JPS58172640A - Data imprinter - Google Patents

Abstract

PURPOSE:To imprint distinct data symbols having good contrast, by using a liquid crystal having a guest-host effect and increasing the difference in transmissivity between lighted segments and non-lighted segments. CONSTITUTION:When the light transmissivity of the segments of a liquid crystal cell 2 impressed with voltage increases and a light source 4 is lighted while a desired symbol is displayed, the light from the light source is made into parallel light by a lens 3. The parallel light goes toward the cell 2 and the light transmitted through the segments arrives at the photosensitive emulsion surface of a film 1 from the rear thereof, whereby the displayed data symbol is imprinted on said surface. The spectral transmissivity of the liquid crystal which is added with a dye of a blue color and has a guest-host effect has a large difference between the lighted stage and the non-lighted stage on a short wavelength side. When the light of a tungsten lamp transmits through such liquid crystal, the difference in the transmitted light between the lighted segments and the non-lighted segments increases on a long wavelength side. When such light is made incident to the base of the red color system of a color negative film, the short wavelength light is cut by the filter effect of the film base, and only the long wave light transmits through the film base, but the long wavelength light from the non-lighted segments is weak and only the long wavelength light transmitted through the lighted elements arrives at the photosensitive film, whereby the distinct imprinting is accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data imprinting device using a liquid crystal.

A data imprinting device for a camera that uses a liquid crystal for displaying data is known, but in conventional devices, there are two segments: a lighting segment, which is a segment to which voltage is applied, and a non-lighting segment, which is a segment to which no voltage is applied. Due to the low contrast with the segments, the non-lit segments may be imprinted on the film, resulting in inconveniences such as the data symbols not being clearly readable.

In order to eliminate these drawbacks, attempts have been made to improve the degree of polarization of the polarizing plate and the rotation performance of the liquid crystal in TNg liquid crystals, but there are limitations and it is not possible to completely eliminate the above drawbacks. Ta.

The present invention utilizes the guest-host effect to match the change in the light transmission characteristics of the liquid crystal to the film, increasing the contrast and imprinting clear data symbols.
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Embodiments of the present invention will be described below with reference to the drawings.

Figure 181 shows the general arrangement of the data imprinting device, in which 1 is a film, 2 is a crystal cell, 4 is an illumination light source, and 3 is a lens that converts the light from the light source into parallel light.

When the light transmittance of the voltage-applied segment of the liquid crystal cell increases and the desired symbol is displayed, the light source 4 is turned on, and the light from the light source is turned into parallel light by the lens 6 and directed toward the liquid crystal cell. The light transmitted through the segments reaches the photosensitive emulsion surface from the back side of the film 1, and the displayed data symbol is imprinted thereon.

FIG. 2 shows the emission distribution of the illumination light source when a tungsten lamp is used.

Figure 6 is a diagram showing the spectral transmittance of a liquid crystal that has a guest-host effect by adding a blue dye, where "B" shows the lighting state with voltage applied, and "B" shows the non-lighting state with no voltage applied. . As shown in the figure, the difference between lighting and non-lighting is large on the short wavelength side.

When light from a tungsten/lamp with the luminous characteristics shown in Figure 2 is transmitted through such a liquid crystal, the difference in transmitted light between the lit segment A and the non-lit segment H is 600, as shown in Figure 4. It is large on the long wavelength side above the plane.

When such light enters the red color pace of a color negative film, the short wavelength light is cut by the filter action of the film base, and only the long wavelength light is transmitted through the film base, but the long wavelength light from the non-lit segments is extremely weak,
Almost only the long wavelength light that has passed through the lighting segment reaches the photoresist film, resulting in clear imprinting.

In the embodiment, we have explained the case where data is imprinted from the back side of the color negative film, but in the configuration where data is imprinted from the front side of the lume, a uniform effect can be obtained by using a filter that cuts short wavelength light such as 550Dxn or less. can get. In this case, any type of film may be used.

If you are using a method that prints from the front of the film and use a strobe light as the light source, add red dye to the liquid crystal to create a transmittance characteristic that is opposite to that shown in Figure 3.
Data symbols with good contrast can be imprinted using true color light by using a filter that cuts long wavelength light of about 0 nm or more.

As described above, the present invention uses a liquid crystal having a guest-host effect to increase the difference in transmittance between a lit segment and a non-lit segment, thereby making it possible to imprint clear data symbols with good contrast.

[Brief explanation of drawings]

Figure 1 is a diagram showing the arrangement of one embodiment of the present invention - Figure 2 is a diagram showing the emission distribution characteristics of a light source for illumination, Figure 3 is a diagram showing the spectral transmittance of liquid crystal, and Figure 4 is a diagram showing the spectral transmittance of liquid crystal. A line diagram showing the relative brightness distribution of a surface. 1; Light #, 2; [Jt nacelle 3: Condenser lens
4; Light source applicant Canon Co., Ltd. agent Gi Marushima -Pa' -25 小）

Claims (1)

[Claims] A data imprinting device characterized in that a data symbol is recorded on a photosensitive material by a transmitted light method by utilizing changes in spectral transmittance of a liquid crystal displaying a data symbol when a voltage is applied and when a voltage is not applied.