Optical scanner

Abstract

An optical scanner is disclosed. The optical scanner includes a sight light source that emits highly polarized light, a window, and a linear polarizer located between the sight light source and the window. In addition, the linear polarizer receives the highly polarized light and converts the highly polarized light into linearly polarized light. In addition, the quarter-wave plate is located between the linear polarizer and the window. In addition, the quarter-wave plate receives the linearly polarized light and converts the linearly polarized light into circularly polarized light. Thus, the linear polarizer and quarter wave plate prevent back reflection of circularly polarized light from the window to the sight light source to prevent sight ghosting light.

Description

TECHNICAL FIELD

[0001] Example embodiments of the present disclosure generally relate to optical scanners, and more particularly to optical scanners for preventing reflections and methods thereof. BACKGROUND

[0002] Bar code scanners generally use either laser or imaging technology to capture and decode information from bar codes. Imaging-based bar code scanners are one of the most common types, which operate by projecting a laser beam onto a bar code. These scanners consist of an imaging system, an illumination system, an aimer projector, and a microcontroller unit (MCU). The aimer projector, which uses a visible laser diode (VLD) as its light source, projects a visible dot that helps to locate the bar code in the image and enhances the decoding capability of the scanner. A lens is located near the VLD to collimate the emitted light and convert the divergent light into a parallel beam. The parallel beam then passes through a protective window before hitting the target laser die. However, in addition to the small emitting area, the VLD has a highly reflective surface. When the light reflected from the protective window hits the reflective surface of the die, it is reflected again, back through the collimating lens and the protective window. This reflection creates a darker aimer "ghost" on the target, creating an unintended secondary projection near the intended laser dot. This ghost image can interfere with the accuracy of the scanner, and can cause confusion, errors, and low efficiency in the operation of the scanner.

[0003] The present inventors have found many deficiencies and problems in the prior art and processes, which are the subject matter of the embodiments described herein. Many of these deficiencies and problems have been addressed through the development of solutions included in the embodiments of the present disclosure, many examples of which are described in detail herein, through the efforts, ingenuity, and innovation of the present inventors. SUMMARY

[0004] The following presents a simplified summary of some example embodiments to provide a basic understanding of some aspects of the present disclosure. This summary is not an extensive overview of the disclosure, is not intended to identify key or critical elements, and is not intended to delineate the scope of the disclosure. It should be appreciated that the summary is intended to present some of the concepts of the disclosure in a simplified form, and that the full scope of the disclosure is defined by the appended claims and their equivalents.

[0005] In example embodiments, an optical scanner is disclosed. The optical scanner includes a collimator light source that emits a high polarization light, a window, a linear polarizer positioned between the collimator light source and the window. Further, the linear polarizer is configured to receive the high polarization light and convert to a linearly polarized light, a quarter wave plate positioned between the linear polarizer and the window. Further, the quarter wave plate receives the linearly polarized light and converts to a circularly polarized light. Further, the linear polarizer and the quarter wave plate prevent back reflection of the circularly polarized light from the window to the collimator light source to prevent a collimator ghost light.

[0006] In some embodiments, the collimator light source corresponds to at least a visible laser diode (VLD) light source.

[0007] In some embodiments, a collimating lens is positioned between the collimator light source and the linear polarizer. In some embodiments, the collimating lens collimates the high polarization light to a parallel beam of light received by the linear polarizer.

[0008] In some embodiments, the high polarization light is converted by the linear polarizer to a linearly polarized light having a parallel direction.

[0009] In some embodiments, the circularly polarized light converted from the linearly polarized light by the quarter wave plate corresponds to a left-handed circularly polarized light or a right-handed circularly polarized light. In some embodiments, the window reflects the left-handed circularly polarized light to a right-handed circularly polarized light or reflects the right-handed circularly polarized light to a left-handed circularly polarized light. In some embodiments, the quarter wave plate is configured to convert the left-handed circularly polarized light or the right-handed circularly polarized light received from the window to a perpendicular polarized light.

[0010] In some embodiments, a direction of the perpendicular polarized light is perpendicular to an axis of the linear polarizer such that the linear polarizer prevents the perpendicular polarized light from reflecting back to the collimator light source, thereby preventing a collimator ghost light. In some embodiments, the axis of the linear polarizer is positioned at a predefined degree to transmit the linearly polarized light at a maximum intensity.

[0011] In some embodiments, the quarter wave plate includes a first axis and a second axis. Further, the quarter wave plate is positioned relative to the linear polarizer such that the first axis and the second axis of the quarter wave plate each forms a 45 degree angle with the axis of the linear polarizer.

[0012] In some embodiments, the collimator light source, the collimating lens, the linear polarizer, the quarter wave plate, and the window are positioned in a same plane and collectively produce a collimator light.

[0013] In another example embodiment, a method is disclosed. The method includes emitting highly polarized light by a sighter light source of an optical scanner; converting the highly polarized light received from the sighter light source into linearly polarized light by a linear polarizer positioned between the sighter light source and a window; and converting the linearly polarized light received from the linear polarizer into circularly polarized light by a quarter wave plate positioned between the linear polarizer and the window. Further, the linear polarizer and the quarter wave plate prevent back reflection of the circularly polarized light from the window from reaching the sighter light source to prevent sighter ghost light.

[0014] The above summary is provided merely for purposes of summarizing some example embodiments to provide a basic understanding of some aspects of the disclosure. Accordingly, it will be appreciated that the above described embodiments are merely examples and should not be construed as limiting the scope or spirit of the disclosure in any way. It will be appreciated that the scope of the disclosure encompasses many potential embodiments, some of which will be further explained in following detailed description and accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0015] Having thus described certain example embodiments of the disclosure in general terms, reference will now be made to the accompanying drawings, which do not necessarily depict all possible embodiments, and wherein:

[0016] Figure 1 An architectural diagram of an optical scanner is shown in accordance with example embodiments of the disclosure;

[0017] Figures 2A-2B Operation of an optical scanner is shown in accordance with example embodiments of the disclosure;

[0018] Figure 3A Linearly polarized light is shown in accordance with example embodiments of the disclosure; and

[0019] Figure 3B Circularly polarized light is shown in accordance with example embodiments of the disclosure. DETAILED DESCRIPTION

[0020] Some embodiments will now be described more fully with reference to the accompanying drawings. The disclosure may, however, be embodied in many different forms and should not be construed as limited to the implementation set forth in the attached claims or in the examples for clarification herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0021] The components shown in the drawings are representative of components that can or can not be present in various embodiments of the disclosure described herein, such that embodiments can include fewer or more components than those shown in the drawings without departing from the scope of the disclosure. Some components can be omitted from one or more of the figures or shown in phantom to aid in visibility of underlying components.

[0022] As used herein, the term “includes” means includes but not limited to, and is to be interpreted in the same manner as the more generic term “comprises.” The use of the more generic term “comprises” or “comprising” is to be understood as permitting the inclusion of more items, or additional items, or the exclusion of some items, or the inclusion of additional items, without the exclusion of other items.

[0023] The phrases “in various embodiments,” “in one embodiment,” “according to one embodiment,” “in some embodiments,” and the like generally mean the particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of the present disclosure, and can include more than one embodiment of the present disclosure (importantly, such phrases are not necessarily referring to the same embodiment).

[0024] The word “example” or “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations.

[0025] If the specification states a component, feature, structure, or characteristic “may,” “might,” “could,” “should,” “would,” “preferably,” “possibly,” “typically,” “optionally,” “for example,” “usually,” or “can” (or other similarly worded language) include or be accompanied by the recitation of a feature, that particular component, feature, structure, or characteristic is not required to be included or be present. Such components, feature, structure, or characteristic can be optionally included in some embodiments or they can be excluded.

[0026] The present disclosure provides various embodiments of an optical scanner. Embodiments of the present disclosure can include a sight source that emits highly polarized light. Embodiments of the present disclosure can include a window. Embodiments of the present disclosure can include a linear polarizer positioned between the sight source and the window. The linear polarizer can receive the highly polarized light and convert it to linearly polarized light. Embodiments of the present disclosure can include a quarter wave plate positioned between the linear polarizer and the window. The quarter wave plate can receive the linearly polarized light and convert it to circularly polarized light. The linear polarizer and the quarter wave plate can prevent back reflections of the circularly polarized light from the window from reaching the sight source to prevent sight ghosting light.

[0027] Figure 1 An architectural diagram of an optical scanner 100 is shown in accordance with example embodiments of the present disclosure.

[0028] In some embodiments, the optical scanner 100 may include a sight 102, an imaging system 104, and an illumination system 106. In some embodiments, the optical scanner 100 may be configured to scan one or more visual codes (not shown) from at least one object (not shown). The one or more visual codes may include at least one of barcodes, quick response (QR) codes, etc. In some embodiments, the at least one object may include at least one of cartons, packaging, etc. In various examples, the optical scanner 100 may be mounted on an external system (not shown), such as a conveyor belt, logistics system, etc. In various other examples, the optical scanner 100 may be integrated into a handheld unit (not shown), a door (not shown), etc. In some embodiments, the optical scanner 100 may be configured to scan one or more visual codes and interpret information encoded within the one or more visual codes. In some embodiments, the information may include, but is not limited to, details about the type of object being scanned, the category or model of at least one object, the manufacturer of at least one object, and / or the supplier of at least one object. In some embodiments, the optical scanner 100 may include a window 116 located in front of the sight 102, the imaging system 104, and the illumination system 106.

[0029] In various examples, the optical scanner 100 may include a housing (not shown). In some embodiments, the housing of the optical scanner 100 may be configured to protect one or more components of the optical scanner 100 (i.e., the aiming device 102, the imaging system 104, and the illumination system 106) from various conditions. Conditions may include, but are not limited to, extreme temperature or high pressure environments. In some embodiments, the housing of the optical scanner 100 may be constructed of various materials. Materials may include, but are not limited to, metals, plastics, or polycarbonate. The material of the housing can be selected such that the housing of the optical scanner 100 can withstand various conditions.

[0030] In some embodiments, the optical scanner 100 may include a sight 102. In some embodiments, the sight 102 of the optical scanner 100 may aid in the positioning of the optical scanner 100 such that the field of view (FOV) of the optical scanner 100 covers at least one object. In some embodiments, the sight 102 of the optical scanner 100 may be configured to project a light pattern onto at least one object. Furthermore, the light pattern may include, but is not limited to, dots, lines, or crosshairs. In some embodiments, the light pattern projected by the sight 102 may aid in the alignment of the optical scanner 100 with at least one object. Furthermore, the alignment of the optical scanner 100 with at least one object can ensure the correct scanning of one or more visual codes on at least one object. For example, the sight 102 of a barcode scanner is configured to project a light pattern onto a barcode that may be printed on packaging. The barcode scanner is positioned at a distance from the packaging such that the light pattern is perfectly aligned with the barcode.

[0031] In some embodiments, the aiming device 102 of the optical scanner 100 may include an aiming device light source 108, a collimating lens 110, a linear polarizer 112, and a quarter-wave plate 114. In some embodiments, the aiming device light source 108 may be integrated within the aiming device 102 of the optical scanner 100. In some embodiments, the aiming device light source 108 may be configured to emit highly polarized light 118 toward the field of view (FOV) of the aiming device 102. In some embodiments, the aiming device light source 108 may correspond to at least a visible laser diode (VLD) light source. In some embodiments, the aiming device light source 108 of the aiming device 102 may be configured to emit a narrow coherent beam of visible light (i.e., highly polarized light 118). In some embodiments, the highly polarized light 118 emitted by the aiming device light source 108 may facilitate the alignment of the optical scanner 100 with a target area (i.e., one or more visual codes on at least one object). In various examples, the aiming device light source 108 of the aiming device 102 may be coupled to a power source (not shown). Furthermore, the power source may be configured to provide power to the aiming device light source 108 for emitting highly polarized light 118 toward at least one object. In some embodiments, highly polarized light 118 corresponds to a light wave in which the magnetic field oscillates primarily in a single direction (i.e., a linear polarization) or plane.

[0032] In some embodiments, the sight 102 may further include a collimating lens 110. In some embodiments, the collimating lens 110 may be located between the sight light source 108 and the linear polarizer 112. In some embodiments, the collimating lens 110 may be located at equal distances from the sight light source 108 and the linear polarizer 112. In some embodiments, the collimating lens 110 of the optical scanner 100 may be configured to collimate highly polarized light 118 into a parallel beam 120 that can be received by the linear polarizer 112. In some embodiments, the collimating lens 110 of the optical scanner 100 may be configured to perform a collimation process. The collimation process may include converting the light rays of the highly polarized light 118 from a divergent (e.g., scattered) state to a state that is parallel or nearly parallel with respect to the field of view (FOV) of the optical scanner 100. In some embodiments, the highly polarized light 118 emitted by the sight light source 108 may be configured to diverge. Furthermore, the collimating lens 110 of the optical scanner 100 may be configured to capture the highly polarized light 118 and redirect the captured highly polarized light 118 into a parallel beam 120.

[0033] In some embodiments, the collimating lens 110 of the optical scanner 100 can be made of various materials. Materials may include, but are not limited to, glass, plastics (i.e., polymers), crystals (e.g., sapphire, quartz, etc.), aspherical materials, Fresnel lenses, etc. In some embodiments, the material of the collimating lens 110 can be selected such that the collimating lens 110 can have precise optical properties, durability, and applicability. In some embodiments, the parallel beam 120 collimated by the collimating lens 110 can propagate along multiple axes (e.g., vertical axis, horizontal axis, longitudinal axis, etc.). In some embodiments, when the parallel beam 120 (i.e., highly polarized light 118) is collimated by the collimating lens 110, the parallel beam 120 can be configured to propagate toward the linear polarizer 112.

[0034] In some embodiments, the linear polarizer 112 of the optical scanner 100 may be located between the aiming light source 108 and the window 116. In some embodiments, the linear polarizer 112 of the optical scanner 100 may be configured to receive highly polarized light 118. In some embodiments, the linear polarizer 112 of the optical scanner 100 may be configured to convert the highly polarized light 118 into linearly polarized light 124 (e.g., ...). Figure 3A (As shown). In various embodiments, the linear polarizer 112 may be positioned equidistantly between the collimating lens 110 and the quarter-wave plate 114. In some embodiments, the linear polarizer 112 of the optical scanner 100 may be configured to control and refine the polarization of the highly polarized light 118. In some embodiments, the linear polarizer 112 may be configured to receive the highly polarized light 118 that can be collimated into a parallel beam 120 by the collimating lens 110. In some embodiments, the highly polarized light 118 entering the linear polarizer 112 may have rays propagating along multiple axes.

[0035] In some embodiments, the linear polarizer 112 of the optical scanner 100 may define a vertical polarization axis 122. In some embodiments, the linear polarizer 112 may be configured to filter light rays having an axis perpendicular to the vertical polarization axis 122 of the linear polarizer 112. In some embodiments, the linear polarizer 112 may be configured to allow light rays having an axis parallel to the vertical polarization axis 122 of the linear polarizer 112 to pass through. In some embodiments, the highly polarized light 118 may be converted by the linear polarizer 112 into linearly polarized light 124 having a parallel direction. In some embodiments, the linear polarizer 112 of the optical scanner 100 may be configured to provide linearly polarized light 124. In some embodiments, the linear polarizer 112 of the optical scanner 100 may be composed of various materials. The material of the linear polarizer 112 may include, but is not limited to, a polarizing film, calcite crystal, quartz crystal, etc. The material of the linear polarizer 112 can be selected such that the linear polarizer 112 of the optical scanner 100 can have a high degree of polarization efficiency and quality.

[0036] In some embodiments, the optical scanner 100 may include a quarter-wave plate 114. In some embodiments, the quarter-wave plate 114 of the optical scanner 100 may be located between the linear polarizer 112 and the window 116. In some embodiments, the quarter-wave plate 114 of the optical scanner 100 may be configured to receive linearly polarized light 124 from the linear polarizer 112 of the optical scanner 100. In some embodiments, the quarter-wave plate 114 of the optical scanner 100 may be configured to convert the received linearly polarized light 124 into circularly polarized light 126 (e.g., ...). Figure 3B (As shown). In some embodiments, the quarter-wave plate 114 can be configured to introduce a 90-degree (i.e., quarter-wavelength) phase difference into the linearly polarized light 124 received from the linear polarizer 112. Furthermore, the phase shift (i.e., 90 degrees) of the linearly polarized light 124 can cause it to be converted into circularly polarized light 126. In some embodiments, the circularly polarized light 126 that can be converted from the linearly polarized light 124 by the quarter-wave plate 114 can correspond to left-handed or right-handed circularly polarized light.

[0037] In some embodiments, the optical scanner 100 may include a window 116. In some embodiments, circularly polarized light 126 passing through a quarter-wave plate 114 may be configured to propagate toward the window 116. In some embodiments, the window 116 of the optical scanner 100 may be configured to receive the circularly polarized light 126. In some embodiments, the window 116 of the optical scanner 100 may be configured to allow the circularly polarized light 126 to pass through. In some embodiments, the circularly polarized light 126 passing through the window 116 may be configured to illuminate a target plane 128 of at least one object. In some embodiments, the optical scanner 100 may be configured to scan one or more visual codes printed on the target plane 128 of at least one object via the circularly polarized light 126 passing through the window 116.

[0038] In some embodiments, the window 116 of the optical scanner 100 may be configured to reflect a portion of the circularly polarized light 130 back toward the quarter-wave plate 114. In some embodiments, the window 116 may be configured to reflect left-handed circularly polarized light into right-handed circularly polarized light, or vice versa. In some embodiments, the quarter-wave plate 114 of the optical scanner 100 may be configured to receive a portion of the circularly polarized light 130 that may be reflected by the window 116. In some embodiments, the quarter-wave plate 114 may be configured to convert the left-handed or right-handed circularly polarized light received from the window 116 into vertically polarized light 132. In some embodiments, the vertically polarized light 132 may define a direction. In some embodiments, the direction of the vertically polarized light 132 may be perpendicular to the axis of the linear polarizer 112 (i.e., the vertical polarization axis 122). In some embodiments, the linear polarizer 112 of the optical scanner 100 may be configured to receive the vertically polarized light 132. In some embodiments, the linear polarizer 112 of the optical scanner 100 may be configured to prevent vertically polarized light 132 from being reflected back to the sight light source 108, thereby preventing sight ghosting. In some embodiments, the linear polarizer 112 and the quarter-wave plate 114 may be configured to prevent back reflection of circularly polarized light 126 from the window 116 to the sight light source 108, thereby preventing sight ghosting.

[0039] In some embodiments, the imaging system 104 of the optical scanner 100 may be configured to capture one or more images of one or more visual codes of at least one object. In some embodiments, the imaging system 104 may include one or more sensors and a processor (not shown), which may be configured to extract desired information from one or more images of one or more visual codes of at least one object. In some embodiments, the illumination system 106 of the optical scanner 100 may be configured to provide ambient light around at least one object to enable accurate scanning of one or more visual codes of at least one object. In some embodiments, the illumination system 106 may include at least one of a light-emitting diode (LED) panel, a light bulb, a fluorescent lamp, etc.

[0040] Figures 2A-2B The operation of an optical scanner 100 according to an example embodiment of the present disclosure is shown. Figure 3A Linearly polarized light 124 is shown according to an example embodiment of the present disclosure. Figure 3B Circularly polarized light 126 is shown according to an example embodiment of the present disclosure.

[0041] In some embodiments, the aiming light source 108 of the optical scanner 100 can be configured to emit highly polarized light 118. In some embodiments, the highly polarized light 118 emitted by the aiming light source 108 can be configured to propagate toward the field of view (FOV) of the optical scanner 100, such as... Figure 2A As indicated by arrow 200 in the diagram. In some embodiments, the aiming light source 108, collimating lens 110, linear polarizer 112, quarter-wave plate 114, and window 116 may be located in the same plane 202 and collectively generate aiming light. In some embodiments, the collimating lens 110 of the optical scanner 100 may be configured to receive highly polarized light 118. Furthermore, the collimating lens 110 of the optical scanner 100 may be configured to collimate the highly polarized light 118 into a parallel beam 120. In some embodiments, the parallel beam 120 may have multiple axes. In some embodiments, the parallel beam 120 may be configured to propagate toward the linear polarizer 112 of the optical scanner 100. In some embodiments, the linear polarizer 112 of the optical scanner 100 may be configured to receive the highly polarized light 118 (e.g., parallel beam 120) from the collimating lens 110. In some embodiments, the linear polarizer 112 may be configured to convert the highly polarized light 118 into linearly polarized light 124 (e.g., parallel beam 120). Figure 3A (As shown).

[0042] In some embodiments, the quarter-wave plate 114 of the optical scanner 100 can be configured to receive linearly polarized light 124 and convert the linearly polarized light 124 into circularly polarized light 126 (in... Figure 3B(as shown in the figure). In some embodiments, the circularly polarized light 126 converted from linearly polarized light 124 by the quarter-wave plate 114 may correspond to left-handed or right-handed circularly polarized light. In some embodiments, the quarter-wave plate 114 of the optical scanner 100 may include a first axis 204 (i.e., the fast axis) and a second axis 206 (i.e., the slow axis). In some embodiments, the first axis 204 of the quarter-wave plate 114 may be positioned perpendicular to the second axis 206 of the quarter-wave plate 114. In some embodiments, the quarter-wave plate 114 of the optical scanner 100 may be positioned relative to the linear polarizer 112 such that the first axis 204 and the second axis 206 of the quarter-wave plate 114 each form a 45-degree angle with the axis of the linear polarizer 112 (i.e., the vertical polarization axis 122).

[0043] In some embodiments, the quarter-wave plate 114 can be configured to convert linearly polarized light 124 into circularly polarized light 126. In some embodiments, the circularly polarized light 126 can correspond to left-handed or right-handed circularly polarized light. In various examples, when the first axis 204 of the quarter-wave plate is arranged clockwise from the axis of the linear polarizer 112 (i.e., the vertical polarization axis 122) and the second axis 206 of the quarter-wave plate is arranged counterclockwise from the axis of the linear polarizer 112, the circularly polarized light 126 corresponds to right-handed circularly polarized light. In various examples, when the first axis 204 of the quarter-wave plate is arranged counterclockwise from the axis of the linear polarizer 112 (i.e., the vertical polarization axis 122) and the second axis 206 of the quarter-wave plate is arranged clockwise from the axis of the linear polarizer 112, the circularly polarized light 126 corresponds to left-handed circularly polarized light.

[0044] In some embodiments, the window 116 of the optical scanner 100 may be configured to receive circularly polarized light 126 (e.g., left-handed or right-handed circularly polarized light). In some embodiments, the window 116 of the optical scanner 100 may be configured to allow the circularly polarized light 126 to pass through. In some embodiments, the circularly polarized light 126 passing through the window 116 may be configured to illuminate a target plane 128 of at least one object. In some embodiments, the optical scanner 100 may be configured to scan one or more visual codes printed on the target plane 128 of at least one object via the circularly polarized light 126 passing through the window 116.

[0045] In some embodiments, the window 116 of the optical scanner 100 can be configured to reflect a portion of the circularly polarized light 130 back toward the quarter-wave plate 114, such as Figure 2BAs indicated by arrow 208. In various examples, window 116 can be configured to reflect left-handed circularly polarized light into right-handed circularly polarized light, or vice versa. In some embodiments, quarter-wave plate 114 of optical scanner 100 can be configured to receive a portion of the circularly polarized light 130 that can be reflected by window 116. In some embodiments, quarter-wave plate 114 can be configured to convert the left-handed or right-handed circularly polarized light received from window 116 into vertically polarized light 132. In some embodiments, vertically polarized light 132 can define a direction. In some embodiments, the direction of vertically polarized light 132 can be perpendicular to the axis of linear polarizer 112 (i.e., vertical polarization axis 122). In some embodiments, linear polarizer 112 of optical scanner 100 can be configured to block vertically polarized light 132. In some embodiments, linear polarizer 112 and quarter-wave plate 114 can be configured to prevent back reflection of circularly polarized light 126 from window 116 from reaching aiming light source 108 to prevent aiming ghosting.

[0046] In some embodiments, a method for an optical scanner 100 is disclosed. The method may include one or more operations. At one operation, a sight light source 108 of the optical scanner 100 may be configured to emit highly polarized light 118. The sight light source 108 may correspond to at least a visible laser diode (VLD) light source. The sight light source 108 may be integrated within a sight 102 of the optical scanner 100. At another operation, a linear polarizer 112 located between the sight light source 108 and a window 116 may be configured to convert the highly polarized light 118 received from the sight light source 108 into linearly polarized light 124. At yet another operation, a quarter-wave plate 114 located between the linear polarizer 112 and the window 116 may be configured to convert the linearly polarized light 124 received from the linear polarizer 112 into circularly polarized light 126. The circularly polarized light 126 converted from the linearly polarized light 124 by the quarter-wave plate 114 may correspond to left-handed or right-handed circularly polarized light. The linear polarizer 112 and the quarter-wave plate 114 can be configured to prevent back reflection of the circularly polarized light 126 from the window 116 from reaching the sight light source 108, so as to prevent ghosting of the sight light.

[0047] This disclosure simplifies the prevention of ghosting light from the sight in an optical scanner 100. Embodiments of this disclosure convert linearly polarized light 124 into vertically polarized light using a linear polarizer 112, a quarter-wave plate, and a window 116. This disclosure ensures accurate scanning of one or more visual codes on at least one object.

[0048] Benefiting from the teachings presented in the foregoing description and related drawings, those skilled in the art to which this disclosure pertains will conceive of numerous modifications and other embodiments of the disclosure set forth herein. Therefore, it should be understood that this disclosure is not limited to the specific embodiments disclosed, and that modifications and other embodiments are intended to be included within the scope of the appended claims. Furthermore, although the foregoing description and related drawings have described exemplary embodiments in the context of certain exemplary combinations of elements and / or functions, it should be understood that alternative embodiments may provide different combinations of elements and / or functions without departing from the scope of the appended claims. In this regard, for example, combinations of elements and / or functions different from those explicitly described above are also contemplated, as may be set forth in some of the appended claims. Although specific terminology is used herein, it is used only in a general and descriptive sense and not for limiting purposes.

Claims

1. An optical scanner, comprising: The sight light source is used to emit highly polarized light; window; A linear polarizer, located between the sight light source and the window, wherein the linear polarizer receives the highly polarized light and converts it into linearly polarized light; and A quarter-wave plate is located between the linear polarizer and the window, wherein the quarter-wave plate receives the linearly polarized light and converts it into circularly polarized light; The linear polarizer and the quarter-wave plate prevent the circularly polarized light from the window from being back-reflected to the sight light source, thereby preventing ghosting of the sight light.

2. The optical scanner of claim 1, wherein the aiming light source corresponds to at least a visible laser diode (VLD) light source.

3. The optical scanner according to claim 1 further includes a collimating lens located between the aiming light source and the linear polarizer.

4. The optical scanner of claim 3, wherein the collimating lens collimates the highly polarized light into a parallel beam received by the linear polarizer.

5. The optical scanner of claim 1, wherein the highly polarized light is converted into linearly polarized light having a parallel direction by the linear polarizer.

6. The optical scanner of claim 1, wherein the circularly polarized light converted from the linearly polarized light by the quarter-wave plate corresponds to left-handed or right-handed circularly polarized light.

7. The optical scanner of claim 6, wherein the window reflects left-handed circularly polarized light into right-handed circularly polarized light or reflects right-handed circularly polarized light into left-handed circularly polarized light.

8. The optical scanner of claim 7, wherein the quarter-wave plate converts left-handed or right-handed circularly polarized light received from the window into vertically polarized light.

9. The optical scanner of claim 8, wherein the direction of the vertically polarized light is perpendicular to the axis of the linear polarizer, such that the linear polarizer prevents the vertically polarized light from being reflected back to the sight light source, thereby preventing ghosting of the sight light.

10. The optical scanner of claim 9, wherein the axis of the linear polarizer is positioned to transmit the linearly polarized light with maximum intensity.

11. The optical scanner of claim 9, wherein the quarter-wave plate comprises a first axis and a second axis; and The quarter-wave plate is positioned relative to the linear polarizer such that the first axis and the second axis of the quarter-wave plate each form a 45-degree angle with the axis of the linear polarizer.

12. The optical scanner of claim 3, wherein the sight light source, the collimating lens, the linear polarizer, the quarter-wave plate and the window are located in the same plane and together generate sight light.

13. A method comprising: Highly polarized light is emitted through the aiming light source of the optical scanner; The highly polarized light received from the sight light source is converted into linearly polarized light by a linear polarizer located between the sight light source and the window. and The linearly polarized light received from the linear polarizer is converted into circularly polarized light by a quarter-wave plate located between the linear polarizer and the window. The linear polarizer and the quarter-wave plate prevent the circularly polarized light from the window from being back-reflected to the sight light source, thereby preventing ghosting of the sight light.

14. The method of claim 13, wherein the aiming light source corresponds to at least a visible laser diode (VLD) light source.

15. The method of claim 13, further comprising positioning a collimating lens between the sight light source and the linear polarizer, wherein the collimating lens collimates the highly polarized light into a parallel beam received by the linear polarizer.

16. The method of claim 13, wherein the highly polarized light is converted by the linear polarizer into linearly polarized light having a parallel direction.

17. The method of claim 13, wherein the circularly polarized light converted from the linearly polarized light by the quarter-wave plate corresponds to left-handed or right-handed circularly polarized light.

18. The method of claim 17, further comprising reflecting left-handed circularly polarized light into right-handed circularly polarized light or reflecting right-handed circularly polarized light into left-handed circularly polarized light through the window.

19. The method of claim 17, further comprising converting left-handed or right-handed circularly polarized light received from the window into vertically polarized light via the quarter-wave plate, wherein the direction of the vertically polarized light is perpendicular to the axis of the linear polarizer, such that the linear polarizer prevents the vertically polarized light from being reflected back to the sight light source, thereby preventing ghosting of the sight light, wherein the axis of the linear polarizer is positioned to transmit the linearly polarized light with maximum intensity.

20. The method of claim 19, wherein the quarter-wave plate includes a first axis and a second axis, and wherein the quarter-wave plate is positioned relative to the linear polarizer such that the first axis and the second axis of the quarter-wave plate each form a 45-degree angle with the axis of the linear polarizer.

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