JPH04133046A - Collimator device and video printer provided therewith - Google Patents

Abstract

PURPOSE:To obtain a collimator device whose optical path length is short by providing an optical fiber layer consisting of many bundles of optical fibers which receives light from a diffusion plate on its one end,make the light the collimated beam of light and projects it from its other end. CONSTITUTION:The optical fiber layer 28 consisting of many bundles of optical fibers 30 is disposed on the side of the diffusion plate 26 opposite to a light source 22. A liquid crystal panel 34 for forming an image is disposed on the main surface 32 of the optical fiber layer 28 on the opposite side to the diffusion plate 26. Then, the light projected from the diffusion plate 26 is made vertically incident all over the image area of the liquid crystal panel 26, and a photosensitive recording medium 16 is effectively exposed to the light. Thus, the collimator device whose optical path length is short is obtained and a video printer and an electronic instant camera are miniaturized.

Description

TECHNICAL FIELD The present invention relates to a collimator device for forming parallel light, and to a video printer and an electronic instant camera having this collimator device.

BACKGROUND ART In general, some electronic instant cameras are of a type in which an image of a scene captured by a solid-state imaging device is recorded on an instant photosensitive material. For example, if a patent application is filed by the same applicant as the applicant of the present application, the Patent Application Hei! 73929 discloses an electronic instant camera of this type. This type of camera is equipped with a video printer mechanism that exposes instant photosensitive material through a liquid crystal panel.

The video printer mechanism receives a video signal representing an image of the subject, drives the liquid crystal panel in accordance with the signal, and irradiates the instant photosensitive material with light from a light source through the liquid crystal panel. An image is recorded on a photosensitive material according to the driving state of the photosensitive material. A liquid crystal panel includes a plurality of liquid crystal cells corresponding to pixels, and when these liquid crystal cells are driven according to a video signal, the brightness of the backlight is modulated according to the video signal and passes through the liquid crystal panel, thereby producing an image. The image represented by the signal is recorded on the photosensitive material. A liquid crystal cell has a relatively long structure in the direction of light incidence. Therefore, if light is incident obliquely with respect to the optical axis direction of the liquid crystal cell, the photosensitive material cannot be effectively exposed, and a blurred image may be recorded on the photosensitive material.

Therefore, for efficient exposure of photosensitive materials, the light incident from the light source needs to have fairly good parallelism.

Traditionally, video printer mechanisms in electronic instant cameras have used collimating lenses to take a synchrotron radiation source and shape it into parallel light. Due to the nature of optical system lenses, a long optical path length is required to obtain a substantially parallel light beam.

One of the major features of electronic instant cameras is their simplicity, so the devices are required to be small. Therefore, the use of a collimator lens with a long optical path length has been a major obstacle in downsizing the device.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the drawbacks of the prior art and to provide a collimator device with a short optical path length, thereby making video printers and electronic instant cameras more compact.

DISCLOSURE OF THE INVENTION A collimator device according to the present invention includes a generally flat diffuser plate that diffuses light incident on one main surface and exits from the other main surface, and a longitudinal direction substantially perpendicular to the other main surface of the diffuser plate. and both end surfaces are arranged to form a flat surface as a whole, and one of the end surfaces receives the light emitted from the other main surface of the diffuser plate and converts it into parallel light to the other end surface. and an optical fiber layer including a bundle of multiple optical fibers emitting from the optical fiber layer.

A video printer according to the present invention includes such a collimator device, a light source that emits light, and a photosensitive surface of a photosensitive recording medium on which an image represented by a video signal is to be recorded. The optical fiber layer includes a liquid crystal panel in which a plurality of liquid crystal cells are arranged in a plane to change the transmittance of the parallel light to the photosensitive surface according to the arranged substantially vertically.

Also according to the invention. An electronic instant camera is provided that includes such a video printer and imaging means for imaging a scene to form a video signal representing an image of the scene.

An embodiment in which a collimator device according to the present invention is applied to an electronic instant camera will be described in detail with reference to the accompanying drawings. Referring to FIG. 1, the electronic instant camera of the embodiment includes a solid-state imaging device 1 through an imaging lens 10.
2, an image of the object is photographed, and the image of the object is transferred to a photosensitive recording medium 16 such as an instant photosensitive material in a film pack 14.
This is an image forming apparatus that records images. This camera includes a control section 18 that controls the entire apparatus, and a video printer section 20 that records images on a photosensitive recording medium 16.

The video printer section 20 basically includes a light source 22 and a collimator device i24. The film pack 14 is loaded below the collimator device 24 in the same figure. The light source 22 is a light emitter that emits light substantially radially, and may be a point light source in this embodiment. Therefore, the light source 22 can be an inexpensive element with a simple configuration.

The collimator device N24 has a generally rectangular and flat diffuser plate 26 corresponding to an image area of one frame to be recorded on the photosensitive recording medium 16. The diffusion plate 26 is made of a light-transmitting material such as plate glass with magnesium oxide smoked on its main surface, and uniformly diffuses the light incident on one main surface from the light source 22 and emits it from the other main surface. do.

An optical fiber layer 28 is disposed on the side opposite to the light source 22 with respect to the diffusion plate 2B. In this embodiment, the optical fiber layer 28 has a substantially rectangular planar shape with the diffuser plate 28 as a whole, and is a bundle of a large number of optical fibers 30 extending in a direction substantially perpendicular to the main surface of the diffuser plate 26. It consists of These optical fibers 30 may be short in length, are formed into a bundle by suitable tightening members, and are held on the diffuser plate 26. The optical fibers 30 are arranged so as to transmit the light incident therein from the end face on the side of the diffuser plate 26, and to output the light as parallel light as a whole from the other end face 32 to the east.

A liquid crystal panel 34 for image formation is disposed on the main surface 32 of the optical fiber layer 28 on the opposite side from the diffuser plate 26 . The liquid crystal panel 34 has a rectangular planar shape corresponding to an image area, and is configured by liquid crystal cells 36 arranged in a rectangular matrix, each pairing with a large number of pixels constituting the image area. A video signal signal line 38 is connected to each liquid crystal cell 36 so that these liquid crystal cells 38 are driven according to the video signal.

The optical fiber 30 is advantageously used to have a diameter sufficiently shorter than the diameter of the effective optical aperture of the liquid crystal cell 36. If such a thin fiber 30 is used, the conometer device 24
During manufacture, individual fibers 30 are connected to individual liquid crystal cells 36.
There is no need to align against. Also, fiber 30
They do not need to be strictly aligned either. therefore,
No adjustment process is required in manufacturing the collimator device 24, and the number of manufacturing steps can be reduced. In the figures, the sizes of the optical fiber 32 and the liquid crystal cell 36 are exaggerated for ease of illustration. In particular, their lateral dimensions in the same figure are exaggerated. Furthermore, although these numbers correspond to the number of scanning lines or pixels in the vertical or horizontal direction of an actual image area of one frame, it goes without saying that these numbers are drawn smaller than the actual number in one figure.

A film pack 14 is loaded below the liquid crystal panel 34 in the figure with its exposure surface 42 in close contact with the liquid crystal panel 34. In this embodiment, the film pack 14 stores a plurality of photosensitive recording media 16, one of which is sequentially fed to the exposure surface 42 and placed on the liquid crystal panel 34. The photosensitive recording medium 16 may be an instant photosensitive material, which may advantageously be of the type comprising a sheet coated with a photosensitive agent and a bag (not shown) provided at the edge of the sheet for containing a developer. applied to. The photosensitive recording medium 16 exposed to the light from the light source 22 through the liquid crystal panel 34 is shown by the arrow 4.
As shown at 4, the toner is fed between a pair of developing rollers 46, whereby the exposed surface 42 is coated with developer to perform development. Of course, in applications where it is not necessary to immediately visualize an image, ordinary silver salt photographic paper or a heat-developable silver salt photographic material may be used instead of the instant photographic material as the photosensitive recording medium 1.
In those cases, a suitable developer roller 46 may be used instead of the developer roller 46. A mechanism is provided.

As described above, the optical fiber layer 28 is disposed such that the longitudinal axis of the optical fiber 30 is substantially perpendicular to the main surface 32 of the liquid crystal panel 34. Therefore, the light emitted from the diffuser plate 2B is substantially perpendicularly incident on the entire image area of the liquid crystal panel 26 and can effectively expose the photosensitive recording medium 16, so that the recording medium 16 can be exposed to a clear image. Images are recorded.

The control unit 18 receives a video signal from the output 40 of the solid-state imaging device 12, and in accordance with the video signal drives the liquid crystal panel 34 from the signal line 38, and also controls the developing roller 46 as conceptually indicated by a control edge 48. This is a control circuit that controls the conveyance operation of the recording medium 16 by. Regarding the video signal, the control unit 18:
2, a signal processing circuit that digitizes the signal and performs signal processing such as gradation correction, a frame memory that stores video signal data, and a drive circuit that drives the liquid crystal panel 34.

In the operating state, when a shirt release button or a record button (not shown) is pressed, the control unit 18 responds to this by capturing the video signal 40 output from the solid-state imaging device 12. The signal line 3 is energized in accordance with the video signal to drive each liquid crystal cell 36 of the liquid crystal panel 34. At the same time, the light source 22 is driven to turn it on.

The light emitted from the light beam 22 enters the diffuser plate 26, where it is uniformly diffused, and then travels inside the multiple optical fibers 30 of the optical fiber 28. This light becomes substantially parallel to each other through the fiber 30 and enters each liquid crystal cell 36 of the liquid crystal panel 34 . liquid crystal cell 36
When driven according to a video signal, one optical fiber layer 34
The transmittance of light incident from the source is changed accordingly. Therefore, the light whose brightness is modulated by the liquid crystal cell 34 is transmitted to the exposure surface 4.
The light enters the photosensitive recording medium 1B at position 2 substantially perpendicularly and exposes it. In this way, an image corresponding to the driving state of the liquid crystal panel 34 is recorded on the photosensitive recording medium 16 as a latent image. After forming the latent image, the control circuit 18 turns on the light source 22.
is deenergized, thereby ending the exposure.

The photosensitive recording medium 16 on which the latent image has been formed is discharged from the bag 14 by the developing roller 46 under the control of the controller Wi1s, and when the developer bag (not shown) is destroyed by the developing roller 46, the developer is released. is applied to the sheet and developed.

In this embodiment, the optical system 24 that illuminates the liquid crystal panel 34 substantially vertically from behind includes a diffuser plate 26 that uniformly diffuses the light emitted from the light source 22, and a diffuser plate 26 that shapes the diffused light into parallel light. It is composed of an optical fiber/layer 12. Therefore, the optical path length is shortened compared to a conventional optical system using a collimator lens.

In an application example where the photosensitive recording medium 16 is a color photosensitive material l,
Color component signals are supplied to the input 38 of the liquid crystal panel 34, for example, in a frame-sequential manner. In synchronization with each color component signal, the color filter 5o of the corresponding color component is connected to the light source 22 of the diffuser plate 26.
is selectively inserted on the side of As a result, each color component image is formed as a latent image on the color photosensitive material 16 in four frames sequentially, and by developing this, one frame of color image is obtained on the recording medium 16.

Effects As described above, according to the present invention, the emitted light from the light source is uniformly diffused by the diffuser plate, and the diffused light is shaped into parallel light by the optical fiber layer. Therefore, a collimator device with a short optical path length is obtained, and miniaturization of video printers and electronic instant cameras is achieved.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment in which a collimator device according to the present invention is applied to an electronic instant camera. Main parts: Solid-state imaging device Photosensitive recording medium control unit Video link unit Light source collimator device Diffuser Optical fiber layer Liquid crystal panel

Claims (1)

[Claims] 1. A generally flat diffuser plate that diffuses light incident on one main surface and exits from the other main surface, and a longitudinal direction of the diffuser plate is substantially perpendicular to the other main surface of the diffuser plate. and both end surfaces are arranged so as to form a flat surface as a whole, and one of the end surfaces receives the light emitted from the other main surface of the diffuser plate and converts it into parallel light to the end surface of the end surface. A collimator device comprising: an optical fiber layer including a bundle of multiple optical fibers emitting from the other end. 2. A light source that emits light; a collimator device that receives the light and emits it as parallel light; and a collimator device that is disposed on the photosensitive surface of a photosensitive recording medium on which an image represented by a video signal is to be recorded; and a liquid crystal panel in which a plurality of liquid crystal cells are arranged in a plane to change the transmittance of the parallel light to the photosensitive surface according to the video signal, the collimator device comprising: a generally flat diffuser plate that receives light on one main surface, diffuses it, and emits it from the other main surface;
and both end surfaces are arranged to form a flat surface as a whole,
an optical fiber layer including a bundle of a large number of optical fibers that receives light emitted from the other main surface of the diffuser plate on one of the end faces and converts the light into parallel light and emits it from the other end face. , wherein the optical fiber layer is arranged such that the longitudinal direction of the optical fiber is substantially perpendicular to the plane of the liquid crystal panel. 3. a light source that emits light; a collimator device that receives the light and emits it as parallel light; and an imaging means that images a field and forms a video signal representing an image of the field; a plurality of liquid crystals disposed on a photosensitive surface of a photosensitive recording medium on which an object scene image is to be recorded, receiving the video signal and changing the transmittance of the parallel light to the photosensitive surface in accordance with the video signal; In an electronic instant camera having a liquid crystal panel in which cells are arranged in a planar manner, the collimator device receives light from the light source on one main surface, diffuses it, and emits the light from the other main surface. a diffuser plate, the longitudinal direction of which is substantially perpendicular to the other main surface of the diffuser plate;
and both end surfaces are arranged to form a flat surface as a whole,
an optical fiber layer including a bundle of a large number of optical fibers that receives light emitted from the other main surface of the diffuser plate on one of the end faces and converts the light into parallel light and emits it from the other end face. . The electronic instant camera, wherein the optical fiber layer is arranged such that the longitudinal direction of the optical fiber is substantially perpendicular to the plane of the liquid crystal panel.