JP2002326395A - Exposure recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To record a highly accurate image using a plurality of light beams at a high speed. SOLUTION: An image can be recorded highly accurately at a timing in consideration of a response delay of an AOD 24 by changing over the AOD 24 between a zero order light outputting state and a first order light outputting state according to a changeover signal b, producing a second delay signal f delayed from the changeover signal b by a predetermined time by a first delay part 44 and a second delay part 48, and supplying zero order data and first order data of image data to a laser diode LD according to the second delay signal f.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure recording apparatus for exposing and recording a two-dimensional image by scanning a light beam output from a light source relative to an image recording material in a main scan and a sub scan.

[0002]

2. Description of the Related Art For example, a drum having an outer peripheral surface on which an image recording material is mounted is rotated in a main scanning direction, and a laser beam modulated in accordance with an image is scanned in a sub scanning direction orthogonal to the main scanning direction. There is used an exposure recording apparatus which records a two-dimensional image on the image recording material.

In such an exposure recording apparatus, the purpose is to record an image at a high speed. For example, an acousto-optical deflecting element (hereinafter, referred to as an AOD (Acousto-Optic Deflector)) is used to apply a laser beam in a sub-scanning direction. There is a configuration in which a plurality of main scanning lines are formed at substantially the same time by deflecting a plurality of main scanning lines. Specifically, the laser beam is diffracted by applying an ultrasonic wave to the AOD to obtain the 0th-order light and the 1st-order light, and the laser beam is modulated in accordance with the image information to thereby perform two scanning operations. The lines can be formed substantially simultaneously.

In the AOD, there is a time delay between the application of the ultrasonic wave and the generation of the diffraction grating. In this case, if the application of the ultrasonic wave to the AOD and the modulation of the laser beam are performed at the same timing, for example, a pixel may be formed by the primary light at a position to be recorded by the zero-order light. There is a problem that the recorded image is disturbed.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problem, and it has been demanded that a light beam be deflected by a small amount in a direction different from the main scanning to expose and record an image with high precision. It is an object of the present invention to provide an exposure recording apparatus capable of recording a complex image at a high speed.

[0006]

According to an exposure recording apparatus of the present invention, a light beam output from a light source is main-scanned and sub-scanned relative to an image recording material.
An exposure recording apparatus for exposing and recording a two-dimensional image, a light beam deflecting means disposed in an optical path of the light beam and deflecting the light beam by a small amount in a direction different from the main scanning based on a switching signal; Delay signal generating means for generating a delay signal delayed by a predetermined time from the switching signal in accordance with the time required for deflecting the light beam by the deflecting means, and modulating the light beam according to image information in accordance with the delay signal And a light beam modulating means for deflecting the light beam by a minute amount in a direction different from the main scanning to generate a plurality of main scanning lines and to expose and record a two-dimensional image.

In this case, the light beam modulating means is driven at a timing when the light beam is deflected to a predetermined position in a direction different from the main scanning, so that a high-precision image can be recorded by exposure.

An acousto-optic deflecting element having a response delay can be used as the light beam deflecting means.

Further, the delay signal generating means is constituted by a first delay section for coarsely adjusting the delay signal and a second delay section for finely adjusting the coarsely adjusted delay signal. , A highly accurate delayed signal can be obtained.

In this case, the first delay section can be constituted by a digital circuit. Further, the second delay unit can be configured by a delay element. Note that, depending on the response delay of the light beam deflecting means, it is possible to configure the delay generating means with only one of the first delay section and the second delay section.

Further, in consideration of the case where the time required for deflecting the light beam by the light beam deflecting means varies depending on the deflecting state, the delay signal is switched in accordance with the duty setting time relating to the duty ratio of the deflecting state, thereby obtaining the light beam. Exposure recording of an image can be performed by driving the light beam modulating means at an appropriate timing according to the characteristics of the deflecting means.

[0012]

FIG. 1 shows a laser recording apparatus 10 to which an exposure recording apparatus according to the present invention is applied. The laser recording device 10 irradiates the recording film F (image recording material) mounted on the drum 14 with the two laser beams L0 and L1 emitted from the exposure head 12 at substantially the same time, thereby obtaining an area-modulated image. Is to be recorded. in this case,
A two-dimensional image is formed on the recording film F by moving the exposure head 12 in the sub scanning direction (arrow Y direction) with respect to the drum 14 rotating in the main scanning direction (arrow X direction). The area-modulated image is obtained by controlling on / off of the laser beams L0 and L1 according to image information.
This is an image in which a plurality of pixels are formed on the recording film F, and a predetermined gradation can be obtained depending on the area occupied by the pixels.

The exposure head 12 has a laser diode LD for outputting a laser beam L modulated according to image information.
(Light beam modulating means), collimator lenses 20a and 20b for collimating the laser beam L, a beam expanding lens 22 for adjusting the beam diameter of the collimated laser beam L, and a laser beam L in the sub-scanning direction (arrow Y direction). AOD which is deflected by a small amount to obtain a laser beam L0 as the zero-order light or a laser beam L1 as the primary light
24 (light beam deflecting means) and an imaging lens 2 for condensing the laser beams L0 and L1 on the recording film F
And 6.

FIG. 2 shows a control circuit 2 of the laser recording apparatus 10.
8 shows a block diagram of the configuration of FIG. The description of the sub-scanning control circuit of the exposure head 12 and the rotation control circuit of the drum 14 will be omitted.

The control circuit 28 generates a pixel clock signal c for adjusting the main scanning recording timing of the pixel from the rotation position signal from the rotary encoder (RE) 30 for detecting the rotation position of the drum 14. (PLL) 32. The pixel clock signal c generated by the PLL 32 is supplied to a switching signal generation unit 34, an n-multiplied clock signal generation unit 36, and an image data output unit 38 that constitute the control circuit 28.

The switching signal generator 34 generates a switching signal b for switching the laser beams L0 and L1 from the pixel clock signal c. This switching signal b is AOD
It is supplied to the driver 40. The AOD driver 40 outputs a drive signal for driving the transducer 42 of the AOD 24 according to the switching signal b.

The n-multiplied clock signal generator 36 outputs an n-multiplied clock signal d obtained by multiplying the pixel clock signal c by n (n is an integer of 2 or more) to the first delay unit 44. The first delay unit 44 supplies the first delay signal e obtained by counting the n-multiplied clock signal d to the second delay unit 48 according to the delay pulse number setting value k and the duty setting value r set in the register 46. Output to Second delay unit 48
A second delay signal f obtained by delaying the first delay signal e by a minute delay time selected by the minute delay time selection value m according to the minute delay time selection value m set in the register 50. Output to Note that the first delay unit 44 and the second delay unit 48 constitute a delay signal generation unit.

The image data output unit 38 includes an image memory 52
Is read and latched in accordance with the pixel clock signal c from the PLL 32,
In accordance with the second delay signal f from the second delay unit 48, the image data a of the 0th-order data or the primary data selected by the switching signal b from the switching signal generation unit 34 is converted into image data g delayed by a predetermined amount as LD. It is supplied to the driver 54. L
The D driver 54 outputs a drive signal for driving the laser diode LD according to the image data g.

FIG. 3 is a detailed block diagram of the circuit configuration of the first delay unit 44 and the second delay unit 48.

The first delay section 44 generates a first delay signal e in which the delay time of the switching signal b is roughly adjusted. After being reset by the switching signal b, the first delay section 44 outputs n from the n-multiplied clock signal generation section 36. A counter 56 (measurement unit) for counting the multiplied clock signal d, a count value K of the n-multiplied clock signal d by the counter 56 and a set value k of the number of delayed pulses from the register 46 are compared. The comparator 58 (first comparing unit) that outputs a high-level signal, compares the count value K counted by the counter 56 with the duty set value r from the register 46, and when the comparison result matches, the high level A comparator 62 (second comparing unit) that outputs the signal of (i) and a signal that compares the multiplier n and the set number of delay pulses k with the multiplier n, and inverts the switching signal b when k ≧ n. Inverter 67 (delay signal switching section)
And comparators 58 and 62 which are outputs of OR gate 64
And a D flip-flop (D-FF) 66 (delay signal output unit) that outputs the switching signal b supplied to the D terminal via the signal inverter 67 as the first delay signal e. Note that the counter 56 can count a count value of 2n or more.

The second delay section 48 selects a delay element 68 for delaying the first delay signal e output from the Q terminal of the D-FF 66 by a minute delay time and a minute delay time according to the minute delay time selection value m. And a signal selector 70. In this case, the delay element 68 has a plurality of output terminals having different minute delay times.
rammable Gate Array) or TTL (Transistor Transist
or Logic). The signal selector 70 outputs the second delay signal f having a desired delay time by selecting the output terminal of the delay element 68 according to the minute delay time selection value m.

The laser recording apparatus 10 of the present embodiment is basically configured as described above, and the operation will be described next.

When the drum 14 on which the recording film F is mounted rotates, the rotation position is detected by the rotary encoder 30 and is input to the PLL 32 as a rotation position signal. The PLL 32 generates a pixel clock signal c from the rotation position signal, and supplies the pixel clock signal c to the switching signal generation unit 34 and the image data output unit 38.

The switching signal generator 34 generates, for example, a switching signal b which is turned on / off at the rising timing of the pixel clock signal c, and outputs it to the AOD driver 40 and the image data output unit 38. AOD driver 40
Supplies the switching signal b to the transducer 42,
The AOD 24 is driven. In this case, the AOD 24 is controlled to guide the laser beam L0, which is the zero-order light, to the recording film F when the switching signal b is off (set to a low level), and the switching signal b is turned on (set to a high level). When,
It is assumed that the laser beam L1 as primary light is controlled so as to be guided to the recording film F.

On the other hand, the image data output unit 38 to which the pixel clock signal c has been supplied receives the two main scanning lines M0 recorded on the recording film F in accordance with the pixel clock signal c.
And the image data relating to the pixels constituting M1 are read from the image memory 52. Next, the image data output unit 38
Selects zero-order data, which is image data recorded on the main scanning line M0, or primary data, which is image data recorded on the main scanning line M1, in accordance with the switching signal b. The selected image data is supplied to the LD driver 54 according to a second delay signal f supplied from a second delay unit 48 described later.

The laser diode LD supplied with the drive signal from the LD driver 54 turns on / off according to the image data.
An off-controlled laser beam L is output. The output laser beam L is converted into a parallel light beam by the collimator lenses 20a and 20b, the beam diameter is adjusted by the beam expander lens 22, and is supplied to the AOD 24.

The AOD 24 is driven and controlled by the transducer 42. The 0-order light is selected by the switching signal b, and the laser beam L0 is applied to the imaging lens 26 during the deflection state in which the 0-order light can be derived. Then, the recording film F is guided to the recording film F to form pixels constituting the main scanning line M0. Also, while the primary light is selected by the switching signal b and is set in a deflected state in which the primary light can be derived, the laser beam L1 is guided to the recording film F via the imaging lens 26, and the main scanning line M1 is changed. The constituent pixels are formed. While the pixels forming the main scanning line M0 and the pixels forming the main scanning line M1 are alternately formed, the drum 14 rotates in the main scanning direction (the direction of the arrow X). L
0 and L1 move simultaneously in the main scanning direction and the sub-scanning direction with respect to the recording film F, and are substantially deflected obliquely to form each pixel. On the other hand, the exposure head 12 for alternately forming the main scanning lines M0 and M1 as described above moves in the sub-scanning direction (the direction of the arrow Y), whereby a two-dimensional image is recorded on the recording film F. Will be formed.

Here, after a drive signal based on the switching signal b is supplied to the transducer 42 via the AOD driver 40, the laser beam L0 or the laser beam L1 is guided to the main scanning lines M0 and M1. There is a predetermined response delay before the state is reached. In the present embodiment, a high-precision image can be formed by supplying the 0th-order data or the 1st-order data of the image data a to the LD driver 54 at a timing considering the response delay.

Then, the 0th-order data and the 1st-order data of the image data a are changed to L according to the response delay of the AOD 24.
A method for generating the second delay signal f to be supplied to the D driver 54 will be described in detail with reference to FIGS. FIG. 4 shows, as an example, a case where the switching signal generator 34 repeatedly turns on and off every four pulses of the quadrupled clock signal d, the multiplied number n = 4, the delayed pulse number set value k = 3,
A timing chart when the duty set value r = n + k = 7 is shown.

First, the pixel clock signal c output from the PLL 32 is supplied to an n-multiplied clock signal generating unit 36, and an n-multiplied clock signal d obtained by multiplying the pixel clock signal c by n (n is an integer of 2 or more) is obtained. Generated. This n-multiplied clock signal d is supplied to the counter 56 of the first delay unit 44 and counted.

After being reset by, for example, the falling edge of the switching signal b, the counter 56 starts counting the n-multiplied clock signal d, and the comparator 58 compares the count value K with the delay pulse supplied from the register 46. Compare with the number setting value k. The delay pulse number setting value k is
This is set as the count value of the n-multiplied clock signal d that can obtain the delay time T for roughly adjusting the response delay time of the AOD 24. When the count value K reaches the delay pulse number set value k, the comparator 58 outputs a high-level signal to the clock terminal of the D-FF 66 via the OR gate 64.

On the other hand, when k <n, the signal inverter 67
That is, when the delay time of the state switching operation of the AOD 24 is equal to or shorter than the switching time of the 0th order light and the 1st order light by the switching signal b (see FIG. 4), the switching signal b is used as it is in the D-FF 66.
To the D terminal. Accordingly, the D-FF 66 outputs the first delay signal e obtained by delaying the switching signal b by the delay pulse number setting value k (corresponding to the delay time T) from the Q terminal, and supplies it to the second delay unit 48.

Further, when k ≧ n, the signal inverter 67
That is, when the delay time of the state switching operation of the AOD 24 is equal to or longer than the switching time of the 0th order light and the 1st order light by the switching signal b, the switching signal b is inverted and supplied to the D terminal of the D-FF 66. In accordance with the inverted switching signal b, for example, when the switching signal b for selecting the next primary light is supplied to the AOD driver 40 in FIG.
The first delay signal e for selecting the immediately preceding zero-order data from the image data output unit 38 is output from the Q terminal, and the second delay unit 48
To supply.

Next, the delay element 68 of the second delay unit 48
Generating a plurality of delay signals obtained by delaying the first delay signal e supplied from the first delay unit 44 by different minute delay times;
Output to the signal selector 70. The signal selector 70 is supplied with the small delay time selection value m from the register 50,
The signal selector 70 selects a delay signal capable of obtaining a desired minute delay time t from the plurality of delay signals from the delay element 68 according to the minute delay time selection value m, and finely adjusts the selected delay signal. And outputs it as a second delayed signal f.

The second delay signal f thus generated
Is supplied to the image data output unit 38. The image data output unit 38 reads out the 0-order data or the primary data selected by the switching signal b with a delay of a desired delay time (T + t) with respect to the switching signal b in accordance with the second delay signal f, and reads out the LD driver. 54. Then, the LD driver 54 outputs a desired laser beam L after a lapse of a delay time (T + t) at which the AOD 24 can reliably output the zero-order light or the primary light.

On the other hand, the comparator 6 constituting the first delay section 44
2, the count value K from the counter 56 and the duty set value r from the register 46 are supplied. In this case, the duty set value r is r when k <n.
= K + n + D, and when k ≧ n, it is set according to the relationship r = kn−D. Note that D is the difference between the time required for the AOD 24 to be set to a state where the zero-order light can be derived and the time required for the AOD 24 to be set to a state where the first-order light can be derived. Shall be given as a value.
FIG. 4 shows a case where the count value D is set to −1.

When the count value K reaches the duty set value r, the comparator 62 outputs a high-level signal to the clock terminal of the D-FF 66 via the OR gate 64.
Therefore, the D-FF 66 generates the first delay signal e based on the output from the comparator 58, and then counts (n + D) pulses, and then, based on the switching signal b supplied via the signal inverter 67. The one-delay signal e is output.

The first delay signal e thus generated
Is supplied to the image data output unit 38 via the second delay unit 48 in the same manner, the LD driver 54 is driven, and the desired laser beam L is output.

By repeating the above operation, AOD
The laser beam L is switched according to the operation delay characteristics including the duty ratios of the 0th-order light side and the 1st-order light side of 24,
The image by the laser beam L0 is reliably recorded at the position of the main scanning line M0 of the recording film F, and the image by the laser beam L1 is reliably recorded at the position of the main scanning line M1.

In the embodiment described above, the first
The delay unit 44 coarsely adjusts the delay time T, and the second delay unit 48 adjusts the minute delay time t. However, according to the delay time generated by the AOD 24,
It is also possible to adjust the response delay with only one of the first delay unit 44 and the second delay unit 48.

In the second delay section 48, the delay element 68 generates a plurality of different delay signals. However, the second delay section 48 may include a plurality of delay elements having different delay times. Further, a delay element for setting a delay time as a physical characteristic or a programmable delay element can be used.

Furthermore, if the light beam deflecting means has a response delay, the response delay is similarly adjusted even when the light beam is deflected by a light beam deflecting means other than the AOD 24, and high-precision image recording is performed. Of course, you can do that.

Further, in the above-described embodiment, the AOD 24 is used for the recording film F rotating in the main scanning direction.
Has been described in which a plurality of main scanning lines M0 and M1 are recorded by deflecting the laser beam L by a small amount in the sub-scanning direction. For example, the laser beam L is different from both the main scanning direction and the sub-scanning direction. It is needless to say that a plurality of main scanning lines M0 and M1 may be recorded by deflecting by a small amount in the direction.

The image recording material applied to the exposure recording apparatus of the present invention may be any material on which an image is recorded by the light energy or heat energy of the light beam output from the light source. And photosensitive materials such as photographic paper, printing plates such as photopolymer printing plates, thermal printing plates, silver salt diffusion transfer printing plates, and the like.

[0045]

As described above, according to the exposure recording apparatus of the present invention, a plurality of light beams obtained by slightly deflecting a light beam in a direction different from the main scanning direction by a light beam deflecting means are used. When an image is exposed and recorded by adjusting the modulation timing of the light beam according to the response delay of the light beam deflecting means, the image can be exposed and recorded with high accuracy.

Further, it is possible to appropriately cope with the case where the response delay time of the light beam deflecting means differs depending on the deflection direction, and to record an image at an optimum modulation timing.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a laser recording apparatus to which an exposure recording apparatus of the present invention is applied.

FIG. 2 is a configuration block diagram of a control circuit in the laser recording device shown in FIG.

FIG. 3 is a circuit configuration diagram of a first delay unit and a second delay unit shown in FIG. 2;

FIG. 4 is a timing chart of a laser recording apparatus to which the exposure recording apparatus of the present invention is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Laser recording device 12 ... Exposure head 14 ... Drum 24 ... AOD 28 ... Control circuit 30 ... Rotary encoder 32 ... Phase lock circuit 34 ... Switching signal generation part 36 ... N-multiplied clock signal generation part 38 ... Image data output part 40 ... AOD driver 42 Transducer 44 First delay unit 46, 50 Register 48 Second delay unit 52 Image memory 54 LD driver 56 Counter 58, 62 Comparator 64 OR gate 66 D flip-flop 67 Signal Inverter 68 ... Delay element 70 ... Signal selector F ... Recording film L, L0, L1 ...
Laser beam LD… Laser diode

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 2C362 AA03 BA29 BA38 BA59 BA70 BA82 BB37 CB71 5C051 AA02 CA07 DB02 DB07 DB22 DB30 DC03 DC04 DC05 DC07 DE02 DE29 FA04 5C072 AA03 BA03 BA04 HA02 HA06 HA16 HB06 HB15 VA03 XA05

Claims (8)

[Claims] An exposure recording apparatus for exposing and recording a two-dimensional image by performing main scanning and sub scanning relative to an image recording material with a light beam output from a light source. A light beam deflecting means arranged to deflect the light beam by a small amount in a direction different from the main scanning based on a switching signal, and corresponding to a time required for deflecting the light beam by the light beam deflecting means, A delay signal generating means for generating a delay signal delayed by a predetermined time from the switching signal; and a light beam modulating means for modulating the light beam in accordance with image information in accordance with the delay signal; An exposure recording apparatus which deflects by a minute amount in a direction different from the above, generates a plurality of main scanning lines, and performs exposure recording of a two-dimensional image. 2. An apparatus according to claim 1, wherein said light beam deflecting means is an acousto-optic deflecting element. 3. The apparatus according to claim 1, wherein the delay signal generation means includes: a measurement unit that measures a time since the switching signal was generated; and a delay unit that compares the time with a predetermined delay setting time. 1. An exposure recording apparatus, comprising: a first comparing unit; and a delay signal output unit that outputs the delay signal in accordance with an output of the first comparing unit when the time matches the delay setting time. 4. The apparatus according to claim 3, wherein a duty setting time relating to a duty ratio of a plurality of deflection states of the light beam by the light beam deflecting unit is compared with the time measured by the measuring unit. An exposure recording apparatus comprising: a second comparing unit; and a delay signal switching unit that switches the delay signal in accordance with an output of the second comparing unit when the duty set time matches the time. 5. The apparatus according to claim 1, wherein the delay signal generating means comprises: a first delay section for coarsely adjusting the delay signal; a second delay section for finely adjusting the coarsely adjusted delay signal; An exposure recording apparatus comprising: 6. An exposure recording apparatus according to claim 5, wherein said second delay section comprises a delay element. 7. The exposure recording apparatus according to claim 1, wherein the direction of deflection of the light beam by the light beam deflecting means is the direction of the sub-scan. 8. The exposure recording apparatus according to claim 1, wherein the direction of deflection of the light beam by the light beam deflecting means is different from any of the main scanning and the sub-scanning.