摘要:
A test procedure is provided for obtaining optimum illumination exposure in a document scanning an exposure system. A document illumination lamp is energized and reflection images from a document platen is transmitted through an optical system onto a linear photosensor array which is positioned in the normal exposure (image) plane. The array outputs, corresponding to individual photodiodes outputs, are amplified and processed under the control of a computer controlled software program to provide a real time display of the illumination characteristics on a display screen. The screen, in one embodiment, displays a colored bar graph which is superimposed against the horizontal line representing an in specification illumination level. The lamp and, or, illuminator, is repositioned while observing the bar graph until an optimum bar graph value is measured below the specification line. Other displays are provided to monitor and adjust performance of an infrared densitometer and to adjust the gain of the individual photodiodes which form the photosensitive array.
摘要:
An automatic exposure control system for a full-frame copier controls the illumination of a flash lamp in response to the reflectivity of a document to be reproduced. A photodetector senses exposure at the wall of a light housing and after sufficient exposure is reached, the light source is turned off (quenched). A compensation circuit anticipates the total energy emitted after quench (representing an over exposure potential) and terminates the light source energizing pulse so as to produce only desired exposure without over-exposure error.
摘要:
An imaging module mounting structure is used for mounting an imaging module to an imaging device that has a support member and a rotatable photoreceptor. The imaging module includes an imaging bar and a corona generating device. The imaging module mounting structure includes a pair of pivot block devices which are pivotably connected to the support member in a spaced apart relationship. The imaging bar and the corona generating device are secured to each one of the pair of pivot block devices. Each pivot block device includes a cam follower element. The pair of pivot block devices are operative to flex independently of one another while the photoreceptor rotates so that the respective cam follower elements remain in contact with the rotating photoreceptor to compensate for photoreceptor run out. A method for practicing the present invention is also described.
摘要:
The light output of a fluorescent lamp is controlled and optimized. Both the light output and the lamp voltage peak at nearly the same value of mercury cold spot temperature. Controlling the lamp voltage therefore controls the light output. Thus, when the lamp voltage is continually monitored, any decline from the peak voltage is detected and a signal is generated which reverses the instant mode of operation of a cooling device placed in proximity to the lamp cold spot. With the cooling mode reversed, the lamp voltage will rise towards the peak. The cooling mode remains unaltered until the lamp voltage falls again.
摘要:
An improved system for segregating and identifying separate job sets from a commonly stacked output of plural job sets of copy sheets sequentially generated by a printer and sequentially outputted into a sheet stacker in which they may be superposed commonly stacked. A control system selects which standard size sheet supply tray of the printer will feed the copy sheets for a selected job set, and can automatically feed and print a cover sheet of a larger size or different orientation before or after the job set copy sheets are fed. The sheet stacker may desirably stack the copy sheets of the job sets commonly edge aligned but so that at least one edge area of the cover sheets extends substantially from at least one edge of the stack of copy sheets of the job sets to provide an exposed printed banner strip for clear job sets segregation and separation even if the commonly stacked plural job sets of copy sheets are misaligned in subsequent handling. The cover sheets may be printed side up even if the job set copy sheets are stacked printed side down. The exposed banner strip may have identifying indicia printed thereon for identifying job sets.
摘要:
An image bar recording system, which, in a preferred embodiment, utilizes an LED image bar, with associated circuitry for recognizing which of individual LEDs comprising the print bar are out of registration in the slow scan, process direction of a moving photoreceptor upon which the image is to be recorded. Modification of the drive circuits to the individual LEDs results in energization signals being delayed to the identified, misregistered LEDs resulting in an exposure line which is in correct slow scan registration.According to another aspect of the invention, the delayed signals are selectively applied to intentionally cause a misregistered exposure line when using the image bar in conjunction with a raster output scan system.
摘要:
An amalgam fluorescent lamp is designed to operate with minimum axial illumination variations when changing from an off to an on state. This is accomplished by incorporating at least three amalgam patches internal to the lamp. Two patches are located at opposite ends of the lamp, and at least a third patch is centrally located. Each patch has an associated thermistor ands external heater sleeve. The patch temperature which correlates wiht the optimum lamp operating temperature is continuously monitored and adjustments are made to the heater sleeve elements to maintain the patches at desired optimum temperature.
摘要:
A low pressure gas discharge lamp is provided with a pair of high power incandescent electrodes to increase output illumination at the lamp ends. In an alternate construction, the electrodes are of high power, low emissivity and are electrically connected to a second pair of high emissivity electrodes which provide the means for enabling the mercury discharge. With this second construction, the low emissivity electrodes can act as ballast for the circuit.
摘要:
An image bar printing system, which, in a preferred embodiment, utilizes a plurality of LED arrays to provide a plurality of color images. The print bars are used in conjunction with a plurality of gradient index lens arrays which optically couple and focus the LED outputs onto a photosensitive surface. In order to maintain image-to-image registration, out of spec deviations in active write length of the image bar and scan line bow are identified and compensated for by selective deformation of one or more lens arrays in a specified manner. The lens deformation serves to reorient the position of certain of the lens elements, redirecting the transmitted LED outputs so as to shorten or lengthen the active write length, or to eliminate bow in the scan line.
摘要:
An image bar recording system, which, in a preferred embodiment, utilizes a plurality of LED image bars to provide a plurality of latent images which may subsequently be developed in different colors. The print bars are initially aligned so that each color image is precisely registered at the same relative position along the exposed area of a photoreceptor belt. The alignment is accomplished by adding non-image fiduciary pixels to the ends of each print bar and by forming a pair of opposed alignment apertures in the surface of the belt. Y-axis alignment of the print bars is accomplished by detecting edge locations of a first pixel and using this location to select a centrally located fiduciary pixel. The X-axis alignment is then obtained by rotating the print bar to bring a second selected image pixel into alignment as sensed through a second aperture. Once the initial X and Y-axis alignments are complete, subsequent alignment is maintained through subsequent passes by checking the positions of the previously identified pixels as they advance past additional lead edge apertures formed in the process direction along the belt surface.