JPH0615979B2 - Manufacturing method of printed film for night lighting adjustment of indicating instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a printing film applied to the back surface of the dial of an indicating instrument to make the illuminance of night illumination of the indicating instrument mainly used for automobiles uniform. It relates to a manufacturing method.

[Prior art]

FIG. 1 shows a cross section of an indicating instrument which has been widely used in the past, and FIG. 2 is a front view of the dial. As shown in the figure, the dial 1 is fixed to the inner unit 3 attached to the case 2, and the periphery thereof is shielded by the dial plate 5. The dial 1 is made of a transparent resin such as acrylic, and the surface of the dial 1 is printed with light-transmitting ink such as numerals 6 and scales 7 and black ink on the other portions. Reference numeral 8 is an illumination lamp attached to the case 2. Further, a printing film 9 for adjusting the illuminance is provided on the back surface of the dial 1. As shown in FIG. 3, a printing original plate 12 for the back printing film 9 is disclosed in Japanese Patent Publication No. 53-2065. As described above, at the position of the dial 1, it is made from the negative film 10 and the contact screen 11 in which the unevenness of the illumination is photographed as it is. However, there are many spots in the bright place and small spots in the dark place. Make the illuminance uniform. Also, the curve 19 in FIG.
Shows the printing characteristics with the back surface printing film 9, and is represented by the relationship between the printed matter density and the original halftone dot%. Also, the curve 20 in FIG.
Indicates the relationship between the density of the negative film 10 and the halftone dot% of the original plate 12, which is determined by the characteristics of the contact screen 11. Further, FIG. 7 shows general characteristics of the negative film. FIG. 6 shows the relationship between the illuminance of illumination and the density of printed matter, which is necessary to make the illuminance of illumination uniform.
The relationship shown in FIG. 6 will be briefly described. Print density As,
Assuming that the target illuminance to be equalized is I ₀ and the unbalanced illuminance before being equalized is I, the print density required to equalize the illuminance I to I ₀ is Aa = log (I / I ₀ ). Becomes That is, As = logI-logI ₀ , and since I ₀ is constant, the characteristic of FIG. 6 is a straight line 21 having an inclination of 45 °. That is, the required print density is determined from the relational characteristics shown in FIG.

Here, the method of obtaining the predetermined density of the back surface printing 9 is briefly described in Japanese Patent Publication No. 53-2065 as described above, but the details of the process are described in the negative film 1.
0 shooting, mesh field by contact screen 11,
It is the order of printing, and when this process is qualitatively and quantified and examined, the negative film 10 is photographed and developed according to the characteristic of FIG. 7, and then the continuous density of the negative film 10 is determined by the characteristic 20 of the solid line in FIG. Decompose into halftone dots, then the fourth
Print according to the characteristics shown in the figure and obtain the print density from the dots.

Then, the print density having the relationship with the illumination illuminance as shown in FIG. 6 is obtained.

However, the printing characteristics of FIG. 4 are almost determined by the printing method, the type of ink, the plate, etc., and it is impossible to control the characteristics. Further, the mesh decomposition characteristic of FIG. 5 is determined by the characteristic of the contact screen 11. Further, comparing the characteristic curves 19 and 20 of FIGS. 4 and 5, they are not the same. Further, the characteristics of the characteristic curve 23 of the negative film shown in FIG. 7 have no degree of freedom other than the inclination of the straight line portion. Therefore, in the conventional method, the characteristic shown in FIG. 6 is not an ideal straight line 21 but a characteristic like a curve 22,
The illuminance cannot be made uniform. As an example, when the illuminance variation of 10 to 100 lx is made uniform to 5 lx, the required print density is 0.3 to 1.3, and the relationship of the straight line 21 is necessary. However, characteristic 20 of FIG. 5 and characteristic 19 of FIG.
From the difference with the conventional method, the positions of 10 lx and 100 lx are 5 lx, but at other positions, the relation characteristic between the print density and the illuminance variation is the curve 22, which makes it brighter than 5 lx. There is a drawback in that

[Object of the Invention]

The present invention focuses on the fact that the non-uniformity of the illuminance is caused by the deviation between the printing characteristics and the halftone dot area characteristics, uses a color scanner that can easily adjust the halftone dot area characteristics, and Is adjusted so as to match the printing characteristics, and the negative film photographed as it is for the imbalance of illumination is net-disassembled to produce a printing original plate, thereby making it possible to uniformize the illuminance accurately.

〔Example〕

 The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 8 is a schematic block diagram of a so-called color scanner having the capability of electronically color-separating and plate-making. The operation principle of the color scanner will be briefly described with reference to FIG. Generally, a color original is attached to
A photographic material for disassembled photographic recording is attached to the recording unit 27. In the scanning unit 25, the scanning light flux is relatively moved with respect to the original so as to sequentially cover the entire surface, the original image is sequentially scanned for each minute area, and the light flux transmitted or reflected by the original is detected. Color separation is performed, and photoelectric conversion is performed on each color to obtain uncorrected color separation electric signals of three colors. These signals are input to the electronic circuit section 26, where the color correction primary and secondary colors are adjusted so that a desired color and tone can be obtained on the printed matter.
Adjustment or modification is performed by adjusting the next circuit or the gradation correction circuit. The corrected decomposition signal is then recorded by the recording unit 27.
, Where the magnitude of the signal is electro-optically converted and returned to the intensity of the thin luminous flux again. By this light, the recording unit 2
The photographic materials attached to No. 7 are sequentially exposed to obtain a corrected color separation photograph. When halftone dots are used to express the density, the electronic circuit section 26 can be made to have a function of generating straight line halftone dots.

Therefore, in this embodiment, the negative film 10 is attached to the scanning portion 25 of the color scanner, the electronic circuit portion 26 is directly provided with the function of generating halftone dots, and the photographic material for disassembled photographic recording attached to the recording portion 27 is used as the original plate 12. It is what

Thus, by using the color scanner of FIG. 8 for halftone decomposition, the characteristic curve of FIG. 5 is changed to the printing characteristic curve 1 of FIG.
The characteristic 24 shown in FIG. Further, since the color scanner can freely change the characteristics shown in FIG. 5 as described above, it is not necessary to use only the linear portion 23a having the characteristics shown in FIG. 7 due to different photographing and developing conditions of the negative film 10. This straight part 23a
Even if the curved line portion 23b is used, the network decomposition characteristic of FIG. 5 can be changed so that the characteristic of FIG. 6 becomes a straight line.

The overall manufacturing method in this embodiment will be briefly described below. Non-uniformity range I of illuminance before forming the print film 9 for adjusting illuminance
The print density range N _{1 to} N ₂ of the print film 9 is obtained from _{1 to} I ₂ and the target illuminance I ₀ to be uniformed, and the density range of the negative film 10 is obtained and the photographing and developing conditions of the negative film 10 are obtained. Then, the negative film 10 is placed instead of the dial 1 shown in FIG. 1, the illumination lamp 8 is turned on, and the image is photographed and developed according to the previously obtained conditions.

Next, the negative film 10 thus photographed is decomposed into a mesh by a color scanner to produce an original plate 12. And the original 1
2. Although not described in detail here, a printing plate is prepared by a generally well-known photolithography method, and an illuminance-adjusting printing film 9 is printed on the back surface of the dial 1 by this printing plate. Then, the illumination can be made uniform with the target illuminance.

〔The invention's effect〕

As described above, in the present invention, in order to create a printing original plate for obtaining a printing film applied to the dial plate back surface of the indicating instrument, using a color scanner that can easily adjust the mesh decomposition characteristics, Moreover, by adjusting the halftone decomposition characteristics to match the printing characteristics, and by performing halftone decomposition of the negative film on which the unbalanced lighting is taken, the deviation between the printing characteristics and halftone decomposition characteristics can be reduced as much as possible. There is an excellent effect that the illuminance can be made uniform with high precision.

According to an experiment conducted by the present inventors, when the illuminance variation on the dial surface, that is, the degree of imbalance is expressed by (maximum illuminance-minimum illuminance) / maximum illuminance (maximum illuminance is the most on the dial surface. The illuminance of a brightly illuminated portion, and the minimum illuminance is the illuminance of the darkest illuminated portion.) It has been confirmed that it will be below%.

[Brief description of drawings]

1 and 2 are a longitudinal sectional view and a plan view showing an embodiment of an indicating instrument to which a printing film for adjusting night illumination manufactured by the conventional method and the method of the present invention is attached, and FIG. 3 is a conventional printing method. Development drawing for explaining the method of manufacturing the original plate of the membrane, No. 4
FIGS. 7 to 7 show examples of respective characteristics of printed matter density-original halftone dot%, negative film density-original halftone dot%, illumination illuminance-printing density, exposure amount-negative film density applied in the conventional method and the method of the present invention. FIG. 8 is a schematic block diagram showing an embodiment of a color scanner applied to the method of the present invention. 1 ... character plate, 8 ... illumination lamp, 9 ... printing film for adjusting night illumination.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsutoshi Suzuki, 1-1, Showa-cho, Kariya city, Aichi Nihon Denso Co., Ltd. (56) References Japanese Patent Publication Sho 53-2065 (JP, B2)

Claims (1)

[Claims] 1. A method for producing a printing film on a back surface of a dial of an indicating instrument by using a printing original plate so as to make the illuminance of night illumination of the indicating instrument uniform. The first step of photographing and the halftone decomposition of the negative film by a color scanner according to the halftone adjustment characteristic which shows the relationship between the density of the negative film and the percentage of halftone dots formed on the printing original plate and which coincides with the following printing characteristics. And a second step of forming halftone dots on the printing base plate, and a relationship between a ratio of halftone dots on the printing base plate obtained by the second step and a print density of a print film applied to the back surface of the dial. A third step of printing the halftone dots on the back surface of the dial according to the predetermined printing characteristics, and a method for producing a print film for night illumination adjustment of an indicating instrument, comprising: