JPS5812781A - Small-type printer - Google Patents

Abstract

PURPOSE:To provide a small-type printer used for a desk-top electronic calculator or the like, which consumes less energy, can be made small in size and produced at low cost, by a method wherein a head is moved by utilizing the resonance of an oscillating member without using any expensive motors. CONSTITUTION:When a signal is impressed on a coil 13, an iron core 11 is attracted in the direction of an arrow A, the oscillating members 7, 7' are rotated with pins 10, 10' as centers, respectively, and a carriage 6 is moved in the direction of an arrow B. When the impressing of the signal on the coil 13 is released, the core 11 is returned in the direction opposite to the arrow A by a spring 14'. When the impressing of the signal on the coil 13 is turned ON and OFF in synchronism with the natural vibration of a vibration system constituted of the oscillating members 7, 7', the carriage 6, the core 11 and the springs 14, 14', the carriage 6 can be resonantly vibrated with an extremely small amount of energy. Concurrently with the oscillation of the oscillating member 7, a recording paper 17 is travelled by a predetermined distance span in the direction of an arrow C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a small printer, and more particularly to a low-cost printer used in a small portable calculator or the like.

Requirements for printers used in small portable calculators and the like include small size, low energy consumption and long battery life, and low price of the printer.

There were also requests for records that included not only numbers but also alphabets, kana, etc.

Dot matrix printing using an ink-on-demand type ink jet is considered to meet these requirements.

However, conventional ink-on-demand type inkjet printers are not necessarily sufficient for use in portable small calculators.

It is therefore an object of the invention to obtain a printer with low energy consumption.

Another object of the invention is to reduce the size of the printer.

Yet another object of the present invention is to reduce the cost of printers.

FIG. 1 shows an embodiment of the present invention.

A single ink-on-demand inkjet head with 30 nozzles 2 of 1.05 steel pitch and a tail. 3 is a piezoelectric element, and the surface is divided by .circlein.: camellia so that ink can be ejected independently to each nozzle 2. 4 is an in-droplet ejected from the nozzle 2. 5 is an ink tank containing ink. 6 is a carriage in which the head 1 and the ink tank 5 are set. 7, 7' is carriage 6
The carriage 6 and the swinging members 7 and 7' are coupled to be swingable about the bins 8 and 8'. 9 printer base with 10 bins on it.
10' are provided, and the swinging members 7, 7' are provided with bins 10,
It is pivotally supported so as to be able to swing around 10'. Regarding the bins 10 and 10' of the swinging members 7 and 7', the carriage 6
Iron cores 1, 1 are pivotally connected to each other by pins 12, 12' at opposite positions. 13 is fixed to the base body 9 with a coil. The iron core 11Fi is movable in the axial direction within the coil 13. Reference numeral 14 denotes a spring that is pulled from both the swinging members 7 and 7'i.

Reference numeral 15 denotes a detector consisting of a Hall element, which is provided on the swinging member 7 and turns on and off as the i1 stone 16 moves. 17
is recording paper.

The operation of the above configuration will be explained. When a signal from a control circuit (not shown) is applied to the coil 13,
The iron core 11Fi is attracted in the direction of arrow A, and the swinging member 7,
7'[The carriage 6 moves in the direction of arrow B because it rotates around the bins 10, 10'i. Release the signal application to the coil 13, remove the iron core 11, and turn the spring 14 in the opposite direction to the arrow A.
Return to Swinging member 7.7', carriage 6, iron core 1
By turning on and off the application of a signal to the coil 13 in accordance with the natural vibration of the vibration system constituted by the coil 1 and the springs 14 and 14', the carriage 6 can be resonated and oscillated with extremely little energy. The signal is applied to the coil 13 by the detector 1.
It is sufficient if it is synchronized with the signal of 5. As the swinging member 7 swings, the recording paper 17 is fed in the direction of the arrow 0 by a paper feeding mechanism (not shown) in increments of 04 sheets.

In FIG. 1, head 1. Tank 5. Carriage 6
The ratio of the sum of the masses of the iron core 11 to the quality of the iron core 11 is selected to be approximately equal to the reciprocal of the ratio of the short distance between the bins 8 and 10 and the distance between the bins 10 and 12. In this way, the rotational torque of the swinging members 7, 7' about the bin 10.degree. 10' due to the external force in the lateral direction acts to cancel each other out, thereby increasing the resistance to external disturbances.

If there is a disturbance that causes the printer to rotate around the middle of the bins 10 and 10', the carriage 6 may begin to vibrate on its own and become unsteady, but such disturbances are generally considered to be rare. It's good.

FIG. 2 shows the state of printing in the embodiment shown in Figure 1. 1
Relative displacements of the leftmost nozzle and the second nozzle with respect to the recording paper 17 are indicated by arrows. As shown in the figure, one nozzle holds a three-digit dot tube holder in the horizontal direction and swings from side to side.
By moving the recording paper 17 in the direction of arrow 0 (FIG. 1), dots are printed in vertical rows. a=13 in Figure 2
5 key.

b=14. It is. Normal printing is done with 7 dots vertically, and the space in the line direction is 3 dots, making 10 dots in total.
A row is formed. The first two lines are not printed and the carriage is oscillated, and after the vibration stabilizes, seven lines of dot printing are performed, and the first line is the oscillation of the carriage and paper feeding.

FIG. 6 shows the relationship between carriage swinging, signals, and printing. S
indicates the displacement of the carriage 6. R indicates the signal of the detector 15. D indicates a drive signal for the coil 13, and 5-P indicates a print signal for ejecting the ink droplet 4 from the nozzle 2. The horizontal axis is time T. When the drive signal is applied, the carriage 6 moves in the positive direction, as shown in FIG. 1, from the left to the right. If you turn off the drive signal when the detection signal R turns off, the carriage will be 6 pieces S.
Perform damped vibration as shown in . The detection signal R is output even while the carriage 6 is returning, but during this time, the drive signal L2 is not applied. The carriage is inverted again and the open drive signal Df is applied, which produces the detection signal shown at R1. Similarly, if a drive signal is applied between the detection signals R2 and R3 while the carriage is moving from left to right, the carriage continues to vibrate with a little less energy than six. Note that printing starts from the location corresponding to the detection B1 signal R2. First, the first dot is printed at the start-up of R2, and the next dot is printed after the time T1 has elapsed. Note that the time T1 is determined by a control circuit (not shown) to be half the time of the previous detection signal R1. The next dot is printed according to the trailing edge of the detection signal R2. Similarly, printing of the next line is performed using the detection signals R3 and R6- and the time T2 calculated from the detection signal R2.

Generally speaking, a serial printer in a broad sense in which a print head performs printing by moving in the horizontal direction requires two signals: a reset signal indicating the start of printing and a timing signal indicating each print timing. Of course, if the carriage is reliably refreshed by a control signal, such as a pulse motor, the timing signal is not necessary. However, the pulse motor is expensive and consumes a lot of energy.The present invention shortens the stroke of the carriage and generates the timing signal by feedback from the pulse width of the previous reset signal, which is not a practical problem. record of poor print quality. (In each example, there is only one print timing.) (Although we have shown an example of printing three times for No. N, it is also possible to obtain four or more printing timings. In this case, as in this example, In an apparatus that performs printing in a non-uniform velocity section, the timing division is equal division "'r", and the control becomes a little complicated.

In FIG. 1, the distance between the recording paper 17 and the head 1 changes as the head 1 swings, but this does not pose much of a problem because the swing stroke is small. Particularly in the case of inkjet printing, it is advantageous because it is difficult to cause any compromise in print quality due to changes in the distance between the recording paper 17 and the head 1. FIG. 4 shows an embodiment in which the vP separation fluctuation between the 3Me record year 17 and the head 1 is made small. In this example, there are 1j20,20' on both sides of carriage 6.
is provided, and this shaft is guided by guides 21 and 21' to linearly swing from side to side. Swinging member 7 and bottle 8. bottle 12
The engaging portions 22 and 23 face the elongated holes.

Note that in the embodiments shown in Figures 1 and 4, a bottle provided in the printer body is used as the center of swing, but conversely, if the bottle is placed in the swinging member, a hole is provided in the printer body. There are various possible modifications by the designer, such as engaging the design with the other hand, and it is not intended to limit the scope of the claim. It is also conceivable to configure the carriage and the print head in one piece. Furthermore, the energy for the swing may be generated by an electromechanical conversion mechanism such as a piezoelectric element instead of the electromagnetic force as in the embodiment.

As can be seen from the above explanation, according to the present invention, the head is moved using the resonance of the swinging member without using an expensive motor, so energy consumption is low, the size can be made small, and the price is low. can.

Furthermore, by selecting the mass of each member and the distance from the center of swing so that the rotational moment is symmetrical with respect to the center of swing of the swing member, the device can be made resistant to disturbances in the lateral direction. Furthermore, since printing is performed without using timing signals, the device can be made smaller and less expensive. By using an ink-on-demand type inkjet as a print head, which is capable of non-contact recording and requires low printing energy, the advantage of low-energy driving can be further exploited. Note that the concept of the present invention can also be partially applied to, for example, thermal printers, wire dot printers, etc.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention. FIG. 2 is a diagram showing the state of printing in the embodiment of FIG. 1. FIG. 5 is a diagram showing the displacement 9- of each main part and output signals in the embodiment of FIG. 1. FIG. 4 is a diagram showing another embodiment of the present invention. Above -10- Figure 1 Figure 3 7

Claims (1)

[Claims] A swinging member that is swingably supported around a swinging center fixed to the printer body, a print head that is swingably disposed at one end of the swinging member, and a print head of the swinging member. The print head and the drive mechanism are arranged so that the rotational moment about the center of rotation due to external force in the lateral direction is approximately canceled out on the print head side and the drive mechanism side, respectively. A small printer featuring