JP2019028980A - Optical information reading device and method of manufacturing optical information reading device - Google Patents

Abstract

To provide constitution allowing for suppression of the influence of a one-sided blur with regard to a change of resolution measured when an optimal focus position is obtained by changing relative positions of an area sensor and an image-forming lens.SOLUTION: An optical information reading device is provided with an image-forming lens 25, and a lens-holding part 60 assembled to a holder 50 while the image-forming lens 25 is held in place. A flange undersurface 63 and end surfaces 61a, 61b are provided in the lens-holding part 60 as reference planes along the optical axis L1 of the image-forming lens 25. In the holder 50, the flange undersurface 63 and the end surfaces 61a, 61b come in contact face-to-face when the lens-holding part 60 is assembled such that the light that has passed through the image-forming lens 25 forms an image on an area sensor 23, and an upper surface 54 and edge surfaces 56a, 56b of an opening 55 are formed as guide surfaces with which the flange undersurface 63 and the end surfaces 61a, 61b make sliding contact when the lens-holding part 60 is moved so as to follow the optical axis L1.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an optical information reader and an optical information reader manufacturing method.

  In recent years, with the spread of two-dimensional codes such as QR code (registered trademark), there is an increasing need for reading two-dimensional codes attached to coupons at retail stores, convenience stores and the like. For this reason, it is expected that the introduction of readers capable of reading not only bar codes but also two-dimensional codes will increase in the future by using area sensors in which image pickup elements are two-dimensionally arranged. On the other hand, there is still a need to read a bar code, and even a reading device capable of reading a two-dimensional code is required to read the bar code. Furthermore, by using a known symbol recognition processing function (OCR), there is an increasing need for recognizing and reading passport information of an imaged passport.

  For this reason, in an optical information reading apparatus having an area sensor, in order to image and read an information code and the like at a stable distance, the area sensor and a connection for imaging reflected light from the information code and the like on the area sensor. A lens barrel has been employed as a member for adjusting and maintaining the relative position with the image lens at a predetermined focal position (best focus). This lens barrel has a threaded portion formed on the outer peripheral surface, and is screwed into a holder in which the area sensor is assembled at the threaded portion with the imaging lens assembled therein. The relative position between the area sensor and the imaging lens is adjusted by adjusting the screwing amount of the lens barrel. As an optical information reader that adjusts the relative position between the area sensor and the imaging lens by adjusting the screwing amount, for example, an optical information reader disclosed in Patent Document 1 below is known. Yes.

JP 2014-026371 A

  An inexpensive imaging lens employed in an optical information reading device has a portion in which performance is deteriorated with respect to imaging in a part of the periphery of the visual field due to manufacturing variations or the like (hereinafter also simply referred to as single blur). May occur. In an imaging lens that does not cause such one-sided blurring, the resolving power changes according to the relative position between the area sensor and the imaging lens, and the resolving power measured when the relative position is the optimum focal position is the highest. Highly appreciated.

  However, in an imaging lens in which one-sided blur occurs, in the configuration in which the relative position between the area sensor and the imaging lens is adjusted according to the screwing amount as described above, it is based on the resolving power measured each time the screwing amount is changed. Thus, when obtaining the optimum focus position, the one-blurred portion also rotates about the optical axis. When the one-blurred portion rotates in this way, the resolving power changes depending on the position of the one-blurred portion, so the resolving power that is measured even if the relative position between the area sensor and the imaging lens is the optimum focal position. May be underestimated. In such a case, there is a problem that it is impossible to adjust to the optimum focus position.

  The present invention has been made to solve the above-described problems, and the object of the present invention is to measure the optimum focal position by changing the relative position of the area sensor and the imaging lens. An object of the present invention is to provide a configuration capable of suppressing the influence of one-sided blur with respect to a change in resolution.

In order to achieve the above object, the invention described in claim 1 of the scope of claims
An optical sensor that includes an area sensor (23) that receives reflected light from the information code (C) via the imaging lens (25), and optically reads the information code based on a signal output from the area sensor. An information reading device (10) comprising:
A holder (50, 150, 250, 350, 450) to which the area sensor is fixed;
A lens holding part (60, 160, 260, 360, 460) which is assembled to the holder in a state where the imaging lens is held and is provided with a reference plane along the optical axis (L2) of the imaging lens; Prepared,
The holder holds the lens so that the reference surface is in surface contact with the optical axis when the lens holding portion is assembled so that light through the imaging lens forms an image on the area sensor. A guide surface is formed in which the reference surface is slidably contacted when the part is moved.

The invention according to claim 11 is
A method for manufacturing an optical information reading device (10) for manufacturing the optical information reading device (10) according to any one of claims 1 to 10,
Assembling the lens holding unit holding the imaging lens so that the reference surface comes into surface contact with the guide surface with respect to the holder to which the area sensor is fixed;
Assembling an arm (510) movable along the optical axis to the lens holder;
Sequentially measuring the resolving power by the area sensor while moving the arm in a direction along the optical axis so that the reference surface is in sliding contact with the guide surface;
Fixing the lens holding portion in a state where the arm is assembled at a peak position where the measured resolving power is regarded as a peak;
Removing the arm from the lens holder;
It is characterized by providing.
In addition, the code | symbol in each said parenthesis shows the correspondence with the specific means as described in embodiment mentioned later.

  According to the first aspect of the present invention, the lens holding portion assembled to the holder to which the area sensor is fixed while holding the imaging lens is provided with a reference plane along the optical axis of the imaging lens. Then, when the lens holder is assembled so that the light passing through the imaging lens forms an image on the area sensor, the reference surface is in surface contact with the holder, and the lens holder is moved along the optical axis. Sometimes a guide surface is formed in which the reference surface is in sliding contact.

  Thereby, when adjusting the relative position of the area sensor and the imaging lens, the lens holding portion is moved along the optical axis with respect to the holder so that the reference surface is in sliding contact with the guide surface. In other words, even an imaging lens with one-sided blur is measured because the one-blurred part does not rotate when determining the optimum focal position by changing the relative position of the area sensor and the imaging lens. The influence of one-sided blur on the change in resolution can be suppressed.

  In the invention of claim 2, the area sensor has a rectangular light receiving surface, and the position where one blur occurs is grasped for each imaging lens. The lens holding unit holds the imaging lens so that the portion of the field of view where one blur occurs is positioned outside the light receiving surface on the long side of the light receiving surface. Thus, unlike the case where the imaging lens is held so that the part of the field of view where the one-side blur occurs is located on the short side of the light receiving surface, the part of the field of view where the one-side blur occurs is positioned outside the imaging field of view by the area sensor. It is possible to improve the resolving power by suppressing the influence of one-sided blur.

  According to a third aspect of the present invention, the reference surface includes a planar first reference surface and a planar second reference surface intersecting the first reference surface, and the guide surface is in sliding contact with the first reference surface. It consists of a possible planar first guide surface and a planar second guide surface on which the second reference surface can slide. In this way, by configuring each of the reference surface and the guide surface with two flat surfaces, it is possible to simply realize a configuration in which the lens holding portion is moved along the optical axis with respect to the holder.

  In the invention of claim 4, at least a part of the flat surface on the imaging lens side of the collar portion of the lens holding portion functions as the first reference surface, and the holder is connected to the flange portion of the lens holding portion when assembled. A part on the image lens side is formed so as to be accommodated through an opening, and at least a part of a plane on which the opening is provided functions as a first guide surface. Thereby, not only can the lens holding portion be assembled to the holder easily, but also the first reference surface and the first guide surface can be easily brought into surface contact during the assembly.

  In the invention of claim 5, the collar portion is formed so as to cover the opening by a plane which becomes the imaging lens side at the time of sliding contact. Thereby, since a collar part functions as a light-shielding part which prevents incidence | injection of the light through opening, the light-shielding property of a holder can be improved.

  As in the sixth aspect of the invention, the first reference surface and the second reference surface are formed by using convex portions provided on the outer surface of the lens holding portion, and the first guide surface and the second guide surface are formed on the holder. You may form using the recessed part provided.

  As in the seventh aspect of the invention, the first reference surface and the second reference surface are formed using a recess provided on the outer surface of the lens holding portion, and the first guide surface and the second guide surface are provided on the holder. It may be formed using a convex portion.

  As in the invention of claim 8, the lens holding portion is formed such that at least a part of the outer peripheral surface having a polygonal cross section when viewed from the surface through which the optical axis passes functions as the first reference surface and the second reference surface. May be.

  As in the ninth aspect of the present invention, the lens holding portion may be formed such that at least a part of the outer peripheral surface having an arcuate cross section as viewed from the surface through which the optical axis passes functions as a reference surface.

  In the invention of claim 10, since the lens holding portion is provided with an engaging portion that is used when the holder is moved along the optical axis, the relative movement of the lens holding portion along the optical axis is provided. Can be performed with high accuracy, and the adjustment to the optimum focus position can be performed with certainty.

  In the eleventh aspect of the invention, the lens holding portion holding the imaging lens is assembled so that the reference surface comes into surface contact with the guide surface with respect to the holder to which the area sensor is fixed, and then moved along the optical axis. Assemble the possible arm to the lens holder, measure the resolving power by the area sensor sequentially while moving the arm along the optical axis so that the reference surface is in sliding contact with the guide surface, and the peak that the measured resolving power is regarded as the peak After fixing the lens holding portion with the arm assembled at the position to the holder, the arm is removed from the lens holding portion.

  As a result, when fixing the lens holding part to the holder at the peak position, since the arm is assembled to the lens holding part, the lens holding part is difficult to shift from the peak position, and the optimum obtained by measuring the resolving power It is possible to surely adjust the focus position.

  In the invention of claim 12, in the step of fixing the lens holding part to the holder, the peak position is obtained while moving the arm in the first direction along the optical axis, so that the arm is lighted so as to exceed the peak position. After moving in the second direction along the axis, the arm is moved in the first direction toward the peak position, and the lens holding portion is fixed to the holder at the peak position.

  When switching the moving direction of the arm from the first direction to the second direction, the lens holder may not move even if the actuator is driven due to play of the actuator for moving the arm, etc. In such a case, if the lens holding unit is adjusted to move in the other direction toward the peak position found while being moved in the first direction, there is a possibility that the position is deviated from the peak position. is there. Therefore, when the peak position is obtained while moving in the first direction, the arm is moved in the second direction along the optical axis so as to exceed the peak position, and then the arm is moved toward the peak position. By moving in the first direction and fixing the lens holding part to the holder at the peak position, the above-described deviation from the peak position can be prevented, and the adjustment to the optimum focus position can be performed more reliably. Can be implemented.

  In the invention of claim 13, in the step of sequentially measuring the resolving power, the amount of movement by the arm when the resolving power of a predetermined value or more is measured is greater than the amount of movement by the arm when the resolving power of less than the predetermined value is measured. Make it smaller. As a result, the measurement time for the measurement up to the vicinity of the peak position is shortened, and the measurement accuracy for the measurement in the vicinity of the peak position is increased. Therefore, both the reduction of the measurement time and the improvement of the measurement accuracy can be achieved.

1 is a block diagram schematically showing a configuration of an optical information reading device according to a first embodiment. It is a figure which shows the structure of a holder in 1st Embodiment, FIG. 2 (A) shows a front view, FIG.2 (B) shows a top view, FIG.2 (C) shows a side view. 3A and 3B are diagrams illustrating a configuration of a lens holding portion in the first embodiment, in which FIG. 3A shows a front view, FIG. 3B shows a plan view, and FIG. 3C shows a side view. Show. It is a figure which shows the state which assembled | attached the lens holding part in the holder in 1st Embodiment, FIG. 4 (A) shows a front view, FIG.4 (B) shows a top view, FIG.4 (C) is FIG. The side view which illustrates a part in cross section is shown. It is explanatory drawing explaining the position of the one blur part with respect to the imaging visual field at the time of moving the imaging lens in this invention relatively with respect to an area sensor. It is explanatory drawing explaining the position of the one blur part with respect to the imaging visual field at the time of moving the imaging lens in a prior art relatively with respect to an area sensor. It is a figure which shows the structure of a holder in 2nd Embodiment, FIG. 7 (A) shows a front view, FIG.7 (B) shows a top view, FIG.7 (C) shows a side view. It is a figure which shows the state which assembled | attached the lens holding | maintenance part to the holder in 2nd Embodiment, FIG. 8 (A) shows a front view, FIG.8 (B) shows a top view, FIG.8 (C) is FIG. , Shows a side view. It is a figure which shows the structure of a holder in 3rd Embodiment, FIG. 9 (A) shows a front view, FIG.9 (B) shows a top view, FIG.9 (C) shows a side view. It is a figure which shows the state which assembled | attached the lens holding | maintenance part to the holder in 3rd Embodiment, FIG. 10 (A) shows a front view, FIG.10 (B) shows a top view, FIG.10 (C) is FIG. , Shows a side view. It is a figure which shows the structure of a holder in 4th Embodiment, FIG. 11 (A) shows a front view, FIG.11 (B) shows a top view, FIG.11 (C) shows a side view. It is a figure which shows the state which assembled | attached the lens holding | maintenance part to the holder in 4th Embodiment, FIG. 12 (A) shows a front view, FIG.12 (B) shows a top view, FIG.12 (C) is FIG. , Shows a side view. It is a figure which shows the structure of a holder in 5th Embodiment, FIG. 13 (A) shows a front view, FIG.13 (B) shows a top view, FIG.13 (C) shows a side view. It is a figure which shows the state which assembled | attached the lens holding | maintenance part to the holder in 5th Embodiment, FIG. 14 (A) shows a front view, FIG.14 (B) shows a top view, FIG.14 (C) is FIG. , Shows a side view. It is a top view which shows roughly the manufacturing apparatus utilized for the manufacturing method of the optical information reader which concerns on 6th Embodiment. It is a side view which shows roughly the manufacturing apparatus utilized for the manufacturing method of the optical information reader which concerns on 6th Embodiment. FIG. 17A is an explanatory diagram illustrating an example of a chart for measuring a contrast value, and FIG. 17B is an explanatory diagram illustrating another example of a chart for measuring a contrast value. FIG. 18A is an explanatory diagram showing the measurement result of the contrast value when the arm is moved in one direction, and FIG. 18B is the measurement of the contrast value when the arm is moved in the other direction. It is explanatory drawing which shows a result. It is explanatory drawing explaining the state which apply | coats a UV adhesive agent to the groove | channel for adhesion | attachment with respect to the lens holding | maintenance part and holder which moved to the peak position.

[First Embodiment]
Hereinafter, an optical information reading apparatus according to a first embodiment of the present invention will be described with reference to the drawings.
The optical information reader 10 according to the present embodiment is configured as an information code reader that optically reads an information code C such as a one-dimensional code or a two-dimensional code. Here, as the one-dimensional code, for example, a so-called barcode consisting of JAN code, EAN, UPC, ITF code, CODE39, CODE128, NW-7, and the like is assumed. Further, as the two-dimensional code, for example, a rectangular information code such as a QR code, a data matrix code, a maxi code, and an Aztec code is assumed.

  The optical information reading apparatus 10 is configured such that a circuit unit 20 is accommodated in a case (not shown). The circuit unit 20 mainly includes an illumination light source 21, a marker light irradiation unit 22, an area sensor 23, and the like. An optical system and a microcomputer (hereinafter referred to as “microcomputer”) system such as a memory 35 and a control unit 40 are provided.

  The optical system is divided into a light projecting optical system and a light receiving optical system. The light projecting optical system includes an illumination light source 21 and a marker light irradiation unit 22. The illumination light source 21 functions as an illumination light source capable of emitting the illumination light Lf, and includes, for example, an LED and a lens provided on the emission side of the LED.

  The marker light irradiation unit 22 functions as a marker light source capable of irradiating the marker light Lm indicating the center of the imaging range by the area sensor 23. For example, the marker light irradiation unit 22 includes an LED and a lens provided on the emission side of the LED. Yes. FIG. 1 conceptually shows an example in which the illumination light Lf and the marker light Lm are irradiated toward the reading object R to which the information code C is attached.

  The light receiving optical system includes an area sensor 23, an imaging lens 25, and the like. The area sensor 23 is configured to be able to image the information code C as a light receiving sensor having a rectangular light receiving surface 23a in which light receiving elements which are solid-state image sensors such as C-MOS and CCD are two-dimensionally arranged. Yes, each cell (pattern) of the received information code is configured to output an electrical signal corresponding to the intensity of the reflected light Lr. The area sensor 23 is mounted on the sensor substrate 20a so as to be able to receive incident light incident through the imaging lens 25.

  The imaging lens 25 is configured to have one or more lenses, and collects incident light incident from the outside through the reading port 13 to form an image on the light receiving surface 23a of the area sensor 23. It functions as a possible imaging optical system. In the present embodiment, the illumination light Lf emitted from the illumination light source 21 is reflected by the information code C or the reading object R to which the information code C is attached, and the reflected light Lr is reflected by the imaging lens 25. And a code image is formed on the light receiving surface 23a of the area sensor 23.

  Further, as shown in FIGS. 2 to 4, the light receiving optical system is provided with a holder 50 to which the sensor substrate 20 a is fixed and a lens holding unit 60 to hold the imaging lens 25. The direction along the optical axis L of the area sensor 23 and the imaging lens 25 is the X direction, and is parallel to the plane where the upper surface 54 of the holder 50 and the collar lower surface 63 of the lens holding portion 60 are in surface contact, and is in the X direction. The direction orthogonal to the Y direction and the direction orthogonal to both the X direction and the Y direction as the Z direction will be described below.

  As shown in FIGS. 2A to 2C, the holder 50 is formed in a substantially box shape, and one end 51 opens so as to fix the sensor substrate 20a, and covers the opening. Since the sensor substrate 20 a is fixed to the area substrate 23, the area sensor 23 mounted on the sensor substrate 20 a is accommodated in the holder 50. In addition, the holder 50 is provided with a circular opening 52a centered on the optical axis L1 of the area sensor 23 at the other end 52 facing the light receiving surface 23a of the area sensor 23. The opening 52a is formed so as to expose only the imaging lens 25 held by the lens holding unit 60 and the vicinity thereof, as viewed from the optical axis L1 direction, in order to improve the light shielding property of the holder 50.

  2A to 2C, the upper surface of the holder 50 has a planar upper surface 54 provided between a pair of edge portions 53 extending in the X direction on the optical axis L1 of the area sensor 23. A rectangular opening 55 is formed at the center. The opening 55 is in sliding contact with a lens holding portion 60 at the time of slide adjustment, which will be described later, at edge surfaces 56a and 56b that face in the Y direction and are orthogonal to the upper surface 54 along the optical axis L1 of the area sensor 23. The length in the Y direction is set so as to restrict the movement of the lens holding unit 60 in a direction different from the direction along the optical axis L1. Further, the opening 55 is set to have a length in the X direction in accordance with a length that allows the lens holding unit 60 to slide during slide adjustment. The pair of edge portions 53 are respectively formed with bonding grooves 53a used for bonding and fixing after slide adjustment. The upper surface 54 may correspond to an example of “guide surface” and “first guide surface”, and the edge surfaces 56 a and 56 b may correspond to examples of “guide surface” and “second guide surface”.

  As shown in FIGS. 3A to 3C, the lens holding portion 60 includes a holding portion main body 61 that holds the imaging lens 25 and a collar portion 62 that is connected to the upper portion of the holding portion main body 61. Yes. The imaging lens 25 is held by the holding unit main body 61 in consideration of the position where one blur occurs as will be described later. The holding portion main body 61 can be slidably contacted with the edge surfaces 56a and 56b of the opening 55 by having both end surfaces 61a and 61b on the Y direction side in the vicinity of the collar portion 62 along the optical axis L2 of the imaging lens 25. It is formed so as to be orthogonal to the collar lower surface 63. Note that the end surfaces 61a and 61b may correspond to examples of “reference surface” and “second reference surface”.

  The collar portion 62 is substantially flat and has a length in the Y direction so as to be in sliding contact with the edge portion 53 at the time of slide adjustment, and a collar lower surface 63 serving as a plane on the imaging lens 25 side is connected. It is formed along the optical axis L2 of the image lens 25. The collar lower surface 63 of the imaging lens 25 is arranged such that the optical axis L2 of the imaging lens 25 and the optical axis L1 of the area sensor 23 coincide with each other as the optical axis L at the time of sliding contact with the upper surface 54 of the holder 50. The length in the Z direction to the optical axis L2 is set. Further, the length of the collar portion 62 in the X direction is set so as to always cover the opening 55 with the collar lower surface 63 at the time of sliding contact. In addition, a pair of concave engaging portions 64 used at the time of slide adjustment and a pair of bonding grooves 65 used for bonding and fixing after slide adjustment are formed on the upper surface of the collar portion 62. The bonding groove 65 is formed to be longer in the X direction than the bonding groove 53a so as to communicate with the bonding groove 53a at any slide adjustment position. The collar lower surface 63 can correspond to an example of a “reference surface” and a “first reference surface”.

  4A to 4C, when the lens holding unit 60 is assembled to the holder 50, the collar lower surface 63 and the upper surface 54 come into surface contact with each other, and the end surfaces 61a and 61b and the edge surface 56a, The holding portion main body 61 that is closer to the imaging lens 25 than the collar portion 62 is accommodated in the holder 50 through the opening 55 in a state where the surfaces 56b are in surface contact with each other. Then, as will be described later, the lens holding portion 60 is moved in the X direction with respect to the holder 50 by using both engaging portions 64 so that the relative position between the area sensor 23 and the imaging lens 25 becomes an optimum focal position. After the slide adjustment is performed, the lens holding portion 60 is assembled to the holder 50 so as not to slide by applying a UV adhesive from the bonding groove 65 to the bonding groove 53a.

  The microcomputer system includes an amplification circuit 31, an A / D conversion circuit 33, a memory 35, an address generation circuit 36, a synchronization signal generation circuit 38, a control unit 40, an operation unit 42, a liquid crystal display 43, a buzzer 44, a vibrator 45, and a light emitting unit. 46, a communication interface 48, and the like. As its name suggests, this microcomputer system is composed mainly of a control unit 40 and a memory 35 that can function as a microcomputer (information processing device), and the image signal of the information code imaged by the optical system described above is hardware. It can perform signal processing in terms of hardware and software. The control unit 40 also performs control related to the entire system of the optical information reading apparatus 10.

  When the image signal (analog signal) output from the area sensor 23 of the optical system is input to the amplifier circuit 31 and amplified by a predetermined amplification factor, the image signal (analog signal) is input to the A / D conversion circuit 33. The signal is converted to a digital signal. When the digitized image signal, that is, image data (image information) is generated and input to the memory 35, it is stored in a predetermined code image information storage area. The synchronization signal generation circuit 38 is configured to generate a synchronization signal for the area sensor 23 and the address generation circuit 36. The address generation circuit 36 is based on the synchronization signal supplied from the synchronization signal generation circuit 38. Thus, the storage address of the image data stored in the memory 35 can be generated.

  The memory 35 is a semiconductor memory device, and corresponds to, for example, a RAM (DRAM, SRAM, etc.) or a ROM (EPROM, EEPROM, etc.). In addition to the above-described code image information storage area, the RAM of the memory 35 is configured to be able to secure a work area and a reading condition table used by the control unit 40 in each processing such as arithmetic operation and logical operation. Yes. The ROM stores in advance a reading program capable of executing a reading process for optically reading an information code, a system program capable of controlling each hardware such as the illumination light source 21 and the area sensor 23, and the like. .

  The control unit 40 is a microcomputer that can control the entire optical information reading device 10 and includes a CPU, a system bus, an input / output interface, and the like. The control unit 40 can constitute an information processing device together with the memory 35 and has an information processing function. . The control unit 40 functions to perform a decoding process (decode) on the code image of the information code captured by the area sensor 23 and stored in the memory 35. The control unit 40 is configured to be connectable to various input / output devices (peripheral devices) via a built-in input / output interface. In the present embodiment, the control unit 42, the liquid crystal display 43, the buzzer, and the like. 44, a vibrator 45, a light emitting unit 46, a communication interface 48, and the like are connected.

  The operation unit 42 includes a plurality of keys, and is configured to give an operation signal to the control unit 40 according to a user's key operation. The control unit 40 receives the operation signal from the operation unit 42. At this time, it is configured to perform an operation according to the operation signal. The liquid crystal display 43 is composed of a known liquid crystal display panel, and the display content is controlled by the control unit 40. The buzzer 44 is configured by a known buzzer, and is configured to generate a predetermined sound according to an operation signal from the control unit 40. The vibrator 45 is configured by a known vibrator mounted on a portable device, and is configured to generate vibration according to a drive signal from the control unit 40. The light emitting unit 46 is, for example, an LED, and is configured to light up in response to a signal from the control unit 40. The communication interface 48 is configured as an interface for performing data communication with the outside (for example, a host device), and is configured to perform communication processing in cooperation with the control unit 40.

Next, detailed configurations of the holder 50 and the lens holding unit 60 will be described.
As described above, in the imaging lens, there may be a case where one-sided blur having a reduced performance with respect to imaging occurs in a part of the periphery of the visual field due to manufacturing variations and the like. Therefore, in the conventional configuration in which the relative position between the area sensor 23 and the imaging lens 25 is adjusted in accordance with the screwing amount of the lens barrel B holding the imaging lens 25 with respect to the holder H, the imaging field of view P illustrated in FIG. As described above, the one-blurred portion S also rotates around the optical axis L during adjustment (see the arrow in FIG. 6). When the one-blurred portion S rotates in this manner, the resolving power changes according to the position of the one-blurred portion S. Therefore, even if the relative position between the area sensor 23 and the imaging lens 25 is the optimum focal position. The resolution to be measured may be evaluated as low.

  Therefore, in the present embodiment, by adopting the holder 50 and the lens holding unit 60 described above, the imaging lens 25 is slid along the optical axis L with respect to the area sensor 23 to adjust the relative position. That is, the lens holding portion 60 is slidably in contact with the upper surface 54 at the collar lower surface 63 and slidably in contact with the edge surfaces 56a and 56b of the opening 55 at both end surfaces 61a and 61b. By being guided so as to slide in the (X direction), the relative position of the imaging lens 25 and the area sensor 23 can be adjusted without rotating the imaging lens 25.

  Then, the lens holding unit 60 is gradually slid with respect to the holder 50 in a state where a predetermined jig is engaged with both engaging portions 64 formed on the collar portion 62, and the resolving power is sequentially measured. Since the influence of the one-sided blur is suppressed with respect to the change in the resolving power measured in this way, the slide position (relative position) evaluated with the highest resolving power is regarded as the optimum focal position, and the position adjusted as such. A UV adhesive is applied and fixed from the bonding groove 65 of the lens holding unit 60 to the bonding groove 53a of the holder 50. Thereby, the lens holding | maintenance part 60 is assembled | attached with respect to the holder 50 at the optimal focus position so that a slide is impossible.

  In particular, in the present embodiment, by grasping the position where one blur occurs for each imaging lens 25, the one blur portion S is located on the long side of the light receiving surface 23a as can be seen from the imaging field of view P illustrated in FIG. The imaging lens 25 is held by the lens holding unit 60 so as to be located outside the light receiving surface 23a. Thereby, even when the lens holding part 60 is slid with respect to the holder 50 and the resolving power is measured, it is possible to suppress the one-blurred portion S from being imaged.

  As described above, in the optical information reading apparatus 10 according to the present embodiment, the lens holding unit 60 assembled to the holder 50 while holding the imaging lens 25 is along the optical axis L1 of the imaging lens 25. A collar lower surface 63 and end surfaces 61a and 61b are provided as reference surfaces. When the lens holding portion 60 is assembled to the holder 50 so that the light passing through the imaging lens 25 forms an image on the area sensor 23, the collar lower surface 63 and the end surfaces 61a and 61b are in surface contact with each other, and the optical axis L When the lens holding portion 60 is moved along the guide surface, the upper surface 54 and the edge surfaces 56a and 56b of the opening 55 are formed as guide surfaces on which the collar lower surface 63 and the end surfaces 61a and 61b are in sliding contact.

  Thereby, when adjusting the relative position of the area sensor 23 and the imaging lens 25, the collar lower surface 63 and the end surfaces 61a and 61b are in sliding contact with the upper surface 54 and the edge surfaces 56a and 56b of the opening 55, respectively. The lens holding unit 60 is moved along the optical axis L with respect to the holder 50. That is, even if the imaging lens 25 has a one-sided blur, the one-blurred portion S does not rotate when the optimum focal position is obtained by changing the relative position between the area sensor 23 and the imaging lens 25. The influence of one-sided blur can be suppressed with respect to the change in the resolution to be measured.

  Further, the area sensor 23 has a rectangular light receiving surface 23 a, and the position where one blur occurs is grasped for each imaging lens 25. The lens holding unit 60 holds the imaging lens 25 so that the one-sided blur portion S is positioned outside the light receiving surface 23a on the long side of the light receiving surface 23a. Thus, unlike the case where the imaging lens is held so that the one-sided blur part S is positioned on the short side of the light receiving surface, the one-sided blur part S can be easily positioned outside the field of view taken by the area sensor 23. The resolving power can be improved by suppressing the influence of the above.

  Even if the position where the one-sided blur occurs is not grasped for each imaging lens 25, the one-blurred portion S is temporarily moved because the one-blurred portion S does not rotate by adopting the lens holding unit 60 and the holder 50 described above. Even if it is located inside the light receiving surface 23a, the influence of one-sided blur can be suppressed with respect to the change in the measured resolving power.

  In particular, the reference surface on the lens holding unit 60 side is a collar lower surface 63 that functions as a planar first reference surface, and end surfaces 61a and 61b that function as planar second reference surfaces orthogonal to the first reference surface. The guide surface on the holder 50 side includes an upper surface 54 that functions as a planar first guide surface on which the first reference surface can slide, and a planar second guide surface on which the second reference surface can slide. The edge surfaces 56a and 56b of the opening 55 functioning as In this way, by configuring each of the reference surface and the guide surface with two types of planes, it is possible to simply realize a configuration in which the lens holding unit 60 is moved along the optical axis L with respect to the holder 50.

  The first reference surface and the second reference surface on the side of the lens holding unit 60 are provided so as to intersect at 90 ° without being orthogonal to each other, and the holder 50 is provided with respect to the first reference surface and the second reference surface in the intersecting state. Even if the first guide surface and the second guide surface on the side are provided so as to be slidable with each other, a configuration for moving the lens holding portion 60 along the optical axis L with respect to the holder 50 can be simply realized. .

  Further, the collar 62 of the lens holder 60 has the collar lower surface 63 on the imaging lens 25 side serving as a first reference plane, and the holder 50 forms an image more than the collar 62 of the lens holder 60 when assembled. The holding body 61 on the lens 25 side is formed so as to be accommodated through the opening 55, and the upper surface 54 on which the opening 55 is formed functions as a first guide surface. Thereby, not only can the lens holding portion 60 be assembled to the holder 50 easily, but also the first reference surface and the first guide surface can be easily brought into surface contact during the assembly.

  Furthermore, the collar part 62 is formed so that the opening 55 may be covered by the collar lower surface 63 at the time of sliding contact. Thereby, since the collar part 62 functions as a light-shielding part which prevents the light from entering through the opening 55, the light-shielding property of the holder 50 can be improved.

  Further, since the lens holding portion 60 is provided with a pair of concave engaging portions 64 used when moving the holder 50 along the optical axis L, the lens holding portion along the optical axis L is provided. The relative movement of the unit 60 can be performed with high accuracy, and the adjustment to the optimum focal position can be performed reliably. Note that the engaging portion 64 is not limited to being formed in a concave shape, and may be formed in a convex shape, for example, as long as the engaging portion 64 can be engaged with a slide adjusting jig.

[Second Embodiment]
Next, an optical information reading apparatus according to the second embodiment will be described with reference to FIGS.
The second embodiment is mainly different from the first embodiment in that a holder 150 and a lens holding portion 160 are employed instead of the holder 50 and the lens holding portion 60 described above.

  Specifically, as shown in FIGS. 7 and 8, the lens holding portion 160 that holds the imaging lens 25 is an upper portion of the outer peripheral surface (outer surface) 161 having a circular cross section when viewed from the surface through which the optical axis L passes. Are formed so as to be provided with a protrusion 162 extending in the optical axis direction. Further, a flange portion 163 used for slide adjustment is provided on the reading port 13 side of the lens holding portion 160.

  In addition, the holder 150 to which the area sensor 23 is fixed has no opening 55 with respect to the holder 50 described above, and an opening 152 that is slidably in contact with the outer peripheral surface 161 of the lens holding unit 160 is formed at the end 151. A concave portion 153 slidably contacting at least a part of the upper surface and the side surface of the convex portion 162 of the lens holding portion 160 is formed on the upper portion of the lens holding portion 160.

  That is, in the present embodiment, the first reference surface and the second reference surface are formed using the outer peripheral surface 161 of the lens holding portion 160 and the convex portion 162 provided on the outer peripheral surface 161, and the first guide surface and the second reference surface are formed. The two guide surfaces are formed using an edge surface of the opening 152 provided in the holder 150 and a recess 153 provided in the opening 152.

  Even in such a configuration, when adjusting the relative position between the area sensor 23 and the imaging lens 25, the lens is held so that the outer peripheral surface 161 and the convex portion 162 are in sliding contact with the opening 152 and the concave portion 153, respectively. The portion 160 can be moved along the optical axis L with respect to the holder 150. For this reason, when the relative position between the area sensor 23 and the imaging lens 25 is changed and the optimum focal position is obtained, the one-blurred portion S does not rotate, so that the influence of the one-sided blur is suppressed with respect to the change in the measured resolving power. can do.

  The lens holding portion 160 is formed so as to be in sliding contact with the opening 152 of the holder 150 only at the lower portion of the outer peripheral surface 161, and the upper surface and the side surface of the convex portion 162 function as the first reference surface and the second reference surface. It may be configured.

[Third Embodiment]
Next, an optical information reading apparatus according to the third embodiment will be described with reference to FIGS.
The third embodiment is mainly different from the first embodiment in that a holder 250 and a lens holding portion 260 are employed instead of the holder 50 and the lens holding portion 60 described above.

  Specifically, as shown in FIGS. 9 and 10, the lens holding portion 260 that holds the imaging lens 25 has an outer peripheral surface (outer surface) that has a circular cross section when viewed from the surface through which the optical axis L (L2) passes. A concave portion 262 extending in the optical axis direction is provided on the upper portion of the H.261. Further, a flange portion 263 used for slide adjustment is provided on the reading port 13 side of the lens holding portion 160.

  In addition, the holder 250 to which the area sensor 23 is fixed eliminates the opening 55 and the like from the holder 50 described above, and an opening 252 is formed at the end 251 so as to be in sliding contact with the outer peripheral surface 261 of the lens holding portion 260. A convex portion 253 is formed on the upper portion of 252 so as to be in sliding contact with at least a part of the bottom surface and the side surface of the concave portion 262 of the lens holding portion 260.

  That is, in the present embodiment, the first reference surface and the second reference surface are formed using the outer peripheral surface 261 of the lens holding portion 260 and the concave portion 262 provided on the outer peripheral surface 261, and the first guide surface and the second reference surface are formed. The guide surface is formed using an edge surface of the opening 252 provided in the holder 250 and a convex portion 253 provided in the opening 252.

  Even in such a configuration, when the relative position between the area sensor 23 and the imaging lens 25 is adjusted, the lens is held so that the outer peripheral surface 261 and the concave portion 262 are in sliding contact with the opening 252 and the convex portion 253, respectively. The portion 260 can be moved along the optical axis L with respect to the holder 250. For this reason, when the relative position between the area sensor 23 and the imaging lens 25 is changed and the optimum focal position is obtained, the one-blurred portion S does not rotate, so that the influence of the one-sided blur is suppressed with respect to the change in the measured resolving power. can do.

  The lens holding portion 260 is formed so as to be in sliding contact with the opening 252 of the holder 250 only at the lower portion of the outer peripheral surface 261, and the bottom surface and the side surface of the concave portion 262 function as the first reference surface and the second reference surface. May be.

[Fourth Embodiment]
Next, an optical information reading apparatus according to the fourth embodiment will be described with reference to FIGS.
The fourth embodiment is mainly different from the first embodiment in that a holder 350 and a lens holding portion 360 are employed instead of the holder 50 and the lens holding portion 60 described above.

  Specifically, as shown in FIGS. 11 and 12, the lens holding portion 360 that holds the imaging lens 25 has an upper surface 361 that has a square cross section when viewed from the plane through which the optical axis L (L2) passes. A lower surface 362 and both side surfaces 363 and 364 are formed.

  Further, the holder 350 to which the area sensor 23 is fixed eliminates the opening 55 and the like with respect to the above-described holder 50, and is in sliding contact with the upper surface 361, the lower surface 362, and both side surfaces 363 and 364 of the lens holding unit 360. A square-shaped opening 352 is formed.

  In other words, in the present embodiment, the first reference surface and the second reference surface are formed using the upper surface 361, the lower surface 362, and both side surfaces 363, 364 of the lens holding portion 360, and the first guide surface and the second guide surface are formed. Is formed using the edge surface of the opening 352 provided in the holder 350.

  Even in such a configuration, when the relative position between the area sensor 23 and the imaging lens 25 is adjusted, the lens so that the upper surface 361, the lower surface 362, and both side surfaces 363 and 364 are in sliding contact with the opening 352, respectively. The holding unit 360 can be moved along the optical axis L with respect to the holder 350. For this reason, when the relative position between the area sensor 23 and the imaging lens 25 is changed and the optimum focal position is obtained, the one-blurred portion S does not rotate, so that the influence of the one-sided blur is suppressed with respect to the change in the measured resolving power. can do.

  In addition, the upper surface 361, the lower surface 362, and both side surfaces 363 and 364 of the lens holding portion 360 are not limited to be formed to have a square cross section when viewed from the surface through which the optical axis L passes. It may be formed to have a cross-sectional polygonal shape including a shape to be formed and a shape to be a cross-sectional pentagonal shape.

[Fifth Embodiment]
Next, an optical information reading apparatus according to the fifth embodiment will be described with reference to FIGS.
The fifth embodiment is mainly different from the first embodiment in that a holder 450 and a lens holding part 460 are used instead of the holder 50 and the lens holding part 60 described above.

  Specifically, as shown in FIGS. 13 and 14, the lens holding portion 460 that holds the imaging lens 25 has a cross-sectional arc shape (cross-sectional arc shape) when viewed from the plane through which the optical axis L (L2) passes. As described above, a flat surface 462 is provided on the upper side of the outer peripheral surface 461. In addition, a flange portion 463 used for slide adjustment is provided on the reading port 13 side of the lens holding portion 460.

  Further, the holder 450 to which the area sensor 23 is fixed eliminates the opening 55 and the like from the holder 50 described above, and the edge portion 451 has an edge surface 452a and an edge with respect to the outer peripheral surface 461 and the flat surface 462 of the lens holding portion 460. An opening 452 is formed so as to be in sliding contact with the surface 452b.

  That is, in the present embodiment, the first reference surface and the second reference surface are formed using the outer peripheral surface 461 and the flat surface 462 of the lens holding portion 460, and the first guide surface and the second guide surface are formed on the holder 450. It is formed using the edge surface 452a and the edge surface 452b of the opening 452 provided.

  Even in this configuration, when the relative position between the area sensor 23 and the imaging lens 25 is adjusted, the outer peripheral surface 461 and the flat surface 462 are in sliding contact with the edge surfaces 452a and 452b of the opening 452, respectively. The lens holding part 460 can be moved along the optical axis L with respect to the holder 450. For this reason, when the relative position between the area sensor 23 and the imaging lens 25 is changed and the optimum focal position is obtained, the one-blurred portion S does not rotate, so that the influence of the one-sided blur is suppressed with respect to the change in the measured resolving power. can do.

[Sixth Embodiment]
Next, a method for manufacturing the optical information reading apparatus according to the sixth embodiment will be described with reference to the drawings.
In the sixth embodiment, in the process of assembling the lens holding unit 60 and the holder 50 constituting the optical information reading device 10, the lens holding unit 60 is attached to the holder in order to reliably perform the adjustment operation to the optimum focal position. The main difference from the first embodiment is that an arm, an X stage, and the like are used for fixing after the slide is gradually slid with respect to 50 and the resolution is sequentially measured.

  As shown in FIGS. 15 and 16, in the method for manufacturing the optical information reading apparatus 10 according to the present embodiment, a mounting table 501 on which a holder 50 to which a lens holding unit 60 before bonding and fixing is assembled is mainly mounted. And an arm 510 and an X stage 520 for moving (sliding) the lens holding unit 60 mounted on the mounting table 501 with respect to the holder 50, and a control unit 530 for driving and controlling the X stage 520. 500 is adopted. Then, the resolution by the area sensor 23 is sequentially measured while moving the arm 510 in the direction along the optical axis L1, and the lens holding unit 60 is fixed to the holder 50 at the peak position where the measured resolution is regarded as a peak. Perform adjustment work to adjust the focal position.

  The mounting table 501 is configured such that an image signal from the area sensor 23 of the holder 50 can be output to the control unit 530 when the holder 50 is mounted at a predetermined position.

  The arm 510 is provided with a pair of engaging projections 513 on the lower surface of the one end side 511, and the other end side 512 can be attached to and detached from the X stage 520. It is comprised so that it may become. The engagement protrusion 513 is formed so as to eliminate play between the engagement portion 64 and the engagement portion 64 at least in the direction (X direction) along the optical axis L1. One end side 511 of the arm 510 is formed so as to expose the two adhering grooves 65 in a state where the engaging protrusions 513 are engaged with the corresponding engaging portions 64 respectively.

  The X stage 520 is a device for moving the arm 510 to which the other end side 512 is assembled in a direction along the optical axis L <b> 1, and is configured such that the movement direction and the movement amount are driven and controlled by the control unit 530. Has been.

  The control unit 530 performs a focus position adjustment process, so that the area sensor 23 fixed to the holder 50 and the imaging lens 25 held by the lens holding unit 60 according to the measured resolving power of the area sensor 23. The X stage 520 is driven and controlled so that the relative position becomes the optimum focal position. The control unit 530 may be configured as, for example, a control board including a CPU, a memory, and the like, or may be configured using an application program installed in a predetermined terminal.

  Next, the manufacturing process performed when the temporarily assembled lens holding unit 60 and the holder 50 are bonded and fixed so that the relative position between the area sensor 23 and the imaging lens 25 is an optimum focal position is specifically described. explain.

  First, the lower surface 63 and the end surfaces 61a and 61b are in surface contact with the upper surface 54 and the edge surfaces 56a and 56b, respectively, with respect to the holder 50 to which the area sensor 23 is fixed. In this way, temporarily assemble. Then, the temporarily assembled holder 50 is placed at a predetermined position on the placing table 501. As a result, the image signal from the area sensor 23 is output to the control unit 530.

  Next, the arm 510 assembled to the X stage 520 is assembled to the lens holding unit 60 so that both the engagement projections 513 are engaged with the engagement unit 64. Further, as shown in FIGS. 15 and 16, a chart M as illustrated in FIG. 17A or FIG. 17B is arranged at a focal position to be adjusted within the imaging field of the area sensor 23.

  In this state, the focus position adjustment process by the control unit 530 is started. Specifically, as illustrated in FIG. 18A, every time the X stage 520 is driven and controlled to move the arm 510 in one direction along the optical axis according to a predetermined amount of movement, the chart M The contrast value obtained based on the output from the area sensor 23 when the image is captured is measured as the resolving power. Here, in order to shorten the measurement time, the amount of movement is a predetermined value based on a predetermined value N1 set to be lower than an assumed peak value as illustrated in FIG. 18A. The amount of movement X2 when a contrast value greater than or equal to N1 is measured is made smaller than the amount of movement X1 when a contrast value less than the predetermined value N1 is measured.

  When the contrast value measured while moving the arm 510 in the one direction starts to decrease beyond the peak and becomes equal to or less than the threshold value N2 set with reference to the previously measured maximum contrast value Po, the X stage The movement of the arm 510 by 520 is stopped. Then, as illustrated in FIG. 18B, the arm 510 is moved in the other direction along the optical axis L1 which is opposite to the one direction, and the contrast values are sequentially measured. In the present embodiment, the movement amount X3 when sequentially moving in the other direction is set to be smaller than the movement amount X2. For example, if the movement amount X3 when moving in the other direction is 1 step, the movement amount X2 can be 5 steps and the movement amount X1 can be 10 steps.

  When the contrast value measured while moving the arm 510 in the other direction starts to decrease beyond the peak, the maximum contrast value measured before and the position of the lens holding unit 60 that measured the contrast value Are set as the peak value Pa and the peak position Px. Thereafter, when the contrast value measured while moving in the other direction is equal to or less than a threshold value N3 set with the peak value Pa as a reference, the movement of the arm 510 by the X stage 520 is stopped.

  Then, after moving the arm 510 in one direction along the optical axis L1 so that the lens holding unit 60 exceeds the peak position Px (see arrow F1 in FIG. 18B), the arm 510 is again directed toward the peak position Px. Is moved in the other direction (see arrow F2 in FIG. 18B), and the movement of the arm 510 by the X stage 520 is stopped at the peak position Px. The other direction along the optical axis L1 may correspond to an example of “first direction”, and the one direction along the optical axis L1 may correspond to an example of “second direction”.

  When the lens holding portion 60 is moved to the peak position Px in this way, the UV adhesive is applied from the bonding groove 65 to the bonding groove 53a using the UV adhesive dispenser 540 as illustrated in FIG. To do. In this state, the lens holding unit 60 is fixed to the holder 50 in a state where the arm 510 is assembled by fixing the UV adhesive using a UV light or the like. At the time of fixing, the arm 510 may be removed from the X stage 520.

  After the lens holding unit 60 is fixed to the holder 50 in this way, the light receiving optical system in which the lens holding unit 60 is fixed to the holder 50 at the peak position Px is removed by removing the arm 510 from the lens holding unit 60. Complete.

  As described above, in the method for manufacturing the optical information reading apparatus 10 according to the present embodiment, the lens holding unit 60 holding the imaging lens 25 is moved from the lower surface 63 and the end surfaces 61a to the holder 50 to which the area sensor 23 is fixed. After assembling so that 61b is in surface contact with the upper surface 54 and the edge surfaces 56a and 56b, an arm 510 that is movable along the optical axis L1 is assembled to the lens holding portion 60, and the lower surface 63 and the end surfaces 61a and 61b are the upper surface 54. The resolution (contrast value) of the area sensor 23 is sequentially measured while moving the arm 510 in the direction along the optical axis L1 so as to be in sliding contact with the edge surfaces 56a and 56b, and the peak position Px where the measured resolution is regarded as a peak. After fixing the lens holding part 60 with the arm 510 assembled to the holder 50, the arm 510 is attached to the lens holding part. Remove from 0.

  Accordingly, when the lens holding unit 60 is fixed to the holder 50 at the peak position Px, the arm 510 is assembled to the lens holding unit 60. Therefore, the lens holding unit 60 is hardly displaced from the peak position Px, and the resolving power is measured. By doing so, it is possible to reliably perform the adjustment to the optimum focal position obtained.

  In particular, in the step of fixing the lens holding unit 60 to the holder 50, the peak position Px is obtained while the arm 510 is moved in the other direction (first direction) along the optical axis L1, thereby exceeding the peak position Px. After moving the arm in one direction along the optical axis L1 (second direction: see arrow F1 in FIG. 18B), the arm 510 is moved toward the peak position Px in the other direction (first direction). : Refer to arrow F2 in FIG. 18B), and the lens holding unit 60 is fixed to the holder 50 at the peak position Px.

  When the arm moving direction is switched from the first direction to the second direction, the lens holding unit is driven even when the X stage 520 is driven due to play of the X stage 520 functioning as an actuator for moving the arm 510. In such a case, if the lens holding unit 60 is adjusted to move in the other direction toward the peak position Px found while moving in the first direction, the peak position There is a possibility that the position is deviated from Px. Therefore, when the peak position Px is obtained while moving in the first direction, the arm 510 is moved in the second direction along the optical axis L1 so as to exceed the peak position Px, and then the peak position Px. By moving the arm 510 in the first direction toward the head and fixing the lens holding unit 60 to the holder 50 at the peak position Px, it is possible to prevent the occurrence of deviation from the peak position Px as described above. Adjustment to the optimum focus position can be performed more reliably.

  Further, in the step of sequentially measuring the resolving power (contrast value), the moving amount when the resolving power of the predetermined value N1 or more is measured is the resolving power less than the predetermined value N1, such as the moving amounts X2 and X3. It is made smaller than the movement amount X1 at that time. As a result, the measurement time for the measurement up to the vicinity of the peak position Px is shortened, and the measurement accuracy for the measurement in the vicinity of the peak position Px is increased. Therefore, both the reduction of the measurement time and the improvement of the measurement accuracy can be achieved.

  The light receiving optical system manufacturing method using the arm 510 and the like described above can be applied to other embodiments.

  In addition, this invention is not limited to said each embodiment and modification, For example, you may actualize as follows.

(1) In the lens holding portions 160, 260, 360, and 460 in the second to fifth embodiments, the pair of engaging portions 64 of the lens holding portion 60 are provided in order to surely perform adjustment to the optimum focal position. As described above, an engaging portion used at the time of slide adjustment may be formed.

(2) The present invention is not limited to being applied to an optical information reader that optically reads an information code, but optically reads character information and the like by using a known symbol recognition processing function (OCR). It may be applied to an optical information reader, or it may be applied to an information reader having other functions in addition to a function of optically reading an information code, for example, a wireless communication function for wireless communication with a wireless communication medium. May be.

DESCRIPTION OF SYMBOLS 10 ... Optical information reader 23 ... Area sensor 23a ... Light-receiving surface 25 ... Imaging lens 50, 150, 250, 350, 450 ... Holder 53 ... Upper surface (guide surface, 1st guide surface)
54 ... Opening 55a, 56b ... Upper surface (guide surface, second guide surface)
60, 160, 260, 360, 460 ... lens holding part 61 ... holding part body 61a, 61b ... end face (reference plane, second reference plane)
62 ... collar part 63 ... collar lower surface (reference plane, first reference plane)
DESCRIPTION OF SYMBOLS 500 ... Manufacturing apparatus 510 ... Arm 520 ... X stage 530 ... Control part L, L1, L2 ... Optical axis S ... One blur part

Claims (13)

An optical information reader comprising an area sensor for receiving reflected light from an information code via an imaging lens, and optically reading the information code based on a signal output from the area sensor,
A holder to which the area sensor is fixed;
A lens holder that is assembled to the holder while holding the imaging lens and provided with a reference surface along the optical axis of the imaging lens;
The holder holds the lens so that the reference surface is in surface contact with the optical axis when the lens holding portion is assembled so that light through the imaging lens forms an image on the area sensor. An optical information reading apparatus, wherein a guide surface is formed on which the reference surface is slidably contacted when the portion is moved. The area sensor has a rectangular light receiving surface,
For each imaging lens, the position at which one blur causing performance degradation with respect to imaging is generated in a part of the field of view through the imaging lens is determined for each imaging lens.
The said lens holding part hold | maintains the said imaging lens so that the part of the visual field which the said one-sided blur may be located in the long side of the said light-receiving surface may be located outside the said light-receiving surface. Optical information reader. The reference surface includes a planar first reference surface and a planar second reference surface intersecting the first reference surface,
The guide surface includes a planar first guide surface capable of sliding contact with the first reference surface and a planar second guide surface capable of sliding contact with the second reference surface. Item 3. The optical information reader according to Item 1 or 2. The lens holding part has a collar part,
In the collar portion, at least a part of a plane on the imaging lens side functions as the first reference surface,
The holder is formed such that a portion of the lens holding portion that is closer to the imaging lens than the collar portion is accommodated through an opening during the assembly, and at least a part of a plane on which the opening is provided is the portion The optical information reading device according to claim 3, wherein the optical information reading device functions as a first guide surface.   The optical information reading apparatus according to claim 4, wherein the collar portion is formed so as to cover the opening by a plane that is on the imaging lens side during the sliding contact. The first reference surface and the second reference surface are formed using a convex portion provided on an outer surface of the lens holding portion,
The optical information reading apparatus according to claim 3, wherein the first guide surface and the second guide surface are formed using a recess provided in the holder. The first reference surface and the second reference surface are formed using a recess provided on an outer surface of the lens holding portion,
The optical information reading apparatus according to claim 3, wherein the first guide surface and the second guide surface are formed using a convex portion provided on the holder.   The lens holding portion is formed such that at least a part of an outer peripheral surface having a polygonal cross section as viewed from a surface through which the optical axis passes functions as the first reference surface and the second reference surface. The optical information reader according to claim 3.   The lens holding portion is formed so that at least a part of an outer peripheral surface having a circular arc shape when viewed from a surface through which the optical axis passes functions as the reference surface. Optical information reader.   10. The engagement portion used when the lens holding portion is moved along the optical axis with respect to the holder is provided. 10. Optical information reader. A method for manufacturing an optical information reading device for manufacturing the optical information reading device according to any one of claims 1 to 10,
Assembling the lens holding unit holding the imaging lens so that the reference surface comes into surface contact with the guide surface with respect to the holder to which the area sensor is fixed;
Assembling an arm movable along the optical axis to the lens holder;
Sequentially measuring the resolving power by the area sensor while moving the arm in a direction along the optical axis so that the reference surface is in sliding contact with the guide surface;
Fixing the lens holding portion in a state where the arm is assembled at a peak position where the measured resolving power is regarded as a peak;
Removing the arm from the lens holder;
A method for manufacturing an optical information reading device.   In the step of fixing the lens holding portion to the holder, the peak position is obtained while moving the arm in the first direction along the optical axis, so that the arm is moved to exceed the peak position. After moving in a second direction that is opposite to the first direction along the axis, the arm is moved again in the first direction toward the peak position, and the peak position is The method for manufacturing an optical information reading device according to claim 11, wherein a lens holding portion is fixed to the holder.   In the step of sequentially measuring the resolving power, the movement amount by the arm when the resolving power of a predetermined value or more is measured is made smaller than the moving amount by the arm when the resolving power of less than the predetermined value is measured. 13. The method for manufacturing an optical information reading device according to claim 11 or 12, characterized in that:

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