JPH0215392B2 - - Google Patents

Abstract

1. A printer operating in accordance with electrostatic principles, in which, in dependence upon an item of information to be printed, charge images of the characters which are to be printed are produced on an intermediate carrier which rotates at a constant speed, in which these charge images are developed with the aid of toner and the toner images of the characters to be printed so produced, are reprinted on to a data carrier in a reprinting station, the data carrier being moved through the reprinting station by a feeding device, and in which after reprinting, the toner images are fixed in a fixing station, characterised in that a compressing circuit (KS) is provided which arranges the information to be printed which is presented linewise in such a way that blank lines (LZ) are omitted and only lines of charge images which contain characters succeed one another on the intermediate carrier (ZT) ; that a store (SP2) is provided, in which the actual line spacing as presented prior to the compressing operation, is contained as feed information in respect of the lines of charge images directly following one another on the intermediate carrier (ZT) after the compressing operation ; that the feed device (VE) is provided with a rapid feed ; that a control unit (VS) is provided, to which the feed information is supplied and which switches on the rapid feed when the actual line spacing (n) from the line of toner images which has just been reprinted from the intermediate carrier (ZT) on to the data carrier (AT), to the next line containing toner images is > 1, and which switches off the rapid feed when the next line of toner images reaches the reprinting station on the intermediate carrier (ZT).

Description

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, a charge image of a symbol to be printed in relation to print information is created on an intermediate support rotating at a constant speed, and this charge image is developed using a toner to form a toner. This toner image is transferred onto a recording support in a transfer section, the recording support is moved within the transfer section by a feeding device, and after the toner image is transferred, it is fixed in a fixing section. It is related to.

This type of electrostatic printing machine is for example
Applied Optics, 17 [6], p. 878-884 (I978). In this printing press, a charge image is created on a photoelectric intermediate support by means of laser light. This laser light is divided into parallel partial beams by an acousto-optic modulator in accordance with the symbol to be printed, and each partial beam performs bright and dark scanning in accordance with the printed information.
As a result, a charge image of the symbol is formed in the form of a dot array on the intermediate support. The charge image (latent image) formed on the intermediate support is colored using toner in a toner section to form a toner image, and this toner image is transferred onto a recording support, such as a paper tape, in a transfer section. The recording support is moved by a feeding device in the transfer section alongside the intermediate support, approaches the intermediate support during transfer, and laterally moves away from the intermediate support during periods when no transfer is performed. The toner image transferred to the recording support is fixed in a fixing section and fixed onto the recording support.

In known electrostatic printing machines, it is common for the recording support and the intermediate support to be moved at equal speeds. This speed is related to printing speed. On the other hand, the speed of the recording support is independent of whether this support is printed or simply moved without being printed. The speed at which the recording support advances through the transfer station is therefore independent of whether a line of printed symbols is followed by one or more blank lines on the recording support.

The aim of the invention is to allow the printing interval to be taken into account when printing on a recording support. The purpose of this is to provide one compression circuit to organize the printed information given in parallel line format, so that blank lines are arranged sequentially on the intermediate support only by lines containing skip marks, and the original before compression is A storage circuit is provided to store the feed information of the rows that are directly aligned in the charge image on the intermediate support after the line spacing is compressed. The number of line intervals from the line of the toner image transferred from the support onto the recording support to the line included in the next toner image is a specified number n (n=1, 2,
3, . . .) or more, by providing a control device which causes the rapid line advance to take place and stops the rapid line advance when the next line of toner image on the intermediate support reaches the transfer station.

The transfer station can be provided with a rocking device which laterally separates the recording support from the intermediate support during rapid feeding. This rocking device has an original line spacing number of i (i=2,
3, 4, ...) or more, the recording support can be controlled to move away from the intermediate support only when two or more blank lines occur in succession. It is removed to the side.

It is advantageous if the fixing process carried out in the fixing station is carried out at one average speed, independent of the speed of the recording support. For this purpose, it is effective to create a sag in the recording support between the fixing section and the transfer section.

The electrostatic printing press according to the invention has the advantage that high printing speeds can be achieved by implementing rapid feed, making it possible to significantly reduce costs. By increasing the paper feed speed during non-printing to several times the speed during printing, it is possible to increase the capacity of the printing press, or to leave the capacity unchanged and shorten the symbol formation time and development time. This makes it possible to save on parts and energy, for example in the optical marking section, the charging device, the fusing section and the cleaning device. Furthermore, consumable materials such as cleaning brushes and toner can be saved.

The invention will be explained in more detail with reference to the drawings which show in principle an embodiment of the invention. Since the configuration up to the rapid feed device of this embodiment is conventionally known, only the parts necessary for explaining the invention are shown, and other parts such as the developing section, corotron, cleaning device, fixing section, etc. are shown in the drawings. has been excluded from

The information to be printed on the recording medium AT, for example a paper tape, is supplied as printing information from the data processing device DVA. Here, it is assumed that only one side of the recording support is printed, and the original image is marked as SE1. S.E.
1 has a printed symbol, say A, in the first line, followed by some blank lines, and then another line with the symbol B. As shown in the drawings below, it is assumed that blank lines and lines containing symbols appear. In electrostatic printing machines known so far, an intermediate support moving at a constant speed
ZT e.g. SE1 on a drum with a photoconductor on the surface
A charge image is created that is an exact mapping of . That is, on the surface of the intermediate support ZT, a first row containing a charge image A is first formed by a symbol generator ZG, for example, a laser, corresponding to the configuration of SE1, and this first row is followed by a blank space containing no charge image. The line containing symbol B is created after the line is repeated until the line containing the next printed symbol appears at the entry location. Therefore, on the intermediate support, there are rows containing the charge image of the symbol and blank rows that do not contain it.
They are mixed and formed in accordance with the configuration of No. 1 and transferred onto the recording support AT.

Print information created in accordance with the configuration of the original drawing SE1 is sent from the data processing device DVA to the printing control device DS of the printing press. This printing information includes information on the symbol to be printed and information on the position at which this symbol is placed on the recording support. The decoder circuit DC separates symbol information and position information from the print information. For example, printing symbols are divided into lines and stored in memory.
Accumulated in SP1. Furthermore, information about when to move from one row to the next is stored in the second memory SP2 as sending information.

The symbol information of SP1 and the sending information of SP2 are compressed by the compression circuit.
Sent to KS. This compression circuit KS organizes the symbolic information, removing all blank lines so that only lines containing symbols continue. Therefore, the symbol information led to the symbol generation control device ZGS includes only lines where symbols exist. At the same time, the compression circuit KS or the memory SP2 holds the actual number of line spacings between two adjacent lines after compression before compression. This feeding information is given to the control device VS of the recording support feeding device VE.

The symbol generator ZG is activated by the symbol generation control device ZGS and creates a charge image of the symbol to be printed on the intermediate support ZT. In this case every row on the intermediate support contains a charge image of the symbol. These rows are intermediate supports
It is shown as three lines containing the symbols X, Y, and Z on ZT. That is, the mapping on the intermediate support has SE1
Blank lines inside are not included. Information from the symbol memory ZSP is used to form the individual symbols on the intermediate support.

The control device VS is coupled to a feed device VE with a feed wheel VR. A known drive mechanism for the feed wheel VR can be used. However, the feeder VE is equipped with a rapid feed mechanism that can be turned on and off as needed. Rapid feed mechanisms of this type are widely used in conventional mechanical printing presses.

The charge image produced on the intermediate support ZT by the symbol generator ZG is developed using toner and sent as a toner image to the transfer station US. In the transfer station, this toner image is transferred onto the recording support AT in a well-known manner. For this reason, a corotron KO controlled by a control device KST is provided in the transfer section. The transfer section is further provided with a swinging device SCH, which brings the recording support AT closer to and away from the intermediate support ZT. The recording support needs to be brought close to the intermediate support only when transferring the toner image. rocking device
SCH is controlled by a control device STE.

Transfer from the intermediate support to the recording support takes place as follows. Assume that the first row of toner images on the surface of the intermediate support has arrived at the transfer section. Now, in order to transfer this first line from the intermediate support to the recording support, the recording support is moved towards the intermediate support, and at the same time the recording support is
The moving speed of AT must match the peripheral speed of intermediate support ZT. Since the corotron KO is introduced, the toner image on the intermediate support is transferred to the recording support. Once the first row of the toner image has been transferred, the control device VS of the feed device VE causes a rapid feed to be carried out, so that the moving speed of the recording support is increased. The rapid feeding of the recording support continues until the next row (second row) of the toner image on the intermediate support reaches the transfer station US.
The rapid feed is now interrupted and the recording support moves at normal speed. The rapid feed is further controlled to undo the compression of the line by the compression circuit KS. By controlling the rapid feed of the feed device VE, the compressed line configuration on the intermediate support is restored, and the empty lines that were removed on the intermediate support are again present on the recording support. The recording support is rapidly fed within the time it takes for two adjacent lines of the toner image on the intermediate support to pass through the transfer station US, corresponding to the number of blank lines existing between the two lines containing printed symbols. The length carried by becomes longer or shorter.

Rapid feed is achieved, for example, when the actual number of line spacings between two adjacent lines on the intermediate support is one specified value n.
This is carried out when n=1, 2, 3, . . . or more. If n is chosen to be 1, rapid forwarding is also carried out when lines containing symbols are successive next to each other on the original drawing SE1. However, it is also possible to choose n≦2, in which case the rapid advance is carried out only if there are at least two empty lines between two lines containing symbols on the original. In this case rapid feeds occur less frequently than in the first case. However, in both cases, the control device VS of the feed device VE must be activated so that rapid feed does not occur when the transfer takes place in the transfer station.

It is advantageous to place the recording support AT at a distance from the intermediate support ZT when rapid transport is carried out. In this case, the rocking device SCH is n
>i, it can be made to always be injected. This causes the rocking device SCH to move around the recording support.
The recording support is moved away from the intermediate support only when the AT has to be moved by at least two blank lines by rapid feed.

When the recording support AT has an average speed, the fixing section FX
Advantageously, the speed at which the toner image passes through and fuses to the recording support is independent of the speed of movement of the recording support within the transfer station. In order to break the link between the fixing speed in the fixing section and the moving speed of the recording support within the transfer section, slack PS can be created in the recording support between the transfer section and the fixing section.

[Brief explanation of drawings]

The drawing basically shows the configuration of an embodiment of the present invention, where SE1 is a printing original, DVA is a data processing device, DC is a decoder circuit, SP1 and SP2 are memories,
KS is a compression circuit, ZG is a symbol generator, ZT is an intermediate support, AT is a recording support, US is a transfer section, and FX is a fixing section.

Claims (1)

[Claims] 1. A charge image of a symbol to be printed is created on an intermediate support that rotates at a constant speed in relation to printing information, and this image is developed using toner to become a toner image in a transfer section. The toner image is transferred onto the recording support,
In an electrostatic printing machine in which the transferred toner image is fixed in a fixing section, printing information given in parallel line format is organized, empty lines are skipped, and only lines containing symbols are arranged sequentially on an intermediate support. A compression circuit is provided for storing the original number of line spacings before compression as feed information for directly adjacent lines in the charge image on the intermediate support after compression, A control device attached to this device receives the feed information and controls the original toner image between the toner image row and the next toner image row transferred from the intermediate support onto the recording support. The number of line spacing is the specified number n (n=1,
2, 3, ...) or more, the electrostatic printing machine starts rapid line feeding and stops it when the next line of the toner image on the intermediate support reaches the transfer section. 2. The printing press according to claim 1, further comprising a rocking device for laterally separating the recording support from the intermediate support during rapid feeding. 3 The rocking device moves the recording support until the original line spacing is 2.
3. The printing press according to claim 2, wherein the printing press is laterally separated from the intermediate support only when this is the case. 4. Claim 1, characterized in that the feeding movement within the fixing section is performed at an average speed by creating slack in the recording support between the transfer section and the fixing section.
The printing machine according to one of items 3 to 3.