JP2000252093A - Electronic parts protecting insulating sheet, lead wire protecting printed circuit board and operation panel provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of arc discharge from a notch and a peripheral edge of an insulating sheet to an electronic part by forming an insulating barrier formed of the insulating sheet extended to a panel body side at a part of the edge of the notch part provided in the insulating sheet at a part close to the electronic part on the electrical wring board. SOLUTION: An insulating sheet 5 having a notch part and formed with an insulating wall 31 is provided between a panel body 3 and a board 9, and an electronic part or the wiring 41 is arranged in the back thereof. When a user contacts with a switch button 11a with a charged finger, arc current 39 is likely to flow from a clearance in the periphery of the switch button 11a to an upper side, the notch part and the peripheral edge of the insulating sheet 5. After the arc current 39 flows from a surface of the insulating sheet 5 along the inside of the insulating wall 31 like a broken line shows, the arc current 39 should flow along the outside of the insulating wall 31. Since the arc current flows more than the case where the insulating wall 31 is not provided by a distance at twice of a height of the insulating wall 31, generation of arc current 43 from the notch part to an electronic part 41 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating sheet for protecting an electronic component such as an LED or a printed lead portion from static electricity in an operation panel of a printer, a printed lead protection substrate, and an operation provided with the same. About the panel.

[0002]

2. Description of the Related Art In an operation panel provided with electronic components such as LEDs, as shown in FIG. 10, when a user touches a switch button 101 of an operation panel 100 with an electrostatically charged finger, an arc current 103 is generated. Of the electronic component or wiring 10 on the substrate 105
7 may cause an arc discharge (indicated by an arrow 108 in FIG. 10) to destroy the function of the electronic component. Conventionally, the following method has been employed in order to prevent arc discharge to electronic components due to such static electricity. (1) A method of inserting an aluminum sheet between the board and the static electricity that has fallen to GND to escape to the metal shield of the main body. (2) Screw the metal shield plate under the board.
How to make static electricity easy to escape (3) How to dissipate static electricity by mounting something that becomes a lightning rod on the board and letting static electricity escape to a route that does not cause inconvenience (4) Put an insulating sheet between the switch button and the electronic component, and insulate the static electricity How to cut off.

[0003]

SUMMARY OF THE INVENTION Among these methods,
The method (4) can be applied to an operation panel having a case structure, and can be widely used because arc discharge can be easily prevented as compared with other methods. However, since the operation panel has recently become thinner, it is necessary to form a notch in the insulating sheet and penetrate the tip of the electronic component therethrough for a member such as an LED that protrudes from the substrate. In addition, it is necessary to form a cutout portion in the insulating sheet also at a connection portion between the panel body and the substrate.

However, the formation of the notch in the insulating sheet makes it impossible to cut off the arc current at the notch. For example, FIG.
9 shows an operation panel 100 provided with an insulating sheet 113 in which a notch 111 (which may be considered as a gap around the insulating sheet) is formed between the substrate 9 and the substrate 105. In FIG. 11, when the operator touches the switch button 101 with a finger, the arc current 103 flows from the gap around the switch button 101 onto the insulating sheet 113, but the arc current 103 flows through a short route with better conductivity. As a result, a problem arises in that an arc discharge 108 enters the notch (or a gap around the insulating sheet) 111 to the electronic component or wiring 107 and destroys the nearby electronic component or wiring 107. There is a point.

Further, the conventional method (4) is insufficient for protecting a printed conductor portion printed on a printed circuit board from arc discharge.

SUMMARY OF THE INVENTION It is an object of the present invention to prevent an arc discharge from being generated from a cutout portion of an insulating sheet or a peripheral portion of the insulating sheet to an electronic component, and to sufficiently protect a printed conductor on a printed circuit board from the arc discharge. It is an object of the present invention to provide an insulating sheet for protecting electronic components, a printed conductor protecting substrate, and an operation panel having the same.

[0007]

According to a first aspect of the present invention, there is provided an image forming apparatus, comprising: a panel body provided with a switch button and an electric wiring board; An insulating sheet for protecting electronic components on the electric wiring board, wherein the insulating sheet has a cutout portion and is formed at a position close to the electronic component on the electric wiring board. The notch is characterized in that at least a part of an edge of the notch has an insulating wall formed of an insulating sheet extending toward the panel body.

According to the present invention, when the user touches the switch button of the operation panel with the charged finger, the arc current flows from the gap of the operation panel to the operation panel side of the insulating sheet, and the arc is most likely to flow. Try to flow. However, since an insulating wall is formed around the notch formed near the electronic component, the arc current must reach the tip of the insulating wall in order to reach the electronic component from the notch. It is necessary to take a route to enter the notch after the current flows. However, since such a route is longer by a distance twice as large as the height of the insulating wall as compared with a case where no insulating wall is present, there is almost no possibility that an arc current flows through the route, and therefore, an arc to the electronic component may be generated. Discharge can be prevented.

According to a second aspect of the present invention, in the first aspect, the insulating wall is formed all around the notch. According to the present invention, it is possible to prevent the arc current from passing through the notch from the entire circumference of the notch.

According to a third aspect of the present invention, in the first aspect, the insulating wall forms an H-shaped cut in a part of the insulating sheet, and the cut portion is directed toward the operation panel. It is characterized by being formed by folding. According to the present invention, an insulating wall is easily formed around the cutout in two directions only by making an H-shaped cut in one insulating sheet and folding the cutout in two directions.

The invention according to claim 4 of the present application is provided between a panel main body having a switch button and an electric wiring board, and protects electronic components on the electric wiring board from occurrence of arc discharge due to static electricity. In an insulating sheet for protecting electronic components, near the electronic components on the electric wiring board,
An insulating wall extending from the peripheral portion to the panel body side is formed at a peripheral portion of the insulating sheet.

According to the present invention, when the arc current intruding from the gap around the switch button is about to flow toward the peripheral edge of the insulating sheet, it is only twice the height of the insulating wall at the peripheral edge of the insulating sheet. It must flow an extra distance.
Therefore, there is almost no possibility that the arc current flows through such a route. Therefore, it is possible to prevent arc discharge from the peripheral portion of the insulating sheet to the electronic component.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the insulating wall is at least 3
It has a height of not less than mm. According to the present invention, in order for the arc current to reach the electronic component, it must flow twice the height of the insulating wall, that is, an extra route of 6 mm or more. Can be prevented.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects of the present invention, the insulating sheet for protecting an electronic component further includes an auxiliary small piece of the insulating sheet on which the insulating wall is formed. An auxiliary piece is mainly used as an auxiliary member of the insulating sheet for protecting electronic parts. According to the present invention, when there is a place where it is difficult to form an insulating wall only by processing one insulating sheet, the auxiliary small piece on which the insulating wall is formed is superimposed on the place, and the part is placed in that part. Insulating walls can additionally be provided.

According to a seventh aspect of the present invention, there is provided an electric wiring board provided with an electronic component, a panel body provided on the electric wiring board and provided with a switch button, and the electric wiring board and the panel main body. Claim 1 provided between
And an insulating sheet for protecting electronic components according to any one of (6) to (8).

According to the present invention, when the worker touches the switch button with a static-charged hand, the arc current entering from the gap between the switch buttons reaches the electronic component protection insulating sheet. However, since there is an insulating wall at the edge of the notch or at the edge of the insulating sheet, the distance from the notch or the edge of the insulating sheet to the electronic component depends on the height of the insulating wall. Is twice as long.
Therefore, the arc current does not flow through such a route, and arc discharge to the electronic component can be prevented.

The printed wire protection board according to the invention of claim 8 is an electrical wiring board provided with a printed wire portion, wherein the electrical wiring corresponding to a position of a switch button on a panel body attached to the electrical wiring board. At the position of the substrate, an insulating sheet is stuck on the electric wiring substrate. According to the present invention, since the insulating sheet directly covers the electric wiring board, the arc current is interrupted by the insulating sheet, and the arc discharge to the printed conductor is sufficiently prevented.

According to a ninth aspect of the present invention, there is provided an operation panel according to the seventh aspect, further comprising the printed conductor protecting substrate according to the eighth aspect. According to the present invention, since the insulating wall exists at the edge of the notch or the peripheral edge of the insulating sheet, the distance from the notch or the peripheral edge of the insulating sheet to the electronic component is reduced by the insulating wall. It becomes longer by a distance twice the height dimension of the electronic component, preventing arc discharge to the electronic components, and interrupting the arc current by the attached insulating sheet, so that the arc discharge to the printed conductor portion is sufficient. Is prevented.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded view of an operation panel 1 of the present invention. As shown in FIG. 1, the operation panel 1 includes a panel main body 3, an insulating sheet 5, a directly attached insulating sheet 7, and an electric wiring board 9.
(Hereinafter, simply referred to as a substrate 9), and the directly attached insulating sheet 7 is attached on the substrate 9 as described later. Hereinafter, each of these components will be specifically described.

FIG. 2 shows the panel main body 3. The panel main body 3 is provided with a plurality of switch buttons, among which the switch buttons 11a to 11d have windows 13 formed therein. The window 13 is provided so that the user can recognize each state of the printer by turning on and off the LEDs 15a to 15d (see FIG. 3) provided on the substrate 9. Although various other switch buttons are provided on the panel main body 3, they are not denoted by reference numerals for simplicity, and description thereof will be omitted.

FIG. 3 shows a part of the substrate 9 before the directly attached insulating sheet 7 is attached. The substrate 9 has four LEDs 15
a to 15d are arranged corresponding to the four windows 13 of the panel body 3, respectively. Switch action parts 17a to 17d are provided adjacent to the LEDs 15a to 15d. When the switch buttons 11a to 11d of the panel main body 3 are pressed with fingers, the switch action sections 17a to 17d are pressed by switch pressing sections 19a to 19d (see FIG. 6) formed on the back side of the switch buttons. Is turned ON, and the corresponding LEDs 15a to 15d are simultaneously turned on.

FIG. 4 shows a substrate 9 to which the directly attached insulating sheet 7 is attached. The directly-attached insulating sheet 7 is attached to the substrate 9 using a double-sided tape or the like so as to cover the entire printed conductor 21 (see FIG. 3) formed on the substrate 9.
By attaching the directly attached insulating sheet 7 to the printed conductor 21 on the substrate 9 in this manner, the switch buttons 11a to
Even if the arc current that has entered from the gap around 11 d reaches the substrate 9, the arc current or arc discharge is interrupted by the directly attached insulating sheet 7, and the printed conductor 21 can be protected.

Next, the insulating sheet 5 for protecting electronic parts of the present invention provided between the panel body 3 and the substrate 9 described above.
Will be described with reference to FIG. When the panel body 3 is attached to the substrate 9, the LED 1
LEDs 15a to 15d are located at locations where 5a to 15d are located.
Notch portions 27a to 27d are formed so that the tip portion can penetrate insulating sheet 5.

As shown in FIG. 5, notches 27a-27
d has a rectangular shape, and the cutout portions 27a to 27d
Are formed by bending the insulating sheet 5 at right angles to the panel body 3 side on a pair of opposing sides (sides near the gaps around the switch buttons 11a to 11d) among the four sides constituting An insulating wall 29 is formed. Insulating wall 2
9 is preferably 3 mm or more, but the positions of the notches 27a to 27d are determined by the switch buttons 11a to 11d.
If the distance from the gap around 11d can be ensured, the height may be less than 3 mm.

In order to form the insulating wall 29 of this embodiment, an H-shaped cut is made at a predetermined position on a flat insulating sheet, and a portion surrounded by the cut is formed by the panel body 3.
Completed by bending to the side. According to this method, the cutout portions 27a to 27d having the two insulating walls 29 can be easily formed only by using one insulating sheet 5. Further, the insulating wall 29 is formed by cutting the
In order to form around notch 27d,
Small pieces of another insulating sheet may be post-fixed to the insulating sheet 5 on which to 27d are formed by using a double-sided tape or the like.

In the above embodiment, the notch 2
An insulating wall 29 is formed at a part of the edge of each of the cutouts 27a to 27d.
May be formed. Furthermore, in the above-described embodiment, the cutouts 27a to 27d have a rectangular shape. However, even when the cutouts have other shapes, the switch button 1
The insulating wall 29 can be provided on the side closer to the gap around 1a to 11d, or the insulating wall 29 can be provided all around the notch.

Next, another embodiment of the insulating wall 29 will be described. As shown in FIG. 5, an insulating wall 31 is formed on one side of a peripheral portion of the insulating sheet 5 by bending the sheet toward the panel body 3. This insulating wall 31
The arc current that has entered through the gaps around the switch buttons 11a to 11d is applied to the switch action portions 17a to 17d and the LEDs 15a to 15 on the substrate 9 from the periphery of the insulating sheet 5.
This is to prevent the flow to d.

FIG. 7 shows an auxiliary piece 33 made of an insulating sheet formed separately from the insulating sheet 5. The auxiliary small piece 33 is formed by bending a flat insulating sheet piece substantially at the center to form an insulating wall 37 extending to the panel body 3 side.
It is provided on the periphery of the insulating sheet 5 at the boundary between the LCD 11b and the LCD 35 (see FIG. 6). Incidentally, in such a position, it is difficult to bend the peripheral edge of the insulating sheet 5 to form an insulating wall. Therefore, the auxiliary small piece 33 of another member is used as an auxiliary of the insulating sheet 5.

Next, the operation of the insulating wall, which is a characteristic configuration of the present invention, will be described with reference to FIGS. FIG. 8 shows that the insulating sheet 5 on which the insulating wall 29 (31) is formed is provided between the panel main body 3 and the substrate 9, and the electronic component or the wiring 41 is arranged behind the insulating sheet 5 having the notch. It shows how it is.

In FIG. 8, when the user touches the switch button 11a with a charged finger, an arc current 39 tends to flow to the upper side of the insulating sheet 5 from a gap around the switch button 11a. When the arc current 39 flows to the notch or the peripheral portion of the insulating sheet 5, as shown by the broken line in FIG. 8, the arc current 39 flows along the inside of the insulating wall 29 (31) from the surface of the insulating sheet 5 and thereafter. Must flow along the outside of 29 (31) (to the left in the figure). This means that compared with the case where the insulating wall 29 (31) does not exist, the extra flow must be performed by a distance corresponding to twice the height of the insulating wall 29 (31). As a result, the arc current cannot follow such a long path. Therefore, as shown by the crosses in the figure, arc discharge 43 from the notch or the like to the electronic component 41 is unlikely to occur.

FIG. 9 shows a substrate 9 in addition to the configuration of FIG.
3 shows a state in which the directly attached insulating sheet 7 is attached to and covered by the printed conductor 21 of FIG. Also in FIG. 9, the arc current 39 tends to flow along the same route as in FIG. In the case of FIG.
, The arc discharge 43 is cut off by the directly attached insulating sheet 7 and the printed conductor 21 is protected.

[0032]

According to the present invention, the presence of the insulating wall around the notch and the peripheral portion of the insulating sheet makes the path of the arc current longer by twice the height of the insulating wall. Therefore, the arc current hardly flows through the route where the insulating wall exists, and the arc discharge to the electronic components on the substrate located near the insulating wall hardly occurs.

Also, by directly attaching the insulating sheet to the printed conductor on the substrate, even if there is an arc discharge on the substrate, the directly attached insulating sheet blocks the arc discharge and protects the printed conductor. can do.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an operation panel of the present invention.

FIG. 2 is a front perspective view of the panel body of the present invention.

FIG. 3 is a partial perspective view of a substrate on which the directly-attached insulating sheet of the present invention is not attached.

FIG. 4 is a front view of a substrate to which the directly-attached insulating sheet of the present invention is attached.

FIG. 5 is a perspective view of the insulating sheet of the present invention.

FIG. 6 is a rear view of the panel main body, showing a state where an insulating sheet is arranged on the rear side of the panel main body of the present invention.

FIG. 7 is a perspective view showing a state in which an auxiliary piece of another component is provided on the insulating sheet of the present invention.

FIG. 8 is an explanatory diagram showing an operation of an insulating wall in the insulating sheet of the present invention.

FIG. 9 is an explanatory view showing the operation of the insulating wall and the directly attached insulating sheet in the insulating sheet of the present invention.

FIG. 10 is an explanatory view showing a conventional technique in which an insulating sheet does not exist between a panel body and a substrate.

FIG. 11 is an explanatory view of a related art showing a state where a conventional insulating sheet is provided between a panel main body and a substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Operation panel 3 Panel main body 5 Insulating sheet 7 Directly-attached insulating sheet 9 Substrate 11a-11d Switch button 13 Window 15a-15d LED 17a-17d Switch action part 19a-19d Switch pressing part 21 Printed conductor part 27a-27d Notch part 29 , 31, 37 Insulating wall 33 Auxiliary piece 35 LCD 39 Arc current 41 Electronic component 43 Arc discharge

Claims (9)

[Claims] 1. An insulating sheet for protecting electronic components provided between a panel body having switch buttons and an electric wiring board and protecting the electronic parts on the electric wiring board from occurrence of arc discharge due to static electricity. The insulating sheet has a notch, and a notch formed at a position close to the electronic component on the electric wiring board has at least a part of an edge of the notch on the panel body side. An insulating sheet for protecting electronic parts, wherein an insulating wall composed of an insulating sheet extending to the bottom is formed. 2. The insulating sheet for protecting electronic parts according to claim 1, wherein the insulating wall is formed all around the notch. 3. The panel according to claim 1, wherein the insulating wall is formed by forming an H-shaped cut in a part of the insulating sheet and folding the cut portion toward the panel body. Insulating sheet for protecting electronic components. 4. An insulating sheet for protecting electronic components, which is provided between a panel body having switch buttons and an electric wiring board and protects electronic parts on the electric wiring board from occurrence of arc discharge due to static electricity, An insulating sheet for protecting an electronic component, wherein an insulating wall extending from the peripheral portion to the panel body side is formed in a peripheral portion of the insulating sheet near the electronic component on the electric wiring board. 5. The insulating sheet according to claim 1, wherein the insulating wall has a height of at least 3 mm. 6. The electronic component according to claim 1, wherein the insulating sheet for protecting electronic components further comprises auxiliary small pieces of the insulating sheet on which the insulating wall is formed, and the auxiliary small pieces are mainly used. An insulating sheet for protecting electronic parts, which is used as an auxiliary member of the insulating sheet for protection. 7. An electric wiring board provided with an electronic component, a panel body provided on the electric wiring board and provided with a switch button, and provided between the electric wiring board and the panel body. An operation panel comprising: the insulating sheet for protecting electronic components according to any one of the above. 8. An electric wiring board provided with a printed conductor portion, wherein an insulating sheet is provided on the electric wiring board at a position of the electric wiring board corresponding to a position of a switch button of a panel main body attached to the electric wiring board. A printed conductor protection board, which is attached. 9. An operation panel according to claim 7, further comprising the printed wire protection board according to claim 8.