Abstract: A defrost heater, in which the strength of an insertion force needed for inserting a second glass tube in a plug is specified to be smaller than that needed for inserting a first glass tube in a plug. Thereby, dispersion in the insertion force needed for attaching the plug with a double glass tube can be reduced, and the assembling efficiency is improved.

Abstract: A defrost heater, in which the strength of an insertion force needed for inserting a second glass tube in a plug is specified to be smaller than that needed for inserting a first glass tube in a plug. Thereby, dispersion in the insertion force needed for attaching the plug with a double glass tube can be reduced, and the assembling efficiency is improved.

Abstract: An inkjet printer for recording dot patterns corresponding to image contents is disclosed. The printer comprises an inkjet head (51) for performing recording by moving in a main scanning direction of a recording medium and injecting ink particles, drive waveform generating sections (24, 25) for generating drive waveforms for injecting said ink particles, and a head drive section (50) for selecting said drive waveforms and driving said inkjet head (51) in accordance with print data. The drive waveform generating sections (24, 25) generate drive waveforms for injecting said ink particles having different ink speeds within a unit cycle, in cycles each corresponding to one of the parts obtained by dividing the unit cycle by an integer. Thereby, by varying the speed of the ink particles injected in one cycle of the drive waveforms, the landing position of each dot in the cycle is controlled and hence the dot pattern in one cycle is varied.

Abstract: A halftone gradation processing method reduces or eliminates the discontinuous gradation reproduction in comparison with conventional error diffusion. A halftone gradation processing method includes obtaining a position and a pixel value of a target pixel in an input image, correcting the pixel value, selecting the closest threshold to the corrected pixel value from among usable thresholds assignable to the pixel value, calculating an error between the corrected pixel value and the selected threshold, and diffusing the error around the target pixel, the pixel value correcting being corrected by the diffused error, and the selected threshold being output to an output device which may handle the assigned thresholds.

Abstract: A gray scale image processing method which converts an input image, each pixel of which has a value between 0 and N, to an output image, each pixel of which is represented by a gray scale value of A levels. The method has a generation step of generating B reference images, in each of which each pixel is represented by a gray scale value of the A levels, from B elementary images, in each of which all pixels have the same value between 0 and N, using one or more different error distribution matrixes according to said A levels, a selection step of selecting one of the B reference images based on a pixel value f(x,y) of the input image at coordinates (x,y) and an output step of outputting a pixel value represented by a gray scale value of the A levels of the selected one of the B reference images at a position corresponding to the coordinates (x,y).

Abstract: An ink-jet printer using a small and a large line feeds has been disclosed. The ink-jet printer comprises a head on which B ink spraying nozzles are arranged at fixed nozzle intervals in the vertical scanning direction and a vertical scanning mechanism, wherein the nozzle interval is A times the dot pitch and the printing action is composed of a single printing scan in the main scanning direction, a small line feed printing that repeats an action (C×A−1) times, in which after a small line feed that relatively moves the recording medium in the vertical scanning direction by the amount of n times the nozzle interval plus one dot pitch ((A×n+1)×d) is performed, a single printing scan in the main scanning direction is performed, and a subsequent large line feed printing that performs a large line feed by the amount of (B×A−(A×n+1)(C×A−1))×d.

Abstract: An inkjet printer for recording dot patterns corresponding to image contents is disclosed. The printer comprises an inkjet head (51) for performing recording by moving in a main scanning direction of a recording medium and injecting ink particles, drive waveform generating sections (24, 25) for generating drive waveforms for injecting said ink particles, and a head drive section (50) for selecting said drive waveforms and driving said inkjet head (51) in accordance with print data. The drive waveform generating sections (24, 25) generate drive waveforms for injecting said ink particles having different ink speeds within a unit cycle, in cycles each corresponding to one of the parts obtained by dividing the unit cycle by an integer. Thereby, by varying the speed of the ink particles injected in one cycle of the drive waveforms, the landing position of each dot in the cycle is controlled and hence the dot pattern in one cycle is varied.

Abstract: An ink-jet printer using a small and a large line feeds has been disclosed. The ink-jet printer comprises a head on which B ink spraying nozzles are arranged at fixed nozzle intervals in the vertical scanning direction and a vertical scanning mechanism, wherein the nozzle interval is A times the dot pitch and the printing action is composed of a single printing scan in the main scanning direction, a small line feed printing that repeats an action (C×A−1) times, in which after a small line feed that relatively moves the recording medium in the vertical scanning direction by the amount of n times the nozzle interval plus one dot pitch ((A×n+1)×d) is performed, a single printing scan in the main scanning direction is performed, and a subsequent large line feed printing that performs a large line feed by the amount of (B×A−(A×n+1)(C×A−1))×d.