JPH04314017A - Laser recorder - Google Patents

Abstract

PURPOSE:To obtain an excellent laser recorder to be used for a digital copying machine, a laser beam printer, etc., by simplifying the adjusting work of a 2nd reflection mirror for leading a laser beam projected from a laser scanner to an optical sensor for detecting a writing position and easily executing reajustment even in a market. CONSTITUTION:This laser recorder is provided with the laser scanner for irradiating a rotational polygon mirror 23 with laser beams projected from a laser oscillator 21 to be a light source and scanning a target with the laser beams, a 1st reflection mirror 25 for leading laser beams projected from the laser scanner to a recording medium, the optical sensor 28 for detecting a writing position, a 2nd reflection mirror 26 for leading the laser beams projected from the laser scanner to the sensor 28, and a slit member 27 to be a laser beam scanning position detecting means arranged in the front of the sensor 28.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser recording device for recording information using laser light.

0002

2. Description of the Related Art In recent years, digital copying machines and laser beam printers using laser recording devices have rapidly become popular. The configuration of a conventional laser recording device will be explained below. FIG. 4 shows a conventional laser recording device using a rotating polygon mirror. As shown in FIG. 4, its components include a laser transmitter 1, a condensing lens 2, a rotating polygon mirror 3, an fθ lens 4, and a photoreceptor drum 5 for directing the laser beam 10a emitted from the laser transmitter 1 to a photoreceptor drum. 9 is a first reflecting mirror for guiding the laser beam 10b emitted from the laser transmitter 1 to the optical sensor 8; 7 is a slit member; 8 is an optical sensor;
9 is a photosensitive drum.

[0003] Regarding the laser recording apparatus comprising the above-mentioned components, the related operations of the components will be explained below. First, a laser beam 10 emitted from a laser transmitter 1 passes through a condensing lens 2 and is deflected by a rotating polygon mirror 3. Furthermore, the first reflection mirror 5 passes through the fθ lens 4.
The laser beam 10a deflected by the laser beam 10a forms a latent image on the photoreceptor drum 9. Further, a part of the laser beam 10 deflected by the rotating polygon mirror 3 passes through the fθ lens 4 and reaches the second mirror 6, and the laser beam 10b deflected by the second mirror 6 passes through the hole of the slit member 7. and is guided to the optical sensor 8.

Generally, in a laser recording device, the above-mentioned optical sensor 8 is essential in order to align the scanning start position of the laser beam on the photoreceptor drum 9. It is necessary to adjust the tilt, position, etc. of the dedicated second reflecting mirror 6. Also,
In order to use a region of the optical sensor 8 where the sensitivity is relatively stable, a slit member 7 formed of a single rectangular hole is placed in front of the optical sensor 8.

[0005]

[Problems to be Solved by the Invention] However, in the conventional configuration as described above, when adjusting the second reflecting mirror 6 for guiding the laser beam to the optical sensor 8, the laser beam is stopped on the optical sensor 8. It is necessary to use a manual polygon mirror to adjust the position, a jig to confirm the position of the laser beam on the optical sensor 8, etc., and the adjustment work in the manufacturing process is complicated, and there is no re-adjustment in the market. The problem is that adjustment work is extremely difficult when the need arises.

The present invention solves the above-mentioned conventional problems, and aims to provide a laser recording device in which the second reflecting mirror b can be easily adjusted in the manufacturing process and readjusted easily in the market. purpose.

[0007]

[Means for Solving the Problems] In order to achieve this object, the laser recording device of the present invention includes a laser scanner that irradiates a rotating polygon mirror or a vibrating mirror with a laser beam emitted from a light source and scans the laser beam. , a first reflecting mirror for guiding the laser beam emitted from the laser scanner to the recording medium, an optical sensor for detecting the starting position of recording by the laser beam, and an optical sensor for guiding the laser beam emitted from the laser scanner to the recording medium. It has a second reflecting mirror for guiding the laser beam, and scanning position detection means for detecting the passing position of the laser beam in front of the optical sensor.

[0008]

[Operation] In the laser recording device of the present invention having the above configuration, when the laser light passes over the optical sensor, it passes through the scanning position detection means, so the laser light to the optical sensor is modulated depending on the position of the laser beam. Since the position information of the laser beam is input as the position information of the laser beam, the position signal of the laser beam can be obtained from the optical sensor, and the adjustment work of the reflecting mirror in the manufacturing process can be easily done by detecting the position signal from the optical sensor. Therefore, a laser recording device that can be easily readjusted can be provided on the market.

[0009]

【Example】

(Embodiment 1) A first embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the components include a laser transmitter 21 as a light source that emits a laser beam 30, a condenser lens 22, a rotating polygon mirror 23, and a rotating polygon mirror 23.
4 is an fθ lens, 25 is a first reflecting mirror for guiding the laser beam 30a emitted from the laser transmitter 21 and deflected by the rotating polygon mirror 23 which operates as a laser scanner to the photosensitive drum 9, and 26 is a laser transmitter. A second reflecting mirror 27 guides the laser beam 30b emitted from the device 21 to the optical sensor 28, and 27 is a slit member as a means for detecting the scanning position of the laser beam. The first hole 37 has a ridge 37a through which the laser beam 30b begins to pass, which is a straight line substantially perpendicular to the laser beam scanning direction, and a ridge 38a through which the laser beam 30b begins to pass is approximately arc-shaped or parabolic. The second holes 38 are arranged in parallel in the laser beam scanning direction, and the interval between the edges 37a and 38a is formed into a concave shape. 28 is a light sensor, 2
9 is a photosensitive drum.

Regarding the laser recording apparatus constructed as described above, the related operations of its constituent elements will be explained below using FIG. 1. First, a laser beam 30 emitted from a laser transmitter 21 passes through a condensing lens 22 and then passes through a rotating polygon mirror 23.
deflected by Furthermore, the laser beam 30 that passes through the fθ lens 24 and is deflected by the reflection mirror 25 forms a latent image on the photoreceptor drum 29.

On the other hand, the laser beam 30b is transmitted to the optical sensor 28.
By adjusting the second reflection mirror 26 provided outside the printing area so as to scan the laser beam 30
The laser beam 3 is emitted by the optical sensor 28 every time b is scanned.
0b and uses the detection signal at the edge 37a, where the laser beam 30b starts passing first, as the reference signal for the scanning start position, the laser beam 30a on the photoreceptor drum 29
Align the start positions of the . When the laser beam 30b scans, for example, the position indicated by the arrow a in FIG.
The signal detected from is a pulse output composed of two rectangular waves with a time interval t1 as shown in FIG. 3(a). The time t1 between the pulses of these two rectangular waves changes depending on the position where the laser beam scans the slit 27, and is shown in FIG.
When scanning the center as shown by the arrow b, the minimum value t2 is obtained as shown in FIG. 3(b). By converting the time t such as t1 and t2 obtained as above into a voltage value and detecting it as a voltage value v proportional to the time t, the second Reflection mirror 2
By adjusting 6, the laser beam can be set at the optimum position. At this time, the detection signal at the edge 37a is used as a reference signal for the scanning start position.

Furthermore, as shown in FIGS. 2(b), 2(c), and 2(d), the two edges through which the laser beam 30b begins to pass first are straight edges substantially perpendicular to the laser beam scanning direction. A straight edge 38b that intersects with the edge 37b, an approximately arcuate or parabolic edge 37c, a straight edge 38c that is approximately perpendicular to the laser beam scanning direction, and a straight edge that intersects with the edge 38d. Two holes each formed by a combination of a side 37d and a straight edge 38d substantially perpendicular to the laser beam scanning direction are arranged in parallel in the laser beam scanning direction, and each hole is formed on the edge 37b.
, 38c, and 38d as reference signals for the scanning start position, the same operation as described above can be obtained.

(Embodiment 2) In a second embodiment of the present invention, as shown in FIG. 2(e), the edge 37e through which the laser beam 30b begins to pass first has a substantially arc-shaped or substantially parabolic shape. The first hole 37 and the second hole 38 whose ridge 38e, through which the laser beam 30b starts passing next, is a straight line substantially perpendicular to the laser beam scanning direction are arranged side by side in the laser beam scanning direction, and the ridges 37e and 38e are arranged side by side in the laser beam scanning direction. The space between the two parts is formed into a convex shape. The operation of the configuration in which the first hole 37e and the second hole 38e are arranged side by side as described above will be explained. second mirror 2
6, when the laser beam 30b scans, for example, the position shown by the arrow a in FIG.
3, resulting in two square wave pulses. The interval t3 between the pulses of these two rectangular waves changes depending on the position where the laser beam scans on the slit member 27, and when scanning the center as shown by the arrow b in FIG. 2(e), the interval t3 in FIG. 3(d) changes. The maximum value is t4 as shown in FIG. t3, t4 obtained as above
The second reflecting mirror 26 is adjusted so that the voltage value v becomes a predetermined value by converting the time t such as the above into a voltage value and detecting it as a voltage value v proportional to the time t. At this time, the detection signal at the edge 38e is used as a reference signal for the scanning start position.

Furthermore, as shown in FIGS. 2(f), (g), and (h), the two edges through which the laser beam 30b begins to pass first are straight edges that are substantially perpendicular to the laser beam scanning direction. A straight edge 37f that intersects the edge 38f, a straight edge 37g that is approximately arc-shaped or a parabolic tip, a straight edge 37g that is approximately perpendicular to the laser beam scanning direction, and a straight line that intersects the edge 37h. Two holes each having a combination of a ridge 38h and a straight ridge 37h substantially perpendicular to the laser beam scanning direction are arranged in parallel in the laser beam scanning direction, and each hole has a ridge 38f.
, 37g, and 37h as reference signals for the scanning start position, the same operation as described above can be obtained.

[0015] That is, among the edges of the two slits,
It goes without saying that a similar effect can be obtained by having at least one side be a straight line for obtaining a reference signal and at least one other side being a curved line having one convex or concave portion for obtaining a position signal.

[0016]

Effects of the Invention As is clear from the above description, the present invention provides scanning position detection means that can detect the passing position of the laser beam in front of the optical sensor that detects the writing start position, so that the laser beam can be Depending on the position passing over the sensor, a signal with position information of the laser light is obtained from the optical sensor, and this time is further converted into a voltage value,
By setting the voltage to a predetermined voltage value, it is possible to easily adjust the reflective mirror after manufacture, and provide an excellent laser storage device that can be readjusted easily in the market.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the main parts of a laser recording device according to an embodiment of the present invention.

[Fig. 2] Front view of the slit member used in the laser recording device of the same example.

[Fig. 3] Waveform diagram showing signals detected from the optical sensor in the laser recording device of the same example.

[Figure 4] A perspective view of the main parts of a conventional laser recording device

[Explanation of symbols]

21 Laser transmitter 22 Condensing lens 23 Rotating polygon mirror 24 fθ lens 25 First reflective mirror 26 Second reflective mirror 27 Slit member 28 Optical sensor

Claims (2)

[Claims] 1. A laser scanner that irradiates a rotating polygon mirror or a vibrating mirror with a laser beam emitted from a light source and scans the laser beam, and a laser scanner that directs the laser beam emitted from the laser scanner to a recording medium. a second reflecting mirror for guiding the laser beam emitted from the laser scanner to the optical sensor; a second reflecting mirror for guiding the laser beam emitted from the laser scanner to the optical sensor; 2. A laser recording device further comprising a scanning position detecting means for detecting a scanning position of the laser beam between the second reflecting mirror and the optical sensor. 2. The scanning position detection means has two or more slits in the scanning direction of the laser beam, and at least one of the long sides of the two or more slits is a straight line, and other than the one side is a straight line. 2. The laser recording device according to claim 1, wherein the slit member is a curved slit member having at least one side having a convex or concave portion.