JP2001092047A - Document printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the print picture quality. SOLUTION: A picture printer is provided with an exposure means EM and carrying rolls R1 and R2. The exposure means EM sets an exposure for each pixel on the basis of picture information of an inputted picture and exposes photographic paper 2 with respect to the whole of the picture in a direction crossing a photographic paper carrying direction and a part of the picture in the photographic paper carrying direction and successively switches picture parts to be exposed in accordance with movement of the carried photographic paper, thereby exposing the entire picture to be printed. Carrying rolls R1 and R2 are arranged on both sides of an exposure position EP in the photographic paper carrying direction and are switched to a press-contact state and a release state. The exposure means EM executes correction processing to compensate the change of the exposure state due to the change of the carrying speed which is accompanied with switching between the press-contact state and the release state of carrying rolls R1 and R2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device that emits light in a state where it is controlled and driven independently for each pixel of an image to be printed. Exposure means for setting the exposure amount and exposing the photographic paper, and transport means for transporting the photographic paper via an exposure position by the exposure means are provided, and the exposure means is provided in a direction intersecting with the photographic paper transport direction. The exposure of the photographic paper is performed for a part of the image width in the photographic paper transport direction in the entire width of the image in the photographic paper transport direction, and the images to be printed are sequentially switched by exposing the photographic paper with the photographic paper transport movement. It is configured to expose the whole, the transport means, on both sides of the exposure position in the photographic paper transport direction,
The present invention relates to an image printing apparatus provided with a transport roller that can be switched between a compression state in which photographic paper is pressed and transported and a release state in which the compression is released, and a calibration method thereof.

[0002]

2. Description of the Related Art In such an image printing apparatus, an exposure means emits light in a state of being independently controlled and driven corresponding to pixels of an image to be printed. In this method, an exposure amount is set for each pixel to expose the photographic printing paper, that is, an exposure method known as so-called digital exposure is used. More specifically, the exposure position by the exposure means is fixedly set, and the photographic paper is conveyed through the exposure position while exposing based on the image information of the image input to the photographic paper. I do. In other words, the exposure unit is a part of the entire image width in the direction intersecting the photographic paper transport direction and a part of the image width in the photographic paper transport direction (generally, an image part having a width of one pixel may be used). The exposure of the photographic paper is performed, and the entire image to be printed is exposed by sequentially switching the images to be exposed in accordance with the photographic paper transport movement at a predetermined timing.

When the exposure means adopts such an exposure format, transport rollers are provided on both sides of the exposure position in the photographic paper transport direction, and these transport rollers are switched between a pressure-bonded state and a released state to transport the photographic paper. . In general, a state in which only the conveyance roller on the upstream side in the conveyance direction is in a crimp state, a state in which both the upstream and downstream conveyance rollers are in a crimp state, and a state in which only the conveyance roller on the downstream side in the conveyance direction is in a crimp state The printing paper is conveyed while sequentially switching to the state. The transport speed of the photographic paper by each of the transport rollers is set to be the same speed, and the photographic paper is set to be transported at a constant speed even when the above-described switching operation is performed. Therefore, the exposing means sequentially changes the images to be exposed at a fixed timing as described above in consideration of the speed of transport of the photographic paper at the exposing position, so that the entire image is exposed. Was not done.

[0004]

However, as a result of the experiment, the inventor of the present invention has designed that the transport speeds of the transport rollers on both sides of the exposure position in the photographic paper transport direction are designed to be the same. In the actually assembled image printing apparatus, the transport speeds of the two are slightly different, and the transport speed of the photographic paper changes with the switching between the pressed state and the released state of each transport roller. It was found that when the images to be exposed were sequentially switched at the timing, the print quality was slightly deteriorated. The present invention has been made in view of the above circumstances, and an object of the present invention is to further improve print image quality.

[0005]

According to the first aspect of the present invention, the exposure means switches between the pressed state and the released state of the transport rollers provided on both sides of the exposure position in the photographic paper transport direction. A correction process for correcting a change in the exposure state due to a change in the transport speed is performed. That is,
As described above, even if each of the transport rollers for transporting the photographic paper on both sides of the exposure position is set to the same transport speed, the transport speed of the photographic paper is slightly reduced by switching between the press-contact state and the release state of the transport rollers. The change in the exposure state due to the change in the transport speed is corrected based on the knowledge that the change causes the image quality to slightly deteriorate due to the change. As a result, the print quality can be further improved.

Further, with the configuration according to the second aspect, the exposing means is configured to measure the density of the image of the photographic paper exposed and developed by the exposing means based on the measurement information of the density measuring means. The correction processing is performed. As such a correction process, for example, a unit that actually measures the transport speed of the photographic paper before and after the switching of the transport roller between the press-contact state and the release state, and performs necessary correction based on the speed information may be considered. By using the measurement information of the density measuring means for measuring the density of the image on the photographic paper, a more precise correction process can be performed.

Further, by providing the configuration according to the third aspect of the present invention, in order to produce a print, the exposure means performs, as the correction processing, the image information of the input image and the exposure amount for each pixel. The processing for changing the correspondence is performed. That is, as the correction processing, a configuration in which the switching timing of the image portion of the image exposed by the exposure unit is changed in accordance with the difference in the transport speed may be considered, but changing the switching timing requires complicated control operations. On the other hand, as described above, in order to make the correspondence between the image information of the input image and the exposure amount for each pixel different, that is, to change the exposure amount data itself by the exposure unit,
The switching timing can maintain a constant state irrespective of the switching between the press-contact state and the release state of the transport roller, and the control operation can be simplified.

Further, with the configuration according to the fourth aspect, the exposure means arranges a light source and a plurality of color filters in a circumferential direction in order to switch light from the light source to a plurality of exposure colors. A rotation filter is provided, and the exposure amount of each pixel is set for each of a plurality of exposure colors. That is, the exposure color is switched by the rotation of the rotary filter, and the photographic printing paper is exposed at the exposure amount set for each exposure color to print a color image. In such an exposure method, since the rotation filter is rotated at a very high speed, it is difficult to change the rotation speed of the rotation filter finely. Therefore, it is difficult to change the switching timing of the image to be exposed by the exposure unit, but in such a case, it is extremely effective to change the exposure amount data itself by the exposure unit and correct it. .

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the image printing apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic block diagram of the image printing apparatus IP. This image printing apparatus IP adopts a digital exposure system, and a film for acquiring a frame image of a photographic film (hereinafter simply referred to as a film) 1 developed as a digital image data by a film developing machine (not shown). A scanner 3; a controller 7 for processing the obtained digital image data to generate print data; a digital printing unit 5 for exposing an image corresponding to a frame image to the photographic paper 2 based on the print data; And a developing section 6 for developing the photographic paper 2. The photographic paper 2 developed by the development processing section 6 is discharged as a finished print through a drying process.

The film scanner 3 includes, as main components, an illumination optical system 31, an image pickup optical system 32, and a photoelectric conversion unit 33 using a CCD sensor. Illumination optical system 31
Is composed of a halogen lamp 31a as a white light source, a dimming filter 31b, a mirror tunnel 31c, and the like.
The color distribution and intensity distribution of the light beam from the light source are adjusted, and a frame image of the film 1 is emitted. The imaging optical system 32 that processes the transmitted light beam from the film 2 includes a mirror 32a that changes the direction of the projection light, a lens unit 32b, and the like. When the film 1 is fed at a predetermined scanning speed by the film transport mechanism 9, the frame image of the film 1 is scanned in the sub-scanning direction, that is, in the longitudinal direction of the film. The photoelectric conversion unit 33, which photoelectrically converts the light beam guided by the imaging optical system 32, performs processing such as amplification and A / D conversion of the CCD line sensor unit 33a and the detection signal of the CCD line sensor unit 33a, and performs processing such as A / D conversion. And a signal processing circuit 33b that outputs the signal to the CPU. In the CCD line sensor unit 33a, a large number (for example, 5000) of light receiving elements arranged in the main scanning direction, that is, the width direction of the film 1, and a transfer unit that transfers electric charges generated by the light receiving elements are red (R). ), Green (G), and blue (B), which are integrated on one chip, and the light receiving surfaces of the light receiving elements in each column have R, G, and B colors, respectively. A filter is formed.

When the frame image of the film 1 is positioned at a predetermined scanning position, a reading process of the frame image is started. The projection light image of the frame image is sequentially read by the CCD line sensor unit 33a in a form divided into a plurality of slit images by feeding the film 1 by the film transport mechanism 9, and the image signals of the R, G, and B color components are read. To the controller 7 as raw digital image data.
Sent to Such control of the illumination optical system 31, the imaging optical system 32, and the photoelectric conversion unit 33 of the film scanner 3 is performed by the controller 7. Film scanner 3
In addition to reading the image data of the film described above,
A magnetic reading head (not shown) has a function of reading print size information and the like magnetically recorded on the film.

In this embodiment, the digital print section 5 employs a PLZT shutter system. That is, a shutter array including a PLZT element is employed as the exposure head 5a. R, G, and R are provided to each shutter from the light source unit 5b via the optical fiber bundle 53.
Light of each color B is introduced. The shutter array extends over the photographic paper 2 arranged in two rows along the width direction of the photographic paper 2, that is, in the transverse direction of the transport direction, and when a voltage of a predetermined level is applied to each shutter, a light transmitting state ( (Open state), and when the application of the voltage is stopped, the light enters a light blocking state (closed state). Corresponding to the pixels of the image exposed by each shutter, opening and closing each shutter exposes one line of image data extending in the transport width direction by one pixel in the photographic paper transport direction at a time.

That is, the exposure range of the exposure head 5a has a full width in a direction intersecting (in this embodiment, orthogonal) with the photographic paper transport direction and a part of the image width in the photographic paper transport direction (specifically, one pixel). Photographic paper 2)
Is exposed. Therefore, in order to expose the entire image of one frame to the photographic paper 2, the images to be exposed are sequentially switched as the photographic paper 2 is conveyed. The switching of the image is controlled by the controller 7, and is controlled by the controller 7, the exposure head 5a, and the light source unit 5b.
Exposure means EM for exposing the printing paper 2 is configured.

As shown in FIG. 4A, the light source unit 5
b is provided with a lamp 50 as a light source, a dimming filter 51 for adjusting light emitted from the lamp 50 to a desired color balance, a rotation filter 52, and the like. As shown in FIG. 4B, the rotary filter 52 includes optical filters 52 of three colors, red (R), green (G), and blue (B).
r, 52g, and 52b are arranged side by side in the circumferential direction, and one of R, G, and B selectively faces the light source by constantly rotating the rotary filter 52 at a constant high speed.
The light of the selected color is sent to the shutter through the optical fiber through the color filter. The rotation phase of the rotation filter 52 is detected by a rotary encoder (not shown) and input to the controller 7, and the controller 7 can recognize the exposure color from the input signal.

The controller 7 controls each pixel, that is, each shutter, based on the image information of the image input from the film scanner 3 so that the image can be properly reproduced on the photographic paper 2, and the above-described R, G , B, the length of time during which the shutter opens is set as the exposure amount. As a method of the digital printing section, in addition to the PLZT shutter method, a liquid crystal shutter method, a fluorescent beam method,
The FOCRT method is known, and can be arbitrarily selected according to the exposure specification.

The transport system of the photographic paper 2 for transporting the photographic paper 2 to the digital print section 5 and further transporting the photographic paper 2 exposed by the digital print section 5 to the development processing section 6 is shown in FIG. As shown in FIGS. 1 to 3, a photographic paper supply line 8A for conveying the photographic paper 2 in a single line,
Exposure conveyance line 8B and development conveyance line 8C for conveying in rows
A sorting device 4 is provided between the photographic paper supply line 8A and the exposure / conveyance line 8B to distribute the photographic paper 2 sequentially sent from the photographic paper supply line 8A to each row of the exposure / conveyance line 8B. ing.

As is apparent from FIGS. 2 and 3, the photographic paper supply line 8A has a long photographic paper 2 with the photosensitive surface facing outward.
Drawer transport unit 8a composed of a group of drawer rollers that selectively pulls out the photographic paper 2 from one of the two photographic paper magazines 10 storing the photographic paper 2 in a roll form, And a transport unit 8b. At the upstream end of the pre-sorting transport section 8b, a paper cutter 11 is provided as cutting means for cutting the photographic paper 2 drawn from the photographic paper magazine 10 according to a print size corresponding to a region for exposing each image. A back print unit 12 is provided on the downstream side of the paper cutter 11. The back print unit 12 prints a film ID, a frame number, correction information indicating image processing performed at the time of creating print data, and the like on the back surface (the surface opposite to the photosensitive surface) of the photographic paper 2. Usually, a dot-in-packed printer is used.

The pre-distribution transport section 8b has two pairs of transport roller units disposed so as to sandwich the back print section 12, and a drive roller 81 which contacts the non-photosensitive surface side of the photographic paper 2 and a photosensitive roller. The pressure roller 82 includes a pressure roller 82 that is in contact with the surface side. The pressure roller 82 can be displaced in a distance from the drive roller 81 and presses or releases the printing paper 2 between the drive roller 81 and the pressure roller 82. be able to.

The exposure transport line 8B is arranged in the transport direction
Intermediate transport section 8c, exposure transport section 8d, and post-exposure transport section 8
e. All of these transport units are provided with a wide transport roller unit and a guide member corresponding to each row so that the photographic paper 2 cut corresponding to each frame can be simultaneously transported in two rows side by side. It has. However, in the intermediate conveyance section 8c, the intermediate drive roller 83
Is a wide roller that covers two rows. The intermediate pressure roller corresponding to the intermediate drive roller 83 is divided into a right row roller and a left row roller. In other words, the intermediate transport section 8c is configured as a transport roller unit that constitutes a two-row carry-in area of the exposure transport line 8B, and the intermediate drive roller 83 that contacts the non-photosensitive surface side of the photographic paper 2 and the intermediate drive roller 83 Roller 8
3 includes a first intermediate pressure roller 84a and a second intermediate pressure roller 84b which can be displaced in near and far directions. The first intermediate pressure roller 84a presses the photographic paper 2 conveyed on the right column of the exposure conveyance line 8B, and the second intermediate pressure roller 84b presses the photographic paper 2 conveyed on the left column of the exposure conveyance line 8B. The crimping and releasing operations can be performed independently of each other. That is, the two cut photographic papers 2 are sequentially placed in the first
It is received and held by the intermediate pressure roller 84a and the second intermediate pressure roller 84b, and at the same time, the two photographic papers 2
Can be sent to

The exposure transport section 8d includes transport means T for transporting the photographic paper 2 via an exposure position EP by the exposure means EM.
M is provided. The transport means TM includes a first transport roller R1 on the entrance side and a second transport roller R2 on the exit side, which are arranged so as to sandwich the exposure head 5a of the digital print section 5, and an electric motor (not shown) for driving these rollers. It is comprised including. The first transport roller R1 includes a first exposure drive roller 85 that contacts the non-photosensitive surface side of the photographic paper 2, a first exposure pressure roller 86 that is driven to move toward and away from the first exposure drive roller 85, and And the second transport roller R2 is driven to move in the direction of approaching and separating from the second exposure driving roller 87, which is in contact with the non-photosensitive surface side of the printing paper 2. The second exposure pressure bonding roller 88 is provided. Switching between the pressure-contact state and the release state of the first and second transport rollers R1 and R2 is controlled by the controller 7, and therefore, the controller 7 also constitutes a part of the transport means TM.

The first and second exposure driving rollers 85 and 87 are 1
The first and second exposure pressure bonding rollers 86 and 88 are separately driven to move toward and away from the opposing exposure driving rollers 85 and 87, respectively, while being synchronously driven by a belt transmission mechanism from two driving sources. That is, the first and second transport rollers R1 and R2 are separately switched to a pressure-contact state in which the photographic paper 2 is pressed and transported and driven, and a release state in which the pressure-bonding is released, and the photographic paper 2 is exposed. The exposure position EP by the head 5a is transported.

The manner in which the photographic paper 2 is transported at the exposure position EP by the exposure head 5a will be briefly described. First, the first transport roller R1 in the released state includes an intermediate drive roller 83 and first and second intermediate pressure rollers. Printing paper 2 from 84a and 84b
Is received, the state is switched from the release state to the pressing state, and the intermediate driving roller 83 and the first and second intermediate pressing rollers 8
4a and 84b are released and the first transport roller R1 is released.
Only the photographic paper 2 is transported and driven. When a sensor (not shown) detects that the leading end of the photographic paper 2 has been conveyed to the exposure position EP, exposure is started under the control of the controller 7.

When the printing paper 2 is further conveyed and the leading end of the printing paper 2 passes a set distance between the second exposure drive roller 87 and the second exposure pressure roller 88 of the second conveyance roller R2 in the released state. Then, the second transport roller R2 is switched from the release state to the pressure-contact state. As a result, the printing paper 2 is brought into a state of being nipped and conveyed by both the first conveyance roller R1 and the second conveyance roller R2. Thereafter, the printing paper 2 is transported by the first and second transport rollers R1 and R2, and the rear end of the printing paper 2 is moved to the first position.
When the first transport roller R1 reaches the position upstream of the transport roller R1 by the set distance, the first transport roller R1 is switched from the pressure-bonded state to the released state, and the photographic paper 2 is transported only by the second transport roller R2. As described above, while the photographic paper 2 is being exposed by the exposure unit EM, the transport state of the photographic paper 2 is changed to the state where the photographic paper 2 is transported and driven only by the first transport roller R1, and the first transport roller R1 and the second transport roller. The state is sequentially switched to a state of being transported and driven by both of R2 and a state of being transported and driven only by the second transport roller R2.

The post-exposure transport section 8e includes a first turn transport roller unit, a second turn transport roller unit, a normal transport roller group 95, and a turn guide 90. The first-turn transport roller unit includes a first-turn drive roller 91 in contact with the photosensitive surface side of the printing paper 2 and a first-turn pressure roller 92 that can be displaced in a distance from the first-turn drive roller 91. The turn transport roller unit is
Second turn drive roller 9 contacting the photosensitive surface side of photographic paper 2
3 and a second turn pressure roller 94 attached to the second turn drive roller 93 so as to be opposed thereto. The turn guide 90 disposed between the first and second turn transport roller units is an inner turn guide 9 on the photosensitive surface side.
0a and an outer turn guide 90b on the non-photosensitive surface side,
The outer turn guide 90b is swingable outward around a swing fulcrum provided on the downstream side of the conveyance, and can inflate the photographic paper 2 passing through the turn guide 90 to the outside as needed. The pressing and holding of the printing paper 2 by the first turn driving roller 91 and the first turn pressing roller 92 is 2
Both the printing paper 2 to be pressed and conveyed in a row are exposed at the exposure position E.
This is performed after the passage of P is completed and the exposure operation is completed.

As shown schematically in FIG. 3, the sorting device 4 for sorting the photographic paper 2 sequentially sent from the carry-out area of the photographic paper supply line 8A to the carry-in area of each row of the exposure / conveyance line 8B, The first and second chuckers 60A and 60 are driven to move in the vertical and horizontal directions.
B is provided. Although not shown, the first chucker unit 60A and the second chucker unit 60B can sandwich and convey the photographic paper 2, and the first chucker unit 60A receives the photographic paper 2 from the downstream end of the photographic paper supply line 8A. The photographic paper 2 is delivered to a pair of an intermediate drive roller 83 and a first intermediate pressure roller 84a, and the second chucker unit 60B transfers the photographic paper 2 received from the downstream end of the photographic paper supply line 8A to the intermediate drive roller 83. It is delivered to a pair with the second intermediate pressure roller 84b, and the first chucker 6
0A and the second chucker section 60B alternately carry up and down, and distribute the photographic paper 2 to each of two rows of carrying paths on the exposure carrying line 8B.

Next, the exposure operation by the exposure means EM will be further described. At the exposure position EP by the exposure means EM, the transport speed of the photographic paper 2 is slightly changed by switching the transport state by switching the first and second transport rollers R1 and R2 between the pressure-bonded state and the released state. Therefore, the controller 7 constituting a part of the exposure means EM
A correction process for correcting a change in the exposure state due to a change in the transport speed accompanying the switching is executed. Hereinafter, this correction processing will be described.

Although various modes can be considered for this correction processing, in the present embodiment, processing for making the correspondence between the image information of the image input from the film scanner 3 and the exposure amount different for each pixel is performed. . More specifically, when the image information input from the film scanner 3 is divided into pixels to calculate the amount of exposure, the size of the divided pixels is made different in the photographic paper transport direction. Of the data input from the film scanner 3 and converted to data corresponding to the density data for a certain color, the data arrangement in the sub-scanning direction at a certain point is temporarily represented by a point D in FIG. Explanation Also, the description will be made on the assumption that the sub-scanning direction corresponds to the photographic paper transport direction at the exposure position EP by the exposure means EM.

Assuming that the width of one pixel in the sub-scanning direction is the width indicated by “a” near the origin of the graph in FIG. 5, the envelope EV of the point D is set within the range of “a” in the sub-scanning direction. ,and,
In the main scanning direction, 2 within a certain range corresponding to the size of one pixel.
The integrated density obtained by the dimensional integration is subjected to arithmetic processing by a predetermined arithmetic expression, thereby obtaining the exposure amount of one pixel by the exposure means EM. Here, the above-mentioned predetermined arithmetic expression is a conversion expression experimentally obtained to obtain an exposure amount such that when exposed to the photographic paper 2 and developed, the same color development as the original image of the film 1 is obtained. For example, a 3 × 3 matrix is used. Assuming that the position at which the first conveyance roller R1 or the second conveyance roller R2 is switched between the pressed state and the released state during the exposure and conveyance of the printing paper 2 corresponds to the point indicated by "CP" in FIG. After this point CP, 1 in the sub-scanning direction
The exposure amount is calculated by changing the width of the pixel. That is,
Even if the transport speed changes due to the switching between the pressure bonding state and the release state, the rotation speed of the rotary filter 52 of the light source unit 5b is constant, and the image is switched to the exposure image data of one pixel width to be exposed by the exposure head 5a. Since the timing is also constant, the photographic paper 2
This corresponds to a change in the width of one pixel in the photographic paper transport direction when the image is exposed to light.

FIG. 5 shows a case where the width of one pixel in the sub-scanning direction is slightly reduced from "a" to "a '". This is the case, for example, in the first case.
From the state where the transport speed of the transport roller R1 is slightly higher than the transport speed of the second transport roller R2 and the photographic paper 2 is transported and driven only by the first transport roller R1, the first and second
There is a case where the state is switched to a state in which both of the transport rollers R1 and R2 are transported. After point CP, the envelope surface E of point D
The integrated density obtained by double integrating V in the range of “a ′” in the sub-scanning direction and in a fixed range corresponding to the size of one pixel in the main scanning direction is calculated by a predetermined arithmetic expression. Thus, the exposure amount of one pixel by the exposure means EM is obtained.
The same arithmetic expression is used regardless of the change in the integration range. The transport speed changes twice due to the switching of the first and second transport rollers R1 and R2 between the pressure-bonded state and the released state, but both of them perform the same processing as described above.

In the processing described above, the position of the point CP and the width of “a ′” must be obtained in advance.
As shown in FIG. 1, it is determined based on the detection information of the flatbed scanner 7a connected to the controller 7. Specifically, first, each line exposed by the exposure head 5a can be identified without performing the above-described correction processing, that is, assuming that the transport speed does not change at all during the exposure. The photographic printing paper 2 is exposed with the image information for the test in which the color is changed, and is developed.
The density of the test print thus produced is read by the flatbed scanner 7a. Therefore, the flatbed scanner 7a functions as a density measuring unit that measures the density of the photographic paper 2 that has been exposed and developed by the exposure unit EM. The image of the test print read by the flatbed scanner 7a is input to the controller 7, and the controller 7 obtains the pitch of each line in the photographic paper transport direction and the position where the pitch changes, thereby obtaining the point CP. And "a '" are obtained. The work of obtaining the position of the point CP and “a ′” is preferably performed not only at the time of the initial setting work of the image printing apparatus IP but also periodically because the time may change over time.

In the above description, the image information input to the controller 7 for exposing the photographic paper 2 by the exposure means EM is only an image of the photographic film 1 read by the film scanner 3. , CD-ROM or M
It is also possible to receive image data from an image data recording medium such as O or FD, or to receive digital image data transmitted via a communication line and expose the photographic paper 2, and input such image data. The external image input unit 7 b for performing the operation is connected to the controller 7.
By providing the external image input unit 7b,
The image printing apparatus IP can use not only a photographic film as an input original image but also an image taken by a digital camera, an image read by an external film scanner, and a CG image created by computer graphic software or the like. Can handle.

[Other Embodiments] Hereinafter, other embodiments of the present invention will be listed. In the above embodiment, the switching operation between the pressure-contact state and the release state of the first transport rollers R1 and R2 is performed by the exposure unit EM.
Is performed independently of the exposure operation, but the position of the point CP is set to an appropriate position in design, and the set point CP and a test print are obtained in the same manner as in the above embodiment. From “a ′”, the exposure amount for each pixel is obtained in exactly the same processing as in the above embodiment, and when exposing to the photographic paper 2, each line is sequentially exposed to correspond to the point CP. When the exposure means EM reaches the position, the exposure means EM sequentially exposes each line, and when the exposure means EM reaches the position of the point CP in FIG. 5, switching of the first and second transport rollers R1 and R2 between the pressed state and the released state. The operation may be commanded. still,
If the time required for the switching operation between the press-contact state and the release state of the first and second transport rollers R1 and R2 is long, it is necessary to instruct the switching operation prior to the position corresponding to the point CP by the operation delay. There is.

In the above-described embodiment, the case where the correction process for correcting the change in the exposure state due to the change in the transport speed is completed before the exposure operation by the exposure unit EM is described. May be performed in real time while the printing paper 2 is being exposed. That is, during the exposure of the data of a certain line of the image to be exposed or at the end of the exposure, the exposure amount of each pixel of the next line is obtained by the same method as described with reference to FIG. The processing of exposing may be configured to be repeated so as to cope with switching between the pressed state and the released state of the first and second transport rollers R1 and R2. In the example of FIG. 5, the arithmetic processing for calculating the exposure amount of the pixels for one line in the range of “a” is executed for each exposure of each line,
When a signal indicating that the second transport rollers R1 and R2 have been switched between the pressure-bonded state and the released state is received, "a '"
In this range, the processing is switched to the calculation processing for obtaining the exposure amount of the pixels for one line.

In the above embodiment, the correction processing for strictly correcting the change in the transport speed due to the switching between the press-contact state and the release state of the first and second transport rollers R1 and R2 is performed. It is also possible to deal with it by a simpler correction process. For example, the first and second transport rollers R
Since the change in the transport speed due to the switching between the pressure-bonding state and the release state of R1 and R2 is very small, an increase in the print density due to a decrease in the transport speed or a decrease in the print density due to an increase in the transport speed is corrected. For this reason, it is also possible to simply correct the exposure amount at a fixed ratio without correcting the width of one pixel, and to cope only with correction of the print density.
That is, assuming that there is no fluctuation in the transport speed as described above, the exposure amount for each pixel is obtained based on the information read by the film scanner 3, and the exposure of each line is performed with the obtained exposure amount. When receiving a signal indicating that the first and second transport rollers R1 and R2 have switched between the pressure-bonding state and the release state, the exposure amount previously obtained is multiplied by a certain correction coefficient, and By exposing the photographic paper 2 with the resulting exposure amount, a change in print density due to a change in the transport speed is reduced, and the image quality is improved. The correction coefficient in this correction process is the same as that of the above-described embodiment, a test print is produced, and the comparison between the target density of the test print and the actual density of the test print read by the flatbed scanner 7a is the first or the first. It can be obtained by performing the process before and after the switching between the press-contact state and the release state of the second transport rollers R1 and R2.

In the above embodiment, the exposure unit EM exposes the photographic paper 2 for a part of the width of the image in the photographic paper transport direction. The exposure head 5a may be configured such that exposure for a plurality of pixels can be performed. Further, the configuration of the exposure head 5a may be configured so that data of one line of pixels is exposed by a plurality of rows of shutter arrays arranged in the photographic paper transport direction. For example, a shutter array may be provided for each row of R, G, and B exposures so as to expose each exposure color independently, or the shutter array may be an even number of pixels of one line. This is a case in which a column for exposing the second pixel and a column for exposing the odd-numbered pixel are separately provided. In these cases, since the shutter arrays are arranged side by side in the photographic paper transport direction,
What is simultaneously exposed is data of pixels on different lines.

In the above embodiment, the exposure means EM
Switches the exposure color by the rotation filter 52 and changes the exposure color.
However, it is also possible to provide a light source separately for each of the R, G, B exposure colors, and to guide the light of each exposure color to the exposure head 5a by a fiber bundle. good.
In such a configuration, the switching timing of the image to be exposed by the exposure head 5a for the switching of the exposure color is not restricted, and therefore, the pressing state and the releasing state of the first and second transport rollers R1 and R2 are not limited. As a correction process for correcting a change in the exposure state due to a change in the transport speed due to the switching between the above and the above, instead of correcting the exposure amount for each pixel, the switching timing is changed according to the change in the transport speed. You may perform the correction process which changes.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image printing apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a main part according to the embodiment of the present invention.

FIG. 3 is a configuration diagram of a main part according to the embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a light source unit according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram of a correction process according to the embodiment of the present invention.

[Explanation of Symbols] EM exposure means EP exposure position TM transport means R1, R2 transport roller 2 photographic paper 7a density measuring means 50 light source 52 rotary filter

Claims (4)

[Claims] 1. An exposure amount is set for each pixel based on image information of an input image by emitting light in a state in which each pixel is controlled and driven independently for each pixel of an image to be printed. Exposure means for exposing the photographic paper and transport means for transporting the photographic paper via an exposure position by the exposure means are provided, and the exposure means has a full width of the image in a direction intersecting with the photographic paper transport direction and While exposing the photographic paper for a part of the image width of the image in the photographic paper transport direction,
The entirety of the image to be printed is exposed by sequentially switching the image to be exposed along with the photographic paper transporting movement, and the transporting means presses the photographic paper on both sides of the exposure position in the photographic paper transporting direction. An image printing apparatus configured to include a conveyance roller that is switched between a pressure state in which the conveyance roller is driven and released and a release state in which the pressure is released. An image printing apparatus configured to execute a correction process for correcting a change in an exposure state due to a change in a transport speed accompanying a change in the state. 2. The exposure device according to claim 1, wherein the exposure device is configured to execute the correction process based on measurement information of a density measurement device that measures the density of an image of the photographic paper exposed and developed by the exposure device. The image printing apparatus according to claim 1, wherein 3. The exposure device according to claim 2, wherein
3. The image printing apparatus according to claim 1, wherein the image printing apparatus is configured to perform a process of changing a correspondence relationship between image information of the input image and an exposure amount for each pixel. 4. The exposure means comprises: a light source; and a rotation filter in which a plurality of color filters are arranged in a circumferential direction in order to switch light from the light source to a plurality of exposure colors. The image printing apparatus according to claim 2, wherein an exposure amount is set for each of the plurality of exposure colors.