JPH01155370A - Laser printer - Google Patents

Abstract

PURPOSE:To accomplish the scaling-down of a printer device by using a laser beam both as a light source for recording information and a light source for reading information. CONSTITUTION:Since a movable reflecting mirror 6 is positioned out of an optical path when the title printer works, the laser beam L is made incident on a photosensitive drum 5 through plural reflecting mirrors 3 and 4 after passing an ftheta lens system 2. Meanwhile, since the movable reflecting mirror 6 is positioned on the optical path when the action of reading an original is performed, the laser beam L is reflected by the movable reflecting mirror after passing the ftheta lens system 2 and reaches a read original scanning part 7 placed on a position which is optically same distance as the photosensitive drum on the optical path of the laser beam. The reflected light from the read original scanning part 7 is condensed by a lens system 8 and made incident on a transducer 9 to be converted into an electrical signal. Thus, the device can be integrated and miniaturized so that the operations for reading the information and recording the information can be executed in one device. Then, a space for setting the device can be saved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention scans a photoreceptor drum at a constant speed with a laser beam modulated based on recorded information through a deflector.
The present invention relates to a laser printer that forms an electrostatic image corresponding to the recorded information on a photoreceptor drum, and particularly to a laser printer equipped with an information reading mechanism that uses the laser beam as both a printer light source and an information reading light source.

[Conventional technology]

Conventionally, a laser beam L emitted from a semiconductor laser 10 is made incident on a rotating polygon mirror or other deflector 1 as parallel linearly focused light, and is deflected and reflected at a predetermined angle by the rotation of the rotating polygon mirror, and is then directed to an fθ lens system 2. This type of optical scanning means, which forms a predetermined electrostatic latent image while scanning the photoreceptor drum after converting it into uniform motion
A commonly used method is to construct a laser printer by incorporating the unit into an electrostatic recording device based on a known electrophotographic recording method.

Furthermore, an apparatus has been proposed in which the scanning unit is configured to be removable and the photo section of the apparatus is also used as a copying machine.

[Problem that the invention seeks to solve]

Are all of these devices laser printers? Information is input to the laser printer using input means configured independently of the laser printer. Therefore, if you try to read information from a document and copy it with a laser printer, you will need two devices: an information reading device and a laser printer, or a device that incorporates these separate devices, which will increase the size of the device. is unavoidable.

In view of the drawbacks of the prior art, an object of the present invention is to provide a laser printer that realizes the two functions of an information reading device and a laser printer in one device by sharing an optical scanning unit and an optical system. do.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a method in which a laser beam deflected and swept by a deflector passes through an imaging lens system having a θ characteristic and then passes through a plurality of reflecting mirrors. a movable reflecting mirror attached between an fθθ lens and the photosensitive drum on the optical path of the laser beam; a laser beam reflected by the movable reflecting mirror; a reading document scanning section placed optically at the same distance from the photoreceptor drum on the optical path of the document, a lens system that collects the reflected light from the document, and a photoelectric converter that converts the collected reflected light into an electrical signal. By providing an information reading mechanism consisting of elements and using the laser beam as both an information recording light source and an information reading light source, it becomes possible for one device to serve both as an information reading device and a laser printer.

〔Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

Figure 1 shows the principle diagram. A laser printer having an optical scanning unit t configured such that a laser beam L deflected and swept by a deflector 1 passes through an fθθ lens 2 and then enters a photoreceptor drum 5 via a plurality of reflection mirrors 3 and 4. , a movable reflection mirror 6 attached on the optical path between the fθθ lens 2 and the first reflection mirror 3 on which the laser beam L enters after passing through the fθ lens system oil; a laser beam reflected by the movable reflection mirror; A reading original axis scanning unit 7 is placed on the optical path of the photosensitive drum at a position optically equidistant from the photosensitive drum, a lens system 8 condenses the reflected light from the document, and converts the condensed reflected light into an electrical signal. When the printer is in operation, a movable reflecting mirror 6
is located outside the optical path, and the laser beam L passes through the fθθ lens 2.
After passing through, the light enters the photosensitive drum 5 via a plurality of reflecting mirrors 3 and 4. On the other hand, during the original reading operation, the movable reflection mirror 6 is located on the optical path, and the laser beam L is f
After passing through the θθ lens 2, the light is reflected by a movable reflection mirror and reaches the reading document scanning unit 7, which is placed on the optical path of the laser beam and optically equidistant from the photoreceptor drum. The reflected light from the reading document scanning section 7 is collected by a lens system 8, enters a photoelectric conversion element 9, and is converted into an electrical signal.

〔Effect of the invention〕

As described above, according to the present invention, by using the information recording light source and optical system together with the information reading light source and optical system,
The information reading and information recording operations, which were conventionally performed by separate devices, can be performed by one device, and the device can be integrated into a compact device, thereby saving space in the device installation location.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the principle of the present invention, and FIG. 2 is an explanatory diagram showing a conventional example. l: Deflector, 2: fθθ lens, 3, 4: Reflection mirror,
5: Photosensitive drum, 6: 5T dynamic reflection mirror, 7: Original scanning section.

Claims (1)

[Claims] 1) The laser beam deflected and swept by the deflector is fθ
In a laser printer configured such that the laser beam passes through an imaging lens system having characteristics and then enters the generatrix of a photoreceptor drum via a plurality of reflecting mirrors, the optical path of the laser beam is connected to the fθ lens system and the photoreceptor drum. A movable reflecting mirror attached between the two, a reading document scanning unit placed optically at the same distance from the photosensitive drum on the optical path of the laser beam reflected by the movable reflecting mirror, and condensing the reflected light from the document. Equipped with an information reading mechanism consisting of a lens system that converts the focused reflected light into an electrical signal, and a photoelectric conversion element that converts the focused reflected light into an electrical signal.
A laser printer characterized in that the laser beam is used in combination as an information recording light source and an information reading light source.