Abstract: In a process of image recording by scanning a recording material with a light beam modulated by an image signal, the density of the recorded image is adjusted by controlling the light intensity during a predetermined interval using a clock pulse for picture elements, recording an image for a predetermined time within the predetermined interval, and changing the predetermined recording time for the entire image or only portions thereof. The recording time is changed in a very simple manner, for example, by operating a variable resistor.

Abstract: A laser recorder in which pictures with gradations at equal density intervals are reproduced with a high accuracy. An input analog video signal is sampled with a sampling pulse at a predetermined sampling rate. For each value of the sampled input signal, a number of high frequency pulses are outputted to modulate a semiconductor laser. The high frequency pulses are outputted so as to be distributed substantially in equal numbers on either side of the center of each sampling period.

Abstract: A semiconductor laser recorder capable of reproducing pictures such as a photograph having half-tones with a high accuracy. An input signal is sampled at a predetermined sampling rate. A first signal is produced in response to a level of the sampled input signal which determines a number of high frequency pulses which are to be outputted during the sampling period. A second signal is also produced in response to the sampled level of the inputs signal which determines the width of at least one pulse which is outputted during the same sampling period. The second signal is produced only when the level of the input signal exceeds a predetermined value. The first and second signals are combined and utilized to binary modulate a semiconductor laser.

Abstract: A laser recorder using a semiconductor laser which is capable of reproducing an image such as a picture having half-tones with a high quality. An input signal is sampled with pulses from a timing processing circuit and converted using a read-only memory into pulse numbers and a corresponding positive-negative pulse identifying bit. The output of the read-only memory is compared with the output of a counter to thereby apply pulses to a laser oscillator in a number and with a polarity specified by the output number from the read-only memory.

Abstract: A laser recorder capable of recording a picture having halftones with densities of more than several tens of levels. An input video signal is sampled with a sampling pulse in response to which a number of high frequency pulses are applied to a beam source with the frequency of the high frequency pulse signal being higher by these two orders of magnitude than the frequency of the sampling pulse signal. The phase of the sampling pulse signal is alternated between adjacent scanning lines to thereby improve the number of available halftone densities.

Abstract: A light beam scanning device in which a light beam is scanned over an image or recording surface at a constant velocity independent of beam position and disturbances in the drive to the system. A position detecting device produces a signal representing the position of the light beam over the surface with the light beam being scanned by an optical deflector device. A feedback loop such as a phase-locked loop controls the movement of the optical deflector in response to a signal produced by the position detecting device and a reference signal.

Abstract: A laser recorder using a semiconductor laser which is capable of reproducing an image such as a picture having half-tones with high quality. An input signal is sampled and converted to a digital number which is used to address a read-only memory in which is stored pulse numbers with corresponding pulse width selection numbers. The outputs of the read-only memory are compared with the output of a counter circuit to determine the number of pulses which are applied to a laser beam modulator. A plurality of modulating pulses are produced, each having a different width. One of these is selected as the modulating signal in accordance with the selection bits stored in the read-only memory.

Abstract: An electric signal obtained by two-dimensionally scanning a color original image through a micro-color filter is processed to be adapted for recording a color image on a subtractive color photosensitive material. The electric signal contains signal components for three primary colors in time series. The electric signal is first converted to a digital signal by use of an A/D converter and then divided into three signals for the three colors. Each signal of different color is processed to have signal sections in which every section of the signal is based on the level of the adjacent section of the signal, each section corresponding to the picture element of the original color image. Then, the three signals are D/A converted to an analog signal, which is used for recording a color image on a subtractive photosensitive material.

Abstract: A light beam scanner having an optical deflector which can repeatedly scan one surface to be scanned in a predetermined direction with a light beam and can start each scan at a desired time instant. A drive mechanism moves the surface to be scanned, in a direction substantially perpendicular to the direction of scanning lines formed on said surface. A signal is outputted whenever the surface to be scanned is moved a predetermined distance and a mechanism is employed for operating the optical deflector in synchronization with the output signal.

Abstract: In a photopolymerizable composition comprising (1) an addition-polymerizable compound having at least one ethylenically unsaturated double bond and (2) a photopolymerization initiator as essential components, the improvement which comprises that said photopolymerization initiator is a combination of (a) p-dialkylamino aromatic carbonyl compounds represented by the general formulae (1) to (4), (b) 5-isoxazolones represented by the general formula (5) and (c) 2,4,6-substituted-1,3,5-triazines represented by the general formula (6): ##STR1## where R.sup.1, R.sup.2 and R.sup.3 each represents an alkyl group or a substituted alkyl group, which may be the same or different from one another, X represents a substituent having a Hammett's .sigma. value in the range from -0.9 to 0.7, m represents 1 or 2, A.sup.1 and A.sup.

Abstract: In a laser beam recording system employing a rotating polygonal mirror for deflecting a recording light beam and a read-out light beam for synchronization, a linear encoder is used to generate a video clock signal in synchronization with the photoelectric pulse signal obtained through the linear encoder. In the video clock signal generator, a clock signal is divided into 1/n where n is an integral number to provide a reference pulse signal to be compared with the photoelectric pulse signal. The displacement of the phase of the photoelectric pulse signal from the reference pulse signal is detected and is corrected by a phase comparator. Thus, a video clock signal having a frequency of n-times as large as that of the photoelectric pulse signal is generated.