The optical scanning system described copier

[REVIEW] is commonly used office equipment copiers, which combines optical technology, electrostatic imaging technology, electronic technology and mechanical technology, and structural principle is more complex.
Copier is commonly used office equipment, which combines optical technology, electrostatic imaging technology, electronic technology and mechanical technology, and structural principle is more complex. The optical system is an important component of the electrostatic copying machine, it is effected by the respective optical element is exposed to the document, thereby forming a light image and the light image is transmitted to the charged surface of the photosensitive drum with a uniform charge, so that the formation and light and shade of the original image corresponding to the electrostatic latent image. Various types of optical system of the copying machine are quite different, but the role of its working principle and the functional components are substantially the same.

One of the basic requirements of the optical system

Since the structure of the optical system great influence on the overall structure of the copier and the copy quality is closely related to the product of the optical system, therefore, the optical system of the electrostatic copying machine must meet the following basic requirements:

The light source and the spectral characteristics of the lens, and should be used to match a drum.

Two light source should have sufficient strength so that sensitized quickly erasing the photosensitive drum.

3 should be used in small power source and a high luminous efficiency to reduce power consumption.

4 optical system to adjust better performance, higher efficiency through the light (ie, small light loss).

5 the optical system of the light conductor and synchronization errors, not more than 0.5%, while the scanning start point to the end point of the entire process, the optical distance is always kept constant.

6. Ensure uniform illumination of the entire manuscript.

7 should have good heat dissipation to ensure continuous copying copier, make the platen glass temperature does not exceed 70 ℃.

8 Repeat accuracy of the system is higher, structural durability, safety and reliability.

9 should have a good sealing to prevent contamination of the external environment of the optical system.

10 The system should be easy handling, adjusting, cleaning and replacement of wearing parts.

11 Install the light source, should be kept on the ground level, especially halogen, or affect their life.

12 through the optical system, the irradiation light conductors should make the surface of the photoconductive layer of the light receiving points are basically the same;

Second, the optical scanning system

Manuscript scanning exposure optical system is called scanning system comprising the platen glass, light exposure, and the mirror scanner, scanner and lens position detecting sensor unit and the like.

(A) the type of optical scanning systems currently used in xerographic copiers scanning platen main mobile slit exposure, the exposure draft stage movement and mirror optical fiber type mobile slit exposure three. The so-called slit exposure when the exposure is a band of light is irradiated through the document and synchronously moving the photosensitive drum scanning exposure, an electrostatic latent image formed on the photosensitive drum.

1 Platen mobile slit exposure platen mobile scanning exposure system using reciprocating platen glass to complete the image scanning. Wherein the exposure lamp, lens and reflector are stationary, and the platen surface speed of the photosensitive drum is synchronized movement or to move a certain percentage. Therefore, this approach has an optical scanning exposure system is simple structure, small size, image clear, accurate, etc., but this machine platen load capacity of the poor, Copy speed is generally quite low, you can not copy a large weight of the original, and larger working space, less zoom level.

2 exposure platen moving fiber type optical fiber is composed of two rows of the optical fiber system alternately stacked with each other, instead of using the fiber matrix of the lens optical system and a mirror, the original image is directly transferred to the reflected light the photosensitive drum surface to form an electrostatic latent image. This type is characterized by the copier platen moves work; optical fiber does not move, simple structure, small size, but can not zoom and low resolution. Commonly used optical fiber has a diameter of about 1.1mm, the fiber length of 29.4mm. If CanonNP-200 copier older models.

3 Platen Platen fixed exposure optical system fixed exposure mode most of the copier is used in xerographic copiers, process the exposure mode is: Before copying the original table and imaging lenses are stationary, while the first scan always moving speed of the mirror and the photosensitive drum surface speed equal to or proportional to, the second scanning mirror in the first half of the moving speed of the scanning mirror and the first scanning mirror with the movement, and the first mirror to either the fourth or fifth mirror image on the left or right lens, must always be in focus of the imaging lens, the conjugate distance kept constant. Stationary platen copier platen which is characterized by a large load capacity, copying thick books, a small working space, copy and fast, but the accuracy of the optical scanning device to move higher, and requires scanning system as light as possible, and In the course of the campaign should be kept stable, vibration small. Ricoh FT-4085 copier platen is fixed.

Constituting two electrostatic copier scanning system) scanning system and a light source is divided into two parts and the light path member member. The main part of the exposure light source, the reflector, the light amount adjusting plate components. Optical components mainly include the platen glass, flat mirrors and imaging lens. For some copier toner contamination from the optical member, the intermediate member and the imaging science preferably also provided with a dust-proof glass.