JP2017050225A - Information input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide, for an information input device comprising push buttons, an operation switch unit that can prevent external static electricity from flowing in an electric circuit with inexpensive constitution never spoiling an operation feeling.SOLUTION: The present invention relates to an operation device comprising: a push button; a printed board; a dome switch mounted on the printed board and electrically connecting with a copper foil pattern formed on a wiring plate of the printed board as the push button is pressed down; a retaining sheet which has insulation properties and retains the dome switch on the printed board; a metallic receiving plate fitted with the printed board; and a both-sided tape for fitting the printed board to the receiving plate. The wiring plate has a through hole in a projection region of the dome switch, the both-sided tape has a partial region, including a through hole projection part, cut, and the insulation sheet is stuck on the receiving plate to cover a region wider than the area at least in an assembled state.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an information input device provided in an electronic apparatus such as a camera or a video camera, and more particularly to an operation switch unit provided with a push button.

  Electronic devices such as single-lens reflex cameras are provided with operation members for performing various operations. In addition to buttons arranged independently on the operation member, for example, it can tilt in multiple directions as a means to select any focus detection area or a menu item from among multiple focus detection areas displayed in the viewfinder Some tilt switches and a plurality of push switches are provided. Further, as means for setting various types of information including camera photographing information, there is one provided with a rotary dial operation member that changes the set amount in accordance with the rotation direction and the rotation amount of the dial.

  However, the rotating or pressing operation member is generally incorporated in the camera exterior with a slight gap for rotation and pressing, but static electricity charged to the photographer enters the gap between the operation member and the camera exterior. In addition, the electric circuit inside the camera may be damaged. Therefore, conventionally, attempts have been made to prevent destruction of the electric circuit inside the camera due to external static electricity on the operation member.

  Patent Document 1 discloses a configuration in which an elastic member provided on a key top of a button is electrically connected to a ground pattern of a substrate, and external static electricity is released to the ground. Patent Document 2 discloses a configuration in which a ground pattern is provided in the vicinity of a terminal end portion of an exterior gap of a substrate, and portions other than the ground pattern are covered with an insulating sheet so that extraneous static electricity is released to the ground.

JP 2004-146203 A JP 2013-251161 A

  However, the conventional technique disclosed in Patent Document 1 described above is disadvantageous in terms of cost and assembly because a conductive elastic material is newly incorporated in the key top. In addition, there is a possibility that the operational feeling is impaired by the addition of the elastic material. In the prior art disclosed in Patent Document 2 described above, since the insulating sheet has an irregular shape for opening the ground pattern portion, workability and assembly are disadvantageous. Further, since it does not cause contact discharge, it cannot be said that it is a reliable countermeasure against static electricity. For example, when an air hole of an insulating sheet is provided in the button portion, static electricity may flow from the portion to the signal line.

  In addition, both conventional technologies are designed to release static electricity to the ground on the board. However, the ground on the board is not always connected to a strong housing ground or the like. It could not be said that the configuration can be surely protected.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an operation switch unit that can prevent external static electricity from flowing into an electric circuit with an inexpensive configuration that does not impair the operational feeling in an information input device having a push button. There is to do.

In order to achieve the above object, an operating device according to the present invention includes:
Push buttons (82), (83),
A printed circuit board (90);
A dome switch mounted on the printed circuit board (90) and conducting with a copper foil pattern formed on the wiring board (92) of the printed circuit board (90) when the push buttons (82) and (83) are pressed. 91)
A holding sheet (94) having insulation and holding the dome switch (91) on the printed circuit board (90);
A metal backing plate (86) to which the printed circuit board (90) is attached;
A double-sided tape (95) for attaching the printed circuit board (90) to a receiving plate (86);
An operating device comprising:
The wiring board (92) has a through hole (96) in the projection area of the dome switch (91),
In the double-sided tape (95), a partial region (95a) including the projection portion of the through hole (96) is cut out,
An insulating sheet (85) is attached to the backing plate (86) so as to cover a region wider than the region (95a) at least in an assembled state.

  According to the present invention, there is provided an operation switch unit capable of preventing external static electricity from flowing into an electric circuit with an inexpensive configuration that does not impair the operational feeling in an information input device including a push button. Can do.

It is an external appearance perspective view of the imaging device in this embodiment. It is a disassembled perspective view of the operation part unit in this embodiment. It is a fragmentary sectional view of the operation part unit in this embodiment. It is the elements on larger scale which looked at the printed circuit board in this embodiment from the back side.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIGS. 1A and 1B are external views of an imaging apparatus 100 as an example of the electronic apparatus of the present invention. FIG. 1A is a front perspective view of the imaging apparatus 100, and FIG. 1B is a rear perspective view of the imaging apparatus 100.

  The shutter button 61 is an operation unit for issuing a shooting instruction. The mode switch 60 is an operation unit for switching various modes. The terminal cover 64 is a cover that protects a connector (not shown) such as a connection cable that connects a connection cable with an external device and the imaging apparatus 100. The main electronic dial 71 is a rotation operation member. By turning the main electronic dial 71, various setting values such as a shutter speed and an aperture can be changed. The power switch 72 is an operation member that switches the power of the imaging apparatus 100 on and off. Reference numeral 80 denotes an operation switch unit including a dial and a push button.

  The sub electronic dial 81 is a rotary operation member, and can move a selection frame, feed an image, and the like. 82 and 83 are push buttons, and 82 is mainly used for determining a selection item. Reference numeral 83 denotes a push button for tilting operation (hereinafter referred to as tilting operation button), which can be tilted up, down, left, and right, and can be operated in each direction.

  The enlargement button 77 is an operation button for turning on / off the enlargement mode and changing the enlargement ratio during the enlargement mode in the live view display in the photographing mode. In the reproduction mode, it functions as an enlargement button for enlarging the reproduction image and increasing the enlargement ratio. The playback button 78 is an operation button for switching between the shooting mode and the playback mode. Pressing the playback button 78 during the shooting mode shifts to the playback mode. The LV lever 73 is an operation member that switches between a still image shooting mode and a moving image shooting mode. The LV button 74 is a button for switching live view ON and OFF in the still image shooting mode.

  In the moving image shooting mode, it is used to start and stop moving image shooting (recording). The quick return mirror 62 is instructed by the system control unit 30 (not shown) and rotated by an actuator (not shown). The communication terminal 63 is a communication terminal for the imaging apparatus 100 to communicate with a photographing lens (not shown) (not shown). The eyepiece finder 16 is a view-type finder for observing a focusing screen (not shown) to confirm the focus and composition of an optical image of a subject obtained through a lens unit (not shown). The lid 66 is a slot lid that allows the recording medium to be attached and detached. The grip portion 65 is a holding portion that is shaped to be easily gripped with the right hand when the user holds the imaging device 100.

  2A is an exploded perspective view of the operation unit 80, and FIG. 2B is an exploded perspective view of a flexible printed circuit board 90 (hereinafter referred to as a flexible substrate) that is a component of the operation unit 80. FIG.

  As shown in FIG. 2A, the operation unit 80 is composed of a sub electronic dial 81 and a push button unit, and the push button unit includes a push button 82, a tilt operation button 83, a rubber member 84, a flexible substrate. 90, the insulating sheet 85, and the receiving plate 86 are laminated.

  Here, the rubber member 84 is arranged for the purpose of enhancing the feeling of button operation and quietness, but may be omitted as appropriate according to the specifications required for the imaging apparatus 100. The receiving plate 86 is a metal plate arranged to receive a button pressing force for the purpose of enhancing the button operation feeling, and is made of stainless steel so that a required rigidity can be satisfied with a thin plate.

  As shown in FIG. 2B, the flexible substrate 90 includes a metal dome switch 91, a cover lay 93 as an insulating member, and a sheet 94 for holding the metal dome switch on a wiring board 92 on which a copper foil pattern is formed by etching or the like. (Hereinafter, holding sheet) is laminated. A double-sided tape 95 used for mounting the flexible substrate 90 is affixed to the surface opposite to the mounting surface of the metal dome switch 91 (hereinafter referred to as the back surface) of the flexible substrate 90.

  When the push button 82 or the tilt operation button 83 is pressed, the metal dome switch 91 on the flexible substrate 90 is pressed. The metal dome switch 91 is a dome-shaped spring made of stainless steel. The metal dome switch 91 operates so that when the central portion is pressed, the apex portion is reversed and when the pressing is released, the dome switch 91 returns to its original shape.

  On the wiring board 92 of the flexible substrate, a copper foil pattern is formed at a position corresponding to the metal dome switch 91. When the metal dome switch is reversed, the copper foil pattern comes into contact with the inside of the metal dome switch and becomes conductive. . This continuity is detected by a camera processing circuit (not shown), and it is determined that the switch has been operated.

  At this time, in order for the metal dome switch operation to be performed with good operability, it is necessary to provide an air escape hole. In general, the holding sheet 94 is often provided with this air escape hole. However, if a hole is provided in the holding sheet 94, an intrusion path of static electricity is created in that portion. Therefore, in this embodiment, no air hole is provided in the holding sheet 94, and each metal dome switch 91 in the wiring board 92 is provided. A through hole 96 serving as an air escape hole is provided in the projection area.

  FIG. 3 is a partial cross-sectional view showing a schematic structure of the operation unit 80. When the photographer is charged, static electricity may be applied from the gap A between the push button 82 and the tilt operation button 83 or from the gap B between the tilt operation button 83 and the sub electronic dial 81.

  As described above, in this embodiment, the metal dome switch 91 mounting portion of the flexible substrate 90 is insulated by the holding sheet 94 without a hole. Therefore, the static electricity applied from the gaps A and B is highly likely to flow into the receiving plate 86.

  Next, countermeasures against static electricity from the back surface of the flexible substrate 90 will be described with reference to FIG. 4A is a partially enlarged view of the flexible substrate 90 as seen from the back side, and FIG. 4B is an enlarged view of the state where the flexible substrate 90 is attached to the receiving plate 86 as seen from the same direction. . In FIGS. 4A and 4B, hidden lines are indicated by broken lines.

  As shown in FIG. 4A, the double-sided tape 95 has a shape in which a partial region 95a including the projection portion of the through hole 96 of the wiring board 92 is cut out. An air vent path connecting the through hole 96 shown in FIG. 6 and the central hole portion of the receiving plate 86 can be secured.

  At this time, if the receiving plate 86 and the through hole 96 are not insulated, when static electricity is applied to the receiving plate 86, static electricity flows from the through hole 96 to the wiring of the flexible substrate 90, and malfunction or failure of the camera processing circuit is prevented. There is a possibility of being invited.

  Therefore, in this embodiment, as shown in FIG. 4B, the insulating sheet 85 is attached to the backing plate 86 so as to cover a region wider than the region 95a where the double-sided tape 95 is cut out. This secures an insulation distance (creeping and space distance) and prevents static electricity from flowing into the wiring of the flexible substrate 90.

  Here, the insulating sheet 85 is, for example, a PET sheet having a thickness of about 50 μm. A PET sheet having a dielectric breakdown voltage of several kV is known even though it is a standard grade, and can be obtained at a relatively low cost.

  In general, there is a known method to prevent static electricity by adding electrical components such as Zener diodes and chip varistors to the circuit. In this case, however, the cost of adding the components for each signal is required, and the mounting area is also required. There is a possibility that the printed circuit board needs to be enlarged by an additional amount.

  On the other hand, the cost of countermeasures against static electricity in the present embodiment is basically only the addition of the insulating sheet 85 regardless of the number of signals, and the cost effect is the number of metal dome switches 91 included in the operation unit 80 (the number of signals accompanying it). ) Is particularly large when there are many.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

81 sub-electronic dial, 82 push button, 83 push button (tilt operation button),
84 rubber member, 85 insulating sheet, 86 backing plate,
90 printed circuit boards (flexible boards), 91 metal dome switches,
92 Wiring board, 93 Coverlay, 94 Holding sheet, 95 Double-sided tape

Claims (3)

Push buttons (82), (83),
A printed circuit board (90);
A dome switch mounted on the printed circuit board (90) and conducting with a copper foil pattern formed on the wiring board (92) of the printed circuit board (90) when the push buttons (82) and (83) are pressed. 91)
A holding sheet (94) having insulation and holding the dome switch (91) on the printed circuit board (90);
A metal backing plate (86) to which the printed circuit board (90) is attached;
A double-sided tape (95) for attaching the printed circuit board (90) to a receiving plate (86);
An operating device comprising:
The wiring board (92) has a through hole (96) in the projection area of the dome switch (91),
In the double-sided tape (95), a partial region (95a) including the projection portion of the through hole (96) is cut out,
An operating device, wherein an insulating sheet (85) is affixed to the backing plate (86) so as to cover a region wider than the region (95a) at least in an assembled state. The operating device according to claim 1, wherein the backing plate is made of stainless steel. The operating device according to claim 1, comprising a plurality of the dome switches (91).