JPS59165661A - Dot matrix printer capable of varying size of character - Google Patents

Abstract

PURPOSE:To manufacture the titled printer, which can print the character of arbitrary size, by inclining a printing head at an arbitrary angle and providing a delay circuit giving the retardation time corresponding to the angle of inclination of the printing head. CONSTITUTION:A mechanism inclining a printing head H with nozzles N1, N2...Nn at arbitrary angles is provided, and a delay circuit (a shift register) SR compensating differences generated at injection timings from each nozzle is interposed between a character signal memory storage CG and a driving circuit D. The delay circuit SR has steps corresponding to the number (n) of the nozzles, and the quantity of delay is set in consideration of lateral displacement generated at every section among adjacent nozzles.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an IJ printing device that can change character size.

It is desirable that the size of the characters printed on the printing target can be changed as appropriate depending on the use or purpose. however,
Changing the character size in conventional devices has drawbacks such as being complicated or accompanied by great technical difficulties. In other words, although the stencil printing method has the advantage of maintaining good printing quality despite size changes, it is performed using separate stencils depending on the character size, but it is usually difficult to print in an atmosphere where paint mist exists. For this reason, it is often undesirable from the health standpoint of workers.

In addition, when performing dot matrix printing using a marking head equipped with multiple paint spray guns and moving the print target and the head relative to each other, it is necessary to limit the number of operating guns in order to reduce the character size. However, methods to reduce the number of dots are considered. However, it is obvious that reducing the number of dots will reduce the distinguishability of printed characters, and since there is a limit to the minimum allowable size, this is not a general solution.

Furthermore, in dot matrix printing using the inkjet method, printing is performed while deflecting the flying ink droplets, so if the deflection angle is set to 0 to obtain a print size larger than a predetermined size, distortion will occur at the edge of the character. therefore undesirable.

SUMMARY OF THE INVENTION An object of the present invention is to provide a dot matrix printing device capable of changing character size, which eliminates the drawbacks of conventional devices as described above.

This purpose is to provide a dot matrix printing device having the structure described in the claims, that is, a mechanism for tilting the print head at an arbitrary angle, and to set a delay time corresponding to the inclination angle of the print head to each injection nozzle. This is accomplished with a dot matrix printing device that includes a delay circuit connected between the character signal storage device and the print head to provide an effect on the electrical signals applied for actuation.

The dot matrix printing device according to the present invention enables printing of any size depending on the size and properties of the object to be printed and the printing purpose or use. Such character size changes are performed quickly and automatically and do not require any additional steps. Furthermore, since the character size is changed by changing the dot spacing with the same number of dots, it is possible to perform good variable size dot matrix printing without the disadvantage of reducing the distinguishability or clarity of the printed content. .

DESCRIPTION OF THE PREFERRED EMBODIMENTS A dot matrix printing apparatus according to the present invention will be disclosed below with reference to the accompanying drawings showing embodiments.

FIG. 1 shows a print head H of a dot matrix printing device according to the present invention, in which n nozzles N1+ are arranged at an interval l.
N2...Nn are arranged on a straight line. Nozzle N
The interval from 1 to Nn is the maximum height of normal printed characters. Generally, such a print head H is moved relative to the object to be printed as shown by an arrow P at a pitch corresponding to the nozzle interval l, and a gun (not shown) corresponding to the required nozzle is operated. Desired dot matrix printing is performed while spraying paint. It is obvious that in this case, the maximum value of the character height is L.

Therefore, if one attempts to print with a height of less than L in the condition shown in Figure 1, the number of operating guns must be limited, and as the number of dots decreases, the defects that impair distinguishability and clarity as described above may occur. will occur.

Therefore, in the present invention, as shown in FIG. 2, the print head H is tilted at an angle θ from the horizontal to obtain the apparent maximum nozzle spacing Lθ, and this Lθ is intended to be the maximum character height. It is.

Since the following relationship holds true, a desired value can be obtained by appropriately changing θ.

Lθ=Lsinθ This relationship Lθ, that is, the relationship between the apparent character height and the angle θ, is as shown in FIG. 3 in an embodiment using a 13-gun print head. Therefore, in order to obtain Lr5L, it is sufficient to tilt the head H so that θ=56.40,5-. An arbitrary character height can be achieved by such operations.

The head H is fixedly disposed perpendicular to the direction of relative movement, ie, on a vertical line. In conventional printing devices, the horizontal dot spacing is selected to be approximately equal to the vertical dot spacing, that is, the nozzle spacing l. This lateral dot spacing is determined by the relative movement speed of the head and the printing target and the timing of jetting from each nozzle. Therefore, in the conventional apparatus, if the relative movement speed is constant, printing in the correct form can be performed with constant injection timing. On the other hand, in the printing apparatus according to the present invention, each nozzle position is shifted in the horizontal direction and the apparent vertical dot spacing is variable, so the ejection timing must be changed accordingly.

FIG. 4 is a block diagram showing the main parts of the printing device according to the present invention. The print head H has n nozzles N1. N2...
・It is equipped with Nn and can be tilted at any angle by a suitable mechanism (not shown).

This tilting mechanism may be made variable by providing a fulcrum on the support member of the head H, and connecting a notch, a gear mechanism, a dial, etc. around this fulcrum, and using these K to manually change the inclination angle. Further, an electric or fluid servo motor can be automatically tilted to a desired setting angle for threading in these mechanisms. These configurations are well known and can be adopted as appropriate, so detailed descriptions thereof will not be given.

The printing device according to the present invention is a character signal storage device (character generator memory) CG that generates an electrical output corresponding to dot matrix representation of characters to be printed.
Equipped with. In the conventional device in which the print head H does not tilt, the output of the character signal storage device is transferred to the drive circuit (which drives each nozzle NN...Nn) without any time change.
gun driver) D1' 2 . Thereby, printing is performed according to the output of the character signal storage device CG.

However, in the printing apparatus according to the present invention, since the head H is tilted as described above, a difference occurs in the timing of jetting from each nozzle. Therefore, a delay circuit (shift register) SR having stages corresponding to the number of nozzles is interposed between the character signal storage device CG and the drive circuit.

The amount of delay in this delay circuit SR takes into consideration the lateral deviation corresponding to 71 cos θ occurring in the open can of the adjacent nozzle.

Since the delay amount of this delay circuit SR is determined according to the inclination of the head H, it is desirable that the delay amount can be changed in accordance with a signal from the inclination detector SD of the head H, for example. However, if the tilting of the head H is manually operated, it can also be manually set.

The signal generation timing for the character signal storage device CG and the delay time for the delay circuit SR are determined by the encoder E.
is controlled by a control counter C which processes the output pulses of . The encoder E and the control counter C are variably controlled by external manual control and/or automatic control based on the output signal of the tilt detector SD.

Note that by changing the output pulse width applied to the head H from the drive circuit, the amount of paint sprayed from each nozzle can be changed. Therefore, by providing a trigger time setting circuit TS in the drive circuit, the dot diameter can be made variable.
Distinguishability can be improved depending on the character size, purpose, properties of the printing surface, etc.

To supplement the above explanation, for example, the inclination angle, dot pitch, character height, when using the 13 gun shown in Fig. 3,
The relationship between the delay amount (-lcos θ) and the optimum dot diameter is shown in the following table.

For the sake of explanation, the operation when normal characters are printed by the 9-printing device according to the present invention having a seven-gun gun, and the operation when the printed characters are reduced will be described below.

The left side of FIG. 5 shows "
2'', and the timings tl, t2... when the 7-gun print head H is vertical as shown in the center of the figure.
Each nozzle N1 at t5. The operating pulses of N2...N7 are as shown on the right side of the figure. This shows that the gun is operated at each timing while the vertically arranged head H moves relative to each other, and the dot matrix print "2" is formed by the paint sprayed from each nozzle.

FIG. 6 shows a state in which the stored content "2" on the left side of FIG. 5 is printed by the head H tilted at an angle θ as shown on the left side of FIG. The character height in this case is 5 (7-sin θ), where l is the nozzle interval. In this state, the horizontal distance between nozzle N1 and nozzle N2 is 71 c
It becomes osθ. Therefore, if nozzle N1 is used as a reference, nozzle N2 will move at a time t' corresponding to distance l cos θ =
10- is required to be activated with a delay of k(7 cos θ). Therefore, as shown on the right side of FIG. 6, the pulse that activates the nozzle N1 is generated at the same timing t2. t3. Emitted at t4. Nozzle N2, on the other hand, is actuated by a pulse occurring at (t1+t'), which is then respectively delayed. For nozzle N7, the original timing t1. t2...
- Pulses generated at the timing when 6t' is added to t5 are applied. Such a delay is performed by the aforementioned delay circuit (shift register) SR.

Note that if this state is left as it is, only the character height will be reduced and the character width will be the same, but the original pulse generation timing, that is, the pulse interval, will be changed by adjusting the encoder E and control counter according to θ. The character width can also be adjusted as appropriate by uniformly reducing or increasing the relative movement/speed using C. As a result, printing of arbitrary character size becomes possible.

The preferred embodiments of the invention have been disclosed. However, many modifications and variations may be made within the scope of the present invention.

=11- It is clear that this is possible.

[Brief explanation of the drawing]

FIG. 1 is a front view of the print head. FIG. 2 is a front view of the print head tilted at an angle θ. FIG. 3 shows the print head inclination angle and the apparent maximum nozzle spacing. FIG. 4 is a block diagram of a printing device according to the present invention. FIG. 5 shows the relationship between character signals and corresponding electrical signal generation timings. FIG. 6 shows a similar relationship to FIG. 5 at an angle θ.

Claims (1)

[Claims] (1) A print head in which a plurality of paint spray nozzles are arranged to be selectively activated, and a device for applying electrical signals to each spray nozzle of the print head to activate them in accordance with the characters to be printed. A dot matrix printing device having a character signal storage device, further comprising: a mechanism for tilting the print head at an arbitrary angle; Dot matrix printing with variable character size, characterized in that a delay circuit is provided between the character signal storage device and the print head in order to provide respective delay times corresponding to the inclination angle of the character signal storage device and the print head. Device.