Abstract: The occurrence of cracks and the like are prevented due to thermal stress associated with Joule heat generated by a semiconductor chip in vias for electrical connection with the back surface, arranged around the semiconductor chip. A substrate 11 with a semiconductor chip 20A mounted face-up on its surface includes a plurality of heat dissipation vias 15 in an area corresponding to a semiconductor chip mounting section. The substrate 11 is covered with an insulating layer 12 made from an insulating resin with low thermal conductivity on a surface exclusive of an opening for a wire 40A and openings 12B for the heat dissipation vias 15.

Abstract: A capacitive load driving circuit (1) for charging and discharging a capacitive load (11) is provided with a voltage divider (5) for dividing a power supply voltage (VH) into a plurality of different voltages (V1–V9), a plurality of condensers (2a–i) to which the voltages (V1–V9) are respectively charged as terminal voltages, and a switch (7) for switching connections between the capacitive load (11) and the condensers (2a–i), the switch (7) sequentially connecting the condensers (2a–i) in an ascending order of the terminal voltages so that electrostatic energy is supplied to the capacitive load (11) when the capacitive load (11) is charged, the switch (7) sequentially connecting the condensers (2a–i) in a descending order of the terminal voltages so that electrostatic energy is collected from the capacitive load (11) when the capacitive load (11) is discharged.

Abstract: A capacitive load driving circuit (1) for charging and discharging a capacitive load (11) is provided with a voltage divider (5) for dividing a power supply voltage (VH) into a plurality of different voltages (V1-V9), a plurality of condensers (2a-i) to which the voltages (V1-V9) are respectively charged as terminal voltages, and a switch (7) for switching connections between the capacitive load (11) and the condensers (2a-i), the switch (7) sequentially connecting the condensers (2a-i) in an ascending order of the terminal voltages so that electrostatic energy is supplied to the capacitive load (11) when the capacitive load (11) is charged, the switch (7) sequentially connecting the condensers (2a-i) in a descending order of the terminal voltages so that electrostatic energy is collected from the capacitive load (11) when the capacitive load (11) is discharged.

Abstract: An ink jet printing apparatus and method for forming images by selectively actuating a multiple number of ink chambers. An amount of energy U0, which is determined by U0=Ui−Ud, is applied to each non-ejecting chamber, wherein Ui is the energy imparted to each ejecting chamber and Ud is the energy that is carried away by a single droplet of ink, when all the nozzles are driven to eject ink at a maximum ejection ratio, with the temperature rise of ink jet head being saturated.

Abstract: In driving an ink-jet head for forming images by selectively actuating a multiple number of ink chambers, a fixed amount of electric power which will not cause ink ejection is applied to each non-ejecting ink chamber to generate a desired amount of power consumption. In an example where 384 nozzles each producing 6000 ink droplets per second, maximum, is used, a compensation power of 0.56 &mgr;J is imparted to each non-ejection chamber per ejection cycle. With this arrangement, all the ink chambers, whether ink is ejected or not, can be uniformly elevated in temperature, whereby the temperature of the multiple number of ink chambers on the ink-jet head increases substantially uniformly across the array whatever the print content is.

Abstract: A novel laser printer is disclosed, in which heat generating parts are positively cooled while reducing the noise generated by a blowing mechanism. A rotor of the motor for rotating a scanning mirror of a scanning device is surrounded by a cover. An air flow inlet port and an air flow outlet port are formed on the sides of the cover. The space in the proximity of the air flow inlet port and the air flow outlet port is divided by an air flow separation member. One longitudinal end of the air flow separation member is close to the rotor and the other longitudinal end and the lateral ends thereof are connected to the cover. The air flow separation member partially divides the rotating air flow generated around the rotor in the proximity of the air flow outlet port, and generates the discharge air flow, which in turn is discharged out of the cover. A suction air flow is introduced from the air flow inlet port to the interior of the cover which is now negative in pressure, in the form of the rotating air flow.

Abstract: A high-voltage power pack includes: a switching circuit for effecting switching control of a low-voltage d.c. signal to generate a low-voltage a.c. signal; a high-voltage transformer for increasing the voltage of the low-voltage a.c. signal outputted from the switching circuit to generate a high-voltage a.c. signal; a combination of a rectifying circuit and a low-pass filter for rectifying and smoothing the high-voltage a.c. signal to generate a high-voltage d.c. signal; resistors dividing the high-voltage d.c. signal obtained from and smoothed through the rectifying circuit and low-pass filter; a feedback circuit for controlling the switching circuit so that the potential at a divided point between the resistors may be kept constant; and an a.c. power source for applying an alternating current to the divided point, the alternating current having a frequency component transmissible through the low-pass filter, whereby an a.c. superimposed voltage made of the high-voltage d.c. signal with an a.c.

Abstract: It is an object of the invention to provide a LED write apparatus wherein the arrangement step of LED chips is eliminated by constituting the LED head by a single LED chip composed of LEDs and electrical connection of the respective LEDs with driving circuits is carried out with ease.A LED head chip is constituted in such a manner that 2400 LEDs in all whose width a is selected to be narrow, namely about 10 .mu.m are formed on a Si substrate having a smaller width (about 30 mm) than that of a photosensitive drum (length of A4 size: 210 mm) through a GaAs substrate and as well peripheral circuits including a driving circuit such as a transistor are integratedly formed on the Si substrate. The light from the LED head chip is magnified via a lens to form an image on the photosensitive drum.

Abstract: A laser beam printer includes a movable mirror which is rotated by a scan mirror motor. Laser light is alternately deflected toward an information reading station and an information writing station by applying the laser light to the movable mirror from a semiconductor laser. The laser light is switched between writing-use light and reading-use light at the time the movable mirror is rotated through a predetermined angle. In the laser beam printer having the semiconductor laser which is used for both writing and reading information, information is written and read out during one rotation of the movable mirror. It is therefore possible to perform a reading operation and a writing operation simultaneously by simply switching the laser light at the predetermined time depending on the rotation angle of the movable mirror.

Abstract: An image forming apparatus comprising a laser optical system for optical scanning on a photosensitive drum. The laser optical system comprises a polygon mirror having mirror surfaces with an inclination of an angle .theta.. The polygon mirror is rotated with each mirror surface inclined by the angle .theta. to a line normal to the scanning plane, while the incident light beams to the polygon mirror are inclined by an angle 2.theta. to the scanning plane, so as to compensate the inclination of the mirror surfaces of the polygon mirror. In this way, the polygon mirror can be easily manufactured by plastic molding without damaging the mirror surfaces.

Abstract: An image recording apparatus which is capable of recording an image by forming a dot for each pixel includes an interface (14) for receiving dot data having 300 dpi dot density, converting unit (15, 16, 17, 18) connected to the interface for converting the received data into dot data having 600 dpi dot density by replacing a dot of a focus pixel with a plurality of dots having patterns corresponding to dot patterns of areas containing the focus pixel, and a base engine unit (13) connected to the converting unit for forming an image in accordance with the converted dot data.

Abstract: A sheet turning device in a sheet transporting path for receiving a sheet transported in a predetermined direction turning the sheet and transporting the sheet in the predetermined direction. A pair of rollers are provided with a belt extending between the rollers for turning the sheet. A switch is provided for stopping the sheet transported onto the lower inner surface of the sheet turning belt. A driving shaft circulates the sheet turning belt to transport the sheet kept on the lower inner surface of the sheet turning belt in a direction orthogonal to the predetermined direction. A pressing member is provided for stopping and pressing the sheet on the upper inner surface of the sheet turning belt, and a sheet transporting roller for transporting the sheet pressed by the pressing member in the predetermined direction.

Abstract: An optical printer of the scanning type includes a light emitting element which is drivable in accordance with printing data for emitting light. The printer also includes an optical system which passes the light through the system to focus the light on a photosensitive member. A mirror is movably interposed between the optical system and the photosensitive member to deflect the beam from the optical system, thereby causing the beam to scan the photosensitive member at a high speed. To realize the scanning process, an operation assembly supports the mirror to pivotally move the mirror so that the mirror's reflecting surfaces faces toward the light emitting element by subjecting the mirror to a simple harmonic motion within a specified range of angles.

Abstract: A controlling apparatus for a laser diode which is used in a laser printer or the like to transmit laser beam light rays. According to the output characteristics of the laser diode, a bias is applied in the current region (from 0 to Ixm) of approximately 0 in radiation output. The control object period (from Ix to Ixm) is divided into many stages to perform the radiation output control so as to effect the high-precision output control without the provision of a more complicated circuit. The central processing unit outputs the control signal into the duty controlling means, so that the output of the laser diode may be automatically held constant in accordance with the predetermined process or the operation arranged in advance.

Abstract: A frequency control device for use in a laser printer which comprises a modulator for modulating an original signal by a modulation signal so that the speed of the printing data of the laser printer is changed to compensate the change of the scanning speed of a light spot projected by a polygon mirror in the laser printer without using a f-.theta. lens.

Abstract: An ink liquid supply system for an ink jet system printer includes an ink intake needle formed in a body of the ink liquid supply system, and an ink cartridge removably mounted on the body of the ink liquid supply system. The ink cartridge includes an opening covered by a rubber seal through which the ink intake needle is inserted when the ink cartridge is mounted on the body of the ink liquid supply system. An ink liquid absorbing pad is attached to the rubber seal so as to cover the seal rubber. The ink liquid absorbing pad functions to prevent the ink liquid from dripping onto the body of the ink liquid supply system when the ink cartridge containing ink is denounted from the body of the ink liquid supply system.

Abstract: A ripple regulating system is disposed in a liquid supply system for minimizing pressure ripples generated by a pump employed in the liquid supply system. The ripple regulating system includes a pressure chamber of which one wall comprises a bellowphragm. A spring is secured to the bellowphragm to apply a predetermined pressure to the pressure chamber. A detection system is associated with the pressure chamber for detecting a balance pressure variation. When the balance pressure becomes higher than the preselected level, an adjusting system is operated to increase the depression pressure generated by the spring, thereby maintaining the constant flow rate supply.

Abstract: A solenoid drive system includes a driver circuit which functions to gradually increase current flowing through a solenoid coil. The attracting force created by the solenoid is proportional to the current flowing through the solenoid coil. When the attracting force becomes greater than a load including the plunger, the plunger moves toward the operating end. At a time when the plunger reaches the operating end, the current is still in the increasing curve and, therefore, an excess force is minimized. This functions to minimize noises created by the plunger movement.

Abstract: A paper sheet setting mechanism in a printer such as an ink jet system printer includes a memory device which stores a desired left setting position at which a left paper pressing roller should be positioned, and a desired right setting position at which a right paper pressing roller should be positioned. C-shaped guide plates are secured to the paper pressing rollers. Each of the C-shaped guide plates includes a roof member which is made contact with a pritrusion secured to a printer head when a shaft of the paper pressing rollers is held at a first stable position. When the printer head is driven to shift while the shaft is held at the first stable position, the paper pressing rollers are shifted on the shaft and controlled to be positioned at the desired left and right setting positions, respectively.

Abstract: An ink liquid supply system for an ink jet system printer includes an atmospheric pressure chamber interposed between an ink tank and a pressurizing pump. An air buffer is immersed in an ink liquid contained in the atmospheric pressure chamber. The air buffer is surrounded by a resilient wall and the inside of the air buffer is communicated with the atmosphere through an air inlet. When the ink liquid contained in the atmospheric pressure chamber freezes, the expansion of the ink liquid is absorbed by the air buffer, thereby preventing the explosion of the atmospheric pressure chamber.