JPH03210549A - Video printer - Google Patents

Abstract

PURPOSE:To obtain a beautiful image free from fogging by moving positional relation between a liquid crystal panel(LCP) and a recording medium and exposing the recording medium 78 plural times. CONSTITUTION:An image is displayed on the LCP 18, the recording medium 78 corresponding to the image is exposed and the recording medium 78 corresponding to the light-intercepted area 102 of the LCP 18 is also exposed to remove the influence of the area 102 of the LCP 18. Namely, the length of respective sides of the transmitting area 104 of the LCP 18 is formed so as to be 1/2 the length of a unit picture element area (each LC shutter) including the area 102 and the area of the transmitting area 104 is 1/4 the area 100. Thus, the LCP 18 is moved four times and the recording medium 78 is exposed by the same video signal and the part which can not be usually exposed due to the light-intercepted area 102 can also be exposed. Consequently, a beautiful print free from fogging due to the insufficient exposure can be obtained.

Description

TECHNICAL FIELD The present invention relates to video printers, and more particularly to video printers that form a hard copy of a visible image from a video signal.

Back JUL Technique Conventionally, there are the following visible image recording devices known as video printers.

For example, the applicant's pending patent application, JP-A-62-
No. 16695 describes an image recording device that receives a video signal of an image taken with an electronic still camera, reproduces it on a CRT, and records the CRT image on color photographic paper6. There are also devices that expose instant photosensitive materials to light using an optical fiber or lens imaging system. Furthermore, for example, Japanese Patent Publication No. 64-10991 (Japanese Patent Publication No. 58-212287)
Thermal printers have also been proposed that transfer heat-diffusible dyes to an image-receiving medium to obtain a hard copy of an image, as described in .

However, none of these devices is simple and is not small enough to be portable, for example, in a pocket.

The present applicant has proposed, for example, in Japanese Patent Application No. 1-237094, a small-sized video printer that can solve these problems and easily obtain a hard copy of a visible image from a video signal. This printer is driven by a video signal, and a liquid crystal panel on which a black and white image is displayed is brought into close contact with a photosensitive recording medium, and light from a light source is guided to the liquid crystal panel through a filter to expose the displayed image onto the photosensitive recording medium. It is then developed to obtain a hard copy print. According to such a printer, hard copies can be easily obtained and the device can also be made smaller.

By the way, when displaying an image according to a video signal on a liquid crystal panel as described above and exposing this image to a photosensitive recording medium, there is a problem that the exposure becomes incomplete. In other words, the liquid crystal panel is provided with a light-blocking area for accommodating wiring for driving the liquid crystal electrodes (the aperture ratio is 100% or less). When a display image is exposed to light on a photosensitive recording medium, the photosensitive recording medium is not exposed to light in the areas corresponding to the light-blocking areas of the liquid crystal panel. It becomes gray instead of completely white. This results in an image with so-called large fog.

In this way, when performing exposure using a liquid crystal panel,
There is a period a when the exposure amount is insufficient due to the light blocking area.

(2) It is an object of the present invention to solve these problems and provide a video printer that is simple and can obtain an appropriate amount of exposure.

According to the present invention, a video signal representing one image is received and the image is displayed as a black and white image on a liquid crystal panel according to the video signal,
A video printer that records a displayed image as a visible image on a photosensitive recording medium has an input terminal for inputting a video signal,
A recording medium accommodating section for accommodating a photosensitive recording medium, a liquid crystal panel disposed corresponding to the photosensitive surface of the photosensitive recording medium and each having a rectangular unit pixel area, and a liquid crystal panel in a wavelength range to which the photosensitive recording medium can be sensitive. A light source that generates photosensitive light, an optical system that guides the photosensitive light from the light source to the liquid crystal panel as a substantially parallel beam, and an input terminal that receives a video signal and displays an image on the liquid crystal panel in accordance with the video signal. The liquid crystal panel also has a control means for moving the position of the liquid crystal panel and the photosensitive recording medium and controlling the light source, and the liquid crystal panel is capable of exposing an image according to the video signal using the photosensitive light generated from the light source. A transmissive region is formed to have half the length of the unit pixel region in the vertical and horizontal directions, and the other portion of the unit pixel region is a light blocking region where the sensitizing light generated from the light source is blocked. When the control means receives a video signal at the input terminal, it displays an image on the liquid crystal panel in accordance with the video signal, causes the light source to emit light, and transmits the image displayed on the liquid crystal panel through the transmission area onto the photosensitive surface of the photosensitive recording medium. The exposure operation was performed four times in total by moving the position of the liquid crystal panel and the photosensitive recording medium by half the length in the vertical and horizontal directions of the unit pixel area, and the entire unit pixel area was exposed. This allows exposure to light.

15551j Next, embodiments of a video printer according to the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIGS. 1, 2, and 3, there is shown an embodiment in which a video printer according to the present invention is applied to a printer housed in a compact housing.

This printer receives a color video signal at an input terminal 46, displays the image represented by the image on a liquid crystal panel 18 for each of the three primary color component signals RGB, and uses a color filter 54 to display the RGH
This is a color image recording device that records a hard copy on a recording medium 78 by making the component light of the image incident on the liquid crystal panel 18.

The features of this printer are that it displays an image on the liquid crystal panel 18 and exposes the recording medium 78;
The recording medium 78 is also used for the portion corresponding to the light blocking area No. 8.
The purpose is to remove the influence of the light-blocking area of the liquid crystal panel 18 by exposing the liquid crystal panel 18 to light.

As shown in FIG. 8, the liquid crystal panel 18 has a large number of liquid crystal display elements two-dimensionally arranged in a rectangular matrix array, and when driven by a drive input 36 according to a video signal, it visualizes a black and white image. It is a device. This drive input 36 is supplied from a drive circuit 44 as described below. As is well known, when the liquid crystal panel 18 is driven in response to a video signal, it changes its light transmittance in accordance with the density of the pixel represented by the video signal. Therefore, the light 34 that has entered one main surface of the panel 18 is luminance-modulated according to the density component of the video signal, and is emitted from the other main surface 42. In this embodiment, the drive circuit 44 and the liquid crystal panel 18 adopt a so-called active matrix drive system. The scanning timing signal for this purpose is controlled by the control circuit 50. 74
It is supplied through

As shown in FIGS. 5 and 6, in the liquid crystal panel 18, a light blocking area 102 in which a drive element and electrode wiring for driving the liquid crystal shutter 100 are provided is provided on the main surface of the glass support substrate. ing. 5 and 6 show schematic cross-sectional views of the liquid crystal panel 18. FIG. Figure 5 shows LCD shutter 1
00, and FIG. 6 shows the transparent state of the liquid crystal shutter 100.

The light blocking area 102 blocks light from the light source 12.

Therefore, only the transmitting region 104 without drive elements etc. is exposed to the light 3.
4 can be transmitted. When the liquid crystal shutter 100 is set to the blocking state by the driving element, the light 34 does not pass through (FIG. 5), but when the liquid crystal shutter 100 is set to the transmitting state, the light 34 passes through the liquid crystal shutter 100 and the transmission area 104. For each liquid crystal shutter 100 area, there is a transmission area 104 through which light can pass (FIG. 6).
is surrounded by a light blocking area 102, and the length of each vertical and horizontal side of the transmitting area 104 is set to be half the vertical and horizontal length of each liquid crystal shutter 100 area including the surrounding light blocking area 102. There is.

Therefore, the area of the transmissive area 104 that can expose an image to the recording medium 78 is one quarter of the area of the entire liquid crystal panel 18.
(aperture ratio of 25%), and when the aperture ratio of the liquid crystal itself is 25% or more, a mask may be arranged to increase the aperture ratio to 25%.

In order to also expose a portion corresponding to such a light blocking area 102, the present apparatus is provided with a panel moving mechanism 28. The panel moving mechanism 28 moves the position of the liquid crystal panel 18 relative to the recording medium 78 in accordance with a control signal sent from the control circuit 50 as described below. The panel moving mechanism 28 may be any mechanism as long as it can move a predetermined distance relative to the liquid crystal panel l^ recording medium 78 in response to a control signal from the control circuit 50.

As the panel moving mechanism 28, for example, as shown in FIG. 4, a moving mechanism using a piezoelectric element having an electrostrictive effect is used. As shown in the figure, when a control signal from the control circuit 70 is input to the transistor Ql, the current flowing through the piezoelectric element 128 changes accordingly, and the piezoelectric element 128
distortion occurs. The liquid crystal panel 18 is moved according to the distortion of the piezoelectric element 128. Such panel moving mechanisms 28 are provided in the vertical and horizontal directions of the liquid crystal panel 18, and the liquid crystal panel 18 is moved as described later. In this way, the liquid crystal panel 18 is moved by the expansion and contraction that occurs in the piezoelectric element 128 in response to the applied voltage.

As the panel moving mechanism 28, instead of using a piezoelectric element, a bimetal may be used to move the liquid crystal panel 18 using strain, or a moving mechanism using a material having a magnetostrictive effect may be used. A moving mechanism using a step motor, a screw feed mechanism, a cam, a wedge, etc. may also be used.

The liquid crystal panel 18 is moved to the tenth position by the panel moving mechanism 28.
As shown in FIGS. A to 10C, it is moved vertically and horizontally by the length of each transmission area 104, that is, by half the length of each liquid crystal shutter 100 area.

That is, as shown in FIG. 9, the transmissive area 104 is first placed at position 101, driven by a video signal, an image is displayed on the liquid crystal panel 18, and the sixth transmissive area 104 is exposed. Position 1 is adjacent to position 101 so as to be at position 102, that is, on the right side of position 101.
02, the liquid crystal panel 18 is moved to position 1.
An image is displayed using the same video signal as in 01, and exposure is performed. The position of the liquid crystal panel 18 at this time is the 10th position.
It is shown in figure A by a dashed line.

Furthermore, the liquid crystal panel 18 is moved to position 103 in FIG. 9, that is, to a position below position 102 and in contact with position 102, and
An image is displayed using the same video signal as in 02, and exposure is performed. The position of the liquid crystal panel 18 at this time is the 10th position.
It is shown in Figure B by a two-dot chain line.

Similarly, the liquid crystal panel 18 is moved to position 104 in FIG. 9, that is, to a position below position 101 and in contact with position 101,
．． An image is displayed using the same video signal as in step 103, and exposure is performed. The position of the liquid crystal panel 18 at this time is indicated by a dotted line in FIG. 10C.

In this way, in this printer, by moving the position of the liquid crystal panel 18 and exposing it four times using the same video signal, the portion corresponding to the light blocking area 102 is also exposed.

1 without moving the liquid crystal panel 18 as described above.
If exposure is performed only at one position, the light blocking area 102 in which the drive element etc. are arranged blocks the light 34, so the coordinates in the X-axis direction on one main surface side of the liquid crystal panel 18 and the light amount are The relationship is as shown in Figure 7. Therefore, for example, when representing a white positive image, the exposure amount is not sufficient and the image becomes gray.

On the other hand, according to the printer of this embodiment, since the position of the liquid crystal panel 18 is moved and the exposure is performed four times using the same video signal, the amount of exposure will not be insufficient, and for example, a white image of a positive image will be exposed. There is no defect that the color turns gray.

FIG. 11 shows the photosensitive characteristics of the photosensitive sheets 78 of negative-positive type photosensitive material (negative type) and positive-type photosensitive material (positive type).

According to the characteristic curve of the positive-positive type sheet 78, the exposure amount is minimum when the liquid crystal shutter 100 is in the cut-off state, so the image density is maximum, and this is designated as point A. On the other hand, when the positive-positive type sheet 78 is completely exposed, the image density becomes the minimum, which is defined as point B. When the liquid crystal shutter 100 is in the transmitting state, the light 34 is diffracted, scattered, reflected, etc. in the shadowed portion of the driving element region 102, so that the exposure amount does not reach the minimum, but reaches the density represented by point E. Therefore, when an image including a white part is exposed and developed, the density of the white part perceived when viewing the developed photosensitive sheet 78 with the naked eye is determined by taking into account the area of the area in the shadow of the frame and the area through which light passes. Since it is approximately equal to the average density, point F is the weighted average of point E and point B.

On the other hand, regarding the characteristic curve of the negative-positive type sheet 78,
When the liquid crystal shutter 100 is in the cut-off state, the image density becomes the minimum, which is set as 0 point. On the other hand, when the image is completely exposed, the image density becomes maximum and this is designated as point D. LCD panel 18
In the shaded portion of the driving element region 102, the density is not the minimum as in the case of the positive-positive type sheet 78, but is the amount represented by point G.

Therefore, the photosensitive sheet 7 on which the image including the white part is exposed
The average density of the white portion after development in No. 8 is the amount represented by the H point.

In this way, both the positive-positive type and the negative-positive type are affected by the light blocking area 102, so for example, in the case of the positive-positive type sheet 78, the white color becomes gray (an image with large fog), and the negative-positive type For seat 78, black (D x ax)
concentration decreases slightly. In this case, visually, the image with a larger fog produced by the positive-positive type sheet 78 has lower image quality. Therefore, if this printer removes the influence of the light-blocking area and performs complete exposure, The effect is particularly great when printing using the positive-positive type sheet 78. It is also effective for the negative-positive type sheet 78, and D ax becomes sufficiently large (at point D in Figure 11). ).

Other mechanical parts of the printer of this embodiment shown in FIGS. 1 to 3 will be explained.

This device basically has a light source 12, mirrors 14 and 16, and a liquid crystal panel 1 inside a rectangular parallelepiped housing lO.
8, a developing roller 20 and a power source 76 are arranged and configured as shown in the figure. As shown in the figure, the main part of the upper part of the housing IO is open, and two lids 22j15 and 24 that can be opened and closed are provided on the upper part.

Inside the lids 22j5 and 24 are mirrors 14i3 and 14i3.
The six lids 22 and 24 to which the six lids are attached are connected by a bellows 26 to optically shield the opening of the housing IO from light. As a result, the interior space of the housing IO is formed into a dark box.

The light source 12 is disposed near the left end inside the housing 1O as shown in the figure. The liquid crystal panel 18 is located approximately at the center of the interior space of the housing 10, is supported by the housing 10 by the panel moving mechanism 28, and is moved to change its position relative to the photosensitive sheet 78 as described above. Lid 22
The housing can be rotated manually using a hinge 30.
As shown in FIG. 2, it opens to a predetermined position slightly larger than 45 degrees to the horizontal, and is held at that position. Similarly, the lid 24 is manually rotatably supported by the housing lO by a hinge 32, and is opened to a predetermined position slightly smaller than 45 degrees to the horizontal as shown in the figure, and is held at that position.

The light source 12, the mirrors 1413 and 16, and the liquid crystal panel 18 are arranged so that when the lids 22j5 and 24 are opened and fixed at predetermined angle positions, the light beam 34 emitted from the light source 12 is
As shown in the figure, the light is reflected by the two mirrors 14 and 16, and is in a positional relationship such that it enters one principal surface 40 of the liquid crystal panel 18 at an almost perpendicular angle as nearly parallel light.

A switch 70 is provided which responds to opening of the lids 22 and 24 to a predetermined position. This switch 70 is connected to the control circuit 50 as shown in FIG. 1, and enables the control circuit 50 to detect opening of the lids 22 and 24 to a predetermined position.

When the opening/closing lid 22i3 and the door 4 are closed, the overall appearance of the housing IO becomes flat as shown in FIG. 3. This transforms the device into a compact form that can be carried, for example, at least in a pocket.

For example, a film bag 38 containing a plurality of photosensitive recording media 78 such as photosensitive members for instant photography is advantageously applied. As is well known, the photosensitive member of this type of film bag 38 consists of a photosensitive sheet 78 and a bag containing a developer provided at the edge of this sheet, and a plurality of these are stacked and stored in the bag. ing.

After recording the latent image on the photosensitive sheet 78, the developer bag is destroyed and the developer is spread on the photosensitive sheet 78, thereby making the latent image visible. For the purpose of spreading the developer, this apparatus is provided with a pair of developing rollers 2o. An opening (not shown) for loading the film bag 38 is provided on the side surface of the housing 10, and the film bag 38 is loaded into the housing 10 through this opening and is ejected from the housing 10.

The photosensitive recording medium 78 is not limited to such an instant photographic photosensitive material, but may be, for example, ordinary color photographic paper or a heat-developable silver salt photosensitive material. As the photosensitive material, a heat-developable silver salt photosensitive material is preferable, and in the case of recording a black and white image, ordinary black and white photographic paper may be used. A developing mechanism is provided in place of the developing roller 20.

As shown in FIG. 2, the topmost sheet 78 of the photosensitive sheets 78 stacked in the film pack 38
As shown in FIG.
can be discharged from one side. The developing roller 20 is
(2) A pair of rollers are rotatably supported by the housing 10 in contact with each other, and are driven by a developing roller drive circuit 52 under the control of a control circuit 50. An opening 80 for discharging the photosensitive sheet 78 is provided on the side surface of the housing 10 as shown.

Note that the developing roller 20 is not driven by such an automatic driving method, but may be driven by a manual operation such as, for example, manually pushing out the end of the photosensitive recording medium 78 in the direction of the arrow 48.

The liquid crystal panel 18 is moved as described above by a panel moving mechanism 28, and is supported by the housing 10 so as to be movable in the vertical direction in FIG. 2 by a support mechanism (not shown). In the operating state, the liquid crystal panel 18 is lowered so that the lower main surface 42 of the panel 18 comes into close contact with the photosensitive recording surface of the uppermost photosensitive sheet 78 stacked in the film back 38.

The photosensitive sheet 78 is attached to a pressing spring (not shown) inside the bag 38.
It is constantly pressed upward by. film pack 3
When discharging the uppermost photosensitive sheet 78 from the panel 8, the support mechanism is configured to be able to move the panel 18 upwardly by a certain distance under the control of the control circuit 50. [Liquid crystal panel] 8 may be configured so that it is always in contact with the surface of photosensitive sheet 78.

In this way, the liquid crystal panel 18 is in close contact with the image recording surface of the uppermost recording medium 78 at least in the operating state.

Further, the light 34 generated from the light source 12 enters the principal surface 40 of the liquid crystal panel 18 as substantially parallel light through an optical system including mirrors 14 and 16. This ensures that a clear image is recorded on the recording medium 78.

By the way, the light source 12 emits white light or visible light 3 close to it.
4 is advantageously used. A single light source may be used, or multiple light sources may be provided to generate white or near-white light. The light source I2, which may be, for example, a light emitting diode, a strobe (xenon lamp), a tungsten lamp, a fluorescent tube, an electroluminescent device or a plasma discharge tube, is driven by a light source drive circuit 66 under the control of the control circuit 5o. Ru.

In the optical path 34 immediately in front of the light source 12, a color filter 54 is disposed as shown. The color filter 54 is composed of, for example, three filters that each transmit a different one of the three primary colors RGB. Although only one of the three filters is shown to avoid complicating the diagram, these filters 54 are supported by a filter drive mechanism 56 and under the control of a control circuit 50, one of the three filters is shown. The light path 34 from the light source 12 is selectively
is configured to be inserted into the by this,
The white light 34 generated from the light source 12 can enter the liquid crystal panel 18 as any RGH component light.

The light source 12 may not be configured as such a single light source, but may include three light sources corresponding to each of the three primary color components RGH. For example, the three light sources may be arranged in a triangle, and one of the RGB filters may be provided for each. Alternatively, the light source 12 may be a light emitting diode or an electroluminescent device.
It may be configured to generate three primary color lights from itself.

In that case, a filter such as the filter 54 and the filter drive mechanism 56 are not necessary, and the light source drive circuit 66 has a function of selectively causing the light sources of these three primary colors to emit light. Furthermore, instead of the additive color method of generating component light, a subtractive color method may be used.

Referring to FIG. 1, the video signal terminal 45 is connected to a video signal circuit 58. The video signal input to the input terminal 46 may be in the form of a TV signal or an electronic still camera signal, for example. The video signal circuit 58 is a signal processing circuit that converts a video signal in such a signal format into digital data of three primary color components RGB. Its output 60
is connected to the data input of frame memory 62.

Note that the video signal input to the input terminal 46 is, of course, 3
It may take the form of primary color component signals RGB or may be such type of digital data; in the latter case, the video signal circuit 58 is not required.

The frame memory 62 is a storage circuit that stores one frame of such RGB component data. Frame memory 62 has its read and write operations controlled by control circuit 50 , and its read data output 64 is connected to liquid crystal panel drive circuit 44 .

The drive circuit 44 rask-drives the individual pixel cells of the liquid crystal panel 18 in a field-sequential manner according to the three primary color component data read out from the frame memory 62.

The control circuit 50 is a functional unit that unifies and controls the operation of the entire device. An operation display section 68 is connected to the control circuit 50, which allows the operator to manually input instructions and to display the status of the apparatus to the operator. In particular, the control circuit 50 outputs a control signal to the panel moving mechanism for moving the position of the liquid crystal panel 18 four times with respect to the same video signal as described above. The power supply 76 is connected to the liquid crystal panel 18
and a DC power source such as a dry battery or a secondary battery, which supplies power to electric circuit elements within the apparatus including the light source 12 and the like.

The operation will be explained.

When the film pack 38 is loaded into the housing IO, the liquid crystal panel 18 is lowered by the panel support mechanism under the control of the control circuit 50 to the position shown in FIG. As a result, the recording surface of the uppermost photosensitive sheet 78 stacked in the film back 38 comes into close contact with the lower main surface 42 of the panel 18. Lids 22 and 24 are opened and held in place as shown in FIG. This state is detected in control circuit 50 by switch 70.

For example, the output of a video signal source such as an electronic still camera playback device is connected to the video signal input terminal 46. Operation display section 68
When the control circuit 5 is operated to instruct to read the video signal, the control circuit 5
0 controls the video signal circuit 58 and frame memory 62 by controls 1I71 and 72, respectively, and takes in the video signal input to the input terminal 46. The video signal circuit 58 converts this into digital data in a predetermined format, for example, RGB color component signals. The converted color component signals are stored in frame memory 62.

When an instruction to print an image is input by operating the operation display unit 68, the control circuit 50 responds to this by first controlling the filter drive mechanism 56 to select a specific color component from the filter 54, for example, the R component. Select filter and light source 12
into the optical path 34 from. At the same time, the frame memory 62 is instructed to read the R component data. There, the R component data is sequentially read out from the frame memory 62 in the order of rask scanning, and this data is amplified by the drive circuit 44 and supplied to the liquid crystal panel 18 from its output 36 as a drive signal. As a result, the liquid crystal panel 18
It is driven by the R component signal and visualizes the black and white image. At this time, the liquid crystal panel 18 is placed at the position 101 described above.

In synchronization with driving the liquid crystal panel 18, the control circuit 50 controls the light source drive circuit 66 to cause the light source 12 to emit light for a predetermined period. In this way, an image of the R color component is recorded as a latent image on the photosensitive sheet 78 with the liquid crystal panel 18 placed at position 101. While the image of the R color component is being displayed on the liquid crystal panel 18, the liquid crystal panel 18 is It moves to position 102 and similarly causes light source 12 to emit light for a predetermined period. Alternatively, after moving the liquid crystal panel 18 to the position 102, the image of the same R color component may be read from the frame memory 62. In this way, the image of the R color component may be read out from the frame memory 62 after the liquid crystal panel 18 is moved to the position 102. The state is recorded on the photosensitive sheet 78 as a latent image.

Similarly, the liquid crystal panel 18 is moved to positions 103 and 104, and an image of the R color component is recorded on the photosensitive sheet 78 as a latent image.

When the recording of the R color component image is completed, the control circuit 50
For the images of the remaining color components, for example, Gj5 and B components, the filter 54 is sequentially changed to the filter of that color.
At the same time, the corresponding color component data is read out from the frame memory 62 to drive the liquid crystal panel 18, and at the same time, the light source 12 is driven to record these images in an overlapping manner on the same photosensitive sheet 78. The control circuit 50 has RGB
By adjusting the exposure time of the photosensitive sheet 78 by the light source 12 for each of the component images, color correction of the original image can be performed. In other words, the color image completed by superimposing exposure on the photosensitive sheet 78 has undergone color correction.

When recording of the three primary color latent images is completed, the control circuit 50 controls the panel support mechanism to lift the liquid crystal panel 18 upward by a certain distance, and controls the developing roller drive circuit 52 to drive the developing roller 52. As a result, the recorded photosensitive sheet 78 is smoothly fed from the film back 38 to the path 48, and is developed by the developing roller 20 along the way. If the photosensitive sheet 78 is for instant photography, the developer is spread during this process, and the latent image is developed and fixed. In this way, the color image represented by the video signal of the input 46 is visualized on the recording medium 78, and the recording medium 78 is
It is discharged through opening 80.

When not in use, the lids 22 and 24 are folded down, as shown in FIG. 3. The control circuit 50 detects this condition through the switch 70 and stops the entire function of the device.

In the above explanation, for one color (R), the liquid crystal panel 1
Change the position of 8 and repeat 4 times (101, 102, 103, 10
41 exposures, but R for one exposure (101)
, G, and B. Similarly, for the other three exposures (102, 103, and 1041, R, G,
Switch to B and expose. According to this method, the liquid crystal panel 18 only needs to be mechanically moved four times, whereas the above-mentioned method requires 12 movements.

According to this embodiment, as described above, the length of each side of the transmissive area of the liquid crystal panel I8 is formed to be half the length of the unit pixel area (each liquid crystal shutter) including the light blocking area, and the transmissive area The area of the area is set to one quarter of the unit pixel area. Since the liquid crystal panel 18 is moved four times as described above and exposed using the same video signal, it is possible to perform exposure even in areas that cannot normally be exposed due to the light blocking area. Therefore, beautiful prints without fog due to insufficient exposure can be obtained. Moreover, since the entire unit pixel area including the light blocking area is exposed without overlapping by four exposures, there is no problem of overexposure caused by multiple exposures.

In the above embodiment, the transmissive area and the unit pixel area of the liquid crystal panel 18 are square, but the printer of the present invention can also be applied to a rectangular area. In that case, the length of the long side, right side, and short side of the transparent area is set to 1/2 of the length of the long side and short side of the unit pixel area, respectively.
And it is sufficient.

Of course, it does not have to be strictly one-half, but approximately one-half is sufficient for the present invention to be effective.

Further, the opening does not have to be a perfect rectangle, and the driving circuit element provided for each pixel may protrude, as long as the protruding portion is about 10~20% of the opening. , you may consider a rectangle that excludes this part.

In addition, if a mass-produced product is used as the liquid crystal panel 18 and the aperture ratio is larger than 25%, a mask may be placed on the liquid crystal panel 18 to achieve an aperture ratio of 25%.
When the aperture ratio of a mass-produced liquid crystal panel 18 is 25% or less, the aperture ratio of the mask can be selected so that m x n exposures can be performed. However, m and n are integers of n=2 and n=2. For example, if m=3 and n=2, this corresponds to an aperture ratio of 16.7%.If m=4 and n=2, then
The aperture ratio is 12.5%.

In addition, the lengths of the long and short sides of the transparent region are set to one-third of the lengths of the long and short sides of the unit pixel region, respectively, and the area of the transparent region is set to one-ninth of the area of the unit pixel region. The liquid crystal panel 18 may be set and moved nine times so that the transparent area covers the unit pixel area. Similarly, the lengths of the long and short sides of the transmissive region are set to 1/m and 1/n of the lengths of the long and short sides of the unit pixel area, respectively, and exposure is performed m−n times. You can.

Furthermore, although the above embodiment is a printer housed in a compact housing, the present invention may be any printer that exposes using a liquid crystal panel, and is not limited to a printer housed in such a housing, for example. The present invention can also be applied to a device that exposes and prints an image displayed on a liquid crystal panel onto a photosensitive material through a lens, such as a printing device that has an enlargement function (enlargement, reduction).

In addition to directly exposing the photosensitive material forming a hard copy through a liquid crystal panel as in the above embodiment,
It can also be applied to those in which recording is performed by exposing a photoconductive material to light and transferring the formed latent image to a recording medium.

Furthermore, in the various embodiments described above, the photosensitive material may be moved instead of moving the liquid crystal panel.

In the above explanation, the photosensitive material is sensitive only to the visible wavelength range, but the photosensitive material does not necessarily have to be sensitive only to the visible wavelength range. The photosensitive materials used in the hard copy system of the product name are yellow, red,
They are sensitive to infrared light and emit yellow, magenta, and cyan dyes, respectively. Examples using such photosensitive materials are also included in the present invention.

In each of the embodiments described above, color images are printed using color video signals, but it goes without saying that the present invention can also be applied to printing black and white images. In the case of printing a black and white image, it is sufficient to send the video signal of the black and white image from the frame memory 62 to the liquid crystal panel 18, and the filter 5
4 is unnecessary.

Effects-1 As described above, the video printer according to the present invention is configured to move the positional relationship between the liquid crystal display panel and the recording medium and perform exposure multiple times to record an image on the recording medium. It is possible to eliminate the influence of a light blocking region such as a driving element provided in the optical system. Furthermore, since exposure is performed using a liquid crystal display panel, the printing time is short and it is easy to make a compact device, and since a mass-produced liquid crystal panel can be used, it is inexpensive. According to the video printer of the present invention, beautiful images without fogging can be obtained even when exposing a positive-positive type photosensitive material.

[Brief explanation of drawings]

Fig. 1 is a functional block diagram showing an example of the circuit configuration of a video printer according to the present invention, Fig. 2 is a side sectional view showing the same embodiment in a used state, and Fig. 3 is a side sectional view showing the same embodiment in a non-used state. 4 is a circuit diagram showing an example of the panel moving mechanism shown in FIG. 1; FIG. 5 is a diagram showing a liquid crystal panel in a blocked state; and FIG. 6 is a diagram showing a liquid crystal panel in a transparent state. Fig. 7 is a diagram showing the light amount of the liquid crystal panel in the transmissive state, Fig. 8 is a diagram showing the arrangement of pixel areas of the liquid crystal panel, Fig. 9 is a diagram showing the movement order of the transmissive area of the liquid crystal panel, and Figs. 10A to 10A. FIG. 10C is a diagram showing the moving position of the transmission area of the liquid crystal panel, and FIG. 11 is a diagram showing the relationship between image density and exposure amount of a positive-positive type sheet and a negative-positive type sheet. Part, c3 - Light source Liquid crystal panel Developing roller Panel moving mechanism Filter Photosensitive sheet Liquid crystal shutter Piezoelectric element

Claims (1)

[Scope of Claims] 1. A video that receives a video signal representing an image, displays the image as a black and white image on a liquid crystal panel according to the video signal, and records the displayed image as a visible image on a photosensitive recording medium. The printer includes: an input terminal for inputting the video signal; a recording medium accommodating section for accommodating the photosensitive recording medium; and a unit pixel area disposed corresponding to the photosensitive surface of the photosensitive recording medium, each having a unit pixel area. a liquid crystal panel formed in a rectangular shape; a light source that generates sensitizing light in a wavelength range to which the photosensitive recording medium can be sensitized; and an optical system that guides the sensitizing light from the light source to the liquid crystal panel as a substantially parallel light beam. a system, receiving a video signal at the input terminal, displaying the image on the liquid crystal panel according to the video signal, moving the position of the liquid crystal panel and the photosensitive recording medium, and controlling the light source. and a control means, wherein the liquid crystal panel has a transmissive area capable of exposing an image according to the video signal by the exposure light generated from the light source, which is arranged in two directions in each of the vertical and horizontal directions of the unit pixel area.
The other part of the unit pixel area is formed as a light blocking area where the photosensitive light generated from the light source is blocked, and the control means is configured to input a video signal to the input terminal. when receiving the video signal, displaying an image on the liquid crystal panel in accordance with the video signal, causing the light source to emit light, and exposing the image displayed on the liquid crystal panel through the transmission area onto the photosensitive surface of the photosensitive recording medium; By moving the positions of the liquid crystal panel and the photosensitive recording medium by half the length in the vertical and horizontal directions of the unit pixel area, the exposure is performed a total of four times to expose all the unit pixel areas. A video printer characterized by: 2. The video printer according to claim 1, wherein the input terminal, recording medium accommodating section, liquid crystal panel, light source, and optical system are housed in a housing, and the liquid crystal panel is disposed in close contact with the photosensitive surface of the photosensitive recording medium. A video printer characterized by: 3. The video printer according to claim 1, wherein the photosensitive recording medium is a positive-positive type photosensitive material.