JPH11242298A - Printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a device small is size, light in weight, low in power consumption and low in cost by bringing photosensitive film into contact with the display surface of a transmission type liquid crystal display(LCD), turning on a light source on the back side for the LCD and printing a picture displayed on the LCD on the photosensitive film. SOLUTION: In this printing device, the instant photosensitive film 2 is brought into contact with the transmission type LCD 1 functioning as a picture display means so that its photosensitive surface 2a may be opposed to the display surface 1a of the LCD 1. A backlight 3 is provided on the back side of the LCD 1. In the case of printing the picture in the device, the LCD 1 is driven by a driving circuit and the backlight 3 is turned on for a specified time by a lighting control circuit. Thus, light from the backlight 3 is transmitted through the LCD 1 and irradiates the film 2, so that the picture (for instance, the picture based on a video signal reproduced and supplied from a video camera to the LCD 1) supplied to the LCD 1 is printed on the film 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus for printing an image on a photosensitive film, and more particularly, to a printing apparatus which is reduced in size and weight and costs.

[0002]

2. Description of the Related Art For example, a printing apparatus (Iwayu video printer) for printing an image photographed by a video camera (camera-integrated video tape recorder) or the like has conventionally employed a sublimation type thermal transfer system. Was mainstream. However, this sublimation-type thermal transfer video printer is disadvantageous in that it takes a relatively long time to complete one print, and its mechanical structure is complicated, so its size and weight are large (thus not suitable for carrying). And large power is required to charge the drum.

[0003] In recent years, video printers employing a method of printing an image on an instant photosensitive film have been proposed. FIG. 5 is a diagram showing an example of an optical system of such a video printer proposed by the present applicant (as disclosed in Japanese Patent Application Laid-Open No. 6-284367).

In this video printer, the display surface of a CRT 21 serving as an image display unit also serving as a light source 23 is provided on a casing 50.
It is arranged toward the bottom of the. An image reproduced from a video camera or the like is displayed on the CRT 21, and the image light is reflected by a first mirror 24 a that is disposed at an angle of approximately 45 degrees facing the display surface of the CRT 21. First mirror 24a
After being focused and diffused by the optical block 71, the image light reflected by the optical block 71 enters the second mirror 25 via the filter and the shutter 74. The second mirror 25 is disposed to be inclined with respect to the bottom surface of the housing 50 so as to face the first mirror 24a, and the image light reflected by the mirror 25 is transmitted to the third mirror 2
6 is incident.

[0005] The third mirror 26 is provided with a film pack 22 in a tray 154 disposed in parallel with the panel 51 of the housing 50.
It is disposed so as to be inclined with respect to the photosensitive surface of the instant photosensitive film that has entered, and is disposed such that its reflection surface faces the second mirror 25. The image light reflected by the third mirror 26 forms an image on the photosensitive surface of the instant photosensitive film of the film pack 22 and exposes the photosensitive surface, whereby the image displayed on the CRT 21 (reproduced from a video camera or the like) Is printed on the instant photosensitive film. The other parts illustrated in FIG. 5 are not directly related to the present invention, and thus description thereof is omitted.

According to such a video printer, the printing time can be reduced, and the size and weight and the power consumption can be reduced to some extent, as compared with a sublimation-type thermal transfer video printer.

[0007]

However, in a video printer as exemplified in FIG. 5, the image display means C
Optical components such as optical blocks and mirrors are indispensable to form image light from the RT on the photosensitive surface of the instant photosensitive film, and an appropriate focal length must be secured. There was a limit.

[0008] Further, the cost of the video printer is required to be further reduced. However, the existence of such optical components has hindered the promotion of the cost reduction.

Also, in this video printer, parts for performing various mechanical operations such as a filter and a shutter and a motor for operating them are indispensable. There was also a limit to power consumption.

The present invention has been made in view of the above points, and is a printing apparatus such as a video printer that employs a method of printing an image on a photosensitive film, which is further reduced in size and weight, consumes less power, and It is an object of the present invention to provide a device that can reduce the cost.

[0011]

In a printing apparatus according to the present invention, a photosensitive film is brought into close contact with the display surface of a transmission type liquid crystal display, a light source is provided on the back side of the liquid crystal display, and the light source is turned on. Is characterized in that an image displayed on a liquid crystal display is printed on a photosensitive film.

This printing apparatus is provided with a transmission type liquid crystal display as an image display means, and a photosensitive film is adhered to a display surface of the liquid crystal display.
By turning on the light source provided on the back side of the liquid crystal display, light from the light source passes through the liquid crystal display and irradiates the photosensitive film, so that the image displayed on the liquid crystal display is printed on the photosensitive film. Will be copied.

As described above, according to this printing apparatus, the image is printed on the photosensitive film by bringing the photosensitive film into close contact with the liquid crystal display as the image display means. There is no need to provide optical components or secure an appropriate focal length as in a printer. Therefore, further reduction in size and weight and cost can be achieved.

[0014] In addition, as a part for performing a necessary mechanical operation in this printing apparatus, at a minimum, the photosensitive film is stored while being shielded from light, the photosensitive film is brought into close contact with the display surface of a liquid crystal display, and a developing solution is applied to the photosensitive film. It is enough if there is a part for applying. Therefore, according to this printing apparatus, the mechanical structure is greatly simplified as compared with the video printer illustrated in FIG. 5, so that the size and weight can be further reduced.

[0015] In this printing apparatus, only the light source and the liquid crystal display must be operated at least electrically. Therefore, according to this printing apparatus,
The power consumption is greatly reduced as compared with the case where a motor is required as in the video printer illustrated in FIG.

In this printing apparatus, it is more preferable to provide a grid between the light source and the liquid crystal display. By doing so, even when the light from the light source is not a parallel light, the diffusion of the light from the light source is suppressed while keeping the distance between the light source and the liquid crystal display short (the light from the light source is converted into a parallel light). (Closer) sharp images can be printed on the photosensitive film. Therefore, further downsizing is possible.

[0017]

FIG. 1 shows an example of a configuration of a main part of a printing apparatus according to the present invention. In this printing apparatus, as shown on the left side of the figure, a transmissive LCD as image display means is used.
An instant photosensitive film 2 is tightly attached to (liquid crystal display) 1 with its photosensitive surface 2a facing display surface 1a of LCD1. As the photosensitive film 2,
It is needless to say that a material which is stored in a light-shielded state until immediately before the close contact is used.

A backlight 3 is provided on the rear surface 1b side of the LCD 1 (in FIG. 1, the LCD 1 and the backlight 3 are drawn in close contact for convenience, but actually, the LCD 1 and the backlight 3 are described later). It is desirable to leave a certain distance between them). The backlight 3 is L
This is a general backlight for CD. Backlight 3
Is illustrated as using a fluorescent tube 3a in the figure, but may be one using an LED or a dispersion EL, for example.

The LCD 1 is an active matrix driving type liquid crystal display such as a color TFT (thin film transistor) liquid crystal display. As shown in an enlarged view on the right side of FIG. 1, a glass substrate on which a display electrode and a common electrode are formed is shown. A liquid crystal layer 13 is sealed between the liquid crystal layers 11 and 12, and polarizers 14 and 15 are attached to the outside of the glass substrates 11 and 12, respectively. A portion of the liquid crystal layer 13 corresponding to each switching element Constitute the pixel px. Thickness of LCD 1 (distance between outer surface of polarizing plate 14 and outer surface of polarizing plate 15)
Is 2.8 mm as an example.

An example of the operation of printing an image by the printing apparatus will be described below. The LCD 1 is driven by a driving circuit (not shown), and the backlight 3 is driven by a lighting control circuit (not shown) for a predetermined time (for example, several tens of milliseconds).
Turn on. As a result, the light from the backlight 3 becomes L
Since the light passes through the CD 1 and irradiates the photosensitive film 2, L
An image displayed on the CD 1 (for example, an image based on a video signal reproduced from a video camera and supplied to the LCD 1) is printed on the photosensitive film 2.

The light from the backlight 3 is not a parallel light. FIG. 2 shows an example in which the backlight 3 is assumed to be a point light source and light from the backlight 3 passes through the LCD 1 (FIG. 2A shows the LCD 1 and the backlight 3).
In the case where the distance L between them is relatively small, FIG.
Are relatively large).

Since the light from the backlight 3 is not parallel light, the light reaching the LCD 1 from the backlight 3 is L
Spreads on the surface of CD1. As a result, the light that has passed through each pixel px of the LCD 1 also spreads, so that when the distance L is relatively small as shown in FIG. 2A, light from adjacent pixels px may intersect on the photosensitive film 2. . Such intersection of light is considered to cause blur (unclearness) of an image printed on the photosensitive film 2.

On the other hand, when the distance L is increased as shown in FIG. 2B, the spread of light on the surface of the LCD 1 is reduced, and the spread of light passing through each pixel px is also reduced. Light from the adjacent pixels px does not cross (or this crossing decreases). Therefore, blurring of the image printed on the photosensitive film 2 is eliminated or reduced.

The specific correlation between the magnitude of the distance L and the degree of blur can vary depending on various conditions. However, as one experiment, the applicant has determined that the rectangular shape between the LCD 1 and the backlight 3 When the image of the dot having a diameter of 0.5 mm displayed on the LCD 1 is printed on the photosensitive film 2 by interposing a hollow cylinder of
The measured values of the vertical dimension are as follows.

(A) When L = 18 mm Horizontal dimension: 1.20 mm Vertical dimension: 0.90 mm (b) When L = 46 mm Horizontal dimension: 0.85 mm Vertical dimension: 0.1 mm 57 mm (b) When L = 86 mm Horizontal dimension: 0.73 mm Vertical dimension: 0.51 mm

The experimental results also show that as the distance L increases, the size of the dots on the photosensitive film 2 approaches the size of the image on the LCD 1 (ie, the blurring of the image printed on the photosensitive film 2 is reduced). Be) is appearing.

In the printing apparatus shown in FIG.
It is desirable to set the distance between the backlights 3 so that the blur of the image printed on the photosensitive film 2 is not recognized by human eyes.

Next, FIG. 3 shows another example of the configuration of the main part of the printing apparatus according to the present invention. The same parts as those in FIG. . In this printing apparatus, a grid 4 is provided between the LCD 1 and the backlight 3, and a spacer 5 is provided between the grid 4 and the LCD 1.

The lattice 4 is formed by forming a large number of through holes 4a in a lattice shape. Light from the backlight 3 passes through these through holes 4a, thereby suppressing diffusion of light from the backlight 3. (To make this light closer to parallel light).

The spacer 5 is, for example, a rectangular hollow cylinder. The light that has passed through the grating 4 does not become completely parallel light, and therefore diffuses somewhat while passing through the spacer 5. Therefore, the light that has just passed through the grating 4 has a shadow at the portion of the framework that partitions each through-hole 4a, whereas the light that has passed through the spacer 5 has no shadow (or a weakened shadow) due to such a framework. ). Utilizing this, the spacer 5 plays a role in preventing the image in the form of the frame of the grid 4 from burning onto the photosensitive film 2.

FIG. 4 shows an example in which the backlight 3 is regarded as a point light source and the light from the backlight 3 passes through the LCD 1 through the grating 4 as in FIG. 2 described above. Since the light from the backlight 3 is made closer to the parallel light by the grating 4, the spread of the light on the surface of the LCD 1 is reduced. As a result, light from adjacent pixels px on the photosensitive film 2 does not cross (or the number of crossings decreases), so that blurring of an image printed on the photosensitive film 2 is eliminated or reduced.

The operation of printing an image by this printing apparatus is the same as that described for the printing apparatus of FIG. However, in this printing apparatus, since the light from the backlight 3 is made closer to the parallel light by the grating 4, the LCD 1
Even if the distance between the backlights 3 is reduced, the blur of the image printed on the photosensitive film 2 is reduced as compared with the image printed by the printing apparatus of FIG.

As one experiment, the present applicant determined that a grid 4
Is 10 mm, the dimension of the through hole 4a is 5 mm square,
The length of the spacer 5 is set to 20 mm, and the distance L between the LCD 1 and the backlight 3 is set to 30 mm, which is the total length of the grid 4 and the spacer 5. The measured values of the horizontal and vertical dimensions of the dots on the photosensitive film 2 when printed on the film 2 are as follows. Horizontal dimension: 0.67mm Vertical dimension: 0.63mm

When this experimental result is compared with the experimental result of the printing apparatus of FIG. 1 described above, the degree of blur reduction is comparable to the case where L = 86 mm is set in the printing apparatus of FIG. You can see that it is. Further, if the size of the through hole 4a is smaller than 5 mm square, it is considered that the same result can be obtained even if the distance L is set shorter than 30 mm.

According to the printing apparatus shown in FIGS. 1 and 3 as described above, the photosensitive film 2 is provided on the LCD 1 as image display means.
The image is printed on the photosensitive film 2 in close contact, so that it is not necessary to provide optical components or secure an appropriate focal length as in the video printer illustrated in FIG. Not required. Therefore, further reduction in size and weight and cost can be achieved.

The components that perform the necessary mechanical operations in these printing apparatuses include at least the photosensitive film 2
It is sufficient that the photosensitive film 2 has a part for applying the developing solution to the photosensitive film 2 while keeping the photosensitive film 2 in close contact with the display surface 1a of the LCD 1. Therefore, according to this printing apparatus, the mechanical structure is greatly simplified as compared with the video printer illustrated in FIG. 5, so that the size and weight can be further reduced.

In these printing apparatuses, only the backlight 3 and the LCD 1, which are light sources, must be operated at least electrically. Therefore, according to the printing apparatus, the power consumption is greatly reduced as compared with the video printer illustrated in FIG. 5 which requires a motor.

Further, in particular, according to the printing apparatus of the example of FIG.
A clear image can be printed on a photosensitive film while keeping the distance between the LCD 1 and the backlight 3 shorter than that of the printing apparatus of FIG. Therefore, further downsizing is possible.

In the printing apparatus of the above example, the LCD
A neutral density filter for adjusting the amount of light from the backlight 3 may be provided between the backlight 1 and the backlight 3.

In the above example, the general LCD backlight 3 is provided on the back side of the LCD 1. However, another appropriate light source (preferably a light source that generates light as close as possible to parallel light) is used. It may be provided on the back side of the LCD 1.

Further, the printing apparatus of the above example can be applied not only to a video printer but also to any use for printing an image which can be displayed on an LCD.

Further, the present invention is not limited to the above-described example, and it is needless to say that various other configurations can be adopted without departing from the gist of the present invention.

[0043]

As described above, according to the printing apparatus of the present invention, the photosensitive film is brought into close contact with the liquid crystal display to print an image on the photosensitive film, so that an optical component can be provided. It is no longer necessary to ensure an appropriate focal length, and the mechanical structure is greatly simplified and the power consumption is greatly reduced. Therefore, it is possible to further reduce the size and weight of the printing apparatus to improve its portability, and to further reduce the cost.

When a grid is provided between the light source and the liquid crystal display, the diffusion of light from the light source is suppressed while keeping the distance between the light source and the liquid crystal display short, and a clear image is formed. Can be printed on a photosensitive film, so that further downsizing can be realized.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of a configuration of a main part of a printing apparatus according to the present invention.

FIG. 2 is a side view showing an example of how light from a backlight 3 passes through an LCD 1 in the printing apparatus of FIG.

FIG. 3 is a perspective view showing another example of the configuration of the main part of the printing apparatus according to the present invention.

4 is a side view showing an example of how light from a backlight 3 passes through an LCD 1 in the printing apparatus of FIG.

FIG. 5 is a perspective view showing an example of the configuration of a conventional printing apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display, 1a ... Display surface of liquid crystal display, 1b ... Back surface of liquid crystal display, 2 ... Instant photosensitive film, 2a ... Photosensitive surface of instant photosensitive film, 3 ... Backlight, 3a ... Fluorescent tube,
4 ... lattice, 4a ... through hole of lattice, 5 ... spacer,
11, 12: glass substrate, 13: liquid crystal layer, 14, 1
5 ... polarizer, px ... pixel

Claims (2)

[Claims] 1. A light-sensitive film is brought into close contact with a display surface of a transmissive liquid crystal display, a light source is provided on a back side of the liquid crystal display, and an image displayed on the liquid crystal display is exposed by turning on the light source. A printing device for printing on film. 2. The printing apparatus according to claim 1, wherein a grid is provided between said light source and said liquid crystal display to suppress diffusion of light from said light source. .