Abstract: Method and apparatus capable of accurately measuring a flow rate using Gaussian quadrature even under a small number of measurement points are provided. An average for the y-coordinate of values of normal-directional component with respect to the cross-section represented by vz0(x, y) among an estimated flow velocities in a flow passage cross-section is used as Vz0(x), and a weighting function of Gaussian quadrature is set to Vz0(x)L(x), where L(x)=ymax(x)?ymin(x). Further, an average for y of values of normal-directional component with respect to the cross-section of an actual flow velocity represented by vz(x, y) is used as Vz(x), and an integrand is set to Vz(x)/Vz0(x). These values are used to determine an approximate value of a flow rate according to Gaussian quadrature. In addition, a method of virtually offsetting zero-point of the flow velocity distribution to apparently avoid a problem such as reverse flow is provided.

Abstract: A method and apparatus for measuring a pulsatingly fluctuating flow rate under a general condition, without needing electrical conductivity for a fluid, and without allowing a phase lag corresponding to a calculation time or attenuation, or resulting from a relation between pressure difference and flow rate, to occur. Ultrasonic waves are repeatedly transmitted with respect to a pulsatingly fluctuating fluid, while the ultrasonic wave is being received, and a signal indicative of the transmission and receipt, and a signal indicative of a timing of the transmission and receipt are recorded. Alternatively, the ultrasonic wave is transmitted and received based on a preliminarily set timing signal, and the signal indicative of the transmission and receipt is recorded. These signals are used to determine flow rates and transmission and receipt timings to plot a pulsating fluctuation. In one or more implementations, the timing signal may be phase-synchronized with a pulsation reference signal.

Abstract: Method and apparatus capable of accurately measuring a flow rate using Gaussian quadrature even under a small number of measurement points are provided. An average for the y-coordinate of values of normal-directional component with respect to the cross-section represented by vz0(x, y) among an estimated flow velocities in a flow passage cross-section is used as Vz0(x), and a weighting function of Gaussian quadrature is set to Vz0(x)L(x), where L(x)=ymax(x)?ymin(x). Further, an average for y of values of normal-directional component with respect to the cross-section of an actual flow velocity represented by vz(x, y) is used as Vz(x), and an integrand is set to Vz(x)/Vz0(x). These values are used to determine an approximate value of a flow rate according to Gaussian quadrature. In addition, a method of virtually offsetting zero-point of the flow velocity distribution to apparently avoid a problem such as reverse flow is provided.

Abstract: [Object] To provide a method and an apparatus capable of measuring a pulsatingly fluctuating flow rate under a general condition, without needing electrical conductivity for a fluid, and without allowing a phase lag corresponding to a calculation time or attenuation or a phase lag resulting from a relation between pressure difference and flow rate to occur. [Means to Accomplish the Object] Ultrasonic waves are repeatedly transmitted with respect to a pulsatingly fluctuating fluid, while the ultrasonic wave being received, and a signal indicative of the transmission and receipt, and a signal indicative of a timing of the transmission and receipt are recorded. Alternatively, the ultrasonic wave is transmitted and received based on a preliminarily set timing signal, and the signal indicative of the transmission and receipt is recorded. These signals are used to determine flow rates and transmission and receipt timings to plot a pulsating fluctuation.

Abstract: A determining unit determines whether a difference between a temperature value and a temperature detected by a temperature detecting unit is equal to or larger than a first value. A pattern forming unit, when the determining unit determines that the difference is equal to or larger than the first value, forms a pattern for measurement including sub-patterns of a plurality of colors on a transfer medium. A calculating unit calculates a misregistration-amount for each sub-pattern based on a detected position of the sub-pattern and a predetermined position of the sub-pattern. A correcting unit corrects a position on which the sub-pattern is to be formed based on the misregistration-amount. An image forming unit forms an image for each color factoring in corrected position for each color.

Abstract: An image forming apparatus includes an image forming mechanism configured to perform an image processing operation for forming a plurality of elementary-color images, superposing the plurality of elementary-color images sequentially and accurately into a single color image on a transfer medium, and transferring the single color image onto a recording sheet. An error correction mechanism is configured to perform a plurality of different recording error corrections for correcting different recording errors in a main scanning direction and a sub scanning direction during a time interval between the image processing operations on the recording sheet and on a following recording sheet. And, a selector is configured to activate at least two of the plurality of different recording error corrections.

Abstract: An image forming apparatus is capable of forming a clear image by using laser beams projected from a plurality of laser light sources. The image forming apparatus forms an electrostatic latent image on a medium to be scanned by laser beams, which are projected from a plurality of laser light sources and periodically deflected by a rotational deflecting unit, so that the laser beams scan the medium, which is uniformly charged and moving in a sub-scanning direction, in a main-scanning direction perpendicular to the sub-scanning direction. A pixel clock generating unit generates pixel clocks, which are used for controlling timings of projection of the laser beams, separately for each of the laser light sources, and for performing a phase change of each of the pixel clocks; and a phase control unit that controls independently each of the pixel clocks.

Abstract: An image forming apparatus including a memory device configured to prestore control information and registration pattern data, a traveling member, a toner pattern forming device forming a toner pattern, which includes a plurality of marks of a plurality of color components, on the traveling member according to the registration pattern data. A position detecting device detects each of the plurality of marks in the toner pattern. A control information correcting device corrects the control information according to a difference among positions of the plurality of marks, and a main-scan registration correcting device adjusts, based on the corrected control information, a start-of-write timing in the main scanning direction in a unit of a pixel clock cycle and adjusts a writing timing in the main scanning direction in a unit smaller than the pixel clock cycle by controlling a phase of the pixel clock cycle.

Abstract: A color image forming apparatus includes a pattern forming mechanism configured to form a pattern for fine adjustment and a pattern for rough adjustment on a transfer medium, a detection mechanism configured to detect the pattern formed thereon, a displacement calculation mechanism configured to obtain a predetermined value and preset reference values, to calculate the amount of displacement based on the detected pattern and the preset reference values, and to determine whether or not the amount of the displacement is equal to or less than the predetermined value, and a displacement correction mechanism configured to correct the displacement based on the calculation.

Abstract: An optical scanning apparatus provides improved image quality by changing the amount of writing scale compensation for a pixel clock during a scanning cycle. A pixel clock generation unit of the optical scanning apparatus divides the scanning cycle into multiple division periods. A phase change of the pixel clock is carried out for each of the division periods. The phase change can also be different from scanning cycle to scanning cycle.

Abstract: A determining unit determines whether a difference between a temperature value and a temperature detected by a temperature detecting unit is equal to or larger than a first value. A pattern forming unit, when the determining unit determines that the difference is equal to or larger than the first value, forms a pattern for measurement including sub-patterns of a plurality of colors on a transfer medium. A calculating unit calculates a misregistration-amount for each sub-pattern based on a detected position of the sub-pattern and a predetermined position of the sub-pattern. A correcting unit corrects a position on which the sub-pattern is to be formed based on the misregistration-amount. An image forming unit forms an image for each color factoring in corrected position for each color.

Abstract: The present invention provides a Fresnel lens sheet capable of successfully avoiding the “collapse”, “abrasion” and “moire” problems. A Fresnel lens sheet constitutes, together with a lenticular lens sheet, a rear projection screen, which is mounted in the frame of a rear projection type display. The Fresnel lens sheet includes, on one surface of its substrate, a Fresnel lens part containing a plurality of lenses concentrically formed on one plane. The apexes of the lenses situated in the area between the center and the outer edge of the Fresnel lens part are flattened to give flat faces, and the widths of the flat faces of the lenses on the outer edge side are made greater than the widths of the flat faces of the lenses on the center side. The widths of the flat faces of the lenses are from 0 to 30 ?m.

Abstract: An image-forming apparatus is disclosed that includes at least one imaging optical system forming an electrostatic latent image on the scanning surface of a medium moving in a sub scanning direction by scanning the scanning surface in a main scanning direction by periodically deflecting a laser beam with a rotary deflector, a pixel clock generation part generating a pixel clock signal for controlling the emission timing of the laser beam and changing the phase of the pixel clock signal, a region setting part setting the length of each of multiple regions based on image writing magnifications in a line in the main scanning direction, the regions being formed by dividing part of the scanning surface corresponding to the line in the main scanning direction, and a phase control part controlling the changing of the phase of the pixel clock signal region by region based on the image writing magnifications.

Abstract: An image forming apparatus including a memory device configured to prestore control information and registration pattern data, a traveling member, a toner pattern forming device forming a toner pattern, which includes a plurality of marks of a plurality of color components, on the traveling member according to the registration pattern data. A position detecting device detects each of the plurality of marks in the toner pattern. A control information correcting device corrects the control information according to a difference among positions of the plurality of marks, and a main-scan registration correcting device adjusts, based on the corrected control information, a start-of-write timing in the main scanning direction in a unit of a pixel clock cycle and adjusts a writing timing in the main scanning direction in a unit smaller than the pixel clock cycle by controlling a phase of the pixel clock cycle.

Abstract: A projection screen 111 comprises a total reflection prism lens 114 and a lenticular lens 115 provided on the viewer's side of the total reflection prism lens 114. The total reflection prism lens 114 has a plurality of unit prisms 113 on its back surface (the outermost plane of incidence) on which imaging light L is incident. Each unit prism 113 has an apical angle ? that corresponds to the angle between the plane of incidence 113a and the plane of total reflection 113b, and the apical angles ? of the unit prisms 113 vary with the position of each unit prism 113 on the screen plane. In particular, the unit prisms 113 have apical angles ? varying continuously from 30° to 45° so that the apical angles ? on the side distant from the center O of the concentric circles are greater than the apical angles ? on the side close to this center O.

Abstract: A color image forming apparatus includes a pattern forming mechanism configured to form a pattern for fine adjustment and a pattern for rough adjustment on a transfer medium, a detection mechanism configured to detect the pattern formed thereon, a displacement calculation mechanism configured to obtain a predetermined value and preset reference values, to calculate the amount of displacement based on the detected pattern and the preset reference values, and to determine whether or not the amount of the displacement is equal to or less than the predetermined value, and a displacement correction mechanism configured to correct the displacement based on the calculation.

Abstract: An image forming apparatus includes an image forming mechanism configured to perform an image processing operation for forming a plurality of elementary-color images, superposing the plurality of elementary-color images sequentially and accurately into a single color image on a transfer medium, and transferring the single color image onto a recording sheet. An error correction mechanism is configured to perform a plurality of different recording error corrections for correcting different recording errors in a main scanning direction and a sub scanning direction during a time interval between the image processing operations on the recording sheet and on a following recording sheet. And, a selector is configured to activate at least two of the plurality of different recording error corrections.

Abstract: The present invention provides a Fresnel lens sheet that can, in production using a mold, be easily released from the mold and that scarcely produces stray light upon use, and others. Each prism 2 on the incident side of a Fresnel lens sheet 1 is formed to have a nearly triangular cross section and has a plane of refraction 3 that refracts projected light S incident on this plane and a plane of total reflection 4 that totally reflects, toward the viewer's side, at least part of the light refracted at the plane of refraction 3. Each prism 2 is made so that a root 5 between a prism 2 and a prism 3 situated next to the prism 2, on the plane of total reflection side of the prism 2 (a root 5 defined by the plane of refraction 3 of one prism 2B and the plane of total reflection 4 of another prism 2A situated next to the prism 2B, on the side of the plane of refraction 3 of the prism 2B) is curved toward the prism 2A side from the prism 2B side.

Abstract: The present invention provides a Fresnel lens sheet capable of successfully avoiding the “collapse”, “abrasion” and “moiré” problems. A Fresnel lens sheet 10 constitutes, together with a lenticular lens sheet, a rear projection screen, which is mounted in the frame of a rear projection type display. The Fresnel lens sheet 10 includes, on one surface of its substrate, a Fresnel lens part 13 containing a plurality of lenses 11 concentrically formed on one plane. The apexes 11a of the lenses 11 situated in the area between the center O and the outer edge P of the Fresnel lens part 13 are flattened to give flat faces 12, and the widths W of the flat faces 12 of the lenses 11 on the outer edge P side are made greater than the widths W of the flat faces 12 of the lenses 11 on the center O side. The widths W of the flat faces 12 of the lenses 11 are from 0 to 30 ?m.

Abstract: An image-forming apparatus is disclosed that includes at least one imaging optical system forming an electrostatic latent image on the scanning surface of a medium moving in a sub scanning direction by scanning the scanning surface in a main scanning direction by periodically deflecting a laser beam with a rotary deflector, a pixel clock generation part generating a pixel clock signal for controlling the emission timing of the laser beam and changing the phase of the pixel clock signal, a region setting part setting the length of each of multiple regions based on image writing magnifications in a line in the main scanning direction, the regions being formed by dividing part of the scanning surface corresponding to the line in the main scanning direction, and a phase control part controlling the changing of the phase of the pixel clock signal region by region based on the image writing magnifications.