Abstract: An optical scanning device scanning scan target surfaces in a first direction with light includes: a light source emitting first and second light beams corresponding to two of the scan target surfaces; an optical deflector including a reflection surface on which the emitted first and second light beams are obliquely incident while being separated from each other in a second direction perpendicular to the first direction, and deflecting the first and second light beams; a scanning lens disposed on respective optical paths of the deflected first and second light beams; and a branching optical element transmitting therethrough most of the first light beam transmitted through the scanning lens, and reflecting most of the second light beam transmitted through the scanning lens. The deflected first and second light beams intersect between the optical deflector and the branching optical element, when projected on a plane perpendicular to the first direction.

Abstract: An optical scanning device separately scanning plural scan target surfaces in a first direction with light includes: a light source unit configured to emit first and second light beams mutually different in polarization state; an optical deflector configured to rotate around an axis parallel to a second direction perpendicular to the first direction, and deflect the emitted light beams; an imaging optical element provided on respective optical paths of the deflected light beams; a polarization adjustment element provided on the optical paths of the light beams transmitted through the imaging optical element, and configured to correct respective changes in polarization state of the light beams occurring during the transmission of the light beams through the imaging optical element; and a polarization separation element provided on the optical paths of the light beams emitted from the polarization adjustment element, and configured to separate the light beams from each other.

Abstract: An optical scanning apparatus includes a semiconductor laser and a first optical element that are fixed on a single continuous member. A second optical element, which is a diffraction optical element, has a diffracting surface in which a plurality of elliptical grooves is formed and which includes a diffracting portion power such that a change in the beam waist position in a main scan direction and a sub-scan direction due to temperature variation in the optical scanning apparatus becomes substantially zero. The member on which the semiconductor laser and the first optical element are fixed has a linear coefficient of expansion such that the change in the beam waist position becomes substantially zero even when there is temperature variation.

Abstract: In an optical scanning device including a vertical cavity surface emitting laser (VCSEL), an optical scanning device controls so as to satisfy P1<P100 and Wm>Ws, where P1 is light intensity obtained when a period of time corresponding to a minimum pixel unit (referred to as “T1”) has elapsed after start of illumination; P100 is light intensity obtained when a period of time 100 T1 has elapsed after the start of illumination; Wm is the static beam spot diameter in the main-scanning direction; and Ws is the static beam spot diameter in the sub-scanning direction.

Abstract: A communications device is provided which receives data frames in FIR communications mode even if the device has failed to normally receive a connect frame in SIR communications mode. A communications device according to the invention includes an incoming frame processing section for receiving an SNRM frame and UI frames in different frame formats. The SNRM frame contains a setting for a connection for data communications. The UI frames contain data. The communications device also includes a reception processing section and connect command notification sections. The reception processing section renders a light reception section stand by for reception of the UI frames in FIR communications mode. The connect command notification sections generate a connect command for output to an upper layer. The connect command enables establishing of the same connection when a data frame is received from another communications device as when a connect frame was received from the other communications device.

Abstract: An optical scanning device that scans a scanning surface in a main scanning direction. The device includes a surface emitting laser as a light source, an optical deflector that deflects a light flux from the light source while rotating around a rotation axis, a monitor light receiving element, a synchronization detection light receiving element, a monitor optical system that directs the monitor light flux to the monitor light receiving element, a synchronization detection optical system that directs the synchronization detection light flux to the synchronization detection light receiving element, and a scanning optical system that directs a scanning light flux to the scanning surface. A combined focal length of the monitor optical system in the main scanning direction is smaller than a combined focal length of the synchronization detection optical system in the main scanning direction.

Abstract: An optical scanning device includes a first optical system for guiding light beams emitted from a plurality of light emitting units to an optical deflector, and a second optical system for focusing the light beams to optically scan a surface to be scanned. At least one of the first optical system and the second optical system includes a resin lens having a diffractive surface. The diffractive surface includes a diffractive portion and a refractive portion. A power of the diffractive portion and a power of the refractive portion cancel each other.

Abstract: An optical scanning device includes a first optical system for guiding light beams emitted from a plurality of light emitting units to an optical deflector, and a second optical system for focusing the light beams to optically scan a surface to be scanned. At least one of the first optical system and the second optical system includes a resin lens having a diffractive surface. The diffractive surface includes a diffractive portion and a refractive portion. A power of the diffractive portion and a power of the refractive portion cancel each other.

Abstract: A test apparatus provided in common for a plurality of memories under test, comprising an address generating section that sequentially generates addresses to be tested in the memories under test and a plurality of buffer memories that are provided to correspond respectively to the memories under test and that each store addresses to be independently supplied to the corresponding memory under test. The test apparatus (i) compares block data output by a memory under test in response to a read command to an expected value of this block data, for each generated address, (ii) sequentially stores, in the corresponding buffer memory and in response to detection of a discrepancy in the comparison, the address generated for reading the block data, and (iii) writes, in parallel to the plurality of memories under test, disable data that includes, as individual addresses, the addresses stored in the buffer memory.

Abstract: An optical scanning device includes a vertical cavity surface emitting laser, a driving unit that controls modulation driving, a coupling optical system that couples a beam, an aperture that is configured to define a beam spot diameter, a deflecting unit that deflects a laser beam incoming, and a scanning optical system that guides the laser beam, wherein the driving unit controls so as to satisfy conditions 1 and 2 below: condition 1: P1>P100, condition 2: Wm<Ws, where P1 is an amount of light at a time after a period T1 corresponding to a minimum pixel unit has elapsed since beginning of light emission, P100 is an amount of light at a time after a time period of 100×T1 has elapsed since the beginning of light emission, Wm is a static beam spot diameter in a main-scanning direction, and Ws is a static beam spot diameter in a sub-scanning direction.

Abstract: An optical scanning device includes a first optical system for guiding light beams emitted from a plurality of light emitting units to an optical deflector, and a second optical system for focusing the light beams to optically scan a surface to be scanned. At least one of the first optical system and the second optical system includes a resin lens having a diffractive surface. The diffractive surface includes a diffractive portion and a refractive portion. A power of the diffractive portion and a power of the refractive portion cancel each other.

Abstract: An optical scanning device includes: a vertical cavity surface emitting laser; a driving unit that controls modulation driving; a coupling optical system that couples a beam; an aperture that is configured to define a beam spot diameter; a deflecting unit that deflects a laser beam incoming; and a scanning optical system that guides the laser beam, wherein the driving unit controls so as to satisfy conditions 1 and 2 below: condition 1: P1>P100 condition 2: Wm<Ws where P1 is an amount of light at a time after a period T1 corresponding to a minimum pixel unit has elapsed since beginning of light emission, P100 is an amount of light at a time after a time period of 100×T1 has elapsed since the beginning of light emission, Wm is a static beam spot diameter in a main-scanning direction, and Ws is a static beam spot diameter in a sub-scanning direction.

Abstract: A light source device includes a surface emitting laser, a surface emitting laser holding unit on which the surface emitting laser is mounted, a parallel plate that is arranged on a light path of a light flux from the surface emitting laser so that the light flux enters into one surface thereof, and that is made of a transparent material, and a holder having a through hole that functions as a light path of the light flux from the surface emitting laser, wherein the surface emitting laser holding unit is brought into contact with the holder, the parallel plate is fixedly bonded to the holder, and a part of the through hole of the holder is sealed with the surface emitting laser holding unit and the parallel plate.

Abstract: F-theta lenses, included in scanning lens systems, are arranged on a main scanning plane facing an optical deflector and substantially linearly symmetrically on the main scanning plane with reference to a rotational center of the optical deflector. Each f-theta lens has a no-power portion in the main scanning direction. Synchronization-detecting light passes through the no-power portion of the f-theta lens, thus enabling reduction in color shift due to temperature variation in an image forming apparatus without increasing the cost and complexity in controlling color shift.

Abstract: A multi-beam scanning device is disclosed that is able to realize a stable and small beam spot and realize stable scanning line intervals between plural light beams. The multi-beam optical scanning device includes a first optical system which has a first lens for coupling the light beams from the light sources, and a second lens which is an anamorphic element having power at least in a sub scanning direction and for guiding the light beams from the first lens to the deflection unit; and a second optical system. At least the second lens includes a diffracting surface having power.

Abstract: In an optical scanning device including a vertical cavity surface emitting laser (VCSEL), an optical scanning device controls so as to satisfy P1<P100 and Wm>Ws, where P1 is light intensity obtained when a period of time corresponding to a minimum pixel unit (referred to as “T1”) has elapsed after start of illumination; P100 is light intensity obtained when a period of time 100 T1 has elapsed after the start of illumination; Wm is the static beam spot diameter in the main-scanning direction; and Ws is the static beam spot diameter in the sub-scanning direction.

Abstract: A diffractive-optical element that is transparent includes a diffraction surface that is formed by a step. A width of the step is set substantially equal to a common multiple of ?i/{n(?i)?1} for two or more wavelengths, where ?i (i=1, 2, . . . ) is a wavelength and n(?i) is a refractive index with respect to the wavelength ?i.

Abstract: An optical axis of at least one surface of a resin-made diffracting lens is shifted in a main scanning direction with respect to an incident beam. A synchronous detection can cancel a problem of a misalignment in the main scanning direction due to a temperature variation. A light reflected from a second surface of the resin-made diffractive lens condenses on a position that is displaced in an optical axis direction from an optical beam outgoing point of a semiconductor laser, and thereby the light reflected again from the semiconductor laser does not form an image on a scanned surface and an impact on the image becomes low.

Abstract: Provided is a test apparatus provided in common for a plurality of memories under test, comprising an address generating section that sequentially generates addresses to be tested in the memories under test and a plurality of buffer memories that are provided to correspond respectively to the plurality of memories under test and that each store addresses to be independently supplied to the corresponding memory under test. The test apparatus (i) compares block data output by the corresponding memory under test in response to the read command to an expected value of this block data, for each generated address, (ii) sequentially stores, in the buffer memory provided corresponding to each memory under test and in response to detection of a discrepancy in the comparison, the address generated for reading the block data, and (iii) writes, in parallel to the plurality of memories under test, a disable data that includes, as individual addresses, the addresses stored in the buffer memory.

Abstract: An optical scanning device includes a light source having light emitting points for emitting light beams, a coupling optical element that couples the light beams, a deflecting unit that deflects and scans the light beams, and a scanning optical system that focus the light beams to form an image. The optical scanning device satisfies the following condition: F tan(?/2)+A<D/0.7 where A is the maximum distance between the light emitting points and an optical axis of the coupling optical element, ? is a divergence angle (full-width half-maximum) of the light beams, F is a focal length of. the coupling optical element, and D is an effective radius of the coupling optical element.