Abstract: A lens system includes a plurality of lens elements arranged from an object side to an image plane side, and a diaphragm arranged between the plurality of lens elements. The plurality of lens elements include a plurality of freeform lenses each having a freeform surface that is asymmetrical with respect to a first direction and a second direction which cross with each other. At least one freeform lens is placed on the image plane side of the diaphragm. With a lens thickness T1 in the first direction at a maximum height of an axial ray and a lens thickness T2 in the second direction at the maximum height of the axial ray, at least one freeform lens satisfying 0.3<T1/T2<0.76 is placed on the object side of the diaphragm.

Abstract: A lens system includes lens elements and a diaphragm. The lens elements include freeform lenses each having a freeform surface asymmetrical with respect to first and second directions. At least one freeform lens is placed on the image plane side of the diaphragm. The lens system satisfies a following conditional expression (1); 0.0075 < ? ? k = 1 N ? { ( SAG ? ? 1 k - SAG ? ? 2 k ) × ? ? ? nd k } Y ? ? 2 × tan ? ? ? ? ? 1 ? ( 1 ) where N: a total number of the freeform surfaces on the object side of the diaphragm, k: a number indicating a freeform surface among the N freeform surfaces, SAG1k, SAG2k: a sag amount at a position where a height of a k-th freeform surface in the first or second direction is 40% of an image height in the first direction, Y2: an image height in the second direction, ?1: a full angle of view in the first direction, and ?ndk: a difference between refractive indexes on the both sides of the k-th freeform surface.

Abstract: The reading device of the present disclosure includes a housing, a first irradiation part, an imaging device, and a first diffusion part. The housing has an opening in an upper portion with a transparent reading window member. The first irradiation part emits an infrared light. The imaging device is disposed on a bottom portion such that an optical axis is directed to a reading window member. The first diffusion part is disposed on a left side wall connecting the upper and bottom portions. The first diffusion part diffuses the infrared light. The first diffusion part is made up of a light-transmitting first diffusion plate and a light-transmitting second diffusion plate. The first diffusion plate is disposed on the bottom surface side and inclined toward the upper portion. The second diffusion plate is disposed on the upper surface side and inclined toward the bottom portion.

Abstract: A reading device includes a housing, an imaging unit, a reading lighting unit, a guiding unit, and a guiding lighting unit. The housing has an opening covered with a transparent opening cover. An imaging unit is disposed inside the housing. The reading lighting unit illuminates the opening cover from inside the housing. The guiding unit is provided on the same plane as the opening cover at a position separated from the opening cover. The guiding lighting unit emits light from the guiding unit to the outside of the housing.

Abstract: The reading device of the present disclosure includes a housing, a first irradiation part, an imaging device, and a first diffusion part. The housing has an opening in an upper portion with a transparent reading window member. The first irradiation part emits an infrared light. The imaging device is disposed on a bottom portion such that an optical axis is directed to a reading window member. The first diffusion part is disposed on a left side wall connecting the upper and bottom portions. The first diffusion part diffuses the infrared light. The first diffusion part is made up of a light-transmitting first diffusion plate and a light-transmitting second diffusion plate. The first diffusion plate is disposed on the bottom surface side and inclined toward the upper portion. The second diffusion plate is disposed on the upper surface side and inclined toward the bottom portion.

Abstract: A reading device includes a housing, an imaging unit, a reading lighting unit, a guiding unit, and a guiding lighting unit. The housing has an opening covered with a transparent opening cover. An imaging unit is disposed inside the housing. The reading lighting unit illuminates the opening cover from inside the housing. The guiding unit is provided on the same plane as the opening cover at a position separated from the opening cover. The guiding lighting unit emits light from the guiding unit to the outside of the housing.

Abstract: A lens system according to the present disclosure includes a plurality of lens groups, each having at least one lens element, the lens system including, in order from an object side to an image side, a first lens group that is fixed with respect to an image plane in focusing from an infinity in-focus condition to a close-object in-focus condition; an aperture diaphragm; a second lens group that moves in a direction of an optical axis in the focusing; a third lens group that is fixed with respect to the image plane in the focusing; a fourth lens group that moves in the direction of the optical axis in the focusing; and a lens group closest to the image side, wherein the following conditions (1) and (2) are satisfied: 2.5<|f2/f4|<6.5 ??(1) 0.5<|f/f4|<1.5 ??(2) where f2 is a focal length of the second lens group, f4 is a focal length of the fourth lens group, and f is a focal length of the entire optical system in an infinity in-focus condition.

Abstract: A lens system including: a positive most-object-side lens unit; a first most-image-side lens element; and a second most-image-side lens element, wherein the most-object-side lens unit is fixed in focusing, at least one of the first and second most-image-side lens elements has negative optical power, and the conditions: 0.5<DAIR/Y and 1.5<DIM/DOB<4.0 (DAIR: maximum value of air spaces between the lens elements constituting the lens system in an infinity in-focus condition, Y=f×tan ?, f: focal length of the lens system, ?: half view angle of the lens system, DOB: optical axial thickness of the most-object-side lens unit, DIM: optical axial distance from an object side surface of a most-object-side lens element in a lens unit located immediately on the image side relative to the most-object-side lens unit, to an image side surface of the first most-image-side lens element) are satisfied.

Abstract: An inner focus lens system comprising lens units each composed of at least one lens element, wherein a most object side lens unit is provided and is fixed with respect to an image surface in focusing, and the conditions: BF/Y<1.7 and (L×FNo)/f<2.2 (BF: a distance from an image side surface apex of a most image side lens element to the image surface, Y=f ×tan ?, L: an overall length of lens system, FNo: a F-number of lens system,f: a focal length of lens system, ?: a half view angle of lens system) are simultaneously satisfied, or only the condition: (L×FNo)/f<2.0 (L: the overall length of lens system, FNo: the F-number of lens system,f: the focal length of lens system) is satisfied.

Abstract: A light emitting device including a lens in which light radiated from a light source with a wide angle can effectively be oriented while a directional characteristic of the light source is expanded is provided, and a surface light source including the light emitting devices and a liquid crystal display device are provided. The surface light source is configured such that the plural light emitting devices are disposed in a central portion thereof. The light emitting device radiates the light on an optical axis A and around the optical axis A. The light emitting device includes a light source and a lens that radially expands the light from the light source. The lens includes a reflection unit at a bottom surface of the lens partially.

Abstract: A light emitting device (1) is configured to radiate light with an optical axis A at the center, and is provided with a light source (2), and a lens (3) that radially expands the light from light source (2). The light source (2) has a light emitting surface (21) extending in an X direction orthogonal to the optical axis A. The lens (3) is configured to have a greater refractive power in a Y direction orthogonal to the X direction than in the X direction. For example, the lens (3) has a light entrance surface (31) including an anamorphic curved surface with different curve forms between the X direction and the Y direction.

Abstract: An illuminating lens (1) includes a light entrance surface (11), a light exit surface (12), and a bottom surface (13). The light entrance surface (11) has a first light entrance surface (111) and a second light entrance surface (112). The first light entrance surface (111) is a curved surface convex toward the light exit surface (12) and perpendicularly intersecting an optical axis A, and the second light entrance surface (112) extends outwardly from an edge of the first light entrance surface (111) and is connected obliquely to an inner edge of the bottom surface (13).

Abstract: An inner focus lens system comprising lens units each composed of at least one lens element, wherein a most object side lens unit is provided and is fixed with respect to an image surface in focusing, and the conditions: BF/Y<1.7 and (L×FNo)/f<2.2 (BF: a distance from an image side surface apex of a most image side lens element to the image surface, Y=f×tan ?, L: an overall length of lens system, FNo: a F-number of lens system, f: a focal length of lens system, ?: a half view angle of lens system) are simultaneously satisfied, or only the condition: (L×FNo)/f<2.0 (L: the overall length of lens system, FNo: the F-number of lens system, f: the focal length of lens system) is satisfied.

Abstract: The present invention relates to a surface light source, including a light source section made up of plural light emitting diodes and lenses that expand light from these light emitting diodes. The lens in the light source section has a light incident surface on which light from the light emitting diode is incident with an optical axis at a center, and a light exit surface that expands and emits the incident light. The light incident surface has a continued depressed surface, while the light exit surface has a continued projected surface.

Abstract: A light exit surface of an illuminating lens has a first light exit surface and a second light exit surface. The first light exit surface is recessed toward a point on the optical axis, and the second light exit surface extends outwardly from the periphery of the first light exit surface. The first light exit surface has a transmissive region and a total reflection region. When the position of a light source on the optical axis is defined as a starting point, the transmissive region transmits light that has been emitted from the starting point at a relatively small angle with respect to the optical axis, and the total reflection region totally reflects light that has been emitted from the starting point at a relatively large angle with respect to the optical axis.

Abstract: An illuminating lens includes a main body and a ring portion. The main body has a light exit surface, and the light exit surface has a first light exit surface recessed toward a point on the optical axis and a second light exit surface extending outwardly from the periphery of the first light exit surface. The first light exit surface has a transmissive region in the center thereof, and a total reflection region on the peripheral side thereof. The ring portion has a back surface configured to guide the light that has been emitted from a light source, totally reflected repeatedly at the light exit surface, and then entered the ring portion to an end surface by total reflection.

Abstract: A light exit surface of an illuminating lens has a first light exit surface and a second light exit surface. The first light exit surface is recessed toward a point on the optical axis, and the second light exit surface extends outwardly from the periphery of the first light exit surface. The first light exit surface has a transmissive region and a total reflection region. When the position of a light source on the optical axis is defined as a starting point, the transmissive region transmits light that has been emitted from the starting point at a relatively small angle with respect to the optical axis, and the total reflection region totally reflects light that has been emitted from the starting point at a relatively large angle with respect to the optical axis. A reflective layer is formed on a bottom surface that surrounds a light entrance surface and faces oppositely to the light exit surface.

Abstract: A zoom lens system, in order from an object side to an image side, comprising a first lens unit having negative optical power, a second lens unit having positive optical power, a third lens unit having positive optical power, and a fourth lens unit having positive optical power, wherein in zooming, the intervals between the respective lens units vary, the third lens unit comprises a plurality of lens elements, and the condition (I-1): 0.47<|f31/fG3|<1.00 (fT/fW>2.

Abstract: An illuminating lens has a light entrance surface and a light exit surface. The light exit surface has a first light exit surface recessed toward a point on an optical axis A and a second light exit surface extending outwardly from the periphery of the first light exit surface. The first light exit surface includes a transmissive region located in the center of the first light exit surface and a total reflection region located around the transmissive region. The transmissive region transmits light that has been emitted from a starting point Q, which is the position of a light source on the optical axis A, at a relatively small angle with respect to the optical axis A. The total reflection region totally reflects light that has been emitted from the starting point Q at a relatively large angle with respect to the optical axis A.

Abstract: An illuminating lens includes a light entrance surface, a light exit surface, and a reversing surface. The light exit surface has a first light exit surface and a second light exit surface. The first light exit surface is recessed toward a point on the optical axis, and the second light exit surface extends outwardly from the periphery of the first light exit surface. The first light exit surface includes a transmissive region in the center thereof and a total reflection region on the peripheral side thereof. The reversing surface has a shape such that the light that has been emitted from the light source, totally reflected repeatedly at the light exit surface, and then reached the reversing surface is guided to the first light exit surface by total reflection.