WO2005056298A1 - 露光装置 - Google Patents
露光装置 Download PDFInfo
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- WO2005056298A1 WO2005056298A1 PCT/JP2004/018671 JP2004018671W WO2005056298A1 WO 2005056298 A1 WO2005056298 A1 WO 2005056298A1 JP 2004018671 W JP2004018671 W JP 2004018671W WO 2005056298 A1 WO2005056298 A1 WO 2005056298A1
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- gradation
- exposure
- data
- time
- exposure apparatus
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B27/00—Photographic printing apparatus
- G03B27/72—Controlling or varying light intensity, spectral composition, or exposure time in photographic printing apparatus
- G03B27/73—Controlling exposure by variation of spectral composition, e.g. multicolor printers
- G03B27/735—Controlling exposure by variation of spectral composition, e.g. multicolor printers in dependence upon automatic analysis of the original
Definitions
- the present invention relates to an exposure apparatus that outputs an image, and more particularly to a digital exposure apparatus that outputs a stable image while preventing the influence of ambient temperature.
- This fluorescent head has a force source electrode and an anode electrode in a case where a vacuum space is formed, and on the anode electrode, dots arranged in a line by phosphor are arranged.
- a voltage is applied to the force source electrode, electrons are emitted from the cathode electrode, and when the emitted electrons collide with the anode electrode, the phosphor is excited to generate light.
- the generated light is emitted to the outside to expose the photosensitive material and print an image.
- Another digital exposure apparatus is an LED exposure apparatus that arranges light-emitting diodes (hereinafter abbreviated as LED) in a substantially line shape, controls the light emission amount of the LED according to image data, and outputs a photographic image.
- the LED as an exposure light source used in this exposure apparatus has a problem that the light emission amount and the spectral characteristics fluctuate under the influence of the ambient temperature.
- the photosensitive material to be exposed is also affected by the ambient temperature and the spectral sensitivity characteristics fluctuate.
- control the LED drive current in consideration of the light emission amount and spectral characteristics of the LED with respect to the temperature, and the spectral sensitivity characteristics of the photosensitive material, and make the exposure conditions constant with temperature.
- Patent Literature 2 Japanese Patent Publication No. H04-046472.
- the exposure correction method disclosed in Patent Document 2 prepares a correction coefficient table in consideration of the light emission amount and the spectral characteristics with respect to the temperature of the LED and the spectral sensitivity characteristics of the photosensitive material, switches the correction coefficient table according to the temperature, and inputs the correction coefficient table.
- the image data is corrected by multiplying the image data with a correction coefficient by a multiplier, and the aim is to stabilize the exposure conditions.
- an exposure apparatus has been developed in which a photographic image is output by controlling an exposure time in accordance with gradation data by using optical shutters arranged in a line.
- a PLZT element or a liquid crystal shutter is used for the optical shutter of this exposure apparatus.
- photosensitive materials have a non-linear relationship between exposure and exposure density (ie, printing density). Therefore, there is a problem that accurate gradation cannot be expressed even if a photo image or the like is exposed on a photosensitive material by controlling the optical shutter in proportion to the gradation data.
- Patent Document 3 Japanese Patent No. 2956556
- the exposure apparatus disclosed in Patent Document 3 has a conversion table in which gradation data and corrected exposure time data for obtaining an exposure density (or exposure amount) proportional to the gradation data are associated with each other.
- Reference means for outputting corrected exposure time data in accordance with the input gradation data are provided to achieve accurate gradation expression.
- an apparatus that forms an image by an electrophotographic method by performing laser exposure on a photoconductive photoconductor has been developed.
- this laser exposure apparatus there is a problem that the image density changes due to changes in temperature and humidity because the photoconductive photoreceptor has temperature and humidity dependence.
- Patent Document 4 Japanese Patent Application Laid-Open No. 5-19772262. Disclosure of the invention
- the change in the amount of light in units of dots with respect to the cumulative lighting time can be corrected by switching the data table.
- Light amount correction for temperature characteristics is not considered.
- the sensitivity characteristics of a photosensitive material vary depending on the ambient temperature, and the relationship between the exposure amount and the exposure concentration varies depending on the temperature. For this reason, even if the amount of exposure from the fluorescent head is constant, the sensitivity characteristics of the photosensitive material fluctuate due to a change in the ambient temperature, and as a result, the color tone and density of the halftone change, resulting in a good image. There was an important problem that it was not possible to obtain
- the exposure amount is corrected by multiplying the image data by a correction coefficient that changes with temperature.
- this correction method only multiplies the entire gradation range of image data (for example, the range of 0 to 255 for 8-bit gradation) by one correction coefficient.
- the gradation range is corrected with a constant value for temperature.
- the relationship between the number of gradations and the amount of exposure light, and the relationship between the amount of exposure and the density of the photosensitive material are non-linear, and do not have a fixed relationship with temperature.
- correction is performed using a conversion table that associates grayscale data with corrected exposure time data that provides an exposure density (or exposure amount) proportional to the grayscale data.
- a conversion table that associates grayscale data with corrected exposure time data that provides an exposure density (or exposure amount) proportional to the grayscale data.
- Patent Document 3 enables relatively accurate gradation expression when exposed at a constant temperature, but has an opportunity to be used outdoors, such as a portable exposure apparatus. Exposure equipment suffers from the problem that the exposure density changes depending on the ambient temperature due to severe environmental changes, and it is difficult to achieve accurate gradation expression.
- Patent Document 4 has lookup tables as many as the temperature and humidity conditions, and attempts to compensate by switching the lookup tables according to changes in temperature and humidity. ing.
- having a look-up table that covers all humidity temperature conditions requires a huge amount of storage capacity, and there has been a problem that it is necessary to switch the look-up table according to a slight change in temperature and humidity.
- An object of the present invention is to provide an exposure apparatus for solving the above problems.
- Another object of the present invention is to provide an exposure apparatus capable of realizing a stable gradation expression with respect to a temperature change. It is still another object of the present invention to provide an exposure apparatus capable of realizing visually desirable gradation expression by suppressing the influence of a temperature change even when an ambient temperature changes, and outputting a stable photographic image quality.
- Still another object of the present invention is to provide an exposure apparatus in which a printing time on a photosensitive material is constant with respect to a temperature change.
- An exposure apparatus includes: a plurality of conversion units for converting input grayscale data into corrected grayscale data for correcting nonlinearity of exposure density; and a grayscale exposure for a photosensitive material based on the corrected grayscale data.
- Exposure means for performing the temperature detection, temperature detection means for detecting the ambient temperature, and switching means for switching the conversion means in accordance with the temperature detected by the temperature detection means, wherein each of the plurality of conversion means has a temperature range in which the power is divided. Is characterized in that the range of change in the amount of exposure is set so as to be substantially equally divided.
- a plurality of conversion means for correcting the non-linearity of the exposure density are provided corresponding to the temperature region, a temperature detection means for detecting the ambient temperature is provided, and the plurality of conversion means are switched according to the temperature detected by the temperature detection means. Since the gradation data is corrected and exposed, even if the ambient temperature changes, the effect of the temperature change can be suppressed and stable photographic image quality can be obtained.
- the exposure change range is evenly divided and corrected regardless of the temperature range, so that the correction error with respect to temperature becomes uniform, and an exposure device that outputs stable photographic image quality with respect to temperature changes
- the plurality of conversion units correct at least one of a change in an exposure amount of the exposure unit with respect to an ambient temperature and a change in a sensitivity characteristic of the photosensitive material with respect to an ambient temperature. If at least one of the change in the exposure amount with respect to the ambient temperature and the change in the sensitivity characteristics of the photosensitive material with respect to the ambient temperature are corrected, an exposure apparatus that can realize stable gradation expression even when the ambient temperature changes. Can be provided.
- each of the plurality of conversion units is divided into widths in which the temperature range in which the power is increased is different.
- the conversion means is divided in accordance with the non-linear characteristic of the exposure amount with respect to the temperature change, it is possible to provide an exposure apparatus capable of reducing the correction error and efficiently dividing the conversion means.
- the plurality of converters are converters in which the converter in the high temperature region has a wider temperature range than the converter in the low temperature region.
- the conversion means is divided in accordance with the non-linear characteristic of the exposure amount with respect to the temperature change in both the low temperature area and the high temperature area, the correction error is small in both the low temperature area and the high temperature area, and the conversion means is divided. In addition, it is possible to provide an exposure apparatus that can efficiently divide an image.
- the plurality of conversion means can divide the temperature range to cover each of them substantially equally.
- An exposure apparatus includes a line light source for exposure and a plurality of conversion units provided corresponding to a temperature region, wherein each of the conversion units is a stage input in order to correct the non-linearity of the exposure density.
- the shutter means corresponding to the maximum gradation data of each conversion means are set to have substantially the same opening time.
- An exposure apparatus includes: a line light source for exposure; a shutter unit for optically modulating light emitted from the line light source; and a light correcting unit for correcting light amount variation of light emitted from the shutter light.
- the aperture time is controlled in accordance with the corrected gradation data from the conversion means on which the correction is superimposed, and the light emitted from the line light source is light-modulated to perform gradation exposure on the photosensitive material, and corresponds to the maximum gradation data of each conversion means.
- the opening times of the shutter means are set so as to substantially coincide with each other.
- a light amount correcting means for correcting the light amount variation of the light emitted from the shutter means, the density unevenness of the photosensitive material can be reduced.
- the gradation data range controlled by each conversion means includes a first gradation range in which the relationship between the gradation data for each conversion means and the opening time of the shutter means coincides with the gradation density in the photosensitive material, It is preferable that the relationship between each gradation data and the opening time has a second gradation range in which the gradation density does not match the gradation density in the photosensitive material.
- the first gradation range where the relationship between the gradation data and the opening time of the shutter means coincides with the gradation density of the photosensitive material it compensates for the delicate density change of the halftone and stabilizes against temperature.
- An exposure apparatus capable of expressing gradation can be provided.
- the relationship between the gradation data and the opening time has a second gradation range in which the gradation density does not coincide with the gradation density of the photosensitive material, the opening time corresponding to the maximum gradation data of each conversion means can be matched. Can be. Therefore, it is possible to provide an exposure apparatus that prints an image with a constant printing time on a photosensitive material even when the conversion unit is switched due to a temperature change and prints an image that is stable with respect to temperature.
- the second gradation range is preferably a gradation range having a large number of gradations.
- the aperture time corresponding to the maximum gradation data of each conversion means is matched without affecting the change in the density of the halftone which greatly affects the image. be able to.
- An exposure apparatus includes a light source for exposure and a plurality of conversion units provided corresponding to a temperature region, wherein each of the conversion units reduces the non-linearity of the exposure density. And converting the input gradation data into correction gradation data, and modulating the light emitted from the light source. The opening time is controlled according to the correction gradation data from the conversion means; And shutter means for modulating the light emitted from the light source to perform gradation exposure on the photosensitive material, wherein the printing time per predetermined area in each conversion means is set to be substantially the same. I do.
- the printing time per predetermined area is the printing time of one line for the photosensitive material.
- the printing time per predetermined area is the printing time for one line on photosensitive material
- the printing time for one line on photosensitive material is almost the same even if the conversion means is switched due to the change in ambient temperature.
- the printing time for one line preferably includes a mask time for performing data transfer and the like and a maximum gradation opening time corresponding to the maximum gradation data of the shutter means.
- the printing time for one line includes the mask time for data transfer and the maximum gradation opening time that is the exposure time to the photosensitive material, one of the mask time and the maximum gradation opening time for the temperature change, or By adjusting both times, it is possible to provide an exposure apparatus that substantially matches the printing time of one line in each conversion unit.
- the printing time of one line is determined by the maximum opening time, which is the longest maximum gradation opening time among the maximum gradation opening times of the respective conversion means, and the above-described mask. It is preferably a time obtained by adding a disc time.
- the longest printing time for one line is the sum of the longest maximum gradation opening time, which is the longest gradation opening time among the maximum gradation opening times corresponding to the maximum gradation data, and the mask time.
- the mask time in each conversion means is made different so that the printing time of the one line corresponding to each conversion means is substantially the same. Adjustment, so that the printing time for one line can be made to substantially match without correcting the maximum gradation opening time of each conversion means, providing an exposure device with simple exposure control and a constant printing time. Also, by keeping the mask time in each conversion means constant and providing a gradation closing time in addition to the maximum gradation opening time, the printing time of the one line corresponding to each conversion means can be reduced. It is preferable to set them so that they substantially match.
- the mask time is fixed and the difference in the maximum gradation opening time of each conversion means is adjusted by providing a gradation closing time, the mask time is kept constant and the maximum gradation of each conversion means is maintained.
- the printing time for one line can be made almost the same without correcting the opening time. as a result
- the gradation closing time is preferably the same as the time difference between the maximum gradation opening time and the maximum opening time in each conversion means.
- the time difference between the maximum opening time, which is the longest maximum gradation opening time of each conversion means, and the maximum gradation opening time of each conversion means is defined as the gradation closing time.
- the difference is adjusted to the maximum opening time by the gradation closing time.
- the mask time in each conversion means is fixed, and the maximum gradation opening time is substantially equal to the maximum opening time.
- the mask time is kept constant, and the gradation closing time is also maintained.
- the printing time for one line can be almost matched without the need. As a result, it is possible to provide an exposure apparatus in which the exposure control is simple and the printing time is always constant.
- the gradation data range controlled by each conversion means includes a first gradation range in which the relationship between the gradation data for each conversion means and the opening time of the shutter means substantially matches the gradation density in the photosensitive material, It is preferable that the relationship between the gradation data of each means and the opening time has a second gradation range in which the gradation time does not match the gradation density of the photosensitive material.
- the first gradation range where the relationship between gradation data and the opening time of the shutter means substantially matches the gradation density of the photosensitive material compensates for subtle density changes in halftones and stabilizes against temperature.
- An exposure apparatus capable of gradation expression can be provided.
- the second gradation range in which the relationship between gradation data and opening time does not match the gradation density of the photosensitive material it corresponds to the maximum gradation data of each conversion means. Since the maximum gradation opening time can be made to coincide with the maximum opening time, it is possible to provide an exposure apparatus in which the printing time on the photosensitive material is always constant even if the conversion means is switched by a temperature change. .
- the second gradation range is preferably a gradation range with a large number of gradations.
- the maximum gradation opening time corresponding to the maximum gradation data of each conversion means without affecting the halftone density change that greatly affects the image can be matched with the maximum opening time.
- An exposure apparatus includes: a line light source for exposure; a shutter device for optically modulating light emitted from the line light source; a light correcting device for correcting the light amount variation of the light amount of the emitted light light-modulated by the shutter device; A plurality of conversion means provided corresponding to the temperature region, wherein each conversion means non-linearly corrects the gradation data corrected by the light amount correction means and outputs corrected gradation data; The aperture time is controlled according to the corrected gradation data from the conversion means on which the light quantity correction is superimposed, and the light emitted from the line light source is light-modulated to perform gradation exposure on the photosensitive material, and the mask time in each conversion means is fixed.
- the maximum gradation opening time in each conversion means is substantially equal to the maximum opening time, it is set that the printing time of one line in each conversion means is made to substantially match. And butterflies.
- the light amount correcting means for correcting the light amount of light emitted from the shutter means is provided, unevenness in the density of the photosensitive material can be reduced.
- a plurality of conversion means for correcting the nonlinearity of the exposure density are provided corresponding to the temperature region, and a temperature detection means for detecting an ambient temperature is provided.
- the present invention provides an exposure apparatus that outputs stable photographic image quality by suppressing the influence of temperature changes even when the ambient temperature changes, because the conversion means is switched according to the detected temperature to correct the gradation data and expose. be able to.
- a plurality of conversion means for nonlinearly correcting gradation data such as image data are provided for temperature, and the opening time corresponding to the maximum gradation data of each conversion means is provided. Since the values are substantially equal to each other, it is possible to provide an exposure apparatus which can correct a delicate density change of a halftone due to a temperature change to realize a good image and also has a printing time which is always constant with respect to a temperature change. Can be.
- a plurality of converters for different temperatures are provided, and the printing time per predetermined area in each converter is substantially the same. It is possible to provide an exposure apparatus in which the printing time per a predetermined area is always constant with respect to a temperature change even when the switching is performed.
- FIG. 1 is a circuit block diagram schematically showing an exposure apparatus 1 according to the present invention.
- FIG. 2A is an explanatory diagram showing the relationship between the exposure amount and the density of the photosensitive material.
- Figure 2B shows the exposure temperature characteristics using the liquid crystal shutter of the exposure apparatus.
- FIG. 3A is a characteristic diagram showing a method of equally dividing the conversion table in the range of change in the exposure amount with respect to the ambient temperature.
- FIG. 3B is a characteristic diagram showing a method of equally dividing the conversion table in the temperature range.
- FIG. 4 is a flowchart illustrating a conversion table switching operation.
- FIG. 5 is a circuit block diagram schematically illustrating an exposure apparatus 100 according to the present invention.
- FIG. 6 is a conversion table input / output graph showing the relationship between the gradation data input to the conversion table and the opening time output from the conversion table.
- FIG. 6 is a timing chart for explaining an exposure operation in the present embodiment.
- FIG. 7B is a timing chart illustrating an exposure operation in the vicinity of 17 ° C. in exposure apparatus 100.
- FIG. 7C is a timing chart for explaining an exposure operation in the vicinity of 25 ° C. in exposure apparatus 100.
- FIG. 8 is a circuit block diagram schematically showing the exposure apparatus 200 according to the present invention.
- FIG. 9A is a timing chart of the exposure operation at around 6 ° C. in exposure apparatus 200.
- FIG. 9B is a timing chart of the exposure operation in the vicinity of 13.5 ° C. in exposure apparatus 200.
- FIG. 9C is a timing chart of the exposure operation in the vicinity of 25 ° C. in the exposure apparatus 200.
- FIG. 10 is a circuit diagram schematically showing an exposure apparatus 300 according to the present invention.
- FIG. 10 is a circuit diagram schematically showing an exposure apparatus 300 according to the present invention.
- FIG. 11A is a timing chart of the exposure operation in the exposure apparatus 300 at around 6 ° C.
- FIG. 11B is a timing chart of the exposure operation at about 13.5 ° C. in the exposure apparatus 300, which is ⁇ .
- FIG. 11C is a timing chart of the exposure operation at about 25 ° C. with light irf 3 ⁇ 0.
- FIG. 12 is a circuit block diagram schematically showing an exposure apparatus 400 according to the present invention.
- FIG. 13A is an input / output graph showing the relationship between the gradation data input to the conversion table and the opening time output from the conversion table.
- FIG. 13B is a diagram showing the relationship between the gradation data input to the conversion table and the density of the photosensitive material.
- FIG. 14A is an enlarged view in which the range of the gradation data 222 to 255 of FIG. 13A is enlarged.
- FIG. 14B is an enlarged view in which the range of the gradation data 222 to 255 in FIG. 13B is enlarged.
- FIG. 15A is a timing chart of the exposure operation in exposure apparatus 400 at around 6 ° C.
- FIG. 15B is a timing chart of the exposure operation at about 13.5 ° C. in the light emitting device t £ 400. '
- FIG. 15C is a timing chart of the exposure operation at around 25 ° C. in the exposure apparatus 400.
- FIG. 16 is a diagram showing a pixel array of LCS, a light amount graph of emitted light output from the LCS, and a corrected light amount graph as a result of performing shading correction.
- Figure 17 shows an example of 'correction data for performing shading correction. It is a correction data table shown.
- FIG. 18 is an explanatory diagram showing the relationship between the exposure amount and the density of another photosensitive material.
- FIG. 1 shows a configuration of an exposure apparatus 1 according to the present invention.
- a microcomputer 2 that controls the entire operation of the exposure apparatus 1 includes an analog / digital converter (hereinafter abbreviated as “AZD”), an arithmetic circuit, a timer, a storage circuit, and the like.
- ALD analog / digital converter
- the temperature detecting section 3 as a temperature detecting means for detecting the ambient temperature of the exposure apparatus 1 is constituted by a thermistor or the like, and outputs temperature data P 1 as the detected temperature to the microcomputer 2.
- the input interface circuit (hereinafter abbreviated as input IZF) 4 inputs image data and the like from outside the exposure apparatus 1.
- a memory 5 constituted by a RAM or the like stores input data P 2 (ie, image data or the like) input via the input IZF 4.
- the microcomputer 2 outputs the memory control signal P3 to the memory 5, and controls the read Z write operation of the memory 5.
- the conversion table 6 as conversion means receives gradation data P 4 output from the memory 5 and corrects the inputted gradation data P 4 to correct the non-linearity of the exposure density. Convert to data P 6 and output.
- the conversion table 6 is configured by a plurality of conversion tables as shown in the figure. In this example, the conversion table 6 includes seven steps of conversion tables 6a to 6g.
- Each of the conversion tables 6a to 6g receives the gradation data P4, and is selectively switched by a switching signal P11 output from a switching circuit 13 described later. Outputs key data P6.
- the gradation data P 4 is red (hereinafter referred to as the three primary colors of light). R), green (hereinafter abbreviated as G), and blue (hereinafter abbreviated as B) image data, and each color image data is usually composed of 8 bits. Therefore, the memory 5 stores the image data of each RGB, and the conversion table 6 is also composed of three conversion tables different for each RGB corresponding to the gradation data P4. That is, although not shown, the actual conversion table 6 includes a plurality of conversion tables 6a to 6g for each RGB.
- Each of the conversion tables 6a to 6g converts the gradation data P4 in correspondence with the fact that the gradation data P4 is usually 8 bits and can express 256 gradations. It is composed of 256 gradation gradation data P 6.
- the conversion table 6 is preferably constituted by a rewritable nonvolatile memory. 13 is a switching circuit, which receives switching data P5 output from the microcomputer 2 based on the temperature data P1 of the temperature detecting section 3, and converts the individual conversion tables 6a to 6g of the conversion table 6 into The switching signal P 11 for selective switching is output.
- the LCS driving circuit 7 receives the corrected gradation data P6 and outputs an LCS driving signal P7 for controlling the exposure time according to the corrected gradation data P6.
- the LED drive circuit 8 receives the LED control signal P 8 from the microcomputer 2 and outputs a LED drive signal P 9.
- the exposure head 9 as an exposure means is composed of a liquid crystal shutter (hereinafter abbreviated as LCS) 9a having line-shaped pixels (not shown) and an exposure light comprising RGB three-color LEDs (not shown). It is composed of LED unit 9b etc. as a light source.
- LCS liquid crystal shutter
- the photosensitive material 10 includes photographic paper, silver halide instant film, and the like.
- the outgoing light A emitted from the LED unit 9 of the exposure head 9 is light-modulated by the LCS 9a, becomes a linear irradiation light B, and exposes the light-sensitive material 10 to form an image.
- Printed line by line. 1 1 is This is a head drive unit, which inputs a head control signal P10 from the microcomputer 2 to move the exposure head 9 with respect to the photosensitive material 10, and performs surface exposure on the photosensitive material 10.
- Reference numeral 12 denotes a power supply unit composed of a secondary battery or the like. Although not shown, a power supply line supplies necessary power to each block.
- the microcomputer 2 executes an initialization process to initialize each block. Become Along with the initialization, the head driving unit 11 moves the exposure head 9 to the home position and enters a stamp-pay state.
- an external electronic device such as a digital camera
- the microcomputer 2 controls the memory 5 by the memory control signal P 3 and the input from the input I / F 4 Data P 2 (that is, image data) is sequentially written.
- the memory 5 may store image data for one screen, or may store only several lines of image data sequentially.
- image data from a digital camera or the like is often compressed data such as JPEG, but in this case, the uncompressed data that can be decompressed and printed out using the arithmetic function of the microcomputer 2 is used. It is good to convert to data and write it to memory 5.
- the microcomputer 2 outputs the switching data P5 based on the temperature data P1 from the temperature detecting unit 3, and the switching circuit 13 receives the switching data P5, decodes the data internally, and generates the switching signal PI1. Output and select one of a plurality of conversion tables 6 a to 6 g built in conversion table 6. The details of the operation of selecting the conversion table 6 will be described later.
- the microcomputer 2 sequentially outputs the image data stored in the memory 5 as gradation data P 4 for each line of RGB data by the memory control signal P 3.
- the conversion table 6 stores the input gradation data.
- P4 is sequentially converted into exposure correction data P6 and output.
- the LCS drive circuit 7 receives the exposure correction data P6 and outputs an LCS drive signal P7 for driving the LCS 9a.
- the LCS driving circuit 7 The LCS drive signal P7 is output in the order of R, G, and B for each line.
- the LCS 9a is driven by the LCS drive signal P7 in the order of R, G, and B for each line to perform an exposure operation. That is, the LCS 9a of the exposure head 9 is changed by controlling the ON time and the OFF time of the pixel based on the corrected gradation data P6, and controlling the exposure amount to the photosensitive material 10 by controlling the exposure time. In addition, gradation exposure is realized.
- the LED unit 9b lights the RGB three-color LEDs (not shown) sequentially in synchronization with the LCS 9a. That is, when 03 9 & is operating based on the corrected gradation data P 6 of 1, the R LED is lit, and LCS 9 a is operating based on the corrected gradation data P 6 of G When the LCS 9a is operating based on the corrected gradation data P6 of B, the LED of B lights. As a result, the exposure of the three colors overlaps on the photosensitive material 10, and a full-color print is realized. Next, when the exposure operation of RGB for one line is completed, the gradation data P 4 of the second line is output from the memory 5 in the order of :, G, B.
- the conversion table 6 outputs the corrected gradation data P6 of the second line in the order of R, G, and B based on the gradation data P4, and the LCS 9a sets the exposure of the second line to R again. , G, B in order.
- the head driving unit 11 is controlled by a head control signal P 10 from the microcomputer 2, and moves the exposure head 9 in synchronization with the exposure of each line, thereby controlling the photosensitive material 10. Surface exposure is realized. When all lines have been exposed, the head The drive unit 11 returns the exposure head 9 to the home position again, and ends the printing operation.
- FIG. 2A shows an example of the exposure-density (ie, printing density) characteristic of the photosensitive material 10.
- the X-axis is the exposure amount, and the exposure amount for achieving the target white density (when all of R, G, and B are superimposed) is set to 1.
- the Y-axis is the density of the photosensitive material 10, and in the present embodiment, ranges from the black density (here, 2.10) where no light is applied to the target white density (here 0.18). Has reached.
- the density with respect to the exposure amount is non-linear. Overexposure becomes remarkable, and visually desirable gradation expression corresponding to gradation data P 4 cannot be realized.
- FIG. 2B shows an example of the temperature characteristics of the irradiation light A output from the exposure head 9 for each of RGB.
- the X-axis is the ambient temperature of exposure apparatus 1 detected by temperature detection unit 3, and indicates the range of 5 ° C. to 40 ° C.
- the Y-axis indicates the amount of exposure to the photosensitive material 10 by the irradiation light A, and is expressed as a relative value when the amount of exposure at 25 ° C. is set to 1.
- the characteristic diagram of FIG. 2B is data when the value of the gradation data P 4 is 255.
- the exposure amount has a characteristic that rises to the right with respect to the temperature, and has a characteristic that differs for each RGB wavelength.
- the main cause of such temperature characteristics is that the rise time and fall time of LCS 9a are easily affected by temperature.
- this temperature characteristic differs for each RGB is that the temperature dependence of the rise time and fall time of LCS 9a depends on the wavelength of light. It is because it changes by. As described above, this temperature characteristic is obtained when the value of the gradation data P4 is 255, but if this value is different, the temperature characteristic also changes.
- the first measure is to correct the non-linearity of the density with respect to the exposure shown in Fig. 2A. That is, it is a measure to provide a conversion table for inputting the grayscale data P4 and converting it into correction data for correcting non-linearity. This conversion table is the conversion table 6 shown in FIG. 1, and the converted correction data is the correction gradation data P6.
- the reason why the exposure-density characteristic shown in FIG. 2A is non-linear is due to the exposure characteristic of the photosensitive material.
- the conversion table 6 corrects both the nonlinear relationship between the exposure amount and the density of the photosensitive material and the nonlinear relationship between the gradation data P 4 and the exposure amount of the LCS.
- the second measure is to correct the exposure temperature characteristics shown in Fig. 2B for each RGB. That is, a plurality of conversion tables 6 provided in the first measure are provided corresponding to the temperature range, and the conversion tables 6 are switched according to the ambient temperature to correct the fluctuation of the exposure amount in the temperature range.
- This is to output the gradation data P6.
- the exposure level decreases in the low-temperature region, so that the output level of the corrected gradation data P 6 is set to a higher value by the decrease, and conversely, the exposure level increases in the high-temperature region.
- the output level of the correction gradation data P6 may be set to a value lower by the increase.
- the correction amount of the correction gradation data P6 is also the gradation data. Adjusted according to the value of P4 Preferably.
- the temperature characteristic of the exposure amount shown in FIG. 2B is the temperature characteristic of the irradiation light A output from the exposure head 9, but in fact, the sensitivity characteristic of the photosensitive material 10 also has the temperature characteristic. . Therefore, it is preferable that the conversion table 6 corrects both the change of the exposure amount with respect to the temperature of the exposure head 9 and the change of the sensitivity characteristic with respect to the temperature of the photosensitive material 10, but only one of them is corrected. May be.
- One point of the present invention is that the above two measures have been realized at the same time.
- FIG. 3A shows an example of a switching method of the conversion table 6 as a conversion means.
- the method shown in FIG. 3A is a method in which the exposure change range is equally divided, and the divided areas are divided by the conversion tables 6a to 6g.
- the curve R in FIG. 3A corresponds to the temperature characteristic of the exposure amount of R shown in FIG. 2B.
- the X axis and the Y axis in FIG. 3A indicate the temperature and the exposure amount ratio as in FIG. 2B.
- the exposure change width L when the ambient temperature changes from 5 to 40 ° C is evenly divided into seven, and the curve R corresponds to each division range (L1 to L7).
- the range of temperature division is shown as T1 to T7.
- the temperature division ranges ⁇ 1 to ⁇ 7 are greatly different from each other, but the exposure amount change width L is equally divided. That is, the temperature range is narrow in the low temperature range and wide in the high temperature range.
- the above-mentioned conversion tables 6a to 6g are sequentially switched at T1 to T7, which are the temperature division ranges, to force each temperature region.
- FIG. 4 is a flowchart for explaining the conversion table switching operation when the switching method shown in FIG. 3 is used.
- the microcomputer 2 that controls the exposure apparatus 1 performs a print operation before executing the print operation.
- the conversion table switching mode is executed as a step.
- the microcomputer 2 first inputs the temperature data P 1 output from the temperature detection unit 3 (ST 1).
- the temperature data P 1 is an analog signal
- the microcomputer 2 converts the temperature data into digital data by a built-in AZD (not shown) and stores the digital data inside as the ambient temperature data of the exposure apparatus 1.
- the microcomputer 2 determines whether or not the stored temperature data is included in the preset temperature range T1 (that is, equivalent to T1 shown in FIG. 3A) (ST2). Here, if the determination is affirmative, the process proceeds to ST10, and if the determination is negative, the process proceeds to ST3.
- the microcomputer 2 selects the conversion table 6a corresponding to the temperature range T1 because the ambient temperature of the exposure apparatus 1 is included in the temperature range T1, and the conversion table 6 Output switching data P5 specifying a.
- the switching circuit 13 receives the switching data P5 and outputs a switching signal P11 for selecting the conversion table 6a (ST10). After executing ST10, proceed to ST17.
- the microcomputer 2 determines whether the stored temperature data falls within the preset temperature range T 2 (that is, corresponds to T 2 shown in FIG. 3A). Yes (ST3). Here, if the determination is affirmative, the process proceeds to ST11, and if the determination is negative, the process proceeds to ST4.
- the ambient temperature of the exposure apparatus 1 is included in the temperature range T2, and the microcomputer 2 selects the conversion table 6b corresponding to the temperature range T2, and the conversion table 6b Outputs the switching data P5 specifying.
- the switching circuit 13 receives the switching data P5 and outputs a switching signal P11 for selecting the conversion table 6b (ST11). After executing ST11, proceed to ST17.
- the microcomputer 2 determines that the stored temperature data is in the preset temperature range T3 (that is, in FIG. 3A). (Equivalent to the indicated T3) is determined (ST4). Here, if the determination is affirmative, the process proceeds to S ⁇ 12, and if the determination is negative, the process proceeds to S ⁇ 5.
- the ambient temperature of exposure apparatus 1 is included in temperature range ⁇ 3, and microcomputer 2 selects conversion table 6c corresponding to temperature range ⁇ 3, and conversion table 6c.
- the switching data P5 that specifies c is output.
- the switching circuit 13 receives the switching data P5 and outputs a switching signal P11 for selecting the conversion table 6c (ST12). After executing ST12, proceed to ST17.
- the microcomputer 2 determines whether the stored temperature data falls within the preset temperature range T 4 (that is, corresponds to T 4 shown in FIG. 3A). Yes (ST5). Here, if the determination is affirmative, the process proceeds to ST13. If the determination is negative, the process proceeds to ST6.
- the ambient temperature of the exposure apparatus 1 is included in the temperature range T4, and the microcomputer 2 selects the conversion table 6d corresponding to the temperature range T4, and the conversion table 6d Outputs the switching data P5 specifying.
- the switching circuit 13 inputs the switching data P5 and outputs a switching signal P11 for selecting the conversion table 6d (ST13). After executing ST 13, proceed to ST 17.
- the ambient temperature of the exposure apparatus 1 is included in the temperature range T5, so that the microcomputer 2 selects the conversion table 6e corresponding to the temperature range T5, and the conversion table 6e.
- the switching circuit 13 inputs the switching data P5 and outputs a switching signal P11 for selecting the conversion table 6e (ST14). After executing ST 14, proceed to ST 17.
- the microcomputer 2 determines whether the stored temperature data falls within the preset temperature range ⁇ 6 (that is, corresponds to T 6 shown in FIG. 3 ⁇ ). Yes (ST 7). Here, if the determination is affirmative, the process proceeds to ST15, and if the determination is negative, the process proceeds to ST8.
- the microcomputer 2 corresponds to the temperature range T6.
- the conversion table 6f is selected, and the conversion table 6f is selected. Outputs the switching data P5 specifying.
- the switching circuit 13 receives the switching data P5 and outputs a switching signal P11 for selecting the conversion table 6f (ST15). After executing ST15, proceed to ST17.
- the microcomputer 2 determines whether the stored temperature data falls within the preset temperature range T 7 (that is, corresponds to T 7 shown in FIG. 3A). Yes (ST 8). Here, if the determination is affirmative, the process proceeds to ST 16; if the determination is negative, the process proceeds to the error processing.
- the ambient temperature of the exposure apparatus 1 is included in the temperature range T7, and the microcomputer 2 selects the conversion table 6g corresponding to the temperature range T7, and the conversion table 6g. Outputs the switching data P5 specifying.
- the switching circuit 13 receives the switching data P5 and outputs a switching signal P11 for selecting the conversion table 6g (ST16). After executing ST 16, proceed to ST 17.
- the conversion table 6 uses one of the conversion tables 6a to 6g selected by the switching circuit 13 to convert the gradation data P4 into corrected gradation data P6. Transfer the corrected gradation data P 6 to the LCS drive circuit 7 (ST 18).
- the LCS drive circuit 7 drives the LCS 9 a sequentially according to the corrected gradation data P 6 to perform exposure on the photosensitive material 10. Subsequent description will be omitted because it is duplicated.
- the exposure amount change range in which the conversion tables 6a to 6g selected in accordance with the temperature region is improved.
- the error in the correction amount is uniform and the error can be reduced.
- the number of divisions can be reduced in an area where the change in the exposure amount is gentle (that is, in a high-temperature area). According to the present invention, it is possible to provide an exposure apparatus capable of realizing a visually desirable gradation expression while suppressing the influence of the temperature change even when the ambient temperature changes, and outputting a stable photographic surface quality.
- the effects of the present invention are extremely large in a portable exposure apparatus to be taken out and used outdoors because it is easily affected by the ambient temperature.
- FIG. 3A the division of the conversion table 6 is described only for the exposure temperature characteristics of R. However, the conversion table 6 is similarly divided and corrected for the exposure temperature characteristics of G and B. It goes without saying that you can do it.
- FIG. 3B shows another example of the switching method of the conversion table 6 as the conversion means.
- the method shown in FIG. 3B is a method in which the temperature change range is evenly divided, and the divided areas are divided by the conversion tables 6a to 6g.
- a curve R corresponds to the temperature characteristic of the exposure amount of R shown in FIG. 2B.
- the X axis and the Y axis in FIG. 3B show the temperature and the exposure amount ratio as in FIG. 2B.
- the temperature range of the ambient temperature from 5 ° C to 40 ° C is equally divided into seven equal parts (T1 to T7), and the curve R shows the change in the exposure change width corresponding to each divided range.
- the division range is shown as L1 to L7. As shown in the figure, the divided ranges L1 to L7 of the exposure variation range are greatly different, but the divided ranges T1 to T7 of the temperature are equal.
- the above-mentioned conversion table 6 is sequentially switched at ⁇ 1 to ⁇ 7, which are the temperature division ranges, to force each temperature region.
- the conversion table switching operation is as shown in the flowchart of FIG. The description is omitted because they are the same.
- the selected conversion tables 6a to 6g are corrected because the covered exposure change range differs depending on the temperature. Are different from each other.
- the correction error is extremely small in the high-temperature region because the range of change in the amount of exposure to be covered is narrow, but the correction error is relatively large in the low-temperature region because the range of change in the amount of light exposure is wide.
- the temperature range at which the conversion table 6 is switched is uniform, the switching control of the conversion table 6 is simplified, and the processing of the microcomputer 2 is reduced, which is useful for speeding up print output.
- the conversion table 6 is divided only for the exposure temperature characteristic of R.
- the conversion table 6 can be similarly divided and corrected for the exposure temperature characteristics of G and B. Needless to say.
- FIG. 5 shows the configuration of another exposure apparatus 100 according to the present invention.
- the shading correction circuit 20 as the light amount correction means inputs the image data P 2 and outputs the gradation data P 4, and also uniforms the light amount variation of the light emitted from the LCS ′ pixel row described later. It has a function to compensate for
- the correction data memory 21 stores the correction data P3 calculated from the light amount variation information of the light emitted from the LCS pixel array, which will be described later, and outputs the correction data P3 to the shading correction circuit 20.
- the conversion table 16 as conversion means receives the gradation data P 4 and converts the inputted gradation data P 4 into corrected gradation data P 6 so as to correct the non-linearity of the exposure density. Output.
- the conversion table 16 is composed of a plurality of conversion tables as shown in the figure. Here, as an example, the conversion table 16 is composed of seven steps from a conversion table 16a to 16g.
- the conversion tables 16a to 16g receive gradation data P4 and are selectively switched by a switching signal P11 output from a switching circuit 13 described later. Outputs data P6.
- the gradation data P 4 is gradation data composed of three data of three primary colors of light: red (hereinafter abbreviated as R), green (hereinafter abbreviated as G), and blue (hereinafter abbreviated as B).
- the grayscale data P4 for each color is normally composed of 8 bits. Therefore, the conversion table 16 is composed of three different conversion tables for each of RGB corresponding to the gradation data P4. That is, although not shown, the actual conversion table 16 includes a plurality of conversion tables 16a to 16g for each of RGB.
- Each of the conversion tables 16a to 16g corresponds to the fact that the gradation data P4 is usually 8 bits and can express 256 gradations. This is composed of 256 types of corrected gradation data P 6. It is preferable that the conversion table 16 be constituted by a rewritable nonvolatile memory.
- the microcomputer 2 controls the input I / F 4 and sequentially inputs the image data P 2 to the shading circuit 20.
- image data from digital cameras and the like is often compressed data such as JPEG, but in that case, the uncompressed data can be expanded and printed out using the calculation function of the microcomputer 2. It is preferable to convert the data into data and input it to the shading circuit 20.
- the input image data P2 is temporarily stored in a memory circuit such as a RAM (not shown). For example, after storing one screen of image data, the image data P2 is sequentially input to the shading circuit 20. May be.
- the microcomputer 2 outputs the switching data P5 based on the temperature data P1 from the temperature detecting unit 3.
- the switching circuit 13 receives the switching data P5, decodes it internally, outputs the switching signal P11, and outputs one of the plurality of conversion tables 16a to l6g included in the conversion table 6. Select. The details of the operation of selecting the conversion table 16 will be described later.
- the shading circuit 20 corrects the light amount of the input image data P2 based on the correction data P3 from the correction data memory '21, and sequentially outputs corrected gradation data P4. I do. The detailed operation of the shading circuit 20 will be described later.
- the conversion table 16 nonlinearly corrects the gradation data P4 according to any of the selected conversion tables 16a to 16g, and outputs corrected gradation data P6.
- the corrected gradation data P converted by the conversion table 16 Assuming that 6 is output in the order of R, G, and B for each line, the LCS drive circuit 7 performs LCS in the order of R, G, and B for each line based on the corrected gradation data P6. Outputs drive signal P7.
- the LCS 9a is driven by the LCS drive signal P7 line by line in the order of R, G, and B to perform an exposure operation. That is, the LCS 9a controls ON / OFF of each pixel based on the corrected gradation data P6, changes the opening time of each pixel, changes the exposure amount to the photosensitive material 10, and changes the exposure time. Achieving key exposure.
- the gradation data P 4 input to the conversion table 16 is a signal whose light amount has been corrected by the shading correction circuit 20, the correction data which is the output of the conversion table 16 for correcting the non-linearity of the exposure density is used.
- the gradation data P6 is data on which the light amount correction of the shading correction circuit 20 is superimposed. Accordingly, the LCS 9a exposes the photosensitive material 10 by the corrected gradation data P6 on which the light amount correction and the non-linear correction of the exposure density are superimposed.
- the LED unit 9b sequentially turns on LEDs (not shown) of RGB three colors based on the LED drive signal P9 in synchronization with the LCS 9a. That is, when the LCS 9a is operating based on the R corrected gradation data P6, the LED unit 9b turns on the R LED, and the LCS 9a outputs the G corrected gradation data P The LED of G is turned on when the operation is performed on the basis of 6, and the LED of B is turned on when the LCS 9a operates based on the corrected gradation data P of B. As a result, the exposure of the three colors overlaps on the photosensitive material 10, and a full-color print is realized.
- the gradation data P 4 of the second line from the shading correction circuit 20 is output in the order of R, G, and B.
- the LCS 9a executes the exposure of the second line again in the order of R, G, and B.
- the head drive unit 11 is controlled by a head control signal P 10 from the microcomputer 2, and moves the exposure head 9 in synchronization with the exposure of each line, thereby exposing the surface of the photosensitive material 10. To achieve.
- the head driving unit 11 returns the exposure head 9 to the home position again, and ends the printing operation.
- the exposure-density characteristics of the photosensitive material 10 used in the exposure apparatus 100 and the temperature characteristics of the irradiation light B output from the exposure head 9 for each RGB are shown in FIGS. 2A and 2B described above. Since the characteristics are the same as those described above, the description is omitted here.
- FIG. 6 shows an example of the corrected gradation data output from the conversion table 16 of the exposure apparatus 100.
- the conversion table 16 has a plurality of conversion tables 16 a to 16 g that can be switched according to temperature, but here, for convenience of explanation, the conversion tables 16 a to 1
- the 6d correction gradation data P 6 is illustrated and described.
- the X-axis represents the number of gradations of the gradation data P4 input to the conversion table 16.
- the grayscale data P4 since the grayscale data P4 has an 8-bit configuration, the range of the number of grayscales is 0 to 255.
- the Y-axis is the opening time during which the LCS 9 a transmits the outgoing light B, and the opening time is the value of the corrected gradation data P 6 output from the conversion table 16.
- P6a in FIG. 6 is the correction gradation data of the conversion table 16a selected when the ambient temperature near the minimum operating temperature of the exposure apparatus is around 6 ° C.
- P6b is the correction gradation data of the conversion table 16b selected when the ambient temperature is around 13.5 ° C
- P6c is the value when the ambient temperature is around 17 ° C.
- P 6 d is the correction gradation data of the conversion table 16 d selected when the ambient temperature is around 25 ° C. .
- Each of the corrected gradation data P 6 a to P 6 d is non-linear with respect to the number of gradations. As described above, this is due to the non-linear relationship between the gradation data P 4 possessed by the LCS and the exposure and the photosensitive material.
- the opening time of the corrected gradation data P 6 d is shorter than that of the corrected gradation data P 6 d, which is shown in FIG. 2B.
- the opening time corresponding to the maximum gradation data that is, 255) is called the maximum gradation opening time.
- the maximum gradation opening time of each correction gradation data P 6 a to P 6 d is read from the graph
- the maximum gradation opening time of the correction gradation data P 6 a is 3 ms
- the maximum gradation opening time of 6 b is 2.7 mS
- the maximum gradation opening time of the corrected gradation data P 6 c is 2.55 mS
- the control opening time is 2.3 ms.
- the maximum gradation opening time (3 ms) of the corrected gradation data P6a which is the longest maximum gradation opening time among the maximum gradation opening times, is defined as the maximum opening time as shown in the figure. Define.
- exposure apparatus 100 has seven conversion tables 16a to 16g, and each conversion table is switched corresponding to seven temperature ranges T1 to T7. Also, the seven temperature ranges ⁇ 1 to ⁇ 7 indicate that T1 is the lowest temperature. Let T 7 be the highest temperature.
- the switching operation of the conversion table in the exposure apparatus 100 is mainly performed by the microcomputer 2, and the operation flow is the same as that of FIG. 1 except that the conversion tables to be switched are the conversion tables 16 a to 16 g. Since this is the same as that shown in FIG. 4, its description is omitted here.
- the exposure amount change range is equally divided, and each of the divided areas is divided by each of the conversion tables 16a to 16g. Is adopted.
- the exposure apparatus 100 is also set so that the exposure amount change range for each temperature region in which the power is increased is substantially equally divided.
- FIG. 7 shows an example of the exposure timing in the exposure apparatus 100.
- P7a is a mask signal included in the LCS drive signal P7
- P7b is an exposure signal included in the LCS drive signal P7.
- the period of the logic "1" of the mask signal P7a is a mask time.
- the mask time is a period during which an OFF signal is applied to each pixel of the LCS 9a, light is cut off, and each pixel is reset.
- the period of the logic "1" of the exposure signal P7b is the exposure time.
- each pixel of the LCS 9a is turned on according to the opening time based on the corrected gradation data P6, and transmits the light to output the outgoing light B.
- the total of the mask time and the exposure B time is one line printing time for exposing one line to the photosensitive material 10.
- the printing time for one image is the value obtained by multiplying the printing time for one line by the number of lines to be exposed, and then multiplying by three (from three exposures with RGB). That is, if the printing time for one line is constant, the printing time for exposing one image is also constant, and if the printing time for one line changes, the printing time for one image also changes in proportion.
- the exposure time is the maximum gradation data of gradation data P 4 (gradation number 2 It is necessary to set to include the maximum gradation opening time of LCS 9a corresponding to 55).
- the ON time and the OFF time of the LCS 9a are determined according to the correction gradation data P6 during this exposure time. For example, when the number of gradations is zero, the ON time of LCS 9a is zero (that is, the entire OFF time), and when the number of gradations is 255, the LC
- FIG. 7A shows the exposure timing operation when the ambient temperature is around 6 ° C. At an ambient temperature of 6 ° C, the conversion table 1
- the maximum gradation opening time of the corrected gradation data P6a which is the output of the selected conversion table 16a, is 3 ms as shown in FIG. A period of 3 ms that covers the maximum gradation opening time is secured.
- the mask time is lmS
- the maximum gradation opening time (ie, 3 ms) of the corrected gradation data P 6a output from the conversion table 16a, which is selected when the ambient temperature near the minimum operating temperature of the exposure apparatus is around 6 ° C. Is the longest opening time for LCS 9a, so this is defined as the maximum opening time.
- FIG. 7B shows an exposure timing operation near an ambient temperature of 17 ° C., and shows a case where exposure is performed using the corrected gradation data P 6 c shown in FIG.
- the exposure time is Include opening time 2.
- Figure 7C shows the exposure timing operation near an ambient temperature of 25 ° C.
- FIG. 6 shows a case where exposure is performed using the corrected gradation data P 6 d shown in FIG.
- the exposure time is the maximum gradation opening time. Including a 2.4 ms period.
- the mask time is 1 ms as in FIG. 7A
- the corrected gradation data P 6 b to P 6 d are correction gradation data that are close to optimal in correcting the non-linearity of the LCS and the photosensitive material and in correcting the temperature change.
- this correction data is used, a phenomenon that the printing time changes due to a change in the ambient temperature occurs.
- the conversion table 16a to 16g in which the exposure amount change range L is equally divided is adopted, so that the conversion selected in accordance with the temperature region is performed. Since the exposure amount variation range over which the tables 16a to 16g are equal is uniform, the error in the correction amount is uniform and the error can be reduced regardless of which conversion table is selected. In addition, the number of divisions can be reduced in an area where the change in the exposure amount is gentle (that is, a high-temperature area).
- the present invention it is possible to provide an exposure apparatus that can achieve visually desirable gradation expression while suppressing the influence of temperature change even when the ambient temperature changes, and can output stable photographic image quality.
- portable exposure tools that are taken out and used outdoors are easily affected by the ambient temperature.
- the effect of the present invention is extremely large.
- the division of the conversion table 16 is described only for the exposure temperature characteristics of R.
- the conversion table 6 can be similarly divided and corrected for the exposure temperature characteristics of G and B. Needless to say.
- FIG. 8 shows the configuration of still another exposure apparatus 200 according to the present invention.
- the conversion table 26 is configured by a plurality of conversion tables as shown in the figure.
- the conversion table 26 includes seven steps of conversion tables 26a to 26g.
- Each of the conversion tables 26a to 26g receives the gradation data P4 and is selectively switched by a switching signal P11 output from a switching circuit 13 described later. Outputs the corrected gradation data P6.
- the gradation data P 4 is gradation data composed of three data of three primary colors of light, red (hereinafter abbreviated as R), green (hereinafter abbreviated as G), and blue (hereinafter abbreviated as B).
- the grayscale data P4 is usually composed of 8 bits. Therefore, the conversion table 26 is composed of three conversion tables that are different for each of RGB in correspondence with the gradation data P4. That is, although not shown, the actual conversion table 26 includes a plurality of conversion tables 26 a to 26 g for each of RGB.
- each of the conversion tables 26 a to 26 g corresponds to the fact that the gradation data P 4 is usually 8 bits and can express 256 gradations. 4 is converted.
- the correction gradation data is composed of 256 gradation steps P 6. It is preferable that the conversion table 26 is constituted by a rewritable nonvolatile memory.
- the power switch (not shown) of the exposure apparatus 200 is turned on, and each block from the power supply section 12 is turned on.
- the microcomputer 2 performs an initialization process to initialize each block.
- the head driving unit 11 moves the exposure head 9 to the home position and sets the exposure head 9 in a stamped state.
- an external electronic device for example, a digital camera or the like
- the microcomputer 2 controls the input I / F.4 to sequentially input the image data P2.
- image data from a digital camera or the like is often compressed data such as JPEG.
- the gradation data P4 which is an input and output, is once input to the microcomputer 2 and the microcomputer 2 It is preferable to convert the compressed data into non-compressed data that can be printed and input to the conversion table 26. Also, the inputted gradation data P 4 is temporarily stored in a memory circuit (not shown) including a RAM or the like. For example, after storing one screen of image data, the inputted gradation data P 4 is sequentially inputted to the conversion table 26. good.
- the microcomputer 2 outputs the switching data P5 based on the temperature data P1 from the temperature detecting unit 3.
- the switching circuit 13 receives the switching data P5, decodes it internally, outputs the switching signal P11, and outputs one of the plurality of conversion tables 26a to 26g built in the conversion table 26. Select. The details of the operation of selecting the conversion table 26 will be described later.
- the conversion table 26 selects the inputted gradation data P4, nonlinearly corrects it by using any of the conversion tables 26a to 26g, and outputs corrected gradation data P6.
- the LCS drive circuit 7 outputs the corrected gradation data P 6 Based on this, the LCS drive signal P7 is output for each line in the order of R, G, and B.
- the LCS 9a is driven by the LCS drive signal P7 for each line in the order of R, G, and B to perform an exposure operation. That is, the LCS 9a determines each pixel based on the corrected gradation data P6. ONZOFF control is performed, and the exposure time to the photosensitive material 10 is changed by varying the opening time of each pixel, thereby realizing gradation exposure.
- the LED unit 9b sequentially turns on LEDs (not shown) of RGB three colors based on the LED drive signal P9 in synchronization with the LCS 9a. That is, when the LCS 9a is operating based on the R corrected gradation data P6, the LED unit 9b turns on the R LED, and the LCS 9a outputs the G corrected gradation data P The LED of G is turned on when the operation is performed on the basis of 6, and the LED of B is turned on when the LCS 9a operates based on the corrected gradation data P of B. As a result, the exposures of the three colors overlap on the photosensitive material 10, and a full-color print is realized.
- the gradation data P 4 of the second line from the input I 4 is output in the order of R, G, B.
- the conversion table 26 outputs the second line of corrected gradation data P 6 in the order of R, G, and B based on the gradation data P 4.
- LCS 9a performs the second line exposure again in the order of R, G, and B.
- the head driving unit 11 is controlled by a head control signal P 10 from the microcomputer 2, moves the exposure head 9 in synchronization with the exposure of each line, and moves the exposure head 9 to the surface of the photosensitive material 10. Realize exposure.
- the head driving unit 11 returns the exposure head 9 to the home position again, and ends the printing operation.
- the exposure-density characteristics of the photosensitive material 10 used in the exposure apparatus 200 and the temperature characteristics for each RGB of the irradiation light B output from the exposure head 9 are shown in FIGS. 2A and 2B described above. Since the characteristics are the same as those shown, the description is omitted here.
- the correction gradation data output from the conversion table 26 of the exposure apparatus 200 is the same as the conversion table 16 of the exposure apparatus 100 shown in FIG. 6, and therefore the description is omitted here.
- exposure apparatus 200 has seven conversion tables 26a to 26g, and each conversion table is switched corresponding to seven temperature ranges T1 to T7. In the seven temperature ranges ⁇ 1 to ⁇ 7, it is assumed that T1 is the lowest temperature and ⁇ 7 is the highest temperature.
- the switching operation of the conversion tables in the exposure apparatus 200 is mainly performed by the microcomputer 2, and the operation flow is the same as that of FIG. 4 except that the conversion tables to be switched are the conversion tables 26a to 26g. The description is omitted here.
- the exposure amount change range is equally divided, and each of the divided areas is subjected to power conversion by each of the conversion tables 26a to 26g. Is adopted. That is, also in the exposure apparatus 200, the exposure amount change range for each of the covered temperature regions is set to be substantially equally divided.
- FIG. 9 shows an example of exposure timing in the exposure apparatus 200.
- FIG. 9A shows an exposure timing operation near an ambient temperature of 6 ° C.
- P 7 a 1 is a mask signal included in the above-described LCS drive signal P 7
- P 7 a 2 is an LCS drive signal
- P 7 is an exposure signal included in FIG.
- the period of the logic "1" of the mask signal P7a1 is a mask time.
- data is transferred to the LCS 9a based on the corrected gradation data P6, and at the same time, an OFF signal is applied to each pixel of the LCS 9a, light is cut off, and each pixel is reset.
- Period The period of the logic "1" of the exposure signal P7a2 is the exposure time.
- Each pixel 9a is turned on according to the opening time based on the corrected gradation data P6, and transmits the light to output the outgoing light B.
- the sum of the mask time and the exposure time is the printing time for one line to perform exposure of one line on the photosensitive material 10, and the printing time for one line is multiplied by the number of lines to be exposed.
- the value three times as many times as exposure is the printing time for one image. That is, if the printing time for one line is constant, the printing time for exposing one image is also constant, and if the printing time for one line changes, the printing time for one image also changes in proportion. .
- the exposure time needs to be set so as to include the maximum gradation opening time of the LCS 9a corresponding to the maximum gradation data (gradation number 255) of the gradation data P4. This is because in the exposure time, the ON time and the OFF time of the LCS 9a are determined according to the correction gradation data P6. For example, when the number of gradations is zero, the ON time of LCS 9a is zero (that is, the OFF time), and when the number of gradations is 255, the ON time is the maximum gradation opening time.
- FIG. 9A shows the exposure timing operation when the ambient temperature is around 6 ° C. In this case, the conversion table 26 a is selected as described above, and the output is the corrected gradation data P 6 a Exposure is performed.
- the exposure time is the maximum gradation opening time.
- a period of 3 ms including time is secured.
- the printing time for one line is the sum of the mask time and the maximum gradation opening time.
- the correction gradation data which is the output of the conversion table 36a in which the ambient temperature near the minimum operating temperature of the exposure apparatus is selected near 6 ° C.
- the maximum gradation opening time of P6a (that is, 3 ms) is the longest opening time among the maximum gradation opening times, and this time is defined as the maximum opening time.
- Figure 9B shows the exposure timing operation at an ambient temperature of around 13.5 ° C.
- P7b1 is the mask signal included in the LCS drive signal P7
- P7b2 Is an exposure signal included in the LCS drive signal P7.
- the maximum gradation opening time of the correction gradation data P 6 b which is the output of the selected conversion table 26 b is 2.7 ms as described above with reference to FIG.
- the exposure time of b2 secures a period of 2.7 ms including this maximum gradation opening time. That is, the maximum gradation opening time of the exposure signal P 7 b 2 around the surrounding temperature of 13.5 ° C is the maximum gradation opening time of the exposure signal P 7 a 2 near the surrounding temperature of 6 ° C (max.
- Opening time 0.3 ms shorter than 3 ms).
- the mask signal P 7 bl compensates for the shortened exposure signal P 7 b 2, and is 1.3 ms longer than the mask signal P 7 al at an ambient temperature of about 6 ° C, which is 1.3 ms longer. Is set.
- FIG. 9C shows an exposure timing operation at an ambient temperature of about 25 ° C.
- P 7 d1 is a mask signal included in the above-described LCS drive signal P 7, and P 7 d 2 is an LCS drive signal P 7 is an exposure signal included in FIG.
- the exposure signal P 7 d secures a period of 2.3 ms including this maximum gradation opening time. That is, the maximum gradation opening time of the exposure signal P 7 d 2 around the ambient temperature of 25 ° C. is the ambient temperature 6.
- Exposure signal in the vicinity of C Maximum gradation opening time of P7a2 (Maximum opening time: 3 0.7 m S shorter than m S).
- the mask signal P 7 d 1 compensates for the shortened exposure signal P 7 d 2, and is 0.7 ms longer than the mask signal P 7 al at an ambient temperature of about 6 ° C, which is 0.7 ms longer. Is set.
- the difference in the maximum gradation opening time of each conversion table caused by the conversion table 26 being switched according to the temperature change is determined by making the mask time different.
- the feature is that the printing time of one line is matched.
- the LCS drive signals P 7 a, P 7 b, and P 7 d corresponding to the corrected gradation data P 6 a, P 6 b, and P 6 d output from the conversion table 26 are shown. Although only shown, the same applies to other LCS drive signals. All the LCS drive signals P7 compensate for the difference in the maximum gradation opening time of the corrected gradation signal P6, which is the output of the selected conversion table 26, by making the mask time different, and make one line.
- the feature of the exposure device 300 is that the mask time in each of the conversion tables 26a to 26g is fixed, and a gradation closing time is provided in addition to the maximum gradation opening time, so that one line Is to match the printing time of FIG. 10 shows the configuration of the exposure apparatus 300.
- the block diagram of the exposure apparatus 300 and the basic operation thereof are the same as those of the exposure apparatus 200, so that the description thereof will be omitted.
- the change range of the exposure amount is equally divided, and each of the divided areas is divided by each of the conversion tables 26 a to 26 g.
- the method is adopted. That is, the exposure apparatus 300 is also set so that the exposure amount change range with respect to each of the temperature regions in which the power is increased is substantially equally divided.
- FIG. 11 shows an example of exposure timing in the exposure apparatus 300.
- FIG. 11A shows an exposure timing operation at an ambient temperature of about 6 ° C.
- P 7 a 1 is a mask signal included in the aforementioned LCS drive signal P 7
- P 7 a 2 is an LCS drive signal Exposure signal included in P7. Note that the exposure timing operation near an ambient temperature of 6 ° C. is the same as that in FIG.
- Figure 11B shows the exposure timing operation at an ambient temperature of around 13.5 ° C
- P7 bl is the mask signal included in the LCS drive signal P7
- P7 b2 is the LCS This is an exposure signal included in the drive signal P7.
- the maximum gradation opening time of the corrected gradation data P6b which is the output of the selected conversion table 36b, is 2.7 ms as described above with reference to FIG.
- the exposure signal P 7 b 2 is equal to the time difference between the maximum opening time (3 mS) and the maximum gradation opening time (2.7 mS) by the LCS driving circuit 7. .
- a gradation closing time of 3 ms is provided.
- the exposure time by the exposure signal P7b2 is 3 mS, which is the maximum gradation opening time of 2.7 mS plus the gradation closing time of 0.3 mS, and the ambient temperature is 6 ° C.
- the exposure time in the vicinity (that is, the maximum opening time: 3 ms) is matched.
- the mask time by the mask signal P 7 b 1 is equal to the mask signal P 7 a 1 at an ambient temperature of around 6 ° C. Lm S is set.
- the position of the gradation closing time may be set before the maximum gradation opening time.
- the gradation closing time is the time during which the OFF signal is applied to each pixel of the LCS 9a and the light is cut off.
- FIG. 11C shows an exposure timing operation near an ambient temperature of 25 ° C.
- P 7 d 1 is a mask signal included in the aforementioned LCS drive signal P 7
- P 7 d 2 is an LCS drive signal. This is an exposure signal included in the drive signal P7.
- the maximum gradation opening time of the correction gradation data P 6 d which is the output of the selected conversion table 26 d is 2.3 ms as described above with reference to FIG.
- the exposure signal P 7 d 2 is equal to the time difference between the maximum gradation opening time (3 mS) and the maximum gradation opening time (2.3 mS) by the LCS driving circuit 7.
- a gradation closing time of 7 ms is provided.
- the exposure time by the exposure signal P7d2 is 3 mS, which is the maximum gradation opening time of 2.3 mS and the gradation closing time of 0.7 mS, and the ambient temperature is 6 ° C.
- the exposure time in the vicinity (that is, the maximum opening time: 3 mS) is matched.
- the mask time by the mask signal P 7 d 1 is set to 1 ms, which is equal to the mask signal P 7 a 1 at an ambient temperature of about 6 ° C.
- the LCS drive signal P 7 corresponding to each corrected gradation data P 6a, P 6b, and P 6d output from the conversion table 26
- All LCS drive signals P7 have a time equal to the time difference between the maximum aperture time (3 ms) and the respective maximum grayscale aperture time of the corrected grayscale signal P6 output from the selected conversion table 26.
- An adjustment closing time is set, and control is performed so that the printing time of one line matches.
- the difference in the maximum gradation opening time due to the selection of the conversion table 26 is adjusted by adding the gradation closing time, so that the mask time can be kept constant and the maximum gradation of the conversion table 26 can be maintained.
- the printing time for one line can be matched without correcting the opening time. Further, it is possible to provide an exposure apparatus in which the exposure control is simple and the printing time is always constant.
- the feature of the exposure apparatus 400 is that the mask time in each conversion table is fixed, and the maximum gradation opening time in each conversion table is matched with the maximum opening time to match the printing time of one line. .
- the configuration of the exposure apparatus 400 is shown in FIG. The same components as those of the exposure apparatus 1 shown in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.
- the shading correction circuit 20 as the light amount correction means inputs the image data ⁇ 2 from the input ⁇ ZF 4 and uniformly corrects the light amount variation of the outgoing light B from the pixel array of the LCS 9a described later. It has a function and outputs gradation data P4.
- the correction data memory 21 stores correction data P3 calculated from light amount variation information of the light B emitted from the pixel row of the LCS 9a described later, and outputs the correction data P3 to the shading correction circuit 20.
- the conversion table 36 as a conversion means receives the gradation data P 4 output from the shading correction circuit 20 and corrects the inputted gradation data P 4 to correct the nonlinearity of the exposure density. Change to key data P 6 Output.
- the conversion table 36 is configured by a plurality of conversion tables as shown in the figure. Here, as an example, the conversion table 36 is configured by seven steps of the conversion tables 36a to 36g. Each of the conversion tables 36 a to 36 g receives gradation data P 4 and is selectively switched by a switching signal P 11 output from the switching circuit 13, and the selected conversion table is corrected. Outputs gradation data P6.
- the microcomputer 2 executes an initialization process and executes each block. Initialize the lock. Along with the initialization, the head driving unit 11 moves the exposure head 9 to the home position, and enters a stamping state.
- an external electronic device for example, a digital camera or the like
- the microcomputer 2 controls the input IZF 4 to sequentially input the image data P 2 to the shading correction circuit 20. .
- image data from a digital camera or the like is often compressed data such as JPEG, but in this case, the arithmetic function of the microcomputer 2 converts the compressed data to uncompressed data that can be printed and output. Then, it is preferable to input the result to the shading correction circuit 20.
- the input image data P2 is temporarily stored in a memory circuit (not shown) such as a RAM, which is not shown. For example, after storing one screen of image data, the image data P2 is sequentially input to the shading correction circuit 20. Is also good. '
- the microcomputer 2 outputs the switching data P5 based on the temperature data P1 from the temperature detecting unit 3.
- the switching circuit 13 receives the switching data P5, decodes the data internally, outputs a switching signal P11, and outputs any one of the plurality of conversion tables 36a to 36g included in the conversion table 36.
- the shading correction circuit 20 converts the input image data P2 based on the correction data P20 from the correction data memory 21. The light amount is corrected, and the corrected gradation data P4 is sequentially output. The detailed operation of the shading correction circuit 20 will be described later.
- the LCS driving circuit 7 The LCS drive signal P7 is output in the order of R, G, and B for each line based on the data P6.
- the LCS 9a is driven by the LCS drive signal P7 line by line in the order of R, G, and B to perform an exposure operation.
- LCS 9a the corrected gradation data? Based on 6, ONZO F F control of each pixel is performed, and the exposure time to the photosensitive material 10 is changed by varying the aperture time of each pixel to realize gradation exposure.
- the gradation data P 4 input to the conversion table 36 is a signal whose light amount has been corrected by the shading correction circuit 20, the gradation data P 4 is an output of the conversion table 36 for correcting the non-linearity of the exposure density.
- the positive gradation data P6 is data on which the light amount correction of the shading correction circuit 20 is superimposed.
- the LCS 9a exposes the photosensitive material 10 with the corrected gradation data P6 on which the light amount correction and the non-linear correction of the exposure density are superimposed. Subsequent operations are the same as those of the above-described exposure apparatus 200, and a description thereof will not be repeated.
- FIG. 13 shows an example of the supplementary data P6 output from the conversion table 36 of the exposure apparatus 400.
- the conversion table 36 has a plurality of conversion templates 36 a to 36 g that can be switched according to temperature, but here, for convenience of explanation, the conversion tables 36 a to 3
- the corrected gradation data P6A to P6D, which is the output of 6d, will be illustrated and described.
- the X axis represents the number of gradations of the gradation data P4 input to the conversion table 36.
- the range of the gradation number is 0 to 255.
- Y axis is LCS 9 a is the aperture time for transmitting the outgoing light B, and the aperture time is the value itself of the correction gradation data P 6 output from the conversion table 36.
- P 6 A is the conversion selected when the ambient temperature near the minimum operating temperature of the exposure apparatus 400 is around 6 ° C.
- the correction gradation data in Table 36 a, P 6 B Is the conversion gradation data of the conversion table 36 b selected when the ambient temperature is around 13.5 ° C, and P 6 C is the conversion table selected when the ambient temperature is around 17 ° C.
- the correction gradation data of 36c, and P6D is the correction gradation data of the conversion table 36d selected when the ambient temperature is around 25 ° C.
- Each of the corrected gradation data P 6 A to P 6 D is nonlinear with respect to the number of gradations.
- the opening time of the corrected gradation data P 6 D is shorter than that of the corrected gradation data P 6 D.
- This is for correcting the temperature characteristics of LCS 9a. In other words, in a low temperature region, the amount of exposure of the LCS 9a is small, so that the opening time is increased to perform correction, and in a region of high temperature, the amount of exposure of the LCS 9a is large, so that the opening time is reduced. Correction has been performed.
- the change range of the exposure amount is equally divided, and each of the divided areas is divided by each of the conversion tables 36a to 36g.
- the method is adopted. That is, the exposure apparatus 400 is also set so that the exposure amount change range with respect to each of the temperature regions in which the power is increased is substantially equally divided.
- FIG. 13B gradation exposure was performed using the corrected gradation data P 6 D of the conversion table 36 d shown in FIG. 13A (that is, the corrected gradation data at an ambient temperature of 25 ° C.).
- Number of gradations and density in photosensitive material An example of the relationship will be described.
- the X-axis is the number of gradations of the gradation data P4 input to the conversion table 36
- the Y-axis is the density of the photosensitive material.
- the density of the photosensitive material is almost proportional to the density data other than the vicinity of the minimum value and the maximum value of the gradation data P4 (that is, the range of 16 to 240).
- the conversion table 36 corrects the nonlinear relationship between the LCS gradation data and the exposure amount and the nonlinear relationship between the exposure amount and the density of the photosensitive material, and converts the gradation data P4 into the gradation data P4. This is because the tone is adjusted so that it is almost appropriate.
- FIG. 14 shows the relationship between the corrected gradation data P 6 A to P 6 D and the density of the photosensitive material near the upper limit of the gradation data P 4.
- Fig. 14A is an enlarged view near the upper limit of the gradation data P4 of Fig. 13A (gradation range 2 24 to 255)
- Fig. 14B is the gradation data of Fig. 13B. It is an enlarged view near the upper limit of P4 (gradation range 2 24 to 255).
- the corrected gradation data P6A increases almost linearly with respect to the gradation data P4, and the maximum gradation aperture corresponding to the maximum gradation data 255 of the gradation data P4.
- the time is 3 ms.
- the maximum gradation opening time of the corrected gradation data P 6 A is defined as the maximum opening time.
- the corrected gradation data P 6 B to P 6 D increase almost in parallel in the region where the gradation data P 4 is 240 or less, but the gradation data P 4 is 2 4 0 to 25 In the area 5, convergence proceeds as shown in the figure, and the gradation data P 4 matches the maximum opening time (3 ms) described above at the maximum gradation opening time corresponding to the maximum gradation data 255. I have.
- the dotted lines P 6 B, to P 6 D ′ are obtained when the corrected gradation data P 6 B to P 6 D increase linearly and in parallel even in the gradation range 240 to 255.
- This is virtual correction gradation data.
- the virtual correction gradation data P 6 B to P 6 D are correction gradation data that is closer to optimal in correcting the nonlinearity and correcting the temperature change with respect to the gradation data P 4.
- Gradation The maximum grayscale opening time corresponding to the maximum grayscale data (number of grayscales 2 5 5) of data P4 is approximately 2.7 mS for virtual correction grayscale data P6B 'from Fig. 14A.
- the virtual correction gradation data P 6 C is about 2.55 ms
- the virtual correction gradation data P 6 D is about 2.3 ms.
- FIG. 14B an example of the difference between the density when performing gradation exposure with the corrected gradation data P 6 D and the density when performing gradation exposure with the virtual correction gradation data P 6 D ′ will be described.
- the gradient of the opening time is large in the gradation range of 240 to 255, so that the white density tends to be slightly strong (that is, the overexposure tends to be slightly conspicuous).
- the gradient of the opening time is almost the same as that in the gradation range of 240 or less even in the gradation range of 240 to 255.
- White density increases relatively spontaneously, and overexposure is not noticeable.
- the corrected gradation data P 6 D Since the gradation data in the gradation range with a large number of gradations (240 to 255) does not affect the change in the density of the halftone, which greatly affects the image quality, the corrected gradation data P 6 D The difference between the actual image and the virtual corrected tone data P 6 D 'is small. Further, the tendency of the white density to become stronger is further reduced by the operation of the shading correction circuit 20 described later, so that the influence of the corrected gradation data on the image in the exposure apparatus 400 is almost negligible. No.
- the area of 240 or less in the gradation data P 4 indicates that the relationship between the gradation data P 4 and the opening time of the LCS 9 a substantially matches the gradation density in the photosensitive material 10. This is the first gradation range. Further, in the gradation data P4, the area of 240 to 255 with a large number of gradations indicates that the relationship between the gradation data P4 and the opening time of the LCS 9a is the same as the gradation density in the photosensitive material '10. This is the second gradation range that does not match.
- the areas of the first gradation range and the second gradation range are not limited to the number of gradations, but are arbitrarily determined according to the characteristics of the LCS 9a and the characteristics of the photosensitive material 10 to be used. thing Can do. Also, the first gradation range and the second gradation range may be set differently for each of the conversion tables 36a to 36g. Further, in FIG. 17, the corrected gradation data P 6 A to P 6 D which are the outputs of the conversion tables 36 a to 36 d are illustrated and described, but the other conversion tables 36 e to 3 d The same applies to 6 g. In the exposure apparatus 400, the maximum gradation opening time of all the conversion tables 36a to 36g is matched with the maximum gradation opening time (that is, the maximum opening time) of the conversion table 36a.
- FIG. 15 shows an example of the exposure timing operation of the exposure apparatus 400.
- P7a1 is a mask signal included in the aforementioned LCS drive signal P7
- P7a2 is an exposure signal included in the LCS drive signal P7.
- the period of the logic "1" of the mask signal P7a1 is a mask time.
- data is transferred to the LCS 9a based on the corrected gradation data P6, and the OFF signal is applied to each pixel of the LCS 9a to shut off the light and reset each pixel.
- Period The period of the logic "1" of the exposure signal P7a2 is the exposure time.
- each pixel of LCS 9a is turned on according to the opening time based on the corrected gradation data P 6, transmits light, and outputs outgoing light B.
- the sum of the mask time and the exposure time is a one-line printing time for exposing the photosensitive material for 101 lines.
- FIG. 15A shows the exposure timing operation when the ambient temperature is around 6 ° C. The exposure timing is the same as that of FIG. 9A shown in the exposure apparatus 200 described above. Therefore, detailed description is omitted.
- Figure 15B shows the exposure timing operation at an ambient temperature of around 13.5 ° C.
- P7b1 is a mask signal included in the aforementioned LCS drive signal P7
- P7b2 is an exposure signal included in the LCS drive signal P7.
- the correction gradation that is the output of the selected conversion table 36 b Since the maximum gradation opening time of data P 6 B is 3 ms, which is the same as the maximum gradation opening time of correction gradation data P 6 A as shown in Fig. 14A, the exposure time is the maximum gradation opening time.
- FIG. 15C shows an exposure timing operation near an ambient temperature of 25 ° C.
- P7d1 is a mask signal included in the aforementioned LCS drive signal P7
- P7d2 is an exposure signal included in the LCS drive signal P7.
- the maximum gradation opening time of the correction gradation data P 6 D which is the output of the selected conversion table 36 d is the maximum of the correction gradation data P 6 A as shown in FIG. 14A. Since the exposure time is 3 ms, which is the same as the opening time, the exposure time secures a period of 3 ms including this maximum gradation opening time.
- the LCS drive signals P 7 a, P 7 b, and P 7 d corresponding to the corrected gradation data P 6 A, P 6 B, and P 6 D output from the conversion table 36 are shown. Only the same is shown, but the same applies to other selected LCS drive signals. That is, since the maximum gradation opening time of all the corrected gradation data P 6 A to P 6 G matches the maximum opening time (that is, 3 ms), it corresponds to each conversion table 36 a to 36 g. All the exposure timing operations are the same as in Fig. 15A, and the printing time for one line is all the same.
- each of the maximum gradation opening times of the correction gradation data P 6 A to P 6 G of each conversion table 36 a to 36 g is set to Since the convergence is made in the two gradation ranges and the maximum aperture time is matched, it is possible to provide an exposure apparatus in which the printing time is always constant even when the ambient temperature changes.
- the mask time is constant and the closing time is not required, the mask time control and the exposure time control are simplified, the circuit scale of the microcomputer 2 and the LCS drive circuit 7 is reduced, and the exposure apparatus achieves low cost. Can be provided.
- FIG. 16 shows the pixel arrangement of the LCS 9a, the light amount distribution characteristics of the outgoing light B output from the LCS 9a, the operation of the shading correction circuit 20, and the shading correction circuit 20 and the conversion table 36. This shows the cooperative operation with.
- the LCS 9a has a structure in which two glass substrates 30a and 30b are bonded together with a slight gap.
- Transparent electrodes (not shown) are formed on the glass substrates 30a and 3Ob, A liquid crystal material (not shown) is sealed in the gap between the substrates 30a and 30b.
- the linear pixel row 31 formed by the transparent electrodes includes a plurality of substantially rectangular pixels 3 la.
- the shape of the pixel 31a is not limited, and may be, for example, a substantially parallelogram inclined at a predetermined angle. Further, the pixel rows 31 may be arranged in a staggered manner.
- the portion other than the pixel column 31 is covered with a light-shielding film (not shown) made of a material such as a mask, the portion other than the pixel column 31 blocks light and blocks the pixel column 31. Only a plurality of pixels 31a to be formed have a structure that transmits light. Then, the emitted light A from the LED unit 9b that passes through the plurality of pixels 31a is applied to the transparent electrodes formed on the glass substrates 30a and 30b by using the encapsulated liquid crystal material. It is transmitted or cut off according to the applied drive voltage. As a result, 1 ⁇ 0 39 & has a function as an optical shutter for optically modulating the outgoing light A in accordance with the 1.3 drive signal P7.
- a driving IC for applying a driving voltage to the transparent electrode is mounted on the glass substrate 30a or 30Ob of the LCS 9a, but is omitted here.
- the number of pixels and the like may be arbitrarily determined according to the specifications of the exposure apparatus. '
- the light amount graph 40 is an example of the light amount distribution of the outgoing light B output from the pixel 31a when all the pixels 31a of the pixel column 31 of the LCS 9a are driven under the same conditions.
- the X axis corresponds to the pixel column 31 of the LCS 9a, and the Y axis is the amount of light.
- the light amount output from the pixel column 31 has a variation for each pixel 31a. There are various factors in light intensity variation, and there are differences between exposure heads. It is. In the light intensity graph 40, near the left and right ends (excluded pixel area), a decrease in light intensity and a large change in light intensity can be seen.
- the main factors are the light modulation characteristics near both ends of the LCS 9a pixel column. Can be considered.
- the main cause of the change in light modulation characteristics near both ends of the pixel column is thought to be due to the sealing material (not shown) provided near both ends of the pixel column due to the structure of the LCS. In other words, since the vicinity of both ends of the pixel column is close to the seal material, impurities in the sealing material and uncured resin, etc., have an adverse effect on the LCS alignment film and the liquid crystal material. It is considered that the response characteristic of the pixel changes with respect to the response characteristic near the center of the pixel column.
- the shading correction circuit 20 described above with reference to the circuit block diagram of FIG. 12 corrects the amount of light generated by the individual pixels 31 a of the LCS 9 a and reduces the density unevenness of the photosensitive material 10. Having. That is, the light quantity of each pixel of the LCS 9a is measured by a light quantity measuring device (not shown), and correction data calculated from the measured light quantity data of each pixel is stored in the correction data memory 21. The shading correction circuit 20 performs a correction operation on the input image data P 2 based on the correction data P 20 stored in the correction data memory 21, and calculates a correction value for each pixel of the LCS 9 a. Outputs key data P4.
- the corrected light amount graph 41 is an example of the result of the light amount corrected by the shading correction circuit 20.
- the effect of the shading correction circuit 20 is clear when comparing the light intensity graph 40 without light intensity correction and the corrected light intensity graph 41 with light intensity correction, and the effect of the shading correction circuit 20 is clear in most regions of the pixel column 31 of the LCS 9a.
- the light quantity variation has been greatly improved.
- Pixel row 3 The light quantity in the exclusion pixel areas at both left and right ends of 1 varies. This is an area in which the light intensity at both ends of the pixel row is large, as described above, where the light quantity decreases or changes greatly.
- the exclusion pixel area from which correction is excluded is preferably about 5 pixels at both ends of the pixel column, but may be arbitrarily changed depending on the degree of light quantity variation. Further, it is not necessary to have the excluded pixel area.
- Figure 17 shows an example of the correction data table.
- the gradation level refers to the gradation level of the image data P2 input to the shading correction circuit 20, and since the image data P2 is an 8-bit gradation signal.
- the gradation level is represented by 0 to 255. Note that the present invention is not limited to this gradation range.
- the correction data is 255 Therefore, it is output as it is as gradation data P 4.
- the image data P 2 of the maximum gradation level (255) is converted into the correction data of 25 2 and the gradation data P 2 is obtained. Output as 4.
- the image data P2 is corrected for all the pixels based on the minimum light amount F min, it is possible to reduce the light amount variation among the pixels.
- the maximum gradation number of the corrected gradation data P 6 is corrected to 240, and therefore, as shown in FIG.
- the maximum gradation opening time of 23 is about 2.1 ms in the corrected gradation data P 6 D, and the opening time does not become longer than this value.
- the corrected gradation data P6 converges in the region of 240 to 255 of the gradation data P4 (that is, the second gradation range), and the conversion table 3
- the white density generated by matching the maximum gradation opening time corresponding to the maximum gradation data (gradation number 2 5 5) of 6a to 36g with the maximum opening time of the conversion table 36a ( This is effective in suppressing the overexposure) and obtaining good images. That is, in the exposure apparatus 400 according to the present invention, each of the maximum gradation opening times corresponding to the maximum gradation data (gradation number 255 5) of the conversion tables 36 a to 36 g is converted into the conversion table 36.
- the maximum opening time of a With the operation of the shading correction circuit 20, the printing time becomes constant, the tendency that the white density becomes stronger is improved, and the density unevenness is reduced. Therefore, it is possible to realize high-quality image printing with good appearance.
- the shading correction circuit 20 is not required, and even if the light amount is not corrected, no major problem occurs on the image. The effect is great because a stable image can be printed with a constant printing time against temperature changes.
- correction data table in FIG. 17 is correction data for the light emitted from the red LED of the LED unit 9b, actually, the same applies to the light emitted from the green LED and the blue LED according to the same procedure.
- the correction data is obtained, and the obtained correction data is stored in the correction data memory 21.
- the ambient temperature changes and the conversion table Since the printing time of one line is the same even when the image is switched, the printing time on the photosensitive material is always constant, and it is possible to provide an easy-to-use exposure apparatus without giving a user a sense of incongruity.
- printing at around room temperature of 25 ° C is completed relatively quickly, but if the ambient temperature decreases, the printing time increases as the ambient temperature decreases, leading to poor operability.
- the present invention can solve this problem by keeping the printing time constant.
- the conversion table is switched in accordance with the change in the ambient temperature to correct the temperature change, even when the temperature changes, the halftone color and density are stable, and a good image can always be printed.
- the effects of the present invention are extremely large in a portable exposure apparatus to be taken out and used outdoors because it is easily affected by the ambient temperature.
- a line exposure method using a line light source and an LCS having pixels arranged in a line is assumed, and printing per predetermined area is defined as one line printing.
- the present invention is not limited to this, and can be applied to an exposure apparatus of a batch exposure method using a plurality of lines or a surface exposure method using a surface light source or a planar LCS.
- the exposure apparatus according to the present invention uses an LCS having a line light source and pixels arranged in a line, the present invention is applicable to moving the LCS along a fixed photosensitive material. It is possible to support both the method of performing exposure while moving and the method of performing exposure while moving the photosensitive material to a fixed LCS.
- the exposure apparatus may use another type of optical shutter such as PLZT instead of LCS.
- FIGS. 1, 5, 8, 10 and 12 show an exposure apparatus according to the present invention. Although a schematic configuration is shown, the present invention is not limited to this configuration.
- each circuit block is realized by a hard disk.
- FIG. 4 shows a flow chart showing the conversion table switching operation, but the present invention is not limited to the operation flow, and any operation flow that satisfies the function may be used.
- the switching of the conversion tables 6, 16, 26, and 36 is described as seven steps.
- the present invention is not limited to this, and can be performed with higher accuracy. If correction is required, the number of steps may be increased, and if high-precision correction is not required, the number of steps may be reduced.
- the maximum opening time is 3 ms
- the mask time is 1 ms
- the printing time for one line is 4 ms
- it may be arbitrarily selected according to the characteristics of the LCS 9a, the output light amount of the LED unit 9b, the sensitivity characteristics of the photosensitive material 10, and the like.
- a method for matching the printing time of one line is shown.
- the present invention is not limited to these, and a plurality of conversion means for different temperatures may be used. Any method can be applied as long as it has the same printing time per predetermined area (for example, one line) in each conversion means.
- the photosensitive material used in the exposure apparatus according to the present invention is not limited to photographic paper, silver halide instant film, and the like, and the exposure apparatus according to the present invention can be applied to a wide variety of photosensitive materials.
- a photosensitive material 10 of a type in which the color density decreases as the exposure amount increases, as seen in an instant film, for example was used.
- the present invention In the exposure apparatus according to the above, as shown in FIG. 18, it is possible to use a photosensitive material of a type in which the color density increases as the exposure amount increases. That is, in the photosensitive material shown in FIG. 18, when the exposure corresponding to the maximum gradation data is performed, the color develops black instead of white.
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EP (1) | EP1700703A1 (ja) |
JP (1) | JP4864458B2 (ja) |
WO (1) | WO2005056298A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009279852A (ja) * | 2008-05-23 | 2009-12-03 | Mst:Kk | 光照射装置における光照射駆動回路 |
JP2017071097A (ja) * | 2015-10-06 | 2017-04-13 | コニカミノルタ株式会社 | 光書込み装置及び画像形成装置 |
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JPH0698168A (ja) * | 1992-09-11 | 1994-04-08 | Konica Corp | 画像読取装置 |
JPH08227113A (ja) * | 1994-12-06 | 1996-09-03 | Noritsu Koki Co Ltd | 露光装置 |
JP2001008139A (ja) * | 1999-06-18 | 2001-01-12 | Fuji Photo Film Co Ltd | ディジタル・カメラおよびその制御方法 |
JP2001133911A (ja) * | 1999-11-04 | 2001-05-18 | Noritsu Koki Co Ltd | 画像形成装置 |
JP2002072364A (ja) * | 2000-08-23 | 2002-03-12 | Noritsu Koki Co Ltd | 画像記録装置 |
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JP2600652B2 (ja) * | 1986-06-27 | 1997-04-16 | 松下電器産業株式会社 | プリンタ装置 |
JPH01103460A (ja) * | 1987-10-19 | 1989-04-20 | Canon Inc | サーマルヘッド駆動装置 |
JP3306872B2 (ja) * | 1990-03-20 | 2002-07-24 | ミノルタ株式会社 | 電子写真作像装置 |
JPH04189062A (ja) * | 1990-11-22 | 1992-07-07 | Fuji Photo Film Co Ltd | 画像露光装置 |
JP2001171186A (ja) * | 1999-12-17 | 2001-06-26 | Copyer Co Ltd | 印刷データ用画像処理方法およびシステム |
-
2004
- 2004-12-08 EP EP04807030A patent/EP1700703A1/en not_active Withdrawn
- 2004-12-08 WO PCT/JP2004/018671 patent/WO2005056298A1/ja active Application Filing
- 2004-12-08 JP JP2005516234A patent/JP4864458B2/ja not_active Expired - Fee Related
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
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JPH0698168A (ja) * | 1992-09-11 | 1994-04-08 | Konica Corp | 画像読取装置 |
JPH08227113A (ja) * | 1994-12-06 | 1996-09-03 | Noritsu Koki Co Ltd | 露光装置 |
JP2001008139A (ja) * | 1999-06-18 | 2001-01-12 | Fuji Photo Film Co Ltd | ディジタル・カメラおよびその制御方法 |
JP2001133911A (ja) * | 1999-11-04 | 2001-05-18 | Noritsu Koki Co Ltd | 画像形成装置 |
JP2002072364A (ja) * | 2000-08-23 | 2002-03-12 | Noritsu Koki Co Ltd | 画像記録装置 |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009279852A (ja) * | 2008-05-23 | 2009-12-03 | Mst:Kk | 光照射装置における光照射駆動回路 |
JP2017071097A (ja) * | 2015-10-06 | 2017-04-13 | コニカミノルタ株式会社 | 光書込み装置及び画像形成装置 |
Also Published As
Publication number | Publication date |
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JPWO2005056298A1 (ja) | 2007-07-05 |
EP1700703A1 (en) | 2006-09-13 |
JP4864458B2 (ja) | 2012-02-01 |
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