JPS6126049B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical scanning recording device that records a desired image by scanning a light spot generated by a light beam on a recording material. The present invention relates to an improvement in a device that mechanically performs the required deflection.

FIG. 1 is a schematic explanatory diagram showing a conventional example of this type of optical scanning recording device.

In FIG. 1, 1 is a light source that generates a light beam 2, 3 is a modulator driven by a modulation signal 4, 5 is a rotating polygon mirror, and 6 is a recording material.
The modulated light beam incident on the rotating polygon mirror 5 is given a deflection angle θ as the polygon mirror 5 rotates, and is emitted, and a light spot is generated on the recording material 6 by the emitted light beam. 7 scans on the trajectory 8, desired images are sequentially recorded.

FIG. 2 is a time chart of the modulation signal 4 (S(t) shown). In the figure, T is the scanning period, and Ts is the application time of the modulation signal, that is, the effective scanning time.

In the conventional apparatus as described in FIGS. 1 and 2, the effective scanning time Ts during which the light spot 7 actually scans the recording material 6 is relatively short compared to the scanning period T. Therefore, in order to record images at high speed, the rotational speed of the rotating polygon mirror is increased to increase the number of scans per unit time. By increasing the number of surfaces of the rotating polygon mirror, the effective scanning time for the scanning period T
To improve the ratio of Ts, it must be equal.

However, in order to increase the rotational speed of a rotating polygon mirror, it is necessary to (a) improve the weight balance by increasing the dimensional accuracy of the polygon mirror and supporting members, as well as consider strengthening the rigidity and using special bearings, etc. Not necessarily,
A sharp rise in prices is inevitable.

(b) As the rotation speed of the polygon mirror increases, the modulation speed of the light beam must be increased, so a high-speed optical modulator and its driving circuit are required.

(c) In order to compensate for the decrease in the amount of exposure per unit area due to the increase in the scanning speed of the light spot on the recording material, it is necessary to use a high-output light source or use a highly sensitive recording material. However, this also leads to an increase in costs.

Also, the effective scanning time for the scanning period T
If the number of surfaces of the rotating polygon mirror is increased in order to improve the ratio of Ts, (d) a significant increase in the size of the rotating polygon mirror becomes unavoidable.

The present invention is directed to a novel optical scanning recording device that can substantially increase the number of scans, that is, the recording speed, without being bothered by the drawbacks of conventional optical scanning recording devices such as those described in (a) to (d) above. A scanning recording device is provided. This will be explained below based on the figures.

FIG. 3 is an explanatory diagram showing an embodiment of the optical scanning recording apparatus according to the present invention, and FIG. 4 is a schematic plan view thereof. In FIGS. 3 and 4, the light source section 9
is attached to a shaft 10 and continuously rotates by a drive source (not shown). The light source section 9 has a plurality of light beam projection optical axes 1 radially arranged at approximately equal intervals.
It is equipped with N sets of light beam generating means 12-1 to 12-N, which form light beam generating means 1-1 to 11-N. The configuration of each of these light beam generating means 12 is not particularly limited, but may include, for example, a light emitting diode, a semiconductor laser or other appropriate light emitting source 13, a lens 14 provided as necessary, or a light beam generator for modulating the intensity of the projection light beam. It is equipped with a modulation drive circuit (not shown) and the like. Reference numeral 15 denotes a recording material (transfer medium such as a photosensitive drum) provided in a cylindrical shape coaxial with the shaft 10 along the locus 7 (indicated by a broken line) of the light spot 16 formed by the light beam generating means 12. ), and is configured to be fed in the direction of the arrow 19 in synchronization with the rotation of the light source section 9 by the operation of the feed drive section 18. Therefore, the scanning line 20 drawn on the recording material 15 by each of the light spots 16 that moves with the rotation of the light source section 9 has a spiral shape as shown in the figure, and the pitch P thereof is determined by the distance between any two adjacent projection beams. This corresponds to the rotation time between the axes, that is, the amount of movement of the recording material in one scanning period of the light spot 16.

Furthermore, in FIG. 3, 21-1 to 21-N supply a brightness modulation signal S ₁ to each of the light beam generating means 12.
A rotating transformer 22 for supplying ~S _N is a light beam generating means 1 despite the high speed rotation of the light source section 9.
Self-power generation unit to supply stable power to 2.
23 is a rotary encoder that outputs a signal in accordance with the rotation of the shaft 10; 24 is a periodic control section; and 25 is always set the rotational position information of the light source section 9 by counting the signals from the rotary encoder 23. A counter 6 indicates a corresponding start signal when the value of the counter 25 reaches a predetermined value.
Decoder that outputs ST ₁ to ST _N , 27 is recording material 1
5 is a photoelectric conversion element that is provided on the trajectory 17 in the vicinity and detects the passage of the light spot 16, and 28 is a modulation control section. Generally, the decoder 26 includes:
When the projection optical axis 11-n reaches the vicinity of the photoelectric conversion element 27, a start signal ST _o is output. When this start signal ST _o is input to the modulation control section 28, the corresponding OR gate 29 and output amplifier 30 are activated to output the brightness modulation signal Sn. This brightness modulation signal Sn
is supplied to the light beam generating means 12-n via the rotating transformer 21-n to drive it, and the light spot 16
- generate n. When the light spot 16-n reaches the photoelectric conversion element 27 as the light source section 9 rotates, a coincidence signal ID is output. At this time, the corresponding AND gate 31 becomes conductive and the line buffer register read control circuit 32 is activated. The readout control circuit 32 executes readout of the line buffer register 33 in synchronization with the rotation of the light source section 9, that is, the movement of the light spot 16, based on a signal from the synchronization control section 24. At this time, the read control circuit 32 may be provided with a delay operation corresponding to section _L1 in FIG. Light beam generating means 12-1
In _each of the N line buffer registers 33 provided corresponding to . is set. These recorded information are supplied from an external device such as a computer, and when the reading for any one scanning line is completed, the light beam generating means 12
Information regarding the scanning line to be scanned next is newly set. Then, by driving the light beam generating means 12-n with the brightness modulation signal Sn read out from the line buffer register 33 in which recording information is set, a desired recording is made on the corresponding scanning line. It is starting to be implemented.
As is clear from FIG. 3, each of the light beam generating means 12-1 to 12-N is provided so that modulation can be controlled individually, and in the figure, recording is performed simultaneously on three scanning lines. The case is shown.

Next, various other embodiments of the optical scanning recording apparatus according to the present invention will be described based on the schematic diagrams of FIGS. 5 to 8. Note that the same parts as those already explained are indicated by the same numbers in the drawings.

5 is fundamentally different from the case shown in FIG. 4 in that the recording material 15 is flattened by providing an imaging lens 34. In this case, the light beam from the light source 13 is collimated by the lens 14,
By passing through the imaging lens 34, a light spot 16 is formed on the recording material 15 placed at its focal plane. At this time, since the rotational position of the light source section 9 and the positional relationship between the light spot 16 are generally non-linear, a pre-corrected brightness modulation signal is supplied, or the imaging lens 34 is set to a so-called f- By using a θ lens, the distortion of the recorded image due to the non-linearity may be corrected.

FIG. 6 shows the imaging lens 34 as in the case of FIG.
By providing a parabolic cylindrical mirror 35 having a focal axis at the center of the rotating shaft 10,
This is intended to flatten the recording material 15. In this case, the light beam that has passed through the lens 14 is
and forms a light spot 16 on the recording material 15.
At this time, the rotational position of the light source section 9 and the position of the light spot 16 have a non-linear relationship similar to the case of FIG. 5, so in order to record a completely distortion-free image,
The light beam generating means 12 must be driven with a brightness modulation signal that has been corrected in advance.

In the embodiments shown in FIGS. 3 to 6, the light beam generating means 12 themselves are provided radially at equal angular intervals, so that each light beam projection optical axis 11 is set in a desired radial shape. In contrast, in the one shown in FIG. 7, each light beam generating means 12 is arranged in the same direction as the axis 10, and the light beam emitted from there
By reflecting the light beams with a trapezoidal polygon mirror 36 that rotates integrally with the light source section 9, each light beam projection optical axis 11 is radially spaced at desired equiangular intervals. The one shown in FIG. 7 is smaller in size in the direction of the rotation radius compared to the others, making it possible to increase the rotation speed or reduce mechanical strength. Incidentally, the lens 14 can be omitted by making each reflecting surface of the trapezoidal polygon mirror 36 a light-condensing concave mirror.

FIG. 8 shows an embodiment in which a plurality of recording materials 15 are provided, and the recording materials 15 having the shape shown in FIG. 4 are installed at three locations. At this time, as described above, since each light beam generating means 12 can individually and independently modulate the brightness, a plurality of recording materials 1
It becomes possible to simultaneously record arbitrary images for each of the 5 images.

As described in detail above, the optical scanning recording device according to the present invention has a
(N2) a rotating light source section comprising a set of light beam generating means, each of which has projection optical axes corresponding to the respective light beam generating means arranged radially at approximately equal angular intervals on the same plane, and light from the rotating light source section; A recording material onto which a light spot formed by the beam is projected, a feeding drive unit that transports the recording material in the same direction as the rotational axis direction of the rotating light source unit, and each of the light beam generating means,
It consists of a modulation control section that outputs individual brightness modulation signals, and a synchronization control section that synchronizes the rotational operation of the rotating light source section and the operations of the feed drive section and the modulation control section. As a result, the present invention makes it possible to improve the effective scanning time Ts ratio to the scanning period T and to simultaneously scan multiple light points without increasing the price or increasing the size of the device. The actual number of scans per hit is increased to improve the recording speed.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of a conventional optical scanning recording device, FIG. 2 is an operation time chart of the device shown in FIG. 1, and FIGS. 3 and 4 are explanations showing an embodiment of the optical scanning recording device according to the present invention. The drawings, schematic plan views, and FIGS. 5 to 8 are schematic diagrams showing various other embodiments of the optical scanning recording apparatus according to the present invention. 9... Light source section, 11... Projection optical axis, 12... Light beam generating means, 13... Light emitting source, 15... Recording material, 16...
Light spot, 18... Feed drive section, 23... Rotary encoder, 24... Synchronous control section, 25... Counter, 26
...Decoder, 27...Photoelectric conversion element, 28...Modulation control section, 32...Line buffer register read control circuit, 33...Line buffer register, 34...
Imaging lens, 35...parabolic cylindrical mirror, 36... trapezoidal polygon mirror, _S1 to _SN , and S(t)...luminance modulation signal, T...scanning period, _ST1 to _STN ...start signal, Ts …
Effective scan time.

Claims (1)

[Claims] 1. N (N≧2) sets of light beam generation means provided to rotate together and each equipped with an imaging lens, and each projection corresponding to each of these light beam generation means. a rotating light source section whose optical axes are arranged radially at approximately equal angular intervals on the same plane; a recording material onto which a light spot formed by a light beam from the rotating light source section is projected; and the recording material is connected to the rotating light source. a modulation control section that outputs individual brightness modulation signals to the light beam generating means; a modulation control section that outputs individual brightness modulation signals to the light beam generating means; a plurality of modulation signal transmission means for transmitting to the light beam generation means; a rotational operation of the rotating light source section; and a feeding drive section;
An optical scanning recording device comprising: a synchronization control section that synchronizes each operation of the modulation control section.