JPH11129525A - Fluorescent printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an emission intensity of a luminous body from being influenced by various thermal conditions to the luminous body by controlling an output from a print head for exposing by means of a temperature compensating mechanism in accordance with real time information in terms of a temperature of the luminous body detected by a temperature detecting means. SOLUTION: When a film 2 is supplied to an optical exposure device 20 by a rover 11 driven by a motor 12, a controller 7 controls a dimmer filter 22 based on image information of the film 2 read by a scanner 10. As a result, an emission light of a light source 21 is tuned to be in a color balance corresponding to a color density of the image of the film 2. The optical exposure device 20 emits the tuned light to the film 2 and to a photographic paper 3 positioned on an exposure point 1 by making a permeation light based on the image information of the film 2, thereby forming the image on the film to the photographic paper 3. The photographic paper 3 having the formed image is conveyed to a developing operation section 5 by means of a paper conveying mechanism 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent printer having an exposure print head provided with a phosphor element.

[0002]

2. Description of the Related Art As the above-mentioned fluorescent printer, for example, a color printer disclosed in JP-A-6-83243 is known. In this case, a fluorescent head (corresponding to an exposure print head) is used as a fluorescent printer. A grayscale signal corresponding to the image data written in the buffer memory is supplied to the control electrode from the grid drive circuit, and is formed by the anode voltage supplied from the anode drive circuit. The phosphor head is driven by sequentially scanning the anode.

[0003]

However, in general, the phosphor (Zn: ZnO, etc.) used in the above-described fluorescent printer has a so-called quenching characteristic in which the emission intensity decreases as the environmental temperature increases. In the configuration of the fluorescent printer, the heat generated from the linear cathode used in the phosphor element is gradually accumulated in the phosphor by the continuous drive of the exposure print head, and the temperature gradually increases,
As the time elapses, the light emission intensity tends to decrease, and as a result, the print density tends to decrease, and an image as intended cannot be obtained.Moreover, heat generation from peripheral devices used near the fluorescent printer, Seasonal and regional temperature conditions of the use environment also affect the temperature of the phosphor,
There is a problem that it becomes an obstacle to obtaining the desired image, and there is room for improvement.

[0004] It is an object of the present invention to address the aforementioned disadvantages of the prior art fluorescent printers exemplified above, despite the various thermal environmental conditions, especially when the exposure printhead is driven continuously. An object of the present invention is to provide a fluorescent printer in which the intensity of light emitted from a phosphor is not affected and, as a result, a desired print is obtained.

[0005]

In order to achieve the above object, a fluorescent printer according to claim 1 of the present invention comprises a temperature detecting means for detecting the temperature of a phosphor constituting a phosphor element;
A temperature compensating mechanism for controlling the output from the exposure print head in accordance with the temperature detection result.

[0006] In order to have such a characteristic configuration,
In the fluorescent printer according to the first aspect of the present invention, the temperature of the phosphor is detected at predetermined time intervals by the temperature detecting means, and a separately provided temperature compensation mechanism outputs the output from the exposure print head. Since the control is performed in accordance with the result of temperature detection by the temperature detecting means, in other words, real-time information on the temperature of the phosphor, the emission intensity from the phosphor is affected by various thermal environmental conditions for the phosphor and the exposure print head. Is not affected by the rise in the temperature of the phosphor due to the continuous driving, and an effect that a print closer to the image data can be obtained.

As a more specific configuration, a method of controlling the output from the exposure print head by changing the anode voltage of the phosphor element is also possible and effective. The exposure amount balance between the phosphor elements separately adjusted so as not to have a mutual variation may be broken again due to the temperature compensation operation, but as in the invention of claim 2, the temperature compensation mechanism is It has a temperature correction table that holds correction data for each temperature,
Further, after correcting the image data with correction data obtained from the temperature correction table based on the temperature detection result,
With the configuration including the correction unit that supplies the drive circuit of the exposure print head, the anode voltage of the phosphor element is adjusted separately in comparison with the above-described method of correcting the anode voltage with the same correction data based on the temperature detection result. This is convenient because there is no fear that the exposure amount balance between the phosphor elements is lost.

Other features and advantages according to the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view of a fluorescent print head 60 for color printing used in a fluorescent printer according to the present invention. The fluorescent print head 60 is actually R (red), G (green), B (blue)
(See FIG. 4), only the R light-emitting block is shown here. The other two light-emitting blocks have the same configuration. A first strip-shaped anode electrode 62 and a second strip-shaped anode electrode 63 made of an aluminum thin film are formed on the inner surface of a substrate 61 made of a translucent material. The two strip-shaped anode electrodes 62 and 63 can be understood from FIG.
It extends in the main scanning direction perpendicular to the conveying direction of a photosensitive material (hereinafter, simply referred to as photographic paper) 3 such as photographic paper exposed by the fluorescent print head 60 and has a predetermined pitch. Rectangular transmission holes 62a and 63a are provided. Transmission hole 6 of first strip-shaped anode electrode 62
2a and the transmission holes 63a of the second strip-shaped anode electrode 63 are arranged in a staggered manner. Each transmission hole 62a, 63a has a Z
n: a phosphor 64 mainly composed of ZnO is coated, and a plurality of grid electrodes 65 corresponding to the phosphor 64 are extended from the phosphor 64 in a direction transverse to the main scanning direction. ing. In the grid electrode 65, a slit hole 65a as a light transmitting portion is formed in an area facing the phosphor 64. Each grid electrode 65 is electrically independent of each other, and an independent control voltage is applied to each grid electrode 65. An acceleration electrode 66 is provided further away from the grid electrode 65. The accelerating electrode 66 corresponds to the slit hole 65a of the grid electrode 65,
6a is provided with a single metal plate, and a common acceleration voltage is applied. Further, a linear cathode electrode 67 as a filament is provided at a position away from the grid electrode 65 along the main scanning direction. A phosphor 64, a first strip-shaped anode electrode 62 or a second strip-shaped anode electrode 63,
The grid electrode 65 and the accelerating electrode 66 constitute each phosphor element, and light emitted by each phosphor element forms a one-dot latent image on the printing paper 3.

As described above, the strip-shaped anode electrodes 62 and 6
3, grid electrode 65, acceleration electrode 66, cathode electrode 6
Reference numeral 7 is housed in a vacuum space created by the inner surface of the substrate 61 and the cover body 68. On the outer surface of the substrate 61,
A red filter 69 as a color filter is provided to face the phosphor 64. The light beam 70 emitted from the phosphor 64 is modulated by the red filter 69 and is imaged on the photographic paper 3 by the selfoc lens 71. In a state where a predetermined voltage is applied to the cathode electrode 67 and the acceleration electrode 66, a voltage is alternately applied to the first band-shaped anode electrode 62 and the second band-shaped anode electrode 63 at a predetermined timing, and a desired voltage is synchronized with this timing. By applying a positive exposure signal to the grid electrode 65, the thermoelectrons jumping out of the cathode electrode 67 pass through the slit holes 65a according to the state of the grid electrode 65 and collide with the phosphor 64. The phosphor 64 hit by the thermal electrons emits light, and the light beam 70 passes through the transmission hole and reaches the photographic paper 3, so that the photographic paper 3 is exposed in light beam dot units. For example, when all the phosphors 64 emit light, the photographic paper 3 is linearly exposed with one dot width by two rows of phosphor elements.
Since the light emission characteristics of individual phosphor elements vary in the light emission area of the phosphor, the distance between the electrodes, and the like, the amount of light of each phosphor element is the same when operated under the same driving conditions. The control signal sent to the grid electrode 65 is corrected based on the light amount value actually measured under the same driving conditions in advance. Thereby, the light emitted from each phosphor element becomes uniform. A thermistor 109 is disposed between the first strip-shaped anode electrode 62 and the second strip-shaped anode electrode 63, at a position close to the phosphor 64, as a temperature detecting means for detecting a representative temperature of the phosphor 64. As described later, based on the temperature information obtained by the thermistor 109,
Correction data for correcting the image data for driving the exposure print head is selected, and as a result, the output from the exposure print head of the fluorescent printer reflects the real-time temperature detection result of the phosphor 64, That is, control is performed in such a manner that the temperature of the phosphor 64 is compensated (temperature compensation mechanism of the fluorescence printer).

Hereinafter, a printer processor employing the fluorescent printer according to the present invention as a digital exposure apparatus will be described. As is apparent from the schematic block diagram shown in FIG. 3, the printer processor has the same exposure as the optical exposure device 20 that projects and exposes the image of the photographic film 2 on the photographic paper 3 as a photosensitive material at the exposure point 1. At point 1, a fluorescent printer 30 as a digital exposure device that exposes an image to photographic paper 3 in accordance with digital image data, development processing section 5 that develops photographic paper 3 exposed at exposure point 1, and prints photographic paper 3 A photographic paper transport mechanism 6 that transports the paper magazine 4 via the exposure point 1 to the development processing unit 5 and a controller 7 that controls each unit of the printer processor 1 are provided. The exposure point 1 is provided with a paper mask 40 for determining an exposure area of the photographic paper 3 by the optical exposure device 20, and a controller 8 for inputting various information to the controller 7.
And a monitor 9 for displaying images and characters. The sub-controller 107 communicably connected to the controller 7 performs an auxiliary function of the controller 7. The photographic paper 3 pulled out from the photographic paper magazine 4 containing the photographic paper 3 in a roll shape is exposed by the optical exposure device 20 or the fluorescent printer 30 or both exposure devices, and then developed by the development processing unit 5. The image is cut into a size including one frame of image information and discharged. Of course, a configuration in which the photographic paper 3 is cut to a required length before exposure may be adopted.

Hereinafter, each component will be described. The optical exposure device 20 includes an optical exposure light source 21 composed of a halogen lamp, a dimming filter 22 for adjusting the color balance of light applied to the film 2, and a mirror for uniformly mixing light passing through the dimming filter 22. Tunnel 23, film 2
A printing lens 24 and a shutter 25 for forming an image on the printing paper 3 are provided on the same optical axis forming an exposure light path. A scanner 10 that reads an image formed on the film 2 is provided upstream of the optical exposure device 20 on a film transport path. The scanner 10 irradiates the film 2 with white light, decomposes the intensity of the reflected light or transmitted light into three primary colors of red, green, and blue, and outputs the image using, for example, a CCD line sensor or a CCD image sensor. It measures the concentration. The image information read by the scanner 10 is sent to the controller 7 and used to display a simulated image of an image formed on the exposed photographic paper 3 on the monitor 9. As shown in detail in FIG. 4, the fluorescent printer 30 includes:
A fluorescent print head 60 including the R light emitting block 32, the G light emitting block 33, and the B light emitting block 34 having the above-described structure, and a reciprocating mechanism for scanning the fluorescent print head 60 in the transport direction of the printing paper 3. 50 are provided. The light-emitting blocks 32, 33, and 34 of the fluorescent print head 60 are connected to the controller 7, and the driving system of the reciprocating mechanism 50 is a sub-controller 10.
7 is connected. The image data and character data are transferred to the photographic paper 3 based on the control of the phosphor elements by the controller 7 and the scanning control of the fluorescent print head 60 in the sub-scanning direction by the sub-controller 107 via the reciprocating mechanism 50.
Color exposure. The paper mask 40 itself,
Although known in the art, and detailed description is omitted, as schematically shown in FIGS. 5 and 6, the upper side extends in parallel with the transport direction of the printing paper 3 and can reciprocate in the transverse direction of the transport direction. A left side member 43 and a right side member 44 extending in the transverse direction of the transport direction of the printing paper 3 and capable of reciprocating in the transport direction; and a base 45 supporting these members. The exposure range in the width direction of the printing paper 3 is determined by the distance between the upper side member 41 and the lower side member 42, and the exposure range in the length direction of the printing paper 3 is determined by the distance between the left side member 43 and the right side member 44. The movements of the upper side member 41, the lower side member 42, the left side member 43, and the right side member 44 are controlled by the controller 7 via a drive mechanism (not shown).

A reciprocating mechanism 50 for the fluorescent print head 60 is mounted on the base 45 of the paper mask 40, and its basic components are guides provided on both ends of the fluorescent print head 60. A member 51, a guide rail 52 inserted into a guide hole 51a provided in the guide member 51, a wire fastener 53 provided in one guide member 51, a wire 54 having an end fixed to the wire fastener 53, a wire A sprocket 55 which is wound around 54 and arranged at both ends of the base 45;
A pulse motor 56 rotates one of the sprockets 55 under the control of the sub-controller 107. The rotation of the pulse motor 56 moves the fluorescent print head 60 along the guide rail 52 through the movement of the wire 54. FIG. 7 shows the printing paper 3 by the fluorescent print head 60.
3 is a block diagram schematically illustrating the exposure control. The controller 7 includes an image data input port 7a connected to a device for acquiring digital images such as a digital camera, a scanner, and a CD. The controller 7 performs image processing on input image data and bitized character data in dot units. An image processing unit 7b for generating luminance data divided into 256 steps (8 bits), a printer control unit 7c for setting driving conditions of the fluorescent print head 60, and a luminance data obtained by the image processing unit 7b is converted into a temperature for the phosphor 64. Correction is performed based on the detection result, and the printer control unit 7
and a temperature correction unit 7i for sending the data to the control unit 7c. The temperature compensator 7i includes a thermistor 1 provided near the phosphor 64.
09 and a correction coefficient corresponding to the temperature detection signal sent from the thermistor 109 to the temperature correction table 7.
e, and multiplies this correction coefficient by the luminance data obtained by the image processing unit 7b, and sends the obtained product to the printer control unit 7c as final image data. That is, the temperature correction unit 7i constitutes the above-described temperature compensation mechanism in cooperation with the thermistor 109 and the temperature correction table 7e.
The printer control unit 7c includes a cathode control unit 91 that controls a cathode voltage, a grid control unit 92 that controls a grid voltage, and an anode control unit 9 that controls an anode voltage.
3 is provided. FIG. 8 shows an example of the temperature correction table 7e. Here, the temperature of the phosphor 64 is divided into three regions, and one correction coefficient value Kx is assigned to each region. These correction coefficients Kx are determined from a correction equation representing the relationship between the temperature of the phosphor 64 and the correction coefficient Kx, and an example of this correction equation is shown in the graph of FIG. This correction formula is a function obtained from the correlation between the temperature and the light emission amount obtained by measuring the phosphor 64 in advance. The temperature correction unit 7i includes a correction coefficient Kx corresponding to the temperature value tx of the phosphor 64 sent from the thermistor 109.
Is found from the temperature correction table 7e, and the correction coefficient Kx is multiplied by the image data to obtain final image data to be sent to the printer control unit 7c. An example of this operation performed by the temperature correction unit 7i is illustrated in FIG. In FIG. 10, the left column is the luminance data (256 pixels) obtained by the image processing unit 7b.
In the middle column, the temperature value tx of the phosphor 64 is shown.
Is an example of the correction coefficient Kx when the temperature is within the range of 15 to 40 ° C., and is 0.95 here. The right column shows a numerical example of final image data (luminance data) obtained by multiplying the numerical value of the luminance data in the left column by a correction coefficient Kx (in this case: 0.95). If the luminance data obtained by the image processing unit 7b is 230 and the temperature value tx of the phosphor 64 is in the range of 15 to 40 ° C.,
230 is multiplied by the correction coefficient Kx of 0.95, and 219
Is obtained as the final image data (luminance data).

The anode controller 93 sends an applied voltage value suitable for the type of the printing paper 3 to be printed to the print head driver 7f. As a result, an anode voltage that emits light optimal for the printing paper 3 to be printed is applied to the anode electrodes 62 and 63 of the light-emitting blocks 32, 33, and 34. Grid control unit 92
Sends the image data obtained via the temperature correction unit 7i to the print head driver 7f. The luminance value of each color sent to the print head driver 7f is converted into a drive pulse width there, and sent to the grid electrodes 65 of the R light emitting block 32, the G light emitting block 33, and the B light emitting block 34 of the fluorescent print head 60. Further, the controller 7 is provided with a communication port 7g connected to the communication port 107a of the sub-controller 107. The sub-controller 107 includes a scanning control unit 10 that generates a control signal related to the scanning speed and timing of the fluorescent print head 60.
The sub-controller 107 transmits a control signal to the pulse motor 56 via the output port 107c and the motor driver 107d in cooperation with the controller 7. This controller 7 and sub-controller 107
The image printing by the fluorescent print head 60 is performed on a predetermined position of the printing paper 3 by the cooperation of the above.

Next, a schematic operation of the printer processor will be described. When the film 2 is supplied to the optical exposure device 20 by the roller 11 driven by the motor 12, the controller 7 controls the light control filter 22 based on image information of the film 2 read by the scanner 10. Thereby, the irradiation light of the light source 21 is
Adjust the color balance according to the color density of the image. The optical exposure device 20 irradiates the film 2 with the adjusted light, irradiates the image information of the film 2 as transmitted light to the photographic paper 3 located at the exposure point 1, and prints the image of the film 2 on the photographic paper 3. . If necessary, the optical exposure device 20
By the scanning of the fluorescent print head 60 of the fluorescent printer 30 on the periphery of the printing area, additional illustrations such as characters and logos are printed. Of course, when printing an image captured by a digital camera on the photographic paper 3, only the fluorescent printer 30 prints on the photographic paper 3 located at the exposure point 1. The photographic paper 3 on which the image is printed at the exposure point 1 is processed by a photographic paper transport mechanism 6 having a plurality of rollers 13 and a motor 14 controlled by a controller 7 for driving the rollers 13, and then subjected to a developing processing section 5.
And sequentially passes through a plurality of tanks filled with a processing liquid for developing the photographic paper 3, and is subjected to development processing. The photographic paper transport mechanism 6 also functions to stop the photographic paper 3 pulled out from the photographic paper magazine 4 at a predetermined position of the exposure point 1, so that the exposed photographic paper 3 is continuously developed. In the case of adopting the method of transporting the paper to the processing section 5, the photographic paper transport mechanism 6 may be divided on the upstream side and the downstream side in the transport direction from the exposure point 1, and may be independently driven. In the above-described embodiment, the fluorescent print head 60 is configured to move on the photographic paper 3 for exposure over a predetermined area of the photographic paper 3 by the fluorescent print head 60. It is also possible to adopt a configuration in which 60 is fixed at a predetermined position of the exposure point 1 and the photographic paper 3 is moved to expose and scan only a predetermined area. In this case, the printing paper 3 may be moved by operating the printing paper transport mechanism 6 based on a control signal from the controller 7.

[Another Embodiment] <1> In the above-described fluorescent printer, the image processing unit 7b
And sent to the print head driver 7f.
The luminance data of 56 gradations (8 bits) means the number of reference pulses to be applied to the phosphor element. In the above embodiment, the luminance data is multiplied by a correction coefficient selected from the temperature correction table 7e. In other words, by changing the number of reference pulses applied to the phosphor element, the phosphor 64
(Temperature compensation) is performed based on the temperature of the phosphor 64. Here, the temperature compensation is performed by changing the width of the reference pulse itself based on the temperature of the phosphor 64 without changing the number of reference pulses. You may go. That is, without rewriting the data obtained by the image processing unit 7b, the reference transmitted to the grid electrode 65 of each of the R, G, and B light emitting blocks 34 of the fluorescent print head 60 as illustrated in FIG. By providing a temperature correction unit 7j that multiplies the pulse width (time length of the reference pulse) by the correction coefficient described above and corrects the temperature, temperature compensation may be performed on the density of the print finally obtained. In this case, the temperature correction table 7e exemplified in the above embodiment can be used as it is as the correction coefficient.

<2> In the above description of the embodiment, the present invention is applied to a fluorescent printer for color printing. Of course, the present invention can be applied to a fluorescent printer for monochrome printing, in which case only one light-emitting block is provided. Just think that it is provided.

<3> Specific operations for compensating the temperature of the phosphor for the output from the exposure print head include:
Instead of providing a correction unit that supplies the drive circuit of the exposure print head after correcting the image data based on the temperature detection result for the phosphor as in the above-described embodiment, the anode voltage of the phosphor element is reduced. It is also possible to take a method of controlling the output from the exposure print head by making correction based on the temperature detection result of the phosphor.

<4> The temperature detecting means is not limited to the thermistor 109 used in the above embodiment, but may be a temperature sensor IC or a thermocouple.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of a print head of a fluorescent printer according to the present invention.

FIG. 2 is an enlarged plan view as viewed from an arrow A in FIG. 1;

FIG. 3 is a schematic block diagram of a printer processor employing the fluorescent printer according to the present invention.

FIG. 4 is a schematic perspective view of a print head portion.

FIG. 5 is a schematic plan view showing a paper mask and a print head reciprocating mechanism.

FIG. 6 is a schematic side view showing a paper mask and a print head reciprocating mechanism.

FIG. 7 is a functional block diagram schematically illustrating light emission control of the fluorescent printer.

FIG. 8 shows an example of a temperature correction table having correction coefficients for image data.

9 is a graph showing an example of a correction formula serving as a reference of the temperature correction table of FIG.

FIG. 10 is an example of data correction performed using the temperature correction table of FIG. 8;

FIG. 11 is a functional block diagram showing light emission control of a fluorescent printer according to another embodiment.

[Explanation of symbols]

 7c Printer control unit 7d Anode data storage unit 7e Temperature correction table 7f Printer driver 7h Printing paper sensor 7i Temperature correction unit 7j Temperature correction unit 32 R light emission block 33 G light emission block 34 B light emission block 60 print head 62 first belt-shaped anode electrode 62a Transmission hole 63 Second strip-shaped anode electrode 64 Phosphor 65 Grid electrode 66 Acceleration electrode 67 Cathode electrode 69 Color filter 71 Selfoc lens 91 Cathode control unit 92 Grid control unit 93 Anode control unit 109 Thermistor

Claims (2)

[Claims] 1. A fluorescent printer having an exposure printhead having a phosphor element, comprising: a temperature detector for detecting a temperature of a phosphor constituting the phosphor element; and an output from the exposure printhead. To
A fluorescent printer having a temperature compensating mechanism for controlling according to the temperature detection result. 2. The temperature compensating mechanism has a temperature correction table holding correction data for each temperature, and further obtains image data from the temperature correction table obtained from the temperature correction table based on the temperature detection result. After correcting with data,
The fluorescent printer according to claim 1, further comprising a correction unit that supplies a driving circuit for the exposure print head.