GB2112980A

GB2112980A - Supplying print material

Info

Publication number: GB2112980A
Application number: GB08236553A
Authority: GB
Inventors: Peter C Digiulio; Ronald P Sansone
Original assignee: Pitney Bowes Inc
Current assignee: Pitney Bowes Inc
Priority date: 1981-12-28
Filing date: 1982-12-23
Publication date: 1983-07-27
Also published as: GB2112980B

Abstract

The amount of ink or toner supplied to the sump of an ink jet or xerographic printer is controlled by a determination of the number of pixels to be printed (and grey level, in grey scale printing). <IMAGE>

Description

SPECIFICATION Method and apparatus for supplying print material This invention is concerned with electronic printers of the non-impact type. As used throughout this specification, including the claims, the term electronic printer encompasses those printers in which information relative to the text to be printed is supplied electronically. Examples of systems that would have use of electronic printers are facsimile machines, word processors and computers.

In electronic printers of the non-impact type that contain a dispenser for holding print material that is to be used directly during the printing operation, means is usually provided for automatically replenishing the print material, such as ink or toner, as the print material is consumed.

As an example, in an ink jet printer a dispenser is provided for holding liquid ink that is used during the printing operation. There is usually some type of measuring device to determine how much ink remains in the dispenser and filling means for providing additional print material to the dispenser as it is consumed. In a xerographic printer that uses dry, two component development powder, a dispenser also is provided which periodicaily must be supplied with replacement toner. The replacement of print material in such systems is either performed randomly or through a method of measuring the quantity of printing material remaining and replenishing it. With particular reference to a printer using the xerographic process and where a dry, two component toner is used in combination with a magnetic brush, random feeding is usually the case.More specifically, in an electronic printing operation wherein a xerographic printing process is utilized, an image is created on a photoconductive surface, as for example, through either exposure to light emitting diodes (LEDS) or through laser beam exposure. In either case, the image is created by the exposure to light in accordance with information stored in a memory and supplied therefrom to the imaging electronics. Typical of such a system, a hopper containing the print material is stationed over the sump of a magnetic brush unit and a rotary member containing pockets is located at the bottom of the hopper and rotates to supply material to the sump. The rotation of such rotary member is controlled by tie operation of the printer and bears no relationship to the print material being consumed during the development of the image.As a consequence, since there is no relationship between the amount of print material being consumed and the amount of material that is supplied, variations in the density of the printed matter occur. Another means for replacing consumed toner in the xerographic process is a toner density controller wherein the ratio of toner to carrier particles is measured. When the percentage of toner drops below a given level, the toner is replenished. As is known, such toner density controllers are expensive and generally lack accuracy. Obviously, it would be desirable to have a direct correlation between the amount of print material being consumed by an electronic printer and the amount supplied for the printing operation.

The present invention provides apparatus for controlling the amount of print material toner supplied to the dispenser of an electronic printer that reproduces a text in response to pixel formation information electrically supplied, the apparatus comprising: imaging electronics means, means for supplying information relative to the formation of pixels to be printed to said imaging electronics means, developer means for imaging the information supplied connected to said imaging means, accumulator means connected to said information supply means for counting the number of pixels supplied and determining the amount of print material required to print the information supplied, and dispenser means for supplying print material to said developer means, said dispenser means being in electrical communication with said accumulator means.

The invention will be better understood from the following non-limiting particular description of examples thereof given with reference to the accompanying drawings in which: FIG. 1 is a block diagram of an apparatus for controlling the supply of print material for black/white pixel printing, and FIG. 2 is a block diagram of an apparatus for controlling the supply of print material for gray scale pixel printing.

Referring first to FIG. 1, a printer module is shown generally at 10 which is operative to print black/white pixel printing and includes a pixel data input 12. By way of explanation, a character will be printed within a given area of a document by producing a certain number of pixels or black dots that will form an image of the character. This given area will have a maximum number of pixel sites; as an example, an area may have 64 pixel sites in total. Depending upon the character which is to be printed, selected ones of the pixel sites will be filled in. Each pixel is a black dot that will require a certain amount of printing material. The input signal 12 is connected to and will convey to an imaging electronics 14 and to a print material accumulator 1 6 the pixels that are to be printed in a given area so that the given character can be formed.The imaging electronics 14 is connected to a developer 18 and will act upon the developer to image the information supplied by the input signal 1 2. The developer 18 may be either a xerographic type of developer or it may be an ink jet assembly. In the case of a xerographic printer, the use of light emitting diodes (LED's) may be utilized and in this case the imaging electronics will enable the LED's as required in order to create an image on a photoconductor. On the other hand, if the developer is an ink jet printer, then the imaging electronics will control the droplet output of the ink jet head and align it as required in order to create the pixels as indicated by the input 1 2.

The print material accumlator 1 6 is a unit, such as a microprocessor, which counts the number of pixels which are to be reproduced and from this determines the amount of print material that is required based upon information received from the input 12. This member is then supplied to a dispenser 20 which receives print material from a bulk supply source 22. The dispenser 20 sends a signal to the supply 22 which will supply the amount of print material required by the developer 18 as the printing operation continues. A clock 23 is connected to the accumulator 1 6 to provide timing to the system.

Referring now to FIG. 2, a printer module is shown generally at 24 that is capable of printing in gray scale. The input line 26 provides a serial data input of the gray level input and as such requires a serial to parallel conversion to a parallel gray input level code prior to being furnished to the imaging electronics 28. Such conversion is accomplished by a serial to parallel converter 30. It will be appreciated that if the input 26 provides a parallel gray input, the converter would not be required.

The serial to parallel converter 30 is in electrical connection with the imaging electronics 28 and with a gray pixel level look-up table 32 which is in electrical connection with an accumulator 34. A dispenser 36 is in electrical connection with the accumulator 36 and also is in connection with a supply 38 that acts as a bulk supply of print material. A developer 40 is connected to both the imaging electronics 28 and the dispenser 36.

Information relative to the text to be printed is fed directly from the input line 26 to the imaging electronics 28 wherein the image is created upon the developer 40 through the printing of a number of pixels of different gray levels. Print material is supplied to the developer 40 in order to develop the image created in the developer by the imaging electronics 38. The amount of print material that is to be supplied is calculated by the accumulator 34. The input line 26, if in serial form, is converted from serial to parallel by the converter 30 and the look-up table 32 outputs signals indicative of the amount of print material that will be required. This is supplied to the toner accumulator 34. Based upon the gray level and number of dots, a signal is sent back to the dispenser 36 for the purpose of supplying sufficient print material to replenish the amount used in printing.

Claims

1. Apparatus for controlling the amount of print material toner supplied to the dispenser of an electronic printer that reproduces a text in response to pixel formation information electrically supplied, the apparatus comprising: imaging electronics means, means for supplying information relative to the formation of pixels to be printed to said imaging electronics means, developer means for imaging the information supplied connected to said imaging means, accumulator means connected to said information supply means for counting the number of pixels supplied and determining the amount of print material required to print the information supplied, and dispenser means for supplying print material to said developer means, said dispenser means being in electrical communication with said accumulator means.

2. The apparatus of claim 1 including print material supply means connected to said dispenser means.

3. Apparatus for controlling the amount of print material supplied to the dispenser of an electronic printer that reproduces a text in gray scale in response to information electrically supplied, the apparatus comprising: imaging electronics means, means for supplying information in series relative to the formation of pixels to be printed to said imaging electronics means, serial to parallel converting means connected to said information supply means, look-up table means connected to said converting means for determining the pixel level of the information supplied, accumulator means connected to said look-up table means for determining the amount of print material required to print the information supplied.

developer means connected to said imaging means for imaging the information supplied, and dispenser means for supplying print material to said developer means, said dispenser means being in electrical communication with said accumulator means.

4. Apparatus according to claim 3 including means for supplying print material to said dispenser means.

5. A method for controlling the amount of print material supplied to the dispenser of an electronic printer in accordance with the text to be printed, comprising the steps of: supplying information to imaging electronics relative to the location where pixels are to be printed to form a character, determining the number of pixels that will be required to print the information, correlating the amount of print material required based upon the determined pixel number, supplying print material to a developer based upon said correlation, and activating the imaging electronics to act upon the developer to print a text according to the information supplied to the imaging electronics.

6. A method for controlling the amount of print material supplied to the dispenser of an electronic printer in accordance with the text to be printed, comprising the steps of: supplying serial information to imaging electronics relative to the location where pixels are to be printed in gray level to form a printed text, converting the serial information to parallel information, determining the number of pixels that will be required to print the text, correlating the amount of print material required based upon the pixel number determination, supplying print material to a developer based on said correlation, and activating the imaging electronics to act upon the developer to develop a text in accordance with the text information and pixel information fed to the developer.

7. Apparatus for controlling supply of print material substantially as herein described with reference to and as illustrated in the accompanying drawings.

8. Any novel combination or sub-combination disclosed and/or illustrated herein.