JP2007057296A - Optical reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical reader capable of reading easily even a reading object capable of total reflection of illumination light without changing a set position of the reader. <P>SOLUTION: An optical information reader 10 is equipped with two fan-shaped lenses 51 positioned on an optical path of each direct light irradiated from a plurality of LED's 32, capable of changing the emission direction of a plurality of entering direct lights into the optional direction individually of in each prescribed assembly; and a position adjusting mechanism 40 capable of adjusting positions of the fan-shaped lenses 51 between the plurality of LED's 32 and the reading object, on the optical path of the direct lights. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides a plurality of light sources capable of emitting illumination light that can be irradiated to a reading object, a light receiving element that can receive reflected light that is irradiated and reflected from the plurality of light sources onto the reading object, and the reflected light. And an imaging optical system capable of forming an image of the object to be read on the light receiving surface of the light receiving element.

Conventionally, as this type of optical reading device, for example, there is one provided with an “illumination device” disclosed in Patent Document 1 below. The technique disclosed in Patent Document 1 includes a light emitting diode group arranged in a ring shape and a lens (for example, a link-shaped Fresnel lens) that can refract a light beam from the light emitting diode group toward the ring center direction. A ring-shaped illuminating device is fitted and fixed to the outer periphery of a cylindrical portion of a CCD camera, for example. This makes it possible to refract the light flux from the light emitting diode group toward the ring center direction. For example, when photographing and inspecting an object to be inspected placed below the CCD camera, the light flux from the light emitting diode group Can be efficiently irradiated (Patent Document 1; Paragraph Nos. 0002 and 0004, FIG. 1 and the like).
JP 2003-59329 A

  However, according to the conventional optical reading device including such a ring-shaped illumination device, the light beam from the ring-shaped light emitting diode group is refracted from the entire circumference of the ring toward the center of the ring by the ring-shaped lens. The ring-shaped luminous flux is uniformly collected toward the center of the ring. Therefore, for example, when an object that can reflect almost all of the irradiated light (hereinafter referred to as “total reflection”), such as a semiconductor chip, a semiconductor wafer, or a metal surface, is used as a reading object, almost all of the reflected light is reflected. Is incident on a CCD (light receiving element), and when the optical reading device is a CCD camera, the screen becomes white and it is difficult to photograph the reading object.

  Usually, such a problem caused by total reflection can be avoided by adjusting the position and angle from the reading object to the illumination device and setting the optical reading device where total reflection does not occur. May not always exist at a fixed position, a new problem may arise that the position of the optical reader must be reset each time the image is taken, which takes time for setup. Further, when the metal surface that is the reading object is not a flat surface but a curved surface or a spherical surface, even if the position of the optical reading device is adjusted, total reflection occurs in a part of the metal surface. There is a problem that it is difficult to avoid the problem of total reflection only by adjusting the position and angle from the lighting device to the lighting device.

  Such a problem is not limited to the case where the optical reading device is a CCD camera, and when the device is an optical information reading device such as a bar code reader, the bar code information cannot be read. That is, in the case of a barcode reader that uses a one-dimensional or two-dimensional barcode (information code) printed directly on a semiconductor chip, a semiconductor wafer, a metal surface, or the like as an object to be read, the barcode information is difficult to read. There is.

  The present invention has been made to solve the above-described problems, and the object of the present invention is to easily read even an object to be read that can totally reflect illumination light without changing the set position of the apparatus. Is to provide a simple optical reader.

  In order to achieve the above object, in the optical reading device according to claim 1, the plurality of light sources [32] capable of emitting the illumination light [La, Lb] that can be applied to the reading object [W]. A light receiving element [27] capable of receiving the reflected light [Lr] irradiated and reflected from the plurality of light sources [32] to the reading object [W], and the reading object by the reflected light [Lr]. An optical reader including an imaging optical system [24] capable of forming an image of [W] on a light receiving surface [27a] of the light receiving element [27], from the plurality of light sources [32]. An optical member [50, 51 which is located on the optical path of each illumination light [L] to be irradiated and can change the emission direction of the plurality of incident illumination lights [L] individually or in arbitrary directions for each predetermined group. , 150, 151, 250, 251, 252] and the plurality of lights A position adjustment mechanism [40] capable of adjusting the position of the optical member [50, etc.] between [32] and the reading object [W] on the optical path of the illumination light [L]. Technical features. The numbers in [] can correspond to the symbols described in the [Best Mode for Carrying Out the Invention] column (the same applies hereinafter).

  In the optical reading device according to claim 2, in the optical reading device according to claim 1, the optical member [50, etc.] is annular when viewed from the emission side of the incident illumination light [L]. It is a technical feature that it is arranged.

  The optical reading device according to claim 3, wherein the reflected light [Lr] is surrounded by the annular optical member [50 etc.]. A technical feature is that the light receiving element [27] is reached via the section [51a].

  In the optical reading device according to claim 4, wherein the optical member [50] is arranged in a circular shape, the plurality of illumination lights are arranged in the optical reading device according to claim 2 or 3. When the emission direction of [L] can be changed in any direction for each predetermined group, one of the predetermined groups corresponds to one of a plurality of sectors formed by dividing this circle in the circumferential direction [51, 151], and the plurality of light sources [32] arranged corresponding to the annular circle are technically characterized by being positioned corresponding to the plurality of sectors.

  The optical reading device according to claim 5, wherein the annular member on which the optical member [50] is arranged is circular, and the plurality of illumination lights. When the emission direction of [L] can be changed in an arbitrary direction for each predetermined group, one of the predetermined groups corresponds to one of a plurality of concentric ring shapes obtained by dividing the circle in the radial direction [251. 252], and the plurality of light sources [32] arranged corresponding to the annular circle are technically characterized by being positioned corresponding to the plurality of concentric rings.

  In the optical reading device according to claim 6, in the optical reading device according to claim 4 or 5, the light source [32] emits light for each predetermined collection of the plurality of illumination lights [L]. A technical feature is that the lighting control unit [25, 28] capable of controlling the state is provided.

  In the optical reading device according to claim 7, the plurality of light sources arranged corresponding to the annular circle in the optical reading device according to any one of claims 4 to 6. 32] is technically characterized by being movable together with the optical members [51, 151, 251, 252] with respect to the light receiving element [27] and the imaging optical system [24].

  In the optical reading device according to claim 8, the optical reading device according to any one of claims 1 to 7, wherein the plurality of light sources [32] and the optical member [51] A light guide member [361] for guiding illumination light [La, Lb] emitted from the plurality of light sources [32] to be incident on the optical member [51] is provided therebetween. And

  In the optical reading device according to claim 9, the optical member [50 etc.] is a lens, a prism, or a diffusing member, according to any one of claims 1 to 8. It is a technical feature that at least one of them or a combination of two or more thereof.

  In the first aspect of the present invention, each of the incident light beams [L] emitted from the plurality of light sources [32] is positioned on the optical path, and the emission directions of the incident light beams [L] are individually or for each predetermined group. The position of the optical member [50, etc.] that can be changed in any direction and the position of the optical member [50, etc.] between the plurality of light sources [32] and the reading object [W] on the optical path of the illumination light [L] And an adjustable position adjustment mechanism [40]. Thereby, the position of the optical member [50 etc.] is adjusted on the optical path of the illumination light [L] by the position adjusting mechanism [40], so that the optical member [50 etc.] and the plurality of light sources [32] on the optical path are adjusted. Can be changed, so that the emission direction of the plurality of illumination lights [L] incident on the optical member [50, etc.] is changed individually or almost continuously for each predetermined group in the arbitrary direction. Can do. For this reason, by adjusting the position of the optical member [50, etc.] by the position adjustment mechanism [40], the emission direction of the illumination light [La, Lb] emitted from the optical member [50, etc.] is individually or a predetermined collection. Therefore, even if the object to be read [W] can totally reflect the illumination light [La, Lb], the emission direction of the illumination light [La, Lb] is set in a direction in which total reflection does not occur. Can do. Therefore, since total reflection can be avoided without changing the position of the optical reader itself, even a reading object [W] that can totally reflect illumination light [La, Lb] can be easily read.

  In the invention of claim 2, since the optical member [50 etc.] is arranged in an annular shape when viewed from the exit side of the incident illumination light [L], for example, a plurality of light sources [32] are arranged in an annular shape. It can be satisfactorily applied to the ring-shaped illumination device [30]. Therefore, even the reading object [W] that can totally reflect the illumination light [La, Lb] from the ring-shaped illumination device [30] can be easily read without changing the set position of the optical reading device [10]. it can.

  In the invention of claim 3, when the optical member [50 etc.] is arranged in an annular shape when viewed from the exit side of the incident illumination light [L], the reflected light [Lr] is optically arranged in the annular shape. The light receiving element [27] is reached through the space [51a] surrounded by the member [50 etc.]. As a result, the light receiving element [27] receives the reflected light [Lr] from the irradiation light [La, Lb] collected in an arbitrary direction by the annularly arranged optical member [50, etc.]. The incident light can be incident from all around. For this reason, a high illuminance can be obtained as compared with the case of irradiation from a part rather than the entire circumference.

  In the invention of claim 4, when the optical member [150] is arranged in a circular shape, the emission direction of the plurality of illumination lights [La, Lb] can be changed to an arbitrary direction for each predetermined group. One of the predetermined groups corresponds to one of a plurality of fan shapes obtained by dividing the circle in the circumferential direction [51, 151], and a plurality of light sources [32] arranged corresponding to the circular circle are: , Located corresponding to a plurality of sectors. Accordingly, the fan-shaped optical member [51, 151], which is a part of the optical member [50] arranged in an annular shape, is moved by the position adjusting mechanism [40], and the fan-shaped optical member [51, 151] is moved. ] Of the illumination light [La, Lb] emitted from the optical member [51, 151] can be changed for each predetermined group. Therefore, even if the reading object [W] can totally reflect the illumination light [La, Lb] emitted from the optical member [51, 151], the illumination light [La, Lb] can be set so that total reflection can be avoided without changing the position of the optical reader [10] itself. Therefore, even the reading object [W] that can totally reflect the illumination light [La, Lb] can be easily read without changing the set position of the optical reading device [10].

  In the invention of claim 5, the ring in which the optical member [250] is arranged is circular, and when the emission direction of the plurality of illumination lights [L] can be changed in any direction for each predetermined group, the predetermined Is equivalent to one of a plurality of concentric annular shapes obtained by dividing the circle in the radial direction [251, 252], and a plurality of light sources [232a, 232b] arranged corresponding to the annular circle are: It is located corresponding to a plurality of concentric rings. Accordingly, the concentric annular optical member [251, 252], which is a part of the optical member [50] arranged in an annular shape, is moved by the position adjusting mechanism, and the concentric annular optical member [251, 252] is moved. By adjusting the position, the emission direction of the illumination light [La, Lb] emitted from the optical member [251, 252] can be changed for each predetermined group. Therefore, even if the reading object [W] can totally reflect the illumination light [La, Lb] emitted from the optical member [251, 252], the illumination light [La, L Lb] can be set so that total reflection can be avoided without changing the position of the optical reader [10] itself. Therefore, even the reading object [W] that can totally reflect the illumination light [La, Lb] can be easily read without changing the set position of the optical reading device [10].

  In the invention of claim 6, the illumination control section [25, 28] capable of controlling the light emission state of the light sources [32, 232a, 232b] is provided for each predetermined group of the plurality of illumination lights [L]. Thereby, for example, the light emission intensity, light emission timing, light emission color, and the like of the light source [32, 232a, 232b] can be arbitrarily controlled, so that the irradiation light [L] suitable for the reading object [W] is emitted. It is possible to irradiate the reading object [W]. Accordingly, a reading target capable of totally reflecting the illumination light [La, Lb] emitted from the optical member [51, 151, 251, 252] by a combination with the light emission state of such a light source [32, 232a, 232b]. Even an object [W] can be read more easily.

  In the invention of claim 7, the plurality of light sources [32, 232a, 232b] arranged corresponding to the annular circle are optical members [51] with respect to the light receiving element [27] and the imaging optical system [24]. , 151, 251, 252]. As a result, the distance between the light receiving element [27] and the imaging optical system [24] can be adjusted together for the plurality of light sources [32, 232a, 232b] and the optical members [51, 151, 251, 252]. In addition to the adjustment by the position adjustment mechanism [40], a wider adjustment can be performed. Accordingly, the combination of the plurality of light sources [32, 232a, 232b] and the moving means of the optical members [51, 151, 251, 252] allows illumination without changing the position of the optical reader [10] itself. Even a reading object [W] capable of totally reflecting light [La, Lb] can be read more easily.

  In the invention of claim 8, illumination light [L] emitted from the plurality of light sources [32] can be incident on the optical member [51] between the plurality of light sources [32] and the optical member [51]. A light guide member [361] for guiding is provided. Thereby, since the irradiation light [L] emitted from the plurality of light sources [32] can be efficiently incident on the optical member [51], it is possible to suppress light emission by the plurality of light sources [32] to a necessary minimum. It becomes. Therefore, the reading object [W] that can totally reflect the illumination light [La, Lb] can be easily read while reducing the power consumption of the optical reading device [10].

  The optical member [50 etc.] described above is specifically realized as at least one of a lens, a prism, and a diffusing member, or a combination of two or more thereof.

  Hereinafter, an embodiment in which an optical reading device of the present invention is applied to an optical information reading device such as a barcode reader will be described with reference to the drawings. The “bar code” here is not limited to a one-dimensional code (EAN / UPC, interleaved 2 of 5, coder bar, code 39/128, standard 2 of 5, RSS, etc.), and a two-dimensional code (QR). Code, PDF417, data matrix, maxi code, RSS composite, and the like.

  First, the configuration of the optical information reading apparatus 10 according to the present embodiment will be described with reference to FIG. As shown in FIG. 1 (A), the optical information reading apparatus 10 is mainly composed of a main body 20 and a ring illumination unit 30, and emitted light La, Lb (from the ring illumination unit 30). It has a function of reading reflected light Lr reflected by irradiating a reading object (not shown) with illumination light) by the light receiving unit 27 incorporated in the main body unit 20. In the present embodiment, the reading object corresponds to a barcode.

  The main body 20 mainly includes a housing 21, a lens barrel 22, an attachment part 23, and the like. The housing 21 is a box that configures the appearance of the main body 20 almost entirely. The housing 21 accommodates various electronic components that can form an electronic circuit centered on a CPU 25 described later.

  The lens barrel 22 is a bottomless cylindrical body configured to be able to hold a lens therein, and corresponds to a lens housing also referred to as a lens barrel or a lens barrel. In the case of the present embodiment, an imaging lens 24 is housed inside the lens barrel 22, and the opening of the lens barrel 22 is configured to protrude from one end side of the housing 21 to the outside. As a result, the reflected light Lr reflected from a reading object (not shown) can be incident on the imaging lens 24.

  The attachment part 23 is an annular member attached to one end side of the housing 21 so as to surround the outer periphery of the lens barrel 22 protruding from the housing 21, and a male screw capable of attaching the base part 31 a of the ring illumination part 30 to the periphery thereof A portion 23a is formed. That is, the attachment part 23 is formed with a male screw part 23b that can be screwed with the female screw part 31d of the ring illumination part 30 on the outer periphery thereof, so that the housing 21 and the ring illumination part 30 are connected via the attachment part 23. The screw can be fastened. As a result, the ring illumination unit 30 can adjust the separation distance from the imaging lens 24 and the light receiving unit 27 together with a plurality of LEDs 32 and a lens unit 50 described later.

  The imaging lens 24 is an imaging optical system capable of forming an image of a reading object by incident reflected light Lr on a light receiving surface 27a of a light receiving unit 27 described later, and is a single lens accommodated in the lens barrel 22 described above. Or it is comprised by combining with several lenses.

  In the housing 21, an electronic circuit including the interface unit 26, the light receiving unit 27, the LED driving unit 28, and the like is housed around the CPU 25. The CPU 25 is an information processing device including a central processing unit, a control device, a program counter, a semiconductor memory device, a general-purpose register, and the like, and is generally called a microcomputer or a microprocessor. In FIG. 1A, the interface unit 26 is represented by “I / F”, the light receiving unit 27 is represented by “Img”, and the LED drive unit 28 is represented by “Drv”.

  The interface unit 26 is an input / output port that can input data and commands that can be processed by the CPU 25 from the outside, and can output data processed by the CPU 25 to the outside, and has a parallel-serial conversion function and a digital-analog conversion function. I have it. In this embodiment, for example, optical information read by the light receiving unit 27 and processed by the CPU 25 (for example, decoded bar code) can be output to the outside as digital data via the interface unit 26.

  The light receiving unit 27 is a circuit unit including a solid-state imaging device typified by a charge-coupled device (CCD) or a C-MOS image sensor and a drive circuit thereof, and is connected to the CPU 25 via an input / output port (not shown). It is provided at a position where the above-described imaging by the imaging lens 24 can be formed on the light receiving surface 27a. Thereby, for example, when the outgoing lights La and Lb irradiated to the reading object are reflected and enter the imaging lens 24, the image of the reading object can be formed on the light receiving surface 27a by the imaging lens 24. Become.

  The LED drive unit 28 is a driver circuit that can control the turning on / off of the LED 32 that constitutes the ring illumination unit 30 described later, and includes, for example, a current amplification unit AMP, a drive transistor Tr, a current control resistor R, and the like. . A configuration example of the LED drive unit 28 will be described in detail in another embodiment described later (see FIG. 5A).

  While the main body unit 20 is configured in this way, the ring illumination unit 30 is mainly configured by a housing 31, a plurality of LEDs 32, a printed circuit board 33, a position adjustment mechanism 40, a lens unit 50, and the like. The ring illumination unit 30 of the present embodiment functions as a ring illumination by a plurality of LEDs 32 arranged in an annular shape, and the emission direction of the emitted light La and Lb by the ring illumination is changed by the position adjustment mechanism 40 and the lens unit 50. Functions that can be performed. Hereinafter, the configuration of the ring illumination unit 30 will be described with reference to FIGS. 1 and 2.

  As shown in FIGS. 2 (A) and 2 (B), the housing 31 is a bottomed cylindrical body composed of a base portion 31a and a cylindrical wall portion 31b, and includes a plurality of LEDs 32 and a printed board 33 inside. The position adjusting mechanism 40 and the like can be accommodated. The base portion 31a is a thick disk-shaped member that can form the bottom of the housing 31, and is formed integrally with the cylindrical wall portion 31b.

  As shown in FIG. 1 (A) and FIG. 2 (B), a mounting recess 31c capable of receiving the attachment portion 23 of the main body 20 described above is formed substantially outside the center of the base portion 31a. A female screw portion 31d that can be screwed with the male screw portion 23a of the attachment portion 23 is formed on the inner peripheral surface of the mounting recess 31c. In addition, a through hole 31e through which the lens barrel 22 of the main body 20 can pass is formed at substantially the center of the bottom of the mounting recess 31c. Thereby, it is possible to screw the male screw part 23a of the attachment part 23 and the female screw part 31d of the base part 31a in a state where the lens barrel 22 is passed through the through hole 31e.

  On the other hand, the cylindrical wall portion 31b formed integrally with the base portion 31a is a thin cylindrical member, and a set of two long holes 31f to which a roller 41 of a position adjusting mechanism 40 described later can be attached has a circumferential direction. Are formed so as to face two places at intervals of 180 degrees. The long hole 31f is formed to extend in the circumferential direction of the cylindrical wall portion 31b so that the screw fixing position of the roller 41 can be adjusted. In addition, the axial length of the cylindrical wall portion 31b, that is, the height of the cylindrical wall is determined so that the lens barrel 22 protruding from the attachment portion 23 screwed to the base portion 31a extends beyond the cylindrical wall portion 31b to the outside. The length is set so as not to pop out.

  As shown in FIGS. 1 (B) and 2 (A), the LED 32 is a light emitting diode capable of emitting direct light L, and is configured to emit red light, for example. Such a light emitting diode is normally enclosed in a transparent resin mold having a dome-shaped tip in the emission direction, so that the dome-shaped portion functions as a diverging lens. Therefore, the direct light L emitted from the LED 32 is emitted as a conical light beam that expands in diameter.

  The plurality of LEDs 32 are attached to the printed circuit board 33 formed in an annular shape at substantially equal intervals in the circumferential direction. This constitutes ring illumination. The printed circuit board 33 is formed with predetermined printed wirings that can be electrically connected to the LED drive unit 28 with respect to the electrodes of the respective LEDs 32, and screws on the base portion 31 a that forms the bottom of the housing 31. It is fixed.

  In the ring illumination unit 30 according to the present embodiment, as will be described later, two fan-shaped lenses 51 corresponding to an annular lens divided into two in the circumferential direction are used. For this reason, in the gap part G formed in the combination part of these fan-shaped lenses 51, the LED 32 is arranged avoiding the gap part G so that the LED 32 is not positioned, and thus passes straight through the gap part G. The generation of the direct light L is prevented (cross-hatched portion shown in FIG. 2A).

  As shown in FIGS. 1 and 2, the position adjusting mechanism 40 includes a roller 41, a screw 42, nuts 43 and 44, a column 52 of a fan-shaped lens 51, and a stopper 52 a. In other words, the long plate-shaped support 52 provided on the fan-shaped lens 51 is sandwiched so that two pairs of rollers 41 are sandwiched from both sides of the support 52 in the width direction, thereby enabling the support 52 to move in the axial direction. While restricting movement in the width direction.

  Specifically, it is easy to understand by referring to FIG. 1 (C) showing the state before assembly, and FIGS. 1 (A) and 2 (B) showing the state after assembly. This will be explained based on. As shown in FIGS. 1 (A) and 1 (C), the roller 41 is configured to be rotatable about a screw 42 fixed to a long hole 31f of the cylindrical wall portion 31b by a nut 44 as a rotation shaft. The axial position is determined by a nut 43 positioned at the end of the screw 42. As shown in FIG. 2 (B), two rollers 41 that are rotatably attached to the cylindrical wall portion 31b are provided on the cylindrical wall portion 31b of the housing 31 as a pair. And the support | pillar 52 of the fan-shaped lens 51 is located so that it may be pinched | interposed between these rollers 41 by adjusting the attachment position of these rollers 41 by the long hole 31f. In addition, a stopper 52 a protruding in a convex shape on both sides in the width direction is formed at the tip of the support column 52.

  By configuring the position adjustment mechanism 40 in this way, the support column 52 of the fan-shaped lens 51 is sandwiched between the two rollers 41. As a result, when the support column 52 is about to move in the axial direction, these rollers 41 rotate, so that the axial movement is possible (the support column 52 ′ shown in FIG. 2B), When the column 52 is about to move in the width direction, these rollers 41 screwed to the cylindrical wall portion 31b prevent the movement and restrict the movement in the width direction. Further, when the support column 52 moves in the axial direction until it comes out from between the rollers 41, the stopper 52a formed at the tip of the support column 52 becomes an obstacle, and the support column 52 is prevented from coming out from between the rollers 41. .

  Although not shown, the thickness of the column 52 is set to be greater than the width (thickness) of the roller 41, and guide grooves for guiding the roller 41 are formed on both sides of the column 52. By providing guide plates on both sides of the support column 52 that can sandwich the roller 41 from both sides in the width direction, the movement of the support column 52 in the thickness direction can be restricted.

  The lens portion 50 is a lens having an annular shape, and the lens diameter is set to be substantially the same as the opening diameter of the cylindrical wall portion 31 b of the housing 31. In the case of the present embodiment, for example, it is constituted by two fan-shaped lenses 51 that optically function as a condensing lens (positive lens, convex lens, or converging lens). That is, a ring-shaped condensing lens divided into two in the circumferential direction corresponds to one fan-shaped lens 51, and the fan-shaped lens 51 is opened in a fan shape of (180/360) degrees, that is, 180 degrees. It has a fan shape. In the present embodiment, for example, a ring-shaped Fresnel lens corresponding to the one divided into two is used.

  A lens hole 50a is formed at the center by combining the two fan-shaped lenses 51 to form the annular lens portion 50. In the present embodiment, the inner diameter of the lens hole 50a is as follows. The diameter is set larger than the outer diameter of the lens barrel 22 described above. As a result, the reflected light Lr reflected by the reading object can reach the light receiving unit 27 through the lens hole 50a surrounded by the lens unit 50 around the entire circumference. Thus, high illuminance can be obtained.

  Note that the support column 52 described above is erected substantially perpendicular to the lens meridian near the outer peripheral edge of the fan-shaped lens 51 on the one end surface side. Here, the “lens meridian” is a line that is perpendicular to the optical axis, passes through the center of the lens surface, and is drawn from edge to edge of the lens.

  In the present embodiment, a Fresnel lens is applied as the fan-shaped lens 51. However, the lens unit 50 is not limited to this, and the optical path of each direct light L emitted from the plurality of LEDs 32 is changed. For example, a diverging lens (a negative lens or a concave lens), a prism, a diffusion filter (a diffusion member), or the like can be used as long as it is a possible optical member.

  Two such fan-shaped lenses 51 are used as a set to form an annular lens unit 50, and the lens unit 50 is positioned so as to cover the opening of the housing 31. Thereby, the direct light L emitted from the plurality of LEDs 32 constituting the ring illumination is emitted to the outside as the emitted lights La and Lb through the lens unit 50. Further, the support 52 of the fan-shaped lens 51 is sandwiched between the pair of rollers 41 so that the position adjusting mechanism 40 described above can be configured, so that the two fan-shaped lenses 51 constituting the lens unit 50 can be directly irradiated with the direct light L. It is possible to move on the optical path (fan-shaped lens 51 ′ shown in FIG. 1A).

  As a result, as shown in FIG. 2B, the separation distance d between the plurality of LEDs 32 and the fan-shaped lens 51 can be continuously changed on the optical path of the direct light L (d → d ′). Can be arbitrarily changed (Bw → Bw ′). Therefore, the emission direction of the plurality of direct lights L incident on the fan-shaped lens 51 can be changed almost continuously for each fan-shaped lens 51 toward the center direction or the outer side direction of the lens unit 50, and thus the emitted light Even for a reading object that can totally reflect La and Lb, it is possible to set the emission direction of the emitted light La and Lb in a direction in which total reflection does not occur. Therefore, since total reflection can be avoided without changing the position of the optical information reader 10 itself, it is possible to easily read even a reading object that can totally reflect the emitted lights La and Lb.

  In FIG. 2B, among the plurality of LEDs 32, some of the LEDs 32 are illustrated with respect to the beam width Bw of the direct light L and the like. For this reason, although not shown in FIG. 2B, the other LEDs 32 are also directly incident on the fan-shaped lens 51 from the LEDs 32 by changing the distance d from the fan-shaped lens 51 in the same manner. Since the beam width Bw of the light L is also changed, the outgoing direction of the incident direct light L can be changed almost continuously toward the center direction or the outer side direction of the lens unit 50.

Here, how the intensity of the emitted light La, Lb irradiated to the reading object W changes by adjusting the position of the lens unit 50 by the position adjusting mechanism 40 will be described with reference to FIG.
As shown in FIG. 3A, the two fan-shaped lenses 51 constituting the lens unit 50 are in contact with the opening of the housing 31, that is, the distance between the fan-shaped lenses 51 and the plurality of LEDs 32 is the longest. In the small (approaching) state, the direct light L emitted from the LED 32 is collected near the center of the lens unit 50 by the fan-shaped lens 51. Therefore, the reading object W irradiated with the emitted light La and Lb emitted from the fan-shaped lens 51 is brightest in the range α1 where the emitted light La and the emitted light Lb overlap, and such emitted light does not overlap. It gradually darkens toward both sides β1. Such position setting of the fan-shaped lens 51 is suitable for irradiation light particularly when total reflection or the like does not occur because the entire area is brightened around the range irradiated by the emitted light La and Lb.

  On the other hand, one fan-shaped lens 51 constituting the lens unit 50 is adjusted to a position away from the LED 32 by the position adjusting mechanism 40, that is, the position of the fan-shaped lens 51 is set so that the separation distance between the fan-shaped lens 51 and the plurality of LEDs 32 is increased. This is set (reference numeral 51 ′ in FIG. 3B). As a result, only one of the fan-shaped lenses 51 ′ is separated from the LED 32, and the beam width of the direct light L incident on the fan-shaped lens 51 ′ is expanded (Bw ′). Therefore, the emitted light La ′ emitted from the fan-shaped lens 51 ′ is diffused and weakened by the emitted light Lb emitted from the other fan-shaped lens 51. Therefore, the reading object W irradiated with the emitted light La ′ and Lb emitted from the fan-shaped lenses 51 ′ and 51 is brightest in the range α2 where the emitted light La ′ and the emitted light Lb overlap, and such an output It gradually darkens toward both sides β2, γ2 where there is no overlapping of incident light.

  However, the beam width Bw ′ of the direct light L incident on the fan-shaped lens 51 ′ is emitted from the fan-shaped lens 51 ′ as much as the beam width Bw of the direct light L incident on the fan-shaped lens 51 ′ is wider. Since the outgoing light La ′ is also diffused widely, the irradiation range (α2 + γ2) of the outgoing light La ′ applied to the reading object W is also larger than the irradiation range (α2 + β2) of the outgoing light Lb emitted from the fan-shaped lens 51. It will be expanded. For this reason, the dim irradiation range γ2 expands from the range α2 where the emitted light La ′ and the emitted light Lb overlap toward the fan-shaped lens 51 ′ side, and a slightly brighter irradiation range β2 from the range α2 to the fan-shaped lens 51 side in a narrower range. Is formed. That is, the intensity of the illumination light in FIG. 3B decreases in the order of α2> β2> γ2, but the irradiation range decreases in the order of α2> γ2> β2. In the position setting of the fan-shaped lenses 51 and 51 ′, the range γ2 irradiated by the emitted light La ′ is darker than the other ranges α2 and β2, and therefore, the portion may be darkened in a part of the irradiation range. it can. For this reason, since the total reflection can be suppressed by adjusting the position of the fan-shaped lens 51 ′ so as to be dark with respect to a range where total reflection can occur, for example, a partial surface such as a curved or spherical metal surface. When total reflection can occur in a range, it is suitable for irradiation light when reading a barcode or the like directly marked in the range.

  On the other hand, both fan-shaped lenses 51 constituting the lens unit 50 are adjusted to positions away from the LEDs 32 by the position adjusting mechanism 40, that is, the positions of the fan-shaped lenses 51 are set so that the separation distance between the fan-shaped lenses 51 and the plurality of LEDs 32 is increased. (Reference numeral 51 ′ in FIG. 3C). Thereby, since both fan-shaped lenses 51 ′ are separated from the LED 32, the beam width of the direct light L emitted from the LED 32 is expanded (Bw ′). Therefore, the emitted light La ′ emitted from both the fan-shaped lenses 51 ′ is Each is diffused and weakened. Therefore, the reading object W irradiated with the emitted light La ′ and Lb ′ emitted from both the fan-shaped lenses 51 ′ has the brightest range α3 where the emitted light La ′ and the emitted light Lb ′ overlap, but FIG. It becomes weaker than the brightness of the range α1 in (A) and the range α2 in FIG. 3B (α3 <α2 <α1). And it becomes darker further toward both sides β3 where there is no overlap of such emitted light. In such a position setting of the fan-shaped lens 51 ′, since it becomes entirely dark by irradiation with the emitted light La ′, Lb ′, for example, when the range that can be totally reflected on a flat surface such as silicon wear is widened. It is suitable for irradiation light when reading a barcode (QR code) or the like directly marked in the range.

  In the explanatory diagrams shown in FIGS. 3A, 3B, and 3C described above, each of the plurality of LEDs 32 corresponds to two fan-shaped lenses 51. Focusing on only one LED 32, the diffusion of the irradiation light (direct light L, outgoing light La, Lb, etc.) is expressed. Therefore, the ranges α1, β1, α2, β2, γ2, α3, and β3 in each diagram of FIG. 3 are only one standard. Therefore, when the optical information reader 10 according to the present embodiment is actually configured, the irradiation as shown in FIGS. 3A to 3C is performed for each LED 32 depending on the setting position of the fan-shaped lens 51. It should be noted that since the light diffusion phenomenon occurs, the ranges α1, β1, etc. indicating the brightness can be configured more complicatedly.

  As described above, according to the optical information reading apparatus 10 according to the present embodiment, the emission directions of the plurality of incident direct lights L that are positioned on the optical paths of the respective direct lights L emitted from the plurality of LEDs 32 are individually or predetermined. Two fan-shaped lenses 51 that can be changed in any direction for each group, and a position adjusting mechanism 40 that can adjust the position of the fan-shaped lens 51 between the plurality of LEDs 32 and the reading object W on the optical path of the direct light L, . Accordingly, by adjusting the position of the fan-shaped lens 51 on the optical path of the direct light L by the position adjusting mechanism 40, the separation distance between the fan-shaped lens 51 and the plurality of LEDs 32 on the optical path can be changed. The emission direction of the plurality of incident direct lights L can be changed almost continuously in an arbitrary direction individually or for each predetermined group. For this reason, by adjusting the position of the fan-shaped lens 51 by the position adjusting mechanism 40, the emission directions of the emitted lights La and Lb emitted from the fan-shaped lens 51 can be changed individually or for each predetermined group. Therefore, even if the reading object W can totally reflect the outgoing lights La and Lb, the outgoing direction of the outgoing lights La and Lb can be set in a direction in which the total reflection does not occur. Thus, total reflection can be avoided without changing the position, and the reading object W can be easily read.

  In the present embodiment, the LED 32 that can emit a conical light beam that expands in diameter is used as the “plurality of light sources”. However, for example, a light source (laser light source) that can emit an unexpanded laser beam or the like is used. When used as “a plurality of light sources”, a configuration is adopted in which the laser light can be incident on the lens surface of the fan-shaped lens 51 in directions other than the normal direction thereof, that is, obliquely with respect to the lens surface. As a result, the incident position of the laser light incident on the fan-shaped lens 51 can be changed by changing the separation distance between the laser light source and the fan-shaped lens 51, so that a plurality of laser light incident on the fan-shaped lens 51 can be emitted. It becomes possible to change the direction toward the arbitrary direction individually or for each predetermined group almost continuously, and the same actions and effects as described above can be obtained.

  In addition, by forming a lens unit using n fan-shaped lenses with an angle (360 / n) obtained by dividing 360 by the number n of LEDs 32, a plurality of direct lights L incident on the fan-shaped lenses are “individually”. It becomes possible to change the emission direction in an arbitrary direction almost continuously. Also in this case, the same actions and effects as described above can be obtained.

  Here, modified examples of the ring illumination unit 30 of the optical information reading apparatus 10 according to the present embodiment will be described with reference to FIGS.

  First, a configuration of the ring illumination unit 130 as a first modification of the ring illumination unit 30 will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the component substantially the same as the ring illumination part 30 mentioned above, and description is abbreviate | omitted.

  In the ring illumination unit 30 described above, the lens unit 50 is configured by using two fan-shaped lenses 51 set in a sector shape of (180/360) degrees. Therefore, the emission direction of the plurality of direct lights L incident on the fan-shaped lens 51 is changed almost continuously toward the arbitrary direction for each “predetermined group”. However, in the ring illumination unit 130 according to the first modification, As shown in FIG. 4A, the lens unit 150 is configured by using four fan-shaped lenses 151 set in a sector shape of (90/360) degrees. That is, the fan-shaped lens 151 is configured so that the lens unit 150 is divided into four in the circumferential direction and forms a fan shape opened at 90 degrees. Therefore, the position adjusting mechanism 40 is provided for each of the four fan-shaped lenses 151. In addition, the lens hole 150a is formed in the center by comprising the lens part 150 by combining the four fan-shaped lenses 151 in a ring shape.

  By configuring in this way, in the ring illumination unit 130 according to the first modified example, the “every predetermined group” can be subdivided as compared with the fan-shaped lens 51 of the ring illumination unit 30 described above. Thereby, since the emission direction of the emitted light La and Lb emitted from the fan-shaped lens 151 can be changed for each predetermined group in a narrow range compared with the ring illumination unit 30, the reading that can totally reflect the emitted lights La and Lb. Even in the case of the object W, the emission directions of the outgoing lights La and Lb can be set in a fine range in a direction in which total reflection does not occur. Accordingly, since the degree of freedom of the setting can be increased, total reflection can be avoided without changing the position of the optical information reader 10 itself, and the reading object W can be read more easily.

  Next, a configuration of the ring illumination unit 230 as a second modification of the ring illumination unit 30 will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the component substantially the same as the ring illumination part 30 mentioned above, and description is abbreviate | omitted.

  In the ring illumination unit 30 (FIG. 2) and the ring illumination unit 130 (FIG. 4A) described so far, the lens units 50 and 150 (optical members) arranged in an annular shape as “one of the predetermined groups”. ) In the circumferential direction to form fan-shaped lenses 51 and 151. On the other hand, in the ring illumination unit 230 according to the second modified example, as shown in FIG. 4B, the lens unit 250 (optical member) is divided into two in the radial direction to form a concentric annular small-diameter annular lens 251. And a large-diameter annular lens 252. A lens hole 250 a is formed in the center of the annular lens 251.

  A cylindrical body (outer cylindrical body) having an outer diameter set slightly larger than the outer diameter of the annular lens 251 is provided on the outer periphery of the annular lens 251, and the outer peripheral wall of the outer cylindrical body is provided. A male screw groove is formed in the. On the other hand, a cylindrical body (inner cylinder) having an inner diameter set slightly smaller than the inner diameter of the annular lens 252 is provided on the inner circumference of the annular lens 252. Is formed with a female screw groove that can be screwed into the male screw groove of the cylindrical body of the annular lens 251. Further, on the outer periphery of the annular lens 252, a cylindrical body (outer cylindrical body) having an outer diameter set slightly larger than the outer diameter of the annular lens 252 is provided. A male screw groove is formed on the outer peripheral wall of the. A female screw groove that can be screwed into a male screw groove formed in the outer cylindrical body of the annular lens 252 is formed on the inner peripheral wall of the housing 31.

  Thus, the external thread of the annular lens 251 is a male thread groove, the internal thread of the annular lens 252 is an internal thread groove, the external thread of the annular lens 252 is an external thread groove, the internal thread of the housing 31 is an internal thread groove, By forming each of the “position adjusting mechanisms”, the annular lens 252 can be screwed into the housing 31, and the annular lens 251 can be screwed into the annular lens 252. Accordingly, the annular lens 252 can be moved in the axial direction with respect to the housing 31, and further, the annular lens 251 can be moved in the axial direction with respect to the annular lens 252. The annular lens 251 can also move in the axial direction with respect to the housing 31. As described above, in the ring illumination unit 230, the outer cylindrical body of the annular lens 251, the inner cylindrical body and outer cylindrical body of the annular lens 252, and the male screw groove and the female screw groove formed on the inner wall of the housing 31 are “ Since it functions as a “position adjustment mechanism”, the position adjustment mechanism 40 composed of the roller 41 or the like as described above is not provided.

  Further, in the ring illumination unit 230, since it is necessary to arrange a plurality of LEDs 232a and 232b corresponding to the shapes of the respective annular lenses 251 and 252, for example, an annular ring corresponding to the large-diameter annular lens 251 is provided. A shaped printed circuit board 233a and an annular printed circuit board 233b corresponding to the small-diameter annular lens 252 are provided in the housing 31, and LEDs 232a and 232b are provided at substantially equal intervals in the circumferential direction, respectively. In the case of the ring illumination unit 230 of the second modified example, the divided annular lenses 251 and 252 form an annular shape, so that a gap portion G is formed like the fan-shaped lenses 51 and 151. There is no. For this reason, the plurality of LEDs 232a attached to the printed circuit board 233a and the plurality of LEDs 232b attached to the printed circuit board 233b are arranged at substantially equal intervals.

  With this configuration, in the ring illumination unit 230 according to the second modification, the annular lenses 251 and 252 that are part of the lens unit 250 arranged in an annular shape are replaced with the annular lenses 251 and 252. By moving by a “position adjusting mechanism” formed of a screw groove formed in the outer cylinder body or the inner cylinder body and adjusting the position of the annular lenses 251 and 252, the light is emitted from the annular lenses 251 and 252. The emission directions of the illumination lights La and Lb can be changed for each predetermined group. Therefore, even if the reading object W can totally reflect the illumination lights La and Lb emitted from the annular lenses 251 and 252, the emission directions of the illumination lights La and Lb are set in a direction in which total reflection does not occur. Therefore, total reflection can be avoided without changing the position of the optical reader 10 itself. Therefore, even the reading object W that can totally reflect the illumination lights La and Lb can be easily read without changing the set position of the optical reading device 10.

  As shown in FIG. 5A, a plurality of LEDs 232a (hereinafter referred to as “LED group of group X”) provided corresponding to the annular lens 251 and a plurality of LEDs provided corresponding to the annular lens 252 are provided. The LED driving unit 28 of the main body unit 20 may be configured so that lighting / extinguishing control of the LEDs 232b (hereinafter referred to as “group Y LED group”) can be performed individually.

  That is, as shown in FIG. 5A, the LED drive unit 28 receives the output of the current amplification unit AMP based on the current amplification unit AMP that can amplify the luminance control signal output from the CPU 25 and the + power supply. A group X drive unit comprising a drive transistor Tr connecting a group X LED group between Vcc and the collector and connecting a current control resistor R between the ground and the emitter, and this group X drive unit And a group Y driving unit configured to drive the group Y LED group. The current amplifying unit AMP is configured to be output-controlled by an on / off signal input from the outside, and the on / off signal X output from the CPU 25 is supplied to the group Y driving unit AMP. An on / off signal Y output from the CPU 25 is connected to the current amplifier AMP of the drive unit.

  By configuring the LED drive unit 28 in this manner, for example, by increasing or decreasing the signal level of the luminance control signal output from the CPU 25 in an analog manner, the LEDs 232a and 232b that configure the LED groups of the group X and the group Y are controlled. The brightness (light emission intensity) can be arbitrarily controlled. That is, the luminance (light emission intensity) can be arbitrarily controlled as the “light emission state”.

  Further, on / off signals X and Y are output from the CPU 25 to the LED drive unit 28 at the timing shown in FIG. Thus, since the on signal and the off signal are output from the CPU 25 at almost the same timing, the LED group (LED 232a) of the group X corresponding to the annular lens 251 and the group Y corresponding to the annular lens 252 are output. The LED group (LED 232b) can be turned on or off almost simultaneously.

  Further, for example, the on / off signals X and Y are output from the CPU 25 to the LED drive unit 28 at the timing shown in FIG. As a result, the CPU 25 outputs the ON signal and the OFF signal of the ON / OFF signal X and the ON signal and the OFF signal of the ON / OFF signal Y, which are output at opposite timings, so that the group corresponding to the annular lens 251 is output. When the X LED group (LED 232a) is lit, the group Y LED group (LED 232b) corresponding to the annular lens 252 is turned off, and when the group X LED group (LED 232a) is turned off, the annular group The group Y LED group (LED 232b) corresponding to the lens 252 is turned on. That is, as the “light emission state”, the group X and the group Y can be blinked alternately.

  As another example of the “light emission state”, the light emission colors of the LEDs 232a and 232b are not set to a single color, but are set to, for example, the three primary colors of red, blue, and green, and these light emission colors are also controlled by the CPU 25. Configure as possible. Thereby, since it is possible to select a light emission color suitable for the reading object W, by combining the ring illumination units 30, 130, 230 and the like described above with the main body having this function, the illumination light La, Even a reading object W that can totally reflect Lb can be read more easily without changing the set position of the optical reading device 10.

  Subsequently, a configuration of the ring illumination unit 330 as a third modification of the ring illumination unit 30 will be described with reference to FIG. 6B is a cross-sectional view taken along line 6B shown in FIG. 6A. On the right side of FIG. 6B, the separation distance between the fan-shaped lens 51 and the plurality of LEDs 32 is shown. The case where it is set to the smallest position is shown, and the left side of the figure shows the case where the separation distance between the fan-shaped lens 51 and the plurality of LEDs 32 is set to the largest position. Moreover, the same reference numerals are given to substantially the same components as the ring illumination unit 30 described above, and the description thereof is omitted.

  As shown in FIGS. 6 (A) and 6 (B), the ring illumination unit 330 according to the third modification is provided with a light shielding covering the periphery of each of the fan-shaped lenses 51 constituting the ring illumination unit 30 described above. This is an example in which a cover 361 (light guide member) is provided. That is, a cross-sectional fan-shaped cylinder is formed on the back side of the fan-shaped lens 51 (the side on which the direct light L from the LED 32 is incident) having a fan shape slightly smaller than the fan-shaped lens 51 as a cross-sectional shape. A light shielding cover 361 is formed. Further, as shown in FIG. 6B, the light shielding cover 361 is set to have a length that can be accommodated in the housing 31.

  By attaching the light shielding cover 361 configured in this manner to the back side of the fan-shaped lens 51, the direct light L emitted from the plurality of LEDs 32 can be efficiently incident on the fan-shaped lens 51, and thus light emission by the plurality of LEDs 32 is necessary. It can be minimized. Therefore, the reading object W that can totally reflect the emitted lights La and Lb can be easily read while reducing the power consumption by the optical reading device 10.

  As the “light guide member”, in addition to the light shielding cover 361 that covers the periphery of the fan-shaped lens 51, for example, an optical cable that guides the direct light L from the LED 32 optically, such as an optical fiber, or a light guide. It may be an optical member. Also in these cases, it is possible to suppress the light emission by the plurality of LEDs 32 to the minimum necessary, so that the same actions and effects as described above can be obtained.

  Subsequently, the configuration of the ring illumination unit 430 as a fourth modification of the ring illumination unit 30 will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the component substantially the same as the ring illumination part 30 mentioned above, and description is abbreviate | omitted.

  As shown in FIGS. 7 (A) and 7 (B), the ring illumination unit 430 according to the fourth modified example is the back side of the fan-shaped lens 51 constituting the ring illumination unit 30 (direct light L from the LED 32). This is an example in which a diffusion plate 470 is provided on the side where light enters. The diffuser plate 470 intentionally diffuses incident light and blurs the emitted light La and Lb, and is sometimes referred to as a diffusion filter.

  In the fourth modified example, by providing (attaching) such a diffuser plate 470 on the entire back side of the fan-shaped lens 51, not only light diffusion by the fan-shaped lens 51 but also diffusion by the diffuser plate 470 can be expected. Take the configuration. As a result, the direct light L emitted from the plurality of LEDs 32 is more reliably diffused by entering the fan-shaped lens 51 with the diffuser plate 470, so that the reading object that can totally reflect the illumination light La and Lb. Even with W, it is possible to read more reliably and easily without changing the set position of the optical reader 10.

  In addition, as shown in FIG. 8, such a diffuser plate 470 is not provided on the entire back side of the fan-shaped lens 51 but provided on a part thereof like a ring illumination unit 530 (a fifth modification of the ring illumination unit 30). May be. That is, in the ring illumination unit 530 according to the fifth modification of the ring illumination unit 30, the diffusion plate 570 is formed so as to form a fan shape opened at 45 degrees, and the diffuser plate 570 is arranged on the back side of the fan-shaped lens 51 at intervals of 45 degrees in the circumferential direction. Provide (attach). As a result, the range in which the diffusion plate 570 exists and the range in which the diffusion plate 570 does not exist are alternately formed at intervals of 45 degrees. Therefore, compared with the ring illumination unit 430 provided with the diffusion plate 470 on the entire surface. The degree of diffusion can be adjusted.

  Note that such a diffuser plate 570 is attached to a transparent thin circular plate provided separately from the fan-shaped lens 51 at intervals of 45 degrees in the circumferential direction, and the fan-shaped lens 51 can be rotated in the circumferential direction. Since the position where the diffuser plate 570 is present can be set in the circumferential direction by adopting the configuration of attaching to the cover, the degree of diffusion can be further adjusted.

  In the above-described embodiment and its modifications, the description has been made on the premise of so-called ring illumination. However, the scope of the present invention is not limited to this, and illumination light that can irradiate the reading object can be emitted. As long as there are a plurality of light sources, the aggregate form of the light sources may be any of a circle, an ellipse, a rectangle, a polygon, and the like. The positional relationship between the plurality of light sources and the light receiving element (light receiving unit 27) is not necessarily described above as long as the reflected light reflected on the reading object is at a position where the reflected light enters through the imaging optical system (imaging lens 24). The positional relationship may not be as in the embodiment. In these cases, the same actions and effects as described above can be obtained.

FIG. 1A is an explanatory diagram illustrating a configuration example of an optical information reading device according to an embodiment of the optical reading device of the present invention, and FIG. 1A illustrates an electrical configuration example of a main body and a mechanical configuration example of a ring illumination unit. Fig. 1 (B) shows an example of the mechanical structure of the ring illumination unit as viewed from the direction 1B shown in Fig. 1 (A). Fig. 1 (C) shows the position adjustment mechanism shown in Fig. 1 (A). This shows an assembly configuration example. FIG. 2A is a diagram illustrating a configuration of a ring illumination unit of the optical information reading apparatus according to the present embodiment, FIG. 2A is a configuration diagram viewed from an illumination light emitting side, and FIG. 2B is a diagram illustrating FIG. It is 2B sectional view taken on the line. It is explanatory drawing which shows the example from which the irradiation range and intensity | strength of the illumination light which irradiates a reading target change with the positional relationship of the two fan-shaped lenses which comprise the ring illumination part of the optical information reader which concerns on this embodiment. When 3 (A) is set at a position where the distance between both fan-shaped lenses and the plurality of LEDs is the smallest, FIG. 3 (B) shows that only one of the fan-shaped lenses increases the distance between the plurality of LEDs. When the position is set, FIG. 3C shows the case where the distance between both the fan-shaped lenses and the plurality of LEDs is set to the largest position. FIG. 4A is an explanatory diagram showing a modification of the ring illumination unit that constitutes the optical information reading apparatus according to the present embodiment, and FIG. FIG. 4B shows a configuration of a second modification in which the lens portion is divided into two in the radial direction (no circumferential division). FIG. 5A is a circuit diagram showing a connection relationship between the LED driving unit of the main body part and the peripheral circuit constituting the optical information reading apparatus according to this embodiment, and FIG. 5B and FIG. These are timing charts of each on / off signal output from the CPU. FIG. 6A is a diagram illustrating a third modification of the ring illumination unit constituting the optical information reading apparatus according to the present embodiment, FIG. 6A is a configuration diagram viewed from the illumination light emitting side, and FIG. It is the 6B sectional view taken on the line shown to FIG. 6 (A). FIG. 7A is a diagram illustrating a fourth modification of the ring illumination unit constituting the optical information reader according to the present embodiment, FIG. 7A is a configuration diagram viewed from the illumination light emitting side, and FIG. It is the 7B sectional view taken on the line shown to FIG. 7 (A). FIG. 8A is a diagram illustrating a fifth modification of the ring illumination unit constituting the optical information reading apparatus according to the present embodiment, FIG. 8A is a configuration diagram viewed from the illumination light emitting side, and FIG. It is the 8B sectional view taken on the line shown to FIG. 8 (A).

Explanation of symbols

10: Optical information reader (optical reader)
DESCRIPTION OF SYMBOLS 20 ... Main-body part 21 ... Housing 22 ... Lens barrel 23 ... Attachment part 23a ... Male screw part 24 ... Imaging lens (imaging optical system)
27. Light receiving part (light receiving element)
27a ... Light-receiving surface 28 ... LED drive part 30, 130, 230, 330, 430, 530 ... Ring illumination part 31 ... Housing 31d ... Female thread part 31e ... Through hole 31f ... Long hole 32 ... LED (light source)
40 ... Position adjustment mechanism 50 ... Lens part (optical member)
50a, 150a, 250a ... Lens hole (space part)
51, 151 ... Fan-shaped lens 52 ... Struts 251, 252 ... Annular lens 361 ... Light-shielding cover (light guide member)
L ... Direct light (illumination light)
La, Lb ... outgoing light (illumination light)
Lr ... reflected light W ... reading object

Claims (9)

A plurality of light sources capable of emitting illumination light that can irradiate the reading object, a light receiving element capable of receiving reflected light that is irradiated and reflected by the reading object from the plurality of light sources, and the reading object by the reflected light An optical reading apparatus comprising: an imaging optical system capable of forming an image of an object on a light receiving surface of the light receiving element;
An optical member that is located on the optical path of each illumination light emitted from the plurality of light sources, and that can change the emission direction of the plurality of incident illumination lights individually or in predetermined directions for each predetermined group,
A position adjusting mechanism capable of adjusting the position of the optical member between the plurality of light sources and the reading object on the optical path of the illumination light;
An optical reading device comprising:   The optical reading device according to claim 1, wherein the optical member is arranged in a ring shape when viewed from an emission side of the incident illumination light.   The optical reader according to claim 2, wherein the reflected light reaches the light receiving element via a space surrounded by the annular optical member. The ring in which the optical member is arranged is circular, and when the emission direction of the plurality of illumination lights can be changed in an arbitrary direction for each predetermined group, one of the predetermined groups has this circular shape. It corresponds to one of a plurality of sectors divided in the circumferential direction,
4. The optical reader according to claim 2, wherein the plurality of light sources arranged corresponding to the annular circle are positioned corresponding to the plurality of sectors. The ring in which the optical member is arranged is circular, and when the emission direction of the plurality of illumination lights can be changed in an arbitrary direction for each predetermined group, one of the predetermined groups has this circular shape. Equivalent to one of a plurality of concentric rings divided in the radial direction,
The optical reading device according to claim 2, wherein the plurality of light sources arranged corresponding to the annular circle are positioned corresponding to the plurality of concentric rings.   The optical reader according to claim 4, further comprising an illumination control unit capable of controlling a light emission state of the light source for each predetermined group of the plurality of illumination lights.   The plurality of light sources arranged corresponding to the annular circle are movable together with the optical member with respect to the light receiving element and the imaging optical system. An optical reading device according to claim 1.   The light guide member which guides the illumination light emitted from the plurality of light sources so as to be incident on the optical member is provided between the plurality of light sources and the optical member. The optical reading device according to any one of claims 7 to 9.   The optical reading apparatus according to claim 1, wherein the optical member is at least one of a lens, a prism, and a diffusing member, or a combination of two or more thereof.

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