Abstract: An exposure apparatus having a transparent base member opposed to a photosensitive drum and forming part of a vacuum chamber, an electrode formed in the vacuum chamber for discharging thermoelectrons, a fluorescent member formed on the base member for emitting light when receiving the thermoelectrons, an anode for supplying the fluorescent member with a potential for colliding the thermoelectrons against the fluorescent member, the anode shaping the configuration of light emitted from the fluorescent member, and a microlens formed in the base member in contact with the fluorescent member, for converging onto the photosensitive drum the light emitted from the fluorescent member. When thermoelectrons are discharged from the electrode, the fluorescent member emits light, which has a configuration limited by the anode and is efficiently converged onto the photosensitive drum through the microlens formed in the base member in contact with the fluorescent member, to perform exposure.

Abstract: In a printer apparatus according to the present invention, the amount of charge applied to a photoconductor is measured at at least two points. A variation in dark decay which controls an image density, is recognized for the developing position of each developing unit. The grid bias voltage applied to the grid screen of the main charging device and the developing bias voltage applied to each of the developing units are set so as to satisfy the intensities of the contrast voltage and background voltage predetermined for each of the developing positions of the developing units.

Abstract: In an apparatus for adjusting the intensity of a light beam, the light beam from a semiconductor laser is deflected to scan a photosensitive drum and is detected to generate a positional signal by a photodetector outside of the drum. The intensity of the light beam is also detected by a monitor detector and compared with a predetermined value. The comparison result is latched in a latch circuit in accordance with the positional signal and the semiconductor laser is controlled depending on the latched comparison result.

Abstract: In an apparatus for adjusting the intensity of a light beam, the light beam from a semiconductor laser is deflected to scan a photosensitive drum and is detected to generated a positional signal by photodetector outside of the drum. The intensity of the light beam is also detected by a monitor detector and compared with a predetermined value. The comparison result is latched in a first latch circuit in accordance with the positional signal and a driving data is determined in accordance with the latched comparison data. The driving data is also latched in a second latch circuit and the semiconductor laser is controlled depending on the latched driving data.

Abstract: In an apparatus for adjusting the intensity of a light beam, a driving current which is gradually increased is supplied to a semiconductor laser in a warming-up mode. The intensity of the light beam is detected by a monitor detector and compared with a predetermined value. The comparison result is latched in a first latch circuit and a preset drive data is determined in accordance with the latched comparison data and stored in a memory. The semiconductor laser is driven in a printing mode, in accordance with the preset drive data stored in the memory mode so that a printing condition can be established in a relatively short time. In the printing mode, the intensity of the light beam is adjusted in accordance with the comparison result obtained in the printing mode.

Abstract: An image forming apparatus according to this invention includes a main charger for uniformly charging a surface of a photoconductive drum, an electrostatic latent image forming unit for forming an electrostatic latent image on the drum charged by the main charger, a developing unit for making visible the electrostatic latent image formed on the drum by the electrostatic latent image forming unit, and a transfer charger for transferring the image made visible by the developing unit onto a paper sheet. Power supply circuits supply operation voltages to the main charger and the transfer charger, and currents flowing from the power supply circuits to the main charger and the transfer charger are detected by current detectors. The current values detected by the current detectors are compared with corresponding predetermined values by comparators.

Abstract: A recording apparatus according to the present invention in which a data is recorded by charging a recording medium, scanning laser beams on the recording medium to form electrostatic latent images thereon, and developing and transferring the electrostatic latent image, comprises a charger for charging the recording medium; and at least two image forming device disposed around the recording medium for recording multi-colored and/or uni-colored data in a plurality of print modes. In the recording apparatus, the print modes is controlled so as to drive the second image forming device corresponding to the second print mode after the operation of the first print mode is closed, when the second print mode is designated in the operation of the first image forming means corresponding to the first print mode. And, the driver for driving the recording medium is controlled so as to continuously drive the recording medium when the first print mode is switched to the second print mode by the switching device.

Abstract: A recording apparatus according to the present invention in which a data is recorded by charging a driven recording medium, scanning laser beams on the driven recording medium to form electrostatic latent images thereon, and developing and transferring the electrostatic latent image, comprises a charger for charging the driven recording medium; and at least two image forming device disposed around the recording medium for recording multi-colored and/or uni-colored data in a plurality of print modes. In the recording apparatus, the print modes is controlled so as to drive the second image forming device corresponding to the second print mode after the operation of the first print mode is closed, when the second print mode is designated in the operation of the first image forming means corresponding to the first print mode.

Abstract: A recording apparatus having a photosensitive body, a charger for charging the photosensitive body, an exposure unit for forming a latent image on the photosensitive body charged by the charger, and a developing unit for developing the latent image into a visible image on the photosensitive body. The recording apparatus also includes a first surface potential sensor for measuring the surface potential of the photosensitive body before the latent image has been developed by the developing unit, a second surface potential sensor for measuring the surface potential of the photosensitive body after the latent image has been developed by the developing unit, a computer for computing the surface potential of the photosensitive body at a position between the first and second surface potential sensors to estimate the surface potential at the position of the developing unit, and a controller for controlling the charger so that the estimated surface potential becomes a determined level.

Abstract: A recording apparatus according to the present invention in which a data is recorded by charging a drived recording medium, scanning laser beams on the drived recording medium to form electrostatic latent images thereon, and developing and transferring the electrostatic latent image, comprises a charger for charging the drived recording medium; and at least two image forming device disposed around the recording medium for recording multi-colored and/or uni-colored data in a plurality of print modes. In the recording apparatus, the print modes is controlled so as to drive the second image forming device corresponding to the second print mode after the operation of the first print mode is closed, when the second print mode is designated in the operation of the first image forming means corresponding to the first print mode.