Abstract: A lead frame includes a plurality of lead portions. At least a part of an upper surface of the lead portion and a sidewall surface of the lead portion is a rough surface having been subjected to roughening treatment. A value of a* in a CIELab color space of the rough surface is within a range from 12 to 19, and a value of b* is within a range from 12 to 17.

Abstract: There is provided an image forming apparatus including: a photosensitive member that is driven to rotate; an exposure head that includes a plurality of light-emitting portions arranged at different positions in an axial direction of the photosensitive member, wherein each of pixels of an image corresponding to an output resolution of the image forming apparatus is formed by multiple light-emitting portions of the plurality of light-emitting portions, and a control unit configured to control the number of light-emitting portions to be driven to form each of the pixels of the image based on correction data.

Abstract: An imaging optical system wherein the number of lenses is three to seven, one to four lenses, each of which is an aspheric lens in which radius of curvature of each of both surfaces is infinity in the paraxial region and which has a power of the third-order aberration region in the peripheral area are provided, the first lens from the object side is a negative lens or the aspheric lens, the relationship 0 . 1 ? 8 < ( ? i = 1 i = n ? "\[LeftBracketingBar]" 1 f i ? "\[RightBracketingBar]" ) · f n < 0 . 9 is satisfied where i represents a natural number, fi represents focal length of the i-th lens from the object side, f represents focal length of the whole system and n represents the number of the lenses, and the relationship 40°<HFOV<80° is satisfied where HFOV represents angle that the principal ray of bundle of rays that enters the imaging optical system and reaches the maximum value of image height forms with the optical axis.

Abstract: A lens for headlamps of vehicles provided with a diffraction grating on a surface, wherein a phase function of the diffraction grating is represented by ? ? ( r ) = ? i = 1 N ? ? ? 2 ? i ? r 2 ? i where r represents distance from the central axis of the lens, and the relationship |?2|·(0.3R)2<|?4|·(0.3R)4 is satisfied where R represents effective radius of the lens, and wherein a second derivative of the phase function has at least one extreme value and at least one point of inflection where r is greater than 30% of R, a difference in spherical aberration between the maximum value and the minimum value at any value of r in 0?r?R is equal to or less than the longitudinal chromatic aberration for visible light, the diffraction grating is at least partially on the surface where r is greater than 30%, and the relationship 1 < ? ? ? ( R ) R 2 ? < 10 is satisfied.

Abstract: A diffusion element is configured by combining: a structure for diffusion constituted by combining periodic surface structures having multiple periods to achieve a light intensity distribution in which the light intensity is uniform at angles less than or equal to a predetermined diffusion angle ? and the light intensity is as close as possible to zero intensity at angles greater than the diffusion angle ?; and a diffractive structure having a period of 1 or more and 2 or less times of ?max, where ?max is the maximum period of the structure for diffusion.

Abstract: A diffuser provided with plural shapes obtained by translation on an xy plane of at least one of z=g(x, y) and z=?g(x, y), z=g(x, y) being a smooth function within a rectangle having sides of length of s in x direction and sides of length of t in y direction, the origin being the center of the rectangle, wherein on the sides of the rectangle, g ? ( x , y ) = 0 , ? ? g ? ( x , y ) ? x = 0 , ? ? g ? ( x , y ) ? y = 0 , ? ? 2 ? g ? ( x , y ) ? x 2 = 0 , and ? 2 ? g ? ( x , y ) ? y 2 = 0 , and wherein z=g(x, y) has a single vertex at (xv,yv) g(x,y)=h1(x)·h2(y), first derivative of z=h1(x) is continuous in ( - s 2 , s 2 ) , second derivative of z=h1(x) has a single point of discontinuity in ( - s 2 , x v ) and ? ( x v , s 2 ) , first derivative of z=h2(y) is continuous in ( - t 2 , t 2 ) , and second derivative of z=h2(y) has a single

Abstract: The optical system includes an optical element having a curvature in a first direction alone; and first and second lens array surfaces. Each of the lens array surfaces is provided with plural toroidal lens surfaces arranged in a second direction orthogonal to the first direction, the plural lens surfaces have a curvature mainly in the second direction, any lens surface on one of the lens array surfaces corresponds to one of the toroidal lens surfaces on the other, the direction of a first straight line connecting the vertexes of two toroidal lens surfaces corresponding to each other is orthogonal to the second direction, and in a cross section containing the first straight line and a second straight line that is in the second direction, one of the two toroidal lens surfaces is configured so as to form an imaging surface of the other for the object point at infinity.

Abstract: An illumination optical system having a light source and a single convex lens with a diffractive structure, wherein the phase function of the diffractive structure is represented by ? ? ( r ) = ? i = 1 N ? ? ? 2 ? i ? r 2 ? i where r represents distance from the central axis of the lens, the relationship |?2|·(0.3R)2<|?4|·(0.3R)4 is satisfied where R represents effective radius of the lens, the second derivative of the phase function has at least one extreme value and at least one point of inflection where r is greater than 30% of R, and the area of a surface of the light source is equal to or greater than 3% of the area of the entrance pupil when the light source side of the lens is defined as the image side.

Abstract: An illumination optical system having a light source and a single convex lens with a diffractive structure, wherein the phase function of the diffractive structure is represented by ? ? ( r ) = ? i = 1 N ? ? ? 2 ? i ? r 2 ? i where r represents distance from the central axis of the lens, the relationship |?2|·(0.3R)2<|?4|·(0.3R)4 is satisfied where R represents effective radius of the lens, the second derivative of the phase function has at least one extreme value and at least one point of inflection where r is greater than 30% of R, and the area of a surface of the light source is equal to or greater than 3% of the area of the entrance pupil when the light source side of the lens is defined as the image side.

Abstract: A diffusion element is configured by combining: a structure for diffusion constituted by combining periodic surface structures having multiple periods to achieve a light intensity distribution in which the light intensity is uniform at angles less than or equal to a predetermined diffusion angle ? and the light intensity is as close as possible to zero intensity at angles greater than the diffusion angle ?; and a diffractive structure having a period of 1 or more and 2 or less times of ?max, where ?max is the maximum period of the structure for diffusion.

Abstract: The imaging optical system is provided with a first lens having a negative refractive power, a second lens having a positive refractive power, an aperture stop, and a third lens having a positive refractive power, disposed from the object side to the image side. With |d| being the distance between the image-side principal point of the first lens and the object-side principal point of the second lens, d=?|d| being the signed distance between the image-side principal point of the first lens and the object-side principal point of the second lens when the image-side principal point of the first lens is further towards the image side than the object-side principal point of the second lens, and f12 being the composite focal length of the first lens and the second lens, the relationships d<0 and 0.005<d/f12<16 are established.

Abstract: A diffuser provided with plural shapes obtained by translation on an xy plane of at least one of z=g(x, y) and z=?g(x, y), z=g(x, y) being a smooth function within a rectangle having sides of length of s in x direction and sides of length of t in y direction, the origin being the center of the rectangle, wherein on the sides of the rectangle, g ? ( x , y ) = 0 , ? ? g ? ( x , y ) ? x = 0 , ? ? g ? ( x , y ) ? y = 0 , ? ? 2 ? g ? ( x , y ) ? x 2 = 0 , and ? 2 ? g ? ( x , y ) ? y 2 = 0 , and wherein z=g(x, y) has a single vertex at (xv,yv) g(x,y)=h1(x)·h2(y), first derivative of z=h1(x) is continuous in ( - s 2 , s 2 ) , second derivative of z=h1(x) has a single point of discontinuity in ( - s 2 , x v ) and ? ( x v , s 2 ) , first derivative of z=h2(y) is continuous in ( - t 2 , t 2 ) , and second derivative of z=h2(y) has a sin

Abstract: A lens for headlamps of vehicles provided with a diffraction grating on a surface, wherein a phase function of the diffraction grating is represented by ? ? ( r ) = ? i = 1 N ? ? ? 2 ? i ? r 2 ? i where r represents distance from the central axis of the lens, and the relationship |?2|·(0.3R)2<|?4|·(0.3R)4 is satisfied where R represents effective radius of the lens, and wherein a second derivative of the phase function has at least one extreme value and at least one point of inflection where r is greater than 30% of R, a difference in spherical aberration between the maximum value and the minimum value at any value of r in 0?r?R is equal to or less than the longitudinal chromatic aberration for visible light, the diffraction grating is at least partially on the surface where r is greater than 30%, and the relationship 1 < ? ? ? ( R ) R 2 ? < 10 is satisfied.

Abstract: A microlens array includes N microlenses arranged in a predetermined direction on an x-y plane. A projection onto the x-y plane of the vertex of each microlens is arranged in the vicinity of a lattice point of a reference lattice on the x-y plane, the lattice spacing of the reference lattice in the predetermined direction being D/M (millimeters) where M is a positive integer. A distance between two sides of a lens facing each other is approximately equal to D, and a distance between the projection onto the x-y plane of the vertex of the lens and the projection onto the x-y plane of a side of the lens is D/2+?i. Letting n represent the refractive index of the material of each microlens and letting f (millimeters) represent the focal length of each microlens, the following relationships are satisfied. 0.0042 D < D 2 ? ? f = D ? ( n - 1 ) 2 ? ? R 0.0048 ? f ? { 1 + ( D / 2 ? ? f ) 2 } < ? < 0.

Abstract: A microlens array, each microlens containing N sides of a convex polygon and N curved surfaces corresponding to the sides, wherein when the line passing through the microlens vertex and perpendicular to the polygon plane is z axis, the line passing through the intersection point (origin) between z axis and the plane and perpendicular to a side is x axis, z coordinate of the curved surface corresponding to the side is z=f(x), a distance from the origin to the side is t, a virtual curved surface in 0?|x|?t is z=F(x), refractive index of the microlens is no, A and C represents constants, and g ? ( x ) = dF ? ( x ) dx = - x ? x ? · Cx 2 + A n 0 ? 1 + ( Cx 2 + A ) 2 - 1 , ? g ? ( x ) - 0.035 ? df ? ( x ) dx ? g ? ( x ) + 0.035 is satisfied and f (x) is determined such that an illuminance distribution in an illuminated area is more uniform than that in the case that the curved surface is shaped in a segment of a circle.

Abstract: A diffuser is provided with a recess-protrusion structure formed on a plane. When a z-axis is defined as a normal to the plane, an x-axis is defined on the plane, the x-axis is divided into plural intervals, Snx represents length of an interval nx, Sx-max and Sx-min represent the maximum and the minimum of Snx, respectively, the relationship 2<Sx-max/Sx-min holds, Snx varies on a random basis between Sx-min and Sx-max, in an xz cross section, a recess portion and a protrusion portion are formed on each of adjacent intervals along the x-axis, respectively, and when dznx represents a difference between the maximum and the minimum of z coordinate of the recess-protrusion structure in the interval nx in the xz cross section, Anx represents a ratio between dznx and Snx, Anx-max and Anx-min represent the maximum and the minimum of Anx, the relationship Ax-max/Ax-min<1.3 holds.

Abstract: The imaging optical system is provided with a first lens having a negative refractive power, a second lens having a positive refractive power, an aperture stop, and a third lens having a positive refractive power, disposed from the object side to the image side. With |d| being the distance between the image-side principal point of the first lens and the object-side principal point of the second lens, d=?|d| being the signed distance between the image-side principal point of the first lens and the object-side principal point of the second lens when the image-side principal point of the first lens is further towards the image side than the object-side principal point of the second lens, and f12 being the composite focal length of the first lens and the second lens, the relationships d<0 and 0.005<d/f12<16 are established.

Abstract: A sliding bearing may include vertically-arranged half members obtained by halving a cylinder, wherein a narrow groove is provided circumferentially to both axial direction ends of a lower half member at a downstream side of a rotational direction. A peripheral section may be formed on a surface on an outer side of the narrow groove. The peripheral section may be formed to have a height from an outer peripheral surface of the half member that is shorter than a height of a contact surface from an outer peripheral surface of the half member. An inclined part that is inclined toward an inner peripheral side is provided to a downstream side end, of the narrow groove, and a coating layer is provided to an inner peripheral surface of the half member only part of an inner peripheral surface of the narrow groove including an inner peripheral surface of the inclined part.

Abstract: A manufacturing method for a sliding bearing including half members, obtained by splitting a cylinder in half in a direction parallel with an axial direction, arranged in an upper and lower direction, may include a first step including forming a narrow groove extending in the circumference direction on an axial direction end of one of the half members on a lower side, on a downstream side in a rotation direction, a second step including performing shot blasting on a surface of the narrow groove; and a third step including forming coating layers on a surface of the half member. The coating layers may be formed only on an upstream-side end and a downstream-side end as parts of the narrow groove.

Abstract: It is possible to provide a sliding bearing that can obtain a friction reduction effect, and can suppress the total amount of outflow oil.