JP2554163B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus capable of adjusting the gradation of a formed image by sub-exposure.

<Prior Art> Conventionally, in various image forming apparatuses, gradation adjustment is performed as one of the methods for adjusting the image quality of an image to be formed.

As the gradation adjustment method, a method of adjusting the exposure conditions such as the light amount of the exposure light source and the exposure time, a method of adjusting the development conditions such as the development processing temperature and the development processing time, and inserting various filters in the exposure optical path Although a method, a method of changing a photosensitive material or an image receiving material, and the like are known, a sub-exposure method is often used in view of the cost of a formed image, the cost of an image forming apparatus, workability, and the like. .

As a gradation adjustment method of a formed image by sub-exposure, for example, in the case of a copying apparatus by direct exposure, a gray (achromatic color) sub-exposure reflector is provided near the document table, and before or after main exposure. , The sub-exposure reflector is illuminated by the exposure light source, and the reflected light illuminates the photosensitive material to 1 /
It is performed by exposing with a constant amount of light within the range of 50 to 1/100.

Further, the applicant of the present invention adjusts the gradation of the formed image by performing the sub-exposure by using the white reference plate and the variable diaphragm for adjusting the light amount without using the reflection plate for the sub-exposure, and the gradation desired by the user. Japanese Patent Application No. 63-13
Proposed to No. 4602.

This copying machine uses 1/50 to 1/100 of the light quantity at the main exposure by the variable diaphragm for the reflected light from the white reference plate during the sub-exposure.
The gradation is adjusted by adjusting the amount of light to the sub-exposure. Since the light amount of the sub-exposure can be freely adjusted by adjusting the light amount by the variable diaphragm, a copy image having a desired gradation can be formed.

<Problems to be Solved by the Invention> By the way, in an apparatus that performs a sub-exposure using a gray reflection plate dedicated to the sub-exposure, such as the copying apparatus described above, the sub-exposure amount is constant, and the sub-exposure amount should be changed. Therefore, there is a problem that the user cannot change the gradation adjustment amount according to the formed image and finish the image with a desired gradation.

Further, in the copying apparatus proposed by the present applicant in the above-mentioned Japanese Patent Application No. 63-134602, only the sub-exposure amount is set within the range of 1/50 to 1/100 of the main exposure amount according to the change amount of gradation. Since it can be changed linearly, the desired gradation adjustment is possible to some extent, but even if the optimum conditions for the main exposure color filter and diaphragm are automatically set as standard setting conditions, the gradation adjustment amount In some cases, the color balance of the formed image is disturbed, resulting in an unnatural image. For this reason,
There is a problem that the gradation adjustment image intended by the user cannot be obtained.

Like the above-mentioned copying machine, the scanning exposure device and the one-shot surface exposure device differ in the intensity of the exposure light and the exposure time even if the light amount applied to the photosensitive material is the same. However, when the sub-exposure is performed with the same light amount, a difference occurs in the gradation change amount. In particular, in the case of scanning exposure, the intensity of the exposure light is small and the exposure time is long even with the same sub-exposure amount as compared with the case of surface exposure, so that there are three primary colors such as yellow (Y) and magenta (M). ) And cyan (C), there is a difference in the amount of change in gradation.

Therefore, in order to always form a good image with good color balance, whatever the amount of gradation adjustment by sub-exposure is, sub-exposure is performed and the target image or test chart is displayed. By actually forming an image using the image forming apparatus, the user can see the obtained hard copy and manually adjust the yellow (Y), magenta (M), cyan (C) color filters and apertures during sub-exposure. It was necessary to repeatedly set the optimum conditions for the sub-exposure.

Furthermore, even if the color filter and diaphragm conditions during sub-exposure are set to the optimum conditions, the characteristics of the photosensitive material and the image receiving material,
If the characteristics of the image, the characteristics of the processing solution such as development / fixing or the characteristics of the heat development processing temperature change, and, for example, the lot difference of the photosensitive material or the processing conditions change, it is assumed that only the main exposure color and light intensity value are adjusted. However, the optimum conditions for sub-exposure change, resulting in an unnatural image with an imbalanced color balance.

Therefore, some devices adjust the optimum conditions for sub-exposure independently of the main exposure as standard setting conditions, but since the standard setting conditions for main exposure and sub-exposure are separately calculated, complicated image adjustment is required. .

An object of the present invention is to solve the above-mentioned problems of the prior art, and in an image forming apparatus that adjusts the gradation of a formed image by sub-exposure, the lot of the photosensitive material or the image receiving material is changed, or the heat development temperature is changed. When the characteristics of the light-sensitive material and the image-receiving material and the processing conditions change, the optimum conditions for the main exposure color filter and diaphragm to obtain the optimum image are automatically set as standard setting conditions, and An object of the present invention is to provide an image forming apparatus that can automatically set the optimum standard setting condition of sub-exposure from the standard setting condition and can always form an image of a natural color tone with good color balance. .

<Means for Solving the Problems> In order to achieve the above object, the present invention provides an image forming apparatus capable of adjusting the gradation of a formed image by sub-exposure, comprising: To store the correlation between the standard setting conditions and the standard setting conditions of the light quantity and light quality of the main exposure when the sub-exposure is not performed, and to perform optimum image formation during image formation. An image characterized by automatically determining the standard setting conditions of the sub-exposure by the storage device from the standard setting conditions of the main exposure light quantity and light quality obtained from A forming apparatus is provided.

 The main exposure is preferably scanning exposure.

The sub-exposure is preferably performed before and / or after the main exposure.

The light amount of the sub-exposure is 1/50 of the light amount of the main exposure.
It is preferably ˜1 / 100.

Further, it is preferable that the standard setting conditions of the light quantity and light quality of the sub-exposure are automatically set.

The image forming apparatus preferably uses a photosensitive material.

Further, the image forming apparatus is preferably a copying apparatus.

<Operation of the Invention> In the image forming apparatus of the present invention, particularly in the apparatus for performing scanning exposure, there are variations in characteristics and processing conditions of the photosensitive material and the image receiving material for each lot. When exchanging materials, changing processing conditions, and even periodically, a test chart or test chart pattern is used to actually form an image so that an optimal image can be obtained. The color densities are read by the sensors of the three primary colors R, G, B, and compared with the color densities of the test chart or the pattern that is stored or read in advance, and the light quantity and light quality (density and color (color (color Balance)) Specifically, specifically, standard setting of the insertion amounts ΔY, ΔM, ΔC, ΔD of the Y, M, C color filters and the aperture D in the optical path (for example, the reference value is 0). It can be set as a matter.

Next, the apparatus of the present invention uses the standard setting condition ΔY,
From ΔM, ΔC, and ΔD, standard setting conditions for light quantity and light quality (density and color (color balance)) of the sub-exposure, that is, when the sub-exposure amount is ΔD _s , insert a color filter for the sub-exposure. In quantity,
ΔY _s , ΔM _s , ΔC _s (for example, the reference value is 0) corresponds to ΔD _s from the data stored in the storage device.
It is obtained from k ₁ , k ₂ , k ₃ , α, β, γ according to the following formula.

ΔY _s = k ₁ · ΔY + α ΔM _s = k ₂ · ΔM + β ΔC _s = k ₃ · ΔC + γ Thus, including the sub-exposure amount ΔD _s , the standard setting conditions for the sub-exposure (ΔY _s , ΔM _s , ΔC _s , ΔD _s ) are automatically set.

Therefore, the image forming apparatus of the present invention can automatically set the standard setting conditions (ΔY, ΔM, ΔC, ΔD) of the light amount and the light quality of the main exposure, and of course, the sub-exposure amount from the standard setting conditions. △
Based on D _s and the related data stored in the storage device, standard setting conditions of the light quantity and light quality of the sub-exposure ΔY _s , ΔM _s , Δ
Since C _s and ΔD _s can be set automatically, the color balance is always maintained in both normal image formation where only the main exposure is performed and image formation where the main exposure is performed after the sub-exposure to adjust the gradation. A good image having good color density and good density reproducibility can be formed.

<Embodiment> Hereinafter, the image forming apparatus according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

In the image forming apparatus of the present invention, in particular, when performing scanning exposure, since there are variations in the characteristics of each lot of the photosensitive material and the image receiving material and variations in the heat development condition, the photosensitive material and the image receiving material are not changed when the apparatus is installed. Optimum image forming conditions, especially standard setting conditions of light quantity and light quality for main exposure, are set at the time of replacement and periodically after installation of the device.At the same time, standard setting of light quantity and light quality for sub-exposure is performed at the same time. The conditions are set. To set the standard setting conditions for the light quantity and light quality of the main exposure, use a test chart for copying machines and test chart patterns for printers, etc., and perform a hard copy test actually formed from these test charts and test chart patterns. The color reproduction and the density reproduction with the chart are read and compared by a red (R) sensor, a green (G) sensor and a blue (B) sensor of the image sensor provided in the exposure device in the image forming apparatus. Thus, the colors are adjustment amounts of Y (yellow), M (magenta) and C (cyan), that is, Y filter, M filter,
The standard value is set so that the insertion amount of the C filter is finished to the optimum color, and the density is set to the standard value so that the aperture D is finished to the optimum density. In this way, as standard setting conditions, the set values of the Y, M, and C filters and the set value of the aperture D, which are the main exposure conditions capable of forming an optimum image, are set as the main exposure conditions in the present invention. Based on the correlation between the main exposure condition and the sub-exposure condition stored in the storage device, the optimum sub-exposure condition that results in the optimum image after the main exposure and the gradation adjustment is performed is performed. Can be asked.

Here, the reference value of Y, M, C, D in the main exposure, for example,
When the insertion amount is 0 when each filter is not inserted in the exposure optical path, the standard setting condition set due to the variation of the characteristics of the photosensitive material and the image receiving material for each lot and the variation of the processing condition is Δ.
If Y, ΔM, ΔC, and ΔD, the difference between the reference value and the standard setting condition actually set is ΔY, ΔM, ΔC, and ΔD. At this time, the standard setting conditions and secondary exposure of the sub-exposure for optimal imaging that when the sub-exposure (a difference from the reference value) sub exposure amount _{△ D s Y, M, C} , D reference value (e.g., insertion The difference from the quantity 0) is ΔY _s , ΔM _s , ΔC _s , ΔD _s .

Here, the relational expression between ΔY, ΔM, ΔC, ΔD and ΔY _s , ΔM _s , ΔC _s , ΔD _s is shown as follows.

ΔY _s = k ₁ · ΔY · α, ΔM _s = k ₂ · ΔM + β, ΔC _s = k ₃ ·
ΔC + γ where k ₁ , k ₂ , k ₃ and α, β, γ are constants determined by ΔD _s , ΔD.

More specifically, for the i-th sub-exposure amount ΔD _si
Set the sub-exposure standard setting conditions for Y, M, and C filters to (△ Y _si , △ M
_si , ΔC _si ) (i = 1 ... n), the following formula is established.

The storage device of the present invention is shown here. Is to be remembered. Since the conventional apparatus does not correct the color balance in the sub-exposure, it can be considered that K = 0 and AL = 0 in the above relational expression.

FIG. 1 shows, as an image forming apparatus according to the present invention, a photosensitive material which requires a heat development step for a recording material and which transfers and forms an image on an image receiving material having an image receiving layer in the presence of an image forming solvent such as water. An example of the copying apparatus used is shown.

The copying apparatus 10 shown in FIG. 1 is basically composed of an exposure device 14 arranged on an upper part of a housing 12 and a photosensitive material / image receiving material supply part 16 (hereinafter referred to as a supply part) arranged on a side part of the housing 12.
16) and the heat development transfer section 18 disposed on the side opposite to the supply section 16 of the housing 12, the supply section 16 and the heat development transfer section.
It is composed of a water application part 20 arranged between the water application part 18 and the water application part 18.

The supply unit 16 is arranged and loaded with a photosensitive material magazine 22 that winds and stores the photosensitive material A and an image receiving material magazine 24 that winds and stores the image receiving material C. The photosensitive material magazine 22 and the image receiving material Both of the magazines 24 are constructed so that they can be pulled out to the front side surface of the housing 12 (the front side in the direction perpendicular to the conveyance direction of the photosensitive material A in the figure).

Further, the photosensitive material magazine 22 is configured so as to be completely shielded from light when it is housed in the housing 12, so that the photosensitive material A is prevented from being inadvertently exposed. ing.

In the illustrated example, the light-sensitive material A requires a heat development step as described above, and forms an image on the image receiving material C having an image receiving layer in the presence of an image forming solvent such as water. It has a photosensitive silver halide, a binder, a dye-donating substance, a reducing agent and the like. In the copying machine 10 of the illustrated example, the photosensitive material A is wound so that the photosensitive surface thereof faces the lower surface and is stored in the photosensitive material magazine 22.

Further, the image receiving material C is formed by applying a dye fixing material having a mordant on a support. The image receiving material C is
The width of the image receiving material is narrower than that of the photosensitive material A, and the image receiving surface is wound so that the image forming surface faces upward.
It is stored in 24.

In front of the photosensitive material magazine 22 and the image receiving material magazine 24, pull-out roller pairs 26 and 28 are arranged respectively corresponding to their outlets, and in front of them, the photosensitive material A and the image receiving material C are respectively set to a predetermined length. Cutters 30 and 32 for cutting are arranged.

Here, the image receiving material C is cut a little shorter than the photosensitive material A in order to facilitate peeling after the heat development transfer.

The pull-out roller pair 26 corresponding to the photosensitive material A is a cutter 30.
After the operation, the front end of the photosensitive material A is reversed to a position where it is slightly clamped to prevent the front end of the photosensitive material A from being unnecessarily exposed and deteriorated. Further, the pull-out roller pair 28 corresponding to the image receiving material C releases the nipping of the image receiving material C after the operation of the cutter 32 and prevents the leading end of the image receiving material C from being damaged.

An exposure unit 34 is provided behind the cutter 30 (hereinafter, the rear is a downstream side in the transport direction of the photosensitive material A and the image receiving material C).
However, the reversing unit 36 is arranged behind it.

The photosensitive material A that has been pulled out by the pull-out roller pair 26 and cut into a predetermined length by the cutter 30 once passes through the exposure unit 34 and is inverted upside down by the reversal unit 36, and then is re-exposed to the exposure unit 34. It is conveyed and exposed by the exposure device 14 described later.

The exposure section 34 includes a pair of conveying rollers 38 and 40, an exposing surface glass 41 which defines a conveying path and an exposing position of the photosensitive material A arranged between the pair of conveying rollers 38 and 40, and an exposing surface glass 41 which is exposed to the light. And a pressing plate 43 for pressing the material A. That is, the photosensitive material A is conveyed by the conveying roller pairs 38 and 40 while being sandwiched between the exposure surface glass 41 and the pressing plate 43, and is conveyed to the reversing section 36, and the photosensitive surface is raised by the reversing section 36. In this way, it is conveyed again to the exposure unit 34, and while being conveyed in the same manner, scanning exposure is performed by the exposure device 14.

The conveying roller pairs 38 and 40 are configured to be reversible by various known means in order to perform sub-exposure for gradation adjustment.

The reversing unit 36 includes a branch guide 42 that vertically branches the conveyance path of the photosensitive material A, a flapper 44 that defines the conveyance path of the photosensitive material A in the branch guide 42, conveyance roller pairs 46a and 46b, and a pair of conveyance rollers of the photosensitive material A. It is composed of a guide guide 48 that constitutes the reverse conveyance path.

When the photosensitive material A is conveyed through the exposure section 34, the flapper 44 first acts on the path below the branch guide 42,
The photosensitive material A is guided to a path above the branch guide 42.

The photosensitive material A conveyed above the branch guide 42 is guided by a guide guide 48 and is conveyed while being turned upside down by the conveying rollers 46a and 46b, and is conveyed again to the exposure section 34 with its photosensitive surface facing upward. To be done. At this time, the flapper 44 acts on the path above the branch guide 42 and opens the path below the branch guide 42.

At the upper portion of the exposure unit 34, that is, at the upper portion of the housing 12, the exposure device 14 which is the most characteristic part of the present invention is provided.
Is arranged.

On the upper surface of the housing 12 of the copying apparatus 10, a document table 52 such as transparent glass for placing the document 50 and a document table cover 54 for fixing the document 50 to the document table 52 are arranged.

An achromatic reflector plate 56 such as gray is arranged on the side of the document table 52 on the side of the supply unit 16 (hereinafter referred to as the right side).

The reflection plate 56 is irradiated by a light source 60 described later at the time of sub-exposure for adjusting the gradation of the formed image, and reduces the light amount of the reflected light to 1 /.
The photosensitive material A is subjected to sub-exposure by the reflected light from the reflecting plate 56 before or after the main exposure in the above-mentioned exposure section 34 to adjust the gradation of the image to be formed. To do.

A white reference plate 58 for white balance adjustment is arranged on the left side of the reflection plate 56 of the document table 52.

Below the document table 52, a light source 60 for exposure and a reflector are provided.
A light source unit in which 60a and the mirror 62 are integrally configured is arranged.

This light source unit moves the lower surface of the document table 52 in the scanning direction indicated by the arrow a, and irradiates the document 50 with the light source 60. Further, at the time of sub-exposure and during white balance adjustment, the reflector 56 or the white reference plate 58 can be moved to a position where irradiation can be performed.

As the light source 60, any light source such as a halogen lamp that can be used as a light source for exposure of a normal copying apparatus can be used.

Illuminated by the light source 60, the original 50 (reflector 56, white reference plate
The reflected light reflected at 58) then enters the mirror unit and is reflected along the optical path L in a predetermined direction.

The mirror unit is formed by integrally forming two mirrors 64a and 64b, and is configured to move in the same direction as the above-mentioned light source unit at a speed of 1/2.

A variable diaphragm 66 for adjusting the amount of light is arranged behind the mirror unit in the optical path L.

FIG. 2 shows an example of the variable diaphragm 66 and the lens unit 68.

The variable aperture 66 is basically a plate cam 194 and a pair of aperture plates 1.
It consists of 96, 198, and diaphragm cams 196 and 19 with plate cam 194.
The light quantity of the reflected light traveling along the optical path L is adjusted by contacting and separating with 8.

The plate cam 194 has an opening 200 and is used for the rack 20.
6 is formed, and a stepping motor 212 is meshed with this rack 206 via gears 208 and 210. Therefore, the plate gum 194 moves to the right in the figure by the clockwise rotation of the stepping motor 212, and the stepping motor 212 is moved.
Is configured to move to the left in the figure by rotating counterclockwise.

Further, such plate cam 194 is formed with inclined grooves 202a, 202b and 204a, 204b, and in each inclined groove, pins 196a, 196b of diaphragm plate 196 and pin 1 of diaphragm plate 198 are respectively formed.
98a and 198b are inserted.

Further, the diaphragm plates 196 and 198 are fixed in the left-right direction by means not shown, but the rotation of the stepping motor 212 causes the plate cam 194 to move in the left-right direction in the drawing, so that the diaphragm plate 196 is moved.
And 198 move up and down along the inclined grooves 202a, 202b, 204a and 204b, and the insertion amount into the optical path L changes to determine the diaphragm amount D.

The reflected light, the amount of light of which is adjusted by the variable diaphragm 66 and which travels along the optical path L, then enters the lens unit 68.

The lens unit 68 is a combination of an image forming lens for forming an image of the reflected light of the document 50 on the conveyed photosensitive material A and a color filter for adjusting the light quality. Front lens group 220, first color filter plate 222,
A fixed diaphragm 224, a second color filter 226, and a lens rear group 228 are arranged and configured.

The first and second color filter plates 222, 226 are made of, for example, transparent glass plates, the central part is transparent, and color filter films of different colors are vapor-deposited on both sides. In the example shown in FIG. The first color filter plate 222 is C (cyan) and Y (yellow), and the second color filter plate 226 is C (cyan) and Y (yellow).
It has (cyan) and M (magenta) color filters, respectively.

Such first and second color filter plates 222 and 226
Is for adjusting the light quality of the reflected light traveling along the optical path L by adjusting the insertion amount Y, M, C of each color filter into the optical path L.

The adjustments of the insertion amounts Y, M, C of the respective color filters in the first and second color filter plates 222 and 226 into the optical path L are performed by gears 222b provided at the shaft ends of the stepping motors 222a and 226a serving as drive sources, respectively. And 226b and this gear 222b
And reduction gears 222c and 226c that mesh with 226b, respectively.
And racks provided on the first and second color filter plates 222 and 226 that mesh with the reduction gears 222c and 226c.
Performed by 222d and 226d.

It should be noted that the variable diaphragm 66 and the lens unit 68 described above include a variable diaphragm 66 during sub-exposure and main exposure, as will be described later.
Amount of light from the diaphragm and the amount of insertion of the aperture filter D, color filters Y, M, and C (Y, M, C) to adjust the light quality with each color filter plate Y, M, and C
A control device 76 for controlling the is connected.

Behind the lens unit 68 in the optical path L, mirrors 70a, 70b and 70c for reflecting the reflected light in a predetermined direction are arranged. The reflected light traveling along the optical path L is reflected by each of these mirrors in a predetermined direction to proceed along the optical path L, and the exposure unit 34
An image is formed on the photosensitive material A which is scanned and conveyed at a predetermined position of, and the photosensitive material A is exposed.

A moving mirror 74 that switches the optical path of the reflected light between the exposure unit 34 side and the image sensor 72 side is disposed behind the mirror 70c.

The movable mirror 74 is moved by a known means during normal exposure and is in a state of being retracted from the optical path L, but is moved to a position shown in the figure during auto setup, white balance adjustment, and prescan. Is inserted into the optical path L,
The reflected light is reflected by the image sensor 72.

The image sensor 72 measures the amount and quality of the reflected light during auto setup, white balance adjustment, and pre-scan. As shown in FIG. 3, the red (R) sensor 73R and the green (G) sensor 73G are used. , A blue (B) sensor 73B is built in. Here, one sensor for each color may be used, but a total of six optical sensors that measure the light intensity of two different wavelengths for each color may be used.

The image sensor 72 is electrically connected to the control device 76, and the photometric data of each color of R, G, B by the image sensor 72 is sent to the control circuit 76. A storage device 78 is connected to the control circuit 76. Further, as described above, the motor 212 of the variable diaphragm 66 and the motor 222 of the lens unit 68.
a and 226a are also connected to the controller 76. Controller 7
6 comprises a CPU and ROM, and further RAM, and the storage device 78 comprises RAM and further ROM.

The controller 76 transmits the R, G, B color density signals from the image sensor 72 at the time of pre-scanning to the storage device 78 for storage, or alternatively, the color density signals and the color density signals previously stored in the storage device. The standard setting conditions for light quantity and light quality for main exposure, standard setting conditions for light quantity and light quality for sub-exposure, and color and density during adjustment and exposure during auto setup and white balance adjustment based on Determine the exposure correction conditions, etc., and according to these conditions, Y, M,
C Adjust the amount of each color filter inserted and the amount of aperture D (aperture amount).

The storage device 78 stores the color density of each color of Y, M, and C and the correlation data of the color filter of each color, the correlation data of the standard setting condition of the main exposure and the standard setting condition of the sub-exposure, for example, the data of the matrix K and AL described above, In addition, the data necessary for determining the main exposure condition, the sub-exposure condition, and the like are stored as, for example, an LUT (lookup table).

The exposure apparatus 14 of the copying apparatus 10 in the illustrated example is basically configured as described above, but the exposure apparatus 14 is configured as one unit as a whole, and the housing
It is configured so that it can be opened by a hinge (not shown) provided at 12, and the inside can be easily inspected and repaired.

The photosensitive material A, which has been exposed by the exposure device 14 in the exposure unit 34, is inverted by the reversing unit 80 so that the photosensitive surface thereof faces downward, and is conveyed by the conveying roller pair 82 and the guide roller 84 to the water applying unit.
Transported to 20.

The water application section 20 applies water as an image forming solvent to the exposed light-sensitive material A.

 FIG. 4 shows an example of the water application section 20.

The water coating section 20 shown in FIG. 4 has a coating tank 86, a pair of conveying rollers 88 arranged in front of the coating tank 86, a pair of squeeze rollers 90 arranged behind the coating tank 86, and a water replenishing tank 92. is there.

Further, in the illustrated example, a conveyance guide 94 for the photosensitive material A is arranged so as to face the coating tank 86.

The photosensitive material A conveyed from the reversing section 80 is a pair of conveyance rollers.
At 88, it is carried into the coating tank 86, and while being transported between the coating tank 86 and the transport guide 94, water that is an image forming solvent is coated, and while the squeeze roller pair 90 removes excess water, the next step is performed. Be transported.

A supply line 100 having a pump 96 and a filter 98 is connected to the coating tank 86, and water is supplied from a replenishment tank 92.

A discharge line 104 having a solenoid valve 102 is connected to the bottom of the coating tank 86, and the normally closed solenoid valve 102 is opened to discharge the water filled in the coating tank 86 to the replenishment tank 92. .

Further, an overflow line 106 is connected to the coating tank 86, and excess water in the coating tank 86 is discharged to the replenishment tank 92.

Both the discharge line 104 and the overflow line 106 are configured such that the end portions on the side of the replenishment tank 92 are connected to the water tank portion 108, and water is discharged to the replenishment tank 92 via the filter 110.

The image forming solvent in the present invention is not limited to water and may be a mixture of water and a low boiling point solvent such as methanol, DMF, acetone or isobutyl ketone. Further, it is preferable that not only the image forming solvent but also an antifoaming agent is arranged in the replenishment tank 92.

A heat development transfer section 18 is disposed behind the water application section 16.

On the other hand, the image receiving material C pulled out from the image receiving material magazine 24 of the supply section and cut into a predetermined length by the cutter 32 is conveyed by the conveying roller pair 112 and is conveyed to the heat development transfer section 18.

A bonding roller 114 is arranged at the entrance of the heat development transfer unit 18 and bonds the water-applied photosensitive material A to the conveyed image receiving material C. Here, the photosensitive material A and the image receiving material C are bonded so that the photosensitive material A is about 5 mm forward.

A registration roller pair 116 is arranged in front of the laminating roller 114 in the conveying path of the image receiving material C, and the position of the image receiving material C is detected by a sensor (not shown) so that the photosensitive material A and the image receiving material C are separated by a predetermined distance. It is configured to be stuck in position.

The heat development transfer section 18 includes a halogen lamp 11 as a heating source.
A heating drum 118 including 8a and 118b, and an endless belt 122 wound around an outer peripheral surface of the heating drum 118 at an angle of about 270 ° and stretched by four belt supporting rollers 120a, 120b, 120c and 120d. The photosensitive material A and the image receiving material C are heated in a state of being bonded to each other. By this heating, the latent image of the photosensitive material A formed by being exposed by the above-mentioned exposure unit 34 is developed and transferred to the image receiving material C,
Develops color.

One of the heating halogen lamps 118a and 118b has an output of about 400 W and the other has an output of about 800 W. When heating the heating drum 118 to a predetermined temperature (about 78 ° C.), both The heating drum 118 is heated by a lamp, and the heating drum 118 is heated by one 800 W halogen lamp during normal operation.

In such a heat development transfer section 18, the photosensitive material A is peeled from the image receiving material C, and the first peeling claw 126 and the guide roller 128, which convey the photosensitive material A to the discard tray 124, and the image receiving material C are peeled from the heating drum 118. The second peeling claw 132 and the guide roller 134, which are conveyed to the takeout tray 130, are arranged.

The photosensitive material A and the image receiving material C, which have been transferred by heating by the heating drum 118 and the endless belt 122, are first separated by the first separating claw 126, and conveyed by the guide roller 128 toward the waste tray 124. , Transport roller pair 136 for waste tray
Transported to 124. On the other hand, the image receiving material C remaining on the heating drum 118 is peeled from the heating drum 118 by the second peeling claw 132 by further rotation of the heating drum 118, and is conveyed by the guide roller 134 toward the ejection tray 130, and is conveyed. It is conveyed to the take-out tray 130 by the roller pair 138.

A cutter 140 for shredding the photosensitive material A to be discarded is arranged behind the conveying roller pair 136, and the photosensitive material A is scraped and discarded in the discard tray 124.

The image forming apparatus of the present invention is not limited to the copying apparatus shown in FIG. 1 described above, and may be a photosensitive material such as a silver salt photographic photosensitive material, a pressure sensitive resin photosensitive material, or a photothermographic material, or an image receiving material. It may be equipped with any processing device necessary for image formation, such as an exposure device, a processing tank composed of a developing tank, a fixing tank, a water washing tank, a pressure transfer device, and a heat developing device. Alternatively, it may be a color printer.

The image forming apparatus according to the present invention is basically configured as described above, and its operation will be described below by taking the copying apparatus 10 shown in FIG. 1 as a typical example.

The copying apparatus 10 which is the image forming apparatus of the present invention is configured so that the gradation of the formed image can be adjusted by performing sub-exposure. Normally, the copying machine 10 is subjected to fluctuations in characteristics of each manufacturing rod of the photosensitive material / image receiving material, processing conditions or conditions of the heat developing device, etc. during installation, replacement of the photosensitive material / image receiving material, and periodic inspection. Since there are fluctuations in the value, use the test chart shown in FIG.
Standard conditions of light quantity and light quality of main exposure, that is, standard setting conditions are set (setup) so that the formed image is optimally finished according to the photosensitive material and the image receiving material.
At the same time, the standard conditions of the amount and quality of light of the sub-exposure when the sub-exposure is performed, the gradation is adjusted, and the main exposure is performed, that is, standard setting conditions are automatically set. Here, it is preferable that the standard setting condition of the main exposure is automatically set, that is, automatically set up.

At the time of auto setup, the auto setup mode is selected, the test chart 51 shown in FIG. 5 is placed on the original table 52 of the copying apparatus 10, and a start switch (not shown) is pressed to perform prescan by the exposure device 14.

In the prescan, the light source 60 is turned on and the light source unit scans the lower surface of the document table 52, and the reflected light from the document 50 is reflected by the mirror unit that moves in the same direction at half the speed of the light source unit, The light passes through the open variable diaphragm 66 and the lens unit 68 in which the color filter is not inserted, is reflected by the mirrors 70a, 70b and 70c, is further reflected by the reflection mirror 74 arranged at the position shown in the figure, and is incident on the image sensor 72. R, G, B three color sensor 73R, 73G, 73B
The R, G, B color densities are read as electrical signals. The color density signal of each color is immediately transmitted to the control device 76, and further transmitted to the storage device 78 to be stored therein.
At 76, the correction amount of the color filter and the diaphragm of the main exposure is determined.

On the other hand, during this prescan, the photosensitive material A is pulled out from the photosensitive material magazine 22 by the pull-out roller pair 26 and cut into a predetermined length by the cutter 30.

The photosensitive material A cut into a predetermined length is conveyed by the pair of conveying rollers 38 and 40 of the exposure section 34, guided by the flapper 44 to the conveyance path above the branch guide 42, and the photosensitive surface is inverted by the reversing section 36. The sheet is reversely conveyed so as to be upward, is conveyed again to the exposure section 34 through the branch guide 42 with the photosensitive surface as the upper surface, and stands by at a predetermined position.

The prescan ends and the light source unit and the mirror unit return to their home positions.

Here, Y, M, C of the variable diaphragm 66 and the lens unit 68
The color filter plates 222, 226 of the respective colors of the motors 212, 222a, 226a
The amount of insertion of the diaphragm and each color filter into the exposure optical path L is corrected in accordance with the above-described correction amount. Further, the moving mirror 74 retracts from the optical path L and directs the optical path L toward the exposure unit 34 side.

Next, the main exposure is started. In the main exposure, the exposure device 14 operates in the same manner as in the prescan, the light source 60 scans the test chart 51, and at the same time, the photosensitive material A is conveyed by the transport rollers 38, 4.
The test chart 51 is sandwiched between 0 and is scanned and conveyed rightward in FIG. 1 in synchronization with the scanning speed of the light source 60.
Image is scanned and exposed on the photosensitive material A.

When the exposure is completed, the photosensitive material A is reversely conveyed by the reversing section 80, is conveyed to the water coating section 20 with the photosensitive surface facing downward, and is conveyed by the conveying roller pair 88 and the squeeze roller pair 90 while being applied to the coating tank 86. And is coated with water as an image forming solvent. The excess water applied in the application tank 86 is removed by the squeeze roller pair 90.

On the other hand, the image receiving material C is pulled out from the image receiving material magazine 24 by the pull-out roller pair 28, cut into a predetermined length by the cutter 32, transported to the transport roller pair 112, and registered to the registration roller pair 116.
To wait in place.

When the photosensitive material A is conveyed to a predetermined position, the registration roller pair 116 starts conveying the image receiving material C, and the laminating roller 114 bonds the photosensitive material A and the image receiving material C together.

The photosensitive material A and the image receiving material C bonded by the bonding roller 114 are nipped and conveyed by the heating drum 118 and the endless belt 122 in the thermal development transfer section 18, and the latent image carried by the photosensitive material A is heated. While being developed, it is transferred to the image receiving material C to develop a color.

Then, the photosensitive material A is transferred to the image receiving material C by the first peeling claw 126.
The sheet is separated from the sheet, guided by the guide roller 128, conveyed by the pair of conveying rollers 136, shredded by the cutter 140, and discarded in the discard tray 124. On the other hand, the image receiving material C is the second peeling nail 1.
It is separated from the heating drum 118 at 32, guided by the guide roller 134, conveyed to the conveying roller pair 138, and conveyed to the take-out tray 130.

When the test chart copy thus obtained as the image receiving material C is placed on the original table 52 again and the start switch is pressed again, the prescan is performed in the same manner as described above, and the respective colors R, G, B of the test chart copy are performed. The color density is read as an electric signal by the image sensor 72 and then transmitted to the control device 76.

The control device 76 compares the transmitted color density data of the test chart copy with the color density data of the test chart previously stored in the storage device 78, calculates the difference between each color and density, and calculates the difference from these differences. From the correlation data of the respective color densities and the respective color filters stored in the storage device 76 and the density and the diaphragm, the insertion amounts ΔC, ΔM, ΔY, of the color filters C, M, Y and the diaphragm D into the optical path L are stored. ΔD is set as a standard setting condition for optimum main exposure. Furthermore, at the time of main exposure, each color filter C, M, Y
And adjust the insertion amount of the diaphragm D.

In this way, when the standard setting conditions ΔY, ΔM, ΔC, and ΔD of the main exposure are determined, in the present invention, the standard setting conditions ΔY _S , ΔM _s , ΔC _s , and ΔD of the sub-exposure according to the following equations as described above. _s is determined.

Is measured in advance or calculated according to the photosensitive material / image receiving material to be used, development processing conditions, etc. and stored in the storage device 78.

As an example, the sub-exposure amount ΔD _s is +20 to +10, +10 to −1.
When it is varied in three stages of 0, -10 to -20, ΔD _s ΔY _s +20 to +10 k ₁₁ · ΔY + α ₁ +10 to −10 k ₂₁ · ΔY + α ₂ −10 to −20 k ₃₁ · ΔY + α ₃ ΔM _s ΔC _{It can be obtained as s} k ₁₂ · ΔM + β ₁ k ₁₃ · ΔC + γ ₁ k ₂₂ · ΔM + β ₂ k ₂₃ · ΔC + γ ₂ k ₃₂ · ΔM + β ₃ k ₃₃ · ΔC + γ ₃ .

When the sub-exposure amount ΔD _s = −20 cc, for example, , That is, k ₃₁ = k ₃₂ = k ₃₃ = 1, α ₃ = β ₃ = γ ₃ =
When 0, when the sensitivity changes due to changes in the photosensitive material or processing conditions, Becomes

In the present invention, when the operator copies the image of the document 50, in order to adjust the gradation of the copy image finally obtained, by the sub-exposure standard setting conditions thus determined before or after the main exposure, The photosensitive material A is subjected to sub-exposure.

In the copying machine 10 shown in the figure, the operator is the manuscript 50.
Is placed on the document table 52, the document table cover 54 is closed, the sub-exposure mode is selected, and the start switch is pressed. First, as described above, the exposure device 14 performs prescan. The image sensors read the Y, M, and C color densities of the document 50 by prescanning, and the color densities are stored in the storage device 78 via the control device 76.

When the prescan ends, the light source unit moves to a position where the light source 60 can irradiate the sub-exposure reflection plate 56 for the sub-exposure, and the mirror unit also moves accordingly. Further, the variable diaphragm D66 and the color filters Y, M, and C in the lens unit 68 are set by the control device 76 to the standard setting conditions for the sub-exposure. For example, the respective filters and diaphragms have the insertion amounts of Y = 10 cc, M = 5 cc, C = 0 cc, D = 20 cc described above. The sub-exposure amount ΔD _s may be arbitrarily selected. Also, the moving mirror 74
Withdraw from the optical path L.

Thus, when the sub-exposure condition is set, the light source 60 irradiates the reflecting plate 56, the reflected light from the reflecting plate 56 is reflected by the mirror unit, and the variable diaphragm 66 and the variable stop 66 set to a predetermined sub-exposure condition. The photosensitive material A that has passed through the lens unit 68, is dimmed, is reflected by the mirrors 70a, 70b, and 70c, is sandwiched by the exposure surface glass 42 and the pressing plate 44, and is conveyed by the conveying roller pairs 38 and 40. Sub-exposure is performed with a predetermined amount of light which is about 1/50 to 1/100 of the main exposure.

When the sub-exposure is completed, the pair of conveying rollers 38 and 40 reversely rotate and conveys the photosensitive material to the reversing unit 36.

The photosensitive material A is in the reverse direction to the predetermined position (inversion part 36 direction)
, The light source unit returns to the home position,
When the variable diaphragm 66 and the lens unit 68 are appropriately adjusted according to the image information obtained in the previous prescan, the main exposure is started. At this time, the reference values of the filter conditions for the main exposure are Y = 10cc, M = 5cc, C = 0cc, D = 40cc,
Considering the sub-exposure, only D may be 45cc.

The light-sensitive material A, which has been subjected to the main exposure in the same manner as described above, is coated with water as described above and is superimposed on the image-receiving material C,
After thermal development, the image is peeled off and an image is formed on the image receiving material C.

The copied image formed in this way is not affected by the characteristic variations of the photosensitive material / image receiving material for each lot or the variation of processing conditions. It is a copy image.

The image forming apparatus according to the present invention has been described above in detail with reference to the preferred embodiments shown in the accompanying drawings. However, the present invention is not limited to this, and a silver salt photographic light-sensitive material is used. The present invention can be applied to various image forming apparatuses such as an image forming apparatus by wet development, an image forming apparatus using a heat-sensitive pressure sensitive photosensitive material, and an electrophotographic image forming apparatus.

Further, the exposure method is not limited to the light source moving type scanning exposure of the illustrated example, but can be applied to the original table moving type scanning exposure and surface exposure.

The present invention is not limited to the above examples,
It goes without saying that various changes and improvements may be made without departing from the spirit of the present invention.

<Effects of the Invention> According to the present invention, since the correlation data between the exposure conditions of the main exposure and the sub-exposure is stored in the storage device in advance, the light amount of the main exposure set for optimal image formation is set. And the standard setting conditions of light quality are automatically set by sub-exposure to set the standard setting conditions of the light amount and light quality of the sub-exposure when the main exposure is performed. Even if there is a change in the characteristics for each time, a change in the processing solution, a change in the processing temperature, and a change in the heat development processing conditions, the light amount of the sub-exposure and the light amount The light quality is suitably adjusted, and even when an image with any gradation is formed, the color balance is not lost and a natural and excellent image can be formed.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an embodiment of the image forming apparatus according to the present invention. FIG. 2 is a perspective view of an embodiment of the variable diaphragm and lens unit applied to the copying machine shown in FIG. FIG. 3 is a schematic view of an embodiment of a color sensor in the image sensor applied to the copying machine shown in FIG. FIG. 4 is a schematic view of an example of a water application unit applied to the copying machine shown in FIG. FIG. 5 is a front view of an example of a test chart used for setting up the copying apparatus shown in FIG. Explanation of reference numerals 10 …… Copier, 12 …… Housing, 14 …… Exposure device, 16 …… Photosensitive material / image receiving material supply section, 18 …… Heat development transfer section, 20 …… Water application section, 22 …… Photosensitive Material magazine, 24 …… Receiving material magazine, 34 …… Exposure section, 36 …… Inversion section, 51 …… Test chart, 66 …… Variable diaphragm, 68 …… Lens unit, 76 …… Control unit, 78 …… Memory Device, 118 ... Heating drum, 122 ... Endless belt, 124 ... First peeling claw, 132 ... Second peeling claw

Claims (1)

(57) [Claims] 1. An image forming apparatus capable of adjusting gradation of a formed image by sub-exposure, comprising standard setting conditions of light quantity and light quality of the sub-exposure and main exposure when the sub-exposure is not performed. Having a storage device for storing the correlation between the light amount and the standard setting conditions of the light quality, when forming an image, obtain the standard setting condition of the light amount and the light quality of the main exposure for performing the optimum image formation, An image forming apparatus, wherein the storage device automatically sets the standard setting condition of the sub-exposure from the obtained standard setting condition of the main exposure.