Abstract: An image transmission system includes a modulating part for independently modulating a luminance signal and two kinds of color difference signals and a demodulating part for independently demodulating the modulated luminance signal and the two kinds of modulated color difference signals. The demodulating part includes a signal correcting part for shifting at least one of the modulated luminance signal and the two kinds of modulated color difference signals by a predetermined number of picture elements in a scanning line direction to correct an error introduced by the modulation.

Abstract: A video phone comprising an input device for entering input image data to be transmitted, a circuit for digitizing the input image data into digital image data, a memory for storing the digital image data, a first circuit for producing an output image signal based on the digital image data from the memory, a display device for displaying an image of the output image signal, a second circuit for compressing the digital image data from the memory into compressed image data, a telephone part having telephone functions, a line control circuit coupled to a public analog telephone line for selectively coupling the second circuit and the telephone part to the public analog telephone line, and a control device.

Abstract: In a gas carburizing method, a hydrocarbon gas and air are supplied to a furnace main body that carburizes a workpiece. The hydrocarbon gas and air react with one another in the furnace main body to generate an atmospheric gas having a carburizing property. The flow rate of the hydrocarbon gas to be supplied is maintained at a predetermined value. The flow rate of air to be supplied can be altered by adjusting the carbon potential of the atmospheric gas.A gas carburizing apparatus includes a furnace main body and load and unload chambers provided on two ends of the furnace main body. The load and unload chambers have combustion units. The combustion units communicate with the interiors of the load and unload chambers and burn a hydrocarbon gas. The combustion gas of the hydrocarbon gas is supplied to the load and unload chambers.

Abstract: A gradation data processing apparatus comprising,an extractor for extracting a gradation data corresponding to first small region of an original image distributed in a 2-dimension and a gradation data corresponding to a second small region in adjacent with said first small region,a detector for detecting whether a difference between a content of the gradation data corresponding to the first small region and a content of the gradation data corresponding to the second small region in adjacent with said first small region is within a predetermined range or not, anda generator for generating a data indicating a maximum value in a gradation if said difference exceeds an upper value of the range, while generating a data indicating a minimum value in the gradation if said difference goes below a lower value of the range as an output gradation data.

Abstract: A printer interface circuit is provided in a host system so as to allow a printer having its own clock signal for its printing operation to be directly connected to the host system. In the present invention, data to be printed is first stored in a data latch as supplied in association with the clock signal of the host system, and then the data stored in the data latch is transferred to the printer in association with the printer. Thus, even if use is made of a laser printer, which has its own clock signal, it can be directly connected to a host system, such as a personal computer. In the preferred embodiment, the printer interface circuit modifies the frequency of the clock signal of the printer and the data is transferred to the printer at this modified frequency, so that the data may be expanded when printed.

Abstract: An image processing system processes a composite original image having both of letter and picture information to have the letter information extracted. An image signal in the form of pixel is checked to see if it is a letter pixel, in which case "1" is assigned, or a picture pixel, in which case "0" is assigned, so that a plane data of "1s" and "0s" is obtained and stored in a plane memory. At the same time, the image signal is converted into a binary image data which is stored into an image memory. The data stored in the plane memory is subjected to two-step digital filtering processing, first step to eliminate isolated black and white dots and second step to smooth the data, thereby obtaining filtered data which define one or more letter regions in an original document. Using the thus defined letter region data, the binary image data stored in the image memory is processed, thereby extracting only the letter image data.