JPH08227113A - Exposure device - Google Patents

Abstract

PURPOSE: To perform exposure in exact gradation in accordance with exposure data and to express the smooth gradation by outputting corrected exposure time based on previously set specified characteristic in accordance with the inputted exposure data and setting the characteristic. CONSTITUTION: The conversion circuit 63 is provided with a conversion table TBL where gradation data is made to correspond to impressing time being the non-linear function of the gradation data, and set so that color developing density is proportioned to the gradation data. A PLZT control circuit 64 impresses specified applied voltage on a PLZT element during the impressing time. As for the gradation data in the table TBL, the impressing time and exposure are the non-linear functions of the gradation data, and the impressing time is set so that the color developing density may be proportioned to the gradation data. By changing the data on the impressing time in the table TBL in accordance with the kind of a photosensitive material to be used, the color developing density in proportion to the exposure data is obtained for various photosensitive materials, so that the exact expression of the gradation is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus used in a photographic printing apparatus or the like, and particularly,
The present invention relates to a digital exposure apparatus using an electronically controlled shutter such as a line exposure shutter.

[0002]

2. Description of the Related Art As a conventional digital exposure apparatus using a line exposure shutter, a photosensitive material is exposed a plurality of times when blue, green and red (herein, simply referred to as BGR) are exposed. There is a configuration in which the BGR is reciprocally moved to sequentially expose the BGR, and the voltage applied to the line exposure element is changed in accordance with the exposure.

In this way, each dot is exposed with a color corresponding to the exposure data. When the exposure data includes gradation data, the exposure amount may be controlled to increase or decrease based on the gradation data. Therefore, conventionally, the exposure amount is controlled by controlling the length of time for applying a voltage to the line exposure element.

For example, when expressing gradations of 32 levels,
In order to control the exposure amount in 32 steps, as shown in Table 1 below,
The time for applying the voltage to the line exposure element may be controlled in 32 steps.

[0005]

[Table 1] In Table 1, the gradation data is 0, 1,
It is omitted except for cases of 2, 4, 8 and 16.

[0006]

However, in reality,
As shown in FIG. 6, a rise time t1 from application of a predetermined voltage to the line exposure element to a predetermined light-transmitting state and a fall time from turning off the voltage to a non-light-transmitting state. Due to the presence of t2, the voltage application time and the exposure amount are not exactly proportional.

Further, as shown in FIG. 7, since the relationship between the exposure amount of the light-sensitive material and the color density is not exactly proportional, even if the exposure amount is controlled to be double or quadruple, the color density Is 2
It did not double or quadruple. For the above reason, simply apply the voltage application time to the line exposure element,
There is a problem that an accurate gradation cannot be expressed only by controlling in proportion to the gradation data.

Therefore, the present invention has been made for the purpose of providing an apparatus for expressing smooth gradation by controlling the time for applying a voltage to a line exposure element so as to be proportional to the actual color density. It is a thing.

[0009]

According to claim 1 of the present invention,
In an exposure device that performs gradation exposure on a photosensitive material by controlling the exposure time in an exposure unit according to input exposure data, a predetermined characteristic set in advance according to the input exposure data. A means is provided which includes a conversion means for outputting the corrected exposure time based on the above, and an exposure control means for controlling the exposure time in the exposure means based on the corrected exposure time.

The corrected exposure time based on a preset predetermined characteristic is a corrected exposure time which is not proportional to the exposure data.

Further, in claim 2, the converting means comprises:
A conversion table that associates the exposure data with a correction exposure time based on a predetermined characteristic set in advance, and a reference unit that refers to the conversion table and outputs a correction exposure time according to the input exposure data. And with. Further, in claim 3, the conversion means includes exposure data,
A conversion table that associates a correction exposure time based on a predetermined characteristic set in advance with the conversion table is referred to, and the correction exposure time corresponding to the input exposure data is combined to output the correction exposure time. And a reference means.

Further, in claim 4, the converting means comprises:
A conversion table that correlates exposure data with a correction exposure time that produces a printing density proportional to this exposure data, and references the conversion table to output a correction exposure time according to the input exposure data. And means. Further, in claim 5, the conversion means inputs the exposure data by referring to the conversion table in which the exposure data and the correction exposure time for obtaining the exposure amount proportional to the exposure data are associated with each other, and the conversion table. The reference means for outputting the corrected exposure time according to the exposure data is provided.

In the sixth aspect, conversion data setting means for setting the correction exposure time in the conversion table to a desired correction exposure time is provided.

[0014]

According to the first aspect of the present invention, the light from the light source is supplied to the exposing means, and the exposure time in the exposing means is controlled to be short or long in accordance with the input exposure data, so that the gradation can be obtained with respect to the photosensitive material. In the exposure apparatus that performs exposure, the conversion unit outputs the corrected exposure time based on the preset predetermined characteristic according to the input exposure data, so by appropriately setting the characteristic, the rise time of the exposure unit is set. , The fall time, and the non-linear relationship between the exposure amount and the printing density can be compensated for, and the exposure can be performed with an accurate gradation according to the exposure data.

Further, in claim 2, the converting means comprises:
Since the conversion table is provided which associates the exposure data with the corrected exposure time based on the preset predetermined characteristic, the conversion table is referred to by the reference means and the exposure data corresponding to the input exposure data is obtained. By outputting the corrected exposure time, it is possible to perform exposure with an accurate gradation according to the exposure data.

Further, in claim 3, the converting means is:
Since the conversion table is provided which associates the exposure data with the corrected exposure time based on the preset predetermined characteristic, the conversion table is referred to by the reference means and the exposure data corresponding to the input exposure data is obtained. By combining the corrected exposure times, the corrected exposure times corresponding to various exposure data can be obtained from a small number of conversion tables.

Further, in claim 4, the converting means comprises:
Since there is a conversion table that associates the exposure data and the corrected exposure time that produces a printing density proportional to this exposure data, the actual printing density can be made proportional to the exposure data and It can be exposed with accurate gradation. Further, in the present invention, since the conversion means is provided with a conversion table that associates the exposure data with the corrected exposure time for obtaining the exposure amount proportional to the exposure data, the exposure amount is proportional to the exposure data. The exposure can be performed with accurate gradation.

In the sixth aspect, the conversion means is
Since the conversion data setting means for setting the corrected exposure time in the conversion table to the desired corrected exposure time is provided, it is possible to express a smooth gradation and also an arbitrary gradation.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A photographic printing apparatus having one embodiment of an exposure apparatus according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is an overall configuration diagram of the photographic printing apparatus, and FIG. 2 is a configuration diagram of essential parts thereof.

In FIG. 1, 1 is a magazine for supplying photographic paper as a photosensitive material, 2 is photographic paper, 3 is a negative exposure stage for exposing an image on a negative film, 4 is a line exposure stage for exposing a digital image, Reference numeral 5 denotes a development processing unit for developing the exposed photographic printing paper, and reference numeral 7 denotes a transfer mechanism which transfers the photographic printing paper 2 in the longitudinal direction for each dot and for each frame. 6 is a line exposure control unit.

As shown in FIG. 4, the line exposure controller 6
Is a time control unit 61 that controls the exposure time and the like in the line exposure stage 4, a voltage control unit 62 that controls the applied voltage according to the position of the disk 13, and a transfer timing and the like in the transfer mechanism 7. And a control unit for performing the operation. The time control unit 61 includes a conversion circuit 63 as conversion means and a PLZT control circuit 64 as reference means.

The conversion circuit 63, as shown in Table 2,
A conversion table TBL1 as shown in Table 2 in which the gradation data D is associated with the application time T which is a non-linear function thereof.
It has. In this conversion table TBL1,
The color density is set to be proportional to the gradation data.

The PLZT control circuit 64 applies a predetermined applied voltage to the PLZT element during the applying time T. For example, the conversion table TBL1 has gradation data D = 1.
, Application time T = t, exposure amount S = s, color density V =
In the case of the photosensitive material under the condition of v, the application time t2 is set in advance so that the color density v2 = 2 × v when the gradation data D = 2. In the conversion table TBL1, the gradation data D, the application time T and the exposure amount S are both non-linear functions of the gradation data D,
The application time is set so that the gradation data and the color density are proportional.

[0024]

[Table 2] By changing the application time data of the conversion table TBL1 according to the type of photosensitive material used, it is possible to obtain a coloring density that is accurately proportional to the exposure data even for various photosensitive materials. It is possible to express various gradations.

In the negative exposure stage 3, the lamp 31
The image of the negative 32 is imaged on the photographic printing paper 2 through the lens 33 by the light from and exposed.

In FIGS. 1 and 2, the line exposure stage 4 decomposes a digital image read by a scanner or a digital image separately created by an electronic processing device such as a computer into dots to generate exposure data, and this exposure is performed. The photographic printing paper 2 is exposed on the basis of data. This exposure data includes color data decomposed into BGR and gradation data that specifies the gradation of each color. When such exposure data is input as, for example, a serial signal, the line exposure control controller 6 distributes the serial signal to parallel data for each PLZT element. The parallel data thus obtained is composed of color data and gradation data. Then, the color data is supplied to the voltage control unit 62, and the gradation data is supplied to the time control unit 61.

A PLZT as an exposing means composed of a plurality of PLZT elements 44 arranged in the width direction of the printing paper 2.
Shutter 41 and each PLZ of this PLZT shutter 41
PLZ for supplying BGR light in a state where a plurality of optical fibers 42 connected to the T element 44 and each optical fiber 42 are bundled
The light source unit 43 for T is provided. The relationship between the number of PLZT elements 44 and the number of optical fibers 42 connected to them is not limited to 1: 1.

The light from the lamp 11 passes through the mirror tunnel 12 and illuminates the disk 13 on which the BGR color filters are formed every 120 °. Any BGR light that has passed through the disk 13 is supplied to a bundle of optical fibers 42. The light passing through each optical fiber 42 is applied to each PLZT element 44. The PLZT element 44 is supplied with a predetermined applied voltage according to the position (BGR) of the disk 13 from the voltage controller 62 in accordance with the rotation timing of the disk 13 and the exposure data. Only the wavelength of the light passing through 42 is selectively passed.

The rotation timing of the disc 13 is obtained by detecting the passage timing of the mark 14 on the disc 13 by the sensor 15. The colors of the filters that come around the optical axis of the optical fiber 42 are in the order of B, G, R, the mark 14 is arranged at the boundary between B and G, and the light of the sensor 15 and the optical fiber 42 is They are arranged 120 ° apart from the axis.

Next, based on FIGS. 2, 3 and 5, B
The exposure timing for each color of GR will be described. First, in step S1, the mark 15 on the disk is detected by the sensor 15
Is detected, it can be seen that the color of the filter is B for 120 ° from now on. Therefore, in step S2, the line exposure control unit 6 is controlled to change the voltage control unit 62 from the voltage control unit 62 to the PLZT element 44 to be exposed. The applied voltage of is switched to 45 V, and is applied for the application time corresponding to the gradation data for the dot. Therefore, as shown in FIG. 3A, the light of B that has passed through the filter is reflected by the dots D1 and D of the printing paper 2.
A predetermined dot such as 2 is exposed with an application time corresponding to each gradation data.

Next, after the mark 14 is detected, the disk 13 is moved to 12
When it is detected that the image has rotated 0 °, it can be seen that the color of the filter is G for 120 ° from now on. Therefore, the line exposure controller 6 is controlled in the same manner as described above, and the voltage controller 62 outputs G
The voltage applied to the PLZT element 44 to be exposed is switched to 50V, and the voltage is applied to the dot for an application time corresponding to the gradation data. Therefore, as shown in FIG.
The G light that has passed through the filter is the dots D1 on the photographic paper 2.
A predetermined dot such as D3 is exposed for an application time corresponding to each gradation data.

Next, when it is detected that the disk 13 has further rotated 120 °, the color of the filter is R for 120 ° from now on.
Therefore, the line exposure control unit 6 is controlled in the same manner as described above to switch the voltage applied from the voltage control unit 62 to the PLZT element 44 to 55V, and only the application time corresponding to the gradation data for the dot is changed. Apply. Therefore, as shown in FIG. 3C, the R light that has passed through the filter exposes a predetermined dot such as the dot D1 of the printing paper 2 at an application time corresponding to each gradation data.

In the above exposure process, the dot D1 is exposed to three colors of BGR, the dot D2 is exposed to two colors of B and R, the dot D3 is exposed to only G, and the dot D4 is not exposed to any color. Does not expose.

The application time for each dot is determined by the time control unit 61 by the conversion table T in Table 2.
Since the time is controlled based on BL1, the exposure of the color gradation according to the gradation data is performed. At this time, the application time of each color to the PLZT element in each dot is controlled so that the color density and the gradation data are proportional to each other, so that accurate gradation expression is possible.

Since the photographic printing paper 2 is in a stopped state during the exposure of the three BGR colors in the above steps, the exposure of one line in the width direction of the photographic printing paper 2 is completed. Then, after the series of steps shown in FIG. 5 is completed, the printing paper 2 is transported by one dot. The exposure position at this time is from (D) to FIG.
As shown in (F), it is a position moved by one dot on the printing paper.

Also in this case, similarly to the above, the BGR data is sequentially exposed in synchronization with the rotation of the disk 13, so that the exposure for one column is completed. Then, after the BGR exposure is completed, the printing paper 2 is further transported by one dot. In this way, the exposure is performed in the longitudinal direction of the printing paper 2 by sequentially exposing the printing paper one by one.

In the development processing section 5, the photographic printing paper 2 exposed by either or both of the negative exposure stage 3 and the line exposure stage 4 is subjected to development processing, cut into individual frames, and discharged.

The rotation timing of the disk 13 for each 120 ° may be based on the number of pulses applied to the stepping motor for rotating the disk 13 or the rotary encoder or the mark provided for each 120 °.

Instead of the conversion table TBL1 in Table 2, a conversion table TBL2 as shown in Table 3 may be provided. At this time, the application time T is set so that the gradation data D and the exposure amount S have a proportional relationship. That is, also in this conversion table TBL2, the application time T is a non-linear function of the gradation data D.

[0040]

[Table 3] In reality, the color density of the photosensitive material is a non-linear function of the exposure amount. Therefore, when the conversion table TBL2 is used, the actual color density is not exactly proportional to the gradation data. However, there is no problem in practical use. This has the effect of eliminating the need to change the data in the conversion table according to the photosensitive material.

At this time, the application time is t
It is also possible to provide six types of times of 1, t2, t3, t4, t5, and t6, and combine the six types of application times with the exposure data of 32 stages. For example, when the gradation data D = 13 (= 8 + 4 + 1), the application time T
= T5 + t4 + t2. At this time, the application time t
If 1, t2, t3, t4, t5, and t6 are individually set to arbitrary times, more accurate gradation expression can be performed and can be changed to arbitrary gradation expression.

The corrected exposure time in the claims corresponds to the application time when the PLZT element is used as the exposure means, but when other exposure means is used, the respective exposure means. Corresponds to the corrected exposure time at. As the exposure means, an exposure means using a liquid crystal shutter or the like can be used in addition to the exposure means using the PLZT element. Further, in addition to the line exposure element in which the exposure means is linearly arranged, a surface exposure means arranged in a plane or an exposure head including a set of exposure elements may be mechanically scanned.

As a means for guiding the light from the light source to the exposing means, a structure using a reflecting mirror other than the optical fiber may be used. Alternatively, the light source and the exposure means may be arranged close to each other. For example, as an exposing means using a liquid crystal shutter, an exposing means using TFT (thin film field effect transistor) color liquid crystal technology will be described with reference to FIG.
Amorphous silicon TFTs are formed on a glass substrate by using a semiconductor integrated circuit process, and a TFT array substrate 81 is formed. Each TFT element f corresponds to a dot, and a transparent dot electrode for driving a liquid crystal is formed. A color filter substrate 82 divided into RGB corresponding to each dot is arranged so as to face the TFT array substrate 81, and a liquid crystal 83 is enclosed between the two substrates. A transparent common electrode 84 is formed over the entire surface of the color filter substrate 82, a polarizing plate 85 is arranged, and a photosensitive material 87 is further arranged on the upper surface. T
A polarizing plate 86 is arranged on the lower surface of the FT array substrate 81 and is irradiated with light from a white light source (not shown).

When the TFT element f operates, electric charge is accumulated between the dot electrode and the common electrode 84, and the liquid crystal in the meantime rises due to the accumulated electric charge to transmit light,
A predetermined color is exposed on the photosensitive material 87 by the corresponding color filter.

The exposure apparatus of the present invention is not limited to a photographic printing apparatus, and can be applied to various photosensitive materials.

[0046]

According to the first aspect of the present invention, since the corrected exposure time based on the predetermined characteristic set in advance is output according to the input exposure data, the characteristic can be set appropriately. It is possible to perform exposure with an accurate gradation according to the exposure data, by compensating for the delay in the rise time of the exposure unit, the delay in the fall time, and even the characteristics between the exposure amount and the printing density. The effect that smooth gradation can be expressed is obtained.

According to a second aspect of the present invention, a conversion table in which the exposure data and the corrected exposure time are associated with each other by the characteristics is provided, and the conversion table is referred to according to the input exposure data. Thus, it is possible to perform exposure with an accurate gradation according to the exposure data and obtain an effect that a smooth gradation can be expressed. Further, according to claim 3, a conversion table is provided in which the exposure data and the corrected exposure time are associated with each other in the same manner as described above, and by referring to the conversion table according to the input exposure data, the appropriate correction is performed. By obtaining the combination of the exposure times, it is possible to obtain the effect that the smooth gradation can be expressed in the same manner as described above from a small number of conversion tables.

According to the present invention, since the conversion table is provided in which the exposure data and the correction exposure time for obtaining the printing density proportional to the exposure data are associated with each other, the conversion table is provided according to the photosensitive material to be used. The effect that the actual printing density can be accurately proportional to the exposure data and that smooth gradation can be expressed is obtained. Further, according to the present invention, since the conversion table is provided in which the exposure data and the corrected exposure time for obtaining the exposure amount proportional to the exposure data are provided, it is possible to make the exposure amount proportional to the exposure data. It is possible to obtain an effect that a smooth gradation can be expressed.

According to the sixth aspect, since the conversion data setting means for setting the correction exposure time in the conversion table to a desired correction exposure time is provided, smooth gradation can be expressed and an arbitrary gradation can be expressed. The effect that the key can also be expressed is obtained.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a photographic printing apparatus including an exposure apparatus of the present invention.

FIG. 2 is a configuration diagram of a main part of the photo printing apparatus.

FIG. 3 is a diagram illustrating an exposure process.

FIG. 4 is a configuration diagram of a main part of the photo printing apparatus.

FIG. 5 is a flowchart illustrating an exposure process.

FIG. 6 is a diagram showing characteristics of a PLZT element.

FIG. 7 is a diagram showing characteristics of a PLZT element.

FIG. 8 is a configuration diagram of a main part of an exposure unit using a TFT color liquid crystal.

[Explanation of symbols]

 2 photographic paper (photosensitive material) 41 PLZT shutter (exposure means) 42 optical fiber 43 PLZT light source section 44 PLZT element 61 time control section 63 conversion circuit (conversion means) 64 PLZT control circuit (PLZT control means) TBL1, TBL2 conversion table

Claims (6)

[Claims] 1. An exposure apparatus that performs gradation exposure on a photosensitive material by controlling the length of exposure time in an exposure unit according to input exposure data, and preset in accordance with the input exposure data. An exposure apparatus comprising: a conversion unit that outputs a corrected exposure time based on the determined predetermined characteristic, and an exposure control unit that controls the exposure time in the exposure unit based on the corrected exposure time. 2. The conversion means refers to the conversion table in which the exposure data is associated with a corrected exposure time based on a preset predetermined characteristic, and the conversion table is referred to to convert the input exposure data into the input exposure data. The exposure apparatus according to claim 1, further comprising a reference unit that outputs a corrected exposure time corresponding to the reference exposure unit. 3. The conversion means refers to the conversion table in which the exposure data is associated with a corrected exposure time based on a predetermined characteristic set in advance, and the input exposure data is referred to by referring to the conversion table. 3. The exposure apparatus according to claim 1, further comprising a reference unit that outputs the corrected exposure time by combining the corrected exposure times corresponding to each other. 4. A conversion table in which the conversion means associates the exposure data with a corrected exposure time for obtaining a printing density proportional to the exposure data, and the input exposure data with reference to the conversion table. And a reference unit for outputting a corrected exposure time according to the above.
The exposure apparatus according to any one of 1 to 3. 5. A conversion table in which the conversion means associates exposure data with a corrected exposure time for obtaining an exposure amount proportional to the exposure data, and the exposure data input with reference to the conversion table. And a reference unit for outputting a corrected exposure time according to the above.
The exposure apparatus according to any one of 1 to 3. 6. The exposure apparatus according to any one of claims 1 to 5, further comprising conversion data setting means for setting a correction exposure time in the conversion table to a desired correction exposure time.