Abstract: In a temperature control system having a heating element and a temperature sensor for sensing the temperature generated by the heating element and providing signals effective to control electric energy to be supplied to the heating element, both the heating element and the temperature sensor are implemented with a single element structure for example a power transistor, which is enabled as a heating element during a first period of time and as a temperature sensor during a second period of time. Thus, the heating/temperature sensing element is enabled on a time-shared basis, compensating for heat resistance incurred during transmission of heat from the heating element to the temperature detecting element. Such a temperature control is useful with precision devices such as an ink jet printer.

Abstract: A piezo activated liquid supply pump system includes a cylinder shaped vibration pipe made of a piezo element, and a cone shaped pressure chamber surrounded by a rubber wall. The cone shaped pressure chamber is disposed in the cylinder shaped vibration pipe in a manner that a cavity is formed therebetween. Polyethylene glycol is filled in the cavity for transferring the vibration of the piezo element to the rubber wall of the cone shaped pressure chamber. The volume of the pressure chamber varies in response to the vibration of the piezo element to achieve the liquid supply. The cone configuration of the pressure chamber ensures an effective removal of air bubbles from the pressure chamber. The cavity is communicated with a buffer chamber so as to introduce the polyethylene glycol into the buffer chamber when the liquid contained in the pressure chamber freezes, whereby the expansion of the pressure chamber caused by the freezing of the liquid is absorbed.

Abstract: A combined ink cartridge/bubble removing device is detachably secured to an ink liquid supply system for an ink jet system printer of the charge amplitude controlling type. The combined ink cartridge/bubble removing device includes a housing having a bottom wall provided with an ink inlet portion and an ink outlet portion. An ink liquid tray is disposed in the housing near the middle height of the housing. The ink liquid tray has an inlet opening which is connected to the ink inlet portion via a vertically disposed pipe, and an outlet small opening for dropping ink liquid within the housing. Ink liquid collected by a beam gutter is introduced into the combined ink cartridge/bubble removing device through the ink inlet portion. While the ink liquid travels upward in the vertically disposed pipe, bubbles included in the ink liquid are removed, and the bubbles are discharged from the free surface of the ink liquid held on the ink liquid tray.

Abstract: A liquid supply system comprising a plunger pump and a ripple regulating system. The ripple regulating system includes a ripple regulator having a pressure chamber of which one wall is implemented with a bellowphragm for varying the volume of the pressure chamber. A solenoid mechanism is associated with the bellowphragm to shift the bellowphragm. The solenoid mechanism is activated in synchronization with the drive of the plunger pump, thereby minimizing the pressure ripples generated by the plunger pump.

Abstract: An ink jet system printer of the charge amplitude controlling type includes a carriage travelling across the printing region. A nozzle for emitting ink droplets and a slidable member are disposed on the carriage. The slidable member supports a charging tunnel and a cleaning pad for cleaning the front surface of the nozzle. When the carriage is positioned at the leftmost position before initiating the actual printing operation, the slidable member is slided on the carriage so that the cleaning pad contacts the front surface of the nozzle for cleaning purposes. Thereafter, the slidable member is held stationary on the carriage at a position wherein the charging tunnel confronts the nozzle.

Abstract: An ink jet system printer of the charge amplitude controlling type includes a beam gutter for collecting ink droplets not contributing to the actual printing operation. An ink returning system is provided for returning the collected ink liquid to an ink liquid reservoir. An optical detection system is provided in the course of the ink returning system for detecting whether the ink liquid is properly collected by the beam gutter. When the ink liquid is not observed by the optical detection system for a period longer than a preselected period, a determination system develops a control signal for terminating the formation of the ink droplets.

Abstract: In an ink jet system printer of the charge amplitude controlling type, an electric current flows through an ink droplet issuance unit to ink liquid when an ink droplet is properly charged by a charging tunnel. A detection circuit is connected to the ink droplet issuance unit for detecting the electric current flowing through the ink droplet issuance unit, a determination output of the detection circuit being used for the phase synchronization purposes. A search pulse comprises a first group of search pulse of a predetermined phase and a second group of search pulse of another phase deviated from the predetermined phase. These two groups are alternatingly applied to the charging tunnel at a given selection frequency. If the application of either one group of the search pulse is timed in agreement with the droplet separation phase, an alternating current of a frequency corresponding to the selection frequency of the search pulse group is detected by the detection circuit.

Abstract: A plurality of ink droplet issuance units are provided for emitting plural streams of ink droplets toward a record receiving paper. The ink droplets in the respective streams are charged by a bi-valued signal through the use of a plurality of charging means in accordance with print information. The ink droplets charged by one value of the bi-valued signal are deflected as they pass through a deflection means and deposited on the record receiving paper. The ink droplets charged by the other value of the bi-valued signal are directed to a beam gutter and not deposited on the record receiving paper. In this way, one column of a dot matrix pattern is printed at a time utilizing plural streams of ink droplets.

Abstract: In an ink jet system printer of the charge amplitude controlling type, an electric current flows through an ink droplet issuance unit to ink liquid when an ink droplet is properly charged by charging means. A detection circuit is connected to the ink droplet issuance unit for detecting the electric current flowing through the ink droplet issuance unit, thereby developing a phase OK signal when a predetermined electric current is detected.

Abstract: In a temperature control having a heating element and a temperature sensor for sensing the temperature of an object being heated by the heating element and providing signals effective to control electric energy to be supplied to the heating element, there is provided compensator means for compensating for a variation in the temperature of the object which may be caused by heat resistance and other factors while transmitting heat from the heating element to the object. The temperature of the object is equivalent to a desired one without any influences of the heat resistance. In one preferred form, an operational amplifier having two input terminals is provided one connected to the temperature sensor such as a thermistor and the other connected to a reference potential representative of the desired temperature. An output terminal of the operational amplifier is connected to the heating element.

Abstract: A protection film formation means is disposed in front of an orifice of a nozzle for isolating the orifice from the ambience. A control means function to form a protection film when an ink jet system printer does not operate, and to remove the protection film when the ink jet system printer operates.

Abstract: A plurality of ink droplet issuance units are provided for emitting plural streams of ink droplets toward a record receiving paper. The ink droplets in the respective streams are charged by a bi-valued signal through the use of a plurality of charging means in accordance with print information. The ink droplets charged by one value of the bi-valued signal are deflected as they pass through a deflection means and deposited on the record receiving paper. The ink droplets charged by the other value of the bi-valued signal are directed to a beam gutter and not deposited on the record receiving paper. In this way, one column of a dot matrix pattern is printed at a time utilizing plural streams of ink droplets.

Abstract: An electromagnetic cross valve is provided for selectively connecting a nozzle with an ink liquid supply conduit and an ink liquid drain conduit. When the nozzle is connected with the ink liquid drain conduit, ink liquid is maintained at the atmospheric pressure and remains in the nozzle in such a manner that the ink liquid is filled to the tip end of the nozzle or the orifice of the nozzle. Fluid resistance means are disposed between the electromagnetic cross valve and the ink liquid drain conduit for preventing generation of negative pressure at the nozzle side when the nozzle is connected with the ink liquid drain conduit.

Abstract: A printer head is mounted on a carriage which is driven to travel in the row direction at a predetermined constant speed. A pulse generation device is provided for developing a pulse signal in response to the travel of the carriage in order to determine print width. A detection device develops a detection signal when the carriage reaches the first print position to initiate printing of the first character. The detection signal is applied to a counter which counts a time interval from a time at which the last pulse is developed from the pulse generation device to a time at which the detection signal is developed. The following character printing is effected each time the pulse generation device develops a predetermined number of pulses indicative of one character width or print pitch and the time interval determined by the counter has passed from the time at which the last pulse of the predetermined number is developed.

Abstract: In an ink jet system printer of the charge amplitude controlling type, when it is desired to charge a specific ink drop being formed, the amplitude of charge for the specific ink drops is increased in accordance with the total field strength of the electric fields due to the charge amplitude of the preceding ink drops, the charge of the thus increased amplitude being supplied to the specific ink drop to thereby alleviate any charge distortion.

Abstract: In an ink jet system printer of the charge amplitude controlling type which records character patterns in, for example, a 5 .times. 7 dot matrix pattern, ink droplets not assigned to primary matrix dots are used for interpolation dots which will be deposited between two adjacent primary matrix dots on a record receiving member. The printing quality can be enhanced by provision of these interpolation dots.

Abstract: A primary matrix pattern such as 5 .times. 7 matrix structure and an auxiliary matrix pattern such as 4 .times. 6 matrix structure are combined with each other in an ink jet system printer in such a manner that auxiliary dots contributing to the auxiliary matrix pattern are shifted in both column and row directions by a half dot position with respect to the primary matrix pattern. These auxiliary dots function to increase dot density along oblique lines in the dot matrix pattern.

Abstract: A vertical tabulation control for a high speed printer comprises a presettable memory, such as a random access memory (RAM), for storing vertical tabulation addresses, a counter for counting the number of line feed operations, a comparator for developing a continuous line feed termination command when the contents of the counter reach the preset vertical tabulation address, and a rechargeable battery means which is charged when the printer is activated through a power switch. The rechargeable battery supplies the presettable memory and the counter with a necessary voltage for maintaining their contents when the power supply through the power switch is terminated.

Abstract: An electronic tabulator for use in non-impact printers and similar data terminal printout apparatus includes a random access memory (RAM) having a capability of storing the maximum of printing carriage positions to be tabulated at random order in response to TAB preset instructions, which in one preferred form may be implemented with MOS integrated circuit technology. While the carriage is moved in incremental steps along a given path in the course of the printing operation, address signals representative of the instantaneous positions of the carriage are developed from a carriage address counter. If there is evaluated an equivalence between the address signal and the preset signal of the memory, the memory produces its output which is in turn applied to the carriage bearing a printing member to indicate that the printing operation should be effected at that position.

Abstract: In an ink jet system printer of the charge amplitude controlling type, wherein a printing head is transported in a horizontal direction and vertical deflection is achieved by a pair of high voltage deflection plates, it is required to transport the printing head at a fixed velocity in the printing process. More particularly, in order to execute intermittent printing by repetition of the transporting and stopping of the printing head in response to intermittent input signals, it is necessary that printing is restricted during the time required for increasing the velocity of the printing head to a desired level and then permitted after that time. The present invention provides a system wherein the generation of printing start signals is delayed by a predetermined period following the application of input signals, and also a system wherein printing start signals are generated when the actual velocity of the head has been sensed as reaching the desired velocity.