JP2013046347A - Image sensor module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image sensor module capable of reducing thickness while avoiding improper degradation of rigidity.SOLUTION: An image sensor module 101 comprises: a light source unit 200; a reflection surface 311 which reflects linear light reflected by a reading target 890, in a sub scanning direction y; a lens unit 400 which transmits therethrough the light reflected by the reflection surface 311; a reflection surface 312 which reflects the light transmitted through the lens unit 400 in a thickness direction z; a sensor IC 500 which receives the light reflected by the reflection surface 312; and a case 700 which has the reflection surfaces 311 and 312 fixed thereto and is made of metal.

Description

  The present invention relates to an image sensor module used for, for example, a document scanner.

  FIG. 14 shows an example of a conventional image sensor module. The image sensor module 900 shown in the figure is for reading the description content of the reading object 890 conveyed in the sub-scanning direction y as image data. The image sensor module 900 includes a case 91, a substrate 92, an LED module 93, a light guide 94, a lens unit 95, a sensor IC 96, and a transmission plate 97. The case 91 has an elongated shape extending in the main scanning direction that is perpendicular to the sub-scanning direction y and the thickness direction z. The substrate 92 has a long rectangular shape extending in the main scanning direction, and is fitted in the case 91. The LED module 93 includes a plurality of LED chips 93 a and is disposed near one end of the case 91 in the main scanning direction.

  The light guide 94 is for emitting the light from the LED module 93 toward the reading object 890, and is made of a transparent resin. The light guide 94 has an elongated shape extending in the main scanning direction, and has an incident surface (not shown), a reflective surface 94a, and an output surface 94b. The incident surface is one end surface of the light guide 94 in the main scanning direction and faces the LED chip 93a. The reflection surface 94a is a surface for reflecting light coming from the incident surface. The exit surface 94b is an elongated shape extending in the main scanning direction, and is a surface for emitting the light traveling in the light guide 94 to the reading object 890 as linear light extending in the main scanning direction. The light emitted from the light guide 94 passes through the transmission plate 97 and is applied to the reading object 890 and reflected by the reading object 890. This reflected light is condensed on the sensor IC 96 by the lens unit 95. The sensor IC 96 is configured to be able to output a signal corresponding to the amount of received light. By storing the light from the sensor IC 96 in a memory not shown in the figure, the description content of the reading object 890 can be read as an image.

  If the reading object 890 has a fold or a wrinkle, the reading object 890 is likely to be lifted from the transmission plate 97. In such a state, in order to clearly form the description of the reading object 890 on the sensor IC 96, it is advantageous to lengthen the optical path from the reading object 890 to the sensor IC 96. However, if the sensor IC 96 is moved downward for the purpose of extending the optical path, the thickness direction z dimension of the image sensor module 900 becomes large. For this reason, it is difficult to appropriately accommodate the image sensor module 900 in, for example, a document scanner in which the image sensor module 900 is used.

JP 2007-300536 A

  The present invention has been conceived under the circumstances described above, and it is an object of the present invention to provide an image sensor module that can be thinned while avoiding an unreasonable decrease in rigidity. To do.

  An image sensor module provided by the present invention includes a light source unit that emits linear light extending in the main scanning direction, and a first reflecting surface that reflects the linear light reflected by the reading object in the sub-scanning direction. A lens unit that transmits the light reflected by the first reflecting surface; and a second unit that reflects the light transmitted through the lens unit in a thickness direction perpendicular to both the main scanning direction and the sub-scanning direction. It is characterized by comprising a reflecting surface, a sensor IC that receives light reflected by the second reflecting surface, and a case made of metal, the first and second reflecting surfaces being fixed.

  In a preferred embodiment of the present invention, a first mirror having the first reflecting surface and a second mirror having the second reflecting surface, both of which are fixed to the case, are provided.

  In preferable embodiment of this invention, the said 1st reflective surface and the said 2nd reflective surface are comprised by each part of the surface of the said case.

  In a preferred embodiment of the present invention, the case includes a first part to which the first reflecting surface is fixed and a second part to which the second reflecting surface is fixed.

  In a preferred embodiment of the present invention, the first and second parts respectively have engaging portions that are provided at both ends in the main scanning direction and overlap each other when viewed in the thickness direction.

  In a preferred embodiment of the present invention, the optical axis of the lens unit is parallel to the sub-scanning direction and perpendicular to the main scanning direction.

  In a preferred embodiment of the present invention, the first reflecting surface is inclined 45 ° with respect to the sub-scanning direction.

  In a preferred embodiment of the present invention, the second reflecting surface is inclined 45 ° with respect to the sub-scanning direction.

  In a preferred embodiment of the present invention, the lens unit has an incident end face and an exit end face located at both ends in the sub-scanning direction, and the first part is formed on the exit end face of the lens unit. The second part has a second contact surface that contacts the incident side end surface of the lens unit.

  In a preferred embodiment of the present invention, the first contact surface is in contact with a portion near the sensor IC in the thickness direction on the exit side end surface of the lens unit.

  In a preferred embodiment of the present invention, the second contact surface is in contact with a portion closer to the reading object in the thickness direction on the incident side end surface of the lens unit.

  In a preferred embodiment of the present invention, the lens unit is located at both ends in the thickness direction, and has a first side surface on the sensor IC side and a second side surface on the reading object side. The first part has a third contact surface that contacts the first side surface of the lens unit, and the second part contacts the second side surface of the lens unit. It has a contact surface.

  In a preferred embodiment of the present invention, the optical axis position of the lens unit intersects a portion of the first reflecting surface that is closer to the reading object than the center in the thickness direction.

  In a preferred embodiment of the present invention, the position of the optical axis of the lens unit intersects a portion of the second reflecting surface that is closer to the reading object than the center in the thickness direction.

  In a preferred embodiment of the present invention, the light source unit, the first reflecting surface, the lens unit, and the second reflecting surface overlap each other in the thickness direction.

  In a preferred embodiment of the present invention, the sensor IC includes a substrate on which the sensor IC is mounted. The light source unit includes one or more LED chips, one or more leads on which the LED chips are mounted, and one of the leads. An LED module having a resin package in which an opening that exposes the LED chip is formed and a terminal portion that conducts to the lead, and extends as a whole in the main scanning direction. A light guide having a front-facing incident surface, a reflecting surface that reflects light traveling from the incident surface, and an emitting surface that emits light traveling from the reflecting surface as linear light extending long in the main scanning direction; The terminal portion protrudes from the resin package in the thickness direction from a position retracted in the sub-scanning direction with respect to the opening. , It is connected to the substrate.

  In a preferred embodiment of the present invention, the substrate and at least a part of the light guide are arranged so as not to overlap in the sub-scanning direction.

  In a preferred embodiment of the present invention, the case is made of aluminum.

  According to such a configuration, the optical path from the reading object to the sensor IC is bent. For this reason, even if the said optical path is lengthened, it can avoid that the said thickness direction dimension of the said image sensor module expands. Moreover, the rigidity of the said case can be improved by forming the said case with a metal. Furthermore, since the first and second reflecting surfaces are fixed to the case, there is little risk of being unjustly twisted. Therefore, it is possible to reduce the thickness of the image sensor module in the thickness direction while avoiding a decrease in rigidity of the case.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

It is a top view which shows the image sensor module based on 1st Embodiment of this invention. It is a principal part top view which shows the image sensor module of FIG. It is sectional drawing which follows the III-III line of FIG. It is sectional drawing which follows the IV-IV line of FIG. It is a side view which shows the image sensor module of FIG. FIG. 2 is an exploded cross-sectional view showing the image sensor module of FIG. 1. It is a front view which shows the LED module of the light source unit used for the image sensor module of FIG. It is a side view which shows the LED module of the light source unit used for the image sensor module of FIG. It is sectional drawing of the light source unit which follows the IX-IX line of FIG. It is sectional drawing of the light source unit which follows the XX line of FIG. It is a principal part enlarged front view which shows the opening part of the LED module of FIG. It is principal part sectional drawing which follows the XII-XII line | wire of FIG. It is sectional drawing which shows the image sensor module based on 2nd Embodiment of this invention. It is principal part sectional drawing which shows an example of the conventional image sensor module.

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

  FIGS. 1-6 has shown an example of the image sensor module based on 1st Embodiment of this invention. The image sensor module 101 of this embodiment includes a light source unit 200, mirrors 301 and 302, a lens unit 400, a sensor IC 500, a substrate 600, a case 700, and a transmission plate 800. The image sensor module 101 is used, for example, in a document scanner that generates electronic data including characters and designs by optically reading characters and designs printed on the reading object 890. In FIG. 2, the transmission plate 800 is omitted for the sake of understanding.

  The case 700 constitutes the outer shape of the image sensor module 101 and accommodates other components. As shown in FIGS. 1 and 2, the case 700 extends long in the main scanning direction x, and the cross-sectional shape defined by the sub-scanning direction y and the thickness direction z is a substantially rectangular shape. Case 700 is made of metal, and preferably aluminum.

  As shown in FIGS. 3 to 6, the case 700 includes a first part 710 and a second part 720. The first part 710 and the second part 720 constitute a case 700 by being combined with each other. As shown in FIG. 5, the engaging part 715 is formed on the first part 710, and the engaging part 725 is formed on the second part 720. The engaging portions 715 and 725 are engaged so as to overlap each other in the sub-scanning direction y (in the thickness direction z view).

  The case 700 includes a substrate housing portion 741, a light guide body housing portion 742, and a terminal through hole 744. The terminal through-hole 744 is formed near one end in the main scanning direction x of the case 700, and penetrates the case 700 in the thickness direction z as shown in FIG.

  As shown in FIG. 2 and FIG. 3, the light guide housing portion 742 extends long in the main scanning direction x and is disposed near one end in the sub scanning direction y. The light guide housing part 742 has a substantially rectangular cross section and opens upward in the thickness direction z. The substrate housing portion 741 extends long in the main scanning direction x and opens downward in the thickness direction z as shown in FIGS.

  As shown in FIG. 3, the first part 710 is formed with a first contact surface 711 and a third contact surface 712. The first contact surface 711 is provided in the vicinity of the right end of the first part 710 in the sub-scanning direction y in the figure, and is a surface having a relatively small area facing leftward in the sub-scanning direction y. The third contact surface 712 is connected to the lower end in the thickness direction z of the first contact surface 711 and faces upward in the thickness direction z.

  As shown in FIG. 3, a second contact surface 721 and a fourth contact surface 722 are formed on the second part 720. The second contact surface 721 is provided in the vicinity of the left end of the second part 720 in the sub-scanning direction y in the drawing, and is a surface having a relatively small area facing rightward in the sub-scanning direction y. The fourth contact surface 722 is connected to the upper end of the second contact surface 721 in the thickness direction z and faces downward in the thickness direction z.

  The substrate 600 is made of an insulating material such as ceramics or glass epoxy resin and a wiring pattern (not shown) formed on the insulating material, and has a long rectangular shape extending long in the main scanning direction x. The substrate 600 is accommodated in the substrate accommodating portion 741 of the case 700, and is fixed to the case 700 with, for example, an adhesive. As shown in FIGS. 3 and 4, a sensor IC 500 is mounted on the substrate 600. A connector 610 is mounted on the substrate 600.

  The transmission plate 800 is a plate material made of a transparent material such as glass, and is attached so as to cover the upper side of the case 700 in the thickness direction z.

  The light source unit 200 is a unit that emits linear light necessary for image reading by the image sensor module 101, and includes an LED module 210, a light guide 280, and a reflector 285.

  The LED module 210 is a module that performs the light emitting function of the light source unit 200. As shown in FIGS. 7 and 8, the LED chips 221, 222, 223, Zener diodes 224, 225, leads 241, 242, 243, 244, A terminal portion 255 and a resin package 270 are provided.

  The resin package 270 is made of a white resin such as a liquid crystal polymer resin or an epoxy resin, and covers a part of each of the leads 241, 242, 243, and 244. The resin package 270 has an opening 271 and a plurality of positioning holes 272. The opening 271 is provided near one end in the sub-scanning direction y and has a circular cross section. The plurality of positioning holes 272 are provided at positions avoiding the leads 241, 242, 243, 244, and penetrate the resin package 270 in this embodiment.

  As shown in FIGS. 7 and 11, the lead 241 has a mounting portion 251. The lead 241 as a whole has a portion extending long in the sub-scanning direction y and a portion extending in the thickness direction z. The mounting portion 251 is provided on the left side in the drawing of the portion extending in the sub-scanning direction y, and the LED chips 221, 222, 223 and the Zener diodes 224, 225 are mounted. In the present embodiment, the lead 241 has a constricted shape in which the mounting portion 251 has a partially smaller z dimension in the thickness direction than the surrounding portion. The mounting portion 251 is exposed from the opening 271 of the resin package 270.

  The lead 242 has a wire bonding part 252. The lead 242 as a whole has a portion extending in the sub-scanning direction y and a portion extending in the thickness direction z. The wire bonding part 252 is provided in the vicinity of the left end in the figure of a part extending in the sub-scanning direction y. In the present embodiment, the wire bonding portion 252 protrudes downward in the thickness direction z toward the mounting portion 251 of the lead 241. The wire bonding part 252 is exposed from the opening part 271 of the resin package 270.

  The lead 243 has a wire bonding part 253. The lead 243 as a whole has a part extending in the sub-scanning direction y and a part extending in the thickness direction z. The wire bonding part 253 is provided in the vicinity of the left end in the figure of a part extending in the sub-scanning direction y. In the present embodiment, the wire bonding portion 253 protrudes upward in the thickness direction z toward the mounting portion 251 of the lead 241. The wire bonding part 253 is exposed from the opening 271 of the resin package 270.

  The lead 244 has a wire bonding part 254. The lead 244 has a portion extending in the sub-scanning direction y and a portion extending in the thickness direction z as a whole. The wire bonding part 254 is provided in the vicinity of the left end in the figure of the part that extends long in the sub-scanning direction y. In the present embodiment, the wire bonding portion 254 is located on the lower right side of the mounting portion 251 in the drawing and on the right side of the wire bonding portion 253 in the drawing. The wire bonding part 254 is exposed from the opening 271 of the resin package 270.

  The terminal portion 255 is attached to a portion of the leads 241, 242, 243, and 244 that is exposed below the resin package 270 in the thickness direction z, and has internal wiring (not shown) that is electrically connected to each of them. It consists of a flexible wiring board. Terminal portion 255 is connected to connector 610 of substrate 600.

  The LED chip 221 emits green light in the present embodiment. As shown in FIGS. 11 and 12, the LED chip 221 includes a submount substrate 221a, a semiconductor layer 221b, and a pair of surface electrodes 231. The submount substrate 221a is made of Si, for example, and is transparent. The semiconductor layer 221b is made of, for example, a GaN-based semiconductor, and includes an n-type semiconductor layer, a p-type semiconductor layer, and an active layer (all not shown) sandwiched between the n-type semiconductor layer and the p-type semiconductor layer. A pair of surface electrodes 231 is formed on the submount substrate 221a and is electrically connected to the n-type semiconductor layer and the p-type semiconductor layer.

  The LED chip 222 emits blue light in this embodiment. In FIG. 12, for convenience of understanding, the reference numerals of the constituent elements of the LED chip 222 corresponding to the constituent elements of the LED chip 221 are shown in parentheses. The LED chip 222 has a submount substrate 222a, a semiconductor layer 222b, and a pair of surface electrodes 232. The submount substrate 222a is made of Si, for example, and is transparent. The semiconductor layer 222b is made of, for example, a GaN-based semiconductor, and includes an n-type semiconductor layer, a p-type semiconductor layer, and an active layer (all not shown) sandwiched between the n-type semiconductor layer and the p-type semiconductor layer. A pair of surface electrodes 232 are formed on the submount substrate 222a and are electrically connected to the n-type semiconductor layer and the p-type semiconductor layer.

  The LED chip 223 emits red light in this embodiment. As shown in FIGS. 11 and 12, the LED chip 223 includes a semiconductor layer made of, for example, a GaAs-based semiconductor material, a front surface electrode 233, and a back surface electrode 234. The semiconductor layer includes an n-type semiconductor layer, a p-type semiconductor layer, and an active layer (all not shown) sandwiched between the n-type semiconductor layer and the p-type semiconductor layer. The surface electrode 233 is provided on the upper side of the LED chip 223 in the thickness direction z. The back electrode 234 is provided on the lower side in the thickness direction z of the LED chip 223.

  The Zener diode 224 is an element for preventing an excessive voltage from being applied to the LED chip 221. The Zener diode 224 has a front electrode 235 and a back electrode 236. The Zener diode 225 is an element for preventing an excessive voltage from being applied to the LED chip 222. Zener diode 225 has a front electrode 237 and a back electrode 238.

  The LED chips 221 and 222 are arranged in the thickness direction z, and are mounted on the mounting portion 251 of the lead 241 via the insulating layer 262. The insulating layer 262 is transparent in the present embodiment, and is made of, for example, a transparent resin. The zener diodes 224 and 225 are arranged in the thickness direction z, and are disposed on the right side in the sub-scanning direction y with respect to the LED chips 221 and 222. The LED chip 223 is disposed on the opposite side of the LED chips 221 and 222 in the sub-scanning direction y with the Zener diodes 224 and 225 interposed therebetween. The LED chip 223 and the Zener diodes 224 and 225 are mounted on the mounting portion 251 of the lead 241 via the conductive layer 261. More specifically, the back electrode 234 of the LED chip 223 and the back electrodes 236 and 238 of the Zener diodes 224 and 225 are electrically connected to the lead 241 through the conductive layer 261. The conductive layer 261 is made of Ag, for example.

  The mounting process of the LED chips 221, 222, 223 and the Zener diodes 224, 225 is performed in the following order. First, a conductive paste that is a material of the conductive layer 261 is applied to the mounting portion 251 of the lead 241. Then, the LED chip 223 and the Zener diodes 224 and 225 are bonded. When the conductive paste is cured by firing, for example, a conductive layer 261 is obtained. Next, a resin paste as a material for the insulating layer 262 is applied to the mounting portion 251. Then, the LED chips 221 and 222 are bonded. The insulating layer 262 is obtained by curing the resin paste.

  According to the order of the above steps, the insulating layer 262 is formed after the conductive layer 261 is formed. For this reason, when the application range of the conductive paste and the application range of the resin paste overlap, the conductive layer 261 is interposed between a part of the insulating layer 262 and the mounting portion 251 of the lead 241. . 11 and 12 show the conductive layer 261 and the insulating layer 262 in such a coating relationship. Depending on the application range of both, the conductive layer 261 and the insulating layer 262 may not overlap each other. However, according to the order of the above steps, the insulating layer 262 is not interposed between the conductive layer 261 and the mounting portion 251 of the lead 241.

  One of the pair of surface electrodes 231 of the LED chip 221 is connected to the mounting portion 251 of the lead 241 by a wire 265, and the other is connected to the wire bonding portion 252 of the lead 242 by a wire 265. One of the pair of surface electrodes 232 of the LED chip 222 is connected to the mounting portion 251 of the lead 241 by a wire 265, and the other is connected to the wire bonding portion 253 of the lead 243 by a wire 265.

  The surface electrode 233 of the LED chip 223 is connected to the wire bonding portion 254 of the lead 244 by a wire 265. The surface electrode 235 of the Zener diode 224 is connected to the wire bonding portion 252 of the lead 242 by a wire 265, and the surface electrode 237 of the Zener diode 225 is connected to the wire bonding portion 253 of the lead 243.

  The light guide 280 is for converting light from the LED module 210 into linear light extending in the main scanning direction x, and is made of a transparent acrylic resin such as PMMA (polymethyl methacrylate). The light guide 280 has a columnar shape extending long in the main scanning direction x, and has an incident surface 281, a reflective surface 282, and an output surface 283 as shown in FIGS. 3 and 10.

  The incident surface 281 is an end surface in the main scanning direction x of the light guide 280, closes the opening 271 of the resin package 270 of the LED module 210, and faces the LED chips 221, 222, and 223. The reflective surface 282 is a surface extending in the main scanning direction x and is formed in the lower left portion of the light guide 280 in FIG. The reflective surface 282 is a surface that reflects light that has traveled through the light guide 280 after being incident from the incident surface 281. Examples of the configuration of the reflecting surface 282 include a surface on which fine irregularities are formed, a surface on which a white paint is applied, and the like. The exit surface 283 is an elongated surface extending in the main scanning direction x, and in the present embodiment, has an arcuate cross section. The light reflected by the reflecting surface 282 is emitted as linear light extending from the emitting surface 283 in the main scanning direction x.

  The reflector 285 performs a function of positioning the light guide 280 with respect to the LED module 210 and a function of preventing light from leaking from the light guide 280 inappropriately, and is made of, for example, a white resin. The reflector 285 has a base portion 286 and a semi-cylindrical portion 287. The base 286 is a rectangular plate-like part having a size and shape similar to the resin package 270 of the LED module 210 in the main scanning direction x. A plurality of protrusions 288 are formed on the base portion 286. As shown in FIG. 9, each protrusion 288 is fitted in the positioning hole 272 of the resin package 270 of the LED module 210. Thereby, the reflector 285 is positioned with respect to the LED module 210.

  The semi-cylindrical portion 287 is a semi-cylindrical portion extending long in the main scanning direction x, and houses the light guide 280 as shown in FIG. The portion of the reflector 285 that directly faces the reflecting surface 282 of the light guide 280 serves to return the light emitted from the reflecting surface 282 to the light guide 280 again. The light guide 280 is fixed to the reflector 285 by accommodating the light guide 280 by the semi-cylindrical portion 287. Therefore, the light guide 280 is positioned with respect to the LED module 210 together with the reflector 285.

  The LED chips 221, 222, and 223 and the light guide 280 are arranged at positions retracted leftward from the terminal portion 255 in the sub-scanning direction y. The substrate 600 has a dimension in the sub-scanning direction y that can be connected to the terminal portion 255, and does not provide an excessive margin space. Therefore, the LED chips 221, 222, 223 and the light guide 280 are in a position retracted to the left in the sub scanning direction y with respect to the substrate 600. In the present embodiment, the light guide 280 and the substrate 600 do not overlap at all in the sub-scanning direction y, but the present invention is not limited to this, and a part of the light guide 280 and the substrate 600 is used. Each may overlap in the sub-scanning direction y.

  The mirror 301 corresponds to the first mirror in the present invention, and has a shape that extends long in the main scanning direction x. As shown in FIG. 3, the mirror 301 has a reflecting surface 311. The reflection surface 311 corresponds to the first reflection surface in the present invention, and reflects the light reflected by the reading object 890 after being emitted from the light source unit 200 toward the sub-scanning direction y. In the present embodiment, the reflecting surface 311 is inclined 45 ° with respect to the sub-scanning direction y and the thickness direction z. The mirror 301 is fixed to the first part 710 of the case 700 by, for example, an adhesive.

  The lens unit 400 transmits light that has traveled along the sub-scanning direction y after being reflected by the reflecting surface 311 of the mirror 301. The lens unit 400 accommodates a plurality of rod lenses and these rod lenses. Consists of cases. These rod lenses are configured to form an image described on the reading object 890 on the sensor IC 500 at an equal magnification, and the optical axis thereof is along the sub-scanning direction y, and the main scanning direction x Is perpendicular to.

  The lens unit 400 has an incident side end surface 411, an emission side end surface 412, a first side surface 421, and a second side surface 422. The incident side end surface 411 is located on the incident side of the lens unit 400 in the sub-scanning direction y. The upper side portion in the thickness direction z of the incident side end surface 411 is in contact with the second contact surface 721 of the second part 720 of the case 700. The exit side end surface 412 is located on the exit side y in the sub scanning direction of the lens unit 400. The lower side portion in the thickness direction z of the emission side end surface 412 is in contact with the first contact surface 711 of the first part 710 of the case 700. Thereby, the positional relationship between the first part 710 and the second part 720 in the sub-scanning direction y is determined via the lens unit 400. The first side surface 421 is a surface facing the lower side in the thickness direction z, and is in contact with the third contact surface 712 of the first part 710 of the case 700. The second side surface 422 is a surface facing upward in the thickness direction z, and is in contact with the fourth contact surface 722 of the second part 720 of the case 700.

  The mirror 302 corresponds to the second mirror in the present invention, and has a shape that extends long in the main scanning direction x. The mirror 302 has a reflecting surface 312. The reflection surface 312 corresponds to the second reflection surface in the present invention, and reflects the light transmitted through the lens unit 400 toward the thickness direction z. In the present embodiment, the reflecting surface 312 is inclined 45 ° with respect to the sub-scanning direction y and the thickness direction z. The mirror 302 is fixed to the second part 720 of the case 700 with, for example, an adhesive.

  The optical axis of the lens unit 400 is along the sub-scanning direction y and intersects the reflecting surfaces 311 and 312 of the mirrors 301 and 302. The intersection position of the optical axis of the lens unit 400 and the reflecting surface 311 of the mirror 301 is above the center of the reflecting surface 311 in the thickness direction z. Further, the intersection position of the optical axis of the lens unit 400 and the reflection surface 312 of the mirror 302 is above the center of the reflection surface 312 in the thickness direction z.

  The sensor IC 500 is an element having a photoelectric conversion function for converting received light into an electric signal, and is mounted on the substrate 600. The sensor IC 500 has a plurality of light receiving surfaces (not shown) arranged in the main scanning direction x. The light reflected by the reading object 890 by the lens unit 400 is imaged on the light receiving surface.

  FIG. 6 shows an assembly process of the image sensor module 101. The first part 710 and the second part 720 are separately formed by casting, for example. The mirror 301 is attached to the first part 710 and the mirror 302 is attached to the second part 720. Then, the first part 710 and the second part 720 are combined so that the lens unit 400 is sandwiched between the first part 710 and the second part 720. At this time, the light source unit 200 is also incorporated. Next, the terminal portion 255 of the light source unit 200 is fitted into the connector 610 of the substrate 600. Then, the substrate 600 is fixed to the substrate housing portion 741 of the case 700. Further, the transmission plate 800 is attached to the case 700. In this way, the image sensor module 101 can be assembled.

  Next, the operation of the image sensor module 101 will be described.

  According to the present embodiment, as shown in FIG. 3, the optical path from the reading object 890 to the sensor IC 500 is bent, and the portion that passes through the lens unit 400 is parallel to the sub-scanning direction y. For this reason, even if the said optical path is lengthened, it can avoid that the thickness direction z dimension of the image sensor module 101 expands. In addition, by forming the case 700 with a metal typified by aluminum, the rigidity of the case 700 can be increased. Furthermore, since the mirrors 301 and 302 are fixed to the case 700, there is little risk of being unjustly twisted. Therefore, it is possible to reduce the thickness of the image sensor module 101 in the thickness direction z while avoiding a decrease in rigidity of the case 700.

  By making the case 700 into a divided structure including the first and second parts 710 and 720, it is possible to easily attach the mirrors 301 and 302 and the lens unit 400 to the case 700.

  The lens unit 400 is sandwiched between the first contact surface 711 of the first part 710 and the second contact surface 721 of the second part 720 in the sub-scanning direction y. However, the length of the optical path from the reading object 890 to the sensor IC 500 is substantially constant. Since the lens unit 400 that forms an image at an erecting equal magnification is generally designed so that the distance from the subject to the imaged portion is constant, the optical path can be obtained even if there is some variation in the overall length. The length of is substantially constant. Therefore, according to the image sensor module 101, the lens unit 400 can be arranged optically preferable. The terminal portion 255 of the light source unit 200 is made of a flexible wiring board that is rich in flexibility. For this reason, even if the relative positions of the first part 710 and the second part 720 are slightly different due to variations in the lens unit 400, the terminal portion 255 absorbs the deviation between the resin package 270 of the LED module 210 and the substrate 600. sell.

  By sandwiching the lens unit 400 in the thickness direction z between the third contact surface 712 of the first part 710 and the fourth contact surface 722 of the second part, the thickness direction of the first and second parts 710 and 720 is determined. Positioning in z can be performed accurately.

Since the intersecting position of the optical axis of the lens unit 400 and the reflecting surfaces 311 and 312 of the mirrors 301 and 312 is above the center in the thickness direction z of the reflecting surfaces 311 and 312, the lens is positioned with respect to the mirrors 301 and 302. The unit 400 can be relatively disposed on the upper side in the thickness direction z. Thereby, a larger space can be secured for the sensor IC 500 arranged below the mirror 302 and the lens unit 400 in the thickness direction z. The sensor IC 500 often uses a plurality of wires for connection to the substrate 600. The larger the space, the more convenient it is to avoid interference between this wire and the case 700.
The arrangement in which the light guide 280, the mirror 301, the lens unit 400, and the mirror 302 are arranged in the sub-scanning direction y is advantageous in reducing the thickness of the image sensor module 101. Setting the width of the substrate 600 so as not to overlap the light guide 280 and the LED chips 221, 222, and 223 in the sub-scanning direction y is suitable for avoiding the generation of useless areas on the substrate 600. Cost reduction can be achieved.

  FIG. 13 shows an image sensor module according to the second embodiment of the present invention. The image sensor module 102 of this embodiment is different from the above-described embodiment in that the mirrors 301 and 302 are not provided. In addition, about the element similar to embodiment mentioned above, while attaching | subjecting the same code | symbol, the description is abbreviate | omitted.

  In the present embodiment, the reflective surface 311 is configured by a part of the surface of the first part 710 of the case 700, and the reflective surface 312 is configured by a part of the surface of the second part 720 of the case 700. Yes. Specifically, the reflecting surfaces 311 and 312 are formed by performing a mirror polishing process on a part of the surface of each of the first part 710 and the second part 720.

  Even with such a configuration, the image sensor module 102 can be reduced in thickness and rigidity. In addition, by configuring the reflecting surfaces 311 and 312 by a part of the surface of the case 700, the distortion of the reflecting surfaces 311 and 312 can be more reliably prevented.

  The image sensor module according to the present invention is not limited to the above-described embodiment. The specific configuration of each part of the image sensor module according to the present invention can be varied in design in various ways.

x Main scanning direction y Sub scanning direction z Thickness direction 101, 102 Image sensor module 200 Light source unit 210 LED modules 221, 222, 223 LED chips 224, 225 Zener diodes 231, 232, 233 Surface electrode 234 Back surface electrodes 235, 237 Surface Electrodes 236, 238 Back electrodes 241, 242, 243, 244 Lead 251 Mounting portion 252, 253, 254 Wire bonding portion 255 Terminal portion 261 Conductive layer 262 Insulating layer 265 Wire 270 Resin package 271 Opening portion 272 Positioning hole 280 Light guide 281 Incident surface 282 Reflective surface 283 Outgoing surface 285 Reflector 286 Base 287 Semi-cylindrical portion 288 Protrusion 301 (first) mirror 311 (first) reflective surface 321 (first) end surface 302 (second) mirror 312 (second) Reflecting surface 322 (second) end surface 400 lens unit 411-incident surface 412 exit side end surface 421 the first side 422 second side 500 sensor IC
600 substrate 610 connector 700 case 710 first part 711 first contact surface 712 third contact surface 715 engagement portion 720 second part 721 second contact surface 722 fourth contact surface 725 engagement portion 741 substrate housing portion 742 Light guide housing part 744 Terminal through hole 800 Transmission plate 890 Reading object

Claims (18)

A light source unit that emits linear light extending in the main scanning direction;
A first reflecting surface that reflects the linear light reflected by the reading object in the sub-scanning direction;
A lens unit that transmits the light reflected by the first reflecting surface;
A second reflecting surface that reflects light transmitted through the lens unit in a thickness direction perpendicular to both the main scanning direction and the sub-scanning direction;
A sensor IC that receives light reflected by the second reflecting surface;
A case in which the first and second reflecting surfaces are fixed and made of metal;
An image sensor module comprising:   2. The image sensor module according to claim 1, comprising a first mirror having the first reflection surface and a second mirror having the second reflection surface, both of which are fixed to the case. The first reflection surface and the second reflection surface are each constituted by a part of the surface of the case.
The image sensor module according to claim 1.   4. The image sensor module according to claim 1, wherein the case includes a first part to which the first reflecting surface is fixed and a second part to which the second reflecting surface is fixed. 5.   5. The image sensor module according to claim 4, wherein the first and second parts respectively have engaging portions that are provided at both ends in the main scanning direction and overlap each other in the thickness direction view.   The image sensor module according to claim 5, wherein an optical axis of the lens unit is parallel to the sub-scanning direction and perpendicular to the main scanning direction.   The image sensor module according to claim 6, wherein the first reflecting surface is inclined by 45 ° with respect to the sub-scanning direction.   The image sensor module according to claim 6, wherein the second reflecting surface is inclined by 45 ° with respect to the sub-scanning direction. The lens unit has an incident side end surface and an emission side end surface located at both ends in the sub-scanning direction,
The first part has a first abutting surface that abuts on the exit side end surface of the lens unit;
9. The image sensor module according to claim 6, wherein the second part has a second contact surface that contacts the incident-side end surface of the lens unit. 10.   The image sensor module according to claim 9, wherein the first contact surface is in contact with a portion of the exit side end surface of the lens unit that is closer to the sensor IC in the thickness direction.   The image sensor module according to claim 9 or 10, wherein the second contact surface is in contact with a portion of the incident side end surface of the lens unit that is closer to the reading object in the thickness direction. The lens unit is located at both ends in the thickness direction, and has a first side surface on the sensor IC side and a second side surface on the reading object side,
The first part has a third contact surface that contacts the first side surface of the lens unit;
The image sensor module according to claim 9, wherein the second part has a fourth contact surface that contacts the second side surface of the lens unit.   13. The image sensor module according to claim 1, wherein an optical axis position of the lens unit intersects a portion of the first reflecting surface that is closer to the reading object than a center in the thickness direction.   14. The image sensor module according to claim 1, wherein an optical axis position of the lens unit intersects a portion of the second reflecting surface that is closer to the reading object than a center in the thickness direction.   The image sensor module according to claim 1, wherein the light source unit, the first reflection surface, the lens unit, and the second reflection surface overlap each other in the thickness direction. A board on which the sensor IC is mounted;
The light source unit includes one or more LED chips, one or more leads on which the LED chips are mounted, a resin package that covers a part of the leads and exposes the LED chips, and the leads An LED module having a terminal portion that is electrically connected to the light source, and a long extension as a whole in the main scanning direction. The incident surface directly facing the opening, the reflective surface that reflects light traveling from the incident surface, and the reflective surface. A light guide having an emission surface that emits light that has traveled as linear light that extends long in the main scanning direction, and
16. The terminal according to claim 1, wherein the terminal portion protrudes from the resin package in the thickness direction from a position retracted in the sub-scanning direction with respect to the opening, and is connected to the substrate. An image sensor module according to claim 1.   The image sensor module according to claim 16, wherein the substrate and at least a part of the light guide are arranged so as not to overlap in the sub-scanning direction.   The image sensor module according to claim 1, wherein the case is made of aluminum.

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