JP2013105107A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device configured to prevent damage to an electric substrate interposed between a cover and a frame.SOLUTION: A plurality of elastic members 42-44 are arranged between at least two regulation members 46. An initial load of the elastic members 42-45 located closer to the center between the regulation members is set smaller. Even if an external force is applied to a casing cover 25 to significantly deform the casing cover 25, and the casing cover 25 comes into contact with the electric substrate 41, the elastic members 42-45 receive the external force. While the elastic members 42-45 receive the external force, the electric substrate 41 can be deformed moderately into a catenary shape along the natural deflection of the electric substrate 41. The external force to be applied to the electric substrate 41 is distributed to the whole of the electric substrate 41, thereby preventing damage to the electric substrate 41.

Description

  The present invention relates to an image forming apparatus.

  For example, in the image forming apparatus described in Patent Document 1, an electric substrate is disposed between a plate-shaped frame and a cover. The frame is a member that directly or indirectly supports the image forming unit or the like. The cover is a member that covers the frame and forms the external design surface of the image forming apparatus.

JP 2006-53255 A

  By the way, since the cover is a member constituting the appearance design surface, generally, the cover is less rigid than a strength member such as a frame and is easily bent and deformed by an external force. Therefore, when a large external force acts on the cover, the cover is greatly bent and deformed, and the cover may come into contact with the electric board.

If the cover comes into contact with the electric board, an external force is transmitted to the electric board, and the electric board may be damaged.
SUMMARY An advantage of some aspects of the invention is that in an image forming apparatus in which an electric substrate is disposed between a cover and a frame, damage to the electric substrate is suppressed.

  In order to achieve the above object, according to the present invention, an image forming unit (2) that forms an image on a sheet, a frame (20A) that supports the image forming unit (2), and a cover (25A) that covers the frame (20A). ), The frame (20A) and the cover (25), the electric board (41) on which the electronic component (41A) is mounted, and the frame (20A) and the electric board (41). A first elastic member (43) and a second elastic member (44) that are elastically deformable and press the plate surface (41B) of the electric board (41) toward the cover (25), and the cover (25). At least two restricting members (46) that come into contact with the electric substrate (41) from the side and restrict the electric substrate (41) from moving toward the cover (25), and between the two restricting members (46) When the center is called the center between the regulating portions, the first elastic member ( 3) and the second elastic member (44) are disposed between the two restricting members (46), and the first elastic member (43) is closer to the center between the restricting portions than the second elastic member (44). Further, when the external force is not applied to the cover (25), the first elastic member (43) applies a pressing force smaller than the second elastic member (44) to the electric board (41). It is characterized by letting

  Thus, in the present invention, even when the cover (25) is greatly bent and deformed due to an external force acting on the cover (25) and the cover (25) is in contact with the electric board (41), External force is received by the plurality of elastic members (43, 44).

  Further, when an external force acts on the electric board (41), a portion of the electric board (41) located between the two restricting members (46) is usually deformed like a bow so that the center between the restricting parts is most greatly bent.

  On the other hand, in the present invention, when no external force is applied to the cover (25), the first elastic member (43) exerts a smaller pressing force than the second elastic member (44) on the electric board (41). Is acting on. Hereinafter, the pressing state by the first elastic member (43) and the second elastic member (44) is referred to as an initial load setting state.

  Therefore, in the present invention, the electric board (41) is gently deformed into a bow shape along the natural bending shape of the electric board (41) while receiving the external force by the plurality of elastic members (43, 44). Can do. Therefore, since the external force acting on the electric board (41) can be dispersed throughout the electric board (41), damage to the electric board (41) can be suppressed.

  On the other hand, if no external force is applied to the cover (25), the first elastic member (43) and the second elastic member (44) exert the same pressing force on the electric board (41). In this case, it is difficult to gently deform the electric board (41) into a bow shape so as to follow the natural bending shape of the electric board (41).

  Therefore, when the first elastic member (43) and the second elastic member (44) apply the same pressing force to the electric board (41), any part of the electric board (41) Since the bending stress is concentrated on the part, it is difficult to suppress damage to the electric substrate (41).

  In the present invention, the frame (20A) that supports the image forming unit (2) directly supports the image forming unit (2) and indirectly supports the image forming unit (2). Any of these may be used.

  Incidentally, the reference numerals in parentheses for each of the above means are examples showing the correspondence with the specific means described in the embodiments described later, and the present invention is indicated by the reference numerals in the parentheses of the above respective means. It is not limited to specific means.

1 is a central sectional view of an image forming apparatus according to an embodiment of the present invention. 2 is a perspective view illustrating an arrangement configuration of a frame 20 and the like of the image forming apparatus according to the embodiment of the present invention. FIG. FIG. 3 is a diagram illustrating a support structure for an electric substrate 41 in the image forming apparatus according to the first embodiment of the present invention. (A) It is a figure which shows the arrangement position of each elastic member 42-45 in the image forming apparatus which concerns on embodiment of this invention, (b) is a figure which shows the bending distribution state of the electric board | substrate 41 when an external force acts. is there. It is sectional drawing of the electric board | substrate 41 etc. when external force acts. (A) It is a figure which shows the support structure of the electric substrate 41 in the image forming apparatus which concerns on 2nd Embodiment of this invention, (b) is sectional drawing of the electric substrate 41 etc. when external force acts. (A) It is a figure which shows the support structure of the electric substrate 41 in the image forming apparatus which concerns on 3rd Embodiment of this invention, (b) is sectional drawing of the electric substrate 41 grade | etc., When external force acts. (A) is a figure which shows the bending distribution state of the electric board | substrate 41 when an external force acts in the image forming apparatus which concerns on 4th Embodiment of this invention, (b) is 4th Embodiment of this invention. It is a figure which shows the arrangement position of each elastic member 42-45 in the image forming apparatus which concerns.

  The “embodiment of the invention” described below shows an example of the embodiment. In other words, the invention specific items described in the claims are not limited to the specific means and structures shown in the following embodiments.

In this embodiment, the image forming apparatus according to the present invention is applied to a monochrome laser printer. Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
1. Structure of Image Forming Apparatus As shown in FIG. 1, the image forming apparatus 1 houses an image forming unit 2, a paper feeding device 10, and the like. As shown in FIG. 2, the image forming unit 2, the paper feeding device 10, and the like are directly or indirectly supported by a pair of frames 20 disposed on both sides in the horizontal direction with the image forming unit 2 interposed therebetween. ing. In FIG. 2, the image forming unit 2 is omitted, and the paper feeding device 10 is not illustrated.

  The pair of frames 20 are resin-made strength members including a frame main body 20A formed in a substantially rectangular plate shape, wall-shaped reinforcing ribs 20B integrally formed on the outer peripheral portion of the frame main body 20A, and the like. Then, as shown in FIG. 3, the pair of frames 20 are covered with a housing cover 25 from the side opposite to the image forming unit 2. The housing cover 25 according to the present embodiment constitutes the external appearance design surface of the image forming apparatus 1.

  Incidentally, the housing cover 25 and the frame 20 are made of resin such as polystyrene, and the mechanical strength of the frame main body 20 </ b> A, that is, the frame 20 is set to be higher than that of the housing cover 25.

  The image forming unit 2 is an electrophotographic image forming unit that forms an image on a sheet. That is, as shown in FIG. 1, the image forming unit 2 includes a developing unit including a process cartridge 3, an exposure unit 4, a transfer roller 8, and the like, and a fixing unit 5.

  The process cartridge 3 houses a photosensitive drum 3A on which a developer image is carried, a charger 3B for charging the photosensitive drum 3A, and the like. The transfer roller 8 transfers the developer image carried on the photosensitive drum 3A onto a sheet such as paper.

  The fixing device 5 includes a heating roller 5A that heats the sheet and a pressure roller 5B that presses the sheet against the heating roller 5A. The sheet discharged from the fixing device 5 is discharged from a pair of paper discharge rollers 9 to a paper discharge tray 1A set on the upper surface of the image forming apparatus 1.

  The sheet feeding device 10 is a sheet feeding unit that sends at least one sheet out of one or more sheets placed on the sheet feeding tray 30 to the image forming unit 2. The paper feeder 10 includes a pickup roller 11 and a separation mechanism 12.

  The pickup roller 11 contacts at least one sheet placed on the sheet feeding tray 30 with the sheet positioned at the upper end in the stacking direction, and sends out at least one sheet to the image forming unit 2 side.

  The separation mechanism 12 includes a separation pad 12A, a separation roller 12B, and the like. The separation mechanism 12 separates one or more sheets sent from the pickup roller 11 one by one and sends them to the image forming unit 2.

  The pair of registration rollers 6 correct the posture of the single sheet, and then transfer the single sheet at a predetermined timing set in advance, the transfer position of the photosensitive drum 3A, that is, the transfer of the photosensitive drum 3A. It rushes into a part facing the roller 8.

  The paper feed tray 30 includes a tray main body 31 and a pressing plate 32. That is, the tray body 31 and the pressing plate 32 are arranged in series along the sheet conveyance path. The one or more sheets placed on the paper feed tray 30 are placed so as to straddle the tray main body 31 and the pressing plate 32.

  Further, the tray main body 31 can swing between a position where the refill port 25A is closed and a position where the refill port 25A is opened. The pressing plate 32 swings upward to cause the pickup roller 11 to press the pressing plate 32, that is, one or more sheets placed on the paper feed tray 30.

2. Electrical Board Support Structure As shown in FIG. 4A, a substantially rectangular electrical board 41 is assembled to at least one frame body 20 </ b> A of the pair of frames 20. For this reason, the electric board | substrate 41 will be in the state arrange | positioned between the flame | frame 20 and the housing | casing cover 25, as shown in FIG. Note that an electronic component 41 </ b> A is mounted on the electric board 41 in order to supply electric power and a control signal to an electric device such as the fixing device 5.

  A plurality of elastic members 42 to 45 that press the plate surface 41B of the electric board 41 toward the housing cover 25 are disposed between the frame body 20A and the electric board 41. The elastic members 42 to 44 are configured by compression springs having linear characteristics wound in a coil shape.

  In addition, on the end side of the electric board 41, at least two regulating members 46 are provided that regulate the movement of the electric board 41 to the housing cover 25 side by contacting the electric board 41 from the housing cover 25 side. ing.

  In addition, the regulating member 46 according to the present embodiment is provided outside the region of the electric board 41 where the elastic members 42 to 44 are disposed, as shown in FIG. Specifically, each of the at least two regulating members 46 is provided at each of two corners located diagonally among the four corners of the electric board 41.

  Further, as shown in FIG. 3, the regulating member 46 according to the present embodiment contacts the electric board 41 from the housing cover 25 side and engages with the electric board 41, and the frame main body 20A. It is a pan-screw-like member composed of a shaft portion 46B and the like that are inserted and fixed to the head. Two elastic members 45 arranged at positions corresponding to the regulating member 46 among the plurality of elastic members 45 press the electric board 41 against the head 46A.

  The elastic members 42 to 45 are compression springs having the same spring characteristics with the same elastic coefficient and natural length. Of the elastic members 42 to 45, the elastic member that is located near the centroid Go of the plate surface 41 </ b> B is set so that the elastic force that the elastic member acts on the electric substrate 41 in the initial state is reduced. ing.

  The “initial state” refers to a state in which no external force is applied to the housing cover 25 and the electric board 41 is not deformed. In the initial state, the pressing elastic force that the elastic members 42 to 45 act on the electric board 41 is referred to as an initial load. Incidentally, the “centroid” is also referred to as “face center” in some literatures, and specifically refers to a point where the area moments are balanced on the plate surface 41B.

  And in this embodiment, the initial load of each elastic member 42-45 is set with the following methods. That is, the spacers 47A to 47C for compressing the elastic members 43 to 45 are provided in the frame body 20A, and the protrusions are set to be smaller in the spacers provided in the portions closer to the centroid Go among the spacers 47A to 47C. doing.

The spacers 47A to 47C according to the present embodiment are protrusions that protrude from the frame main body 20A toward the electric board 41, and are integrally formed with the frame main body 20A.
Further, the elastic member 45 shown in FIG. 3 is the elastic member 45 disposed in the fixing portion provided with the regulating member 46, but the elastic member 45 is fixed as shown in FIG. It is provided in addition to the part. In the present embodiment, the elastic member 45 disposed in a portion other than the fixed portion is also compressed by the spacer 47C to apply a predetermined initial load to the electric board 41.

  On the other hand, the elastic member 42 disposed at the position closest to the centroid Go is assembled and fixed to the frame body 20A directly or indirectly without the spacers 47A to 47C. On the other hand, each of the elastic members 43 to 45 is assembled and fixed directly or indirectly to the spacers 47A to 47C.

  The spacer 47A for the elastic member 43 is a spacer having a smaller projecting dimension than the spacers 47B and 47C for the elastic members 44 and 45, and the spacer 47B for the elastic member 44 is more than the spacer 47C for the elastic member 45. A spacer with a small protruding dimension. For this reason, the magnitude of the initial load of each of the elastic members 42 to 45 is “initial load of the elastic member 42 <initial load of the elastic member 43 <initial load of the elastic member 44 <initial load of the elastic member 45”.

  Incidentally, in the present embodiment, the two restricting members 46 are provided at two corners at diagonal positions of the electric board 41 formed in a rectangular shape. For this reason, the centroid Go of the plate surface 41 </ b> B coincides with the center between the two restricting members 46. Therefore, hereinafter, the centroid Go is also referred to as the center between the regulation parts.

  Therefore, in a cross section orthogonal to the plate surface 41B and parallel to the diagonal line provided with the two restricting members 46, the elastic members 42 to 45 are provided between the restricting members 46 as shown in FIG. And the elastic members 42 to 45 are arranged in the order of the elastic member 42, the elastic member 43, the elastic member 44, and the elastic member 45 from the center side between the regulating portions toward the end portion side of the electric board 41. It becomes a state.

  Incidentally, a pair of stopper members 48 for restricting the deformation of the electric board 41 are provided between the frame main body 20 </ b> A and the electric board 41. These stopper members 48 are boss-like protrusions that are located on the portion of the frame body 20 </ b> A corresponding to the centroid Go side from the end of the electric substrate 41 and protrude from the position toward the electric substrate 41. The stopper member 48 according to the present embodiment is integrally formed with the frame main body 20A.

  When the electric board 41 is bent and deformed toward the frame body 20A, the distal end side of the stopper member 48 comes into contact with the electric board 41, so that the electric board 41 is excessively bent and deformed toward the frame body 20A. . Note that a pilot protrusion 48 </ b> A that penetrates a through hole 41 </ b> C provided in the electric board 41 is provided at the tip of each stopper member 48 according to the present embodiment.

3. Features of Image Forming Apparatus (Particularly Electric Board Support Structure) According to this Embodiment In this embodiment, a plurality of elastic members 42 to 44 are disposed between at least two regulating members 46, and the elastic member 42. The elastic member closer to the central side between the restricting portions among ˜45 is characterized in that the initial load is smaller.

  Thereby, in this embodiment, even if it is a case where external force acts on the housing | casing cover 25 and the housing | casing cover 25 is greatly bent and deform | transformed and the housing | casing cover 25 has contacted the electric board 41, the external force Are received by the elastic members 42 to 45.

  When an external force is applied to the electric board 41, the portion of the electric board 41 located between the two restricting members 46 is usually located at the center between the restricting portions, as shown in FIG. 5 and FIG. The cross-sectional shape passing through the centroid Go is deformed into a suspended curve so that the center Go is bent most greatly.

  On the other hand, in this embodiment, when an external force is not acting on the housing cover 25, the elastic member closer to the central side between the regulating portions among the elastic members 42 to 45 has a smaller initial load. The initial load setting state is set.

  For this reason, in the present embodiment, the electric board 41 can be gently deformed into a hanging curve shape along the natural bending shape of the electric board 41 while receiving the external force by the elastic members 42 to 45. Therefore, since the external force acting on the electric board 41 can be dispersed throughout the electric board 41, even the electric board 41 having a low rigidity made of paper phenol resin or the like can be prevented from being damaged.

  If no external force is applied to the housing cover 25 and the initial loads of the elastic members 42 to 45 are the same, the electric board 41 is made to follow the natural bending shape of the electric board 41. It is difficult to deform. For this reason, there is a high possibility that any part of the electric board 41 protrudes and is greatly deformed, and bending stress concentrates on the part, so that it is difficult to suppress damage to the electric board 41.

In addition, the present embodiment is characterized by including spacers 47 </ b> A to 47 </ b> C that form initial load setting portions that are in a state of being compressed and deformed in the elastic members 43 to 45 in the initial state.
Thereby, in this embodiment, the initial load setting state can be easily obtained using the elastic members 43 to 45 having the same characteristics. Therefore, an increase in manufacturing cost of the image forming apparatus 1 can be suppressed.

  In the present embodiment, the electric board 41 is deformed between the frame main body 20A and the electric board 41 by contacting the electric board 41 when the electric board 41 is bent and deformed toward the frame main body 20A. A restricting stopper member 48 is provided.

  Thereby, in this embodiment, it can prevent that each elastic member 42-45 deform | transforms elastically excessively. Therefore, when the electric board 41 is bent and deformed, it is possible to prevent the elastic force that each of the elastic members 42 to 45 acts on the electric board 41 from being excessively increased. it can.

In addition, the present embodiment is characterized in that a pilot protrusion 48 </ b> A that penetrates a through hole 41 </ b> C provided in the electric board 41 is provided at the tip of the stopper member 48.
Thereby, even when the external force acting on the electric board 41 is not orthogonal to the plate surface 41B and the component in the thrust direction parallel to the plate surface 41B is large in the external force, the electric board 41 Can be prevented from being greatly displaced in the thrust direction. Therefore, it is possible to effectively cause the elastic members 42 to 45 to function and to prevent the electric substrate 41 from being damaged.

(Second Embodiment)
In this embodiment, as shown in FIG. 6A, the spacers 47A to 47C are eliminated, and among the elastic members 42 to 45, the elastic member closer to the center side between the regulating portions, that is, the elastic member closer to the centroid Go is smaller. A compression spring having For this reason, the magnitude of the elastic coefficient of each of the elastic members 42 to 45 is “elastic coefficient of elastic member 42 <elastic coefficient of elastic member 43 <elastic coefficient of elastic member 44 <elastic coefficient of elastic member 45”.

  In addition, about the fixing | fixed part provided with the control member 46, it has the same structure as 1st Embodiment. That is, the spacer 47C is abolished only for the elastic members disposed in the portions other than the fixed portion among the plurality of elastic members 45, and the elastic coefficient is made larger than the elastic coefficient of the elastic member 44.

  Incidentally, in this embodiment, all the some elastic members 45 employ | adopt the compression spring which has the same characteristic as the elastic member 45 which concerns on 1st Embodiment. That is, the present embodiment makes (a) the elastic coefficient of the elastic members 42 to 44 smaller than that of the elastic member 45 so that the elastic coefficient closer to the centroid Go is smaller than that of the first embodiment. (B) It becomes the structure which abolished spacers 47A-47C other than a fixed part among the elastic members 42-45.

  Thereby, in this embodiment, when an external force acts on the housing cover 25 and the electric board 41 starts to bend and deform by the external force, a state similar to the initial load setting state in the first embodiment is obtained.

  Therefore, also in this embodiment, as shown in FIG. 6B, the electric board 41 is gently deformed so as to follow the natural bending shape of the electric board 41 while receiving the external force by the elastic members 42 to 45. be able to. For this reason, since the said external force which acts on the electric board | substrate 41 can be disperse | distributed to the whole electric board 41, damage to the electric board 41 can be suppressed.

  In addition, although each elastic member 42-44 which concerns on this embodiment is making almost no elastic force act on the electric board | substrate 41 in an initial state, this embodiment is not limited to this, For example, in an initial state You may set each elastic member 42-44 so that it may become the initial stage load setting state similar to 1st Embodiment.

(Third embodiment)
In the present embodiment, as shown in FIG. 7A, a compression spring 50 is provided between the housing cover 25 and the electric board 41 as a cushioning material that absorbs external force acting on the housing cover 25. It is.

  Accordingly, in the present embodiment, as shown in FIG. 7B, it is possible to suppress the housing cover 25 from being greatly deformed, so that the external force that acts on the electric board 41 with the deformation of the housing cover 25 is greatly increased. Can be reduced. Therefore, damage to the electric substrate 41 can be effectively suppressed.

  FIG. 7A is a diagram illustrating an example in which the present embodiment is applied to the image forming apparatus 1 according to the second embodiment. However, the present embodiment is not limited to this, and the first embodiment is not limited thereto. The present invention can also be applied to the image forming apparatus 1 according to the embodiment.

  FIG. 7A shows an example in which the compression spring 50 is disposed immediately above the stopper member 48. However, the present embodiment is not limited to this, and the compression spring 50 may be disposed in other parts. Good. However, since the bending of the electric board 41 and the housing cover 25 is usually the largest in the vicinity of the centroid Go, the compression spring 50, that is, the buffer material, is arranged on the centroid Go side from the end of the electric board 41. It is desirable.

In FIG. 7A, the buffer material is configured by the compression spring. However, the present embodiment is not limited to this, and the buffer material may be configured by an elastic member such as rubber.
(Fourth embodiment)
In the above-described embodiment, since the electric substrate 41 has a simple rectangular shape, the elastic members 42 to 45 are disposed on the assumption that the centroid Go is most greatly deformed and deformed.

  For this reason, as shown in FIG. 8 (a), when the shape of the electric board 41 is asymmetric and the position where the restricting member 46 is provided is also asymmetric with respect to the centroid Go, it is the largest. The position where the bending deformation occurs may not necessarily coincide with the centroid Go.

  However, even in the asymmetric case as described above, the direction A is parallel to the perpendicular bisector of the virtual line L passing through the two restricting members 46 and parallel to the plate surface 41B of the electric board 41. When observed, there is a high possibility that the electric board 41 is most greatly bent and deformed at the center between the regulating portions or in the vicinity thereof.

  Therefore, in the present embodiment, as shown in FIG. 8B, the elastic members 42 to 45 are disposed on the assumption that the electric board 41 is most greatly bent and deformed at the center between the restricting portions or in the vicinity thereof. In addition, this embodiment is the same structure as any one of 1st Embodiment-3rd Embodiment except the arrangement | positioning position of each elastic member 42-45, and the position of the control member 46. FIG.

(Other embodiments)
In the above-described embodiment, the present invention is applied to a monochrome laser printer. However, the present invention is not limited to this, and can be applied to, for example, a direct tandem electrophotographic image forming apparatus, an inkjet image forming apparatus, and the like.

  Moreover, in the above-mentioned embodiment, although each elastic member 42-45 was comprised with the compression coil spring, this invention is not limited to this, For example, elastic members 42-45 with rubber | gum or another elastic material. May be configured.

  In the first embodiment, the elastic members 42 to 45 are configured by using compression springs having the same characteristics. For example, the number of turns (elastic coefficient) of the springs is the same, and among the elastic members 42 to 45, between the restricting portions. The elastic member closer to the center or centroid Go may have a smaller natural length and the spacers 47A to 47C may be eliminated.

  In the first embodiment, since each elastic member 42 to 45 is configured by a coil spring, the characteristics of the elastic members 42 to 45 are the same by making the material, the number of turns, the wire diameter, the coil average diameter, and the like the same. However, the present invention is not limited to this. For example, the elastic members 42 to 45 may be made of the same material rubber or the like.

In the above-described embodiment, the stopper member 48 is provided. However, the present invention is not limited to this, and the stopper member 48 may be omitted.
In the above-described embodiment, the pilot protrusion 48A is provided on the stopper member 48. However, the present invention is not limited to this, and the pilot protrusion 48A may be eliminated.

  In the above-described embodiment, the stopper member 48 and the spacers 47A to 47C are integrally formed with the frame body 20A. However, the present invention is not limited to this, and the stopper member 48 and the spacers 47A to 47C are separate parts. After molding, the frame body 20A may be assembled and fixed.

  In the above-described embodiment, each elastic member 42 to 45 is configured by a spring having a linear characteristic. However, the present invention is not limited to this, and for example, a nonlinear characteristic such as an unequal pitch spring or a conical spring. The elastic members 42 to 45 may be configured by springs having

  Further, the present invention is not limited to the above-described embodiment as long as it matches the gist of the invention described in the claims.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 1A ... Paper discharge tray 2 ... Image forming part 3 ... Process cartridge 3A ... Photosensitive drum 4 ... Exposure device 5 ... Fixing device 5A ... Heating roller 5B ... Pressure roller 6 ... Registration roller 8 ... Transfer roller 9 ... Paper discharge roller 10 ... Paper feed device 11 ... Pickup roller 12 ... Separation mechanism 12A ... Separation pad 20 ... Frame 20A ... Frame body 25 ... Housing cover 25A ... Replenishment port 30 ... Paper feed tray 31 ... Tray body 32 ... Press plate 41 ... Electric board 41A ... Electronic component 41B ... Plate surface 41C ... Through hole 42-45 ... Elastic member 46 ... Restriction member 46A ... Head 47A-47C ... Spacer 48 ... Stopper member 48A ... Pilot projection

Claims (9)

An image forming unit for forming an image on a sheet;
A frame that supports the image forming unit;
A cover covering the frame;
An electric board disposed between the frame and the cover and mounted with electronic components;
A first elastic member and a second elastic member which are disposed between the frame and the electric substrate and which are elastically deformable and press the plate surface of the electric substrate toward the cover;
Comprising at least two restricting members that contact the electric substrate from the cover side and restrict the electric substrate from moving to the cover side;
When the center between the two restricting members is called the center between restricting parts,
The first elastic member and the second elastic member are disposed between the two restricting members, and the first elastic member is located closer to the center between the restricting portions than the second elastic member. ,
Furthermore, when no external force is applied to the cover, the first elastic member applies a smaller pressing force to the electric substrate than the second elastic member. The first elastic member and the second elastic member are elastic members having the same characteristics,
2. The apparatus according to claim 1, further comprising an initial load setting unit configured to cause the second elastic member to be compressed and deformed larger than the first elastic member when no external force is applied to the cover. Image forming apparatus.   The image forming apparatus according to claim 2, wherein the initial load setting unit is integrally formed with the frame. An image forming unit for forming an image on a sheet;
A frame that supports the image forming unit;
A cover covering the frame;
An electric board disposed between the frame and the cover and mounted with electronic components;
A first elastic member and a second elastic member which are disposed between the frame and the electric substrate and which are elastically deformable and press the plate surface of the electric substrate toward the cover;
Comprising at least two restricting members that contact the electric substrate from the cover side and restrict the electric substrate from moving to the cover side;
When the center between the two restricting members is called the center between restricting parts,
The first elastic member and the second elastic member are disposed between the two restricting members, and the first elastic member is located closer to the center between the restricting portions than the second elastic member. ,
Further, the image forming apparatus is characterized in that an elastic coefficient of the first elastic member is smaller than an elastic coefficient of the second elastic member.   5. The image forming apparatus according to claim 1, wherein the first elastic member is located on a centroid side of the plate surface with respect to the second elastic member. 6.   Between the frame and the electric board, there is provided a stopper member that regulates the deformation of the electric board by contacting the electric board when the electric board is bent and deformed to the frame side. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. A third elastic member for pressing the electric board against the two restricting members;
Further, when an external force is not applied to the cover, the third elastic member applies a larger pressing force to the electric board than the first elastic member and the second elastic member. The image forming apparatus according to any one of claims 1 to 6. A third elastic member for pressing the electric board against the two restricting members;
The image forming apparatus according to claim 1, wherein an elastic coefficient of the third elastic member is larger than elastic coefficients of the first elastic member and the second elastic member.   The image forming apparatus according to claim 1, wherein the first elastic member and the second elastic member are configured by a coil spring.