JP2003131359A - Image exposing and recording method and image exposing and recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image exposing and recording method which is capable of controlling the length in the main scanning direction of the images to be formed to a desired length in exposing and recording the images by relatively moving an exposing position and a recording medium. SOLUTION: In exposing, either of the processing to delay the timing of an exposure on with respect to the timing at which the top end of the pixel position to be recorded on the recording medium passes the exposure position and the processing to expedite the timing of an exposure off with respect to the timing at which the pixel position termination passes the exposure position is at least performed, by which the time for exposure is shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention scans and records each pixel in an image by turning exposure on and off while moving an exposure position where a recording beam is focused relative to a recording medium. For example, a CTP (Computer) To Plate), Imagesetter, DDCP (Direct Digital Color Proofer)
The present invention relates to an image exposure recording apparatus having a scanning type exposure recording head and the image exposure recording method thereof.

[0002]

2. Description of the Related Art Today, in an exposure recording apparatus for a printing CTP or the like, a desired image is exposed and recorded by forming one dot as one pixel by turning exposure on and off while moving an exposure position and a recording medium relatively. The scanning exposure recording method is widely used. In this scanning type exposure recording method, the light beam emitted from the light source is controlled to be turned on and off according to the image to be recorded. Focus. on the other hand,
The recording medium is wound around a recording drum that rotates at a constant speed and rotates. As a result, scanning recording by exposure is performed while moving the exposure position on the recording medium. Further, during this scanning recording, the exposure head is moved along the sub-scanning rail in a direction parallel to the rotation axis of the recording drum, and an image is recorded on the entire recording medium.

According to this method, when the recording medium is exposed by the recording beam to form one pixel (one dot) when the exposure is turned on, the recording medium rotates during the exposure, so that the recording beam focused at the exposure position is used. Scanning exposure is performed while dragging on the recording medium. Here, the exposure time for forming each pixel depends on the time obtained by dividing the length of each pixel in the scanning direction (main scanning direction) of the recording medium by the moving speed (scanning speed) in the main scanning direction, that is, the scanning time. It is set.

By the way, today, in order to provide a high quality image, it is desired to expose and record a high resolution image. Therefore, even in the above method, the size of the pixel to be formed is often set to be equal to or smaller than the exposure spot diameter of the recording beam. For example, when the exposure spot diameter of the recording beam is 15 μm, the pixel size of the pixel to be formed is 10 μm which is smaller than this spot diameter.
And

[0005]

By the way, one pixel formed by exposure-on is not formed by exposing the entire area of the exposure spot at the time of exposure in the case of, for example, a positive photosensitive material, and a predetermined exposure amount. A region that receives an amount of light exceeding 1 is exposed, that is, a pixel smaller than the size of the exposure spot is formed. However, when the size of the pixel to be formed by exposure is smaller than the exposure spot diameter of the recording beam, there is a problem that the formed pixel size becomes larger than the pixel size to be formed.

[0006] In practice, when exposure recording is performed in a printing CTP using a thermal photosensitive material, for example, in a positive photosensitive material, an exposure amount level at which a residual film is eliminated by exposure, that is, a light amount of several times the clear level is not applied. There is a problem that the amount of exposure cannot be reduced and the formed pixels become large because there is a restriction such that it cannot occur. In this way, as the size of one pixel to be formed becomes larger than the size of the image to be formed, the image quality deteriorates, so that it is not possible to expose and record a high-resolution image.

Therefore, in order to solve the above-mentioned problems, the present invention provides an image recording method capable of controlling the length of a pixel formed in the main scanning direction to a desired length in the scanning exposure recording apparatus. An object is to provide an exposure recording method and an image exposure recording device.

[0008]

In order to achieve the above object, the present invention, when exposing and recording an image, records the image by turning on and off the exposure while moving the exposure position relative to the recording medium. An image exposure recording method for performing scanning recording on a medium, wherein during exposure, a process of delaying an exposure-on timing with respect to a timing at which an exposure position passes a tip of a pixel position to be recorded on the recording medium, and a recording medium There is provided an image exposure recording method characterized by performing at least one of a process of advancing an exposure off timing with respect to a timing of passing an exposure position through a pixel position end to be recorded.

Here, the exposure time at the time of the exposure is preferably set according to the type of the recording medium and the exposure power used at the exposure, and the exposure time is increased with the increase of the exposure power used. It is preferably short.

The exposure time for the exposure is preferably set according to the liquid sensitivity of the developer used for development after image exposure and the exposure power used for the exposure. Sensitivity is the electrical conductivity of the developer,
More preferably, it is calculated from at least one information of the processing area of the developing solution and the solution temperature of the developing solution. Alternatively, it is also preferable that the exposure time for the exposure is set according to the drawing resolution for exposure recording and the exposure power used for exposure.

The present invention is also an image exposure recording apparatus for performing scanning recording on a recording medium by turning exposure on and off while moving an exposure position relative to the recording medium, which is a main unit on the recording medium. Exposure position monitoring means for monitoring the exposure position in the scanning direction; an exposure control signal in which the exposure-on timing is delayed with respect to the timing at which the monitored exposure position passes the tip of the pixel position to be recorded on the recording medium, and An exposure control signal in which an exposure off timing is advanced with respect to a timing at which the monitored exposure position passes a pixel position end to be recorded on a recording medium, and the exposure on timing is monitored by the exposure Position is delayed with respect to the timing at which the position of the pixel passes the tip of the pixel position, and the exposure-off timing is set at To provide an image exposure recording apparatus characterized by comprising a signal controller for generating at least one of exposure control signals earlier to the timing of passing the pixel position tip.

Here, the exposure time during the exposure is preferably set according to the type of the recording medium and the exposure power used during the exposure, and the exposure time increases with the increase in the exposure power used. It is preferably shortened.

The exposure time for the exposure is preferably set according to the liquid sensitivity of the developing solution used for the development after the image exposure and the exposure power used for the exposure. More preferably, the liquid sensitivity of the developing solution is calculated from at least one information of the electrical conductivity of the developing solution, the processing area of the developing solution, and the solution temperature of the developing solution. Alternatively, it is also preferable that the exposure time at the time of exposure is set according to the drawing resolution at the time of exposure recording and the exposure power used at the time of exposure.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An image exposure system 10 using the image exposure recording apparatus of the present invention for carrying out the image exposure recording method of the present invention will be described in detail with reference to the preferred embodiments shown in the accompanying drawings. explain. 1A and 1B show the configuration of the image exposure system 10.

The image exposure system 10 includes an exposure head 14 having a light source (not shown) and an optical system (not shown) having a focusing position (exposure position) for focusing the light from the light source on the recording medium 12, and the recording medium. Figure 12 with 12 wound
A recording drum 16 that moves the recording medium 12 in the X direction (main scanning direction) with respect to the exposure head 14 by rotating at a constant speed (scanning speed) in the middle R direction, and at the time of exposure recording,
A sub-scanning moving mechanism 20 for moving the exposure head 14 along the sub-scanning rail 18 in the Y direction in FIG. 1, and an exposure control signal for exposure on and exposure off according to an image during scanning exposure are sent to the exposure head 14. It has a control device 22 and a development processing device 26 that develops the recording medium 12 that has been exposed and recorded. Further, an encoder 24 that outputs the rotation amount of the recording medium as a pulse signal and monitors the exposure position in the main scanning direction on the recording medium 12 is provided at the end of the rotation shaft of the recording drum 16. Is sent to the controller 22. The encoder 24 forms exposure position monitoring means for monitoring the exposure position in the main scanning direction according to the present invention. The exposure head 14 and the recording drum 1 are mainly used.
6. By the sub-scanning moving mechanism 20 and the control device 22,
The image exposure recording apparatus according to the present invention is formed.

The light source in the exposure head 14 can emit a sufficient amount of light, and various light sources can be used according to the spectral sensitivity of the recording medium to be exposed. For example, if the recording medium is a commonly used PS plate (conventional PS plate) that can be exposed to ultraviolet rays, an ultra-high pressure mercury lamp or a metal halide lamp may be used. For a heat mode plate having sensitivity to infrared light, an infrared Broad area Laser Diode or the like may be used.
In addition, a halogen lamp, a xenon lamp, a two-dimensional array light source (LED), etc. can be used according to the recording medium. As a method of controlling the exposure on and the exposure off, for example, a method of controlling the on / off of the light emitted from the light source, or the DMD of the light emitted from the illumination light source is used.
An example is a method in which a two-dimensional spatial light modulator using a (Digital Micromirror Device) or the like is made incident, and light from each DMD micromirror is reflected in a predetermined direction to form an exposure-on recording beam. In this way, the pixels (dots) of the image to be recorded are recorded at the exposure position on the recording medium 12 rotating at a constant speed by exposure on and exposure off. A sensor 28 that measures the exposure power of the emitted recording beam is provided at the tip of the exposure head 14, and the sensor 28 measures the exposure power as needed, and the measurement result is sent to the control device 22.

The control device 22 is a device that sends an exposure control signal for exposure on and exposure off to the exposure head 14 according to an image being scanned and exposed, and includes a shortened time setting unit 22a, a signal generation unit 22b, and these parts. And a CPU 22c that controls and manages driving of the sub-scanning moving mechanism 20.
Here, the exposure control signal is generated so that the exposure time at the time of exposure is shorter than the scanning time obtained by dividing the dot length of the pixel to be exposed and recorded by the moving speed (scanning speed) of the exposure position. The shortening time Δt of the exposure time at this time is set to be the same whether recording is performed with one dot exposed to light or continuous recording with several dots exposed to light. Specifically, this shortened time Δt is
It is set based on the type of exposure power used and the exposure power used during exposure, and becomes longer as the exposure power used increases. Therefore, the exposure time becomes shorter as the used exposure power increases. In this way, the exposure time is set according to the type of the recording medium 12 and the exposure power used at the time of exposure. The shortening time Δt is set based on the type of the recording medium 12 because the composition differs depending on the type of the recording medium such as the positive sensitive material and the negative sensitive material.

The shortening time setting unit 22a is used in the development processing device 2
Table data stored from the liquid sensitivity of the developer sent from No. 6, the type of the recording medium 12, the measurement result of the exposure power sent from the sensor 28, the drawing resolution to be exposed and recorded, and the like. Is a part for setting the shortened time Δt. Such a shortened time Δt is sent to the signal generator 22b.

The signal generator 22b is a portion for generating an exposure control signal for controlling exposure on and exposure off, and counts the pulse signal sent from the encoder 24 to determine the exposure position on the recording medium 12. You can see if this exposure position passes the tip position of the pixel to be recorded,
It is possible to determine whether or not the timing at which the pixel tip position to be recorded passes through is determined.

The exposure-on timing is delayed by a shortened time a · Δt (coefficient a is a predetermined real number of 0 or more and 1 or less) with respect to the timing at which the exposure position passes through the pixel tip position to be recorded, and the exposure-off timing The exposure control signal is generated with a shortened time (1-a) · Δt earlier than the timing of passing the end position of the pixel to be recorded. That is, the exposure control signal is generated so that the exposure time is shorter than the scanning time by the shortening time Δt. Here, by setting the coefficient a to 0.5, the delay time of the exposure on timing and the time of advancing the exposure off timing become the same.
By setting the coefficient a to 0 or 1, only one of the exposure on timing and the exposure off timing is adjusted.

In the present embodiment, the exposure on / off timing reference is based on the pulse signal sent from the encoder 24. However, instead of the encoder 24, the drive motor of the recording drum 16 is changed. It may be performed based on the drive control signal. The generated exposure control signal is sent to the exposure head 14.

The exposure head 14 emits a recording beam to the recording medium 12 based on the exposure control signal to expose the recording medium rotating at a constant speed at the exposure position. During the exposure recording, the sub-scanning moving mechanism 20 is controlled by the control device 22, the exposure head 14 is moved along the sub-scanning rail 18, and the entire recording medium 12 is scan-recorded.

Now, the setting of the exposure time shortening time Δt in the control device 22 will be described more specifically. FIG. 2A shows, as an example, an exposure time timing in the case where two dots are vacant after exposure recording of one dot and two dots are continuously exposed and recorded as an image to be subjected to exposure recording. There is. In this case, the exposure time of one dot is a value t obtained by subtracting the shortening time Δt from the scanning time t ₀ obtained by dividing the dot length of the pixel to be recorded by the scanning speed.
It is set to _0- Δt. Regarding the exposure time of 2 dots, the exposure time of 2 dots is calculated by shortening the scan time 2
It is set to a value 2t ₀ -Δt which is obtained by subtracting from t _0. As a result, as shown in FIG. 2B, it is possible to form a dot length equivalent to the originally desired dot length. Conventionally, as shown in FIG. 3A, each dot is exposed by making the exposure time equal to the scanning time.
As shown in (b), the formed dot length was extremely longer than the originally desired dot length.

For example, a near-infrared laser beam of 830 nm is emitted and the beam spot diameter is 15 μm (FWHM: Fu).
ll Width Half Meter), while using a printing CTP thermal positive type recording medium as the recording medium, the length of one dot to be recorded is 10.5 μm, and the scanning time is 600 nS, the conventional method Exposure time 6
Since it is set to 00 nS, the dot length of one dot formed is 16 μm, which is 50% longer than the length of one dot to be recorded. On the other hand, in the present invention, for example, the shortened time Δt = 75 nS is set and the exposure on timing and the exposure off timing are adjusted by a method described later, and the exposure time is 525 nS (<scan time 60
Since it is set to 0 nS), the dot length of one dot formed can be set to 13 μm, and the length is increased by only about 23% with respect to the length of one dot to be recorded. Also, 2
When dots are continuously exposed and recorded, the present invention sets 112
Exposure is carried out for recording with an exposure time of 5 nS (= 600 × 2-75). In this case, the length of 2 dots is 24 μm, and the length is increased by only 14% with respect to the length of 21 μm for 2 dots to be recorded. Of course, by adjusting the exposure time more finely, it is possible to form dots that match the length of the dots to be recorded.

The shortening time Δt of the exposure time is set by the shortening time setting section 22a based on the type of the recording medium and the exposure power used for the exposure. Then, from this shortened time Δt, for example, the exposure-on timing is Δ
The exposure control signal is set so as to delay t / 2 and advance the exposure off timing by Δt / 2. Of course, the exposure on timing may be delayed by the shortened time Δt, and the exposure off timing may be advanced by the shortened time Δt.

Here, in the setting of the shortening time Δt of the exposure time, for example, in the case of a photosensitive material using a recording medium for printing CTP, as shown in FIG. 4, first, the type of the photosensitive material, the positive photosensitive material or the negative photosensitive material is used. Information such as the sensitive material is input to the shortened time setting unit 22a (step 100). Next, it is judged whether the input sensitive material is a positive sensitive material or a negative sensitive material (step 10).
2) The exposure power used is input (step 104,
Step 106). This input may be manually input by an operator through an operation system 30 such as a mouse or a keyboard, or may be automatically input by sending a measurement result from the sensor 28. In this way, the shortening time Δt is set by referring to the table data stored in the shortening time setting unit 22a from the type of the photosensitive material and the exposure power used, and the dots to be exposed and recorded based on the shortening time Δt. The corresponding exposure time is set (step 10).
8, 110). That is, the exposure time is set according to the type of photosensitive material and the exposure power used.

In addition to the above examples, for example, in the case of a photosensitive material using a recording medium for CTP for printing, a developing solution is used when a developing solution is applied to the photosensitive material on which the latent image is exposed by exposure with a developing solution. It is also possible to receive information on the liquid sensitivity from the developing processing device 26, and use this information to set the shortening time Δt to determine the exposure time corresponding to the dot to be exposed and recorded. Here, the liquid sensitivity is a parameter calculated from single or plural information such as electric conductivity of the developing solution, PH, development processing area, solution temperature, and carbon dioxide concentration in the atmosphere at the time of development. The degree of development is associated with the exposure amount during exposure recording. Here, the development processing area is a cumulative processing area that has been subjected to past development processing with the same developing solution. For example, as shown in FIG. 5, the liquid sensitivity is calculated from the inputted electric conductivity of the developing solution, the development processing area, and the developing solution temperature, and the optimum exposure amount is determined by this. From this exposure amount, the shortened time Δt is set based on the used exposure power measured by the sensor 28, and from this shortened time Δt, the exposure time corresponding to the dot to be printed by exposure is set.
That is, the exposure time is set according to the liquid sensitivity of the developing solution used for development after image exposure and the exposure power used during exposure. Shortening the exposure time from the above optimum exposure amount Δ
When obtaining t and the exposure time, the method shown in FIG. 4 may be used. As a result, it is possible to suppress the variation in the width of the recording line (the length of the recording pixel) in the main scanning direction, which is caused by the variation in the sensitivity of the photosensitive material between lots.

In addition to the above example, the shortened time Δt and the exposure time are set based on the drawing resolution at the time of exposure recording and the exposure power used at the time of exposure. Thus, the timing of exposure on or exposure off may be adjusted. The drawing resolution of the image recorded on the recording medium is determined by the size of the spot diameter of the recording beam recorded on the recording medium.
The drawing resolution is set to dpi, 4000 dpi, or the like.
When increasing the drawing resolution, it is necessary to reduce the spot diameter of the recording beam. Therefore, when changing the drawing resolution, the shortening time Δt of the exposure time and the exposure time are set based on the drawing resolution at the time of exposure recording and the exposure power used at the time of exposure.

The shortening time Δt of the exposure time is determined by appropriately measuring the exposure power of the recording beam at the start of the exposure recording or during the exposure recording, and during the exposure recording or the exposure for rewinding a plurality of recording media onto the recording drum. It may be changed between recordings based on the above measurement results.

The image exposure recording method and the image exposure recording apparatus of the present invention have been described in detail above.
Of course, the present invention is not limited to the above examples, and various modifications and changes may be made without departing from the scope of the present invention.

[0031]

As described above in detail, according to the present invention, the timing of exposure on and exposure off is changed, and the exposure time at the time of image recording is obtained by dividing the pixel length for image recording by the scanning speed. Since the exposure recording of the image is performed in a time shorter than the time, the length of the dots formed by the exposure in the main scanning direction can be controlled to a desired length. For example, when the scanning time is 600 nS, the exposure time for one dot is 52
By setting it to 5 nS, the length of one dot in the main scanning direction, which has been widened to about 16 μm in the past, can be suppressed to 13 μm with respect to the length of 1 dot of 10.5 μm to be formed. The shortening of the exposure time and the exposure time are set according to the type of recording material, the liquid sensitivity of the developing solution, the beam diameter of the exposure beam, etc., so that the exposure time can be optimized and a stable image is always obtained. Can be formed.

[Brief description of drawings]

FIG. 1A is a diagram for explaining an example of an image exposure system using an example of the image exposure recording apparatus of the present invention for performing the image exposure recording method of the present invention, and FIG. 3 is a block diagram showing an example of a control device of the image exposure recording apparatus of FIG.

2A and 2B are diagrams illustrating an example of the image exposure recording method of the present invention.

3A and 3B are diagrams illustrating a conventional image exposure recording method.

FIG. 4 is a diagram showing a flow of an example of an image exposure recording method of the present invention.

FIG. 5 is a diagram showing a flow of another example of the image exposure recording method of the present invention.

[Explanation of symbols]

10 Image exposure system 12 recording media 14 Exposure head 16 recording drum 18 Sub-scanning rail 20 Sub-scanning movement mechanism 22 Control device 22a Shortening time setting section 22b signal generator 22c CPU 24 encoder 26 Development Processing Equipment 28 sensors 30 operation system

Claims (12)

[Claims] 1. An image exposure recording method for performing scanning recording on a recording medium by turning exposure on and off while moving an exposure position relative to the recording medium when the image is exposed and recorded. At this time, the process of delaying the exposure ON timing with respect to the timing at which the exposure position passes the tip of the pixel position to be recorded on the recording medium, and the timing at which the exposure position passes the end of the pixel position to be recorded on the recording medium. On the other hand, an image exposure recording method characterized by performing at least one of processing for advancing the timing of exposure off. 2. The image exposure recording method according to claim 1, wherein the exposure time during the exposure is set according to the type of the recording medium and the exposure power used during the exposure. 3. The image exposure recording method according to claim 2, wherein the exposure time becomes shorter as the used exposure power increases. 4. The image according to claim 1, wherein the exposure time during the exposure is set according to the liquid sensitivity of the developing solution used for the development after the image exposure and the exposure power used during the exposure. Exposure recording method. 5. The liquid sensitivity of the developing solution is calculated from at least one information of the electric conductivity of the developing solution, the processing area of the developing solution, and the solution temperature of the developing solution. 5. The image exposure recording method according to item 4. 6. The image exposure recording method according to claim 1, wherein the exposure time at the time of the exposure is set according to a drawing resolution at the time of exposure recording and an exposure power used at the time of exposure. 7. An image exposure recording apparatus for performing scanning recording on a recording medium by turning exposure on and off while moving an exposure position relative to the recording medium, the exposure in the main scanning direction on the recording medium. Exposure position monitoring means for monitoring the position, an exposure control signal in which the exposure-on timing is delayed with respect to the timing at which the monitored exposure position passes the tip of the pixel position to be recorded on the recording medium, and the monitored An exposure control signal in which the exposure-off timing is advanced with respect to the timing when the exposure position passes the end of the pixel position to be recorded on the recording medium, and the exposure-on timing is monitored, the exposure position is the pixel. The exposure-off timing is delayed with respect to the timing of passing the position leading edge, and the exposure position monitored is the pixel position leading edge. Image exposure recording apparatus; and a signal control unit for generating at least one of exposure control signals earlier to the timing of passing. 8. The image exposure apparatus according to claim 7, wherein the exposure time for the exposure is set according to the type of the recording medium and the exposure power used for the exposure. 9. The image exposure recording apparatus according to claim 8, wherein the exposure time becomes shorter as the used exposure power increases. 10. The exposure time during the exposure is set according to the liquid sensitivity of the developing solution used for the development after the image exposure and the exposure power used during the exposure.
The image-exposure recording apparatus according to item 1. 11. The signal controller calculates the liquid sensitivity of the developing solution from at least one information of the electrical conductivity of the developing solution, the processing area of the developing solution, and the solution temperature of the developing solution. The image exposure recording apparatus according to claim 7. 12. The image exposure recording apparatus according to claim 7, wherein the exposure time at the time of the exposure is set according to a drawing resolution at the time of exposure recording and an exposure power used at the time of exposure.