JPH01187541A - Contact exposure device - Google Patents

Abstract

PURPOSE:To obtain accurate, stable and uniform exposure by making the length of a fluorescent lamp longer than that of an original in a direction perpendicular to a scanning direction. CONSTITUTION:One or plural bar-shaped light source lamps are provided in the center part of an exposure part. When the fluorescent lamp is used as the bar-shaped light source lamp, the illuminance of the fluorescent lamp whose length is 950mm is uniformly 4,400lx to a spot 300mm from the center part and it begins to lower therefrom to be 2,000lx at a terminal. When the fluorescent lamp whose length is 1,050mm is used as longer one, the illuminance of the terminal part of a photosensitive material is 4,000lx and it can be very usable in practice. When the fluorescent lamp longer than the effective width of the photosensitive material is thus applied, the size of the exposure part becomes a little larger but the stable accurate and uniform exposure can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in uniform exposure of an exposure apparatus that performs scanning exposure by bringing a document screen into close contact with a photosensitive material.

[Conventional technology]

Conventionally, exposure devices have two methods: one method is to irradiate light source light onto the document surface and form an image on the photosensitive material using a projection lens that has the function of enlarging, reducing, or equal magnification, and the other method is to overlap the document and photosensitive material and irradiate the light source light. There was a method of contact exposure.

Furthermore, there are scanning exposure and static exposure methods for irradiating light source light, and the former requires a small light source to create a compact exposure apparatus, while the latter requires a fairly large light source, resulting in a large exposure apparatus.

In the plate inspection process, in order to check the correctness of multiple originals of printing plates for color printed matter using an exposure device, the originals are stacked one by one on a color photosensitive material and sequentially exposed to produce an image with the same color tone as the printed material. We create it and inspect it to see if it works as intended.

The exposure equipment used in this process that uses a projection lens to perform static exposure is quite large, and the amount of light at the periphery of the document screen that is illuminated by appropriately arranging multiple light sources is limited. This is done so that when an image is formed on a photosensitive material through a projection lens, the exposure amount distribution on the photosensitive material is naturally corrected by the cosine fourth power law of the lens and becomes uniform.

On the other hand, the contact exposure method uses static exposure.
The correction method for uniformly illuminating the document surface is complicated, and even if a plurality of light sources are appropriately arranged, it is difficult to obtain a satisfactory appearance. Furthermore, when performing scanning exposure using this method, slit light with a uniform exposure distribution is required, but generally the light intensity at the end of the tubular lamp is low and uniformity cannot be obtained.

[Problem that the invention seeks to solve]

As mentioned above, a rod-shaped lamp that exhibits a uniform illuminance distribution in order to obtain uniform slit light for contact exposure using scanning exposure has not been realized. In particular, fluorescent lamps are
It is convenient because the energy spectral distribution characteristics are good, but the fifth
As shown in the figure, there is a problem because the amount of light at the edges is significantly reduced.

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems and provide a small-sized contact exposure apparatus that can safely and correctly overexpose an original and a photosensitive material and provide accurate, stable, and uniform exposure.

[Failure to solve the problem]

This object is achieved by a contact exposure device that scans and exposes an original on an exposure screen using a fluorescent lamp as a light source, and is characterized in that the length of the fluorescent lamp is greater than the length of the original in a direction perpendicular to the scanning direction. be done.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A printing plate inspection apparatus equipped with a contact exposure apparatus according to an embodiment of the present invention will be described with reference to a front view in FIG. 1, a side view in FIG. 2, and a top view in FIG. However, the present invention is not limited to this example.

The printing plate inspection device checks whether there are any mistakes in the layout of the original film before creating the actual printing plate using each printing plate original film color-separated into 0, M, Y, and black plates.
This is a device for inspecting for color differences, character errors, etc., which positions the original film one by one and overlays it on a color photosensitive material for multiple contact exposure to produce a color photograph in the same state as the printed matter. This allows users to easily find errors in the printed version of the manuscript and take action to correct the manuscript in advance.

The main body 100 includes a document table 140 having an upper surface 141 and a lower surface 142 on which a document positioning pinper 143 is installed above the main body frame 101 supported by legs 102.
A light-shielding cover 120 is provided above the light-shielding cover 120, which can be freely opened and closed to form a dark room as a first room.

Further, an exposure section 300 for scanning and exposing the contact exposure surface of the document table is provided in the first chamber. At the center of the exposure section, one or more (three in this embodiment) rod-shaped light source lamps 302A are installed.
, 302B, and 302C are provided surrounded by a drum-shaped internal reflecting mirror 306 fixed to a housing 316 and a transmission window 304. A polygonal cylinder 301 is rotatably provided on the outside thereof, with filters such as B, G, R, ND, etc. arranged on each cylinder surface concentrically at the center, and the filter surface and the transmission window are arranged on the contact exposure surface. It is designed to face. Then, on the outside thereof, there is a shielding plate 308, a solenoid 312 for operating it, a return spring 314, and an exposure window 31.
A housing 316 is provided having a value of 0. The exposure section 300 can run on the rails 317A and 317B for scanning purposes.

When a fluorescent lamp is used as a rod-shaped light source lamp, the illuminance distribution in the length direction of the fluorescent lamp for white exposure is 5th.
The result will be as shown in the figure. Figure 5 shows the illuminance distribution on a parallel plane 10 cm away from a three-wavelength fluorescent lamp with an energy distribution suitable for positive color photosensitive materials. The illuminance was uniformly 4400ffx up to 300mm, but from there the illuminance started to drop and decreased to 2000I2x at the terminal. Moreover, since the required exposure range of the photosensitive material is 850 mm (425 mm measured from the center), the illuminance at the end of the photosensitive material is reduced to 320012x, resulting in an insufficient amount of light. To prevent this, use a longer fluorescent lamp.
050 mm, the illuminance at the end of the photosensitive material is 4000 ffx, which is not much lower than the illuminance at the center. And it will be enough for practical use.

In this way, in the present invention, in order to sufficiently uniformly expose the effective exposure range of the photosensitive material, the size of the exposure section 300 is made slightly thicker by employing a fluorescent lamp that is longer than the effective width of the photosensitive material. However, stable and accurate uniform exposure can now be obtained.

Incidentally, whether a single fluorescent lamp or a plurality of such fluorescent lamps are arranged in parallel, the tendency of uniform exposure is exactly the same.

A photosensitive material mounting section 200 is provided inside the main body frame 101 as a second chamber. And the sensitive material mounting table 201 is
It is driven by a motor 214 and can be moved up and down.

On the other hand, an endless light-shielding belt 242 as a light-shielding member is wrapped around rollers 241, 242A, 243, and 244, and a length 7 is a complete light-shielding curtain, and at least a light-sensitive material mounting table is placed approximately in the middle of the following length 7. An exposure window with a size larger than the cross section of the moving area is opened. In such a light-shielding member 240, the light-shielding belt runs on a surface slightly lower than the lower surface 142 of the document table, that is, the boundary area between the first chamber and the second chamber.
The first chamber is provided so as to be able to switch between forming and releasing light tightness to the first chamber.

Further, a long roll 402 of positive silver salt color photosensitive material is loaded into a macazine 401 to form a photosensitive material loading section 400, and the leading end of the long roll of photosensitive material is sent out by a nipping roller 511, and the leading end is are aligned at the cutter section 510 and are on standby. Then, the clamping roller 511 is used to hold the fixing base 5.
The tip is fed to the left end of the photosensitive material 27 and is sucked by a suction cup 523, and a traveling head 522 having the suction cup guides its rollers 525, 526 to the traveling rails 521 on both sides, and the predetermined length of the photosensitive material is The photosensitive material moves to a measuring position and stops, is cut by the cutter section 510, and then moves so that the leading edge of the photosensitive material is positioned at a predetermined position on the photosensitive material mounting table 201, and then hits the suction of the suction cup of the traveling head. Then, the traveling head 522 returns to its original position.

Here, solenoids 535 are attached to both sides of the traveling head 522 via brackets 534, and the movable iron core 53
A frame 531 is fixed to 6, and the traveling head 522,
A suction cup 5 coupled to the hose 524 on the frame 531
23 is attached, and a holding vibrator 537 of the suction cup is provided through a guide hole drilled in the head and frame, and is fixed to the frame in the thrust direction, and is slidable to the head along the hole. It floats above the exposure table surface via a spiral spring 532 placed between the traveling head 522 and a frame 531. When the solenoid is energized and the suction valve is opened, the suction cup descends to attract the photosensitive material, and then, when the solenoid is de-energized, the suction cup lifts up and the photosensitive material is conveyed.

When the photosensitive material is transported and placed on the photosensitive material mounting table 201 in this manner, suction pressure is applied to the suction hole formed on the photosensitive material placing table by driving the blower 204A via the flexible hose 205. The photosensitive material is closely fixed on the photosensitive material mounting table.

This tightly fixed state is maintained until multiple exposures are completed and the photosensitive material begins to be transported to the developing section.

Furthermore, in this state, the light-shielding curtain 242 is in a light-shielding position, so that the second chamber in which the photosensitive material mounting table is located remains in a state where a dark room is formed.

Here, the upper light-shielding cover 120 is passed through, the first chamber is brightened with external light, and the reference hole of the original (one of the black version and YMC, for example, Y version) is inserted into the registration pin (pin bar) 143 set on the upper surface part 141. A large part of the document is placed on the light-shielding curtain.

In this state, the light-shielding cover 120 is closed to make the first room a dark room and light-tight, and the light-sensitive material mounting table is raised slightly below the surface of the light-shielding curtain belt, and then the light-shielding curtain belt 242 is moved to open it. Then, in a state where the first room with the upper surface of the document table and the second room with the photosensitive material placement table are a common dark room, the photosensitive material placement table 201 is raised to match the exposure surface, that is, the document reference surface.

At this time, the airtight gasket 201c provided on the abutting surface around the photosensitive material mounting table in the second chamber comes into close contact with the lower surface 142 of the document table 140 in the first chamber, and the surface of the photosensitive material mounting table that fits into the opening is The created gap forms a suction channel groove 204, and airtightness is maintained between the document table surface, the photosensitive material mounting table surface, and the document and photosensitive material sandwiched between the transparent cover sheet.

That is, a transparent cover sheet roll 274 is wound around a shaft 273, and its tip passes through a squeeze roller 276 and is stopped by a stopper 272.
71 is guided by the rails 281A and 281B to the second
Cover sheet roll 27 by moving to the right in the figure.
The cover sheet 275 that is removed from the cover sheet 275 is pressed by a spring 278 and squeezed by a squeeze roller 276 which is rotatably fixed to a shaft 277, and the document and photosensitive material are covered with the cover sheet. When the pressure reaches the point where the blower 206 acts as a decompression device, the photosensitive material mounting table 20
Through the suction hose 207 connected to the suction hole 201f drilled in The original and the cover sheet are overlapped and held in close contact with each other in a plane. However, the suction hole 201f may be a hole bored in the original table.

At this time, as shown in FIG.
The dimensional relationship between the abutting surface 201b, the airtight packing 2010 attached thereto, and the lower surface 142 of the document table 140 is adjusted so that the upper surface 201a of the photosensitive material mounting table 201 is on the same plane. By doing this, the air flows smoothly between the transparent cover sheet, the document table and the photosensitive material mounting table through the channel grooves, and the cover sheet, the document and the photosensitive material are arranged in the correct flat shape. Close contact is achieved.

In this state, the exposure section 300 is connected to the guide rail 317A.
, 317B to perform scanning exposure, and complete the first color exposure using the filter.

Next, in order to perform a second image exposure using a different color original and a different color filter, the cover sheet is returned to its original position, and the photosensitive material mounting table is lowered to a position slightly below the travel path of the light-shielding curtain.
15 or by switching the blowing side of the blower 206 to blow air into the flow path groove 204 and then closing the light shielding curtain, the original and the photosensitive material can be easily and completely separated. When the light-shielding cover 120 is opened, the first room becomes a bright room, but the second room is light-dense compared to the first room, forming a dark room.

In this state, set the second original (black version and one of Y, M, and C, for example, M version) on the registration pins, cover with a light-shielding cover, and then open the light-shielding curtain and raise the photosensitive material mounting table to the original platen surface. Then cover the cover sheet again and apply suction to bring each sheet into close contact.Turn the polygonal tube 301 to face the cylindrical surface provided on another filter, and perform scanning contact exposure using a second color filter. Then, the second exposure is completed.

Similarly, the third original (black version and one of Y, M, and C, for example, C version) is exposed using the filter corresponding thereto, and the third exposure is completed.

Finally, the photosensitive material mounting table is lowered to the lowest position, the suction is released to release the photosensitive material, and the tip of the photosensitive material is fed to the nipping roller 552 by a device (not shown).

The photosensitive material whose tip has reached the nipping roller 552 is guided by the guides 561, 562, 563, 56 of the conveyance chute section 550.
4,565 and switching chute 566 and guide roller 5
After being sent downward by
By switching around 68, the guide roller 5 moves on the guide 564.565° and 567.568, starting from the rear end of the previous guide.
56 , 557 , 558 , and 559 and sent to the development processing section 600 . And color developing tank 6
01, the exposure lamp 35 of the second exposure section 350
1, a filter device 352, reflectors 353, 354, and an exposure window 355 to perform fogging exposure. and a bleach-fix tank,
After passing through the stabilizing tank, the drying section 680 is transferred to the conveying roller 6g16.
The photosensitive material is slowly transported and dried at g2, and the developed photosensitive material is collected at the right end of the apparatus.

It should be noted that as the exposed photosensitive material begins to be conveyed through the conveying shoe ($550), subsequent photosensitive materials are transferred to the photosensitive material mounting table 2.
The process of being conveyed onto the 01, measured, cut by the cutter section 510, and set in close contact is repeated as described above.

When using an internal latent image type direct positive, the photosensitive material is the second
Although exposure is necessary, when using a negative color photosensitive material, the second exposure is not necessary and the light remains off.

Of course, when exposing direct positive light-sensitive materials, a black plate is overlaid on each Y, M, and C version of the original, and the Y and black versions are BXM, and the black and black versions are G and C. The black and black plates are exposed three times using R filters, but when exposing negative color photosensitive materials, the Y, M, and 0 versions of the original are individually superimposed on the photosensitive material. For the Y version, for the 81M version, and for the GXC version, add an R filter and add 3
The image was exposed twice, and then a black plate was layered and exposed using an ND filter for the fourth time.

Note that the photosensitive material in the exposed area once enters the guide chute 565 and is then turned over and enters the developing device with the emulsion side facing up; however, it can also be placed in the developing device without entering the guide chute 565 by turning the knee as it is. , the light source position for the second exposure must be installed from above the developing device to below the photosensitive material transport path, which makes maintenance and installation somewhat difficult.
This is not very preferable because it requires an exposure window to be opened on the side of the developer tank, which makes it difficult to clean up leakage.

There are two types of photosensitive materials: those with high sensitivity and those without. When using a photosensitive material with low sensitivity, the exposure area 30
A plurality of light source lamps 302 are provided in the polygonal cylinder 301, and a large number of light source lamps 302 are turned on so that the exposure can be made more powerful.

In addition, by using the measures of lowering the scanning speed and the measures of making the opening/closing of the exposure window 310 variable, in combination or alone, it is possible to perform high-quality exposure without worsening the reciprocity law failure condition.

〔Effect of the invention〕

According to the present invention, the exposure apparatus can be made compact, and the exposure amount of scanning exposure for the photosensitive material can be made uniform, so that excellent image reproduction can be obtained. Therefore, when the present invention is applied to a plate inspection device, an image equivalent to that of a printed matter is formed by closely exposing a document film onto a photosensitive material, and an accurate document inspection can be carried out.

[Brief explanation of the drawing]

FIG. 1 is a front view of a printing plate inspection device equipped with an exposure device of the present invention. FIG. 2 is a side view of one embodiment of the exposure apparatus of the present invention. FIG. 3 is a top view of the printing plate inspection apparatus shown in FIG. 1. FIG. 4 is a side sectional view showing the positional relationship between the document table and the photosensitive material mounting table. FIG. 5 is a diagram showing the illuminance distribution in the length direction of the fluorescent lamp used in the exposure apparatus of the present invention. 100... Printing plate inspection device main body 120... Light shielding cover 140... Document table 14
1...Top surface 142...Bottom surface 200...
・Sensitive material mounting section 201...Sensitive material mounting table 201a.
...Top surface 201b...Abutment surface 201c
...Airtight packing 204...Suction channel groove 2
40... Light shielding member 242... Light blocking curtain bell) 270... Cover sheet device 275... Cover sheet 300... Exposure parts 302A, 302B, 302C... Rod-shaped light source lamp (fluorescent lamp) 306.・Internal reflector

Claims (1)

[Claims] A contact exposure apparatus that performs scanning exposure through an original on an exposure screen using a fluorescent lamp as a light source, wherein the length of the fluorescent lamp is larger than the length of the original in a direction perpendicular to the scanning direction.