JPH01128072A - Unpleasant noise eliminating device for image forming device - Google Patents

Abstract

PURPOSE:To change unpleasant oscillation noise to harmonized ones and to eliminate unpleasant noise by providing a sound signal outputting means which generates sound signals resonant with the unpleasant oscillation noise of constant frequency. CONSTITUTION:The title device is provided with the sound signal outputting means which generates sound signals resonant with the oscillation noise of constant frequency. That is, the oscillation noise of constant frequency generated by a separating mechanism turns into the harmonized one without the unpleasantness by resonating with the sounds outputted by the sound signal outputting means. For example, when a transferring charger 7 and an AC separating charger 8 are driven by a 1kHz AC from a high voltage unit 14 and the oscillation noise of 1kHz frequency occurs, the sound signal outputting devices 16, 17, and 18 output sound signals of frequencies which are resonant with the oscillation noise of 1kHz frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a structure for removing unpleasant sounds in an image forming apparatus.

(Prior Art) A copying machine will be taken up as a typical example of an image forming apparatus using an electrostatic latent image, and an outline of its image forming mechanism will first be explained.

FIG. 3 is a schematic front view showing an example of the structure of a copying machine. This copying machine is of a type in which a document table 1 provided on the machine and on which a document is placed moves. The upper part of the copying machine is equipped with an optical system including an exposure lamp 2 and a condensing lens 3. The light from the exposure lamp 2 scans and exposes the document moved by the document table 1, and the reflected light is condensed. The light is applied to the surface of the photosensitive drum 4 via the lens 3.

The photosensitive drum 4 is configured to rotate clockwise,
Around it, in order, a charging charger 5, a developing device 6,
A transfer charger 7, an AC separation charger 8 and a cleaner 9 are arranged. Further, a paper feed mechanism 10 and a conveyance/fixing mechanism 11 are provided for conveying the transfer paper in conjunction with the rotation of the photoreceptor drum 4.

The copying operation of this copying machine is generally as follows.

With the start of copying, the photosensitive drum 4 rotates to the right, and in conjunction with this, the document table 1 begins to move for exposure, and the paper feeding mechanism 10 feeds the transfer paper. When the exposed and scanned light falls on the surface of the photoreceptor drum 4 on which negative charges are formed by the charger 5, an electrostatic latent image of the original is formed. Toner is applied thereto by the developing device 6, and the image is developed. Next, the transfer paper fed by the paper feeding mechanism 10 is brought into close contact with the transfer paper, and the toner image is transferred onto the transfer paper by the transfer charger 7. This transfer paper is AC
The toner image is separated from the photoreceptor drum 4 by the separation charger 8 and sent to the conveying/fixing mechanism 11, where the toner image is fixed. The surface of the photosensitive drum 4 from which the transfer paper has been separated is cleaned by the cleaner 9 and charged again by the charger 5.

In a copying machine having such a configuration, the AC separate charger is currently generally driven by an alternating current of around 1 kHz. This is because it has been experimentally found that the transfer paper can be separated from the photoreceptor drum best when the AC separation charger is operated with an alternating current of this frequency.

<Problems to be Solved by the Invention> However, when the AC separated charger is operated with an alternating current of around 1 kHz, the thin wire included in the AC separated charger vibrates at that frequency, producing vibration noise. Normally, the human ear is most sensitive to a frequency band around 1 kHz, and there is a problem in that the vibration sound at a frequency of around 1 kHz can be heard as a very harsh and unpleasant sound.

Therefore, an object of the present invention is to provide a device that eliminates the above-mentioned harsh and unpleasant sound.

Means for Solving the Problems This invention includes a mechanism that develops an electrostatic latent image with toner, transfers the toner image onto transfer paper, and then separates the transfer paper from the electrostatic latent image forming section. An unpleasant sound removal device applied to an image forming apparatus in which the separation mechanism includes a member that generates a vibration sound of a certain frequency, wherein the separation mechanism generates a sound signal that resonates with the vibration sound of a certain frequency. A signal output means is provided.

Effect> The vibration sound of a certain frequency generated by the separation mechanism resonates with the sound output from the audio signal output means, thereby changing into a consonant sound that does not cause discomfort.

<Example> An example of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration around an unpleasant sound removal mechanism according to an embodiment of the present invention, which is incorporated into, for example, a copying machine shown in FIG. 3. In Figure 1,
The CPU 12 is a control center for controlling the entire operation of the copying machine, and the signals output from a predetermined output port are
The signal is applied to the AC remote terminal of the high voltage unit 14 via the inverter 13. The high voltage unit 14 outputs a 1 kHz alternating current from the AC output terminal in response to a signal applied to the AC remote terminal to drive the transfer charger 7 and the AC separation charger 8 at the same time.

This embodiment is an audio output device as follows, which is incorporated into a drive mechanism for a transfer charger 7 and an AC separation charger 8 in a copying machine 1.

That is, a signal applied from the CPU 12 to the high voltage unit 14 via the inverter 13 is simultaneously applied to the remote terminal of the oscillation circuit 16 via the inverter 15. The oscillation circuit 16 is a circuit that oscillates a signal at a constant frequency, and its output is given to the driver 17.
The piezoelectric buzzer 18 is vibrated by the oscillation output of the driver 17, and an audio signal is output.

FIG. 2 shows the oscillation circuit 16. It is a circuit example of the driver 17 and the piezoelectric buzzer 18. As shown in FIG. 2, the oscillation circuit can be constructed using an oscillation circuit IC 19, and the oscillation frequency can be set to a desired frequency by adjusting the values of the resistor 20, resistor 21, or capacitor 22.

Therefore, when the transfer charger 7 and the AC separation charger 8 are driven by a 1 kHz alternating current applied from the high voltage unit 14 and generate a vibration sound with a frequency of 1 kHz, the audio output device 16, 17, 18 generates a vibration sound with a frequency of 1 kHz. What is necessary is to output an audio signal at a resonant frequency. This resonant audio signal is, for example, an audio signal that is three degrees higher or lower in pitch than the reference vibration sound. Specifically, for example, the oscillation frequency of the oscillation circuit 16 is 636Hz or 12kHz.
A signal with an oscillation frequency such as 72 Hz is a resonant audio signal, and this frequency may be selected.

By doing so, the output sound of the piezoelectric buzzer 18 resonates with the vibration sound with a frequency of 1 kHz generated by the transfer charger 7 and the AC separation charger 8, forming a consonant sound that does not cause discomfort to the human ear, and eliminating unpleasant vibrations. Sound is removed.

In the above embodiment, a case where the unpleasant sound removal device is incorporated into a copying machine has been described. The same applies as long as it includes a mechanism for separating from the section.

Furthermore, although this embodiment uses the piezoelectric buzzer 18 as the audio output device, other audio output devices such as a speaker or the like may also be used.

<Effects of the Invention> As described above, the present invention is capable of converting an unpleasant vibration sound into a consonant sound by providing an audio signal output means that generates an audio signal that resonates with an unpleasant vibration sound of a certain frequency. It is possible to remove unpleasant sounds.

In particular, according to one embodiment of the present invention, an image forming apparatus that does not generate unpleasant noise even when using an AC separation charger operated by an alternating current with a frequency of around 1 kHz, which can most effectively separate transfer paper, can be provided. can be made.

[Brief explanation of the drawing]

・FIG. 1 is a block diagram showing the configuration of an unpleasant sound removal mechanism according to an embodiment of the present invention. FIG. 2 is a circuit diagram showing a specific example of an oscillation circuit, etc., and FIG. 3 is a structure of a copying machine. FIG. In the figure, 4... photosensitive drum, 7... transfer charger, 8... AC separation charger, 14... high voltage unit, 16... oscillation circuit, 18... piezoelectric buzzer.

Claims (1)

[Scope of Claims] 1. An image forming apparatus including a mechanism for developing an electrostatic latent image with toner, transferring the toner image to transfer paper, and then separating the transfer paper from the electrostatic latent image forming section. , an unpleasant sound removal device applied to a device in which the separation mechanism includes a member that generates a vibration sound of a certain frequency, the apparatus comprising an audio signal output means that generates an audio signal that resonates with the vibration sound of a certain frequency. An unpleasant sound removal device for an image forming apparatus, characterized in that: 2. Claims characterized in that the separation mechanism includes a separator driven by an alternating current signal of a constant frequency, and the audio signal output means is driven in conjunction with the drive of the separator. 2. An unpleasant sound removal device for an image forming apparatus according to claim 1.