JP5039483B2 - Printed circuit board protection structure and image forming apparatus having the same - Google Patents

Description

  The present invention relates to a printed circuit board protection structure for preventing a failure caused by a user coming into contact with a printed circuit board attached to a base frame of a device. The present invention also relates to an image forming apparatus provided with this printed circuit board protection structure.

  Electronic devices used in offices and homes require various electronic components for controlling operations, and image forming apparatuses represented by copying machines and printers are no exception. Such electronic components are mounted and bonded together on a printed circuit board on which patterns necessary for operation control are formed in advance.

  The printed circuit board as described above is firmly held by a base frame that is an internal structural member of the electronic apparatus. Examples of a printed circuit board holding mechanism that holds a printed circuit board on a base frame can be found in Patent Documents 1 and 2. In the printed circuit board holding mechanism described in Patent Documents 1 and 2, a support part is formed by cutting and raising a base frame made of a sheet metal, and the printed circuit board is attached to and held by the support part. As described above, forming the support portion of the printed circuit board by cutting and raising from the sheet metal does not require labor for processing and is low in manufacturing cost.

However, there is a concern that the printed board holding mechanism as described above may cause a user to insert a finger, a stick, or the like into the opening formed in the base frame due to the cutting and raising process. As a result, a terminal or the like of the printed circuit board may be touched, and a static electricity finger or stick may cause an overcurrent to damage the printed circuit board, or the user may get an electric shock or injure the finger. Therefore, in order to solve such a problem, a method for closing the opening formed in the base frame due to the cutting and raising process is proposed, and an example thereof can be seen in Patent Document 3.
JP2007-150719A (9th page, FIG. 1-2) JP 2007-19204 (page 6-7, FIG. 3) JP 2006-196773 A (page 6-7, FIG. 1-5)

  A printed circuit board holding method described in Patent Document 3 includes a cover member that closes an opening formed in a base frame (sheet metal) due to cutting and raising processing, and a support portion (printed circuit board mounting portion) that is a cut and raised piece. ), The cover member is also fixed to the opening at the same time, so that it is possible to prevent the user from inserting a finger or a rod into the opening. However, in this configuration, one cover member is required for one opening. As a result, the number of parts increases, resulting in an increase in cost and an increase in labor during assembly for fastening the printed circuit board.

  Further, the cover member needs to be configured in a shape that matches the size of the opening, and also requires a portion into which a printed circuit board fastening screw is inserted. Therefore, the cover member has a complicated structure and must be redesigned in detail each time the shape of the opening changes. As a result, there is a concern that further significant cost increases will occur.

  The present invention has been made in view of the above points, and closes the opening formed in the base frame due to the cutting and raising process while saving the labor during assembly and suppressing a significant increase in the number of parts. An object of the present invention is to provide a printed circuit board protection structure capable of protecting the printed circuit board from the harmful effects caused by the presence of the opening. It is another object of the present invention to provide an image forming apparatus having such a printed circuit board protection structure and further improved in safety while reducing costs.

  In order to solve the above-described problems, the present invention provides a printed circuit board protection structure including a base frame, at least two support portions formed by cutting and raising from the base frame, and supporting the printed circuit board, and support for these. The base frame has an opening formed in the base frame due to the cutting and raising process, and a size for simultaneously closing the plurality of openings. The base frame is opposite to the side on which the printed circuit board is disposed. A substrate protection film mounted on the side surface, and the substrate protection film can be inserted into and removed from each of the plurality of openings, and extends at least a pair of opposite directions. Suppose that it has a stop piece and the expansion part projected on the outer side of these latching pieces.

  Further, in the printed circuit board protection structure configured as described above, a positioning hole provided in the board protection film, a positioning piece provided to protrude from the base frame, and to position and hold the board protection film by being inserted into the positioning hole; It was decided to prepare.

  Further, in the printed circuit board protection structure configured as described above, the positioning piece includes a positioning portion that extends in a substantially normal direction of the base frame, and a pressing portion that is bent at a substantially right angle from the positioning portion and extends substantially parallel to the base frame. And the substrate protection film includes a slit extending from the positioning hole.

  According to the present invention, the image forming apparatus is provided with the printed circuit board protection structure configured as described above.

  According to the configuration of the present invention, the printed circuit board protection structure is formed by cutting and raising the base frame from the base frame, and supports at least two support parts for supporting the printed circuit board, and at the base of these support parts. An opening formed in the base frame due to the cutting and raising process, and a size for simultaneously closing the plurality of openings, on the surface of the base frame opposite to the side on which the printed circuit board is disposed. A substrate protection film to be mounted, and the substrate protection film can be inserted into and removed from each of the plurality of openings, and at least a pair of locking pieces extending in opposite directions; Since it is provided with an extended portion that protrudes outside these locking pieces, it is possible to simultaneously close all the openings using a substrate protective film. That. Therefore, since it is not necessary to individually close each opening, it is possible to save labor during assembly and suppress a significant increase in the number of parts. Then, the printed circuit board protection structure capable of closing the opening formed in the base frame due to the cutting and raising process and protecting the printed circuit board from the harmful effects caused by the presence of the opening is provided. can do.

  In addition, since the positioning hole provided in the substrate protection film and the positioning piece provided so as to protrude from the base frame and positioning the substrate protection film by being inserted into the positioning hole, the substrate protection is provided. The film can be held in place. That is, the substrate protective film does not cause a positional shift with respect to the opening of the base frame to be covered, and it is not necessary to newly prepare another member for positioning. Therefore, it is possible to reliably close the opening portion of the base frame while further saving labor during assembly and suppressing a significant increase in the number of parts.

  The positioning piece includes a positioning portion that extends in a substantially normal direction of the base frame, and a pressing portion that is bent at a substantially right angle from the positioning portion and extends substantially parallel to the base frame. Since the slit extending from the positioning hole is provided, it is difficult for the substrate protective film to move due to the action of the L-shaped positioning piece, and only the location of the positioning hole of the substrate protective film is locally curved. Can do. Thereby, the positioning accuracy of the substrate protection film is improved, and the insertion of the positioning piece into the positioning hole is facilitated. Therefore, it is possible to reliably close the opening of the base frame while further saving labor during assembly.

  Further, in the present invention, since the image forming apparatus is provided with the printed circuit board protection structure configured as described above, it is possible to save time during assembly and suppress the significant increase in the number of parts, and the base frame due to cutting and raising processing. To provide an image forming apparatus capable of closing a formed opening, protecting a printed circuit board from harmful effects caused by the presence of the opening, and reducing cost and safety. Can do.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  First, an image output operation of the image forming apparatus including the printed circuit board protection structure according to the first embodiment of the present invention will be described while explaining the outline of the structure with reference to FIGS. 1 is a schematic vertical sectional front view of the image forming apparatus, FIG. 2 is a perspective view seen from the front side of the image forming apparatus, and FIG. 3 is a perspective view seen from the back side of the lower part of the image forming apparatus. In FIG. 1, a solid line arrow indicates a sheet conveyance path and a conveyance direction, and a one-dot chain line arrow indicates a laser beam L. In FIG. 2, drawing of the document feeding unit and the lower caster above the image forming apparatus main body is omitted, and drawing above the sheet feeding unit is omitted in FIG.

  As shown in FIG. 1, a paper feed cassette 3, which is a paper feed unit, is disposed below the inside of the main body 2 of the image forming apparatus 1. The paper feed cassette 3 stores and accommodates paper P such as cut paper before printing. The sheets P are separated and sent one by one toward the upper left of the sheet cassette 3 in FIG. The paper feed cassette 3 can be pulled out horizontally from the front side of the main body 2 (see FIG. 5).

  A first paper transport unit 4 is provided inside the main body 2 and to the left of the paper feed cassette 3. The first paper transport unit 4 is formed substantially vertically along the left side surface of the main body 2. The first paper transport unit 4 receives the paper P sent out from the paper feed cassette 3 and transports the paper P vertically upward along the left side surface of the main body 2 to the transfer unit 12.

  A manual paper feed unit 5 is provided above the paper feed cassette 3 at a location on the right side which is the side opposite to the left side of the main body 2 where the first paper transport unit 4 is formed. Yes. In the manual sheet feeder 5, paper P of a size that is not contained in the paper cassette 3, thick paper, and OHP sheets that are to be fed one by one are placed.

  A second paper transport unit 6 is provided on the left side of the manual paper feed unit 5. The second paper transport unit 6 is located immediately above the paper feed cassette 3, extends substantially horizontally from the manual paper feed unit 5 to the first paper transport unit 4, and joins the first paper transport unit 4. Then, the second paper transport unit 6 receives the paper P or the like sent from the manual paper feed unit 5 and transports it to the first paper transport unit 4 substantially horizontally.

  On the other hand, as shown in FIGS. 1 and 2, a document feeding unit 7 is provided on the upper surface of the main body 2 of the image forming apparatus 1, and a document image reading unit 8 is provided below the document feeding unit 7. When a user copies a document, a document on which an image such as a character, a figure, or a pattern is drawn is stacked on the document feeding unit 7. The document feeding unit 7 separates the documents one by one and sends the document, and the document image reading unit 8 reads the image data. The information of the image data is sent to the exposure device 9 disposed above the second paper transport unit 6 and at the center of the main body 2. The exposure apparatus 9 irradiates the image forming unit 10 with laser light L controlled based on the image data.

  An image forming unit 10 and a transfer unit 12 are provided above the first paper transport unit 4 and to the left of the exposure device 9. In the image forming unit 10, an electrostatic latent image of a document image is formed by the laser light L emitted by the exposure device 9, and a toner image is developed from the electrostatic latent image. The toner is supplied to the image forming unit 10 from a toner container 11 provided above the exposure device 9. The toner image formed by the image forming unit 10 is transferred by the transfer unit 12 to the pre-printing paper P sent in synchronization by the first paper transport unit 4.

  A fixing device 13 is provided above the transfer unit 12. The paper P carrying the unfixed toner image in the transfer unit 12 is sent to the fixing device 13 where the toner image is heated and pressed by a heat roller and a pressure roller to be fixed.

  A branch portion 14 is provided above the fixing device 13. When the double-sided printing is not performed, the paper P discharged from the fixing device 13 is discharged from the branching unit 14 to a cylinder paper discharge unit 15 (see FIG. 2) provided in the cylinder of the image forming apparatus 1.

  The discharge port portion from which the paper P is discharged from the branch portion 14 toward the in-body paper discharge portion 15 functions as the switchback portion 16. When performing duplex printing, the switchback unit 16 switches the transport direction of the paper P discharged from the fixing device 13. Then, the paper P is sent downward through the branching unit 14, the left side of the fixing device 13, and the left side of the transfer unit 12, and is sent again to the transfer unit 12 through the first paper transport unit 4.

  In the image forming apparatus 1 configured as described above, the printed circuit board protection structure 20 of the present invention is provided to protect the printed circuit board 17 provided on the back side of the paper feed cassette 3 shown in FIG.

  Next, a detailed configuration of the printed circuit board protection structure 20 will be described with reference to FIGS. 4 to 7 in addition to FIG. 4 is a perspective view of the periphery of the printed circuit board protection structure as seen from the back side, FIG. 5 is a perspective view of the paper feed unit as seen from the front upper side, and FIG. 6 is a view of the paper feed unit from which the paper feed cassette is removed as seen from the front side. FIG. 7 is a perspective view of the periphery of the printed circuit board protection structure as seen from the front side. In FIG. 4, drawing of the substrate protective film is omitted, and in FIGS. 5 and 6, drawing above the sheet feeding unit is omitted as in FIG. 3.

  As described above, the printed circuit board protection structure 20 is provided to protect the printed circuit board 17 provided on the back side of the paper feed cassette 3 shown in FIGS. The printed circuit board protection structure 20 includes a base frame 21, a support part 22, an opening 23, and a board protection film 24 (see FIGS. 5 to 7).

  As shown in FIG. 3, the base frame 21 is provided vertically on the back side of the paper feed cassette 3. The base frame 21 is composed of a sheet metal member.

  As shown in FIG. 4, the support portions 22 are provided at the corner portions of the rectangular printed circuit board 17 and at four locations in the vicinity thereof. The four support portions 22 are formed by cutting and raising from the base frame 21 so as to protrude from the surface of the base frame 21 to the back side. The printed circuit board 17 is supported by the base frame 21 with a space provided between the four support portions 22 and the base frame 21.

  The opening 23 is provided at the base portion of each support portion 22 of the base frame 21. The openings 23 are formed at four locations so as to penetrate the base frame 21 due to the cutting and raising process for forming the support portions 22.

  Here, as shown in FIGS. 5 and 6, the base frame 21 of the printed circuit board protection structure 20 is viewed from the front of the apparatus when the paper feed cassette 3 is pulled out from the front side of the image forming apparatus 1 and removed. Can be touched.

  As shown in FIGS. 5 to 7, the substrate protective film 24 is attached to such a base frame 21 on the front surface, that is, the surface opposite to the back surface on which the printed circuit board 17 is disposed. It has been. The substrate protective film 24 is made of a synthetic resin such as PET (polyethylene terephthalate), and is large enough to simultaneously close the four openings 23 as shown in FIG.

  The substrate protective film 24 includes a total of four locking pieces 25 at locations corresponding to the respective openings 23. The locking piece 25 is large enough to be inserted into and removed from the opening 23. Of each of the four locking pieces 25, the upper two extend upward, and the lower two extend downward. That is, the locking piece 25 is provided with two pairs extending in opposite directions.

  By inserting such locking pieces 25 into the openings 23, the substrate protective film 24 can be mounted on the front side of the base frame 21, as shown in FIG. At this time, the upper two locking pieces 25 are positioned in the vicinity of the upper side of the upper opening 23, and the lower two locking pieces 25 are positioned in the vicinity of the lower side of the lower opening 23. The large movement of the substrate protective film 24 in the vertical direction is prevented.

  The substrate protective film 24 includes an extended portion 26 on the outer side of each locking piece 25. The extended portion 26 is a portion in which the hatched lines in FIG. 7 are drawn, and greatly extends outward from the location of each locking piece 25. Due to the presence of the extended portion 26, even if the portion of the substrate protective film 24 corresponding to the opening 23 is pushed from the front side, this portion of the substrate protective film 24 does not sink into the back side.

  Further, as shown in FIG. 7, the printed circuit board protection structure 20 is a location corresponding to the approximate center in the vertical direction of the substrate protection film 24, and is arranged in three locations in the horizontal direction, with positioning pieces 27 and positioning holes 28. And a slit 29.

  Next, detailed configurations of the positioning piece 27, the positioning hole 28, and the slit 29 will be described with reference to FIGS. 8 to 11 in addition to FIG. 8 is a perspective view showing a positioning piece, FIG. 9 is a perspective view showing a positioning piece similar to FIG. 8, and shows a state in which the positioning piece is inserted into a positioning hole of the substrate protective film, and FIG. 10 is a vertical view showing the periphery of the positioning piece. FIG. 11 is a vertical sectional side view showing the periphery of the positioning piece similar to FIG. 10 and shows a state where the insertion into the positioning hole is completed. is there.

  As shown in FIG. 7, the positioning piece 27 is provided on the side where the substrate protection film 24 is disposed, that is, on the front surface of the base frame 21. As shown in FIG. 8, the three positioning pieces 27 are formed by cutting and raising from the base frame 21 so as to protrude from the surface of the base frame 21. The positioning piece 27 is bent in an L shape so that the tip is directed upward, and the positioning portion 27a extends in a substantially normal direction of the base frame 21 and bends at a substantially right angle from the positioning portion 27a. And a pressing portion 27b extending in parallel.

  As shown in FIG. 7, the positioning hole 28 is provided at a location corresponding to the positioning piece 27 of the substrate protection film 24. The positioning hole 28 has a rectangular shape extending in the lateral direction so as to substantially match the cross-sectional shape of the positioning portion 27a that is the root portion of the positioning piece 27 when the substrate protective film 24 is disposed close to the base frame 21. (See FIG. 9).

  As shown in FIGS. 7 and 9, the slit 29 extends downward from each of the positioning holes 28 of the substrate protective film 24. As shown in FIG. 9, two slits 29 extend downward from the left and right corners of the positioning hole 28 having a rectangular shape with respect to each positioning hole 28. The length of the slit 29 is substantially the same as the vertical length of the positioning piece 27, that is, the pressing portion 27b.

  The method for inserting the positioning piece 27 into the positioning hole 28 is as follows.

  First, as shown in FIG. 10, the substrate protective film 24 is pressed against the positioning piece 27 using the slit 29 while elastically deforming so that the lower side of the positioning hole 28 is largely opened. At this time, the upper end of the pressing portion 27 b of the positioning piece 27 passes through the position of the positioning hole 28.

  Next, the substrate protective film 24 is moved in the direction of the white arrow shown in FIG. Thereby, at the final stage of movement, as shown in FIG. 11, the positioning portion 27 a that is the root portion of the positioning piece 27 is accommodated in the positioning hole 28. The substrate protective film 24 at the slit 29 returns to the state before deformation due to the elasticity of the film.

  In this way, by inserting the positioning piece 27 into the positioning hole 28, the substrate protective film 24 can be hooked and positioned and held at a predetermined position.

  As described above, the printed circuit board protection structure 20 is formed by cutting and raising the base frame 21 from the base frame 21, and the four support portions 22 that support the printed circuit board 17. At the base, the opening 23 formed in the base frame 21 due to the cutting and raising process and the size of the four openings 23 are simultaneously closed, and the side of the base frame 21 on which the printed circuit board 17 is disposed And a substrate protective film 24 mounted on the opposite surface of the substrate, and the substrate protective film 24 can be inserted into and removed from each of the four openings 23 in two directions opposite to each other. And the extended portion 26 projecting outside the locking pieces 25, so that the substrate protection film 24 is used to It can be closed mouth 23 simultaneously. Therefore, since it is not necessary to close each opening 23 individually, it is possible to save labor during assembly and suppress a significant increase in the number of parts. Then, the opening 23 formed in the base frame 21 due to the cutting and raising process can be closed and the printed circuit board 17 can be protected from the harmful effects caused by the existence of the opening 23. A protective structure 20 can be provided.

  In addition, the printed circuit board protection structure 20 is provided with a positioning hole 28 provided in the board protection film 24 and a protrusion protruding from the base frame 21, and a positioning piece that positions and holds the board protection film 24 by being inserted into the positioning hole 28. 27, the substrate protective film 24 can be held in a fixed position. That is, the substrate protective film 24 does not cause a positional shift with respect to the opening 23 of the base frame 21 to be covered, and it is not necessary to newly prepare another member for positioning. Therefore, it is possible to reliably close the opening 23 of the base frame 21 while further saving the time for assembly and suppressing a significant increase in the number of parts.

  The positioning piece 27 includes a positioning portion 27a that extends in a substantially normal direction of the base frame 21, and a pressing portion 27b that is bent at a substantially right angle from the positioning portion 27a and extends substantially parallel to the base frame 21, and includes a substrate protection film. 24 includes a slit 29 extending from the positioning hole 28, so that the substrate protective film 24 is difficult to move by the action of the L-shaped positioning piece 27, and the position of the positioning hole 28 of the substrate protective film 24 is Only can be curved locally. Thereby, the positioning accuracy of the substrate protection film 24 is improved, and the insertion of the positioning piece 27 into the positioning hole 28 is facilitated. Therefore, it is possible to reliably close the opening 23 of the base frame 21 while further saving labor during assembly.

  Further, according to the present invention, since the image forming apparatus 1 includes the printed circuit board protection structure 20 having the above-described configuration, the time required for assembling can be saved, and the base frame caused by the cutting and raising process can be suppressed while suppressing a significant increase in the number of parts. 21 can be closed, and the printed circuit board 17 can be protected from the harmful effects caused by the presence of the opening 23. The image forming apparatus can be reduced in cost and safety. 1 can be provided.

  Next, a detailed configuration of the printed circuit board protection structure according to the second embodiment of the present invention will be described with reference to FIG. FIG. 12 is a front view of the substrate protective film of the printed circuit board protection structure. Since the basic configuration of this embodiment is the same as that of the first embodiment described with reference to FIGS. 1 to 11, the configuration common to the first embodiment is described in the drawings, and The description will be omitted.

  The printed circuit board protection structure according to the second embodiment includes a board protection film 24 having a form as shown in FIG. The substrate protective film 24 includes two locking pieces 25 in total, one at each of the upper end and the lower end in FIG. The base frame 21 (not shown) has two openings 23 (not shown) corresponding to the respective locking pieces 25. The upper locking piece 25 extends upward, and the lower locking piece 25 extends downward. That is, a pair of locking pieces 25 are provided that extend in opposite directions.

  In this way, even when the substrate protective film 24 includes the two locking pieces 25, the same operations and effects as in the first embodiment can be obtained. That is, it is possible to simultaneously close the two openings 23 formed in the base frame 21 due to the cutting and raising process, while saving labor during assembly and suppressing a significant increase in the number of parts. Therefore, it is possible to provide the printed circuit board protection structure 20 that can protect the printed circuit board 17 from the harmful effects caused by the presence of.

  Next, a detailed configuration of the printed circuit board protection structure according to the third embodiment of the present invention will be described with reference to FIG. FIG. 13 is a front view of the substrate protective film of the printed circuit board protection structure. Since the basic configuration of this embodiment is the same as that of the first embodiment described with reference to FIGS. 1 to 11, the configuration common to the first embodiment is described in the drawings, and The description will be omitted.

  The printed circuit board protection structure according to the third embodiment includes a board protection film 24 having a form as shown in FIG. The substrate protective film 24 includes a total of three locking pieces 25, one on the upper side and two on the lower end in FIG. The base frame 21 (not shown) has three openings 23 (not shown) corresponding to the respective locking pieces 25. The upper one locking piece 25 extends upward, and the lower two locking pieces 25 extend downward. That is, at least one pair of the locking pieces 25 extending in opposite directions is provided.

  In this way, even when the substrate protective film 24 includes the three locking pieces 25, the same operations and effects as in the first embodiment can be obtained. That is, it is possible to simultaneously close the three openings 23 formed in the base frame 21 due to the cutting and raising process, while saving labor during assembly and suppressing a significant increase in the number of parts. Therefore, it is possible to provide the printed circuit board protection structure 20 that can protect the printed circuit board 17 from the harmful effects caused by the presence of.

  Next, a detailed configuration of the printed circuit board protection structure according to the fourth embodiment of the present invention will be described with reference to FIG. FIG. 14 is a front view of the substrate protective film of the printed circuit board protection structure. Since the basic configuration of this embodiment is the same as that of the first embodiment described with reference to FIGS. 1 to 11, the configuration common to the first embodiment is described in the drawings, and The description will be omitted.

  The printed circuit board protection structure according to the fourth embodiment includes a board protection film 24 having a form as shown in FIG. The substrate protection film 24 includes a total of four locking pieces 25, two on each of the left and right sides in FIG. The base frame 21 (not shown) has four openings 23 (not shown) corresponding to the respective locking pieces 25. The right two locking pieces 25 extend rightward, and the left two locking pieces 25 extend leftward. That is, two pairs of locking pieces 25 extending in opposite directions are provided.

  In this way, even when the substrate protective film 24 includes the four locking pieces 25 and these locking pieces 25 extend in the lateral direction, the same operations and effects as in the first embodiment. Is obtained. That is, it is possible to simultaneously close the four openings 23 formed in the base frame 21 due to the cutting and raising process, while saving labor during assembly and suppressing a significant increase in the number of parts. Therefore, it is possible to provide the printed circuit board protection structure 20 that can protect the printed circuit board 17 from the harmful effects caused by the presence of.

  Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

  For example, in the embodiment of the present invention, the opening 23 and the locking pieces 25 of the substrate protective film 24 corresponding to the opening 23 are provided at two to four places, respectively. Although not limited to four places, if there are at least one pair of locking pieces 25 extending in opposite directions, the locking pieces 25 are inserted into the openings 23 and the substrate protective film 24 is attached to the base frame 21. Therefore, five or more locations may be provided.

  Similarly, the positioning pieces 27 and the positioning holes 28 corresponding to the positioning pieces 27 are 2 to 4 places each, but the number thereof is not limited to 2 to 4 places. A large number or a small number may be provided. Further, the arrangement positions of the opening 23, the locking piece 25, the positioning piece 27, and the positioning hole 28 are not limited to the positions described in the present embodiment.

  The present invention can be used in a structure in which a support portion is formed by cutting and raising from a base frame and a printed circuit board is held by this support portion.

1 is a schematic vertical sectional front view of an image forming apparatus including a printed circuit board protection structure according to a first embodiment of the present invention. FIG. 2 is a perspective view seen from the front side of the image forming apparatus of FIG. 1. FIG. 2 is a perspective view seen from the back side of the lower part of the image forming apparatus in FIG. 1. It is the perspective view which looked at the printed circuit board protection structure periphery of FIG. 3 from the back side. It is the perspective view which looked at the paper feed part of Drawing 1 from the front upper part. FIG. 6 is a perspective view of the paper feeding unit from which the paper feeding cassette of FIG. 5 is removed as seen from the front side. It is the perspective view which looked at the printed circuit board protection structure periphery of FIG. 6 from the front side. It is a perspective view which shows the positioning piece of FIG. FIG. 9 is a perspective view showing the same positioning piece as in FIG. 8 and shows a state where the positioning piece is inserted into the positioning hole of the substrate protective film. FIG. 10 is a vertical sectional side view showing the periphery of the positioning piece in FIG. 9 and shows a stage in the middle of being inserted into the positioning hole. FIG. 11 is a vertical sectional side view showing the periphery of a positioning piece similar to FIG. 10, and shows a state where insertion into the positioning hole is completed. It is a front view of the board | substrate protective film of the printed circuit board protection structure which concerns on the 2nd Embodiment of this invention. It is a front view of the board | substrate protective film of the printed circuit board protection structure which concerns on the 3rd Embodiment of this invention. It is a front view of the board | substrate protective film of the printed circuit board protection structure which concerns on the 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Main body 3 Paper feed cassette 17 Printed circuit board 20 Printed circuit board protection structure 21 Base frame 22 Support part 23 Opening part 24 Substrate protective film 25 Locking piece 26 Expansion part 27 Positioning piece 27a Positioning part 27b Holding part 28 Positioning hole 29 Slit

Claims (4)

The base frame was formed by cutting and raising from the base frame, and at least two supporting parts for supporting the printed circuit board, and the base frame was formed at the base of these supporting parts due to the cutting and raising process. An opening and a substrate protective film that is sized to simultaneously close the plurality of openings and is attached to the surface of the base frame opposite to the side on which the printed circuit board is disposed;
The substrate protective film can be inserted into and removed from each of the plurality of openings, and includes at least a pair of locking pieces extending in opposite directions to each other, and an extended portion projecting outside the locking pieces. And a printed circuit board protection structure.   The positioning hole provided in the said board | substrate protective film, and the positioning piece which protrudes from the said base frame and is provided and which positions and hold | maintains a board | substrate protective film by inserting in a positioning hole is provided. The printed circuit board protection structure as described.   The positioning piece includes a positioning portion that extends in a substantially normal direction of the base frame, and a pressing portion that is bent at a substantially right angle from the positioning portion and extends substantially parallel to the base frame, and the substrate protection film includes the positioning hole The printed circuit board protection structure according to claim 2, further comprising a slit extending from the printed circuit board.   An image forming apparatus comprising the printed circuit board protection structure according to claim 1.

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