printing dots at selected dot positions within a dot matrix.
A horizontal character line comprises a plurality of adjacent character positions and a fixed blank space horizontally adjacent to each character position to provide a space between printed characters. In addition, a fixed vertical space is provided between lines of printed characters. It is oftentimes desirable to perform graphics plotting functions with impact printers of this type either separately or intermixed with alphanumeric character printing. Plotting with these printers can only be accomplished in a very rudimentary fashion by printing a selected alphanumeric character (for example, the letter "X") at the character position along a horizontal ` character line which is closest to the actual location of the data point to be plotted. This method of plotting is generally unsatisfactory because of the lack of resolution. Resolution is understood in the art to be the number of data points which can be plotted per inch.
It is therefore an obiect of an aspect of this invention to provide an alphanumeric impact line printer in which the user may select either a printing mode or a graphics plotting mode of operation and in which signif-icantly enhanced resolution is provided in the plotting mode.
This object is accomplished in accordance with the illustrated preferred embodiment of this invention by providing logic circuitry responsive to selection of the graphics plotting mode of operation for increasing the number of available dot positions at which dots may be printed to include the space :' ~
' 106694~
between character positions of a horizontal character line as well as the vertical space between adjacent character lines.
By way of added explanation, in accordance with one aspect of this invention there is provided an improved impact printer for printing alphanumeric characters on a flexible print medium, each of said alphanumeric characters being formed at discrete spaced character positions along a - plurality of discrete spaced horizontal character lines by lQ printing dots at selected dot positions within a dot matrix of rows and columns at each desired character position, the impact printer being of the type having a frame; a plurality of aligned print hammers mounted on a hammer ,~., support, each print hammer being associated with a character.
: position along a horizontal character line and each carry-ing a striking means for printing a dot; means movably securing the hammer support to the frame with the print hammers adjacent the flexible print medium; a stationary platen positioned opposite the print hammers and on the opposite side of.the flexible print medium; horizontal stepping means connected to the hammer support for stepping the hammer support and print hammers a discrete number of horizontal step positions across the flexible print medium to align each print hammer with successive adjacent ones of the matrix columns, the discrete number of horizontal step positions being equal to the number of columns within the dot matrix; a plurality of electromagnets immovably secured to the frame, each associated with a single one of the print hammers and each positioned to actuate, when energized, its associated print hammer when that print hammer is in any one of the discrete step ~)66949 positions; and vertical stepping means for vertically advancing the flexible print medium a discrete number of vertical step positions to align the print hammer striking means with successive adjacent ones of the matrix rows of a horizontal character line and for vertically advancing the flexible print medium an increased increment between the last matrix row and the first matrix row respectively ~
of adjacent character lines to create a space therebetween, :
wherein the improvement comprises: input/output control means for receiving ASCII-coded character information and graphics dot data from an external source, said input/
output control means.including mode select means for designating a graphics plotting mode of operation and for issuing a signal indicative of the type of information being ~
received from the external source; character generation and ~ .
storage means, including read-only memory means for storing matrix row and column information relating to an alpha-numeric character set employed by the printer, said character generation and storage means being connected to said input/
output control means for storing ASCII-coded character information and graphics dot data to be printed on a given horizontal character line; and operation sequence control-ling means connected to said input/output control means and to said character generation and storage means, said operation sequence controlling means being responsive to the signal issued by said input/output control means indicating that graphics dot data is being received from the external source for increasing the number of horizontal step posi-tions to which the print hammers are stepped and for addressing said character generation and storage means on a dot row basis and for receiving therefrom dot information ~ -2a-~, 1()669q~9 pertaining to all the dots to be printed on a current horizontal dot row, said operation sequence controlling means thereupon being operative for selectively energizing the electromagnets for printing that dot information.
_scription of the Drawings Figure 1 is a plot of the parabolic curve Y =
7.45-X made with a prior art printer.
Figure 2 is a plot of the parabolic curve Y =
7.45-X made with a printer/plotter constructed according to the present invention.
Figure 3 is a diagram illustrating the dot position matrices associated with three adjacent character positions along a horizontal character line when the printer is operating in the alphanumeric printing mode.
Figure 4 is a diagram illustrating how the number of dot positions associated with the three character positions illustrated in Figure 3 is increased when the graphics plotting mode of operation is selected.
Figure 5 is a detailed block diagram of logic circuitry for controlling operation of the printer/plotter in accordance with the present invention.
Description of the Preferred Embodiment Operation of the present printer/plotter in the printing mode is basically the same as described in the referenced patent. As illustrated -2b-~ .
in Figure 3 of the present application, each discrete character position along a horizontal character line comprises a dot matrix of rows and columns, a 5 x 7 dot matrix being shown as exemplary. A space is provided between ad~jacent horizontal character rositions. hs shown and described in the referenced patent, a horizontal bank of print hammers is employed ` for printing dots at selected dot positions of each dot matrix. Each character position is associated with just one of the print hammers com-prising the bank. The print hammers are simultaneously stepped horizontally ~ -to sequentially align each hammer with each of the matrix columns of the character position associated with that hammer. In the case of a 5-column dot matrix, the print hammer bank is stepped five times. The total horizon-tal excursion of the print hammer bank in the printing mode is shown in Figure 3 hereof. The hammers are selectively actuated at each step to print the appropriate dots. After the hammer bank has completed stepping through each matrix column position, a paper feed motor steps the paper an incre-mental distance corresponding to the distance between adjacent rows of the dot matrices. The print hammers are again stepped through each matrix column position to facilitate printing of dots at the appropriate dot matrix column positions of the new row. This procedure is repeated for all dot matrix rows until all the dots associated with a line of characters have been printed. At this point the paper feed motor steps the paper an incremental distance greater than the distance between dot matrix rows to create a space between printed lines, and the next line of printed characters is constructed in the manner just described.
An attempt to plot graphics data points using the printer described in the referenced pat~ent by printing an alphanumeric character at the character position closest to the actual location of each graphics data point results in the plot illustrated in Figure 1. Such a plot is quite unsatis-factory for most plotting operations because of the discontinuities resulting from the inability of the printer to print a single dot at or very close to . . : : . . . : . .
10669~9 the actual location of each graphics data point to be plotted. This serious drawback is overcome by the present invention which facilitates plots of the type illustrated in Figure 2.
Referring now to Figure 4 of the prese~t application, there is shown a diagram of how the dot matrices representing the two character positions illustrated in Figure 3 are expanded, when the graphics plotting mode of operation is selected, to provide dot positions at which dots may be printed within the horizontal space between character positions and within the vertical space between character lines. By means of logic circuitry descrihed in detail hereinafter these additional dot positions, as well as the dot positions within the 5 x 7 dot matrix at each character position, are each separately addressable in the graphics plotting mode of operation to provide greatly enhanced resolution such that a given data point can be plotted within a few thousandths of an inch of its actual location. If desired, the dot position density of the basic character position matrix~nlay be increased, and the horizontal space between character positions, as well as the vertical space between character lines, may be arranged to include additional dot positions to provide an even greater degree of resolution in the graphics plotting mode of operation. For purposes of illustration, as indicated by Fi~ures 3 and 4, a 5 x 7 dot matrix has been chosen, and the horizont;al space between adjacent character positions has been divided to include two additional dot columns. The total horizontal excursion oF the print hammer bank is increased in the graphics plotting mode of operatlon, as shown in Figure 4, to allow dots to be printed at the selected dot positions within these two additional dot columns The vertical space between adjacent character lines has been divided to include three additional dot rows, also as illustrated in Figure 4.
- Referring now to Figure 5 of the present application, t:here is shown a block diagram of logic circuitry for controlling the printer in both the alphanumeric printing and graphics plotting modes of operation. The illus-_4_ , ` ' ' .
0669~9 trated logic blocks may be constructed in accordance with any of the techniques well known to those persons skil1ed in the art of logic implementation. An input/output control unit 100 receives print ;~
commands5 ASCII-coded character infornlation to be printed9 and graphics dot data to be plotted via a multi-bit bus 116. The source of such informa-` tion is typically a computer or a desk-top calculator. A mode select line 118 is provided for signalling the input/output control unit 100 on a char-acter-by-character basis whether the information received on bus 116 is ASCII-coded character information or graphics dot data. hn alternative method of distinguishing between ASCII-coded character information and graphics dot data is to provide an ASCII control code to specify that all information subsequently received will be graphics dot data. Receipt of a second ASCIJ
control code would then signal the end of graphics dot data and the beginning of ASCII-coded character information. A multi-bit bus 108 is provided to transmit ASCII-coded character information and graphics dot data from input/
output control unit 100 to a character generation and storage unit 300.
Character generation and storage unit 300 includes a storage register fol^
storing information relative to a full character line which may comprise alphanumeric characters and/or graphics dot data. A graphics bit line 110 is set by input/output control unit 100 to indicate to character generation and storage unit 300 that information being transmitted on bus 10~ is graphics dot data.
A multi-bit command bus 102 transmits hardware commands to an operation sequence controller 200. In response to such commands operation sequence controller 200 appropriately actuates a bank of hammer solenoids 21, a paper feed motor 23, and a hammer stepper 22, all of which are shown and described in detail in the referenced patent. A multi-l)it status blls 104 provides an indication of the current operational status of the various components of the printer system to input/output control unit 100. A graphics control line 106 carries a signal from input/output control unit 100 to oper-:' . ~
`-` 1066949 ation sequence controller 200 indicating whether the current dot row (i.e. the dot row about to be printed) contains graphics dot data. If it does, operation sequence controller 200 serves to increase 1:he excursion of the hammer bank provided by hammer stepper 22 as descril)ed above. This facilitates selectively printing graphics dot data within the horizontal space between adjacent character positions. The two extra columns of dot positions provided by the increased excurs'on of the hammer bank are ignored at those character positions along a horizontal character line at which alphanumeric characters are to be printed. This results in printing alphanumeric characters within the normal 5 x 7 dot matrix at the desired character positions while permitting graphics dot data to be printed within an expanded dot matrix at other character positions along the same hori-zontal character line. Alphanumeric characters may be printed at locations offset from the discrete character positions by selecting the graphics plotting mode of operation, in which dot data is supplied for each individual dot position at which dots must be printed to form the desired offset character. In the event it is desired to print graphics dot data on one or more of the three dot rows provided within the vertical space between a given two adjacent character lines, a signal on graphics control line 106 indicates to operation sequence controller 200 tha1; paper feed mctor 23 is to be stepped in dot row increments between those two character lines.
Character generation and storage circuil; 300 incl~des a read-only memory which contains the matrix row and column dot information relating to each character of a chosen alphanumeric character set employed by the printer. When printing the dots associated with a given alphanumeric character, the read-only memory is addressed via a mull;i-bit address line 112 on a dot row basis by operation seguence controller 200 to extract the dot information pertaining to all five of the dot columns of the character position at which the character is to be printed. This information is trans-. . .
- .
... : . . .. : :
106~949 mitted on a dot data line 114 back to operation sequence controller 200, which then appropriately actuates hammer stepper 22 and the hammer solenoids 21. Graphics dot data to be printed on a particular dot row is similarly supplied by character generation and storage unit 200 to operal:ion sequence controller 200, except that the dot data is not retrieved from the read- :-only memory but rather from the storage register contained within character generation and storage unit 300. All the dot information relative to the current dot row is transmitted via dot data line 114 for accumulat.ion hy operation sequence controller 200 prior to being printed.
While the present invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may he made therein without departing from the spirit and scope of the invention.
, .
.
, ~
patent No. 3,782,278 issued January 1, 1974, David L. Barnett et al, forms characters by printing dots at selected dot positions within a dot matrix.
A horizontal character line comprises a plurality of adjacent character positions and a fixed blank space horizontally adjacent to each character position to provide a space between printed characters. In addition, a fixed vertical space is provided between lines of printed characters. It is oftentimes desirable to perform graphics plotting functions with impact printers of this type either separately or intermixed with alphanumeric character printing. Plotting with these printers can only be accomplished in a very rudimentary fashion by printing a selected alphanumeric character (for example, the letter "X") at the character position along a horizontal ` character line which is closest to the actual location of the data point to be plotted. This method of plotting is generally unsatisfactory because of the lack of resolution. Resolution is understood in the art to be the number of data points which can be plotted per inch.
It is therefore an obiect of an aspect of this invention to provide an alphanumeric impact line printer in which the user may select either a printing mode or a graphics plotting mode of operation and in which signif-icantly enhanced resolution is provided in the plotting mode.
This object is accomplished in accordance with the illustrated preferred embodiment of this invention by providing logic circuitry responsive to selection of the graphics plotting mode of operation for increasing the number of available dot positions at which dots may be printed to include the space :' ~
' 106694~
between character positions of a horizontal character line as well as the vertical space between adjacent character lines.
By way of added explanation, in accordance with one aspect of this invention there is provided an improved impact printer for printing alphanumeric characters on a flexible print medium, each of said alphanumeric characters being formed at discrete spaced character positions along a - plurality of discrete spaced horizontal character lines by lQ printing dots at selected dot positions within a dot matrix of rows and columns at each desired character position, the impact printer being of the type having a frame; a plurality of aligned print hammers mounted on a hammer ,~., support, each print hammer being associated with a character.
: position along a horizontal character line and each carry-ing a striking means for printing a dot; means movably securing the hammer support to the frame with the print hammers adjacent the flexible print medium; a stationary platen positioned opposite the print hammers and on the opposite side of.the flexible print medium; horizontal stepping means connected to the hammer support for stepping the hammer support and print hammers a discrete number of horizontal step positions across the flexible print medium to align each print hammer with successive adjacent ones of the matrix columns, the discrete number of horizontal step positions being equal to the number of columns within the dot matrix; a plurality of electromagnets immovably secured to the frame, each associated with a single one of the print hammers and each positioned to actuate, when energized, its associated print hammer when that print hammer is in any one of the discrete step ~)66949 positions; and vertical stepping means for vertically advancing the flexible print medium a discrete number of vertical step positions to align the print hammer striking means with successive adjacent ones of the matrix rows of a horizontal character line and for vertically advancing the flexible print medium an increased increment between the last matrix row and the first matrix row respectively ~
of adjacent character lines to create a space therebetween, :
wherein the improvement comprises: input/output control means for receiving ASCII-coded character information and graphics dot data from an external source, said input/
output control means.including mode select means for designating a graphics plotting mode of operation and for issuing a signal indicative of the type of information being ~
received from the external source; character generation and ~ .
storage means, including read-only memory means for storing matrix row and column information relating to an alpha-numeric character set employed by the printer, said character generation and storage means being connected to said input/
output control means for storing ASCII-coded character information and graphics dot data to be printed on a given horizontal character line; and operation sequence control-ling means connected to said input/output control means and to said character generation and storage means, said operation sequence controlling means being responsive to the signal issued by said input/output control means indicating that graphics dot data is being received from the external source for increasing the number of horizontal step posi-tions to which the print hammers are stepped and for addressing said character generation and storage means on a dot row basis and for receiving therefrom dot information ~ -2a-~, 1()669q~9 pertaining to all the dots to be printed on a current horizontal dot row, said operation sequence controlling means thereupon being operative for selectively energizing the electromagnets for printing that dot information.
_scription of the Drawings Figure 1 is a plot of the parabolic curve Y =
7.45-X made with a prior art printer.
Figure 2 is a plot of the parabolic curve Y =
7.45-X made with a printer/plotter constructed according to the present invention.
Figure 3 is a diagram illustrating the dot position matrices associated with three adjacent character positions along a horizontal character line when the printer is operating in the alphanumeric printing mode.
Figure 4 is a diagram illustrating how the number of dot positions associated with the three character positions illustrated in Figure 3 is increased when the graphics plotting mode of operation is selected.
Figure 5 is a detailed block diagram of logic circuitry for controlling operation of the printer/plotter in accordance with the present invention.
Description of the Preferred Embodiment Operation of the present printer/plotter in the printing mode is basically the same as described in the referenced patent. As illustrated -2b-~ .
in Figure 3 of the present application, each discrete character position along a horizontal character line comprises a dot matrix of rows and columns, a 5 x 7 dot matrix being shown as exemplary. A space is provided between ad~jacent horizontal character rositions. hs shown and described in the referenced patent, a horizontal bank of print hammers is employed ` for printing dots at selected dot positions of each dot matrix. Each character position is associated with just one of the print hammers com-prising the bank. The print hammers are simultaneously stepped horizontally ~ -to sequentially align each hammer with each of the matrix columns of the character position associated with that hammer. In the case of a 5-column dot matrix, the print hammer bank is stepped five times. The total horizon-tal excursion of the print hammer bank in the printing mode is shown in Figure 3 hereof. The hammers are selectively actuated at each step to print the appropriate dots. After the hammer bank has completed stepping through each matrix column position, a paper feed motor steps the paper an incre-mental distance corresponding to the distance between adjacent rows of the dot matrices. The print hammers are again stepped through each matrix column position to facilitate printing of dots at the appropriate dot matrix column positions of the new row. This procedure is repeated for all dot matrix rows until all the dots associated with a line of characters have been printed. At this point the paper feed motor steps the paper an incremental distance greater than the distance between dot matrix rows to create a space between printed lines, and the next line of printed characters is constructed in the manner just described.
An attempt to plot graphics data points using the printer described in the referenced pat~ent by printing an alphanumeric character at the character position closest to the actual location of each graphics data point results in the plot illustrated in Figure 1. Such a plot is quite unsatis-factory for most plotting operations because of the discontinuities resulting from the inability of the printer to print a single dot at or very close to . . : : . . . : . .
10669~9 the actual location of each graphics data point to be plotted. This serious drawback is overcome by the present invention which facilitates plots of the type illustrated in Figure 2.
Referring now to Figure 4 of the prese~t application, there is shown a diagram of how the dot matrices representing the two character positions illustrated in Figure 3 are expanded, when the graphics plotting mode of operation is selected, to provide dot positions at which dots may be printed within the horizontal space between character positions and within the vertical space between character lines. By means of logic circuitry descrihed in detail hereinafter these additional dot positions, as well as the dot positions within the 5 x 7 dot matrix at each character position, are each separately addressable in the graphics plotting mode of operation to provide greatly enhanced resolution such that a given data point can be plotted within a few thousandths of an inch of its actual location. If desired, the dot position density of the basic character position matrix~nlay be increased, and the horizontal space between character positions, as well as the vertical space between character lines, may be arranged to include additional dot positions to provide an even greater degree of resolution in the graphics plotting mode of operation. For purposes of illustration, as indicated by Fi~ures 3 and 4, a 5 x 7 dot matrix has been chosen, and the horizont;al space between adjacent character positions has been divided to include two additional dot columns. The total horizontal excursion oF the print hammer bank is increased in the graphics plotting mode of operatlon, as shown in Figure 4, to allow dots to be printed at the selected dot positions within these two additional dot columns The vertical space between adjacent character lines has been divided to include three additional dot rows, also as illustrated in Figure 4.
- Referring now to Figure 5 of the present application, t:here is shown a block diagram of logic circuitry for controlling the printer in both the alphanumeric printing and graphics plotting modes of operation. The illus-_4_ , ` ' ' .
0669~9 trated logic blocks may be constructed in accordance with any of the techniques well known to those persons skil1ed in the art of logic implementation. An input/output control unit 100 receives print ;~
commands5 ASCII-coded character infornlation to be printed9 and graphics dot data to be plotted via a multi-bit bus 116. The source of such informa-` tion is typically a computer or a desk-top calculator. A mode select line 118 is provided for signalling the input/output control unit 100 on a char-acter-by-character basis whether the information received on bus 116 is ASCII-coded character information or graphics dot data. hn alternative method of distinguishing between ASCII-coded character information and graphics dot data is to provide an ASCII control code to specify that all information subsequently received will be graphics dot data. Receipt of a second ASCIJ
control code would then signal the end of graphics dot data and the beginning of ASCII-coded character information. A multi-bit bus 108 is provided to transmit ASCII-coded character information and graphics dot data from input/
output control unit 100 to a character generation and storage unit 300.
Character generation and storage unit 300 includes a storage register fol^
storing information relative to a full character line which may comprise alphanumeric characters and/or graphics dot data. A graphics bit line 110 is set by input/output control unit 100 to indicate to character generation and storage unit 300 that information being transmitted on bus 10~ is graphics dot data.
A multi-bit command bus 102 transmits hardware commands to an operation sequence controller 200. In response to such commands operation sequence controller 200 appropriately actuates a bank of hammer solenoids 21, a paper feed motor 23, and a hammer stepper 22, all of which are shown and described in detail in the referenced patent. A multi-l)it status blls 104 provides an indication of the current operational status of the various components of the printer system to input/output control unit 100. A graphics control line 106 carries a signal from input/output control unit 100 to oper-:' . ~
`-` 1066949 ation sequence controller 200 indicating whether the current dot row (i.e. the dot row about to be printed) contains graphics dot data. If it does, operation sequence controller 200 serves to increase 1:he excursion of the hammer bank provided by hammer stepper 22 as descril)ed above. This facilitates selectively printing graphics dot data within the horizontal space between adjacent character positions. The two extra columns of dot positions provided by the increased excurs'on of the hammer bank are ignored at those character positions along a horizontal character line at which alphanumeric characters are to be printed. This results in printing alphanumeric characters within the normal 5 x 7 dot matrix at the desired character positions while permitting graphics dot data to be printed within an expanded dot matrix at other character positions along the same hori-zontal character line. Alphanumeric characters may be printed at locations offset from the discrete character positions by selecting the graphics plotting mode of operation, in which dot data is supplied for each individual dot position at which dots must be printed to form the desired offset character. In the event it is desired to print graphics dot data on one or more of the three dot rows provided within the vertical space between a given two adjacent character lines, a signal on graphics control line 106 indicates to operation sequence controller 200 tha1; paper feed mctor 23 is to be stepped in dot row increments between those two character lines.
Character generation and storage circuil; 300 incl~des a read-only memory which contains the matrix row and column dot information relating to each character of a chosen alphanumeric character set employed by the printer. When printing the dots associated with a given alphanumeric character, the read-only memory is addressed via a mull;i-bit address line 112 on a dot row basis by operation seguence controller 200 to extract the dot information pertaining to all five of the dot columns of the character position at which the character is to be printed. This information is trans-. . .
- .
... : . . .. : :
106~949 mitted on a dot data line 114 back to operation sequence controller 200, which then appropriately actuates hammer stepper 22 and the hammer solenoids 21. Graphics dot data to be printed on a particular dot row is similarly supplied by character generation and storage unit 200 to operal:ion sequence controller 200, except that the dot data is not retrieved from the read- :-only memory but rather from the storage register contained within character generation and storage unit 300. All the dot information relative to the current dot row is transmitted via dot data line 114 for accumulat.ion hy operation sequence controller 200 prior to being printed.
While the present invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may he made therein without departing from the spirit and scope of the invention.
, .
.
, ~
Claims
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An improved impact printer for printing alphanumeric characters on a flexible print medium, each of said alpha-numeric characters being formed at discrete spaced character positions along a plurality of discrete spaced horizontal character lines by printing dots at selected dot positions within a dot matrix of rows and columns at each desired character position, the impact printer being of the type having a frame; a plurality of aligned print hammers mounted on a hammer support, each print hammer being associated with a character position along a horizontal character line and each carrying a striking means for print-ing a dot; means movably securing the hammer support to the frame with the print hammers adjacent the flexible print medium; a stationary platen positioned opposite the print hammers and on the opposite side of the flexible print medium; horizontal stepping means connected to the hammer support for stepping the hammer support and print hammers a discrete number of horizontal step positions across the flexible print medium to align each print hammer with successive adjacent ones of the matrix columns, the discrete number of horizontal step positions being equal to the number of columns within the dot matrix; a plurality of electromagnets immovably secured to the frame, each asso-ciated with a single one of the print hammers and each positioned to actuate, when energized, its associated print hammer when that print hammer is in any one of the discrete step positions; and vertical stepping means for vertically advancing the flexible print medium a discrete number of vertical step positions to align the print hammer striking means with successive adjacent ones of the matrix rows of a horizontal character line and for vertically advancing the flexible print medium an increased increment between the last matrix row and the first matrix row respectively of adjacent character lines to create a space therebetween, wherein the improvement comprises: input/output control means for receiving ASCII-coded character information and graphics dot data from an external source, said input/
output control means including mode select means for designating a graphics plotting mode of operation and for issuing a signal indicative of the type of information being received from the external source; character generation and storage means, including read-only memory means for storing matrix row and column information relating to an alphanumeric character set employed by the printer, said character generation and storage means being connected to said input/
output control means for storing ASCII-coded character information and graphics dot data to be printed on a given horizontal character line; and operation sequence control-ling means connected to said input/output control means and to said character generation and storage means, said operation sequence controlling means being responsive to the signal issued by said input/output control means indicating that graphics dot data is being received from the external source for increasing the number of horizontal step positions to which the print hammers are stepped and for addressing said character generation and storage means on a dot row basis and for receiving therefrom dot information pertaining to all the dots to be printed on a current horizontal dot row, said operation sequence controlling means thereupon being operative for selectively energizing the electromagnets for printing that dot information.
output control means including mode select means for designating a graphics plotting mode of operation and for issuing a signal indicative of the type of information being received from the external source; character generation and storage means, including read-only memory means for storing matrix row and column information relating to an alphanumeric character set employed by the printer, said character generation and storage means being connected to said input/
output control means for storing ASCII-coded character information and graphics dot data to be printed on a given horizontal character line; and operation sequence control-ling means connected to said input/output control means and to said character generation and storage means, said operation sequence controlling means being responsive to the signal issued by said input/output control means indicating that graphics dot data is being received from the external source for increasing the number of horizontal step positions to which the print hammers are stepped and for addressing said character generation and storage means on a dot row basis and for receiving therefrom dot information pertaining to all the dots to be printed on a current horizontal dot row, said operation sequence controlling means thereupon being operative for selectively energizing the electromagnets for printing that dot information.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US56601575A | 1975-04-07 | 1975-04-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1066949A true CA1066949A (en) | 1979-11-27 |
Family
ID=24261097
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA248,713A Expired CA1066949A (en) | 1975-04-07 | 1976-03-22 | Impact line printer having graphics plotting capability |
Country Status (4)
| Country | Link |
|---|---|
| CA (1) | CA1066949A (en) |
| DE (1) | DE2613643A1 (en) |
| FR (1) | FR2306835A1 (en) |
| GB (1) | GB1542447A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4213714A (en) * | 1977-11-01 | 1980-07-22 | General Electric Company | Printer having variable character density |
| US4364024A (en) * | 1979-12-07 | 1982-12-14 | International Business Machines Corporation | Signature presentation method and apparatus |
| FR2504454B1 (en) * | 1981-04-24 | 1987-06-05 | Widmer Michel | PRINTER FOR CHECKS, TICKETS AND NEWSPAPERS OF THE DAY WITHIN A FINANCIAL TRANSACTION AUTOMATION |
| JPS5961277A (en) * | 1982-09-29 | 1984-04-07 | Toshiba Corp | Forming device of pattern |
| FR2554616B1 (en) * | 1983-11-04 | 1987-06-05 | Sintra Alcatel Sa | MIXED REPRODUCTION METHOD AND DEVICE |
-
1976
- 1976-03-12 GB GB1000976A patent/GB1542447A/en not_active Expired
- 1976-03-22 CA CA248,713A patent/CA1066949A/en not_active Expired
- 1976-03-31 DE DE19762613643 patent/DE2613643A1/en active Pending
- 1976-04-05 FR FR7609802A patent/FR2306835A1/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| FR2306835A1 (en) | 1976-11-05 |
| DE2613643A1 (en) | 1976-10-14 |
| GB1542447A (en) | 1979-03-21 |
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