JP2017034437A - Contact-type image sensor and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contact-type image sensor having a structure capable of reducing a positional variation of an optical system of a light source and a lens caused by a dimensional variation of a reference component.SOLUTION: A contact-type image sensor comprises: a light guide body 5 which is provided to extend in a main scanning direction that is a reading width direction of a document 1, and irradiates a reading surface of the document 1 with a light; a light guide body 6 which is provided in parallel with the light guide body 5 and irradiates the document 1 with a light; a lens body 9 for receiving and converging on an incident surface a reflection light resulting from reflecting the lights radiated by the light guide body 5 and the light guide body 6 on the reading surface of the document 1; and a sensor 10 including a light-receiving surface for receiving the reflection light converged by the lens body 9. The lens body 9 is disposed between the light guide body 5 and the light guide body 6, and opposing side faces thereof are in contact with the light guide body 5 and the light guide body 6.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a contact image sensor used in an image reading apparatus such as a copying machine or a digital multifunction machine.

  The optical system of the contact image sensor is irradiated with uniform light in the main scanning direction (longitudinal direction) as the reading depth is secured and the resolution of the copying machine is increased, and the document, lens and sensor are mutually connected. A structure that defines the position with high accuracy is required. Therefore, in the assembly of the light guide body and the lens body, irradiation is performed by holding the holder that holds both ends of the light guide body and the housing that supports the holder in a fixed arrangement as parts for positioning. A technique that enables uniform light irradiation with little variation on a document portion is disclosed (Patent Document 1 and Patent Document 2).

JP 2012-199983 A JP 2013-21604 A

  However, in the conventional contact type image sensor, there is a problem that, when there is a dimensional variation of the reference component, there is a variation in the position of the optical system of the light source and the lens.

  The present invention has been made in order to solve the above-described problems, and its object is to have a structure that can reduce the positional variation of the optical system of the light source and the lens due to the dimensional variation of the reference component. To obtain a mold type image sensor.

  In the contact image sensor according to the present invention, a first light guide that is provided so as to extend in the main scanning direction, which is the longitudinal direction, and irradiates light on the reading surface of the document, and the first light guide , A second light guide that irradiates light on the reading surface of the document, a lens body that collects the reflected light reflected on the reading surface of the document, and a reflection that is collected by the lens body And a sensor having a light receiving surface for receiving light, the lens body is disposed between the first light guide and the second light guide, and the opposing side surfaces are each the first light guide. And in contact with the second light guide.

  There is an effect of obtaining a contact image sensor having a structure capable of reducing the positional variation of the optical system of the light source and the lens due to the dimensional variation of the reference component.

1 is an exploded perspective view of the overall configuration of a contact image sensor according to Embodiment 1 of the present invention. It is a composition perspective view showing a part of contact type image sensor concerning Embodiment 1 of the present invention in detail. It is sectional drawing of the subscanning direction of the lens unit in the contact type image sensor which concerns on Embodiment 1 of this invention. It is a perspective view which shows the structure of the light guide holding body of the contact | adherence image sensor which concerns on Embodiment 1 of this invention. It is sectional drawing of the lens unit for demonstrating the light propagation form of a contact | adherence image sensor. It is the schematic which shows the flow of the manufacturing process of the contact | adherence image sensor which concerns on Embodiment 1 of this invention. It is sectional drawing of the subscanning direction of the jig | tool used for an assembly process. It is sectional drawing of the subscanning direction for demonstrating a lens body mounting process. It is sectional drawing of the subscanning direction for demonstrating a light guide body mounting process. It is sectional drawing of the subscanning direction for demonstrating a lens body clamping process. It is sectional drawing of the subscanning direction for demonstrating a holding body fitting process. It is sectional drawing of the subscanning direction for demonstrating a lens unit fixing process. It is sectional drawing of the subscanning direction for demonstrating a board | substrate fixing process.

Embodiment 1 FIG.
FIG. 1 is an exploded perspective view of the overall configuration of a contact image sensor 100 according to Embodiment 1 of the present invention. FIG. 2 is a structural perspective view showing in detail a part of the contact image sensor 100 according to the first embodiment of the present invention. In FIG. 1, a document 1 is an object to be read by the contact image sensor 100, and the document 1 is placed on the transparent plate 1a with the reading surface facing the transparent plate 1a. In describing the embodiment of the present invention, the main scanning direction, the sub-scanning direction, and the height direction are defined as follows. The main scanning direction is the longitudinal direction of the contact image sensor 100, and the sub-scanning direction is the short direction of the contact image sensor. Further, the height direction is the normal direction of the reading surface of the document 1.

  Further details will be described with reference to FIGS. The contact image sensor 100 is provided at the end of the lens unit 2 that irradiates light onto the reading surface of the document 1 and collects the reflected light reflected by the reading surface. 2 is provided with a holder unit 3 that is incident from the end of 2 and a sensor unit 4 that converges and receives light collected by the lens unit 2.

  The lens unit 2 includes a light guide 5 that irradiates the reading surface of the document 1 with light propagating in the main scanning direction, a light guide 6 provided in parallel with the light guide 5, and a light guide 5 and a light guide holder 8 that holds the light guide 6. Further, a lens body 9 that collects the reflected light reflected by the reading surface of the document 1 is provided, and the lens body 9 is disposed between the light guide 5 and the light guide 6.

  The light guide 5 and the light guide 6 are formed of a transparent resin, extend in parallel with each other in the main scanning direction, and are disposed symmetrically with respect to the lens body 9. The document 1 has a columnar shape in which the surface facing the reading surface is parallel to the reading surface. The light guide 5 and the light guide 6 do not have to be parallel over the entire length in the main scanning direction. In the embodiment of the present invention, since the light guide is exposed, it is preferable to use PMMA (polymethyl methacrylate resin) having excellent oil resistance as the light guide 5 and the light guide 6. A cycloolefin resin or polycarbonate may be used instead of PMMA. Instead of using a resin, a metal may be used, or a combination of a metal and a resin may be used.

  The light guide holder 7 and the light guide holder 8 extend in the main scanning direction and are arranged symmetrically with respect to the lens body 9. The light guide holder 7 holds or fixes the light guide 5, and the light guide holder 8 holds or fixes the light guide 6. The light guide holder 7 and the light guide holder 8 are formed by integral molding of metal, resin, or metal and resin. The light guide holder 7 and the light guide holder 8 are formed with portions for positioning in the sub-scanning direction and the height direction, respectively. That is, a plurality of reference surfaces for positioning in the sub-scanning direction and the height direction are provided. Note that the detailed description of the reference planes provided in the light guide holders 7 and 8 will be made in the description of the arrangement of the lens unit 2.

  The lens body 9 is composed of a lens array such as a rod lens array or a microlens array that converges light on the sensor 10 on the sensor unit 4. In the embodiment of the present invention, the lens body 9 is described as an erecting equal-magnification lens, but lenses other than erecting equal-magnification may be used in accordance with the specifications of the contact image sensor 100. .

  The holder unit 3 makes light incident on the light guide 5 and the light guide 6. A holder unit 3 is provided at one end of the light guide 5 and the light guide 6, and another holder unit 3 is provided at the other end of the light guide 5 and the light guide 6.

  The holder unit 3 is provided with a holder 12 provided at one end of the light guide 5 and the light guide 6 and a holder 13 provided at the other end of the light guide 5 and the light guide 6. A light source substrate 14 for attaching the light source 16 and the light source 18 and a light source substrate 15 for attaching the light source 17 and the light source 19 are provided. In addition, light sources 16 and 17 that make light incident on the light guide 5, light sources 18 and 19 that make light incident on the light guide 6, a heat transfer plate 20 and a light source substrate for improving the thermal conductivity of the light source substrate 14. A heat transfer plate 21 for improving the thermal conductivity of 15 is provided. Furthermore, a heat radiating plate 22 that radiates heat conducted through the heat transfer plate 20 and a heat radiating plate 23 that radiates heat conducted through the heat transfer plate 21 are provided.

  As shown in FIGS. 1 and 2, the holder 12 has openings 12a and 12b, and the holder 13 has openings 13a and 13b. The opening 12a is a through hole penetrating from the end face side of the light guide 5 to the light source 16 side. Similarly, the opening 12b is a through-hole penetrating from the end face side of the light guide 6 to the light source 18 side.

  Similarly, the holder 13 has openings 13a and 13b. The opening 13a is a through-hole penetrating from the end face side of the light guide 5 to the light source 17 side. The opening 13b is a through hole penetrating from the end face side of the light guide 6 to the light source 19 side.

  The openings 12a, 12b, 13a, and 13b may be any one that optically penetrates the end surfaces of the light guides 5 and 6 that are in contact with the holders 12 and 13 and the surfaces of the holders 12 and 13 that face the end surfaces. That is, if the light emitted from the light sources 16, 17, 18, 19 is made of a material that can enter the light guides 5, 6, the openings 12 a, 12 b, 13 a, 13 b are not necessarily space. In particular, the holders 12 and 13 and the light guides 5 and 6 do not have to communicate with each other. Specifically, when the openings 12a, 12b, 13a, and 13b are formed as through holes, a transmissive material that propagates light to the light guides 5 and 6 may be inserted into the holders 12 and 13. The light source 16 and the light source 17 are disposed on the two end surfaces of the light guide 5, and the light source 18 and the light source 19 are disposed on the two end surfaces of the light guide 6. It goes without saying that only one light source 16 may be disposed on one end face and only one light source 18 may be disposed on one end face of the light guide 6.

  The light sources 16 and 17 are light source elements such as LEDs that make light incident on two opposing end faces of the light guide 5 in the main scanning direction. Similarly, the light sources 18 and 19 are light source elements such as LEDs that make light incident on two opposing end faces of the light guide 6 in the main scanning direction. The light source is constituted by an LED in which an LED chip is resin-molded or a bare chip LED. The photoelectric conversion output of the sensor 10 preferably has a wide dynamic range. However, when the reading operation of the document 1 is driven at high speed, the driving current of the light source must be increased in order to ensure a wide dynamic range. As a result, heat generation from the light source is increased by the increased driving current.

  In order to obtain an effective heat dissipation structure for heat generation from the light source, the heat transfer plates 20 and 21 and the heat dissipation plates 22 and 23 need to be configured. Specifically, as shown in FIG. 1, the heat transfer plate 20 is disposed on the surface of the light source substrate 14 that faces the surface on which the light sources 16 and 18 are formed. Here, the heat transfer plate 20 conducts heat generated by the light source substrate 14 to the heat radiating plate 22, and the heat radiating plate 22 radiates the conducted heat to the outside of the holder unit 3. The heat radiating plate 22 is disposed on a surface opposite to the surface where the heat transfer plate 20 contacts the light source substrate 14, and is fixed to the holder 12 by fixing means such as screws.

  A heat transfer plate 21 is disposed on the surface of the light source substrate 15 that faces the surface on which the light sources 17 and 19 are formed. Here, the heat transfer plate 21 conducts heat generated by the light source substrate 15 to the heat radiating plate 23, and the heat radiating plate 23 radiates the conducted heat to the outside of the holder unit 3. The heat radiating plate 23 is disposed on a surface opposite to the surface where the heat transfer plate 21 is in contact with the light source substrate 15, and is fixed to the holder 13 by fixing means such as screws.

  In the holder unit 3, the light guide holder 7 and the light guide holder 8 are fixed to the heat radiating plate 22 and the holder 12 by fixing means such as screws at one end surface of the heat radiating plate 22. Yes. Therefore, the heat generated by the light sources 16 and 18 can be efficiently radiated. Similarly, the light guide holder 7 and the light guide holder 8 are fixed to the heat radiating plate 23 and the holder 13 by fixing means such as screws at the heat transfer surface of the heat radiating plate 23 at the other end face. Therefore, the heat generated by the light sources 17 and 19 can be efficiently radiated.

  By having an effective heat dissipation structure as described above, the distortion due to expansion and contraction of the sensor substrate 11 of the contact image sensor equipped with the light source is eliminated, and the entire length in the main scanning direction is not affected by the ambient temperature. It is possible to realize stable light irradiation over a wide range.

  The sensor unit 4 includes a sensor 10 and a sensor substrate 11 that fixes the sensor 10. The sensor 10 is constituted by an optical sensor IC and extends in the main scanning direction by the reading length of the document 1. The sensor 10 receives the light collected by the lens body 9 and photoelectrically converts it. The sensor substrate 11 is attached to the surface of the light guide holders 7 and 8 on the surface opposite to the surface facing the reading surface of the document 1 by fixing means such as screws. The sensor board 11 is a circuit board to which the sensor 10 as a light receiving element is attached, and has a connector (not shown) that can be connected to the outside. The connector outputs an electrical signal photoelectrically converted by the sensor 10 mounted on the sensor substrate 11 to the outside of the sensor substrate 11 as an image signal. The configuration of the contact image type image sensor has been described above.

  Next, the arrangement of the components included in the lens unit 2 will be described with reference to FIGS. FIG. 3 is a cross-sectional view of the lens unit 2 in the sub-scanning direction in the contact image sensor 100 according to the first embodiment of the invention.

  The lens unit 2 is positioned in the sub-scanning direction as follows. As shown in FIG. 3, the lens body side surface 9c which is one side surface of the lens body 9 is in contact with the lens sub-scanning direction reference surface 5b, and the lens body side surface 9d which is the other side surface of the lens body 9 is the lens sub-scanning direction reference. It arrange | positions so that the surface 6b may be touched. That is, the lens body 9 is sandwiched between the light guide body 5 and the light guide body 6, and the light guide bodies 5 and 6 can be arranged symmetrically with respect to the lens body 9.

  FIG. 4 is a perspective view showing the configuration of the light guide holders 7 and 8. As shown in FIG. 4, the light guide holder 7 is provided with a holder sub-scanning direction reference plane 7 a and a holder height direction reference plane 7 b to define the position of the light guide 5. It has become. Although not shown, the light guide holder 8 is similarly provided with a holder sub-scanning direction reference plane 8a and a holder height direction reference plane 8b. Here, the holder sub-scanning direction reference plane 7a is in contact with the light guide sub-scanning direction reference plane 5a, and the holder sub-scanning direction reference plane 8a is in contact with the light guide sub-scanning direction reference plane 6a. In the drawings, the same reference numerals denote the same or corresponding parts, and detailed descriptions thereof are omitted.

  The reference planes provided on the light guides 5 and 6 and the lens body 9 will be described in more detail with reference to FIG. A dotted line shown in FIG. 3 indicates a reading surface of the document 1. A document reference surface 5 d provided on the light guide 5 is a surface parallel to the reading surface of the document 1 and is a reference surface in the height direction with respect to the reading surface of the document 1. Similarly, the document reference surface 6 d provided on the light guide 6 is a surface parallel to the reading surface of the document 1 and is a reference surface in the height direction with respect to the reading surface of the document 1.

  The lens body 9 has an incident surface 9 a facing the reading surface of the document 1, an exit surface 9 b facing the incident surface 9 a, a lens body side surface 9 c that is a surface in contact with the light guide 5, and a surface in contact with the light guide 6. A lens body side surface 9d. The incident surface 9a is a surface on which reflected light from the reading surface of the document 1 is incident on the lens body 9, and the emission surface 9b is a surface on which the light incident from the incident surface 9a is collected by the lens body 9 and emitted. . Further, by positioning the light guides 5 and 6 and the lens body 9 in the height direction on the basis of the document reference surfaces 5d and 6d, the distance between the reading surface of the document 1 and the incident surface 9a can be determined. It can be set according to the lens characteristics.

  Further, the lens sub-scanning direction reference surface 5b provided on the lens body 9 side of the light guide 5 is orthogonal to the document reference surface 5d, and the lens sub-scanning direction reference provided on the lens body 9 side of the light guide 6 is used. The surface 6b is orthogonal to the document reference surface 6d.

  The lens sub-scanning direction reference surface 5b is a surface in contact with the lens body side surface 9c, and the lens sub-scanning direction reference surface 6b is a surface in contact with the lens body side surface 9d. That is, the lens sub-scanning direction reference surfaces 5b and 6d are also reference surfaces used to arrange the light guides 5 and 6 symmetrically across the lens body 9. The lens sub-scanning direction reference surfaces 5b and 6b are subjected to a light shielding process so that light does not leak from the light guides 5 and 6 to the lens body 9. Needless to say, for example, an aluminum vapor-deposited layer having a light-shielding property may be formed as the light-shielding treatment, and light-shielding treatment may be performed by other treatments.

  The light guide sub-scanning direction reference surface 5a is a surface facing the lens sub-scanning direction reference surface 5b and parallel to the lens sub-scanning direction reference surface 5b, and the light guide sub-scanning direction reference surface 6a is a lens sub-scanning direction reference surface 6a. It is a surface facing the scanning direction reference surface 6b and parallel to the lens sub-scanning direction reference surface 6b. That is, the light guide sub-scanning direction reference surface 5 a is a reference surface for positioning the light guide 5 in the sub-scanning direction with respect to the light guide holder 7. Similarly, the light guide sub-scanning direction reference plane 6 a is a reference plane for positioning the light guide 6 in the sub-scanning direction with respect to the light guide holder 8.

  The light guide height direction reference surface 5c provided on the light guide 5 is a surface facing the document reference surface 5d and parallel to the document reference surface 5d. Similarly, 6c provided on the light guide 6 is a surface facing the document reference surface 6d and parallel to the document reference surface 6d. The light guide height direction reference surface 5 c is a surface for positioning the light guide 5 in the height direction with respect to the light guide holder 7. Similarly, the light guide height direction reference surface 6 c is a reference surface for positioning the light guide 6 in the height direction with respect to the light guide holder 8.

  The light receiving surface 10 a of the sensor 10 that receives the light collected by the lens body 9 faces the emission surface 9 b of the lens body 9. Therefore, the height direction of the light guides 5 and 6 and the sensor 10 through the light guide holders 7 and 8, the substrate fixing body 25, and the sensor substrate 11 with reference to the light guide height direction reference surfaces 5 c and 6 c. Thus, the distance between the exit surface 9b of the lens body 9 and the light receiving surface 10a of the sensor 10 can be set according to the lens characteristics of the lens body 9.

  In FIG. 3, the component fixing body 24 on the left side of the drawing fixes the light guide 5, the light guide holder 7 and the lens body 9, and the component fixing body 24 on the right side of the drawing includes the light guide 6 and the light guide holding member. The body 8 and the lens body 9 are fixed. Here, the component fixing body 24 is preferably made of a highly light-shielding material in order to shield the light from the light guides 5 and 6 from the sensor 10. The component fixing body 24 is obtained by curing, for example, an adhesive having a light shielding property. Instead of configuring the component fixing body 24 with a highly light-shielding member, aluminum or the like that imparts light shielding properties is vapor-deposited on the contact surface between the light guide 5 and the light guide 6 and the component fixing body 24, thereby improving the light shielding performance. You may comprise the component fixing body 24 with the material which does not have. In that case, a transparent adhesive can be cured instead of the light-shielding adhesive. The substrate fixing body 25 fixes the lens unit 2 and the sensor unit 4 while adjusting the positions of the lens unit 2 and the sensor unit 4.

  Positioning in the height direction when the lens body 9 is an erecting equal-magnification lens is performed as follows. First, the holder height direction reference plane 7b and the light guide height direction reference plane 5c are combined, and the holder height direction reference plane 8b and the light guide height direction reference plane 6c are combined. Next, using a jig, the distance from the incident surface 9a to the reading surface of the document 1 and the distance from the exit surface 9b to the light receiving surface 10a of the sensor 10 are equal to each other from the incident surface 9a to the document reference surface 5d. , 6d while adjusting the distance up to 6d. Next, after the light guides 5 and 6, the lens body 9, and the light guide holders 7 and 8 are fixed by the component fixing body 24, the sensor substrate 11 and the light guide holders 7 and 8 are fixed by the substrate fixing body 25. Fix it. Here, the substrate fixing body 25 adjusts the distance between the light receiving surface 10a of the lens body 10 and the exit surface 9b again. Therefore, it is desirable that the substrate fixing body 25 is an adhesive layer obtained by, for example, solidifying an adhesive that fills the gap between the sensor substrate 11 and the light guide holders 7 and 8. A specific method for assembling the contact image sensor 100 using a jig will be described in detail in the following assembly process.

  Before describing the method of assembling the contact image sensor 100, the light propagation form in the contact image sensor 100 will be described. FIG. 5 is a cross-sectional view of the lens unit 2 for explaining the light propagation form of the contact image sensor 100. In FIG. 5, the light incident from the light source 16 provided at one end of the light guide 5 is guided inside the light guide 5, and repeats reflection on the wall surface of the light guide 5. The light incident from the light source 17 is guided in the light guide 5 in the direction opposite to the light incident from the light source 16, and is repeatedly reflected on the wall surface of the light guide 5. It is possible to irradiate uniform light over the entire length in the longitudinal direction of the light guide 5 by making light traveling in opposite directions from both ends of the light guide 5. Then, the original is scattered by the white printed pattern or the uneven scattering region 26 formed along the longitudinal direction of the light guide 5 and as line light from the portion facing the scattering region 26 as indicated by the arrow in FIG. 1 is output to the reading surface.

  Similarly, in FIG. 5, the light incident from the light source 18 provided at one end of the light guide 6 is guided inside the light guide 6 and is repeatedly reflected on the wall surface of the light guide 6. The light incident from the light source 19 is guided in the light guide 6 in the opposite direction to the light incident from the light source 18, and repeats reflection on the wall surface of the light guide 6. It is possible to irradiate uniform light over the entire length in the longitudinal direction of the light guide 6 by making the light traveling in opposite directions from both ends of the light guide 6. And light is scattered by the white printed pattern or uneven | corrugated shaped scattering area | region 27 formed along the longitudinal direction of the light guide 6, and light is shown in FIG. In this way, the light is emitted to the document 1 placed on the transparent plate 1a.

  The lens body 9 condenses light diffused and reflected from the light guide 5 and the light guide 6 as line light on the reading surface of the document 1. The sensor 10 receives the light collected by the lens body 9 by the light receiving surface 10a and performs photoelectric conversion. In the drawings, the same reference numerals denote the same or corresponding parts, and detailed descriptions thereof are omitted.

  Next, an assembly process of the contact image sensor 100 will be described. FIG. 6 is a diagram for explaining the flow of the assembly process of the contact image sensor 100. As shown in FIG. 6, the contact image sensor 100 according to the present invention is manufactured through the following steps. That is, a lens body placing step (step S1), a light guide placing step (step S2), a lens body sandwiching step (step S3), a holding body fitting step (step S4), and a lens unit fixing step (step S5). And a substrate fixing step (step S6).

  In describing the assembly process, the structure of the jig 28 used for assembling the contact image sensor according to the present invention will be described with reference to FIG. FIG. 7 is a sectional view of the jig 28 used in the assembly process in the sub-scanning direction. The jig 28 is formed in an inverted T shape in which a convex portion extending in the main scanning direction is connected to a flat plate extending in the main scanning direction. The light guide body mounting surface 28a for mounting, the lens body mounting surface 28b which is the upper surface of the convex part of the jig 28 for mounting the lens body 9, and the convex part of the jig 28 in the sub main scanning direction. Convex side surfaces 28c and 28d, which are side surfaces, are provided.

  FIG. 8 is a cross-sectional view in the sub-scanning direction for explaining the lens body placing step (step S1). First, the lens body 9 is mounted on the jig 28 so that the lens body mounting surface 28b of the jig 28 is in contact with the incident surface 9a. In the drawings, the same reference numerals denote the same or corresponding parts, and detailed descriptions thereof are omitted.

  FIG. 9 is a cross-sectional view in the sub-scanning direction for explaining the light guide placing step (step S2). As shown in FIG. 9, the light guides 5 and 6 are placed on the jig 28 so that the document reference surfaces 5 d and 6 d are in contact with the light guide placement surface 28 a of the jig 28. In the drawings, the same reference numerals denote the same or corresponding parts, and detailed descriptions thereof are omitted.

  FIG. 10 is a cross-sectional view in the sub-scanning direction for explaining the lens body sandwiching step (step S3). As shown in FIG. 10, the light guide 5 and the light guide 6 are moved by sliding the light guide 5 and the light guide 6 in the direction toward the center in FIG. The sub-scanning direction reference surface 5b is brought closer to the convex side surface 28c of the jig 28, and the lens sub-scanning direction reference surface 6b is brought closer to the convex side surface 28d of the jig 28. As a result, the lens body 9 is disposed between the light guides 5 and 6. The jig 28 is formed such that the width of the convex portion in the sub-scanning direction is narrower than the width of the lens body 9 in the sub-main scanning direction. Accordingly, the lens body side surfaces 9c and 9d, which are the side surfaces of the lens body 9, and the lens sub-scanning direction reference surfaces 5b and 6b are completely in contact with each other, and the light guides 5 and 6 are symmetrical with each other with the lens body 9 in between. Can be arranged. In the drawings, the same reference numerals denote the same or corresponding parts, and detailed descriptions thereof are omitted.

  FIG. 11 is a cross-sectional view in the sub-scanning direction for explaining the holding body fitting step (step S4). In the holder fitting step, the light guide holder 7 is fitted to the light guide 5 and the light guide holder 8 is fitted to the light guide 6. Here, the light guide body height direction reference plane 5c of the light guide 5 is joined to the holder height direction reference plane 7b formed on the light guide holder 7, and the light guide sub-scanning direction reference plane 5a is guided. The optical body holder 7 is fitted so as to be joined to the holder sub-scanning direction reference surface 7a. Similarly, the light guide body height direction reference plane 6c of the light guide 6 is joined to the holder height direction reference plane 8b formed on the light guide holder 8, and the light guide sub-scanning direction reference plane 6a is guided. The optical body holder 8 is placed so as to be bonded to the holder sub-scanning direction reference surface 8a formed on the optical body holder 8. In the drawings, the same reference numerals denote the same or corresponding parts, and detailed descriptions thereof are omitted.

  FIG. 12 is a cross-sectional view in the sub-scanning direction for explaining the lens unit fixing step (step S5). In the lens unit fixing step, the light guides 5 and 6, the light guide holders 7 and 8, and the lens body 9 are held in the positional relationship defined by the jig 28, and the lens is fixed. In this step, the body 9 and the light guide holders 7 and 8 are fixed by the component fixing body 24. In the embodiment of the present invention, the light guides 5 and 6, the light guide holders 7 and 8, and the lens body 9 are fixed by the component fixing body 24, but the light guides 5 and 6 and the lens body 9 are fixed. Then, the light guide holders 7 and 8 may be fixed respectively after fixing them with the component fixing bodies 24. In the drawings, the same reference numerals denote the same or corresponding parts, and detailed descriptions thereof are omitted.

  FIG. 13 is a cross-sectional view in the sub-scanning direction for explaining the substrate fixing step (step S6). Finally, in the substrate fixing step, the exit surface 9b depends on the focal length of the lens body 9, the distance from the incident surface 9a to the document reference surfaces 5d and 6d, and the distance from the document reference surfaces 5d and 6d to the reading surface of the document 1. To the light receiving surface 10a of the sensor 10 is calculated. Then, the light guide holder 7 and the sensor substrate 11 are fixed by the substrate fixing body 25 on the left side of the drawing so that the distance from the light exit surface 9b to the light receiving surface 10a of the sensor 10 becomes the calculated distance. The body holding body 8 and the sensor substrate 11 are fixed by the substrate fixing body 25 on the right side of the figure. The substrate fixing body 25 is preferably an adhesive that fills the gap, but may be fixed with a double-sided adhesive tape or a screw having a constant thickness according to the required assembly accuracy.

  It should be noted that the distance from the original 1 to the light guides 5 and 6 is provided with at least two holding body height direction reference surfaces 7b and 8b in the main scanning direction so that the positional relationship in the height direction can be maintained over the entire length in the main scanning direction. It is possible to keep it constant. In the drawings, the same reference numerals denote the same or corresponding parts, and detailed descriptions thereof are omitted.

  The positioning accuracy of the lens unit will be described. When positioning in the main scanning direction with respect to the lens unit by the steps from the lens body placing step (step S1) to the lens unit fixing step (step S5), the light guides 5 and 6 are arranged with the lens body 9 interposed therebetween. Thus, the light guides 5 and 6 can be arranged so as to be symmetrical to each other. That is, by sandwiching the lens body 9 between the lens sub-scanning direction reference surfaces 5b and 6b of the light guides 5 and 6, the center of the lens body 9 in the sub-main scanning direction is not affected by the dimensional variation of other parts. The light guides 5 and 6 can be arranged symmetrically with respect to the line. Further, by using the jig 28, the distance between the document reference surfaces 5d and 5d and the incident surface 9a can be kept constant over the entire length in the main scanning direction.

  Further, in the substrate fixing step (step S6), the distance from the entrance surface 9a to the document reference surfaces 5d and 6d and the distance from the exit surface 9b to the light receiving surface 10a of the sensor 10 are adjusted to have a fixed relationship. Fixing. For example, when an erecting equal-magnification lens body is used, the distance from the reading surface of the document 1 to the incident surface 9a is the same as the distance from the emitting surface 9b to the light receiving surface 10a. The distance to the document reference surfaces 5d and 6d is adjusted. Needless to say, the distance from the reading surface of the document 1 to the entrance surface 9a and the distance from the exit surface 9b to the light receiving surface 10a may be set according to optical characteristics such as the focal length of the lens body 9. In this case, depending on the focal length of the lens body 9 and the distance from the document reference surfaces 5d and 6d to the reading surface of the document 1, the distance from the entrance surface 9a to the document reference surfaces 5d and 6d and the exit surface 9b The distance from the light receiving surface 10a of the sensor 10 changes.

  Note that the order of the lens body placement step (step S1) and the light guide placement step (step S2) may be interchanged, or assembly may be performed by changing the order of the assembly steps shown in FIG.

  As described above, by configuring the contact image sensor 100, in the embodiment of the present invention, the positional relationship in the height direction between the contact image sensor and the document 1 is directly positioned on the document reference surfaces 5d and 6d. By doing so, it is possible to suppress position variations due to assembly variations of a plurality of parts. Further, the light guides 5 and 6 with respect to the document 1 and the lens body 9 are positioned in the height direction by holding body height direction reference surfaces 7b and 8b formed at two or more places on the light guide holders 7 and 8, respectively. The relationship can be the same. Further, after determining the distance in the height direction between the document reference surfaces 5d and 6d and the incident surface 9a, the distance in the height direction between the light receiving unit 10a and the exit surface 9b of the sensor 10 is adjusted and arranged. The document 1, the lens body 9, and the light receiving unit 10a can be adjusted to a suitable arrangement, and a contact image sensor having a good resolution can be obtained.

  In the embodiment of the present invention, the case where the document 1 is positioned on the upper side of the contact image sensor 100 has been described as an example. However, as long as the document can be held and conveyed, the orientation of the contact image sensor can be determined. It goes without saying that it may be suitable for. Further, the case where the contact image sensor 100 is fixed and the document 1 is conveyed has been described as an example. Conversely, the document is placed and the contact image sensor moves on the reading surface side of the document. Needless to say, you can.

100 Contact type image sensor 1 Documents 5, 6 Light guides 5a, 6a Light guide sub-scanning direction reference surfaces 5b, 6b Lens sub-scanning direction reference surfaces 5c, 6c Light guide height direction reference surfaces 5d, 6d Document reference surface 7 , 8 Light guide body holding body 7a, 8a Holder body sub-scanning direction reference surface 7b, 8b Holder body height direction reference surface 9 Lens body 9a Incident surface 9b Output surface 9c, 9d Lens body side surface 10 Sensor 10a Light receiving surface 11 Sensor substrate 24 Component fixing body 25 Substrate fixing body 28 Jig 28a Light guide mounting surface 28b Lens body mounting surfaces 28c, 28d Convex side surface

Claims (11)

A first light guide provided to extend in the main scanning direction, which is the longitudinal direction, and irradiates light on the reading surface of the document;
A second light guide which is provided in parallel with the first light guide and irradiates light on the reading surface of the document;
A lens body for collecting the reflected light reflected by the reading surface of the document;
A sensor having a light receiving surface that receives the reflected light collected by the lens body, and
The lens body is
It is disposed between the first light guide and the second light guide, and opposite side surfaces are in contact with the first light guide and the second light guide, respectively. Close contact type image sensor. The first light guide is
A first document reference surface parallel to the document reading surface;
The second light guide is
A second document reference surface parallel to the first document reference surface;
The lens body is
An incident surface on which the reflected light is incident;
It is opposed to the reading surface of the document, and is a surface parallel to the reading surface of the document,
The contact image sensor according to claim 1, wherein the first document reference surface and the second document reference surface exist on the same plane. The lens body is
Regarding the normal direction of the reading surface of the document, the distance from the entrance surface of the lens body to the first document reference surface is equal to the distance from the entrance surface of the lens body to the second document reference surface. Arranged as
The contact image sensor according to claim 2, wherein the first light guide and the second light guide are arranged so as to be symmetric with respect to the lens body. The lens body is
An exit surface that is a surface facing the entrance surface;
Based on the focal length of the lens body, the distance from the first document reference surface to the entrance surface of the lens body, and the distance from the first document reference surface to the document reading surface, from the exit surface of the lens body The distance to the light receiving surface of the sensor is calculated, and the lens body, the first light guide, the second light guide, and the sensor are arranged so as to be the calculated distance. The contact image sensor according to claim 2 or 3, wherein: The first light guide is
A first lens sub-scanning direction reference surface provided on a side surface orthogonal to the first document reference surface and close to the lens body;
The second light guide is
A second lens sub-scanning direction reference surface provided on a side surface orthogonal to the second document reference surface and close to the lens body;
The lens body is
A first lens body side surface orthogonal to the first document reference surface;
A second lens body side surface facing the first lens body side surface,
The first lens sub-scanning direction reference surface is in contact with the first lens body side surface,
5. The contact image sensor according to claim 2, wherein the second lens sub-scanning direction reference surface is in contact with a side surface of the second lens body. 6. A first light guide having a first document reference surface parallel to a document reading surface and a first lens sub-scanning direction reference surface provided on a plane orthogonal to the first document reference surface; ,
A second document reference surface provided on the same plane including the first document reference surface and a second lens sub-scanning direction reference surface provided on a plane orthogonal to the second document reference surface; A second light guide having
The document reading surface and the document reading surface; a parallel incident surface; an exit surface facing the incident surface; a first lens body side surface orthogonal to the first document reference surface; A lens body having a second lens body side surface facing the first lens body side surface;
A contact image sensor comprising: a sensor having a light receiving surface provided to face the emitting surface. The first light guide is
A first light guide body height direction reference surface that is parallel to the first document reference surface and faces the first document reference surface;
A first light guide sub-scanning direction reference plane that is parallel to the first lens sub-scanning direction reference plane and faces the first lens sub-scanning direction reference plane;
The second light guide is
A second light guide height direction reference plane that is parallel to the second document reference surface and faces the second document reference surface;
7. A second light guide sub-scanning direction reference plane that is parallel to the second lens sub-scanning direction reference plane and faces the second lens sub-scanning direction reference plane. Contact image sensor as described in 1. Provided on the first light guide and the second light guide on the side opposite to the direction from the first light guide and the second light guide toward the reading surface; A light guide holder having a holder height direction reference plane parallel to the one light guide height direction reference plane and a holder sub-scanning direction reference plane which is a plane orthogonal to the holder height direction reference plane;
The first light guide sub-scanning direction reference plane and the second light guide sub-scanning direction reference plane are:
Each of the holders is provided so as to contact the reference plane in the sub-scanning direction,
The first light guide body height direction reference plane and the second light guide body height direction reference plane are:
The contact image sensor according to claim 7, wherein the contact image sensor is provided so as to be in contact with the reference surface in the height direction of the holder. The light guide holder is
At least two of the holder sub-scanning direction reference planes;
The contact image sensor according to claim 8, further comprising: at least two reference surfaces in the height direction of the holding body. A first protrusion which is formed in an inverted T shape in which a convex portion extending in the main scanning direction is connected to a flat plate extending in the main scanning direction, and is a side surface of the convex portion extending in the main scanning direction. A side surface of the convex portion, a side surface of the second convex portion facing the side surface of the first convex portion, a lens body mounting surface that is a flat surface at a tip of the convex portion, and a surface on the convex portion side of the flat plate. A manufacturing method of a contact image sensor that manufactures the contact image sensor according to any one of claims 6 to 9, using a jig having a light guide mounting surface,
A lens body mounting step of mounting the incident surface of the lens body on the lens body mounting surface;
The first light guide is placed so that the first document reference surface and the light guide placement surface are in contact with each other, and the second document reference surface and the light guide placement surface are A light guide placing step of placing the second light guide so as to contact;
The first light guide and the second light guide are moved in a direction approaching the first convex side and the second convex side, and the first lens sub-scanning direction reference plane is the The first light guide and the second light guide make contact with the first lens body side surface and the second lens sub-scanning direction reference surface is in contact with the second lens body side surface. A method of manufacturing a contact image sensor comprising: a lens body sandwiching step of sandwiching a lens body. A first protrusion which is formed in an inverted T shape in which a convex portion extending in the main scanning direction is connected to a flat plate extending in the main scanning direction, and is a side surface of the convex portion extending in the main scanning direction. A side surface of the convex portion, a side surface of the second convex portion facing the side surface of the first convex portion, a lens body mounting surface that is a flat surface at a tip of the convex portion, and a surface on the convex portion side of the flat plate. A manufacturing method of a contact image sensor that manufactures the contact image sensor according to claim 8 or 9, using a jig having a light guide mounting surface,
A lens body mounting step of mounting the incident surface of the lens body on the lens body mounting surface;
The first light guide is placed so that the first document reference surface and the light guide placement surface are in contact with each other, and the second document reference surface and the light guide placement surface are A light guide placing step of placing the second light guide so as to contact;
The first light guide and the second light guide are moved in a direction approaching the first convex side and the second convex side, and the first lens sub-scanning direction reference plane is the The first light guide and the second light guide make contact with the first lens body side surface and the second lens sub-scanning direction reference surface is in contact with the second lens body side surface. A lens body sandwiching step for sandwiching the lens body; a sensor substrate to which the sensor is attached; and a substrate fixing body for fixing the sensor substrate and the light guide holder.
Each of the first light guide height direction reference plane and the second light guide height direction reference plane is in contact with the holding body height direction reference plane, and the first light guide sub-scanning direction reference plane and the The first light guide and the second light guide are fitted to the light guide holder so that each of the second light guide sub-scanning direction reference planes is in contact with the holder height direction reference plane. Holding body fitting process to be combined,
A lens unit fixing step of fixing the first light guide, the lens body, and the light guide holder, and fixing the second light guide, the lens body, and the light guide holder. When,
Based on the focal length of the lens body, the distance from the first document reference surface to the entrance surface of the lens body, and the distance from the first document reference surface to the document reading surface, from the exit surface of the lens body A method of manufacturing a contact image sensor, comprising: a substrate fixing step of calculating a distance to a light receiving surface of the sensor and fixing the sensor substrate and the light guide holder so as to be the calculated distance.

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