JPH0355949Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a liquid crystal data imprinting device that imprints various data onto a film using a liquid crystal display device.

In display devices, an electric field is applied to a mixture of an organic dye and an inorganic material to change the absorption and emission spectra of the dye, or a dye is mixed with a liquid crystal to generate light in a desired wavelength range as a guest-host liquid crystal. The technique for cutting is generally well known.

Further, the liquid crystal has a property that the transmittance is different between a part to which a voltage is applied and a part to which no voltage is applied.

On the other hand, in conventional transmission type field-effect nematic liquid crystal display devices, the contrast is insufficient for use in imprinting, and as the light intensity is increased, light leaks from non-lit areas, leaving the film exposed to areas other than the lit areas. There was a drawback that some parts were visible in the photo.

In view of the above points, the present invention was developed in order to solve such problems and eliminate such drawbacks. Data using a liquid crystal that improves the contrast between the character forming area and the area other than the character forming area by applying the technology mentioned above and absorbing light in a certain wavelength range that passes through the liquid crystal of the liquid crystal display device. The present invention provides an imprinting device.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

First, before describing embodiments, the constituent elements of a color negative film and the principle of the present invention will be explained in order to facilitate understanding of the present invention. All color negative films are developed using a multilayer emulsion coupler internal color development method, and from the subject side, the photosensitive material has a blue-sensitive layer, a yellow filter layer, a green-sensitive layer, a red-sensitive layer,
Since it is composed of an anti-reflection layer and a film base, the relative sensitivity of the film to white light differs depending on whether the data light source is irradiated from the subject side (front side of the film) and the data is imprinted, or when it is irradiated from the back side of the film. , there is a peak in blue from the front side and a red peak from the back side.

On the other hand, when a conventional twisted nematic liquid crystal is used as a display element for imprinting, the contrast is insufficient, and if you try to increase the brightness of the lit areas, the leakage from the non-lit areas will also increase. , the non-lit parts will be imprinted on the film.
Then, light is irradiated onto the color film from the back side,
When exposed to light, the sensitivity of the film varies greatly depending on the wavelength, reaching a maximum in the red wavelength region of 600 nm to 700 nm. Therefore, if the amount of light in the red wavelength range can be reduced when the light is not lit, it is possible to avoid the non-lighted portion from appearing on the film.

Therefore, the conventional twisted nematic type liquid crystal has an absorption band in the red wavelength region, and has two colors.
By incorporating a chromatic dye, it is possible to reduce the amount of light in the red wavelength region of the transmitted light of the non-lit parts, and to prevent the non-lit parts from being photographed. In this case, the amount of transmitted light in the illuminated area also decreases to some extent due to the absorption of the dye, but since the absorption rate of the dye is different between the illuminated area and the non-lit area, the decrease in the amount of light in the illuminated area is small, and it is not due to the mixing of the dye. The impact is small.

Figures 1 to 5 show characteristic diagrams used to explain the present invention, and Figure 1 shows the relative sensitivity when a color film is irradiated with light, with the wavelength in nm on the horizontal axis and the relative sensitivity on the vertical axis. The distributions are shown in (a) where the color film is irradiated with light from the front side, and (b) where the color film is irradiated with light from the back side. FIG. 2 shows the spectral transmittance of the dye mixed into the liquid crystal. Third
The figure shows the spectral transmittance of the lighting section of a field-effect nematic liquid crystal device, _A1 when no dye is added, and _A2 when a dye is added. Figure 4 shows the non-lighting part of a field-effect nematic liquid crystal element.
Spectral transmittance is shown for B ₁ without dye and B ₂ with dye. Figure 5 shows the contrast (A ₁ /B ₁ and A ₂ /
_B2 ) is shown.

Now, the present invention is implemented as follows.

FIG. 6 is a block diagram showing an embodiment of a data imprinting device using a liquid crystal according to the present invention, and shows an example of a transmissive type. In the figure, reference numeral 1 denotes a film, and the film 1 is constructed so that characters are imprinted within the dotted line 1a from the back side of the film. 2 holds film 1 and
a pressure plate for imprinting onto the film 1 through the hole 2a;
3 is a transmission type liquid crystal display element, through which part of the light emitted from the white source 4 is transmitted;
It is configured to create the character shape of the data.

Next, the operation of the embodiment shown in FIG. 6 will be explained with reference to the block diagram in FIG. In the block diagram shown in FIG. 7, the same reference numerals as in FIG. 6 indicate corresponding parts, 5 is a switch section, and 6 is a drive that is controlled by the operation of the switch section 5 and drives the transmissive liquid crystal display element 3. The circuit and 7 are the camera body.

First, the liquid crystal display element 3 is driven by a drive circuit 6 that is controlled based on the operation of the switch section 5, and the display contents can be changed by operating the switch section 5. Next, the camera body 7
In response to the imprint signal 8 from the white light source 4, the white light source 4 emits light, and the light is transmitted through the liquid crystal display element 3.The transmitted light passes through the hole 2a of the pressure plate 2 (see FIG. 6) and exposes the film 1, thereby displaying the data. is imprinted.

For example, when light is irradiated from the back side of the film 1, by mixing in the liquid crystal a dye that has an absorption band in the wavelength range where the film has high sensitivity and has color dichroism, it is possible to make the film 1 non-active in the wavelength range mentioned above. The contrast between the lit portion and the lit portion is significantly increased, and leakage from the non-lit portion can be prevented when the liquid crystal display device is used for imprinting in a data imprinting device. Note that it is more effective if the absorption band is formed not only in the red part but also in the green part. Furthermore, since the dye absorption rate in the lit portion is lower than that in the non-lit portion, the effect of mixing the dye is slight. For example, FIG. 8 shows a case where the number "2" is displayed. In FIG. 8, the black part (c) shows the lit part, and the shaded part (d) shows the non-lit part.

In conventional liquid crystal display elements, when the amount of light is increased in order to clearly capture the illuminated area, light from the non-illuminated area leaks, resulting in the inconvenience that the shaded area (d) in the figure is also captured. occurs. However, in the present invention, this unnecessary part, that is, the shaded part (d)
can be prevented from appearing in the image.

In the above embodiment, the case where the image is imprinted from the back side of the film 1 was explained as an example, but the present invention is not limited to this, and by absorbing an appropriate wavelength, the image is imprinted from the surface of the film 1. It is also possible to improve the contrast in imprinting.

White light is also effective when irradiating from the back side of the film, and if you use this white light,
Monochromatic light is affected by the background color of the subject, but yellow,
The color is a mixture of green and red, and the degree of influence is small.

Note that leakage from areas other than the text area of the liquid crystal display element can be prevented by covering the area other than the text area with an opaque material.

As explained above, according to the present invention, since the liquid crystal is mixed with a dye that has an absorption band in the wavelength range where the relative sensitivity of the film on which data is imprinted is high, the wavelengths of high sensitivity passing through the liquid crystal are In this case, due to the nature of liquid crystal, the light absorption rate of the dye in the non-lit areas (other than the character forming area) is high, and the transmitted light is attenuated.
In the illuminated portion (character forming portion), the absorption rate of light by the pigment is lower than in the non-lit portion, and transmitted light is not attenuated much. Therefore, light leakage from the non-lit portions is reduced, and contrast can be significantly improved. Furthermore, since there is no need for an optical film provided outside the liquid crystal display element, the size can be made smaller and the cost can also be reduced.

[Brief explanation of the drawing]

Figures 1 to 5 are characteristic diagrams used to explain the present invention. Figure 1 is the relative sensitivity distribution characteristics with respect to wavelength when a color film is irradiated with light, and Figure 2 is the spectrum of the dye mixed in the liquid crystal. Transmittance characteristics. FIGS. 3 and 4 show spectral transmittance characteristics of a field-effect nematic liquid crystal element, and FIG. 5 shows contrast characteristics. FIG. 6 is a block diagram showing an embodiment of a data imprinting device using a liquid crystal according to the present invention, and FIGS. 7 and 8 are block diagrams and display configuration diagrams for explaining the operation of the embodiment shown in FIG. 6. . 1...Film, 3...Liquid crystal display element, 4...
white light source.

Claims (1)

[Scope of utility model registration request] In a data imprinting device that applies light from a light source to a liquid crystal display element and irradiates a color film with light based on the transmitted light to imprint data, the liquid crystal display element has a structure in which the relative sensitivity of the color film is set in the liquid crystal. Contains a dichroic dye that has an absorption band in a large wavelength range of 600 to 700 nm.
A data imprinting device using a liquid crystal, characterized in that the difference in brightness between a character forming part and a part other than the character forming part is improved by lowering the transmittance of light in the wavelength range passing through the liquid crystal. .