JP3325931B2 - Marking method for photosensitive material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for marking a photosensitive material, and more particularly to a method for recording a high-definition image, such as a CT scanner, on a photosensitive film of high sensitivity which is important for flatness and used in a hard copy device. The present invention relates to a marking method suitable for use in, for example, the present invention.

[0002]

2. Description of the Related Art Conventionally, marking on a photosensitive film such as an X-ray film (recording of a manufacturer's name, product type, etc.) is performed by pressing printed characters on the surface of the photosensitive material to generate fog due to pressure.

[0003]

The above-described marking method using type has the following problems. The switching time is long, and instantaneous switching and online setting are difficult. It is difficult to adjust the pressure balance between types and it takes a long time to adjust. Type is expensive and has a long delivery time, and requires a preparation period when developing new varieties. Image recording film that emphasizes flatness due to unevenness on the film plane (especially film used for hard copy of high-definition images after image processing by CT scanner etc.)
Cannot be printed on. Therefore, at present, there is inconvenience such that it is difficult to identify the film because no marking is made on the film that requires such high flatness.

In order to solve such a problem, the present inventor has proposed to perform laser marking using a marker using a maskless, dot-printing type CO ₂ laser capable of performing printing, The practicality was examined, and as a result, the following problems became clear.

That is, since the beam intensity of the CO ₂ laser marker is considerably high, sparks are generated due to the state of the photosensitive material surface (for example, dust adhesion). In this case, it has been found that harmful fog is generated by the sparks. .

In general, a polygon mirror is used for scanning with laser light. In this case, the laser beam has an elliptical shape extending in the main scanning direction. In the vertical line, it was also found that a part of the elliptical dots overlapped with each other, the light irradiation density increased, and thermal fogging (thermal denaturation) at that portion increased, so that sparks were easily generated. That is, such an increase in the irradiation density due to the partial overlap of the beams, coupled with the presence of foreign matter such as dust adhering to the film surface, may cause abnormal combustion.

The present invention has been made based on the results of such studies by the present inventors. The object of the present invention is to solve the above-mentioned problems and to use a laser marker to mark a photosensitive material. Practical use and establishment of the marking method to be formed.

[0008]

(1) According to the present invention, a laser beam is applied to a marking area of the photosensitive material in a state where the photosensitive material is placed in an inert gas atmosphere to generate fog due to heat. Is performed. For example, a laser beam is irradiated while blowing an inert gas such as CO ₂ , N ₂ , He, or Ar onto the vicinity of the surface of the photosensitive material. (2) Further, the present invention is characterized in that, in a state where the photosensitive material is placed in an inert gas atmosphere, a laser beam is scanned using a polygon mirror, and printing of a dot configuration is performed on a marking area of the photosensitive material. Is what you do.

[0009]

In the inert gas atmosphere, combustion on the surface of the photosensitive material is suppressed, and the generation of sparks is prevented. Thereby, harmful fog does not occur, and good laser marking can be performed with only the original thermal fog.

[0010]

Next, embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) FIGS. 1 (a) and 1 (b) are diagrams each showing a typical embodiment of the method of the present invention, and FIG. 1 (a) shows an embodiment using a dedicated nozzle for blowing inert gas. (B) shows a mode in which an inert gas is supplied to the condenser lens protecting nozzle.

The photosensitive material in this embodiment is a high-sensitivity photosensitive film in which flatness is emphasized, for example, an X-ray film 7 such as a film for CT image recording. Respectively, emulsion layer 1
1 and a back coat layer 12.

As a laser light source, a CO ₂ gas sealed laser is used. The laser light is scanned by using a polygon mirror, focused by the condenser lens 1 to form an image on the emulsion layer 11, and heat fog is generated. Is printed.

In FIG. 1A, using a special nozzle 2,
An inert gas such as Ar is blown at a predetermined flow rate. As a result, combustion on the printing surface is suppressed, and the occurrence of sparks due to laser beam irradiation is prevented, thereby preventing harmful fog.

The air injected from the opening 3 is
This is for preventing scattered matter from adhering to the condenser lens 1. In FIG. 1B, instead of air from the opening 3,
An inert gas such as Ar is allowed to flow therein. In this case, the inert gas is blown to both the condenser lens 1 and the surface of the photosensitive material, and simultaneously plays two roles of cleaning the lens surface and suppressing combustion on the printing surface. In this case, a dedicated nozzle is not required, and the configuration is simplified and convenient.

FIGS. 2A and 2B are diagrams showing an example of the configuration of a laser marking device for executing printing in the mode of FIG. 1A (with a dedicated nozzle 2), wherein FIG. FIG. 3B shows the entire configuration, and FIG.

The laser control unit 21 has a CO ₂ gas-sealed laser as a light source, and turns on and off the light source based on input information from a mark setting means 20 such as a keyboard, etc. Is output.

The laser light is transmitted to the head section 24 via the reflection mirror. The head unit 24 scans the laser beam in the main scanning direction by the polygon mirror 25 to form the mark 13 on the X-ray film 7. In this case, as described above, the inert gas is blown onto the printing surface from the nozzle 2 to prevent the generation of a spark.

The scanning in the sub-scanning direction is performed by moving the film itself by rotation of the drum about the rotation shaft 26. The rotation position of the rotation shaft 26 is detected by the rotation position detection means 27, and is fed back to the laser control unit 21 as needed to maintain a constant character width following a change in the transport speed.

A marking device using scanning by a polygon mirror is relatively inexpensive and widely used. By adopting the marking in the inert gas atmosphere of this embodiment, the marking device can be used as a marker on a photosensitive material. You can use it.

FIGS. 3A and 3B are diagrams for explaining the effect of the present embodiment. FIG. 3A shows a marking example according to a conventional example as a comparative example, and FIG. An example of marking by the method of (1) is shown.

In the case of (a), harmful fogging is caused by the occurrence of combustion on the film surface, and it is difficult to read the print. On the other hand, in the case of (b), there is no such fog, and clear printing is performed.

(Embodiment 2) Although harmful fogging can be prevented by Embodiment 1, even in the case of dot printing by beam scanning by a polygon mirror, a part of elliptical dots overlaps, and the beam is locally localized. Concentration may occur, and dangers such as local fog enhancement and burning are not eliminated.

Therefore, in this embodiment, in order to more completely control fog (printing), in addition to printing in an inert gas atmosphere, a device for changing a font (ie, adoption of a skip font) is used. I do. Hereinafter, a specific description will be given.

FIGS. 4A to 4C are diagrams for explaining the characteristic points of the font shape of this embodiment (a marking method involving beam scanning by a polygon mirror). FIGS. Indicates the dot printing pattern by
(D) to (f) show dot print patterns by the marking method of the present invention.

In the figure, the vertical direction is the main scanning direction of the laser beam by the polygon mirror, and the dots are elongated in this direction. Therefore, when dots are continuously formed in the main scanning direction, the tips of the ellipses overlap ((a) to (c)). Therefore, skip fonts are adopted as in (d) to (f), and in the case of continuous dot printing in the main scanning direction, overlapping between dots is eliminated by performing thinning (skip) for each dot. Prevent local concentration of the beam. As a result, abnormal fog due to combustion can be completely suppressed, and the density in characters can be maintained uniform.

(Embodiment 3) Elimination of the overlap between print dots can also be achieved by using an apparatus having a plurality of laser light sources as shown in FIG.

The marking device shown in FIG. 5 is composed of a plurality of CO ₂ gas-sealed laser light sources (3
0a to 30g), and irradiates the film 7 with the laser beams from the respective light sources via the corresponding reflection mirrors 35a to 35g and the common reflection mirror 40 to form dots corresponding to the respective beams.

In this case, since there is no deformation of the dots and the dot positions are predetermined (that is, the resolution of printing is determined by the irradiation position of each laser beam), FIGS. Can be formed at substantially uniform intervals. Since there is no overlap between dots, beam concentration does not occur, uniform density printing can be performed, and skip fonts need not be used, which is convenient.

[0029]

As described above, according to the present invention, by performing printing in an inert gas atmosphere, combustion on the surface of the photosensitive material can be suppressed, and generation of sparks can be prevented. Thereby, harmful fog does not occur, and good laser marking can be performed with only the original thermal fog.

[Brief description of the drawings]

FIGS. 1 (a) and 1 (b) are diagrams each showing a representative embodiment of the method of the present invention, wherein (a) shows an embodiment using a dedicated nozzle for blowing inert gas, and (b) () Shows a mode in which an inert gas is supplied to the condenser lens protecting nozzle.

FIGS. 2A and 2B are diagrams showing a configuration example of a laser marking device for performing the printing of FIG. 1;
Shows the entire configuration, and (b) shows the vicinity of the printing surface partially enlarged.

FIGS. 3 (a) and 3 (b) are diagrams for explaining the effects of the embodiment of FIG. 1; FIG. 3 (a) shows a marking example according to a conventional example as a comparative example, and FIG. 5 shows a marking example by the example method.

FIGS. 4A to 4C are diagrams for explaining the characteristic points of a font according to the second embodiment (a marking method involving beam scanning by a polygon mirror), wherein FIGS. Indicates the print pattern, and (d) to
(F) shows a dot print pattern by the marking method of the present invention.

FIG. 5 is a diagram illustrating an overall configuration example of a laser marking device for performing printing according to a third embodiment.

FIGS. 6A to 6C are diagrams illustrating examples of fonts when marking is performed using the apparatus of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Condensing lens 2 Dedicated nozzle for spraying inert gas 3 Opening 7 X-ray film 10 PET base 11 Emulsion layer 12 Back coat layer 13 Mark 20 Mark setting section 21 Laser control section 24 Head section 25 Polygon mirror 26 Rotation axis

Claims (2)

(57) [Claims] 1. A method for marking a photosensitive material , wherein the marking is performed by irradiating a laser beam to a marking area of the photosensitive material in a state where the photosensitive material is placed in an inert gas atmosphere to generate fog by heat. Marking method. 2. A laser beam is scanned using a polygon mirror while the photosensitive material is in an inert gas atmosphere.
2. A method for marking a photosensitive material according to claim 1, wherein a dot configuration printing is performed on a marking area of the photosensitive material.