摘要:
Control operations to access a memory changes respective priorities of the operations depending on the situation of the memory, and the operations are arbitrated and scheduled according to the respective, changed priorities, in order to avoid concentration on or rejection of a specific memory access operations and to eliminate an ineffective period. This realizes an efficient memory system without increasing the capacity of a buffer memory, the width of a memory bus, or an operating frequency.
摘要:
An eye examination apparatus includes an accommodation power acquisition unit, a corrected accommodation power calculation unit, a drive unit and an accommodative microfluctuation measurement unit. The accommodation power acquisition unit acquires an accommodation power which is determined from a difference between a near point and a distant point of an examined eye. The corrected accommodation power calculation unit calculates an integrated value of the accommodation power and a correction coefficient. The drive unit drives a vision target in a direction of an optical axis of the examined eye. The accommodative microfluctuation measurement unit controls the drive unit to cause the vision target to be arranged onto a corrected accommodation position corresponding to the integrated value, such that the accommodative microfluctuation measurement unit measures an eye accommodation function based on a frequency of appearance of a high frequency component representative of ciliary body accommodative microfluctuation.
摘要:
An eye examination apparatus includes an accommodation power acquisition unit, a corrected accommodation power calculation unit, a drive unit and an accommodative microfluctuation measurement unit. The accommodation power acquisition unit acquires an accommodation power which is determined from a difference between a near point and a distant point of an examined eye. The corrected accommodation power calculation unit calculates an integrated value of the accommodation power and a correction coefficient. The drive unit drives a vision target in a direction of an optical axis of the examined eye. The accommodative microfluctuation measurement unit controls the drive unit to cause the vision target to be arranged onto a corrected accommodation position corresponding to the integrated value, such that the accommodative microfluctuation measurement unit measures an eye accommodation function based on a frequency of appearance of a high frequency component representative of ciliary body accommodative microfluctuation.
摘要:
A warm air generating apparatus includes: a blowing apparatus for generating an air flow in a predetermined direction; a heating member disposed on a flow path of the air flow for heating air; a temperature detection member that has a heat sensing portion and detects a temperature of the heating member; and a biasing member for applying a biasing force that causes the heat sensing portion to contact a part of the heating member.
摘要:
A switchback device has an inverting tray for temporarily holding a sheet guided inside the switchback device thereon; a guide unit for guiding the sheet in pressing contact with the inverting tray when the sheet exits the switchback device in an exiting direction on the inverting tray, the exiting direction opposite to an entering direction of the sheet on the inverting tray; a guide switching unit for selectively changing the guide unit to a sheet guide allow state to allow the sheet to enter in the entering direction on the inverting tray and a sheet pressing state to make the sheet in pressing contact with the inverting; and a sheet transporting unit for transporting the sheet out of the switchback device in the exiting direction on the inverting tray.
摘要:
Apparatus and methods for measuring refractive power and radius of curvature of a lens are disclosed. The apparatus comprises a refractive-power measurement subsystem in combination with a curvature-radius measurement subsystem. Each subsystem has its own optical axis and includes at least two point sources of light symmetrically situated relative to the respective optical axis in a plane perpendicular to the axis. Light fluxes from the light sources pass through or reflect from, respectively, the subject lens and impinge on a light-position sensor such as a CCD. The optical axes are preferably separate but become coaxial before reaching the light-position sensor. The refractive-index measurement subsystem senses the positions of images of the light sources on the light-position sensor as affected by refraction of light fluxes passing through the subject lens relative to positions of images obtained with no lens is being measured. The curvature-radius measurement subsystem senses the positions of images of the light sources as affected by reflection of light fluxes from the lens surface relative to positions of images obtained when the surface is planar.
摘要:
An eye examination apparatus enables the examination of a condition of an eye (e.g., the refractive power of an eye, the focus state of the apparatus on the eye) being examined with high precision even when there is a partial obstruction such as a partial crystalline lens cloudiness or partial vitreum cloudiness in the eyeball of the eye. A light projecting optical system projects light (an image) onto a fundus of the eye being examined. A light-receiving element receives the light (the image) reflected from the eye fundus and outputs a waveform representative of the received reflected light. A waveform rectifying device rectifies the output waveform from the light-receiving element by correcting a disorder of the light-receiving element output waveform caused by partial obstruction in the eyeball or the like when such a disorder is determined to be present. The condition (e.g., refractive power, the focus states, etc.) of the partially obstructed eye is then determined using the rectified waveform from the waveform rectifying device. The eye examining device can further include an illuminating optical system that emits illuminating light on the eye fundus and a photographic optical system for photographing or observing the eye fundus illuminated by the illuminating optical system.
摘要:
An eyepiece capable of compensating, various aberrations despite its simple construction including a relatively small number of lenses. The eyepiece includes, in the order from an eyepoint side, a first lens group of a positive refractive power composed of a single positive lens and a second lens group of a positive refractive power composed of a cemented lens of a positive lens and a negative lens, and the positive lens of the first lens group has at least one of its lens surfaces formed into an aspherical surface shape. The radius of curvature at the peripheral portion of the aspherical surface is greater than the radius of curvature at the apex portion of the aspherical surface.
摘要:
An aspherical ophthalmic lens having a negative refractive power, an axis of symmetry and a periphery includes front and rear refractive surfaces. The front refractive surface has a meridional plane and a sagittal plane that intersects the meridional plane. The sagittal plane has a sagittal plane curvature of .rho..sub.s, and the meridional plane has a meridional plane curvature of .rho..sub.m. A curvature difference Z, defined as Z=.rho..sub.m -.rho..sub.s, increases over a range of at least approximately 20 mm in a direction from the axis of symmetry toward the periphery. As a result, a thinner and flatter lens having superior optical performance is provided.
摘要:
A fixing device for an image forming apparatus comprising a heat roller including a hollow roller body and a heater mounted through the roller body. The heater has a plurality of heating portions arranged at equal intervals along the axis thereof. The heater is shifted in the direction opposite to an air flow generated by an exhaust fan with respect to a recording-sheet contact area of the roller body so as to heat the end portion of the roller body located upstream of the air flow sufficiently enough to compensate for the drop of the temperature at the end portion of the recording-sheet contact area located upstream of the air flow cooled below a predetermined temperature by the unheated air flow.