JP2018017933A - Manufacturing method of image reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily specify a non-tin surface side and to reliably execute plasma processing and fluorine coating processing on the non-tin surface side.SOLUTION: A manufacturing method of an image reading device includes: a first step of manufacturing a contact glass by a float method; a second step of forming a mark showing a first main surface in contact with a molten metal and a second main surface not in contact with the molten metal on s contact glass; a third step of giving plasma processing to the second main surface shown by the mark; a fourth step of giving fluorine processing to the second main surface shown by the mark; a fifth step of baking the contact glass; and a sixth step of fixing the contact glass inside a case so that the second main surface shown by the mark after the fifth step is located at the side coming into contact with a manuscript conveyed inside the case of the image reading device and the first main surface shown by the mark is located at the side disposed with the image sensor inside the case.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a method for manufacturing an image reading apparatus, and more particularly to a method for manufacturing a contact glass of a sheet-through type image reading apparatus.

  In the sheet-through type image reading apparatus, a document to be read is conveyed toward the main surface of the contact glass, and the original is read by an image sensor fixed on the surface opposite to the main surface of the contact glass. Then, an image showing a document is acquired. The contact glass is generally manufactured by a float method in which molten glass is flowed and formed on a molten metal accommodated in a bathtub. By manufacturing the contact glass by the float process, the thickness of the glass can be made uniform.

JP 2014-53845 A

  Each time a document is read, the document is transported toward the main surface of the contact glass, and the document contacts the main surface of the contact glass. Therefore, the main surface of the contact glass is required to have high durability against friction with the document. . In order to increase the durability against friction with the document, in general, a liquid fluorine coating agent is applied to the main surface of the contact glass and the main surface of the contact glass is naturally dried. A coating film is formed.

  Here, in order to further enhance the durability against friction between the main surface of the contact glass and the original, plasma processing may be performed on the main surface of the contact glass before fluorine coating, or the contact glass may be fired after fluorine coating. Conceivable.

  However, depending on which of the two main surfaces of the contact glass manufactured by the float process is subjected to plasma treatment or fluorine coating, performance such as durability of the contact glass may change. When contact glass is manufactured by the float method, the two main surfaces of the contact glass have a tin surface in contact with tin and a non-tin surface not in contact with tin. Yes. When plasma treatment or fluorine coating is performed on the tin surface, tin adhered to the contact glass may adversely affect the durability of the contact glass.

  For this reason, when performing plasma treatment or fluorine coating, specify which of the two main surfaces of the contact glass is a non-tin surface, and apply plasma treatment or fluorine coating to the specified non-tin surface. By doing so, the performance of the contact glass can be improved, such as durability.

  The present invention has been made in view of the above circumstances, and when performing plasma treatment or fluorine coating on contact glass, any of the two main surfaces of the contact glass is a non-tin surface. An object of the present invention is to make it possible to easily specify the plasma processing and the fluorine coating processing on the non-tin surface side.

  An image reading apparatus manufacturing method according to an aspect of the present invention includes an image sensor that conveys a document to be read toward a contact glass and fixes the conveyed document at a predetermined position on the contact glass. A manufacturing method for manufacturing a sheet-through type image reading apparatus that reads by a first method, wherein the contact glass is manufactured by a float method in which molten glass is flowed and formed on a molten metal accommodated in a bathtub; The first main surface of the contact glass in contact with the molten metal in the first step after the first step and the surface opposite to the first main surface, and the molten metal in the first step A second step of forming a mark on the contact glass indicating the second main surface of the contact glass that is not in contact with the contact glass, and after the second step, A third step of performing plasma treatment on the second main surface indicated by the mark formed on the tact glass, and after the third step, on the second main surface indicated by the mark formed on the contact glass A fourth step of performing a fluorine coating treatment; a fifth step of baking the contact glass after the fourth step; and a second main surface indicated by the mark formed on the contact glass after the fifth step. Is located on the side of the image reading device in contact with the conveyed document, and the first main surface indicated by the mark is located on the side of the housing on which the image sensor is installed. Thus, a sixth step of fixing the contact glass in the housing is a method for manufacturing an image reading apparatus.

  According to the present invention, when performing plasma treatment or fluorine coating on contact glass, it is possible to easily identify which of the two main surfaces of the contact glass is a non-tin surface. It is possible to reliably perform plasma treatment and fluorine coating treatment on the non-tin surface side.

1 is a perspective view illustrating an image forming apparatus including an image reading apparatus that is a manufacturing target according to a manufacturing method according to an embodiment of the present invention. It is sectional drawing which shows the image reading apparatus which is a manufacturing object by the manufacturing method concerning one Embodiment of this invention. It is a perspective view which shows the image reading apparatus which is a manufacturing object by the manufacturing method concerning one Embodiment of this invention. FIG. 3 is an enlarged view showing a configuration around a conveyance guide member of the image reading apparatus shown in FIG. 2. It is the figure which showed the apparatus which manufactures the 1st contact glass of an image reading apparatus. It is the flowchart which showed the process of manufacturing the 1st contact glass of an image reading apparatus. (A)-(C) are figures which show the 1st contact glass after a marking process. (A) is a flowchart which shows the process of fixing the 1st contact glass and the 2nd contact glass in the housing | casing of a reading part, (B) is detailed of the one part process shown to (A). It is a flowchart which shows a process. It is a top view which shows the housing | casing of the reading part of the image reading apparatus which is a manufacturing object by the manufacturing method concerning one Embodiment of invention. It is a figure which shows the experimental result regarding the manufacturing method concerning one Embodiment of invention. It is a figure which shows the experimental result regarding the manufacturing method concerning one Embodiment of invention.

  A method for manufacturing an image reading apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

  First, an image reading apparatus to be manufactured by an image reading apparatus manufacturing method according to an embodiment of the present invention will be described. As shown in FIG. 1, the image forming apparatus 1 is generally configured by an apparatus main body 80 and an image reading apparatus 10 disposed above the apparatus main body 80.

  An image forming unit (not shown) and the like are accommodated inside the housing 81 that forms the outline of the apparatus main body 80. The image forming unit forms a toner image of a document read by the image reading device 10 through charging, exposure, and development processes, and discharges the recording paper onto which the toner image has been transferred onto a discharge tray 82.

  The image reading apparatus 10 includes a reading unit 30 and a document conveying unit 20 disposed above the reading unit 30. FIG. 2 is a cross-sectional view showing the image reading apparatus 10, and FIG. 3 is a perspective view showing the image reading apparatus 10. As shown in these drawings, the document conveyance unit 20 of the image reading apparatus 10 includes a document table 21, a document discharge tray 22, a pickup roller 25, a conveyance roller 26, and a discharge roller 27.

  The document transport unit 20 feeds documents one by one from a bundle of documents placed on the document placing table 21 by a pickup roller 25, and feeds the document fed by the transport roller 26 to the main contact glass 32 described later. Transport toward the surface (first surface). The document conveyed to the first contact glass 32 is read by a scanner 34 described later at a predetermined document reading position, and then discharged to the document discharge tray 22 by a discharge roller 27.

  The reading unit 30 includes a box-shaped housing 31. An opening is provided in the upper surface 31A of the casing 31 (the surface facing the document conveying unit 20 when the document conveying unit 20 is closed), and the first contact glass 32 and the second contact glass are provided in the opening. 33 is attached. The first contact glass 32 is a contact glass for document conveyance reading, and a document is conveyed from the document conveyance unit 20. The second contact glass 33 is a contact glass for reading and fixing a document, on which a document is placed. The document conveying unit 20 provided above the second contact glass 33 is provided to be openable and closable with respect to the main surfaces of the first contact glass 32 and the second contact glass 33, and the document conveying unit 20. As a result, the document placed on the second contact glass 33 is fixed.

  On the lower surface (second surface) side opposite to the main surfaces of the first contact glass 32 and the second contact glass 33, a scanner 34 that is movable in the sub-scanning direction is provided. The scanner 34 incorporates a CIS (Contact Image Sensor) type image sensor extended in the main scanning direction.

  In the original fixed reading, the scanner 34 reciprocates in the sub-scanning direction to read the original placed on the second contact glass 33. On the other hand, in document conveyance reading, the scanner 34 is fixed at a predetermined position (image reading position) on the back surface of the first contact glass 32 and is directed toward the main surface of the first contact glass 32 by the document conveyance unit 20. Scan the original that was conveyed. Image data obtained by reading the document is stored in an image memory or HDD built in the image reading apparatus 10.

  The reading unit 30 further includes a conveyance guide member 35 on the main surface of the first contact glass 32. FIG. 4 is an enlarged cross-sectional view showing a configuration around the transport guide member 35. As shown in FIGS. 2 to 4, the conveyance guide member 35 is a long sheet extending in the main operation direction, and has an adhesive at a predetermined position on the main surface of the first contact glass 32. 36 is adhered. This predetermined position is a position near the position (image reading position) of the scanner 34 at the time of document conveyance reading, and is a position outside the reading range by the scanner 34 at the time of document conveyance reading. The leading end portion of the conveyance guide member 35 provided at the predetermined position enters the conveyance path of the document conveyed by the conveyance roller 26. As a result, as shown in FIG. 4, the leading end portion of the conveyance guide member 35 contacts the document discharged from the opening 26 </ b> A on the upstream side in the document conveyance direction with respect to the reading range of the scanner 34. The document discharged from the opening 26 </ b> A is directed to the image reading position of the first contact glass 32 while being in contact with the leading end portion of the conveyance guide member 35. When the document comes into contact with the leading end of the conveyance guide member 35, foreign matters such as dust attached to the document are removed by the leading end of the conveyance guide member 35. As described above, the conveyance guide member 35 plays a role of removing foreign matters attached to the document in addition to the role of guiding the document to the image reading position of the first contact glass 32.

  Next, a method for manufacturing the image reading apparatus 10 described above will be described. Note that a configuration other than the reading unit 30 of the image reading apparatus 10, for example, a method for manufacturing the document conveying unit 20, is not particularly different from a general manufacturing method, and thus description thereof is omitted.

  First, a method for manufacturing the first contact glass 32 will be described. FIG. 5 is a view showing an apparatus for manufacturing the first contact glass 32. FIG. 6 is a flowchart showing a process for manufacturing the first contact glass 32.

  First, glass raw materials such as silica sand, sodium carbonate (soda ash), calcium carbonate, and dolomite are put into a melting tank (step S1), and the glass raw material is heated to 1600 ° C. or more to be melted to produce molten glass. (Step S2). And the produced | generated molten glass is poured into the float bath filled with the molten metal (this embodiment tin) (step S3). The molten glass poured into the float bath floats in a strip shape on the tin filled in the melting tank. By floating the molten glass on the molten tin, a glass having a uniform thickness and a smooth surface can be generated. In addition, you may add the process of lowering | hanging the temperature of a molten glass to 1100 degreeC-1300 degree | times, and venting an internal air between said melt | dissolution process (step S2) and a float process (step S3).

  After the float process in step S3, the glass temperature is gradually lowered in the slow cooling line (step S4). By gradually lowering the temperature of the glass, it is possible to prevent distortion from occurring inside.

  After the slow cooling step of step S4, the glass is cut into the size of the first contact glass 32 (step S5). And after cut | disconnecting glass, it is a surface on the opposite side to the 1st surface (tin surface) of the 1st contact glass 32 which contact | connected the tin melt | dissolved in the float process of step S3, and a 1st surface, Float process A mark indicating the second surface (non-tin surface) of the first contact glass 32 not in contact with the dissolved tin is formed on the first contact glass 32 (step S6).

  FIGS. 7A to 7C are views showing the first contact glass 32 after the process of step S6. In FIG. 7A, the main surface 33B facing upward on the paper surface is a second surface (non-tin surface) that is not in contact with tin, and the main surface 33A facing downward on the paper surface is the first surface (tin) Surface). In the present embodiment, when viewed from the first surface side (Z-axis direction in the drawing), one of the four corners of the first contact glass 32 is cut out at an angle of about 45 degrees. Is formed on the first contact glass 32 as the above-mentioned mark.

  Here, if the main surface 33A and the main surface 33B of the first contact glass 32 have a square rectangular shape, any one of the four corners of the first contact glass 32 is cut out. Of the two main surfaces of the first contact glass 32, a surface that is a tin surface or a non-tin surface cannot be specified only by the notched portion 331. In the present embodiment, since the main surface 33A and the main surface 33B of the first contact glass 32 are rectangular in shape, the position where the notch 331 is formed is stored, and then the first visual inspection is performed. Of the two main surfaces of the contact glass 32, a surface that is a tin surface or a non-tin surface can be specified. Although details will be described later, by forming a mark as described above on the first contact glass 32, a step of bonding a sheet-like member to be performed later, a plasma treatment step, a fluorine coating treatment step, and a first In the process of fixing the contact glass 32 to the housing 31 of the reading unit 30, the main surface that can be subjected to more effective processing is specified out of the two main surfaces of the first contact glass 32, Since the identified main surface can be processed, the durability of the first contact glass 32 can be improved.

  In addition, when manufacturing the 2nd contact glass 33, it is not necessary to perform the marking process of step S6 among the processes of said step S1-step S6.

  Next, a method for fixing the first contact glass 32 and the second contact glass 33 in the housing 31 of the reading unit 30 will be described. FIG. 8A is a flowchart illustrating a process of fixing the first contact glass 32 and the second contact glass 33 in the housing 31 of the reading unit 30. FIG. 8B is a flowchart showing detailed steps of the step S12 shown in FIG. As shown in these drawings, first, the first contact glass 32 and the second contact glass 33 manufactured by the above-described method are prepared (S11). Then, the first contact glass 32 is processed (step S12), and then the processed first contact glass 32 and second contact glass 33 are placed in the housing 31 of the reading unit 30. (Step S13). Note that in order to complete the manufacture of the reading unit 30, a process of mounting the scanner 34 and other members in the housing 31 of the reading unit 30 and a wiring process are required. Since there is no particular difference from the method, explanation is omitted.

  Details of the processing step for the first contact glass 32 in step S12 will be described. In this process, first, a sheet-like member is bonded to a predetermined position on the main surface of the first contact glass 32 as the conveyance guide member 35 (step S21). In step S21, a member having heat resistance and insulation is used as the sheet-shaped member. Here, the heat resistance specifically refers to performance capable of withstanding heat of 150 degrees or more. Such a member corresponds to, for example, a member based on polyvinyl chloride or polyethylene.

  In the process of step S <b> 21, the main surface to which the sheet-like member is bonded is the non-tin surface of the two main surfaces of the first contact glass 32. In the step S21, from the position of the notch 331 formed in the step S6, after specifying which of the two main surfaces of the first contact glass 32 is a non-tin surface, A sheet-like member is bonded to the specified non-tin surface.

  The sheet-like member is bonded to the non-tin surface instead of the tin surface in the process (step S22 and step S23) to be described later, and the sheet-like member is bonded to the non-tin surface. This is because it is necessary to perform a treatment process and a fluorine coating treatment process.

  Here, the conveyance guide member 35 is a member that plays a role of guiding the document to the image reading position of the first contact glass 32 and removing foreign matters attached to the document, but only for these roles. If so, the conveyance guide member 35 may be simply a sheet-like member, and there is no need to employ a member having heat resistance and insulation as described above. In this embodiment, the sheet-like member having heat resistance and insulation is adopted as the conveyance guide member 35 for the following reason.

  Usually, when another member such as the conveyance guide member 35 is bonded to the first contact glass 32, the process is performed after the processing for the first contact glass 32 is performed. However, in this embodiment, in order to improve the durability and the like of the first contact glass 32, the first contact glass 32 is subjected to plasma treatment, fluorine coating treatment, and baking treatment. It is difficult to adhere another member to the contact glass 32. For this reason, in this embodiment, the conveyance guide member 35 is adhered to the first contact glass 32 before performing the plasma treatment, the fluorine coating treatment, and the firing treatment.

  However, when the conveyance guide member 35 is adhered to the first contact glass 32 before performing the plasma treatment, the fluorine coating treatment, and the firing treatment, the conveyance guide is used in the plasma treatment, the fluorine coating treatment, and the firing treatment. The member 35 is deformed or peeled off.

  Further, it is conceivable to cover the area where the conveyance guide member 35 is adhered with a masking tape, and then to perform plasma treatment or fluorine coating treatment on the main surface of the first contact glass 32. As a result, the main surface of the first contact glass 32 can be subjected to plasma treatment or fluorine coating except for a range where another member such as the conveyance guide member 35 is bonded, and the conveyance guide member 35 is removed after the plasma treatment or fluorine coating. It can be adhered to the main surface of the first contact glass 32. However, in this case, the masking tape is deformed or peeled off in the steps of plasma treatment, fluorine coating treatment, and baking treatment. Further, since the number of work steps is increased by the masking step, the manufacturing work efficiency of the image reading apparatus 10 is lowered.

  In this regard, according to the manufacturing method according to one embodiment of the present invention, a sheet-like member having heat resistance and insulation is adopted as the conveyance guide member 35, and before the plasma processing step and the fluorine coating processing step. In order to perform the process of bonding the sheet-like member to the first contact glass 32 as the transport guide member 35, the transport guide member 35 is bonded to the main surface of the first contact glass 32 with a small number of work steps. The image reading apparatus 10 can be manufactured. Although details will be described later, since plasma treatment, fluorine coating treatment, and baking treatment are performed on the first contact glass 32, durability against friction between the first contact glass 32 and the document is generally provided. Higher than the image reading apparatus.

  After the step S21, plasma processing is performed on the non-tin surface of the first contact glass 32 (step S22). At this time, which of the two main surfaces of the first contact glass 32 is a non-tin surface is specified from the position of the notch 331 formed in the step S6. Moreover, you may specify that the surface by which the conveyance guide member 35 was adhere | attached by the process of step S21 is a non-tin surface.

  Of the two main surfaces of the first contact glass 32, tin is thinly adhered to the tin surface. For this reason, as described above, the surface treatment effect by the plasma treatment can be enhanced by specifying the tin surface and the non-tin surface and performing the plasma treatment on the non-tin surface side.

  In the plasma treatment, the first contact glass 32 is set in the chamber, plasma is generated in the chamber, and the generated plasma is irradiated onto the non-tin surface of the first contact glass 32. Since this plasma irradiation gives energy higher than the binding energy of atoms constituting the foreign matter such as C—C bond, C—H bond, and C—O bond, the foreign matter attached to the non-tin surface of the first contact glass 32 is removed. In addition, since molecules such as OH groups ionized by plasma irradiation are modified on the surface of the first contact glass 32, the wettability of water is improved.

  Since the conveyance guide member 35 bonded to the non-tin surface of the first contact glass 32 is made of an insulating member, it does not burn even when a voltage of several hundred volts is applied by plasma processing. .

  After the step S22, the non-tin surface of the first contact glass 32 is subjected to a fluorine coating process (step S23). Specifically, the liquid fluorine coating agent is sprayed toward the non-tin surface of the first contact glass 32 by spraying, and the fluorine coating agent sprayed on the non-tin surface of the first contact glass 32 is solidified. Let Thereby, a fluorine coating film is formed on the non-tin surface of the first contact glass 32. In the step S22, the non-tin surface foreign matter of the first contact glass 32 is removed and the wettability of water is improved, so that a fine fluorine coating film can be formed.

  Here, normally, a fluorine coating film is formed on the main surface of the contact glass by applying a liquid fluorine coating agent and naturally drying the main surface of the contact glass. Compared with this normally performed process, a dense fluorine coating film can be formed by spraying the liquid fluorine coating agent by spraying as described above.

  Further, in the process of step S23, which of the two main surfaces of the first contact glass 32 is a non-tin surface is specified from the position of the notch 331 formed in the process of step S6. Moreover, you may specify that the surface by which the conveyance guide member 35 was adhere | attached by the process of step S21 is a non-tin surface. Thus, the surface treatment effect by the fluorine coating treatment can be enhanced by specifying the tin surface and the non-tin surface and performing the fluorine coating treatment on the non-tin surface side.

  After the step S23, the side surfaces (the surfaces 33C, 33D, 33E, 33F shown in FIG. 7B) of the first contact glass 32 are polished (step S24). Since another member may be adhered to the side surface of the first contact glass 32 or an adhesive may be applied in the assembly process of step S26 described later, the first contact is performed by performing the above process. The fluorine coating on the side surface of the glass 32 is removed. Note that it is not always necessary to polish all four side surfaces of the first contact glass 32, and it is not necessary to polish the side surfaces to which other members are not bonded. Moreover, you may perform the grinding | polishing process of step S24 after the baking process of step S25 mentioned later.

  After the process of step S25, the first contact glass 32 is baked in a thermostatic bath. Specifically, baking is performed at a temperature of 150 degrees for 30 minutes (step S25). Since the conveyance guide member 35 bonded to the non-tin surface of the first contact glass 32 is made of a heat-resistant member, the conveyance guide member 35 is not damaged or burnt in the firing step of step S25.

  The above is the details of the processing step for the first contact glass 32 in step S12. After the step S12, the first contact glass 32 and the second contact glass 33 are mounted in the housing 31 of the reading unit 30 (step S13). At this time, the non-tin surface indicated by the mark formed on the first contact glass 32 is located on the side in contact with the conveyed document, and the tin surface is on the side where the image sensor 34 in the housing 31 is installed. The first contact glass 32 is fixed in the housing 31 so as to be positioned.

  FIG. 9 is a top view showing the housing 31 of the reading unit 30. As shown in the figure, a fitting hole 31B into which the first contact glass 32 is fitted and a fitting hole 31C into which the second contact glass 33 is fitted are formed on the upper surface 31A of the housing 31. The fitting hole 31B has a shape corresponding to the cutout portion 331 formed in the first contact glass 32. By fitting the first contact glass 32 into the fitting hole 31B, plasma treatment and fluorine coating are performed. The first contact glass 32 is placed in a state where the treated non-tin side is located on the side in contact with the conveyed document, and the tin side is located on the side where the scanner 34 in the case 31 is installed. Fixed in the body 31.

  <Experiment>

  The applicant conducted the following experiment based on earnest research, and came up with the above technique from the experimental result.

<Experiment 1>
(1) Three types of fluorine coating agents A, B, and C having different friction coefficients, (2) presence / absence of plasma treatment, (3) fluorine coating method (spray spray or application) The surface processing of 1 contact glass 32 was performed. The result is shown in FIG. In FIG. 10, durability refers to the water contact angle when the first contact glass 32 is worn using steel wool under the conditions of load: 1 kg, contact area: 1 cm × 1 cm, speed: 60 cycles / min. It shows the number of times required to reach 100 degrees or less. Moreover, the water contact angle at the time of 1000 times has shown the water contact angle at the time of wearing 1000 times using steel wool. The dynamic friction coefficient is a value measured using paraffin paper under a load of 200 gf and a speed of 200 mm / min.

  Comparing the results of sample numbers 3, 4 and 5, 6 shown in FIG. 10, the durability of the first contact glass 32 is greatly improved by performing the plasma treatment before the fluorine coating treatment. I understand. Further, when comparing the results of sample numbers 1, 2, and 9, when the fluorine coating is performed by spray injection, the dynamic friction coefficient is significantly lower than when the fluorine coating is applied by application. In addition, when the fluorine coating is performed by spraying, the water contact angle is higher than when the fluorine coating is applied by application. For this reason, when the document is conveyed to the first contact glass 32, unnecessary friction is not applied to the document from the first contact glass 32. Sample Nos. 7 and 8 using the fluorine coating agent having the lowest friction coefficient have the best results for the indices of durability, dynamic friction coefficient, and water contact angle.

  From the above consideration, it is understood that it is optimal to perform plasma treatment on the first contact glass 32 and then perform fluorine coating by spray coating.

<Experiment 2>
After bonding each member of polycarbonate, polyethylene terephthalate, crepe paper, polyvinyl chloride, and polyethylene to the first contact glass 32, each step of plasma treatment, fluorine coating treatment, and firing treatment was performed. The result is shown in FIG.

  Polycarbonate and polyethylene terephthalate expanded or contracted due to the heat of the firing process, resulting in misalignment. In addition, the crepe paper was found to be burnt or damaged by the plasma treatment. This is presumably because the crepe paper has a heat resistance of 160 degrees but is not insulating. For polyvinyl chloride and polyethylene, no scorching or damage was observed even when plasma treatment, fluorine coating treatment, and firing treatment were performed. This is considered to be because polyvinyl chloride has a heat resistance of 150 degrees and is insulative, and polyethylene has a heat resistance of 200 degrees and is insulative.

  From the above consideration, a sheet-like member having heat resistance and insulation is adopted as the conveyance guide member 35, and this sheet-like member is used as the first contact glass before the plasma treatment process or the fluorine coating treatment process. By performing the process of adhering to 32 as the conveyance guide member 35, the image reading apparatus 10 in which the conveyance guide member 35 is adhered to the main surface of the first contact glass 32 can be manufactured with a small number of work processes. I understand.

<Modification>
The present invention is not limited to the configuration of the above embodiment, and various modifications can be made.

  For example, in the polishing step of step S24 described above, not all of the four side surfaces of the first contact glass 32 are polished, but a side surface at a predetermined position (for example, the surface shown in FIG. 7B). Only 33C) may be polished. By memorizing the position where the side surface of the first contact glass 32 is polished together with the position where the notch 331 is formed, the tin of the two main surfaces of the first contact glass 32 is visually observed thereafter. A surface that is a surface or a non-tin surface can be identified more reliably.

  Moreover, although said embodiment demonstrated the case where the notch part 331 was formed as a mark which shows a tin surface and a non-tin surface, this invention is not necessarily limited to this case. For example, a cut may be made at the end on the tin surface side as the mark.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 10 Image reading apparatus 20 Original conveyance part 30 Reading part 31 Case 32 1st contact glass 33 2nd contact glass 34 Scanner 35 Conveyance guide member 331 Notch

Claims (7)

A manufacturing method for manufacturing a sheet-through type image reading apparatus that conveys a document to be read toward a contact glass and reads the conveyed document by an image sensor fixed at a predetermined position of the contact glass. There,
A first step of manufacturing the contact glass by a float method in which molten glass is flowed and formed on a molten metal accommodated in a bathtub;
After the first step, the first main surface of the contact glass in contact with the molten metal in the first step, and the surface opposite to the first main surface, and the molten metal in the first step A second step of forming a mark on the contact glass indicating the second main surface of the contact glass that is not in contact;
After the second step, a third step of performing a plasma treatment on the second main surface indicated by the mark formed on the contact glass;
After the third step, a fourth step of applying a fluorine coating treatment to the second main surface indicated by the mark formed on the contact glass;
A fifth step of firing the contact glass after the fourth step;
After the fifth step, the second main surface indicated by the mark formed on the contact glass is positioned on the side in contact with the conveyed document in the housing of the image reading apparatus, and indicated by the mark. And a sixth step of fixing the contact glass in the casing so that the first main surface is positioned on the side where the image sensor is installed in the casing. The contact glass is a rectangular parallelepiped in which the first main surface and the second main surface are rectangular.
In the second step, a notch portion in which any one of the four corners of the contact glass as viewed from the first main surface side is notched is formed in the contact glass as the mark,
2. The first main surface and the second main surface of the contact glass are specified based on a position where the notch is formed in the third step, the fourth step, and the sixth step. A method for manufacturing the image reading apparatus according to claim 1. The housing is formed with a fitting hole having a shape corresponding to the shape of the contact glass in which the notch is formed,
In the sixth step, by inserting the contact glass into the fitting hole, the second main surface is positioned on the side in contact with the conveyed document in the housing of the image reading device, and the first The method for manufacturing an image reading apparatus according to claim 2, wherein the contact glass is fixed in the casing in a state where a main surface is located on a side where the image sensor is installed in the casing.   The said 4th process WHEREIN: Furthermore, the process of grind | polishing the side surface in which the said notch part is not formed among the side surfaces of the longitudinal direction of the said contact glass is included. A method for manufacturing an image reading apparatus. The image reading device contacts the document at a predetermined position outside the reading range by the image sensor of the contact glass on the upstream side of the reading range with respect to the document conveying direction. An image reading apparatus provided with a conveyance guide member for guiding to a reading range,
After the second step and before the third step, the method further includes a step of adhering a heat-resistant and insulating sheet-like member to the predetermined position of the contact glass as the conveyance guide member. A method for manufacturing an image reading apparatus according to claim 1.   The method for manufacturing an image reading apparatus according to claim 5, wherein the sheet-like member is a member based on polyvinyl chloride or polyethylene.   In the fourth step, a liquid fluorine coating agent is sprayed toward the main surface of the contact glass by spraying, and the sprayed fluorine coating agent is solidified on the main surface of the contact glass. The method for manufacturing an image reading apparatus according to claim 5, wherein a fluorine coating film is formed on a main surface of the glass.