JPH0497331A - Photograph printer - Google Patents

Abstract

PURPOSE:To eliminate a mechanical movable part, to improve durability and reliability, to simplify constitution, to make a printer compact, to prevent the deterioration of liquid crystal etc., and to stabilize actuation by providing a light intensity modulating means, a means for controlling the shutter opening time or the light transmissivity of a light valve and an infrared cut filter and an ultraviolet cut filter. CONSTITUTION:The light intensity modulating means(liquid crystal panel) 13 is provided between a light source(lamp) 10 and a photographic film(negative film) 21, and the fine electrooptical light valves 13A by which the transmitted quantity of light is changed are arranged in a matrix state, then the color filters R, G and B of three primary colors are arranged in a matrix state corresponding to the respective light valves 13A. A control means 19 controls the shutter opening time or the light transmissivity of the light valves 13A in accordance with exposure. Furthermore, the infrared cut filter 14 and the ultraviolet cut filter 15 are provided between the light source 10 and the means 13. Thus, the constitution is simplified, the printer is made compact, the mechanical movable part is eliminated, the durability and the reliability are improved, the deterioration of the liquid crystal, etc., is prevented, and the actuation is stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photographic printer, and more particularly to a photographic printer in which a light quality adjustment section has a simple configuration.

[Conventional technology]

In a photo printer, each frame of negative film is photometered, the exposure amount is calculated based on the obtained full screen average density (LATD), etc., and the color filter setting position is determined based on this exposure amount, and the color filter is placed within the printing optical axis. is set to ensure proper color balance, etc., and then print exposure is performed.

[Problems to be Solved by the Invention] However, the above-mentioned light quality adjustment type photographic printer includes three color filters, a filter drive unit that inserts these into the optical axis, and a color filter that adjusts the light quality. A diffusion box is required to uniformly diffuse the printing light. Further, since the color filter has a movable part, the device configuration becomes complicated, and there are problems with durability and reliability. Furthermore, the above-mentioned diffusion box has a problem in that it is difficult to control the mixing ability in terms of design and manufacturing. Furthermore, it is difficult to make it compact and cost-effective due to the light quality adjustment section and diffusion box.

For this reason, it is conceivable to use a light intensity modulating means such as a liquid crystal panel instead of the filter driving section to control the amount of light transmission for each color and perform printing exposure.

However, if you simply use a liquid crystal panel or the like, the light source will be 0.
．． 5-1. In order to use a high-intensity lamp of about 1,000 kW,
New problems arise, such as the operation of the liquid crystal panel etc. becoming unstable due to the heat from the light source, and the liquid crystal itself deteriorating due to ultraviolet rays from the light source.

The present invention is intended to solve the above-mentioned problems, and its purpose is to improve durability and reliability by eliminating mechanically moving parts, to simplify and compact the device configuration, and to provide a liquid crystal, etc. An object of the present invention is to provide a photographic printer that can operate stably while preventing deterioration of the printer.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a matrix of minute electro-optic light valves that are provided between a light source and a photographic film and that change the amount of light transmitted. a light intensity modulation means in which color filters of three primary colors are arranged in a matrix; a means for controlling the shutter opening time or light transmittance of each light valve according to the exposure amount; and a light intensity modulation means provided between the light source and the light intensity modulation means. It has an infrared cut filter and an ultraviolet cut filter.

[Function] When the exposure amount is calculated based on the photometric results of the frame to be printed, the shutter open time or light transmittance of the light valve corresponding to the three primary color filters of the light intensity modulation means such as a liquid crystal panel is adjusted according to the exposure amount. The image is adjusted as follows, and printing exposure is performed. At this time, since the infrared rays of the light from the light source are cut by the infrared cut filter, the temperature of the liquid crystal, etc. is prevented from rising, and the liquid crystal, etc. operate stably. Further, since ultraviolet rays are cut by the ultraviolet ray cant filter, deterioration of liquid crystals and the like is prevented.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

In FIG. 1 schematically showing a photographic printer, a lamp 10
After being reflected by a reflector 11, the light is made into parallel light by a light source lens 12, and then enters a liquid crystal panel 13. An infrared cut filter 14 and an ultraviolet cut filter 15 are arranged between the light source lens 12 and the liquid crystal panel 13 to prevent the temperature of the liquid crystal panel 13 from rising due to the infrared rays from the light source 12 and to prevent the liquid crystal panel 13 from increasing in temperature due to the infrared rays from the light source 12. This prevents the liquid crystal itself from deteriorating due to ultraviolet rays.

The cooling fan 16 is driven by a motor 17 to apply outside air to each cut filter 14, 15 to prevent the temperature of these from rising, and to discharge hot air from the light source to the outside.

The liquid crystal panel 13 is composed of a well-known active matrix liquid crystal display (LCD), and each cell (light valve) is arranged in a matrix, and red (R), It ( C;).

Blue (B) color filters are arranged in a matrix. In this embodiment, the number of cells of this liquid crystal panel 13 is 20X.
20, but is not limited to this. This liquid crystal panel 13 is of a normally open type and is controlled by a controller 19 via a driver 18.

Note that a normally closed type may be used instead of a normally closed type.

The driver 18 drives each of the R, G, and B cells for each color in response to a control signal from the controller 19. By this driving, each cell of the liquid crystal panel 13 changes from an open state to a closed state, and print light is sequentially cut off starting from the color that has reached the exposure amount.

A diffusion plate 20 is disposed above the liquid crystal panel 13, and sufficiently diffuses the light from the lamp 10 that has passed through the liquid crystal panel 13 to illuminate the frame to be printed on the negative film 21. Negative film 21 is set on film carrier 22. As is well known, the film carrier 22 detects the frame position and sets the frame to be printed at the print position.

The image of the frame to be printed is formed by a printing lens 23 onto a color paper 24 centered at the print position. A shutter 25 is arranged between the printing lens 23 and the color vapor 24, and a shutter drive section 26
It is opened and closed by

Further, a half mirror 28 is arranged on the printing optical axis between the film carrier 22 and the printing lens 23, and branches the printing light to a photometry/monitoring system 30. The branched light passes through a lens 31 and a half mirror 32, and is focused on an image area sensor 33 for simulation and an image area sensor 34 for photometry (scanner). Incidentally, instead of the half mirror 28, a half prism may be used, or a movable mirror may be provided to be freely inserted and removed from the printing optical axis.

The image area sensor 33 for simulation captures a negative image of the frame to be printed, and sends this video signal to the monitor image processing section 36. As is well known, the monitor image processing unit 36 performs A/D conversion, negative/positive conversion one-tone correction, saturation correction, etc., and displays a monitor image simulating a finished print on the color CRT 37. The saturation correction not only corrects the difference between the spectral sensitivity of the color paper 24 and the spectral sensitivity of the image area sensor 33, but also performs color correction to display an image simulating this correction when inputting correction data. Input the correction data using controller 1.
The input density correction data and color correction data are displayed on the display 41 and are also processed by the image processing unit 36.
sent to.

The photometric image area sensor 34 performs three-color separation photometry on each point of the frame to be printed. This photometric signal is sent to the characteristic value calculation section 45. The characteristic value calculation unit 45 calculates LATD and other various characteristic values, and applies the calculated values to the exposure amount calculation unit 46.
send to The exposure calculation section 46 calculates the exposure amount for each color using a well-known exposure calculation section, and calculates the exposure amount for each color.
send to

When calculating the exposure amount, correction data input from the keyboard 40 is also used as necessary.

The controller 19 opens and closes the shutter 25 for a certain period of time via the shutter drive section 26, and converts the exposure amount into exposure time using the exposure time conversion section 47, as shown in FIG. , G, and B cells 13A, the exposure voltage control signal generator 48 generates a voltage control signal, and outputs the voltage control signal to the driver 18 via the selector 49. Driver 1
8 uses this voltage control signal to sequentially close each cell 13A of the liquid crystal panel 13 for each color in accordance with the exposure amount. Note that the relationship between the exposure amount and the closing timing of each cell 13A of the liquid crystal panel 13 is determined in advance through experiments or the like, and a conversion table thereof is stored in the memory 51 in the controller 19.

Furthermore, during photometry/monitoring, the controller 19 sends voltage control signals from exposure to photometry via a selector 49 in order to prevent each image area sensor 33, 34 from becoming saturated due to excessive light intensity and becoming unable to measure photometry. Generating part 5
0, and sends a voltage control signal in photometry mode to the driver 18.

As a result, a predetermined voltage is applied to each cell 13A of the liquid crystal panel 13 for each color. Therefore, each cell has a predetermined light transmittance, and the amount of light for each color from the lamp 10 is narrowed down, so that the amount of light can be matched to the dynamic range of each image area sensor 33, . The voltage applied to each cell 13A for controlling the light intensity is determined in advance through experiments or the like, and is stored in the memory 51 of the controller 19. Note that if the dynamic ranges of the image area sensors 33 and 34 are different, the applied voltage is determined for each sensor, and the liquid crystal panel 13 is first driven in accordance with the sensor 33 for simulation.
Take a negative image. Thereafter, the 'ζ liquid crystal panel 13 is driven in accordance with the photometry sensor 34 to perform photometry.

Next, the operation of this embodiment will be explained with reference to FIG. First, when the negative film 21 is set on the film carrier 22 and the frame advance key on the keyboard 40 is operated, the film carrier 22 transports the negative film 21 and sets the frame to be printed at the print position. This setting is performed by detecting the edges of the frames, as is well known. Next, the frame to be printed is illuminated by the lamp 10. At this time, the photometry voltage control signal generation section 50 of the controller 19 sends a photometry control signal to the dryer 18, and the liquid crystal panel 13 is set to the photometry mode, and according to the dynamic range of the image area sensor 3334,
Each cell 13A is driven to have a predetermined light transmittance for each color.

Then, a negative image of the frame to be printed is captured by the imaging image area sensor 33, and this video signal is subjected to A/D conversion, digital conversion, gradation correction, and saturation correction in the monitor image processing unit 36, and the finished print is processed. A simulated monitor image is displayed on the color CRT 37. When observing this monitor image and determining that density or color correction is necessary, each correction data is input using the keyboard 40. Each of the input correction data is sent from the controller 19 to the monitor image processing section 36, where correction processing is performed using each correction data, and the corrected monitor image is displayed on the color CRT 37.

Observe the monitor image, and if correction is required again, input correction data in the same manner. Furthermore, if this is acceptable, printing is started by operating the print key.

First, each correction data is determined by operating the print key, and based on this correction data and various characteristic values, the printing exposure amount for each color is calculated using a well-known exposure calculation formula, and this is sent to the controller 19. The controller 19 determines the printing exposure amount for each color and the closing timing of each cell 13A of the liquid crystal panel 13, sends this control signal to the driver 18, and also sends this control signal to the shank 25 via the shutter drive unit 26.
open for a certain period of time. As a result, a negative image is formed on the color paper 24 and printing exposure is started. Then, since the driver 18 drives each cell 13A at a predetermined timing and sequentially closes the cell 13A, the printing light is cut off for each color that has reached the exposure amount, and printing exposure is performed at the predetermined exposure amount. Thereafter, each frame is printed and exposed in the same manner.

During printing exposure, the cooling fan 16 rotates to send outside air to each cut filter 14.15, thereby preventing the temperature of these filters 14.15 and the liquid crystal panel 13 from rising. In addition, since infrared rays are cut by the cut filter 14, the temperature of the liquid crystal is prevented from rising, and the liquid crystal is kept at a constant temperature by the action of the cooling fan, so there is little change in the characteristics of the liquid crystal itself due to temperature changes. The liquid crystal operates stably. Furthermore, by cutting off ultraviolet rays, deterioration of the liquid crystal itself is prevented.

In addition, when changing the gradation of a print, the image density is spot-metered by the photometric image area sensor 34, and the light transmittance of each corresponding cell is set according to the density of each spot. In addition, when changing the gradation in the case of a super overexposed frame or a super underexposed frame, the degree is detected by the photometric value of the photometric image area sensor 34, and each corresponding cell is adjusted by a preset amount according to the degree. Set the light transmittance and change the gradation.

In the embodiment described above, the light intensity modulating means is constituted by the liquid crystal panel 13, but PLZT may also be used. Further, in the above embodiment, the printing exposure is performed by controlling the shutter open time of each cell 13A, but in addition to this, the printing exposure may be performed only by controlling the light transmittance of each cell. By controlling the shutter open time and controlling the light transmittance, the exposure amount may be controlled at a more detailed level.

Further, in the above embodiment, the present invention is applied to a printer for a small laboratory that performs negative verification for each frame before printing. The present invention may also be implemented in a large laboratory type printer that prints based on this negative verification data.

Furthermore, when controlling exposure using the liquid crystal panel, unevenness correction may be performed in order to eliminate unevenness caused by the light source, the lens, and the shutter. In this case, set an elemental negative film with only the base density on a film carrier, measure the uneven pattern in advance using a photometric image area sensor, and adjust the amount of light transmitted through each cell to eliminate this uneven pattern. control. In addition, if you want to cancel the unevenness caused by the lens or shutter together with the unevenness of the light source, install an accumulation type photometric sensor that can be placed at the same position as the photosensitive surface of the color paper, and use this to cancel the unevenness caused by the light source. Detects unevenness caused by the lens and shutter all at once. The unevenness detection sensor is configured to be evacuated from the paper transport path except during photometry so that it does not interfere with the transportation of color paper or the printing exposure during printing exposure.

〔Effect of the invention〕

As explained above, according to the present invention, a light intensity modulation means such as a liquid crystal panel is provided, and the shutter opening time or light transmittance is changed for each color according to the exposure amount, so that it is possible to There is no need to provide a movable color filter, a filter drive unit for setting the color filter in the printing optical axis, a diffusion box, etc., and the configuration can be made simple and compact.

Furthermore, since there are no mechanically moving parts, durability and reliability can be improved.

Moreover, since an infrared cut filter and an ultraviolet cut filter are placed between the light intensity modulation means such as a liquid crystal panel and the light source, the heat from the lamp is cut by the infrared cut filter, and the liquid crystal etc. do not become hot. It is possible to reduce the effects of deterioration of the liquid crystal caused by this and the temperature characteristics of the liquid crystal. This enables accurate exposure control. Furthermore, the ultraviolet cut filter prevents ultraviolet rays from hitting the liquid crystal, etc., thereby preventing deterioration of the liquid crystal due to ultraviolet rays. Therefore, since the liquid crystal etc. are not exposed to high temperatures or ultraviolet rays, the life of the liquid crystal can be extended, and moreover, the liquid crystal can be stably operated.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the configuration of a photographic printer of the present invention. FIG. 2 is a functional block diagram showing the main parts of the photo printer. FIG. 3 is a flowchart showing the control procedure of the photo printer. 10... Lamp 13... Liquid crystal panel 13A... Cell 14... Infrared cut filter 15... Ultraviolet cut filter 16... Cooling fan 19... Controller 21... Negative film 33.34 ...Image area sensor.

Claims (1)

[Claims] (1) In a photographic printer that illuminates an image recorded on a photographic film with a light source and prints and exposes it onto a photosensitive material, a minute electro-optic device is installed between the light source and the photographic film and changes the amount of light transmitted. A light intensity modulation means in which target light valves are arranged in a matrix, color filters of three primary colors are arranged in a matrix in correspondence with each light valve, and a shutter opening time or light transmittance of each light valve is adjusted depending on the exposure amount. What is claimed is: 1. A photographic printer comprising: a means for controlling a light source; and an infrared cut filter and an ultraviolet cut filter provided between a light source and a light intensity modulation means.