GB2055010A - Image reproduction equipment - Google Patents

Abstract

To record on a single sheet (9) both a picture image and alphanumeric characters, each character to be recorded is stored (24) in the form of signals representing a multi-column pattern of dots which make up that character. Signals derived in synchronism with the scanning of successive lines on the recording sheet are applied to circuits (19, 20, 23, 25) to derive a column address signal for the character store (24), which is also addressed with a data signal representative of a selected character (32). In this way, signals corresponding to a selected column of the required character are taken from store and are applied to a selector circuit which also receives the picture signals and applies either the picture signals or the character signals to the recording head. <IMAGE>

Description

SPECIFICATION Image reproduction equipment This relates to recording on a single recording sheet from both a source of picture signals and a source of signals representing standard characters, such as alphanumeric characters.

According to the invention, such recording is effected by storing for each character to be recorded data defining a multi-column pattern of dots which make up that character in the recorded image, causing a recording head to scan a recording surface in a succession of parallel lines, addressing the character data store with a coded data signal representative of a selected character and with a column address signal generated in synchronism with the line scanning of the recording surface and defining a required column of dots for the selected character; and, during the scanning of the recording surface, applying to the recording head both a signal representing the picture data for the line which is being recorded and a signal derived from the store in accordance with the said character-selecting signals and column address signal and representing the dot pattern for the required column of the selected character. The invention also relates to apparatus for carrying the said method into effect.

In the preferred form, the apparatus also serves for register mark generation, the register mark data being stored in a separate store; the character store and the register mark store are addressed in parallel with a binary signal of which one digit serves to select one store or the other.

The register mark may occupy a single picture element in a single scanning line.

In order that the invention may be better understood, one example of apparatus embodying the invention will now be described with reference to the accompanying drawings, in which: Figure 1 illustrates a character recorded by a method embodying the invention; Figure 2 shows a register mark recorded to the same scale as the character of Figure 1; and Figure 3 illustrates apparatus for carrying the method embodying the invention into effect.

In Figure 1 , the numeral 7 is represented by dots in an 8x6 matrix. For this numeral, only five columns are used and only seven rows. In this example, if a scanning pitch of 200/inch is in use (each scanning line being 1/8 mm wide) four scanning lines, each of width a, are required to reproduce one character dot, the dot occupying a column of width b. In a similar way, in each such scanning line the dot length is equal to four picture elements. At scanning pitches of 400 and 600 lines/inch, eight and tweive lines respectively are required for each dot of the character.

In the apparatus which is to be described register marks are recorded in addition to the alpha-numerical characters. For register marks, a finer resolution of the dot pattern is required. For this reason a larger memory store is used, giving a dot size of approximately 1/8 mm.

Turning now to Figure 3, an exposing drum 8, carrying a photosensitive sheet 9, is rotated by a motor 10. On the same shaft are two discs, a first disc 11 providing a signal once in each revolution of the drum, and a second disc 12 constituting an incremental encoder providing eight clock pulses per millimeter of drum circumference. A recording head 1 3 comprising a modulator 14 and light source 1 5 is mounted on a lead screw 1 6 rotated by a driving unit 1 7 under the control of pulses from the disc 11. The pulses from the incremental encoder are counted in a row address counter 1 8.

The pulses from the disc 11 are passed through a scan pitch counter 1 9 which has no effect on the pulse rate for a scanning pitch of 200 lines/inch and divides by two and three respectively for scanning pitches of 400 and 600 lines/inch. The pulses from the counter 19 are counted in a line counter 20. They are also applied to a character dot pitch counter 23 with a division of four. The circuit 23 provides one pulse every 4 lines (at 200 lines per inch); thus it provides one pulse for each dot-width or character column of travel of the recording head. These column address pulses are applied to a character column counter 25.The counter 25 supplies the memory 24 with a 3-bit signal representing the column address and also divides the incoming pulses by eight to supply to a character address counter 36 a pulse for each completed character width. In fact, the character width is only 6 columns, the remaining two lines being used for spaces between characters.

A delay counter 22 also receives the pulses from the disc 12, as well as the reset pulses derived from the disc 11.

Date representing the dot patterns which define all the characters which may be required is stored in a character memory store 24, each character being represented by signals corresponding to points defining the character in a matrix of rows and columns. Register mark data is stored in a store 26.

Seven-bit signals provided on a character data bus 28 define each required character (or register mark) in turn. The signals are temporarily stored in a character buffer store 30. From the store a 6-bit address signal is applied by way of line 32 both to the character memory store 24 and the register mark store 26. This enables the selection of one of up to 64 characters in the character memory store and can also be used to select one of 64 register mark "characters" although only one form of register mark is shown in Figure 2 and only this mark and a "negative" thereof are used in the system which is being described.

A further 1-bit signal on line 34 is used as a switching bit to call up alphanumeric or register mark data from their respective stores. This bit is also applied to the row address counter 1 8 for use in the selection of different row and line counting rates, in particular to change the address rate when switching from character to register mark information.

The character address signal applied to the store 24, and the column address signal from the column counter 25, also applied to the store 24, together select signals corresponding to the required column of a dot pattern corresponding to the required character. It will be appreciated that for each revolution of the drum, a single column of each of a large number of dot patterns is selected, and this selection continues through a number of scanning lines until this column is complete. The remaining columns of the same characters are then selected in succeeding revolutions of the exposing drum; again. to complete each column a number of scanning lines is necessary.

The delay counter 22 sets the physical position of the characters around the drum circumference.

It is reset to zero in each revolution by the reset pulses derived from the disc 11. It then counts the grating line pulses from the incremental encoder disc 12 until a present value is reached. This preset value represents the point determined for the character information to be output on to film.

At this point the row address counter 18 is enabled, and one line of character dot data is output on to film.

The character address counter 36, fed from the character column counter 25, steps the selection of characters from the buffer memory 30. This counter thus controls character positions horizontally along the drum.

The register mark store 26 is similarly addressed, except that a higher resolution is required because the mark can be anywhere in the matrix. For this reason, the store 26 receives a 5bit line address signal from line counter 20 and a 2-bit row address signal from counter 18.

Eight-bit signals from the store 24 or the store 26 (whichever is selected) are multiplexed into serial form by an 8-to-1 line multiplexer 38, the output signals from which are combined with the analogue picture signal; following amplification in an amplifier 40, the resulting signal is applied to the modulator 14 to control the intensity of the light beam reaching the recording sheet 9.

The characters exposed on to the recording surface on the exposing drum may, for example, represent a trade house name to be present in the final reproduction or may represent information for an operator responsible for preparing the final reproduction. As an example, these characters could be used to identify three colour separations by printing on them "cyan", "magenta" and "yellow", respectively; or they may record the settings of various controls on the apparatus by means of which the colour separations were made. Problems can exist where separations are not properly identified. For example at the printing stage considerable expense can be involved in rectifying and/or having to reproduce prints which have been produced from the wrong separations.

The use of the present invention can obviate these problems.

It will be appreciated that in Figure 3, the supply of trains of analogue picture signals, each train corresponding to one line of the original, is synchronised with the rotation of the drum 8, and that the supply of character-coded signals to the buffer memory 30 is similarly synchronised with the drum rotation.

Claims (8)

1. A method of recording on a single recording sheet from both a source of picture signals and a source of signals representing standard characters, comprising storing for each character to be recorded data defining a multi-column pattern of dots which make up that character in the recorded image, causing a recording head to scan a recording surface in a succession of parallel lines, addressing the character data store with a data signal representative of a selected character and with a column address signal generated in synchronism with the line scanning of the recording surface and defining a required column of dots for the selected character; and, during the scanning of the recording surface, applying to the recording head both a signal representing the picture data for the line which is being recorded and a signal derived from the store in accordance -Nith the said character-selecting signal and the column address signal and representing the dot pattern for the required column of the selected character.

2. A method in accordance with claim 1 , for additionally recording on the recording sheet a register mark occupying a fraction of the area occupied by a standard character, comprising storing data defining register marks and addressing the register mark store with a coded data signal representative of the required register mark and with an address signal generated in synchronism with the line scanning of the recording surface and defining the line in which the register mark is to be recorded; and, during the scanning of the recording surface, applying to the said recording head the signal derived from the register mark store.

3. Apparatus for recording on a single recording sheet from both a source of picture signals and a source of signals representing standard characters, comprising: a recording scanner having a recording head to which the signals for recording are applied; a source of picture signals for application to the recording head; a store of signals representing standard characters, each character being represented by a set of signals which correspond to the points in a characterrepresenting matrix of rows and columns; a source of signals defining required characters, connected to address the store of standard characters with coded data signals representative of the selected characters; means controlled in synchronism with the operation of the recording scanner to generate a column address signal corresponding to the line scanning of the recording surface, and applying the column address signal to the character data store; the recording head receiving, during the scanning of the recording surface, both signals representing the picture data and signals derived from the character data store.

4. Apparatus in accordance with claim 3, further comprising a store of signals representing register marks, each mark being represented by a set of signals which correspond to points in a matrix of rows and columns, representing the said mark; and including a source of signals defining required register marks, connected to address the register marks store; the means which generates a column address signal applying that signal to the register mark store, whereby the recording head receives, during the scanning of the recording surface, register mark signals in addition to the picture signals and the signals derived from the character data store.

5. Apparatus in accordance with claim 3, in which in response to the application of a selected character-representing signal and a column address signal, bit-representing signals corresponding to the points in a column of the character matrix are applied in parallel to a parallel-to-serial converter, from which they are applied to the recording head in series.

6. Apparatus in accordance with claim 3,4 or 5, further comprising means for generating a succession of signals each of which corresponds to one column-width of the characters to be printed; a character column counter for generating a column address signal for application to the character store, a further counter responsive to the column-representing signals, and a buffer memory connected to receive coded characterrepresenting signals for addressing the character store, the replacement of characters in the said memory being controlled by the said further counter.

7. Apparatus for recording on a single recording sheet from both a source of picture signals and a source of signals representing standard characters, substantially as herein described with reference to the accompanying drawings.

8. A method of recording on a single recording sheet from both a source of picture signals and a source of signals representing standard characters, substantially as herein described.