JPH05193219A - Printer cover - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a cover for a printer, which facilitates mounting and discharging of printing paper and can significantly reduce noise during printing operation. [Structure] Five print sheets are fed between the print head 9 and the platen 11 to perform printing on the print sheet 5. The print sheet 5 is closely attached to the inlet or outlet of the print sheet 5 of the printer. Thus, a soundproof wall mechanism that forms a wavy paper path is provided, and the soundproof wall that forms the soundproof wall mechanism forms a hollow silencer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer, and more particularly to a printer cover which is often used for an output device of a computer.

[0002]

2. Description of the Related Art Conventionally, an impact printer disperses a considerable amount of noise to the surroundings during its printing operation. The cover of the printer is provided with an opening for feeding and discharging the printing paper, and most of the noise leaks out from this opening. In order to reduce noise leakage, it can be solved to some extent by narrowing this opening.

Further, the paper path is blocked by a printing paper,
Japanese Patent Application Laid-Open No. 59-146880 discloses a printer cover that attempts to reduce noise leaking from the opening. This is because the shelf is inserted into the opening of the printer cover to separate the front and back of the printing of the printing paper, and the protrusions are formed on the shelf and the upper surface of the printer cover facing each other. Slide the printing paper between the
The opening that causes sound leakage is made as small as possible.

[0004]

However, if the opening is narrowed, it becomes difficult to mount and discharge the printing paper. Further, even if the paper path is blocked by the print paper, the print paper is thin, so that noise cannot be sufficiently prevented.

The present invention has been made to solve the above-mentioned problems, and provides a printer cover that facilitates mounting and discharging of printing paper and can significantly reduce noise during printing operation. To do.

[0006]

In order to achieve this object, the cover of the printer of the present invention feeds a print sheet between the print head and the platen and prints on the print sheet. A sound deadening wall mechanism that forms a corrugated paper path is provided in close contact with the inlet or outlet of the printing paper of the printer, and a hollow silencer is formed by the sound deadening wall that forms the sound deadening wall mechanism.

[0007]

The cover of the printer of the present invention having the above structure has a soundproof wall mechanism for forming a corrugated paper path, and the printing paper discharged from the printer contacts the soundproof wall to block the paper path. To run. Since the printing paper blocks the paper path, the noise leaking from the inside of the printer is reduced.

Furthermore, since the sound deadening wall constitutes a hollow silencer, it is possible to absorb the noise that could not be prevented by closing the opening with printing paper.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of the present invention. The cover 1 of the printer is composed of an upper cover 2, a lower cover 3 and a paper path 4, and prints the inserted print paper 5 in the cover 1 and moves the print paper 5 for discharging after printing. The mechanism 6 is housed. The printing mechanism 6 includes a print head 9 movably mounted on a guide shaft 8 fixed to a side plate 7, a platen 11 facing the print head 9 with an ink ribbon 10 interposed, and a guide roller 1.
It consists of 2, 13 and so on. Platen 11, guide roller 1
2, 13 have a predetermined speed by a driving means (not shown),
Rotate at a predetermined pitch. Reference numeral 14 is a guide fixed to the lower cover 3, and guides the printing paper 5 inserted in the cover 1 to the platen 11 through the passage 14a. Further, the upper surface of the cover 1, that is, the upper cover 2, has a cover opening 2a for ejecting the printing paper 5.

The paper path 4 has a hollow silencer structure between the insertion port 4a of the printing paper 5 after printing and the discharge port 4b of the printing paper 5 after printing. Specifically, the first member 24 having a box-like shape having a slit-shaped opening in appearance.
And the second member 25.

The first member 24 includes a first soundproof wall 24a and a second soundproof wall 24a.
Soundproof wall 24b, third soundproof wall 24c, fourth soundproof wall 24d,
A fifth soundproof wall 24e, a first partition wall 24f, a second partition wall 24g,
The third partition 24h, the fourth partition 24i, and the top plate 24j. The second member 25 includes a first soundproof wall 25a and a second soundproof wall 2
5b, a third soundproof wall 25c, a fourth soundproof wall 25d, a fifth soundproof wall 25e, a first partition wall 25f, a second partition wall 25g, a third partition wall 25h, a fourth partition wall 25i, and a bottom plate 25j.

The first chamber 26a includes a first soundproof wall 24a, a second soundproof wall 24b, a first partition wall 24f, a top plate 24j, a first soundproof wall 25a, a second soundproof wall 25b, a first partition wall 25f and a bottom plate 25.
j. The second chamber 26b is replaced with the second soundproof wall 24.
b, the third soundproof wall 24c, the second partition wall 24g, the top plate 24j,
Second soundproof wall 25b, third soundproof wall 25c, second partition wall 25
g, the bottom plate 25j. Third chamber 26c
Soundproof wall 24c, fourth soundproof wall 24d, third partition wall 24h, top plate 24j, third soundproof wall 25c, fourth soundproof wall 25d, third
It is composed of a partition wall 25h and a bottom plate 25j. Fourth chamber 26
d is the fourth soundproof wall 24d, the fifth soundproof wall 24e, the fourth partition wall 2
4i, top plate 24j, fourth soundproof wall 25d, fifth soundproof wall 25
e, the fourth partition wall 25i, and the bottom plate 25j.

Each partition wall guides the printing paper 5 so that the printing paper 5 can smoothly pass through the paper passage, and also extends from the first chamber 26a to the fourth chamber.
The rooms up to room 26d are each divided into smaller rooms. The paper path from the insertion port 4a to the ejection port 4b has a corrugated shape,
The printing paper 5 passes through the paper passage while contacting the first member 24 or the second member 25. As a result, the inside and outside of the printer can be shielded by the printing paper, and the noise generated inside the printer can be shielded.

In the cover 1 of this printer, the printing paper 5
The paper path 4, that is, the first member 24 and the second member 25 are removed to attach and detach the sheet. The printing paper 5 is the guide roller 1.
It is guided by 2 and 13 and inserted into the insertion port 4a.

Each of the first chamber 26a to the fourth chamber 26d has a hollow silencer structure, and the noise generated from the printing mechanism 6, that is, the print head 9 passes through the sheet path 4 having the hollow silencer structure. As a result, it is sufficiently absorbed and attenuated, and the noise of the entire printer becomes extremely small. The cavity type silencer is a silencer having a structure in which the cross-sectional area of the duct is changed, and the sound incident on the silencer is reflected and reduced at the changing section of the cross section.

Transmission loss TL of a cavity silencer as shown in FIG.
(DB) is given by the following equation.

[0018]

[Equation 1]

M = S ₁ / S ₂ : expansion ratios S ₁ and S ₂ : cross-sectional area (m ² ) k = 2πf / c: wave number (1 / m) f: frequency (Hz) c: sound velocity (m / s) ) L: Length of cavity (m) FIG. 4 is a graph of the transmission loss TL (dB) calculated by the above equation. From FIG. 4, the maximum value of the transmission loss is obtained at the frequency f = c / (4l). Therefore, if the cavity length is determined so that this frequency matches the drive cycle of the print head 5, a large noise reduction is achieved. The effect is obtained.

Assuming that the printing cycle is 4 (kHz) and the sound velocity is c = 340 (m / s), the length of the cavity is l = 21.
It becomes 25 (mm). First soundproof wall 24a and second soundproof wall 2
4b interval, second soundproof wall 24b and third soundproof wall 24c, third soundproof wall 24c and fourth soundproof wall 24d, fourth
Between the soundproof wall 24d and the fifth soundproof wall 24e, l = 21.25
If it is set to (mm), a great sound reduction effect can be obtained.

The present invention is not limited to the embodiments described above, and various changes can be made without departing from the spirit of the invention.

In the present embodiment, the intervals of the soundproof walls are all the same so that the noise of the printing cycle can be silenced. However, the intervals of the soundproof walls can be changed little by little so that the noise of various frequencies can be silenced. You can

Further, although the number of the small chambers is four in the present embodiment, the number of the small chambers may be one and is not limited.

In this embodiment, the hollow type silencer structure is attached to the discharge port of the printing paper, but it may be attached to the supply port of the printing paper.

[0025]

As is apparent from the above description, the cover of the printer of the present invention is provided with a soundproof wall mechanism which is in close contact with the inlet or outlet of the printing paper to form a corrugated paper path. Since the sound deadening wall forming the sound deadening wall mechanism constitutes the hollow silencer, the noise generated in the print head is absorbed in the printer cover, and the opening is closed with the printing paper, so that the outside of the printer can be prevented. It is possible to prevent leaking noise.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a printer cover of the present invention.

FIG. 2 is a partial cross-sectional perspective view showing a hollow silencer used for the cover of the printer of the present invention.

FIG. 3 is a schematic view of a cavity silencer.

FIG. 4 is a characteristic diagram showing the transmission loss of a cavity silencer.

[Explanation of symbols]

 1 Cover 4 Paper Path 5 Printing Paper 9 Print Head 11 Platen

Claims (1)

[Claims] 1. A printer for feeding printing paper to the inside of a casing to print on the printing paper, wherein the printing paper feed port or discharge port of the printer is in close contact with the corrugated paper path. A cover for a printer, characterized in that a sound deadening wall mechanism for forming a hollow silencer is provided, and the sound deadening wall for forming the sound deadening wall mechanism constitutes a hollow silencer.