JPH0455846A - Photographic printer - Google Patents

Abstract

PURPOSE:To simplify constitution and to provide the compact printer by providing a light intensity modulating means, such as liquid crystal panel, and changing the shutter opening time thereof for each of respective colors according to exposures. CONSTITUTION:A controller 16 opens and closes the shutter for a specified period of time via a shutter driving section, converts the exposure to exposing time by an exposing time converting section 47, determines the timing for closing the respective cells 48 of R, G, B of the liquid crystal panel 13 in accordance therewith and outputs the control signal thereof via a selector 49 to a driver 15. The driver 15 puts the respective cells 48 of the liquid crystal panel 13 successively into a closed state for each of the respective colors in correspondence to the exposure. The relations between the exposures and the timing for closing the respective cells of the liquid crystal panel 13 are previously determined by experience, etc., and the conversion table thereof is stored into the memory in a controller 16. The simple and compact device constitution is obtd. in this way.

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.

[Problem to be solved by the invention]

However, the light quality adjustment type photo printer described above requires three color filters, a filter drive unit that inserts these into the optical axis, and a diffusion box that uniformly diffuses the printing light whose light quality has been adjusted by the color filters. is required. 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, in this case, the light intensity variable step (resolution) is about 5 bits (32 gradations) at most. On the other hand, as a light source for a printer, the above resolution is 9~
Approximately 10 bits are required, and simply controlling the amount of light transmission using a liquid crystal panel or the like does not provide the control level necessary for the printer.

The present invention is intended to solve the above-mentioned problems, and improves durability and reliability by eliminating mechanically movable parts, making the device configuration simple and compact, and also allowing exposure control at a fine level. The purpose is to capture and provide a photographic printer that has the following features.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a light source that illuminates a photographic film, and a matrix arrangement of minute electro-optic light valves that are provided between the light source and the photographic film and that change the amount of light transmitted. At the same time, a light intensity modulating means has color filters of three primary colors arranged in a matrix in correspondence with each light valve, and each light valve of this light intensity modulating means is used as a shutter, and the shutter of each light valve is adjusted according to the exposure amount. and means for controlling the opening time. Further, in another invention, the light intensity modulation means is separated from the photographic film so that the pattern of minute color filters arranged in a matrix of the light intensity modulation means will not be imaged on the photosensitive material. It is something.

[Effect]

When the exposure amount is calculated based on the photometry results of the frame to be printed, the opening time of the light intensity modulation means, for example, the light valve corresponding to the three primary color filters of the liquid crystal panel, is adjusted according to the exposure amount, and printing exposure is performed. be exposed.

〔Example〕

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

In FIG. 2 schematically showing a photo 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. A heat shielding filter 14 is disposed between the reflector 11 and the light source lens 12 to prevent the temperature of the liquid crystal panel 13 from rising due to heat from the light source 12.

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), green ( G).

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 16 via a driver 15. The driver 15 drives each of the R and CB cells for each color in response to a control signal from the controller 16. 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. Note that a normally closed type may be used instead of a normally open type.

A diffusion plate 7 is disposed above the liquid crystal panel 13, and the light from the lamp 10 transmitted through the liquid crystal panel 13 is sufficiently diffused to illuminate the frame to be printed on the negative film 19. Negative film 19 is set on film carrier 20. As is well known, the film carrier 20 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 barber 24 set at a printing position. A shutter 25 is arranged between the printing lens 23 and the color paper 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 20 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 two-tone correction, saturation correction, etc., and displays a monitor image simulating a finished print on the color CRT 37. Saturation correction is
In addition to correcting the difference between the spectral sensitivity of the color paper 24 and the spectral sensitivity of the image area sensor 330, color correction is also performed to display an image simulating this correction when inputting correction data. Input of correction data is performed by operating a keyboard 40 connected to the controller 16, and the input density correction data and color correction data are displayed on the display 41 and are also displayed on the image processing section 3.
Sent to 6.

The photometric Inno-2 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 formula, and calculates the exposure amount for each color using a well-known exposure calculation formula.
send to

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

As shown in FIG. 1, the controller 16 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, and based on this, the R , G, and B, and outputs a control signal thereof to the driver 15 via the selector 49. The driver 15 uses this voltage control signal to control each cell 48 of the liquid crystal panel 13.
are sequentially closed for each color in accordance with the exposure amount.

Note that the relationship between the exposure amount and the closing timing of each cell 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 within the controller 16.

Further, during photometry/monitoring, the controller 16 receives a voltage control signal from the exposure time converter 47 via the selector 49 in order to prevent the image area sensors 33 and 34 from becoming saturated due to excessive light intensity and becoming unable to perform photometry. The generator 50 is switched to send a voltage control signal in photometry mode to the driver 15. As a result, a predetermined voltage is applied to each cell 48 of the liquid crystal panel 13 for each color. therefore,
Each cell transmits a predetermined amount of light, and the amount of light for each color from the lamp IO is narrowed down, so each image area sensor 33
．． The amount of light can be set to match the dynamic range of 34. The voltage applied to each cell 48 for controlling the light intensity is determined in advance through experiments or the like, and is stored in the memory of the controller 16. Note that if the image area sensors 33 and 34 have different dynamic ranges, the applied voltage is determined for each sensor, and the liquid crystal panel 13 is first driven in accordance with the simulation sensor 33 to capture a negative image. . After that, sensor 3 for photometry
4, the liquid crystal panel 13 is driven to perform photometry.

Next, the operation of this embodiment will be explained with reference to FIG. First, when the negative film 19 is set on the film carrier 20 and the frame advance key on the keyboard 40 is operated, the film carrier 20 transports the negative film 19 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 voltage control signal generator 50 of the controller 16 sends a control signal to the driver 15, the liquid crystal panel 13 is set to photometry mode, and the image area sensor 33
, 34, each cell 48 is driven to transmit a predetermined amount of light 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, negative/positive 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 16 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 16. The controller I6 determines the printing exposure amount for each color and the closing timing of each cell 48 of the liquid crystal panel 13, sends this control signal to the driver 15, and opens the shutter 25 for a certain period of time via the shutter drive unit 26. This allows the negative image to be transferred to the color paper 2.
4, and printing exposure is started. Then, since the driver 15 drives each cell at a predetermined timing to sequentially close the cells, 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.

Note that in the above embodiment, the light intensity modulation means is the liquid crystal panel 1.
3, but PLZT may also be used.

In addition, the above embodiment is a printer for a small laboratory that performs negative verification for each frame before printing. The present invention can also be implemented in a large laboratory type printer.

Further, in the above embodiment, the diffusion plate 17 is arranged between the liquid crystal panel 13 and the negative film 19 to prevent the pattern of each cell of the liquid crystal panel 13 from being imaged on the photosensitive surface of the color paper 24. However, instead of this, the influence of the pattern of each cell of the liquid crystal panel may be reduced by omitting the diffusion plate and separating the liquid crystal panel from the negative film.

〔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 is changed for each color according to the exposure amount.
There is no need to provide a movable color filter, a filter drive unit for setting the color filter within 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. Furthermore, since the exposure amount is controlled by changing the shutter open time of the light valve of the light intensity modulation means for each color, the printing exposure amount can be controlled at a detailed level, unlike the method that controls exposure by changing the amount of light transmitted through each cell. can do.

Further, the light intensity modulation means is placed apart from the photographic film,
By setting the printing lens at a defocused position, it is possible to reduce the influence of the pattern of each cell of the light intensity modulating means and improve print quality.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram showing the main parts of a photographic printer of the present invention. FIG. 2 is a schematic diagram showing a photo printer. FIG. 3 is a flowchart showing the control procedure of the photo printer. 10...Lamp 13...Liquid crystal panel 15...Driver 16...Controller 19...Negative film 33.34...Image area sensor 48...Cell.

Claims (2)

[Claims] (1) In a photographic printer that prints and exposes an image recorded on a photographic film onto a photosensitive material, a light source illuminates the photographic film, and a microscopic light source is installed between this light source and the photographic film and changes the amount of light transmitted. A light intensity modulation means in which electro-optic light valves are arranged in a matrix and color filters of three primary colors are arranged in a matrix in correspondence with each light valve, and each light valve of the light intensity modulation means is used as a shutter, 1. A photographic printer comprising means for controlling the shutter opening time of each light valve according to the amount of exposure. (2) In a photographic printer that prints and exposes an image recorded on a photographic film onto a photosensitive material, a light source that illuminates the photographic film, and a light source provided between this light source and the photographic film, separated from the photographic film, so that the light transmits A light intensity modulating means in which minute electro-optic light valves whose quantity changes are arranged in a matrix, and color filters of three primary colors are arranged in a matrix in correspondence with each light valve, and each light of the light intensity modulating means is arranged in a matrix. 1. A photographic printer comprising means for using a valve as a shutter and controlling the shutter opening time of each light valve according to the amount of exposure.