JPS6072473A - Laser recorder - Google Patents

Abstract

PURPOSE:To generate a timing clock with high accuracy by providing plural concave mirrors, detecting a scanning light reflected in each concave mirror with plural photodetectors provided opposite to each concave mirror and amplifying properly respectively the output signals of the photodetectors so as to give a slit transmitted light with good quality to the photodetectors. CONSTITUTION:The laser light converted into a scanned light by a polygon mirror at first is led to a slit 10 via a scanning lens 6 and projected onto the concave mirror 18 through a light diffusing plate 16 provided closely to the rear side of the slit 10. The projected scanned light has an angle to the concave mirrors 18a-18e, collected by the concave mirror 18a and detected by the photodetector 17a provided opposite thereto. The adjacent laser beam projected continuously is collected respectively by the concave mirrors 18b, 18c- and detected by the photodetectors 17b, 17c-. After the reflected light is amplified respectively by individual amplifier 19a, 19b-, the result is inputted to an adder 20 to generate a recording timing pulse.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laser recording apparatus that scans an optically modulated laser beam to form a latent image on the surface of a photoreceptor, develops the latent image, and outputs it as a hard copy.

[Conventional technology]

Conventionally, there has been a laser recording device of this type as shown in Fig. gA1. In the figure, 1 is a laser light source, 2 is, for example, an AOM (acousto-optic modulator) for imparting optical modulation to the beam from the laser light source 1 via a half mirror 3;
is a mirror... - reflects the transmitted light of the mirror 3 as it is. 5 is a rotating polygon mirror (hereinafter abbreviated as polygon mirror) for reflecting the laser beam output from the laser light source 1; one side scans the recording material 7 through the scanning lens 6;
The other projects a laser beam onto the slit lo via mirrors 8 and 9. Reference numeral 11 denotes a concave mirror that reflects one nose beam that has passed through the aforementioned Surin 10 and focuses it on a light receiver 12 . 13 is an amplifier, 14 is a waveform shaper that shapes the output signal of the amplifier 13, and 15 is an information source, which is an AOM driver 2a.
The operation will be explained below. One of the laser beams output from the laser light source 1 is incident on the AOM 2 via the half mirror 3, where optical modulation is applied to the recording material 7 as image data. On the other hand, the laser spot transmitted through the half mirror 3 is "
When reflected, it is converted into a scanning beam of a predetermined width by the polygon beam 5 as described above and guided to the line 10 for forming a timing clock for recording. The scanning light that has passed through the concave mirror 11 causes a laser spot to run at a constant period, and the laser spot passes through the light receiver 12.
When the light is focused, a timing clock as an electric signal is photoelectrically converted by the photoreceiver 12 and outputted, and is supplied to the AOM driver 2a via the amplifier 13 and waveform shaper 14 at the subsequent stage. The AOM driver 2a is synchronized with this timing clock signal [7 and is input from the information source 15 and received -1
It is configured to provide evening light to A OAi 2. : The nose of a conventional laser recording device condenses the laser transmitted beam through the slit 1o with one concave mirror with the width of the scanning line Nagai, receives the light with one light receiver, and performs a timing check.・T): 1) Therefore, for example, when performing high-resolution recording or when using large-sized recording materials, concave mirror aberrations and manufacturing errors may be caused. It is difficult to increase the timing clock δ due to the deviation of the beam of the receiver, etc.
There were drawbacks such as difficulty in obtaining high-quality notes.・ [Object of the present invention] 1 The present invention was developed to eliminate the above-mentioned drawbacks of the conventional laser recording device, and includes a plurality of concave mirrors,
The scanning beams reflected by each of the concave mirrors are detected by a plurality of light receivers provided oppositely to each concave mirror, and the output signals of the light receivers are amplified accordingly.
A high-quality slit-transmitted light was applied to the receiver, a high-precision timing clock was generated, and a large recording material was used. Hey. Yes, □.

[Embodiment of the present invention] An embodiment of the present invention will be described with reference to the drawings.

In the figure, the same □- parts as in Figure 1 are shown with the same reference numerals.・17e
are each □ concave mirror 1 □ 8゛a・・・・・・18e
19a......1
9e is the plurality of light receivers 171a...7
This is an amplifier that amplifies the output signal of e and provides No. 1 to the adder '20 at the subsequent stage.

Next: The operation of the present invention will be explained below. first,
Bo・+7 d 7oi, '-5+Yo, scanning light, U The converted laser □ laser beam is passed through the scanning lens 6 as shown in Figure □2.
After passing through the slit 10, the light is guided through the slit 10, passes through the diffuser plate 16 provided closely behind it, and is projected onto the concave mirror '18. The projected scanning light has a certain angle with respect to each concave mirror 18a...:...1:8e as shown in FIG. The light is focused by the concave mirror 18a and received by the opposite receiving light 'W17a'. Adjacent and continuous projection: The scanning angle θhθ3 of the stirring saw 1 and the beam... Concave mirrors 18b, 18C...:... by the same principle as above 1 and □.
...The light is collected and received by the receivers 17b, 17c...
...is □receiver. As described above, the laser beam in one scan is divided and focused by 'n concave square mirrors, each of which receives one photoreceiver 17a, 17b...
Detect the reflected light at: Output 1 each: Separate amplifier 1
9., 19b, . . . are amplified: and then input to the adder '20. The adder ILI output signal mentioned above is applied to the waveform shaper 14 to generate a recording 1 timing pulse. As shown in Fig. 31 □, the scanning light condensed by the concave mirror falls within the light receiving range of the light receiver 1, but in the case where it falls outside the light receiving range, the 4th As shown in the figure, the light receiving efficiency can be improved by arranging ζ-convex lenses 26a, 26b, . . . in front of the light receiver.

FIG. 5 shows another embodiment in which the scanning light focused by each concave mirror is focused by an optical fiber 22 in one-to-one correspondence with each concave mirror, and is output from the output end of the optical fiber. The emitted light is received by a light receiver 24 via a condensing lens 23. In this case, in order to allow the scanning light to enter the optical fiber 22 perpendicularly, deterioration of the sight can be prevented by attaching concave lenses or convex lenses 21a, 21b, . . . to the input end of the optical fiber 22. In the case of this method, as shown in Figure 2, there is no need to provide as many photodetectors and amplifiers as there are for each concave mirror, and by using optical fibers, only one set of photodetectors and amplifiers is required. .

[Effects of the present invention]

As described above, according to the present invention, a plurality of concave mirrors are provided, each of which is arranged at a predetermined angle to the laser scanning light transmitted through the slit, and a light receiver that reflects the scanning light and faces toward the other;
Alternatively, optical fibers (2) can be used to condense light, so the concave mirror, photodetector, and amplifier can be combined into a single unit (seven units can be assembled, so when designing an actual machine, connect the units for the required scanning line length). In addition, the length of the unit can be selectively used to increase the number of recording materials (according to the increase in the number of recording materials).Also, in the event of a failure, it is possible to easily replace the unit and improve the optical relationship between the concave mirror and the receiver. This has the effect of simplifying position adjustment.Furthermore, by dividing the concave mirror into n pieces, processing becomes easier and the processing precision of each concave mirror improves, resulting in higher light collection efficiency and lower cost. As a result, an accurate recording timing clock can be obtained and high quality laser recording can be performed.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the main parts showing the optical system and electrical system of a conventional laser recording device, and Fig. 2 is a block diagram of the optical system for timing clock generation using laser scanning light, showing an embodiment of the present invention. , FIG. 3 and FIG. 4 are optical system diagrams for condensing and receiving light in the present invention, and FIG. 5 is a diagram showing the configuration of an optical system showing another embodiment of the present invention. 1--- v-the light source, 2-A OM 12 a・
AOM driver, 3... Half mirror 14, 8, 9.
...Mizzy, 5...Polygonomiror, 6...[
E lens, 7...Recording material, 10...Slit, 11°18...Concave mirror, 12,17.24...
・Photoreceiver, 13.19.25...Amplifier, 14...
- Waveform shaper, 15... Information source, 16... Diffusion plate, 20... Adder, 21... Concave lens, 22.
...Optical fiber, 23...Condensing lens, 2
6... Convex lens. Patent applicant Shaken Co., Ltd. Figure 3 Figure 4

Claims (3)

[Claims] (1) A slit is placed on the scanning optical path of the clock generation light beam, and the laser beam that passes through the slit is reflected by a condensing section made of a concave mirror and directed toward the light receiving section to generate a recording timing clock. In such a laser recording device, there is provided a condensing unit in which n concave mirrors are arranged in parallel with a width corresponding to the scanning line length of the laser beam, and a scanning light condensed by the concave mirror is paired with each concave mirror. What is claimed is: 1. A laser recording apparatus, comprising: a light receiving section that receives light using n light receivers, and generates a recording timing clock by receiving the reflected scanning light. (2) A patent claim characterized in that the pair of opposed light condensing parts and light receiving parts are each made into a unit, and the units are connected in a number corresponding to the required scanning line length for the width of the scanning light. The laser recording device according to item 1. (3) The scanning light condensed by n concave mirrors is incident on an optical fiber arranged in one-to-one correspondence with each concave mirror, and the scanning light emitted from the output end of the optical fiber is passed through a condenser lens. 2. A laser recording apparatus according to claim 1, wherein the laser beam is received by 71 sets of light receivers.