JP6904277B2 - Manufacturing method of optical information reader and optical information reader - Google Patents

Description

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

In recent years, with the spread of two-dimensional codes such as QR codes (registered trademarks), there is an increasing need for reading two-dimensional codes attached to coupons and the like at retail stores, convenience stores, and the like. Therefore, in the future, it is expected that the introduction of a reader capable of reading not only a barcode but also a two-dimensional code will increase by using an area sensor in which the image sensor is arranged in a two-dimensional manner. On the other hand, there is still a need to read barcodes, and even a reader capable of reading a two-dimensional code is required to read barcodes. Further, there is an increasing need to recognize and read the passport information of the captured passport by using the known symbol recognition processing function (OCR).

Therefore, in an optical information reading device having an area sensor, in order to capture and read the information code or the like at a stable distance, the area sensor and the area sensor are connected to form an image of the reflected light from the information code or the like. A lens barrel has been adopted as a member for adjusting and maintaining a predetermined focal position (best focus) relative to the image lens. This lens barrel has a threaded portion formed on the outer peripheral surface, and with the imaging lens assembled inside, the lens barrel is screwed into the holder to which the area sensor is assembled at the threaded portion. Then, by adjusting the screwing amount of this lens barrel, the relative position between the area sensor and the imaging lens was adjusted. As an optical information reading device that adjusts the relative position between the area sensor and the imaging lens by adjusting such a screwing amount, for example, the optical information reading device disclosed in Patent Document 1 below is known. There is.

Japanese Unexamined Patent Publication No. 2014-026371

In the inexpensive imaging lens used in the optical information reader, the performance of the imaging is deteriorated in a part around the visual field due to variations during manufacturing (hereinafter, also simply referred to as one-sided blur). May occur. In an imaging lens that does not have such one-sided blur, 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 becomes the optimum focal position is the most. Highly appreciated.

However, in an imaging lens with one-sided blur, in a 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 force measured each time the screwing amount is changed. When finding the optimum focal position, the one-sided blurred portion also rotates around the optical axis. When the one-sided bokeh portion rotates and moves in this way, the resolving power changes according to the position of the one-sided bokeh portion. Therefore, the resolving power 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 the optimum focal position cannot be adjusted.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to measure when the relative position between the area sensor and the imaging lens is changed to obtain the optimum focal position. It is an object of the present invention to provide a configuration capable of suppressing the influence of one-sided blur on a change in resolution.

In order to achieve the above object, the invention according to claim 1 of the claims is
An area sensor (23) that receives light reflected from the information code (C) via an imaging lens (25) is provided, and the information code is optically read based on a signal output from the area sensor. Information reader (10)
Holders (50, 150, 250, 350, 450) to which the area sensor is fixed, and
A lens holding portion (60, 160, 260, 360, 460) that is assembled to the holder while holding the imaging lens and is provided with a reference plane along the optical axis (L2) of the imaging lens. Prepare,
When the lens holding portion is attached to the holder so that the light passing through the imaging lens forms an image on the area sensor, the reference surface comes into surface contact with the holder, and the lens is held so as to be along the optical axis. A guide surface is formed in which the reference surface is in sliding contact when the portion is moved.
The reference plane is composed of a flat first reference plane and a flat second reference plane intersecting the first reference plane.
The guide surface is composed of a planar first guide surface to which the first reference surface can be slidably contacted and a planar second guide surface to which the second reference surface can be slidably contacted.
The lens holding portion has a brim portion and has a brim portion.
In the brim portion, at least a part of the plane on the imaging lens side functions as the first reference plane.
The holder is formed so that a portion of the lens holding portion that is closer to the imaging lens than the brim portion is accommodated through the opening at the time of assembly, and at least a part of the plane on which the opening is provided is said. characterized that you function as a first guide surface.

Further, the invention according to claim 5 is
An optical information reading device comprising an area sensor that receives light reflected from an information code through an imaging lens and optically reading the information code based on a signal output from the area sensor. The holder includes a holder to which the sensor is fixed, and a lens holding portion that is assembled to the holder while holding the imaging lens and is provided with a reference plane along the optical axis of the imaging lens. When the lens holding portion is assembled so that the light passing through the imaging lens forms an image on the area sensor, the reference surface comes into surface contact and the lens holding portion is moved along the optical axis. It is a manufacturing method of an optical information reading device for manufacturing an optical information reading device (10) in which a guide surface to which the reference surface is in sliding contact is formed.
A step of assembling the lens holding portion holding the imaging lens to the holder to which the area sensor is fixed so that the reference surface comes into surface contact with the guide surface.
A step of assembling an arm (510) that can move along the optical axis to the lens holding portion, and
A step of sequentially measuring the resolving force 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.
A step of fixing the lens holding portion with the arm assembled to the holder at a peak position where the measured resolving force is regarded as a peak, and a step of fixing the lens holding portion to the holder.
The step of removing the arm from the lens holding portion and
It is characterized by having.
The reference numerals in the parentheses indicate the correspondence with the specific means described in the embodiments described later.

In the invention of claim 1, 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 holding portion was attached to the holder so that the light passing through the imaging lens was imaged on the area sensor, the reference surface was in surface contact and the lens holding portion was moved along the optical axis. A guide surface is sometimes formed in which the reference surface is in sliding contact.

As a result, when adjusting the relative position between 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. That is, even if the imaging lens has one-sided blur, the one-sided blur portion does not rotate and move when the relative position between the area sensor and the imaging lens is changed to obtain the optimum focal position, so that the measurement is performed. The effect of one-sided blur on the change in resolution can be suppressed.
In particular, the reference plane is composed of a flat first reference plane and a flat second reference plane intersecting the first reference plane, and the guide plane is a flat surface to which the first reference plane can be slidably contacted. It is composed of a first guide surface and a flat second guide surface to which the second reference surface can be slidably contacted. In this way, by configuring the reference plane and the guide plane with two planes each, 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.
As for the brim portion of the lens holding portion, at least a part of the plane on the imaging lens side functions as the first reference plane, and the holder is closer to the imaging lens side than the brim portion of the lens holding portion at the time of assembly. The portion is formed so as to be accommodated through the opening, and at least a part of the plane on which the opening is provided functions as a first guide surface. As a result, not only can the lens holding portion be easily assembled to the holder, but also the first reference surface and the first guide surface can be easily brought into surface contact during this assembly.

In the invention of claim 2, the area sensor has a rectangular light receiving surface, and the position where one-sided blur occurs is grasped for each imaging lens. Then, the lens holding portion holds the imaging lens so that the portion of the visual field where one-sided blur occurs is located on the long side side of the light receiving surface and outside the light receiving surface. As a result, unlike the case where the imaging lens is held so that the part of the field of view where one-sided blur occurs is located on the short side side of the light receiving surface, the part of the field of view where one-sided blur occurs is positioned outside the field of view imaged by the area sensor. It can be facilitated, and the influence of one-sided blur can be suppressed to improve the resolution.

In the invention of claim 3 , the brim portion is formed so as to cover the opening with a plane that is on the imaging lens side at the time of sliding contact. As a result, the brim portion functions as a light-shielding portion for preventing light from entering through the opening, so that the light-shielding property of the holder can be improved.

In the invention of claim 4 , since the lens holding portion is provided with an engaging portion used for moving the holder 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 adjustment to the optimum focal position can be reliably performed.

In the invention of claim 5 , the lens holding portion holding the imaging lens is assembled along the optical axis so that the reference surface is in surface contact with the guide surface with respect to the holder to which the area sensor is fixed. Assemble the possible arm to the lens holding part, measure the resolution by the area sensor sequentially while moving the arm in the direction along the optical axis so that the reference surface slides in contact with the guide surface, and the measured resolution is regarded as the peak. After fixing the lens holding part with the arm assembled at the position to the holder, remove the arm from the lens holding part.

As a result, when the lens holding portion is fixed to the holder at the peak position, an arm is attached to the lens holding portion, so that the lens holding portion is less likely to deviate from the peak position, and the optimum resolution obtained by measuring the resolving force is obtained. It is possible to reliably perform adjustment to a proper focal position.

In the invention of claim 6 , 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 illuminated 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 holding portion may not move even if the actuator is driven due to the play of the actuator for moving the arm. In such a case, if the lens holder is adjusted to move in the other direction toward the found peak position while moving in the first direction, the lens holding portion may be fixed at a position 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 the lens in the first direction and fixing the lens holding portion to the holder at the peak position, it is possible to prevent the occurrence of deviation from the peak position as described above, and the adjustment to the optimum focal position is more reliable. Can be carried out.

In the invention of claim 7 , in the step of sequentially measuring the resolving force, the amount of movement by the arm when the resolving force of the predetermined value or more is measured is larger than the amount of movement by the arm when the resolving force of less than the predetermined value is measured. Make it smaller. As a result, the measurement time is shortened for the measurement up to the peak position, and the measurement accuracy is improved for the measurement near the peak position. Therefore, both the reduction of the measurement time and the improvement of the measurement accuracy can be achieved.

It is a block diagram which shows schematic structure of the optical information reading apparatus which concerns on 1st Embodiment. It is a figure which shows the structure of the holder in 1st Embodiment, FIG. 2A shows a front view, FIG. 2B shows a plan view, and FIG. 2C shows a side view. It is a figure which shows the structure of the lens holding part in 1st Embodiment, FIG. 3A shows a front view, FIG. 3B shows a plan view, and FIG. 3C shows a side view. Shown. FIG. 4A is a view showing a state in which the lens holding portion is assembled to the holder in the first embodiment, FIG. 4A shows a front view, FIG. 4B shows a plan view, and FIG. 4C shows a plan view. , A side view showing a part of the cross section is shown. It is explanatory drawing explaining the position of the one-sided blur portion with respect to the imaging field of view when the imaging lens in this invention is moved relative to an area sensor. It is explanatory drawing explaining the position of the one-sided blur part with respect to the imaging field of view when moving the imaging lens relative to the area sensor in the prior art. It is a figure which shows the structure of the holder in 2nd Embodiment, FIG. 7A shows a front view, FIG. 7B shows a plan view, and FIG. 7C shows a side view. 2A and 8B are views showing a state in which the lens holding portion is assembled to the holder in the second embodiment, FIG. 8A shows a front view, FIG. 8B shows a plan view, and FIG. 8C shows a plan view. , A side view is shown. 9 (A) is a front view, FIG. 9 (B) is a plan view, and FIG. 9 (C) is a side view. FIG. 10 (A) is a front view, FIG. 10 (B) is a plan view, and FIG. 10 (C) is a view showing a state in which the lens holding portion is assembled to the holder in the third embodiment. , A side view is shown. It is a figure which shows the structure of the holder in 4th Embodiment, FIG. 11A shows a front view, FIG. 11B shows a plan view, and FIG. 11C shows a side view. FIG. 12A is a view showing a state in which the lens holding portion is assembled to the holder in the fourth embodiment, FIG. 12A shows a front view, FIG. 12B shows a plan view, and FIG. 12C shows a plan view. , A side view is shown. It is a figure which shows the structure of the holder in 5th Embodiment, FIG. 13A shows a front view, FIG. 13B shows a plan view, and FIG. 13C shows a side view. FIG. 14A is a view showing a state in which the lens holding portion is assembled to the holder in the fifth embodiment, FIG. 14A shows a front view, FIG. 14B shows a plan view, and FIG. 14C shows a plan view. , A side view is shown. It is a top view which shows typically the manufacturing apparatus used in the manufacturing method of the optical information reading apparatus which concerns on 6th Embodiment. It is a side view which shows typically the manufacturing apparatus used in the manufacturing method of the optical information reading apparatus which concerns on 6th Embodiment. FIG. 17A is an explanatory diagram showing an example of a chart for measuring a contrast value, and FIG. 17B is an explanatory diagram showing 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 the result. It is explanatory drawing explaining the state which applies the UV adhesive to the adhesive groove with respect to the lens holding part and a holder which moved to a peak position.

[First Embodiment]
Hereinafter, the optical information reading device according to the first embodiment of the present invention will be described with reference to the drawings.
The optical information reading device 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 bar code composed of JAN code, EAN, UPC, ITF code, CODE39, CODE128, NW-7, etc. is assumed. Further, as the two-dimensional code, for example, a square information code such as a QR code, a data matrix code, a maxi code, or an Aztec code is assumed.

The optical information reading device 10 includes a circuit unit 20 housed inside a case (not shown), and the circuit unit 20 mainly includes an illumination light source 21, a marker light irradiation unit 22, an area sensor 23, and the like. It includes an optical system and a microcomputer (hereinafter referred to as "microcomputer") system such as a memory 35 and a control unit 40.

The optical system is divided into a light projecting optical system and a light receiving optical system. The projection 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 illumination light Lf, and is composed of, 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 is composed of an LED and a lens provided on the emission side of the LED. There is. Note that FIG. 1 conceptually shows an example of irradiating the illumination light Lf and the marker light Lm toward the reading target R to which the information code C is attached.

The light receiving optical system is composed of an area sensor 23, an imaging lens 25, and the like. The area sensor 23 is configured to be capable of imaging the information code C as a light receiving sensor having a rectangular light receiving surface 23a in which light receiving elements that are solid-state imaging elements such as C-MOS and CCD are arranged two-dimensionally. Yes, each cell (pattern) of the received information code is configured to output an electric signal according 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 the incident light incident on 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 and the reading target R to which the information code C is attached, and the reflected light Lr is reflected by the imaging lens 25. 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 20a is fixed and a lens holding portion 60 for holding 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 the upper surface 54 of the holder 50 and the lower surface 63 of the brim of the lens holding portion 60, which will be described later, are parallel to the plane of surface contact and are in the X direction. The direction orthogonal to the Y direction is defined as the Y direction, and the direction orthogonal to both the X direction and the Y direction is defined as the Z direction, which will be described below.

As shown in FIGS. 2A to 2C, the holder 50 is formed in a substantially box shape, and one end portion 51 has an opening capable of fixing the sensor substrate 20a so as to cover the opening. By fixing the sensor board 20a to the holder 50, the area sensor 23 mounted on the sensor board 20a is housed in the holder 50. Further, 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 portion 60 and its vicinity when viewed from the direction of the optical axis L1 in order to enhance the light-shielding property of the holder 50.

Further, as shown in FIGS. 2A to 2C, the upper portion of the holder 50 has a flat 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. It is formed along the same direction, and a rectangular opening 55 is provided in the center thereof. The opening 55 is in sliding contact with the lens holding portion 60 at the time of slide adjustment described later on the edge surfaces 56a and 56b facing in the Y direction along the optical axis L1 of the area sensor 23 and orthogonal to the upper surface 54. The length of the lens holding portion 60 in the Y direction is set so as to restrict the movement of the lens holding portion 60 in a direction different from the direction along the optical axis L1. Further, the length of the opening 55 in the X direction is set according to the length of the lens holding portion 60 that allows the slide of the lens holding portion 60 at the time of slide adjustment. Further, each of the pair of edge portions 53 is formed with adhesive grooves 53a used for adhesive fixing after slide adjustment. The upper surface 54 may correspond to an example of the "guide surface" and the "first guide surface", and the edge surfaces 56a and 56b may correspond to an example of the "guide surface" and the "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 brim portion 62 that is connected to the upper portion of the holding portion main body 61. There is. The imaging lens 25 is held by the holding unit main body 61 in consideration of the position where one-sided 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 brim portion 62 along the optical axis L2 of the imaging lens 25, respectively. It is formed so as to be orthogonal to the lower surface 63 of the brim. The end faces 61a and 61b can correspond to an example of the "reference plane" and the "second reference plane".

The brim portion 62 has a substantially flat plate shape, and the length in the Y direction is set so as to be in sliding contact with the edge portion 53 at the time of slide adjustment, and the lower surface of the brim 63, which is a flat surface on the imaging lens 25 side, is connected. It is formed along the optical axis L2 of the image lens 25. The lower surface of the brim 63 is formed on the imaging lens 25 so 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 up to the optical axis L2 is set. Further, the length of the brim portion 62 in the X direction is set so that the lower surface 63 of the brim always covers the opening 55 at the time of sliding contact. Further, on the upper surface of the brim portion 62, a pair of concave engaging portions 64 used for slide adjustment and a pair of adhesive grooves 65 used for adhesive fixing after slide adjustment are formed. The adhesive groove 65 is formed so as to be longer in the X direction than the adhesive groove 53a so as to communicate with the adhesive groove 53a at any slide adjustment position. The lower surface of the brim 63 can correspond to an example of the "reference plane" and the "first reference plane".

Then, as shown in FIGS. 4A to 4C, when the lens holding portion 60 is assembled to the holder 50, the lower surface 63 and the upper surface 54 come into surface contact with each other, and the end faces 61a and 61b and the edge faces 56a, The holding portion main body 61, which is closer to the imaging lens 25 than the brim portion 62, is housed in the holder 50 through the opening 55 in a state where the 56b is in surface contact with each other. Then, as will be described later, the lens holding portion 60 uses both engaging portions 64 in the X direction with respect to the holder 50 so that the relative position between the area sensor 23 and the imaging lens 25 becomes the optimum focal position. After adjusting the slide along the line, the lens holding portion 60 is assembled to the holder 50 so as not to slide by applying a UV adhesive or the like from the adhesive groove 65 to the adhesive groove 53a.

The microcomputer system includes an amplifier 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. It is composed of 46, a communication interface 48, and the like. As the name implies, 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 hardware the image signal of the information code captured by the above-mentioned optical system. It can process signals in terms of hardware and software. The control unit 40 also controls the entire system of the optical information reading device 10.

The image signal (analog signal) output from the area sensor 23 of the optical system is amplified by a predetermined amplification factor by being input to the amplifier circuit 31, and then input to the A / D conversion circuit 33 to be analog. It is converted from a signal to a digital signal. Then, 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 be capable of generating a synchronization signal for the area sensor 23 and the address generation circuit 36, and the address generation circuit 36 is based on the synchronization signal supplied from the synchronization signal generation circuit 38. Therefore, the storage address of the image data stored in the memory 35 can be generated.

The memory 35 is a semiconductor memory device, and for example, a RAM (DRAM, SRAM, etc.) or a ROM (EPROM, EEPROM, etc.) corresponds to this. In addition to the code image information storage area described above, the RAM of the memory 35 is configured to be able to secure a work area and a read condition table used by the control unit 40 for each process such as arithmetic operation and logical operation. There is. Further, the ROM stores in advance a reading program capable of executing a reading process for optically reading the 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 capable of controlling the entire optical information reading device 10, and includes a CPU, a system bus, an input / output interface, and the like. It can form an information processing device together with a memory 35 and has an information processing function. .. The control unit 40 functions to perform decoding processing (decoding) on the code image of the information code imaged by the area sensor 23 and stored in the memory 35. Further, 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 case of this embodiment, the operation unit 42, the liquid crystal display 43, and the buzzer 44, a vibrator 45, a light emitting unit 46, a communication interface 48, and the like are connected.

The operation unit 42 is composed of a plurality of keys and is configured to give an operation signal to the control unit 40 in response to a user's key operation. The control unit 40 receives an operation signal from the operation unit 42. At that 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 composed of a known buzzer, and is configured to generate a predetermined sound in response to an operation signal from the control unit 40. The vibrator 45 is composed of a known vibrator mounted on a mobile device, and is configured to generate vibration in response 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 an external device (for example, a host device), and is configured to perform communication processing in cooperation with the control unit 40.

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

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

Then, the lens holding portion 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 brim portion 62, and the resolving force is sequentially measured. Since the effect of one-sided blurring is suppressed with respect to the change in the resolving force measured in this way, the slide position (relative position) where the resolving force is most highly evaluated is assumed to be the optimum focal position, and the position adjusted so as such. A UV adhesive is applied from the adhesive groove 65 of the lens holding portion 60 to the adhesive groove 53a of the holder 50 to bond and fix the lens. As a result, the lens holding portion 60 is assembled to the holder 50 in a non-sliding manner at the optimum focal position.

In particular, in the present embodiment, by grasping the position where one-sided blur occurs for each imaging lens 25, as can be seen from the imaging field of view P illustrated in FIG. 5, the one-sided blur portion S is on the long side side of the light receiving surface 23a. The imaging lens 25 is held by the lens holding portion 60 so as to be located outside the light receiving surface 23a. As a result, even when the lens holding portion 60 is slid with respect to the holder 50 to measure the resolving force, it is possible to suppress that the one-sided blurred portion S is imaged.

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

As a result, when adjusting the relative positions of the area sensor 23 and the imaging lens 25, the lower surface of the brim 63 and the end faces 61a and 61b are in sliding contact with the upper surface 54 and the edge faces 56a and 56b of the opening 55, respectively. The lens holding portion 60 is moved with respect to the holder 50 along the optical axis L. That is, even in the imaging lens 25 in which one-sided blur occurs, the one-sided blur portion S does not rotate and move when the relative position between the area sensor 23 and the imaging lens 25 is changed to obtain the optimum focal position. , The influence of one-sided blur can be suppressed with respect to the change in the measured resolution.

Further, the area sensor 23 has a rectangular light receiving surface 23a, and the position where one-sided blur occurs is grasped for each imaging lens 25. Then, the lens holding portion 60 holds the imaging lens 25 so that the one-sided blurred portion S is located on the long side side of the light receiving surface 23a and outside the light receiving surface 23a. As a result, unlike the case where the imaging lens is held so that the one-sided bokeh portion S is located on the short side side of the light receiving surface, the one-sided bokeh portion S can be easily positioned outside the imaging field of view by the area sensor 23, and the one-sided bokeh portion S can be easily positioned outside the imaging field of view. It is possible to suppress the influence of the above and improve the resolution.

Even if the position where one-sided blur occurs is not grasped for each imaging lens 25, the one-sided blur portion S does not rotate and move by adopting the lens holding portion 60 and the holder 50 described above, so that the one-sided blur portion S is assumed. Is located inside the light receiving surface 23a, it is possible to suppress the influence of one-sided blur on the change in the measured resolving force.

In particular, the reference plane on the lens holding portion 60 side includes a brim lower surface 63 that functions as a flat first reference plane and end faces 61a and 61b that function as a flat second reference plane orthogonal to the first reference plane. The guide surface on the holder 50 side is composed of an upper surface 54 that functions as a flat first guide surface to which the first reference surface can be slidably contacted, and a flat second guide surface to which the second reference surface can be slidably contacted. It is composed of the edge surfaces 56a and 56b of the opening 55 that function as. In this way, by configuring 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 portion 60 is moved with respect to the holder 50 along the optical axis L.

The first reference plane and the second reference plane on the lens holding portion 60 side 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 plane and the second reference plane in this crossed state. Even if the first guide surface and the second guide surface on the side are provided so as to be slidable, it is possible to simply realize a configuration in which the lens holding portion 60 is moved along the optical axis L with respect to the holder 50. ..

Further, in the brim portion 62 of the lens holding portion 60, the lower surface 63 of the brim on the imaging lens 25 side functions as the first reference surface, and the holder 50 is imaged more than the brim portion 62 of the lens holding portion 60 at the time of assembly. The holding portion main 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 the first guide surface. As a result, not only can the lens holding portion 60 be easily assembled to the holder 50, but also the first reference surface and the first guide surface can be easily brought into surface contact during this assembly.

Further, the brim portion 62 is formed so as to cover the opening 55 at the lower surface 63 of the brim at the time of sliding contact. As a result, the brim portion 62 functions as a light-shielding portion for preventing light from entering through the opening 55, so that 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 60 is provided so as to hold the lens along the optical axis L. The relative movement of the unit 60 can be performed with high accuracy, and the adjustment to the optimum focal position can be surely performed. 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 it has a shape that allows it to be engaged with a jig for slide adjustment.

[Second Embodiment]
Next, the optical information reading device according to the second embodiment will be described with reference to FIGS. 7 and 8.
The second embodiment is mainly different from the first embodiment in that the holder 150 and the lens holding portion 160 are used 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 holding the imaging lens 25 is the 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. Is formed so as to be provided with a convex portion 162 extending in the optical axis direction. Further, a flange portion 163 used at the time of slide adjustment is provided on the reading port 13 side of the lens holding portion 160.

Further, the holder 150 to which the area sensor 23 is fixed has no opening 55 for the holder 50 described above, and an opening 152 is formed at the end portion 151 so as to be in sliding contact with the outer peripheral surface 161 of the lens holding portion 160. A concave portion 153 that is in sliding contact with 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 by utilizing 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 guide surface is formed by utilizing the edge surface of the opening 152 provided in the holder 150 and the recess 153 provided in the opening 152.

Even with this configuration, when adjusting the relative positions of 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 with respect to the holder 150 along the optical axis L. Therefore, when the relative position between the area sensor 23 and the imaging lens 25 is changed to obtain the optimum focal position, the one-sided blur portion S does not rotate and move, so that the influence of the one-sided blur is suppressed with respect to the change in the measured resolving force. 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 so that 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, the optical information reading device according to the third embodiment will be described with reference to FIGS. 9 and 10.
The third embodiment is mainly different from the first embodiment in that the holder 250 and the lens holding portion 260 are used 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 for holding the imaging lens 25 has an outer peripheral surface (outer surface) having a circular cross section when viewed from the surface through which the optical axis L (L2) passes. A recess 262 extending in the optical axis direction is provided in the upper part of the 261. Further, a flange portion 263 used at the time of slide adjustment is provided on the reading port 13 side of the lens holding portion 160.

Further, the holder 250 to which the area sensor 23 is fixed has no opening 55 or the like with respect to the holder 50 described above, and an opening 252 is formed at the end portion 251 so as to be in sliding contact with the outer peripheral surface 261 of the lens holding portion 260. A convex portion 253 that is 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 is formed on the upper portion of the 252.

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

Even with this configuration, when adjusting the relative positions of the area sensor 23 and the imaging lens 25, 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 with respect to the holder 250 along the optical axis L. Therefore, when the relative position between the area sensor 23 and the imaging lens 25 is changed to obtain the optimum focal position, the one-sided blur portion S does not rotate and move, so that the influence of the one-sided blur is suppressed with respect to the change in the measured resolving force. 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 so that the bottom surface and the side surface of the recess 262 function as the first reference surface and the second reference surface. May be done.

[Fourth Embodiment]
Next, the optical information reading device according to the fourth embodiment will be described with reference to FIGS. 11 and 12.
The fourth embodiment is mainly different from the first embodiment in that the holder 350 and the lens holding portion 360 are used instead of the holder 50 and the lens holding portion 60 described above.

Specifically, as shown in FIGS. 11 and 12, the upper surface 361 of the lens holding portion 360 holding the imaging lens 25 has a square cross section when viewed from the surface 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 holder 50 described above, and slides the end portion 351 into the upper surface 361, the lower surface 362, and both side surfaces 363 and 364 of the lens holding portion 360. A square opening 352 is formed.

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

Even with this configuration, when adjusting the relative position of the area sensor 23 and the imaging lens 25, the lens is such 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 portion 360 can be moved with respect to the holder 350 along the optical axis L. Therefore, when the relative position between the area sensor 23 and the imaging lens 25 is changed to obtain the optimum focal position, the one-sided blur portion S does not rotate and move, so that the influence of the one-sided blur is suppressed with respect to the change in the measured resolving force. can do.

The upper surface 361, lower surface 362, and both side surfaces 363 and 364 of the lens holding portion 360 are not limited to being formed so as to have a square cross section when viewed from the surface through which the optical axis L passes, and are, for example, rectangular in cross section. It may be formed so as to have a polygonal cross section, including a shape having a rectangular cross section and a shape having a pentagonal cross section.

[Fifth Embodiment]
Next, the optical information reading device according to the fifth embodiment will be described with reference to FIGS. 13 and 14.
The fifth embodiment is mainly different from the first embodiment in that the holder 450 and the lens holding portion 460 are used instead of the holder 50 and the lens holding portion 60 described above.

Specifically, as shown in FIGS. 13 and 14, the lens holding portion 460 that holds the imaging lens 25 has an arc-shaped cross section (bow-shaped cross section) 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 and is formed. Further, 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 with respect to the holder 50 described above, and 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 at the end portion 451. 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 by 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 by utilizing the edge surface 452a and the edge surface 452b of the provided opening 452.

Even with this configuration, when adjusting the relative positions of the area sensor 23 and the imaging lens 25, 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 portion 460 can be moved with respect to the holder 450 along the optical axis L. Therefore, when the relative position between the area sensor 23 and the imaging lens 25 is changed to obtain the optimum focal position, the one-sided blur portion S does not rotate and move, so that the influence of the one-sided blur is suppressed with respect to the change in the measured resolving force. can do.

[Sixth Embodiment]
Next, a method of manufacturing the optical information reader according to the sixth embodiment will be described with reference to the drawings.
In the sixth embodiment, in the assembling step of the lens holding portion 60 and the holder 50 constituting the optical information reading device 10, the lens holding portion 60 is held in order to surely perform the adjustment work to the optimum focal position. The main difference from the first embodiment is that an arm, an X stage, or the like for fixing the lens after gradually sliding it with respect to 50 and measuring the resolving force in sequence is adopted.

As shown in FIGS. 15 and 16, in the method of manufacturing the optical information reading device 10 in the present embodiment, the mounting table 501 on which the holder 50 to which the lens holding portion 60 before adhesive fixing is assembled is mainly mounted. A manufacturing apparatus including 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 force 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 portion 60 is fixed to the holder 50 at the peak position where the measured resolution force is regarded as a peak. Perform adjustment work to adjust the focal position.

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

The arm 510 is provided with a pair of engaging projections 513 that engage with each of the engaging portions 64 of the lens holding portion 60 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 configured to be. The engaging projection 513 is formed so as not to play with the engaged engaging portion 64 at least in the direction (X direction) along the optical axis L1. The one end side 511 of the arm 510 is formed so as to expose both the bonding grooves 65 in a state where both engaging projections 513 are engaged with the corresponding engaging portions 64.

The X stage 520 is a device for moving the arm 510 to which the other end side 512 is assembled in the direction along the optical axis L1, and is configured so that the moving direction and the amount of movement are driven and controlled by the control unit 530. Has been done.

The control unit 530 performs the focal 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 are brought into contact with each other according to the measured resolution of the area sensor 23. It is configured to drive and control the X stage 520 so that the relative position is the optimum focal position. The control unit 530 may be configured as a control board including a CPU, a memory, or the like, or may be configured by using an application program installed in a predetermined terminal.

Next, the manufacturing process performed when the temporarily assembled lens holding portion 60 and the holder 50 are adhered and fixed so that the relative positions of the area sensor 23 and the imaging lens 25 are the optimum focal positions is specifically described. explain.

First, the lower surface 63 and the end faces 61a and 61b come into surface contact with the upper surface 54 and the edge faces 56a and 56b of the lens holding portion 60 holding the imaging lens 25 with respect to the holder 50 to which the area sensor 23 is fixed. Temporarily assemble in this way. Then, the holder 50 temporarily assembled in this way is placed at a predetermined position on the mounting 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 portion 60 so that both engaging protrusions 513 engage with the engaging portion 64, respectively. Further, as shown in FIGS. 15 and 16, a chart M as illustrated in FIGS. 17 (A) or 17 (B) is arranged at a focal position within the imaging field of view of the area sensor 23 to be adjusted.

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

Then, when the contrast value measured while moving the arm 510 in one direction starts to fall 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 the 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 value is sequentially measured. In the present embodiment, the movement amount X3 when sequentially moving in the other direction is set to be further smaller than the movement amount X2. For example, assuming that the movement amount X3 when moving in the other direction is one step, the movement amount X2 can be 5 steps and the movement amount X1 can be 10 steps.

Then, when the contrast value measured while moving the arm 510 in the other direction starts to decrease beyond the peak, the maximum contrast value previously measured and the position of the lens holding unit 60 where this contrast value is measured are displayed. Is set as the peak value Pa and the peak position Px. After that, when the contrast value measured while moving in the other direction becomes equal to or less than the threshold value N3 set with reference to the peak value Pa, 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 portion 60 exceeds the peak position Px (see arrow F1 in FIG. 18B), the arm 510 is again directed toward the peak position Px. (See arrow F2 in FIG. 18B) to stop the movement of the arm 510 by the X stage 520 at the peak position Px. The other direction along the optical axis L1 may correspond to an example of the "first direction", and the one direction along the optical axis L1 may correspond to an example of the "second direction".

When the lens holding portion 60 is moved to the peak position Px in this way, as illustrated in FIG. 19, the UV adhesive is applied from the adhesive groove 65 to the adhesive groove 53a using the dispenser 540 for the UV adhesive. To do. By fixing the UV adhesive with a UV light or the like in this state, the lens holding portion 60 is fixed to the holder 50 with the arm 510 assembled. At the time of this fixation, the arm 510 may be removed from the X stage 520.

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

As described above, in the method of manufacturing the optical information reading device 10 according to the present embodiment, the lens holding portion 60 holding the imaging lens 25 is provided with the lower surface 63 and the end face 61a with respect to the holder 50 to which the area sensor 23 is fixed. After assembling the 61b so as to make surface contact with the upper surface 54 and the edge surfaces 56a and 56b, respectively, an arm 510 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 force (contrast value) by 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 measured resolution force is regarded as a peak at the peak position Px. After the lens holding portion 60 with the arm 510 assembled is adhesively fixed to the holder 50, the arm 510 is removed from the lens holding portion 60.

As a result, when the lens holding portion 60 is fixed to the holder 50 at the peak position Px, the arm 510 is attached to the lens holding portion 60, so that the lens holding portion 60 is less likely to deviate from the peak position Px, and the resolution is measured. By doing so, it is possible to reliably perform the adjustment to the optimum focal position required.

In particular, in the step of fixing the lens holding portion 60 to the holder 50, the peak position Px is obtained while moving the arm 510 in the other direction (first direction) along the optical axis L1, and thus exceeds 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). : Move to the arrow F2 in FIG. 18B) and fix the lens holding portion 60 to the holder 50 at the peak position Px.

When the moving direction of the arm is switched from the first direction to the second direction, the lens holding portion is driven even if the X stage 520 is driven due to the play of the X stage 520 that functions as an actuator for moving the arm 510. The 60 may not be moved. In such a case, if the lens holding portion 60 is adjusted to move in the other direction toward the found peak position Px while moving in the first direction, the peak position is adjusted. It may be fixed at a position 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 toward the above-mentioned first direction and fixing the lens holding portion 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 focal 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 measured as the resolving power of less than the predetermined value N1 like the moving amounts X2 and X3. Make it smaller than the amount of movement X1. As a result, the measurement time is shortened for the measurement up to the peak position Px, and the measurement accuracy is improved for the measurement near the peak position Px. Therefore, both the reduction of the measurement time and the improvement of the measurement accuracy can be achieved.

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

The present invention is not limited to the above embodiments and modifications, and may be embodied as follows, for example.

(1) The lens holding portions 160, 260, 360, 460 according to the second to fifth embodiments are formed by a pair of engaging portions 64 of the lens holding portions 60 in order to surely adjust 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 reading device that optically reads an information code, and character information or the like is optically read 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 another function in addition to the function of optically reading an information code or the like, for example, a wireless communication function for wireless communication with a wireless communication medium. May be done.

10 ... Optical information reader 23 ... Area sensor 23a ... Light receiving surface 25 ... Imaging lens 50, 150, 250, 350, 450 ... Holder 53 ... Top surface (guide surface, first guide surface)
54 ... Opening 55a, 56b ... Top surface (guide surface, second guide surface)
60, 160, 260, 360, 460 ... Lens holding part 61 ... Holding part main body 61a, 61b ... End face (reference plane, second reference plane)
62 ... Brim part 63 ... Brim lower surface (reference surface, first reference surface)
500 ... Manufacturing equipment 510 ... Arm 520 ... X stage 530 ... Control unit L, L1, L2 ... Optical axis S ... One-sided blurred part

Claims (7)

An optical information reader comprising an area sensor that receives light reflected from an information code through an imaging lens and optically reading the information code based on a signal output from the area sensor.
The holder to which the area sensor is fixed and
A lens holding portion that is assembled to the holder while holding the imaging lens and is provided with a reference surface along the optical axis of the imaging lens.
When the lens holding portion is attached to the holder so that the light passing through the imaging lens forms an image on the area sensor, the reference surface comes into surface contact with the holder, and the lens is held so as to be along the optical axis. A guide surface is formed in which the reference surface is in sliding contact when the portion is moved.
The reference plane is composed of a flat first reference plane and a flat second reference plane intersecting the first reference plane.
The guide surface is composed of a planar first guide surface to which the first reference surface can be slidably contacted and a planar second guide surface to which the second reference surface can be slidably contacted.
The lens holding portion has a brim portion and has a brim portion.
In the brim portion, at least a part of the plane on the imaging lens side functions as the first reference plane.
The holder is formed so that a portion of the lens holding portion that is closer to the imaging lens than the brim portion is accommodated through the opening at the time of assembly, and at least a part of the plane on which the opening is provided is said. optical information reading apparatus characterized that you function as a first guide surface. The area sensor has a rectangular light receiving surface and has a rectangular light receiving surface.
The position where one-sided blur that causes performance deterioration in imaging occurs in a part of the field of view through the imaging lens is grasped for each imaging lens.
The first aspect of claim 1, wherein the lens holding portion holds the imaging lens so that the portion of the field of view where the one-sided blur occurs is located on the long side side of the light receiving surface and outside the light receiving surface. Optical information reader. The optical information reading device according to claim 1 or 2, wherein the brim portion is formed so as to cover the opening on a plane that is on the imaging lens side at the time of sliding contact. The invention according to any one of claims 1 to 3, wherein the lens holding portion is provided with an engaging portion used for moving the holder along the optical axis. Optical information reader. An optical information reading device comprising an area sensor that receives light reflected from an information code through an imaging lens and optically reading the information code based on a signal output from the area sensor. The holder includes a holder to which the sensor is fixed, and a lens holding portion that is assembled to the holder while holding the imaging lens and is provided with a reference plane along the optical axis of the imaging lens. When the lens holding portion is assembled so that the light passing through the imaging lens forms an image on the area sensor, the reference surface comes into surface contact and the lens holding portion is moved along the optical axis. It is a manufacturing method of an optical information reading device for manufacturing an optical information reading device in which a guide surface to which the reference surface is in sliding contact is formed.
A step of assembling the lens holding portion holding the imaging lens to the holder to which the area sensor is fixed so that the reference surface comes into surface contact with the guide surface.
A process of assembling an arm that can move along the optical axis to the lens holding portion, and
A step of sequentially measuring the resolving force 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.
A step of fixing the lens holding portion with the arm assembled to the holder at a peak position where the measured resolving force is regarded as a peak, and a step of fixing the lens holding portion to the holder.
The step of removing the arm from the lens holding portion and
A method for manufacturing an optical information reader, which comprises the above. 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 lighted so as to exceed the peak position. After moving along the axis in the second direction opposite to the first direction, the arm is moved again in the first direction toward the peak position, and the arm is moved in the first direction again at the peak position. The method for manufacturing an optical information reader according to claim 5, wherein the lens holding portion is fixed to the holder. In the step of sequentially measuring the resolving force, the amount of movement by the arm when the resolving force of the predetermined value or more is measured is made smaller than the amount of movement by the arm when the resolving force of less than the predetermined value is measured. The method for manufacturing an optical information reader according to claim 5 or 6.

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