JP3061395B2 - Standard exposure condition correction method for copier - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a standard exposure condition correcting method for a copying machine, and more particularly, to a standard exposure condition set when a copying machine is used for the first time. The present invention relates to a standard exposure condition correction method for a copying apparatus that corrects a standard exposure condition that is reset when it changes.

[Problems to be solved by conventional technology and invention]

In order for the quality of color prints to be constantly improved by the printer processor, it is necessary to correctly carry out the development processing and to set the exposure conditions of the printer section correctly in the device. For this reason, the standard exposure conditions are set when the printer processor is installed.However, when using color paper with a different emulsion number, replacing the printer lamp, replacing the developing solution, or changing seasons, etc. When the color changes from a color having a large number to a color having a small number of colors, or vice versa, the color development condition of the print changes. Therefore, it is necessary to correct and reset the standard exposure condition. In addition, since the coloring condition of the print changes due to dirt or deterioration of the light source system including the light control filter, the halogen lamp, the reflector, and the like, it is necessary to correct and reset the standard exposure condition as described above. To correct the standard exposure conditions, use a reference negative film with a part corresponding to the negative that photographed the average subject color around the part that corresponds to the negative that photographed the gray subject, and print-developed from this reference negative film. The density of the test print thus obtained is compared with the density of a reference print (target density) which has been printed and developed in advance as a standard. That is, since the above-mentioned reference negative film has a standard subject density and a medium gray subject density, the standard exposure conditions are corrected so that a print obtained from this reference negative film develops a medium gray color.

However, in the above method, since the reference negative film is used, the correction accuracy is reduced due to fading of the reference negative film, or the reference negative film is manually set on the negative carrier, so that the correction is performed by the contamination of the reference negative film. There is a problem that accuracy is reduced. In addition, since the reference negative film needs to be created for each film type, there is a problem that the load on the creator increases as the number of film types increases.

In order to solve this problem, Japanese Patent Application Laid-Open No. Sho 60-113233 discloses a flap in which a test film for producing a test copy in contact with a copying material is provided. It is disclosed that a proper exposure condition is obtained. This method has the advantage that the test film is automatically set, so that the correction accuracy does not decrease due to dirt. However, the use of the test film causes the same problem of fading as described above. In addition, since the light source system cannot be measured through the test film because the test film is in contact with the copy material, whether the change in the exposure condition has occurred due to the light source system of the printer, whether the change of the exposure condition has occurred due to the copy material and the development processing (mainly, the developer However, there is a problem that it is not possible to discriminate whether or not the exposure condition has occurred due to the change, and it is not possible to correct the exposure condition for each change occurrence cause.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a standard exposure condition determining method capable of preventing a decrease in correction accuracy due to fading or stain.

[Means for solving the problem]

In order to achieve the above object, the present invention has a dimming filter that moves in an exposure light path, irradiates light from a light source through the dimming filter, and applies light to an original image of a film supported by a film carrier. A standard of a copying apparatus that exposes an image of an original image to a copying photosensitive material with an exposure amount obtained by using a photometric value of the original image and a set standard exposure condition from a predetermined formula for irradiating and obtaining an exposure amount To correct the exposure conditions, a dimming filter with many narrow slits
In the exposure light path between the light source and the film carrier, the narrow slit is automatically inserted so that the length direction of the narrow slit faces the moving direction of the light control filter, and the photometric value of the light reduction filter and the light Using the standard exposure conditions, the photosensitive material is exposed through a dimming filter with the exposure amount obtained from the above formula, and the standard exposure condition is obtained using the copy density and the target density obtained by developing the exposed photosensitive material. Is corrected.

[Action]

The copying apparatus has a light control filter that moves in an exposure light path, irradiates light from the light source through the light control filter, and irradiates light to an original image of a film supported by a film carrier and obtains an exposure amount. The image of the original image is exposed to the copy photographic material at an exposure amount obtained from the photometric value of the original image and a set standard exposure condition from a predetermined formula for the purpose. In this copying apparatus, the standard exposure condition is corrected when a switch for giving an instruction to correct the standard exposure condition is turned on.

As described above, in correcting the standard exposure condition, the present invention relates to a method in which a dimming filter having a large number of narrow slits is provided in an exposure optical path between the light source and the film carrier. Automatically inserted so that the length direction of the dimming filter is oriented in the moving direction of the dimming filter, and through the dimming filter with the exposure amount obtained from the above equation using the photometric value of the dimming filter and the standard exposure condition. The standard exposure condition is corrected using the copy density and the target density obtained by exposing the copy photosensitive material and developing the exposed copy photosensitive material.

The exposure amount when exposing the copying photographic material through the neutral density filter is preferably obtained under the conditions of full collection or high collection.

 The target density can be determined for each film type.

〔The invention's effect〕

As described above, according to the present invention, a dimming filter having a large number of narrow slits is provided in an exposure optical path between a light source and a film carrier so that the length direction of the narrow slit is dimmed. Since the light is automatically inserted so as to be oriented in the moving direction of the filter, an effect is obtained that the photometric value of the dimming filter with respect to the unit movement amount of the dimming filter can be prevented from changing stepwise.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a printer processor to which the present invention can be applied. This printer processor is C,
The light source unit 10 includes a light control filter 17 composed of M and Y filters, a light diffusion box 15 and a halogen lamp 19, and a paper magazine unit 12 containing color paper.
In addition, a photometer 16 for measuring the average screen density (LATD) of the color negative film sandwiched between the negative carriers 11 is provided. The photometer 16 automatically corrects the standard exposure conditions, and It is connected to a control circuit 50 for controlling a dimming filter to control exposure conditions. The color paper drawn from the paper magazine section 12 is printed with a negative film image in an exposure section 14 and supplied to a color developing section 20 of a processor section via a reservoir section 18. The color paper developed in the color developing unit 20 is subjected to fixing processing in the bleach-fixing unit 22 and then washed with water in the rinsing unit 24 to produce a color print. The washed color print is dried in a drying unit 26 and then cut in image units in a cutter unit 28. The cutter unit 28 includes a densitometer 30 connected to a control circuit 50 so as to sandwich the color print to be conveyed.
Is arranged. Further, a CRT 51 for displaying data and the like and a keyboard 53 for inputting data and the like are connected to the control circuit 50.

The dimming filter 17 and the light diffusion box 15 of the light source section 10 described above.
Between them, a dimming filter 34 is arranged so as to be insertable into the exposure optical path. As shown in FIGS. 2 and 3, the dimming filter 34 includes a deposition filter 36 on which a multilayer film is deposited and a slit filter 38 made of metal. The neutral density filter 34 may be disposed between the negative carrier and the light source, but preferably between the light diffusion box and the light source. In addition,
Instead of the vapor deposition filter 36, a white plate glass or a color glass filter may be used. Both ends of the vapor deposition filter 36 are supported by a slit filter 38 having both ends bent in a U-shape. The bottom of the evaporation filter 36 and the slit filter 38
A pair of spacers having the same width as the width of the bent portion of the slit filter 38 so that the bottom surfaces do not contact each other.
44 are interposed. The heat is conducted from the slit filter 38 to the vapor deposition filter 36 by the spacer 44 so that the vapor deposition filter 36
Is prevented from being damaged, and may be omitted. Near the corner of the slit filter 38, one end of a mounting arm 40 is fixed. The other end of the mounting arm 40 is
The motor 42 is fixed to a rotating shaft. Therefore, the motor 42
, The dimming filter 34 rotates in a horizontal plane about the rotation axis of the motor 42. Slit filter 38
A large number of slits 46 having a predetermined width are formed at predetermined intervals in parallel on the entire bottom surface by etching or the like. It is preferable that the transmitted light of the slit filter is 1/2 or less. That is, the width of the slit 46 is 1.0 mm or less,
The interval between the slits 46 is preferably 1.0 mm or more. Note that a large number of fine holes may be formed instead of the slits. The diameter of the hole should be 1.5 mm or less, preferably less than 1.0 mm. Both sides of the slit filter 38 are painted black to prevent reflection.

The deposition filter 36 has a multilayer film deposited so that the transmittance distribution becomes a curve shown in FIG. Therefore, the transmittance distribution of the neutral density filter 34 is larger in the long wavelength band than in the short wavelength band. The neutral density filter 34 preferably has an average spectral distribution of the average subject of various film types, but may have the above-described characteristics or flat characteristics.

As shown in FIG. 5, the dimming filter 34 is arranged such that the length direction of the slit 46 of the dimming filter 34 is directed to the moving direction of the dimming filter 17 (the direction indicated by the arrow in FIG. 5). Have been. As described above, since the length direction of the slit is oriented in the moving direction of the dimming filter 17, the dimming filter 34
Is continuously changed in accordance with the movement of the light control filter, so that the photometric value can be prevented from changing stepwise. Further, a slit filter 38 is arranged below the vapor deposition filter 36.

In the above description, the vapor deposition filter 36 and the slit filter 38
Thus, the dimming filter 34 is configured. However, the dimming filter 34 may be configured by sandwiching a slit filter with a pair of vapor deposition filters.

When the width or the fine hole of the slit 46 is 0.3 mm or more, clogging is small, and the glass member 36 such as a vapor deposition filter or white sheet glass is not necessarily used.

Next, the operation of the present embodiment will be described. First, the control circuit 50
Performs printing by controlling the light control filter 17 based on the exposure control value Ej shown in the following equation.

logEj = Sj · {Aj (dDj−dwj) + dwj} + Cj (1) where dDj = Dj−DNj (2) J: any one of 1 to 3 representing any of R, G and B Dj: photometric value of the film image frame to be printed, reduced if a dimming filter is inserted in the exposure optical path Photometric value of the light transmitted through the optical filter DNj: The photometric value of the image frame of the reference negative film,
It is stored as a reference value for determining the amount of exposure.

Sj: Slope control value Aj: Color correction value Cj: Color balance value depending on printer, film and photographic paper characteristics Next, color balance value Cj, which is one of the standard exposure conditions
The method for setting the standard value of the parameter will be described. Exposure conditions are set when the printer processor is in the standard state and the developer is in the standard state. The light-attenuating filter 34 is retracted from the exposure light path, and a reference negative film (a negative or a filter having a condition in which many film frames can be properly printed) is used.
Exposure is performed by an automatic correction exposure function (full correction or high correction) using the above-described formula (1) of the printer processor and setting the color correction value Aj to a value of 1.0 or more or less than 1.0 and close to 1.0. Darkening filter 34
Is retracted from the exposure optical path, so that Dj = DNj.
Therefore, dDj = 0, dwj = 0, and logEj = Cj. Note that the color balance value is a value that depends on the characteristics of the printer, the film, and the photographic paper as described above, and
Since the type of the reference negative film is determined in advance, a predetermined value depending on the printer, the type of the reference negative film, and the characteristics of the photographic paper is used as the color balance value Cj in equation (1). The exposed print is developed, fixed, and dried by a processor section of a printer processor, thereby producing a print. The screen density of this print is measured, and this measured value is used as a target density value. The target density value is determined for each film type using a reference negative film for each film type. Next, the motor 42 is driven to insert the dimming filter 34 into the exposure optical path.
Exposure with film collection or high collection according to the formula. Since Dj is the photometric value of the light transmitted through the neutral density filter, dDj ≠ 0 and dwj ≠ 0. Note that DNj in equation (1) is a photometric value of an image frame of the reference negative film, and a color balance value Cj is a predetermined value that depends on a printer (considering a neutral density filter) and photographic paper characteristics. . Then, a color balance value is obtained by a known method so that the screen density of the print obtained by this exposure becomes the target density value, and the value is set to Cj '. Since the characteristics of the reference negative and the neutral density filter are different, the color balance value Cj
And the color balance value Cj ′, the characteristic difference Δ for each primary color of the reference negative and the neutral density filter, that is, for each of R, G, and B colors.
Cj has occurred. In the normal case, the color balance value Cj
When the standard exposure condition is managed, the standard exposure condition is managed by the exposure using the color balance value Cj ′, and when the color balance value Cj ′ changes, the characteristic difference is obtained. The color balance value Cj is corrected according to ΔCj. When the spectral characteristics of the neutral density filter and the spectral characteristics of the standard negative film are similar,
What is necessary is just to manage as Cj = Cj '.

In the above, the target density value and the characteristic difference ΔCj
In the case where standard exposure conditions are set for a plurality of printer processors of the same model, for example, the standard exposure conditions are the same. , Characteristic difference ΔCj
The standard exposure conditions may be set for the remaining printer processors by inputting target density values, color balance values Cj and Cj ′, characteristic differences ΔCj, and the like.

Next, a method of managing and maintaining the standard exposure conditions set as described above will be described. Standard values are preset for the average image density DNj, the slope control value Sj, and the color balance values Cj and Cj 'as standard exposure conditions. The standard exposure condition, the target density value PD _{BASE, and the} like are stored in the memory of the control circuit in advance. This target density value is set for each channel.
That is, it is stored for each film type. When the channel is designated and the switch for correcting the exposure condition is turned on, the correction routine shown in FIG. 7 is started, and the lamp of the densitometer 30 is turned on at step 102. Tens of seconds after the lamp is turned on, the density measurement of the densitometer 30 becomes possible.

In step 104, the motor 42 is driven to insert the dimming filter 34 into the exposure optical path. In step 106, the lamp of the light source unit 10 is turned on, and the light is filtered by the photometer 16.
The light transmitted through 34 is measured. The metering value when metering is Dj
Is stored in the memory. In the next step 108, the reference value DNj stored in the memory is fetched, and in step 110
In comparing the absolute value of the difference between the photometric values Dj and the reference value DNj with a predetermined value D _0. | Dj-DNJ | For ≧ D _0, determines that the light source system is varied, such as by dust adhesion or a halogen lamp is degraded in the light source unit, in step 112, the reference value D
The magnitude of Nj is corrected, and the corrected DNj is stored. | Dj−
DNJ | <For D _0, the process proceeds to determine that there is no change in the light source system to directly step 114.

In step 114, the color correction value Aj is set to a value of 1.0 or more or a value less than 1.0 and close to 1.0. This allows the color correction to be a high correction or a full correction, which can correct the color falia, i.e., when determining the exposure of the three primaries, for any one of the three primaries the other two primaries. May have little or no effect. The high correction or the full correction is performed in order to correct the difference between the characteristic A of the conventional reference negative and the characteristic B of the neutral density film 34 as shown in FIG. In the next step 116, the color balance value is set to C.
The exposure control value Ej is calculated based on the above equation (1) using j ′ and the corrected DNj. In step 118, exposure is performed by controlling the light control filter based on the exposure control value Ej, and the exposed paper is developed.

In the next step 120, it is determined whether or not a predetermined time has elapsed since the exposure, so as to determine whether or not the print has reached the photometry position. If it is determined that the print has reached the photometric position, the density of the print is measured by the densitometer 30 in step 122, and the measured value is stored in the memory as PDj. In step 124, the absolute value determines whether or not a predetermined value PD ₀ or more differences in the target density value PDj _BASE corresponding to the designated channel read and print the photometric value PDj and the target density value PDj _BASE in step 126 I do. | PDj
When −PDj _BASE | ≧ PD _0, the target density value cannot be obtained despite the correction of the variation of the light source system in step 112, and therefore the paper and the paper processing system (particularly, the developer)
Judge that there is a change in at least one of
At 128, the magnitude of the slope control value Sj and the magnitude of the color balance value Cj are corrected so that the measured value PDj becomes the target density value PDj _BASE , and the result is stored in the memory. When correcting the color balance value Cj, the characteristic difference ΔCj is further considered. As a result, by correcting the color balance value so that the density of the print using the neutral density filter becomes the target density, it is possible to correct the fluctuation of the print meter including the light source, the paper characteristics, and the paper development characteristics.

In the above description, the automatic exposure correction function of the printer processor is operated to use the target density value obtained from the reference negative film and the color balance value Cj ′ when using the neutral density filter to obtain a color balance value Cj for exposure. Although an example in which correction is performed has been described, management may be performed as follows using a target density value obtained from a neutral density filter. First, an appropriate standard exposure condition is set in a printer processor by a method using a conventional reference negative film or a method using the above-described darkening filter. A darkening filter is inserted into the exposure light path, and the density of the print created by the automatic exposure correction function of the printer processor is set as the target density. In the management after setting the target density, the color balance value Cj 'is manually corrected and set so that a print of the target density can be obtained under a constant exposure condition without operating the automatic exposure correction function.

Photometry is performed by dividing the film image into multiple pieces, comparing the photometric value with the reference value, selecting the photometric value, and controlling the exposure under the condition of full correction or high correction based on the average density of the selected photometric value. The printer is suitable as a copying apparatus to which the present invention is applied because it is not necessary to set exposure conditions for each film type. In addition, the above-mentioned printing includes a one-channel type printer. The one-channel type printer can print various negative films under one printer condition.
-311241, JP-A-63-311242, JP-A-64
No. 77041 and the like. In a printer having a built-in neutral density filter, it is difficult to incorporate a filter similar to various negative films in terms of space. Therefore, usually, one type of filter is built in. This filter has a density characteristic similar to that of a reference negative film and manages exposure conditions for each type of the reference negative film, thereby enabling high-precision management.

[Brief description of the drawings]

1 is a schematic view of a printer processor to which the present invention is applied, FIG. 2 is a side view of a dimming filter, FIG. 3 is a plan view of the dimming filter, and FIG. 4 is a line showing characteristics of a vapor deposition filter. FIG. 5 is a plan view showing the arrangement of the neutral density filter, FIG. 6 is a diagram showing the characteristic difference between the reference negative film and the neutral density filter, and FIG. 7 is a flowchart showing a routine for correcting the standard exposure conditions. It is. 34 ... Dim filter, 36 ... Evaporation filter, 38 ... Slit filter.

Claims (3)

(57) [Claims] A light source for irradiating light from a light source through the light adjusting filter, and irradiating light to an original image of a film supported by a film carrier, and controlling an exposure amount. In correcting the standard exposure conditions of a copying apparatus that exposes an image of an original image to a copying photosensitive material with an exposure amount obtained by using a photometric value of the original image and a standard exposure condition set from a predetermined formula for calculation. A light-reducing filter provided with a plurality of narrow slits is placed in an exposure optical path between the light source and the film carrier so that the length direction of the narrow slits is directed to the moving direction of the light control filter. Then, the light-sensitive material is automatically inserted, and the light-sensitive material is exposed through the light-attenuating filter using the photometric value of the light-attenuating filter and the standard exposure condition with the exposure amount obtained from the above formula, and the exposed light-sensitive material is developed. Copy density and eye Standard exposure condition correction method of the copying apparatus, characterized by correcting the standard exposure conditions using the density. 2. The method according to claim 1, wherein the exposure amount when exposing the copying photographic material through the neutral density filter is determined under full collection or high collection conditions. 3. The method according to claim 1, wherein said target density is determined for each film type.