JPH11188919A - Fluorescent printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent printer capable of setting an optimum light quantity also with respect to various kinds of printing papers requiring the tuning of the light quantity in a simple structure. SOLUTION: There is disclosed a fluorescent printer that comprises light emitting blocks 32, 33, 34 of which light emission is controlled in accordance with a driving signal having a variable pulse width and forms a latent image on a photosensitive material based on image data by virtue of relative movement of the light emitting blocks with respect to the photosensitive material in a sub-scanning direction. The number of times of the driving signal is determined corresponding to a density value of the image data and the pulse width is set greater as the movement speed in the sub-scanning direction is lower.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a light emitting block in which light emitting elements whose light emission is controlled by a drive signal having a variable pulse width are arranged at predetermined intervals in the main scanning direction, and a light emitting element is provided between the light emitting block and the photosensitive material. And a fluorescent printer that forms a latent image based on image data on a photosensitive material by relative movement in the sub-scanning direction.

[0002]

2. Description of the Related Art A fluorescent printer for forming an image on a light-sensitive medium is disclosed in, for example, Japanese Patent Application Laid-Open No. 5-92622, a cathode electrode for emitting thermoelectrons, a grid electrode, and a predetermined electrode. A plurality of strip-shaped anode electrodes coated with a phosphor with a pitch and a size are sealed in a vacuum vessel, and a control signal based on image data is applied to a grid electrode to heat the phosphor. Electron collision, that is, light emission of the phosphor is controlled. One phosphor corresponds to one pixel constituting an image, that is, one dot. In order to obtain a high resolution, the arrangement pitch of the phosphors needs to be fine. Are arranged in multiple rows, and by appropriately adjusting the light emission timing of the phosphors in each row with the relative movement in the sub-scanning direction, the dots from the phosphors in the multiple rows are arranged in a straight line in the sub-scanning direction. .

[0003]

A fluorescent printer which develops a latent image formed on a photosensitive drum by light dots emitted from each light emitting element in synchronization with rotation of the photosensitive drum and transfers the latent image to transfer paper. In, the photosensitive characteristics of the photosensitive drum are kept constant, but, for example, in a fluorescent printer used for exposing a photosensitive material such as photographic paper, the photosensitive characteristics vary depending on the type of photographic paper. , Combining an appropriate filter with the light-emitting block,
The light quantity must be adjusted. However, in the light amount adjustment using the filters, a large number of filters must be prepared in order to produce the optimum light amounts for many types of photographic papers having different photosensitive characteristics, and the adjustment work is troublesome. In addition, the inconvenience of having to prepare a filter to apply to each new photographic paper may occur. SUMMARY OF THE INVENTION It is an object of the present invention to provide a fluorescent printer capable of setting an optimum light amount with a simple configuration even for many types of photosensitive materials requiring light amount adjustment.

[0004]

A light emitting block in which light emitting elements whose light emission is controlled by a drive signal having a variable pulse width is arranged at predetermined intervals in a main scanning direction, and a sub light emitting block between the light emitting block and the photosensitive material is provided. In a fluorescent printer that forms a latent image based on image data on a photosensitive material by relative movement in the scanning direction, in order to achieve the above object, in the present invention,

The number of times of the driving signal is determined according to the density value of the image data, and the pulse width of the driving signal is set longer as the relative moving speed in the sub-scanning direction is lower.

In this configuration, first, in order to express the density of image data for each dot, if, for example, 256 gradations are to be expressed, the relative movement of one dot in the sub-scanning direction when the input value is the maximum value (255). During this period, the photosensitive material is exposed by applying a light-emission pulse of 255 times as a drive signal. When the input value is the minimum value (0), no light emission is performed during the relative movement of one dot in the sub-scanning direction. The width of this light emission pulse, that is, one light emission time, is changed according to the relative movement speed in the sub-scanning direction. If the relative movement speed becomes slower, the time required for the relative movement by one dot becomes longer, so that the width of the light emission pulse becomes longer. As a result, even when the input value of the same density is the same, exposure is performed with a large amount of light, and as a result, the amount of light is adjusted. For example, for a photosensitive material that requires more exposure, the relative light speed in the sub-scanning direction can be reduced to adjust the light amount to an optimum value. Therefore, a substantially stepless light quantity adjustment, which is impossible with a conventional method using a filter, is realized.

In one preferred embodiment of the present invention, the relative movement in the sub-scanning direction is created by a transport mechanism for transporting the photosensitive material. Since the transport mechanism is always provided for supplying the photosensitive material, image data is exposed to the photosensitive material by synchronizing the feeding of the photosensitive material by the transport mechanism with the light emission by the light emitting block. As a result, the light-emitting block can be kept fixed, which is advantageous in terms of simplification of the structure and space saving.

In another preferred embodiment of the present invention, a reciprocating mechanism for moving the light-emitting block in the sub-scanning direction is provided, and the reciprocating mechanism creates relative movement in the sub-scanning direction. In this configuration, a reciprocating mechanism for the light-emitting block is additionally required.However, the exposure area can be made as flat as possible by stopping the photosensitive material and, if necessary, so that more accurate exposure is possible. Becomes

In the present invention, the relative movement in the sub-scanning direction as described above is performed by the stepping motor, and the driving signal (light emitting pulse) for the light emitting element is changed according to the frequency of the driving pulse signal of the stepping motor. It is proposed as a particularly preferred embodiment that the pulse width is set. In the stepping motor, the speed increases when the frequency of the drive pulse signal increases, and decreases when the frequency decreases. If the speed decreases, the time required for moving one dot increases, so that the exposure time for one dot can be prolonged. That is, the width of the light emission pulse, that is, one light emission time can be increased. As described above, if the width of the light emission pulse, that is, one light emission time becomes long, the exposure is performed with a large amount of light even if the density value of the image data is the same. Therefore, if a configuration is adopted in which the pulse width of the light emission pulse is changed in accordance with the frequency of the drive pulse signal of the stepping motor that determines the relative movement speed in the sub scanning direction, the sub scanning direction between the photosensitive material and the light emitting block By appropriately selecting the relative movement speeds of the light-emitting blocks, the light-emitting blocks are adjusted so as to obtain the optimum light-emission amount for photosensitive materials having different photosensitive characteristics. In such light emission amount adjustment, it is not necessary to change the anode application voltage of the light emitting element, and it is not necessary to selectively mount a filter. Other features and advantages according to the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0010]

FIG. 1 is a schematic sectional view of a fluorescent print head 60. FIG. Fluorescent print head 6
0 actually has three light-emitting blocks of R (red), G (green), and B (blue), but here only the light-emitting block of R is shown. The other two light-emitting blocks have the same configuration.

On the inner surface of the substrate 61 made of a translucent material,
A first strip-shaped anode electrode 62 and a second strip-shaped anode electrode 63 made of an aluminum thin film are formed. As can be clearly understood from FIG. 2, the two strip-shaped anode electrodes 62 and 63 are arranged in the transport direction of photographic printing paper (hereinafter simply referred to as printing paper) 3 as an example of a photosensitive material exposed by the fluorescent print head 60. It extends in the main scanning direction at right angles to the main scanning direction, and has rectangular transmission holes 62a and 63a at a predetermined pitch. The transmission holes 62a of the first strip-shaped anode electrode 62 and the transmission holes 63a of the second strip-shaped anode electrode 63 are arranged in a staggered manner.

Each of the transmission holes 62a and 63a has a phosphor 64
Is coated, and spaced from the phosphor 64,
A plurality of grid electrodes 65 corresponding to the phosphors 64 extend in a direction transverse to the main scanning direction. 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 acceleration electrode 66 is made of a single metal plate provided with slit holes 66a corresponding to the slit holes 65a of the grid electrode 65, 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. The phosphor 64, the first strip-shaped anode electrode 62 or the second strip-shaped anode electrode 63, the grid electrode 6, and the accelerating electrode 66 constitute each light emitting element, and light emitted by each light emitting element emits light. A one-dot latent image is formed 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.

While a predetermined voltage is applied to the cathode electrode 67 and the accelerating 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. By applying a positive exposure signal to the desired grid electrode 65, the thermoelectrons jumping from the cathode electrode 67 pass through the slit holes 65 a 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, if all the phosphors 64 emit light, 2
The photographic paper 3 is exposed linearly with a width of one dot by the light emitting elements of the row.

To describe the exposure of one dot in more detail, the image data of one dot (one pixel) is density data for giving the brightness of the dot, and is represented by a resolution of 256 gradations in this embodiment. The density data is 255
When the density data has a value of 128, the reference light emission is repeated 255 times. When the density data has a value of 128, the reference light emission is repeated 128 times. When the density data has a value of 0, no light emission is performed. Such light emission for one dot is performed by a light emitting element driven to emit light by a light emission pulse during movement in the sub-scanning direction for one dot. This is represented by a schematic time chart in FIG. 3 ignoring control accuracy. P1 is a drive pulse signal for controlling the movement of the print head 60 in the sub-scanning direction. Here, it is assumed that the print head 60 moves by one dot by one pulse. Accordingly, one cycle of the drive pulse signal P1 is a time interval provided for performing exposure of one dot, and this exposure timing is indicated by T1. By setting the pulse width of the light emission pulse not to exceed the length obtained by dividing the time interval given for exposure of one dot into 255 equal parts, 256 gradations can be expressed for one dot. . In one light emission, the control voltage is applied to the grid electrode 65 for the duration of the pulse width of the light emission pulse, and the phosphor 6
4 is realized by emitting a light beam. FIG. 3A shows a state in which the moving speed of the print head 60 in the sub-scanning direction is fast, and FIG. 3B shows a state in which the moving speed of the print head 60 in the sub-scanning direction is slow. When the moving speed in the sub-scanning direction is slow, the time interval given for exposure of one dot becomes longer, so that the pulse width of the light emission pulse is set longer accordingly. The amount of light for The pulse width of the emission pulse is changed in inverse proportion to the frequency of the drive pulse signal P1 which determines the moving speed in the sub-scanning direction.

Hereinafter, the fluorescent print head 6 according to the present invention will be described.
A description will be given of a printer processor that employs a fluorescent printer 0 as a fluorescent printer. As is apparent from the schematic block diagram shown in FIG. 4, the printer processor has an optical exposure device 20 for projecting and exposing an image of the photographic film 2 to a photographic paper 3 as a photosensitive material at an exposure point 1.
A fluorescent printer 30 as a digital exposure device for exposing an image on the photographic paper 3 at the same exposure point 1 in accordance with digital image data; a developing processing unit 5 for developing the photographic paper 3 exposed at the exposure point 1; A photographic paper transport mechanism 6 for transporting the paper 3 from the photographic paper magazine 4 via the exposure point 1 to the development processing unit 5 and a controller 7 for controlling each part of the printer processor 1 are provided. The exposure point 1 is provided with a paper mask 40 for determining the exposure area of the photographic paper 3 by the optical exposure device 20. The controller 7 has a console 8 for inputting various information and a monitor 9 for displaying images and characters. Is connected. 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 is cut into a size including one frame of image information and discharged. of course,
A configuration in which the printing paper 3 is cut to a required length before exposure may be employed.

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 for reading an image formed on the film 2 is provided on the upstream side of a film transport path with respect to the optical exposure device 20. This scanner 10
Irradiates the film 2 with white light, decomposes the intensity of the reflected light or transmitted light into the three primary colors of red, green, and blue, and measures the image density with, for example, a CCD line sensor or a CCD image sensor. Is what you do. 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. 5, the fluorescent printer 30 includes an R light emitting block 32, a G light emitting block 33, and a B light emitting block 3 having the above-described structure.
And a reciprocating mechanism 50 for scanning the fluorescent print head 60 in the transport direction of the printing paper 3. Each light-emitting block of the fluorescent print head 60 is connected to the controller 7, and the driving system of the reciprocating mechanism 50 is a sub-controller 10
7 is connected. Phosphor 64 by controller 7
The image data and the character data are transferred to the photographic paper 3 based on the scanning control of the fluorescent print head 60 in the sub-scanning direction by the sub-controller 107 via the reciprocating movement mechanism 50 and
Color exposure.

The paper mask 40 itself is a known one, and a detailed description thereof will be omitted. As shown schematically in FIGS. 6 and 7, the paper mask 40 extends in parallel to the transport direction of the photographic paper 3 and is transported. The upper side member 41 and the lower side member 42 which can reciprocate in the transverse direction, the left side member 43 and the right side member 44 which extend in the transverse direction of the transport direction of the printing paper 3 and can reciprocate in the transport direction. A supporting base 45 is provided, and the exposure range in the width direction of the printing paper 3 is changed by the distance between the upper side member 41 and the lower side member 42.
The exposure range in the length direction of the printing paper 3 is determined by the distance between the right side member 44 and the right side member 44. Upper side member 41, lower side member 42,
The movement of the left side member 43 and the right side member 44 is 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 at 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 stepping motor 56 for rotating one of the sprockets 55 under the control of the sub-controller 107. The rotation of the stepping motor 56 causes the fluorescent print head 60 to move through the movement of the wire 54 to the guide rail 5.
Move along 2.

FIG. 8 is a block diagram schematically illustrating exposure control of the photographic printing paper 3 by the fluorescent print head 60. The controller 7 includes a digital camera, a scanner, a CD or other device for acquiring a digital image, an input port 7a connected to a console 8, and performs image processing of input image data and bitized character data and performs dot processing. An image processing unit 7b for generating luminance data divided into 256 steps (8 bits) in units, a printer control unit 7c for setting driving conditions of the fluorescent print head 60,
By changing the pulse width of the light emission pulse in accordance with the rotation speed of the stepping motor 56, each light emission block 3
A light emission characteristic adjusting unit 7d for setting the light emission characteristics 2, 33, and 34 to light emission characteristics according to the photosensitive characteristics of the printing paper 3 is provided.

The printer controller 7c includes a cathode controller 91 for controlling a cathode voltage, a grid controller 92 for controlling a grid voltage, and an anode controller 93 for controlling an anode voltage. The grid control unit 92 sends the density data of each color sent from the image processing unit 7b to the print head driver 7e as the number of emission pulses for one dot. A signal for determining the pulse width of the light emission pulse for each light emission block is sent from the light emission characteristic adjustment unit 7d to the print head driver 7e, whereby the R light emission block 32, G light emission block 33, A predetermined light emission pulse can be sent to the B light emission block.

Further, the controller 7 is provided with a communication port 7f connected to the communication port 107a of the sub-controller 107. The sub-controller 107 includes a scanning control unit 107b that generates a control signal related to the scanning speed and timing of the fluorescent print head 60. The sub-controller 107 cooperates with the controller 7 to output the output port 107c and the motor driver 107.
A drive pulse signal of a predetermined frequency is sent to the stepping motor 56 via d. The frequency of the drive pulse signal is set by the light emission characteristic adjustment unit 7d in accordance with the photosensitive characteristic of the photographic paper 3 input from the console 8. Such a controller 7
The image printing by the fluorescent print head 60 is performed on a predetermined position of the photographic paper 3 by the cooperation of the sub-controller 107 and the printer.

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 dimming filter 22 based on the image information of the film 2 read by the scanner 10.
Control. Thereby, the irradiation light of the light source 21 is adjusted to a color balance according to the color density of the image on the film 2. 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, optical exposure device 2
By scanning the fluorescent print head 60 of the fluorescent printer 30 around the printing area of the print area 0, illustrations such as additional characters and logo marks are printed. of course,
For example, 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 printing paper 3 on which the image has been printed at the exposure point 1 is provided with a plurality of rollers 13 and a printing machine 14 having a motor 14 controlled by a printing paper transport controller 7g of the controller 7 to drive these rollers 13. Paper transport mechanism 6
The developer is conveyed to the development processing unit 5 and sequentially passes through a plurality of tanks filled with a processing solution 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 embodiment, the fluorescent print head 60 exposes the photographic paper 3 over a predetermined area.
The configuration in which the fluorescent print head 60 moves on the photographic paper 3 has been adopted.
It is also possible to adopt a configuration in which 0 is fixed at a predetermined position of the exposure point 1 and a predetermined area is exposed and scanned by moving the photographic printing paper 3. In this case, the motor 14 of the photographic paper transport mechanism 6 is constituted by a stepping motor, and the frequency of the driving pulse signal is adjusted by the light emission characteristic adjusting unit 7.
What is necessary is just to set by d. Of course, except during the exposure by the fluorescent print head 60, the motor 14 is driven by a drive pulse signal having a frequency that realizes a separately set photographic paper transport speed, irrespective of the emission characteristic adjustment unit 7d.
Is driven.

[Another Embodiment] Another embodiment of the fluorescent printer according to the present invention will be described with reference to a functional block diagram of light emission control shown in FIG. This fluorescent printer is provided with a photographic paper sensor 7h for detecting the type of photographic paper 3, and the printer control unit 7c is provided with the photographic paper sensor 7h.
The light emission characteristic adjustment unit 7d determines the light emission characteristics of each light emitting block based on the detection result of the above, and the frequency of the drive pulse signal sent to the stepping motor 56 is set accordingly.

[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 time chart illustrating a relationship between a moving speed of a light emitting block and light emission control of the light emitting block.

FIG. 4 is a schematic block diagram of a printer processor employing the fluorescent printer according to the present invention.

FIG. 5 is a schematic perspective view of a print head portion.

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

FIG. 7 is a schematic side view showing a paper mask and a reciprocating mechanism for a print head.

FIG. 8 is a functional block diagram schematically illustrating light emission control of the fluorescent printer.

FIG. 9 is a functional block diagram schematically illustrating light emission control of a fluorescent printer according to another embodiment.

[Explanation of symbols]

 7c Printer control unit 7d Light emission characteristic adjustment unit 7e Printer driver 7h Printing paper sensor 32 R light emission block 33 G light emission block 34 B light emission block 60 print head 62 first band-shaped anode electrode 62a transmission hole 63 second band-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

Claims (4)

[Claims] 1. A light emitting block in which light emitting elements whose light emission is controlled by a drive signal having a variable pulse width are arranged at predetermined intervals in a main scanning direction, and in a sub scanning direction between said light emitting block and a photosensitive material. In a fluorescent printer that forms a latent image based on image data on a photosensitive material by relative movement, the number of times of the drive signal is determined according to a density value of the image data, and the lower the relative movement speed in the sub-scanning direction is, A fluorescent printer, wherein a pulse width of the drive signal is set long. 2. The fluorescent printer according to claim 1, wherein a relative movement in the sub-scanning direction is created by a transport mechanism that transports the photosensitive material. 3. A reciprocating mechanism for moving the light-emitting block in the sub-scanning direction, wherein relative movement in the sub-scanning direction is created by the reciprocating mechanism. The fluorescent printer as described in the above. 4. The apparatus according to claim 2, wherein the relative movement in the sub-scanning direction is performed by a stepping motor, and a pulse width of the driving signal is set according to a frequency of a driving pulse signal of the stepping motor. Or the fluorescent printer according to 3.