Contact exposure apparatus

In a contact exposure apparatus, a film original is overlaid on a photosensitive material, a transparent cover sheet is covered on the film original, the film original and the photosensitive material are brought into contact with each other by vacuum suction, and the film original is exposure-scanned by an exposure unit through the transparent cover sheet. The exposure unit includes a honeycomb board for collimating light emitted from a light source.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a contact exposure apparatus suitable for 
forming a proof (color proof) in the field of printing process. 
2. Description of the Prior Art 
In the field of printing process, a large amount of film is used in a step 
of forming a printing plate consisting of halftone images from a 
continuous-tone image such as a reversal film, a color negative film or 
color paper, thereby separating colors and synthesizing an image. For this 
reason, the work procedures are complex to cause many failures such as 
character and layout errors. In addition, since a client irregularly 
requests changes in characters (e.g., prices), layout, colors or the like, 
an operator tends to forget to perform some of these changes. Also, 
whether a printed material has a desired color tone and gradation must be 
checked beforehand. All these checks are included in so-called "proofing". 
For this purpose, in addition to a trial print called a "proof", a variety 
of systems are now commercially available. Examples are a CRT system, a 
system using a non-silver photosensitive material such as a photopolymer 
or diazo, a system in which an image is formed by a dry toner, and an 
electrophotography system. All these proofing systems, however, require a 
long time period to complete one color proof. In addition, a material cost 
is high and workability is poor. Therefore, the above systems are not 
satisfactory in practical use. 
Another method of forming a color proof prints a color-separated halftone 
original on a color photosensitive material by color-separated light. For 
example, Japanese Unexamined Patent Publication (Kokai) No. 62-280746 
discloses a method of obtaining a color proof on a color photosensitive 
material by a photographing system using a projection lens. Although an 
apparatus for use in such a method is large in size, it is designed to 
satisfy a so-called "roomlight specification" in which an operation can be 
performed in an ordinary room. That is, since a photosensitive material is 
kept inside the apparatus, exposure need not be performed in a darkroom 
but can be performed under normal illumination. Therefore, color proofing 
can be easily performed in a short time period at low cost to realize 
characteristics superior to those of the other proofing systems. Since the 
method utilizes the photographing system, however, an operation is 
adversely affected by flare or the like of a lens to degrade the gradation 
reproducibility. That is, by the flare or the like, a small-dot portion of 
a halftone image tends to be omitted, and its large-dot portions tend to 
become continuous. 
Another method of forming a color proof from a color photosensitive 
material is a contact exposure system of an enlarge type such as "The 
Carlson Proofmaster System" (tradename) available from Chesley F. Carlson 
Company or a "Color Proofing System" (tradename) available from Kreonit, 
Inc. In these systems, a color-separated halftone film original is 
directly brought into contact with and exposed on a color photosensitive 
material. Therefore, the gradation reproducibility is largely improved as 
compared with that of the photographing system. The above systems, 
however, cannot be handled under roomlight because a color photosensitive 
material has a photosensitive range in the overall visible range. 
Therefore, an operator is forced to perform an operation in a darkroom. In 
addition, since a large light source device is necessary, an installation 
space of the apparatus must be increased and its operation is not easy. In 
this case, a compact light source may be used if a uniform slit beam is 
scanned to expose the entire surface so that the entire surface of an 
image forming region to be contact-exposed is uniformly exposed. 
The present inventors proposed a color proof formation apparatus in U.S. 
Ser. No. 285,937. In this apparatus, a film original is overlaid on a 
photosensitive material, and they are set on an exposure table. 
Thereafter, a transparent cover sheet is covered on the film original, so 
that the film original is brought into contact with the photosensitive 
material through the cover sheet in vacuum. Exposure printing is then 
performed from the side of the cover sheet. This apparatus employs the 
contact exposure system, is compact, and allows roomlight operations. 
In a scanning exposure apparatus such as a copier, parallelness and 
uniformity of light are not so important. In an apparatus for forming a 
color proof using a color-separated halftone original in the field of 
printing process, gradation reproducibility is an important problem. When 
a small-dot portion is omitted or large-dot portions become continuous, it 
is difficult to satisfactorily recognize reproducibility of the 
color-separated halftone original on a proof, and the reproducibility must 
be checked again using a film, resulting in a cumbersome operation. In 
addition, it is very difficult to recognize accurate image reproducibility 
and color reproducibility upon mixing of colors. 
Furthermore, when a color-separated halftone original of a negative film is 
color-separation exposed on a negative color photosensitive material, one 
original film can be brought into contact with the photosensitive 
material. However, when a positive color-separated halftone original is 
color-separation exposed on a positive color photosensitive material, at 
least one of color plates (Y, M, and C plates), and a black plate, i.e., a 
total of two color-separated halftone films must be brought into contact 
with the photosensitive material. For this reason, one of the two 
color-separated halftone films is exposed on the photosensitive material 
through a base thickness corresponding to one film. Upon exposure of a 
positive color-separated halftone film for a printed material for which 
printing using a specific ink called "specific color" is simultaneously 
performed, two or more color-separated halftone films must be stacked and 
simultaneously exposed. In this system, parallelness and uniformity of 
light considerably influence reproducibility of an image. In particular, 
when parallelness is insufficient, satisfactory image reproducibility 
cannot be obtained even in contact exposure. More specifically, 
degradation of image quality such as formation of continuous dots, 
omission of dots, local fogging, or the like occurs due to dot fringes or 
the like. In particular, when a plurality of (two in FIG. 8A) originals 
are stacked and are directly exposed with diffused light from a light 
source, degraded reproducibility of the second original which is not in 
direct contact with a photosensitive material is observed. Of course, it 
is important to bring the color-separated original films and the 
photosensitive materials in tight contact with each other to keep 
flatness. For this purpose, in U.S. Ser. No. 285,937 described above, the 
interior of the covered region is subjected to vacuum suction to obtain 
flatness. However, even if flatness is satisfied, it is impossible to form 
a satisfactory color proof if collimated light cannot be obtained. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a compact contact 
exposure apparatus capable of performing image formation with high 
halftone reproducibility, i.e., with high gradation reproducibility for a 
halftone original. 
In order to achieve the above object, a film original is overlaid on a 
photosensitive material, a transparent cover sheet is covered on the film 
original, the film original and the photosensitive material are brought 
into contact with each other by vacuum suction, and light emitted from a 
light source is radiated on the film original from the side of the cover 
sheet through a light collimating means to expose the film.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
A color proof formation apparatus assembled with an embodiment of a contact 
exposure apparatus according to the present invention will be described 
hereinafter. 
FIG. 1 is a front view of the color proof formation apparatus, FIG. 2 is a 
side view thereof, FIG. 3 is a plan view thereof, and FIG. 4 is a partial 
enlarged sectional view thereof. 
As shown in FIG. 1, the color proof formation apparatus comprises a main 
body 100, and a development processing unit 600 .arranged beside the main 
body 100. The main body 100 has an original table 140 (see FIG. 4) at an 
upper portion of a main body frame 101 supported by legs 102. The original 
table 140 has an upper surface 141 for placing an original positioning pin 
bar (registration pin) 143 and a lower surface 142. A light-shielding 
cover 120 which can form a darkroom as a first chamber is arranged on the 
original table 140 to be opened/closed through a hinge 121 and a gas 
damper 122 (see FIG. 2). 
An exposure unit 300 for exposure-scanning a contact-exposure surface of 
the original table 140 is arranged in the first chamber. As shown in FIG. 
5, one or a plurality of (three in this embodiment) tubular light source 
lamps 302A, 302B, and 302C are arranged at the central portion of the 
exposure unit 300 to be surrounded by a drum-like inner surface reflecting 
mirror 306 fixed to a box member 316 and by a transmission window 304. A 
polygonal cylinder 301 having filters of B, G, R, ND, and the like on the 
respective cylinder surfaces is rotatably arranged in the central portion, 
so that filter surfaces and the transmission window 304 face the 
contact-exposure surface. Below the light source, the box member 316 
includes a shielding plate 308, a rotary solenoid 312 for driving the 
plate 308, an exposure window, i.e., a slit 310, and a honeycomb board 342 
fixed to the slit 310 and the shielding plate 308 on the side of the light 
source. The honeycomb board 342 is held in a holding frame 341 provided to 
the box member 316. 
The honeycomb board 342 is constituted by arranging hexagonal prisms each 
having a maximum diagonal distance l of about 4.6 mm, a minimum opposite 
side distance l' of about 3.1 mm, a thickness d of each side of about 0.5 
mm, and a height, i.e., thickness h of about 30 mm (FIG. 7A) to constitute 
a honeycomb structure having a length of 900 mm or more and a width of 35 
mm, as shown in FIG. 7B. The inner surface of each side is painted in flat 
black to provide a reflection preventing effect. Most of oblique light 
components of light emitted from the tubular light sources through the 
transmission window and the filters are absorbed by the black wall 
surfaces, and collimated light components and light components approximate 
to the collimated light components pass through the honeycomb board 342. 
If the minimum opposite side distance l' or the maximum diagonal distance l 
is represented by L, a minimum incident angle .theta. at which light 
becomes incident on the honeycomb board 342 and can emerge therefrom is 
given by: 
##EQU1## 
The table below summarizes calculation values of the minimum incident 
angle 0 to the honeycomb board 342 when the thickness h and distance L of 
the honeycomb board 342 are changed. 
______________________________________ 
.theta..degree. 
.theta..degree. 
h l (maximum diagonal 
l' (minimum opposite side 
(mm) distance) = 4.6 mm 
distance) = 3.1 mm 
______________________________________ 
10 65.8 72.3 
20 77.3 81.2 
30 81.5 84.1 
40 84.9 85.6 
______________________________________ 
As the thickness h of the honeycomb board is increased, the ratio of 
collimated light components is increased, thus improving halftone 
reproducibility. However, since an illuminance is lowered, an exposure 
time is prolonged. 
In this manner, the shape, length, and thickness of each column of the 
honeycomb board are appropriately selected in correspondence with the 
types of light source, a maximum exposure size, an illuminance to a 
desired photosensitive material, and halftone reproducibility, so that a 
proper exposure state can be obtained. In this embodiment, since the 
honeycomb board has a thickness of about 20 to 30 mm, collimated light 
components can be incident at an incident angle of 81.5.degree. to 
84.1.degree. with respect to the surface of the photosensitive material. 
Therefore, since most of oblique light components are shielded, when two 
or more originals are stacked, a line width of an original image can be 
prevented from being increased/decreased, and the original image can be 
formed as the first original. Thus, a contact exposure effect can be 
properly exhibited, and problems of formation of continuous dots or 
omission of dots can be prevented, thus realizing high-quality halftone 
reproduction, that is, image reproduction. 
The effect could be demonstrated when a color proof was formed using the 
apparatus of this embodiment. More specifically, positive type color paper 
KP-110P (available from KONICA CORP.) was used as a color photosensitive 
material, and a halftone scale tablet (150 lpi, and 5 to 95%) was used as 
an original. In addition, a 100-.mu. thick PET (polyethylene terephtalate) 
base was added between the photosensitive material and the halftone scale, 
so that two originals were stacked, thus preparing an original. 
Color-separation exposure was performed using, as a light source, a 
three-wavelength fluorescent lamp (available from TOSHIBA CORP.) having 
spectral wavelength characteristics shown in FIG. 9 through Kodak Wratten 
filters 47B (blue), 58 (green), and 25 (red). As an exposure time, a 
minimum exposure time upon which color development of yellow, magenta, and 
cyan ceases during exposure with each color-separated light was set. For 
example, a magenta image was obtained as follows. That is, exposure was 
performed with green light through the positive original film, and 
exposure was then performed with red light and blue light after the 
original was removed. Thereafter, predetermined second exposure, color 
development, de-silver bleaching, and a stabilization treatment were 
performed to obtain the magenta image. Table-1 below shows the 
relationship between an original halftone area of a magenta image and a 
reproduced halftone area of an image when two originals are stacked. 
Table 1 
______________________________________ 
Image 
Number of Reproduction 
Original Halftone 
Overlapping 
Honeycomb Area *1 
Originals Thickness (mm) 
10(%) 50(%) 90(%) 
______________________________________ 
1 20 8 48 88 
30 9 50 90 
None 4 42 82 
2 20 8 46 86 
30 9 48 88 
None Not 35 79 
Repro- 
duced 
______________________________________ 
*1 Measured by the halftone area measuring device SAKURA Areadac 
(available from KONICA CORP.) 
The same measurement as for the magenta image was performed for yellow and 
cyan, and almost the same results were obtained. 
As can be seen from the above description, when the honeycomb board 342 is 
mounted, the contact exposure effect can be properly exhibited, and 
high-quality image reproduction free from formation of continuous dots or 
omission of dots can be realized. 
The exposure unit 300 can travel along rails 317A and 317B for scanning. 
The reciprocal movement of the exposure unit is performed by coupling by 
pins the box member 316 to a link 324A of a roller chain 324 looped 
between chain sprockets 321 and 322. 
Therefore, light collimated by the honeycomb board 342 is then focused by 
the slit 310 to minimize the influence of diffused light as much as 
possible and to adjust a light amount. The honeycomb board 342 may be held 
to be in contact with the slit 310 or may be held to be separated 
therefrom. However, it is preferable that the honeycomb board 342 is 
arranged to be separated from the photosensitive material PS by a given 
distance. The preferable distance between the honeycomb board 342 and the 
photosensitive material PS is 30 mm or more. The width of the slit 310 is 
preferably small to minimize the influence or diffused light. The 
preferable slit width is 30 mm or less. 
The positional relationship among the center of the light source, the 
bottom surface of the honeycomb board, and the photosensitive material PS 
of this embodiment is as shown in FIG. 5. 
A photosensitive material mounting unit 200 as a second chamber is arranged 
in the main body frame 101. A photosensitive material mounting table 201 
is driven by a motor (not shown) to be vertically movable. 
As shown in FIG. 2 and FIG. 6 as the partial enlarged view of FIG. 2, a 
light-shielding curtain 240 is placed on rods 249 each of which is held at 
two ends by link attachments 247 of roller chains 246 symmetrically 
traveling at two sides and which are arranged at equal intervals. The 
leading and trailing ends of the curtain 240 are fixed to a start rod 294A 
and a tail rod 249B of the rods 249 by an adhesive or screws 249C. In this 
embodiment, as the light-shielding curtain 240, a Tetoron cloth is used as 
a core member, and its surface is coated with a nitrile rubber-based 
resin. The light-shielding curtain 240 has slight expandability. Thus, 
when the curtain 240 passes a sprocket 241, it absorbs a small increase in 
curtain orbit to allow a smooth operation. The light-shielding curtain 240 
has an area larger than at least a cross-section of the photosensitive 
material mounting table moving region. 
In this embodiment, the light-shielding curtain 240 shields an opening 
portion 144 while being held by many rods 249. Therefore, the 
light-shielding curtain 240 can be prevented from hanging down and its 
flatness can be almost kept. Therefore, an original mounting operation is 
facilitated. Furthermore, since the flatness is good, as described above, 
a light-shielding effect is high, and the area of the light-shielding 
curtain 240 need not be so large as compared that of the opening portion 
144, thus assuring a complete light-shielding effect. 
The roller chains 246 looped between the sprockets 241, 242A, 243, and 244 
are reciprocally driven by a motor (not shown), so that the window 
(opening portion) 144 through which the photosensitive material mounting 
table 201 is fitted in the original table 140 can be opened or closed. The 
light-shielding curtain 240 travels along a plane at a level slightly 
lower than the lower surface 142 of the original table, i.e., a boundary 
region between the first and second chambers, so that formation and 
release of a light-shielded state of the second chamber storing the 
photosensitive material mounting table 201 with respect to the first 
chamber can be switched. 
An elongated roll 402 of a silver chloride photosensitive material is 
loaded in a magazine 401 to form a photosensitive material loading unit 
400. The starting portion of the photosensitive material roll 402 is fed 
by clamp rollers 511, and its leading end portion is registered at a 
cutter 510 to stand by. The leading end is further fed by the clamp 
rollers 511 to the left end of a fixing base 527 and chucked by suction 
disks 523. A movable head 522 having the suction disks 523 moves to and 
stops at a position at which a predetermined length of the photosensitive 
material is measured while rollers 525 and 526 are guided by rails 521 
located at both the sides of the movable head 522. The photosensitive 
material is cut by the cutter 510 and moved so that the leading end is 
located at a predetermined position of the photosensitive material 
mounting table 201. After a suction force of the suction disks 523 of the 
movable head 522 is switched off, the movable head 522 returns to its home 
position. 
Solenoids 535 are mounted at both the sides of the movable head 522 through 
brackets 534. A frame 531 is fixed to movable iron cores 536 of the 
solenoids 535. A holding pipe 537 of each suction disk 523 which is 
connected to a hose 524 is provided between the movable head 522 and the 
frame 531 so as to extend through a guide hole formed in the head 522 and 
the frame 531. The end portion in the thrust direction of the pipe 537 is 
fixed to the frame 531. The pipe 537 is arranged on the head 522 to be 
slidable along the hole, and is floated from the surface of the exposure 
table through a helical spring 532 inserted between the movable head 522 
and the frame 531. When the solenoids 535 are energized and a suction 
valve is opened, the suction disks 523 are moved downward to vacuum-chuck 
the photosensitive material. Thereafter, the solenoids 535 are deenergized 
to move the suction disks 523 upward, thus conveying the photosensitive 
material. 
When the photosensitive material is conveyed and placed on the 
photosensitive material mounting table 201 in this manner, a suction 
pressure is applied to suction holes formed on the photosensitive material 
mounting table through a flexible hose 205 by driving a blower 204A, and 
the photosensitive material is chucked on the photosensitive material 
mounting table 201. The chucked state is held until a plurality of 
exposure operations are completed, and conveyance of the photosensitive 
material to a developing unit is started. 
In this state, since the light-shielding curtain 240 is located at a 
light-shielding position, the second chamber where the photosensitive 
material mounting table 201 is located keeps forming a darkroom. 
The light-shielding cover 120 at the upper portion is opened upward to 
guide external light into the first chamber. In this state, positioning 
holes of a color-separated halftone original (the black plate and one of 
Y, M, and C plates, e.g., Y plate, or one or a plurality of Y, M, C, and 
black plates) are fitted on the registration pins (pin bars) 143 extending 
from the upper surface 141 of the original table 140. Most part of the 
original is placed on the light-shielding curtain 240 and the rods 249 for 
holding it. 
In this state, the light-shielding cover 120 is closed so that the first 
chamber becomes a darkroom and is kept shielded from light. After the 
photosensitive material mounting table 201 is moved upward slightly below 
the surface of the light-shielding curtain 240, the light-shielding 
curtain 240 is moved to release the light-shielded state. When the first 
chamber where the upper surface 141 of the original table is located and 
the second chamber where the photosensitive material mounting table 201 is 
located form a common dark room, the photosensitive material mounting 
table 201 is moved upward to the same level as the exposure surface, i.e., 
a color-separated halftone original reference surface. At this time, an 
airtight packing 201c formed on an abutting surface 201b around the 
photosensitive material mounting table 201 in the second chamber is 
brought into tight contact with the lower surface 142 of the original 
table 140 in the first chamber, and a gap defined by a fitting surface 
201d of the photosensitive material mounting table 201 into the opening 
portion 144 forms a suction groove 204. In addition, a portion between the 
surface of the original table, the original sandwiched between the surface 
of the photosensitive material mounting table and a transparent cover 
sheet 275, and the photosensitive material can be kept airtight. 
One end of the transparent cover sheet 275 is fixed to a plate 124 
detachably arranged near an opening defined when the light-shielding cover 
120 is opened/closed, and the other end thereof is fixed to a tension 
member 277 provided in the first chamber below the hinge 121. 
The tension member 277 may be a simple spring. In this embodiment, a 
torsion bar is fixed, and the cover sheet 275 is wound around it by one 
turn to be fixed thereto. 
The torsion bar is biased by a torque spring in a direction to wind up the 
cover sheet 275. 
In this manner, when the light-shielding cover 120 is opened or closed or 
in an intermediate state between the opened and closed states, a linear 
distance between the fixed positions of the two ends of the transparent 
cover sheet 275 absorbs geometrically different events, so that the cover 
sheet 275 can always be kept in a state approximate to a flat surface and 
in a state wherein it is applied with a uniform and appropriate tension. 
When the light-shielding cover 120 is closed in the set state of the 
transparent cover sheet 275 described above, since the two ends of the 
cover sheet 275 are located at a level slightly lower than the surface of 
the original table, the transparent cover sheet 275 is urged against the 
surfaces of the original table 140 and the photosensitive material 
mounting table 201 on which the original halftone film and the 
photosensitive material are placed. 
In this state, a squeeze roller 276 performs squeezing and air between the 
transparent cover sheet 275 and the original table 140 is evacuated by a 
reduced-pressure blower or a vacuum pump, thus keeping a high contact flat 
surface state. 
In this embodiment, the squeeze roller 276 is provided to the exposure unit 
300. When the light-shielding cover 120 is closed, the exposure unit 300 
is reciprocally moved. During forward movement, neither squeezing nor 
exposure are performed. During backward movement, a movable iron core of a 
solenoid 284 is actuated on a portion 282B of a swing lever 282A which is 
pivoted about a rotating shaft of a mounting bracket 283 upon energization 
so as to urge the squeeze roller 276 against the transparent cover sheet 
275, thus completing squeezing. 
When no squeezing is performed, the solenoid 284 is deenergized, and a 
spring 286 functions to cause the squeeze roller 276 to float from the 
original mounting surface or the original table surface. 
A window is formed on a region of the transparent cover sheet 275 near a 
portion where the cover sheet 275 is brought into contact with the 
registration pins 143, and a flexible rubber sheet 278 is adhered to and 
closes this portion, as shown in FIG. 2. 
When the transparent cover sheet 275 is covered, the cover sheet surface 
can be prevented from being deformed or broken by the registration pins 
143 and a satisfactory suction reduced-pressure effect can be achieved 
upon vacuum suction. 
It is important to clean the transparent cover sheet 275. The plate 124 for 
fixing one end of the sheet 275 can be disengaged from the light-shielding 
cover 120, and contaminated upper and lower surfaces of the cover sheet 
can be easily wiped out. 
The light-shielding cover 120 can be smoothly and lightly opened/closed 
since the two end portions of the gas damper 122 and pivotally supported 
on a bracket 126 of the main body and a bracket 127 of the light-shielding 
cover 120. 
When squeezing is completed, a blower 206 as the reduced-pressure device is 
operated, and air present between the photosensitive material mounting 
table 201, the upper surface of the original table 140, and the 
transparent cover sheet 275 is evacuated through a suction hose 207 
connected to a suction hole 201f formed in the photosensitive material 
mounting table 201 via the groove 204, so that the photosensitive 
material, the original, and the cover sheet 275 are kept in a flat contact 
state while overlapping each other. The suction hole 201f may be formed in 
the original table 140. 
As shown in FIG. 4, the dimensional relationship between the abutting 
surface 201b, the airtight packing 201c adhered thereon and the lower 
surface 142 of the original table 140 is adjusted so that the upper 
surface 141 of the original table 140 and an upper surface 201a of the 
original table 201 are set at the same level. In this manner, air between 
the transparent cover sheet 275, the original table 140, and the 
photosensitive material mounting table 201 can smoothly flow through the 
groove 204, and the transparent cover sheet 275, the original, and the 
photosensitive material are brought into tight surface-contact with each 
other. The photosensitive material mounting table 201 may be located at a 
level slightly lower than the original table 140. 
In this state, the exposure unit 300 travels along the guide rails 317A and 
317B again to perform exposure scanning, thus completing color exposure of 
the first filter. Of course, the squeeze roller 276 is deenergized and 
floated so as not to interfere with exposure. 
In order to perform image exposure using the second filter of another 
color, the photosensitive material mounting table 201 is moved downward to 
a position slightly below the travel path of the light-shielding curtain 
240, and air is blown by a nozzle or the blower 206 is switched to a blow 
side to blow air into the groove 204. Furthermore, the light-shielding 
curtain 240 is closed, so that the original and the photosensitive 
material are easily and completely separated from each other. The order of 
the blowing by the blower and the downward movement of the photosensitive 
material mounting table 201 may be reversed or these operations may be 
performed at the same time. When the light-shielding cover 120 is opened, 
the first chamber is set in a bright room. However, the second chamber is 
kept shielded from light and forms a darkroom with respect to the first 
chamber. 
The transparent cover sheet 275 whose one end is fixed to the 
light-shielding cover 120 is lifted obliquely upward simultaneously with 
an opening operation of the light-shielding cover 120, and is inevitably 
set in a state wherein the next film can be easily loaded. 
In this state, the second original (the black plate and one of the Y, M, 
and C plates, e.g., M plate, or one a plurality of Y, M, C, and black 
plates) is set on the registration pins 143, and is covered with the 
light-shielding cover 120. Thereafter, the light-shielding curtain 240 is 
opened to move the photosensitive material mounting table 201 upward to 
the level of the surface of the original table 140. Thus, the transparent 
cover sheet 275 is automatically covered again, and the squeeze roller 276 
attached to the exposure unit 300 is reciprocally moved to perform 
squeezing and to perform vacuum suction, so that the sheets are brought 
into tight contact with each other. The polygonal cylinder 301 is rotated 
to cause a cylinder surface with the second filter to face the exposure 
surface. Contact exposure scanning using the second color filter by moving 
the exposure unit is performed to complete the second exposure. 
Similarly, exposure with the third original (the black plate and one of the 
Y, M, and C plates, e.g., C plate, or one or a plurality of Y, M, C, and 
black plates) and a corresponding filter is performed in the same 
procedure. Thus, the third exposure is completed. In this manner, one or a 
plurality of exposures are repeatedly performed as needed. 
Finally, the photosensitive material mounting table 201 is moved to the 
lowermost position, and the photosensitive material is released from the 
tight contact state by releasing vacuum suction. The leading end of the 
photosensitive material is then fed to clamp rollers 552 by driving the 
suction disks 523. 
The photosensitive material whose leading end has reached the clamp rollers 
552 is fed to the development processing unit 600 on the left side. When 
an internal latent image direct positive photosensitive material is used, 
it is subjected to fogging exposure by a second exposure unit 350 during 
conveyance in a color development bath 601. The photosensitive material 
passes a bleaching/fixing bath and a stabilization bath, and is dried by a 
drying unit 680 while being conveyed. Thus, the processed photosensitive 
material is recovered at the left end of the unit. 
When the exposed photosensitive material is started to be conveyed in the 
developing processing unit 600, and the surface of the photosensitive 
material mounting table becomes empty, the following photosensitive 
material is conveyed onto the photosensitive material mounting table 201. 
The following photosensitive material is measured, cut by the cutter 510, 
and set in a contact state. Thus, such processes are repeated as described 
above. 
When an internal latent image direct positive photosensitive material is 
used, second exposure is necessary. However, when a negative color 
photosensitive material or a solarization type direct positive 
photosensitive material is used, no second exposure is required, and the 
second exposure unit is kept off. In addition, a photosensitive material 
of another type, e.g., a dye-bleaching type color photosensitive material 
or a color-reversal or diffusion-transfer photosensitive material can be 
similarly exposed/developed by a system using a processing bath 
corresponding to the photosensitive material. 
The direct positive photosensitive material is exposed as follows. That is, 
a black plate is overlaid on each of originals of Y, M, and C plates, and 
a combination of Y and black plates is exposed using a B filter; the M and 
black plates, G; and the C and black plates, R, thereby performing three 
exposure operations. A conventional negative color photosensitive material 
is exposed as follows. Each of Y, M, and C plates of originals is solely 
overlaid on the photosensitive material. The B, G, and R filters are 
respectively overlaid on the Y, M, and C plates to perform three exposure 
operations. Furthermore, the black plate is overlaid, and fourth exposure 
is performed using an ND filter and a color filter for color correction if 
necessary, or triple exposure of B, G, and R is performed. 
If necessary, additional exposure is performed using light corresponding to 
another separated color in addition to the above-mentioned color-separated 
exposure operations to form a fundamental color suitable for a printing 
ink. In order to blend light corresponding to different separated colors 
in advance, emission light of colors of B, G, and R may be blended or may 
be made using a combination of filters. Similarly, in order to reproduce a 
color suitable for a specific ink, so-called specific color, other than 
standard inks of Y, M, C, and black, exposure may be repeatedly performed, 
or emission light of different colors may be blended, or filters may be 
combined. In some cases, a color-separated halftone film called a special 
color plate must be used, or other films and the special-color 
color-separated halftone film must be combined. In addition, contact 
exposure may be performed while overlapping other color-separated halftone 
films. 
The photosensitive material includes two types, i.e., high- and 
low-sensitive types. When the low-sensitivity photosensitive material is 
to be used, a plurality of light source lamps 302 of the polygonal 
cylinder 301 in the exposure unit 300 may be turned on to increase the 
intensity of exposure light. 
By performing an operation of reducing a scanning rate and an operation of 
varying an opening ratio of the exposure window 310 solely or in a 
combination, exposure can be performed with high quality by properly 
satisfying contrary conditions. 
In the above embodiment, as a light collimating means for collimating 
diffused light from an exposure light source, a honeycomb structure having 
a hexagonal opening has been exemplified. When the honeycomb structure has 
the hexagonal opening, a light loss can be minimized, and collimated light 
can be obtained. However, according to the present invention, the shape of 
the opening need not be hexagonal but may be other polygonal or circular 
shapes at the cost of a small increase in light loss. The dimensions of 
the opening and the thickness of the honeycomb board can be arbitrary 
selected in favor of design. 
A contact exposure apparatus according to the present invention and a color 
proof formation apparatus using the same can perform a roomlight 
operation, and are rendered compact. When not one but a plurality of 
originals are stacked and are simultaneously subjected to exposure 
scanning, obliquely incident light components are shielded. Blurring or 
omission of dots can be prevented. Thus, halftone reproducibility, i.e., 
image gradation in contact multiple exposure of color-separated halftone 
original films for a photosensitive material can be improved. An image 
approximate to a printed material can be quickly formed on a color 
photosensitive material, and accurate original checking can be 
appropriately performed. Thus, a high-quality poster using the 
photosensitive material can be formed.