JPH0138573Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention irradiates the photosensitive surface of the photosensitive drum with a light beam that is modulated based on printing information from an electronic computer, etc., and thereby creates a latent image formed on the photosensitive surface. This relates to, for example, an electrostatic printing type optical printer in which a hard copy is obtained by visualizing the image using various developing means. The present invention relates to an optical printer having an optical scanning mechanism for scanning.

An optical printer in which a modulated light beam is scanned onto a photosensitive surface by a spiral reflecting surface set up on a rotating drum has already been proposed by the applicant of this invention (patent application). Showa 54-
No. 115416). This patent application No. 115416 (1982)
The printer of No. 39519) scans one light beam onto one photosensitive drum using one optical scanning mechanism.

On the other hand, in order to enable simultaneous printing of multiple pieces of data and also to enable color printing in one pass without reducing the printing speed, multiple light beams are sent to multiple locations on one photosensitive drum using one optical scanning mechanism. An optical printer that projects images onto a certain position is disclosed in Japanese Patent Application Laid-open No. 161566/1983. The printer disclosed in this publication uses a rotating mirror as an optical scanning mechanism, and an f-
A θ lens is used. In order to image multiple light beams using a single f-theta lens, a structure is adopted in which the angle of incidence of each light beam on the f-theta lens is different.
A cylindrical lens is provided to correct distortion of the light beam that has passed through the θ lens.

However, the conventional structure described above causes a problem of mutual interference between multiple light beams passing through the f-theta lens.
In order to avoid this, if the deviation angle of the incident angle is increased, the problem arises that distortion increases and correction becomes difficult. In addition, the optical system requires at least a rotating mirror, an f-theta lens, and a cylindrical lens, and a reflecting mirror for splitting the plurality of light beams at predetermined intervals is also required.
There is a problem in that assembly requires a large number of man-hours and a high degree of skill. Furthermore, since there are multiple types of optical paths for the light beams, there is a problem in that the shape and adjustment work of the lenses for matching the positional accuracy and focal length of the light beams passing through different optical paths becomes extremely complicated.

Therefore, by further developing the invention of Japanese Patent Application No. 54-115416, this invention does not have the above-mentioned problems, and also enables multi-task processing with a single optical scanning mechanism. This was done with the aim of obtaining an optical printer that can also print.

In other words, the optical printer of this invention includes a rotating cylinder with a spiral reflecting surface erected thereon, and a plurality of light sources arranged to project a modulated light beam onto the reflecting surface in parallel with the axis of the rotating cylinder. and a photosensitive drum of the same number as the light sources arranged parallel to the rotating cylinder so as to receive each of the plurality of light beams reflected by the reflecting surface, and facing each light source with the rotating cylinder in between. Further, the rotary cylinder has a slit between the light source side end and the opposite end of the spiral reflecting surface through which the light sensor can be seen from the light source side. It is characterized by having the following. Here, the modulated light beam is
It refers to a narrow beam of light that is turned on and off based on signals from a computer or other command device, or whose luminous intensity is changed over time.

The following description will be based on the illustrated embodiment. In the figure, 1 is a rotating cylinder, 2 is a reflective surface erected on the outer peripheral surface of the rotating cylinder 1, 3 is an electric motor for rotating the rotating cylinder 1, 4a, 4b and 4c are laser oscillators,
5a, 5c, 5c are laser oscillators 4a, 4b, 4
A modulator 7a, 7b, 7c modulates the light beams 6a, 6b, 6c from the rotary cylinder 1 based on print information given from an electronic computer (not shown); 8a, 8b, 8c are the reflected lights, 9a,
9b, 9c are photosensitive drums arranged parallel to the rotating cylinder 1 to receive reflected lights 8a, 8b, 8c, respectively; 10a, 10b in FIGS. 2 and 3;
10c is a developing device, 12a, 12b, 1 in FIG.
2c and 12 in FIG. 3 are printing paper.

The rotating cylinder 1 has a large diameter surface 13 and a small diameter surface 14, and the large diameter surface 13 and the small diameter surface 14 are perpendicular to these surfaces and have a spiral reflecting surface 2 with a lead angle of 45 degrees. It is connected by a stepped surface 15 parallel to the axis of the rotating cylinder 1.

Laser beams 6a, 6b, 6c from laser oscillators 4a, 4b, 4c are transmitted to optical modulators 5a, 5b,
5c and are respectively modulated and projected onto the reflecting surface 2. Modulated laser beams 7a, 7b, 7c
is reflected by the reflective surface 2 in the connecting direction of the rotating cylinder 1, and these reflected lights 8a, 8b, 8c are reflected by the photosensitive drum 9.
The light is projected radially toward the photosensitive drums 9a, 9b, and 9c, and is irradiated onto the photosensitive surfaces of the photosensitive drums 9a, 9b, and 9c as light spots 16a, 16b, and 16c. These light spots 16a, 16b, 16c are connected to the electric motor 3.
When the rotating cylinder 1 is rotated in the direction of arrow A in the figure, it moves on the photosensitive drums 9a, 9b, and 9c in the direction of arrow B in the figure.
Movement of a, 16b, 16c and photosensitive drums 9a, 9
Due to the intermittent rotation of photosensitive drums 9a and 9c,
Desired characters or figures can be separately formed as latent images on the photosensitive surfaces of the sheets 9b, 9c, and these latent images are visualized by a known electrostatic printing means and printed on the printing paper 12 or 12a, 12b, 12c.

Here, FIG. 2 is a diagram showing a state when performing multitasking processing using the optical printer of this invention, in which light beams modulated separately by light modulators 5a, 5b, and 5c are transmitted to a photosensitive drum 9a. ,9
b, 9c, respectively, and this photosensitive drum 9
Printing paper 12 attached separately to a, 9b, 9c
A, 12b, and 12c print printing information that is not related to each other, making it possible to perform parallel printing processing for as many light sources and photosensitive drums as there are disposed, greatly increasing the overall printing speed. It becomes possible to do so. It is also possible to obtain a plurality of hard copies by supplying the same print information to the modulators 5a, 5b, and 5c. Figure 3 shows the state in which color printing is performed using the printer of this invention.
The latent images formed on the three photosensitive drums 9a, 9b, 9c are visualized with toner of different colors and transferred onto the paper 12, and one sheet of printing paper is developed with the photosensitive drums 9a, 9b, 9c. Device 10a, 1
0b and 10c in order to perform color printing using the three primary colors. In this case, it goes without saying that the print information given to the modulators 5a, 5b, and 5c are mutually related information.

In addition, 17 in FIG. 1 is a slit formed between the reflecting surface 2 and the stepped surface 15 at the end of the rotating cylinder 1, and 18a, 18b, and 18c are arranged on the projection line of the light beams 7a, 7b, and 7c, respectively. These optical sensors 18a, 18b, 18
The light beams 7a, 7 that passed through the slit 17 at c
By detecting b and 7c, the scanning start time point is detected for each optical scan. 19a, 19b, and 19c in FIGS. 2 and 3 are paper guide rollers.

As explained above, the optical printer of this invention has a plurality of independent light sources and a plurality of photosensitive drums corresponding to each of these light sources. The beam is scanned onto each photosensitive drum by a single rotating cylinder, and the optical paths of multiple light beams can be made exactly the same, and the optical system is complicated. There is no need for an f-theta lens, a correction lens, a reflective mirror for branching the optical path, etc. of the structure. Furthermore, since a plurality of light sources and photosensitive drums can be arranged in an orderly manner on an arc centered on the axis of the rotating cylinder at regular intervals and parallel to the rotating cylinder, assembly and maintenance of its accuracy is extremely easy. Furthermore, a slit is provided between the light source side end and the opposite end of the reflective surface of the rotating cylinder so that the side opposite to the light source can be seen from the light source side, and an optical sensor is provided facing each light source. The operation timing of each light source can be controlled accurately, and accurate operation can be performed with simple control. Therefore, with this idea, we have created a high-precision optical printer that can print multiple pieces of data simultaneously and print in color in one pass by projecting multiple light beams onto multiple photosensitive drums using a single optical scanning mechanism. It has the advantage of being simple in structure and can be realized at low cost.

[Brief explanation of drawings]

The figures show one embodiment of this invention, in which Fig. 1 is a perspective view showing the main parts, Fig. 2 is a side view showing a state in which parallel printing is performed by the apparatus of this invention, and Fig. 3 is a perspective view showing the main part. The figure is a side view showing a state in which color printing is performed using the apparatus of this invention. In the figure, 1 is a rotating cylinder, 2 is a reflective surface, 3 is an electric motor, 4a, 4b, 4c are laser oscillators, 5a, 5
b, 5c are modulators, 7a, 7b, 7c are light beams, 8a, 8b, 8c are reflected lights, 9a, 9b, 9
10a, 10b, 10c are developing devices; 12, 12a, 12b, 12c are printing sheets; 17 is a slit; 18a, 18b, 18c are optical sensors; 19a, 19b, 19c are paper guide rollers.

Claims (1)

[Scope of utility model registration request] A rotating cylinder 1 with a spiral reflecting surface 2 erected thereon, and a plurality of light sources 4a, 4b arranged to project a plurality of individually modulated light beams onto the reflecting surface parallel to the axis of the rotating cylinder. 4c, and photosensitive drums 9a, 9b, and 9c of the same number as the light sources arranged parallel to the rotating cylinder so as to receive the reflected light of the plurality of light beams separately, and facing each light source with the rotating cylinder in between. Each optical sensor 18a, 18
b, 18c, and a slit 17 through which the optical sensor can be seen from the light source side is formed between the light source side end and the opposite end of the spiral reflective surface of the rotating cylinder. , optical printer.