JPH0583861U - Optical reader - Google Patents

Abstract

(57) [Summary] [Object] To obtain an optical reading device capable of positioning a lens constituting an optical reading device and correcting even if a deviation of a focal value of the lens or a displacement of a CCD position occurs. A lens frame 26 having a recess on an outer wall is held in upper and lower cases 20 and 21 of an optical reader so as to be movable in the optical axis direction. Upper and lower cases 20, 2 of the lens frame 26
The cap 23, which serves as an adjusting member for adjusting the movement in the optical axis direction within the optical disc 1, has an engaging portion 2 that engages with the concave portion of the lens frame 26.
7 and is rotatably held in the upper and lower cases 20 and 21. The lens frame 26 is adjusted in the optical axis direction by rotating the cap 23, and the lens frame 26 is fixed to the adjustment position by fixing the cap 23 to the upper and lower cases 20 and 21 with screws 50.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical reading device such as a bar code scanner, and more particularly to an optical reading device capable of adjusting the focal position of a lens incorporated in the main body of the device.

[0002]

[Prior Art]

 In general, an optical reading device such as a hand-held bar code scanner has an outer case 1 bent at a predetermined angle as shown in FIG. 6, and the outer case 1 optically stores information. It has a recording medium for recording information, for example, an open end 3 facing a bar code 2. In the outer case 1, an LED array 4 usually composed of a plurality of LEDs 11 and light emitted from the LED array 4 are condensed into a bar code 2 through an opening end 3. A semi-cylindrical light guide 5, a reflection mirror 7 that bends the optical path of the light reflected by the bar code 2 and incident from the opening end 3 by a predetermined angle and guides it to the reading optical path 6, and A lens 8 for condensing the light bent by the reflection mirror 7 to form an image of the bar code 2, a lens frame 8a for fixing the lens inside, and the bar code. A line sensor 9 composed of a detector for detecting the image of No. 2 such as a CCD, and a detection signal emitted from the line sensor 9 are processed to read the information recorded in the bar code 2. And a circuit 10. Although omitted in FIG. 6, an adapter case is provided in the outer case 1 to configure the main body as a means for installing the LED array 4, the light guide 5, the reflection mirror 7, the lens 8, the line sensor 9, and the like. Sometimes.

In this bar code scanner, although not shown, a drive circuit is operated in response to an operation of a push button or the like, each LED 11 emits light for a predetermined time, and this light is emitted from the light guide 5 at the opening end. It is projected onto the bar code 2 through the line 3. Along with this, when the light reflected by the bar code 2 is incident from the opening end 3, the light is bent by the reflection mirror 7 by a predetermined angle and guided to the reading optical path 6, and the lens 8 The image of the imaged bar code 2 is collected by the line sensor 9 and detected. Next, the detection signal emitted from the line sensor 9 is processed by the reading circuit 10 to read the information recorded in the bar code 2.

[0004]

[Problems to be solved by the device]

 In such a conventional optical reading device, the lens frame 8a is merely fitted and held and fixed according to the shape of the inside of the main body. However, the focal length of the lens 8 actually used has a deviation, and the installation positions of the respective members also have a deviation. If the lens defocus (hereinafter referred to as f-value shift) or the position shift of the line sensor or the like occurs in this way, it deviates from the normal conjugate length, but it cannot be corrected. Therefore, in the conventional barcode scanner, there is a problem that the performance such as the reading depth and the resolution is likely to vary and the reading performance is low. In order to solve such a problem, the present invention provides an optical reading device which enables the position adjustment of a lens and can easily correct the conjugate length as designed even if the lens f value shifts. To aim.

[0005]

[Means for Solving the Problems]

 The optical reading device of the present invention comprises an optical reading device main body, a lens frame which is movably held in the optical axis direction in the main body and has a concave portion or a convex portion on an outer wall portion thereof, and the concave portion or the convex portion is engaged with the lens frame. And an adjusting member which is rotatably held in the main body and adjusts the movement of the lens frame in the main body in the optical axis direction by the rotation. And a fixing member for fixing the lens frame to the adjustment position by fixing the lens frame to the main body.

[0006]

[Action]

 The adjusting member is made rotatable, and the engaging portion provided on the adjusting member is engaged with the concave portion or the convex portion of the lens frame, and the engaging portion is moved so as to have a conjugate length as designed in the optical system. Adjust the lens position. After that, the lens frame is fixed by fixing the adjusting member in the apparatus main body with the fixing member.

[0007]

【Example】

 An embodiment in which the present invention is applied to a bar code scanner will be described below with reference to FIGS. The same parts and portions used in the conventional bar code scanner are designated by the same reference numerals and detailed description thereof will be omitted. As shown in FIGS. 1 and 2, there are an upper case 20 and a lower case 21 as adapter cases which are installed in an outer case 1 of a hand-held bar code scanner to form a main body. The side plate 21a of the lower case 21 is provided with a cylindrical boss 22 for screwing the upper case 20, and a cap 23 as an adjusting member described later is rotatable on the boss 22. Is fitted to. The boss 22 is formed with a screw hole 28, and the upper case 20 and the cap 23 are formed with screw insertion holes 20a and 24, respectively. The screw 50 passed through the insertion holes 20a and 24 is inserted into the screw hole 28. The upper case 20 and the lower case 21 can be fixed via the cap 23 by screwing. Further, the cap 23 is fixed in both cases 20 and 21 by tightly tightening the screw 50. On the outer surface of the cap 23, there is provided a stopper 27 which is an engaging portion extending in a strip shape parallel to the axis of the cap 23. A window portion 31 is provided on the upper case 20, and the cap 23 can be pivotally adjusted from the outside of the upper case 20 through the window portion 31 during assembly. The upper case 20 and the lower case 21 are provided with pedestals 20b and 21b for holding a cylindrical lens frame 26 having the lens 8 fixed therein so as to be movable in the axial direction. A hole 29 is provided between the pedestal 21b and the side plate 21a, and the cap 23 is provided with a protrusion 25 that engages with the hole 29 and restricts the rotation of the cap 23. On the cylindrical side surface of the lens frame 26, a ring-shaped groove 30 is provided along the lens side surface.

As shown in FIGS. 3 and 4, the groove 30 and the stopper 27 are engaged in the upper and lower cases. Then, an adjustment jig or the like is inserted through the window portion 31 and the cap 23 is moved so that the lens frame 26 can be adjusted and moved in the optical axis direction. At this time, the protrusion 25 is cut in advance so that the cap 23 can move.

Next, the assembly of the bar code scanner will be described. First, the LED array-4 (see FIG. 6), the light guide 5 to which the array-4 is attached, and the reflection mirror 7 are mounted in predetermined positions in the lower case 21. Further, the lens frame 26 is fitted into the lower case 21. The stopper 27 of the cap 23 is brought into contact with the groove 30 of the lens frame 26, and the cap 23 is attached so that the protrusion 25 of the cap 23 fits into the hole 29 of the case 21. Further, the upper case 20 is covered on the lower case 21, and the screw 50 is inserted through the hole 20a formed in the upper case 20 and screwed into the screw hole 28 of the lower case 21. At this time, the cap 23 is fixed by the screw 50, and the lens frame 26 is fixed together therewith.

Now, in this bar code scanner, finally, it is necessary to adjust the conjugate length of the optical system according to the design value to adjust the f-value shift, the line sensor position shift, and the like. Therefore, after assembly, it is checked whether the conjugate length as designed is obtained. If each part is manufactured according to the design value and passes the inspection, it will be a finished product without adjustment. On the other hand, even when assembled by the method described above, if the conjugate length as designed is not obtained, the protrusion 25 of the cap 23 is cut and the cap 23 can be rotated with respect to the boss 28. And The stopper 27 abutting on the groove 30 of the lens frame 26 inserts an adjusting jig from the window 31 formed in the upper case 20 before screwing the two cases 20 and 21 with the screw 50. Alternatively, the lens frame 26 is moved and adjusted in parallel to the case side plate 21a, that is, in the optical axis direction. Then, at the position where the conjugate length of the design value is reached, the screw 50 is strongly tightened to fix the cap 23 in both cases 20, 21, and thereby the lens frame 26 is placed in both cases 20, 21. Fix it. Thus, the projection 25 of the cap 23 plays an auxiliary role for fixing the cap 23 and the lens frame 26 to the cases 20 and 21 when the dimensional accuracy of the assembly is correct. On the other hand, when the dimensional accuracy is not obtained, the cap 23 and the lens frame 26 can be adjusted by cutting.

A concave portion is provided on the cap 23 instead of the protrusion 25, and a convex portion that engages with the concave portion is provided on the lower case 21 or upper case 20 side, or the stopper 27 of the cap 23 is formed into a concave shape. The lens frame 26 may be provided with a convex portion that engages with the concave portion. As a second embodiment of the present invention, as shown in FIG. 5, there are an upper case 120 and a lower case 121 as adapter cases installed in the outer case 1 to form a main body, and a side plate of the lower case 121. 121a is provided with a circular recess 122, and the bottom of the recess 122 is provided with a screw hole 122a for screwing the upper case 120. A cap 123 as an adjusting member is rotatably fitted in the recess 122. On the outer surface of the cap 123, there is formed a recess 127 which is a groove-like engaging portion extending parallel to the axis of the cap 123. Further, a hole 129 is formed on the top surface of the cap 123, and the pin 125 fitted into the hole 129 can be inserted into the upper case 120. On the cylindrical side surface of the cylindrical lens frame 126 having the lens 8 fixed therein, a ring-shaped convex portion 130 is provided along the lens side surface. The convex portion 130 and the concave portion 127 are engaged in the upper and lower cases. As in the above-described embodiment, the cap 123 is moved from the window 131 provided in the upper case 120 so that the lens frame 126 can be adjusted and moved in the optical axis direction. At this time, the pin 125 is pulled out in advance so that the cap 123 can move.

In the embodiments configured as described above, even if the f-number of the lens is deviated or the position of the line sensor is deviated, the protrusion 25, the pin 125, and the like can be easily cut or pulled out in the front-back direction. The position of the lens frame can be adjusted. Therefore, the cumulative dimensional tolerance of optical components can be adjusted even if a primary failure occurs, and can be set uniformly in a high-performance state.Therefore, a complicated correction circuit is required for the electrical circuit that complements the optical system. Therefore, it is possible to provide a high-performance bar code scanner with a simple structure.

Since the protrusion 25, the pin 125 and the like are merely auxiliary fixing means, even if they are omitted, the intended purpose of the present invention can be achieved. Further, the present invention can be effectively applied to an optical reader other than a barcode scanner.

[0014]

[Effect of the device]

 Since the present invention is configured as described above, when performing lens positioning, an optical reading device that can easily correct the conjugate length according to the design value even if the f-value of the lens deviates, etc. Can be provided.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the internal configuration of an optical reading device of the present invention.

FIG. 2 is a cross-sectional view of the internal configuration of the optical reading device shown in FIG.

FIG. 3 is a plan view of a main part of the internal configuration of the optical reading device shown in FIG.

4 is a cross-sectional view of the optical reading device shown in FIG. 1 taken along the line AA ′ in FIG.

FIG. 5 is a sectional view showing a second embodiment of the internal configuration of the optical reading device of the present invention.

FIG. 6 is an assembly schematic diagram of a general hand-held bar code scanner.

[Explanation of symbols]

 1 Outer Case 8 Lens 20 Upper Case (Part of Main Body) 21 Lower Case (Part of Main Body) 23 Cap (Adjusting Member) 25 Projection 26 Lens Frame 27 Stopper (Engaging Part) 50 Screw (Fixing Member)

Claims (1)

[Scope of utility model registration request] 1. An optical reading device main body, a lens frame which is movably held in the main body in the optical axis direction and has a concave portion or a convex portion on an outer wall portion, and an engaging portion which engages with the concave portion or the convex portion. And an adjustment member which is rotatably held in the main body and adjusts the movement of the lens frame in the optical axis direction in the main body by the rotation, and the adjustment member is fixed to the main body. Accordingly, the optical reading device comprises a fixing member for fixing the lens frame at the adjustment position.