Image forming method, silver halide photographic light-sensitive material, and monosheet laminate

Abstract

One aspect of the present invention provides an image forming method, a silver halide photographic light-sensitive material, and a monosheet laminate. The image forming method according to one aspect of the present invention is an image forming method having an exposure step for exposing a direct positive-type silver halide photographic light-sensitive material containing internal latent image-type silver halide grains that are not pre-covered on a support, wherein the exposure step includes an X-ray exposure step for forming a surface negative-type latent image and / or an internal latent image through exposure to X-rays. In addition, the silver halide photographic light-sensitive material according to another aspect of the present invention is a silver halide photographic light-sensitive material in which a surface negative-type latent image is formed by irradiating, with X-rays, a direct positive-type silver halide photographic light-sensitive material containing internal latent image-type silver halide grains that are not pre-covered on a support. The monosheet laminate according to yet another aspect of the present invention is a monosheet laminate in which the silver halide photographic light-sensitive material according to the present invention is used as a photosensitive element.

Description

Image forming method, silver halide photographic photosensitive material, and monosheet laminate

[0001] The present invention relates to an image forming method that includes an X-ray exposure step in addition to an exposure step for a direct positive image forming region, using a photosensitive material containing an internal latent image type direct positive silver halide emulsion. The present invention also relates to a silver halide photographic photosensitive material in which a surface negative type latent image is formed by X-ray irradiation. Furthermore, the present invention relates to a monosheet laminate using the silver halide photographic photosensitive material as a photosensitive element.

[0002] A well-known method involves using silver halide photographic photosensitive materials to directly form positive photographic images without the need for intermediate processing steps or negative images. Positive-type silver halide photographic photosensitive materials have been used in instant photography, photocopying, and proofing for print originals because they form an image in a positive state without inverting the image seen by the observer. They are particularly widely used in diffusion transfer instant photography because the subject seen at the time of shooting is obtained as an image immediately and quickly on the spot.

[0003] One method of photographing photosensitive materials involves superimposing multiple different images onto the material to form an image through multiple exposures. When positive-type photosensitive materials are exposed to multiple different images, the positive-type photographic response is superimposed, causing the material to become brighter the more it is exposed. Therefore, for example, if the brightest area of ​​another input image overlaps with the original image, the information of the original image may disappear. This phenomenon was generally accepted as an inherent property of positive-type photosensitive materials. Conventional photographic techniques had limitations on the types of images that could be represented when forming images through multiple exposures.

[0004] Methods used to create positive images using direct positive silver halide photographic material can be broadly divided into two types. One type uses a pre-coated silver halide emulsion and obtains a direct positive image after development by destroying the fogging nuclei (latent image) in the exposed area using solarization or the Herschel effect. The other type uses an uncoated internal latent image type silver halide emulsion and obtains a direct positive image by performing surface development after image exposure, or while performing fogging treatment. The above-mentioned "internal latent image type silver halide photographic emulsion" refers to a type of silver halide photographic emulsion in which the photosensitive nuclei are mainly located inside the silver halide particles, and a latent image is mainly formed inside the particles upon exposure.

[0005] Details of the direct positive image formation mechanism are described, for example, in T.T. James's "The Theory of the Photographic Process," 4th edition, Chapter 7, pages 182-193, and in U.S. Patent No. 3,761,276 (Patent Document 1).

[0006] On the other hand, the mechanism of latent image formation of silver halide emulsions by X-rays has been reported by Ihama in the Journal of the Photographic Society of Japan, Vol. 67, No. 6, pp. 532-537, 2004 (Non-Patent Literature 1).

[0007] U.S. Patent No. 3,761,276

[0008] Journal of the Photographic Society of Japan, Vol. 67, No. 6, 2004, pp. 532-537.

[0009] One embodiment of the technology described herein provides an image forming method, a silver halide photographic photosensitive material, and a monosheet laminate.

[0010] An image forming method according to a first aspect of the present invention is an image forming method having an exposure step of exposing a direct positive type silver halide photographic photosensitive material containing internal latent image type silver halide particles that have not been pre-covered on a support, wherein the exposure step includes an X-ray exposure step of forming a surface negative type latent image and / or an internal latent image by exposure with X-rays.

[0011] In the second embodiment of the image forming method, in the first embodiment, the amount of X-ray exposure to the area of ​​the silver halide photographic photosensitive material to be exposed is partially changed during the X-ray exposure step.

[0012] In the third embodiment of the image forming method, in the second embodiment, the X-ray exposure step partially changes the amount of X-ray exposure by using a material that absorbs or shields at least a portion of the X-rays irradiated onto the area to be exposed.

[0013] In the fourth embodiment, the image forming method is formed from a material containing at least one element with atomic numbers 13 to 83.

[0014] The image forming method according to the fifth embodiment further comprises a developing step in any one of the first to fourth embodiments, in which an exposed silver halide photographic photosensitive material is subjected to a developing process.

[0015] The image forming method according to the sixth embodiment, in the fifth embodiment, is performed under the condition that at least one of the following equations (Equation 1) to (Equation 3) is satisfied in the formed image after development: (Equation 1) 2 ≤ [Dmax(posi) - Dmax(Xray)] / [Dmax(posi) - Dmin(posi)] × 100 ≤ 95 (Equation 2) 2 ≤ [Dmin(Xray) - Dmin(posi)] / [Dmax(posi) - Dmin(posi)] × 100 ≤ 130 (Equation 3) -30 ≤ [Dmax(posi) - Dmax(Xray)] / [Dmax(posi) - Dmin(posi)] × 100 ≤ 0 Dmax(posi) is the highest image density in the direct positive image formation method (in the formation of a direct positive image) under conditions without visible light exposure, Dmax(Xray) is the highest image density after X-ray irradiation under conditions without visible light exposure, Dmin(posi) is the lowest image density when irradiated with white light in the direct positive image formation method, and Dmin(Xray) is the image density when irradiated with white light that gives Dmin(posi) after X-ray irradiation.

[0016] The image forming method according to the seventh embodiment, in the fifth or sixth embodiment, has a silver halide photographic photosensitive material having a first image region and a second image region exposed to X-rays of different exposure amounts, wherein in the first image region, the X-ray exposure is performed under the condition that the formed image after development satisfies the following (Equation 4) and (Equation 5): (Equation 4) 0 ≤ [Dmax(Xray) - Dmin(Xray)] / [Dmax(posi) - Dmin(posi)] × 100 ≤ 5 (Equation 5) 90 ≤ [Dmax(Xray)] / [Dmax(posi)] × 100 ≤ 130 In the second image region, the X-ray exposure is performed under the condition that the formed image after development satisfies the following (Equation 6) and (Equation 7): (Equation 6) 5 ≤ [Dmax(Xray) - Dmin(Xray)] / [Dmax(posi) - Dmin(posi)] × 100 ≤ 25 (Equation 7) 50 ≤ [Dmax(Xray)] / [Dmax(posi)] × 100 ≤ 80 Dmax(posi) is the highest image density in the direct positive image formation method (in the formation of a direct positive image) under conditions without visible light exposure, Dmax(Xray) is the highest image density in the direct positive image formation method (in the formation of a direct positive image) under conditions without visible light exposure, Dmin(posi) is the lowest image density when white light is irradiated in the direct positive image formation method (in the formation of a direct positive image), and Dmin(Xray) is the image density when white light that gives Dmin(posi) is irradiated after X-ray irradiation.

[0017] The image forming method according to the eighth aspect is, in any one of the fifth to seventh aspects, the silver halide photographic photosensitive material has a third image area and a fourth image area which are exposed to X-rays and a direct positive image forming area, the exposure of the positive image forming area of ​​the third image area and the exposure of the positive image forming area of ​​the fourth image area are substantially equivalent, and the image density after the development process of the third image area and the fourth image area satisfies the following (Equation 8): (Equation 8) 0.05 ≤ |Dc(Xray1) - Dd(Xray2)| ≤ 2.5 Dc(Xray1) is the image density after the development process in the third image area of ​​the silver halide photographic photosensitive material, and Dd(Xray2) is the image density after the development process in the fourth image area of ​​the silver halide photographic photosensitive material.

[0018] The image forming method according to the ninth embodiment, in any one of the first to eighth embodiments, further includes a visible light exposure step, which is performed after the X-ray exposure step, and involves directly exposing the positive image forming area with visible light.

[0019] The image forming method according to the tenth embodiment, in any one of the first to eighth embodiments, further includes a visible light exposure step, which is performed before the X-ray exposure step, and involves directly exposing a positive image forming area with visible light.

[0020] The image forming method according to the eleventh embodiment is performed in any one of the first to tenth embodiments by superimposing multiple single-sheet silver halide photographic photosensitive materials, with means for partially adjusting the amount of X-ray exposure in the exposed area of ​​the silver halide photographic photosensitive material placed between the X-ray source and the silver halide photographic photosensitive material, and by exposing the superimposed silver halide photographic photosensitive material with X-rays from the direction of superimposition, thereby exposing the exposed area of ​​the superimposed silver halide photographic photosensitive material with substantially the same amount of X-rays.

[0021] The image forming method according to the twelfth embodiment, in any one of the first to tenth embodiments, is performed by exposing the exposed areas of the arranged silver halide photographic photosensitive materials with X-rays at different exposure amounts, with a means for partially adjusting the amount of X-ray exposure in the exposed areas of the silver halide photographic photosensitive materials placed between the X-ray source and the silver halide photographic photosensitive materials.

[0022] The image forming method according to the 13th embodiment is performed in any one of the first to ten embodiments by superimposing multiple sheets of silver halide photographic photosensitive material of the same shape, with means for partially adjusting the amount of X-ray exposure in the exposed area of ​​the silver halide photographic photosensitive material placed between the X-ray source and the silver halide photographic photosensitive material, and by exposing the superimposed silver halide photographic photosensitive material with X-rays from a direction at an angle of 10° to 85° with respect to the direction of superimposition, thereby exposing the exposed area of ​​the superimposed silver halide photographic photosensitive material with X-rays at different exposure amounts.

[0023] In the image forming method according to the 14th embodiment, in any one of the first to 13 embodiments, the X-ray exposure step is performed by changing the shape of the exposed region of the silver halide photographic photosensitive material and / or the amount of X-ray exposure by changing the spatial arrangement of the means with respect to the X-ray irradiation direction, while a means for partially adjusting the amount of X-ray exposure in the exposed region of the silver halide photographic photosensitive material is arranged between the X-ray source and the silver halide photographic photosensitive material.

[0024] In the image forming method according to the 15th embodiment, the X-ray exposure step is performed by changing the spatial arrangement by changing at least one of the number, shape, size, position, and direction of the means.

[0025] The image forming method according to the 16th embodiment is performed in any one of the first to tenth and thirteenth to fifteenth embodiments, wherein the X-ray exposure step is performed by superimposing multiple silver halide photographic photosensitive materials, with means for partially adjusting the amount of X-ray exposure in the exposed area of ​​the silver halide photographic photosensitive material being placed between the X-ray source and the silver halide photographic photosensitive material, and by exposing the superimposed silver halide photographic photosensitive material with X-rays from the direction of superimposition, and the total amount of metal compounds contained in the multiple superimposed silver halide photographic photosensitive materials is 70 g / m² in terms of metal equivalent. ２ More than 700g / m ２ By doing the following, the X-ray fogging density after development is changed among multiple superimposed silver halide photographic materials.

[0026] In the image forming method according to the 17th embodiment, in any one of the 5th to 8th embodiments, the development step is a step of surface development while applying a nucleating treatment using a nucleating agent.

[0027] In the image forming method according to the 18th embodiment, in any one of the first to 17 embodiments, the silver halide photographic photosensitive material is a diffusion transfer type silver halide photographic photosensitive material.

[0028] In the image forming method according to the 19th embodiment, in any one of the first to 18 embodiments, the X-ray exposure step involves irradiating a silver halide photographic photosensitive material, which is packaged in a material that blocks visible light, with X-rays from the outside of the packaging to form a surface negative latent image and / or an internal latent image.

[0029] A 20th aspect of the present invention is a silver halide photographic photosensitive material in which a surface negative type latent image is formed by X-ray irradiation on a direct positive type silver halide photographic photosensitive material containing internal latent image type silver halide particles that are not pre-covered on a support.

[0030] In the 21st embodiment, the silver halide photographic photosensitive material has an image-like surface negative latent image formed as a surface negative latent image in the 20th embodiment.

[0031] The silver halide photographic photosensitive material according to the 22nd embodiment has partially different amounts of X-ray exposure in the exposed region, as in the 20th or 21st embodiment.

[0032] In the 23rd embodiment, the silver halide photographic photosensitive material, in any one of the 20th to 22nd embodiments, has a surface negative latent image formed by irradiating the photosensitive material, which is packaged with a light-shielding material that blocks visible light, with X-rays from the outside of the packaging.

[0033] In the 24th embodiment, the silver halide photographic photosensitive material is further exposed in the positive image forming region by irradiation with visible light, in any one of the 20th to 23rd embodiments.

[0034] In the 25th embodiment, the silver halogen photographic photosensitive material is not subjected to development in any one of the 20th to 24th embodiments.

[0035] In the single-sheet laminate according to the 26th aspect of the present invention, in a single-sheet laminate in which a processing element is disposed between a peel-free film unit in which an image receiving element and a photosensitive element are laminated on one support, and a cover sheet laminated on the peel-free film unit, the photosensitive element is a silver halide photographic light-sensitive material according to any one of the 20th to 25th aspects.

[0036] FIG. 1 is a schematic view of X-ray exposure of an overlapped photosensitive material. FIG. 2 is a schematic view of X-ray exposure of a plurality of photosensitive materials arranged without overlapping on a plane. FIG. 3 is a schematic view of X-ray exposure of a plurality of photosensitive materials arranged with partial overlap on a plane. FIG. 4 is a schematic view of X-ray exposure of an overlapped photosensitive material at an angle different from the overlapping direction. FIG. 5 is a graph showing an example of photographic response when an X-ray exposure is given to a photosensitive material containing an internal latent image type direct positive silver halide emulsion. FIG. 6 is a table showing density measurement results. FIG. 7 is a table showing evaluation results regarding the shielding performance of X-rays. FIG. 8 is a table showing combinations of exposure amount adjusting means and X-ray exposure conditions. FIG. 9 is an image outline when evaluating the speed of image appearance. FIG. 10 is a mask for exposure of an image whose display content changes with the progress of development and an image example.

[0037] As a result of intensive studies, the inventors of the present application have found that "although the conventional mixing of colors in visible light used for a photographic light-sensitive material containing a direct positive emulsion is based on the principle of additive color mixing, in addition to this, by using X-ray exposure in combination, subtractive color mixing can be used in the low-density part and additive color mixing can be used in the high-density part." For example, the inventors of the present application have found that "even in an exposed portion where white light is irradiated in the positive region and becomes white by additive color mixing and image information is lost, in the portion where image information is input by X-ray irradiation, the X-ray image does not disappear and shows subtractive color mixing. Also, in the black portion of the positive region, in the portion where image information is input by X-ray irradiation, the X-ray image does not disappear and shows additive color mixing as a decrease in density."

[0038] This special effect of the present invention, including the estimated part, can be considered as follows. Further technical details will become clear in future research.

[0039] [Direct positive image forming mechanism] The direct positive image forming mechanism is described as follows. That is, when silver halide emulsion grains formed so as to form a latent image inside the grains are exposed, an internal latent image is formed inside the emulsion grains. When these grains are then covered with a chemical nucleating agent and processed, the surface desensitizing action due to this internal latent image works, and no development nuclei (fog nuclei) are generated on the surface of the emulsion grains. Therefore, the exposed area is not surface-developed. Also, in the unexposed area, since no internal latent image is formed, fog nuclei are generated on the surface of the emulsion grains by the covering treatment with the nucleating agent, and surface development proceeds. As a result of these actions, a positive type photographic response is shown in which the unexposed area is developed and the exposed area is not developed.

[0040] [Development behavior of X-ray exposed area] The development behavior of the X-ray exposed area is presumed as follows. When irradiated with X-rays, while secondary electrons generated by colliding with silver halide in the light-sensitive material pass through the silver halide emulsion grains in the vicinity, pairs of photoelectrons and holes are generated. Since the time for secondary electrons to pass through silver halide is on the order of 10 －１４ seconds, it is a situation corresponding to short-time exposure at high illuminance. In some emulsions, the photoelectrons are processed at sites that form internal latent images existing inside the emulsion grains. In some grains, the excess photoelectrons form latent images on the surface of the emulsion grains as well because they cannot be completely processed at the internal latent image forming sites. This is called a surface negative type latent image. The latent image formed on the surface of the emulsion grains is rapidly developed with a surface developing solution.

[0041] Thus, silver halide grains having a negative type latent image on the grain surface formed by X-ray exposure develop starting from this surface latent image even when given white light in the direct positive type area, so density is generated, enabling subtractive color mixing. Furthermore, in silver halide grains in which an internal latent image is formed by X-ray exposure, since the formation of a surface latent image by the nucleating agent is suppressed by this latent image, in the case of an image with black coloring that is not given visible light exposure, a density decrease occurs, enabling additive color mixing, and it becomes possible to leave the input image by X-rays.

[0042] The following description may be based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In this specification, numerical ranges represented by "~" mean a range that includes the numbers written before and after "~" as the lower and upper limits.

[0043] In the image forming method of the present invention, there are two types of exposure steps for the photosensitive material. These are an X-ray exposure step and a visible light exposure step for the direct positive image forming area.

[0044] In the present invention, "exposure of the direct positive image forming region" refers to the exposure of a region in which a direct positive image is obtained by performing surface development after or while performing a fogging treatment after image exposure, using an uncoated internal latent image type silver halide emulsion, where the exposure amount to the intrinsic part or color-sensitized part of the silver halide emulsion is increased from an unexposed state, causing the final image density to decrease and then remain constant at a low density. Furthermore, it does not refer to the exposure of a re-inverted negative image region in which the exposure amount is increased further than that region and the final image density begins to increase. In addition, in the present invention, "including exposure of the direct positive image forming region" means that the exposure of that region is included as the main exposure, and does not prohibit the inclusion of exposure of the intensity of the re-inverted negative image region incidentally. Furthermore, in the present invention, "exposure with visible light" refers to exposure with light in the wavelength range of 360 nm to 780 nm, and is exposure to the intrinsic part or color-sensitized part of the silver halide emulsion. It is sufficient that the light in the relevant wavelength range is the main component; the presence of shorter or longer wave components incidentally is not prohibited.

[0045] <X-ray source> In the present invention, X-rays can be used as the exposure light source. X-rays have a shorter wavelength than visible light and ultraviolet light, and have a strong ability to penetrate materials. The wavelength and intensity can be controlled by adjusting the target material, tube voltage, and tube current of a vacuum tube (X-ray tube) made of glass or ceramics. Examples of target materials include copper, molybdenum, tungsten, silver, and rhodium. In this application, in order to expose a silver halide emulsion to light, a tube voltage of, for example, 2 kV to 300 kV is preferred. From the viewpoint of reducing attenuation by the photosensitive materials themselves when exposing a large number of stacked photosensitive materials at once, a tube voltage of 40 kV to 300 kV is preferred, and 100 kV to 200 kV is more preferred. Furthermore, from the viewpoint that X-rays can be shielded using materials with relatively low atomic numbers and that the amount of X-ray exposure during exposure can be easily adjusted, the tube voltage is preferably 2kV to 100kV, more preferably 10kV to 70kV, even more preferably 15kV to 60kV, and most preferably 20kV to 55kV. The tube current and application time can be freely set to obtain the required X-ray photosensitivity, but for example, a value of about 5mA to 700mA can be adopted. In addition, a value of about 1 / 100th of a second to 100 seconds can be adopted as the time for applying the tube current.

[0046] <X-ray exposure adjustment means> In the present invention, during the X-ray exposure process, the amount of X-ray exposure to the exposed area of ​​the silver halide photographic photosensitive material can be partially changed. To perform such exposure adjustment, means for partially adjusting (or changing) the amount of X-ray exposure to the exposed area of ​​the photosensitive material can be placed between the X-ray source and the photosensitive material (silver halide photographic photosensitive material). Here, "exposed area of ​​the photosensitive material" refers to the entire area of ​​the image formed after the development process in which the positive image formation area is finally exposed with X-rays and / or visible light. The exposure adjustment members 200, 202, and 206, described later in Figures 1 to 3, are one embodiment of this "means for partially adjusting the amount of X-ray exposure".

[0047] The adjustment means described above is preferably composed of a material that absorbs or shields at least a portion of the X-rays irradiated onto the exposure area. Specifically, the material for adjusting the amount of X-rays irradiated onto the photosensitive material is preferably a material containing at least one element with an atomic number between 13 and 83. For example, by including 5% by mass or more of a metal in the material and using a thickness of 20 μm or more in terms of elemental metal, the amount of X-ray transmission can be reduced. Generally, elements with higher atomic numbers tend to shield X-rays more easily. Practically preferred metallic elements include calcium and barium from Group 2, aluminum from Group 13, tin and lead from Group 14, and titanium, chromium, manganese, iron, nickel, copper, zinc, zirconium, molybdenum, silver, tungsten, platinum, gold, mercury, and antimony from the transition metals of Groups 3 to 12. Among these, barium, aluminum, tin, lead, chromium, iron, nickel, copper, zinc, zirconium, and silver are readily available and easy to use. These can be used as elemental metals, but they can also be in the form of alloys, oxides, or salts. To efficiently shield a wide wavelength range of irradiated X-rays, it is preferable to use metals from different groups in combination.

[0048] While known alloys can be used, the following combinations of elements are particularly useful: Iron-containing alloys include (iron, carbon), (iron, nickel), (iron, chromium), (iron, nickel, chromium), (iron, manganese, molybdenum), (iron, chromium, molybdenum); copper-containing alloys include (copper, zinc), (copper, tin), (copper, nickel), (copper, gold); aluminum-containing alloys include (aluminum, copper), (aluminum, magnesium); and lead-containing alloys include (lead, tin), (lead, tin, antimony), etc. Preferred oxides are those of elements such as aluminum, iron, tin, zinc, and zirconium. Salts include calcium carbonate, calcium phosphate, and barium sulfate. Nonmetallic elements with high atomic numbers are also effective; for example, compounds containing halogen elements are preferred. Examples of alkali metal salts include sodium chloride, potassium chloride, cesium chloride, sodium bromide, potassium bromide, and potassium iodide. Furthermore, silver chloride and copper chloride, which have low solubility in water, can be used. Potassium bromide and potassium iodide are particularly useful. Organic compounds containing halogen elements, such as polyvinyl chloride resin, can also be used.

[0049] By changing the amount of these materials during the X-ray transmission process, the amount of X-ray exposure can be adjusted. By three-dimensionally shaping these materials, the amount of X-ray exposure can be changed, and image information for exposure can be prepared. Specifically, examples include substrates on which images or text information are shaped three-dimensionally, including in the thickness direction as well as the plane direction, using metal nanoparticles, metal oxide particles, metal salts, etc., with binders as needed; materials from which desired images or text information is carved out of metal plates; conversely, materials from which desired images or text information is formed on metal plates; and metal wires. Processing equipment for these materials includes 3D printers using metal-based materials and laser cutters for metal-based materials.

[0050] Furthermore, it is possible to use a system in which textual or three-dimensional information is formed three-dimensionally using plastic materials, and the voids where there is no plastic material are filled with a material that reduces X-ray transmission in the form of fine particles. Using a 3D printer when molding the plastic material is preferable because it allows for the free formation of three-dimensional structures. By continuously changing the thickness of the material that reduces X-ray transmission, it is possible to continuously change the exposure amount. When using X-ray shielding material in the form of fine particles, the state may be metal powder, alloy powder, oxide powder, or magnetic powder. Magnetic powder is preferable because it is easy to remove and collect for reuse after filling the voids. Alternatively, the material's inherent crystal structure may be used as is. For example, in the case of textual information, individual character parts can be created and multiple parts can be combined to represent words or sentences.

[0051] Furthermore, the above materials can be used in combination to adjust the exposure amount. Examples include laminates of aluminum and copper plates with character or image information cut out from each, laminates of copper and stainless steel plates, and laminates of brass and stainless steel plates. A plate-shaped material in which powder of a metal element-containing material is filled into the voids can also be layered on top of another metal plate. In addition, materials with a large atomic number and high X-ray shielding properties can be used in small quantities, and can be used as metallic ink to draw image information on a substrate without having to consider the thickness. Furthermore, as an exposure amount adjustment means, it is sufficient to partially change the X-ray exposure amount in the exposed area on the photosensitive material, and can be used without particular restrictions on everyday items, crafts, jewelry, etc. that include the above-mentioned metal material parts. The above exposure amount adjustment means may be used in close contact with the photosensitive material or at a distance.

[0052] <X-ray exposure method> In the present invention, X-rays irradiated onto the photosensitive material from the X-ray source through the exposure amount adjustment means can also be scanned by moving the relative positions of the X-ray source, the exposure amount adjustment means, and the photosensitive material. From the standpoint of making the apparatus compact, it is preferable to move the position of the exposure amount adjustment means or the photosensitive material. For this reason, the apparatus used to carry out the image forming method preferably includes means for moving the relative positions of the X-ray source, the exposure amount adjustment means, and the photosensitive material, such as an extendable and / or rotating arm mechanism, a sliding mechanism (which can be constructed using rails, belts, etc.). Furthermore, the exposure amount can be increased by performing X-ray exposure multiple times, or by changing the exposure amount adjustment means to combine different exposure patterns.

[0053] [Preferred Embodiment of Image Forming Method] (Embodiment 1: X-ray exposure to superimposed sensitive materials) A preferred embodiment (Embodiment 1) of the image forming method of the present invention corresponds to the eleventh embodiment of the present invention described above. Specifically, in this image forming method, multiple single-sheet photosensitive materials (silver halide photographic photosensitive materials) are superimposed, and means for partially adjusting the amount of X-ray exposure in the exposure area of ​​the photosensitive material are placed between the X-ray source and the photosensitive materials, and the superimposed photosensitive materials are exposed with X-rays from the direction of superimposition, thereby providing substantially the same X-ray exposure to the exposure area of ​​the superimposed photosensitive materials (Figure 1). The photosensitive materials may have the same shape or different shapes.

[0054] In the example shown in Figure 1, multiple sheets of photosensitive material 10 (silver halide photographic photosensitive material) of the same shape are superimposed, for example, in the vertical direction, and exposure with X-rays (X-ray exposure process) is performed from the direction of superimposition (in this case, vertically upward). An exposure amount adjustment member 200 is positioned between the X-ray source and the photosensitive material 10. In the example shown in Figure 1, the exposure amount adjustment member 200 is provided with a petal-shaped opening 200A, which transmits X-rays. In the exposure amount adjustment member 200, the portion other than the opening 200A is formed using a material that absorbs or shields at least a portion of the X-rays irradiated onto the exposure area. Specific examples of such materials are described above in the section "<X-ray exposure amount adjustment means>". Note that the transmission, absorption, and shielding of X-rays do not have to be complete (100%), and it is sufficient for the degree of transmission, absorption, and shielding to differ depending on the region of the exposure amount adjustment member 200.

[0055] In this state, X-rays are irradiated from an X-ray source (not shown), and the exposure amount adjustment member 200 is used to partially change the amount of X-ray exposure to the exposed area of ​​the photosensitive material 10 (silver halide photographic photosensitive material) to form a surface negative latent image and / or an internal latent image (exposure step, X-ray exposure step). In this case, an image-like surface negative latent image can be formed as a surface negative latent image. Such X-ray exposure can be performed in the same manner in other embodiments described later. The photosensitive material 10 may be a self-developing instant film such as the one used in Fujifilm's "INSTAX®" or a monosheet laminate according to the 26th embodiment. The "self-developing instant film" is a film equipped with a developing solution pod containing a developing solution, and the developing solution is squeezed out from the pod and spread to the exposed area when the film is passed between a pair of rollers, and the developing process is performed.

[0056] In this embodiment, because X-rays have high penetrability through photosensitive materials, the X-rays hardly attenuate in the superimposed photosensitive materials, making it possible to expose a large number of photosensitive materials with substantially the same amount of X-rays at once. In this case, the attenuation of X-rays in the photosensitive materials can be reduced by increasing the X-ray tube voltage. The amount of silver-equivalent silver halide emulsion coating is approximately 2 g / m². ２With a certain degree of photosensitive material, it is possible to expose about 20 sheets simultaneously. "Substantially equivalent X-ray exposure" here means that the image of the photosensitive material after development by positive exposure with white light following X-ray irradiation has a variation of 5% or less in the two-dimensional position within the photosensitive material and the image density of that region. Here, the photosensitive materials are superimposed so that the emulsion-coated planes are approximately parallel, and they are exposed by X-rays from the direction of superposition via an exposure amount adjustment means. "Exposed by X-rays from the direction of superposition" here means that the X-ray images at the upper and lower ends of the superimposed photosensitive materials are exposed to a substantially equivalent state, and as long as this condition is met, an error of about 10% relative to the direction of superposition is acceptable. The direction of superposition can be vertical, horizontal, or any other direction. For example, in the examples in Figures 1 to 4, the vertical direction of the figures may or may not coincide with the vertical direction.

[0057] (Examples of images formed by the X-ray exposure process) The surface negative latent image and / or internal latent image formed by X-ray exposure may be one or more of the following, or a combination thereof: patterns as shown in the examples in Figures 1 to 3, frames, background images, letters, numbers, symbols, fictional characters (such as cartoon characters, anime characters, or theme park characters), or images of real-life celebrities (such as entertainers or athletes). The same applies to other embodiments of the image forming method (including embodiments 2 to 5).

[0058] (Irradiation of packaged photosensitive material with X-rays) In the X-ray exposure process described above, a surface negative image and / or an internal latent image may be formed by irradiating one or more photosensitive materials, which are packaged using a light-shielding material that blocks visible light, with X-rays from the outside of the packaging. In this embodiment, if the photosensitive material is packaged in a darkroom (a place where visible light is blocked), the X-ray exposure process can be performed in a bright place, improving the handling of the sensitizer. The light-shielding material described above can consist of, for example, a metal or resin film, a resin or paper cartridge, a box-shaped packaging material, etc.

[0059] The irradiation of the packaged photosensitive material with X-rays can also be carried out in the same manner in other embodiments of the image forming method (including embodiments 2 to 5).

[0060] (Part 2: X-ray exposure to photosensitive materials arranged in a planar offset) A preferred embodiment (Part 2) of the image forming method of the present invention corresponds to the twelfth embodiment of the present invention described above. Specifically, in the X-ray exposure step, multiple single-sheet photosensitive materials are arranged in a planar offset so that the areas to be exposed are different, and means for partially adjusting the amount of X-ray exposure in the areas to be exposed of the photosensitive materials are arranged between the X-ray source and the photosensitive materials, and the areas to be exposed of the arranged photosensitive materials are exposed with X-rays at different exposure amounts. According to this embodiment, the image information irradiated via the means for partially adjusting the exposure amount of the areas to be exposed is exposed in divided portions across multiple photosensitive materials. Therefore, the original image information can only be recognized by combining the multiple photosensitive materials. The X-ray exposure images (surface negative latent image and / or internal latent image) divided across multiple photosensitive materials do not need to be the same for each photosensitive material, and may be exposed without overlapping (Figure 2) or with overlapping exposure (Figure 3).

[0061] In the example shown in Figure 2, an exposure adjustment member 202 is positioned between an X-ray source (not shown) and the photosensitive material 10. The exposure adjustment member 202 is provided with a heart-shaped opening 202A, which allows multiple exposure areas of the photosensitive material 10 to be exposed with X-rays at different exposure levels. The user can recognize a heart-shaped mark by combining the multiple photosensitive materials 10 exposed in this way after the development process. Similarly, in the example shown in Figure 3, X-ray exposure can be performed, and the user can recognize a heart-shaped mark by combining the multiple photosensitive materials 10 exposed in this way after the development process.

[0062] (Parts 3-5: Changing the exposure position with angled exposure) The following three further embodiments (Parts 3-5) are embodiments that can intentionally form different images even when using the same X-ray exposure preparation means. This makes it possible to provide photosensitive materials with a variety of exposure conditions, rather than simply identical X-ray exposed products.

[0063] (Part 3: X-ray exposure from an oblique direction to superimposed photosensitive materials) A preferred embodiment (Part 3) of the image forming method of the present invention corresponds to the 13th embodiment described above. Specifically, in an image forming method that includes means for partially adjusting the amount of X-ray exposure to the exposed area of ​​the photosensitive material between an X-ray source and a photosensitive material, the superimposed photosensitive material is exposed with X-rays from a direction at an angle of 10° to 85° with respect to the direction of superposition, so that the exposed areas of the superimposed photosensitive material are each exposed with X-rays. The direction of superposition may be vertical, horizontal, or any other direction.

[0064] X-ray exposure according to the third embodiment will be explained using Figure 4. An exposure amount adjustment member 206 (X-ray exposure amount adjustment means) is placed parallel to the superimposed photosensitive material 10. The exposure amount adjustment member 206 has an opening 206A, and the photosensitive material 10 is exposed by X-rays passing through the opening 206A. When X-rays are irradiated from a direction tilted θ from the direction of superimposition of the superimposed photosensitive material, the area of ​​the superimposed photosensitive material exposed by X-rays gradually changes from the upper layer to the lower layer, and if the thickness of the superimposed material is d, it is possible to displace the uppermost layer by a distance of d × tanθ from the lowermost layer.

[0065] According to the above embodiment, different images can be formed for each photosensitive material. In addition, during exposure, a member for holding the photosensitive material 10 may be used, or the photosensitive material 10 may be in a packaged state.

[0066] (Part 4: Changing the pattern by angled exposure of a three-dimensional stencil) A preferred embodiment (Part 4) of the image forming method of the present invention corresponds to the 14th embodiment described above. Specifically, the X-ray exposure step is performed by changing the shape of the area to be exposed of the photosensitive material and / or the amount of X-ray exposure by changing the spatial arrangement of the X-ray exposure adjustment means with respect to the X-ray irradiation direction, while means for partially adjusting the amount of X-ray exposure of the area to be exposed of the photosensitive material are arranged between the X-ray source and the photosensitive material. The spatial arrangement of the X-ray exposure adjustment means can be changed by changing at least one of the number, shape, size, position, and direction of the means for partially adjusting the amount of X-ray exposure. Specifically, for example, the spatial arrangement of the X-ray exposure adjustment means can be changed using a mechanism for changing the position of the X-ray source and / or the direction of X-ray irradiation, an increase or decrease in the number of X-ray sources irradiating with X-rays, or a mechanism for inserting, moving, changing the direction, or retracting X exposure adjustment means such as the exposure amount adjustment members 200, 202, 204 shown in Figures 1 to 4. As means of changing the spatial arrangement, as described above, extendable and / or rotating arm mechanisms, sliding mechanisms (which can be constructed using rails, belts, etc.), etc., can be employed.

[0067] The fourth aspect can be further classified into the following two aspects. The first aspect is a method in which the X-ray source and photosensitive material are fixed and only the exposure adjustment means is changed in relative spatial arrangement. The second aspect is in which the X-ray source is fixed alone and the relative spatial arrangement of the "set of fixed exposure adjustment means and photosensitive material" is changed. There is no specific definition of "relative spatial arrangement" here, but it is sufficient if the shape of the shadow of the exposure adjustment means projected onto the photosensitive material and the amount of transmitted X-ray light change to a degree that can be recognized as an image after processing. Also, "the exposure adjustment means has a three-dimensional structure" means that if it is 1 mm or more in the thickness direction relative to a plane, the X-ray shadow projected onto the photosensitive material surface of that three-dimensional structure can be recognized by changing the spatial arrangement.

[0068] (Part 5: Attenuation by Sensitive Material) A preferred embodiment (Part 5) of the image forming method of the present invention corresponds to the above-described 14th embodiment. Specifically, in the X-ray exposure step, a plurality of photosensitive materials (silver halide photographic light-sensitive materials) are superimposed, and means for partially adjusting the X-ray exposure amount in the exposed area of the photosensitive material is arranged between the X-ray source and the photosensitive material. Then, X-ray exposure is performed on the superimposed photosensitive materials from the superimposed direction. By setting the total amount of the metal compounds contained in the plurality of superimposed photosensitive materials to be 70 g / m ２ or more and 700 g / m ２ or less in terms of metal conversion, the fog density due to X-rays after development is changed between the superimposed photosensitive materials.

[0069] The "fog density due to X-rays" referred to here is the image density when development processing is performed by giving white exposure to the positive image forming area in the X-ray irradiation area. The order of X-ray irradiation and white light exposure of the positive image forming area may be either first.

[0070] In this embodiment, metal compounds that can be preferably used include, in addition to silver halide emulsions for light sensitivity, for example, colloidal silver, iron oxide, copper oxide, etc., as black coloring materials in the photosensitive material, and titanium oxide, barium sulfate, silicon dioxide, aluminum oxide, etc., as white coloring materials. The amount of silver halide emulsion is often used in the range of 0.5 g / m ２ to 3 g / m ２ per sheet of photosensitive material in terms of metallic silver. For example, when titanium oxide is used as a white colorant, it can be used in the range of 6 to 20 g / m ２ per sheet of photosensitive material in terms of metallic titanium, and the range of 8 to 16 g / m ２ is more preferable. Also, at this time, in order to shield X-rays more effectively and change the effective X-ray exposure amount above and below in the superimposed direction, the tube voltage of the X-ray is more easily affected by a lower value, preferably 10 to 55 KV, more preferably 15 to 30 KV, and even more preferably 15 to 25 KV.

[0071] The purpose of this embodiment is to actively change the image density after X-ray exposure to the superimposed photosensitive material above and below it. However, if it is desired to eliminate the effect of X-ray attenuation by the photosensitive material itself, this can be solved by irradiating the superimposed photosensitive material with X-rays from both above and below. Furthermore, by performing X-ray exposure in a region where increasing the X-ray irradiation dose does not further increase the color density, the density of the final image after processing can be kept constant.

[0072] In X-ray exposure, the direction of X-ray irradiation may be the same as with visible light exposure, from the emulsion side, or, if necessary, the orientation of the exposed image may be reversed and irradiation may be performed from the opposite support side, or from both sides. In this case, the five preferred embodiments of the image forming method of the present invention described above may be used individually or in combination. Furthermore, the photosensitive material does not necessarily have to be a single sheet, but may be wound around a roll once or multiple times. One embodiment of performing X-ray exposure on a roll of photosensitive material is to irradiate it with X-rays from the normal direction from the center of the roll toward the photosensitive material via an exposure amount adjustment means. By using a material that does not transmit X-rays or by surface processing the roll, exposure of the photosensitive material on the back side of the roll to X-rays can be avoided. The roll can also be rotated as necessary to perform X-ray exposure.

[0073] <Exposure Order, etc.> As described above for the ninth and tenth aspects of the present invention, there are no particular restrictions on the order of exposure with X-rays and exposure of the direct positive image formation area with normal visible light; X-ray exposure may come first, later, or simultaneously. Also, each exposure may be performed once or multiple times. In this application, the exposure process for the direct positive image formation area with visible light includes an exposure process in which visible light is not irradiated for the purpose of developing black. Furthermore, it is also possible to perform X-ray exposure to form an image after first exposing the photosensitive material with white light to create a white background in direct positive image formation. In such cases, if many photosensitive materials are exposed with white or other background colors at once, a highly efficient image formation method can be realized.

[0074] X-rays largely penetrate even colored plastic packaging materials that block visible light, as well as the silver halide photographic material itself. Therefore, even when photosensitive materials are layered and packaged in light-shielding packaging, it is possible to expose multiple photosensitive materials simultaneously at once. In the present invention, this property can be utilized to create a highly productive (efficient) image forming system.

[0075] <Preferred range of X-ray exposure amount> In the present invention, the preferred range of X-ray exposure amount will be described. As described above in the sixth aspect, in the image forming method of the present invention, it is preferable that the X-ray exposure has an image region in the formed image after development that satisfies at least one of the following equations (1) to (3). (Equation 1) 2 ≤ [Dmax(posi) - Dmax(Xray)] / [Dmax(posi) - Dmin(posi)] × 100 ≤ 95 (Equation 2) 2 ≤ [Dmin(Xray) - Dmin(posi)] / [Dmax(posi) - Dmin(posi)] × 100 ≤ 130 (Equation 3) -30 ≤ [Dmax(posi) - Dmax(Xray)] / [Dmax(posi) - Dmin(posi)] × 100 ≤ 0 Where Dmax(posi): The highest image density in the direct positive image formation method (in the formation of a direct positive image) under conditions without visible light exposure Dmax(Xray): The highest image density after X-ray irradiation under conditions without visible light exposure Dmin(posi): The lowest image density when exposed to white light in a direct positive image formation method. Dmin(Xray): The image density when exposed to white light that gives Dmin(posi) after X-ray irradiation.

[0076] Here, "white light" refers to a mixture of visible light in such proportions that all the color-sensitive layers in the photosensitive material become photosensitive. Generally, for a photosensitive material consisting of three color-sensitive layers (B, G, R), it refers to white light mixed with visible light components of B, G, and R. The color temperature is not particularly limited, but for example, values ​​from 2700K to 6500K can be used.

[0077] Equation (1) expresses, as a percentage, the rate by which the maximum image density decreases due to X-ray exposure, relative to the maximum and minimum image densities in the direct positive image formation method (formation of a direct positive image). Equation (2) expresses, as a percentage, the rate by which the minimum image density increases due to X-ray exposure, relative to the maximum and minimum image densities in the direct positive image formation method. Equation (3) expresses, as a percentage, the rate by which the maximum image density actually increases due to X-ray exposure, relative to the maximum and minimum image densities in the direct positive image formation method.

[0078] Image density can be determined using the density measured with a Status A filter under a D65 light source. The density only needs to satisfy the above equation if any of the B, G, or R densities are equal. Unless otherwise specified, the density represents the density after 48 hours of development at 25°C.

[0079] Figure 5 shows an example of X-ray exposure, Dmax(Xray), and Dmin(Xray) when using a photographic photosensitive material containing an internal latent image type direct positive silver halide emulsion. Dmax(Xray) decreases with increasing X-ray exposure, but after passing a minimum value, it begins to increase when the exposure is further increased, becoming equivalent to the highest density Dmax(posi) in the direct positive image formation method (direct positive image formation), and in some cases even surpassing it depending on the photosensitive material. On the other hand, Dmin(Xray) continues to increase with increasing X-ray exposure, approaching Dmax(Xray), and eventually becoming identical to Dmax(Xray) when the exposure is further increased. The reason why Dmax(Xray) can sometimes be larger than Dmax(posi) is that in conventional direct positive image formation methods, when the highest density is obtained by cabling, a surface latent image that can be developed with 100% efficiency is not necessarily formed on the silver halide emulsion particles. However, it is understood that development proceeds because a surface latent image is formed by a different mechanism through X-ray exposure.

[0080] This curve illustrates the following regarding the capabilities of an image formation method that combines exposure of the direct positive image formation region with visible light and X-ray exposure: X-ray exposure allows the density to be increased to Dmin(Xray) even with subsequent exposure with white light, enabling color reproduction by subtractive color mixing in addition to additive color mixing with direct positive type photosensitive materials. Furthermore, while X-ray exposure provides Dmax(Xray), the X-ray exposure information can be recorded as a density reduction equal to the density difference compared to the highest density portion in the direct positive type. Additionally, image information can be recorded by the photographic response of the direct positive type within the density difference of [Dmax(Xray) - Dmin(Xray)] obtained according to the amount of X-ray exposure.

[0081] The preferred exposure dose for X-ray exposure can be set appropriately depending on the purpose of the output image, but the following ranges can be cited. One preferred region is the relatively low exposure region (region A in Figure 5). In this irradiation dose region, the decrease in Dmax(Xray) and the increase in Dmin(Xray) are at a level that can be weakly perceived, and it is possible to express the image with small changes in density due to the presence or absence of X-ray exposure. Because a wide density difference between [Dmax(Xray) and Dmin(Xray)] can be taken, the range for additional recording of image information in a direct positive type for the X-ray exposed area is wide. Specifically, expressed numerically, the ratio of [Dmax(posi) - Dmax(Xray)] / [Dmax(posi) - Dmin(posi)] × 100 can be around 2 to 30, and may also be around 5 to 20. The ratio of [Dmin(Xray) - Dmin(posi)] / [Dmax(posi) - Dmin(posi)] × 100 can be around 2 to 20, and may also be around 3 to 10.

[0082] Another preferred region is the relatively intermediate irradiation dose region (region B in Figure 5). In this irradiation dose region, the decrease in Dmax(Xray) and the increase in Dmin(Xray) are at a moderate level, and the change in formed image density due to the presence or absence of X-ray exposure can be represented to a moderate degree. Since the density difference of [Dmax(Xray) - Dmin(Xray)] is moderate, there is a sufficient density range for additional recording of image information in the positive type directly for the X-ray exposed area. Specifically, expressed numerically, the ratio of [Dmax(posi) - Dmax(Xray)] / [Dmax(posi) - Dmin(posi)] × 100 can be around 15 to 45, and may also be around 20 to 40. The ratio of [Dmin(Xray) - Dmin(posi)] / [Dmax(posi) - Dmin(posi)] × 100 can be approximately 5 to 45, and may also be approximately 10 to 40.

[0083] Another preferred region is the region with relatively high irradiation doses (region C in Figure 5). In this irradiation dose region, the absolute density of the image formed by X-ray exposure is high. Because the density difference of [Dmax(Xray) - Dmin(Xray)] is small, the width over which additional image information can be directly recorded in the positive type relative to the X-ray exposed area is small. In this region, it is possible to obtain a density higher than the maximum density obtainable with direct positive type by increasing the irradiation dose. Specifically, the ratio of [Dmax(posi) - Dmax(Xray)] / [Dmax(posi) - Dmin(posi)] × 100 can be around 2 to 20 in regions where the density decreases due to X-ray exposure, and may also be around 2 to 15. Conversely, in regions where the density is the same or increases due to X-ray exposure, this ratio can be around -30 to 0, and may also be around -25 to -5. The ratio of [Dmin(Xray) - Dmin(posi)] / [Dmax(posi) - Dmin(posi)] × 100 can be approximately 45 to 130, and may also be approximately 75 to 125.

[0084] Furthermore, in direct positive type photosensitive materials, if a latent image is formed inside the silver halide emulsion due to deterioration over time, the Dmax(posi) may decrease significantly. Even in such cases, the formation of a surface latent image by X-ray exposure is effective, and therefore the image formation method of the present invention is effective. In such cases, the region C in Figure 5 may have the following ratios. Specifically, the ratio of [Dmax(posi) - Dmax(Xray)] / [Dmax(posi) - Dmin(posi)] × 100 may be around -60 to -20, and may even be around -150 to -20. Also, the ratio of [Dmin(Xray) - Dmin(posi)] / [Dmax(posi) - Dmin(posi)] × 100 may be around 100 to 150, and may even be around 100 to 220.

[0085] In this invention, a particularly preferred mode of X-ray exposure is described, which is one that is less affected by the superimposed positive image. This mode uses two regions in an irradiation region with a relatively high X-ray exposure: (a) a high irradiation region (first image region) where the density of actual Dmin(Xray) is equivalent to that of Dmax(posi), and (b) a region with a relatively lower X-ray exposure (second image region). For example, patterns and text information can be exposed with X-rays at a relative exposure of 6 in Figure 5, and the surrounding background area can be exposed with X-rays at a relative exposure of 4. In this case, even if any image from white to black is superimposed with positive exposure, the density of the patterns and text information remains unchanged (density is approximately 2.4), and the density difference in the surrounding background area is greatly reduced (density is 1.5 to 1.7), thus forming an image that is almost the original X-ray image. The X-ray exposure regions (a) and (b) can be freely combined and used, including other X-ray exposure regions, as long as the effects of the present invention are obtained. However, it is also preferable to use only the two regions in combination, and it is even more preferable that they are in contact in at least a part of the image. When a QR code (registered trademark; two-dimensional code) was created by combining the exposure regions of region (a) for the code portion and region (b) for the background portion, it was possible to read the QR code regardless of the pattern of the positive image subsequently captured.

[0086] Expressing the above X-ray exposure regions numerically, the high-dose region (a) satisfies the following equations (4) and (5), and the region (b) with a relatively reduced X-ray dose satisfies the following equations (6) and (7). (Formula 4) 0≦[Dmax(Xray)-Dmin(Xray)] / [Dmax(posi)-Dmin(posi)]×100≦5 (Formula 5) 90≦[Dmax(Xray)] / [Dmax(posi)]×100≦130 (Formula 6) 5≦[Dmax(Xray)-Dmin(Xray)] / [Dmax(posi)-Dmin(posi)]×100≦25 (Formula 7) 50≦[Dmax(Xray)] / [Dmax(posi)]×100≦80

[0087] Here, the following ranges are considered to be even more preferable for the numerical values ​​in the equations: The even more preferable range for (Equation 4) is 0 to 4, the even more preferable range for (Equation 5) is 95 to 120, the even more preferable range for (Equation 6) is 6 to 15, and the even more preferable range for (Equation 7) is 60 to 70. Within these ranges, the difference in color density is large in regions (a) and (b), sufficient image contrast is obtained in the X-ray image portion, and the influence of the positive image is reduced, so the original X-ray image is less likely to become difficult to see.

[0088] (Preferred X-ray exposure) In this invention, the preferred X-ray exposure will be explained using the processed image. Two regions of the photosensitive material, (c) (third image region) and (d) (fourth image region), are exposed to X-rays and the positive image formation region is directly exposed. The exposure of the positive image formation region in both regions (c) and (d) is substantially equivalent, and the image density after development of both regions satisfies the following equation: (Equation 8) 0.05 ≤ |Dc(Xray1) - Dd(Xray2)| ≤ 2.5 Where Dc(Xray1): Image density after development of region (c) of the photosensitive material (third image region) Dd(Xray2): Image density after development of region (d) of the photosensitive material (fourth image region)

[0089] Here, "substantially equivalent exposure in the positive image formation region" means that in the irradiation dose region where the image density has gradations depending on the exposure light amount, the exposure dose difference should be within approximately 20%. To minimize the image density difference after development, it is more preferable to have an exposure dose difference of 12% or less, and most preferably within 8%. Furthermore, irradiation dose regions where the image density does not change depending on the exposure light amount, such as the lowest density region exposed with white light and the highest density region where the density does not begin to decrease from the unexposed state, are also considered to have substantially equivalent exposure in the positive image formation region.

[0090] Here, to satisfy (Equation 8), it is highly probable that regions (c) and (d) are exposed under different X-ray exposure conditions. Specifically, "different conditions" preferably means that the amount of X-ray exposure is changed by means of X-ray tube voltage, tube current, irradiation time, X-ray exposure amount adjustment means, etc. This also includes cases where one of the regions is not exposed to X-rays. In the processed image, the value of the above equation can be measured and evaluated in parts where the exposure of positive image formation regions other than X-ray exposure can be determined to be the same based on the continuity of the subject and formed image. Examples of such parts include the lowest density area exposed to white light, the highest density area that is not exposed, a background image area of ​​constant density, a continuous blue sky, and artificial objects such as walls that are continuous. Furthermore, a characteristic of the X-ray exposed area is that the highest density area, which is given a sufficient amount of X-ray exposure, has a high density that cannot be achieved with conventional direct positive image formation methods. In addition, the exposure interface between the X-ray exposed area and the unexposed area has a very sharp image density profile with a large reduction in light blurring that inevitably occurs with visible light exposure.

[0091] The value of |Dc(Xray1) - Dd(Xray2)| can be sufficiently recognized as a concentration change if it is between 0.05 and 2.5, and it can also be in the range of 0.10 to 2.0. For this evaluation, the concentration that best expresses the largest concentration difference among B, G, and R can be used.

[0092] There are no particular restrictions on the order and interval between X-ray exposure and direct positive image formation exposure. If X-ray exposure is performed first, the interval between the two exposures can be, for example, simultaneous to 5 years, preferably 1 minute to 1 year. For example, in a scenario where a photosensitive material exposed with X-rays at the time of shipment is subjected to further exposure by the user, the interval between the two exposures can preferably be 1 day to 3 years.

[0093] <Light sources for exposure in the direct positive image region> Exposure in the direct positive image region includes photographing a subject illuminated by sunlight or a general-purpose light source (incandescent lamp, fluorescent lamp, LED, EL, strobe, etc.). Furthermore, light sources for the positive exposure region can be incorporated into known exposure systems. For example, Japanese Patent Nos. 3818563, 3818564, 2662442, Japanese Patent Publication Nos. 2000-313137, 2003-156733, and Japanese Patent Publication No. 11-344772 describe light-emitting diodes (LEDs), electroluminescence, and devices using a light-emitting element and liquid crystal segment in combination.

[0094] <Pre-exposed photosensitive material> When carrying out the image forming method of the present invention, a "silver halide photographic photosensitive material that has been exposed to X-rays at least once, and which will be further exposed to a direct positive area at least once more, and subsequently subjected to development processing" can be used. Also, when carrying out the image forming method of the present invention, a "silver halide photographic photosensitive material in which a surface negative type latent image is formed by X-ray irradiation on a direct positive type silver halide photographic photosensitive material containing internal latent image type silver halide particles that have not been pre-covered on a support" (silver halide photographic photosensitive material according to the 20th embodiment described above) can also be used. A preferred embodiment of the pre-exposed photosensitive material is a photosensitive material that has been exposed to a common display image, a special effect image, an advertising image, manufacturing control number information, etc., by X-ray exposure as the first exposure. A user can use this pre-exposed photosensitive material to photograph and expose a normal subject through an optical lens and output an image, or to expose desired digital image information with a positive type general-purpose printer and output an image. In this process, multiple photosensitive materials can be exposed to images simultaneously using X-ray exposure, resulting in high production efficiency.

[0095] Furthermore, when implementing the image forming method of the present invention, it is also possible to use a silver halide photographic photosensitive material that has undergone at least one X-ray exposure step and at least one direct positive image forming region exposure, and is developed without further additional exposure. A preferred embodiment of the exposed photosensitive material is a photosensitive material that has been exposed with X-rays to create a common display image, a special effect image, an advertising image, manufacturing control number information, etc., and then subsequently exposed with a positive type exposure to create a desired digital image. In this case, the order of X-ray exposure and positive type exposure may be reversed. The user can develop this exposed photosensitive material using a general-purpose printer or the like without further exposure to create an image and output the image.

[0096] There are no particular restrictions on the interval between X-ray exposure and visible light exposure, however, for example, in cases where a photosensitive material exposed to X-rays at the time of shipment is subjected to further exposure by the user, it is preferable to have an interval of 1 day to 5 years. Furthermore, for such products, it is preferable to display information that informs (certifies) that a negative latent image has been formed by X-ray irradiation, the exposure conditions, latent image information, etc. The display can be made by one or more of the following: letters, numbers, symbols, patterns, images, or a combination of one or more of these and colors, and may be done by printing, labeling, etc., or by using barcodes, two-dimensional codes, URLs (Uniform Resource Locators), etc.

[0097] The display may be placed on the photosensitive material itself (image area, non-image area, front, back, etc.), the cartridge containing the photosensitive material, the aluminum bag packaging it, the cardboard box outside the aluminum bag, etc. When such a display is made, it may or may not be possible to display "what kind of negative latent image has been formed" (for example, what kind of frame, pattern, letters, numbers, symbols, cartoon or anime characters, images of celebrities or athletes, etc. have been formed). Displaying the information can make it easier for the user to select the desired product, or conversely, not displaying it and keeping the user "unaware of what kind of latent image has been formed" can create a sense of excitement.

[0098] (Silver Halogen Photosensitive Material) A silver halogen photographic sensitive material according to one aspect of the present invention is a direct positive type silver halogen photographic sensitive material containing internal latent image type silver halogen particles that are not pre-coated on a support, and exhibits a positive type photographic response in a specific exposure range. Another aspect of the present invention is a silver halogen photographic sensitive material in which a surface negative type latent image is formed by X-ray irradiation on a direct positive type silver halogen photographic sensitive material containing internal latent image type silver halogen particles that are not pre-coated on a support.

[0099] The "internal latent image type direct positive silver halide emulsion" of the present invention (hereinafter sometimes abbreviated as "internal latent image type silver halide emulsion") is a silver halide emulsion that forms a latent image mainly inside the silver halide particles when exposed to image light. Specifically, it is preferable that the maximum concentration obtained when a certain amount of the silver halide emulsion is coated onto a transparent support, exposed for a fixed time of 0.01 to 1 second, and developed in developer A ("internal type" developer) at 20°C for 5 minutes is at least five times greater than the maximum concentration obtained when a second sample exposed in the same manner as above is developed in developer B ("surface type" developer) at 20°C for 5 minutes. Here, the maximum concentration is measured by a normal photographic density measurement method.

[0100] Developer A: N-methyl-p-aminophenol sulfite 2g, sodium sulfite (anhydrous) 90g, hydroquinone 8g, sodium carbonate (monohydrate) 52.5g, potassium bromide 5g, potassium iodide 0.5g. Add water to make 1 liter.

[0101] Developer B: 2.5g N-methyl-p-aminophenol sulfite, 10g l-ascorbic acid, 35g potassium metanitrate, 1g potassium bromide. Add water to make 1 liter.

[0102] To obtain a positive image directly, the above-mentioned internal latent image type silver halide emulsion can be exposed to light, and then a uniform second exposure can be applied to the front of the exposure layer before or during development ("photo-blink method," e.g., British Patent No. 1,151,363), or development can be performed in the presence of a nucleating agent ("chemical-blink method," e.g., Research Disclosure, Vol. 151, No. 15162, pp. 76-78). In the present invention, however, the method of obtaining a positive image directly by the "chemical-blink method" is preferred.

[0103] As nucleating agents, hydrazines described in U.S. Patent Nos. 2,563,785 and 2,588,982, hydrazides and hydrazones described in U.S. Patent No. 3,227,552, heterocyclic quaternary salt compounds described in British Patent No. 1,283,835, JP 52-69613, JP 55-138742, JP 60-11837, JP 62-210451, JP 62-291637, U.S. Patent Nos. 3,615,515, JP 3,719,494, JP 3,734,738, JP 4,094,683, JP 4,115,122, JP 4,306,016, JP 4,471,044, etc., U.S. Patent No. 3, Examples of sensitizing dyes used include those described in Patent No. 718,470, which have nucleogenic substituents in the dye molecule; thiourea-linked acylhydrazine compounds described in U.S. Patents Nos. 4,030,925, 4,031,127, 4,245,037, 4,255,511, 4,266,013, 4,276,364, and British Patent No. 2,012,443; and siahydrazine compounds linked to heterocyclic groups such as thioamide rings, triazoles, and tetrazoles as adsorbent groups, as described in U.S. Patents Nos. 4,080,270, 4,278,748, and British Patent No. 2,011,391B.

[0104] The amount of nucleating agent used here should preferably be such that it provides a sufficient maximum concentration when the internal latent image emulsion is developed with a surface developer. In practice, the appropriate content can vary over a wide range, as it depends on the characteristics of the silver halide emulsion used, the chemical structure of the nucleating agent, and the development conditions. However, a range of approximately 0.1 mg to 5 g per mole of silver in the internal latent image silver halide emulsion is practically useful, and preferably approximately 0.5 mg to 2 g per mole of silver. When the nucleating agent is included in a hydrophilic colloid layer adjacent to the emulsion layer, the same amount as above should be included relative to the amount of silver contained in the internal latent image emulsion of the same area.

[0105] In this invention, silver halide particles of various shapes can be used. Examples include those having regular crystal shapes such as cubes, octahedra, tetrahedrons, and rhombic dodecahedrons, as well as those having irregular crystal shapes such as spheres and plates, those having higher-order faces ((hkl) faces), or mixtures of particles of these crystal shapes. For particles with higher-order faces, see pages 247 to 254 of the Journal of Imaging Science, Volume 30 (1986). The silver halide particles used in this invention can be normal crystals that do not contain twinning planes, or they can be selected and used according to the purpose from examples such as single twins containing one twinning plane, parallel multiple twins containing two or more parallel twinning planes, and nonparallel multiple twins containing two or more nonparallel twinning planes, as explained on page 163 of "Fundamentals of Photographic Industry, Silver Halide Photography" edited by the Photographic Society of Japan (Corona Publishing Co., Ltd.). Furthermore, an example of mixing particles of different shapes is disclosed in U.S. Patent No. 4,865,964, and this method can be chosen as needed.

[0106] In particular, a core / shell type internal latent image type silver halide emulsion is preferably used in the present invention because it is easy to control the sensitivity of the re-inverted negative image to a low level. Examples of core / shell type internal latent image type silver halide emulsions include conversion type silver halide emulsions as described in U.S. Patent No. 2,456,953 and No. 2,592,250, etc., multilayer structure type silver halide emulsions in which the halogen compositions of the first and second phases are different as described in U.S. Patent No. 3,935,014, etc., and metal ion-doped silver halide emulsions. Other examples of core / shell type silver halide emulsions are described in U.S. Patents 3,206,313, 3,317,322, 3,761,266, 3,761,276, 3,850,637, 3,923,513, 4,035,185, 4,184,878, 4,395,478, 4,504,570, and Japanese Unexamined Patent Publications S57-136641, S61-3137, S61-299155, S62-208241, etc. In the present invention, the "shell" refers to the silver halide phase formed after chemical sensitization of the silver halide particles that form the core in the emulsion preparation process. The shell manufacturing method can be based on the examples in Japanese Patent Publication No. 63-151618, and U.S. Patents 3,206,316, 3,317,322, 3,761,276, 4,269,927, and 3,367,778, etc. In this case, the core / shell molar ratio (mole by weight ratio) is preferably 1 / 30 to 5 / 1, more preferably 1 / 20 to 2 / 1, and even more preferably 1 / 10 to 1 / 1.

[0107] Because the inverted positive image has high sensitivity, the re-inverted negative image has low sensitivity, and the storage stability of the photosensitive material in an unexposed state is excellent, it is preferable that the particles used in the core / shell type internal latent image type silver halide emulsion of the present invention are doped with a metal complex containing a cyanide ligand in the core portion of the particles. Examples of specific metal complex structures, amounts added, and core / shell emulsion structures are described in Japanese Patent Application Publication No. 2002-40607 and No. 2003-107616, among others.

[0108] Furthermore, in the present invention, various anti-fogging agents, photographic stabilizers, etc., can be used to prevent a decrease in sensitivity and the occurrence of fogging, and known additives can be used to adjust the performance of the photosensitive element. These additives can be those described in Japanese Patent Publication No. 2002-40607, Japanese Patent Publication No. 2003-107616, etc.

[0109] Next, we will describe the diffusion transfer photosensitive material (diffusion transfer type photosensitive material) that is preferably used in the present invention. The most representative form of the diffusion transfer material of the present invention is a color diffusion transfer film unit, and the typical form of this unit is one in which an image-receiving element and a photosensitive element are laminated on a single transparent support, and there is no need to peel the photosensitive element from the image-receiving element after the transfer image is completed. More specifically, the image-receiving element consists of at least one mordant layer, and in a preferred embodiment of the photosensitive element, it is composed of a combination of a blue-sensitive emulsion layer, a green-sensitive emulsion layer and a red-sensitive emulsion layer, or a combination of a green-sensitive emulsion layer, a red-sensitive emulsion layer and an infrared-sensitive emulsion layer, or a combination of a blue-sensitive emulsion layer, a red-sensitive emulsion layer and an infrared-sensitive emulsion layer, with each of the aforementioned emulsion layers being combined with a yellow pigment image-forming compound, a magenta pigment image-forming compound and a cyan pigment image-forming compound, respectively (here, "infrared-sensitive emulsion layer" refers to an emulsion layer that has a spectral sensitivity maximum for light with a wavelength of 700 nm or more, especially 740 nm or more). Between the mordant layer and the photosensitive layer or the pigment image-forming compound-containing layer, a white reflective layer containing a solid pigment such as titanium dioxide is provided so that the transferred image can be viewed through a transparent support. To enable development in bright light, a light-shielding layer may be provided between the white reflective layer and the photosensitive layer. Alternatively, a release layer may be provided at an appropriate position to allow all or part of the photosensitive element to be detached from the image-receiving element, if desired. Such embodiments are described, for example, in Japanese Patent Publication No. 56-67840 and Canadian Patent No. 674,082.

[0110] Furthermore, the pigment image-forming compounds combined with the emulsion layers having different photosensitive wavelengths are not limited to the three primary colors of yellow, magenta, and cyan, but can be freely selected. Mixtures of multiple colors are also acceptable. By mixing the three primary colors in a balanced manner, it is possible to form an image with a color tone that is close to gray.

[0111] In addition to the above, the configurations of the photosensitive element and the image-receiving element can be broadly classified into those that require separation of the two and those that do not. For these configurations, the embodiments described in paragraphs

[0111] to

[0112] of Japanese Patent Application Publication No. 2002-40607 can also be adopted.

[0112] The pigment image-forming material used in the present invention is a diffusion-resistant compound that releases a diffusible dye (which may also be a dye precursor) in relation to silver development, and is represented by general formula (II). General formula (II): (DYE-Y)n-Z

[0113] In formula (II), DYE represents a dye group, a temporarily short-wave dye group, or a dye precursor group; Y represents a simple bond or a bonding group; Z represents a group having properties that cause a difference in the diffusivity of a compound represented as (DYE-Y)n-Z, corresponding to a photosensitive silver salt having a latent image in the image; n represents 1 or 2, and when n is 2, the two DYE-Y groups may be the same or different. This compound is described in the fourth edition of "The Theory of the Photographic Process".

[0114] Specific examples of Z in this compound include those that oxidize and cleave upon development, releasing diffusive dyes. Specific examples of Z are U.S. Patents 3,928,312, 3,993,638, 4,076,529, 4,152,153, 4,055,428, 4,053,312, 4,198,235, 4,179,291, 4,149,892, 3,844,785, 3,443,943, 3,751,406, 3,443,939, 3,443,940, 3,628,952, 3,980,479, 4,183,753, 4,142,891, 4,278,750, and 4,139,3 This is described in Japanese Patent Publication Nos. 79, 4,218,368, 3,421,964, 4,199,355, 4,199,354, 4,135,929, 4,336,322, 4,139,389, Japanese Patent Publication Nos. 53-50736, 51-104343, 54-130122, 53-110827, 56-12642, 56-16131, 57-4043, 57-650, 57-20735, 53-69033, 54-130927, 56-164342, 57-119345, etc. Among the groups of Z, particularly preferred groups include N-substituted sulfamoyl groups (groups derived from aromatic hydrocarbon rings or heterocycles as N-substituted groups).

[0115] In addition to the above-described configuration of photosensitive and image-receiving elements, a pressure-bursting container (processing element) containing an alkaline processing solution may be further combined. In particular, in a peel-free film unit in which the image-receiving element and photosensitive element are laminated on a single support, it is preferable that this processing element be placed between the photosensitive element and the cover sheet superimposed thereon. The processing element preferably contains either or both a light-shielding agent (such as carbon black or a dye whose color changes depending on the pH) and a white pigment (such as titanium dioxide), depending on the form of the film unit. Furthermore, in a color diffusion transfer type film unit, it is preferable that a neutralization timing mechanism consisting of a neutralization layer and a neutralization timing layer is incorporated in the cover sheet, the image-receiving element, or the photosensitive element. As for the form of these monosheet laminates, those described in Japanese Patent Application Publication No. 2021-22039 are preferred, as for the form of the processing solution pod, those described in Japanese Patent Application Publication No. 11-334766 are preferred, and as for the form of the film pack, those described in Japanese Patent Application Publication No. 7-159931 are preferred.

[0116] The constituent materials that can be used in a monosheet-type laminate, such as alkali, developer, light-shielding material, transparent support, image-receiving layer, white reflective layer, color-mixing inhibitor, high-boiling point organic solvent, neutralizing layer, surfactant, polymer latex, etc., can be those described in Japanese Patent Publication No. 2002-4067, Japanese Patent Publication No. 2003-107616, and Japanese Patent Publication No. 2006-113291.

[0117] <Method for creating differences in image appearance speed> When a silver halide photographic photosensitive material was exposed using the image formation method of the present invention and the appearance of the transfer dye image was observed in detail, it was found that the area exposed with X-rays according to the present invention showed a faster image appearance speed than the area exposed with positive-type X-rays. This effect was particularly noticeable in the X-ray exposed area of ​​region C in Figure 5 mentioned above. By intentionally setting a time interval in the image appearance recognition time for each region in which an observation image is formed, messages from each image can be made to appear in sequence.

[0118] The effects of displaying each image in sequence include: effects such as each image in the first and second image regions being recognized like a two-panel comic strip, where the second panel is recognized only after the first panel is recognized; effects where focus gradually shifts to a specific object within the same screen; effects where the information in the first image is overwritten by the information in the second image over time; and effects where the meaning changes as the information in the second image is added to the information in the first image. "Changes in meaning" includes, for example, changes in directional relationships, length-to-short relationships, size-to-size relationships, and superior-inferior relationships that can be read from the entire image, as well as changes in what is represented as numbers, text, or symbols. It also includes changes in barcodes and QR codes (registered trademarks) from being readable to unreadable, and vice versa.

[0119] While anticipating the final observational image, the chronological order of image appearance recognition can be set based on the spatial relationships between each subject within the image and the "semantic context" within the image. Examples of combinations of "semantic context" include, but are not limited to, [question vs. answer], [question vs. hint for the question], [announcement vs. answer], [announcement vs. implementation], [title vs. details], [early vs. late in the flow of time], [first half vs. second half of a tanka poem], and [applicable vs. inapplicable].

[0120] The image forming method of the present invention can be used as a means to control the difference in image appearance recognition speed between a first image region and a second image region in the image forming method of Japanese Patent Application Publication No. 2021-196519. Specifically, in claims 1 to 9 and 18 to 20 of Japanese Patent Application Publication No. 2021-196519, the first image region is exposed with X-rays and the second image region is exposed with a positive type.

[0121] The peculiar effect that "the area exposed to X-rays develops images faster than the area exposed to positive film" is presumed to be due to the difference in the development mechanism of the silver halide emulsion between the X-ray-exposed and positive film areas. In other words, in the silver halide emulsion exposed to X-rays, a developable surface latent image is formed on the surface of the silver halide particles before they reach the processing solution, allowing development to begin quickly. On the other hand, in the positive film area, a reaction process is required in which a nucleating agent present near the emulsion injects electrons into the silver halide emulsion during the development process, forming a surface latent image that makes the surface of the emulsion particles developable. It is presumed that the time required for this reaction process is what causes the difference in image development speed.

[0122] [Examples] The present invention will be described in more detail below based on examples. The materials, usage conditions, image forming procedures, etc., shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the specific examples shown below.

[0123] <Example 1>

[0124] [Preparation of Photosensitive Material] Sample 102, which is a direct positive type silver halide photographic photosensitive material, was prepared in accordance with the description of Example 1 in Japanese Patent Application Publication No. 2003-107616, and an image was formed using the cover sheet and alkali treatment composition described in Example 1 according to the following steps. The photosensitive material used was stored for 7 days at 30°C and 70% relative humidity after coating.

[0125] [X-ray exposure] X-ray target W / Rh Tube voltage: Select from two conditions: 22kV and 49kV Tube current × application time: Select from three conditions: 100mAs, 300mAs, and 450mAs

[0126] A 1.5 mm thick lead plate and a 1.5 mm thick copper plate were used as the X-ray shielding material. A 2.5 cm square window was cut out of this X-ray shielding material to create an X-ray exposure adjustment mechanism. This X-ray exposure adjustment mechanism was inserted between the X-ray source and the photosensitive material, and X-ray exposure was performed.

[0127] The photosensitive material that had been X-ray exposed as described above was subjected to visible light exposure under conditions that would transfer white and black to the positive region by direct exposure of the photosensitive material. The photosensitive material and a cover sheet were placed on top of each other, and the alkali treatment composition described above was spread between them to a thickness of 55 μm using a pressure roller. Exposure and treatment were carried out at 25°C, and the transferred dye density was measured after 2 hours. For comparison, a sample that was not exposed to X-rays at all was also prepared. Figure 6 (Table 1) shows the measurement results of the R density under status A under the D65 light source for four conditions in which the exposure state differed depending on the presence or absence of shielding material in the X-ray exposure and the combination of white and black in direct exposure of the positive region, under a single X-ray exposure condition. In Table 1, Dmax(posi): The highest image density under the direct positive image formation method (in the formation of a direct positive image) without visible light exposure. Dmax(Xray): The highest image density under the condition of X-ray irradiation followed by no visible light exposure. Dmin(posi): The lowest image density under the direct positive image formation method when exposed to white light (when irradiated with white light). Dmin(Xray): The image density when exposed to white light that gives Dmin(posi) after X-ray irradiation.

[0128] According to Table 1, the X-ray exposure amount could be adjusted using the above-mentioned X-ray shielding material to the point where the photographic material produced the same color density as when it was not irradiated with X-rays at all (results for the group of samples ending in a and b). Furthermore, the density of the black areas without visible light exposure (Dmax(Xray)) decreased once as the X-ray exposure amount increased, then increased again, and even increased to a level higher than when there was no X-ray irradiation. In addition, the density when exposed to white light (Dmin(Xray)) showed an increase in fogging density as the X-ray exposure amount increased, and ultimately, it was found that both achieved high color density regardless of whether or not there was visible light exposure. These results are for the brightest white and darkest black in visible light exposure, but when a color image in the positive-type photographic response region was exposed and processed on the X-ray-exposed photosensitive material, it was found that a color image was formed within the density range of Dmax(Xray) and Dmin(Xray), similar to the evaluation results for black and white above. Under the conditions of this embodiment, the image formed by X-ray exposure was a roughly gray color with a slight greenish tint, as all three colors developed and mixed together.

[0129] [Example 2] In Example 1, the material of the X-ray light intensity adjustment means was changed as shown in Figure 7 (Table 2), and the X-ray shielding performance of the material was evaluated. The evaluation results are shown in Table 2. For barium sulfate, two PET substrates with a thickness of 200 μm were placed with spacers between them to ensure a constant thickness, and the thickness was determined by sandwiching them from above and below. Barium sulfate with a bulk specific gravity of 1.3 was used. For other metals, metal plates were used. According to Table 2, it can be seen that the X-ray shielding performance changes greatly depending on the exposure intensity adjustment means used. It was found that by increasing the film thickness of the barium sulfate powder, shielding performance almost equivalent to that of copper or a combination of copper and lead could be obtained in terms of photographic evaluation (comparison of samples 203a, 203b, 204a, 204b, 209a, and 209b).

[0130] [Example 3] A monosheet type laminate of instant photographic film was created by integrating the unexposed silver halide photographic photosensitive material, cover sheet, and processing solution pod described in Example 1. Ten monosheet laminates were packed into a plastic film pack shielded with carbon black. These were then placed in a plastic film bag shielded with aluminum vapor deposition. Monosheet laminate size: 54 mm wide, 86 mm long, of which the image-forming surface size is 46 mm wide, 62 mm long. Film pack size: 58 mm wide, 90 mm long, 19 mm thick.

[0131] Regarding the X-ray light intensity adjustment method, the following four types were created: S1: Stainless steel plate A 1.5 mm thick, 60 mm wide x 90 mm long stainless steel plate was cut out with font size 20 to display text information. "VWXY" was written in the upper right corner of the screen. S2: Copper plate-1 A heart mark the size to be inscribed in a 40 mm circle was cut out from a 1.5 mm thick copper plate. The cut-out heart mark copper plate was fixed to the center of a 60 mm wide x 90 mm long plastic plate. S3: Barium sulfate filling into a 3D printer mold A 60 mm wide x 90 mm long, 10 mm thick rectangular prism was used as the outer edge, and a plastic molded body was created using a 3D printer that included a groove in the center with a heart mark the size to be inscribed in a 40 mm circle and with a maximum depth of 5 mm. The heart mark groove was sloped so that it gradually deepens from the edge towards the center, and reaches its maximum depth 8 mm inward from the edge. BaSO4 powder (bulk density 1.3) was filled into the space of the groove. S4: Copper Plate - 2 A heart shape was cut out from a 1.5 mm thick copper plate, sized to inscribe within a 55 mm circle. The cut-out heart shape from the copper plate was fixed to the center of a plastic plate measuring 125 mm wide x 90 mm long.

[0132] X-ray exposure conditions X-ray target W / Rh conditions X1 Tube voltage 22kV, Tube current × Application time 300mAs X2 Tube voltage 49kV, Tube current × Application time 160mAs X3 Tube voltage 49kV, Tube current × Application time 450mAs X4 Tube voltage 49kV, Tube current × Application time 600mAs

[0133] As shown in Figure 8 (Table 3), exposure was performed by combining exposure adjustment means and X-ray exposure conditions. When using exposure adjustment means S1 to S3, the photosensitive material was exposed from the same side as when it is exposed to visible light, by placing it in close contact with one film pack box that was packaged in a plastic film from the photosensitive material side. When using exposure adjustment means S4, two film pack boxes were placed side by side and exposed at the same time. In this way, X-ray exposed silver halide photographic photosensitive material samples 301X to 305X were obtained.

[0134] The above-mentioned film pack was attached to an electronic still camera, which incorporates a printer unit having an array of three-color organic EL light-emitting elements, as described in Japanese Patent Publication No. 3818564. Various subjects, from bright to dark, were freely photographed with this electronic still camera, and the captured images were exposed to a monosheet laminate, and a processing solution was unfolded to form an image. This exposure by the printer corresponds to the exposure of the positive area. The interval between the first and second exposures was evaluated in the range of approximately one hour to one month. The image formed after processing contained both text information and image information input by X-ray exposure, and the subject image input by the second exposure.

[0135] The area where the text information of sample No. 301X was exposed to X-rays is the area irradiated with relatively weak X-rays (area A in Figure 5). In the second exposure, when the background of the text information was relatively bright, the text information appeared to have a higher density than the surrounding area, making it possible to read the information. Conversely, when the second exposure resulted in a darker image, the text information appeared to have a lower density than the surrounding area, making it possible to read the information.

[0136] The text information of sample No. 302X, when exposed to X-rays, is in a relatively moderate X-ray irradiation area (area B in Figure 5). In the image obtained after the second exposure, the text image obtained by X-ray exposure was readable, similar to sample No. 301X. Compared to the image group of sample No. 301X, the processed image group of sample No. 302X showed a tendency for the X-ray exposed area to be less affected by the second exposure image.

[0137] Outside the heart-shaped mark of sample No. 303X, there is a region with relatively strong X-ray irradiation (region C in Figure 5). This region retained its X-ray image without any decrease in density, regardless of the positive region image during the second exposure. This served as a template for the black heart-shaped mark.

[0138] The heart mark of sample No. 304X, created using a 3D printer, exhibited a gradient in the X-ray exposure at the edges of the mark, and the final formed image also showed a gradient in density, resulting in a three-dimensional representation.

[0139] The area outside the heart mark in sample No. 305 X is a region with a relatively high dose of X-rays (region C in Figure 5).

[0140] Furthermore, regarding samples 301X to 305X, when the same subject image was output to the first and tenth superimposed exposures, sample 305X produced identical images, and no differences could be found. On the other hand, in samples 301X and 302X, the tenth photosensitive material, which was farther from the X-ray source, showed approximately 20% less fogging in the area exposed to white light during the positive exposure of the X-ray irradiation section of the first material, which was closest to the X-ray source. The photosensitive material used in this experiment contained 10 vertically superimposed photosensitive materials with a metal compound content of 140 g / m² in terms of metal equivalent. ２ The main component was silver at approximately 2g / m². ２ Titanium is 12 g / m ２ That is the case.

[0141] Furthermore, when samples 301X to 305X were mounted on a general-purpose analog instant camera and photographed, and developed, the same results as described above were obtained.

[0142] According to the present invention, it was confirmed that image information written with X-rays in the first exposure is recorded in the final image regardless of whether the superimposed image in the second exposure is a bright or dark image area. It was also confirmed that it is possible to expose multiple light-shielding packaged products simultaneously with X-rays.

[0143] [Example 4] (Angled exposure, three-dimensional stencil) In the exposure of sample 302X in Example 3, X-ray exposure was performed in exactly the same manner as in Example 3, except that the exposure amount adjustment means S1 was kept in close contact with the film pack containing the photosensitive material, which consisted of 10 sheets superimposed in the vertical direction, and the film pack was tilted 30° relative to the X-ray source. The monosheet material, formed by integrating the photosensitive material, cover sheet, and processing liquid pod, had a thickness of approximately 9 mm when consisting of 10 sheets.

[0144] After X-ray exposure, the photosensitive material was subjected to white exposure using the printer of Example 2, and the processing solution was developed to form an image. Upon examination of the obtained image, it was found that the X-ray irradiation amount was reduced to approximately 87%, equivalent to cos 30°, due to the tilted exposure. Furthermore, because the X-rays were irradiated at an angle onto the 1.5 mm thick stainless steel plate of the exposure amount adjustment means S1, the edges of the characters after development showed a gradient change in density. Moreover, from the first to the tenth sheet, the image formation position gradually shifted, totaling approximately 5.2 mm, which was consistent with the value expected from the relationship between the layer thickness of the monosheet photosensitive material and the tilt angle.

[0145] Furthermore, when the X-ray exposure conditions were changed as follows, nearly identical results were obtained: X-ray target W / Rh conditions X5 Tube voltage 100kV, Tube current × application time 600mAs X6 Tube voltage 200kV, Tube current × application time 200mAs

[0146] [Example 5] (Comparison of Image Appearance Speed) This is an example of an image formation method in which the first exposure was performed with X-rays and the second exposure was performed with positive area exposure. A text image like the one in Figure 9(A) was formed using two different exposure methods and the image appearance speed was compared. The silver halide photographic photosensitive material, cover sheet, and processing liquid pod described in Example 1 were integrated to create a monosheet type laminate of instant photographic film.

[0147] [First Exposure (X-ray Exposure)] The letter "XRAY ■" is exposed with a line width of 4 mm. For X-ray exposure, a mask for X-ray exposure was created using a 3D printer and made of plastic so that the lettering of the logo would allow X-rays to pass through. Figure 9(B) is a schematic diagram of this mask. A rectangular parallelepiped measuring 60 mm wide x 90 mm long and 10 mm thick was used as the substrate, and the outer frame was made into a box shape with an outer wall of 5 mm width and 5 mm thickness around the outer edge. On the substrate surface at the bottom of the box, a mold was created of the lettering of "XRAY ■" in plastic to a height of 5 mm. The empty spaces without lettering were filled with BaSO4 powder (bulk density 1.3). In this way, a mask, which is a means for adjusting the amount of X-ray exposure, was created.

[0148] A monosheet laminate was placed in a bag that could block visible light, and the X-ray exposure mask described above was placed on top. X-ray exposure was then performed using the exposure condition X3 of Example 3. To prevent the text information from being reversed, the X-ray exposure was performed from the observation side opposite to the side exposed to visible light on the photosensitive material.

[0149] [Second Exposure (Direct Positive Image Formation Region Exposure)] In the image region where X-rays were shielded by BaSO4 during the first exposure, an image was created as an input image in JPEG format, displaying "POSI ■" in black on a white background. Figure 9(C) is a schematic diagram of this. At this time, a white background image was created over the entire surface, including the logo area that was exposed in the first exposure with X-rays. A second exposure was given to form this image using a printer having an array of organic EL light-emitting elements as described in Japanese Patent Publication No. 3818564. This exposure was an exposure of the intensity of the positive response region. After the second exposure, the monosheet laminate was developed by unfolding the processing solution to form the image. A schematic image of the output image is shown in Figure 9(A).

[0150] The speed at which the appearance of the image was recognized was evaluated using the method described in Japanese Patent Publication No. 2021-196519. Density measurements were performed at the "■" (black square) at the end of the logo.

[0151] T1: Time when the density in the X-ray exposure area (first image area) becomes 0.04 or higher. T2: Time when the density in the X-ray exposure area (first image area) becomes 0.08 or higher. T3: Time when the density in the positive image exposure area (second image area) becomes 0.04 or higher.

[0152] The evaluation results are shown below. T2-T1 2.5 seconds T3-T2 10 seconds Density of the X-ray image at T3 0.60 Image density (X-ray image) (24hr) 2.27 Image density (positive image) (24hr) 1.92

[0153] In the first exposure, the text portion exposed with X-rays remained visible even when the white image of the positive region was superimposed during the second exposure. Furthermore, the evaluation results for image appearance recognition speed showed that at time T1, the X-ray image appeared at a very low density (0.04), and then at time T2, the density became clearly recognizable (0.08). Only then did the positive image begin to appear at a very low density (0.04) at T3. At time T3, the X-ray image that had already appeared earlier had a density of 0.60. This clearly indicates that the X-ray image appears at a much earlier time than the positive image.

[0154] The above examples demonstrate that, by using an image forming method that combines exposure of an X-ray exposure area and a positive area, it is possible to represent an image without the X-ray exposure image disappearing even with superimposed exposure of the positive area. Furthermore, it is possible to create a difference in the speed at which the image appears, enabling photographic expression that was not possible with conventional methods.

[0155] [Example 6] (Auto-positive exposure first) In Example 6, an exposed monosheet laminate was created in exactly the same manner, except that the order of the X-ray exposure process and the exposure process of the direct positive image formation area using visible light was swapped. The processing solution was then unfolded and developed to form an image. The results of the evaluation were almost the same as in Example 5.

[0156] [Example 7] (Image formation of characters disappearing and changing) This is an example of an image formation method in which the first exposure is performed with X-rays and the second exposure is performed with positive area exposure. In this example, the image formed by X-ray exposure is recognized first, and then the image of the positive area appears, making it possible to represent images in which the displayed numbers change or disappear.

[0157] A single-sheet laminate of instant photographic film was created by integrating the silver halide photographic photosensitive material, cover sheet, and processing solution pod described in Example 1.

[0158] [First exposure (X-ray exposure)] A component was created from a 1 mm thick stainless steel plate, with the black hexagonal portion of the image shown in Figure 10(A) removed. At this time, the removed hexagonal portion was made so that it could be reinserted. The stainless steel component processed in this way can be used as a mask for an X-ray light intensity adjustment means that can freely represent two-digit numbers.

[0159] First, a mask was prepared in which eight elongated hexagons could be fitted back together to form the number "14," as shown in Figure 10(B). The monosheet laminate was placed in a light-shielding bag, the X-ray exposure mask was placed on top, and X-ray exposure was performed under the following exposure conditions: X-ray target W / Rh, tube voltage 49KV, tube current × application time 400mAs. These exposure conditions were designed so that Dmin (Xray) and Dmax (posi) would be substantially the same density in the subsequent processing. To prevent the character information from being reversed, the X-ray exposure was performed from the observation side opposite to the side exposed to visible light on the photosensitive material.

[0160] [Second Exposure (Direct Positive Image Formation Region Exposure)] In the first exposure, the image region where the X-rays were shielded by the hexagonal plate was used to create the image shown in Figure 10(C), which displays a black hexagon on a white background in JPEG format as the input image. Using a printer having an array of organic EL light-emitting elements as described in Japanese Patent Publication No. 3818564, a second exposure was given to the X-ray exposed photosensitive material to form this image. This exposure was an exposure of the intensity of the positive response region. After the second exposure, the monosheet laminate was developed by spreading the processing solution to form the image.

[0161] [Observation of Output Image] In the output image after the start of image formation using the diffusion transfer method, the X-ray exposure image "14" shown in Figure 10(B) was initially observed. However, after an induction period, the horizontal bar of the positive image shown in Figure 10(C) was gradually added, and the image gradually changed to "39" shown in Figure 10(D). After 5 minutes of processing solution development, it was virtually impossible to recognize the original "14".

[0162] The above example illustrates the change from "14" to "39," but we will now explain other variations of the change. For example, even if "14" is used as the first exposure image, it is possible to change it to other numbers by selecting and drawing elongated hexagons as appropriate in the positive image formation area as the second exposure. In this case, it is possible to change from "1" to "3," "4," "7," "8," and "9," and from "4" to "8" and "9."

[0163] Furthermore, as another variation in image representation, by inputting a positive image like Figure 10(E) as the second exposure, the "14" from the X-ray exposure image is initially observed, but then, after an induction period, the entire background gradually blackens to virtually the same density, eventually making it impossible to read the number.

[0164] While embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications are possible.

[0165] 10 Photosensitive material 200 Exposure adjustment member 200A Aperture 202 Exposure adjustment member 202A Aperture 203a Sample 203b Sample 204a Sample 204b Sample 206 Exposure adjustment member 206A Aperture 209a Sample 209b Sample 301X Sample 302X Sample 305X Sample

Claims

1. An image forming method comprising an exposure step of exposing a direct positive type silver halide photographic photosensitive material containing internal latent image type silver halide particles that are not pre-covered on a support, wherein the exposure step comprises an X-ray exposure step of forming a surface negative type latent image and / or an internal latent image by X-ray exposure.

2. The image forming method according to claim 1, wherein in the X-ray exposure step, the amount of X-ray exposure to the area of ​​the silver halide photographic photosensitive material to be exposed is partially changed.

3. The image forming method according to claim 2, wherein in the X-ray exposure step, the amount of X-ray exposure is partially changed by using a material that absorbs or shields at least a portion of the X-rays irradiated onto the area to be exposed.

4. The image forming method according to claim 3, wherein the material is formed of a material containing at least one element with atomic numbers 13 to 83.

5. The image forming method according to any one of claims 1 to 4, further comprising a developing step of performing a developing process on the silver halide photographic photosensitive material that has been exposed.

6. The X-ray exposure is performed in the formed image after the development process under conditions that satisfy at least one of the following equations (Equation 1) to (Equation 3): (Equation 1) 2 ≤ [Dmax(posi) - Dmax(Xray)] / [Dmax(posi) - Dmin(posi)] × 100 ≤ 95 (Equation 2) 2 ≤ [Dmin(Xray) - Dmin(posi)] / [Dmax(posi) - Dmin(posi)] × 100 ≤ 130 (Equation 3) -30 ≤ [Dmax(posi) - Dmax(Xray)] / [Dmax(posi) - Dmin(posi)] × 100 ≤ 0 Dmax(posi) is the highest image density under the direct positive image formation method without visible light exposure. The image forming method according to claim 5, wherein Dmax(Xray) is the highest image density under conditions of no visible light exposure after X-ray irradiation, Dmin(posi) is the lowest image density when irradiated with white light in the direct positive image forming method, and Dmin(Xray) is the image density when white light that gives Dmin(posi) is irradiated after X-ray irradiation.

7. The silver halide photographic photosensitive material has a first image region and a second image region exposed by X-rays of different exposure amounts, wherein in the first image region, the X-ray exposure is performed under the condition that the formed image after the development process satisfies the following (Equation 4) and (Equation 5): (Equation 4) 0 ≤ [Dmax(Xray) - Dmin(Xray)] / [Dmax(posi) - Dmin(posi)] × 100 ≤ 5 (Equation 5) 90 ≤ [Dmax(Xray)] / [Dmax(posi)] × 100 ≤ 130 In the second image region, the X-ray exposure is performed under the condition that the formed image after the development process satisfies the following (Equation 6) and (Equation 7): (Equation 6) The image forming method according to claim 5, wherein 5 ≤ [Dmax(Xray) - Dmin(Xray)] / [Dmax(posi) - Dmin(posi)] × 100 ≤ 25 (Equation 7) 50 ≤ [Dmax(Xray)] / [Dmax(posi)] × 100 ≤ 80 Dmax(posi) is the highest image density under the direct positive image forming method without visible light exposure, Dmax(Xray) is the highest image density under the direct positive image forming method without visible light exposure, Dmin(posi) is the lowest image density under the direct positive image forming method with white light irradiation, and Dmin(Xray) is the image density when white light that gives Dmin(posi) is irradiated after X-ray irradiation.

8. The image forming method according to claim 5, wherein the silver halide photographic photosensitive material has a third image region and a fourth image region which are exposed to X-rays and a direct positive image forming region, the exposure of the positive image forming region of the third image region and the exposure of the positive image forming region of the fourth image region are substantially equivalent, and the image densities of the third image region and the fourth image region after the development process satisfy the following equation (Equation 8): (Equation 8) 0.05 ≤ |Dc(Xray1) - Dd(Xray2)| ≤ 2.5 Dc(Xray1) is the image density of the third image region of the silver halide photographic photosensitive material after the development process, and Dd(Xray2) is the image density of the fourth image region of the silver halide photographic photosensitive material after the development process.

9. The image forming method according to any one of claims 1 to 4, further comprising a visible light exposure step, which is performed after the X-ray exposure step, for directly exposing a positive image forming area with visible light.

10. The image forming method according to any one of claims 1 to 4, further comprising a visible light exposure step, which is performed before the X-ray exposure step, for directly exposing a positive image forming area with visible light.

11. The image forming method according to any one of claims 1 to 4, wherein the X-ray exposure step is performed by superimposing a plurality of single-sheet silver halide photographic photosensitive materials, and means for partially adjusting the amount of X-ray exposure in the exposed area of ​​the silver halide photographic photosensitive material is arranged between the X-ray source and the silver halide photographic photosensitive material, and by exposing the superimposed silver halide photographic photosensitive material with X-rays from the direction of superimposition, and by exposing the exposed area of ​​the superimposed silver halide photographic photosensitive material with substantially the same X-ray exposure.

12. The image forming method according to any one of claims 1 to 4, wherein the X-ray exposure step is performed by arranging a plurality of single-sheet silver halide photographic photosensitive materials in a planar offset manner so that the areas to be exposed are different, and means for partially adjusting the amount of X-ray exposure in the areas to be exposed of the silver halide photographic photosensitive materials is arranged between the X-ray source and the silver halide photographic photosensitive materials, and by exposing the areas to be exposed of the arranged silver halide photographic photosensitive materials to X-ray exposure with different amounts of exposure.

13. The image forming method according to any one of claims 1 to 4, wherein the X-ray exposure step is performed by superimposing multiple sheets of silver halide photographic photosensitive material of the same shape, with means for partially adjusting the amount of X-ray exposure in the exposed area of ​​the silver halide photographic photosensitive material positioned between the X-ray source and the silver halide photographic photosensitive material, exposing the superimposed silver halide photographic photosensitive material to X-rays from a direction at an angle of 10° to 85° with respect to the superimposed direction, and exposing the exposed area of ​​the superimposed silver halide photographic photosensitive material to X-rays with different exposure amounts.

14. The image forming method according to any one of claims 1 to 4, wherein the X-ray exposure step is performed by changing the shape of the exposed region of the silver halide photographic photosensitive material and / or the amount of X-ray exposure, with respect to the direction of X-ray irradiation, while means for partially adjusting the amount of X-ray exposure in the exposed region of the silver halide photographic photosensitive material is arranged between the X-ray source and the silver halide photographic photosensitive material.

15. The image forming method according to claim 14, wherein the X-ray exposure step is performed by changing the spatial arrangement by changing at least one of the number, shape, size, position, and direction of the means.

16. The X-ray exposure process is carried out by superimposing multiple sheets of the silver halide photographic photosensitive material, with means for partially adjusting the amount of X-ray exposure in the exposed area of ​​the silver halide photographic photosensitive material positioned between the X-ray source and the silver halide photographic photosensitive material, and by exposing the superimposed silver halide photographic photosensitive material with X-rays from the direction of superimposition, wherein the total amount of metal compounds contained in the multiple superimposed silver halide photographic photosensitive materials is 70 g / m² in terms of metal equivalent. ２ More than 700g / m ２ The image forming method according to any one of claims 1 to 4, wherein the density of X-ray fogging after development is changed among the superimposed silver halide photographic materials, by doing the following.

17. The image forming method according to claim 5, wherein the developing step is a step of surface development while applying a nucleating agent.

18. The image forming method according to any one of claims 1 to 4, wherein the silver halide photographic photosensitive material is a diffusion transfer type silver halide photographic photosensitive material.

19. The image forming method according to any one of claims 1 to 4, wherein in the X-ray exposure step, the surface negative latent image and / or internal latent image are formed by irradiating the silver halide photographic photosensitive material, which is packaged in a material that blocks visible light, with X-rays from outside the packaging.

20. A silver halide photographic photosensitive material in which a surface negative type latent image is formed by X-ray irradiation on a direct positive type silver halide photographic photosensitive material containing internal latent image type silver halide particles that are not pre-covered on a support.

21. The silver halide photographic photosensitive material according to claim 20, wherein an image-like surface negative latent image is formed as the surface negative latent image.

22. The silver halide photographic photosensitive material according to claim 20 or 21, wherein the amount of X-ray exposure in the exposed region is partially different.

23. The silver halide photographic photosensitive material according to claim 20 or 21, wherein a surface negative latent image is formed on a photosensitive material packaged with a light-shielding material that blocks visible light by irradiating the package with X-rays from the outside of the package.

24. The silver halide photographic photosensitive material according to claim 20 or 21, wherein the positive image forming region is further exposed by irradiation with visible light.

25. The silver halogen photographic photosensitive material according to claim 20 or 21, which has not undergone development processing.

26. A monosheet laminate in which a processing element is disposed between a non-peelable film unit in which an image-receiving element and a photosensitive element are laminated on a single support and a cover sheet superimposed on the non-peelable film unit, wherein the photosensitive element is the silver halide photographic photosensitive material according to claim 20 or 21.

Images