JPH03166978A - Printer - Google Patents

Abstract

PURPOSE:To reduce noise without varying the structure and size of a printer by provid ing a generated sound sensor which detects a soundwave or an oscillation generated by a mechanism, a speaker device which generates a soundwave or an oscillation which cancels a noise and its control device. CONSTITUTION:A generated sound sensor device 3 is installed preferably at a place where a soundwave or an oscillation generated a mechanism is conducted directly. A speaker device 5 is installed at a place where a generated sound is effectively cancelled or near a sound generation source. The generated sound sensor device 3 generates an output at a phase angle of oscillation rotated almost by pi using a phase angle rotation device 14, and this output is amplified to any appropriate amplitude which cancels a generated sound using an AF amplification device 16. Then this ampli fied output drives the speaker device 5. A phase angle adjustment device 15 and a gain adjustment device 17 adjust the gain of an amplifier and the phase angle finely. In addition, these devices 15, 17 correct an error attributed to a position where the generated sound sensor device 3 and the speaker device 5 are installed and their intrin sic phase delay, the shape of a case and the frequency characteristics of an electric circuit. Thus the devices 15, 17 are set so that the generated sound is effectively can celled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for reducing noise in a printer. [Prior technology] Printers include impact type serial dot matrix printers, which create characters in a dot matrix by holding down paper and passing an ink ribbon through it and hitting selective locations with a thin bottle, as well as thermal transfer and non-impact printers. ．． In any case, since it is a device that prints on paper, it originally has a mechanism that is driven by a control circuit to perform the desired operation.When a mechanism is driven at high speed, sound waves or vibrations are inevitably generated for some reason.
During operation, it makes noise and disturbs the surrounding environment. In particular, impact-type serial printers generate extremely loud noise due to problems with the printing method itself. In such cases, noise countermeasures have been taken by: ・Putting sound-absorbing material on the inside of the printer's case ・Reducing the level of noise by purchasing materials and improving the structure of the source of the noise ・Resonance, These included designing the entire printer with a structure and materials that avoid resonance, making the opening small to prevent noise radiation, and using the printer in a special noise-prevention case, such as a soundproof case. [Problems to be Solved by the Invention] However, with the above-mentioned conventional technology, in the case of impact-type serial printers, it is not possible to expect much effective improvement other than using the printer in a special soundproof case. Specifically: - Sound absorbing materials cannot be used on transparent parts of the case, and their effectiveness will be halved if there are openings. Also, if you use it a lot, it will become large - It is unthinkable to have a printer without an opening (you can't get paper out) - Changing the material would cost a lot of money to improve the effect - Changing the structure is better than a small printer. However, there is an effective method of using it in a special case, which has the problem of being difficult to apply.
Unfortunately, it is very difficult to use and large. Therefore, the present invention is intended to solve such problems, and its purpose is to be able to be additionally attached to the conventional structure,
Another object of the present invention is to provide a printer device with effective noise reduction without increasing the size of the device. [Means for Solving the Problems] The noise-reducing printer device of the present invention includes (1) one or more generated sound sensor means for detecting sound waves or vibrations emitted by a mechanism; sound waves or vibrations for canceling noise; or (2) one or more sound sensor means for detecting sound waves or vibrations emitted by the mechanism, and one or more sound sensor means for detecting sound waves emitted to the outside. The present invention is characterized by comprising at least one radiated sound sensor means, one or more speaker means for generating sound waves or vibrations that cancel noise, and a control means therefor. [Operation] According to the above configuration (1) of the present invention, the sound wave or vibration emitted by the mechanism is detected, and the speaker means generates a sound wave or vibration whose phase angle is delayed by approximately π to cancel the detected sound wave or vibration. By adjusting the phase rotation angle and output amplitude of the control means, it is possible to actively absorb noise. Further, according to the precept (2) of the first part of the present invention, the sound wave or vibration emitted by the mechanism is detected, and the sound wave or vibration whose phase angle of the vibration is delayed by approximately π to cancel the detected sound wave or vibration is transmitted from the speaker means. By automatically adjusting the phase rotation angle and output amplitude of the control means to minimize the sound waves radiated to the outside, the noise can be actively absorbed. [Embodiment] FIG. 1 is a sectional view showing the structure of a printer device in an embodiment of the present invention. There are no major structural changes. The added elements are a generated sound sensor means (3),
Only the speaker means (5), the radiated sound sensor means (l2) and their control means are present in the control circuit and power supply (1). The generated sound sensor means (3) is installed at a location where the sound waves or vibrations generated by the mechanism are transmitted as directly as possible. On the other hand, the radiated sound sensor means (12) is provided with a damper (l) near the opening of the case so that the sound waves or vibrations generated by the mechanism are not directly transmitted as much as possible and the sound waves or vibrations radiated to the outside can be successfully detected.
It can be installed using 1). The speaker means (5) is
It can be installed in a convenient position to cancel the generated sound, near the source. FIG. 2 is a block diagram of an embodiment of the present invention, in which the radiated sound sensor means (12) is not used. The output of the generated sound sensor means (3) has the phase angle of vibration rotated by approximately π by the phase angle rotation means (14), and is converted into an AF (Audio F).
frequency) is amplified by the amplifier means (16) to an amplitude suitable for canceling the generated sound, and drives the speaker means (5). The phase angle adjustment means (15) and the gain adjustment means (17) finely adjust the phase angle and the gain of the amplifier, and adjust the mounting positions of the generated sound sensor means (3) and the speaker means (5>) and their own phase delays. , corrects errors caused by the shape of the case, the frequency characteristics of the electric circuit, etc., and is set so that the generated sound can be canceled as well as possible. Fig. 3 is a block diagram of an embodiment of the present invention, in which the radiated sound sensor means (12〉) is used.The difference from the case in Fig. 2 is that the phase angle adjustment means (l5〉) and the gain adjustment means (
17), a radiation sound sensor means (12), a sound pressure/voltage conversion means (28), and a phase angle and gain control section (29) are provided. With these, the phase and amplitude of the sound waves output by the speaker means (5>) are always adjusted to the optimal state for canceling the generated sound.The phase angle and gain control section (29>
It is controlled by the PU (24), the input is the A/D conversion means (27), the output is the D/A conversion means (20),
(21), and the sound pressure/voltage conversion means (28
) so that the output level of the phase angle rotation means (1
4) Phase rotation angle and AF (Audio Freque
ncy) Adjust the gain of the amplifier means (16). The storage means (25) is provided because it is necessary to store the previous level when differentiating the sound pressure/voltage conversion means (28). The specific method of control will be described in the flowchart of Figure 6. FIG. 4 is a block diagram of an embodiment of the present invention, and is an example in which optimal automatic adjustment of the phase rotation angle and output amplitude is performed more precisely by dividing it into several cases depending on the frequency. What is different from the case in Fig. 3 is the generated sound sensor means (3) and the radiated sound sensor means (l).
The output of 2) is initially separated into three frequency components by frequency separation means 1 (30) and frequency separation means 2 (31), each of which is independently processed by the method shown in FIG. 3, and finally mixed by mixer means. (41), A
F (Audio Frequency) is to drive the speaker means (5) through the amplifier means (42>.Originally, the generated sound sensor means (3>) and the speaker means (5)
> The phase delay caused by the mounting position of the components, their own phase delay, the shape of the case, and the complex characteristics of the electrical circuit change depending on the frequency, so strictly speaking, the phase rotation angle and output will vary over the entire frequency range. It is impossible to perform optimal automatic adjustment of the amplitude. Therefore, by separating the frequency bands into a limited number of (three in this case) frequency bands from the beginning, we can eliminate the frequency characteristics of electrical and physical characteristics as much as possible, and create a system that aims for more optimal control. This is the configuration shown in Figure 4. The finer the separation of frequency VL borrowed areas, the better the results will be, but it is not practical to have too many.
Particularly for serial impact printers, where the frequency of generated sound is limited, the frequency should be selected roughly and optimally so that control can be achieved at that frequency. FIG. 5 is a diagram showing the operation of the embodiment of the present invention, showing the generated sound and the sound waves from the speaker means (5) created to cancel it. The generated sound and the sound waves from the speaker means (5) made to cancel it are 2
If there are two ideal sound sources, the sound waves from the speaker means (5) whose phase is delayed by π will almost completely cancel the generated sound, but in reality, the difference in the physical position of the two sound sources,
Differences in propagation paths, differences in generation forms, etc. cause complex interference, and it cannot be expected to work well in all frequency ranges. but,
The source of the dominant single frequency component is generally local;
It is also effective because the sound source is small compared to the wavelength. FIG. 6 is a flowchart showing the operation of the phase angle and gain control section (29) in the embodiment of the present invention.
(46) is the initial setting, (47) is to take in the data from the radiation sound sensor means (l2), (48> is to compare with the previous data and change is examined, (49) is to adjust the phase angle or gain. Select whether to adjust or not. When you find out that the result is worse from judgments (50) and (51), (52),
(53) to change the direction of control and reverse it (reverse the sign of the numerical value to be slightly changed), (50), (51>
If the result is not bad, leave the current direction and make small changes to the settings in (54) and (55).
The decision as to whether to adjust the phase angle or the gain in (49) should be made alternately at intervals longer than the time required for the control system to settle down. [Effects of the Invention] As described above, according to the present invention, it can be additionally attached to a conventional structure, and it is possible to effectively improve noise without increasing the size of the device. It is possible to provide a low-noise printer without changing the structure or size of current printers, including printers, and has the effect of not disturbing the environment around the printer.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of a printer device in an embodiment of the present invention. FIG. 2 is a block diagram of an embodiment of the present invention, in which the radiated sound sensor means (12) is not used. FIG. 3 is a horizontal diagram in an embodiment of the present invention, in which the radiated sound sensor means (12)
This is the case when using FIG. 4 is a block diagram of an embodiment of the present invention, and is an example in which optimal automatic adjustment of the phase rotation angle and output amplitude is divided into several cases depending on the frequency and performed more precisely. Fig. 5 is a diagram showing the operation of the embodiment of the present invention, showing the generated sound and the sound wave from the speaker means (5) made to cancel it. Fig. 6 shows the phase in the embodiment of the present invention. It is a flowchart showing the operation of the angle and gain control section (29).

Claims (2)

[Claims] (1) In a printer device that prints by driving a mechanism, one or more sound sensor means for detecting sound waves or vibrations emitted by the mechanism, and one or more speakers for generating sound waves or vibrations that cancel the noise. What is claimed is: 1. A printer device comprising a means and a control means for the printer. (2) In a printer device that prints by driving a mechanism, one or more generated sound sensor means for detecting sound waves or vibrations emitted by the mechanism, and one or more emitted sound sensor means for detecting sound waves radiated to the outside. 1. A printer device comprising one or more speaker means for generating sound waves or vibrations that cancel noise, and a control means therefor.