DE2454237A1 - PRINTING DEVICE - Google Patents

Description

The invention is based on one specified in the preamble of claim 1 Kind of

It is already an inkjet printer (C £ 2 361 237)
been proposed that of the ink jet print head carriage carrying a particular control of the movement is an optically _f
. Palpable line grid used and for the movement this
■ Car has a spring-loaded rope and ratchet gear.

It is the object of the invention characterized in claim 1 to optimally regulate the carriage return movement, d, h. to make the time required for this as short as possible without any negative impact on the print quality. In a aufgebau- according to the invention '■■ th ink jet printer is thus by regulating the Rücklaufbe-' movement of the carriage its output power increases. .. - "- >-""""~'

; ι

Many features of the invention can be found in the claims.

! i

Details of the invention are set out below with reference to one shown in FIGS Guren illustrated embodiment described. It shows:

igen: · I

Fig. 1

one a printer and one connected to the same j dene magnetic card unit having ink jet printing system, '

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2 shows the ink jet print head with a cooperating grid,

Fig. 3 is a block diagram of a circuit for the

Control of the carriage return movement, ■;

Figs. 4a + 4b diagrams to illustrate various:

Carriage positions and their speeds and \

Fig. 5 is a view of the driving parts of the ink jet print head carrying car,

The inkjet printing system shown in Fig. 1 includes the
Typewriter 1 _f to which the magnetic card unit 2 is connected. Instead of the magnetic card unit 2, other types are also available

Save usable. The typewriter 1 has the keyboard j 3, which in a known manner from electromechanical! Construction is. the

Typewriter 1 has the ink jet print head 4, which is in front of ^;

the recording medium 7 can be moved back and forth in the line direction j

is. The inkjet printhead has an inkjet nozzle and: for the determination of the current position of the car a radar

; ster 8 (described in more detail in connection with Fig. 2), The ·

Typewriter 1 has the various control buttons 10 to _;

; 13 for an automatic printing, a line printing, a word- '

print and a character print, other push buttons 15 to 18 are i for the selection of the type of recording, replaying, adjustment

jrens, the interlace and the like provided, ■

The magnetic card unit 2 has the loading slot 25, a track
! anzeiger 26, the card eject button 27, a track-down-shift button 28 and a track-up-shift button 29,
for setting the magnetic head to different tracks of the
! Magnetic card, instead of the known magnetic card unit shown
A magnetic tape unit or a data processing unit can of course also be used.

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The typewriter 1 has the carriage return switch 30 and the
right edge switch 32 (Fig. 5).

The ink jet print head 4 (Fig.2) has the pump 40 to ink
from the ink supply line 41 on request against the energized
Crystal 42 to be directed, the one with high frequency in the order of magnitude
100 kHz is applied. The ink drops are caught by the
, Nozzle 43 and pass the charging electrode 44 to be in
Correspondence with the output signal of the charging electrode amplifier
; kers to be charged accordingly, for a distraction in one; Print column to display a value that represents the vertical or height posi-; ; represents tion of the drop within a given character.
The letter S shown is composed of several vertical columns 51. Printing takes place in such a way that the sequence of
vertical columns, each of which contains a plurality of drops j, for example 40, is acted upon by the nozzle 43 with ink drops. If individual ink drops are not _{necessary for printing:} they are directed against the ink collecting diaphragm 53,; from where it is returned to the ink reservoir via line 54 _; be directed. A pair of baffles 60, 61 is the charging electrode arranged in the motion \ abandoned path of 44 drops. A constant high voltage potential is applied to the plates 60, 61, which! | in connection with the different charge of the individual Tin- \ tentropfen the value of the deflection of the individual droplets determined bas j grid 8, displayed horizontally in this case,
however, as shown in FIG. 1, it can also be arranged vertically. The J

! Grid 8 has two parts 8a, 8b. j

I ι

£ n the ink jet print head 4 is a sensing device 39 for
: the translational movement relative to the grid 8 is fixed. These
Sensing device has a light-emitting diode that has a
Light beam through the grid 8 and a parent grid
, aimed at a pair of photocells. This facility allows in

Connection with a meter the exact determination of the instantaneous Location of the carriage carrying the printhead, each count representing one of the columns 51.

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Assuming that the typewriter 1 after a line print-j process works and the printing system according to a transfer process, results in the appropriate position of the magnetic card, not shown, within the magnetic card unit 2 signals that the typewriter 1 to designate the printing of characters. An exit, with "pressure", is provided and remains open an upper level until an end-of-character signal is received from the magnetic card unit 2.

In Fig. 5 the drive parts for the carriage are shown, a line print, a print serial by characters, a carriage return, Allow tabs, backspace keys and the like.

The carriage 5 is mounted on the shaft 100 in front of the recording medium 7 for the purpose of its translational movement from left to right. The rope 101, which is guided around the rollers 105 to 108, is attached to both sides of the carriage 5. The rope 101 is over the drum 110, which is mounted on the shaft 111, is laid. With The hubs 112 and 113 are firmly connected to the drum 110. the assembly consisting of the drum 110 and the hubs 112, 113 is freely rotatable on the shaft 111. The hub 112 is of the Wrap spring 116, which belongs to the wrap spring clutch 118, while the hub 113 is surrounded by the wrap spring 120, which belongs to the wrap spring clutch 121. The latter decouples the planetary gear 170 during a carriage return to avoid the noise of the wheels. The wrap spring clutch 118 is active in the return of the carriage, i. h, while the carriage 5 moves from moved right to left, while the wrap spring clutch 121 is provided for moving the carriage 5 from left to right is.

The main spring 130, the return clutch 131 and related Components are arranged one behind the other and are operated by the mechanical control system 132. Besides, they are Index device 133 and tab control 134 are provided.

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j It is assumed that the carriage 5 is on the left edge. 1 When a print is desired of a line are first through 'the return movement of the clutch 131, the pawls 141, 142 (specifically, In; Fig illustrated. 5) out of engagement with the ratchet wheel 143 GE-I introduced. As a result, the drive movement is transmitted by the main spring 130 'via the hub 113 and the drum 110 to the cable 101! that the carriage 5 in front of the recording medium 7 from left to

i pulls right. The movement of the carriage 5 is maintained,

; until an end-of-line signal is received from the data source or. \ the right margin switch 32 indicates that the right margin is reached

is. A carriage return is then initiated with the motor 150:

tet, which is actuated by the carriage return magnet 156 Baren shoe 155 via the hub 112, the drum 110 and the.

Wrap spring 116 of the wrap spring clutch 118 is coupled. j Accordingly, the carriage 5 is moved from right to left until |

^! the left margin switch indicates the completion of the carriage return. While the carriage 5 is in motion, the main spring 130 is activated

• tense and thus for a step movement and tabulation movement I ¹ ι

ι prepared in a subsequent line, I

! ■ ■ ■ - 1

ι I

According to the proposed device mentioned at the beginning ! the carriage is located at the beginning to the right of the character to be printed. Printing a character requires the return of the Carriage to the left in front of the desired character position, whereupon the carriage is moved to the right and thereby the character position and then stops to the right of the character position, making the print line easier to see.

The logic of this proposed device is effective to initiate a 7.62 mm carriage return movement corresponding to three characters, assuming a character pitch of 2.54 mm. The carriage return is initiated by energizing the reverse movement clutch 131, which moves the arm 161 pivotable about the bolt 162 via the lever 160. Here, the part 161a moves away from the viewer in FIG. 5, while the part 161b opens up

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moves the viewer too. The movement of arm 161 causes J Pawl 142, the ratchet wheel 143 moves counterclockwise when looking at uie shaft 111 from the right. The ratchet 143 is directly connected to the drum 110, where j

; by moving the carriage 5 by three character divisions j ^; is called.

; The release magnet 140 is then energized to release the ratchet wheel j 143 so that the drum 110 rotates clockwise, ! see from the right end of the shaft 111, through the main spring : 130 is rotated.

During a tabulation movement under the influence of the main; spring 130 takes place, the speed of movement is through! the tabulation regulator 134 is controlled via the planetary gear 170, which has the ring gear 171, the planet gear 172 and the sun gear 179. The control is carried out via the Schling-I spring clutches 121, 180 and the tabulation regulator 134 _f to ensure that excessive speeds do not occur.

: By the action of the main spring 130 and the rotation of the drum I110 becomes carriage 5, along with its inkjet printhead moved from left to right, the printing of a character in the character field being controlled by the electronics, the Character and column positions of the ink drops through the grid J 8 and the connected counter during the movement of the carriage 5 are monitored. The release magnet 140 is de-energized before the carriage is stopped behind the character being printed.

Successive characters are printed in this way step by step for as long as necessary. Line printing is seeing for successively continuously moving the carriage 5 from the left edge to the right edge on a line by line basis a carriage return after each line is printed, whereas line printing normally moves backward-forward of the carriage, as if for a step-by-step pressure

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. wrote, not required.

^; The following algorithms and expressions have been used in the present I system:

I. CARRIAGE RETURN ALGORITHM

ι ■ Definitions

! 3. CRMIN

. 4. TURN

5. DELTAS

6. DELTAP

7. CRCVT

-ι left margin

- wagon position

- Minimum distance between carriage return tip and drop points for matching Revolution distance,

-. Measured distance from the carriage return drop point to the point at which the carriage moved speed

zero speed reached.

- Free flight distance before printing,

- Minimum distance in which a carriage return can be started and ended if the carriage is in circulation poses no problem.

- The distance within which the carriage return can be terminated and which guarantees that the Car does not hit the frame.

Algorithms

A, If CPCLM, tabulate to ⁴ LM and set index.

jB. If CP = LM, set output index.

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C. LM <CRCVT

case 1

j CP 1 LM + TURN - DELTAS + CRMIN j 1. Tabulation after LM + TURN - DELTAS + CRMIN

I 2. Initiate carriage return with waste point at LM + TURN -

DELTAS

j 3. Loss of the award magnet at LM

I case 2

i CP> LM + TURN - DS + CRMIN

1. Initiate carriage return with waste point at LM + TURN DELTAS

2, drop of the release magnet at LM

D, LM> CRCVT

case 1

CP ^ LM + TURN - DELTAS + CRMIN CP - LM > DELTAP

1. Initiate carriage return with drop point at LM

2, waste of the release magnets at LM

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j case 2

CP <LM + TURN - DELTAS + CRI-IIN
j CP - LM <DELTAP

i1, set tabulator to LM + DELTAP ^!

I. ■; ■ i

j2, initiate carriage return with drop point at LM;

3, drop of the release magnet at LM "

Case 3;

CPü LM + TURN - DELTAS + CRMIN j

1, initiate carriage return with waste point at LM + TURN i DELTAS

2, drop of the release magnet at LM

In the block diagram shown in Fig. 3, the falling point becomes of the carriage return magnet controlled during a carriage return. 4a shows the course of the return movement expected during a normal carriage return. Curve 94 shows the expected return movement th course of the speed while pressing,

In Fig, 4b, a speed profile is also shown, namely the minimum requirements that are necessary to guarantee that the carriage reaches a minimum speed during the return movement in order to ensure the correctness of the information provided by the control electronics to ensure evoked estimation schemes during the entire print line. As in Fig. 4b the requirements mentioned have three primary intervals a, b and c on, the interval "a" is the delay part of the carriage return

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running movement. The interval "c" is the acceleration part of the carriage return movement and the interval "b" represents the speed curve of the carriage forward movement before reaching the ' first printing position. A carriage return movement begins at ί, point 92 with the movement to the left, and the Speed J! Increases along the curve part 93. The carriage return magnetic \ i falls at point 89 and the speed decreases along the j! Curve 94 to zero at point 95 off. The carriage movement is now changed to moving to the right and the speed increases, until the minimum printing speed is reached at point 97, whereupon an adjustment to part 98 of the curve takes place. The carriage return estimation scheme is based on an estimation of the part of the speed curve which is marked with "a". The interval "c" of the speed profile and also> the interval "b" are fixed values. The difference between "c" and "b" is programmed in register 78 (FIG. 3). This number represents a number of raster pulses translated into a distance the carriage can move during its return travel. This number is entered into register 78 when it is initialized by a pulse on terminal 75. This happens while the system is being switched on. Immediately following this process, the carriage is moved in a test cycle. The purpose of this cycle is to measure part "a" (Fig. 4b) so that this information is added to the number in register 78 and thereby the drop-off point of the carriage return magnet is estimated for all subsequent carriage returns until another test cycle is performed. At this time, the number representing the interval "a" is updated. The grid information from block 70 (FIG. 3) comes from grid 8 (FIG. 2). This information then enters the down or up counting counter 72 via the counter controller 71. A counting scheme for an i-step decoder is described in the IBM Technical Disclosure Bulletin, VoI. 16, No. 3, August 1973, pages 799-803.

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The counter control 71 determines, depending on the forward or backward movement of the carriage, when the counter 72 should count up or down. This is performed because the \ counter must contain the detent narrative showing iPosition the respective Wagen4. During the test cycle, the counter 72 overall> ■ starts when the shunt passes the carriage return shaving liter 30 74 (Fig. 5), whereby the counter in its initial condition overall!; ! is brought. The counter counts until the carriage reaches zero speed, at which time the number of ratchet pulses has been transferred to register 78. Register 78 now contains the number which is used for all further carriage return movements. The output of register 78 is then the

jComparator number 1 register 79 and then the comparator number

2 registers 87 are always supplied. The register 79 is used to determine 'whether the car left or right return distance of Mindestwagen- \ is necessary to provide sufficient speed for completing the carriage return Iabschätzschemas sure. If the carriage is too far to the left, this information is transmitted on line 82 (FIG. 3) and the carriage is moved to the right by control circuitry 86 prior to energizing the carriage return magnet

8 the carriage return is initiated. When the car is too far is located on the right, the carriage return is immediately transmitted by a signal which is fed to the carriage return magnet 88 via the line 83 Is initiated. Regardless of where the carriage return begins, i.e. whether the carriage is moved to the right or the Carriage return is executed immediately, the drop point of the carriage return magnet is determined by the same signals on the Lines 84, 85. This comparison is performed by the comparison register 87. As soon as the comparison finds equality, the carriage return magnet 88 drops out, through an output of the comparison register 87. As a result, the fall point of the carriage return, based on the estimation scheme. The waste following the carriage return, the carriage moves freely until. to zero speed and its movement then becomes in the forward direction changed to the first printing position with sufficient

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Speed to arrive.

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Claims (1)

- 13 - PATENT CLAIMS Printing device with a carriage which can be displaced back and forth along the printing line and carries a print head, wherein; printing can only take place in one direction of movement of the carriage, j characterized in that the movement of the carriage (5) influencing control circuit (Fig. 3) is provided, which can also perform test cycles to determine a Point within the trajectory of the carriage, (5) at which the return movement, causing a change in the direction of the Movement of the carriage (5) in the direction of pushing includes ^ :, can be initiated with the shortest duration. j 2, printing device according to claim 1, characterized in that that the control circuit has a register (78) into which : when the control circuit is switched on, a value is entered ben is the difference, formed from one for the j acceleration during the carriage return charal statistical value (c) and the acceleration of the water J gens (5) in the printing direction characterizing value (b) represents, 3, printing device according to claims 1 and 2, characterized net that during the test cycle the value representing the point mentioned in register (78) is formed by a addition of a to the register content (c minus b) Value that is formed from measurement of the inside of the carriage return the deceleration period (a) following the acceleration period (c). 4, printing device according to claim 3, characterized in that that a device (39) determining the current position of the carriage (5) is connected to a counter (72) which can be connected and started to the register (78) by a carriage return switch during the test cycle, as soon as the shunt coil (74) hits the carriage return switch LE 973 004 509822/066 2 ter (30) happens and that the counter (72) counts until until the carriage (5) has reached zero speed. ! 5. Printing device according to claim 1 and 4, characterized in that the counter (72) to a counter control circuit (72) is connected which, depending on the current direction of movement of the carriage (5), an up or down counting of the counter (72) initiates. 6. Printing device according to claim 2 and 4, characterized in that net that the counter (72) together with the register (78) is connected to one input each of a comparison circuit (72) is that, depending on the two input signals, a carriage return either immediately or only after a move to the right of the carriage (5) " 7. Printing device according to claim 2 and 4, characterized in that net that a further comparison circuit (87) is connected to the counter (72) and the register (78), which only if the signals from the counter (72) and from the register (78) are equal, an output signal is generated which the carriage return magnet (88) is supplied for the purpose of its falling. LE 973 004 509822/0662