JP2688054B2 - Light beam recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light beam recording apparatus, and more particularly, to a light beam recording apparatus that records information such as characters on a recording material using a light beam. [Prior Art] As an apparatus for recording information such as characters on a recording material by a light beam, for example, a laser beam is scanned based on computer output information to directly record information such as characters on a recording material such as a microfilm. A laser computer output microfilmer (Lasercom) is known. (JP-A-55-67722, etc.). This laser comb has a helium neon laser and an argon laser. After optical scanning with the same optical system, the two lasers are separated by utilizing the difference in wavelength, and the helium neon laser is used as a reading beam. In addition, an argon laser is used as a writing beam. The reading laser beam is used to generate a synchronization signal for obtaining the writing timing of the writing laser beam. That is, after the reading laser beam and the writing laser beam are combined and deflected in the main scanning direction, only the reading laser beam is separated by the dichroic mirror, and the reading laser beam is used to transmit the transmitting portion and the light shielding portion. A timing pulse is obtained by an optical encoder configured by alternately arranging and in the scanning direction, and a synchronization signal is obtained from the timing pulse. And
The recording timing on the recording material can be obtained from the synchronization signal and the recording information. As the above recording material, a material such as a laser direct film (LDF) that records in a heat mode as a recording layer a substance such as a metal thin film that causes thermal deformation such as melting, evaporation, and aggregation by high-density energy such as laser is used. Modal recording materials can be used. The material of the heat mode recording material is preferably a single metal or a multilayer, a mixture or an alloy of a plurality of metals, but may be a dye, a pigment or a synthetic resin. Further, a substance for increasing the sensitivity of heat mode recording may be contained in the recording layer, or a layer for increasing the sensitivity may be present separately, and a protective layer may be provided. Such a heat mode recording material can be prepared by forming a recording layer by a known method such as vapor deposition, electric plating, electroless plating, sputtering, ion plating and the like. Generally, heat mode recording materials have a large threshold effect,
Recording cannot be performed at all below the threshold energy, but it can be completely recorded at energy exceeding the threshold even a little. [Problems to be Solved by the Invention] However, in the laser comb, which is an example of the above-described optical beam recording apparatus, there are two sources, a light source that emits a reading laser beam and a light source that emits a writing laser beam for obtaining a synchronization signal. Two light sources, and an optical system for combining and separating these laser beams,
There was a problem that the number of parts was large and the device was large. The present inventor has the following problems when recording the above heat mode recording material such as LDF which should solve the above problems as a recording material.
We proposed a light beam recorder that can record using two light sources. However, in the light beam device, since the writing laser beam and the reading laser beam are emitted from one light source, they cannot be separated, and the energy of the writing laser beam is higher than that of the reading laser beam. The laser beam for use may pass through the light blocking portion of the optical encoder provided to obtain the timing pulse. Therefore, there is a problem in that the sync signal becomes inaccurate due to the transmitted light. The present invention has been made to solve the above-mentioned problems, and when recording a heat mode recording material such as the above LDF as a recording material, it is possible to generate an accurate synchronization signal by using one light source. An object is to provide a beam recording device. [Means for Solving the Problems] In order to achieve the above object, the present invention provides a light beam recording apparatus for irradiating a recording material capable of recording with light having an energy of a predetermined level or more with a light beam to record information. A light source that emits the light beam, a scanning optical system that scans the light beam emitted from the light source onto the recording material, and an energy of the light beam emitted from the light source that is less than the predetermined level. Based on the light beam transmitted through the member, a limiting means for limiting the Pulse signal generating means for generating a pulse signal having a pulse width corresponding to the width of the transmissive portion and a cycle corresponding to the arrangement interval of the transmissive portions, an amplifier circuit for amplifying the pulse signal, and an output of the amplifier circuit A low-pass filter circuit that cuts the signal of the leaked light amount portion from the light-shielding portion from the signal, a multiplication circuit that multiplies the frequency of the pulse signal output from the low-pass filter circuit, and synchronization based on the output pulse signal of the multiplication circuit. It is characterized by further comprising: a synchronizing signal generating means for generating a signal; and a controlling means for controlling the energy of the light beam to be equal to or higher than the predetermined level based on the synchronizing signal and the information to be recorded. [Operation] According to the present invention, the light beam emitted from the light source has its energy limited by the limiting means to become bias light, which is scanned in the main scanning direction by the scanning optical system. The recording material is not recorded because the energy of is less than the predetermined level. At this time, the light beam scanned in the main scanning direction is applied as a so-called reading light beam for obtaining a synchronization signal for recording information on the recording material. The light beam for reading passes through a member in which a plurality of transmitting portions and light-shielding portions are alternately arranged in the scanning direction and which is arranged on the light beam irradiation side of the scanning optical system. The pulse signal generating means generates a pulse signal having a pulse width corresponding to the width of the transmissive portion of the member and a cycle corresponding to the arrangement interval of the transmissive portions of the member by the transmitted light beam. Next, this pulse signal is multiplied by the multiplication circuit, and the synchronizing signal generating means generates a synchronizing signal from the multiplied pulse signal. Based on the synchronization signal and the information to be recorded, the control means increases the energy of the light beam emitted from the light source above the predetermined level to generate a so-called writing light beam. The writing light beam emitted from the light source is scanned in the main scanning direction by the scanning optical system, and an image is formed on the recording material to record the recording information on the recording material. At this time, the writing light beam passes through the light-shielding portion of the member in which a plurality of transmitting portions and light-shielding portions are alternately arranged in the scanning direction, so that noise is generated from the pulse signal generating means. The pulse signal containing this noise is amplified by the amplifier circuit and cut by the low-pass filter circuit, thereby cutting off the signal of the leak light amount portion from the light shielding portion. That is, in the present invention, the signal transmitted through the light shielding unit has a lower frequency than the write signal multiplied by the multiplier circuit, noise is removed from the signal having the low frequency, and then the
A signal from which noise has been removed is multiplied by a multiplication circuit to generate a synchronization signal. As a result, the error of the synchronization signal generated by noise is dispersed, and an extremely accurate synchronization signal can be obtained. The recording material may be moved in the sub-scanning direction by moving the recording material itself, or by using another scanning optical system for scanning the light beam in the sub-scanning direction. [Effect of the Invention] As described above, according to the present invention, since the reading light beam and the writing light beam are emitted from one light source, the number of parts is reduced and the apparatus itself can be made compact. Furthermore, an excellent effect that an accurate synchronization signal is obtained can be obtained. [Embodiment] FIG. 1 shows a schematic configuration diagram of a light beam recording apparatus according to an embodiment of the present invention. First, the optical system of this device will be described. This optical system includes a semiconductor laser 10 as a light beam light source. A laser beam emitted from the semiconductor laser 10 is collimated by a collimator lens 12 arranged on the emission side and converged by a cylindrical lens 14, and then reaches a rotary polygon mirror (polygon mirror) 16. The polygon mirror 16 has a plurality of reflecting surfaces 17 for deflecting the laser beam in the main scanning direction. A focusing lens 18 is arranged on the reflection side of the polygon mirror 16, and a beam splitter 20 for reflecting a part of the laser beam emitted from the focusing lens 18 is arranged on the exit side of the focusing lens 18. A lens 22 that focuses the laser beam reflected by the beam splitter 20 is provided on the reflection side of the beam splitter 20.
Is arranged. An optical encoder 24 in which a plurality of transmissive portions for transmitting or blocking a laser beam and light shielding portions are alternately arranged in the scanning direction on the focal plane on the exit side of the lens 22.
Is arranged. On the transmission side of the optical encoder 24, a photodiode 26 that outputs a voltage according to the amount of transmitted light of the laser beam that has passed through the optical encoder 24 is arranged, and this output value is supplied to an amplifier circuit 38 described later. It is supposed to be done. Further, on the transmission side of the beam splitter 20, when the energy of the laser beam imaged by the imaging lens 30 through the cylindrical lens 28 that focuses the laser beam transmitted through the beam splitter 20 in one direction is above a predetermined level. A recording material 32 on which information is recorded is arranged. Next, the control system of the light beam recording apparatus will be described with reference to FIG. An amplifier circuit 38 is arranged on the output side of the photodiode 26. A clip circuit 40 is arranged on the output side of the amplifier circuit 38 so that a voltage above a certain level is cut. On the output side of the clip circuit 40, a low-pass filter circuit 41 that passes only pulses of a predetermined frequency or lower is arranged.
A PLL 42 as a multiplication circuit is arranged on the output side of. The PLL 42 multiplies the frequency of the timing pulse (for example, 10, multiplies). The synchronization signal generator 44 is arranged on the output side of the PLL 42,
The timing pulse output from 42 is input.
The output of the synchronization signal generator 44 is the control circuit 46 and the print driver 54.
And has been supplied to. The control circuit 46 controls the print driver 54 and the semiconductor laser driver based on the input synchronizing signal.
Control 56. Character information is input to the print driver 54 from a computer or the like. A semiconductor laser driver 56 including a bias current generator and a pulse current generator is arranged on the output side of the print driver 54, and the input current to the semiconductor laser 10 is changed according to the signal output from the print driver 54. Let A large current (I _{1 in} FIG. 2A and I _{1 in} FIG. 3) and a small current (I _{0 in} FIG. 2A) are applied to the semiconductor laser 10.
And I ₀ ) in FIG. 3). As shown in FIG. 3, when I _S is a threshold current, the recording material is supplied when a small current I ₀ is supplied. A so-called reading laser beam that is not recorded is output, and a so-called writing laser beam that can record the recording material 32 is output when the large current I ₁ is supplied. Further, the control circuit 46 is connected to the driving unit of the polygon mirror 16 via the polygon mirror driver 52 and also connected to the imaging lens 30 via the autofocus mechanism 50.
Further, the recording material 32 is connected via a sub-scanning driver 48 to a motor 34 that conveys the recording material 32 in a direction opposite to the sub-scanning direction, and controls each of them. Next, the operation of the present embodiment will be described. As shown in FIG. 1, the print driver 54 is a semiconductor laser 10 through the laser driver 56, for reading and outputting the read laser beam output current (I ₀ and Figure 3 I ₀ in Fig. 2 A) Irradiate a laser beam. At this time, the reading laser beam emitted from the semiconductor laser 10 is emitted to the polygon mirror 16 via the collimator lens 12 and the cylindrical lens 14. The light beam reflected by the polygon mirror 16 is applied to the beam splitter 20 via the focusing lens 18, a part of which passes through the beam splitter 20, and the rest is reflected in the direction of the optical encoder 24. The laser beam transmitted through the beam splitter 20 is a cylindrical lens 28.
The recording material 32 is irradiated via the. However, since the laser beam for reading is not irradiated with the laser beam having the energy of the predetermined level or higher, the recording material 32 is not recorded due to the insufficient light amount (FIG. 3). The laser beam reflected by the beam splitter 20 is applied to the optical encoder 24 via the lens 22. The reading laser beam that has passed through the transparent portion of the optical encoder 24 is applied to the photodiode 26. When the photodiode 26 is irradiated with the reading laser beam, the photodiode 26 generates an output voltage according to the amount of transmitted light. The photodiode 26 has a voltage corresponding to the amount of received light when receiving the laser beam, and has OV when not receiving the laser beam, and outputs a pulse signal (FIG. 2B) to the amplifier circuit 38. The pulse signal input from the photodiode 26 to the amplifier circuit 38 is amplified by the amplifier circuit 38 and output to the clip circuit 40. Amplifier circuit 38
The pulse signal input from the clipping circuit 40 to the clipping circuit 40 is output to the low-pass filter circuit 41 by the clipping circuit 40 as a pulse signal (J in FIG. 2) from which a pulse of a certain level or more (P in FIG. 2) has been removed. It The pulse signal (J in FIG. 2) input from the clip circuit 40 to the low-pass filter circuit 41 is the pulse signal (second pulse) from which the pulse having a certain frequency or more (Q in FIG. 2) is removed by the low-pass filter 41.
It is output as shown in FIG. Here, for the pulse (P in FIG. 2) above a certain level, the writing laser beam described below is the optical encoder 24.
The light passes through the transparent portion of the photo diode 26 and is emitted to the photodiode 26. Further, since the energy level of the laser beam for writing is considerably higher than that of the laser beam for reading, the pulse of a certain frequency or more (FIG. 2Q) is transmitted through the light shield portion of the optical encoder 24 and the photodiode 26 It is irradiated and generated. The pulse signal input from the low-pass filter circuit 41 to the PLL 42 has its frequency multiplied by 10 and becomes a basic timing pulse (in FIG. 2D, an example of 6 multiplication) is output to the synchronizing signal generator 44. The synchronizing signal generator 44 outputs a synchronizing signal (FIG. 2F) to the control circuit 46 and the print driver 54 after counting a fixed number of the basic timing pulses. Character information is input to the print driver 54 from a computer or the like (not shown), and the print driver 54 converts the character information into dots per main scanning, and a write signal generated from the converted dots and the synchronizing signal. (FIG. 2G) is output to the semiconductor laser driver 56. The high level portion of the signal in FIG. 2G corresponds to a part of the character. The semiconductor laser 10 write signal input from the semiconductor laser driver 56, the high-level portion irradiated with the laser beam for writing the input current increases (I ₁ and Fig. 3 I ₁ in Fig. 2 A). This writing laser beam is irradiated onto the recording material 32 for recording with a light amount of a predetermined level or more. At this time,
The recording material for the exposure amount E of the writing laser beam
As shown in FIG. 3, the density D on 32 becomes 0.3 or more, and the writing laser beam is clearly recorded on the recording material 32. Further, the sync signal output from the sync signal generator 44 is also input to the control circuit 46, and the control circuit 46 keeps the motor 34 constant via the sub-scan driver 48 from the start time of the main scan based on the sync signal. Rotate at speed to perform sub-scan. The control circuit 46 uses the autofocus mechanism 50 to form the imaging lens 30.
Is controlled automatically so that a minute light spot is formed on the recording material 32. In this way, in this embodiment, since the reading light beam and the writing light beam can be emitted from one light source, the number of parts can be reduced and the device itself can be made compact.
Further, since the clip circuit 40 and the low-pass filter circuit 41 are used to remove noise generated by the writing laser beam passing through the optical encoder 26, an accurate synchronization signal can be obtained. In the above embodiment, the low pass filter circuit 41 is connected between the clip circuit 40 and the PLL 42, but the amplifier circuit 38
And the clip circuit 40 may be connected. Further, in the above-described embodiment, the semiconductor laser 10 is used as the light source and the semiconductor laser output is modulated by the semiconductor laser driver 56. However, an Ar ion laser (other laser, for example, a krypton ion laser or a YAG ion laser) may be emitted. The acousto-optic modulator may modulate the signal from the modulator driver, and the O-order light including the bias light may be used as the light source.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of an optical system and an electrical system of an embodiment of a light beam recording apparatus of the present invention, and FIG. 2 shows a photoelectric pulse signal obtained from a photodiode of this embodiment. FIG. 3 is a diagram showing a relation with a semiconductor laser driver output signal, and FIG. 3 is a diagram showing a relation between a semiconductor laser input current, an exposure amount and a recording density. 10 ... Semiconductor laser, 16 ... Rotating polygon mirror, 24 ... Optical encoder, 26 ... Photodiode, 38 ... Amplification circuit, 41 ... Low-pass filter circuit, 42 ... PLL (Multiplication circuit) ), 44 ... Synchronous signal generator, 46 ... Control circuit.

Claims (1)

(57) [Claims] A light beam recording device for recording information by irradiating a recording material capable of recording with light having an energy of a predetermined level or more, the light source irradiating the light beam, and the light beam irradiated from the light source. A scanning optical system for scanning the recording material onto the recording material, a limiting means for limiting the energy of the light beam emitted from the light source to a value less than the predetermined level, and a plurality of transmissive portions and light-shielding portions alternate in the scanning direction. A member arranged on the light beam irradiation side of the scanning optical system and a pulse width corresponding to the width of the transmission part based on the light beam transmitted through the member and corresponding to the arrangement interval of the transmission parts. Pulse signal generating means for generating a pulse signal of a cycle, an amplifier circuit for amplifying the pulse signal, and a low-pass filter for cutting a signal of a leaked light amount part from the light shielding part from an output signal of the amplifier circuit. Filter circuit, a multiplication circuit that multiplies the frequency of the pulse signal output from the low-pass filter circuit, a synchronization signal generation unit that generates a synchronization signal based on the output pulse signal of the multiplication circuit, and the synchronization signal is recorded. Control means for controlling the energy of the light beam above the predetermined level based on the power information.