JPH0980651A - Exposure control method - Google Patents

Abstract

(57) [Summary] (Modified) PROBLEM TO BE SOLVED: To provide a stable quality photo printer for a liquid crystal photo printer.
Make lint. Drive voltage V for obtaining maximum light transmittance ₁
Maximum transmitted light amount E when applying to the liquid crystal panel₁,as well as
Drive voltage V for obtaining the minimum light transmittance₂When applying
Minimum transmitted light amount E₂To measure. Next, the measured
Large amount of transmitted light E₁And the minimum transmitted light amount E₂Intermediate transmitted light amount E
_Three{= (E₁+ E₂) / 2} and this intermediate transmitted light amount E
_ThreeDrive voltage V_ThreeAsk for. Then warm
The LCD panel each time you make adjustments to compensate
Intermediate drive voltage V_ThreeIntermediate transmitted light amount E when applying_ThreeBut
Based on the fact that it can be obtained, the reference value of the drive voltage
adjust.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure control method, and more particularly, to display an image on a liquid crystal panel by applying a predetermined drive voltage to each pixel of the liquid crystal panel, and the liquid crystal on which the image is displayed. The present invention relates to an exposure control method in a photographic printer, which irradiates a panel with light from a light source and exposes the image on a photosensitive material by the transmitted light transmitted through the liquid crystal panel.

[0002]

2. Description of the Related Art Conventionally, an index in which reduced frame images are arranged in a matrix at predetermined intervals and printed so that it is possible to easily search what kind of photograph is taken on one developed negative film. The print is known.

As a technique for producing this index print, after each frame image of the negative film is read by a scanner or the like in a photographic printer and a predetermined image processing is performed,
The image data stored in the image memory is read from the image memory for a few frames at a predetermined timing and displayed on the liquid crystal panel.The displayed image data is irradiated with light from a light source, and the transmitted light converts the image data. There has been proposed a technique relating to a so-called liquid crystal photographic printer which is produced by exposing and processing photographic paper.

[0004]

However, the liquid crystal constituting the liquid crystal panel used in the liquid crystal photographic printer as described above includes the light transmission difference, the drive voltage-light transmission characteristic difference, and the surroundings. There is a change in the light transmittance or the drive voltage-light transmittance characteristic due to the temperature change, and a technique for compensating for these machine differences and fluctuations has not yet been established. Therefore, it has been difficult to produce stable quality photographic prints with liquid crystal photographic printers.

The present invention has been made to solve the above problems, and an object thereof is to provide an exposure control method for producing a photographic print of stable quality in the above liquid crystal photographic printer. And

[0006]

In order to achieve the above object, the invention according to claim 1 displays an image on a liquid crystal panel, irradiates the liquid crystal panel with light from a light source, and An exposure control method for a photographic printer, which exposes the image on a photosensitive material by transmitted light transmitted through the liquid crystal panel, comprising: driving for obtaining maximum light transmittance of each pixel of the liquid crystal panel prior to displaying the image on the liquid crystal panel. To measure the maximum transmitted light amount E ₁ of the liquid crystal panel when the voltage V ₁ is applied to each pixel of the liquid crystal panel, and obtain a reference transmitted light amount E ₀ that is smaller than the measured maximum transmitted light amount E ₁ . obtains the driving voltage V _0, corresponds to the driving voltage V ₀ reference transmitted light amount E
The reference value of the drive voltage V to be applied to each pixel of the liquid crystal panel is adjusted on the basis of obtaining ₀ .

In order to achieve the above-mentioned object,
The invention according to item 2 displays an image on a liquid crystal panel,
Irradiates the crystal panel with light from the light source and transmits it through the liquid crystal panel
The photographic process in which the image is exposed on the photosensitive material by the transmitted light
An exposure control method in a linter, comprising the liquid crystal panel
Prior to displaying the image on the
Drive voltage V for obtaining light transmittance₁Each of the liquid crystal panel
Maximum transmitted light amount of the liquid crystal panel when applied to the pixel
E₁, And obtain the minimum light transmittance of each pixel of the liquid crystal panel
Drive voltage V for₂Was applied to each pixel of the liquid crystal panel
Minimum transmitted light amount E of the liquid crystal panel when₂Measure and measure
Maximum transmitted light amount E₁And the minimum transmitted light amount E₂Intermediate transmission with
Light intensity E_Three{= (E₁+ E₂) / 2}, and the intermediate transmission
Light intensity E_ThreeDrive voltage V_ThreeSeeking the intermediate drive
Dynamic voltage V_ThreeCorresponding to the intermediate transmitted light amount E _ThreeCan be obtained
Drive voltage to be applied to each pixel of the LCD panel.
It is characterized in that the reference value of the dynamic voltage V is adjusted.

In order to achieve the above object, the invention according to claim 3 displays an image on a liquid crystal panel, irradiates the liquid crystal panel with light from a light source, and transmits the transmitted light through the liquid crystal panel. An exposure control method in a photographic printer for exposing the image to a photosensitive material according to the above, wherein an actual drive voltage V ₄ 'for obtaining a predetermined transmitted light amount E ₄ is measured before displaying the image on the liquid crystal panel. , and the measured drive voltage V ₄ ', and the driving voltage V ₄ to obtain a theoretical amount of transmitted light E _4, based on the difference between the reference value of the drive voltage V to be applied to each pixel of the liquid crystal panel Is adjusted.

The reference value of the drive voltage V is a reference voltage value when setting the drive voltage V to be applied in the actual application operation, and the reference value is actually applied by adjusting the reference value. The value of the drive voltage V to be changed uniformly increases or decreases by the adjustment amount. That is, by adjusting the reference value of the drive voltage V, in the graph showing the drive voltage V-transmitted light amount E characteristic, the drive voltage V- is changed so that the characteristic curve moves in parallel along the axis showing the drive voltage V. The transmitted light amount E characteristic is corrected.

The present invention is based on the difference in light transmittance of liquid crystal panels.
And the difference in voltage-light transmittance characteristics from each other. The voltage-light transmittance characteristic is, for example, as shown in FIG.
The range used in actual exposure is the range of voltages V _{1 to} V ₂ .

In this way, a predetermined range (for example, voltage V ₁ to
In order to further reduce the error of the numerical value of the light transmittance and the voltage-light transmittance characteristic in V ₂ ), it is necessary to specify the voltage within the range of V _{1 to} V ₂ as in the invention of claims 1 to 3. It is effective and simple method to adjust the reference value of the driving voltage so as to obtain appropriate light transmittance and voltage-light transmittance characteristics in respect of (1).

That is, according to the first aspect of the invention, in the photographic printer, when the driving voltage V ₁ for obtaining the maximum light transmittance of each pixel of the liquid crystal panel is applied to each pixel of the liquid crystal panel, The maximum transmitted light amount E ₁ is measured, and the reference transmitted light amount E that is set to be smaller than this maximum transmitted light amount E ₁
The drive voltage V ₀ for obtaining ₀ is obtained.

Then, the reference value of the drive voltage V to be applied to each pixel of the liquid crystal panel is adjusted on the basis that the reference transmitted light amount E ₀ is obtained corresponding to the drive voltage V ₀ . That is, the actual drive voltage V ₀ 'for obtaining the reference transmitted light amount E ₀
Is measured, and the reference value of the drive voltage V to be applied to each pixel of the liquid crystal panel is adjusted (shifted) based on the difference between the measured drive voltage V ₀ 'and the drive voltage V ₀ .

Thus, not the maximum transmitted light amount E ₁ in the liquid crystal panel of the photographic printer, but the maximum transmitted light amount E _1.
Since the reference value of the drive voltage V is adjusted with reference to the reference transmitted light amount E ₀ which is set smaller than ₁ , the maximum transmitted light amount E
_As compared with the case where the reference value of the drive voltage V is adjusted with ₁ as the reference, the deviation of the voltage-light transmittance characteristic in a predetermined range (for example, the voltages V _{1 to} V ₂ ) can be reduced as a whole.

Further, in the above description, the reference value of the transmitted light amount is not the reference value obtained experimentally in advance, but the maximum transmitted light amount E ₁ measured using the liquid crystal panel of the actual photographic printer.
Since the reference transmitted light amount E ₀ determined based on the above is set, an appropriate reference transmitted light amount can be set for each photographic printer even if there is a large difference in light transmittance. Differences can also be compensated.

In this way, the quality of the image to be exposed can be stabilized by correcting the machine difference of the light transmittance and the machine difference of the voltage-light transmittance characteristic.

When the reference amount of transmitted light E ₀ is set to a value around 50% of the maximum amount of transmitted light E ₁ , the error of the voltage-light transmittance characteristic is evenly distributed in both the small range and the large range of the transmitted light amount. Can be reduced and is more effective.

Next, according to the second aspect of the invention, the photographic
Drive voltage V to obtain maximum light transmittance in₁To
Maximum amount of transmitted light when applied to each pixel of the liquid crystal panel
E₁, And the drive voltage V for obtaining the minimum light transmittance₂The liquid
Transmitted light amount E when applied to each pixel of crystal panel₂To
taking measurement. Furthermore, the measured maximum transmitted light amount E₁And minimum transparency
Overlight E₂Intermediate transmitted light amount E_Three{= (E₁+ E₂) /
2}, and the intermediate transmitted light amount E _ThreeIntermediate drive voltage
V_ThreeAsk for. And the intermediate drive voltage V_ThreeIn response to
Light intensity E_ThreeBased on the fact that
The reference value of the drive voltage V to be applied to each pixel
(shift).

As described above, not only the maximum transmitted light amount E ₁ but also the minimum transmitted light amount E in the liquid crystal panel of the photographic printer.
₂ was also measured, and the intermediate transmitted light amount E ₃
The reference value of the drive voltage V is adjusted with reference to. That is,
Since the intermediate transmission light amount E _{3 at} the intermediate point of the predetermined range used in actual exposure and the reference value of the driving voltage V based on the intermediate driving voltage V ₃ so as to become the intermediate transmission light amount E ₃ are adjusted, It is possible to reduce the deviation of the voltage-light transmittance characteristic in a predetermined range (for example, the voltages V _{1 to} V ₂ ) while compensating for the difference in light transmittance.

In this way, by correcting the difference in light transmittance and the difference in voltage-light transmittance characteristics, the quality of the exposed image can be further stabilized.

Furthermore, when the machine difference in light transmittance is small,
According to the invention of claim 3, in the photographic printer,
Predetermined amount of transmitted light E_FourDrive voltage V to obtain_Four'
The measured drive voltage V is measured._Four'And theoretically the amount of transmitted light
E_FourVoltage V for obtaining _FourLCD based on the difference between
Adjust the reference value of drive voltage V to be applied to each pixel of the panel
You may do it.

Further, in order to achieve the above-mentioned object, the invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the adjustment of the photographic printer for compensating for temperature fluctuation is performed. Sometimes, the amount of transmitted light when a drive voltage serving as a reference is applied is measured, and based on the measured amount of transmitted light and the amount of reference transmitted light, the liquid crystal panel set prior to displaying an image on the liquid crystal panel. The reference value of the drive voltage V to be applied to each pixel of the liquid crystal panel is adjusted so that the relationship between the drive voltage V to the liquid crystal panel and the transmitted light amount E of the liquid crystal panel does not change.

The voltage-light transmittance characteristic shifts in the direction of the driving voltage V (left-right direction in FIG. 9) due to temperature fluctuations as shown in FIG. 9, for example. Therefore, as in the invention described in claim 4, when adjusting the photographic printer for compensating for temperature fluctuations, the amount of transmitted light when a reference drive voltage is applied is measured, and the measured amount of transmitted light and the reference are measured. The reference value of the drive voltage V is adjusted so that the transmitted light amount becomes equal to that of the drive voltage V, that is, the relationship between the drive voltage V and the transmitted light amount E set prior to the display of the image on the liquid crystal panel does not change.

This makes it possible to compensate for variations in light transmittance and voltage-light transmittance characteristics due to temperature fluctuations, and stabilize the quality of the exposed image.

In each of the above claims, "prior to displaying an image on the liquid crystal panel" means "before the actual exposure process of the image." However, this is not to be performed every time before the actual image exposure process, but one example thereof is the factory shipment of the photographic printer according to the present invention, the market installation, or the maintenance such as part replacement.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

The configuration of the printer processor 10 in this embodiment will be described with reference to FIGS. 1 and 2. The printer processor 10 whose outside is covered with a casing 12 performs a process of developing, fixing, rinsing, and drying a printer unit 58 that exposes the printing paper of the main print and the sub-print, and the exposed printing paper. And a processor unit 72.

First, the structure of the printer unit 58 will be described.
A work table 14 protruding from the casing 12 to the left in FIG. 1 is installed in the printer processor 10, and a negative film 16 is provided on the upper surface of the work table 14.
There are arranged a negative carrier 18 for setting and a keyboard 15 for the operator to input commands, data and the like.

A main exposure light source section 36 is installed below the work table 14. A light source 38 is installed in the main exposure light source section 36, and the light emitted from the light source 38 is
Color correction filter (hereinafter, Color-Correction Filter: C
The negative film 16 set on the negative carrier 18 is reached via a C filter 40) and a diffusion tube 42.
The CC filter 40 has C (cyan), M (magenta), Y
It is composed of three sets of (yellow) filters, and each filter operates under the control of the CC filter control unit 39,
The light emitted from the light source 38 can appear and disappear on the optical axis.

A cover 44 is formed above the negative carrier 18 (upper side in FIG. 1). Inside the cover 44, a main print optical system 46 and a sub print for exposing a sub print such as an index print. A section 22 is provided.

A half mirror 43 is arranged at the lowermost part of the main exposure optical system 46, and the light transmitted through the negative film 16 set on the negative carrier 18 reaches the half mirror 43. In the traveling direction of the light passing through the half mirror 43, an exposure lens 48 for changing the magnification of an image to be exposed, a black shutter 50 for blocking the exposure light, and a mirror 51 for reflecting the exposure light in a substantially right angle direction.
Are arranged in order. The exposure light reflected by the mirror 51 is applied to the photographic printing paper 54 set in the exposure chamber 52, whereby the photographic printing paper 54 is exposed.

On the other hand, in the traveling direction of the light reflected by the half mirror 43, a photometric lens 45 for changing the magnification of the photometric image and a half mirror 47 are sequentially arranged. In the direction in which light is reflected by the half mirror 47,
A scanner 108 configured by an image sensor or the like is arranged, and the scanner 108 is connected to an image signal processing unit 102 that performs predetermined image processing on image data of each frame of the negative film 16 read by the scanner 108. There is.

A simulator 104 as an image display device is connected to the image signal processing unit 102, and the simulator 104 is used in the case where the image of each frame of the negative film 16 is produced based on the set conditions. A print simulation image is displayed.

An image memory 106 for storing image data is connected to the image signal processing unit 102, and the image signal processing unit 102 stores the image data of each frame of the negative film 16 read by the scanner 108. It is stored in the image memory 106.

A negative density measuring section 56 for measuring the image density of each frame of the negative film 16 is provided in the traveling direction of the light passing through the half mirror 47, and the negative density measuring section 56 has an image sensor. Scanner 56B composed of the like and the negative film 1 read by the scanner 56B
Negative density measuring device 56A for measuring the image density of each frame of 6
And are installed.

In the sub-printing section 22, a light emitting diode (hereinafter referred to as B-LED) 25 for emitting a blue component of light and a light emitting diode for emitting a red component (hereinafter referred to as R-) are used as light sources for exposure of index printing. Called LED)
26, and a light emitting diode that emits a green component (hereinafter,
A G-LED) 27 is provided, and the operation of these is controlled by the light source controller 24. B-LED2
5 is arranged on the exposure optical axis X, a dichroic mirror 28 is arranged in the traveling direction of the light emitted from the B-LED 25, and the optical axis of the red light emitted from the R-LED 26; The optical axis of the green light emitted from the LED 27 matches the exposure optical axis X.

On the downstream side of the dichroic mirror 28 in the light traveling direction, the end of the optical path (a position not affecting the image)
A light source light sensor 29 for measuring the light amount of the light emitted from the light source is arranged in the direction in which the mirror 30 reflects light.

On the downstream side of the arrangement position of the mirror 30,
The liquid crystal panel 31 is arranged on a surface perpendicular to the exposure optical axis X. On the image display surface of the liquid crystal panel 31, a large number of pixels capable of displaying white, black, and their intermediate colors (for example, 256 levels of gradation) by electric means are regularly arranged in a matrix. . A liquid crystal panel driver 32 for driving image display on the liquid crystal panel 31 is connected to the liquid crystal panel 31.
2 is connected to a sub-control unit 23 for monitoring and controlling various processing states in the sub-print unit 22. The image display surface of the liquid crystal panel 31 is composed of an image section for displaying an image to be exposed and a photometric section for measuring the amount of light transmitted through the liquid crystal panel 31.
The liquid crystal panel driver 32 can drive the photometric unit and the image unit separately.

The sub control unit 23 is a CPU, RA (not shown).
M, a ROM, an input / output controller, and the like, and are connected to the image memory 106 via the input / output controller. The sub control unit 23 reads out the image data of each frame of the negative film 16 stored in the image memory 106, forms one piece of index image data in which the frame images are arranged according to a predetermined rule, and forms one piece of the formed index. An image corresponding to image data of a predetermined number of frames of the image data, for example, five frames (one column) is displayed on the liquid crystal panel 31 by the liquid crystal panel driver 32. In addition, among the image data for one column, R color, G
An image corresponding to the image data of only the color components of the colors B and B can be displayed on the liquid crystal panel 31.

On the downstream side of the position where the liquid crystal panel 31 is arranged, a mirror 34 is provided at the end of the optical path (position that does not affect the image).
Is disposed, and a transmitted light amount sensor 33 for measuring the amount of light transmitted through the liquid crystal panel 31 is disposed in the direction in which light is reflected by the mirror 34.

On the downstream side of the arrangement position of the mirror 34,
An exposure lens 35 for changing the magnification of the image of the sub-print to be exposed is arranged, and an index print image displayed on the liquid crystal panel 31 by the exposure lens 35 and projected by exposure light is provided on a photographic paper 54 by a predetermined amount. An image is formed at a magnification.

The sub-control unit 23 includes the above-mentioned light source control unit 2
4. The light source light amount sensor 29 and the transmitted light amount sensor 33 are connected, and the sub-control unit 23 determines an appropriate correction amount of the light amount based on the light amount value of each of the R, G, and B colors measured by the light source light amount sensor 29. Calculate, B-LED25, R-LED2
6. The light amount of the light emitted from the G-LED 27 is corrected by the light source control unit 24. Similarly, the sub control unit 23
Based on the transmitted light amount value measured by the transmitted light amount sensor 33, the liquid crystal panel driver 32 is controlled by the control method according to the present invention to be described later so that the appropriate transmitted light amount is obtained, and the density of the image displayed on the liquid crystal panel 31 is adjusted. adjust.

Like the sub control unit 23, the main control unit 20 for controlling and monitoring the entire printer processor 10 is provided.
Is provided below the exposure chamber 52. The main control unit 20 includes a CPU (not shown), a RAM, a ROM, an input / output controller, and the like. The main control unit 20 includes:
The above-described CC filter control unit 39 and the negative density measuring device 56
A, the image signal processing unit 102 and the sub control unit 23 are connected, and monitor and control the operation of each of these components.

A mounting portion 60 is provided at a corner between the upper right side surface of the cover 44 and the upper surface of the casing 12. The mounting portion 60 is a paper for accommodating the photographic printing paper 54 wound on the reel 62 in layers. The magazine 64 is mounted.

A roller pair 66 is arranged near the mounting portion 60, and holds the photographic printing paper 54 in a horizontal state to expose it in the exposure chamber 52.
Transport to The photographic paper 54 is covered with the roller 6 in front of the cover 44.
It is wound around 7, turned 90 degrees, and hangs down. A first stock unit 69 is provided between the roller 66 and the roller 67 to guide and stock the photographic paper in a substantially U-shape.

A roller 68 is provided below the exposure section of the exposure chamber 52.
A, 68B, and 68C are arranged, and the printing paper 54 on which the image of the negative film 16 is printed in the exposure chamber 52 is turned by approximately 90 degrees by each of the rollers 68A, 68B, and 68C, and is turned to a processor unit 72 described later. Conveyed.

A cutter 71 is arranged on the downstream side of the roller 68A, and the cutter 71 cuts the rear end of the printing paper 54 after the exposure processing. The printing paper 54 that has been cut by the cutter 71 and left in the exposure chamber 52 can be rewound into the paper magazine 64 again. Also, the roller 68
A between the printing paper 54 and the roller 68B.
There is provided a second stock portion 73 for guiding and stocking in a substantially U shape. In the second stock unit 73,
By stocking the printing paper 54, the printer unit 58
And the difference in processing time between the processor unit 72 and the processor unit 72 is absorbed.

Next, the configuration of the processor section 72 will be described. The processor section 72 is provided with a color developing processing tank 74 storing a color developing processing liquid, a bleach-fixing processing tank 76 storing a bleach-fixing processing liquid, and a plurality of rinsing processing tanks 78 storing a washing processing liquid. The photographic printing paper 54 is sequentially transported through the color developing tank 74, the bleach-fixing tank 76, and the plurality of rinsing tanks 78, so that the developing, fixing, and rinsing processes are sequentially performed. Photographic paper 54 that has been washed
Is transported to the drying section 80 adjacent to the rinsing tank 78,
In the drying section 80, the photographic paper 54 is wound around rollers and exposed to high-temperature air to be dried.

The photographic printing paper 54 is nipped by a pair of rollers (not shown), and is discharged from the drying section 80 at a constant speed after the completion of the drying process. A cutter unit 84 is provided on the downstream side of the drying unit 80, and the cutter unit 84 has a cut mark sensor 86 for detecting a cut mark applied to the photographic printing paper 54.
A paper density measuring unit 90 for measuring the density of the printing paper 54 and a cutter 88 for cutting the printing paper 54 are installed.

The cut mark sensor 86, the paper density measuring section 90, and the cutter 88 are connected to the main control section 20, respectively. In the cutter unit 84, the photographic printing paper 54 is cut by the cutter 88 for each image frame, and the photographic print is completed.

The completed photographic prints are discharged to the sorter unit 92, sorted in the sorter unit 92, and subjected to a predetermined inspection work. By this verification work, after defective prints such as so-called out-of-focus images are extracted, normal photographic prints are returned to the customer together with the negative film.

Next, the operation of the present embodiment will be described. First, the exposure process of the main print in the printer unit 58 of the printer processor 10 will be described. Black shutter 5
With 0 closed, the negative film 16 on which the image to be printed is recorded is set on the negative carrier 18, the light source 38 is turned on, and the density of the image of the negative film 16 formed by the light transmitted through the negative film 16 is adjusted. Negative density measuring unit 56
To measure. Based on the measured image density of the negative film 16, the main control unit 20 sets appropriate exposure conditions (for example, the amount of each filter of the filter unit 40 inserted). Next, the black shutter 50 is opened, and the image on the negative film 16 is exposed on the photographic printing paper 54 based on the set exposure conditions.

Next, in order to make an index print of the frame images recorded on the negative film 16, one frame image of the negative film 16 is set on the negative carrier 18, the light source 38 is turned on, and the negative film 16 is transmitted. The frame image formed by the light is read by the scanner 108, and the read image data is stored in the image memory 106 by the image signal processing unit 102. Such image reading and image processing are executed for each frame image of the negative film 16.

Next, the process of calculating the intermediate drive voltage V _{3 according to} the exposure control method of the present invention will be described with reference to FIG. This process is a process for calculating the intermediate transmitted light amount E ₃ and the intermediate drive voltage V ₃ which are the reference of the adjustment amount calculation process of the drive voltage reference value in the drive voltage-transmitted light amount characteristic described later. It should be noted that this processing is executed at the time of factory shipment of the printer processor 10, at the time of market installation, or at the time of maintenance such as replacement of parts of the sub print unit 22.

When the operator uses the keyboard 15 to instruct the calculation process of the intermediate drive voltage V ₃ , the sub control unit 23 starts the control routine shown in FIG.

In step 202 of FIG. 4, the drive voltage V ₁ corresponding to the maximum transmittance T _max shown in FIG. 3A is applied to each pixel of the photometric section of the liquid crystal panel 31, and the image section of the liquid crystal panel 31 is applied. Each pixel of is completely closed. Next step 2
In 04, the LED of any color of R, G, and B is turned on.
At this point in time, the image portion of the liquid crystal panel 31 is in the light-shielded state, and the light is transmitted only through the photometric portion. Therefore, the LED can be turned on even when the photographic printing paper 54 is set.

In the next step 206, the transmitted light amount at this time, that is, the maximum transmitted light amount E ₁ when the drive voltage V ₁ corresponding to the maximum transmittance T _max is applied to the liquid crystal panel 31, is measured by the transmitted light amount sensor 33. To do. Then, in the next step 208, after turning off the LED, the processes of steps 204 to 208 are executed for the other colors of R, G, and B.

In this way, when the processes of steps 204 to 208 are completed for all R, G, and B colors, the process proceeds to step 212 (step 210). At this point, the maximum amount of transmitted light E ₁ for each of the colors R, G, B is obtained.

In step 212, the drive voltage V ₂ corresponding to the minimum transmittance T _min shown in FIG.
The liquid crystal panel 31 is applied to each pixel of the first photometry unit.
Each pixel in the image part of is completely closed. In the next step 214, the LED of any color of R, G, and B is turned on, and in the next step 216, the drive voltage V ₂ corresponding to the amount of transmitted light at this time, that is, the minimum transmittance T _min is set to the liquid crystal panel 31. The minimum transmitted light amount E ₂ applied to the sensor is measured by the transmitted light amount sensor 33. Then, in the next step 218, the LED
After turning off, the processes of steps 214 to 218 are executed for the other colors of R, G, and B.

In this way, when the processes of steps 214 to 218 are completed for all the colors of R, G and B, the process proceeds to step 221 (step 220). At this point, the minimum transmitted light amount E ₂ for each color of R, G, B is obtained.

At step 221, the maximum amount of transmitted light E
An intermediate transmitted light amount E ₃ corresponding to an intermediate value between ₁ and the minimum transmitted light amount E ₂ is calculated. That is, the relationship of the following expression (1) is established. E ₃ = (E ₁ + E ₂ ) / 2 (1) In the next step 222, the amount of transmitted light is determined by trial and error.
An intermediate drive voltage V ₃ that gives the intermediate transmitted light amount E ₃ calculated in step 221 is calculated. That is, a voltage near the middle of the driving voltages V ₁ and V ₂ is applied to the photometry section of the liquid crystal panel 31 in order at predetermined voltage values, and the transmitted light amount when the LED is turned on is measured each time, and the transmitted light amount is the intermediate value. The voltage value when it becomes equal to the transmitted light amount E ₃ is the intermediate drive voltage V ₃ .

The steps 221, 222 are R, G, B.
Execute for each color. When the intermediate drive voltage V ₃ is calculated for all R, G, B colors, the control routine of FIG. 4 is terminated.

Next, the printing process involving temperature compensation of the driving voltage-transmitted light amount characteristic will be described with reference to FIG. This process is executed when the printer processor 10 is adjusted to compensate for temperature fluctuations.

When the operator uses the keyboard 15 to instruct execution of the printing process involving temperature compensation of the drive voltage-transmitted light amount characteristic, the sub-control unit 23 starts execution of the control routine shown in FIG.

In step 230 of the control routine (main routine) shown in FIG. 5, a subroutine (see FIG. 6) for calculating the adjustment amount of the drive voltage reference value is executed. In step 234 of FIG. 6, the intermediate drive voltage V ₃ calculated in step 222 is applied to each pixel of the photometric section of the liquid crystal panel 31, and each pixel of the image section of the liquid crystal panel 31 is fully closed. In the next step 236, the LED corresponding to any of the colors R, G, B is turned on, and in the next step 238, the transmitted light amount E _T at this time is measured by the transmitted light amount sensor 33.

Then, after the LED is turned off in the next step 240, in the next step 242, the above step 238 is performed.
It is determined whether or not the transmitted light amount E _T measured in 1 is equal to the intermediate transmitted light amount E ₃ . If the transmitted light amount E _T is not equal to the intermediate transmitted light amount E ₃ , the process proceeds to step 244, where the transmitted light amount E _T
Based on the difference between _T and the intermediate transmitted light amount E ₃ , the drive voltage reference value is adjusted so that the measured transmitted light amount E _T becomes the intermediate transmitted light amount E ₃ . Along with this, the intermediate drive voltage V ₃ is corrected and becomes the intermediate drive voltage V ₃ ′.

As described above, in the present embodiment, as shown in FIG. 3 (B), the amount of transmitted light becomes the intermediate transmitted light amount E ₃ when the intermediate drive voltage V ₃ is applied.
The drive voltage-transmitted light amount characteristic (equivalent to the drive voltage-light transmittance characteristic) as shown in (B) is corrected.

In the next step 246, the corrected intermediate drive voltage V ₃ 'is applied to each pixel of the photometric section of the liquid crystal panel 31, and in this state, the process returns to step 236 and the step 2 is performed again.
36 to 240 are executed. Then, in step 242, it is determined whether or not the again measured transmitted light amount E _T is equal to the intermediate transmitted light amount E ₃ .

Here, when the transmitted light amount E _T is not equal to the intermediate transmitted light amount E ₃ again, the process proceeds to step 244, and the processes after step 244 are executed again.

On the other hand, in step 242, the amount of transmitted light E_TIn
Light intensity E_ThreeIf equal to, step
Proceed to 248, and this transmitted light amount E_TIntermediate drive voltage corresponding to
Pressure V _Three(Or V_ThreeDrive voltage reference when deriving '...)
The value adjustment amount is stored in the RAM of the sub control unit 23.

The above steps 234 to 248 are executed for each color of R, G and B (step 2).
50). When the processes of steps 234 to 248 are completed for all R, G, and B colors, the process returns to the main routine of FIG.

In this way, the printer processor 10
It is possible to obtain the adjustment amount of the drive voltage reference value such that the transmitted light amount E _T becomes the intermediate transmitted light amount E ₃ in the temperature environment at the time of adjustment, that is, the adjustment amount of the drive voltage reference value capable of compensating the temperature fluctuation. .

In step 260 of the main routine of FIG. 5, a print processing subroutine (see FIG. 7) is executed. In step 262 of FIG. 7, the frame image data for a predetermined number of frames is read from the image memory 106, and the photographic printing paper 54 is set at a predetermined exposure position. Next step 2
In 64, the adjustment amount of the drive voltage reference value for any of R, G, and B colors is read from the RAM of the sub-control unit 23, and in the next step 266, the drive voltage reference value is adjusted based on the adjustment amount of the drive voltage reference value. Adjust the value.

In the next step 268, under the condition that the drive voltage reference value is adjusted as described above, the above step 2
The image data read out at 62 is displayed on the image portion of the liquid crystal panel 31. In the next step 270, the LED of the corresponding color is turned on for a predetermined exposure time to perform exposure with the transmitted light that has transmitted the image displayed on the liquid crystal panel 31. Then, after turning off the LED in the next step 272, the processes of steps 264 to 272 are executed for the other colors of R, G, and B.

In this way, when the processes of steps 264 to 272 have been completed for all the colors of R, G and B, the process proceeds to step 276 (step 274).

In step 276, it is determined whether or not the exposure has been completed for all the frame images to be index-printed. If there are unexposed frame images, the process returns to step 262 and the unexposed frames are returned. Steps 262 to 274 for a predetermined number of frame images of the image
Exposure process is executed.

When the exposure of all the frame images is completed, an affirmative decision is made in step 276 and the operation proceeds to step 278. In step 278, the exposed printing paper 54 is developed and fixed on the printing paper 54 by sequentially transporting the color development processing tank 74, the bleach-fixing processing tank 76, and the plurality of rinse processing tanks 78 of the processor unit 72.・ Sequentially wash with water. The photographic printing paper 54 that has been washed with water is conveyed to the drying unit 80 and is dried with high temperature air. The photographic printing paper 54 that has been dried is conveyed to the cutter unit 84, and the cutter 88
Each image frame is cut by and becomes a photographic print. Then, the photographic prints are discharged to the sorter unit 90 and sorted in the sorter unit 90.

According to the embodiment described above, the secondary purine
The maximum amount of transmitted light E₁And the minimum transmitted light amount E₂
And both are measured, and the intermediate transmitted light corresponding to these intermediate values
Quantity E _ThreeAnd this intermediate transmitted light amount E_ThreeIntermediate drive voltage corresponding to
Pressure V_ThreeThe reference value of the drive voltage is adjusted with reference to. Immediately
The middle of the range of actual exposure
Amount of transmitted light E_ThreeAdjust the drive voltage reference value based on
Therefore, while compensating for the difference in light transmittance,
For example, voltage V₁~ V₂) Voltage-light transmittance characteristics
The difference can be compensated.

When the printer processor is adjusted, the drive voltage V ₃ set prior to the display of an image on the liquid crystal panel is set.
Since the reference value of the drive voltage is adjusted so that the relationship between the transmission light amount E ₃ and the transmission light amount E ₃ does not change, it is possible to compensate for changes in light transmittance and voltage-light transmittance characteristics due to temperature changes.

Further, by compensating for the difference in the light transmittance, the difference in the voltage-light transmittance characteristic, and the temperature variation thereof, the quality of the exposed image can be stabilized.

In the above-described embodiment, it is assumed that the liquid crystal panels installed in various printer processors have different light transmittances, that is, there is a large difference in light transmittance between machines. E
An example has been shown in which ₁ and the minimum transmitted light amount E ₂ are measured, and the intermediate transmitted light amount E ₃ that serves as a reference for the adjustment processing of the drive voltage reference value is calculated. However, when it is expected that the machine difference of the light transmittance is small, as shown in FIG. 8, it corresponds to the reference transmitted light amount E ₀ and the reference transmitted light amount E ₀ which are the reference of the adjustment processing of the drive voltage reference value. The drive voltage V ₀ is set in advance for each manufacturing lot based on the result of the manufacturing test, and the reference transmitted light amount E ₀ and the drive voltage V ₀ are generally used as the reference for the adjustment processing of the drive voltage reference value. You may do it. In this case, it is not necessary to measure the maximum transmitted light amount E ₁ and the minimum transmitted light amount E ₂ in each printer processor. Further, in general, the minimum transmittance is often 0%, and in such a case, the minimum transmitted light amount E ₂ is inevitably 0. Therefore, only the maximum transmitted light amount E ₁ is measured, and 50% thereof is measured. Can be set as the intermediate transmitted light amount E ₃ . In addition, as a ratio, the maximum transmitted light amount E ₁
Is not limited to 50%, and may be a ratio of around 50% or a predetermined ratio obtained experimentally or empirically.

Further, in the above-described embodiment, an example in which the present invention is applied to the printer processor having the sub-printing section is shown. However, a photographic print system including an index printer and a paper processor, an image memory, It can also be applied to a liquid crystal photographic printer having a liquid crystal panel for displaying the image data stored in the image memory and an exposure system capable of exposing the image displayed on the liquid crystal panel.

[0083]

According to the invention described in claim 1 or 2,
An effect that the quality of the exposed image can be stabilized because the deviation of the voltage-light transmittance characteristics in a predetermined range can be reduced as a whole while compensating for the difference in light transmittance. Is obtained.

According to the third aspect of the present invention, the actual drive voltage V ₄ ′ for obtaining the predetermined transmitted light amount E ₄ is measured when the machine difference of the light transmittance is small, and this is measured. was based on the difference between the driving voltage V ₄ to obtain a theoretical amount of transmitted light E ₄ and the driving voltage V ₄ ', by adjusting the reference value of the drive voltage V to be applied to each pixel of the liquid crystal panel, voltage There is an effect that it is possible to correct the machine difference of the light transmittance characteristic and stabilize the quality of the exposed image.

According to the invention described in claim 4, when adjusting the photographic printer, the drive voltage is set so that the relationship between the drive voltage V and the transmitted light amount E set prior to the display of the image on the liquid crystal panel does not change. Since the reference value of V is adjusted, it is possible to compensate for variations in light transmittance and voltage-light transmittance characteristics due to temperature changes, and stabilize the quality of an image to be exposed.
The effect is obtained.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a printer processor according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a printer unit.

FIG. 3A is a diagram showing a drive voltage-light transmittance characteristic in a liquid crystal panel, and FIG. 3B is a diagram showing a drive voltage-transmitted light amount characteristic based on the characteristic of FIG. 3A.

FIG. 4 is a flow chart showing a control routine of a calculation process of an intermediate drive voltage V ₃ .

FIG. 5 is a flow chart showing a control routine of a printing process accompanied by temperature compensation of a driving voltage-transmitted light amount characteristic.

FIG. 6 is a flowchart showing a subroutine of a drive voltage reference value adjustment amount calculation process.

FIG. 7 is a flowchart showing a print processing subroutine.

FIG. 8 is a diagram showing a predetermined drive voltage reference value V ₀ and a transmitted light amount reference value E ₀ .

FIG. 9 is a diagram showing drive voltage-light transmittance characteristics under various temperature conditions.

[Explanation of symbols]

 10 Printer Processor 23 Sub-Control Unit 25 B-LED 26 R-LED 27 G-LED 31 Liquid Crystal Panel 33 Transmitted Light Quantity Sensor 54 Photographic Paper (Photosensitive Material)

Claims (4)

[Claims] 1. An exposure control method for a photographic printer, which displays an image on a liquid crystal panel, irradiates the liquid crystal panel with light from a light source, and exposes the image on a photosensitive material by the transmitted light transmitted through the liquid crystal panel. The maximum transmission of the liquid crystal panel when a driving voltage V ₁ for obtaining the maximum light transmittance of each pixel of the liquid crystal panel is applied to each pixel of the liquid crystal panel prior to displaying an image on the liquid crystal panel. the quantity E ₁ was measured to obtain the measured drive voltage V ₀ which for maximum transmission reference transmitted light amount E ₀ of less-determined from the amount of light E ₁ was, the reference transmitted light amount E ₀ corresponding to the drive voltage V ₀ An exposure control method, wherein the reference value of the drive voltage V to be applied to each pixel of the liquid crystal panel is adjusted on the basis of the obtained value. 2. An image is displayed on a liquid crystal panel, and the liquid crystal panel is
The panel was irradiated with light from the light source and transmitted through the liquid crystal panel.
Photographic pudding that exposes the image to a light-sensitive material with transmitted light
An exposure control method for a liquid crystal panel, the method comprising:
Drive voltage V for obtaining the maximum light transmittance of each pixel of₁The
The maximum of the liquid crystal panel when applied to each pixel of the liquid crystal panel
Large amount of transmitted light E₁, And the minimum light transmission of each pixel of the liquid crystal panel.
Drive voltage V for obtaining excess rate₂Each pixel of the liquid crystal panel
Minimum transmitted light amount E of the liquid crystal panel when applied to₂Measure
The maximum transmitted light amount E determined and measured₁And the minimum transmitted light amount E₂In between
Amount of transmitted light E_Three{= (E ₁+ E₂) / 2}, and the intermediate
Amount of transmitted light E_ThreeDrive voltage V_ThreeThe intermediate drive voltage V_ThreeCorresponding to the intermediate transmitted light amount E_ThreeIs obtained
Based on that, the voltage is applied to each pixel of the liquid crystal panel.
An exposure control method comprising: adjusting a reference value of a driving voltage V to be used. 3. An image is displayed on a liquid crystal panel, and the liquid crystal panel is displayed.
The panel was irradiated with light from the light source and transmitted through the liquid crystal panel.
Photographic pudding that exposes the image to a light-sensitive material with transmitted light
An exposure control method in a computer, wherein a predetermined transmitted light is emitted before displaying an image on the liquid crystal panel.
Quantity E_FourDrive voltage V to obtain_Four'Is measured and this measured drive voltage V_Four', And the theoretical amount of transmitted light E_FourTo
Drive voltage V to obtain _FourAnd the liquid crystal based on the difference between
Adjust the reference value of drive voltage V to be applied to each pixel of the panel
An exposure control method comprising: 4. The amount of transmitted light when a reference drive voltage is applied is measured during adjustment of the photographic printer for compensating for temperature fluctuations, and based on the measured amount of transmitted light and the amount of reference transmitted light. Drive that should be applied to each pixel of the liquid crystal panel so that the relationship between the drive voltage V to the liquid crystal panel and the transmitted light amount E of the liquid crystal panel set prior to displaying an image on the liquid crystal panel does not change. 4. The exposure control method according to claim 1, wherein the reference value of the voltage V is adjusted.