1 Laser Camera General Working Principle
Laser camera's light source is a laser beam, the laser beam is projected through the evanescent lens system to a rotating prism and then refracted, the refracted laser beam through the focusing lens system to print on the film.
The intensity of the laser beam can be adjusted by a regulator, which is controlled by a digital signal. The imaging device inputs the pixel unit values of the image digitally into the memory of the laser printer, which directly controls the intensity of the laser exposure for each pixel unit. If the computer sequentially outputs contemporaneous information about the position of the laser beam film, electrical signals in a different order can be illuminated by the laser onto the film as a flat image. After exposure, the film is then processed by developing and fixing, so as to obtain a photo image.
2 laser camera work process
When the laser camera is powered on, the machine control system (MCS) to the central processing unit (CPU) and the delivery system for self-test. After the self-test is completed, the MCS sends a hardware
reset command to the image management system (/MS) to initialize the IMS. While the above program is working, the film drying system heats up; in the case of a wet camera, the infrared heater heats up the developing and fixing fluids. When the ~iReady lamp is on, the laser camera is ready for use. The operator stores each image with the keyboard memory button and sends instructions and image data to the multiplexer (MMV).After the MMV receives the instructions, the CPU controls the output arranger, which arranges the laser camera images into rows and enlarges them according to the operator's settings. Then, the image data is converted from digital to analog signals. When the laser generator works properly, the image analog signal controls the laser modulator, which is used to change the brightness of the laser beam, through a series of lenses focusing and reflectors (about 10) to transmit the laser beam to the film. During this process, a photodetector is used to continuously collect signals from a stationary beam splitter, which are fed back to the laser generator to stabilize the source laser beam. A rotating beam splitter is used to control the delivery of the beam to the film to sensitize it in a manner known as X-axis fast scanning. The drum in the camera cabinet delivers the film at a fixed speed, in a manner known as Y-axis slow scanning. In this way, the camera accurately reproduces the entire image at a rate of 6o0 lines/second of image data transfer.
The film is automatically supplied from the supply storage cassette (which holds 100 laser sheets) and is loaded on a special print drum under a guide axis transport, which then turns to the print position. At this time, the laser beam in accordance with the computer and matrix instructions, the image pixel unit PIX-EL gray value of the digitized density transmitted to the laser camera memory, direct control of each pixel unit of the laser exposure time for the intensity of the change. The laser beam is scanned and printed by rotation of the prism. During all exposures, the drum and the laser beam move in precise synchronization, and the image union and arrangement of multiple photographs are selected for printing according to the layout and image size programmed by the host imaging unit, which is accomplished with an operating panel. An image of the matrix pixels for 4kx5k, to be all the images printed, the film that is transferred to the receiving box or transferred to the self-expression machine, automatic development.
3 laser camera structure
3.1 wet laser camera
Wet laser camera structure is mainly composed of six parts: switching power supply, image control system (IMS), gripping mechanism control system (PCB), laser print control system, film drive control system (MCS), automatic processing unit. The main functions of each part are as follows:
(1) Switching power supply: Provide suitable working power for each working unit of laser camera.
(2) image control system: responsible for the host of the image signal to organize, according to the need for compartmentalized layout; at the same time, the image contrast, density can be adjusted and so on. Image control system controlled by the computer is the core of the laser camera. Camera image signals transmitted to the laser camera, after a series of processing corrections to adjust the image size, size, layout. The laser head outputs lasers of different strengths and weaknesses according to the image signals after layout, thus completing the scanning process of the film. The processing power of the laser camera determines the camera's image quality, adaptability and range of applications.
(3) gripping mechanism control system: responsible for the need to scan the film grabbed, sent to the laser scanning area.
(4)Laser printing control system: the wet laser printing control system consists of 2 parts: laser scanning and film transmission. Layout completed image signals, through the control circuit is transformed into a laser scanning light signal required. Laser beam calibrated according to the "line scanning" (from left to right) in the film to form the image signal latent shadow. Film transfer system in the servo system controlled by a high-precision motor to ensure that the laser scanning, driving the film in the direction of the Y-axis uniform speed forward through the scanning area, so as to complete the entire film scanning (printing) process.
(5) Film transmission control system: responsible for the entire film transmission process.
(6) automatic processing unit: laser camera and automatic film processor connected together, so that the printing of the formation of latent image of the film does not enter the receiving box, but directly into the film processor for processing.
3.2 Dry Laser Camera
The structure of dry laser camera is mainly composed of six parts: switching power supply, image control system (IMS), gripping mechanism control system (PCB), laser printing control system, film drive control system (MCS), film development rotary heating system. The main functions of each part are as follows:
(1) Switching power supply, image control system, gripping mechanism control system, film transfer control system, the four parts of the function and the wet laser camera is largely the same.
(2) laser printing control system: different from the wet laser camera, dry laser camera in the laser printing process, the film is always at rest, the laser beam in the film X-axis and Y-axis direction of the scanning of the laser head attached to the control mechanism to complete. Different manufacturers or models of laser cameras, the scanning method is different.
(3) film development rotary heating system: the system will be heated after the laser scanning film to make it develop, so as to complete the wet laser camera in the automatic film developer, fixing, washing, drying and other work.
4 laser camera maintenance and maintenance
Whether dry or wet laser camera, its instruction manual provides maintenance instructions and methods, should be strictly in accordance with the requirements of the manual carefully operated. If the camera malfunction, you can follow the fault prompts for general processing; for more complex faults. It is recommended to find the manufacturer's engineers and technicians to repair.
4.1 Wet laser camera
(1) machine room humidity should be maintained at about 2O ℃, and maintain proper ventilation and dry. Because, the liquid volatile acid and alkali gases and humid indoor air on the machine's circuitry and components have a certain degree of corrosion, easy to cause the machine to work poorly or malfunction.
(2) according to the amount of film washing and the degree of attenuation of the liquid regularly replace the liquid, each replacement of the liquid should be thoroughly cleaned developing, fixing and washing tank, remove the crystallization of each place. Carefully clean and wipe each liquid level probe to keep it in good working condition. Carefully and carefully brush and clean each washing roller, taking care to avoid damaging the gears and roller surface. When replacing or cleaning the liquid, use a special baffle plate to prevent the liquid from splashing into the printer along the film inlet. The developer and fixer tanks can be manually filled with liquid each time the liquid is changed to prevent the probe from burning the hot bar when it is not working properly. The water in the water washing tank is filtered with a filter rod to prevent impurities in the water from contaminating the film and affecting the image quality of the photographs. After the liquid is replaced, turn on the machine and observe the information on the display panel, and pay attention to whether the sound of each part of the action is normal. Machine self-test heating is complete and display "on line" before printing the film.
4.2.2 Dry Laser Camera
4.2.1 Safety Guidelines for Maintaining the Dry Laser Camera
(1) Electrical or machine malfunctions should only be repaired by experienced personnel; (2) Do not replace or disassemble the integrated safety devices; (3) Do not cover the ventilation openings; (4) Do not lubricate the printer; (5) Before carrying out any maintenance work, make sure that the equipment is turned off and unplugged from the outlet. turn off the unit and unplug the power cord from the outlet (when not turned off, you can remove the film jam or clean the printer thermal head).
4.2.2 Surface Cleaning of the Dry Laser Imager
(1) Turn off the unit; (2) unplug the power cord from the outlet; and (3) wipe the surface with a clean, soft, damp cloth. If necessary, clean with an appropriate amount of soapy water or detergent, but do not use ammonia-based cleaners. Be careful when cleaning, and do not allow any liquid to enter the power cord end el or flow inside the camera; (4) turn on
the device after plugging it in.
4-2.3 Cleaning of the laser head
(1) Turn off the power; (2) Turn on the device according to the camera's instructions; (3) Use a lint-free cloth impregnated with a small amount of ethanol to gently wipe it in the same direction, do not lift the cloth, and do not apply any pressure to the laser head to avoid damage; (4) Install the device and turn on the power.
4.2.4 Laser Camera Card
Laser camera card occurs, there is generally a fault prompt: Film Jam. caused by the card for many reasons . Such as: film input disk can not feed the film, drive shaft axis ask friction mismatch, sensor failure, sudden power outages and so on. Therefore, it is necessary to analyze carefully, accurately determine the location of the card, the right remedy to remove the carded film.
References
1] Meng Wei. AGFA laser camera common faults and maintenance [JJ. Medical and health equipment, 2005, 26 (7): 78.
2] Pan Guobin. Kodak l9O medical laser camera card troubleshooting [JJ. Medical and health equipment, 2005, 26(10): 86.