An illumination apparatus for reducing speckle effect in light reflected off an illumination target (120, 130, 290), the apparatus comprising: a light source (150, 210) configured to emit coherent light (152, 212); a linear diffuser (157, 270) positioned on an optical path between an illumination target (120+130, 290) and the light source (150, 210), the linear diffuser (157, 270) being configured to diffuse the coherent light (152, 212) into diffused light (330F, 340F, 350F) that spreads in one dimension across at least a portion of the illumination target (120+130, 290), which has an associated exposure time for illumination of the illumination target (120+130, 290) by the diffused light (330F, 340F, 350F), wherein the diffused light (330F, 340F, 350F) forms a planar fan of light (158, 280) that is generally free of broadening in a direction perpendicular to the one dimension; a beam deflector (153, 220) positioned between the light source (150, 210) and the linear diffuser (157, 270) on the optical path; a cylinder lens (156, 250) positioned on the optical path and configured to operate as a field lens, wherein the cylinder lens (156, 250) is distinct from the linear diffuser (157, 270), and wherein the cylinder lens (156, 250) is positioned in the optical path between the linear diffuser (157, 270) and the beam deflector (153, 220) and transmits the coherent light (152, 212) to the linear diffuser (157, 270); and a controller (155, 240) coupled with the beam deflector (153, 220); wherein the controller (155, 240) is configured to operate the beam deflector (153, 220) to direct the coherent light (152, 212) incident on the beam deflector (153, 220) to sweep across different locations on the linear diffuser (157, 270) within the exposure time for illumination of the illumination target (120+130, 290) by the diffused light (330F, 340F, 350F); wherein the different locations span a distance across the linear diffuser (157, 270) that provides sufficient uncorrelated speckle patterns at an image sensor in light reflected from an intersection (159, 260) of the planar fan of light (158, 280) with the illumination target (120+130, 290) so that the uncorrelated speckle patterns add incoherently when imaged by the image sensor within the exposure time for illumination of the illumination target (120+130, 290) by the diffused light (330F, 340F, 350F) to significantly average to a smooth line; wherein the cylinder lens is configured to maintain the intersection (159, 260) of the planar fan of light (158, 280) with the illumination target (120+130, 290) substantially stationary on the illumination target (120+130, 290). a light source (150, 210) configured to emit coherent light (152, 212); a linear diffuser (157, 270) positioned on an optical path between an illumination target (120+130, 290) and the light source (150, 210), the linear diffuser (157, 270) being configured to diffuse the coherent light (152, 212) into diffused light (330F, 340F, 350F) that spreads in one dimension across at least a portion of the illumination target (120+130, 290), which has an associated exposure time for illumination of the illumination target (120+130, 290) by the diffused light (330F, 340F, 350F), wherein the diffused light (330F, 340F, 350F) forms a planar fan of light (158, 280) that is generally free of broadening in a direction perpendicular to the one dimension; a beam deflector (153, 220) positioned between the light source (150, 210) and the linear diffuser (157, 270) on the optical path; a cylinder lens (156, 250) positioned on the optical path and configured to operate as a field lens, wherein the cylinder lens (156, 250) is distinct from the linear diffuser (157, 270), and wherein the cylinder lens (156, 250) is positioned in the optical path between the linear diffuser (157, 270) and the beam deflector (153, 220) and transmits the coherent light (152, 212) to the linear diffuser (157, 270); and a controller (155, 240) coupled with the beam deflector (153, 220); wherein the controller (155, 240) is configured to operate the beam deflector (153, 220) to direct the coherent light (152, 212) incident on the beam deflector (153, 220) to sweep across different locations on the linear diffuser (157, 270) within the exposure time for illumination of the illumination target (120+130, 290) by the diffused light (330F, 340F, 350F); wherein the different locations span a distance across the linear diffuser (157, 270) that provides sufficient uncorrelated speckle patterns at an image sensor in light reflected from an intersection (159, 260) of the planar fan of light (158, 280) with the illumination target (120+130, 290) so that the uncorrelated speckle patterns add incoherently when imaged by the image sensor within the exposure time for illumination of the illumination target (120+130, 290) by the diffused light (330F, 340F, 350F) to significantly average to a smooth line; wherein the cylinder lens is configured to maintain the intersection (159, 260) of the planar fan of light (158, 280) with the illumination target (120+130, 290) substantially stationary on the illumination target (120+130, 290).